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Characterization and Electrochemical properties of Nanostructured Zr-Doped Anatase TiO_2 Tubes Synthesized by Sol–Gel Template Route

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Journal of Materials Science & Technology 2017年第6期33卷 527-534页

作者： denis p.opra Sergey V.Gnedenkov Sergey L.Sinebryukhov Elena I.Voit Alexander A.Sokolov Evgeny B.Modin Anatoly B.podgorbunsky Yury V.Sushkov Veniamin V.Zheleznov Institute of Chemistry Far Eastern Branch of Russian Academy of Sciences Far Eastern Federal University National Research Centre "Kurchatov Institute"

A series of nanostructured Zr-doped anatase TiO_2 tubes with the Zr/Ti molar ratio of 0.01, 0.02, 0.03, and0.09 were prepared by a sol–gel technology on a carbon fiber template. The electrochemical performance of Zr-doped anatase TiO_2 as anodes for rechargeable lithium batteries was investigated and compared with undoped titania. Tests represented that after 35-fold charge/discharge cycling at C/10 the reversible capacity of Zr-doped titania（Zr/Ti = 0.03） reaches 135 m A h g^（-1）, while the capacity of undoped titania（Zr/Ti = 0） yielded only 50 m A h g^（-1）. Based on the results of the physicochemical investigation, three reasons of improving electrochemical performance of Zr-doped titania were suggested. According to the scanning electron microscopy and transmission electron microscopy, Zr^（4＋） doping induces a decrease in nanoparticle size, which facilitates the Li＋diffusion. The Raman investigations show the more open structure of Zr-doped TiO_2 as compared to undoped titania due to changing of the unit cell parameters, that significantly affects on the reversibility of the insertion/extraction process. The electrochemical impedance spectroscopy results indicate that substitution of Zr^（4＋） for Ti^（4＋） into anatase TiO_2 has favorable effects on the conductivity.

关键词： Li-ion batteries Anatase titania Nanostructured materials Sol–gel template process Doping Electrochemical performance

The penetration depth of atomic radicals in tubes with catalytic surface properties

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plasma Science and Technology 2024年第7期26卷 157-164页

作者： Domen pAUL Miran MOZETIC Rok ZApLOTNIK Alenka VESEL Gregor pRIMC denis DONLAGIC Jozef Stefan Institute Jamova Cesta 39Ljubljana 1000Slovenia Jozef Stefan International postgraduate School Jamova Cesta 39Ljubljana 1000Slovenia Faculty of Electrical Engineering and Computer Science University of MariborKoroska Cesta 46Maribor 2000Slovenia

Catalysis of molecular radicals is often performed in interesting experimental *** possible configuration is tubular *** radicals are introduced into the tubes on one side,and stable molecules are exhausted on the other *** penetration depth of radicals depends on numerous parameters,so it is not always feasible to calculate *** article presents systematic measurements of the penetration depth of oxygen atoms along tubes made from nickel,cobalt,and *** source of O atoms was a surfatron-type microwave *** initial density of O atoms depended on the gas flow and was 0.7×10^(21)m^(-3),2.4×10^(21)m^(-3),and 4.2×10^(21)m^(-3)at the flow rates of 50,300,and 600 sccm,and pressures of 10,35,and 60 pa,*** gas temperature remained at room temperature throughout the *** dissociation fraction decreased exponentially along the length of the tubes in all *** penetration depths for well-oxidized nickel were 1.2,1.7,and 2.4 cm,*** cobalt,they were slightly lower at 1.0,1.3,and 1.6 cm,respectively,while for copper,they were 1.1,1.3,and 1.7 cm,*** results were explained by gas dynamics and heterogeneous surface *** data are useful in any attempt to estimate the loss of molecular fragments along tubes,which serve as catalysts for the association of various radicals to stable molecules.

关键词： oxygen plasma penetration depth catalysis heterogeneous surface recombination atom loss

Electrochemical performance of Klason lignin as a low-cost cathode-active material for primary lithium battery

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Journal of Energy Chemistry 2015年第3期24卷 346-352页

作者： Sergey V Gnedenkov denis p.opra Ludmila A Zemnukhova Sergey L Sinebryukhov Iliya A Kedrinskii Olga V patrusheva Valentin I Sergienko Institute of Chemistry Far Eastern BranchRussian Academy of Sciences Far Eastern Federal University Siberian State Technological University

A few classes of organic compounds are promising electrode-active materials due to their high power and energy densities,low cost,environmental friendliness,and *** the present work,the possibility of using Klason lignin extracted from buckwheat husks as a cathode-active material for a primary lithium battery has been investigated for the first *** reaction mechanism in the lithium/lignin electrochemical cell was suggested based on the deep galvanostatic discharge（up to 0.005 V） data and cyclic voltammetry *** dependence of the electrochemical behavior of the Klason lignin on the milling degree was *** maximum specific capacity of the lignin is equal to 600 m Ah g-1at a discharge current density of 75 μA *** effect of the thermal treatment of the Klason lignin cathode at250°C on the cell performance was *** was found that the discharge capacity of the cell increased by 30% in the range from 3.3 to0.9 V for the treated cathode *** results demonstrate the prospects of using Klason lignin-based electrochemical cells as low-rate primary power sources.

关键词： Klason lignin primary lithium battery organic electrode buckwheat husks

Laser-optimized pt-Y alloy nanoparticles embedded in pt-Y oxide matrix for high stability and ORR electrocatalytic activity

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Journal of Energy Chemistry 2024年第5期92卷 508-520页

作者： Riccardo Brandiele Andrea Guadagnini Mattia parnigotto Federico pini Vito Coviello denis Badocco paolo pastore Gian Andrea Rizzi Andrea Vittadini Daniel Forrer Vincenzo Amendola Christian Durante Department of Chemical Sciences University of PaduaVia Marzolo 135131 PadovaItaly Istituto di Chimica della Materia Condensata e di Tecnologie per l’Energia ICMATE-CNR via Marzolo 1 I-35131 PadovaItaly

The development of active yet stable catalysts for oxygen reduction reaction(ORR)is still a major issue for the extensive permeation of fuel cells into everyday *** nanostructured pt catalysts are to date the best available systems in terms of activity,the same is not true for stability,particularly under operating *** this work,pt_(Х)Y alloy nanoparticles are proposed as active and durable electrocatalysts for ***_(Х)Y nanoalloys are synthesized and further optimized by laser ablation in liquid followed by laser fragmentation in *** novel integrated laser-assisted methodology succeeded in producing pt_(Х)Y nanoparticles with the ideal size(pt catalysts,yet resulting remarkably more active with E_(1/2)=0.943 V ***,specific activity=1095μA cm^(-2) and mass activity>1000 A g^(-1).At the same time,the nanoalloys are embedded in a fine pt oxide matrix,which allows a greater stability of the catalyst than the commercial pt reference,as directly verified on a gas diffusion electrode.

关键词： Electrocatalysis GDE ORR pt_(2)Y pt_(3)Y LAL LFL Oxide support pto Nanoalloys

prevalence and Factors Associated with Refractive Errors among University Students at Mbarara University of Science and Technology, Uganda

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Open Journal of Ophthalmology 2024年第3期14卷 324-338页

作者： denis Kamara John Onyango Simon Arunga Mwanja pius pliers denis Tusingwire Mary Assumpta Ayoo Eric Ronald Mulongo Barnabas Atwiine Department of Ophthalmology Mbarara University of Science and Technology Mbarara City Uganda College of Health Sciences Makerere University Kampala Uganda London School of Hygiene and Tropical Medicine London England Faculty of Business and Development Studies Gulu University Gulu Uganda College of Health Sciences Lira University Lira Uganda

Introduction: WHO estimated that uncorrected refractive errors are the leading cause of visual impairment and second leading cause of blindness globally. University students are prone to developing refractive errors due to their curriculum that requires a lot of near work affecting their performance and quality of life unknowingly. Genetic and environmental factors are thought to play a role in the development of refractive errors. This study addresses the paucity of knowledge about refractive errors among university students in East Africa, providing a foundation for further research. Objectives: To determine the prevalence and factors associated with refractive errors among students in the Faculty of Medicine at Mbarara University of Science and Technology. Methodology: This was a cross-sectional descriptive and analytical study in which 368 undergraduate students selected using random sampling were assessed for refractive errors from March 2021-July 2021. Eligible participants were recruited and their VA assessment done after answering a questionnaire. Students whose VA improved on pin hole had subjective retinoscopy and results were compiled and imported to STATA 14 for analysis. Results: The prevalence of refractive errors was 26.36% with (95% CI) among university students especially myopia. Myopia is most predominant at 60%, followed by 37% Astigmatism and hyperopia of 3% among medical students. Astigmatism consisted of largely myopic astigmatism 72% (26) and 28% (10) compound/mixed astigmatism only. Student positive family history of refractive error was found to have a statistically significant relationship with refractive errors with AOR 1.68 (1.04 - 2.72) (95% CI) and p (0.032). Conclusion: The prevalence of refractive errors among university students, especially myopia, was found to be high and family history was associated with students having refractive errors.

关键词： Refractive Errors prevalence Myopia Astigmatism Hyperopia Hypermetropia University Students Blindness Visual Impairment

predictors of Fatal Outcome in Hospitalised Adult patients with Acute Kidney Injury at Two Tertiary Hospitals in Sub-Saharan Africa

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Open Journal of Nephrology 2024年第1期14卷 86-103页

作者： denis Georges Teuwafeu Fombo Enjeh Jabbossung Maimouna Mahamat Eric Aristide Nono Tomta Mbapah Leslie Tasha Francois Kaze Folefack Gloria Ashuntantang Faculty of Health Sciences University of Buea Buea Cameroon Triad Research Fundation Buea Cameroon Faculty of Medicine and Biomedical Sciences University of Yaounde I Yaounde Cameroon Department of nephrology Yaounde General Hospital Yaounde Cameroon Departement of Nephrology Yauonde Teaching Hospital Yaounde Cameroon

Introduction: Data on mortality in acute kidney injury (AKI) derives from high-income countries where AKI is hospital-acquired and occurs in elderly patients with a high burden of cardiovascular disease. In sub-Saharan Africa (SSA), AKI is community-acquired occurring in healthy young adults. We aimed to identify predictors of fatal outcomes in patients with AKI in two tertiary hospitals in Cameroon. Methods: Medical records of adults with confirmed AKI, from January 2018 to March 2020 were retrieved. The outcomes of interest were in-hospital deaths and presumed causes of death. We used multiple logistic regressions modeling to identify predictors of death. The study was approved by the ethics boards of both hospitals. Values were considered significant for a p-value of 0.05. Results: We included 285 patient records (37.2% females). The mean (SD) age was 50.1 (19.0) years. Hypertension (n = 97, 34.0%), organ failure (n = 88, 30.9%), and diabetes (n = 60, 21.1%) were the main comorbidities. The majority of patients had community-acquired AKI (78.6%, n = 224), were KDIGO stage 3 (88.8%, n = 253), and needed dialysis (52.6%, n = 150). Up to 16.7% (n = 25) did not receive what was needed. The in-hospital mortality rate was 29.1% (n = 83). Lack of access to dialysis (OR = 27.8;CI: 5.2 - 149.3, p = 0.001), hypotension (OR = 11.8;CI: 1.3 - 24.8;p = 0.001) and ICU admission (OR = 5.7;CI: 1.3 - 24.8, p = 0.001) were predictors of mortality. The presence of co-morbidities or underlying diseases (n = 46, 55%) were the main causes of death. Conclusions: In-hospital AKI mortality is high, as in other low- and middle-income economies. Lack of access to dialysis and the severity of the underlying illness are major predictors of death.

关键词： predictors Fatal Outcome Acute Kidney Injury Tertiary Hospital

prevalence of Dyslipidemia among patients Received at the Biochemistry Unit of the Charles de Gaulle pediatric University Hospital in Ouagadougou

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Advances in Biological Chemistry 2024年第1期14卷 16-26页

作者： Fabienne Marie Soudre Arnaud Kouraogo Alice Kiba Ollo Da Mahutin Benoîte Hounhoui Diema Nadia Karama Seraphine Mano denis Claude Drabo Augustin Kyetega Raoul Karfo Elie Kabre Jean Sakande Health Sciences Training and Research Unit Joseph Ki-Zerbo University Ouagadougou Burkina Faso Charles de Gaulle pediatric University Hospital Ouagadougou Burkina Faso Health Sciences Institute Nazi BONI University Bobo Dioulasso Burkina Faso Biochemistry Unit Sourou Sanou University Hospital Bobo Dioulasso Burkina Faso Tengandogo University Hospital Ouagadougou Burkina Faso Faculty of Health Sciences Saint Thomas d’Aquin University Ouagadougou Burkina Faso Yalgado Ouedraogo University Hospital Ouagadougou Burkina Faso National Agency for Environmental Food Labor and Health Product Safety Ouagadougou Burkina Faso

Introduction: Cardiovascular disease represents a major public health burden worldwide. Research and management of risk factors contribute to the prevention of these diseases. The aim of this study was to assess the prevalence of dyslipidemia in the biochemistry unit of the Charles De Gaulle pediatric University Hospital (CHUp-CDG) in Ouagadougou. Material and Methods: This was a descriptive and analytical cross-sectional study, with retrospective data collection from January 1, 2020 to December 31, 2022. patients of all ages who performed a lipid panel in the CHUp-CDG biochemistry unit during the study period have been included. Results: A total of 2872 patients have been included. The mean age of the study population was 27.72 ± 19.51 years and the M/F sex ratio was 0.81. Among the patients, 22.84% had at least one dyslipidemia. The prevalences of hypercholesterolemia, hypo-HDL cholesterolemia and hyper-LDL cholesterolemia were 11.57%, 49.19% and 57.50% respectively. Hypertriglyceridemia and mixed hyperlipidemia were present in 9.04% and 2.08% of patients. Hypercholesterolemia was significantly more frequent in the female sex (p = 0.0077);hyper-LDL cholesterolemia (p = 0.0255) and mixed hyperlipidemia (p Conclusion: The relatively high prevalence of dyslipidemia in the study indicates a worrying situation. It would therefore appear essential to extend the search for risk factors nationwide, particularly those that can be modified, in order to reduce morbidity and mortality linked to cardiovascular disease.

关键词： Dyslipidemia Lipid profile Lipid Abnormalities prevalence Burkina Faso

DGpS/INS Data Fusion for Land Navigation

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Journal of Donghua University(English Edition) 2004年第3期21卷 88-93页

作者： denis Berdjag denis pomorski L.A.G.I.S. UMR 8021 B timent P2 Cité ScientifiqueUniversité des Sciences et Technologies de Lille 59655 Villeneuve d' Ascq cedex FranceL.A.G.I.S. UMR 8021 B timent P2 Cité ScientifiqueUniversité des Sciences et Technologies de Lille 59655 Villeneuve d' Ascq cedex France

The interest for land navigation has increased for the recent years. With the advent of the Global position System (GpS) we have now the ability to determine the absolute position anywhere on the globe. The problem is that the GpS systems work well only in open environments with no overhead obstructions and they are subject to large unavoidable errors when the reception from some of the satellites are blocked. This occurs frequently in urban environments, forests and tunnels. GpS systems require at least four “visible” satellites to maintain a good position fix. In many situations in which higher level of accuracy is required, the navigation cannot be achieved by GpS alone. This paper discusses the design of a reliable multisensor fusion algorithm using GpS and Inertial Navigation System in order to decrease the implementation cost of such systems on land vehicles. The major contribution of this paper is in the definition of the possible developments and research axes in land navigation.

关键词： Data fusion inertial navigation system (INS) GpS system Kalman filter informational filter

Ethnopharmacological potentials of Warburgia ugandensis on Antimicrobial Activities

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Chinese Journal of Integrative Medicine 2021年第8期27卷 633-640页

作者： denis Okello Youngmin Kang Korean Convergence Medicine Major University of Science and TechnologyDaejeonRepublic of Korea Gombe Secondary School P.O.Box 192Butambala/MpigiUganda Herbal Medicine Research Division Korea Institute of Oriental MedicineDaejeon34054Republic of Korea

Warburgia ugandensis(***)is known by various names,including the East African greenheart,pepper bark tree,and Ugandan greenheart,and has a rich history of extensive use in the treatment of a host of human diseases in many African *** review is based on the botany and ethnopharmacological potentials of *** for the treatment of pneumonia,asthma,malaria,candidiasis,skin infections,human immunodeficiency virus opportunistic infections,diarrhea,and measles given the common use in the management of these *** from *** have strong antimicrobial activities against a broad spectrum of pathogens mainly because of the presence of abundant terpenoids,drimane,and coloratane type sesquditerpenoids amongst which are ugandensial,warburganal,mukaadial,and other secondary metabolites,such as tannins,flavonoids,saponins,steroids,and *** group of compounds gives the plant a high therapeutic *** on the review,there is a need for identification and isolation of the highly therapeutic phytochemical constituents and a drive for more preclinical and clinical trials to validate the safety and efficacy of the *** gives basis for the potential development of new therapeutic drugs from the plant.

关键词： Ethnopharmacological potential Warburgia ugandensis greenheart pharmacological activity review