33 research outputs found
Impedance spectroscopy, electrical relaxation and Ac conductivity studies of organic-inorganic hybrid compound: NH3(C6H4)2NH3HgCl4
Organic–inorganic hybrid sample NH3(C6H4)2NH3HgCl4 was characterized by differential scanning calorimetry (DSC), TGA analysis and electrical impedance spectroscopy. DSC studies indicated the presence of a one-phase transition at 391 K. As for the ac conductivity of the compound NH3(C6H4)2NH3HgCl4, it has been measured in the temperature range of 358 - 413K and the frequency range of 209 Hz–5 MHz. Concerning the Z’ and Z’’ versus frequency plots, they were well-fitted to an equivalent circuit model. The equivalent circuit is composed of a series of combination of two parallel (R//CPE) circuits. Besides, the frequency dependence of the conductivity was interpreted in terms of Jonscher's law σ(ω) = σdc +A ωn.  As regards the conductivity, it follows the Arrhenius relation. The variation of the value of the conductivity with temperatures confirmed the availability of the phase transition at 391K detected by DSC and electrical measurements
Impedance Spectroscopy, Electrical Relaxation and Ac Conductivity Studies of an Organic-Inorganic Hybrid Compound: C12H14N2CuCl4
The AC conductivity of the compound, C12H14N2CuCl4, in the temperature and frequency range from 373 to 423 K and 209 Hz – 5 MHz, respectively, is reported. The differential scanning calorimetry and thermogravimetric analysis indicate the presence of a phase transition at 400 K. The Z’ and Z’’ vs. frequency plots are found to be well fit by using the equivalent circuit model. The circuits consist of a parallel combination of bulk resistance Rp and constant phase element. Besides, the analysis of the experimental data based on the jump relaxation model shows that the translation motion of the charge carrier and reorientation hopping between the equivalent sites of the metal chloride anion and the cation groups are responsible for the observed AC conductivity in the temperature regions I (373–400 K) and II (400–423 K). The frequency dependence of the conductivity which follows the Arrhenius equation is interpreted in terms of Jonscher's law: σ (ω) = σdc +A ω S.Â
Multivitamin supplementation in HIV infected adults initiating antiretroviral therapy in Uganda: the protocol for a randomized double blinded placebo controlled efficacy trial.
BACKGROUND: Use of multivitamin supplements during the pre-HAART era has been found to reduce viral load, enhance immune response, and generally improve clinical outcomes among HIV-infected adults. However, immune reconstitution is incomplete and significant mortality and opportunistic infections occur in spite of HAART. There is insufficient research information on whether multivitamin supplementation may be beneficial as adjunct therapy for HIV-infected individuals taking HAART. We propose to evaluate the efficacy of a single recommended daily allowance (RDA) of micronutrients (including vitamins B-complex, C, and E) in slowing disease progression among HIV-infected adults receiving HAART in Uganda.
METHODS/DESIGN: We are using a randomized, double-blind, placebo-controlled trial study design. Eligible patients are HIV-positive adults aged at least 18 years, and are randomized to receive either a placebo; or multivitamins that include a single RDA of the following vitamins: 1.4 mg B1, 1.4 mg B2, 1.9 mg B6, 2.6 mcg B12, 18 mg niacin, 70 mg C, 10 mg E, and 0.4 mg folic acid. Participants are followed for up to 18 months with evaluations at baseline, 6, 12 and 18 months. The study is primarily powered to examine the effects on immune reconstitution, weight gain, and quality of life. In addition, we will examine the effects on other secondary outcomes including the risks of development of new or recurrent disease progression event, including all-cause mortality; ARV regimen change from first- to second-line therapy; and other adverse events as indicated by incident peripheral neuropathy, severe anemia, or diarrhea.
DISCUSSIONS: The conduct of this trial provides an opportunity to evaluate the potential benefits of this affordable adjunct therapy (multivitamin supplementation) among HIV-infected adults receiving HAART in a developing country setting.
TRIAL REGISTRATION: Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01228578
Infant feeding among HIV-positive mothers and the general population mothers: comparison of two cross-sectional surveys in Eastern Uganda
<p>Abstract</p> <p>Background</p> <p>Infant feeding recommendations for HIV-positive mothers differ from recommendations to mothers of unknown HIV-status. The aim of this study was to compare feeding practices, including breastfeeding, between infants and young children of HIV-positive mothers and infants of mothers in the general population of Uganda.</p> <p>Methods</p> <p>This study compares two cross-sectional surveys conducted in the end of 2003 and the beginning of 2005 in Eastern Uganda using analogous questionnaires. The first survey consisted of 727 randomly selected general-population mother-infant pairs with unknown HIV status. The second included 235 HIV-positive mothers affiliated to The Aids Support Organisation, TASO. In this article we compare early feeding practices, breastfeeding duration, feeding patterns with dietary information and socio-economic differences in the two groups of mothers.</p> <p>Results</p> <p>Pre-lacteal feeding was given to 150 (64%) infants of the HIV-positive mothers and 414 (57%) infants of general-population mothers. Exclusive breastfeeding of infants under the age of 6 months was more common in the general population than among the HIV-positive mothers (186 [45%] vs. 9 [24%] respectively according to 24-hour recall). Mixed feeding was the most common practice in both groups of mothers. Solid foods were introduced to more than half of the infants under 6 months old among the HIV-positive mothers and a quarter of the infants in the general population. Among the HIV-positive mothers with infants below 12 months of age, 24 of 90 (27%) had stopped breastfeeding, in contrast to 9 of 727 (1%) in the general population. The HIV-positive mothers were poorer and had less education than the general-population mothers.</p> <p>Conclusion</p> <p>In many respects, HIV-positive mothers fed their infants less favourably than mothers in the general population, with potentially detrimental effects on both the child's nutrition and the risk of HIV transmission. Mixed feeding and pre-lacteal feeding were widespread. Breastfeeding duration was shorter among HIV-positive mothers. Higher educational level and being socio-economically better off were associated with more beneficial infant feeding practices.</p
Poor newborn care practices - a population based survey in eastern Uganda
BACKGROUND: Four million neonatal deaths are estimated to occur each year and almost all in low income countries, especially among the poorest. There is a paucity of data on newborn health from sub-Saharan Africa and few studies have assessed inequity in uptake of newborn care practices. We assessed socioeconomic differences in use of newborn care practices in order to inform policy and programming in Uganda. METHODS: All mothers with infants aged 1-4 months (n = 414) in a Demographic Surveillance Site were interviewed. Households were stratified into quintiles of socioeconomic status (SES). Three composite outcomes (good neonatal feeding, good cord care, and optimal thermal care) were created by combining related individual practices from a list of twelve antenatal/essential newborn care practices. Multiple logistic regression analysis was used to identify determinants of each dichotomised composite outcome. RESULTS: There were low levels of coverage of newborn care practices among both the poorest and the least poor. SES and place of birth were not associated with any of the composite newborn care practices. Of newborns, 46% had a facility delivery and only 38% were judged to have had good cord care, 42% optimal thermal care, and 57% were considered to have had adequate neonatal feeding. Mothers were putting powder on the cord; using a bottle to feed the baby; and mixing/replacing breast milk with various substitutes. Multiparous mothers were less likely to have safe cord practices (OR 0.5, CI 0.3 - 0.9) as were mothers whose labour began at night (OR 0.6, CI 0.4 - 0.9). CONCLUSION: Newborn care practices in this setting are low and do not differ much by socioeconomic group. Despite being established policy, most neonatal interventions are not reaching newborns, suggesting a "policy-to-practice gap". To improve newborn survival, newborn care should be integrated into the current maternal and child interventions, and should be implemented at both community and health facility level as part of a universal coverage strategy
The duration of diarrhea and fever is associated with growth faltering in rural Malawian children aged 6-18 months
Nutrition support programs that only focus upon better complementary feeding remain an insufficient means of limiting growth faltering in vulnerable populations of children. To determine if symptoms of acute infections correlate with the incidence of growth faltering in rural Malawian children, the associations between fever, diarrhea, and cough with anthropometric measures of stunting, wasting, and underweight were investigated. Data were analyzed from a trial where 209 children were provided with adequate complementary food and followed fortnightly from 6-18 months of age. Linear mixed model analysis was used to test for associations. Diarrheal disease was inversely associated with changes in height-for-age Z-score (HAZ), mid-upper arm circumference Z-score (MUACZ), and weight-for-age Z-score (WAZ). Fever was also inversely associated with changes in MUACZ and WAZ. These results suggest that initiatives to reduce febrile and diarrheal diseases are needed in conjunction with improved complementary feeding to limit growth faltering in rural Malawi
The prevalence of stunting, overweight and obesity, and metabolic disease risk in rural South African children.
BACKGROUND: Low- to middle-income countries are undergoing a health transition with non-communicable diseases contributing substantially to disease burden, despite persistence of undernutrition and infectious diseases. This study aimed to investigate the prevalence and patterns of stunting and overweight/obesity, and hence risk for metabolic disease, in a group of children and adolescents in rural South Africa. METHODS: A cross-sectional growth survey was conducted involving 3511 children and adolescents 1-20 years, selected through stratified random sampling from a previously enumerated population living in Agincourt sub-district, Mpumalanga Province, South Africa. Anthropometric measurements including height, weight and waist circumference were taken using standard procedures. Tanner pubertal assessment was conducted among adolescents 9-20 years. Growth z-scores were generated using 2006 WHO standards for children up to five years and 1977 NCHS/WHO reference for older children. Overweight and obesity for those or = 25 and > or = 30 kg/m2 for overweight and obesity respectively were used for those > or = 18 years. Waist circumference cut-offs of > or = 94 cm for males and > or = 80 cm for females and waist-to-height ratio of 0.5 for both sexes were used to determine metabolic disease risk in adolescents. RESULTS: About one in five children aged 1-4 years was stunted; one in three of those aged one year. Concurrently, the prevalence of combined overweight and obesity, almost non-existent in boys, was substantial among adolescent girls, increasing with age and reaching approximately 20-25% in late adolescence. Central obesity was prevalent among adolescent girls, increasing with sexual maturation and reaching a peak of 35% at Tanner Stage 5, indicating increased risk for metabolic disease. CONCLUSIONS: The study highlights that in transitional societies, early stunting and adolescent obesity may co-exist in the same socio-geographic population. It is likely that this profile relates to changes in nutrition and diet, but variation in factors such as infectious disease burden and physical activity patterns, as well as social influences, need to be investigated. As obesity and adult short stature are risk factors for metabolic syndrome and Type 2 diabetes, this combination of early stunting and adolescent obesity may be an explosive combination
Prevalence and Socio-behavioral Influence of Early Childhood Caries, ECC, and Feeding Habits among 6-36 Months Old Children in Uganda and Tanzania.
Early childhood caries (ECC) is a serious problem that has remained unexplored in sub-Saharan Africa. This study aimed to identify possible socio-behavioral correlates of ECC focusing 6-36 months old children and their caretakers.\ud
Cross sectional studies were conducted in a high fluoride rural area, Manyara, Tanzania and a low fluoride urban area, Kampala, Uganda. Totals of 1221 and 816 child - caretaker pairs attending health care facilities for growth monitoring were recruited in Manyara and Kampala, respectively. All caretakers completed face to face interviews at the health care facility. Children underwent oral clinical examination whereby ECC and Enamel hypoplasia were recorded using the dmft (WHO 1997) and the DDE index (FDI 1992). The prevalence of ECC was 3.7% in Manyara and 17.6% in Kampala. According to multiple logistic regression analyses, received oral health information from health worker was the strongest determinant of ECC in Manyara, adjusted OR 0.3, 95% CI 0.09 - 0.93. In Kampala, visible plaque, high sugar intake and presence of enamel hypoplasia associated with ECC, adjusted ORs 2.8 (95% CI 1.61- 4.95), 3.0 (95% CI 1.39 - 6.34) and 2.3 (95% CI 1.36 - 3.95). Oral health education aimed at caretakers of 6-36 months, including health care workers' information regarding the detrimental consequences for oral health of frequent sugar consumption and poor oral hygiene is important for prevention of ECC in Tanzania and Uganda