305 research outputs found

    Comparing methods for handling missing cost and quality of life data in the Early Endovenous Ablation in Venous Ulceration trial

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    This study was funded by the National Institute for Health Research (NIHR HTA) Programme (EVRA, project number 11/129/197) and European Union's Horizon 2020 research under Grant agreement 733203.Objectives: This study compares methods for handling missing data to conduct cost-effectiveness analysis in the context of a clinical study. Methods: Patients in the Early Endovenous Ablation in Venous Ulceration (EVRA) trial had between 1 year and 5.5 years (median 3 years) of follow-up under early or deferred endovenous ablation. This study compares completecase- analysis (CCA), multiple imputation using linear regression (MILR) and using predictive mean matching (MIPMM), Bayesian parametric approach using the R package missingHE (BPA), repeated measures fixed effect (RMFE) and repeated measures mixed model (RMM). The outcomes were total mean costs and total mean quality-adjusted life years (QALYs) at different time horizons (1 year, 3 years and 5 years). Results: All methods found no statistically significant difference in cost at the 5% level in all time horizons, and all methods found statistically significantly greater mean QALY at year 1. By year 3, only BPA showed a statistically significant difference in QALY between treatments. Standard errors differed substantially between the methods employed. Conclusion: CCA can be biased if data are MAR and is wasteful of the data. Hence the results for CCA are likely to be inaccurate. Other methods coincide in suggesting that early intervention is cost-effective at a threshold of ÂŁ30,000 per QALY 1, 3 and 5 years. However, the variation in the results across the methods does generate some additional methodological uncertainty, underlining the importance of conducting sensitivity analyses using alternative approaches.National Institute for Health Research (NIHR HTA) Programme (EVRA) 11/129/197European Commission 73320

    L’histoire d’un voyage fait en la terre du BrĂ©sil de Jean de LĂ©ry lue par l’abbĂ© PrĂ©vost et par Claude LĂ©vi-Strauss

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    International audienc

    Diagnostic des pratiques d'utilisation et quantification des pesticides dans la zone des Niayes de Dakar (Sénégal)

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    L'agriculture urbaine dans la zone des Niayes de Dakar fournit 60% des besoins en lĂ©gumes de cette rĂ©gion Ă  fort taux d'urbanisation. Les maraĂźchers de cette zone ont de plus en plus recours aux pesticides pour lutter contre les ravageurs et maladies des cultures. Les objectifs de ce travail sont de tenter de rĂ©pondre Ă  la problĂ©matique suivante : les pratiques d'utilisation des pesticides ont-elles un impact sur la qualitĂ© des ressources environnementales dans cette zone? La consommation des produits horticoles et des eaux souterraines de cette zone comporte-t-elle un risque pour les populations? Nous avons tentĂ© de rĂ©pondre Ă  ces questions par le biais d'enquĂȘtes de terrain et d'analyses. Les rĂ©sultats des enquĂȘtes ont mis en Ă©vidence l'application de diverses matiĂšres actives appartenant aux organophosphorĂ©s, organochlorĂ©s, carbamates et pyrĂ©thrinoĂŻdes sur une variĂ©tĂ© de spĂ©culations. Les pesticides appliquĂ©s ne sont pas gĂ©nĂ©ralement homologuĂ©s et certains d'entre eux sont des polluants organiques persistants et donc interdits d'utilisation au SĂ©nĂ©gal. Les pratiques d'utilisation (frĂ©quences, quantitĂ©s appliquĂ©es, conditions de stockage, mĂ©thodes d'Ă©limination des emballages) ne respectent pas les rĂšgles prescrites par les bonnes pratiques agricoles. Les analyses ont portĂ© sur 80 Ă©chantillons d'eaux souterraines, 119 de sol, et 175 de lĂ©gumes, collectĂ©s au niveau des sites de Niaga, de Thiaroye, de CambĂ©rĂšne et de Malika sur quatre campagnes. Les rĂ©sultats montrent des niveaux de contamination environnementale Ă©levĂ©s de la zone des Niayes avec la dĂ©tection de 15 (eaux souterraines et lĂ©gumes) et de 17 (sol) pesticides sur 21 recherchĂ©s. Dans toutes les matrices, les molĂ©cules ayant Ă©tĂ© dĂ©tectĂ©es Ă  des frĂ©quences Ă©levĂ©es sont celles qui avaient enregistrĂ© des frĂ©quences de citation d'au minimum 6%. PrĂšs de 56% des points d'eau ont prĂ©sentĂ© au moins une substance dont la concentration moyenne est supĂ©rieure Ă  la norme de qualitĂ© correspondante et 38% ne respectaient pas la norme de concentration totale. Pour les lĂ©gumes, des pourcentages de non-conformitĂ© variant entre 58 et 76% selon les sites ont Ă©tĂ© obtenus. Les apports journaliers estimĂ©s ont montrĂ© que prĂšs de 80% des quantitĂ©s de rĂ©sidus de pesticide ingĂ©rables correspondent aux rĂ©sidus des trois premiĂšres classes de pesticides (extrĂȘmement dangereux, hautement dangereux et modĂ©rĂ©ment dangereux) selon l'OMS. Cette observation montre que le risque liĂ© Ă  l'exposition des populations Ă  l'eau et aux aliments contaminĂ©s est rĂ©el.Urban agriculture in the Niayes zone of Dakar provides 60% of the vegetable needs of this region which has a high urbanization rate. Farmers in this area rely heavily on pesticides to protect crops from pests and diseases. The main objectives of this work were to try to answer the following questions : Do pesticide use patterns and management have an impact on the quality of environmental resources of the area? Does consumption of horticultural products and groundwater of this area pose a risk? We tried to bring answers through field surveys and analyses. The survey results showed the application of various pesticides belonging to organophosphates, organochlorines, carbamates and pyrethroids on a variety of speculations. Pesticides applied are not generally approved and some of them are persistent organic pollutants and thus prohibited for use in Senegal. Use practices (frequency, amount, storage conditions, packaging disposal) do not respect the rules of good agricultural practices. The analyses were performed on 80 groundwater samples, 119 of soil samples and 175 of vegetables collected at Niaga, Thiaroye, CambĂ©rĂšne and Malika during 4 campaigns. Results show high contamination levels of the environment with detection of 15 (in groundwater and vegetables) and 17 (in soil) pesticides out of 21. The molecules that have been detected with high frequencies in the matrices are those cited with frequencies greater than 6%. Nearly 56% of groundwater samples showed at least one substance with level exceeding the corresponding standard. 38% did not meet the standard set for total residues concentration. For vegetables, the percentages of exceeding standards ranged between 58 and 76% depending on the site. The estimated daily intake showed that nearly 80% of pesticide residues belong to the following WHO classes (extremely hazardous, highly hazardous and moderately hazardous). This observation evidences the risk of human exposure to contaminated food and water.DUNKERQUE-SCD-Bib.electronique (591839901) / SudocSudocFranceF

    DIMETHYL N-CYANODITHIOIMINOCARBONATE AND TRIPHENYLPHOSPHINE OXIDE METAL HALIDE COMPLEXES: MOLECULAR CRYSTAL ELUCIDATION

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    Two MX2 (M = Ni, Zn; X = Cl, Br) dimethyl N-cyanodithioiminocarbonate compounds and one CrCl2 triphenylphosphine oxide complex were isolated and elucidated by single crystal X-ray crystallography. NiCl2[(CH3S)2C═NC≡N]2 (1) features inversion-related hydrogen bonded dimers linked into chains interacting through C-H···Cl growing layers along [110] whose junction into a 3D structure is enabled by H-bonds. ZnBr2[(CH3S)2C═NC≡N]2 (2) also exhibits inversion-related H-bonded dimers. In contrast with 1, the structure of 2 comprises chains along [110], connected via C-H···Br and C-H···S into a 2D layer along [-110]. CrCl2(OPPh3)2 (3) obtaining undergone redox processes, oxidizing [CH3C(O)CH2PPh3]+ to form PPh3PO, and reducing Cr from CrVI to CrII. In the structure, each molecule is linked to height neighbors through H-bonds affording a 3D network

    The chicken eggshell membrane: a versatile, sustainable, biological material for translational biomedical applications

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    Naturally derived materials are often preferred to than synthetic materials for biomedical applications due to their innate biological characteristics, relative availability, sustainability, and agreement with conscientious end-users. The chicken eggshell membrane (ESM) is an abundant resource with a defined structural profile, chemical composition, and validated morphological and mechanical characteristics. These unique properties have not only allowed the ESM to be exploited within the food industry, but has also led to it be considered for other novel translational applications such as tissue regeneration and replacement, filtration aids and barrier devices, and environmental health engagement. However, challenges still exist in order to enhance the native ESM: the need to improve its mechanical properties, the ability to combine/join fragments of ESM together, and the addition or incorporation of drugs/growth factors to advance its therapeutic capacity. This review article provides a succinct background to the native ESM, its extraction, isolation, and consequent physical, mechanical and biological characterisation including possible approaches to enhancement. Moreover, it also highlights current applications of the ESM in regenerative medicine and hints at future novel applications in which this novel biomaterial could be exploited to beneficial use

    Seroprevalence of transfusion-transmissible infections among family replacement donors and voluntary non-remunerated blood donors during the COVID-19 pandemic in sub Saharan Africa

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    Introduction : According to WHO,  regular, voluntary, unpaid blood donors are the safest group of donors, as they have the lowest prevalence of blood transmitted infections. However, family/replacement blood donors is widely used in sub Saharan Africa and this practice was exacerbated during the COVID 19 pandemic. This study aimed to compare the seroprevalence of infectious markers in family replacement blood donors and voluntary non-remunerated  blood donors during the COVID 19 pandemic in a country of sub Saharan Africa.   Materials and Methods Blood donors received at the National Centre of Blood Transfusion (NBTC) of Dakar from August 1st to October 31th 2021, were included in this study. All donors completed a pre-donation questionnaire. Donors identity, epidemiological parameters, reasons for donation and laboratory results were collected in the InlogŸ software of the NBTC. The serological tests for HBV, HIV and HCV were performed with chemiluminescence technology. The Rapid Plasma Reagent test was used to find out treponemal antibodies. The determination of ABO and Rh blood groups was performed using monoclonal antisera following classical hemagglutination test on a plate. Results A total of 5002 donors were collected during this COVID-19 pandemic period. Blood family/replacement donors represented 54.0% and new voluntary donors represented 52.6%. Comparison of HIV, HCV and syphilis markers seroprevalence showed no statistically significant difference between new voluntary donors and new family replacement donors (p>0.05). However, for HBV the seroprevalence was significantly higher in new family replacement donors (p=0,002). Conclusion The proper supply of blood was impacted by the COVID-19 pandemic meanwhile replacement donations had contributed to limiting the damage observed with blood shortages. However, the significant differences noted on the seroprevalences of transfusion-transmissible infections between voluntary non-paid donors and family/replacement donors strengthens WHO recommendations for the selection of volunteer non-paid donors to lower transfusion-transmissible HBV in sub Saharan Africa.                

    Preservation of the metabolic rate of oxygen in preterm infants during indomethacin therapy for closure of the ductus arteriosus

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    Background:The aim of this study was to assess and quantify the effects of indomethacin on cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO 2) in preterm infants undergoing treatment for a patent ductus arteriosus (PDA).Methods:CBF and CMRO 2 were measured before and after the first dose of a 3-d course of indomethacin to close hemodynamically significant PDA in preterm neonates. Indocyanine-green (ICG) concentration curves were acquired before and after indomethacin injection to quantify CBF and CMRO 2.Results:Eight preterm neonates (gestational age, 27.6 ± 0.5 wk; birth weight, 992 ± 109 g; 6 males:2 females) were treated at a median age of 4.5 d (range, 4-21 d). Indomethacin resulted in an average CBF decrease of 18% (pre- and post-CBF = 12.9 ± 1.3 and 10.6 ± 0.8 ml/100 g/min, respectively) and an OEF increase of 11% (pre- and post-OEF = 0.38 ± 0.02 and 0.42 ± 0.02, respectively) but no significant change in CMRO 2 (pre- and post-CMRO 2 = 0.83 ± 0.07 and 0.76 ± 0.07 ml O 2 /100 g/min, respectively). Corresponding mean blood pressure (BP), arterial oxygen saturation (S a O 2), heart rate, and end-tidal carbon dioxide tension levels remained unchanged.Conclusion:Indomethacin resulted in significant reduction in CBF but did not alter CMRO 2 because of a compensatory increase in OEF. Copyright © 2013 International Pediatric Research Foundation, Inc

    A Sustainable, Green-Processed, Ag-Nanoparticle-Incorporated Eggshell-Derived Biomaterial for Wound-Healing Applications

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    The eggshell membrane (ESM) is a natural biomaterial with unique physical and mechanical properties that make it a promising candidate for wound-healing applications. However, the ESM’s inherent properties can be enhanced through incorporation of silver nanoparticles (AgNPs), which have been shown to have antimicrobial properties. In this study, commercially produced AgNPs and green-processed AgNPs were incorporated into ESM and evaluated for their physical, biological, and antimicrobial properties for potential dermal application. The ESM was extracted using various techniques, and then treated with either commercially produced AgNPs (Sigma-Aldrich, Poole, UK) or green-synthesized AgNPs (Metalchemy, London, UK) to produce AgNPs-ESM samples. The physical characteristics of the samples were evaluated using scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, and the biological properties were assessed through in vitro studies using human dermal fibroblasts (HDFs) and BJ cells. The SEM analysis of the AgNPs-ESM samples showed localization of AgNPs on the ESM surface, and that the ESM maintained its structural integrity following AgNP incorporation. The FTIR confirmed loading of AgNPs to ESM samples. The biological studies showed that the 5 ÎŒg/mL AgNPs-ESM samples were highly biocompatible with both HDFs and BJ cells, and had good viability and proliferation rates. Additionally, the AgNPs-ESM samples demonstrated pro-angiogenic properties in the CAM assay, indicating their potential for promoting new blood vessel growth. Assessment of the antimicrobial activity of the enhanced AgNPs/ESMs was validated using the International Standard ISO 16869:2008 methodology and exploited Cladosporium, which is one of the most commonly identified fungi in wounds, as the test microorganism (≄5 × 106 cells/mL). The AgNPs-ESM samples displayed promising antimicrobial efficacy as evidenced by the measured zone of inhibition. Notably, the green-synthesized AgNPs demonstrated greater zones of inhibition (~17 times larger) compared to commercially available AgNPs (Sigma-Aldrich). Although both types of AgNP exhibited long-term stability, the Metalchemy-modified samples demonstrated a slightly stronger inhibitory effect. Overall, the AgNPs-ESM samples developed in this study exhibited desirable physical, biological, and antimicrobial properties for potential dermal wound-dressing applications. The use of green-processed AgNPs in the fabrication of the AgNPs-ESM samples highlights the potential for sustainable and environmentally friendly wound-healing therapies. Further research is required to assess the long-term biocompatibility and effectiveness of these biomaterials in vivo

    CAD-Based Shielding Analysis for ITER Port Diagnostics

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    Radiation shielding analysis conducted in support of design development of the contemporary diagnostic systems integrated inside the ITER ports is relied on the use of CAD models. This paper presents the CAD-based MCNP Monte Carlo radiation transport and activation analyses for the Diagnostic Upper and Equatorial Port Plugs (UPP #3 and EPP #8, #17). The creation process of the complicated 3D MCNP models of the diagnostics systems was substantially accelerated by application of the CAD-to-MCNP converter programs MCAM and McCad. High performance computing resources of the Helios supercomputer allowed to speed-up the MCNP parallel transport calculations with the MPI/OpenMP interface. The found shielding solutions could be universal, reducing ports R&D costs. The shield block behind the Tritium and Deposit Monitor (TDM) optical box was added to study its influence on Shut-Down Dose Rate (SDDR) in Port Interspace (PI) of EPP#17. Influence of neutron streaming along the Lost Alpha Monitor (LAM) on the neutron energy spectra calculated in the Tangential Neutron Spectrometer (TNS) of EPP#8. For the UPP#3 with Charge eXchange Recombination Spectroscopy (CXRS-core), an excessive neutron streaming along the CXRS shutter, which should be prevented in further design iteration

    Gene pools and the genetic architecture of domesticated cowpea

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    Open Access JournalCowpea [Vigna unguiculata (L.) Walp.] is a major tropical legume crop grown in warm to hot areas throughout the world and especially important to the people of sub-Saharan Africa where the crop was domesticated. To date, relatively little is understood about its domestication origins and patterns of genetic variation. In this study, a worldwide collection of cowpea landraces and African ancestral wild cowpea was genotyped with more than 1200 single nucleotide polymorphism markers. Bayesian inference revealed the presence of two major gene pools in cultivated cowpea in Africa. Landraces from gene pool 1 are mostly distributed in western Africa while the majority of gene pool 2 are located in eastern Africa. Each gene pool is most closely related to wild cowpea in the same geographic region, indicating divergent domestication processes leading to the formation of two gene pools. The total genetic variation within landraces from countries outside Africa was slightly greater than within African landraces. Accessions from Asia and Europe were more related to those from western Africa while accessions from the Americas appeared more closely related to those from eastern Africa. This delineation of cowpea germplasm into groups of genetic relatedness will be valuable for guiding introgression efforts in breeding programs and for improving the efficiency of germplasm managemen
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