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ampD-ampR调节基因与阴沟肠杆菌AmpC酶表达关系的研究

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首都医科大学学报 2004年第1期25卷 44-48页

作者：顾怡明张杰俞云松周志慧杜小玲首都医科大学附属北京天坛医院呼吸科浙江大学医学院附属第一医院传染科首都医科大学附属北京朝阳医院检验科

为了解ampD ampR调节基因与阴沟肠杆菌AmpC酶表达的关系 ,对 58株阴沟肠杆菌采用表型筛选法初筛 ,PCR法扩增AmpC酶的调节基因ampD和ampR ,并对部分PCR产物进行克隆测序。表型筛选结果显示 :去阻遏高产突变株为 50株 ,高度诱导产酶株为 ... 详细信息

为了解ampD ampR调节基因与阴沟肠杆菌AmpC酶表达的关系 ,对 58株阴沟肠杆菌采用表型筛选法初筛 ,PCR法扩增AmpC酶的调节基因ampD和ampR ,并对部分PCR产物进行克隆测序。表型筛选结果显示 :去阻遏高产突变株为 50株 ,高度诱导产酶株为 3株。PCR法扩增目的基因片段显示 ,4 9株携带ampD基因 ,51株携带ampR基因。对其中 15株细菌的ampD基因和ampR基因进行克隆测序 ,发现 3株高度诱导型中 2株ampD基因存在 95位氨基酸的突变位点 ,而ampR基因未发现突变位点 ;12株去阻遏高产型中 ,8株ampD基因存在羧基端可疑的突变位点 ,5株ampR基因存在可疑的突变位点。结果提示 :ampD蛋白羧基端的氨基酸缺失或替代可能与AmpC酶的去阻遏表达有关。

关键词： ampD-ampR调节基因阴沟肠杆菌 AmpC酶表达

Microstructure and properties of an Al-Zn-Mg-Cu alloy pre-stretched plate under various ageing conditions

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Rare Metals 2008年第6期27卷 652-656页

作者： DONG Xiaorui LI zhihui College of Mechatromc Engineering North University of China Taiyuan 030051 China State Key Laboratory for Fabrication and Processing of Nonferrous Metals General Research Institute for Nonferrous Metals Beijing 100088 China

The microstructures after various ageing treatments and their relation to the strength, fracture toughness, and corrosion behavior of an Al-Zn-Mg-Cu alloy pre-stretched plate were investigated. The results show that retrogression and reaging （RRA） treatment led to a combination of high strength and stress corrosion cracking （SCC） resistance of the alloy. The TEM microstructure of the RRA-treated alloy is a distribution of very fine precipitates in the aluminum matrix grains, similar to that obtained under T6 condition, and the distribution of coarse η MgZn2 precipitates on the grain boundaries similar to that obtained by T7 temper. SEM observations revealed that most of the intergranular fracture characteristics were present on the fracture surface of both the T6 and RRA-treated specimens. On the contrary, the fractographs of the T7 treated specimens mainly consisted of dimple-type ductile transgranular fracture with minor intergranular cracking.

关键词： Al-Zn-Mg-Cu alloy microstructure tensile strength stress corrosion cracking fracture characteristics

Effects of Optimized Operating Parameters on Combustion Characteristics and NO_(x)Emissions of a Burner based on Orthogonal Analysis

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Journal of Thermal Science 2021年第4期30卷 1212-1223页

作者： XU Qian AKKURT Nevzat YANG Gang ZHU Lidong SHI Kejian WANG Kang ZOU Zhenwei LIU zhihui WANG Jiulong du Zhiwei School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory for Energy Conservation and Emission Reduction for Metallurgical Industry Beijing 100083China Department of Mechanical Engineering Munzur UniversityTunceli 62000Turkey Department of Big Data Technology and Application Development Computer Network Information CenterChinese Academy of SciencesBeijing 100190China AVIC Xinxiang Aviation Industry(group)CO. LTDHenan 453002China

To optimize the structure of the burner,improve the combustion performance,and reduce the emission of NO_(x),a self-circulating low NO_(x)combustion technology was used to design a new type of flue gas self-circulating low NO_(x)*** on previous research on the numerical model of combustion and the composition of mixed gas on combustion and NO_(x)emissions,the effect of various factors on the ejection coefficient of the flue gas self-circulating structure was analyzed using the orthogonal test method,and the burner operating parameters,such as preheating temperature and excess air coefficient,were deeply studied through the three-dimensional finite element numerical model in this *** results show that the diameter ratio of the nozzle and the length of the cylindrical section of the flue gas self-circulating structure have great influence on its ejection and mixing *** optimal ejection coefficient was ***,the amount of NO_(x)emissions greatly increased from 6.23×10^(-6)(volume fraction)at the preheating temperature 973 K to 3.5×10^(-3)at preheating temperature 1573 *** the excess air coefficient decreased from 1.2 to 1,the maximum combustion temperature decreased from 2036.3 K to 1954.22 K,and the NO_(x)emissions decreased from 352.29×10^(-6)to 159.73×10^(-6).

关键词： preheating temperature excess air coefficient self-circulating flue gas low oxygen combustion low-NO_(x)emissions

特发性矮小症患儿血清Vaspin和SFRP5水平表达及其诊断价值研究

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现代检验医学杂志 2024年第1期39卷 95-99页

作者：吴迎爽薛向东杜志辉王利红程渊博牛晓庆王大伟张家口市第一医院儿科河北张家口075000 张家口市第一医院骨二科河北张家口075000

目的探索特发性矮小症(idiopathic short stature,ISS)患儿血清中内脏脂肪特异性丝氨酸蛋白酶抑制剂(visceral adipose tissue-derived serine protease inhibitor,Vaspin)和分泌型卷曲相关蛋白5(secreted frizzled-related protein5,SFRP5)的表达水平及其诊断价值。方法选取2021年12月~2023年2月在张家口市第一医院确诊的70例ISS患儿作为疾病组,同期选择72例体检健康的志愿儿童作为对照组。采用免疫发光法检测Vaspin的表达水平,酶联免疫吸附法(enzyme-linked immunosorbent assay,ELISA)检测SFRP5的表达水平,对两组儿童的临床资料进行分析。受试者工作特征(receiver operator characteristics curve,ROC)曲线分析血清Vaspin和SFRP5对ISS的诊断价值,多因素Logistic回归分析ISS发生的影响因素。结果与对照组比较,疾病组的血清Vaspin水平显著升高(2.89±0.92 ng/ml vs1.81±0.42 ng/ml),SFRP5水平显著降低(10.22±2.84 pg/ml vs 13.21±3.53 pg/ml),差异具有统计学意义(t=9.040,5.552,均P<0.05)。疾病组儿童的体重、身高、身体质量指数(body mass index,BMI)、性发育状态Ⅱ~Ⅴ期比例显著低于对照组儿童,差异具有统计学意义(t=7.687,6.330,5.559,7.074,均P<0.05);ROC曲线下面积(AUC)显示,Vaspin,SFRP5及二者联合检测诊断ISS患儿的AUC分别为0.768,0.849和0.925,二者联合诊断效能优于血清Vaspin,SFRP5各自单独诊断(Z=3.829,P<0.001;Z=2.141,P=0.032)。多因素Logistic回归分析显示BMI(OR=0.508,95%CI=0.260~0.991),Vaspin(OR=3.458,95%CI:1.125~10.631),SFRP5(OR=0.378,95%CI:0.153~0.935)是ISS的影响因素(均P<0.05)。结论ISS患儿血清中Vaspin表达水平显著升高,SFRP5表达水平显著降低,二者是ISS发生的影响因素,二者联合检测对ISS的诊断具有一定的价值。

关键词：特发性矮小症内脏脂肪特异性丝氨酸蛋白酶抑制剂分泌型卷曲相关蛋白5

Chemical mapping of cement pastes by using confocal Raman spectroscopy

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Frontiers of Structural and Civil Engineering 2016年第2期10卷 168-173页

作者： Fengjuan LIU zhihui SUN Department of Civil Construction and Environmental Engineering The University of Alabama Tuscaloosa AL 35487 United States Department of Civil and Environmental Engineering University of Louisville Louisville KY 40292 United States

In the present study, chemical mapping on the hydration process of cement paste with water-to-cement （w/c） ratio of 0.60 was implemented by Raman spectroscopy （RS）. The RS was applied to study the paste from 12 hours after mixing to 28 days. Cement ingredients and hydration products, including calcium silicates （C3S and C2S）, calcium hydroxide （CH）, and ettringite, were quantitatively studied. From the research, it is observed that calcium silicates were consumed gradually with the increased hydration age. Calcium hydroxide increased and tended to cluster in the pore vicinity during hydration. Ettringite was found to form on the surface of the unreacted particles, which was shown as a mixed zone of ettringite and calcium silicates in the maps. It is concluded from the study that chemical mapping was an effective method to assist in visualizing particle dispersion and connection on top of the quantitative analysis.

关键词： chemical mapping Raman spectroscopy calcium silicates calcium hydroxide ettringite

Microglia Interact with Neurons by Forming Somatic Junctions

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Neuroscience Bulletin 2020年第9期36卷 1085-1088页

作者： Yongjie Wang zhihui Huang Key Laboratory of Elemene Anti-Cancer Medicine of Zhejiang Province and Holistic Integrative Pharmacy Institutes Hangzhou Normal UniversityHangzhou 311121China Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province and Holistic Integrative Pharmacy Institutes Hangzhou Normal UniversityHangzhou 311121China Department of Neurosurgery The Affiliated Hospital of Hangzhou Normal UniversityHangzhou 310015China

Microglia are the main immune cells of the central nervous system that maintain normal neuronal *** cells are also linked with major diseases in humans including neurodegenerative disorders such as Alzheimer’ s disease,stroke,epilepsy,and psychiatric diseases such as schizophrenia [1].Microglia perform surveillance of the brain microenvironment through their motile processes.

关键词： epilepsy diseases functions.

Performance of a water hyacinth(Eichhornia crassipes)system in the treatment of wastewater from a duck farm and the effects of using water hyacinth as duck feed

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Journal of Environmental Sciences 2008年第5期20卷 513-519页

作者： LU Jianbo FU zhihui YIN Zhaozheng Institute of Agro-Ecology and Ecological Engineering College of Life Sciences Zijingang Campus Zhejiang University Hangzhou 310058 China College of Animal Sciences Huajiachi Campus Zhejiang University Hangzhou 310029 China

Nowadays, intensive breeding of poultry and livestock of large scale has made the treatment of its waste and wastewater an urgent environmental issue, which motivated this study. A wetland of 688 mz was constructed on an egg duck farm, and water hyacinth （Eichhornia crassipes） was chosen as an aquatic plant for the wetland and used as food for duck production. The objectives of this study were to test the role of water hyacinth in purifying nutrient-rich wastewater and its effects on the ducks＇ feed intake, egg laying performance and egg quality. This paper shows that the constructed wetland removed as much as 64.44% of chemical oxygen demand （COD）, 21.78% of total nitrogen （TN） and 23.02% of total phosphorus （TP）. Both dissolved oxygen （DO） and the transparency of the wastewater were remarkably improved, with its transparency 2.5 times higher than that of the untreated wastewater. After the ducks were fed with water hyacinth, the average daily feed intake and the egg-laying ratio in the test group were 5.86% and 9.79% higher, respectively, than in the control group; the differences were both significant at the 0.01 probability level. The egg weight in the test group was 2.36% higher than in the control group （P 〈 0.05）, but the feed conversion ratios were almost the same. The eggshell thickness and strength were among the egg qualities significantly increased in ducks fed with water hyacinth. We concluded that a water hyacinth system was effective for purifying wastewater from an intensive duck farm during the water hyacinth growing season, as harvested water hyacinth had an excellent performance as duck feed. We also discussed the limitations of the experiment.

关键词： water hyacinth (Eichhornia crassipes) duck farm constructed wetland chemical oxygen demand (COD) treatment effect egg-laying ratio egg quality

Impact vibration reduction for flexible manipulators via controllable local degrees of freedom

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Chinese Journal of Aeronautics 2013年第5期26卷 1303-1309页

作者： Bian Yushu Gao zhihui Deng Yuchun School of Mechanical Engineering and Automation Beihang University

When performing operation tasks, the interaction between a flexible manipulator and a grasped object usually results in an impact. In this paper, a new way is suggested to alleviate impact vibration of a flexible manipulator via its structural characteristic when capturing a moving object. Controllable local degrees of freedom are introduced to the topological structure of the flexible manipulator, and used as an effective tool to combat impact vibration through dynamic coupling. A corresponding method is put forward to reduce impact vibration responses of the flexible manip- ulator via the controllable local degrees of freedom. By planning motion of the controllable local degrees of freedom, appropriate control force can be constructed to increase the modal damping and stiffness and eliminate the exciting force simultaneously, thereby reducing impact vibration responses of the flexible manipulator. Simulations are conducted and results are shown to prove the presented method.

关键词： Degrees of freedom Dynamics Flexible manipulators Impact Vibration control

Biomechanics of Musculoskeletal System and Its Biomimetic Implications： A Review

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Journal of Bionic Engineering 2014年第2期11卷 159-175页

作者： Lei Ren zhihui Qian Luquan Ren School of Mechanical Aerospace and Civil Engineering University of Manchester Manchester M13 9PL UK Key Laboratory of Bionic Engineering (Ministry of Education China) Jilin University Changchun 130022 P. R. China

Biological musculoskeletal system （MSK）, composed of numerous bones, cartilages, skeletal muscles, tendons, ligaments etc., provides form, support, movement and stability for human or animal body. As the result of million years of selection and evolution, the biological MSK evolves to be a nearly perfect mechanical mechanism to support and transport the human or animal body, and would provide enormously rich resources to inspire engineers to innovate new technology and methodology to develop robots and mechanisms as effective and economical as the biological systems. This paper provides a general review of the current status of musculoskeletal biomechanics studies using both experimental and computational methods. This includes the use of the latest three-dimensional motion analysis systems, various medical imaging modalities, and also the advanced rigid-body and continuum mechanics musculoskeletal modelling techniques. Afterwards, several representative biomimetic studies based on ideas and concepts inspired from the structures and biomechanical functions of the biological MSK are dis- cussed. Finally, the major challenges and also the future research directions in musculoskeletal biomechanics and its biomimetic studies are proposed.

关键词： musculoskeletal system biomechanics multi-scale biomimetics biologically inspired robots and mechanisms