检索结果-南通市图书馆

Chinese Science Bulletin 2002年第9期47卷 732-736页

作者： Zhang, j Cao, Yj Liu, WM Zhao, BS Zeng, GQ Duan, EK Chinese Acad Sci Inst Zool State Key Lab Reprod Biol Beijing 100080 Peoples R China

There are striking similiarities present between the behavior of invasive placentaL cells and that of invasive cancer cells. Matrix metalloproteinases (MMPs) are one of the most important mediators. MMP-28, the new member of MMPs, was sequenced and identified recently. Expression of MMP-28 mRNA and protein in the cytotrophoblast cells and a choriocarcinoma cell line, jEG-3 cell, was conducted by zymography, RT-PCR and Northern blot. There is MMP-28 mRNA expression in both the cytotrophoblast cells and jEG-3 cells by RT-PCR. The activity of MMP-28 in cytotrophoblast cells was significantly weaker than that in jEG-3 (P jEG-3 than in human cytotrophoblast cells in a time-dependent way by Northern Blot. Our results suggest that MMP-28 may play a role in some of the tissue-remodeling events associated with normal pregnancy and tumor progression.

关键词： cytotrophoblast cell choriocarcinoma cell line jEG-3 matrix metalloproteinases MMP-28.

EFFECT OF TEMPERATURE ON THE FRACTURE MODES OF BHW-35 STEEL UNDER MODE-Ⅱ LOADING

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 1997年第1期10卷 76-85页

作者： Fu Yongqing Gu Yanwei(School of Mat.Sci.and Eng.,Xi’an jiao Tong Univ.Xi’an 710048,China)jing Xiaotian(School of mal.Sci.Eng.,Xi’an Univ.of Technology.Xi’an 710048.China)Margam Chandrasekaran(Materinls Lab.School of MPE.Nangang Technological Univ.Singapore 639798) brc.edu

Finite element method(FEM)has been used to analyze the stress and strain fields and the stress tri-axial levels around the tip of the crack under mode-Ⅱ *** results show that: under mode-Ⅱ loading,the direction of the maximum tensile stress and that of the maximum tri-axial levels(R_ )exist at an angle of-75.3°from the original crack plane:the maximum shear stress and R_ =0 exist along the original crack plane. Mode-Ⅱ loading experiment using BHW-35 steel at different temperatures show that there are two kinds of fracture *** mode(or tensile mode)and sliding mode(or shear mode).A de- crease in temperature causes the fracture mode to change from shear mode to tensile *** BHW- 35 steel,this critical temperature is *** any kind of loading mode(mode Ⅰ,mode Ⅱ,mode Ⅲ or mixed mode),there always exist several kinds of potenital fracture modes (for example,opening *** *** mode or mixed mode).The effect of temperature under mode-Ⅱ loading is actually related to the change of the elastic-plastic properties of the material.

关键词： finite element method mode-Ⅱ loading j integral

Respiratory plasticity following spinal cord injury:perspectives from mouse to man

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2022年第10期17卷 2141-2148页

作者： Katherine C.Locke Margo L.Randelman Daniel j.Hoh Lyandysha V.Zholudeva Michael A.Lane Department of Neurobiology&Anatomy Drexel UniversityPhiladelphiaPAUSA Marion Murray Spinal Cord Research Center PhiladelphiaPAUSA Lillian S.Wells Department of Neurosurgery University of FloridaGainesvilleFLUSA Cardiovascular Disease Gladstone InstitutesSan FranciscoCAUSA

The study of respiratory plasticity in animal models spans *** the bench,researchers use an array of techniques aimed at harnessing the power of plasticity within the central nervous system to restore respiration following spinal cord *** field of research is highly clinically *** living with cervical spinal cord injury at or above the level of the phrenic motoneuron pool at spinal levels C3-C5 typically have significant impairments in breathing which may require assisted *** who are ventilator dependent are at an increased risk of ventilator-associated co-morbidities and have a drastically reduced life ***-clinical research examining respiratory plasticity in animal models has laid the groundwork for clinical *** how widely researched this injury is in animal models,relatively few treatments have broken through the preclinical *** three goals of this present review are to define plasticity as it pertains to respiratory function post-spinal cord injury,discuss plasticity models of spinal cord injury used in research,and explore the shift from preclinical to clinical *** investigating current targets of respiratory plasticity research,we hope to illuminate preclinical work that can influence future clinical investigations and the advancement of treatments for spinal cord injury.

关键词： breathing phrenic plasticity rehabilitation respiration spinal cord injury translation

Characterizing and engineering promoters for metabolic engineering of Ogataea polymorpha

在线全文

学校读者我要写书评

暂无评论

Synthetic and Systems Biotechnology 2022年第1期7卷 498-505页

作者： Chunxiao Yan Wei Yu Xiaoxin Zhai Lun Yao Xiaoyu Guo jiaoqi Gao Yongjin j.Zhou School of Biological Engineering Dalian Polytechnic UniversityDalian116034PR China Division of Biotechnology Dalian Institute of Chemical PhysicsChinese Academy of Sciences457 Zhongshan RoadDalian116023PR China CAS Key Laboratory of Separation Science for Analytical Chemistry Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023PR China Dalian Key Laboratory of Energy Biotechnology Dalian Institute of Chemical PhysicsCAS457 Zhongshan RoadDalian116023PR China University of Chinese Academy of Sciences Beijing100049China

Bio-manufacturing via microbial cell factory requires large promoter library for fine-tuned metabolic *** polymorpha,one of the methylotrophic yeasts,possesses advantages in broad substrate spec-trum,thermal-tolerance,and capacity to achieve high-density ***,a limited number of available promoters hinders the engineering of *** for ***,we systematically characterized native promoters in *** by both GFP fluorescence and fatty alcohol *** constitutive promoters(P_(PDH),P_(PYK),P_(FBA),P_(PGM),P_(GLK),P_(TRI),P(GPI),P_(ADH1),P_(TEF1) and P_(GCW14))were obtained with the activity range of 13%–130% of the common promoter P_(GAP)(the promoter of glyceraldehyde-3-phosphate de-hydrogenase),among which P_(PDH) and P_(GCW14) were further verified by biosynthesis of fatty ***,the inducible promoters,including ethanol-induced P_(ICL1),rhamnose-induced P_(LRA3) and P_( LRA4),and a bidirectional promoter(P_(mal)-P_(Per))that is strongly induced by sucrose,further expanded the promoter toolbox in ***,a series of hybrid promoters were constructed via engineering upstream activation sequence(UAS),which increased the activity of native promoter P LRA3 by 4.7–10.4 times without obvious leakage ***,this study provided a group of constitutive,inducible,and hybrid promoters for metabolic engineering of ***,and also a feasible strategy for rationally regulating the promoter strength.

关键词： Ogataea polymorpha Promoter Hybrid promoter Upstream activation sequence Metabolic engineering Fatty alcohols

Crack patterns corresponding to the residual strength plateau of ceramics subjected to thermal shock

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2012年第3期28卷 670-674页

作者： H.-L.Hou X.-E Wu P.Yan F.Song j.Li C.-P.jiang School of Aeronautic Science and Engineering B eihang University100191 BeijingChina State Key Laboratory of Nonlinear Mechanics(LNM) Institute of MechanicsChinese Academy of Sciences100190 BeijingChina LSPM CNRS UPR 3407Universite Paris XIII99 Avenue Jean-Baptiste Clement93430 VilletaneuseFrance

The formation strength plateau of ceramics is addressed. A set of of 99A1203 are conducted, mechanism of the residual subjected to thermal shock thermal shock experiments where the thin specimens of 1 mm× 10 mm×50 mm exhibit parallel through edge cracks, and thus permit quantitative measurements of the crack patterns. The cracks evolve with the severity of ther- mal shock. It is found that there is a correlation between the length and density of the thermal shock cracks. The increase of crack length weakens the residual strength, whereas the increase of crack density improves it. In a considerably wide temperature range, the two contrary effects just counteract each other; consequently a plateau appears in the variation curve of the residual strength. A comparison between the numerical and experimental results of the residual strength is made, and they are found in good agreement. This work is helpful to a deep understanding of the thermal shock failure of ceramics.

关键词： Ceramics Thermal shock Crack patterns Residual strength - Stress intensity factor

THE PATHOLOGY AND TREATMENT OF jOINT SPRAIN

在线全文

学校读者我要写书评

暂无评论

中华医学杂志(英文版) 1935年第6期49卷 521-528页

作者： LEO j.MILTNER H.C.FANG From the Division of Orthopedic Surgery Department of Surgery and the Department of PathologyPeiping Union Medical CollegePeipingChina

The term sprain signifies an injury of the soft tissues within oraround a joint when the movements of that joint are carried beyondtheir normal physiological limits,or when the bones entering into theformation of the joint are deflected in some abnormal plane,withoutactual *** conditions such as previous injury or mal-alignment due to congenital or acquired causes(i.e.,congenital clubfoot,rachitic knock knee,etc.),predispose to *** lesions which occur during sprain vary consider-

关键词：

基于若当基底的含CAAWTS的三相动态最优潮流

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

电力系统及其自动化学报 2019年第11期31卷 53-61页

作者：崔志威李佩杰白晓清 CHENG j 广西大学广西电力系统最优化与节能技术重点实验室南宁530004 Department of Electrical and Computer Engineering University of Nebraska-LincolnLincolnUSA

建立了含小型压缩空气储能的风力发电系统CAAWTS(compressed-air-assisted wind turbine system)的配电网三相动态最优潮流模型,以达到在配电系统运行中发挥CAAWTS的最大效能,进一步提高风能利用效率的目的,同时能够提高配电系统运行的... 详细信息

建立了含小型压缩空气储能的风力发电系统CAAWTS(compressed-air-assisted wind turbine system)的配电网三相动态最优潮流模型,以达到在配电系统运行中发挥CAAWTS的最大效能,进一步提高风能利用效率的目的,同时能够提高配电系统运行的经济性。提出一种基于若当基底的配电网三相动态最优潮流求解算法,基于若当基底的锥优化技术,寻求原问题的特征值和特征向量,将原问题转换为混合整数二阶锥优化问题进行求解,此外,若当基底所得锥处于标准二阶锥的边界,可显著提高求解效率。IEEE33和IEEE123测试系统仿真验证了所提模型的可行性以及所提求解方法的高效性和寻优精确性。

关键词：分布式电源配电网若当基底动态最优潮流混合整数规划

用H_2/^(13)CO_2呼吸试验检测乳糖不耐受者呼气成分的研究

在线全文

学校读者我要写书评

暂无评论

卫生研究 2002年第3期31卷 180-183页

作者：钟燕阴文娅黄承钰 R.j.Vonk 四川大学华西公共卫生学院成都610041 Groningen University The Netherlands

为了找出能反映乳糖在肠道内分解吸收程度的良好指标 ,本研究根据乳糖负荷试验结果对筛选出的成人乳糖吸收不良者、轻度及重度乳糖不耐受者 ,研究乳糖不耐受症状与呼气成分之间的关系。在给予1 3C 乳糖 2 5g之后 ,收集 6小时的呼气样本 ... 详细信息

为了找出能反映乳糖在肠道内分解吸收程度的良好指标 ,本研究根据乳糖负荷试验结果对筛选出的成人乳糖吸收不良者、轻度及重度乳糖不耐受者 ,研究乳糖不耐受症状与呼气成分之间的关系。在给予1 3C 乳糖 2 5g之后 ,收集 6小时的呼气样本 ,分别采用气相色谱法和气相同位素质谱法测定各时间点呼气中的H2 浓度和1 3CO2 含量并计算其累积呼出量 ;通过问卷调查摄入乳糖后 12小时内出现的不适症状及其严重程度。结果显示 :乳糖不耐受组呼气H2 浓度升高达到峰值时间较吸收不良组快 ,且峰值显著高于吸收不良组 (P <0 .0 1) ;6小时累积H2 呼出量显著高于吸收不良组 (P <0 .0 1) ;口结肠转运时间 (OCTT)与不耐受症状评分呈负相关 (r=- 0 .70 5 ,P <0 .0 1) ;各时间点1 3CO2 的呼出量以及 6小时累积呼出量在乳糖不耐受组和吸收不良组之间无显著性差异。提示呼气中H2 浓度与不耐受症状的严重程度有相关关系 ,可以反映出乳糖在小肠内的吸收程度 ;口 -结肠转运时间与乳糖不耐受症状之间有一定相关关系 ;而呼气1 3CO2

关键词： H2/^13CO2呼气试验乳糖不耐受呼气成分研究口-结肠转运时间

ASTUDY OF VALENCE OF YTTRIUM IN Y_2O_3 Mo CATHODE

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1999年第4期12卷 602-606页

作者： j.S.Wang1,2) ,M.L.Zhou2) ,j.X.Zhang2) ,Z.R.Nie2) T.Y.Zuo2) and G.j.Zhang2) 1) State Key Laboratory of Materials Chemistry and Applications,Peking University ,Beijing 100871 ,China2) Schoolof Materials Science and Engineering ,Beijing Polytechnic Univers

The valenceofelementyttrium of Y2 O3 Mocathode materialhasbeenstudied by usingther mal weight analysis, X ray diffraction analysis, Scanning electron microscopy and X rayphotoelectronspectrum . It hasbeen provedthatyttrium oxidecan bereduced by molybdenum carbide. Thereaction between powdered Y2 O3 and Mo2 Ccan happen at 1173 , and Y2 O3may bereduced to metallicyttrium . Afterthepowder mixtureof Y2 O3 and Mo2 Cwasheat treated at1873 K, Yttrium existsin two kinds of chemicalstate- yttrium of zero valence and yttrium ofthreevalences.

关键词： valence,yttrium Y2 O3 Mo,cathode

无鱼粉日粮中豆饼与豆粕质量对肉用仔鸡和蛋鸡生产性能的影响

在线全文

学校读者我要写书评

暂无评论

中国农业科学 1992年第1期25卷 75-82页

作者：沈慧乐,张志博,j.D.Summers,S.M.Mirsalimi 北京农业大学北京农业大学加拿大圭尔富大学畜牧家禽系加拿大圭尔富大学兽医学院病理系北京 100094 北京 100094北京市饲料所

本文就无鱼粉日粮中豆饼与豆粕质量对肉用仔鸡和商品蛋鸡生产性能的影响进行了研究。试验结果表明:生豆粕使21日龄肉用仔鸡增重较正常豆粕组低159克,饲料转换率差0.4。饲喂生豆饼的母鸡与饲喂正常豆饼的母鸡的产蛋率相差20%(51.8%对72.2... 详细信息

本文就无鱼粉日粮中豆饼与豆粕质量对肉用仔鸡和商品蛋鸡生产性能的影响进行了研究。试验结果表明:生豆粕使21日龄肉用仔鸡增重较正常豆粕组低159克,饲料转换率差0.4。饲喂生豆饼的母鸡与饲喂正常豆饼的母鸡的产蛋率相差20%(51.8%对72.2%);蛋重相差1.8克(54.7对56.5克);饲料转换率差1.21(3.94对2.73);试验期末母鸡体重相差309克(1483对1792克),饲喂生豆饼母鸡处于减重状态。对豆饼与豆粕质量化学指标的评估表明,豆饼和豆粕化学指标关系密切。添加适量赖氨酸有助于克服过熟豆饼与豆粕的不利影响。

关键词：豆饼豆粕赖氨酸蛋白溶解度尿酶