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Antioxidant and antiglycation properties of two mango(Mangifera indica L.) cultivars from Senegal

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Asian Pacific Journal of Tropical Biomedicine 2018年第3期8卷 137-141页

作者： Samba Fama Ndoye Didier Fraisse Blandine Akendengue Mbaye Diaw Dioum Rokhaya Sylla Gueye Cheikh Sall Insa seck Catherine Felgines Matar seck Francois Senejoux Laboratory of Organic and Therapeutic Chemistry Faculty of Medicine Pharmacy and Odontology Cheikh Anta Diop University Universite Clermont Auvergne INRAUNH Department of Pharmacology and Toxicology Faculty of Medicine and Health Sciences (USS) Laboratory of Chemistry Training and Research Unit of Health Thies University

Objective: To evaluate the total phenolic contents, antioxidant and antiglycation activities of leaves, barks, roots and kernels from two cultivars of Mangifera indica(Anacardiaceae). Methods: Total phenolic contents were determined by using Folin-Ciocalteu's method. The antioxidant activities were assessed by three different protocols including DPPH, oxygen radical absorbance capacity and iron(Ⅱ) chelation assays. In addition, in vitro bovine serum albumin/D-ribose assay was chosen to evaluate the antiglycation properties of the extracts. Results: All the investigated extracts were found to contain high level of total phenols as well as potent antioxidant activities. Kernel extracts showed the highest total phenol contents and DPPH radical scavenging activities whereas higher oxygen radical absorbance capacity values were observed for leave, root and bark extracts. Besides, extracts from leaves, roots and barks from both cultivars exhibited potent inhibitory effects against the formation of advanced glycation end products, with IC_(50) values lower than the standard positive control aminoguanidine. Conclusions: The potent antiglycation and antioxidative activities of these two Mangifera indica cultivars suggest a possible role in targeting aging, diabetic complications and oxidative stress related diseases.

关键词： Mangifera indica Cultivars Polyphenols Antioxidant Antiglycation

Numerical Approach of Network Problems in Optimal Mass Transportation

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Applied Mathematics 2012年第5期3卷 457-466页

作者： Lamine Ndiaye Babacar Mbaye Ndiaye Pierre Mendy Diaraf seck Laboratory of Mathematics of Decision and Numerical Analysis (LMDAN) FASEG University of Cheikh Anta Diop Dakar Senegal Unité Mixte Internationale UMMISCO Institut de Recherche pour le Développement Bondy France

In this paper, we focus on the theoretical and numerical aspects of network problems. For an illustration, we consider the urban traffic problems. And our effort is concentrated on the numerical questions to locate the optimal network in a given domain (for example a town). Mainly, our aim is to find the network so as the distance between the population position and the network is minimized. Another problem that we are interested is to give an numerical approach of the Monge and Kantorovitch problems. In the literature, many formulations (see for example [1-4]) have not yet practical applications which deal with the permutation of points. Let us mention interesting numerical works due to e. Oudet begun since at least in 2002. He used genetic algorithms to identify optimal network (see [5]). In this paper we introduce a new reformulation of the problem by introducing permutations . And some examples, based on realistic scenarios, are solved.

关键词： Optimal Mass Transportation Network Urban Traffic Monge-Kantorovich Problem Global Optimization

Contribution to the Analytical equation Resolution Using Charts for Analysis and Design of Cylindrical and Conical Open Surge Tanks

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Journal of Water Resource and Protection 2015年第15期7卷 1242-1256页

作者： Aboudou seck Musandji Fuamba Department of Civil Geological and Mining Engineering Polytechnique Montréal 2500 Chemin de Polytechnique Montreal QC Canada Department of CGeM Polytechnique Montréal Succursale Centre Montréal Canada

In the event of an instantaneous valve closure, the pressure transmitted to a surge tank induces the mass fluctuations that can cause high amplitude of water-level fluctuation in the surge tank for a reasonable cross-sectional area. The height of the surge tank is then designed using this high water level mark generated by the completely closed penstock valve. Using a conical surge tank with a non-constant cross-sectional area can resolve the problems of space and height. When addressing issues in designing open surge tanks, key parameters are usually calculated by using complex equations, which may become cumbersome when multiple iterations are required. A more effective alternative in obtaining these values is the use of simple charts. Firstly, this paper presents and describes the equations used to design open conical surge tanks. Secondly, it introduces user-friendly charts that can be used in the design of cylindrical and conical open surge tanks. The contribution can be a benefit for practicing engineers in this field. A case study is also presented to illustrate the use of these design charts. The case study’s results show that key parameters obtained via successive approximation method required 26 iterations or complex calculations, whereas these values can be obtained by simple reading of the proposed chart. The use of charts to help surge tanks designing, in the case of preliminary designs, can save time and increase design efficiency, while reducing calculation errors.

关键词： Hydraulic Transients Surge Tank Water Hammer First-Order Non-Homogeneous Differential equation with Variables Coefficients Friendly Charts

Prevalence and outcomes of polycystic kidney disease in African populations:A systematic review

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World Journal of Nephrology 2024年第1期13卷 33-40页

作者： Modou Ndongo Lot Motoula Nehemie Baratou Coundoul Abou Abdallah Malick Diouara Sidy Mohamed seck Department of Nephrology and Dialysis Regional Hospital of KedougouKedougou 26005Senegal Department of Nephrology and Dialysis Military Hospital of OuakamDakar 28216Senegal Department of Chemical engineering and Applied Biology Polytechnic high School of Cheikh Anta Diop UniversityDakar 5085Senegal Department of Nephrology Faculty of Health SciencesUniversity Gaston BergerSaint-Louis 234Senegal

BACKGROUND Polycystic kidney disease(PKD)is the most common genetic cause of kidney *** is a progressive and irreversible condition that can lead to end-stage renal disease and many other visceral *** comprehensive data on PKD patterns in Africa is *** To describe the prevalence and outcomes of PKD in the African *** A literature search of PubMed,African journal online,and Google Scholar databases between 2000 and 2023 was *** Preferred Reporting Items for Systematic Reviews and Meta-Analyses were followed to design the *** presentations and outcomes of patients were extracted from the included *** Out of 106 articles,we included 13 studies from 7 African *** of them were retrospective descriptive studies concerning 943 PKD patients with a mean age of 47.9 *** accurate prevalence and incidence of PKD were not known but it represented the third causal nephropathy among dialysis *** majority of patients,the diagnosis of the disease was often *** function impairment,abdominal mass,and hypertension were the leading symptoms at presentation with a pooled prevalence of 72.1%(69.1-75.1),65.8%(62.2-69.4),and 57.4%(54.2-60.6)*** and infections were the most frequent *** was performed in few studies that revealed a high proportion of new mutations mainly in the PKD1 *** The prevalence of PKD in African populations is not clearly *** symptoms were almost present with most patients who had kidney function impairment and abdominal mass at the *** studies including genetic testing are needed to determine the burden of PKD in African populations.

关键词： Polycystic kidney disease Africa Genetic disorder Systematic review

Dirichlet-to-Neumann Map for a Hyperbolic equation

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Journal of Applied Mathematics and Physics 2023年第8期11卷 2231-2251页

作者： Fagueye Ndiaye Mouhamadou Ngom Diaraf seck Department of Mathematics Cheikh Anta Diop University Dakar-Fann Senegal Alioune Diop University Bambey Senegal Cheikh Anta Diop University of Dakar Dakar Fann Senegal

In this paper, we provide an explicit expression for the full Dirichlet-to-Neumann map corresponding to a radial potential for a hyperbolic differential equation in 3-dimensional. We show that the Dirichlet-Neumann operators corresponding to a potential radial have the same properties for hyperbolic differential equations as for elliptic differential equations. We numerically implement the coefficients of the explicit formulas. Moreover, a Lipschitz type stability is established near the edge of the domain by an estimation constant. That is necessary for the reconstruction of the potential from Dirichlet-to-Neumann map in the inverse problem for a hyperbolic differential equation.

关键词： Hyperbolic Differential equation Calderón’s Problem Schrödinger Operator Potential Inverse Potential Problem Dirichlet-to-Neumann Map Numerical Simulations Lipschitz Stability

Minimal Time of Null Controllability for the 1D Heat equation by a Strategic Zone Profile

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Journal of Applied Mathematics and Physics 2021年第7期9卷 1707-1717页

作者： Cheikh seck Mame Libasse Laye Ane Département de Mathématiques de la FASTeF ex eNS de l’Université Cheikh Anta Diop de Dakar Dakar Sénégal Laboratoire d’Analyse Numérique et d’Informatique (LANI) de l’UFR SAT de l’Université Gaston Berger de Saint-Louis Saint-Louis Sénégal Département de mathématiques et d’Informatique de la Faculté des Sciences et Techniques de l’Université Cheikh Anta Diop de Dakar Dakar Sénégal

The aim of this work is to improve the minimum time of null controllability of the 1D heat equation by using the notion of strategic zone actuators. In fact, motivated by the work of Khodja on the null controllability of the heat equation and of el Jai on the controllability by the use of strategic zone actuators, we managed, in this work, to improve the minimal time of null controllability to the 1D heat equation. However, the restrictions and difficulties to establish the inequality of coercivity of the parabolic operator, require to seek other methods of internal control. Thus in this paper, a mixed method combining the method of moments and the notion of strategic profile was used to find a better minimal time of null controllability of the 1D heat equation.

关键词： Control Null Controllability Moment Methods estimations Strategic Actuator

中国外企与合资企业中方中层经理频繁跳槽之原因探析

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中国外企与合资企业中方中层经理频繁跳槽之原因探析

作者： Mamadou seck 北京交通大学

学位级别：硕士

员工跳槽现象在中国极为普遍,在中国保留关键的中层管理人员也是人力资源管理的一大难点,因为在跨国人才市场上人才不仅飞走了,而且他们飞走得很快。本篇硕士论文旨在探讨中国的中层管理人员在国内的合资企业和跨国公司中主动跳槽真正... 详细信息

员工跳槽现象在中国极为普遍,在中国保留关键的中层管理人员也是人力资源管理的一大难点,因为在跨国人才市场上人才不仅飞走了,而且他们飞走得很快。本篇硕士论文旨在探讨中国的中层管理人员在国内的合资企业和跨国公司中主动跳槽真正诱因或根源,并提出一些相应的建议以解决这个管理层面的问题.该项研究的结果将会有助于国际性公司的人力资源经理确保他们的整体人才战略是合理的,能够很好的满足员工在生理、安全、社会、尊重以及自我实现等多方面的。通过涵盖组织、环境和人员组成这三方面因素的调查问卷,我们进行了一项定性研究。调查结果表明,与环境因素相比而言,组织因素是中国中层管理人员跳槽主要因素。而且,该项调查结果还表明,和新员工相比老员工更加稳定,不会轻易跳槽;和男性员工相比,女性员工跳槽的机会更大。人力资源经理应该利用各种工具和模型,比如Lee ***和Terrence ***关于如何重新架构组织的理论,以及AbrahamMaslow的需求层次理论,以便将导致员工跳槽的各种因素的真正根源进行分类和研究,进而通过匹配组织环境和员工的合理期望的方法来解决上述难题。

关键词：跳槽中国中层管理人员跨国公司合资企业

Spectroscopic electrochemical Properties and DFT Calculation of 1-Aryltriazenes

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International Journal of Organic Chemistry 2023年第4期13卷 109-128页

作者： Insa seck Mohamed Lamine Sall Atoumane Ndiaye Samba Fama Ndoye Lalla Aïcha Ba Matar seck Organic Chemistry Coordination Laboratory Cheikh Anta Diop University of Dakar Dakar-Fann Senegal Organic Chemistry and Therapeutic Chemistry Laboratory Cheikh Anta Diop University of Dakar Dakar-Fann Senegal Organic Physical Chemistry and environmental Analysis Laboratory Cheikh Anta Diop University of Dakar Dakar-Fann Senegal Department of Physics Cheikh Anta Diop University of Dakar Dakar-Fann Senegal Amadou Mahtar Mbow University Dakar Nafa VDN Senegal

electrochromic materials are of great interest for their potential in eyewear protection and data storage devices, as they change colors in response to electrochemical switching. While many of the systems currently used are based on inorganic materials, organic materials such as triazenes have emerged as viable alternatives due to their unique properties, including optical properties. Triazenes are a class of organic compounds with three consecutive nitrogen atoms in an acyclic arrangement, and they have been used for a variety of applications in medicinal and synthetic chemistry. However, the effects of solvents on the UV-visible absorption spectrum of triazenes have not been fully investigated. The neutral molecules of 3,3-diisopropyl-1-phenyltriazene and 1-(4-chlorophenyl)-3-cyclopentyltriazene in acetonitrile, the UV-visible spectra corresponded respectively to HOMO → LUMO transitions with a large maximum absorption at 299.74 nm (4.1364 eV) and 299.57 nm (4.1387 eV) and the most intense oscillator strength (f = 0.6988) and (f = 0.7372). These results suggest that the electronic transitions of the compounds are highly influenced by the nature of the substituents on the triazene unit, as well as the solvent used in the experiment. The redox couple 0.92 and -0.44 V/Ag/AgCl is attributed to the phenyl group. Compound III showed an oxidation and reduction peak respectively -0.27 and -0.8 V/Ag/AgCl attributed to the phenyl molecule. The study concluded that all three compounds were electroactive and exhibited reversible characteristics with oxidizing/reducing couples. This study aims to contribute to research on the optical properties of triazenes compounds and the application of quantum chemical calculation methods for understanding their molecular structures. By investigating the solute-solvent interactions occurring in the solvation shell of the solutes, we aim to gain insights into the effects of solvents on the UV-visible absorption spectrum of triazenes. Our fin

关键词： Triazenes UV-Visible Spectroscopy electrochemical DFT Calculations

Improved Resistance to Cracking of a Cement Mortar through the Incorporation of Crumb Rubber

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Journal of Physical Science and Application 2017年第3期7卷 37-40页

作者： Moulay Smaine Ghembaza Mbaye seck Laboratory of Civil engineering and environment University Djillali Liabes Sidi BelAbbes 22000 Algeria

Within a context of sustainable development, innovative processes for various applications to recycle rubber are put in place to make aggregates or crumb rubber. These uses include sports floor coverings, to manufacture of sealants, sound absorbing walls, to make roads, as an alternative fuel in cement kilns, etc. In this study, the addition of crumb rubber to mortar was investigated through optical and mechanical tests. The results showed that the incorporation of crumb rubber from used tires into mortar produced a better resistance to shrinkage cracking, but a compressive strength/tensile is reduced. This feature could lend itself to making playgrounds and sports grounds more absorbing and flexible, which would allow a more significant fall to be withstood without injury and consequently enhance the safety of playgrounds.

关键词： Max. resistance cracking cement mortar crumb rubber.