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Acute and Sub-Chronic Toxicity Evaluation of the Crude Methanolic Bark Extract of Bridelia micrantha (Hochst.) Baill. (Phyllanthaceae) and Its Fraction

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Journal of Biosciences and Medicines 2023年第10期11卷 76-89页

作者： Colette Elysée Aboudi Etono Landry Lienou Lienou fabrice fabien dongho dongmo Aristide Laurel Mokale Kognou Raphael Tchientcheu Rebecca Madeleine Ebelle Etame Rosalie Anne Ngono Ngane Laboratory of Biochemistry Faculty of Science University of Douala Douala Cameroon Centre for Research on Medicinal Plants and Traditional Medicine Institute of Medical Research and Medicinal Plants Studies Ministry of Scientific Yaounde Cameroon

Bridelia micrantha, commonly known as coastal golden leaf, is a member of the family Phyllanthaceae. In preliminary studies nine fractions, named F1 - F9, were obtained by fractionating the crude methanol extract of the stem bark of Bridelia micrantha using column chromatographic techniques. The fraction F6 was the most active when tested for antibacterial activity. Thus, toxicity of this fraction was investigated for further use. The present study evaluated the acute and sub-chronic toxicity of the crude methanolic bark extract of Bridelia micrantha and its fraction. The acute toxicity was carried out according to the experimental protocol of Organization for Economic Co-operation and Development (OECD). The plant extract or the fraction F6 was administered orally to female mice at a single dose of 2000 mg/kg and the animals were observed for any behavioral changes or mortality for 14 days. In the sub-chronic toxicity study, the extract and fraction were administered orally at 200, 400 and 800 mg/kg bw/day for 28 days to healthy Wistar rats. The general behavior and body weight of the rats were recorded daily. At the end of the experimental period, hematological and biochemical analyses, changes in vital organ weight (liver, lung, heart, spleen and kidney), and histopathological examination of the liver and kidney were performed. No mortality or adverse effects were noted at the 2000 mg/kg dose during the oral acute toxicity test. In the sub-chronic study, the crude methanolic bark extract of Bridelia micrantha and the fraction F6 induced no mortality or treatment-related adverse effects on body weight, general behavior, relative organ weights, hematological and biochemical parameters. Histopathological examination of the liver and kidney showed normal architecture suggesting no morphological alterations. In conclusion, the oral administration of the crude methanolic bark extract of Bridelia micrantha and the fraction F6 for 28 days

关键词： Bridelia micrantha Acute Toxicity Sub-Chronic Toxicity Biochemical Parameters Hematological Parameters

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Evaluation of Acute and Sub-Acute Oral Toxicities of Momordica foetida Schumach. (Cucurbitaceae) Leaves Methanol Extract in Wistar Rats

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Journal of Biosciences and Medicines 2023年第1期11卷 123-142页

作者： Cedric Laurel Cidjeu Pouaha Landry Lienou Lienou fabrice fabien dongho dongmo Colette Elysée Aboudi Etono Raphael Tchientcheu Azaber Masoohe Mamoune Sandrine Suzanne Beack Bayengue Rebecca Madeleine Ebelle Etame Rosalie Anne Ngono Ngane Faculty of Science University of Douala Douala Cameroun Institute of Medical Research and Medicinal Plant Studies (IMPM) Yaounde Cameroon

Momordica foetida is a plant widely used in tropical Africa to manage gastroenteric diseases. Previous studies demonstrated interesting antibacterial activity against human pathogenic bacteria. However, the security or toxicity of methanol leaf extract has not been determined yet. The aim of this study was to evaluate the acute and sub-acute toxicity of the leaf extract of Momordica foetida. In the acute toxicity study, a single oral dose of 5000 mg/kg body weight was administered to rats which were observed for 14 days in order to identify signs of toxicity or death. In the sub-acute toxicity, the animals were treated with 250, 500 and 1000 mg/kg of the extract for 28 consecutive days. Body weights and behavior were noted throughout the experiment. Upon treatment, blood and urine were collected for hematological and biochemical analysis. Liver, lungs, heart, kidneys, testes and ovaries were analyzed for relative weights and histopathology. The acute toxicity study of M. foetida leaf extract revealed no signs of toxicity related to the treatment, indicating that the median-lethal-dose (LD50) value is greater than 5000 mg/Kg of body weight. In the sub-acute toxicity assay, the extract did not affect the general behavior of animals, meanwhile, it led to a significant increase in the levels of red blood cells, platelets, hemoglobin, granulocytes and Mid-Cells (MIDs). Biochemical parameters showed an increase in total cholesterol, HDL cholesterol, serum urea, serum and urinary glucose and a decrease in urinary proteins, serum creatinine, urinary urea levels, serum activities of AST, ALT and proteins levels, as well as increases in lung, spleen and ovaries relative weight were noticed, all compared to control animals. Histological analysis revealed a normal architecture of kidneys, liver, heart, lung, ovaries and testes. This study provides valuable data on the safety of per os administration of Momordica foetida leaf methanol extract that could be very useful for future

关键词： Momordica foetida Acute Toxicity Sub-Acute Toxicity Biochemical Parameters Hematological Parameters

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SmartMicro Grid Energy System Management Based on Optimum Running Cost for Rural Communities in Rwanda

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Energy Engineering 2024年第7期121卷 1805-1821页

作者： fabien Mukundufite Jean Marie Vianney Bikorimana Alexander Kyaruzi Lugatona Electrical and Electronic Engineering Department University of RwandaKigaliRwanda Electrical Engineering Department University of Dar es SalaamDar es SalaamTanzania

The governmental electric utility and the private sector are joining hands to meet the target of electrifying all households by ***,the aforementioned goal is challenged by households that are scattered in remote *** far,Solar Home Systems(SHS)have mostly been applied to increase electricity access in rural *** have continuous constraints to meet electricity demands and cannot run income-generating *** current research presents the feasibility study of electrifying Remera village with the smart microgrid as a case *** renewable energy resources available in Remera are the key sources of electricity in that *** generation capacity is estimated based on the load *** microgrid configurations are simulated with HOMER,and the genetic algorithm is used to analyze the optimum *** analyzing the impact of operation and maintenance costs,the results show that the absence of subsidies increases the levelized cost of electricity(COE)five times greater than the electricity price from the public *** microgrid made up of PV,diesel generator,and batteries proved to be the most viable solution and ensured continuous power supply to *** considering the subsidies,COE reaches 0.186$/kWh,a competitive price with electricity from public utilities in Rwanda.

关键词： Load demand load profile optimum running cost power demand satisfaction smart meters and smart micro grid

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Knotting ligands to control metal coordination geometry

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Science China Chemistry 2024年

作者： fabien B.L.Cougnon Department of Chemistry and Nanoscience Centre University of Jyv?skyl?

Zinc is a metal of particular importance for life [1]. It is the most abundant transition metal in biological systems after iron and contributes both structural and catalytic roles to many cellular processes. The properties of ZnII, unlike those of any other first-row transition metal ions, explain its biological relevance. Due to its filled d-shell orbitals, ZnIIis redox-stable, has a ligand-field energy stabilization of zero and, consequently, no typical coordination number and geometry. Zinc metalloproteins exploit these features to carry a broad range of chemical reactions in mild *** metalloenzymes, unsaturated ZnIIcentres often act as redox-stable Lewis acids. The protein backbone provides a highly preorganized environment around the metal centre and accompanies the changes in coordination geometry occurring as substrate transformation proceeds, thereby modulating the metal reactivity.

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Why China Still Has Room to Grow

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Beijing Review 2024年第34期67卷 20-21页

作者： fabien Pacory French Chamber of Commerce and Industry in China

The world economy is experiencing what the World Bank calls"the slowest halfdecade of GDP growth in 30 years."As some of China's key growth catalysts weaken against this backdrop,a few stakeholders in the Western econ... 详细信息

关键词： economy Room Still

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Numerical Study of the Vibrations of Beams with Variable Stiffness under Impulsive or Harmonic Loading

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World Journal of Engineering and Technology 2024年第2期12卷 401-425页

作者： Moussa Sali fabien Kenmogne Jean Bertin Nkibeu Abdou Njifenjou Laboratory of Materials Mechanics and Civil Engineering National Higher Polytechnic School of Maroua University of Maroua Maroua Cameroon Department of Civil Engineering Advanced Teachers Training College of the Technical Education University of Douala Douala Cameroon Laboratory Engineering Civil and Mechanics National Advanced School of Engineering University of Yaound&#233 1 Yaound&#233 Cameroon Laboratory of Energy Materials Modeling and Method (E3M) National Advanced School of Engineering University of Douala Douala Cameroon Laboratory of Mathematical Engineering and Information Systems National Advanced School of Engineering University of Yaound&#233 1 Yaound&#233 Cameroon

The behavior of beams with variable stiffness subjected to the action of variable loadings (impulse or harmonic) is analyzed in this paper using the successive approximation method. This successive approximation method is a technique for numerical integration of partial differential equations involving both the space and time, with well-known initial conditions on time and boundary conditions on the space. This technique, although having been applied to beams with constant stiffness, is new for the case of beams with variable stiffness, and it aims to use a quadratic parabola (in time) to approximate the solutions of the differential equations of dynamics. The spatial part is studied using the successive approximation method of the partial differential equations obtained, in order to transform them into a system of time-dependent ordinary differential equations. Thus, the integration algorithm using this technique is established and applied to examples of beams with variable stiffness, under variable loading, and with the different cases of supports chosen in the literature. We have thus calculated the cases of beams with constant or variable rigidity with articulated or embedded supports, subjected to the action of an instantaneous impulse and harmonic loads distributed over its entire length. In order to justify the robustness of the successive approximation method considered in this work, an example of an articulated beam with constant stiffness subjected to a distributed harmonic load was calculated analytically, and the results obtained compared to those found numerically for various steps (spatial h and temporal τ ¯ ) of calculus, and the difference between the values obtained by the two methods was small. For example for ( h=1/8 , τ ¯ =1/ 64 ), the difference between these values is 17%.

关键词： Successive Approximations Method Direct Integration Differential Equations Beams of Variable Stiffness Quadratic Parabola Impulse and Harmonic Loads

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Spatial Variation and Trend of Extreme Precipitation in Africa during 1981-2019 and Its Projected Changes at the End of 21^st Century

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Journal of Geoscience and Environment Protection 2024年第3期12卷 192-221页

作者： fabien Habiyakare Tong Jiang Ibrahim Yahaya Daudi Ndabagenga James Kagabo Buda Su School of Atmospheric Sciences Key Laboratory of Meteorological Disaster of Ministry of Education Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and Technology Nanjing China Rwanda Meteorology Agency (Meteo Rwanda) Kigali Rwanda Institute for Disaster Risk Management/School of Geographical Sciences Nanjing University of Information Science & Technology Nanjing China Department of Geography Gombe State University Gombe State Nigeria

This study comprehensively examines the patterns and regional variation of severe rainfall across the African continent, employing a suite of eight extreme precipitation indices. The analysis extends to the assessment of projected changes in precipitation extremes using five General Circulation Models (GCMs) from Coupled Model Intercomparison Project Phase 6 (CMIP6) under four Shared Socioeconomic Pathways (SSPs) scenarios at the long-term period (2081-2100) of the 21st century. Furthermore, the study investigates potential mechanisms influencing precipitation extremes by correlating extreme precipitation indices with oceanic system indices, specifically Ni?o 3.4 for El Ni?o-Southern Oscillation (ENSO) and Dipole Mode Index (DMI) for the Indian Ocean Dipole (IOD). The findings revealed distinct spatial distributions in mean trends of extreme precipitation indices, indicating a tendency toward decreased extreme precipitation in North Africa, Sahel region, Central Africa and the Western part of South Africa. Conversely, West Africa, East Africa and the Eastern part of South Africa exhibit an inclination toward increased extreme precipitation. The changes in precipitation extreme indices indicate a general rise in both the severity and occurrence of extreme precipitation events under all scenarios by the end of the 21st century. Notably, our analysis projects a decrease in consecutive wet days (CWD) in the far-future. Additionally, correlation analysis highlights significant correlation between above or below threshold rainfall fluctuation in East Africa and South Africa with oceanic systems, particularly ENSO and the IOD. Central Africa abnormal precipitation variability is also linked to ENSO with a significant negative correlation. These insights contribute valuable information for understanding and projecting the dynamics of precipitation extreme in Africa, providing a foundation for climate adaptation and mitigation efforts in the region.

关键词： Extreme Precipitation Mann-Kendall Trend Projections Oceanic System Africa

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Vaccination and Measles Epidemic in the Republic of Congo

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Open Journal of Epidemiology 2024年第1期14卷 45-55页

作者： Léa Gwladys Gangoue Yanne Mavougou fabien Rock Niama Pembe Issamou Mayengue Etienne Nguimbi National Public Health Laboratory (LNSP) Ministry of Health and Population Brazzaville Republic of Congo Cellular and Molecular Biology Laboratory (BCM) Faculty of Sciences and Techniques Marien Ngouabi University Brazzaville Republic of Congo

Measles is a highly infectious, vaccine-preventable viral disease. Often forgotten, it is potentially fatal. Its main symptoms are: fever, cough, conjunctivitis, rhinitis and skin rash. Serological diagnoses by ELISA test based on the detection of anti-measles virus immunoglobulins M and G (IgM and IgG), are used respectively for the confirmation of suspected cases notified by means of clinical signs of the disease in health structures of the twelve departments of the Republic of Congo involved in the epidemiological surveillance of the disease, and for the evaluation of the immunity conferred by vaccination. During 2021, 459 suspected cases of measles were reported and sampled throughout the country, despite the administration under the Expanded Routine Immunization Program (EPI), of 2 doses of the combined measles-rubella vaccine (RR1 and RR2) in 2020. The notification rate was higher in the south of the country, more precisely in the health structures of the departments of Pointe-Noire (42%) and Brazzaville (11%). During the year 2021, 459 suspected cases of measles were notified and sampled throughout the country with a high notification rate in the south of the country, more precisely in the health structures of the Pointe-Noire departments (42%) and Brazzaville (11%). The samples consisting of human blood (serum) were sent to the National Public Health Laboratory and analyzed by various ELISA tests for the detection of anti-measles immunog-lobulins M and G. The analysis of the results obtained shows that the measles virus circulated in all departments of the country. 154 cases (33.55%) were confirmed positive by IgM ELISA and 98 positive cases (63.63%) were patients vaccinated against measles. Vaccination coverage in RR1 of [50%-95% [(first dose) as well as the lowest RR2 < 50% (second dose) undoubtedly because the COVID-19 pandemic could be the cause of the high frequency of cases positive vaccinated. The non-detection of IgG immunoglobulins in vaccinated pat

关键词： Vaccination Measles Epidemic

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Preclinical and clinical evidence of the association of colibactinproducing Escherichia coli with anxiety and depression in colon cancer

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World Journal of Gastroenterology 2024年第21期30卷 2817-2826页

作者： fabien Rondepierre Maëva Meynier Johan Gagniere Vincent Deneuvy Anissa Deneuvy Gwenaelle Roche Elodie Baudu Bruno Pereira Richard Bonnet Nicolas Barnich Frédéric Antonio Carvalho Denis Pezet Mathilde Bonnet Isabelle Jalenques Service de Psychiatrie de l’Adulte A et Psychologie Médicale CHU Clermont-FerrandClermont-Ferrand 63000France M2iSH UMR 1071INSERMUniversity of Clermont AuvergneINRAE USC 1382Clermont-Ferrand 63001France NeuroDol UMR 1107INSERMUniversity of Clermont AuvergneClermont-Ferrand 63001France Department of Digestive Surgery CHU de Clermont-FerrandClermont-Ferrand 63001France Biostatistics Unit Department of Clinical Research and InnovationCHU Clermont-FerrandClermont-Ferrand 63000France Department of Bacteriology CHU de Clermont-FerrandClermont-Ferrand 63001France UniversitéClermont Auvergne INPCNRSClermont Auvergne Institut PascalClermont-Ferrand 63000France

BACKGROUND The association between the intestinal microbiota and psychiatric disorders is becoming increasingly *** gut microbiota contributes to colorectal carcinogenesis(CRC),as demonstrated with colibactin-producing Escherichia coli(CoPEC).AIM To evaluate the association between CoPEC prevalence and anxiety-and depressive-like behaviors with both preclinical and clinical *** Patients followed after a CRC surgery and for whom the prevalence of CoPEC has been investigated underwent a psychiatric *** were compared according to the CoPEC *** parallel C57BL6/J wild type mice and mice with a CRC susceptibility were chronically infected with a CoPEC *** behavior was assessed using the Elevated Plus Maze test,the Forced Swimming Test and the Behavior recognition system PhenoTyper®.RESULTS In a limited cohort,all patients with CoPEC colonization presented with psychiatric disorders several years before cancer diagnosis,whereas only one patient(17%)without CoPEC *** result was confirmed in C57BL6/J wildtype mice and in a CRC susceptibility mouse model(adenomatous polyposis colimultiple intestinal neoplasia/+).Mice exhibited a significant increase in anxiety-and depressive-like behaviors after chronic infection with a CoPEC *** This finding provides the first evidence that CoPEC infection can induce microbiota-gut-brain axis disturbances in addition to its procarcinogenic properties.

关键词： Colorectal cancer Colibactin Escherichia coli Colibactin-producing Escherichia coli Inflammation Anxiety Depression Behavior

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Profile of Factors of Arduous Work among Healthcare Professionals in Healthcare Facilities in Northern Benin in 2021

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Occupational Diseases and Environmental Medicine 2024年第1期12卷 41-48页

作者： Gounongbé Ahoya Christophe fabien Mama Cissé Ibrahim Lompo Marthe Sandrine Azandjèmè Colette Bèhanzin Luc Faculty of Medicine University of Parakou Parakou Benin Health Sciences Training and Research Unit Joseph Ki-Zerbo University Ouagadougou Burkina Faso Regional Institute of Public Health of Ouidah University of Abomey-Calavi Abomey-Calavi Benin National Training School for Senior Technicians in Public Health and Epidemiological Surveillance University of Parakou Parakou Benin

Introduction: Work environments create the basis for arduous nursing work. This is what led us to research the factors of arduousness in the exercise of the health profession in North Benin, through this study. Methods: This is a cross-sectional and descriptive study which focused on health professionals in the health zones of Parakou-N’dali and Tchaourou. The sampling was an exhaustive census. All health workers who had given their free and informed consent were included. The data was collected using a questionnaire. The variables studied were the factors of arduous work and socio-professional characteristics. The data collected was processed and analyzed with the Epi info 7.***.0.1 software. Results: A total of 692 were surveyed, the participation rate was 85.11% and the sex ratio (M/F) equal to 0.7. The average age was 38 years old. Nurses made up 32.66% of the sample. They were 86.42% subject to night work and 82.66% to alternating work. Overall, 70.23% worked more than 40 hours per week. Between 78.12% and 96.46% of non-specialist doctors, nurses, midwives and biomedical analysis technicians were required to work night shifts. Nurses, midwives, radiology and laboratory technicians were between 89.53% and 97.35%, organized in alternating work. In the sample, 55.20% complained about the insufficient number of work materials, 26.29% handled harmful chemical substances. Among those surveyed, 58.14% had been attacked. Conclusion: All professional categories of caregivers are subject to arduous work. Measures are needed to reverse the situation.

关键词： Hard Work Professionals Health North-Bénin

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