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受控多体系统的力约束分析与实验研究 被引量:6
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作者 王树新 刘又午 周大宁 《天津大学学报》 EI CAS CSCD 1997年第5期601-606,共6页
针对受控多体系统,提出力约束的概念、力学描述及其性质.通过引入偏(角)速度和广义力,以Kane方程为基础,建立了具有力约束的受控多体系统动力学方程,并实现了动力学求解.以工业机器人为例,分析了系统在力约束下的动力学解... 针对受控多体系统,提出力约束的概念、力学描述及其性质.通过引入偏(角)速度和广义力,以Kane方程为基础,建立了具有力约束的受控多体系统动力学方程,并实现了动力学求解.以工业机器人为例,分析了系统在力约束下的动力学解算方法,并进行了实验验证. 展开更多
关键词 系统 力约束 偏速度 偏角速度 机器人
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受控航行体水动参数的极大似然辨识 被引量:9
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作者 丁文镜 罗仁凡 +1 位作者 董琳 王树桂 《清华大学学报(自然科学版)》 EI CAS CSCD 北大核心 1992年第2期89-95,共7页
由受控航行体的非线性微分方程组导出小扰动线性方程;按实际可行的量测方案建立观测方程:根据极大似然原理导出辨识非线性动力学系统参数的全部算式;利用模拟观测数据作仿真辨识,求得7个水动参数。
关键词 航行 水动参数 参数辨识
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Modulatory Effect of Rg_1 on the Activity of ProteinTyrosine Kinase of Lymphocytes in the Elderly
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作者 刘俊达 王舒 刘红涛 《Journal of Chinese Pharmaceutical Sciences》 CAS 1996年第1期7-12,共6页
The effect of Rg1,a saponin extracted froin Panax ginseng, on the phenotype,receptor and the activity of protein tyrosine kinase (PTK) of lymphocytes isolated from 7 healthy oldpersons were studied. The CD25, CD45RA a... The effect of Rg1,a saponin extracted froin Panax ginseng, on the phenotype,receptor and the activity of protein tyrosine kinase (PTK) of lymphocytes isolated from 7 healthy oldpersons were studied. The CD25, CD45RA and CD45RO phenotypes of lymphocytes were 4eter-mined by indirect immunofluorescence technique. The percentage of CD25, CD45RA and CD45ROpositive lymphocytes was 38.3%±17.3%, 46.0% 15.1%, and 52.6%±14.1% respectively after incu-bation with PHA (5 μ±/ml) for 72 hours. However, there were 58.0%±12.5%, CD25, 64.1% ± 12.4%,CD45RA, and 74.0%±8.0%, CD45RO positive cells in the presence of Rg, ( 1μg/ml) along with PHA(5 μg/ml) over the sanie period of incubation. A significant increase was induced by Rgi (P<0.05).The activities of PTK in the cytoplasm and membrane of lymphocytes were measured by ELISAmcthod after incubation with PHA or PHA+Rg1. The absorbance value of PTK activity in cytoplasmafter 72 hr incubation was 0. 120±0.020 in PHA group, but 0. 1 38±0.015 in PHA+Rg1 group. In thelymphocyte membrane, it was 0.374± 0.060 in PHA group and 0.403 ± 0.008 in PHA+Rg1 group(P<0.001). These results showed that Rgi significantly arid simultaneously increased both the PT Kactivity and the expression of phenotype of lymphocytes. 展开更多
关键词 LYMPHOCYTE RG1 RECEPTOR Protein tyrosine kinase
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Wnt signaling control of bone cell apoptosis 被引量:30
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作者 Bodine,PV 《Cell Research》 SCIE CAS CSCD 2008年第2期248-253,共6页
Wnts are a large family of growth factors that mediate essential biological processes like embryogenesis, morpho- genesis and organogenesis. These proteins also play a role in oncogenesis, and they regulate apoptosis ... Wnts are a large family of growth factors that mediate essential biological processes like embryogenesis, morpho- genesis and organogenesis. These proteins also play a role in oncogenesis, and they regulate apoptosis in many tissues. Wnts bind to a membrane receptor complex comprised of a frizzled (FZD) G-protein-coupled receptor and a low-density lipoprotein (LDL) receptor-related protein (LRP). The formation of this ligand-receptor complex initiates a number of signaling cascades that include the canonical/beta-catenin pathway as well as several noncanonical pathways. In recent years, canonical Wnt signaling has been reported to play a significant role in the control of bone formation. Clinical studies have found that mutations in LRP-5 are associated with reduced bone mineral density (BMD) and fractures. Investigations of knockout and transgenic mouse models of Wnt pathway components have shown that canonical Wnt signaling modulates most aspects ofosteoblast physiology including proliferation, differentiation, function and apoptosis. Transgenic mice expressing a gain of function mutant of LRP-5 in bone, or mice lacking the Wnt antagonist secreted frizzled-related protein-l, exhibit elevated BMD and suppressed osteoblast apoptosis. In addition, preclinical studies with pharmacologic compounds such as those that inhibit glycogen synthase kinase-3β support the importance of the canonical Wnt pathway in modulation of bone formation and osteoblast apoptosis. 展开更多
关键词 LDL receptor-related protein secreted frizzled-related protein glycogen synthase kinase OSTEOBLAST bone formation programmed cell death
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Preparation of spherical cobalt carbonate powder with high tap density 被引量:1
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作者 肖劲 王剑锋 +2 位作者 刘永东 李劼 刘业翔 《Journal of Central South University of Technology》 EI 2006年第6期642-646,共5页
Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and p... Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and precipitator. The effects of pH value and reaction time on crystallization and physical properties of cobalt carbonate were studied. The results show that the key factors influencing the preparation process of spherical cobalt carbonate with high tap density and good crystallization are how to control pH value (7.25±0.05) and keep some reaction time (about 10 h). Co4O3 was prepared by sintering spherical morphology CoCO3 samples at varied temperatures. The results show that as the decomposition temperature increases, the as-obtained Co4O3 products with porous structure transform into polyhedral structure with glazed surface, and simultaneously the cobalt content and tap density increase. However, the specific surface area shows a trend of decrease. 展开更多
关键词 controlled chemical crystal method spherical cobalt carbonate tap density crystal structure
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建筑施工风险管控模式研究
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作者 潘建军 潘超 《现代职业安全》 2019年第7期69-72,共4页
建筑业的安全生产特点和问题主要是:一是工作场地可变因素多,有限的场地内集中了大量的工人、建筑材料、设施机具;建设工程项目的参与主体涉及业主、勘察、设计、工程监理、施工等多个单位;同时涉及工程管理、经济、建筑、结构、电气、... 建筑业的安全生产特点和问题主要是:一是工作场地可变因素多,有限的场地内集中了大量的工人、建筑材料、设施机具;建设工程项目的参与主体涉及业主、勘察、设计、工程监理、施工等多个单位;同时涉及工程管理、经济、建筑、结构、电气、给水、暖通、电子等多个专业交叉作业。多家企业在一个场地内工作,多个交叉项目、多项高风险作业、多个作业工序,因此,作业风险高。 展开更多
关键词 高处作业 零伤害 系架构 非致命 作业风险 受控体 风险管 模式 施工风险
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SNAP23-Kif5 complex controls mGlu1 receptor trafficking 被引量:1
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作者 Fabrice Raynaud Vincent Homburger +4 位作者 Martial Seveno Oana Vigy Enora Moutina Laurent Fagni Julie Perroy 《Journal of Molecular Cell Biology》 SCIE CAS CSCD 2018年第5期423-436,共14页
Metabotropic glutamate receptors are expressed at excitatory synapses and control synaptic transmission in mammalian brain. These receptors are involved in numerous patho-physiological functions. However, little is kn... Metabotropic glutamate receptors are expressed at excitatory synapses and control synaptic transmission in mammalian brain. These receptors are involved in numerous patho-physiological functions. However, little is known about the molecular determinants responsible for their intracellular transport and membrane targeting. Here we investigated the nature of the molecular motor and adaptor protein responsible for trafficking and membrane localization of the group I metabotropic glutamate mGlu1 postsynaptic receptor in cultured hippocampal neurons. In proteomic studies, we identified the synaptosome-associated protein 23 (SNAP23) and the molecular motor Kif5 kinesin as proteins interacting with mGlu1 receptor. We showed that SNAP23, but not Kif5, directly interacts with mGlu1 receptor carboxyl terminus. Using a recombination approach to impair or enhance the interaction between SNAP23 and KifS, we found that the SNAP23-Kif5 complex controls the trafficking of mGlu1 receptor along microtubules. Additional fluorescence recovery after cleavage experiments allowed us to identify a role of the complex in the receptor cell surface targeting. In conclusion, our study indicates that along dendritic processes Kif5-SNAP23 complex contributes to proper mGlu1 receptor trafficking and cell surface expression. 展开更多
关键词 mGlu1 SNARE KINESIN NEURON TRAFFIC
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Plant pattern-recognition receptors controlling innate immunity 被引量:17
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作者 Lei Li Yufei Yu +1 位作者 Zhaoyang Zhou Jian-Min Zhou 《Science China(Life Sciences)》 SCIE CAS CSCD 2016年第9期878-888,共11页
Plants are exposed to numerous potential pathogenic microbes. To counter the threat, plants have evolved diverse patternrecognition receptors(PRRs), which are receptor kinases(RKs) and receptor proteins(RPs) specializ... Plants are exposed to numerous potential pathogenic microbes. To counter the threat, plants have evolved diverse patternrecognition receptors(PRRs), which are receptor kinases(RKs) and receptor proteins(RPs) specialized to detect conserved pathogen/microbe-associated molecular patterns(PAMPs/MAMPs). Although only a handful of RKs and RPs are known PRRs,they belong to the receptor-like kinase(RLK) and receptor-like protein(RLP) superfamilies that undergo lineage-specific expansion, suggesting that many of these RLKs and RLPs are potential PRRs. Analyses of existing PRRs have uncovered ligand-induced RLK-RK or RLK-RP oligomerization as a common mechanism for immune activation. PRRs can recruit additional components to form dynamic receptor complexes, which mediate specific cellular responses. Detailed analyses of these components are shedding light on molecular mechanisms underlying the regulation of PRR activity and downstream signaling. 展开更多
关键词 receptor kinase receptor protein receptor-like cytoplasmic kinase plant innate immunity
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Juvenile hormone membrane signaling phosphorylates USP and thus potentiates 20-hydroxyecdysone action in Drosophila 被引量:4
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作者 Yue Gao Suning Liu +8 位作者 Qiangqiang Jia Lixian Wu Dongwei Yuan Emma Y.Li Qili Feng Guirong Wang Subba R.Palli Jian Wang Sheng Li 《Science Bulletin》 SCIE EI CSCD 2022年第2期186-197,M0004,共13页
Juvenile hormone(JH) and 20-hydroxyecdysone(20 E) coordinately regulate development and metamorphosis in insects. Two JH intracellular receptors, methoprene-tolerant(Met) and germ-cell expressed(Gce), have been identi... Juvenile hormone(JH) and 20-hydroxyecdysone(20 E) coordinately regulate development and metamorphosis in insects. Two JH intracellular receptors, methoprene-tolerant(Met) and germ-cell expressed(Gce), have been identified in the fruit fly Drosophila melanogaster. To investigate JH membrane signaling pathway without the interference from JH intracellular signaling, we characterized phosphoproteome profiles of the Met gce double mutant in the absence or presence of JH in both chronic and acute phases.Functioning through a potential receptor tyrosine kinase and phospholipase C pathway, JH membrane signaling activated protein kinase C(PKC) which phosphorylated ultraspiracle(USP) at Ser35, the PKC phosphorylation site required for the maximal action of 20 E through its nuclear receptor complex Ec RUSP. The usp;mutant, in which Ser was replaced with Ala at position 35 by genome editing, showed decreased expression of Halloween genes that are responsible for ecdysone biosynthesis and thus attenuated 20 E signaling that delayed developmental timing. The usp;mutant also showed lower Yorkie activity that reduced body size. Altogether, JH membrane signaling phosphorylates USP at Ser35 and thus potentiates 20 E action that regulates the normal fly development. This study helps better understand the complex JH signaling network. 展开更多
关键词 Juvenile hormone Receptor tyrosine kinase PHOSPHOPROTEOMICS USP 20-Hydroxyecdysone action Yorkie activity
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