775 research outputs found

    Structural and magnetic properties of Pr-alloyed MnBi nanostructures

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    The structural and magnetic properties of Pr-alloyed MnBi (short MnBi-Pr) nanostructures with a range of Pr concentrations have been investigated. The nanostructures include thin films having Pr concentrations 0, 2, 3, 5 and 9 atomic percent and melt-spun ribbons having Pr concentrations 0, 2, 4 and 6 percent respectively. Addition of Pr into the MnBi lattice has produced a significant change in the magnetic properties of these nanostructures including an increase in coercivity and structural phase transition temperature, and a decrease in saturation magnetization and anisotropy energy. The highest value of coercivity measured in the films is 23 kOe and in the ribbons is 5.6 kOe. The observed magnetic properties are explained as the consequences of competing ferromagnetic and antiferromagnetic interactions

    Diazoxide-responsive hyperinsulinemic hypoglycemia caused by HNF4A gene mutations

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    Objective: The phenotype associated with heterozygous HNF4A gene mutations has recently been extended to include diazoxide responsive neonatal hypoglycemia in addition to maturity-onset diabetes of the young (MODY). To date, mutation screening has been limited to patients with a family history consistent with MODY. In this study, we investigated the prevalence of HNF4A mutations in a large cohort of patients with diazoxide responsive hyperinsulinemic hypoglycemia (HH). Subjects and methods: We sequenced the ABCC8, KCNJ11, GCK, GLUD1, and/or HNF4A genes in 220 patients with HH responsive to diazoxide. The order of genetic testing was dependent upon the clinical phenotype. Results: A genetic diagnosis was possible for 59/220 (27%) patients. KATP channel mutations were most common (15%) followed by GLUD1 mutations causing hyperinsulinism with hyperammonemia (5.9%), and HNF4A mutations (5%). Seven of the 11 probands with a heterozygous HNF4A mutation did not have a parent affected with diabetes, and four de novo mutations were confirmed. These patients were diagnosed with HI within the first week of life (median age 1 day), and they had increased birth weight (median +2.4 SDS). The duration of diazoxide treatment ranged from 3 months to ongoing at 8 years. Conclusions: In this large series, HNF4A mutations are the third most common cause of diazoxide responsive HH. We recommend that HNF4A sequencing is considered in all patients with diazoxide responsive HH diagnosed in the first week of life irrespective of a family history of diabetes, once KATP channel mutations have been excluded

    Protection From Clinical Peripheral Sensory Neuropathy in Alström Syndrome in Contrast to Early-Onset Type 2 Diabetes

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    OBJECTIVE—Alström syndrome, with type 2 diabetes, and blindness could confer a high risk of foot ulceration. Clinical testing for neuropathy in Alström syndrome and matched young-onset type 2 diabetic subjects was therefore undertaken

    Evaluating future risk of NAFLD in adolescents:a prediction and decision curve analysis

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    BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the commonest liver condition in the western world and is directly linked to obesity and the metabolic syndrome. Elevated body mass index is regarded as a major risk factor of NAFL (steatosis) and NAFLD fibrosis. Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC), we sought to investigate whether other variables from adolescence could improve prediction of future NAFL and NAFLD fibrosis risk at 24 years, above BMI and sex. METHODS: Aged 24 years, 4018 ALSPAC participants had transient elastography (TE) and controlled attenuation parameter (CAP) measurement using Echosens 502 Touch. 513 participants with harmful alcohol consumption were excluded. Logistic regression models examined which variables measured at 17 years were predictive of NAFL and NAFLD fibrosis in young adults. Predictors included sex, BMI, central adiposity, lipid profile, blood pressure, liver function tests, homeostatic model assessment for insulin resistance (HOMA-IR), and ultrasound defined NAFL at 17 years (when examining fibrosis outcomes). A model including all these variables was termed “routine clinical measures”. Models were compared using area under the receiver operator curve (AUROC) and Bayesian Information Criterion (BIC), analysis, which penalises model complexity. Models were tested in all participants and those with overweight or obese standardised BMIs (BMI SDS) centiles at the 17-year time point. A decision curve analysis (DCA) was performed to evaluate the clinical utility of models in overweight and obese adolescents predicting NAFLD fibrosis at a threshold probability of 0.1. RESULTS: The “routine clinical measures” model had the highest AUROC for predicting NAFL in all adolescent participants (AUROC 0.79 [SD 0.00]) and those with an overweight/obese BMI SDS centile (AUROC 0.77 [SD 0.01]). According to BIC analysis, insulin resistance was the best predictor of NAFL in all adolescents, whilst central adiposity was the best predictor in those with an overweight/obese BMI SDS centile. The “routine clinical measures” model also had the highest AUROC for predicting NAFLD fibrosis in all adolescent participants (AUROC 0.78 [SD 0.02]) and participants with an overweight/obese BMI SDS centile (AUROC 0.84 [SD 0.03]). However, following BIC analysis, BMI was the best predictor of NAFLD fibrosis in all adolescents including those with an overweight/obese BMI SDS centile. A decision curve analysis examining overweight/obese adolescent participants showed the model that had the greatest net benefit for increased NAFLD fibrosis detection, above a treat all overweight and obese adolescents’ assumption, was the “routine clinical measures” model. However, the net benefit was marginal (0.0054 [0.0034–0.0075]). CONCLUSION: In adolescents, routine clinical measures were not superior to central adiposity and BMI at predicting NAFL and NAFLD fibrosis respectively in young adulthood. Additional routine clinical measurements do provide incremental benefit in detecting true positive fibrosis cases, but the benefit is small. Thus, to reduce morbidity and mortality associated with NASH cirrhosis in adults, the ultimate end point of NAFLD, the focus must be on obesity management at a population level. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12876-022-02401-y

    Role of the employment status and education of mothers in the prevalence of intestinal parasitic infections in Mexican rural schoolchildren

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    <p><b>Background:</b> Intestinal parasitic infections are a public health problem in developing countries such as Mexico. As a result, two governmental programmes have been implemented: a) "National Deworming Campaign" and b) "Opportunities" aimed at maternal care. However, both programmes are developed separately and their impact is still unknown. We independently investigated whether a variety of socio-economic factors, including maternal education and employment levels, were associated with intestinal parasite infection in rural school children.</p> <p><b>Methods:</b> This cross-sectional study was conducted in 12 rural communities in two Mexican states. The study sites and populations were selected on the basis of the following traits: a) presence of activities by the national administration of albendazole, b) high rates of intestinal parasitism, c) little access to medical examination, and d) a population having less than 2,500 inhabitants. A total of 507 schoolchildren (mean age 8.2 years) were recruited and 1,521 stool samples collected (3 per child). Socio-economic information was obtained by an oral questionnaire. Regression modelling was used to determine the association of socio-economic indicators and intestinal parasitism.</p> <p><b>Results:</b> More than half of the schoolchildren showed poliparasitism (52%) and protozoan infections (65%). The prevalence of helminth infections was higher in children from Oaxaca (53%) than in those from Sinaloa (33%) (p < 0.0001). Giardia duodenalis and Hymenolepis nana showed a high prevalence in both states. Ascaris lumbricoides, Trichuris trichiura and Entamoeba hystolitica/dispar showed low prevalence. Children from lower-income families and with unemployed and less educated mothers showed higher risk of intestinal parasitism (odds ratio (OR) 6.0, 95% confidence interval (CI) 1.6–22.6; OR 4.5, 95% CI 2.5–8.2; OR 3.3, 95% CI 1.5–7.4 respectively). Defecation in open areas was also a high risk factor for infection (OR 2.4, 95% CI 2.0–3.0).</p> <p><b>Conclusion:</b> Intestinal parasitism remains an important public health problem in Sinaloa (north-western Mexico) and Oaxaca (south-eastern Mexico). Lower income, defecation in open areas, employment status and a lower education level of mothers were the significant factors related to these infections. We conclude that mothers should be involved in health initiatives to control intestinal parasitism in Mexico.</p&gt

    Incorporation of Zn in GaAs during organometallic vapor phase epitaxy growth compared to equilibrium

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    The zinc concentration measured after organometallic vapor phase epitaxy (GMVPE) growth on (100)-oriented GaAs at 700 °C has been compared to the zinc concentration measured after in-diffusion under near-equilibrium conditions. During diffusion, the concentration of Zn 20 nm below the surface was found to vary with PZn1/2, as expected for bulk solid-vapor equilibrium. During growth, the concentration of Zn varied linearly with PZn up to a maximum value which was found to correspond to the solubility limit set by second phase formation, e.g., growth of Zn3As2. Although large differences were observed between the results of the two experiments when using nominally identical ambient conditions, all of the results are consistent with a thermodynamic model in which the Fermi level at the surface is pinned approximately 200 meV below the intrinsic Fermi level. Typical OMVPE growth conditions appear to give a buIk zinc concentration which is supersaturated relative to the ambient partial pressures used, and to enhance the diffusion of Zn into the substrate

    Overweight and obesity in children aged 3-13 years in urban Cameroon:a cross-sectional study of prevalence and association with socio-economic status

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    BACKGROUND: Childhood overweight/obesity is increasing rapidly in developing countries. There is a need to provide more evidence on its burden in sub-Saharan Africa, and to identify associated factors in order to set preventive measures. We aimed to determine the prevalence of overweight/obesity and assess its association with the socioeconomic status in nursery and primary school children in urban Cameroon. METHODS: In this cross-sectional study, we included by multi-staged cluster random sampling 1343 children from high (HSES, n = 673) and low (LSES, n = 670) socioeconomic status schools in Douala. Parent/child demographic data were collected, and children’s anthropometric parameters were measured using validated methods. The World Health Organization body mass index-for-age reference curves were used. RESULTS: The prevalence of overweight/obesity was 12.5% (13.2% in girls, 11.8% in boys). The risk of overweight/obesity was 2.40 (95% CI 1.70, 3.40) higher in HSES children compared to LSES after adjusting for age and gender. However this association was attenuated to 1.18 (95% CI 0.59, 2.35) once adjustment had been made for a range of potential confounders. CONCLUSIONS: Overweight/obesity is relatively common in sub-Saharan African children and prevalence is associated with HSES. However, this association may be mediated by sweet drink consumption, passive means of travel to school and not doing sport at school. We suggest that these potentially modifiable behaviors may be effective targets for obesity prevention. Further studies should specifically focus on unhealthy behaviors that mediate overweight/obesity as well as other non communicable diseases in children. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40608-017-0146-4) contains supplementary material, which is available to authorized users
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