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Pharmacochemical Aspects of the Evolution from Erythromycin to Neomacrolides, Ketolides and Neoketolides

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Open Journal of Medicinal Chemistry 2020年第3期10卷 57-112页

作者： ouattara mahama Coulibaly Songuigama N’Guessan Deto Jean-Paul Department of Therapeutic Chemistry and Organic Chemistry UFR Pharmaceutical and Biological Sciences FHB University Abidjan C&#244 te d’Ivoire

Antibiotic macrolides are experiencing renewed interest in anti-infective therapy since the advent of ketolides. This therapeutic class was introduced in order to broaden the narrow antibacterial spectrum of macrolides and to cope with the emergence of germs resistant to Erythromycin A and its hemisynthetic derivatives or neomacrolides (Clarithromycin, Roxithromycin, Azithromycin, Dirithromycin). From a pharmacochemical point of view, ketolides were first of all obtained by operating chemical modulations on Erythromycin A to obtain the neomacrolides, then, by replacing the neutral sugar (L-cladinose) in C3 by a ketone function coupled with the creation of an oxazolidinone like heterocycle in C11 and C12 in place of the hydroxyls present in these positions (Telithromycin, Cethromycin, Solithromycin). These modulations have enabled the improvement of the chemical stability of ketolides in gastric acid medium and increase their affinity for the ribosomal target, hence the broadening of their spectrum of action towards Gram positive germs including strains resistant to other macrolides and to neomacrolides. Therefore, the objective of this systematic review is to report the various pharmacochemical aspects undertaken since 1952 in the macrolide series based on the structure of Erythromycin A. These aspects will focus on the pharmacomodulations that have led, year after year, to the optimization of stability, the improvement of the pharmacodynamic and pharmacokinetic profile and that have allowed the development of neomacrolides, ketolides and neoketolides, which are today essential in the management of severe bronchopulmonary infections.

关键词： Pharmacochemistry Erythromycin Neomacrolide Ketolide Neoketolide Structure-Activity Relationships

Anticancer Activities and QSAR Study of Novel Agents with a Chemical Profile of Benzimidazolyl-Retrochalcone

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Open Journal of Medicinal Chemistry 2020年第3期10卷 113-127页

作者： ouattara mahama Koné Aboudramane Koné Soleymane Collet Sylvain Diomandé Sekou Sissouma Drissa Department of Therapeutic Chemistry and Organic Chemistry UFR SPB FHB University Abidjan C&#244 te d’Ivoire Department of Chemistry UFR Environment Jean LorougnonGuédé University Daloa C&#244 te d’Ivoire Laboratory of Organic Chemistry and Natural Substances UFR SSMT FHB University Abidjan C&#244 te d’Ivoire Chemistry and Interdisciplinarity: Synthesis Analysis Modelling (CEISAM) University of Nantes Nantes France

The present pharmacochemical and modelling work focused on a benzimidazolyl-chalcone series. These previously synthesized compounds were evaluated in vitro for their anticancer activities against a panel of seven human cancer cell lines and normal fibroblasts. Among the new benzimidazole-supported chalcones, nine (9) compounds (compounds 1 - 4, 6 - 8 and compounds 10 and 11) showed promising anticancer activities with IC50s ranging from 0.83 to 2.58 μM. Compounds 2 and 6 with IC50s of 0.83 and 0.86 μM, respectively, were shown to be potent inhibitors of HCT-116 colon cancer cell proliferation. It was therefore necessary, for a development of this new series of chalcones, to establish through a QSAR study, their quantum descriptors according to the DFT calculation method and following the B3LYP/6-31+G (d,p) theory. These descriptive and predictive studies focused on the colon HCT 116 cell line which was found to be more sensitive to the anticancer action of our benzimidazolyl-retrochalcones. QSAR study showed that the electronic energy (Eelec), lipophilicity (logP), chemical softness (S) and chemical hardness (η) of benzimidazolyl-retrochalcones play an important role in inhibiting cancer cell proliferation.

关键词： Retrochalcone Benzimidazole Anticancer Agents QSAR Quantum Descriptors DFT Method

DNA Barcoding of Insects and Its Direct Application for Plant Protection

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Open Journal of Applied Sciences 2024年第3期14卷 676-686页

作者： Peter Quandahor Iddrisu Yahaya Francis Kusi Issah Sugri Julius Yirzagla Abdul Karim Alhassan Jerry A. Nboyine George Y. mahama Godwin Opoku Mohammed Mujitaba Dawuda Asieku Yahaya Theophilus Kwabla Tengey Rofela Combey John Abraham CSIR-Savanna Agricultural Research Institute Tamale Ghana Faculty of Agriculture Food and Consumer Science University for Development Studies Tamale Ghan Department of Conservational Biology and Entomology School of Biological Sciences University of Cape Coast Ghana

The introduction of invasive insect pests across national borders has become a major concern in crop production. Accordingly, national plant protection organizations are challenge to reinforce their monitoring strategies, which are hampered by the weight and size of inspection equipment, as well as the taxonomic extensiveness of interrupted species. Moreover, some insect pests that impede farmer productivity and profitability are difficult for researchers to address on time due to a lack of appropriate plant protection measures. Farmers’ reliance on synthetic pesticides and biocontrol agents has resulted in major economic and environmental ramifications. DNA barcoding is a novel technology that has the potential to improve Integrated Pest Management decision-making, which is dependent on the ability to correctly identify pest and beneficial organisms. This is due to some natural traits such as phenology or pesticide susceptibility browbeaten by IPM strategies to avert pest establishment. Specifically, Deoxyribonucleic acid (DNA) sequence information was applied effectively for the identification of some micro-organisms. This technology, DNA barcoding, allows for the identification of insect species by using short, standardized gene sequences. DNA barcoding is basically based on repeatable and accessible technique that allows for the mechanisation or automation of species discrimination. This technique bridges the taxonomic bio-security gap and meets the International Plant Protection Convention diagnostic standards for insect identification. This review therefore discusses DNA barcoding as a technique for insect pests’ identification and its potential application for crop protection.

关键词： DNA Barcoding Integrated Pest Management Taxonomy Biosecurity Crop Protection

A deep semantic segmentation-based algorithm to segment crops and weeds in agronomic color images

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Information Processing in Agriculture 2022年第3期9卷 355-364页

作者： Sovi Guillaume Sodjinou Vahid Mohammadi Amadou Tidjani Sanda mahama Pierre Gouton Institute of Mathematics and Physical Sciences University of Aboney CalaviDangboBenin ImViA UFR Sciences et TechniquesUniversite de BourgogneFranche-ComteDijonFrance

In precision agriculture,the accurate segmentation of crops and weeds in agronomic images has always been the center of *** methods have been proposed but still the clean and sharp segmentation of crops and weeds is a challenging issue for the images with a high presence of *** work proposes a segmentation method based on the combination of semantic segmentation and K-means algorithms for the segmenta-tion of crops and weeds in color *** images of two different databases were used for the segmentation *** the thresholding technique,everything except plants was removed from the ***,semantic segmentation was applied using U-net followed by the segmentation of crops and weeds using the K-means subtractive *** comparison of segmentation performance was made for the proposed method and K-Means clustering and superpixels *** proposed algorithm pro-vided more accurate segmentation in comparison to other methods with the maximum accuracy of equivalent to 99.19%.Based on the confusion matrix,the true-positive and true-negative values were 0.9952 and 0.8985 representing the true classification rate of crops and weeds,*** results indicated that the proposed method successfully provided accurate and convincing results for the segmentation of crops and weeds in the images with a complex presence of weeds.

关键词： Weed coverage Semantic segmentation Convolutional neural network Subtractive clustering algorithm Simple Linear Iterative Clustering (SLIC) K-means

Design of a Flagging Protocol for a Cooperative Adaptive Cruise Control Lane Change

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Design of a Flagging Protocol for a Cooperative Adaptive Cru...

作者： Halid mahama 北京工业大学

学位级别：硕士

在汽车自动化研究领域中，自适应协调巡航控制(CACC)已经得到了广泛的研究。自适应协调巡航控制可以追溯到几十年前，这一新的研究领域已经变得非常流行，随着全球车辆运输系统增多，交通拥堵和事故发生变得更加频繁，因此，不仅需要汽... 详细信息

在汽车自动化研究领域中，自适应协调巡航控制(CACC)已经得到了广泛的研究。自适应协调巡航控制可以追溯到几十年前，这一新的研究领域已经变得非常流行，随着全球车辆运输系统增多，交通拥堵和事故发生变得更加频繁，因此，不仅需要汽车制造商不断创新，更重要的是强烈需要自动化汽车和公路配套设施。CACC是传统巡航控制系统的一个分支，其中所涉及的车辆间通过无线通信交换他们的位置和速度信息，而不是通过自适应巡航控制技术单独的控制各车辆，这使得自适应协调巡航控制不那么复杂。提出了一种有效的控制模式，其中采用滑模控制处理不明确的交通状况，并选择一种梯形加速度曲线，同时考虑横向运动和加速度对驾驶员的舒适性影响。还考虑了各种情景变换车道的时间和每个场景需要换道开始之前应满足的安全性等条件。换道协议中进一步考虑了平滑性与安全性，提出了连续的标记系统，提出了车辆间合作的可靠性与有效性。利用Matlab，进一步讨论了该方法在节省时间和变道的过程中加入安全性的优点，并进行了协议的仿真与分析。

关键词： CACC 滑模控制梯形加速度曲线轨迹标记系统 Matlab

The Concept of eGovernment: ICT Policy Guidelines for the Policy Makers of Ghana

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Journal of Information Security 2017年第2期8卷 106-124页

作者： S. K. mahama Ewurah College of Public Administration Huazhong University of Science and Technology Wuhan China

It is obvious that no government or business operation can be done without some kinds of involvement of ICTs in the process. However, research shows that, the policies and implementation of ICTs in delivering public services face several challenges in different countries due to country level peculiarities and cultures. These challenges are socio-technical from the prospective of soft and hard implications of the eGovernment systems. This paper tries to follow the soft or social issues limiting the efforts in designing and implementing ICT policies in Ghana. We identify some of the challenges in respect of the policy makers and back and front office users of ICT systems. This paper has therefore, elaborated the concept of eGovernment within context of the understanding of the lay ICT policy maker and systems users of Ghana. The issues addressed in this article range from development to the sustainability of eGovernment systems, policies and stages that resonate with norms and culture, political and the administrative style of Ghana.

关键词： ICT Policy Guidelines eGovernment Stages Ghana

Investigating the Determinants of Maternal Care Services Utilization in the Brong Ahafo Region of Ghana

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Open Journal of Statistics 2019年第3期9卷 309-326页

作者： Abdul-Karim Iddrisu Dominic Otoo Bashiru mahama Department of Mathematics and Statistics University of Energy and Natural Resources Sunyani Ghana Environmental Health and Sanitation College of Nursing and Midwifery Nalerigu Ghana

Ghanaian governments have made some social interventions in order to reduce risks associated with pregnancy and child delivery. However, most pregnant women do not seek maternal care. Previous studies have examined factors contributing to maternal care services utilization in Ghana using national data which limit such study applicability in some areas with specific background characteristics. These studies have mostly limited it to rural areas where the utilization is very low. This study seeks to bridge the gaps identified by exploring the factors which influence maternal care utilization in urban and rural communities in the Brong Ahafo Region of Ghana. The Chi-Square test of association and the logistic regression models are used to analyze data obtained from the 2014 Ghana Demographic and Health Survey (DHS). The data analyses were carried out using R and STATA softwares. The results revealed that women with at least 5 children were less likely (OR = 0.374, 95% CI: 0.173 - 0.796) to utilize antenatal care compared to those who had less than five live births. Educated women are three times likely (95% CI: 1.929 - 5.257) to deliver at a health facility compared to uneducated women. Women from the rich wealth quintile were nearly 16.9 times more likely (95% CI: 4.816 - 107.124) to deliver in a health facility compared to those from the poor wealth quintile. On the other hand, residing in rural communities makes it less likely (OR = 0.569, 95% CI: 0.350 - 0.913) for women to receive postnatal care within 2 months of delivery compared to living in urban communities. This study has demonstrated that maternal educational level plays a crucial role in maternal health care service utilization in the region. Therefore, government policies and programs aimed at providing more educational opportunities for girls in the region should be reinforced.

关键词： Antenatal Care Chi-Square Institutional Delivery Logistic Regression Postnatal Care Maternal Health

绿色人力资源管理对企业环保绩效的影响及作用机制研究

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绿色人力资源管理对企业环保绩效的影响及作用机制研究

作者： mahama Abdul-Barry 山东大学

学位级别：硕士

作为一名来华留学的外国留学生,在中国的学习生涯中,让我亲眼目睹了中国经济的迅速发展。随着中国经济不断发展,2019年中国以14.4万亿美元的总量稳居世界经济第二的地位。而在中国经济不断向前突破的发展过程中,中国企业对于环境保护的... 详细信息

作为一名来华留学的外国留学生,在中国的学习生涯中,让我亲眼目睹了中国经济的迅速发展。随着中国经济不断发展,2019年中国以14.4万亿美元的总量稳居世界经济第二的地位。而在中国经济不断向前突破的发展过程中,中国企业对于环境保护的意识也越来越强,并开始使用绿色人力资源管理来提高企业的环保绩效。本文通过研究绿色人力资源管理对企业环保热情的影响,进而研究其对企业环保绩效的影响作用。绿色人力资源管理对于企业内部环保热情的作用还可能受到企业文化认同和组织承诺的影响。本文通过研究这些变量与企业环保绩效的关系,以期促进中国企业提高环保绩效。本文通过实证研究分析绿色人力资源管理对企业环保绩效的影响及作用机制。首先,本文通过阐述绿色人力资源管理对环保热情的作用关系、环保热情对企业环保绩效的作用效果、环保热情的中介作用和企业文化认同与组织承诺的调节作用四个部分来提出研究假设;其次,本文进行了问卷设计分析,并对统计分析与假设检验方面进行了阐述。本文得出了以下五个结论:（1）绿色人力资源管理对于环保热情具有正向促进作用;（2）环保热情对企业环保绩效起正向促进作用;（3）环保热情在绿色人力资源管理和企业环保绩效中起部分中介作用;（4）企业文化认同在绿色人力资源管理和环保热情之间起调节作用;（5）组织承诺在绿色人力资源管理和环保热情之间起调节作用。最后本文提出了实施绿色人力资源管理战略、注重培训和薪酬绿色化、鼓励员工参与绿色环保公益活动、改进招聘和绩效考核的绿色化、培养员工组织认同感五个研究政策,以期能够给中国企业在环境保护政策提供借鉴作用。

关键词：绿色人力资源管理环保热情组织承诺企业文化认同企业环保绩效

Perceptions and Experiences of Adult Learners of Online Learning in the Era of COVID-19 in Ghana

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Journal of Psychological Research 2022年第4期4卷 35-46页

作者： Samuel Richard Ziggah Peter Eshun Inuusah mahama Department of Counselling Psychology University of EducationP.O.Box 25WinnebaGhana Department of Educational Foundations University of EducationP.O.Box 25WinnebaGhana

The COVID-19 Pandemic has undoubtedly affected learners,and as such,adjustments need to be made for successful teaching and learning through online ***,in Ghana,the effects of the COVID-19 Pandemic did not spare adult learners who are compelled by educational reforms to upgrade themselves academically using online learning *** a descriptive design,the study explored the perceptions and experiences of 166(online data collection)adult learners as they pursue their academic programs through online *** adapted questionnaire on perceptions and online learning experiences developed by Khan,Nabi,Khojah,and Tahir(2021)was used for the data *** Confirmatory Factor Analysis technique was used to analyse the *** study revealed that respondents felt confident while using online learning content but refuted that those technologies permit them to take tests and submit assignments ***,the study revealed that online learning service was making the learning process very *** revelation means that adult learners possess positive experiences and perceptions about online ***,online teaching and learning in higher education institutions should be made a routine activity in Ghana even after the COVID-19 Pandemic because the world is approaching a technological world.

关键词： Perception Experiences Pandemic Adult learners COVID-19 Self-efficacy Ghana