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Mechanism and prediction of failure of diamond films deposited on various substrates by HFCVD

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中国有色金属学会会刊：英文版 2004年第z1期14卷 229-233页

作者： ZHOU Ling-ping SUN xin-yuan LI Shao-lu LI De-yi CHEN Xiao-hua College of Material Science and Engineering Hunan University Changsha 410082 China College of Material Science and Engineering Hunan University Changsha 410082 China College of Material Science and Engineering Hunan University Changsha 410082 China College of Material Science and Engineering Hunan University Changsha 410082 China College of Material Science and Engineering Hunan University Changsha 410082 China

Diamond films were deposited on the WC-Co cemented carbide and Si3N4 ceramic cutting tool substrates by hot-filament-assisted chemical vapour deposition. The adherence property of diamond films was estimated using the critical load (Pcr) in the indentation test. The adhesive strength of diamond films is related to the intermediate layer between the film and the substrate. Poor adhesion of diamond films to polished cemented carbide substrate is owing to the formation of graphite phase in the interface. The adhesion of diamond films deposited on acid etched cemented carbide substrate is improved, and the peeling-off of the films often happens in the loosen layer of WC particles where the cobalt element is nearly removed. The diamond films' adhesion to cemented carbide substrate whose surface layer is decarbonizated is strengthened dramatically because WC phase forms by reaction between the deposited carbon and tungsten in the surface layer of substrates during the deposition of diamond, which results in chemical combination in the film-substrate interface. The adhesion of diamond films to silicon nitride substrate is the firmest due to the formation of chemical combination of the SiC intermediate layer in the interfaces. In the piston-turning application, the diamond-coated Si3N4 ceramic and the cemented carbide cutting tools usually fail in the form of collapsing of edge and cracking or flaking respectively. They have no built-up edge(BUE) as long as coating is *** it wears through, BUE develops and the cutting force on it increases 1 - 3 times than that prior to failure. This can predict the failure of diamond-coated cutting tools.

关键词： diamond film cutting tool adhesion failure prediction cemented carbide

Effect of carrier screening on ZnO-based resistive switching memory devices

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Nano Research 2017年第1期10卷 77-86页

作者： yihui Sun Xiaoqin Yan xin Zheng Yong Li yichong Liu Yanwei Shen yi Ding Yue Zhang State Key Laboratory for Advanced Metals and Materials School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Municipal Key Laboratory of New Energy Materials and Technologies University of Science and Technology Beijing Beijing 100083 China

The carrier screening effect occurs commonly in dielectric materials. It reduces the electric potential gradient, thus negatively affecting the functionality of resistive random access memory （RRAM） devices. An Au/ZnO film/Al-doped ZnO device fabricated in this work exhibited no resistive switching （RS）, which was attributed to the carrier screening effect. Therefore, annealing was used for alleviating the screening effect, significantly enhancing the RS property. In addition, different on/off ratios were obtained for various bias values, and the screening effect was accounted for by investigating electron transport mechanisms. Furthermore, different annealing temperatures were employed to modulate the free carrier concentration in ZnO films to alleviate the screening effect. The maximal on/off ratio reached 10s at an annealing temperature of 600 ℃, yielding the lowest number of free carriers and the weakest screening effect in ZnO films. This work investigates the screening effect in RS devices. The screening effect not only modulates the characteristics of memory devices but also provides insight into the mechanism of RS in these devices.

关键词： resistive switch carrier screening effect carrier concentration potential gradient annealing

Application of Induced Pluripotent Stem Cells Derived from Human Periodontal Ligament Cells in Bone Regeneration

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Wuhan University Journal of Natural Sciences 2020年第5期25卷 404-410页

作者： HE Tianrong YAN Qi WU xinyu shi Bin LIN yi Shengli Clinical College of Fiyian Medical University Fujian Provincial HospitalFuzhou 350001FujianChina School of Stomatology Wuhan UniversityWuhan 430072HubeiChina

The purpose of this study was to primarily culture human periodontal ligament cells(hPDLCs)and to reprogram hPDLCs with exogenous genes via a lentivirus-mediated transfection *** induced pluripotent stem cells derived from h PDLCs(hPDLC-iPSCs)were *** red staining was used to observe the formation of mineralized nodules and real-time Polymerase Chain Reaction(PCR)was used to detect the expression of osteogenic *** the in vivo experiment,nude mouse skull defect models were established and cell sheets were made to repair the bone *** reprogrammed cells were positive for alkaline phosphatase(ALP)staining and embryonic stem cells(ESCs)-specific proteins,and could form *** osteogenic induction,alizarin red staining showed that the number of mineralized nodules in the h PDLC-i PSCs group was more and the osteogenic related factors ALP,osteocalcin(OCN),Col-I and Runx2 were also expressed higher in *** hPDLC-iPSC cell sheets were all successfully *** analysis showed that the h PDLC-i PSC cell sheet got new bone *** results demonstrated that hPDLC-iPSCs were successfully generated from human periodontal ligament fibroblasts and hPDLC-iPSC cell sheets provided new options for bone tissue engineering.

关键词： induced pluripotent stem cells(iPSCs) osteogenesis cell sheet bone defect periodontal tissue regeneration

Bayesian mapping of neural tube defects prevalence in Heshun County, Shanxi Province, China during 1998～2001

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第6期8卷 921-925页

作者： CHI Wen-xue WANG Jin-feng LI xin-hu ZHENG Xiao-ying LIAO yi-lan China University of Geosciences Beijing 100083 China Institute of Geographical Sciences and Nature Resources Research Chinese Academy of Sciences Beo＇ing 100101 China Institute of Population Research Peking University Beijing 100871 China

Objective: To estimate the prevalence rates of neural tube defects (NTDs) in Heshun County, Shanxi Province, China by Bayesian smoothing technique. Methods: A total of 80 infants in the study area who were diagnosed with NTDs were analyzed. Two mapping techniques were then used. Firstly, the GIS software ArcGIS was used to map the crude prevalence rates. Secondly, the data were smoothed by the method of empirical Bayes estimation. Results: The classical statistical approach produced an extremely dishomogeneous map, while the Bayesian map was much smoother and more interpretable. The maps produced by the Bayesian technique indicate the tendency of villages in the southeastern region to produce higher prevalence or risk values. Conclusions: The Bayesian smoothing technique addresses the issue of heterogeneity in the population at risk and it is therefore recommended for use in explorative mapping of birth defects. This approach provides procedures to identify spatial health risk levels and assists in generating hypothesis that will be investigated in further detail.

关键词： Birth defects Neural tube defects (NTDs) Disease map Spatial analysis Bayesian smoothing China

基于OBE教育理念的高职“外科护理学”课程教学模式研究

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教育教学论坛 2024年第24期 158-161页

作者：黄艳张恒彪李时宜周方才云南新兴职业学院护理学院云南昆明655100

为探讨OBE教育理念在高职“外科护理学”课程教学中的应用与实践成效,通过对临床外科护理能力的调研,形成能力需求报告,运用OBE教育理念,将外科护理能力需求融入课程教学目标,对教学措施、教学策略和教学评价进行改革设计,在学校2021级... 详细信息

为探讨OBE教育理念在高职“外科护理学”课程教学中的应用与实践成效,通过对临床外科护理能力的调研,形成能力需求报告,运用OBE教育理念,将外科护理能力需求融入课程教学目标,对教学措施、教学策略和教学评价进行改革设计,在学校2021级高职护理专业学生中随机选取两个班级,其中一个班级采用传统教学法教学,另一个班级采用融入OBE理念的教学模式教学,课程结束后对两个班级的学生成绩和能力提升进行对比分析。结果发现,融入OBE教育理念的“外科护理学”课程教学实验组的学习成绩、对理论知识理解、分析问题和解决问题能力明显高于传统教学对照组。OBE教育理念运用于“外科护理学”课程教学效果良好,一些教学措施和教学评价环节有待完善。

关键词： OBE教育理念外科护理学教学模式

HDAC2抑制剂CAY10683通过自噬对急性肝衰竭小鼠的保护作用

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中西医结合肝病杂志 2024年第2期34卷 126-130页

作者：张璐懿石春霞张丹眉龚作炯武汉大学人民医院感染科湖北武汉430061

目的:探究HDAC2抑制剂CAY10683在急性肝衰竭小鼠模型中的保护机制。方法:将C57BL/6雄性小鼠随机分为正常组、模型组、CAY10683组、自噬抑制剂MRT68921组和CAY10683/MRT68921联合组。D-氨基半乳糖和脂多糖诱导建立急性肝衰竭小鼠模型,获... 详细信息

目的:探究HDAC2抑制剂CAY10683在急性肝衰竭小鼠模型中的保护机制。方法:将C57BL/6雄性小鼠随机分为正常组、模型组、CAY10683组、自噬抑制剂MRT68921组和CAY10683/MRT68921联合组。D-氨基半乳糖和脂多糖诱导建立急性肝衰竭小鼠模型,获取小鼠血清及肝脏标本。检测血清中丙氨酸氨基转移酶和天门冬氨酸氨基转移酶含量;一部分肝组织用于HE染色和电镜下观察,另一部分肝组织用于生化检测,蛋白质印迹法检测自噬蛋白UNC-51样激酶1和苹果酸脱氢酶1(MDH1)的相对含量,生化试剂盒检测组织中葡萄糖、丙酮酸、乳酸和乳酸脱氢酶含量。结果:CAY10683可增加急性肝衰竭小鼠模型中肝脏内的自噬水平,对小鼠肝脏具有一定的保护作用,CAY10683可降低急性肝衰竭小鼠模型中肝组织内的葡萄糖、丙酮酸、乳酸和LDH含量,增加肝组织内MDH1含量;MRT68921则相反;CAY10683一定程度上可拮抗MRT68921的作用。结论:HDAC2抑制剂CAY10683在小鼠肝衰竭进程中可能通过提高自噬水平改善肝脏内代谢,对肝脏起到一定的保护作用。

关键词：急性肝衰竭自噬代谢 HDAC2抑制剂

Excitation-Contraction Coupling Time is More Sensitive in Evaluating Cardiac Systolic Function

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Chinese Medical Journal 2018年第15期131卷 1834-1839页

作者： Juan Gao Min Zhu Hai-yi Yu shi-Qiang Wang xin-Heng Feng Ming Xu Department of Cardiology and Institute of Vascular Medicine Peking University Third Hospital Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides Ministry of Health Key Laboratory of Molecular Cardiovascular Science Ministry of Education Beijing Key Laboratory of Cardiovascular Receptors Research Beijing 100191 China State Key Laboratory of Membrane Biology College of Life Sciences Peking University Beijing 100871 China

Background： Pressure overload-induced myocardial hypertrophy is a key step leading to heart failure. Previous cellular and animal studies demonstrated that deteriorated excitation-contraction coupling occurs as early as the compensated stage of hypertrophy before the global decrease in left ventricular ejection fraction （LVEF）. This study was to evaluate the cardiac electromechanical coupling time in evaluating cardiac systolic function in the early stage of heart failure. Methods： Twenty-six patients with Stage B heart failure （SBHF） and 31 healthy controls （CONs） were enrolled in this study. M-mode echocardiography was performed to measure LVEF. Tissue Doppler imaging （TDI） combined with electrocardiography （ECG） was used to measure cardiac electromechanical coupling time. Results： There was no significant difference in LVEF between SBHF patients and CONs （64.23 ± 8.91% vs. 64.52 ± 5.90%; P= 0.886）. However, all four electromechanical coupling time courses （Qsb： onset of Q wave on ECG to beginning of S wave on TDI, Qst： onset of Q wave on ECG to top of S wave on TDI, Rsb： top of R wave on ECG to beginning orS wave on TDI, and Rst： top of R wave on ECG to top orS wave on TDI） of SBHF patients were significantly longer than those of CONs （Qsb： 119.19 ± 35.68 ms vs. 80.30 ± 14.81 ms, P 〈 0.001 ; Qst： 165.42 ± 60.93 ms vs. 129.04 ± 16.97 ms, P = 0.006; Rsb： 82.43 ± 33.66 ms vs. 48.30 ± 15.18 ms, P 〈 0.001; and Rst： 122.37 ± 36.66 ins vs. 93.25 ± 16.72 ms, P = 0.001 ）, and the Qsb, Rsb, and Rst time showed a significantly higher sensitivity than LVEF （Rst： P =0.032; Rsb： P = 0.003; and Qsb： P = 0.004）. Conclusions： The cardiac electromechanical coupling time is more sensitive than LVEF in evaluating cardiac systolic function.

关键词： Excitation-Contraction Couplings Heart Failure Left Ventricular Dysfunction

Effect of modification degrees on the interfacial properties and EOR efficiency of amphiphilic Janus graphene oxide

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Petroleum Science 2023年第2期20卷 1217-1224页

作者： Han Jia xin Wei Qiu-Xia Wang Yuan-Bo Wang shi-Jie Wen Fang-Ning Fan Qiang Wang Zhe Wang De-xin Liu Pan Huang Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdaoShandong 266580China Shandong Key Laboratory of Oilfield Chemistry School of Petroleum EngineeringChina University of Petroleum(East China)QingdaoShandong 266580China Bohai Oilfield Research Institute Tianjin BranchCNOOC China LimitedTianjin 300459China Department of Chemical and Materials Engineering University of AlbertaEdmonton AB T6G 1H9Canada

Asymmetrically modified Janus graphene oxide(JGO)has attracted great attention due to its unique physical chemistry properties and wide *** modification degree of Janus nanosheets inevitably affects their interfacial activity,which is essential for their performances in enhanced oil recovery(EOR).In this study,the interfacial properties of Janus graphene oxide(JGO)with various modification degrees at liquid-liquid and liquid-solid interfaces were systematically evaluated via the measurements of interfacial tension(IFT),dilatational modulus,contact angle,and EOR efficiency was further assessed by core flooding *** is found that JGO-5 with higher modification degree exhibits the greater ability to reduce IFT(15.16 mN/m)and dilatational modulus(26 mN/m).Furthermore,JGO can construct interfacial and climbing film with the assistance of hydrodynamic power to effectively detach the oil from the rock surface and greatly enhance oil *** modified JGO-2 can highly improve recovery of residual crude oil(11.53%),which is regarded as the promising EOR agent in practical *** present study firstly focuses on the effects of modification degrees on the JGO interfacial properties and proposes diverse EOR mechanisms for JGO with different modification degrees.

关键词： Graphene oxide Modification degrees Janus nanosheets Interfacial film EOR

Perioperative transcutaneous electrical acupoint stimulation for improving postoperative gastrointestinal function:A randomized controlled trial

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Journal of Integrative Medicine 2021年第3期19卷 211-218页

作者： Wen-jing Li Chao Gao Li-xin An Yu-wei Ji Fu-shan Xue yi Du Department of Anesthesiology Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China Department of Anesthesiology Beijing Hui-Min HospitalBeijing 100053China Department of Traditional Chinese Medicine Beijing Friendship HospitalCapital Medical UniversityBeijing 100050China

Background:Postoperative gastrointestinal dysfunction(PGD)is one of the most common complications in patients undergoing major abdominal *** has been used widely in gastrointestinal diseases due to its effectiveness and minimally invasive ***:This study evaluated the efficacy of using transcutaneous electrical acupoint stimulation(TEAS)during the surgery and postoperative recovery in patients with gastric and colorectal surgery for improving postoperative gastrointestinal ***,setting,participants and interventions:A total of 280 patients undergoing abdominal surgery were stratified by type of surgery(i.e.,gastric or colorectal surgery)and randomly allocated into the TEAS group(group T)or the sham group(group S).Patients in group T received TEAS at LI4,PC6,ST36 and *** in group S received pseudo-TEAS at sham *** stimulation was given from 30 min before anesthesia until the end of *** same treatment was performed at 9 am on the 1st,2nd and 3rd days after surgery,until the recovery of flatus in *** outcome measures:The primary outcome was the time to the first bowel motion,as detected by *** secondary outcomes included the first flatus and ambulation time,changes of perioperative substance P(SP),incidence of PGD,postoperative pain,postoperative nausea and vomiting(PONV)and some economic ***:The time to first bowel motion,first flatus and first ambulation in group T was much shorter than that in group S(P<0.01).In patients undergoing colorectal surgery,the concentration of SP was lower in group T than in group S on the third day after the operation(P<0.05).The average incidence of PGD in all patients was 25%,and the frequency of PGD was significantly lower in group T than in group S(18.6%vs.31.4%,respectively;P<0.05).TEAS treatment(odds ratio=0.498;95%confidence interval:0.232–0.786)and type of surgery were relevant factors for the development of ***

关键词： Transcutaneous electrical acupoint stimulation Postoperative period Gastrointestinal disorders Substance P