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Mineral Uptake of Heavy Metals by Some Marine Organisms along the Limbe Coastline in Cameroon and Health Risk Assessment

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Journal of Geoscience and Environment Protection 2022年第6期10卷 106-120页

作者： Jean Faustin Sabouang Roland ndi Mbongko Lawan Loubou Mohamadou National Radiation Protection Agency Yaounde Cameroon Specialized Research Station for Fisheries and Oceanography IRAD Limbe Cameroon

This study aimed at investigating the content of heavy metals in some marine organisms of the Cameroon Atlantic coast and assessing the health risk due to their consumption by the population. Nine fish and one shrimp species were collected for this study. These fish species were Ethmolosa fimbriata, Drepane africana, Dentex moroccanus, Arius latiscotatus, Scarus hoefleri, Cynoglossus browni, Sardinella madorensis, Pseudotolithus elongatus, Pseudotolithus typus. The shrimp species was Macrobranchium macrobranchium. The elements investigated in this study were: Fe, Co, Cu, Cd and Pb. For seven fish species it was found that the concentration of heavy metals followed the order Fe > Co > Cd > Cu > Pb. For most fish species the Target Hazard Quotient (THQ) value calculated showed the following trend Cd > Co > Pb > Fe ≥ Cu. Cadmium was found to be the main contributor to health risk that may result from the consumption of the fish species under study. The THQ for this element was in the range 0.7 - 1.2 while the Target Cancer Risk (TR) due to ingestion of this metal was in the range (3 × 10-4 - 6 × 10-4). These values are slightly above the threshold limits established for both carcinogenic and non carcinogenic risks by the United States, Environmental Protection Agency. The estimated weekly intake of cadmium due to consumption of some fishes under study was greater or equal to the Provisional Tolerable Weekly Intake (PTWI) determined by Food and Agriculture Organization/World Health Organization.

关键词： Marine Fish Heavy Metal Health Risk Target Hazard Quotient

Isolation and characterization of three pairs of verrucosidin epimers from the marine sediment‑derived fungus Penicillium cyclopium and confguration revision of penicyrone A and related analogues

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Marine Life Science & Technology 2023年第2期5卷 223-231页

作者： Yan-He Li Attila Mándi Hong-Lei Li Xiao-Ming Li Xin Li Ling-Hong Meng Sui-Qun Yang Xiao-Shan Shi Tibor Kurtán Bin-Gui Wang CAS and Shandong Province Key Laboratory of Experimental Marine Biology Institute of OceanologyChinese Academy of Sciencesand Laboratory of Marine Biology and Biotechnology at the Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China School of Marine Science University of Chinese Academy of SciencesBeijing 100049China Department of Organic Chemistry University of DebrecenEgyetem Tér 1Debrecen 4032Hungary Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

Verrucosidins,a methylatedα-pyrone class of polyketides rarely reported upon,have been implicated in one or more neurological diseases.Despite the signifcance of verrucosidins as neurotoxins,the absolute confgurations of most of the derivatives have not been accurately characterized yet.In this study,three pairs of C-9 epimeric verrucosidin derivatives,including the known compounds penicyrones A and B(1a/1b)and 9-O-methylpenicyrones A and B(2a/2b),the new compounds 9-O-ethylpenicyrones A and B(3a/3b),together with the related known derivative verrucosidin(4),were isolated and identifed from the culture extract of Penicillium cyclopium SD-413,which was obtained from the marine sediment collected from the East China sea.Their structures were established based on an in-depth analysis of nuclear magnetic resonances(NMR)and mass spectroscopic data.Determination of the absolute confgurations of these compounds was accomplished by Mosher’s method and time-dependent density functional theory(TDDFT)calculations of electronic circular dichroism(ECD)and optical rotation(OR).The confgurational assignment of penicyrone A demonstrated that the previously reported C-6 absolute confguration of verrucosidin derivatives needs to be revised from(6S)to(6R).The 9R/9S epimers of compounds 1–3 were found to exhibit growth inhibition against some pathogenic bacteria,indicating that they have potential as lead compounds for the creation of antimicrobial agents.

关键词： Marine-derived fungus Penicillium cyclopium Verrucosidin derivatives TDDFT-ECD calculations Mosher’s method Antimicrobial activity

Transcatheter mitral valve repair in nonagenarians

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Journal of Geriatric Cardiology 2022年第1期19卷 90-94页

作者： Pedro Luis Cepas-Guillén Isaac Pascual Eulogio Garcia Pilar Jimenez-Quevedo Alfonso Jurado-Roman Tomás Benito-González Rodrigo Estevez-Loureiro Pedro Li dabit arzam.ndi Bruno Melica Eduardo Infante de Oliveira Pedro Martín Lorenzo Felipe Fernández-Vázquez Guillermo Galeote Luis Nombela-Franco Leire Unzue Pablo Avanzas Manel Sabate Xavier Freixa Cardiology Department Cardiovascular Institute(ICCV)Hospital ClinicIDIBAPSUniversity of BarcelonaBarcelonaSpain Interventional Cardiology Unit Hospital Universitario Central de AsturiasDepartment of MedicineUniversity of OviedoOviedoSpain Servicio de Hemodinámica y Cardiología Intervencionista HM CIEC-Centro Integral de Enfermedades CardiovascularesHospital Universitario HM MontepríncipeHM HospitalesMadridSpain Facultad de Medicina Universidad CEU San PabloMadridSpain Cardiology Department Cardiovascular InstituteHospital Clínico San CarlosIdISSCMadridSpain Division of Interventional Cardiology University Hospital La PazIdiPAZCIBER-CVMadridSpain Department of Cardiology University Hospital of LeónLeónSpain Interventional Cardiology Unit HospitalÁlvaro CunqueiroVigoSpain Interventional Cardiology Unit Hospital Sant Pau i Santa CreuBarcelonaSpain Serviço de Cardiologia Centro Hospitalar de Vila Nova de Gaia/Espinho-EPEVila Nova de GaiaPortugal Serviço de Cardiologia Hospital de Santa MariaCentro Hospitalar Lisboa NorteCentro Académico Médico de LisboaLisboaPortugal Servicio de Cardiología Hospital Universitario de Gran Canaria Dr.NegrínLas Palmas de Gran CanariaSpain

Given the increase in life expectancy indeveloped countries,nonagenarian population will become clinically and numerically relevant in our daily routine practice in the near future.Age has been observed to exert a profound influence on the prevalence of severe mitral regurgitation (MR) in the population.[1]Mitral valve surgery remains the gold standard of care for patients with symptomatic severe MR.

关键词： mitral routine surgery

Composite Activated Carbon from Canarium schweinfurthii/Polyethylene Terephthalate: Adsorption Test of Rhodamine B Dye Removal in Aqueous Solution

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Journal of Materials Science and Chemical Engineering 2023年第11期11卷 75-105页

作者： Gadjui Youatou Boris Ankoro Naphtali Odogu Lekene Ngouateu René Blaise Kouotou Daouda ndi Julius Nsami Ngomo Horace Manga Ketcha Joseph Mbadcam Applied Physical and Analytical Chemistry Laboratory Department of Inorganic Chemistry Faculty of Science University of Yaoundé I Yaoundé Cameroon Department of Chemistry Faculty of Science University of Buea Buea Cameroon

The present work deals on one hand with the valorization of wastes plastics, polyethylene terephthalate (PET) and Canarium schweinfurthii (CS) for the preparation of polyethylene terephthalate activated carbon (PETAC) and Canarium schweinfurthii/polyethylene terephthalate activated carbon (CS/PETAC). These adsorbents, on the other hand, were used for removal Rhodamine B (RhB) in an aqueous solution. PET and CS precursors were subjected to thermogravimetric analysis (TGA) and differential scanning colorimetry (DSC). Meanwhile PETAC and CS/PETAC were characterized using scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), X-ray fluorescence (XRF), Fourier transformed infrared spectroscopy (FT-IR) and nitrogen adsorption/desorption (N2-BET). The N2-BET results revealed an increase of the specific surface area from 6.75 m2/g to 1282.0 m2/g for PETAC and CS/PETAC. The results of characterization indicated the key role played by plastic wastes to enhance the structural and functional properties of CS/PETAC. The RhB removal from the aqueous solution onto PETAC and CS/PETAC was found to be independent of pH, with an optimal contact time of RhB removal within 10 min for materials. The non-linear adsorption isotherm data for the adsorption process showed that the Langmuir and Freundlich models best fitted the RhB adsorption onto PETAC meanwhile only the Freundlich adsorption isotherm gave the best fit for CS/PETAC according to the correlation coefficient value closed to unity. The pseudo-first and pseudo-second-order kinetic models best described the RhB dye removal on both adsorbents. Additionally, the Elovich model confirmed that chemisorption was the main mechanism followed. These findings proved that CS seeds and PET wastes are low-cost precursors that should be given an added value by transforming them into an outstanding carbon material for dye removal in liquid effluent.

关键词： Activated Carbon Rhodamine B Canarium schweinfurthii Plastics Wastes Pollution Wastewaters

Height-Diameter Relationship of Some Forest Species Exploited for Wood in the Natural Tropical Forest of the Congo Basin

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Open Journal of Forestry 2022年第2期12卷 235-247页

作者： Amougou ndi Yves Achille Hans Beeckman Ndongo Din Amougou Amougou François Borgia Zekeng Jules Christian Mbolo Marie Marguerite Botany-Ecology Laboratory Department of Plant Biology Faculty of Science The University of Yaounde 1 Yaounde Cameroon Wood Biology and Xylarium Laboratory Royal Museum for Central Africa Tervuren Belgium Department of Plant Biology Faculty of Science The University of Douala Douala Cameroon Institut de Recherche Agronomique pour le Développement (IRAD) Ngaoundéré Cameroon

To enrich knowledge on the growth dynamics of commercial forest species in the Congo Basin, a study was conducted in Cameroon, within a community forest in savannah forest transition zone (Zone 1) and within FMU 10 052 in dense semi-deciduous humid forest (Zone 2). It aimed to obtain, in 8 species, the height (H) of the tree from its diameter (D) more accessible: Entandophragma cylindricum (Meliacea), Eribroma oblongum, Sterculia rhinopetala et Triplochiton scleroxylon (Malvaceae);Erythrophleum suaveolens et Piptadeniastrum africanum (Fabaceae), Milicia excelsa (Moraceae) et Terminalia superba (Combretaceae). The destructive method was used. After felling and flushing out a tree, the dendrometric parameters were measured and/or calculated. In Zone 1, 6 species including T. scleroxylon were calibrated using 30 trees of each. In Zone 2, 45 trees of E. cylindricum, 99 of E. suaveolens and 82 of T. scleroxylon constituted the sample. At the 5% threshold (95% confidence interval), the height-diameter relationship is a linear model. In all species, the height of a tree is predicted by measuring its diameter through linear regression. In Zone 1 regression equation is: H(m) = 28.13 + 19.09 * D(m) for T. scleroxylon;H(m) = 12.35 + 30.38 * D(m) for S. rhinopetala;H(m) = 23.09 + 26.42 * D(m) for E. oblongum;H(m) = 14.86 + 20.92 * D(m) for P. africanum;H(m) = 14.98 + 24.78 * D(m) for T. superba and H(m) = 1.55 + 32.37 * D(m) for M. excelsa. In Zone 2, the relationship is: H(m) = 27.40 + 14.21 * D(m) for T. scleroxylon;H(m) = 7.79 + 20.18 * D(m) for E. cylindricum and H(m) = 20.08 + 9.74 * D(m) for E. suaveolens (probability associated with F < 0.0001). The influence of site parameters (biotic and abiotic) on the height-diameter relationship should be more studied in multilayers forests specifically in the Congo Basin.

关键词： Relationship Height Diameter Tree Natural Rainforest

Clinical Presentation, Management and Materno-Fetal Outcome of Patients with HELLP Syndrome at the Yaoundé Gyneco-Obstetrics and Pediatric Hospital

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Open Journal of Obstetrics and Gynecology 2023年第8期13卷 1432-1451页

作者： Nzometia Crysantus Yimlefack Foumane Pascal Dohbit Julius Sama Kenn Chi ndi Daniel Tarh Ketchen Claude Hector Mbia Robinson Enow Mbu Faculty of Medicine and Biomedical Sciences University of Yaounde 1 Yaoundé Cameroon

Background: HELLP (Hemolysis, Elevated Liver enzymes and Low Platelets) syndrome is a common complication of severe preeclampsia, with a high maternal and perinatal mortality rate. Data on HELLP syndrome is scanty in our setting. We sought to study the clinical presentation, management, and materno-fetal outcome of patients with HELLP syndrome at the Yaoundé Gyneco-Obstetrics and Pediatric Hospital (YGOPH). Methods: This was a cross-sectional, analytical study with a retrospective data collection of patients, diagnosed with HELLP syndrome at the YGOPH between 1st January 2020 and 31st July 2021. Data were analyzed using the software R version 4.0.2. Results are presented as mean ± standard deviation, frequencies and percentages. P values < 0.05 were considered statistically significant. Results: Of 254 cases of severe preeclampsia, 17 developed HELLP syndrome, giving us a frequency of 6.7%. One patient who presented with hepatitis B was excluded. The mean age was 27.19 ± 6.44 years. Most patients (56.3%) had poor follow up during antenatal contacts. The most common symptom was headache (93.8%). Most cases (56.3%) were diagnosed during post-partum, prepartum (25.0%), and per partum (18.8%). Obstetrical management was done by cesarean section (62.5%) and vaginal delivery (37.5%). Post-partum management of HELLP syndrome consisted of antihypertensive medication, anticonvulsants, sedatives, transfusion of blood and blood products, and fluid resuscitation. Of the 50% of patients who presented with acute kidney injury, only 12.5% (1) were referred for dialysis. Over 50% of our study participants presented severe complications after delivery, but 43.8% recovered, while 56.2% finally died. The fetal outcome was: still birth (31.2%), intra-uterine growth restriction/low birth weight (12.5%), term delivery (≥37 weeks) (31.3%), and preterm deliveries (<37 weeks) (68.7%). Three (18.8%) of the neonates delivered alive presented with a poor Apgar score at the 5th minute. Conclusion: Although rare, HELLP syndrome exists in our

关键词： HELLP Syndrome Clinical Presentation Management Maternal and Fetal Outcomes

Experimental and Computational Analysis of the Solution and Solid-State Conformations of Hexadepsipeptides from Beauveria felina

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Chinese Journal of Chemistry 2022年第3期40卷 378-384页

作者： Feng-Yu Du Attila Mandi Xiao-Ming Li Ling-Hong Meng Tibor Kurtan Bin-Gui Wang CAS&Shandong Province Key Laboratory of Experimental Marine Biology Institute of OceanologyChinese Academy of Sciencesand Laboratory of Marine Biology and BiotechnologyQingdao National Laboratory for Marine Science and TechnologyNonhoi Rood 7QingdaoShandong 266071China College of Chemistry and Pharmacy Qingdao Agricultural UniversityQingdooShandong 266109China Department of Organic Chemistry University of DebrecenPOB 4004002 DebrecenHungary College of Marine Science University of Chinese Academy of SciencesYuquon Rood 19ABeijing 100049China Center for Ocean Mego-Science Chinese Academy of SciencesNonhoi Road 7t QingdaoShandong 266071China

Chemical investigation of Beouverio felina,a marine-derived entomopathogenic fungus,obtained two new destruxin hexadepsipeptides(1 and 2)containing an/.-Ala^(5)residue instead of the usual A/-Me-L-Ala^(5).Interestingly,the presence of the/.-Ala^(5)residue enabled two slowly-exchanging solution conformers with cis/trons(ILE^(3))-(A/-Me-Val^(4))amide bond for 1 and 2 with 1.5:1 and 1:1 cis/trans ratios,respectively,while only the conformer with c/s amide bond was found in the solid-state.The solution and solid-state conformers were studied by NMR,X-ray diffraction and solution and solid-state ECD measurements,as well as by TDDFT-ECD calculations.Structural(conformational)parameter-activity correlations suggested that the extended destruxin geometry with the preferred c/s(ILE^(3))-(A/-Me-Val^(4))bond probably resulted in improved bioactivity and reduced toxicity for the destruxin class.This was the first report on the interconversion phenomenon of cis/trans amide bonds of destruxin class,which could give insights in the development of bioactive destruxin agents with lower toxicity.

关键词： Beouveria felina Natural products Destruxin hexadepsipeptides Structure elucidation Conformation analysis

CI Acid Orange 52 Dye Removal Using Natural and Formulated Clay-Lime Materials: Isotherm, Kinetic and Thermodynamic Studies

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Journal of Materials Science and Chemical Engineering 2023年第11期11卷 48-74页

作者： Fumba Gaston Essomba Jean Serge Ankoro Naphtali Odogu Kouotou Daouda Bélibi Bélibi Placide Désiré ndi Julius Nsami Ketcha Mbadcam Joseph Laboratory of Applied Physical and Analytical Chemistry Department of Inorganic Chemistry Faculty of Science University of Yaoundé I Yaoundé Cameroon Inorganic and Physical Chemistry Lab CSIR-Central Leather Research Institute Chennai India Department of Chemistry Faculty of Science University of Buea Buea Cameroon

The main objective of the study is to improve the removal efficiency of Ourlago-kaolin (Kao), sodium montmorillonite (Na-MMT), and two formulated clay-lime (F13 and F23) towards CI Acid Orange 52 dye (AO52). F13 and F23 were obtained by chemical stabilization through thermal treatment at 300°C. Fourier Transform Infrared spectra showed different surface functional groups on the clay materials, X-ray diffraction patterns revealed the raw materials contain many crystalline phases, scanning electron microscopy micrographs showed the variation of the layered structures of different clay materials, energy dispersive X-Ray analysis micrographs revealed compositional information and thermogravimetric-differential scanning calorimetry curves indicated the higher weight loss of 11.26% and 11.38% were observed for F13 and F23 respectively. BET surface area analyzed gave 133.0071 m2•g−1 for F13 and 132.34803 m2•g−1 for F23. The optimum pH value was 2.0 for Kao and Na-MMT. The adsorption experiments indicated that F13 and F23 have the maximum uptake abilities of 7.8740 and 3.1645 mg•g−1, respectively, compared to Kao (0.8761 mg•g−1) and Na-MMT (2.6178 mg•g−1). The pseudo-second-order model well described the adsorption kinetic model of AO52 dye onto the overall samples;Langmuir and Freundlich’s isotherms appropriately described the uptake mechanism. The positive values of ∆G° and negative value ∆H° indicated that the adsorption process was spontaneous and endothermic for Na-MMT, and non-spontaneous and exothermic for Kao, F13, and F23 because of their positive values of ∆G° and negative value of ∆H°. The modified clays have higher adsorption capacities and better life cycles compared hence opening new avenues for efficient wastewater treatment.

关键词： Ourlago-Kaolin Sodium Montmorillonite Formulated Clay Lime Adsorption Acid Dye Thermodynamic

MAMNID: A Load Balance Network Diagnosis Model Based on Mobile Agents

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Journal of Information Security 2012年第4期3卷 281-294页

作者： Thomas Djotio ndié Claude Tangha Guy Bertrand Fopak Lirima/Aloco University of Yaounde 1 Yaounde Cameroon Lirima/Masecness University of Yaounde 1 Yaounde Cameroon

In this paper, we propose MAMNID, a mobile agent-based model for networks incidents diagnosis. It is a load-balance and resistance to attack model, based on mobile agents to mitigate the weaknesses of centralized systems like that proposed by Mohamed Eid which consists in gathering data to diagnose from their collecting point and sending them back to the main station for analysis. The attack of the main station stops the system and the increase of the amount of information can equally be at the origin of bottlenecks or DDoS in the network. Our model is composed of m diagnostiquors, n sniffers and a multi-agent system (MAS) of diagnosis management of which the manager is elected in a cluster. It has enabled us not only to reduce the response time and the global system load by 1/m, but also make the system more tolerant to attacks targeting the diagnosis system.

关键词： Diagnosis Incident Intrusion MAMNID MAS