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Correct Interpretation of Creep Rates: A Case Study of Cu

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Journal of Materials Science & Technology 2015年第11期31卷 1065-1068页

作者： W.Blum J.Dvoák p.Král p.Eisenlohr V.Sklenika Institut für Werkstoffwissenschaften University of Erlangen-Nürnberg Institute of physics of Materials Academy of Sciences of the Czech Republic Department of Chemical Engineering and Materials Science Michigan State University

Traditionally the deformation resistance in creep is characterized by the minimum creep rate εmin and its sensitivity to stress （stress exponent n） and temperature （activation energy Q）. Various values of constant n have been reported in the literature and interpreted in terms of specific mechanisms. The present case study of coarse-grained Cu at 573 K yields a stress exponent n = 9 for εmin. in tension and a relatively low activation energy. The evolution of the deformation resistance with strain at constant tensile creep load and comparison with creep in compression without fracture indicates that the tensile εmin. result from transition from uniform deformation to strain localization during fracture. This is confirmed by the results of creep in compression where fracture is suppressed. Both the tensile εmin, and the compressive creep rate at strains around 0.3 can be described using existing equations for quasi-stationary deformation containing the subgrain boundary misorientation θ as structure parameter. While in the latter case constant θ leads to monotonic increase of n with stress, the tensile nine-power-law results from variable θ, and has no simple meaning. The result of this case study means that uncritical interpretation of minimum tensile creep rates as stationary ones bears a high risk of systematic errors in the determination of creep parameters and identification of creep mechanisms.

关键词： Cu Creep Minimum creep rate Activation energy Stress exponent

A rationale for the development of thermally stable nanostructured CeO_2-ZrO_2-containing mixed oxides

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Journal of Rare Earths 2008年第2期26卷 136-140页

作者： Roberta Di Monte Jan ka.par Heather Bradshaw Colin Norman Department of Chemistry Sciences Interuniversity Consortium INCA University of Trieste Via L.Giorgieri34127 Trieste Italy MEL Chemicals P.O. Box 6 Clifton Junction SwintonManchester M27 8LS England

CeO2-ZeO2 solid solutions are extensively used as oxygen storage promoters in the current automotive three-way catalysts. High thermal stability of the textural properties is one of the most important requirements for practical application since temperatures up to 1273 K are easily experienced by these materials under real working conditions. In the present paper, we investigated how hydrothermal treatments applied to cakes of doped and undoped ZrO2-rich CeO2-ZrO2 precursors might improve the thermal stability of the final CeO2-ZrO2 solid solution. A rationale was developed that allowed to correlate the morphology of the hydrothermaUy treated cake with the thermal stability at 1273 K of the final product, which did not depend on the composition of the mixed oxides.

关键词： CeO2-ZrO2 mixed oxides CeO2-ZrO2 solid solution CeO2-ZrO2 mixed oxides, thermal stability of three-way catalysts oxygen storage capacity rare earths

Advantageous mechanochemical synthesis of copper(Ⅰ)selenide semiconductor,characterization,and properties

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Frontiers of Chemical Science and Engineering 2022年第3期16卷 433-442页

作者： katarína gáborová Marcela Achimovičová Michal Hegedüs Vladimír girman Mária kaňuchová Erika Dutková Institute of geotechnics Slovak Academy of SciencesKošice04001Slovakia Institute of Metallurgy Faculty of MaterialsMetallurgy and RecyclingTechnical UniversityKošice04201Slovakia Synthon s.r.o.Blansko67801Czech Republic Faculty of Science Pavol JozefŠafárik UniversityKošice04154Slovakia Institute of Earth Resources Faculty of MiningEcologyProcess Control and GeotechnologiesTechnical UniversityKošice04200Slovakia

Copper(I)selenide-nanocrystalline semiconductor was synthesized via one-step mechanochemical synthesis after 5 min milling in a planetary ball *** kinetics of synthesis was followed by X-ray powder diffraction analysis and specific surface area measurements of milled 2Cu/Se *** X-ray diffraction confirmed the orthorhombic crystal structure of Cu_(2)Se with the crystallite size∼25 *** surface chemical structure was studied by X-ray photoelectron spectroscopy,whereby the binding energy of the Cu 2p and Se 3d signals corresponded to Cu^(+)and Se^(2−)oxidation *** electron microscopy revealed agglomerated nanocrystals and confirmed their orthorhombic structure,as *** optical properties were studied utilizing ultraviolet-visible spectroscopy and photoluminescence *** direct bandgap energy 3.7 eV indicated a blue-shift phenomenon due to the quantum size *** type of Cu_(2)Se synthesis can be easily adapted to production dimensions using an industrial vibratory *** advantages of mechanochemical synthesis represent the potential for inexpensive,environmentally-friendly,and waste-free manufacturing of Cu_(2)Se.

关键词： Cu_(2)Se berzelianite nanocrystalline semiconductor mechanochemical synthesis planetary ball mill

Understanding the role of pIN1 in hepatocellular carcinoma

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World Journal of gastroenterology 2016年第45期22卷 9921-9932页

作者： Chi-Wai Cheng ka-Wai Leong Eric Tse Department of Medicine The University of Hong Kong Queen Mary Hospital

pIN1 is a peptidyl-prolyl cis/trans isomerase that binds and catalyses isomerization of the specific motif comprising a phosphorylated serine or threonine residue preceding a proline(p Ser/Thr-pro) in proteins. pIN1 can therefore induce conformational and functional changes of its interacting proteins that are regulated by proline-directed serine/threonine phosphorylation. Through this phosphorylation-dependent prolyl isomerization, pIN1 fine-tunes the functions of key phosphoproteins(e.g., cyclin D1, survivin, β-catenin and x-protein of hepatitis B virus) that are involved in the regulation of cell cycle progression, apoptosis, proliferation and oncogenic transformation. pIN1 has been found to be over-expressed in many cancers, including human hepatocellular carcinoma(HCC). It has been shown previously that overexpression of pIN1 contributes to the development of HCC invitro and in xenograft mouse model. In this review, we first discussed the aberrant transcription factor expression, miR NAs dysregulation, pIN1 gene promoter polymorphisms and phosphorylation of pIN1 as potential mechanisms underlying pIN1 overexpression in cancers. Furthermore, we also examined the role of pIN1 in HCC tumourigenesis by reviewing the interactions between pIN1 and various cellular and viral proteins that are involved in β-catenin, NOTCH, and pI3K/Akt/mT OR pathways, apoptosis, angiogenesis and epithelial-mesenchymal transition. Finally, the potential of pIN1 inhibitors as an anti-cancer therapy was explored and discussed.

关键词： phosphorylation Hepatocellular carcinoma pIN1 Isomerization Hepatocarcinogenesis

新疆生产建设兵团人间布鲁氏菌病流行特征分析及发病趋势预测

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中国人兽共患病学报 2024年第3期40卷 276-282页

作者：范奔马晓玲杨柳根赵倩王童敏李凡卡石河子大学医学院预防医学系石河子832000 新疆生产建设兵团疾病预防控制中心乌鲁木齐830002

目的分析新疆生产建设兵团2010-2022年布病流行特征,建立Holt-Winters乘法模型(Holt-Winters Smoothing,HWS)并预测后期布病发病趋势,为制定布病防治措施提供参考依据。方法收集“中国疾病预防控制信息系统”的传染病报告信息管理系统... 详细信息

目的分析新疆生产建设兵团2010-2022年布病流行特征,建立Holt-Winters乘法模型(Holt-Winters Smoothing,HWS)并预测后期布病发病趋势,为制定布病防治措施提供参考依据。方法收集“中国疾病预防控制信息系统”的传染病报告信息管理系统中的兵团2010-2022年布病发病数据,采用描述性流行病学方法分析兵团2010-2022年布病流行特征;运用python 3.7软件建立Holt-Winters模型并预测兵团2022-2024年布病月发病数。结果兵团2010-2022年共报告布病病例6278例,年均报告发病率为16.68/10万,整体呈现上升趋势(趋势χ^(2)=44.874,ppp<0.001)。兵团报告病例数最多的地区为第八师1051例(16.76%);其次为第六师911例(14.53%)和第三师853例(13.60%)。Holt-Winters乘法模型预测2022-2024年报告发病数分别为675例、644例和679例,预测模型的R 2=0.78,拟合效果较好。结论近年来,兵团布病发病人数整体仍处于上升阶段,兵团各师应继续加强对于布病的管控。

关键词：布鲁氏菌病新疆生产建设兵团流行特征发病预测

Mechanism of metastasis by membrane type 1-matrix metalloproteinase in hepatocellular carcinoma

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World Journal of gastroenterology 2005年第40期11卷 6269-6276页

作者： Ying-Chi Ip Siu-Tim Cheung ka-Ling Leung Sheung-Tat Fan Centre for the Study of Liver Disease and Department of Surgery

AIM To investigate the precise role of membrane type 1-matrix metalloproteinase （NTI-NNp） in hepatocellular carcinoma （HCC） metastasis. METHODS- Human HCC cells Hep3B with overexpression of MTT-MMp were established by stable transfection, and compared with control cells carrying the empty vector. Cells were examined in vivo for their differences in the metastatic ability of athymic nude mice, and analyzed in vito for their differences in invasion ability by invasion chamber coated with Matrigel, adhesion towards collagen I and migration through culture chamber. Cell proliferation and apoptosis in adherent and suspension status were evaluated by MTr and flow cytometry analysis. RESULTS We found that overexpression of MT1-MMp could increase intrahepatic metastasis in nude mice with orthotopic implantation of HCC cells （incidence of 100% [MT1-MMp transfectants] vs 40% [vector control transfectants], p〈0.05）. NT1-MMp could also enhance cell invasion through Natrigel （107.7 vs 39.3 cells/field, p〈0.001）, adhesion towards matrix （0.30 vs 0.12 absorbance unit at 540 nm, p〈0.001）, cell migration （89.3 vs 39.0 cells/field, p〈0.001）, and cell proliferation （24.3 vs 40.5 h/doubling, p〈0.001）. We also observed that NTI-NNp supported cell survival （71.4% vs 23.9%, p〈0.001） with reduced apoptosis （43.7% vs51.0%, p〈0.05） in an attachment-free environment. CONCLUSION： MT1-MMp overexpression could enhance metastasis. In addition to its active role in matrix degradation during tumor invasion, MT1-MMp enhances tumor cell survival upon challenge of detachment, which is important during metastasis when cells enter the circulation.

关键词： MT1-MMpIMMp14 Liver cancer Invasion Metastasis

Clinical and economic consequences of pancreatic fistula after elective pancreatic resection

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Hepatobiliary & pancreatic Diseases International 2013年第5期12卷 533-539页

作者： Filip Ceka Bohumil Jon Zdeněk ubrt Alexander Ferko Department of Surgery Faculty of Medicine and University Hospital Hradec Králové Department of Field Surgery Military Health Science FacultyHradec KrálovéDefence University Brno

BACKgROUND:postoperative pancreatic fistula is the main cause of morbidity after pancreatic *** study aimed to quantify the clinical and economic consequences of pancreatic fistula in a medium-volume pancreatic surgery ***:Hospital records from patients who had undergone elective pancreatic resection in our department were *** fistula was defined according to the International Study group on pancreatic Fistula(ISgpF).The consequences of pancreatic fistula were determined by treatment cost,hospital stay,and out-patient follow-up until the pancreatic fistula was completely *** costs of the treatment are calculated in *** cost increase index was calculated for pancreatic fistula of grades A,B,and C as multiples of the total cost for the no fistula ***:In 54 months,102 patients underwent elective pancreatic *** patients(39.2%) developed pancreatic fistula,and 54 patients(52.9%) had one or more *** median length of hospital stay for the no fistula,grades A,B,and C fistula groups was 12.5,14,20,and 59 days,*** hospital stay of patients with fistula of grades B and C was significantly longer than that of patients with no fistula(pgrades A,B,and C fistula groups,***:The grading recommended by the ISgpF is useful for comparing the clinical severity of fistula and for analyzing the clinical and economic consequences of pancreatic *** fistula prolongs the hospital stay and increases the cost of treatment in proportion to the severity of the fistula.

关键词： pancreatic resection pancreatic fistula cost analysis

Amelioration of experimental colitis by Astragalus membranaceus through anti-oxidation and inhibition of adhesion molecule synthesis

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World Journal of gastroenterology 2005年第37期11卷 5787-5794页

作者： Joshua ka-Shun Ko Flora Ying-Lee Lam Andrew pok-Lap Cheung School of Chinese Medicine Hong Kong Baptist University Hong Kong China

AIM: To investigate the protective effects of Astragalus membranaceus(Am) against hapten-induced colitis in male Sprague-Dawley rats as well as its underlying ***: Experimental colitis was induced in rats by enema administration of 2,4-dinitrobenzene sulfonic acid (DNBS). Rats were either pretreated with Am extract (2 or 4 g/kg, p.o. once daily) starting from 10 d before DNBS enema, or received Am post-treatment (2 or 4 g/kg, *** daily) on the three consecutive days following DNBS administration. Colonic lesion area and histological damage were determined, while the activities of myeloperoxidase (MpO) and xanthine oxidase, as well as reduced glutathione (gSH) content were measured in the excised colonic tissues. Besides, protein expression of inducible nitrite oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1) and p-selectin was also detected by Western blot ***: Our findings had shown that both macroscopic lesion area and histological colonic damage induced by DNBS were significantly reduced by both Am pre- and post-treatments. These were accompanied by attenuation of the elevated colonic MpO activity and downregulation of the iNOS, p-selectin, and ICAM-1 protein ***, deprivation of colonic gSH level under colitis condition was also ***: These results demonstrate that Am possesses both preventive and therapeutic potential in experimental colitis. The anti-inflammatory actions involve anti-oxidation along with inhibition of adhesion molecule synthesis in the colonic tissues.

关键词： IBD, Astragalus membranaceus, Reactiveoxygen metabolites Adhesion molecules

Q-p process Optimization With the Use of Quenching Dilatometer

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Journal of Iron and Steel Research International 2011年第S1期18卷 417-421页

作者： Hauserová Daniela Novy Zbysek Motyka.petr Dzugan Jan COMTES FHT a.s. Prumyslová 995334 41 DobranyCzech Republic

The current efforts in production of low-alloyed steels are aimed at achieving high ultimate and yield strengths,while maintaining sufficient elongation and good weldability in these *** advanced heat treatment processes capable of reaching this goal,there is also the Q-p process (Quenching and partitioning).The process consists in rapid quenching of the material between the M s and M f temperatures in order to prevent full martensitic *** immediately following heating leads to tempering of the martensite and to diffusion of excess carbon from martensite to retained *** increases the stability of the *** aim of the Q-p process is to produce very fine martensite microstructure with retained austenite between martensite *** experimental programme was carried out on a high-strength low-alloyed steel containing 0.2% carbon and a higher amount of silicon about 1.5%.Higher silicon content in the microstructure contributes to stabilization of retained austenite by suppressing formation of *** grade of steel is an advantageous material thanks to its low amount of alloying *** group of low-alloyed steels,if heat treated or thermomechanically treated in a suitable manner,offers a favourable combination of strength,elongation and *** paper is aimed at possibility of the Q-p process optimization with the use of quenching *** experimental material is CMnSiMo *** process optimization consists of standard samples treatment in laboratory furnaces and *** procedure can be time consuming with higher requirements on the experimental ***,it was proposed that the Q-p process optimization can be done with the use of quenching dilatometer and in this way the development of new procedures can be accelerated.Q-p processes were conducted in the standard way and with the aid of a *** of the obtained results provided by the standard procedure and

关键词： Q-p process dilatometer low-alloyed steel