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characterization of the High-Strength Mg–3Nd–0.5Zn Alloy Prepared by Thermomechanical Processing

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Acta Metallurgica Sinica(English Letters) 2019年第3期32卷 321-331页

作者： Ji■í Kub■sek Drahomír Dvorsk■ Jozef Vesel■ Peter Min■rik M■ria Zemkov■ Dalibor Vojtěch Department of Metals and Corrosion Engineering Faculty of Chemical Technology University of Chemistry and Technology Prague Department of Physics of Materials Charles University

Magnesium alloys based on Nd and Zn are promising materials for both aviation industry and medical *** mechanical properties of these materials can be achieved by thermomechanical processing such as extrusion or rolling and by aging treatment, which can significantly strengthen the alloy. The question remains especially about the connection of texture strength created in the alloys based on the specific conditions of preparation. This work focuses on the Mg–3 Nd–0.5 Zn magnesium alloy prepared by hot extrusion of the as-cast state at two different temperatures combined with heat pre-treatment. Extrusion ratio of 16 and rate of 0.2 mm/s at 350 and 400 °C were selected for material preparation. The structures of prepared materials were studied by scanning electron microscopy and transmission electron microscopy. The effect of microstructure on mechanical properties was evaluated. Obtained results revealed the strong effect of thermal pre-treatment on final microstructure and mechanical properties of extruded materials. The Hall–Petch relation between grain size and tensile yield strength has been suggested in this paper based on the literature review and presented data. The observed behavior strongly supports the fact that the Hall–Petch of extruded Mg–3Nd–0.5 Zn alloys with different texture intensities cannot be clearly estimated and predicted. In addition, Hall–Petch relations presented in literature can be sufficiently obtained only for fraction of the Mg–3Nd–0.5 Zn alloys.

关键词： Mg–Nd–Zn alloys Extrusion Thermal treatment Microstructure Mechanical properties

Practice of Glycemic Self-Monitoring in Diabetic Patients Followed at the Endocrinology Department of Donka University Hospital in Guinea

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Open Journal of Endocrine and Metabolic Diseases 2024年第2期14卷 33-38页

作者： Mamadou Dian Mamoudou Diallo Mamadou Mansour Diallo Mamadou chérif Diallo Alpha Mamadou Diallo Kadija Dieng Abdoul Mazid Diallo Mody Abdoulaye Barry Kadidiatou Bah El’Hadj Zainoul Bah Mamadou Alpha Diallo Ibrahima Condé Ousmane Kourouma Amadou Kaké Diabetology Unit Labe Regional Hospital Labé Guinea Faculty of Health Sciences and Techniques Gamal Abdel Nasser University of Conakry Conakry Guinea Endocrinology and Diabetology Department of Donka University Hospital Conakry Guinea Pediatrics Department of Donka University Hospital Conakry Guinea

Diabetes is a chronic pathology whose evolution is marked by micro and macroangiopathic complications. Optimal management can prevent the onset of complications and improve patients’ quality of life. Objectives: To determine the frequency of self-monitoring of blood glucose and to describe the errors found during self-monitoring in diabetic patients followed at the Endocrinology Department of Donka University Hospital in Guinea. Materials and methods: Descriptive cross-sectional study carried out between August and September 2020 involving diabetic patients followed up at the Endocrinology and Diabetology Department of the Donka National Hospital, chU Conakry. results: A total of 301 patients were enrolled, with an average age of 44.24 ± 21.01 years. 64.12% were female. Type 2 diabetes predominated in 64% of cases. The mean duration of diabetes was 6.14 ± 4.67 years, and 75.08% of patients lived in urban areas. Patients were on insulin in 36.21% of cases, insulin and biguanides (26.25%), hypoglycemic sulfonamide and biguanides (19.27%) and biguanides in 18.27% of cases. The frequency of self-monitoring of blood glucose was 43%, and 38% of patients made errors, notably reusing lancets (60%), not checking the expiration date (55.65%) and not washing their hands (48%). Conclusion: This study shows that self-monitoring of blood glucose is not performed by the majority of patients. Numerous errors were identified during blood glucose testing. Continued therapeutic education on the use of blood glucose meters will help empower patients and improve their quality of life.

关键词： Self-Monitoring of Blood Glucose Diabetes Conakry University Hospital

Unveiling osteoprotective potential of biologically active naringenin in rats with dexamethasone-induced osteoporosis

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Digital chinese Medicine 2024年第2期7卷 171-183页

作者： Tejal r.Waykar Satish K.Mandlik Deepa S.Mandlik Poona College of Pharmacy Bharati VidyapeethPune 411038India

Objective To investigate the protective effects of naringenin(NrG)against dexamethasone(DEX)-induced osteoporosis(OP)in *** Molecular docking of NrG was done with AutoDock Vina 1.2.0 ***-eight female Wistar rats were randomly divided into six groups(n=8 each):normal control(NC),DEX(7 mg/kg,i.m.),NrG-low(NrG-L;25 mg/kg,i.g.),NrG-medium(NrG-M;50 mg/kg,i.g.),NrG-high(NrG-H;100 mg/kg,i.g.),and alendronate(ALN;0.25 mg/d,i.g.)*** was induced by administering DEX once a week for five weeks in all groups except NC *** in the third week after the initial DEX administration,the rats in NrG-L,NrG-M,NrG-H,and ALN groups received the corresponding treatments daily for three weeks,while NC and DEX groups received no additional *** samples were collected at the end of the experiment for biochemical,bone turnover,antioxidant,lipid profile,and inflammatory cytokine *** bones underwent physical parameter testing and histopathological *** The molecular docking results illustrated that NrG docked with calcitonin(CT),lowdensity lipoprotein(LDL),bone morphogenetic protein(BMP),vascular endothelial growth factor(VEGF)receptor,forkhead transcription factors,and osteoprogenitor cells showed good binding *** rats administered with 25,50,and 100 mg/kg NrG,there was a significant enhancement in serum biochemical indices,characterized by a reduction in tartrate-resistant acid phosphatase(TrAP),parathyroid hormone(PTH),and an elevation in osteocalcin(OC)and CT levels(Prespectively).Despite no significant changes in thickness,weight,and length(P>0.05),there was a marked increase in bone mineral density(BMD)(Prespectively).Antioxidant enzyme markers showed significant upregulation,with higher glutathione,superoxide dismutase,and catalase,and a concurrent decrease in malondialdehyde(MDA)(Prespectively).The lipid profile also improved significa

关键词： Naringenin Osteoporosis Dexamethasone Bone turnover markers Inflammatory cytokines

rumen microbial degradation of bromoform from red seaweed(Asparagopsis taxiformis)and the impact on rumen fermentation and methanogenic archaea

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Journal of Animal Science and Biotechnology 2024年第1期15卷 412-426页

作者： Pedro romero Alejandro Belanche Elisabeth Jiménez rafael Hueso Eva ramos-Morales Joan King Salwen Ermias Kebreab David r.Yáñez-ruiz Estacion Experimental del Zaidin Consejo Superior de Investigaciones Cientificas(CSIC)Profesor Albareda 1Granada 18008Spain Department of Animal Production and Food Sciences University of ZaragozaMiguel Servet 177Saragossa 50013Spain Blue Ocean Barns Inc. Redwood CityCAUSA Department of Animal Science University of CaliforniaDavisCA 95618USA

Background The red macroalgae Asparagopsis is an effective methanogenesis inhibitor due to the presence of halogenated methane(ch_(4))analogues,primarily bromoform(chBr_(3)).This study aimed to investigate the degradation process of chBr3 from A taxiformis in the rumen and whether this process is *** in vitro batch culture system was used according to a 2×2 factorial design,assessing two A taxiformis inclusion rates[0(CTL)and 2%DM diet(AT)]and two diets[high-concentrate(HC)and high-forage diet(HF)].Incubations lasted for 72 h and samples of headspace and fermentation liquid were taken at 0,0.5,1,3,6,8,12,16,24,48 and 72 h to assess the pattern of degradation of chBr_(3) into dibromomethane(ch_(2)Br_(2))and fermentation ***,an in vitro experiment with pure cultures of seven methanogens strains(Methanobrevibacter smithii,Methanobrevibacter ruminantium,Methanosphaera stadtmanae,Methanosarcina barkeri,Methanobrevibacter millerae,Methanorhermobacter wolfei and Methanobacterium mobile)was conducted to test the effects of increasing concentrations of chBr3(0.4,2,10and 50μmol/L).results The addition of AT significantly decreased ch_(4) production(P=0.002)and the acetate:propionate ratio(P=0.003)during a 72-h *** concentrations of chBr_(3) showed a rapid decrease with nearly 90%degraded within the first 3 h of *** the contrary,ch_(2)Br_(2) concentration quickly increased during the first 6 h and then gradually decreased towards the end of the *** chBr_(3) degradation nor ch_(2)Br_(2) synthesis were affected by the type of diet used as substrate,suggesting that the fermentation rate is not a driving factor involved in chBr_(3)*** in vitro culture of methanogens showed a dose-response effect of chBr3 by inhibiting the growth of ***,***,***,***,***,***,and *** The present work demonstrated that chBr_(3) from *** is quickly degrad

关键词： Bromoform metabolism Dibromomethane metabolism Methane mitigation Methanogens rumen microbiota Seaweed

Effect of TCA-depletion of extrinsic polypeptides on electron transport on oxidizing side of PS II

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chinese Science Bulletin 1997年第3期42卷 227-231页

作者： Li, r Shen, YG Xu, ch Lu, W Tu, TC Yao, S Lin, NY Shanghai Institute of Plant Physiology Chinese Academy of Sciences Shanghai China Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai China Shanghai Institute of Nuclear research Chinese Academy of Sciences Shanghai China

PHOTOSYSTEM Ⅱ （PS Ⅱ） particles capable of O2 evolution contain reaction center polypeptides D1 and D2, cytchrome b559, chlorophyll （chl）-binding proteins CP47 and CP43, three extrinsic polypeptides （with apparent molecular masses of 17, 23 and 33 ku） and cofactors needed for light energy conversion. After illumination, PS Ⅱ oxygen evolution complex （OEC） catalyzes the oxidization of water to molecular oxygen through S0→S4 redox state transition. The three extrinsic polypeptides have been revealed to be closely related to the photosynthetic O2 evolution.

关键词： PSⅡ extrinsic polypeptide trichloroacetate (TCA-NaOH) FTIr EPr signal Ⅱ.

Multirange Fractal Analysis on the Negative Correlation between Fractal Dimension of Fractured Surface and Toughness of Materials

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Journal of Materials Science & Technology 1996年第4期12卷 318-320页

作者： Lung, CW Jiang, JA Zhang, ch International Centre for Materials Physics Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

Applying the concept of multirange fractals, a new explanation to the Williford's multifractal curve on the relationship of fractal dimension with fracture properties in materials has been given. It shows the importance of factorizing out the effect of fractal structure from other physical causes and separating the appropriate range of scale from multirange fractals.

关键词： Fracture

Electronic Absorption Spectroscopy of H2X （X=O, Te, Po）： Theoretical Treatment of Spin-Orbit Effects

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chinese Journal of chemical Physics 2009年第2期22卷 171-177页

作者： chérif A. A. Ndoye chantal Daniel Laboratoire de chimie Quantique Institut de Chimie UMR 7177 CNRS-Université de Strasbourg 4 Rue Blaise Pascal 67000 Strasbourg France

The electronic spectroscopy of H2X （X=O, Te, Po） was investigated by means of spinorbit configuration interaction （EPCISO） and restricted active space state interaction （SOrASSI）. The transition energies to the low-lying singlet and triplet states of H2O, in which the SO interaction is zero, compare rather well with the experimental data as well as to other theoretical values. The theoretical electronic absorption spectrum is characterized by three allowed transitions A^1B1 （2px（O）→σ^＊g/3s（O））, B^1A1（σg→σ^＊g/3s（O）） and A^1S2（σg→σ^＊u） calculated at 7.68, 9.94, and 11.72 eV, respectively. The theoretical absorption spectra of H2X （X=Te, Po） are shifted to the red with the A^1B1 （npx（X）→σ^＊g） states calculated at 5.06 eV （H2Te） and 4.40 eV （H2Po） and the A^1B2 （σg→σ^＊u） states calculated at 7.89 eV （H2Te） and 7.77 eV （H2Po）. The largest SO splitting amounts to 0.34 eV and is found for the lowest a^3A1 of H2Po. In H2Te the SO effects are still negligible with a maximum splitting of 0.04 eV for the lowest a^3B2. The two methods lead to comparable results but the EPCISO approach depends strongly on the reference wavefunction.

关键词： Spin-orbit Excited state Group Ⅵ dihydride

Ship Hull Slamming Analysis with Nonlinear Boundary Element Method

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china Ocean Engineering 1997年第4期12卷 411-418页

作者： Lu, ch He, YS Shanghai Jiao Tong Univ Dept Mech Engn Shanghai 200030 Peoples R China

A boundary element method is developed for calculating the flare ship hull slamming problem. The nonlinear free surface elevation and the linear element assumption are employed. The method has been verified by comparisons with results for the water entry of wedges with various deadrise angles. Numerical results show that the pressure distribution varies greatly with the ship hull with different curvilinear equations, and the slamming features are also different; From the numerical simulation, the authors found that the structural damage of the flare hull might be caused by the increasing hydrodynamic pressure over an extensive area on the flare when the upper part of the flare comes into contact with water.

关键词： slamming boundary element method ship full slamming analysis

Enhanced biological wastewater treatment using sodium alginate-immobilized microorganisms in a fluidized bed reactor

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Water Science and Engineering 2022年第2期15卷 125-133页

作者： Yaneth A.Bustos-Terrones Erick r.Bandala Gabriela E.Moeller-chávez Victoria Bustos-Terrones Division of Graduate Studies and research CONACYT-TecNM-Technological Institute of CuliacánCuliacánSinaloa 80220Mexico Division of Hydrologic Sciences Desert Research InstituteLas VegasNV 89119-7363USA Academic Direction of Environmental Technology Engineering Polytechnic University of the State of MorelosJiutepecMorelos 62550Mexico

In this study,a microbial consortium isolated from an activated sludge tank of a conventional wastewater treatment plant was immobilized using sodium alginate(SA)as a support material for contaminant biodegradation in wastewater.A volume of 500 mL of activated sludge was immobilized in the SA beads(with a mass concentration of 25 g/L).The resulting SA beads were characterized,introduced into a fluidized bed reactor,fed with 1000 mL of the sample,and characterized again after the treatment *** SA-immobilized microorganisms were tested first for degradation of organic matter(expressed as chemical oxygen demand)and total phosphorous in domestic wastewater,achieving removal efficiencies of 71%and 93%,respectively,after 12 ***,the SA-immobilized microorganisms were tested for degradation of a basic blue 9(BB9)textile dye in a condition that simulated textile *** efficiency of the BB9 degradation was found to be as high as 99.5%after 2 *** to these results,SA-immobilized microorganisms were found to be an environmentally friendly and cost-effective alternative for treatment of municipal and industrial wastewater effluents.

关键词： Domestic wastewater Basic blue 9 Immobilized microorganisms Fluidized bed reactor Sodium alginate