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Understanding the catalysis of chromium trioxide added magnesium hydride for hydrogen storage and Li ion battery applications

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Journal of Magnesium and Alloys 2024年第3期12卷 1117-1130页

作者： D.Pukazhselvan IhsanÇaha Catarina de Lemos Sergey M.Mikhalev francis leonard deep.k Duncan Paul Fagg Department of Mechanical Engineering TEMA-Centre for Mechanical Technology and AutomationUniversity of AveiroAveiro 3810-193Portugal LASI-Intelligent Systems Associate Laboratory Guimarães 4800-058Portugal Nanostructured Materials Group International Iberian Nanotechnology Laboratory(INL)Avenida Mestre Jose VeigaBraga 4715-330Portugal

This study explores how the chemical interaction between magnesium hydride(MgH_(2))and the additive CrO_(3) influences the hydrogen/lithium storage characteristics of MgH_(2).We have observed that a 5 wt.%CrO_(3) additive reduces the dehydrogenation activation energy of MgH_(2) by 68 kJ/mol and lowers the required dehydrogenation temperature by 80℃.CrO_(3) added MgH_(2) was also tested as an anode in an Li ion battery,and it is possible to deliver over 90%of the total theoretical capacity(2038 mAh/g).Evidence for improved reversibility in the battery reaction is found only after the incorporation of additives with MgH_(2).In depth characterization study by X-ray diffraction(XRD)technique provides convincing evidence that the CrO_(3) additive interacts with MgH_(2) and produces Cr/MgO *** free energy analyses confirm the thermodynamic feasibility of conversion from MgH_(2)/CrO_(3) to MgO/Cr,which is well supported by the identification of Cr(0)in the powder by X ray photoelectron spectroscopy(XPS)*** high resolution transmission electron microscopy(HRTEM)and energy dispersive spectroscopy(EDS)we found evidence for the presence of 5 nm size Cr nanocrystals on the surface of MgO rock salt *** is also convincing ground to consider that MgO rock salt accommodates Cr in the *** observations support the argument that creation of active metal–metal dissolved rock salt oxide interface may be vital for improving the reactivity of MgH_(2),both for the improved storage of hydrogen and lithium.

关键词： Hydrogen storage Rechargeable batteries Binary hydrides Metal oxides Catalytic mechanism.

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Boosting acidic water oxidation performance by constructing arrays-like nanoporous Ir_(x)Ru_(1−x)O_(2) with abundant atomic steps

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Nano Research 2022年第7期15卷 5933-5939页

作者： Junjie Li Zan Lian Qiang Li Zhongchang Wang Lifeng Liu francis leonard deep.k Yanping Liu Bo Li Junyuan Xu Zuxin Chen CAS key Laboratory of Functional Materials and Devices for Special Environments Xinjiang Technical Institute of Physics&ChemistryChinese Academy of SciencesUrumqi 830011China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China International Iberian Nanotechnology Laboratory(INL) Braga 4715-330Portugal Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai 200093China School of Physics and Electronics Hunan Key Laboratory for Super-microstructure and Ultrafast ProcessCentral South UniversityChangsha 410083China Laboratory of Advanced Spectro-electrochemistry and Li-ion Batteries Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Institute of Semiconductors South China Normal UniversityGuangzhou 510631China

The fabrication of electrocatalysts with high activity and acid stability for acidic oxygen evolution reaction(OER)is an urgent need,yet extremely ***,we report the design and successful fabrication of a high performance self-supported cogwheel arrays-like nanoporous Ir_(x)Ru_(1−x)O_(2) catalyst with abundant atomic steps for acidic OER using a facile alloy-spinningelectrochemical activation method that allows large-scale *** obtained Ir_(x)Ru_(1−x)O_(2) catalysts merely need overpotentials of 211 and 295 mV to deliver catalytic current densities of 10 and 300 mA·cm^(−2) in 0.5 M H_(2)SO_(4),respectively,and can sustain constant OER electrolysis for at least 140 h at a high current density of 300 mA·cm^(−2).Further density functional theory(DFT)calculations uncover that such high intrinsic activities mainly originate from the largely exposed high-index atomic step planes,which markedly lower the limiting potential of the rate-determining step(RDS)of *** findings provide an insight into the exploration of high performance electrocatalysts,and open up an avenue for further developing the state-of-theart Ir and/or Ru-based catalysts for large-scale practical applications.

关键词： oxygen evolution reaction(OER)electrolysis nanoporous structure Ir_(x)Ru_(1−x)O_(2) defects atomic steps

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Cervical Cancer Screening, Adherence to and Challenges of Follow-Up in Resources Poor Setting

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Open Journal of Preventive Medicine 2019年第9期9卷 105-114页

作者： Theophilus Ogochukwu Nwankwo Silas Onyemaechi Okoro francis Ikechukwu Ukekwe leonard Ogbonna Ajah Benjamin Chukwuma Ozumba Faculty of Medical Sciences Department of Obstetrics and Gynaecology University of Nigeria Nsukka Enugu State Nigeria Faculty of Medical Sciences Department of Pathology University of Nigeria Nsukka Enugu State Nigeria

Background: Organized cervical cancer screening program has contributed to the reduction in incidence of cervical cancer in developed countries. Follow up, to ensure adherence to regular screenings, still poses challenges in poor resource settings. Objective: This study aims at determining the cervical cancer screening uptake, adherence to follow up instructions and interval cervical cancer screening and intervention to improve adherence through personalized reminders (phone calls and text messages). Methods: This was a prospective study of clients screened for cervical cancer at the University of Nigeria Teaching Hospital, Enugu from January 2012 to December 2016. The participants were studied for adherence to interval follow-up screening. Eligible participants were followed up using phone calls and text messages and the outcome noted. The data was analysed using statistical software for social sciences (SPSS) version 17. Results: The mean age and parity of 1146 participants screened for cervical intra-epithelial abnormalities within the study period was 44.18 ± 11.08 years and 3.78 ± 2.08 respectively. Most of the subjects (91.8%) screened negative to squamous intra-epithelial lesion (SIL) or malignancy, 8.2% (94/1146) had various grades of SIL. Thirty-five (37%), 29 (31%), 16 (17%) and 14 (15%) of the 94 SIL positive cases had atypical cells of unknown significance (ASCUS), low-grade squamous intra-epithelial lesion (LGSIL), high-grade squamous intra-epithelial lesion (HGSIL) and cervical carcinoma respectively. Adherence to instructions for repeat cytology was only 37.7% while that for 3 yearly interval rescreening was 17.5%. Phone calls and messages to clients improved adherence to appreciable extent. Conclusion: Adherence to interval and follow-up screening for cervical cancer was low. The use of phone calls and short message services (SMS) to remind clients of screening appointments increased adherence and should be employed in developing countries.

关键词： Cervical Cancer Intra-Epithelial Lesion Screening Follow-Up Adherence

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Hemodialysis patients’ satisfaction and associated factors in National Teaching Hospital Hemodialysis Center, Cotonou (Benin)

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Open Journal of Nephrology 2019年第4期9卷 127-138页

作者： Séraphin Ahoui Jacques Vigan Bruno Léopold Agboton Evariste Eteka francis Tchegnonsi Tognon A. Anselme Djidonou Prosper Gandaho leonard Fourn Department of Nephrology Borgou Regional Teaching Hospital Parakou Benin Nephrology-Hemodialysis University Clinic (CUNH) Hubert Koutoukou Maga National Teaching Hospital Cotonou (CNHU-HKM) Benin Department of Psychiatry Borgou Regional Teaching Hospital Parakou Benin Faculty of Health Sciences University of Abomey-Calavi Abomey-Calavi Benin

Background: Patients’ satisfaction is a relevant component in assessing healthcare services. The objective of this study was to study the level of satisfaction of chronic hemodialysis patients and the associated factors in Cotonou CNHU-HkM dialysis center. Patients and Methods: It was a cross-sectional, descriptive and analytical study conducted by administering a questionnaire on days off dialysis. It was carried out from 1st November 2015 to 1st January 2016 in CNHU-HkM Nephrology University Clinic of Cotonou. Hemodialysis patients aged 18 years and above having given their informed consent were included in the study. Patients’ recruitment was comprehensive. Likert scale was used in assessing the level of satisfaction with 4 as “very satisfied” and 1 for “very dissatisfied”. Satisfaction was evaluated on the basis of Ware dimensions. The threshold for satisfaction was 50. Outcomes: Overall, 377 patients were included in the study. Respondents’ mean age was 51.5 ± 13.3 years with 1.37 as sex ratio. Arteriovenous fistula was used for 80.1% of hemodialysis patients. 77.7% of the patients underwent dialysis twice a week while 45.9% were administered a four-hour dialysis. The overall average proportion of “satisfied” was 76.5%. The level of satisfaction was 52% for healthcare environment, 61% for service delivery, 73.9% for healthcare accessibility, 76.1% for healthcare structure, 77.5% for healthcare management, 90.3% for quality of healthcare, 88.3% for interpersonal relationship and 93.2% for efficiency and continuum of healthcare. Factors associated with satisfaction included age (p = 0.02), vascular access (p = 0.04) and urea reduction ratio (p = 0.01). In addition, the degree of satisfaction of hemodialysis patients was not statistically associated with sex, marital status, educational level, history of the disease, age of dialysis, number of sessions per week, and duration per session. Conclusion: The overall level of hemodialysis patients’ satisfaction is above

关键词： Satisfaction Chronic Hemodialysis Cotonou

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