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| 1 | Step kinematic calibration of a 3-DOF planar parallel kinematic machine tool显示文摘This paper presents a novel step kinematic calibration method for a 3 degree-of-freedom(DOF) planar parallel kinematic machine tool,based on the minimal linear combinations(MLCs) of error parameters.The method using mapping of linear combinations of parameters in error transfer multi-parameters coupling system changes the modeling,identification and error compensation of geometric parameters in the general kinematic calibration into those of linear combinations of parameters.By using the four theorems of the MLCs,the sets of the MLCs that are respectively related to the relative precision and absolute precision are determined.All simple and feasible measurement methods in practice are given,and identification analysis of the set of the MLCs for each measurement is carried out.According to the identification analysis results,a step calibration including step measurement,step identification and step error compensation is determined by taking into account both measurement costs and observability.The experiment shows that the proposed method has the following merits:(1) the parameter errors that cannot influence precision are completely avoided;(2) it reflects the mapping of linear combinations of parameters more accurately and enhances the precision of identification;and(3) the method is robust,efficient and effective,so that the errors in position and orientation are kept at the same order of the measurement noise.Due to these merits,the present method is attractive for the 3-DOF planar parallel kinematic machine tool and can be also applied to other parallel kinematic machine tools with weakly nonlinear kinematics. | CHANG Peng,WANG JinSong,LI TieMin,LIU XinJun & GUAN LiWen Department of Precision Instruments and Mechanology,Tsinghua University,Beijing 100084,China | 2008 | Science China(Technological Sciences)2008，51，12： | 9 |
| 2 | Homing Strategy for a 4RRR Parallel Kinematic Machine显示文摘Returning home is the most important process of a parallel kinematic machine (PKM) with incremental encoders.Currently,most corresponding articles focus on the accuracy of homing process,and there lacks the investigation of the operation's safety.For a 4RRR PKM,all servoaxes would be independently driven to their zero positions at the same time based on the traditional homing mode,and that can bring serious interfere of the kinematic chains.This paper systemically investigates this 4RRR PKM's safety of homing process.A homing strategy usually contains three parts which are the home switches' locations,the platform's initial moving space,and each links' homing direction,and all of them can influence the safety of homing operation.For the purpose of evaluating and describing the safety of the homing strategy,some important parameters are introduced as follows:Safely homing ratio (SHR) is used to evaluate the probability of a machine's successfully returning home from an initial moving space;Synchronal rotational angle (SRA) is the four links' largest synchronal rotational angle with given directions from a given pose.Whether a machine can safely return home from a given pose can be judged by comparing the SRA with all four home switches' mounting angles.By meshing the initial moving space and checking the safeties of returning home from all the initial poses on the nodes,the SHR of this initial moving space can be calculate.For the sake of convenience,the platform's initial moving space should be as large as possible,and in this 4RRR PKM,a square zone in the center of the workspace with a giving initial rotation range is selected as the platform's initial moving space.The forward direction is selected as each link's homing direction according to custom,and the platform's initial rotational angle is selected as larger than 0° based on this 4RRR PKM's kinematic characteristics.The platform's initial moving space can be defined only by the side length of the initial moving square.By setting a probable searching step and calculating the SHR of the initial moving square,an optimal procedure of searching for the largest side length of the platform's initial moving square is proposed.The homing strategy proposed is based on a systemic research on the safety of homing process for PKM,and the two new indexes SHR and SRA can clearly describe the safety of homing operation.The homing operation based on this strategy is fast and safe,and the method can also be used in other PKMs with the situation of serious components' interference. | WANG Liping LIU Dawei LI Tiemin | 2011 | Chinese Journal of Mechanical Engineering2011，24，3： | 2 |
| 3 | Protective effects of Purendan superfine powder on retinal neuron apoptosis in a rat model of type 2 diabetes mellitus显示文摘This study sought to investigate the effects of Purendan superfine powder comprised of Momordica charantia, Radix Ginseng, and Radix Salviae Miltiorrhiae on neuronal apoptosis and expression of bcl-2, bax, and caspase-3, which are retinal apoptosis-associated factors in rats with diabetes mellitus induced by continuous intraperitoneal injection of streptozotocin. The results showed that Purendan superfine powder could upregulate the expression of bcl-2 protein and mRNA, and downregulate the expression of bax and caspase-3 in the retina of diabetes mellitus rats. In addition, Purendan superfine powder was shown to reduce the number of apoptotic neurons. Our experimental findings indicate that Purendan superfine powder can inhibit neuronal apoptosis in the retina of diabetes mellitus rats and has protective effects on diabetic retinopathy. | Zhijun Dong Xiangyi Tao Xiaoxiao Fu Haibin Wang Donghua Wang Tiemin Zhang | 2012 | Neural Regeneration Research2012，7，3： | 2 |
| 4 | Gankyrin promotes tumor growth and metastasis through activation of IL‐6/STAT3 signaling in human cholangiocarcinoma显示文摘 | Tongsen Zheng Xuehui Hong Jiabei Wang Tiemin Pei Yingjian Liang Dalong Yin Ruipeng Song Xuan Song Zhaoyang Lu Shuyi Qi Jiaren Liu Boshi Sun Changming Xie Shangha Pan Yuejin Li Xiaohe Luo Shuai Li Xiang Fang Nishant Bhatta Hongchi Jiang Lianxin Liu | 2014 | Hepatology2014，，： | 2 |
| 5 | Running Accuracy Analysis of a 3-RRR Parallel Kinematic Machine Considering the Deformations of the Links显示文摘Parallel kinematic machines have drawn considerable attention and have been widely used in some special fields.However,high precision is still one of the challenges when they are used for advanced machine tools.One of the main reasons is that the kinematic chains of parallel kinematic machines are composed of elongated links that can easily suffer deformations,especially at high speeds and under heavy loads.A 3-RRR parallel kinematic machine is taken as a study object for investigating its accuracy with the consideration of the deformations of its links during the motion process.Based on the dynamic model constructed by the Newton-Euler method,all the inertia loads and constraint forces of the links are computed and their deformations are derived.Then the kinematic errors of the machine are derived with the consideration of the deformations of the links.Through further derivation,the accuracy of the machine is given in a simple explicit expression,which will be helpful to increase the calculating speed.The accuracy of this machine when following a selected circle path is simulated.The influences of magnitude of the maximum acceleration and external loads on the running accuracy of the machine are investigated.The results show that the external loads will deteriorate the accuracy of the machine tremendously when their direction coincides with the direction of the worst stiffness of the machine.The proposed method provides a solution for predicting the running accuracy of the parallel kinematic machines and can also be used in their design optimization as well as selection of suitable running parameters. | WANG Liping JIANG Yao LI Tiemin | 2014 | Chinese Journal of Mechanical Engineering2014，27，5： | 2 |
| 6 | Lztfl1/BBS17 controls energy homeostasis by regulating the leptin signaling in the hypothalamic neurons显示文摘在前脑的视下丘表明小径的 Leptin 受体(LepRb ) 响应一个改变的精力状态控制食物吸入和精力开销。在表明小径的 LepRb 的缺点能导致 leptin 抵抗和肥胖。象 1 一样的白氨酸拉链抄写因素(Lztfl1 )/BBS17 是 Bardet-Biedl 症候群(BBS ) 的一个成员基因家庭。人的 BBS 病人包括肥胖有大量病理。位于调整 Lztfl1 的肥胖下面的细胞、分子的机制是未知的。这里,我们产生了 Lztfl1 Lztfl1 能全球性并且以织物特定的方式在被删除的 f/f 老鼠模型。全球 Lztfl1 缺乏包括肥胖导致了多种的显型。Lztfl1 / 老鼠是 hyperphagic 并且作为 WT 同窝出生的人显示出类似的精力开销。Lztfl1 / 老鼠的肥胖的显型被 Lztfl1 的损失在大脑然而并非在 adipocytes 引起。Lztfl1 / 老鼠是 leptin 抵抗的。Lztfl1 的 Inactivation 在在 leptin 刺激之上在视下丘表明小径的 LepRb 废除了 Stat3 的 phosphorylation。Lztfl1 的删除没在 LepRb 膜本地化上有效果。而且,我们观察了胚胎的成纤维细胞(MEF ) 有的那只 Lztfl1 / 老鼠显著地更长的睫比 WT MEF。我们识别了潜在地与 Lztfl1 交往的几蛋白质。当这些蛋白质被知道涉及肌动朊 / 细胞骨架动力学的规定,我们建议 Lztfl1 可以调整 leptin 经由这些蛋白质发信号和睫的结构。我们的学习在在控制精力动态平衡的视下丘表明小径的 LepRb 作为一个新奇播放器识别了 Lztfl1。 | Qun Wei Yi-Feng Gu Qing-Jun Zhang Helena Yu Yan Peng Kevin W. Williams Ruitao Wang Kajiang Yu Tiemin Liu Zhi-Ping Liu | 2018 | Journal of Molecular Cell Biology2018，10，5： | 1 |
| 7 | Dynamic analysis of the 2- DOF planar parallel manipulator of a heavy duty hybrid machine tool 显示文摘 | Wu Jun Wang Jinsong Li Tiemin | 2007 | The International Journal of Advanced Manufacturing Technology2007，34，12： | 1 |
| 8 | Stiffness and natural frequency of a 3-DOF parallel manipulator with consideration of additional leg candidates显示文摘 | WU Jun LI Tiemin WANG Jinsong | 2013 | Robotics and Autonomous Systems2013，61，8： | 1 |
| 9 | Analysis and application of a 2-DOF planar parallel mechanism显示文摘 | WU Jun WANG Jinsong LI Tiemin | 2007 | Journal of Mechanical Design2007，129，4： | 1 |
| 10 | Nerve growth factor downregulates c-jun mRNA and Caspase-3 in striate cortex of rats after transient global cerebral ischemia/reperfusion显示文摘BACKGROUND: Immediate early gene (IEG) c-jun is a sensitive marker for functional status of nerve cells. Caspase-3 is a cysteine protease, which is a critical regulator of apoptosis. The effect of exogenous nerve growth factor (NGF) on the expression of c-jun mRNA and Caspase-3 protein in striate cortex of rats with transient global cerebral ischemia/reperfusion (IR) is unclear. OBJECTIVE: To study the protective effect of exogenous NGF on the brain of rats with transient global cerebral IR and its effecting pathway by observing the expression of c-jun mRNA and Caspase-3 protein. DESIGN: Randomized controlled animal trial. SETTING: Department of Neural Anatomy, Institute of Brain, China Medical University.MATERIALS:Eighteen healthy male SD rats of clean grade, aged 1 to 3 months, with body mass of 250 to 300 g, were involved in this study. NGF was provided by Dalian Svate Pharmaceutical Co.,Ltd. c-jun in situ hybridization detection kit, Caspase-3 antibody and SABC kit were purchased from Boster Biotechnology Co.,Ltd.METHODS: This trial was carried out in the Department of Neural Anatomy, Institute of Brain, China Medical University during September 2003 to April 2005. ① Experimental animals were randomized into three groups with 6 in each: sham-operation group, IR group and NGF group.②After the rats were anesthetized, the bilateral common carotid arteries and right external carotid arteries of rats were bluntly dissected and bilateral common carotid arteries were clamped for 30 minutes with bulldog clamps. Reperfusion began after buldog clamps were removed. Normal saline of 1mL and NGF (1×106 U/L) of 1 mL was injected into the common carotid artery of rats via right external carotid arteries in the IR group and NGF group respectively. The injection was conducted within 30 minutes, and then the right external carotid arteries were ligated. In the sham-operation group, occlusion of bilateral common carotid arteries and administration of drugs were omitted.③All the rats were executed by decollation at 3 hours after modeling. The animals were fixed with phosphate buffer solution (PBS, 0.1 mol/L) containing 40 g/L polyformaldehyde, their brains were quickly removed. The coronal section tissue mass containing striate cortex about 3 mm before line between two ears was taken and made into successive frozen sections.④The expression of c-jun mRNA and Caspase-3 protein in striate cortex of global cerebral ischemia rats were detected with in situ hybridization, immunohistochemistry and microscope image analysis. ⑤t test was used for comparing the difference of the measurement data.MAIN OUTCOME MEASURES:Comparison of the expression of IEG c-jun mRNA and Caspase-3 protein in striate cortex of brain of rats in each group.RESULTS:All the 18 SD rats were involved in the analysis of results. The c-jun mRNA and Caspase-3 protein positive reaction cells were found brown yellow in the striate cortex of rats, and most of them were in lamellas Ⅱ and Ⅲ, mainly presenting round or oval. The expression of c-jun mRNA and Caspase-3 protein in sham-operation group was weak or negative. The average gray value of c-jun mRNA and Caspase-3 protein in the IR group was significantly lower than that in the sham-operation group (49.52±4.13 vs. 95.48±5.28; 74.73±4.29 vs. 162.38±9.16,P < 0.01). The average gray value of c-jun mRNA and Caspase-3 protein in the NGF group was significantly higher than that in the IR group (63.96±4.25 vs.49.52±4.13; 83.98±4.13 vs. 74.73±4.29, P < 0.05). CONCLUSION: NGF can protect ischemic neurons by down-regulating the expression of c-jun mRNA and Caspase-3 protein in striate cortex of global cerebral ischemia rats. | Dacheng Jin Tiemin Wang Xiubin Fang | 2006 | Neural Regeneration Research2006，1，4： | 1 |
| 11 | Study on the stiffness of a 5-DOF hybrid machine tool with actuation redundancy显示文摘 | WANG Jinsong WANG Liping LI Tiemin | 2009 | Mechanism and Machine Theory2009，44，2： | 1 |
| 12 | Over-expression of CXCR4 on mesenchymal stem cells augments myoangiogenesis in the infarcted myocardium显示文摘 | Dongsheng Zhang Guo-Chang Fan Xiaoyang Zhou Tiemin Zhao Zeeshan Pasha Meifeng Xu Yi Zhu Muhammad Ashraf Yigang Wang | 2007 | Journal of Molecular and Cellular Cardiology2007，，2： | 1 |
| 13 | PolyvasculaR Evaluation for Cognitive Impairment and vaScular Events (PRECISE)-a population-based prospective cohort study: rationale, design and baseline participant characteristics显示文摘Background and purpose Cardiovascular diseases and dementia are two major diseases in the elderly.Atherosclerosis is associated with future vascular events and cognitive impairment.The PolyvasculaR Evaluation for Cognitive Impairment and vaScular Events(PRECISE)study is a population-based prospective cohort study with comprehensive evaluation of multiterritorial artery stenosis and plaque using advanced vascular imaging techniques and prospective collection of vascular events and cognitive assessments.Methods Between May 2017 and September 2019,the PRECISE study enrolled 3067 community-dwelling adults with ages between 50 and 75 years cluster sampled from six villages and four communities of Lishui city in China.Data are collected in face-to face interviews at baseline,2-year and 4-year follow-up visits.Brain MRI including high-resolution sequences for intracranial and carotidal arteries and CT angiography for thoracoabdominal arteries were performed at baseline and will be rescanned after 4 years.Cardiovascular/cerebrovascular events and cognitive assessment will be prospectively collected after the enrollment.Blood and urine samples were collected and biomarkers were tested at baseline.Results A total of 3067 subjects were enrolled,among which 53.5%were female with an average age of 61.2±6.7 years.Among them,2.8%,8.1%,43.1%and 21.6%had a history of stroke,coronary heart diseases,hypertension and diabetes mellitus,respectively.Conclusions The PRECISE study is a population-based prospective cohort study with comprehensive evaluation of atherosclerotic stenosis and plaque using advanced vascular imaging techniques.Data from this cohort provide us an opportunity to precisely evaluate polyvascular atherosclerosis and its association with future vascular events and cognitive impairment. | Yuesong Pan Jing Jing Xueli Cai Yilong Wang Suying Wang Xia Meng Chunlai Zeng Jiong Shi Jiansong Ji Jinxi Lin Lingchun Lyu Zhe Zhang Lerong Mei Shiping Li Shan Li Wanlin Zhu Hao Li Tiemin Wei Yongjun Wang | 2021 | Stroke & Vascular Neurology2021，6，1： | 1 |
| 14 | Dynamic dexterity of a planar 2-DOF parallel manipulator in a hybrid machine tool显示文摘 | WU Jun WANG Jinsong LI Tiemin | 2007 | Robotica2007，26，1： | 1 |
| 15 | Thermal sensor selection for the thermal error modelingof machine tool based on the fuzzy clustering method显示文摘 | WANG Haitong WANG Liping LI Tiemin | 2013 | International Journal of Advanced ManufacturingTechnology2013，69，14： | 1 |
| 16 | Dynamic formulation of redundant and nonredundant parallel manipulators for dynamic parameter identification显示文摘 | Jun Wu Jinsong Wang Liping Wang Tiemin Li | 2009 | Mechatronics2009，，4： | 1 |
| 17 | Dynamics and control of a planar 3-DOF parallel manipulator with actuation redundancy显示文摘 | Jun Wu Jinsong Wang Liping Wang Tiemin Li | 2008 | Mechanism and Machine Theory2008，，4： | 1 |
| 18 | Work- space and Singularity Analysis of a 3--DOF Planar Parallel Manipulator with Actuation Redundancy 显示文摘 | Wang Jinsong Wu Jun Li Tiemin | 2009 | Robotiea2009，27，： | 1 |
| 19 | Analysis and application of a 2-DOF planar parallel mechanism显示文摘 | WU Jun WANG Jinsong LI Tiemin | 2007 | Journal of Mechanical Design2007，129，4： | 1 |
| 20 | Analysis and application of a 2-DOF planar parallel mechanism显示文摘 | WU Jun WANG Jinsong LI Tiemin | 2007 | Journal of Mechanical Design2007，129，4： | 1 |
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