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Open Journal of Inorganic Chemistry 2021年第2期11卷 43-53页

作者： Alvine Loris Djoumbissie alain Clovis Tayo Djampouo Tanyi Rogers Fomuta Giscard Doungmo Golngar Djimassingar alain.charly tagn. kuate Jean Ngoune Department of Chemistry University of Dschang Dschang Cameroon Institute of Inorganic Chemistry Christian-Albrechts University of Kiel Kiel Germany Department of Chemistry Mongo Polytechnique University Institute (IUPM) Mongo Chad

Two novel copper complexes (1,2) with N,O-donor ligands were synthesized by reaction of copper(II) malonates with 3,3’-bis(pyrazolyl)pentane and 4,4’-trimethylenedipyridine in methanol at moderate temperature. These compounds were characterized by elemental analysis, UV-VIS, IR spectroscopies and powder X-ray diffraction analyses. Compound (1) melts at higher temperature (202°C) than compound (2) (100°C). The IR spectra showed typical vibrations related to C=N and C=C, characteristic of pyrazolyl and pyridine ligands.

关键词： Copper Malonate 3 3’-Bis(pyrazolyl)pentane 4 4’-Trimethylenedipyridine UV-Vis IR Powder X-Ray Diffraction

Synthesis, Structural Characterization and Computational Studies of Bis(2-Ethylimidazole) Bis(Formato)Zinc(II)-Water (1/1)

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Crystal Structure Theory and Applications 2018年第1期7卷 1-18页

作者： Nana Odette Ngnabeuye Tayo alain Djampouo Ndosiri Ndoye Bridget Tanyi Rogers Fomuta Djimassingar Golngar tagn. alain.charly kuate Ngoune Jean Department of Chemistry University of Dschang Dschang Cameroon Department of Inorganic Chemistry University of Yaounde I Yaounde Cameroon Department of Chemistry Mongo Polytechnique University Institute (IUPM) Mongo Chad

The reaction of 2-ethylimidazole and zinc formate monohydrate in 1:2 ratio in toluene leads to the formation of bis(2-ethylimidazole)bis(formato)zinc(II)-water (1/1), [Zn(N2H8C5)2(OCHO)2]·H2O, 1 which has been characterized by several techniques, including elemental and thermal analyses, IR, 1HNMR and 13CNMR spectroscopies, single crystal X-ray diffraction and DFT studies. The results obtained show that this complex crystallizes in the orthorhombic crystal system of the Pbca space group, with cell parameters a = 14.7230(2) Å, b = 7.3880(10) Å, c = 29.0843(4) Å, α = 90°, β = 90°, γ = 90°, V = 3163.73 Å3 and Z = 8. The zinc center is bound to two molecules of 2-ethylimidazole, two formate molecules in a tetrahedral coordination geometry. One water of crystallization is present in the coordination sphere of the compound. Its molecular crystalline structure is strengthened by O/N-H…O, O-H…π, O-H…H, C-H…O, H…π, π…O and π…π interactions. The optimized structure, frontier molecular orbitals, global reactivity descriptors, molecular electrostatic potential, natural bond orbitals and the Mulliken atomic charges were investigated through theoretical studies.

关键词： Zinc Complex 2-Ethylimidazole Hydrogen Bonds Thermogravimetric Analysis 1HNMR 13CNMR X-Ray Theoretical Studies

Synthesis, Characterization and DFT Studies of Two Zinc(II) Complexes Based on 2-Isopropylimidazole

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Open Journal of Inorganic Chemistry 2018年第4期8卷 105-124页

作者： Jean Jacques Anguile Odette Nana Ngnabeuye Ndosiri Ndoye Bridget Tanyi Rogers Fomuta Alvine Loris Djoumbissie alain.charly kuate tagn. Jean Ngoune Department of Chemistry University of Sciences & Techniques of Masuku Franceville Gabon Department of Chemistry University of Dschang Dschang Cameroon Department of Inorganic Chemistry University of Yaounde 1 Yaounde Cameroon

Two novel coordination compounds, [Zn(L)2(OOCH)2] (1) and [Zn(L)3(OCHO)](OCHO)]·H2O (2) (where L = 2-isopropylimidazole, C6H10N2) have been prepared by reaction of 2-isopropylimidazole with zinc(II) formate at room temperature using toluene as solvent. These compounds were characterized by elemental and thermal analyses, IR, 1HNMR and 13CNMR spectroscopies, single crystal X-ray diffraction and DFT studies. The Zn centers in 1 and 2 adopt pseudo-tetrahedral coordination geometries. Compound 1 crystallizes in the monoclinic system P2/c space group whereas compound 2 crystallizes in the P-1 space group of the triclinic crystal system. Several types of hydrogen intra-/intermolecular interactions are observed in these materials and extend into a two-dimensional leaf like network in 1 and a two-dimensional lattice of rectilinear pillars in 2. Compounds 1 and 2 were also optimized and their frontier molecular orbitals, global reactivity descriptors, molecular electrostatic potential, natural bond orbitals were investigated using density functional theory (DFT). In fact the induced structural differences from complex 1 to complex 2 led to the reduction of the frontier molecular orbital energy gap by 1.338 eV and a decrease of the chemical hardness by 0.669 eV.

关键词： Zinc(II) Complexes of 2-Isopropylimidazole Thermogravimetric Analysis 1H-MR 13C-MR Crystal Structure DFT Studies

Synthesis, Structural Characterization and Antimicrobial Activity of a Novel Cobalt(II) Complex Based on 3-Methyl-1-Phenyl-4-(2-Thienoyl)-Pyrazol-5-One

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Journal of Modern Physics 2023年第8期14卷 109-126页

作者： Emeline Sorelle Mefouegang Claudelle Sybilline Anensong Djadock Golngar Djimassingar Gabriel Tchuente Kamsu Donald Raoul Tchuifon Tchuifon alain.charly tagn. kuate Dirk Bockfeld Jean Ngoune Research Unit of Noxious Chemistry and Environmental Engineering Department of Chemistry Faculty of Science University of Dschang Dschang Cameroon Department of Fundamental Sciences Mongo Polytechnique University Institute (IUPM) Mongo Chad Research Unit of Microbiology and Antimicrobial Substances Department of Biochemistry Faculty of Science University of Dschang Dschang Cameroon Department of Process Engineering Laboratory of Energy Materials Modeling and Method National Higher Polytechnic School of Douala University of Douala Douala Cameroon Institute of Inorganic and Analytical Chemistry Technical University of Braunschweig Braunschweig Germany

New cobalt(II) complex, [Co(O2C15H11N2S)2(OH2)2]∙2H2O (1∙2H2O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)2∙6H2O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H2O. Compound 1∙2H2O crystallizes in the orthorhombic crystal system with a Pbca space group and with the cobalt atom being pseudo-octahedral coordinated. The broth microdilution technique was used to screen the free ligand (HL) and the complex (1∙2H2O) for antimicrobial activities. HL has a low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound 1∙2H2O displayed moderate activity (10 ∙2H2O exhibited bactericidal and fungicidal activity respectively on all the bacteria and yeasts tested. These findings reveal that the antimicrobial activity of HL was enhanced upon coordination to Co(II) ion against all microorganisms (bacteria and fungus).

关键词： Cobalt Acylpyrazolone X-Ray Diffraction Antimicrobial Activity 3-Methyl-1-Phenyl-4-(2-Thienoyl)-Pyrazol-5-One

Suicidal Behaviours in Sickle Cell Patients at the Douala Sickle Cell Care Centre in Cameroon

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Open Journal of Psychiatry 2024年第3期14卷 265-281页

作者： Christian Eyoum Léonce Kengno Kologne Charlotte Eposse Ekoube Annick Mélanie Magnerou Joséphine Manga Befolo Cindy Laura Ndepa Daniel Gams Massi Aurore Nzesseu Djomo Guy Jonas Basseguin Atchou Guy Calvin Mbongo’O Rihta Mbono Mbekoto Iyawa Hassanatou Fabiola Tchouankeu Kounga Christiane Medi Sike Josiane Essola Jacques Narcisse Doumbe Erero Njiengwe Callixte kuate Tegueu Faculty of Medicine and Pharmaceutical Sciences University of Douala Douala Cameroon Laquintinie Hospital Douala Cameroon Faculty of Health Sciences University of Buea Buea Cameroon Faculty of Medicine and Biomedical Sciences University of Yaound&#233 1 Yaound&#233 Cameroon

Introduction: Sickle cell anaemia is a hereditary disease that combines physical and psychological manifestations, including suicidal tendencies. So far, to our knowledge, no study has been conducted on suicidal behaviours among people with sickle cell disease in Cameroon. This is what justifies our study on the prevalence and factors related to suicidal behaviors in our study population. Methods: We conducted a cross-sectional, analytical study of 171 sickle cell patients aged from 12 years upwards who came to the sickle cell disease care service of the Laquintinie Hospital in Douala, over a period of 6 months, that is, from 1 January to 31 June 2022. Data were collected using a structured questionnaire with questions on suicidal behaviours based on the “MINI” (Mini International Neuropsychiatric Interview). The data were processed using the SPSS 26.0 software. The related factors were studied in both a bivariate and multivariate analysis. Results: Female sickle cell patients accounted for 60.2% of the sample. The mean age was 23.36 ± 8.42 years. Suicidal ideation was prevalent in 56% of cases and 13% attempted suicide. The factors most associated with suicidal ideation were: primary level of education (OR = 0.08 (0.09 - 0.79);p = 0.03), feeling unworthy of life (OR = 0.40 (0.08 - 1.96);p = 0.02), not often being considered by those around them (OR = 2.97 (1.26 - 6.99);p = 0.01), lack of family support (OR = 0.34 (0.15 - 0.77);p = 0.01). Meanwhile, the factors associated with suicide attempts were: the fact of being rarely exposed to suicide-related media (OR = 4.17 (1.40 - 71.80);p = 0.03), and a constant feeling of sadness when returning home (OR = 18.02 (1.59 - 20.55);p = 0.01). Conclusion: More than half of sickle cell patients had had suicidal thoughts and 1/6 had made at least one suicide attempt, women and young adults being the most concerned. It is therefore necessary to ensure optimum psychological care for patients with sickle cell disease.

关键词： Sickle Cell Disease Suicidal Behaviours Self-Harm

Synthesis and Structural Characterization of a New Two-Dimensional Polymeric Hybrid Material {[Cu3(μ3-1,2,3-BTC)(μ2-1,2,3-BTC)(en)3(OH2)2(OH)(μ2-OH2)]2·5H2O·O}n

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Open Journal of Inorganic Chemistry 2020年第4期10卷 52-62页

作者： Alvine L. Djoumbissie Francis W. Njifack alain T. Djampouo Tanyi R. Fomuta Golngar Djimassingar alain C. tagn. kuate Jean Ngoune Department of Chemistry Faculty of Science University of Dschang Dschang Cameroon Department of Chemistry Mongo Polytechnique University Institute (IUPM) Mongo Chad

The reaction of benzene-1,2,3-tricarboxylate copper(II) trihydrate (Cu3(1,2,3-BTC)2·3H2O) and ethylenediamine (en) gave after recrystallization from methanol at room temperature violet crystalline solid of the polymeric two dimensional material {[Cu3(μ3-1,2,3-BTC)(μ2-1,2,3-BTC)(en)3(OH2)2(OH)(μ2-OH2)]2·5H2O·O}n (1) as identified by single crystal X-ray diffraction analysis. The compound was also characterized by elemental analysis, FT-IR spectroscopy, UV-vis spectroscopy, thermogravimetric analysis (TGA) and magnetic susceptibility. The molecular structure indicates crystallization in the triclinic space group P-1 with the unit cell parameters a = 12.1205(3) Å, b = 12.7026(3) Å, c = 13.9890(3) Å, α = 75.034(1)°, β = 74.957(1)°, γ = 68.415(1)°. Structural analysis also revealed that the dimeric compound is connected by Cu-O-Cu bridges and the dimer is further converted into a polymeric chain structure through bridging of one benzene-1,2,3-tricarboxylate ligand. Different coordination modes are observed at the copper atom. The Cu atom at the center is octahedral while the two other ones are pentacoordinated. Thermal analysis of the compound showe

关键词： Copper Ethylenediamine Benzene-1 2 3-Tricarboxylate Coordination Polymer Magnetism

Stroke Associated with Covid-19 at the YaoundéGeneral Hospital, Cameroon: Series of 10 Cases

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World Journal of Neuroscience 2021年第3期11卷 221-230页

作者： Paul-Cédric Mbonda Victor Sini Jose Kamgang Hadja Cherif alain Menanga Victor Eyenga Callixte kuate Vincent de Paul Djientcheu Faculty of Medicine and Biomedical Sciences University of Yaoundé 1 Yaoundé Cameroon Neurology Department Yaoundé General Hospital Yaoundé Cameroon Emergencies Department Yaoundé General Hospital Yaoundé Cameroon Infectious diseases Department Yaoundé General Hospital Yaoundé Cameroon

Background: The Covid-19 pandemic, which is an infection due to the SARS Cov-2 virus, mainly causes severe damage to the respiratory system, but several studies have reported neurological damage with different manifestations including headaches, seizures, encephalopathies, and stroke. We report a series of 10 patients infected with Covid-19 who had an ischemic stroke at the Yaoundé General Hospital, Cameroon. Patients and Methods: We carried out a prospective study for 12 months between April 2020 and March 2021 by collecting data from patients admitted for Covid-19 at the Yaoundé general hospital. Were included all patients with a diagnosis of stroke confirmed by brain imaging (CT/MRI) following a focal neurological deficit of sudden onset and whose test (nasopharyngeal swab confirmed by PCR) for Covid-19 was positive. Patients diagnosed with a stroke more than 2 weeks (14 days) after the positive Covid-19 PCR test were excluded. Results: The prevalence of ischemic stroke in this hospital-based series was 1.46%. These were six men and four women. The mean NIHSS score was 13.57. The average age of our patients was 58 years. Brain imaging was performed in each patient revealing hypodense lesion in a large arterial territory in 8 of them, for two patients we found multilacunar infarcts. All patients had negative HIV serology and D-dimers greater than 500 μg/L. Conclusion: This work on strokes in Covid-19 infected patients shows that it is a fairly frequent neurological complication, which can occur even in young subjects without known risk factors, the symptoms of viral infection are not systematically present before the onset of stroke.

关键词： Covid-19 Stroke Ischemia

Parasympathetic Dysfunction in Black African Patients with Heart Failure:A Cross-Sectional Study in Sub-Saharan Africa

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World Journal of Cardiovascular Diseases 2020年第4期10卷 178-187页

作者： Ba Hamadou Sylvie Ndongo Amougou Ismaila Daouda Chris Nadege Nganou-Gnindjio Liliane Mfeukeu-kuate Jerome Boombhi Ahmadou Musa Jingi alain Menanga Samuel Kingue Department of Medicine and Specialties Faculty of Medicine and Biomedical SciencesUniversity of Yaounde IYaoundeCameroon Cardiology Unit Central Hospital of YaoundeYaoundeCameroon Cardiology Unit University Teaching Hospital of YaoundeYaoundeCameroon Faculty of Medicine and Biomedical Sciences University of Yaounde IYaoundeCameroon Cardiology Unit Medicine BGeneral Hospital of YaoundeYaoundeCameroon

Background: Heart Failure (HF) is a major public health problem worldwide. Neurohormonal changes associated with HF are current therapeutic targets. The parasympathetic system in HF has not been well studied especially in black Africans. Aim: This study aimed to report on the prevalence and determinants of parasympathetic dysfunction in patients with heart failure in sub-Saharan Africa. Methods: We conducted a cross-sectional study between December 2017 and April 2018 in the outpatient and inpatient departments in two teaching hospitals in Yaounde-Cameroon. Cases were patients with HF matched with controls without HF according to age, sex, and risk factors (hypertension, diabetes, and obesity). We assessed the parasympathetic function via the Deep Breathing Test using an electrocardiograph. Results: We recruited 35 patients in each group. The mean age was 57 ± 11.68 years. Vagal dysfunction was seen in 51.4% of cases and 11.4% of controls (aOR: 10.1 [95% CI: 2.7 - 38.3], p = 0.001). This risk increased with the severity of HF-aOR: 11.8, [95% CI: 1.8 - 77.9], p = 0.01 for dyspnea stage III-IV, and aOR: 9.27, [95% CI: 1.3 - 65.3], p = 0.025) for HF with reduced Ejection fraction. This risk was not associated with the classic cardiovascular risk factors. Conclusion: Parasympathetic dysfunction as assessed with the Deep Breathing Test was seen in over half of the patients with HF and this was associated with the severity and type of HF.

关键词： Heart Failure Parasympathetic Dysfunction Heart Rate Variability Deep Breathing Test

Analysis of the Behavior of a Square Plate in Free Vibration by FEM in Ansys

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World Journal of Mechanics 2020年第2期10卷 11-25页

作者： Pascal kuate Nkounhawa Dieunedort Ndapeu Bienvenu Kenmeugne Tibi Beda Department of Physics Faculty of Sciences University of Dschang Dschang Cameroon Dschang University/IUT-FV Bandjoun Dschang Cameroon National Advanced School of Engineering (ENSP) Yaounde Department of Industrial and Mechanical Engineering University of Yaounde I Yaounde Cameroon Department of Physics Faculty of Sciences University of Ngaoundere Ngaoundere Cameroon

In the realization of mechanical structures, achieving stability and balance is a problem commonly encountered by engineers in the field of civil engineering, mechanics, aeronautics, biomechanics and many others. The study of plate behavior is a very sensitive subject because it is part of the structural elements. The study of the dynamic behavior of free vibration structures is done by modal analysis in order to calculate natural frequencies and modal deformations. In this paper, we present the modal analysis of a thin rectangular plate simply supported. The analytical solution of the differential equation is obtained by applying the method of separating the variables. We are talking about the exact solution of the problem to the limit values. However, numerical methods such as the finite element method allow us to approximate these functions with greater accuracy. It is one of the most powerful computational methods for predicting dynamic response in a complex structure subject to arbitrary boundary conditions. The results obtained by MEF through Ansys 15.0 are then compared with those obtained by the analytical method.

关键词： Free Vibration Vibration Modes Modal Analysis Natural Frequencies Modal Deformations Thin Rectangular Plate Finite Element Method (FEM)

Effect of Therapeutic Group Education on Adherence and Blood Pressure Control among Uncontrolled Hypertensive Patients in Sub Saharan Africa

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World Journal of Cardiovascular Diseases 2018年第3期8卷 183-195页

作者： Chris Nadege Nganou-Gnindjio Heloise Guidelle Kenmogne Domning Liliane Mfeukeu-kuate Ba Hamadou Felicite Kamdem Georges Bediang Aurel T.Tankeu alain Patrick Menanga Samuel Kingue Faculty of Medicine and Biomedical Sciences University of Yaounde IYaoundeCameroon Cardiology Unit Yaounde Central HospitalYaoundeCameroon Faculty of Health Sciences Universite des MontagnesBangangteCameroon Faculty of Medicine and Pharmaceutical Sciences University of DoualaDoualaCameroon Internal Medicine Department Douala General HospitalDoualaCameroon Internal Medicine Department Yaounde General HospitalYaoundeCameroon

Background: Hypertension is the leading cardiovascular risk factor worldwide, with the greatest burden in low-income settings. Blood pressure (BP) control is usually low resulting in high rates of uncontrolled patients and complications. Low awareness resulting in poor therapeutic adherence represents an important factor for insufficient blood pressure control in developing countries. Methods: This was a three months non-randomized control trial at the cardiology clinic of the Yaoundé Central Hospital. We included adults with essential and uncontrolled hypertension. The intervention consisted of group educative sessions every week focusing on knowledge of hypertension risk factors, complications, treatment, comorbidities, home self-monitoring of BP. Home blood pressure figures, drug compliance, and knowledge regarding hypertension were evaluated before and after. Results: 17 participants (8 women) with a mean age 56.2 ± 8.1 years. During intervention, mean SBP decreased by 30 mmHg while mean DBP drooped by 11 mmHg using home BP measures. Knowledge regarding hypertension, adherence and drug compliance increased by 36.5%, 88.2% and 81.4% respectively. Conclusion: Therapeutic group education resulted in a significant improvement in BP control amongst uncontrolled hypertensive patients in sub Saharan Africa.

关键词： Therapeutic Group Education Hypertension Adherence Knowledge