Monthly Archives: October 2019

Where is Unimolecular Electronics?

DOI: 10.31038/NAMS.2019233

 

The field of proposed “unimolecular devices” consisting of a single molecule between measuring electrodes was born in the 1974 theoretical paper by Arieh (now Ari) Aviram and his doctoral adviser Mark A. Ratner [1], which proposed a one-molecule rectifier (=one-way conductor) of electricity, as the molecular equivalent of the inorganic “pn junction” rectifier using macroscopic  “p or n-doped” semiconductors.

The first such rectifier was a heterojunction monolayer in 1990 [2], confirmed in 1993 [3] and proven as a homojunction monolayer rectifier in 1997 [4]. Since then, at least 50 rectifiers have been studied world-wide, along with many more unimolecular wires [5–7].

The hope had been that such unimolecular devices (of size 2 nm each)could match or replace the competing gradual yet dramatic decrease in component size of inorganic semiconductor devices in integrated circuits (Moore’s “law”) [8]. That hope has been dashed [7] because (i) the currents measured through single molecular wires or rectifiers have varied by two to three orders of magnitude (high dispersion), (ii) the proposed molecular equivalent of a junction transistor [9] has not been realized, (iii) the rectification ratios have remained too small (but see below), and (iv) because of limited funding.

There has been, however some hopeful progress:

Nijhuis and co-workers have seen rectification in monolayers of alkyne-linked bisferrocene with a pentadecanethiol “tail” sandwiched between template-stripped Pt and Ga In eutectic electrodes that reached a rectification ratio RR(V) = –I(V)/I(–V) of 630,000 [10];

Cyganik and co-workers have created a periodic closed-packed monolayer of a phenylcarbene covalently bonded to Au (111) but have not yet measured any currents across the monolayer [11]: in the future this may facilitate a current through these carbenes with minimal dispersion, as the best way to measure unimolecular wires and rectifiers (if the other end can also be suitably bonded to the second electrode in similar close-packed fashion). Never, never, never, never give up [12].

References

  1. Aviram A, Ratner MA (1974) Molecular Rectifiers. Chem Phys Lett 29: 277–283
  2. Ashwell GJ,  Sambles JR, Martin AS, Parker WG,  Szablewski M (1989) Rectifying Characteristics of Mg |(C16H33-Q3CNQ LB Film) | Pt Structures, J Chem Soc Chem Commun 1989: 1744–1376.
  3. Martin AS, Sambles JR, Ashwell GJ (1993) Molecular Rectifier. Phy Rev Lett 70: 218–221.
  4. Metzger RM, Chen B, Hoepfner U, Lakshmi kantham MV, Vuillaume D, et al. (1997) Unimolecular Electrical Rectification in Hexadecyl quinolinium Tricyano quinodi methanide. J Am Chem Soc 119: 10455–10466.
  5. Metzger RM (2003) Unimolecular Electrical Rectifiers. Chem Rev. 103: 383–3834.
  6. Metzger RM (2015) Unimolecular Electronics. Chem Rev 115: 5056–5115.
  7. Metzger RM (2018) Quo Vadis, Unimolecular Electronics? Nanoscale 10: 1016–10332
  8. Moore GE (1965) Electronics 38: 114.
  9. Toher C, Nozaki D, Cuniberti G, Metzger RM (2013) Unimolecular Amplifier: Principles of a Three-Terminal Device with Power Gain. Nanoscale 5: 6975–6984.
  10. Chen X, Roehmer M, Yuan L, Du W, Thompson D, et al. (2017) Molecular Diodes with Rectification Ratios Exceeding 105 Driven by Electrostatic Interactions. Nature Nanotechnol 12: 797–803.
  11. Cyganik P (Jagiellonian University, Krakow), unpublished results.
  12. Sir Winston Churchill, high-school graduation speech, ca. 1941.

Perinatal and Child Mortality, Under-Nutrition and Cerebral Palsy: A Cross Sectional Survey in Rural Bangladesh

DOI: 10.31038/AWHC.2019254

 

Bangladesh has achieved commendable progress in alleviation of poverty in recent years and, in association, the overall nutritional status of mothers and children has improved, and child mortality has fallen [1,2]. According to the regular Bangladesh Demographic and Health Surveys, the Stillbirth Rate (SBR) fell from 37 per 1000 pregnancies in 2004 to 21 in 2014 [3], and the Perinatal Mortality Rate (PMR) fell from 65 deaths per 1000 pregnancies in 2000 to 44 in 2014. And from 1994 to 2014, for every 1000 live births, the Neonatal Mortality Rate (NMR) fell from 52 to 28, the Infant Mortality Rate from 87 to 38, and the <5 year Child Mortality Rate from 133 to 46. While BDHS provide information from many regions, they do not provide specific data from the far north of Mymensingh District where two non-government agencies, Symbiosis International and the Mennonite Central Committee, have, for many years, been involved in developmental projects. In November 2018, in order to review their progress and to plan for the future, these organisations surveyed indices of child and maternal health, and related socio-economic factors, in 25 sites in that region. This paper reviews aspects of morbidity and mortality of children in those sites and compares them with BDHS and other sources. In other reports we examine anthropometry of children and factors relating to maternal health.

Methods

Over two consecutive weeks in November 2018 surveys were performed in 25 sites in and around the administrative centres of Haluaghat and Dhobaura, and the main obstetric facility, Joyramkura Hospital. Cross -sectional data was collected by two teams of Bangladeshi and Australian NGO workers, and senior medical students from Western Sydney University, under the supervision of an Australian general practitioner experienced in rural, remote and indigenous medicine, and the Professor of Paediatrics from Western Sydney University. Data was recorded on paper, transcribed to a computer, and later analysed with reference to WHO standards. Anthropometric data was gained by specially constructed stadiometers with fixed metal measuring ‘tapes’ and with portable weighing machines which were carried, along with other equipment, into the various villages. Anthropometric data of age, heights and weights was reported as Height Per Age (HAZ), Weight Per Age (WAZ) and Weight For Height (WHZ), and expressed as Standard Deviations (SD) from the mean of the reference population in accordance with World Health Organisation practice [4,5]. Moderate disturbances of anthropometry are defined as greater or less than 2SD from the mean: severe from 3SD. Reduced HAZ ratios denote the presence and degree of ‘stunting’, mostly due to chronic under-nutrition and or disease. Reduced WHZ suggests ‘wasting’ from acute malnutrition or disease, and reduced WAZ suggests ‘marasmus’ associated with acute or chronic loss of weight. SBR is defined as death of a foetus equal to or after 28 weeks of gestation. PMR is defined as the total of Stillbirths and Deaths in the first week of life per 1000 pregnancies. NMR is the number of deaths in the first month of life per 1000 live births. IMR is the number of deaths in the first year of life per 1000 live births. Under 5 CMR is the number of children dying <5 years of age per 1000 live births.No verbal post-mortem assessment of cause of death was undertaken: the mother’s simple explanation was accepted. Nor were undertaken any detailed histories of children suffering from chronic disease. Major clinical features were classified and some children were referred for further investigation at Joyramkura Hospital. Those with cardiac abnormalities confirmed by echocardiography were referred to higher centres.

Statistics

Data was cleansed and imported into a relational database enabling cross correlating queries to be executed. WHO anthropometric factors of Height Vs Age (HAZ), Weight Vs Age (WAZ), Weight Vs Height (WHZ) were calculated using the WHO published mathematical algorithms [6]. Outliers were identified according to WHO statements of limits and discarded as per WHO stated process. Data was converted to Z Scores and expressed as the Standard Deviation (SD) from the mean of the WHO reference standard population for both male and female [7]. Continuous unpaired data was analysed using zTest,. Count data was analysed using Chi-Squared Best Fit assuming equal proportions and trend data analysed using Chi-Squared Tend Analysis. Correlations were performed using Pearson’s correlation. In all tests sample size was > 30 and the null hypothesis rejected for results > 95% confidence, resultant P-Values are reported. We perform all comparisons against the combined male-female scores, unless otherwise stated. We used Minitab Express for all statistical analysis.

Ethics

The surveys were approved by governance of both Symbiosis International and Mennonite Central Committees as quality assurance of current programmes and preparation for future activity. Representatives of those NGOs visited the sites in advance, explained the aims and the process, and invited participation. Mothers and their children attended voluntarily. Data was de-identified for analysis but a list was kept in confidence in case of need to contact the parents eg with regard to medical concerns.

Results

Surveys were held in 25 sites, and included 2987 children and 1982 mothers.

Anthropometry

Growth restriction was revealed to be a major problem. In summary, and with regard to combined sexes of children <5 years of age, 36.2% were moderately stunted (HAZ <-2SD) and 14.6% severely stunted (<-3SD). 32.5% were moderately (WAZ <-2SD) and 10.4% were severely underweight (<-3SD). 15.8% were moderately (WHZ<-2SD) and 6.5% were severely wasted (<-3SD). Similar restriction was found in children aged from 5–14 years: 25.6% were moderately (HAZ <-2SD) and 6.5% were severely stunted (<-3SD). 29.4% were moderately (WAZ<-2SD) and 10.7% were severely underweight (<-3SD). Growth restriction was also common in mothers, of whom 15.3% were stunted. That this rate increased to 25.6% in children 5–14, and then to 36.2% in those <5 years, suggests stunting is increasing in recent years.

Mortality

Of 4408 live births, 93 died in the first week of life, 122 within the first month, 199 in the first year, and 275 within the first five years of life. These statistics suggest a PMR of 109.0, and an NMR of 27.7, IMR of 17.5, and an <5 CMR of 62.4. These live born deaths had been preceded by 435 stillbirths, giving an SBR of 89.8. No data was collected on the sex of the deceased. Thus, the SBR in our surveyed sites would appear to be almost four times greater than the national average (89.8 vs 21), the PMR to be over twice the national rate (109 vs 44), the NMR similar to that rate (27.7 vs 28), the IMR half that rate (17.5 vs 38) and the CMR one and half times greater than the national rate (62.4 vs 46). The CMR was 25% higher in stunted mothers, than non stunted (p=0.0326), and was inversely related to family income (p=0.0179) which is a surrogate for maternal education.

Causes of Death

In almost half of the deaths (46.5%), the mother declared she did not know why her child had died. In 18.9% of cases, she thought deaths were related to the birth process. In 12.0%, she declared pneumonia to have been the cause. 6.9% of the children had drowned. 3.3% were reported to have become suddenly ‘sick’, and diarrhoea featured in another 2.2%. Trauma accounted for 1.8% of deaths, and others appeared to have died of malformations and malignancy.

Morbidity

Children with chronic disease were identified by the mother during the surveys, and significant abnormality was confirmed in 106 children. 52 were suffering from Cerebral Palsy (CP): 12 with serious cardiac disease; 12 with syndromes including 5 with Down Syndrome; 5 with unspecified developmental delay; 5 with external eye problems including severe strabismus and microphthalmia; 4 with deaf-mutism; 2 with congenital dislocation of the hip; and 2 with treated myelo-meningocoele . Overall, this gave a prevalence of physical impairment due to neurological causes of 18.1 per 1000. Sundry cases included one each of elephantiasis, rheumatoid arthritis, urinary incontinence, and renal hydronephrosis, while 5 had inguinal hernias, and one a huge omphalocoele.

Of the 52 children with cerebral palsy, 27 were boys and 25 girls with a mean age of 5.3 years. All were severely affected with Gross Motor Function Classifications in the range of 4 and 5 but none were receiving physiotherapy or special schooling, and none appeared to have mechanical aids. All appeared to have been associated with birthing difficulties, except for one associated with head injury at 3 years of age, another with febrile illness at 18/12 of age, and another with severe gastro-enteritis at a similar age. Under-nutrition was a major complication of CP: 42.3% were stunted (HAZ < -2SD) compared with 25% of local children without CP (PValue 0.0048) and 23.1% were <-3SD. 44.2% were underweight (WAZ<-2SD) compared with 23.7% without CP (PValue 0.0006), and 18 of that 23 were <-3SD. There was no gender difference. Cardiac abnormalities included 3 with Tetralogy of Fallot, 2 with cardiomyopathy, 3 with septal defects, 3 with valvular disease (2 stenoses and 1 incompetence) and 1 patent ductus arteriosus. All appeared to be of congenital origin.

Discussion

The survey revealed severe levels of morbidity and mortality in children in rural areas in the north of the Mymensingh District. The degree of growth restriction rivals the worst in the country and must be fundamental to the high rate of mortality. It is well known that under-nutrition reduces immunity and is associated with a three to four times greater rate of mortality. Our survey confirmed the presence of socio-economic correlations of under-nutrition that have international recognition. As reported elsewhere, the stunting of children was associated with stunting of mothers, and maternal stunting was associated with reduced age at marriage, income, education and proper disposal of human waste. As most of our children were born at home with untrained birth attendants, birth weights are unknown, but the 9% prevalence of in-utero growth restriction recorded in the private obstetric facility, Joyramkura Hospital, suggests a much higher rate in poor, undernourished mothers delivering in the villages. Intra-uterine growth restriction will contribute to the stunting of children and thus the mortality rate. That the survey revealed the rate of stunting to have increased from 15.3% in mothers, to 25.6% in children 5–14, and then to 36.2% in those <5 years, suggests its prevalence is increasing in the north, despite the nation’s fall in poverty. Why this should be so is not clear: perhaps poverty has worsened in the north. Alternatively, the rising prevalence of overweight in stunted and other mothers (as discussed in another report) might suggest disposable income is being spent on calorie dense foods and drinks which fatten the mother but do not provide sufficient nutrition for linear growth in the child.

The very high rate of stunting and underweight in children with CP confirms their special vulnerability. Reasons for under-nutrition include difficulties in feeding and swallowing, problems with consistency of the diet, problems with understanding the cause of CP, and poverty [8]. It was reassuring the rate of undernutrition was similar for males and females because, sometimes, the latter are perceived as a greater burden. Home births, attended by un-trained personnel, distant in time and location from the obstetric facility at Joyramkura, must be the basis of the appalling rate of still and perinatal death rates. The gestational age of babies still born in poor rural areas is often unknown [9] but up to 50% of such deaths are likely to be due to intra-partum difficulties [10]. The low rate of hypertensive and diabetic complications at Joyramkura Hospital would support this concept of ‘mechanical’ rather than medical causation [11]. Therefore, prolonged and obstructed labour is likely to be a major cause of deaths of children of all ages, and of cerebral palsy in survivors [12].

Given the extraordinary Stillbirth Rate, it may not be reassuring that the NMR and IMR in northern Mymensingh approximate the national rate. It could merely signify that babies are expiring during rather than after birth. The <5 CMR of 62.4 in northern Mymensingh, however, rivals the highest rate in Bangladesh (67 per 1000) reported from rural Sylhet [13]. The striking feature in our survey is that the cause of almost half of the deaths was unknown to the mother. This would suggest reliance on village ‘physicians’ without recourse to trained opinion. In confirmation, only 1452 emergency visits and 1578 admissions of children <5 years were recorded in 2018 in the government hospital at Dhobaura which serves a population of 225,399 [14]. In the same year, only 1331 emergency visits and 875 admissions of children <5years were recorded in the government hospital in Haluaghat, the other administrative centre in the region, serving a population of 333,065 inhabitants [15]. Only 8 visits a day from a population of over half a million people supports the concept of help being sought elsewhere. While almost half the mothers seemed to have little understanding of why their children had died, some deaths were ascribed to unspecified problems at birth, and others to such recognised causes as pneumonia [16] and drowning [17]. Preventable infections must have played a role: though almost all mothers declared their children had been vaccinated, no details were available, and a ‘drop out’ rate of around 50% of Bacille Calmette Guerin, Pentavalent, Measles and even poliomyelitis vaccinations was reported by health authorities in Dhubaura. Similarly, there was no guarantee that government distribution of vitamin A had been successful, though gastro-enteritis was not a prominent cause of death. 52 cases of cerebral palsy from 4408 live births suggests an extremely high rate of CP (11.8 per 1000) compared to the international rate of around 2 per 1000 live births. Regrettably, rates 5 to 10 times higher than the international one may not be unusual in Low to Middle Income Countries [18,19]. In one study in Bangladesh it was calculated to be 3.4 per 1000, but estimated to be much higher because of early deaths and difficulties in diagnosis [20]. The overall rate of Physical Impairment (PI) due to neurological disease in our ‘broad brush’ survey was 18.1 per 1000, three times higher than the 6.1 per 1000 revealed in a much more sensitive study in Bangladesh [21]. Most likely, our study has seriously underestimated the prevalence of PI. We only counted survivors with gross impairment. Consideration should be given to cause of death, and sensitive screening should be performed to assess true prevalence and plan for intervention.

The consequences of cerebral palsy extend beyond the child to include psychological and financial costs to the family, especially to the mother [22,23]. The quality of maternal life has been shown to be much reduced in association with a child with CP. Early diagnosis, therefore, may provide opportunity for positive intervention: for neurological improvement by taking advantage of cerebral plasticity, for reduction of spasticity, for provision of aids from eye glasses to wheelchairs, for community understanding and cultural acceptance of handicap, and thus for improvement in maternal quality of life. Such early diagnosis might be achieved by the ‘Key Informant’s Method’ developed by the Child Sight Foundation in Shajadpur, Bangladesh, in which ‘knowledgeable members of the community (key informants) are trained to effectively identify children with moderate-severe physical impairments, sensory impairments and epilepsy’ [24]. Identified children and carers then gather for evaluation and low cost, family and community based intervention. Details are recorded for the creation of a Bangladesh Cerebral Palsy Register [25] which is intended to reveal causes and initiate response. CP incurs cultural, financial, logistic and staffing challenges but surveys should progress from prevalence to intervention [26–28]. At present, interventions are limited. In the Shajadhur study, 78.2% of children had never received rehabilitation, and only a fifth were attending regular school [29]. In northern Mymensingh District, such services do not existent. Our survey revealed 10 children with congenital heart disease and another 2 with dilated cardiomyopathy of possible congenital origin. The mean age was 7.2 years raising the likelihood of under-estimation because of survivor bias. Therefore, our rate of 3 per 1000 does not confront reports of a ‘normal’ incidence of moderate to severe abnormalities of around 6 per thousand [30]. In rural Bangladesh, one problem is diagnosis, the other is cost of surgery when even the bus fare to Dhaka may be prohibitive.

Our survey has limitations. First, given the propensity for home births attended by untrained personnel, dates, weights and gestations were usually unrecorded and as lamented in BDHS 2014, ‘any memory of ages and causes of death, even of stillbirths themselves, dims with passing years in retrospective, cross sectional studies’. Second, associated with decreasing memory is the tendency to ‘heap’ ages at standard digits of, say, 6 months or 1 year. We sought to minimise this limitation by expressing age in half years. For example, if a mother declared the child to be 3 years old, we calculated on the basis of it being 3 1/2. We were reassured, however, by the BDHS declaration that the ratio of deaths under one week to those under one month should be around 70 % if estimation of age is reasonable. Our ratio was 76%, probably reflecting increased obstetric difficulties. A third limitation is that we relied on mothers’ statements as interpreted through a single translator.

Conclusion

Despite limitations, our survey has revealed major problems of morbidity and mortality of children in northern Mymensingh District. Stunting is prevalent and inter-generational. Home deliveries prevail and are rewarded by an extra-ordinary rate of still and perinatal death, and subsequent development of cerebral palsy. There is also a high rate of death in older children, for reasons often unknown to the mothers. Attendance rates at local government hospitals suggest reliance on village ‘physicians’. There is an urgent need for timely referral of obstetric and child health problems to an equipped facility. Screening for cerebral palsy and provision for intervention should be performed…and will be in the near future.

References

  1. Headey D, Hoddinott J, Ali D, Tesfaye R, Dereje M (2015) The Other Asian Enigma: Explaining the Rapid Reduction of Undernutrition in Bangladesh. World Development 66: 749–761.
  2. World Bank (2018) Bangladesh continues to reduce poverty but at a decreased rate. Available online: https://www.worldbank.org/en/news/feature/2017/10/24/bangladesh-continues-to-reduce-poverty-but-at-slower-pace (accessed June 7, 2019).
  3. Abir T, Agho KE, Ogbo FA, Stevens GJ, Page A, et al. (2017) Predictors of stillbirths in Bangladesh: evidence from the 2004–2014 nation-wide household surveys. Glob Health Action 10: 1410048.
  4. WHO Multicentre Growth Reference Study Group (2006) Reliability of anthropometric measurements in the WHO Multicentre Growth Reference Study. Acta Paediatr Suppl 450: 38–46.
  5. The WHO Anthro Survey Analyser. https://www.who.int/nutgrowthdb/software/en/ (accessed June 7, 2019).
  6. de Onis M, Adelheid Onyango , Elaine Borghi , Amani Siyam , Monika Blössner, et al. (2012) Worldwide implementation of the WHO Child Growth Standards. Public Health Nutrition 15: 1603–1610.
  7. de Onis M (2006) Reliability of anthropometric measurements in the WHO Multicentre Growth Reference Study. Acta Pædiatrica 95: 38–46.
  8. Jahan I, Muhit M, Karim T, Smithers-Sheedy H, Novak I, et al. (2019) What makes children with cerebral palsy vulnerable to malnutrition? Findings from the Bangladesh cerebral palsy register (BCPR). Disabil Rehabil 41: 2247–2254.
  9. Lawn JE, Yakoob MY, Haws RA, Soomro T, Darmstadt GL, (2009) 3.2 million stillbirths: epidemiology and overview of the evidence review. BMC Pregnancy Childbirth 9: 1.
  10. Campbell O, Gipson R, el-Mohandes A, Issa AH, Matta N, et al. (2004) The Egypt National Perinatal/Neonatal Mortality Study 2000. J Perinatol 24: 284–289.
  11. Joyramkura Hospital Annual Report; Annual Report (2018) Joyramkura Hospital: Joyramkura, Bangladesh.
  12. Baqui AH, Choi Y, Williams EK, Arifeen SE, Mannan I, et al. (2011) Levels, timing, and etiology of stillbirths in Sylhet district of Bangladesh. BMC Pregnancy Childbirth 11: 25.
  13. National Institute of Population Research and Training, Mitra and Associates, ICF International (2016) Bangladesh Demographic and Health Survey 2014; Dhaka, Bangladesh and Rockville, Maryland, USA.
  14. Local Health Bulletin 2018 for Dhobaura Upazila Health Complex (2018) Health Bulletin for Ministry of Health and Family Welfare: Mymensingh, Bangladesh.
  15. Local Health Bulletin 2018 for Haluaghat Upazila Health Complex (2018) Health Bulletin for Ministry of Health and Family Welfare: Mymensingh, Bangladesh.
  16. Baqui AH, Black RE, Arifeen SE (1998) Pneumonia mortality and healthcare utilization in young children in rural Bangladesh a prospective verbal autopsy. Bull World Health Organ 76: 161–171.
  17. Rahman A, Giashuddin SM, Svanstrom L, Rahman F (2006) Drowning–a major but neglected child health problem in rural Bangladesh: implications for low income countries. Int J Inj Contr Saf Promot 13: 101–105.
  18. Couper J (2002) Prevalence of childhood disability in rural KwaZulu-Natal. S Afr Med J 92: 549–552.
  19. Cruz M, Jenkins R, Silberberg D (2006) The burden of brain disorders. Science 312: 53.
  20. Khandaker G, Muhit M, Karim T, Smithers-Sheedy H, Novak I, et al. (2019) Epidemiology of cerebral palsy in Bangladesh: a population-based surveillance study. Dev Med Child Neurol 61: 601–609.
  21. Murthy GV, Mactaggart I, Mohammad M, Islam J, Noe C (2014) Bangladesh, K.I.M.S.G. Assessing the prevalence of sensory and motor impairments in childhood in Bangladesh using key informants. Arch Dis Child 99: 1103–1108.
  22. Mobarak R, Khan NZ, Munir S, Zaman SS, McConachie H (2000) Predictors of stress in mothers of children with cerebral palsy in Bangladesh. J Pediatr Psychol 25: 427–433.
  23. Ones K, Yilmaz E, Cetinkaya B, Caglar N (2005) Assessment of the quality of life of mothers of children with cerebral palsy (primary caregivers). Neurorehabil Neural Repair 19: 232–237.
  24. Mackey S, Murthy GV, Muhit MA, Islam JJ, Foster A (2012) Validation of the key informant method to identify children with disabilities: methods and results from a pilot study in Bangladesh. J Trop Pediatr 58: 269–274.
  25. Khandaker G, Smithers-Sheedy H, Islam J, Alam M, Jung J, et al. (2015) Bangladesh Cerebral Palsy Register (BCPR): a pilot study to develop a national cerebral palsy (CP) register with surveillance of children for CP. BMC Neurol 15: 173.
  26. Maloni PK, Despres ER, Habbous J, Primmer AR, Slatten JB, (2010) Perceptions of disability among mothers of children with disability in Bangladesh: implications for rehabilitation service delivery. Disabil Rehabil 32: 845–854.
  27. McConachie H, Huq S, Munir S, Kamrunnahar, Akhter N et al. (2001) Difficulties for mothers in using an early intervention service for children with cerebral palsy in Bangladesh. Child Care Health Dev 27: 1–12.
  28. Yousafzai AK, Lynch P, Gladstone M (2014) Moving beyond prevalence studies: screening and interventions for children with disabilities in low-income and middle-income countries. Arch Dis Child 99: 840–848.
  29. Khandaker G, Muhit M, Rashid H, Khan A, Islam J, et al. (2014) Infectious causes of childhood disability: results from a pilot study in rural Bangladesh. J Trop Pediatr 60: 363–369.
  30. Hoffman JI, Kaplan S (2002) The incidence of congenital heart disease. J Am Coll Cardiol 39: 1890–1900.

Transparent electrodes based on graphene

DOI: 10.31038/NAMS.2019232

Abstract

Novel architectures of transparent electrodes incorporating graphene into its design are explored to improve the silicon-heterojunction-cell technology. Two configurations are studied based on the place where the atomic graphene is. The main results obtained reveal the dramatic dependence of atomic graphene position on the transparent-electrode properties. In addition, the electrode performance is also affected by the transparent conductive oxide material chosen in the designed structure. Specifically, the incorporation of graphene into an electrode shows a significant reduction of its sheet resistance (55 Ω/sq.) and the weighted reflectance of whole structure down up to 10% when combined with a transparent conductive oxide such as indium tin oxide. Such electrode shows an average conductance value as high as 13.12 mS. These data undergone so far clearly suggest the possibility to noticeably improve transparent electrode technology when graphene is incorporated, and therefore to further enhance the contact technology for solar cells.

Keywords

graphene, transparent conductive oxides, front-electrode, solar devices.

Introduction

The exceptional properties of graphene, a two dimensional version of carbon, turn this material into very attractive from both companies and research groups since the publication of pioneering work by Novoselov et al. [1]. Its high thermal conductivity, its excellent mechanical properties, its huge specific surface area and its exceptional electronic conductivity make graphene a promising candidate for a large field of applications such as displays, touch screens or solar cells [2-4].

On the other hand, photovoltaic (PV) technology is expected to play a major role in the renewable-energy sector because of the fight against the climate change. This climate action has as its main aim to reduce greenhouse gas emissions. The targets defined by European Union within the framework of “Clean Energy for All European package” reflect the need for changing markets dynamics in the energy sector, considering the PV sector as one of the most involved in this issue [5]. PV market is currently being dominated by silicon-wafer technology in a 90%. This sector requires exhaustive technological solutions to achieve thinner and cheaper products. In this sense, silicon-heterojunction (SHJ) technology is emerging as a low-temperature reliable solution, where new architectures of transparent conductive electrodes to generate and extract the current in a more efficient way are required [6]. In this sense, this work presents the development of a novel transparent electrode that incorporates graphene with the main aims of exploring its possible advantages and improving solar cell performance.

Methods and materials

The transparent conductive electrodes (TCEs) are based on the combination between atomic graphene and a transparent conductive oxide (TCO). In this design, the graphene would help to improve the electrical properties, and the TCO would play the role of antireflective layer (AR), essential property for the specific application in SHJ technology.

The synthesis of graphene was carried out by chemical vapour deposition (CVD) using a commercial cold-wall CVD reactor from Aixtron. All the process gases (argon (Ar), hydrogen (H2), and methane (CH4)) were flushed before the growth. The temperature was then raised to 1050°C under Ar atmosphere. Once the temperature was stabilized, a mixture of 0.7 % CH4 / 31% H2 / 68.3 % Ar (in volume) was introduced for 15 minutes at 50 mbar of pressure. The synthesized graphene on the Cu foil was transferred to the different substrates using a home-built system designed to automatically transfer graphene [7].

The TCO materials were fabricated at low temperature using a commercial UNIVEX 450B sputtering system with confocal geometry from Leybold. The gas used in the sputtering process was Ar with a purity of 99.999%, and its flux was controlled with a mass-flow controller. The choice of TCO materials was aluminum-doped zinc oxide (AZO), from 4-inch ZnO:Al2O3 (98/2 wt.%, Neyco) commercial ceramic target operated by Radio-Frequency (RF), and indium tin oxide (ITO) from 4-inch In2O3: SnO2 (90/10 wt.%, Neyco) commercial ceramic target operated by Direct Current (DC).

The TCE performance is determined by analysing the electrical and optical properties. From electrical point of view, the sheet resistance and conductivity are evaluated from a mapping of electrical conductance carried out using a non-contact and non-destructive commercial Onyx system from Das Nano Company, based on reflection-mode terahertz time-domain spectroscopy (THz-TDS). Finally, the optical analysis consists on the evaluation of the AR capability of the TCE. This AR capability was determined from the analysis of weighted reflectance Rp defined as,

NAMS_2019_Susana M Fernández_F4

where Rhem is the hemispherical reflectance measured by using a UV/Visible/NIR Perkin-Elmer Lambda 1050 spectrophotometer equipped with a 6 mm integrating sphere accessory; and  e(λ) is the global spectral AM1.5G irradiance.

Results and discussion

The challenges of introducing graphene in the TCE structure were evaluated. Two different configurations were studied: configuration 1, where the atomic graphene was transferred on top of sputtered TCO-on-substrate (crystalline silicon); and configuration 2, where the TCO was sputtered on top of the atomic graphene, transferred directly onto the crystalline silicon. It was found that the compatibility between the process temperatures required in each step was extremely relevant into the electrode performance. For this reason, the transfer process was carried out at room temperature; thereby, a possible damage into the TCO layer would be avoided. In addition, the dependence of the place where the atomic graphene was located and the number of monolayers transferred were also crucial. The effect of sputtering deposition parameters on the electrical electrode performance was checked carefully. As the first choice, the TCO used in the design was an 80nm-thick AZO thin film. Measured electrical data of the TCEs fabricated incorporating up to three graphene monolayers at different places are pictured in Figure 1. It can be observed that the measured sheet resistances were far from the theoretical ones (straight line). More precisely, the sheet resistances of TCE fabricated with configuration 1 were far lower than those measured in the TCEs with configuration 2. This was attributed to the huge damage produced in the graphene atomic order because of the bombardment generated during sputtering process [8]. This fact would be making possible to exclude the configuration 2 from the study. With regard to the number of graphene monolayers, any preliminary conclusion may be determined from the experimental results. On contrary, from the theoretical point of view, an improvement of the sheet resistance would be expected with each graphene monolayer incorporated. As summary from these preliminary experimental electrical results, the optimum TCE design would be that one in which the atomic graphene was placed on top of TCO material, named configuration 1 in this work.

NAMS_2019_Susana M Fernández_F1

Figure 1. TCE’s sheet resistance measured as function of number of monolayers incorporated in the design, depending on its place (configuration 1: monolayer graphene transferred on top of TCO; configuration 2: TCO sputtered on top of graphene). In this case, the TCO incorporated into the design was an 80 nm-thick AZO layer. As comparison, theoretical values are also included.

The next step was to determine which TCO material was more appropriated to be used in the TCE structure. Taking theoretical sheet resistances into account (showed as a straight line in
Figure 1), three graphene monolayers were used. Table 1 shows the sheet resistance values of TCEs fabricated as function of the TCO material used. As these data revealed, a strong effect was observed depending on the TCO incorporated in the structure, reaching ~55 Ω/sq. with ITO versus ~116 Ω/sq. with AZO. This difference was attributed to the possible aluminum diffusion from the AZO layer into graphene monolayers. This aluminum diffusion would lead to the formation of other compounds, such as aluminum carbide, affecting the graphene order and hence, the electrical parameters [9]. As conclusion, the electrical performance was considerably improved using an aluminum-free TCO material, just as in the case of ITO.

Table 1. Measured sheet resistances of the TCEs fabricated in configuration 1.

TCO Material

Graphene monolayers

Rsheet (Ω/sq.)

ITO

3

55 ± 5

AZO

3

116 ± 6

Figure 2 shows the THz-TDS conductance and resistance maps acquired in reflection-mode for the TCE based on three graphene monolayers transferred on top of 80 nm-thick ITO thin film. It can be appreciated a central region with an average conductance of 13.12 mS, and a maximum value of 14.03 mS measured in the center of the sample. A region of lower conductivity close to 10-12 mS was observed in the edge of sample, attributed to the edge effect of graphene transfer. The average conductance value of 13.12 mS was considerably higher than the measured one of a common TCO, ~10mS, making the TCE presented here an alternative and competitive front-electrode [10]. In addition, from the resistance map, a sheet resistance of 76.2 Ω/sq. was extracted in the center region of the sample, slightly higher than the measured one using conventional transmission line method.

NAMS_2019_Susana M Fernández_F2

Figure 2. THz-TDS conductance and resistance maps acquired in reflection-mode for the optimum TCE based on three graphene monolayers transferred on top of 80nm-thick ITO thin film sputtered on crystalline silicon.

With regard to optical properties, Figure 3 pictures the total (hemispherical) reflectance measured with the integrated sphere of two TCEs based on AZO and ITO, respectively. It should be noted that the combination of graphene with a TCO reduced the weighted reflectance of the whole TCE, close to 10%, providing a better AR capability than a bare common TCO (~12%). This superior AR capability is considered as very promising result that could be advantageous for SHJ technology, reducing the amount of light reflected and hence, improving the solar cell performance.

NAMS_2019_Susana M Fernández_F3

Figure 3. Total (hemispherical) reflectance spectra in the visible range (300-875 nm) of a system of two graphene monolayers stacked on top of a 80 nm-thick AZO film on crystalline silicon (fill circle symbol), on top of 80 nm-thick ITO film on crystalline silicon (open circle symbol), and the bare crystalline silicon wafer (straight line).

Finally, taking the electrical and optical properties studied into account, the optimized TCE is based on three graphene monolayers transferred on top of 80 nm-thick ITO. This result clearly suggests the possibility to improve the TCEs with the incorporation of graphene, and therefore, to further enhance the SHJ technology performance.

Conclusions

In this work, the key parameters for choosing the most appropriated and reliable combination of TCE were determined. Firstly, the compatibility of the TCO and graphene fabrication processes was analysed. The choice of the most appropriate TCO material was studied, observing a negative influence on electrical properties when TCO was based on aluminum. Hence, it was demonstrated the excellent performance of a TCE based on three graphene monolayers transferred on top of 80 nm-thick ITO thin films sputtered on crystalline silicon. This is a very attractive result that allows predicting that the incorporation of graphene to a cell’s front electrode could be very benefit on (i) the reduction of silicon-heterojunction transparent-electrode sheet resistances, and (ii) the decrease of the cell’s reflectance, favouring the absorption of more photons.

Acknowledgements

Authors acknowledge the partial financial support provided by the Spanish Ministry of Science & Innovation under the project DIGRAFEN (ENE2017-88065-C2-1-R) and (ENE2017-88065-C2-2-R); A. Inés and I. Arnedo acknowledges the financial support provided  by FEDER and the Spanish Ministry of Science, Innovation and Universities – State Research Agency, under the project TEC2017-85529-C3-2-R (AEI/FEDER, UE).

References

  1. Novoselov KS, Geim AK, Morozov SV, Jiang D, et al. (2004) Electric Field Effect in Atomically Thin Carbon Films. Science.
  2. Pang S, Hernandez Y, Feng X, Müllen K (2011) Graphene as transparent electrode material for organic electronics. Adv. Mater.
  3. Ahn JH, Hong BH (2014) Graphene for displays that bend. Nature Nanotech.
  4. Zang Y, Li LB, Chu Q, Pu H, et al. (2018) Graphene as transparent electrode in Si solar cells: A dry transfer method. AIP Advances.
  5. Web page. Available: https://ec.europa.eu/energy/en/topics/energy-strategy-and-energy-union/clean-energy-all-europeans
  6. Green MA, Emery K, Hishikawa Y, Warta, et al. (2017) Solar cell efficiency tables (version 49). Prog. Photovolt: Res. Appl.
  7. Bosca A, Pedrós J, Martínez J, Palacios T, et al. (2016) Automatic Graphene transfer system for improved material quality and efficiency. Scientific Reports.
  8. Qiu XP, Shin YJ, Niu J, Kulothungasagaran N, et al. (2012) Disorder-free sputtering method on graphene. AIP Advances
  9. Rashad, M, Pan, F, Yu, Z, Asif, M, et al. (2015) Investigation on microstructural, mechanical and electrochemical properties of aluminum composites reinforced with graphene nanoplatelets. Prog. Nat. Sci.-Mater.
  10. Bøggild P, Mackenzie DMA, Whelan PR, Petersen DH, et al. (2017) Mapping the electrical properties of large-area graphene. 2D Materials.

Sensory Stimulation and Bradykinesia Aponeurotic Stimulation Effects on Parkinson Bradykinesia

DOI: 10.31038/JCRM.2019244

Abstract

Introduction: Bradykinesia is one of the main motor symptoms in Parkinson Disease (PD). Studies have shown that patients with PD exhibit bradykinesia because they have difficulties integrating multi-sensorial information, mainly proprioception, leading to difficulties in modulating the velocity of self-paced voluntary movements. We hypothesized that stimulation of aponeurotic tissues of the upper limb, which contains numerous types of mechanoreceptors, could therefore have a therapeutic effect on PD-induced bradykinesia.

Method: We investigated changes in bradykinesia in patients with PD after aponeurotic stimulation (AS) of tissues of upper limb muscles with a metallic hook, according to the diacutaneous fibrolysis method. A control group received placebo stimulation (PS) that consisted of manipulating the skin over the muscles that were the targets for AS treatment. We assessed symptoms of bradykinesia in a total of 10 patients with PD in terms of movement velocity for upward rotations of the outstretched arm and in terms of UPDRS motor score, before and after AS or PS treatment.

Results: Parkinson’s motor symptoms, as measured by the UPDRS motor scored, decreased for the AS group from 31.3±13.2 % to 26.8±12 % (p<0.003), whereas for the control group there was no significant difference after PS treatment. AS treatment also led to an increase in peak velocity at the shoulder (8.1±1.3°/s before vs. 10.2±1.1°/s after; p=0.037), whereas the placebo treatment induced no significant modifications.

Conclusions: The results of this pilot study suggest that aponeurotic stimulation directly improves motor output, with the potential of alleviating bradykinesia in patients with PD.

Introduction

Current knowledge attributes movement disorders in PD to a dysfunction of the basal ganglia-motor cortex circuits, but it is also known that abnormalities in the processing of peripheral afferents may interfere with movement execution [1]. Studies have shown that patients with PD rely excessively on visual information to guide movements [1–3] and that they present deficits in the conscious perception of limb and body motion (i.e. kinaesthesia) [4]. Exploring rehabilitation possibilities for PD-related movement disorders via sensory stimulation is therefore very attractive, especially since cutaneous and proprioceptive stimulation strongly activates both the olivo-cerebellum and basal ganglia networks [5–6]. In this light, we hypothesized that diacutaneous fibrolysis method, a form of aponeurotic manipulation, could be beneficial. By applying this approach on the triceps surae, Vezsely et al [7]. Showed that dorsi-flexion at the ankle increased while passive tension decreased. More importantly, tendon reflexes decreased, indicating a modification of proprioceptive information processing. To the extent that sensory processes may underlie bradykinesia in PD, aponeurotic stimulation could affect, and hopefully alleviate, some of these symptoms.

Methods

Participants

Ten participants gave written consent and the Ethical Committee of the “Hôpital Brugmann” (Brussels) approved the study. Table 1 shows the characteristics of each participant. Each participant continued their usual medical treatment and for those using deep brain electrical stimulation (DBS), the stimulation was turned on during the experiment.

Experimental procedure

Participants performed a pointing task consisting of an upward rotation of the outstretched arm around the shoulder joint, initiated after a self-timed delay. Patients were seated in front of a panel showing two targets and pointed at these targets with a laser pointer fixed to their index finger (Figure 1A). Movements of reflective markers attached to the upper limb were recorded in 3D at 100 Hz with an optoelectronic device (BTS Elite System).

An experimental session consisted of 10 pointing movements performed before and after 45 minutes of AS or PS treatment (see below). At the beginning and end of the session, a therapist performed the UPDRS test (part III: Motor evaluation) [8] concerning motor function. One week before the recording session, each patient was trained to perform the pointing movements at their own ‘natural’ velocity.

JCRM 2019-119 - Ana Bengoetxea Belgium_F1

Figure 1:

A) Experimental conditions. Seated subjects pointed with a laser to targets (diameter of 4 cm) located at a distance of 3.5m. The starting target was in the middle of the panel and the ending target 42 cm above. They were asked to perform the movements with the upper arm in an extended position (shoulder movements around a nominal position of 90° flexion, with the elbow fully extended).

B) Mean peak shoulder velocity (Vy) before (ordinate) versus after (abscissa) treatment. Open circles represent the PS treatment group and black circles the AS treatment group. Dashed lines show the range (mean±SD) for the healthy control group.

C) Mean and SD for Vy before and after PS and AS treatment, and for healthy control subjects.

A second therapist imposed passive movements of the patient’s shoulder and elbow used to localize the muscles manifesting the greatest rigidity. In general the main muscles manipulated were: the superior or inferior trapezium, the anterior and posterior deltoid, the external or internal rotators of the shoulder, the pectoralis major, the triceps brachii and the brachialis. AS treatment consisted of back-and-forth displacements of the aponeurotic tissues enrobing the heads of the target muscles, applied by a hook perpendicular to the axis of the muscular fibers. PS stimulation consisted of manipulating the skin over the same target muscles. The second therapist was the only person to know if AS or PS was applied to a given patient.

We computed the peak angular velocity for rotation at the shoulder (Vy) from the 3D marker data for each pointing movement. Statistical analyses consisted of repeated measure ANOVA (Statistica®, StatSoft) with treatment (AS or PS) and repetition (before or after treatment) as within-subjects factors, applied to Vy and to UPDRS scores.

Results

Before manipulation the AS and PS groups presented no significant differences in their motor UPDRS scores. ANOVA showed a significant cross-effect (F(1, 9)=8.76, p=0.016) between test repetition (before or after treatment) and treatment type (AS or PS). The subsequent Bonferroni-corrected post-hoc analyses showed a highly significant decrease of the UPDRS motor score from 31.3±13.2% to 26.8±12 % after AS treatment compared to before (p<0.003), whereas for the PS treatment group there was no significant difference (Table 1).

Table 1. Profile and clinical features of subjects. UPDRS score for part III (Motor evaluation) and scores on selected items before and after treatment.

JCRM 2019-119 - Ana Bengoetxea Belgium_F2

We then assessed what items of the UPDRS presented the main changes after treatment. Table 1 shows the values before and after treatment for 6 specific items (the values correspond only to the treated upper limb); 3 of them corresponding to the ‘triad’ of main symptoms of PD disease and the 3 others corresponding to hand movements. It is interesting to note that treatment produced a significant cross-effect between the ‘hand’ and ‘triad’ groups (F(1, 9)=6.024, p=0.04). After treatment the mean of hand-movement items decreased from 1.36±0.16 to 1.06±0.18 (Bonferroni post-hoc p<0.01), whereas the mean values of the triad symptoms remained stable (1.26±0.13 and 1.23±0.15, respectively).

Figure 1B shows Vy measured for our participants, compared to the mean±SD of “natural” shoulder velocity for 10 healthy control subjects (area between dashed lines) who performed this pointing movement after the same training as our patients. Patients presented significantly lower Vy on average than the control group (8.8±0.8°/s vs. 13.8±1.5°/s), however, we found no difference in Vy between our two patient groups prior to treatment (8.2±1.3°/s for AS vs. 9.9±1.9°/s for PS). Repeated measures ANOVA showed a significant main effect of test period (before and after treatment) on Vy (F(1,9)=5.7, p=0.04). Bonferroni post-hoc tests showed that treatment modified Vy only for the AS group (10.23±1.13°/s after versus 8.17±1.28°/s before; p=0.037) whereas the PS treatment induced no significant modifications (Figure 1C).

Discussion

Aponeurotic stimulation increased the shoulder velocity for vertical pointing movements (Vy) and improved the velocity of hand gestures (UPDRS’s items), indicating a decrease of bradykinesia in our PD patients. It is worth noting that our participants performed these movements under conditions that increase the risk of bradykinesia, because they were voluntary, internally driven movements with accuracy constraints [9] and because repeating movements makes the symptoms more prominent [10]. It is also worth noting that our treatment produced a positive effect on the UPDRS items concerning repetitive sequential movements of isolated fingers, hand and wrist (items 23, 24 and 25 respectively).

Conclusions

More research is needed to understand the mechanisms of motor output improvement brought on by the aponeurotic stimulation. Whatever the cause, however, the results from this pilot study indicate that aponeurotic manipulation could provide a new therapeutic approach to improve the quality of every-day movements in patients with PD.

Acknowledgments

This work was funded by the Belgian National Fund for Scientific Research (FNRS), the Research Fund of the Université Libre de Bruxelles (Belgium), the Belgian Federal Science Policy Office, the European Space Agency (AO-2004, 118), the FP7 support (ICT-247959-MINDWALKER). The authors thank J. McIntyre for fruitful comments about the manuscript, J. Burnotte for teaching all the subtleties of the aponeurotic technique, all the persons who participated in the study, the LNMB team for rich discussions, E. Hortmanns and T. d’Angelo for expert technical assistance and C. de Scoville for administrative assistance.

References

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  8. Fahn S, Elton RL, Members of the UPDRS Development Committee. (1987) The Unified Parkinson’s Disease Rating Scale. In Fahn S, Marsden CD, Calne DB, Goldstein M, editors. Recent developments in Parkinson’s disease, vol 2. Florham Park, NJ: Macmillan Health Care Information 153–163, 293–304
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  10. Agostino R, Berardelli A, Formica A, Stocchi F, Accornero N, Manfredi M. (1994) Analysis of repetitive and nonrepetitive sequential arm movements in patients with Parkinson’s disease. Mov Disord 9(3): 311–4 [Crossref]

Prenatal Weight Management: What Can Care Providers Do to Prevent Maternal Excessive Weight Gain?

DOI: 10.31038/AWHC.2019253

Abstract

Maternal prenatal weight data can be used to estimate infant birth weight, connect weight concerns of the women before and after pregnancy, and prevent offspring obesity. Prenatal weight data can be interpreted in relation to many contexts, such as BMI, weight loss or gain, body fat, and patient perspectives. The primary goals for weight management during pregnancy include helping pregnant women achieve an optimal weight but to avoid excessive gestational weight gain. To prevent excessive gestational weight gain among pregnant women, healthcare providers can focus on utilizing integrated and inter professional collaborative team care approach, the 5A’s method for lifestyle counseling, and self-monitoring strategy to empower pregnant women for behavioral change. Prenatal weight management is important for a healthy pregnancy with short- and long-term health implications for the mother and the baby.

Keywords

Weight Gain, Weight Management, Excessive Gestational Weight Gain, 5a’s Method, Self-Monitoring, Obesity

There are many reasons for why prenatal weight management is needed. First, maternal prenatal weight gain can be used to predict the size of an infant. A previous population study, based on 2,438 pregnant women from four ethnic groups and with a viable singleton pregnancy, found an increased risk of giving birth to a baby of either small or large for gestational age among women with below or above the average of gestational weight gain [1]. Second, prenatal weight management is part of the life course weight control intervention for women. Overweight and obesity before pregnancy is strongly associated with excessive gestational weight gain during pregnancy [2]. For some women, concerns about body weight before pregnancy may continue or intensify throughout the pregnancy. Moreover, three-quarter of women retain, on average, 3.5 kg of pregnancy weight at 6 months postpartum and those who gain excessive weight during pregnancy are likely to retain weight after birth [3]. The third reason is that prenatal weight management may prevent intergenerational obesity in the offspring. Growing evidence has pointed to the link between unfavorable intrauterine environment (e.g., excessive gestational weight gain, maternal obesity, and over nutrition) and offspring excess adiposity and childhood obesity [4]. Prevention of childhood obesity can start in the fetal stage by avoiding maternal excessive gestational weight gain through maternal healthy lifestyle. Prenatal weight, therefore, has short- and long-term health implications for the mother and the baby. Healthcare providers should be cognizant of prenatal weight management.

Prenatal Weight and Objective and Subjective Reference Value

Body Mass Index

Body mass index (BMI) is the most commonly used reference value to define adults who are underweight (BMI < 18.5 kg/m2), normal weight (BMI = 18.5–24.9 kg/m2), overweight (BMI = 25–29.9 kg/m2), or obese (BMI ≥ 30 kg/m2) [5]. Assessing prepregnancy BMI is important because optimal gestational weight gain recommended for each woman is individualized and based on her prepregnancy BMI. For instance, gestational weight gain recommendations by the Institute of Medicine [6] are 38–40 lb, 25–35 lb, 15–25 lb, and 11–20 lb for women of underweight, normal weight, overweight, and obese, respectively.

Weight Change

Body weight can also be assessed in the context of change, such as weight loss or weight gain between two time points. In non-pregnant women with overweight or obesity, a weight loss of 2.5–5.5 kg in two or more years can reduce type 2 diabetes by 30% to 60% [7]. Weight loss, however, is not recommended for pregnant women. A weight gain of more than 40 pounds for a singleton pregnancy from the beginning to the end of pregnancy is not favorable regardless of pre-pregnancy BMI [6]. Prenatal weight change can also be evaluated weekly. For instance, based on the IOM weight gain recommendations, a woman with a prepregnancy BMI ≥ 30 kg/m2 in the second and third trimester is to gain 0.4 to 0.6 lb per week. A recent study indicates that pregnant women not receiving weight gain advice from their healthcare providers are likely to gain inadequate or excessive weight during pregnancy [8]. Care providers should have a conversation with pregnant women regarding their optimal recommended gestational weight gain. Furthermore, accuracy of a weight scale may alter weight readings.

Stein et al. [9] found that about 21% of the 223 weight scales collected from primary care clinics, diabetology/endocrinology clinics, weight loss facilities, and fitness centers were inaccurate by more than 6.0 lb when the scales were tested using the 250.0 lb. (113.6 kg) test. Regular calibration of weight scales following manufacture instructions can increase precision of weight measures.

Body Fat

Another context to consider when evaluating body weight is body fat. About 23.5% of US adults with normal weight are metabolically abnormal (normal-weight obesity) and it is their body fat that makes them susceptible to developing a metabolic disorder [10]. Increased body weight from body fat, particularly from abdominal adiposity, is of concern. A non-pregnant woman with a waist circumference of 35 inches (88 cm) has an increased risk for cardiometabolic disease [11]. For pregnant women, there is no agreeable reference value for body fat. A previous study found that an increase of 0.14 kg per week in abdominal fat among pregnant women is associated with an odds ratio of 1.31 (95% CI: 1.10–1.56) for gestational diabetes [12]. There are many ways to measure body fat and other body compositions, such as dual-energy x-ray absorptiometry, bio-impedance analysis, computed tomography, and magnetic resonance imaging [13]. Some of these methods may be cumbersome, expensive, and impractical in practice but are objective measures often performed in research.

Patient Perspectives

A previous study found that body ‘fatness’ and ‘excess fat’ were not desirable terms perceived by study participants with obesity; instead, they preferred a neutral term such as ‘weight’ [14]. These findings suggest that care providers need to be skillful and sensitive during clinical encounters with pregnant women when addressing gestational weight gain issues. Assessing weight in the context of patient perspectives is essential. Body weight change may connote physical, emotional, and relationship issues. A pregnant woman may report difficulty in climbing staircases, walking longer distances, playing with her young children at length, or lying down to sleep due to the weight she gains during pregnancy. An increase in body weight may also make women feel dissatisfied with their bodies or not want to socialize with their friends. Subjective personal perspective about weight gain from pregnant women can also help healthcare providers create individualized care plans that are meaningful to their pregnant patients.

Prenatal Weight Management

The US Preventive Services Task Force [15] recommends clinicians offer or refer patients with a BMI of 30 kg/m2 or higher to intensive, multicomponent behavioral interventions. This weight management recommendation is based on the evidence that obesity is a risk factor for many chronic diseases and that behavioral interventions can help people lose weight and therefore decrease disease risk. Weight management for pregnant women, however, is unique and challenging due to several reasons. First, currently there are no agreeable guidelines for weight loss during pregnancy. For pregnant women with a BMI of 30 kg/m2 or higher, the American College of Obstetricians and Gynecologists or ACOG [16] suggests dietary control, exercise, and behavioral modifications be the primary weight management strategies. Second, one half of pregnant women gain excessive weight during pregnancy [2] and each woman’s optimal amount of weight gain is individualized based on her prepregnancy BMI. Prenatal weight management, therefore, should be discussed between all pregnant women and their healthcare providers and this demand may require modifications of practice for some care systems. Third, some providers may be reluctant to discuss with their patients weight management due to time constraint and lack of counseling knowledge and skills [17]. As reported in a previous study, patients wanted their primary care providers to be partners in their weight management efforts, but they recognized limitations of provider’s time and expertise [18].

To help pregnant women adhere to IOM weight gain recommendations and prevent excessive weight gain, care providers may consider an integrated approach as addressed in the ACOG [16] clinical guidelines. This approach begins before conception and through pregnancy and postpartum, especially for women with a BMI in the obesity category. As implied in this approach, care providers in various practice settings, such as primary care centers and in-patient units serving reproductive-age women in-between pregnancy, during pregnancy, and after pregnancy, should discuss weight management with the women.

Another approach is to encourage interprofessional collaboration to maximize support for the women from nurses, physicians, nutritionists, health coaches, and other professionals. A practice guide published by the National Blood, Heart, and Lung Institute [19] states that a practitioner is encouraged to involve other professionals in lifestyle counseling. In fact, primary care providers in a previous study reported they were comfortable to involve ancillary staff who had the skills to do lifestyle counseling for patients [17]. The 5 A’s model (ask, advise, assess, assist, and arrange), endorsed by the Agency for Healthcare Research and Quality [20] and originally developed for smoking cessation, is a useful guide for behavior counseling and can be used in prenatal weight and lifestyle counseling. For instance, Eaton et al. [21] used the 5A’s (address the agenda, assess, advise, assist, and arrange) to do nutrition counseling in primary care setting. Vallis et al. [22] provided detailed definitions for the 5 A’s (ask, assess, advice, agree, and assist) for obesity counseling and they added an “agree” step to invite clients to develop a workable, measurable, and achievable plan.

The American Association of Clinical Endocrinologists and the American College of Endocrinology clinical guidelines [23] suggest self-monitoring, goal setting, stress reduction, stimulus control, behavioral contracting, cognitive restructuring, and social support as behavioral change strategies. Among them, self-monitoring is the most used strategy and requires minimal skills of the women. It has also been found that self-monitoring strategy is the most effective strategy as compared to other strategies in promoting health eating and physical activity and postpartum weight loss [24, 25]. Care providers can empower pregnant women by encouraging them to use self-monitoring strategy to monitor body weight change and weight-related behavior, such as food intake and physical activity. Care providers and pregnant women can then look at self-monitored data and collectively decide ‘problem behaviors’ and propose potential solutions.

Summary

Weight gain in pregnancy is an indicator for fetal growth and infant birthweight. Prenatal weight assessment and management should be viewed as part of a life course intervention and as an opportunity to prevent potential obesity in the offspring and the mother. Due to its health implications in the mother and the baby, prenatal weight assessment and management should be incorporated in prenatal practice. Healthcare providers should aim to help pregnant women achieve optimal weight recommended by the Institute of Medicine and avoid excessive gestational weight gain. Healthcare providers can approach prenatal weight management using an integrated team care model, interprofessional collaborative practice, the 5 A’s method for lifestyle behavior counseling, and a self-monitoring strategy to identify problem areas in eating and physical activity, and solutions to modify unfavorable behaviors.

Acknowledgement

The author received no funding for this work. The author thanks Elisabeth Ferris-Rowe, MD, MS for her valuable input and Rosa Lindsey, MA for her assistance with manuscript editing.

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  14. Volger S, Vetter ML, Dougherty M, Panigrahi E (2012) Patients’ preferred terms for describing their excess weight: Discussing obesity in clinical practice. Obesity (Silver Spring) 20: 147–150.
  15. U.S. Preventive Services Task Force (2018) Weight Loss to Prevent Obesity-Related Morbidity and Mortality in Adults: Behavioral Interventions. [Internet] [2019 September 30]. Available: https://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/obesity-in-adults-interventions1
  16. American College of Obstetricians and Gynecologists (2015) Obesity in Pregnancy. Practice Bulletin number 156. Obstet & Gynecol 126: 112–126.
  17. Bennett WL, Gudzune KA, Appel LA, Clark JM (2013) Insights from the POWER practice-based weight loss trial: A focus group study on the PCP’s role in weight management. J Gen Intern Med 29: 50–58.
  18. Bloom K, Adler J, Bridges C, Bernstein J (2018) Examining patient perspectives on weight management support in the primary care setting. J Primary Prevention 39: 387–399.
  19. National Heart, Lung and Blood Institute (2010) The practical guide for identification, evaluation, and treatment of overweight and obese adults. NIH Publication Number 00-4084. [Internet] [2019 September 30].Available: Retried September 18, 2018 from https://www.nhlbi.nih.gov/files/docs/guidelines/prctgd_c.pdf
  20. Agency for Healthcare Research and Quality (2012). Five Major Steps to Intervention (The “5 A’s”). [Internet] [2019 September 30]. Available:  https://www.ahrq.gov/prevention/guidelines/tobacco/5steps.html
  21. Eaton CB, McBride PE, Gans KA, Underbakke GL (2003) Teaching Nutrition Skills to Primary Care Practitioners. J Nutr133: 563–566.
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  23. Garvey WT, Mechanick JI, Brett EM, Garber AJ (2016) American Association of Clinical Endocrinologists and American College of endocrinology Comprehensive clinical practice guidelines for medical care of patient with obesity. Endocr Prac 22: 1–203.
  24. Lim S, O’Reilly S, Behrens H, Skinner T (2015) Effective strategies for weight loss in post-partum women: a systematic review and meta-analysis. Obes Rev 16: 972–987.
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Mental Health Problems Following Military Missions: Veterans’ Experiences of The Quality of Care

DOI: 10.31038/AWHC.2019252

Abstract

The aim of this brief report is to present empirical data on female and male military veterans’ experiences of the quality of care they have received for mental health problems, following international military peace enforcement operations. The sample consists of all Swedish veterans who completed such missions during 2011–2015. The instrument Quality from the Patient’s Perspective (QPP) was used to assess experienced quality of care. Results show that female responders tended to experience the actual care received slightly less favorably than men. The most striking finding is that the mean scores of both men and women, and women in particular, were considerably lower (indicating that the quality of care was perceived as poor) than what has been reported in numerous previous studies using the QPP in a broad array of care contexts. Results were discussed in terms of lack of knowledge regarding veterans among health care professionals and stereotype conceptions of women in the military.

Keywords

Military Veterans, Mental Problems, Quality of Care, Gender Differences

Aim and Background

The aim of this brief report is to present empirical data on female and male officers’ and soldiers’ experiences of the quality of the care they have received for mental health problems, following international military peace enforcement missions. The sample consists of all Swedish military veterans who completed such missions during 2011–2015. Responses were obtained from 1614 men and 199 women (about 41 % response rate in both sexes). The mean age of the female responders was 37.6 years (SD = 10.6) and the mean age of the male group was 39.2 years (SD = 10.9). This difference was not statistically significant.

The questionnaire included a Yes/No question if the participant had sought health care help after the mission due to mental problems caused by the mission. Yes-responses were obtained from 143 men and 21 women. These individuals were asked to respond to follow-up questions on how they perceived the quality of care.

The quality of care questions were taken from the instrument Quality of care from the Patient’s Perspective     [1–3]. This instrument has been used in at least 100 internationally published studies in a broad array of care contexts, but not previously in a military setting. The QPP rests on a theoretical model of quality of care from a patient perspective [2]. This model has been operationalized to the QPP questionnaire. In this study 12 items were selected covering different aspects of received information (e.g. on drugs and their administration and self-care procedures), experienced commitment, empathy and respect from the doctors and perceived possibility to participate in the decision-making process regarding one’s own care. Each item had a 4-point response scale ranging from 1 (lowest quality) to 4 (highest quality). A composite scale score was computed by adding the raw scores of the 12 items and dividing this sum by 12. Thus, the overall quality of care scale score could range from 1 to 4.

The study was approved by the Swedish Regional Ethics Committee of Stockholm [4].

Results and Discussion

Results showed that the male veterans perceived the quality of care slightly more favorably than the female veterans on 11 of 12 items. The composite scale score among men was 2.35 (SD = 0.93), among women it was 1.93 (SD = 1.00). However, the differences between the means were not statistically significant on any of the individual items nor on the composite scale.

The most striking aspect of the results is the low absolute level of the ratings, indicating that the quality of care was perceived as poor. In previous patient studies, the mean scores among young and middle-aged adults tend to range between 3.10 and 3.30 [5]. The mean scores obtained in this study are the lowest (least favorable) that has been reported, at least to the best of my knowledge, in a broad variety of health care contexts. This is particularly the case for female officers and soldiers.

The men and women who take part in military peace enforcement operations are a select group in Sweden with above median physical and mental health. Despite this resourcefulness, some experience post-mission mental problems. When such problems arise, the individual is advised by the Swedish Armed Forces to contact their local primary health care center. In many cases, the personnel at these centers have limited, if any, knowledge of the military selection system and the stressors before, during and after a mission. A possible reason behind the unfavorable result on perceived actual care received is the lack of knowledge on part of the health care professionals. ”They did not understand me at all” is a typical comment. Continuing speculating, it is possible that the very low quality ratings by the female responders reflect stereotype beliefs on part of the health care professionals that the military is something for men and women who serve are a bit odd. Thus, to conclude, a deepened collaboration between the armed forces and the health care providers is recommended. The men and women who risk their lives for their country deserve better care.

References

  1. Larsson G, Wilde Larsson B (2010) Quality of care and patient satisfaction: A new theoretical and methodological approach. International Journal of Health Care Quality Assurance 23: 228–247.
  2. Wilde B, Starrin B, Larsson G, Larsson M (1993) Quality of care from a patient perspective: A grounded theory study. Scandinavian Journal of Caring Sciences 7: 113–120.
  3. Wilde B, Larsson G, Larsson ME, Starrin B (1994) Quality of care: Development of a patient-centred questionnaire based on a grounded theory model. Scandinavian Journal of Caring Sciences 8: 39–48.
  4. Regionala etikprövningsnämnden (2016)  Protokoll EPN 2016/53. Stockholm.
  5. Wilde B (1999) Patients’ views on quality of care: Age effects and identification of patient profiles. Journal of Clinical Nursing 87: 693–700.

Perinatal Mental Health Care across the Globe

DOI: 10.31038/AWHC.2019251

Abstract

The perinatal period is a vulnerable time for new mothers and their families. Broad public awareness and universal health education for all new mothers about perinatal mental illness carries significant impact. Timely screening for mental health disorders in pregnancy and postpartum is essential, followed by referrals to adequate treatments. Integrative care plays a significant role in enhancing reach and uptake. Stepped care models propose a range of treatment options based on symptoms and illness severity, and yield the most optimal outcomes for affected mothers and their children. Perinatal psychiatry, including integrative perinatal care, has over the past decades received more attention and resource allocation worldwide. But today various countries, based on their history of awareness and stigma towards perinatal illnesses, their access to overall mental health care, especially perinatal, based on insurance/payment coverage and established workforce, and based on overall national priorities and economic strength, face various challenges to establish comprehensive and systemic pathways of care for perinatal women suffering mental health challenges. Overall, there is still significant inequality across the globe both in low- and high-income countries in public awareness, infrastructure, and access, and there is still a long way to go to ease the suffering for affected perinatal women and their families.

Keywords

Perinatal Mental Health, Perinatal Care Models, Models in low- and High-Income Countries

Introduction

Perinatal mental health illness affects 10–15% of women during pregnancy and postpartum 1]. Per Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, (DSM 5), the term postpartum defines women up to one month after delivery, however, in practice many postpartum mental health issues emerge during the entire first postpartum year. The last several decades have furthered our understanding regarding perinatal illness 2], primarily in two directions: (1) the recognition of the tremendous impact of untreated maternal mental illness on pregnancy and fetal outcomes, and the lasting consequences on subsequent child development 3]; and (2) the realization that there is a need for more effective models to reach impacted women on a large scale through the establishment of mental health care approaches integrated in primary care and the community 4–7]. Clearly, in order to establish optimal care for women’s perinatal mental health illness, there is the need for interdisciplinary collaboration and integrative treatment approaches [8,9]. In the following sections, we will elaborate on these integrative perinatal treatment approaches using examples from three countries –namely India, United States, and France. The three countries located on three continents represent very different perinatal mental health systems of care. We want to shed light on the cultural and political (i.e., organization and payment scheme of health care systems) contributions to presentation, detection and treatment of perinatal mental health disorders across these three very culturally and political varied countries.

Perinatal Mental Health in India

There are currently no formal protocols in India for any form of mental health screening in the perinatal period, and the integration of mental health into maternal health is quite inadequate. Screening is limited to institutional research and non-systematic administration. This could be attributed to several reasons including, (a) poor attention to mental health by the government until recently; (b) lack of training in mental health issues among midwives and obstetricians; and (c) the limitations of existing screening tools [10]. In particular, the latter point regarding culturally valid screening tools is highly relevant. As described by Bhui & Bhugra in 2008, women from India are more likely to have alternate explanatory models for mental illness, be more affected by stigma, and less likely to seek help [11]. Thus, a self-reported questionnaire is more likely to have false negatives, missing those with poor literacy and limited awareness of their own symptoms. Thus, in India, there is a need to develop simple and culturally relevant screening tools for perinatal depression and anxiety. Other culturally relevant factors are reliance on magico-religious explanatory models for mental illness, hence seeking religious healing instead of health care professionals; the cultural preference for male babies over female causing higher rates of depression with birth of a female infant; high prevalence of partner violence; mental health stigma; and low mental health literacy among professionals. Women with prior history of mental illness are stigmatized and lose autonomy in making decisions about pregnancy and childbirth. Medications are stopped prematurely due to lack of mental health awareness and poorly understood risks, without consulting mental health clinicians. Involving fathers more actively in care is needed but may sometimes be difficult, as childbirth is viewed as a woman’s business and it is often the maternal family which handles childbirth. Thus, India has a long way to go to overcome some culturally based obstacles to provide evidence-based perinatal mental health care. Moreover, culture and stigma are just some of the problems Indian women face when accessing adequate care for perinatal mental health. To date, India lacks a widespread infrastructure for the provision of any mental health care. For a population of 1 billion, there are fewer than 10,000 mental health professionals, with access to specialists limited mostly to urban areas. Only about 1–2% of the total health budget is spent on mental health [12]. Additionally, the priority for maternal and infant health has still been addressing more pressing issues such as malnutrition and anemia, along with ensuring that women have access to safe hospital deliveries. Both maternal and infant mortality are very high, and continue to be priorities over mental health [13].

Over the last decade, under the National Rural Healthcare Mission the Government of India has launched several programs to improve widespread access to health care for women [14]. A major component of this program was the implementation of Community Health volunteers called Accredited Social Health Activists (ASHAs), whose main aim is to form a reliable and consistent link between the community and the health system. They are the frontline staff (usually women) to whom villagers go for education, advice and monitoring of health related issues. By reducing ignorance and superstition, ASHA workers have been responsible for timely access of emergency and institutional childbirth services, and better utilization of outpatient and diagnostic health services. The Janani Suraksha Yojana (JSY) [15] and Janani Shishu Suraksha Karyakram (JSSK) [16] were launched in 2005, to improve access to antenatal care and reduce maternal and infant mortality. Under these programs, women are encouraged to improve nutrition during the antenatal period, ensure regular antenatal care, deliver in government health care facilities, and maintain regular follow up throughout the first year of the child’s life. Apart from that ASHA workers have also been trained in educating families regarding birth spacing and effective use of contraception. Each regional health center has auxiliary Nurse Midwives (ANMs), who act as supervisors and additional skilled resources for ASHA workers. Another current project is to train existing volunteer groups in identifying people with mental illness and connecting them to the right pathways of care. This program has been successfully evaluated outside of perinatal phase [17], but could in future be adopted more widely to include the perinatal population as well. Training of ASHA workers and other health professionals to screen for common mental health disorders specifically with focus on perinatal can be the next step in a wide-spread model of perinatal care

Apart from improving task workers at the ground level, National Mobile Medical Units (NMMUs) have been set up to enable access to remote areas. Mother and Child Health Wings with increased bed capacity have been sanctioned in high case load district hospitals as well as Child Health Centers which create additional beds for mothers and children. Furthermore, through nationally funded programs in many of India’s states, District Hospitals have telemedicine facilities, enabling easy access to specialists in tertiary care centers, including psychiatrists. The National Informatics Centre recently launched an electronic maternal and child tracking system that registers and follows women through pregnancy, postnatal care and children from infancy to adolescents [18]; Phone based infomercials and reminders have also been used to encourage safe pregnancy and aftercare and as a result, more recently the maternal and infant mortality rates have dropped significantly [14].

All the effort noted above demonstrate India’s national priority as a part of national Health Mission to establish a broad infrastructure for an impactful maternal and infant health care system, which would integrate access to perinatal mental health as well. At present perinatal mental health services are still only sparse and limited to academic institutions in a few cities, most of them restricted to outpatient services and only one inpatient mother-baby day-treatment unit (Mother-Baby Hospital in Bangalore). To further support perinatal mental health, the Indian Psychiatric Society now has a section on perinatal mental health, which has been championing the cause of maternal and child mental health. A nationally convened subcommittee of psychiatrists has been assigned the task of developing guidelines for perinatal mental health, with the parallel aim to have mental health incorporated in corresponding guidelines for obstetricians and pediatricians. Liaison between obstetric and psychiatric clinicians has increased and locally developed screening systems are being trialed.

Taken all together, India has still a long road ahead to have a wide-spread perinatal mental health system of care and perinatal mental health integration with primary care established, but activities towards achieving the goal are underway. However, despite many obstacles based on culture (e.g., beliefs, stigma, women’s rights) and other priorities (e.g., safe medical care), India is experiencing a surge of enthusiastic conversations among the responsible stakeholders about the importance of maternal and child mental health. The key is to now start putting these conversations into clinical practice and actively affect change. Successful integration and collaboration across mental health and primary care professionals and community members will reduce stigma and improve acceptance of mental health as a routine aspect of holistic healthcare in the perinatal period. This will ultimately bring positive change not only to the mother and young child, but also the whole family, and eventually the entire society.

Perinatal Mental Health in United States of America

Mental health care throughout the United States (US) varies drastically in access and type of services available. While geographic aspects may be important (e.g., vicinity to large metropolitan centers), one major impacting factor for care delivery in the US is the presence of different tiers of payment (insurance) systems for medical care. The insurance systems range from Medicaid (covering mostly chronically disabled patients, patients with income below the poverty line, and pregnant women) to various private insurance plans, each with its own eligibility and fee structures thus creating an uneven system which leaves many persons unprotected. With the establishment of the Affordable Care Act (ACA), also known as Obama Care, in 2010, an additional 45.7 million (15.7%) Americans became eligible for services. Under ACA all women with inadequate insurance coverage and below poverty line became eligible to receive comprehensive obstetrical care during pregnancy and up to 60 days postpartum and thus also eligible for access to quality mental health care.

From a larger politico-cultural perspective, health care inequality, especially for mental health, has unfortunately a long history in the US. There is a huge racial disparity; while most countries show a decrease in maternal mortality over past years the US is the only country with rising prevalence rate by almost 30% (between 2000 and 2014), and this rise is entirely accounted for by African American mothers [19]. Black women tend to initiate prenatal care later in pregnancy, and have limited access to affordable care overall, as the positive outcomes of ACA are still lagging. Moreover, the US is a racial and cultural “melting pot” in which attitudes towards mental health in general (and in particular towards perinatal mental health) varies widely based on cultural and economic background. Externalized stigma is particularly predominant in some subcultures preventing women from identifying and seeking help. This is true for African American, Latina, Asian or Arabic women, as well as the many other immigrant women from all over the world. Often women feel the need to identify as “strong” because they fear disclosure of any emotional problems may lead to losing child custody. Additionally, immigrants from many parts of the world have often limited knowledge of mental health, and in particular feel ashamed to disclose emotional problems in motherhood. Cultural sensitivity, access to interpreters with awareness of culture-bound obstacles, and provision of new engagement and treatment models is critical. One of such initiatives to overcome cultural barriers and the access gap was the establishment of the Centering Pregnancy group model as a nationwide initiative allowing for groups of women to experience pregnancy and postpartum health care visits together as a group thus promoting social support; however, results from this initiative are not yet known [20].

Despite of all these aforementioned obstacles, maternal perinatal mental health continues to be an important public health concern, and clinicians, professionals, and families alike are pushing for improvements. In an attempt to identify more women suffering from perinatal illness, primary care settings (i.e., family medicine, obstetrics and pediatrics) were recognized as an ideal place in which screening can be conducted. Already in 2009 the US Preventive Task Force (USPSTF) recommended screening adults for depression in general [21]. As a response to this initiative, several US states launched legislations mandating postpartum depression screening [22]. Additionally, The Mother’s Act, a federal legislation passed in 2010, offered government support for research that would support perinatal screening. Since many women in the US receive some level of health care during pregnancy, obstetricians and family practitioners, who deliver such care during pregnancy, were those identified as most feasible to conduct screening [23]. To support this initiative the American Congress of Obstetricians and Gynecologists (ACOG) came out to support such screening for perinatal mental illness in pregnancy and postpartum (ACOG,) [24]. Similarly, the American Academy of Pediatrics (AAP) also made a recommendation that all pediatricians should screen mothers when they present with their child to the 6-months well-baby visit.

However, soon it became apparent that screening without appropriate opportunity for treatment is not effective [25]. Nevertheless, despite recommendations put in place through national professional associations, many women were still not screened for peripartum depression or anxiety. Factors most commonly identified to interfere with follow through with the recommendations were as follows: (1) limited time and lack of reimbursement from insurances for screening; (2) illiteracy regarding perinatal mental illness and how to approach women with perinatal mental illness; (3) insufficient referral resources providing adequate quality perinatal mental health care.

This led to the proposition of several published models. First, models where detection and treatment can take place directly through obstetricians caring for pregnant women (the Perinatal Depression Management Program (PDMR) or Step Care Model [26]. in this model initial universal screening is performed with validated tools for perinatal depression during antenatal care visits. The providers would be educated about perinatal mental illness and be able to approach identified high-risk patients (those who scored above cut off) to complete a brief (~ 5–6 minutes) psychiatric assessment. These providers would also receive education about prescribing medicines for depression and anxiety (e.g., SSRIs), which have a low side effect profile and are safe during pregnancy and breastfeeding, so can easily be prescribed by non-psychiatrists. Patients with mild and moderate depression and anxiety disorder would be treated in the primary care setting. In contrast, patients with severe symptoms of mental illness would be quickly identified and referred out to mental health providers for specialty care. Despite this approach being well described and showing benefits [26], the uptake across the US has not been uniform.

Secondly, detection and referrals can take place in pediatric offices [27]. In this setting, new mothers can be successfully identified using standard screening tools such the Edinburgh Post depression scale (EPDS) [28], and if identified at risk could receive on-site counseling or, if medications are needed, referred out to specialty care. Pediatric primary care providers, unlike adult healthcare providers, have the most frequent contact with postpartum women through well-child visits. Well-child visits thus present an unparalleled opportunity to detect and intervene with postpartum mental illness.

Both these above mentioned models are most effective when mental health providers are embedded into the primary care settings allowing immediate and direct access to counseling [29,30]. Thus, obstetric and pediatric offices may have a mental health worker (often clinicians with social work background) available on site who can further assess all women who screened positive. Women at risk are then immediately identified and provided with either brief counseling by the social worker, or sent to see a psychiatrist either in the same clinic (available during special hours) or referred outside to a psychiatric clinic. However, again, lack of a uniformed health care system and one common health has made budget this great idea challenging to implement. Additionally, there are still large gaps in knowledge among women’s reproductive health care providers on how to optimally and safely screen and treat perinatal women with mental health disorders, and more work has to be done.

Depending on the severity of presenting symptoms among women with perinatal mental health problems, several different levels of care are available: outpatient, day hospital (or else called Partial Hospital) or inpatient treatments. Contrary to inpatient mother baby units (MBU) being widely spread through out the world (e.g., Europe, Australia) over the last 50 years, the US health system does not support resources necessary to keep a baby overnight on an adult psychiatry unit. Currently there exists only one small Perinatal Psychiatry Inpatient unit established in 2011 at the University of North Carolina that provides specialty perinatal inpatient care; Infants are allowed to stay on the unit during the day only. Another level of care is mother-baby partial hospital, where affected women (pregnant or postpartum) attend the program (if possible accompanied by their baby) during the day time for approximately 6 hours, and spend the night back at home or in an unsupervised sleeping arrangement (e.g., hotel). The first such unit opened in 2000 at Brown University [31], and since many more such units opened across the US. Many Academic settings have established specialized outpatient perinatal clinics and offer multimodal treatments. These outpatient clinics may offer also Intensive Outpatient Programs (IOPs), which are more intensive daytime groups of usually 3 hours.

Finally, several programs have been developed to provide therapeutic support for perinatal women with young children and their families who are poor or at high risk based on certain characteristics (e.g., poor, single mothers, young age etc). These programs are mostly government-funded and paid for by Medicaid. Examples of such interventions providing therapeutic support around mental health, coping with stressors and if applicable with parenting are the Nurse-Family Partnership (NFP) [32], or Healthy Families America (HFA) [33] just to name a few. Each State in the US may grant access to a variety of these programs. Specific trauma-focused psychotherapy group interventions for perinatal mothers with interpersonal trauma histories were recently also developed, including TARGET, a program for mothers with depression, PTSD and substance use disorders (SUDs) [34]; Mom Power, a 13 session program for mothers with interpersonal trauma history, mental health and parenting problems [35]; or Survivor Moms’ Companion (SMC), a psychoeducational program for pregnant trauma-survivor women with PTSD and depression delivered in pregnancy [36]. In summary, while perinatal mental health initiatives have started to be more widely implemented across the US, there are still gaps. While over the last years screening for perinatal depression has been mandatory in many States, it has not adequately improved referral and treatment outcomes. Furthermore, gains in perinatal mental health across the US are inconsistent, and large groups, especially Minority women and women living in poverty, have limited access to quality care despite several government-funded programs. Integrative perinatal care model while known to be effective, are still unevenly implemented across the US.

Perinatal Mental Health in Europe: exemplified by France

France has a long tradition of perinatal mental health dating back to the 19th century. Esquirol described women admitted after childbirth to the asylums, and shortly after, in 1858, Louis-Victor Marcé published the first monograph of perinatal psychiatric pathology. In more recent history, after World War II in 1945, France developed a nation-wide, free of charge, community-based Mother and Child Protection Service (PMI) aimed to support families during pregnancy until the child’s 3rd birthday. This service provides home visits by PMI midwives and nursery nurses if necessary, and preventive follow-up visits for children during which developmental screening and are conducted vaccinations, and in this context maternal mental health can also be screened for and referrals to specialty care placed. In addition, there are large governmental programs and recommendations in place supporting perinatal mental health. Recommendations have been established to conduct early prenatal interviews for all pregnant women and future fathers listening to their concerns, needs, difficulties and expectations for pregnancy, childbirth and future parenting, with the goal of defining the best medico-psycho-social follow-up and support for the pregnancy. However, a national survey in 2010 showed that only 40% of the pregnant women receive this early comprehensive prenatal interview, and that, it is mainly mothers with low psychosocial risk that attend this interview and get benefit from it [37]. However, some kind of psychosocial screening of high-risk women during pregnancy and/or in first 3 days postpartum is performed in all regions across France. Additionally, liaison psychiatry networks connected to obstetrical Maternity Units have been established providing psychiatric support to primary care treating pregnant and postpartum women on a wide scale.

Perinatal mental health services range in France, similarly to the US, from inpatient care, partial hospital day-treatment units and outpatient psychiatric clinics, to integrated care in primary care settings. In France, pathway to care has no gatekeeper (and women in France may directly access specialized perinatal psychiatry). In contrast to the US, the number of facilities per capita is much higher in France, and there are many specialized inpatient psychiatric units for joint mother-baby admissions and psychiatric care, run by a multidisciplinary staff. In this regard, France resembles more the broad range of perinatal psychiatry treatment options similar to the UK, Australia and a few others, mostly European, countries. In case of maternal severe psychiatric illness after the childbirth, the mother and her infant can be jointly admitted to an inpatient mother baby unit (MBU), where the mother receives psychiatric attention, while simultaneously the child’s safety, developmental needs and the mother-infant bond are supported [38]. Women (and infants) hospitalized in MBUs have a mean length of stay of about 9 weeks, and improvement rates are very high (69%-82% at discharge depending on primary diagnosis [39]. Discharges from MBUs and subsequent follow up are collaboratively prepared with the women, her social support system, and her treatment providers [40]. In addition, the outpatient perinatal system of care in France, in outpatient academic or governmental clinics or through private practice perinatal psychiatrists, is wide spread and comprehensively covering the country.

In summary, perinatal psychiatry in France (and Europe overall) has a long tradition, and the perinatal psychiatry infrastructure is well established. The offerings span a broad range of stepped care models. Guided by a multilevel administrative health care coordination system, France’s perinatal care spans from mother (-father)-infant psychotherapies offered in outpatient settings to joint mother-baby psychiatric hospitalizations in specialty MBUs. Similarly, to US and India, recent efforts are to enhance preventive public health care models, through integration of perinatal psychiatric care into primary care settings.

Conclusion

Perinatal psychiatry, including integrative perinatal care, has over the past decades received more attention across the globe, both in high- and middle/low- income countries, such as US, France or India. More attention and resources specifically to perinatal mental health are allocated worldwide, yet still the various countries based on historical awareness and stigma towards perinatal illnesses, access to overall mental health care, types of insurance/payment coverage, access to an established and educated workforce, and based on overall national priorities and economic strength, face different challenges in establishment of comprehensive and systemic pathways of care for perinatal women suffering mental health challenges. Overall, there is still significant inequality across the globe in public awareness, infrastructure, and access. In order to ease the suffering of affected women and their families during this critical time period of a new beginning, such that pregnancy and postpartum, we are tasked to do better, and establish more comprehensive and accessible perinatal mental health systems of care.

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  16. Salve HR, Charlette L, Kankaria A, Rai SK, Krishnan A, et al. (2017) Improving Access to Institutional Delivery through Janani Shishu Suraksha Karyakram: Evidence from Rural Haryana, North India. Indian J Community Med 42: 73–76. [crossref]
  17. Patel V, Weiss HA, Chowdhary N, Naik S, Pednekar S, et al. (2010) Effectiveness of an intervention led by lay health counsellors for depressive and anxiety disorders in primary care in Goa, India (MANAS): a cluster randomised controlled trial. Lancet 376: 2086–2095.
  18. Grollman C, Arregoces L, Martínez-Álvarez M, Pitt C, Mills A, et al. (2017) 11 years of tracking aid to reproductive, maternal, newborn, and child health: estimates and analysis for 2003–13 from the Countdown to 2015. Lancet Glob Health 5: e104-104e114. [crossref]
  19. MoaddabA, Dildy GA, Brown HL, Bateni ZH, Belfort MA, Sangi-Haghpeykar H, et al. (2016) Health care disparity and state-specific pregnancy-related mortality in the United States, 2005–2014. Obstetrics and Gynecology 128: 869–875
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  28. Cox JL, Holden JM, Sagovsky R (1987) Detection of postnatal depression. Development of the 10-item Edinburgh Postnatal Depression Scale. British Journal of Psychiatry 150: 782–786.
  29. Schmied V, Kim Psaila, Cathrine Fowler, Sue Kruske, et al. (2010) The nature and impact of collaboration and integrated service delivery for pregnant women, children and families. Journal of Clinical Nursing 19: 3516–3526.
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Determination of Biuret Content in Fertilizers by High Performance Liquid Chromatography: Single-Laboratory Validation and Collaborative Ring Test Study

DOI: 10.31038/JPPR.2019236

Abstract

Urea or urea-based fertilizers has become the leading form of nitrogen fertilizers around the world. Biuret, as one of major by-products formed during the manufacturing of urea, was proved to be harmful to plant growth. A Single-Laboratory Validation (SLV) study for a newly proposed High Performance Liquid Chromatography (HPLC) method was conducted. A total of six samples were tested in the SLV study: two urea samples, and four compound fertilizers with various compositions from different sources. In addition, one biuret standard from Aldrich® and one biuret reference from Alfa Aesar® were used as standard materials. The system was linear over a concentration range of 0~200 ppm biuret, with a correlation coefficient≥0.999. Recoveries were determined by spiking three of the validation samples with known amounts of biuret standard solutions and measuring the biuret level according to the method. The recovery rates lies between 98.14% and 107.24%. Method precision was determined by analyzing of six validation samples under five replicate analyses, the RSDs ranged from 0.69% to 1.85%. Further study by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) has revealed that the biuret was well-separated from urea and other N-containing compounds in the system by this method. Moreover, the proposed method is verified in the international Collaborative Ring Test (CRT) study organized by ISO/TC 134 “Fertilizers and Soil Conditioners”. Systematically statistical analysis on the data obtained has proven that this method is capable of effectively monitoring biuret content in a wide range of fertilizers.

Keywords

Biuret, Collaborative Ring Test, Fertilizer, High Performance Liquid Chromatography, International Standard, Single-Laboratory Validation

Introduction

Fertilizer has played an important role in improving both the quantity and quality of agricultural products [1–2]. Recently, urea, or urea-based fertilizers (Including urea formaldehyde slow release fertilizer, urea ammonium nitrate solution, sulfur coated urea, urea-based complex/compound fertilizer, etc.) has become the leading form of nitrogen fertilizers around the world, while some agricultural and environmental problems raised by the application of urea and urea-based fertilizers have attracted more and more attention [3–4]. Biuret, also known as 2-imidodicarbonic diamide (NH2CONHCONH2), is one of major by-products formed when molten urea was heated near or above its melting point during the manufacturing of urea and urea-based fertilizers [5–6]. The toxicity of biuret to plants was first observed and reported in the 1950s by US scientists during observing damages caused by urea foliage sprays on orchard plants such as citrus and pineapples [7–8]. The exact mechanism of biuret damage to different plants is still under investigation, but the harmful effects of high concentration of biuret to some sensitive plant species have been well documented [4,7,8], and many regulations/standards concerning the maximum allowed concentrations and/or the analysis methods have been published around the world [9–14].

There are at least three analytical methods available for the determination of biuret in fertilizers, including the traditional spectrophotometric methods [10–13], the atomic absorption spectrophotometric methods [14] and the HPLC methods [6,11,15]. The first two methods are based on the formation of complexation of biuret with copper ions [Cu(II)], and subsequent determination of the Cu(II) compound concentration by spectrophotometry [6,10,14]. There are two significant disadvantages of spectrophotometric methods: first, the formation of chromatic copper complexation, although well-known as the “Biuret Reaction”, is actually not the specific character of biuret, many other compounds such as urea-condensates (e.g. triuret), peptides and proteins may interfere with this complexation [15,19] second, both these spectrophotometric methods are complex and tedious, and are therefore more prone to multiple sources of error [6,11–14].

Recently, the HPLC methods have shown superiority over other types of methods, owing to their ability to quantitatively determine biuret content by completely separating biuret from numerous urea-condensates [6,11,15]. Some HPLC methods utilizing the C18 column with the detection wavelength of 200 nm [11] has been found to be effective for a variety of fertilizers, but could lose its efficacy when some specific compounds (e.g. nitrate, with strong adsorption under 200 nm) are present in the fertilizers (e.g. Urea Ammonium Nitrate (UAN) solution, nitrate-containing complex/compound fertilizer, etc.). To seek a uniform, quick and accurate method for the determination of biuret content in fertilizers [16,17], a high performance liquid chromatography method for the determination of biuret content in fertilizers was developed. A Single-Laboratory Validation (SLV) and systematically statistical analysis on the data obtained had proven that the proposed method was capable of effectively monitoring biuret content in a wide range of fertilizers. The reproducibility of the method was verified in the international Collaborative Ring Test (CRT) study organized by ISO/TC 134 “Fertilizers and Soil Conditioners”. On the basis of accuracy and precision of the results obtained in both SLV and CRT studies, it was conclude that the method is capable of measuring the amount of biuret present in the urea containing fertilizer accurately and with no interference from other urea or its adducts.

Experimental Section

This proposed method specifies the test procedure for the determination of the biuret content in liquid and solid urea containing fertilizers based on the HPLC method.

A. Principle

The biuret content in the fertilizer is extracted by aqueous acetonitrile mobile phase, and separated from other contents by reversed liquid chromatography on a propyl amino column, and the peak is detected by a UV detector attached to the HPLC. The external standard method is applied to determine the biuret content in fertilizer samples.

B. Reagents &Validation Materials

(a) Reagents

All reagents were of analytical grade. Acetonitrile (HPLC grade, Merck Co. Ltd., Germany) was used for preparation of the mobile phase. Deionized distilled water (18MOhm*cm) was used throughout the experiment. Biuret standard material (>99%, CAS 108-19-0, Lot #BCBH8859V) was purchased from Sigma-Aldrich® and was used for the HPLC quantitative analysis, and biuret reference material (>97%, CAS 108-19-0, Lot #L00812) from Alfa Aesar® were used in the LC-MS/MS qualitative analysis.

(b) Validation Materials

Two kinds of urea (SLV-054, SLV-108) and four kinds of compound fertilizers (SLV-003, SLV-125, SLV-012, SLV-114) from different sources were used as Single-Laboratory Validation (SLV) materials and are listed in Table 1. Each fertilizer sample to be tested has its distinguished content level of biuret. In order to establish a globally accepted analytical method, the validation materials for the Collaborative Ring Test (CRT) were selected to represent a wide variety of commercially available fertilizer products of different sources and manufacture processes. Seven different fertilizer products, including both liquid and solid urea-based fertilizers were selected for CRT and listed in Table 1, with biuret contents in the range of 0.10% ~ 1.01% (mass fraction).

Table 1. List of validation materials

Serial number

Type of fertilizer

Declared gradec

Note (raw material)

SLV-054a

urea

46–0–0

/

SLV-108

urea

46–0–0

/

SLV-003

compound fertilizer

15–15–15

urea, monoammonium phosphate, ammonium sulphate, potassium chloride

SLV-125

compound fertilizer

25–10–16

urea, monoammonium phosphate, potassium chloride, ammonium chloride

SLV-012

compound fertilizer

15–15–15

urea, monoammonium phosphate, potassium sulphate

SLV-114

compound fertilizer

25–11–10

urea, monoammonium phosphate, calcium superphosphate, potassium sulphate

CRT-001b

NPK compound fertilizer

N/A d

/

CRT -002

urea formaldehyde complex fertilizer

N/A

/

CRT -003

urea

N/A

/

CRT -004

NPK complex fertilizer

N/A

/

CRT -005

urea ammonium nitrate (UAN) solution

N/A

urea, ammonium nitrate

CRT -006

urea formaldehyde slow release liquid fertilizer (Trisert®)

N/A

triazone, as well as other urea-condensates

CRT -007

polymer sulfur coated urea (PSCU)

N/A

/

a SLV=single-laboratory validation

b CRT=collaborative ring test

c Declared grade listed in the order of N-P2O5-K2O

d N/A =not available

All solid fertilizer samples were grinded until they passed through a sieve of aperture size 0.5 mm, and mixed thoroughly for homogeneity before analysed. All liquid fertilizer samples mixed thoroughly for homogeneity before analyses.

C. Apparatus and Analysis Conditions

Ordinary laboratory apparatus, and

  1. High performance liquid chromatography (HPLC). – A Waters® 1525-2489-2707 HPLC system with a UV absorption detector having a minimum detection wavelength of 190 nm. LC operation conditions were: LC column, 250*4.6 mm propylamine (NH2) column with 5 µm particle size (APS-2 Hypersil, ThermoFisher Co. Ltd. Part #30705-254630 or Spherex NH2, Phenomenex Co. Ltd. Part #00G-00051-E0); mobile phase, 85% (v/v) acetonitrile in water; elution mode, isocratic; flow rate, 1.0~1.3 ml/min; injection volume, 10 µl; column temperature, 30~35 oC; and detection wavelength, 195 nm.
  2. Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). – A Shimadzu 20ADXR HPLC system with a UV absorption detector was used for LC separation. An AB Sciex Triple TOF® 4600 with an ESI source in positive ion mode with Analyst® software was used to control the LC and the MS. LC operation conditions were set as the same as the Waters® HPLC system previously described, the MS operation conditions were: ion source, ESI; scan mode, MS(30D~450D)+ MS/MS(30D~450D); curtain gas pressure, 35psi; ion spray voltage, 5500V; heater temperature, 600oC; ion source gas 1 pressure, 50psi; ion source auxiliary gas 2 pressure, 50psi; and collision gas, medium.
  3. Ultrasonic bath. – purchased from Shanghai Kudos ultrasonic instrument Co.,Ltd.
  4. Sample sieve. – With the aperture size of 0.50 mm.
  5. Syringe-driven filter. – With organic filter membrane of 0.22 µm pores.

D. Procedures

(a) Preparation of Test Solution:

For the solid fertilizer samples, weigh 0.1 g~0.5 g test sample (accurately to 0.0002 g, with biuret content of 1 mg~2 mg ca.) into a 25 ml beaker. Add 10 ml mobile phase and dissolve using an ultrasonic bath for 10 min. Transfer to a 25 ml volumetric flask and dilute to volume with mobile phase. Mix thoroughly and leave standing, filter with a syringe filer to obtain the test solution. For the liquid fertilizer samples, directly transfer 0.1 ml~0.5 ml of the test sample (accurately to 0.001 ml, with biuret content of 1 mg~2 mg ca.) into a 25 ml volumetric flask, dilute to volume with mobile phase. Mix thoroughly and leave standing, filter with syringe filer to obtain the test solution.

(b) Preparation of Biuret Stock Solution and Working Standard Solutions:

Weigh 0.5000 g biuret standard material [B(a)], dissolve by mobile phase, and transfer into a 1000ml volumetric flask, dilute to volume with mobile phase and mix to form the biuret stock solution. For the biuret working standard solution, pipette 0.00 ml, 0.50 ml, 1.00 ml, 3.00 ml, 5.00 ml and 10.00 ml biuret stock solution into 6 separate 25 ml volumetric flasks. Dilute with respective volumes of mobile phase and make up to the mark and mix thoroughly. Filter with 0.22 µm organic filter membrane (Table 2).

Table 2. Preparation of biuret working standard solutions

Volume of biuret standard solution (ml)

Mass of biuret (mg)

Concentration of biuret (mg/kg)

0.50

0.25

10.0

1.00

0.50

20.0

3.00

1.50

60.0

5.00

2.50

100.0

10.00

5.00

200.0

(c) Determination of the Biuret Content and Calculation

Ensure the HPLC apparatus operating conditions are optimized. Successively inject 10 μl working standard solution and determine the series of standard solution. Draw the standard curve and deduce the linear regression equation by the average peak areas of the biuret and the corresponding mass. Determine the test solution by the same procedure, measure the peak area, and calculate the biuret mass in each test solution according to the standard curve or linear regression equation.

The mass fraction of biuret (%), w, is calculated as follows:

JPPR 19 - 120_Michael M. Hojjatie_F5

Where m1 is the mass of biuret in mg, of the test solution, calculated according to the standard curve or linear regression equation corresponding to the peak areas; m is the mass in g, of the test portion. The mass fraction of biuret is the arithmetic average of two parallel test results. The statistical analysis of the data obtained from the SLV and CRT study was performed mainly according to procedures in ISO 5725-2:1994 [18].

Results and Discussion

A. Lc Chromatogram and Calibration Curve

The LC chromatogram of biuret standard material is shown in Figure 1. The observed peak is attributed to the biuret, and no any other significant contamination could be found, showing high purity of the biuret standard material [B(a)]. The calibration plot illustrated that the method was linear over the region of 10.00 to 200.0 mg/kg, with a correlation coefficient ≥0.999.

JPPR 19 - 120_Michael M. Hojjatie_F1

Figure 1. LC chromatogram of biuret standard and calibration curve

B. Lc-Ms/Ms Analysis

LC-MS/MS was introduced to analyze biuret reference material (> 97% from Alfa Aesar®) and some representative fertilizer samples, in order to verify the separation of biuret from many other compounds within various fertilizer matrices by the proposed method. Figure 2(a) depicted the LC-MS/MS quantitation ion chromatogram of biuret reference material; Figure 2(b) shows the chromatogram of sample #SLV-054 (Urea); Figure 2(c) is the chromatogram of sample #SLV-114 (Compound Fertilizer); and Figure 2(d) shows the proposed target compounds and their fragmentation pattern under positive ion ESI mode, corresponding to all the significant peaks found in quantitation ion chromatograms. Compound C1 with the retention time of 3.03~3.04 min corresponding to the protonated molecular ions [M+H]+ at m/z 147.0 was identified as triuret (C3H7N4O3+), which was also served as the precursor ion for fragments with [M+H]+ at m/z 130 (C3H7N3O3+), 104 (C2H6N3O2+), 87 (C2H3N2O2+) and 61 (CH5N2O+) in the tandem MS/MS. Compound C2 with the retention time of 3.16~3.18 min corresponding to the protonated molecular ions [M+H]+ at m/z 104.0 could be identified as the target biuret (C2H6N3O2+), which was also served as the precursor ion for fragments with [M+H]+ at m/z 87 (C2H3N2O2+) and 61 (CH5N2O+) in the tandem MS/MS. Compound C3 with the retention time of 3.64~3.65 min corresponding to the protonated molecular ions [M+H]+ at m/z 61 could be identified as urea, which has the strongest ion peak in chromatogram 2(a) in which the urea was the dominant component. Particularly since urea’s lone transition is the rather non-specific loss of ammonia (NH3) and due to its low molecular weight, urea formed no structurally significant ion by LC–MS/MS during our analysis. Compound C4 with the retention time of 4.62~4.63 min corresponding to the protonated molecular ions [M+H]+ at m/z 133.0 was identified as N,N’-methylenediurea (C3H9N4O2+), which was also served as the precursor ion for fragments with [M+H]+ at m/z 73 (C2H5N2O+) and 61 (CH5N2O+) in the tandem MS/MS.

JPPR 19 - 120_Michael M. Hojjatie_F2

Figure 2. LC-MS/MS quantitation ion chromatograms for potential compounds in biuret reference material and fertilizer samples

The LC-MS/MS result has shown that the propylamine (NH2) column utilized in our proposed method can successfully separate biuret form its analogues such as urea, triuret and N,N’-methylenediurea, thus indicated its possibility to be further extend to determine those aforementioned contaminants individually or simultaneously in a separate study.

C. Accuracy and Method Applicability

The accuracy of the proposed method was validated by the recovery rate test running for one urea and two kinds of compound fertilizers. In a typical procedure, a certain amount of biuret working standard solution with the concentrations of 60 mg/kg, 80 mg/kg and 100 mg/kg were spiked into the fertilizer sample, and then the test solutions were prepared and determined as described in the experimental section. The recovery rate was defined as the quotient of the recovery amount of the biuret divided by the amount of the biuret added. A summary of results tabulated in Table 3 below has shown that the spiked recoveries ranged from 98.14% to 107.24%, with a mean recovery of 102.24%.The recovery results met the requirement for standard method performances, in which the acceptable recovery limits for sample concentration around 100ppm (mg/kg) was given by 85%~110% [20].

Table 3. Recoveries for validation samples spiked with biuret

Serial number

Type of fertilizer

Spiking concentration (mg/kg)

Recovery (%)a

SLV-108

urea

60

98.14

SLV-108

urea

80

101.71

SLV-108

urea

100

103.50

SLV-125

compound fertilizer

60

101.46

SLV-125

compound fertilizer

80

100.22

SLV-125

compound fertilizer

100

103.51

SLV-114b

compound fertilizer

60

107.24

SLV-114b

compound fertilizer

80

104.86

SLV-114b

compound fertilizer

100

99.54

a. Average recovery = 102.24%.

b. In order to verify the method applicability, especially no interference from nitrate (common fertilizer component, with strong adsorption under 200 nm), an extra portion of 0.1g ammonium nitrate was added in validation sample SLV-114 during the recovery rate test.

Method applicability has to be verified at a very early stage of method development, since many compounds existing in the fertilizer matrix would have peaks on the HPLC chromatogram and thus may interfere with the analysis of biuret. One sort of those compounds with great high concerning is nitrates, which usually are very common fertilizer components, with strong adsorption under 200 nm. C18 columns were proven to be not suitable to analyze those fertilizer containing nitrates, simply because they cannot separate nitrates from the target compound biuret. In order to verify the proposed method’s applicability, an extra portion of 0.1g ammonium nitrate was added in validation sample SLV-114 during the recovery rate test, with the detection wavelength at 195 nm.

Figure 3(a) depicts the HPLC chromatogram for validation sample SLV-114, and Figure 3(b) shows the HPLC chromatogram for validation sample SLV-114, spiked with 0.1g ammonium nitrate. The peaks with retention time of 4.1 min ca. in both chromatograms were identified as biuret; and the huge bump with retention time of 7.5~14 min ca. was attributed to the nitrate, and show a complete separation from the biuret and many other possible analogous compounds with potential interests.

JPPR 19 - 120_Michael M. Hojjatie_F3

Figure 3. a) HPLC chromatogram for validation sample SLV-114; b) HPLC chromatogram for validation sample SLV-114, spiked with 0.1g ammonium nitrate.

D. Precision

In order to verify the precision of the proposed method, namely, to illustrate the repeatability of the test results, 5 parallel tests on all the six Single-Laboratory Validation (SLV) materials were performed respectively. The Relative Standard Deviations (RSD%) were used to evaluate the results (Table 4) as follows:

Table 4. Precisions for validation samples

Serial number

Type of fertilizer

Results of 5 parallel tests (%)

Average test result of biuret (%)

Relative standard deviations (RSD, %)

SLV-054

urea

1.019; 1.063; 1.065; 1.062; 1.060

1.054

1.85

SLV-108

urea

0.621; 0.611; 0.610; 0.617; 0.612

0.614

0.76

SLV-003

compound fertilizer

0.085; 0.086; 0.087; 0.087; 0.085

0.086

1.10

SLV-125

compound fertilizer

0.949; 0.955; 0.967; 0.955; 0.950

0.955

0.75

SLV-012

compound fertilizer

0.540; 0.533; 0.530; 0.536; 0.535

0.535

0.69

SLV-114

compound fertilizer

0.334; 0.334; 0.333; 0.332; 0.320

0.331

1.81

According to the results from Table 4, all the RSDs of 5 parallel tests lie within the range of 0.69%~1.85%. The method precision results met the requirement for standard method performances, in which the acceptable RSD limits for sample concentration around 1% was given by 2% ca., thus implies that precision of the as-established method is quite convincible [20].

E. Collaborative Ring Test Results

As confirmed by the SLV test, the newly proposed HPLC method with propylamine column has shown a good separation of biuert from urea and other N-containing compounds in many urea-containing fertilizer matrices. The proposed method also has a relatively wide dynamic linear range, convincing accuracy as well as precision. A similar method with minor variation on the chromatographic column for the determination of biuret in water-soluble, urea based commercial inorganic fertilizer materials, urea solutions and surfur-coated urea by another SLV test has been reported [6]. Also, an acetonitrile-free HPLC method with C18 column as the alternative method does exist [23]. A collaborative round robin test was first conducted to compare these three methods. Through careful studies of the data obtained in the collaborative round robin test, the two methods using acetonitrile-water (85:15 ratio) mobile phase are capable of separating the biuret in all the urea-containing fertilizers samples under this study, but the method using C18 column with water as a mobile phase showed some limitations based on the types of fertilizer [17, 23]. Then, the proposed method with propylamine column is verified in an international Collaborative Ring Test (CRT) study organized by ISO/TC 134 “Fertilizers and Soil Conditioners”.

Seven samples, together with the SOP files were sent to 13 globally participating laboratories to ensure that all the participants could meet the identical method requirements and uniformity. The samples choices have shown a very diverse spectrum, from solid fertilizers to liquid fertilizers, from single fertilizer matrix to compound/complex fertilizers and from uncoated fertilizers to coated fertilizer, which including one NPK compound fertilizer (CRT-001), one urea formaldehyde complex fertilizer (CRT-002), one urea (CRT-003), one NPK complex fertilizer (CRT-004), one Urea Ammonium Nitrate (UAN) solution (CRT-005), one urea formaldehyde slow release liquid fertilizer (Trisert®) (CRT-006) and one Polymer Sulfur Coated Urea (PSCU) (CRT-007).

Statistical analysis of these results was carried out in accordance with procedures in related ISO standards on statistics [18], and also referred to the AOAC Guidelines for Standard Method Performance Requirements [20]. Basically, The Cochran’s tests and Grubbs’ tests [18, 21–22] were initially performed on the data collected to eliminate outliers. The mean level (m), the repeatability standard deviation (sr), the reproducibility standard deviation (sR) of this joint-proposed method were calculated and shown in Table 5 below.

Table 5. Mean level (m), repeatability standard deviation (sr), and reproducibility standard deviation (sR) of the joint-proposed method.

Sample

CRT-001

CRT-002

CRT-003

CRT-004

CRT-005

CRT-006

CRT-007

Number of valid data/outliers

13/0

13/0

12/1

13/0

12/1

13/0

12/1

Mean level of biuret , m% (mg/kg)

0.62

0.53

1.01

0.31

0.24

0.94

0.10

Repeatability standard deviation (sr)

1.03E-2

7.81E-3

8.84E-3

4.57E-3

3.14E-3

1.79E-2

1.43E-3

Reproducibility standard deviation (sR)

2.03E-2

3.53E-2

5.22E-2

2.29E-2

2.79E-2

6.18E-2

3.57E-2

An examination of the data in Table 5 above indicate that both the repeatability standard deviation (sr) and the reproducibility standard deviation (sR) tend to be irrelevant with the mean level of biuret (mg/kg). Thus, according to the ISO standards 5725 on statistics, the precision of the proposed method can be represented by the average values of sr and sR over different mean levels, and should be quoted, as a percentage by mass, as:

Repeatability standard deviation, sr = 7.71E–3(2)

Reproducibility standard deviation, sR= 3.66E–2 (3)

During the Collaborative Ring Test (CRT) studies, the method applicability and precision were further confirmed; moreover, some valuable comments from participating laboratories were received when the final results were submitted. Laboratory X reported that due to the delay of logistics they had used another amine column (GRACE Altima amino) instead, which led to a small variation on the retention time of biuret, but still attained a good separation. The committee still took their data into consideration since laboratory X’s data had passed through the entire statistical test. This led to a note that “Other HPLC conditions that can achieve the same separation effects may be used.” Laboratory Y reported that they have done a systematically research on the CRT-007 sample of Polymer Sulfur Coated Urea (PSCU) and had found that the biuret content determined has some relationship with the pre-treatment procedure of the sample, especially with the time of ultrasonic treatment during the dissolve process. The deduction was that the biuret content determined may vary due to the change of extraction percentage which linked to the pre-treatment procedure, and a detailed sample preparation procedure with respect to the time of ultrasonic treatment as precise as 10 minutes in the SOP as well as the draft international standard [17] is necessary. Overall, all the comments from the participating laboratories comments have helped to the further improvement of the proposed method.

Conclusion

A high performance liquid chromatography method for the determination of biuret content in fertilizers was developed for the ISO international standard 18643. A Single-Laboratory Validation (SLV) and systematically statistical analysis on the data obtained had proven that the proposed method was capable of effectively monitoring biuret content in a wide range of fertilizers. The reproducibility of the method was verified in the international Collaborative Ring Test (CRT) study organized by ISO/TC 134 “Fertilizers and Soil Conditioners”. On the basis of accuracy and precision of the results obtained in both SLV and CRT studies, it was conclude that the method is capable of measuring the amount of biuret present in the urea containing fertilizer accurately and with no interference from other urea or its adducts.

Acknowledgement

This work was supported by Research Project for Technology Standard (11DZ0502600, 13DZ0502600, Funded by Science and Technology Commission of Shanghai Municipality, China P. R.). We are indebted to President Mr. William L. Hall Jr. and Secretary Mrs. Mojdeh R. Tabari from ISO/TC134 for many kind help. We would thank Dr. Ruud van Belzen from Yara Sluidkil B. V. to share with their alternative acetonitrile-free HPLC method for a three-side (CHN-USA-NED) round robin test as a preliminary research and Dr. Chengyuan Cai from AB Sciex-China Pte. Ltd. for help on LC-MS/MS analysis.

JPPR 19 - 120_Michael M. Hojjatie_F4

References

  1. Morari F, VellidisG, Gay P (2011) Environment and human health effects: Fertilizers. In: J Nriagu (Ed), editor. Encyclopaedia of Environmental Health. Elsevier Science Publishers Pg No: 727–737.
  2. Foley JA, Ramankutty N, Brauman KA, Cassidy ES, Gerber JS, et al. (2011) D.P.M. Nature 478: 337–342.
  3. Hasan MM (1957) Biuret Phytotoxity. UCLA-Horticultural Science Publication, Los Angeles, CA.
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  10. Fertilizers – Spectrophotometric determination of biuret in urea. EN 15479:2009.
  11. Determination of biuret content for compound fertilizers (complex fertilizers). GB 22924–2008.
  12. Determination of urea-Part 2: Biuret content -Spectrophotometric method. GB 2441.2–2010.
  13. AOAC Official Method 960.04. Biuret in fertilizers-Spectrophotometric method.
  14. AOAC Official Method 976.01. Biuret in fertilizers-Atomic absorption spectrophotometric method.
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  16. ISO/TC 134 Business Plan (2012) Pg No: 1–2.
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  18. Accuracy (trueness and precision) of measurement methods and results-Parts 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method. ISO 5725–2:1994.
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Occupational Performance of Children and Adolescents with Mucopolysaccharidosis Using Assistive Technologies

DOI: 10.31038/IMROJ.2019421

Abstract

Mucopolysaccharidoses (MPS) are a specific group of genetic diseases in which due to the accumulation of glycosaminoglycans (GAGs) in different organs and tissues, causes multisystemic changes that compromise the functionality and occupational performance of individuals. Occupational performance, understood as the participation and execution of activities of daily living, may be favoured using Assistive Technology (AT). Since there are no studies reporting the influence of AT on the occupational performance of children and adolescents with MPS, the objective of this study was to evaluate the occupational performance in self-care activities, based on the use of low-cost AT in children and adolescents with Mucopolysaccharidosis. Six individuals with MPS types I, IV-A and VI, aged 9 to 16 years participated. The instruments used for data collection were the Pediatric Disability Assessment Inventory (PEDI) – self-care area only, and the Canadian Occupational Performance Measure (COPM). The results showed that the tasks that presented the greatest disabilities in the performance are the areas of dressing, personal hygiene and bath. Thus, TA resources were made for five activities related to dressing and one for personal hygiene. After the use of AT, there was a positive and significant change in occupational performance and satisfaction of these individuals. Thus, the use of AT can significantly improve the occupational performance of this population.

Keywords

Adolescent, Assistive Technology, Child, Mucopolysaccharidosis, Occupational Performance, Self-Care Activities

Introduction

Mucopolysaccharidoses (MPS) are rare diseases, characterized by genetically determined metabolic errors, which are part of the Lysosomal Deposit Disease group. In these diseases there is accumulation of substrates that are normally degraded in lysosomes, and in MPS, deficiencies of specific enzymes lead to the accumulation of glycosaminoglycans (GAGs), resulting in a series of signs and symptoms, which together bring systemic impairment [1–3]. There is no cure for this group of diseases, and the current treatment is aimed at delaying its progress. Even with treatments, progression is nonetheless long-term, and changes in body structures and functions (joint stiffness, decreased range of motion, joint laxity, claw hand) result in limited functionality in the areas of occupational performance, especially in self-care tasks – related to dressing, personal hygiene and food [4].

Occupational performance is understood as the ability to perform routines and perform roles and tasks, involving the areas of self-care, productivity and leisure, being influenced by the factors of the individual, their skills and the context in which they are inserted [5]. Thus, for individuals with some form of physical limitation, occupational therapists may use Assistive Technology (AT) as an effort to enable improved independence and occupational performance, to the extent that limitations can be overcome through adaptations and use of ATs.

Assistive Technology allows a person with a limitation to perform activities and tasks more independently, and can be characterized as technology of high complexity (high cost – with electronic components) or low complexity (low cost), the latter being designed from everyday easily accessible materials that can often be made from materials available at home, in the office, at school or in the hospital. This type of AT is something that can be done right away to meet the needs of those who need it, with the resources at hand [7–9]. However, there are no studies linking the use of AT and MPS. Thus, this study aims to evaluate occupational performance in self-care activities, based on the use of low-cost assistive technology in children and adolescents with Mucopolysaccharidoses.

Methods

This is a prospective and descriptive longitudinal quantitative research, conducted at the outpatient infusion and enzyme replacement therapy center of a reference Hospital for the treatment of rare diseases, located in Rio de Janeiro – Brazil. Participated in the study: Six children and adolescents of both sexes between 9 years and 6 months and 16 years and 4 months of age, with type I, IV-A and VI MPS, with biochemical diagnosis of MPS that are treated with enzyme replacement in the institution’s medical genetics department. Were excluded from this research: Individuals with type III MPS because of neurological impairment; children and adolescents who had severe cognitive and / or motor impairment that prevented them from responding to assessments; and children and adolescents who reached the maximum PEDI score. For data collection, the Pediatric Disability Assessment Inventory – PEDI was used, only Part I – Child Abilities, which reports on the child’s functional abilities to perform daily activities and tasks and on the self-care scale [10] and, then, the Canadian Occupational Performance Measure – COPM was applied.

The PEDI was applied through a structured interview with children and adolescents, lasting on average 30 to 40 minutes, where it was identified if individuals can perform certain activities. The COPM was administered in around 10–15 minutes, with participants identifying issues related to their occupational performance related to the activities contained in PEDI. They chose the activities that were meaningful to them, quantifying the degree of satisfaction and importance they attributed to each of the activities. At the end of the application of the instruments, it was made a survey from the chosen activities (the activity that obtained the highest importance score in the COPM) and the possible assistive technology resources to be incorporated in the intervention process of the activity that gained the most quantification, by the participants, including from creating and building a low-cost TA resource to providing guidance to follow during activities performance. With the AT done, its use was trained with the participants and the responsible person accompanying them by the main researcher and after the participant’s minimum 2 weeks of AT use, the COPM was reapplied to assess if there were changes in occupational performance with the aid of the AT. This reapplication was made by a blinded evaluator who had no prior knowledge of previous results.

The COPM was created as an outcome measure, therefore, the total scores of the initial moment and the moment of re-evaluation were used with the objective of comparing the occurrence or not of changes in occupational performance and satisfaction, so it could be proved the effectiveness of an approach or intervention – in this case, the use of Assistive Technology. These changes were calculated by subtracting the evaluation values from the re-evaluation values, both for performance and satisfaction. The participants’ scores were not compared with each other, as COPM is an individual measure. With the completion of research data collection, the assistive technology resource made and/or adapted for each participant remained the same for continuous use. This study is part of a project approved by the Research Ethics Committee of the research site, under the number 1.827.932, valid until 31/10/2021, complying with the ethical principles in accordance with resolution 466/2012, and all participants were informed about the study, objectives, benefits and risks.

Results

From PEDI results we observed impacts on occupational performance, which consequently affects the ability to perform self-care tasks, especially in dressing, personal hygiene and bathing activities, as can be seen in Table 1. The changes in self-care activities observed from PEDI, participants chose the activities that were most significant through COPM, adding a value about it, to quantify its importance in performing it on a daily basis or wanting to execute it. Table 2 shows the chosen activities, the degree of importance and the AT made. It is noted that the activities varied, related to dressing or personal hygiene.

Table 1. Affected items grouped by tasks performed in PEDI self-care.

Participant

ITEMS AFFECTED

Feeding (14)*

Personal hygiene (14)*

Bathing (10)*

Dressing (20)*

Toilet use (5)*

Sphincter control (10)*

1

12

2

2

2

5

2

3

2

2

1

12

1

4

5

11

5

4

9

6

2

4

3

12

2

*:  Number of items contained in each self-care task according to PEDI.

Table 2. Description of activities, importance given by participants – COPM and AT made

Participant

MPS

Activities chosen at COPM

Grau de importância

AT

1

II

Put on socks

9

Sock on Applicator

2

IV-A

Brush hair

9

Hair brush with L-form

3

IV-A

Remove socks

8

Stretch cable to remove socks

4

VI

Put on socks

10

Sock on Applicator

5

VI

Wear lower end (buttoning and zipper handling)

9

Buttoning

6

VI

Dress upper and lower extremity (buttoning and zipper handling)

8

Buttoning

After making and training the ATs, Table 3 presents the changes in occupational performance and satisfaction in performing the selected tasks. The improvement of these two parameters was observed throughout the sample. However, it was observed that it was not possible to infer changes in two cases (participant 4 and participant 6), because they did not use the AT after training: participant 4 started training at home, but didn’t feel willing to keep using the AT, preferring that his mother did the activity for him; and participant 6, did not use, because he did not wear clothes that have button or zipper at home, only using to go out and preferring that his mother performed the activity.

Table 3. Importance / Performance / Satisfaction Relationship – Before and after the application of AT and observed changes

Participant/ MPS

Activity

Importance

Initial Evaluation

Revaluation

Change

Performance 1

Satisfaction 1

Performance  2

Satisfaction  2

Performance

Satisfaction

1 (type II)

Put on socks

9

2

2

5

8

3

6

2 (type  IV)

Brush hair

9

5

3

10

10

5

7

3 (type  IV)

Remove socks

8

2

4

4

7

2

3

4 (type  VI)

Put on socks

10

1

5

*

*

*

*

5 (type  VI)

buttoning and zipper handling

9

2

5

10

10

8

5

6 (type VI)

buttoning and zipper handling

8

3

5

*

*

*

*

Note: *: Data were not obtained as the participant reported not using the AT

Discussion

Children and adolescents with MPS, the limitation of mobility caused by the accumulation of glycosaminoglycans in tissues and joints, causes a loss in the ability to perform occupational activities, especially related to activities of daily living (ADLs), especially those requiring fine movements (eg: buttoning) or of large amplitudes (brush hair) [11–15]. It is widely discussed in the literature that progressive musculoskeletal impairment, found regardless of the type of MPS, impacts occupational performance. Studies show that joint stiffness, common in MPS, and even MPS IV-A-specific ligament laxity and muscle weakness, as well as carpal tunnel syndrome and Dupuytren’s contractures, all contribute to important limitation in self-care activities such as eating, dressing and personal hygiene [14, 16,17,18]. From the knowledge of body structure and function deficiencies related to self-care activities, it is possible to establish intervention priorities and select better strategies to be used, in order to enhance occupational performance. Among the intervention strategies, AT is a possibility of occupational therapist resource for the promotion of functionality [10].

Although the entire sample showed impairment in the area of dressing, the choices of tasks for making the AT were diverse and did not show a pattern by MPS type. This is because each individual sees itself in a way, and different activities may be a priority for one but not to the other. The activities that a person chooses to engage in are full of meaning and purpose and are related to their roles and how they relate to the world/environment [19], and therefore each individual attaches meaning and importance to each task of your day to day, like doing one activity is more important than performing another. With the application of COPM, besides allowing the choices of self-care activities that are significant for individuals, it was possible to measure the importance of the activity and quantify its performance and satisfaction. This is because according to the COPM theory was developed occupational performance is viewed as a subjective individual experience [20].

As much as it is not possible to make inferences between participants and their scores, it is possible to say that in the initial assessment of occupational performance, the average among participants was 2.5 points and in the revaluation, an improvement of the results was observed with an average of 7,25 points (minimum value of 4 and maximum of 10) There was also some improvement in the performance rate of activities, in the initial rating the group average was 4 (minimum 2 and maximum of 5) and in the revaluation the average value was 8.75 points (minimum 7 and maximum of 10). According to Carswell (2004), the variation found from 2 or more points in the COPM can be considered a clinically significant intervention [21]. That said, there was an improvement in the occupational performance of individuals with MPS, based on assistive technology, thus seeking to increase the independence of these individuals.

With these changes presented in a significant way,  it is possible to suggest that the higher the performance in performing self-care activities, the better the satisfaction in performing it, as seen in the work of Mildner et al., 2017, where the use of AT was described as significant in another health condition [22]. According to Persson et al. (2014) changes in occupational performance are associated with changes in psychosocial functioning and psychological well-being of individuals [23]. Regarding the non-use or abandonment of AT devices by users (occurred with two participants), Costa and collaborators (2015) conducted a literature review on the reasons that led individuals to abandon their resources. The most quoted factors were: problems with the user’s physical state; lack of information and training from both professionals and users; pain; functional limitations; preference for another resource or use of remaining capacities [24]. Among the factors mentioned, only the “preference of using remaining capacities” was found in this paper. In addition to this factor it was also quoted “lack of user motivation” and “lack of device functionality”.

Regarding AT, social acceptance is an important variable that permeates the decision of the user or his family to use the resource, because even if a certain resource improves the quality of life and occupational performance, but represents a negative social connotation and stigmatizing, the user tends to abandon it. If there is no support or encouragement from family members or if the device is viewed as a validation of being sick/being different (by the individual or family members) the chances of abandonment may be high [24–26].

Conclusion

AT has become an importante occupation therapeutic resource for children and adolescentes with problems in performing activities of daily living, such as MPS, increasing their autonomy and personal satisfaction. Thus, we highlight the importance of investing in future research in AT field focusing on occupational performance, especially self-care of individuals with MPS to then guide the intervention and occupational therapeutic care.

References

  1. Guarany NR, Schwartz IVD, Guarany FC, Giugliani R (2012) Functional capacity evaluation of patients with Mucopolysaccharidosis. J Pediatr Rehabil Med  1: 37–49.
  2. Nussbaum RL, Mcinnes RR, Willard HF (2008) Thompson e Thompson Genética médica, 7º edição. Saunders, Elsevier.
  3. Schwart, IVD, Boy R (2011) As doenças lisossômicas e tratamento das mucopolissacaridoses. Rev do Hosp Univ Ped Ernest 2.
  4. Silva MCA, Horovitz DDG, Ribeiro CTM (2015) Desempenho ocupacional de crianças e adolescentes com mucopolissacaridose de uma instituição de saúde do município do Rio de Janeiro [dissertação de mestrado]. Rio de Janeiro.
  5. Magalhães LC, Magalhães LV, Cardoso, AA (2009) Medida Canadense de Desempenho Ocupacional – COPM. Belo Horizonte: Editora UFMG.
  6. Barata-Assad DA, Elui VMC (2010) Limitações no desempenho ocupacional de indivíduos portadores de hemofilia em centro regional de hemoterapia de Ribeiro Preto, Brasil. Rev. Ter. Ocup. São Paulo 3: 198–206.
  7. Anson D. (2004) Tecnologia assistiva. In: Pedretti LW, Early MB. Terapia Ocupacional: Capacidades práticas para as disfunções físicas. Quinta edição. São Paulo: Roca P. 276–296
  8. Rodrigues AC (2008) Reabilitação: Tecnologia Assistiva. In: Rodrigues, AC. Reabilitação. Práticas inclusivas e estratégias para a ação.  São Paulo: Livraria e Editora Andreoli p. 39–41.
  9. Sfredo Y, Silva RCR. (2013) Terapia Ocupacional e o uso de tecnologia assistiva como recurso terapêutico na artrogripose. Cad Ter Ocup. UFSCar 3: 479 – 491.
  10. Mancini, MC (2005) Inventário de Avaliação Pediátrica de Incapacidade (PEDI): Manual da versão brasileira adaptada. Belo Horizonte; UFMG.
  11. Rocha JSM, Bonorandi AD, Oliveira LS, Silva MNS, Silva, VF (2012) Avaliação do desempenho motor em crianças com mucopolissacaridose II. Cad Ter Ocup UFSCar 2012 20(3): 403–12.
  12. Amaral IABS, Filho RLO; Neto JAR, Reis MCS. Avaliação da capacidade funcional de adolescentes portadores de Mucopolissacaridose do tipo II. Cad Bras Ter Ocup, São Carlos. 2017; 25(2): 297–303.
  13. Schwart, IVD; Boy, R. (2011) Às doenças lisossômicas e tratamento das mucopolissacaridoses. Rev do Hosp Univ Ped Ernest 2.
  14. Santos AC, Azevedo ACMM, Fagondes S, Burin MG, Giugliani R, Schwartz IVD (2008) Mucopolysaccharidosis type VI (Maroteaux-Lamy syndrome): assessment of joint mobility and grip and pinch strength. Jorn de Ped 2: 130–5.
  15. Pinto LLC, Schwartz IVD, Puga ACS, Vieira TA, Munoz MVR, Giugliani R, et al. (2006) Prospective study of 11 Brazilian patients with mucopolysaccharidosis II. Jornal de Ped 4: 273–8
  16. Vieira TA, Giugliani R, Schwartz I (2007) História natural das mucopolissacaridoses: Uma investigação da trajetória dos pacientes desde o nascimento até o diagnóstico. [dissertação de mestrado] [online]. Universidade Federal do Rio Grande do Sul, Porto Alegre.
  17. Viapina M, Burin MG, Wilke M, Schwartz IVD (2011) Síndrome de Morquio – Mucopolissacaridose IV-A. Serviço de Genética Médica – Hospital de Clínicas de Porto Alegre.
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  19. Pelosi, MB (2009) Tecnologias em comunicação alternativa sob o enfoque da terapia ocupacional. In: Deliberato D.; Gonçalves MJ; Macedo EC (Org.). Comunicação alternativa: teoria, prática, tecnologias e pesquisa. São Paulo: Memnon Edições Científicasp 163–173.
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Macro Elements and Their Concentrations in the Blood Serum and Feed

DOI: 10.31038/IJVB.2019322

Abstract

Within three years was analyzed mineral content (Ca, Mg) in feed and blood serum of dairy cows. Samples of serum and TMR – total mixed ratio, were from dairy farms (n = 24) from different regions of Slovakia. In samples was determined average levels of the calcium (Ca) and the magnesium (Mg) according to the methodology used by the Official lists methods and laboratory diagnosis of food and feed. The significant increase (P≤.0.05) of serum Ca level was found in cows in before calving in the B period and the statistical increase (P≤.0.05) of the serum Ca level were recorded in dairy cows in after calving in period C with comparison to the dairy cows in period A. In the period top lactation in the period B was observed decrease the serum Ca (33.8%) and in in the period C was decrease only 17.64%. In the period antepartum and postpartum was a decrease the serum Ca between from 20.75 to 31.90%. The serum magnesium in the period antepartum in the period B were decrease 38.03 % and 8 % decrease the serum Mg was in the period C – top lactation. Calcium and magnesium contens in TMR for dairy cows in production phases were in the range declared by the NRC (2001).

Key words

Atomic Absortion Spectrometer-AAS, Blood Serum, Calcium, Cows, Feed-TMR Total Mixed Ration For Dairy Cows, Mangnesium

Introduction

The amount of minerals in feed varies within a very wide range depending on ecological conditions, the composition of crops, the content of access nutrients in the soil, and the intensity of fertilization. The use of minerals from feed can be altered by the combination of feeds, but also by the intensity and the way of grass fertilization and the different representation of grasses, clover and herbs [1,2]. Mineral elements have crucial role in animal production and health. Minerals, in the form of chemical compounds, are naturally available through geological processes in the form of simple salts to very complex silicates [3]. Minerals are grouped into macrominerals, i.e. calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), and phosphor (P), and microminerals, i.e. iron (Fe), copper (Cu), zinc (Zn), copper (Co), and manganese (Mn) [4]. Minerals have a special role in ensuring efficient growth, reproduction and immunocompetence in animals. Macrominerals are required in the development of bones and teeth and are also found in lipids, proteins, muscle, and tissue, while microminerals have a great impact on animal’s reproductive physiology and its imbalance causes various problems leading to lower reproductive efficiency. Mineral level can also be used for rapid and accurate in-vivo classification of cattle according to organic and non-organic production type [5]. The dairy cow experiences most physiological stress during the transition period when it moves from the demands of fetal growth through to calving, colostrum production and, eventually, maximal milk production. In addition to these drains on the animal’s physical resources, the cow must be in a suitable physiological state to ensure repair of any tissue damaged during calving, and to maintain resistance to disease challenges [6]. For high-quality control of health and nutrition status it is therefore necessary to gain detailed information about the changes in the internal environment during the individual stages of the productive life of animals [7]. Determination of indicators of the metabolic profile in course of the breeding season helps to diagnose the metabolic problems of the animals [8]. Cows’ nutrition and feed technology belong to the external factors that affect their production. TMR – total mixwed ration (mixed feed) is considered to be the optimal way to provide a balanced amount of nutrients for dairy cows. It is a feeding system for dairy cows, the essence of which consists in the combination of bulk fodder, grain, protein, minerals, vitamins and various additives [9]. Of the voluminous feed, the lucerne, clover and hay are rich in calcium. The most calcium-containing silage contains clover and lucerne silage. The opposite value shows corn silage in which the calcium value is seven times lower. The magnesium content in feed plants depends on the magnesium content of the soil, the soil pH and the fertilizer application method [10]. When feeding dairy cows, the requirements of dairy cows must be taken into account, especially during the breeding cycle [11]. The aim of our work is to monitor the occurrence of calcium and magnesium in TMR and in the blood serum of dairy cows.

Materials and Methods

Within three years (first year A, second year B, third year C), the calcium (Ca) and magnesium (Mg) content of the blood serum of dairy cows and TMR were monitored. Feed samples – TMR and blood serum came from Slovak breeds of production dairy cows (n = 24). Samples of TMR (A – n = 30; B – n = 36; C – n = 36) and blood serum (A – n = 180; B – n = 216; C – n = 216) 21 days before calving, – 21 days after calving and at the peak of lactation. For the determination of mineral substances in samples of plant and biological material, the methodology used in the List of Official Methods and Laboratory Diagnostics of Food and Feed [11] was used.

Blood samples were collected in the morning via the jugular vein. After proper clotting, the blood samples were centrifuged at 3500 rpm for 15 minutes and the serum samples were stored at -20°C until analyses. Before measuring, serum samples were deproteinized by supplementing trichloracetic acid at a 1:1 ratio. After centrifugation, the content of Ca and Mg in the supernatant was measured directly by using the flame method of an atomic absorption spectrometer (Unicam Solar, 939, Great Britain). Feed samples were processed by digestion in the microwave oven (MLS-1200 Mega, Milestone) by using 5 mL HNO3 and 1 mL HCl per 1 g of sample. The program of digestion was as follow: 1st step-250 W, 2 minutes; 2nd step-0W, 2 minutes; 3rd step-250W, 5 minutes; 4th step-400 W, 5 minutes; 5th step-500 W, 5 minutes; and 6th step-600W, 2 minutes. The digested samples of feeders were analyzed for the presence of Cu and Zn by using the flame method of an atomic absorption spectrometer (Unicam Solar, 939, Great Britain). The flame conditions were those recommended by the instrument manufacturer for Ca and Mg (wavelength 422.7 and 285.2, respectively, band pass 0.5 nm). The content of Cu and Zn in forage and blood were determined according to the methodology used by the Official lists methods and laboratory diagnosis of food and feed.

Statistical Analysis

The statistical evaluation of the results has been done by the program of microsoft Excel 7.0, using Student’s ttest at (P≤0.05) and (P≤0.01) level of significance. For the calulation of means, values below the detection limits were set to zero. We compared the values from each of the three years A, B, and C and between the individual production phases.

Results and Discussion

Calcium and Magnesium In Feed

The observed amounts of calcium and magnesium in mixed feed – TMR samples over the reference period are summarized in Table 1. The mean contents of calcium in feed intended for dairy cows in before calving dairy cows in the periods A and B (5.49 ± 1.97, 6.00 ± 0.59 g / kg) were at tolerance values (4.00–6.00 g / kg ) reported by [12]. In the period C, the calcium content was slightly increased by 6.45 ± 2.69 g / kg. The decreased calcium content was recorded in the TMR after calving at each observation period (Table 1) and in the A period at the top of lactation (6.93 ± 1.16 g / kg) and in the period B (5.93 ± 1.34 g / kg) compared to [12]. In the period C in feed intended for dairy cows at the peak of lactation (7.47 ± 2.09 g / kg), the amount of calcium was tolerated. In feed, in the B period was found the significant increase (P≤0.01) of the contents of Mg for dairy cows feeding in before calving in compared to the dairy cows from the period A. In the period C, in the feed was recorded the statistical increase (P≤0.05) of contents Ca in dairy cows feeding in top of lactation with comparison to the dairy cows from period B. Compared to the values reported by [13] in the curve samples of TMR (before calving 7.69g / kg, after calving 8.88 g / kg and at the top of lactation 8.49g / kg), the values of calcium are lower. In India, [14] found average quantities of Ca 0.63% in mixed feeds for dairy cows that are similar to our findings. He pointed to a strong correlation between the calcium and magnesium content of the plants and the blood serum content of the dairy cows.

Table 1. The concentration of Ca and Mg in feed for dairy cows.

g/kg

Before calving

After calving

Top of lactation

 x ± s

 x ± s

x ± s

A

Ca

5.49 ± 1.97

6.52 ± 0.59

 6.93 ± 1.16

Mg

 3.17 ± 0.76

 3.62 ± 0.64

3.87 ± 1.17

B

Ca

 6.00 ± 0.59

6.75 ± 1.38

5.93 ± 1.34

Mg

4.12 ± 0.77 **

 4.07 ± 0.53

 4.10 ± 0.75

C

Ca

 6.45 ± 2.69

6.72 ± 2.9

7.47 ± 2.09 *

Mg

3.94 ± 1.49

 3.87 ± 1.41

 4.18 ± 0.62

x = mean concentrations; s = standard deviation; statistically significant * p≤ 0.05 ; ** p≤ 0.01.

Magnesium content in the TMR monitored was increased compared to NRC (2001). Increased amounts of magnesium were found in postpartum feed during periods A, B, and C (3.62 ± 0.64, 4.07 ± 0.53 and 3.87 ± 1.41 g / kg). In feed, in the B period was found the significant increase (P≤0.01) of the contents of Mg for dairy cows feeding in before calving in compared to the dairy cows from the period A. In India, low levels of magnesium (0.28% Mg) were found in mixed feed for dairy cows [14, 15]  reported low levels of calcium in feed, where the soil had an adequate amount of calcium, and the magnesium concentration in the soils was below the critical level, but the feed was higher.

Calcium and Magnesium In Blood Serum

The mean levels of serum calcium found in the dairy cows before calving, after calving and top of lactation over the reference period were within the reference values (2.25–3.00 mmol / l) (Table 2). The significant increase (P≤.0.05) of serum Ca level was found in cows in before calving in the B period in comapred to the cows in the period A. Similarly, the statistical increase (P≤.0.05) of serum Ca level were recorded in dairy cows in after calving in period C with comparison to the dairy cows in period A. In the A period of the group of dairy cows that were in before calving, individual mild reductions in serum calcium were 31.9%, and 30.9% after calving and 25.72% at the top of lactation. In period B, individual serum calcium reduction was observed in 28.16% of dairy cows before calving, 23.4% after calving, and 33.6% of dairy cows at the top of lactation. A slight decrease in serum calcium was also observed in C period in the individual production stages of dairy cows ranging from 17.64% to 24.07% of dairy cows. Plasma Ca concentrations are reduced in early postpartum cows, because of increased demand of Ca for synthesis of milk coupled with the relativelyslow response in up-regulating Ca absorption from the intestinal tract. The postpartum depression in plasma and ionized Ca is greater in older cows [16]. [16,17] reported the lower concentration in blood serum of Ca of dairy cows in the individual production phases in compared to our results.

Table 2. The concentration of Ca nad Mg in blood serum of dairy cows.

mmol/L

 

before calving

after calving

top of lactation

x ± s

 x ± s

 x ± s

A

Ca

2,21 ± 0.30

2.28 ± 0.31

2.35 ± 0.38

Mg

0.81 ± 0.08

0.78 ± 0.10

0.84 ± 0.13

B

Ca

2.39 ± 0.27 *

2.70 ± 0.72

2.41 ± 0.41

Mg

0.87 ± 0.28

0.80 ± 0.16

0.87 ± 0.19

C

Ca

2,42 ± 0,46

2,34 ± 0,4

2,40 ± 0,30

Mg

0,87 ± 0,14

0,88 ± 0,15 *

0,90 ± 0,10

x = mean concentrations; s = standard deviation; statistically significant * p≤ 0.05.

Similarly, mean serum magnesium levels in the reference period in dairy cows ranged within the reference values (0.74–1.23 mmol/l). We observed a decrease in serum magnesium in period A and B in individual production, before claving 35.2% and 38.03% , after calving 29.55% and 37.41%, top of lactation 22.72% and 19.12%, respectively. In period C, the reduction in serum magnesium over the reference values was lower than 8% for dairy cows in the individual production phases. The observed slight decrease in serum calcium in the production phases in some dairy cows in the studied holdings revealed hypocalcaemia. Hypokalaemia occurs with increased colostrum formation. Insufficient parathyroid hormone concentration and decreased receptor activity for calcium in the gut and bones is not enough to keep blood calcium levels within physiological limits. Concurrent changes in magnesium concentration and disruption of Ca / Mg ratios occur. Disturbance of the mutual relationships of minerals, especially calcium and magnesium, causes CNS disorders, circulatory and energetic metabolism [18, 19, 20]. Some papers present concentrations of biochemical parameters in the blood of cows at different stages of lactation; their comparison is limited as the values are determined by different methods. They have a different number of animals, with different genetic equipment and kept under different conditions [17, 18, 21].

Conclusion

In conclusion, at work we monitored calcium and magnesium content in feed and blood serum of dairy cows in selected breeds of d airy cows for three years. Mineral deficiency in dairy cows can be the primary cause of many metabolic and production disorders. This study revealed some differences in blood serum. Reduction of serum calcium in production phases in dairy cows, the initial stage of hypocalcaemia in dairy cows. By following the principles of differentiated feeding of dairy cows by production phases and by monitoring the levels of minerals in blood serum and feed, avoid metabolic and production disorders.

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