1,356 research outputs found

    Supplementation, optimal status, and analytical determination of vitamin D: Where are we standing in 2012?

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    There is a growing interest for vitamin D in the medical and scientific community as well as in the public medias as illustrated by a huge number of publications. Most experts claim that vitamin D deficiency/insufficiency is widespread with potential important public health consequences. It may seem surprising for many persons that a deficiency in a vitamin may be so frequent in countries where food is so diversified and easily available. In fact, vitamin D is not a vitamin stricto sensu as it is mainly synthesized in the skin under the action of UVB rays, while its food sources are scarce. Furthermore, UVB rays are absent during a marked part of the year at latitudes greater than 35-40°, while pollution and cloud cover reduce the number of UVB reaching the earth, and many factors such as age, skin pigmentation, covering clothes, sun creams reduce the capacity of the skin to synthesize vitamin D3. Vitamin D must be hydroxylated to form 1,25dihydroxyvitamin D (1,25OH2D), the active metabolite. As 1,25OH2D is released into the bloodstream and binds to a receptor present in several distant tissues, it may be considered as a hormone, vitamin D being thus a pre-prohormone. In the present article, we review briefly the metabolism and various effects of vitamin D as well as the vitamin D assays and vitamin D treatments. We define vitamin D deficiency/insufficiency considerin

    MAXIMIZATION OF PULL-IN VOLTAGE OF MICRO-ELECTROMECHANICAL STRUCTURES USING TOPOLOGY OPTIMIZATION

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    The design problem consists in maximizing the pull-in voltage using topology optimization method, which is formulated as an optimal material distribution. In addition to the classical volume constraint, different structural constraints could be taken into consideration. Sensitivity analysis is one of the key issues of the optimization process and is performed with the formulation of eigenvalue topology optimization problems. Here the paper investigates topology optimization of strongly coupled electromechanical systems. To avoid important modifications of the electric field by the optimization process, this first study considers a non design electrode and use topology optimization to design an optimal suspension structure. Solution procedure of the optimization problem is based on CONLIN optimizer using a sequential convex programming. This method that has proved its efficiency in many structural problems (sizing, shape) is here tailored to strongly coupled multiphysics design problems under consideration. The choice of appropriate explicit convex approximations schemes for multiphysic problems is investigated. The proposed method is illustrated and validated on microbeam optimization applications

    Overestimation of the 25OHD serum concentration with the automated IDS EIA kit.

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    We have recently observed an increasing number of patients presenting very high serum levels of 25-hydroxyvitamin D [25(OH)D] (> 150 ng/mL), which, in all cases, had been measured with the IDS EIA kit adapted on different "open" automated platforms. We performed a comparison between the IDS EIA kit adapted on two different "open"automated platforms and the DiaSorin RIA. We found a systematic bias (higher levels with the IDS EIA kit) for concentrations more than 50-60 ng/mL that was less obvious when the IDS EIA was used in its manual procedure. We thus suggest to use the IDS EIA kit in its manual procedure rather than to adapt it on an automated platform, and to interpret cautiously a 25(OH)D greater than 100 ng/mL with this kit

    Perceived impact of the COVID-19 pandemic on young adults with type 1 diabetes in Rwanda

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    Introduction: data on the impact of COVID-19 on people with type 1 diabetes (T1D) in less resourced countries are limited. Our study was undertaken in Kigali, Rwanda, and aimed to investigate and describe the problems and challenges experienced by young adults with T1D resulting from the early phase of the pandemic. The study further aimed to understand the mechanisms being used to solve problems and overcome challenges, and perceived support needs. Methods: this was a cross-sectional study, with anonymous data (n=52) collected through use of questionnaire. Participants were registered, and attending or receiving diabetes-related healthcare through the Rwanda Diabetes Association clinic. Results: mean+standard deviation age and T1D duration were 24.0±2.1 and 7.4±3.4 years respectively, with sex distribution unequal (male n=22, 42.3%). Of 43 participants, the COVID-19 pandemic did not significantly affect participants´ access to diabetes management supplies and care. Eight (18.6%) participants experienced difficulties accessing blood glucose testing strips, 13 (30.2%) insulin, and three (7.0%) syringes and pen devices. Thirty-two (74.4%) experienced difficulty in attending standard diabetes healthcare reviews at the clinic setting. Some participants experienced hardship, through a decrease in personal or family income (n=42, 80.8%) and challenges in accessing food (n=34, 65.4%), with thirty (57.7%) participants having decreased meal frequency (p<0.001). Conclusion: our research illustrates the indirect effects of measures undertaken to curb the spread of COVID-19 on young adults with T1D in Rwanda. Study findings may help inform actions to mitigate negative impacts on T1D care in other crises

    Update on vitamin D and evaluation of vitamin D status.

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    Knowledge about vitamin D has greatly improved during the last few years. Vitamin D cannot any more be considered as exclusively necessary to prevent ricket/osteomalacia. Its role in the prevention of some osteoporotic fractures in the elderly (in association with calcium nutrition) is now well demonstrated and many epidemiologic and laboratory data argue for a role in the prevention of several diseases or anomalies (cancer, auto-immune diseases, cardiovascular events, sarcopenia...). A few intervention studies confirming some of these effects also exist. Vitamin D status can easily be assessed by measuring serum 25 hydroxy vitamin D (25OHD) level. However, many experts have claimed that the population-based reference values for 25OHD are too low and that the cut-off value below which vitamin D insufficiency can be present is somewhere between 20 and 40ng/mL with a clear tendency to target values above 30ng/mL (75nmol/L). The main consequences are that vitamin D insufficiency is highly frequent whereas the currently recommended supplementation doses are not sufficient

    Keys to successful implementation of a French national quality indicator in health care organizations: a qualitative study

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    International audienceBackground: Several countries have launched public reporting systems based on quality indicators (QIs) to increase transparency and improve quality in health care organizations (HCOs). However, a prerequisite to quality improvement is successful local QI implementation. The aim of this study was to explore the pathway through which a mandatory QI of the French national public reporting system, namely the quality of the anesthesia file (QAF), was put into practice
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