12 research outputs found

    A unified moment tensor potential for silicon, oxygen, and silica

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    Si and its oxides have been extensively explored in theoretical research due to their technological and industrial importance. Simultaneously describing interatomic interactions within both Si and SiO2_2 without the use of \textit{ab initio} methods is considered challenging, given the charge transfers involved. Herein, this challenge is overcome by developing a unified machine learning interatomic potentials describing the Si/ SiO2_2/ O system, based on the moment tensor potential (MTP) framework. This MTP is trained using a comprehensive database generated using density functional theory simulations, encompassing a wide range of crystal structures, point defects, extended defects, and disordered structure. Extensive testing of the MTP is performed, indicating it can describe static and dynamic features of very diverse Si, O, and SiO2_2 atomic structures with a degree of fidelity approaching that of DF

    Determination of Natural Radioactivity Level and Hazard Assessment of Groundwater Samples from Mining Area in the North Region of Burkina Faso

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    The activity concentrations of Natural Radionuclides 238U. 232Th and 40K in groundwater samples were measured using a Gamma Spectrometry with High Purity Germanium detector. Also. Radiological Hazard due to these Natural Radionuclides through water ingestion is investigated. The mean activity concentrations of 238U, 232Th and 40K in water samples from boreholes were found to be 0.36 ± 0.07 Bq.L-1. 0.50 ±0.09 Bq.L-1 and 5.32 ± 0.76 Bq.L-1 respectively.  The average Annual Committed Effective Dose was 0.16 ± 0.02 mSv. The  results obtained are below the recommended levels of 10.0 Bq.L-1   and 1.0 Bq.L-1  for 238U and 232Th  respectively for drinking water quality established by the WHO and 1 mSv per year dose limit recommended by the ICRP for public radiation exposure. These results indicate insignificant radiological hazard due to ingestion of NORMS in drinking water from boreholes by the communities in this area. 

    INSIGHTS INTO THE INTERPLAY BETWEEN KIR GENE FREQUENCIES AND CHRONIC HBV INFECTION IN BURKINA FASO

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    Background/Objective: The receptors of natural killer cells "Killer Cell Immunoglobulin-Like Receptor" (KIR) regulate the activity of Natural killer cells in the innate response against viral infections. To date there is no accurate method to identify high risk groups for cirrhosis and HCC in Sub-Saharan Africa. Therefore, this investigation was undertaken to assess the association between KIR genes frequencies and chronic infection HBV infection in Burkina Faso’s population. Methods: Chronic HBV carriers and healthy patients were selected for this study. The viral load for HBV were performed to confirm the serological status for HBV of the studied cohort. In addition, SSP-PCR was used to characterize the frequencies of KIR genes. Results: The study suggested that inhibitory genes KIR2DL2, KIR2DL3 and activator gene KIR2DS2 (p˂0.001 for all and OR = 2.82; 2.48 and 3.84 respectively) might be associated with chronic stages of HBV infection.  While inhibitory genes KIR3DL1 (p = 0.0018 OR = 0.49), KIR3DL2 (p = 0.005 OR = 0.40), the activator gene KIR2DS1 (p = 0.014 OR = 0.47) and the pseudo gene KIR2DP1 (p = 0.011 OR = 0.49) could be associated with immunity against HBV infection. Patients who carried the KIR3DL2 gene had a high HBV viral load compared to the rest of the study population. Conclusion: Our data showed an evidence of correlation between the propensity of developing chronic HBV infection and certain KIR gene frequencies and that KIR3DL1, KIR3DL2, KIR2DS1 and KIR2DP1 might confer a protective status against chronic HBV infection in Burkina Faso’s patients

    Genomic Epidemiology of SARS-CoV-2 in Western Burkina Faso, West Africa.

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    BACKGROUND: After its initial detection in Wuhan, China, in December 2019, SARS-CoV-2 has spread rapidly, causing successive epidemic waves worldwide. This study aims to provide a genomic epidemiology of SARS-CoV-2 in Burkina Faso. METHODS: Three hundred and seventy-seven SARS-CoV-2 genomes obtained from PCR-positive nasopharyngeal samples (PCR cycle threshold score < 35) collected between 5 May 2020, and 31 January 2022 were analyzed. Genomic sequences were assigned to phylogenetic clades using NextClade and to Pango lineages using pangolin. Phylogenetic and phylogeographic analyses were performed to determine the geographical sources and time of virus introduction in Burkina Faso. RESULTS: The analyzed SARS-CoV-2 genomes can be assigned to 10 phylogenetic clades and 27 Pango lineages already described worldwide. Our analyses revealed the important role of cross-border human mobility in the successive SARS-CoV-2 introductions in Burkina Faso from neighboring countries. CONCLUSIONS: This study provides additional insights into the genomic epidemiology of SARS-CoV-2 in West Africa. It highlights the importance of land travel in the spread of the virus and the need to rapidly implement preventive policies. Regional cross-border collaborations and the adherence of the general population to government policies are key to prevent new epidemic waves

    Human immunodeficiency virus type 1 drug resistance in a subset of mothers and their infants receiving antiretroviral treatment in Ouagadougou, Burkina Faso

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    The emergence of HIV-1 drug resistance (HIVDR) is a public health problem that affects women and children. Local data of HIVDR is critical to improving their care and treatment. So, we investigated HIVDR in mothers and infants receiving antiretroviral therapy (ART) at Saint Camille Hospital of Ouagadougou, Burkina Faso. This study included 50 mothers and 50 infants on ART. CD4 and HIV-1 viral load were determined using FACSCount and Abbott m2000rt respectively. HIVDR was determined in patients with virologic failure using ViroSeq HIV-1 Genotyping System kit on the 3130 Genetic Analyzer. The median age was 37.28 years in mothers and 1.58 year in infants. Sequencing of samples showed subtypes CRF02_AG (55.56%), CRF06_cpx (33.33%) and G (11.11%). M184V was the most frequent and was associated with highlevel resistance to 3TC, FTC, and ABC. Other mutations such as T215F/Y, D67N/E, K70R, and K219Q were associated with intermediate resistance to TDF, AZT, and 3TC. No mutation to LPV/r was detected among mothers and infants. The findings of HIVDR in some mothers and infants suggested the change of treatment for these persons

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Etude de la qualité de l’eau chlorée et des conditions d’utilisation au Centre Hospitalier Universitaire Sourou Sanou (CHUSS) de Bobo-Dioulasso

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    L’eau chlorée est un désinfectant efficace et facile à préparer. Le département de la pharmacie du Centre Hospitalier Universitaire Sourou Sanou (CHUSS) est chargé de la préparation de l’eau chlorée qui est utilisée dans les services de l’hôpital depuis 2003. La qualité chimique, les conditions de production et d’utilisation de cette eau chlorée demeurent inconnues alors que les normes de bonnes pratiques exigent un contrôle de qualité de la production et de l’utilisation. Le but de cette étude était de contribuer à évaluer la qualité de l'eau chlorée et les conditions d’utilisation au CHUSS.Il s’agissait d’une enquête sur les conditions de production, d’utilisation et une analyse chimique de la qualité de l’eau chlorée. L’étude s’est déroulée du 1er Juillet au 30 Septembre 2014 au CHUSS.Elle a révélé que la production de l’eau chlorée ne respectait pas les recommandations du fabricant de l’appareil de production. La concentration moyenne en chlore actif mesurée à la production (2,74 ± 0,25 g/L) était inférieure à celle attendue (5 g/L). Le pH de l’eau chlorée à la production était de 8,42 ± 0,03. Les conditions d'utilisation étaient parfois non conformes. Des travaux ultérieurs sur l’efficacité microbiologique de cette eau chlorée doivent être envisagés. Mots-clés: désinfectants, eau chlorée, productions, utilisation, CHUSS. English Title: Study of the quality of chlorinated water and the conditions of use at the Sourou Sanou University Hospital Center (CHUSS) in Bobo-Dioulasso. English Abstract Chlorinated water is an effective disinfectant and easy to prepare. The pharmacy department of the University Hospital Center of Sourou Sanou (CHUSS) is responsible for the preparation of chlorinated water which has been used in hospital departments since 2003. The chemical quality, the conditions of production and use of this chlorinated water remains unknown. However, good practice standards require quality control of production and use. The aim of this study was to help assess the quality of chlorinated water and the conditions of use at CHUSS. It was a survey on the conditions of production, use and a chemical analysis of the quality of chlorinated water. The study took place from July 1 to September 30, 2014 at CHUSS. The investigation revealed that the production of chlorinated water did not meet the recommendations of the manufacturer of the production device. The average concentration of active chlorine measured at production (2.74 ± 0.25 g / L) was lower than that expected (5 g / L). The production pH of chlorinated water was 8.42 ± 0.03. The conditions of use were sometimes non-compliant. Further work on the microbiological effectiveness of this chlorinated water should be considered. Keywords: disinfectants, chlorinated water, production, utilisation, CHUS

    Role of Killer cell immunoglobulin-like receptors (KIR) genes in stages of HIV-1 infection among patients from Burkina Faso

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    A cluster of specialized KIR genes of specialized KIR genes has been shown to be associated with susceptibility or resistance to viral infections in humans. Therefore, this pilot study, this pilot investigation sought to determine the frequencies of KIR genes human immunodeficiency virus type 1( HIV-1) patients and establish their potential clinical involvement in disease progression and staging
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