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Dose Optimization in Computer Tomography Pediatric Cranial Scans

Open Journal of Radiology 2019年第4期9卷 181-193页

作者： Clémence Alla Takam Odette Samba Aurelle Tchagna Kouanou Daniel Tchiotsop Eddy Fotso Kamdem Emilienne Guegang emmanuel fongang Unité de Recherche de Matière Condensée d’Electronique et de Traitement du Signal (URMACETS) Faculty of Science University of Dschang Dschang Cameroon Service de Radiothérapie Hôpital Général de Yaoundé Yaoundé Cameroo Department of Research Development Innovation and Training InchTech’s Yaoundé Cameroon Unité de Recherche d’Automatique et d’Informatique Appliquée (URAIA) IUT-FV de Bandjoun Université de Dschang Dschang Cameroon Service de Radiologie et d’Imagerie Médicale Hôpital Général de Yaoundé Yaoundé Cameroon

Background and Objective: Nowadays, Computer Tomography is one of the best radiological imaging technics which can give right diagnostic information, among the detection of multiphasic adenomas, the detection of cardiac, cerebral and vascular abnormalities. Although these good qualities, this technic is too radiant for the patient. In this paper, we based on the irradiation doses delivered from the current protocols to find a practical method of their optimization during the pediatric cranial scan. Materials and Methods: This work relies on a collection of data from patients in the hospitals, so that analyze them, give the conclusions and, propose an optimal practical method to decrease the irradiation doses. To collect data, we performed a prospective study of seventeen months (from December 2017 to May 2019) carried out simultaneously in three hospitals of the city: The Centre Medical la Cathédrale (H1), the Yaoundé Central Hospital (H2) and the Yaoundé Gyneaco-Obstetric and pediatric hospital (H3). This study included a total of 192 cases of cerebral trauma, of which 11 cases excluded for incomplete information. The dosimetry quality control (CTDIvol) using the PMMA phantoms of 16 cm and 32 cm fulfilled. The scanographic parameters of the patient acquisition protocol were recorded and analyzed. Some of those parameters were modified and entered the CT with the help of a biomedical engineer to reduce the delivered dose. The relationship between CTDIvol and kV is statistically significant (p Results: Among patients, 172 are boys, and the remaining 9 are girls all were in the 0 to 15 age group. CTDIvol values varied from 34.2 mGy to 107.8 mGy and PDLs from 107.8 *** to 2214.5 *** in H1. In H2, CTDIvol varied from 5.8 mGy to 44 mGy and PDLs from 91.4 *** to 665.5 ***. CTDIvol varied between 9.34 mGy to 92.81 mGy and PDLs from 162.38 *** to 2713.67 *** in H3. All values are taken at 75th percentile, with or without contrast injection. Conclusion: The

关键词： Computed Tomography Dose Optimization Pediatric Cranial Scans Protocol

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A Review on Technologies for the Use of CO2 as a Working Fluid in Refrigeration and Power Cycles

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Energy and Power Engineering 2024年第6期16卷 217-256页

作者： Orelien T. Boupda Hyacinthe D. Tessemo Isidore B. Nkounda fongang Francklin G. Nyami Frederic Lontsi Thomas Djiako Laboratory of Energy Higher National Polytechnic School of Douala University of Douala Douala Cameroon Institut Ucac-Icam Douala Cameroon Department of Energy and Mechanical Engineering ISTA-IUG University of Ngaoundere Ngaoundere Cameroon

The use of carbon dioxide as a working fluid has been the subject of extensive studies in recent years, particularly in the field of refrigeration where it is at the heart of research to replace CFC and HCFC. Its thermodynamic properties make it a fluid of choice in the efficient use of energy at low and medium temperatures in engine cycles. However, the performance of transcritical CO2 cycles weakens under high temperature and pressure conditions, especially in refrigeration systems;On the other hand, this disadvantage becomes rather interesting in engine cycles where CO2 can be used as an alternative to the organic working fluid in small and medium-sized electrical systems for low quality or waste heat sources. In order to improve the performance of systems operating with CO2 in the field of refrigeration and electricity production, research has made it possible to develop several concepts, of which this article deals with a review of the state of the art, followed by analyzes in-depth and critical of the various developments to the most recent modifications in these fields. Detailed discussions on the performance and technical characteristics of the different evolutions are also highlighted as well as the factors affecting the overall performance of the systems studied. Finally, perspectives on the future development of the use of CO2 in these different cycles are presented.

关键词： Refrigeration Cycle Power Cycle System Performance Transcritical CO2 Cycles Working Fluid

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A Shift from Ideological to Soft Power Cooperation of Russia and African Countries in Arts, Education and Science

A Shift from Ideological to Soft Power Cooperation of Russia...

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作者： Claire Ayuma Amuhaya Gbadebo Afolabi Joaddan Prisca Kommegni fongang People's Friendship University of Russia

Russia has not colonized any African country, and its relationship with the continent is quite different as compared to other European countries like Britain or France. With the absence of language environment, there has been a need for creating new modern strategies of cooperation especially with President Putin's government shifting from USSR cooperation in education as an ideological strategy to current soft power tool. With a foreign policy of noninterference in domestic affairs of sovereign states Russia is steadily gaining ground in the continent. This article will explore the theory of soft power and analyze how Russia is using it as a tool for expanding its cultural and political influence in Africa through cooperation in arts education and science. It will also examine the changes from the USSR time to present Russian federation while exploring its foreign policy in relation to Africa, and lastly conclude with observations made and prospects.

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超深水平井钻柱的优化设计

超深水平井钻柱的优化设计

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作者：罗丁(Mekontchou fongang Rodin) 中国石油大学（北京）

学位级别：硕士

钻柱设计是超深水平井钻井设计中不可或缺的环节之一。基于钻柱‘软杆模型’,推导出了超深水平井摩擦阻力和扭矩计算公式,同时使用“Matlab”编写软件。综合考虑实际钻井工况,计算钻柱的动态应力,并采用动态安全系数法对钻柱强度分析,... 详细信息

钻柱设计是超深水平井钻井设计中不可或缺的环节之一。基于钻柱‘软杆模型’,推导出了超深水平井摩擦阻力和扭矩计算公式,同时使用“Matlab”编写软件。综合考虑实际钻井工况,计算钻柱的动态应力,并采用动态安全系数法对钻柱强度分析,形成了一套独立的钻柱强度校核方法。此外,结合超深水平井钻柱的实际工作条件以及钻柱自身的力学特性,在整体和部分两个方面对钻柱进行优化设计分析,形成了分段组合并整体优化的设计方法。最后,结合CMR超深水平井进行实例分析,分别用分段优化组合和整体优化设计的方法进行了设计分析,并将软件计算结果和“wellplan”优化设计结果进行了对比,两者的结果一致性较高。

关键词：超深水平井钻柱强度校核安全系数摩阻/扭矩优化设计

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Next Generation Sequencing for Microbial Analysis to Select Prophylactic Antibiotic Selection before Urologic Stone Surgery: A Culture Change

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Open Journal of Urology 2021年第7期11卷 289-304页

作者： Rishi Das Tim Tseng Meghan I. Short Kelly Reveles Allison Wheeler Robert Hudson Bernard fongang Michael A. Liss Department of Urology University of Texas Health San Antonio San Antonio USA Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases San Antonio Texas USA The University of Texas at Austin—College of Pharmacy (PHR) Austin USA

Background: This paper aims to determine if the combination of polymerase chain reaction (PCR) and next-generation sequencing (NGS) could identify bacteria in culture-negative urine that would alter prophylaxis management. Methods: We sent approximately 5 - 10 mL of a preoperative urine sample to MicrogenDx for PCR/NGS analysis performed after surgery (blind to the surgeon). The physician prescribed standard of care antibiotic prophylaxis. Cases modeling the hospital course of 3 random patients were reviewed by eight urologists after surgery to determine if NGS results would change their prophylaxis regimen. An infectious disease pharmacist reviewed the cases and provided the “ideal” regimen. Results: Urine cultures identified bacteria in 11% (2/18) of cases. Culture speciation results were consistent with NGS results. NGS detected a dominant bacteria in 56% (10/18) of negative cultures and targetable bacteria in all samples. There was a 15% (3/20) infection rate. In both cases, NGS results suggest inadequate prophylaxis. In response to the case scenarios, 100%, 88%, and 88% of the urologists reported they would change prophylaxis with NGS results. During a case scenario, physicians would tend to overprescribe antibiotics given PCR/NGS data for prophylaxis selection. Conclusion: NGS identifies a targetable bacterium in up to 80% of negative urine cultures before urologic stone surgery. Responses to case scenarios indicate that physicians would change management based on NGS results. Inter-professional (urologic and pharmacy) antibiotic selection with PCR/16S DNA testing may be helpful to improve antibiotic stewardship.

关键词： Health-Care Associated Infection Urinary Tract Infection Infection Prevention Surgical Site Infection

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Synthesis,Urease Inhibition and Molecular Modelling Studies of Novel Derivatives of the Naturally Occurring b-Amyrenone

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Natural Products and Bioprospecting 2019年第1期9卷 49-59页

作者： Jean J.K.Bankeu Hira Sattar Yannick S.F.fongang Syeda W.Muhammadi Conrad V.Simoben Fidele Ntie-Kang Guy R.T.Feuya Marthe A.T.Tchuenmogne Mehreen Lateef Bruno N.Lenta Muhammad S.Ali Augustin S.Ngouela Department of Chemistry Faculty of ScienceThe University of BamendaP.O.Box 39BambiliCameroon International Center for Chemical and Biological Sciences University of KarachiKarachi 75270Pakistan Department of Chemistry Higher Teacher Training CollegeUniversity of MarouaP.O.Box 55MarouaCameroon Department of Pharmaceutical Chemistry Martin-Luther University of Halle-WittenbergWolfgang-Langenbeck-Str.406120 Halle(Saale)Germany Department of Chemistry Faculty of ScienceUniversity of BueaP.O.Box 63BueaCameroon Department of Chemistry Faculty of ScienceScientific and Technical University of MasukuBox 943FrancevilleGabon Department of Chemistry Faculty of ScienceUniversity of Yaounde´IP.O.Box 812Yaounde´Cameroon Multi-Disciplinary Research Laboratory(MDRL) Bahria University Medical and Dental CollegeBahria UniversityKarachiPakistan Department of Chemistry Higher Teacher Training CollegeUniversity of Yaounde´IP.O.Box 47Yaounde´Cameroon

Urease enzyme(UE)has been reported to be a potent virulence factor for Helicobacter pylori(HP)bacteria indicated to be responsible for various gastrointestinal ***,the spread of HP,currently regarded by the World Health Organization as a class 1 carcinogen,could be better controlled by targeting *** is in this line that we have synthesized three new derivatives(2–4)of the naturally occurring olean-12-en-3-one(1),which was previously isolated from the figs of Ficus vallis-choudae Delile(Moraceae).Among the synthesized compounds,3 and 4 contain an indole *** structures were unambiguously assigned by spectroscopic and spectrometric techniques(1D-NMR,2D-NMR and MS).The starting material and the synthesized compounds were screened for UE inhibition activity,and showed significant activities with IC50 values ranging from 14.5 to 24.6 lM,with compound(1)being the most potent as compared to the positive control thiourea(IC50=21.6 lM).Amongst the synthetic derivatives,compound 4 was the most potent(IC50-=17.9 lM),while the others showed activities close to that of the *** addition,molecular docking study of target compounds 2–4 was performed in an attempt to explore their binding mode for the design of more potent UE inhibitors.

关键词： Helicobacter pylori Urease inhibition Docking Olean-12-en-3-one derivatives

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Novel Hydralazine Schiff Base Derivatives and Their Antimicrobial, Antioxidant and Antiplasmodial Properties

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International Journal of Organic Chemistry 2020年第1期10卷 1-16页

作者： Angelbert F. Awantu Yannick Stephane F. fongang Godfred A. Ayimele Edouard A. Nantia Patrick V. T. Fokou Fabrice F. Boyom Celine K. Ngwang Bruno N. Lenta Silvère A. Ngouela Department of Chemistry The University of Bamenda Bambili Cameroon Department of Chemistry University of Maroua Maroua Cameroon Department of Chemistry University of Buea Buea Cameroon Department of Biochemistry The University of Bamenda Bambili Cameroon Department of Biochemistry University of Yaoundé I Yaoundé Cameroon Department of Chemistry Higher Teachers’ Training College University of Yaoundé I Yaoundé Cameroon Department of Organic Chemistry Faculty of Science University of Yaoundé I Yaoundé Cameroon

Two novel Schiff bases, 3-[1-(2-(phthalazin-1-yl)hydrazono)ethyl)-1,3-oxa- zinane (PHEO) and 2-[(2-(phthalazin-1-yl)hydrazono)methyl]phenol (PHMP), derived from hydralazine hydrochloride, an effective drug against hypertension, were synthesized and characterized by spectroscopic methods, Infrared (IR), Proton Nuclear Magnetic Resonance (1H NMR) and Carbon-13 Nuclear Magnetic Resonance (13C NMR). PHEO showed low antimicrobial activity against one bacterial strain with MIC value of 250 μg/ml while PHMP showed interesting activity against 4 bacterial strains with MIC of 31.25 - 250 μg/ml compared to the standard drug, amoxicillin. PHEO and PHMP showed higher reducing activity on ferric ions compared to Vitamin C. On lipid peroxidation, PHEO showed higher inhibition while PHMP showed lower inhibition compared to Vitamin C. Both compounds presented lower stimulating effect and lower catalase activity compared to the standard Vitamin C. PHEO and PHMP showed less than 80% inhibition in the preliminary antiplasmodial assay and so were not considered for the dose-response studies.

关键词： Hydralazine Hydrochloride Schiff Bases Antimicrobial Anti-Oxidant Anti-Plasmodial Activities

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The Anti-parasitic Effect of Extract of Ceiba pentandra (L.) Gaertn Is Related to Its Anti-inflammatory, Analgesic and Anthelmintic Activities on Haemonchus contortus

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Clinical Complementary Medicine and Pharmacology 2023年第2期3卷 65-73页

作者： Bogning Zangueu Calvin Alowanou Goue Géorcelin Belle Ebanda Kedi Phillipe Olounlade Abiodoun Pascal Magne fongang Annie Laure Kojom Wanche Jacquy Joyce Nguemfo Edwige Laure Azebaze Anatole Guy Blaise Dongmo Alain Bertrand Hounzangbe-Adote Mawulé Sylvie Laboratory of Animal Biology Faculty of ScienceUniversity of DoualaDouala 24157Cameroon Laboratory of Ethnopharmacology and Animal Health Faculty of Agronomics SciencesUniversity of Abomey Calavi01 P.O.Box 526CotonouBenin Pluridisciplinairy Laboratory School of Management and Exploitation of livestock SystemsUniversity National of Agricultural of Porto-Novo01 P.O.Box 55Porto-NovoBenin Department of Biological Sciences Faculty of Medicine and Pharmaceuticals SciencesUniversity of DoualaDouala 2701Cameroon Laboratory of Chemistry Faculty of ScienceUniversity of DoualaDouala 24157Cameroon

Background:Ceiba pentandra is a medicinal plant used as alternative therapy to control parasitic nematodes in ***:This study aims to investigate anti-parasitic effect of aqueous stem back extract of Ceiba pentandra(L.)Gaertn through the evaluation of its anthelmintic,anti-inflammatory and analgesic ***:In vitro,the efficacy of aqueous extract(75 to 2400μg·mL−1)diluted in phosphate buffered saline(PBS)was tested against three stages of the life cycle of Haemonchus contortus through larval migration inhibition assay(LMIA),egg hatch assay(EHA),and adult worms motility inhibition assay(AMIA).In vivo,anti-inflammatory and antinociceptive properties of the aqueous extract(150 and 300 mg·kg−1)was evaluated on rodent using phlogistic and algic ***:Significant inhibition activity(P<0.05)was obtained on EHA with the greatest inhibition of 46.63%obtained at 2400μg·mL−*** plant treatment dramatically(P<0.05)inhibited L3 larval migration as compared to *** highest inhibition rate was 53.33%at 1200μg·mL−*** of polyvinylpolyrrolidone(PVPP)to the extract significantly(P<0.01)reduced at 38.6%the activity of the plant extract on larval migration compared to extract without *** Ceiba pentandra extract reduced(P<0.05)worm motility after 24 h post exposure as compared to *** vitro,aqueous extract significantly(P<0.05)inhibited the paw inflammation induced by carragenine,with a significant(P<0.05)reduction of the number of abdominal contortions induced by acetic acid to 41.11%at 300 mg·kg−1 and the paw licking time induced by formaline in both phases to 57.22%and 63.59%at 300 mg·kg−1 likened to ***:In vitro results suggest that,this plant possess anti-parasitic *** and anti-inflammatory effects of *** can contribute to its anti-parasitic property.

关键词： Anti-inflammatory Antinociceptive Anthelmintic Ceiba pentandra Haemonchus contortus

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