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Contribution of Genomic Surveillance in the Detection and Monitoring of SARS-CoV-2 Variants during the 6 Pandemic Waves in the Central African Republic from 2020 to 2023

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Journal of Tuberculosis Research 2024年第3期12卷 151-164页

作者： Clotaire Donatien Rafaï Ernest Lango-Yaya Marie Roseline Darnicka Belizaire Ouoko Fa-ti-Gbia Maurel Annicet Adonis Marcel Mbeko Simaleko jean-Baptiste Roungou Oscar Senzongo Karl G. Njuwa Fai Boniface Koffi National Laboratory of Clinical Biology and Public Health of Bangui Bangui Republic Central African University of Bangui Bangui Central African Republic World Health Organization Geneva Switzerland Ministry of Health and Population Bangui Central African Republic Africa CDC Addis-Abeba Ethiopia Homegrown Solutions for Health Yaounde Cameroon

Objective: The COVID-19 pandemic has highlighted the need to strengthen diagnosis and genomic surveillance capacities. In 2021, Central African managed five waves of COVID-19 by integrating genomic surveillance into their health monitoring system. This study sought to report surveillance data from the National Laboratory of Clinical Biology and Public Health and describe the circulation of SARS-CoV-2 variants. Materials and Methods: This retrospective, descriptive observational study spans three years, from April 2020 to November 2023. It was conducted on a population of consenting volunteers from across the Central African Republic, who were tested using RT-PCR on nasopharyngeal samples. Data with sufficient information were obtained from the National Laboratory of Clinical Biology and Public Health (LNBCSP) databases. Sequencing was largely carried out at the National Institute of Biomedical Research (INRB) in Kinshasa until May 2023, and subsequently at the LNBCSP. Results and Discussion: Out of 97,864 RT-PCR tests performed, 9,764 were positive, resulting in a prevalence of 9.98%. The average age of the patients was 39.97 years ± 13.76, and the male-to-female sex ratio was 2.12. RT-PCR test positivity was significantly associated with age (p = 0.001), sex (p = 0.013) and clinical manifestations. Ten variants circulated during the five recorded waves, with Omicron (B.1.1.529), Delta (B.1.617.2) variants being predominant. Notably, the B.1.620 and B.640 variants were prominent during the second wave. Conclusion: This retrospective study provides key insights into the COVID-19 pandemic in the CAR. It identifies risk factors and details the circulation of various SARS-CoV-2 variants. Enhancing national genomic surveillance capacities would enable the country to better respond to future pandemic challenges.

关键词： SARS-CoV-2 Variants Central African Republic RT-PCR

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Multi-Elemental Analysis and 2D Image Mapping within Roots, Leaves and Seeds from O. glaberrima Rice Plants Using Micro-PIXE Technique

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World Journal of Nuclear Science and Technology 2024年第2期14卷 97-106页

作者： Alassane Traore Anna Ndiaye Christopher Bongani Mtshali Manneh Baboucarr jean Paul Latyr Faye Daouda Mbodj Kandiaba Traore Tapha Gueye Ababacar Sadikhe Ndao Département de Physique Faculté des Sciences et Techniques Université Cheikh Anta Diop Dakar Senegal Département de Chimie Faculté des Sciences et Techniques Université Cheikh Anta Diop Dakar Senegal Tandetron Laboratory IBA Group iThemba LABS Cape Town South Africa Africa Rice Center St. Louis Senegal

Understanding metal accumulation at organ level in roots, leaves and seeds in O. glaberrima (OG) is crucial for improving physiological and metabolic aspects in growing Asian and African rice in salted areas. The micro-analytical imaging techniques are required to reveal its accumulation and distribution within plant tissues. PIXE studies have been performed to determine different elements in rice plants. The existing microbeam analytical technique at the iThemba LABS will be applied for the 2D image mapping of fresh rice tissues to perform a concentration of low atomic mass elements (such as Al, Si, P, S, Cl, Ca, ti, Mn, Fe, Cu, Br, Zn and K) with detection limits of typically 1-10 μg/g. Comparison of the distribution of the elements between leaves, root and seed samples using uptake and distribution of elements in particular environmental conditions with potential amount of salt in water have been performed. We are also expecting to indicate metal exclusion as salt tolerance strategies from leaves, root, and seed compartments using matrix correlation between samples and between elements on rice species.

关键词： PIXE 2D Mapping Rice Concentration Elemental Analysis

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Phytochemical Analysis and Antioxidant Activity of Aqueous and Hydroethanolic Extracts from Three Anticancerous Fabaceae of Northern Cameroon Pharmacopoeia

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Journal of Biosciences and Medicines 2024年第6期12卷 19-32页

作者： Halmata Mohamadou Landry Lienou Lienou Richard Simo Tagne Herve Pabamé Kada Elisee Libert Enyengue Embolo Grace Kembaou Nganwa jean Louis Oyono Essame Piere Michel Dongmo Jazet Anatomy and Cytology Pathology Laboratory Institute of Medical Research and Medicinal Plants Studies (IMPM) Yaound Cameroon Department of Biochemistry Faculty of Science University of Douala Douala Cameroon Department of Biomedical Sciences University of Ngaoundere Ngaoundere Cameroon General Hospital of Garoua (HGG) Garoua Cameroon Anatomo-Cytopathology Department of Biological Sciences Faculty of Medicine and Pharmacy University of Douala Douala Cameroon

Background: Cancer continues to pose a significant threat to our society, representing one of the most pressing health concerns worldwide. This study aimed to evaluate the chemical composition and the antioxidant activity of aqueous and hydroethanolic extracts from Acacia nilotica (An), Bauhinia reticulate (Br), and Tamarindus indica (ti) of Fabaceae family, traditionally used in Northern Cameroon for cancer treatment. Methods: The phytochemical screening of the three plants was conducted using conventional colorimetric methods, followed by the measurement of total phenol content, flavonoids, and tannins. The antiradical and antioxidant activities of both plant extracts were assessed through FRAP, ABTS, and DPPH methods. A principal components analysis was employed to correlate the quantities of the evaluated secondary metabolites with the activities. Results: Both types of extracts from the three plants contain alkaloids, saponins, flavonoids, phenolic compounds, tannins, glycosides, terpenoids, coumarins, anthocyanins, and anthraquinones. The aqueous extracts of Br and An are significantly richer (p Conclusion: The three Fabaceae plants from northern Cameroon, prepared in different solvents, can be utilized for their antiradical properties in cancer treatment.

关键词： Cancer Antioxidant Fabaceae Phenolic Compounds Aqueous Extract Hydroethanolic Extract

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Study of a Toposequence of West Mayo-Kani Soils (Far North Cameroon)

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Open Journal of Soil Science 2022年第10期12卷 523-539页

作者： Souoré Irène Basga Simon Doumnang Mbaigane jean-Claude Ngaro M’baïti Management of Water Resources Soils and Environment Department of Earth Sciences Faculty of Sciences University of Ngaoundéré Ngaoundéré Cameroon Institute of Agronomic Research for Development (IRAD) of Garoua Garoua Cameroon Laboratory of Geology Geomorphology and Remote Sensing University of N’Djamena N’Djamena Chad

The soils of Gadas, object of the present study, are identified on the macromorphological, physico-chemical level and the indices of erodibility are related to their physico-chemical properties. The physico-chemical analyzes were carried out by standard methods. The macromorphological analysis of a toposequence made it possible to identify five types of soils: the lithosols which occupy the high zones of the landscape, the colluvial soils (arenosols, regosols) which are located high on the piedmont, alluvial soils (fluvisols) which are located at the bottom of the slope in the alluvial plain and are the most extensive, topomorphic vertisols, and brown soils formed on granite are located either between a colluvial soil and alluvial soil. Physico-chemical analyzes of the soils of Gadas show that these soils are weakly acidic to neutral, sandy to sandy-clayey, saturated, low in nitrogen and organic matter and characterized by average proportions of exchangeable bases. The study of soil erodibility, based on the use of erodibility indices, showed that alluvial soils and brown soils formed on granites are the most susceptible to erosion, whereas vertisols and colluvial soils are the least vulnerable to erosion.

关键词： Far North Cameroon West Mayo-Kani Gadas Soils Erodibility

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Contribution of a Geographical Information System to the Study of Soil Loss Dynamics in the Lobo Catchment (Côte d’Ivoire)

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Journal of Geoscience and Environment Protection 2018年第9期6卷 183-194页

作者： jean-Philippe Attoungbré Deguy Alexis Yao N’Go Hervé Kouakou Kouassi Emile Gneneyougo Soro Albert tié Bi Goula Laboratory of Geosciences and Environment UFR Environmental Science and Management Nangui Abrogoua University Abidjan C&#244 te d’Ivoire Laboratory of Sciences and Technologies of Water UFR Environment University Jean Lorougnon Guédé Daloa C&#244 te d’Ivoire

The Lobo watershed is highly anthropogenic since it has become the main production area for cocoa and coffee in C?te d’Ivoire. It therefore seems important to quantify soil loss by water erosion in this region. The Wischmeier modeling was used to model the main factors involved in erosive phenomena. Crosscutting of thematic maps and the application of the USLE formulas made possible to evaluate the erosion rate at the watershed scale in 1986 and 2014. Although soil is susceptible to erosion and erosivity is increased, the results indicate a growth in soil loss estimated at 90.12%. Some agroforestry efforts are still possible to help reducing those soil losses.

关键词： Water Erosion Soil Loss Universal Soil Loss Equation Geographical Information System Lobo

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Phases in the crystallization process of Zr_(65)Al_(7.5)Ni_(10)Cu_(17.5)metallic glass

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Rare Metals 2003年第1期22卷 33-41页

作者： LEIYi DONGChuan HEIZukun MoniqueCalvo－Dahlborg jean－MarieDuboi DepartmentofMaterialsEngineering DalianUniversityofTechnologyDalian116024China InstituteofMaterial＆Technology DalianMaritimeUniversityDalian116024China LaboratoryofScienceandEngineeringofMaterials

The crystallization process of metallic glass Zr_(65)Al_(7.5)Ni_(10)Gu_(17.5)(atom fraction in percent) were studied by transmission electron microscopy and X-ray *** stages of crystallization process, which are indicated by the two exothermic peaks in thedifferential scanning calorimetry diagram, were studied separately. It is found that the phases inthe various stage of the crystallization are different. In the first stage, it consists mainly ofti-CuZr_2 and tP-Al_2Zr_3 phases, between which a definite orientation relationship is found. Whilein the second stage, in addition to the above phases, phase hP^2-Al_2NiZr_6 and phase hP^3-alpha-Zrappear, between which another orientation relationship is also found. At the same time, a comparisonis made based on the study of the phases exist in the arc-melted master ingot. The latticeparameters of the identified phases were determined and some interesting similarities were *** to these similarities, all the phases were classified into two groups. The first is: oB,ti-CuZr_2 and hP^3-alpha-Zr; the other is: hP^2, tP-Al_2NiZr_3 and hP^1-Al_2NiZr_6. Therelationships between phases in these two groups were investigated and the probable reasons that mayresult in these relationships were discussed.

关键词： metallic materials bulk metallic glass crystallization Zr-Al-Cu-Ni transmission electron microscopy

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Antioxidant Activity Evaluation in a Series of Heterocyclic Compounds Derived from 1,8-Diaminonaphthalene

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Journal of Biophysical Chemistry 2021年第1期12卷 1-9页

作者： Tuo Nanou tiéba Kangah Niameke jean Baptiste Ballo Daouda Kablan Ahmont Landry Claude Kodjo Charles Guillaume Yapo Ossey Bernard Ziao Nahossé Laboratoire de Thermodynamique et de Physico-Chimie du Milieu UFR SFA Université NanguiAbrogoua Abidjan C&#244 te d’Ivoire Laboratoire de Chimie Organique Heterocyclique URAC 21 P&#244 le de Compétence Pharmacochimie Faculté des Sciences Université’ Mohammed V Rabat Moroc Laboratoire de Constitution et Réaction de la Matière (LCRM) UFR Sciences des Structures de la Matière et Technologie Université Félix Houphou&#235 t-Boigny Abidjan C&#244 te d’Ivoire UFR Des Sciences Biologiques Université Péléforo Gon Coulibaly de Korhogo Korhogo C&#244 te d’Ivoire Laboratoire Centrale de l’Environnement (LCE) Centre Ivoirien Antipollution (CIAPOL) Abidjan C&#244 te d’Ivoire Laboratoire des Sciences de l’Environnement (LSE) UFR SGE Université Nangui Abrogoua Abidjan C&#244 te d’Ivoire

From (2,3-dihydro-1H-perimidin-2-yl)-phenyl, the substitution of OH group in ortho or para position on the phenyl ring, allows us to synthesize the studied compounds. These three compounds have been characterized by conventional spectroscopic methods (NMR and MS). The interest of this work is to review the antioxidant activity of our compounds. The antioxidant activity screening carried out according to FRAP and DPPH methods revealed significant anti-free radical properties for compounds 1 and 2 even at low concentrations. In contrast to the compound 2, compound 3 for which the OH group is substituted in para position has the lowest activity in both cases. Therefore the para position seems to be the least sensitive position to increase the antioxidant activity of this pharmacophore.

关键词： Perimidine Spectrometry Antioxidant Activity 2 2-Diphenyl-1-Picrylhydrazyl Method and Ferric Reducing Antioxidant Power Method

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Insight on Viscoelasticiy of ti16.7Zr16.7Hf16.7Cu16.7Ni16.7Be16.7 High Entropy Bulk Metallic Glass

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Journal of Iron and Steel Research International 2016年第1期23卷 19-23页

作者： Ji-chao QIAO jean-marc PELLEtiER Ning LI Yao YAO School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi'an 710072ShaanxiChina Universite de Lyon MATEISUMR CNRS5510Bat.B.PascalINSA-LyonF-69621 Villeurbanne cedexFrance Department of Materials Science and Engineering State Key Laboratory for Materials Processing and Die&Mould TechnologyHuazhong University of Science and TechnologyWuhan 430074HuheiChina

High entropy bulk metallic glasses show promising mechanical and physical *** mechanical properties of ti_（16.7）Zr_（16.7）Hf_（16.7）Cu_（16.7）Ni_（16.7）Be_（16.7）high entropy bulk metallic glass were investigated by mechanical spectroscopy（or called dynamic mechanical analysis）.The main（α）relaxation was observed in the framework of the loss modulus G″,which is related to the dynamic glass transition behaviour for the glassy *** physical model point of view,dynamic mechanical properties of the ti_（16.7）Zr_（16.7）Hf_（16.7）Cu_（16.7）Ni_（16.7）Be_（16.7）high entropy bulk metallic glass show good agreement compared with the quasi-point defects theory.

关键词： high entropy bulk metallic glass viscoelasticity mechanical spectroscopy quasi-point defect theory

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Prevalence of Malocclusions and Normative Orthodontic Treatment Need Using IOTN Index for Patients in Yalgado Ouédraogo Teaching Hospital

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Open Journal of Stomatology 2017年第12期7卷 519-529页

作者： Youssouf Ouédraogo tiécoura Camara Raoul Bationo Raoul Bationo Loubna Bahije jean Bertin Beugré Joseph Samba Diouf Papa Ibrahima Ngom Centre Hospitalier Universitaire Yalgado Ouédraogo Université Ouaga I Ouagadougou Burkina Faso Direction de la lute contre la maladie Ouagadougou Burkina Faso Service de chirurgie dentaire du camp Sangoulé Lamizana Ouagadougou Burkina Faso Faculté de Médecine Dentaire Université Mohammed V Rabat Maroc UFRd’odonto-stomatologie Université Félix Houphouet Boigny Abidjan Cote D’Ivoire Institut d’odonto-stomatologie Université Cheikh Anta Diop Dakar Sénégal

Introduction: The assessment of health care needs must be reproducible, independent of the operator, hence the use of indexes like the Index of Orthodontic Treatment Need (IOTN). The aim of this study was to assess both, the prevalence of malocclusions among patients received in the Dental Surgery Unitat Yalgado Ouédraogo Teaching Hospital and their care needs according to IOTN index. Materials and Methods: It is a prospective, cross-cutting diagnostic study of malocclusions at Yalgado Ouédraogo Teaching Hospital (CHUYO), conducted from January 1 to December 31, 2016. The examiner with an examination tray records on the 12- to 16-year-old patients’ medical recorded, the variables based on the polychromatic pictures series, the IOTN rule, and the dental health component table. Results: On the whole, 81 patients were included, with 60.5% of girls and 39.5% of boys. 16- and 12-year-old patients were dominant. The average age was 14.05 years old. Various types of malocclusions were encountered. The need for orthodontic care was 56.8%. For 14 patients, 17.28%, their aesthetic component score is higher than the assessment made by the orthodontist. Conclusion: Aesthetics was an important factor in the need for orthodontic care. The aesthetic deficit entails a psychological impact that should be taken into account in the assessment of care needs.

关键词： Malocclusions Orthodontic Care IOTN Burkina Faso

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Multi-dimensional morphology of hydride diffusion layer and associated sequential twinning in commercial pure titanium

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Journal of Materials Science & Technology 2022年第8期103卷 105-112页

作者： Qian Wang Shun Xu Yajun Zhao jean-Sébastien Lecomte Christophe Schuman Laboratoire d’Etude des Microstructures et de Mécanique des Matériaux(LEM3) Universitéde Lorraine CNRSArts et Métiers ParisTechMetz57073France Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures(DAMAS) University of Lorraine57073France School of Iron and Steel Soochow UniversitySuzhou 215021China School of Materials Science and Engineering Dalian Jiaotong UniversityDalian 116021China

The dominant hydride precipitates have been well demonstrated to follow two types of orientation relationships(ORs)with ti matrix:OR1 with{0001}//{001},//and OR2 with{0001}//{111},//.Within the grains with special orientations,the complicated interactions of different hydride variants inside ti-hydride diffusion layer are characterized in this *** OR1 hydride layer,the orientations of{1010}plane parallel to the sample surface and a-axis parallel to the normal direction prefer multiple OR1 *** orientations favorable for OR2 hydride layer are:{1013}plane parallel to sample surface corresponding to the layer with one OR2 variant dominated and c-axis parallel to the surface normal with multiple OR2 variant layer ***,{1012}extension twins and{1122}contraction twins are activated to accommodate the OR2 hydride-induced surface expansion and local misfit *** stimulation of these two twins is also orientation-dependent:{1012}and{1122}twins are observed in the grains with c-axis parallel to and deviated from the surface normal,*** further variant selection for each twin mode is performed through shear accommodation of hydride-twin pairs.

关键词： titanium Hydride Cross section Twin Variant selection

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