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基于线型物体的主方向关系模型的研究
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作者 刘永山 黄章俊 姜书奎 《燕山大学学报》 CAS 2005年第5期389-393,共5页
在区域物体最小边界矩形MBR(MinimumBoundingRectangle)理论的基础上,对线型物体主方向空间关系模型进行了研究,提出了将线型物体主方向关系转化为MBR关系的方法,以促进应用MBR相关运算法则和定理进行线型物体的空间方向关系的研究。对... 在区域物体最小边界矩形MBR(MinimumBoundingRectangle)理论的基础上,对线型物体主方向空间关系模型进行了研究,提出了将线型物体主方向关系转化为MBR关系的方法,以促进应用MBR相关运算法则和定理进行线型物体的空间方向关系的研究。对于特殊位置的线型物体,分析了基于投影的主方向模型及其特性,研究了对特殊位置线型物体利用投影方法进行的主方向关系合成运算,以便于对线型物体空间方向关系推理的进一步研究。 展开更多
关键词 线型物体 主方向关系 方向模型
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线型物体主方向关系推理的研究
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作者 刘永山 郝忠孝 《小型微型计算机系统》 CSCD 北大核心 2008年第8期1458-1466,共9页
线型物体主方向关系的推理研究是空间方向关系推理中的重要组成部分.在分析线型物体主方向关系模型的基础上,提出了线型物体主方向关系的投影区间矩形代数方法,从而实现了线型物体主方向关系的合理表示、基本推理运算以及线型物体主方... 线型物体主方向关系的推理研究是空间方向关系推理中的重要组成部分.在分析线型物体主方向关系模型的基础上,提出了线型物体主方向关系的投影区间矩形代数方法,从而实现了线型物体主方向关系的合理表示、基本推理运算以及线型物体主方向关系的凸关系判断.结合凸关系网络定理和路径一致性算法,提出了线型物体主方向关系网络一致性检验算法,给出了算法的正确性证明. 展开更多
关键词 空间数据库 线型物体 投影区间矩形代数 凸关系 一致性检验
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以3DMAX软件建立Mini-SG附着体三维实体模型 被引量:1
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作者 董正杰 王德芳 +1 位作者 徐侃 包向军 《中国组织工程研究与临床康复》 CAS CSCD 北大核心 2010年第30期5601-5604,共4页
背景:Mini-SG附着体是一种冠外精密附着体,具有固位作用强,稳定性好,美观舒适,保护基牙等优点。但在常规CT三维建模中,由于其结构精密细小,很难建立精确的附着体模型,虽然利用Micro-CT可达到1μm的精度,但建模工作量庞大,费时费力,更... 背景:Mini-SG附着体是一种冠外精密附着体,具有固位作用强,稳定性好,美观舒适,保护基牙等优点。但在常规CT三维建模中,由于其结构精密细小,很难建立精确的附着体模型,虽然利用Micro-CT可达到1μm的精度,但建模工作量庞大,费时费力,更造成了检测对象的X射线辐射。目的:建立Mini-SG附着体三维实体模型。方法:通过网络查询结合游标卡尺测量获得Mini-SG附着体阳性部件与阴性部件的实际精确尺寸数据,利用3DMAX软件处理,在计算机中还原并建立三维实体模型。结果与结论:通过测量以及现有的Mini-SG附着体精确数据,利用3DMAX软件建模功能,巧妙运用布尔运算可以进行精确Mini-SG附着体实体模型的建立,结合3DMAX软件强大的渲染功能,形象地体现了Mini-SG附着体的三维实体模型。以此类推,只要能够获得附着体,种植体等口腔修复体的精确数据,就可以通过3DMAX软件的建模功能和渲染功能建立精确完整的实体模型。 展开更多
关键词 三维实体模型 Mini-SG附着体 3DMAX软件 非流线型物体 数字化图像与影像技术
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Velocity of a Liquid Drop with a Sorption-Controlled Surfactant
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作者 陈晋南 《Journal of Beijing Institute of Technology》 EI CAS 1996年第2期116+107-116,共11页
The terminal velocity of a liquid droplet settling in a sulfactant solution has been studied for the non-linear adsorption Langmuir frameworks accounting for monolayer saturation and non-ideal surfactant interactions.... The terminal velocity of a liquid droplet settling in a sulfactant solution has been studied for the non-linear adsorption Langmuir frameworks accounting for monolayer saturation and non-ideal surfactant interactions. Most prior research uses a linear adsorption model which cannot capture these effects, The Maragoni migration of a liquid drop settling through a surfactant solution is examined by using Langmuir framework. The solution concentration Ceq is assumed large enough for the surfactant mass transfer to be adsorption-controlled. Langmuir model generates non-linear Marangoni stresses which diverge in the limit of approaching ∝, strongly retarding U'. 展开更多
关键词 Marangoni stresses non-linear adsorption Langmuir isotherm phpsco-chemical hydrodynamics mass transfer dynamic surface tension
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Edaravone protects PC12 cells from ischemic-like injury via attenuating the damage to mitochondria 被引量:16
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作者 SONG Ying LI Meng +1 位作者 LI Ji-cheng WEI Er-qing 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2006年第9期749-756,共8页
Background: Edaravone had been validated to effectively protect against ischemic injuries. In this study, we investigated the protective effect of edaravone by observing the effects on anti-apoptosis, regulation of B... Background: Edaravone had been validated to effectively protect against ischemic injuries. In this study, we investigated the protective effect of edaravone by observing the effects on anti-apoptosis, regulation of Bcl-2/Bax protein expression and recovering from damage to mitochondria after OGD (oxygen-glucose deprivation)-reperfusion. Methods: Viability of PC 12 cells which were injured at different time of OGD injury, was quantified by measuring MTT (2-(4,5-dimethylthia-zol-2-yl)-2,5-diphenyltetrazolium bromide) staining. In addition, PC 12 cells' viability was also quantified after their preincubation in different concentration of edaravone for 30 min followed by (OGD). Furthermore, apoptotic population of PC 12 cells that reinsulted from OGD-reperfusion with or without preincubation with edaravone was determined by flow cytometer analysis, electron microscope and Hoechst/Pl staining. Finally, change of Bcl-2/Bax protein expression was detected by Western blot. Results: (1) The viability of PC12 cells decreased with time (1-12 h) after OGD. We regarded the model of OGD 2 h, then replacing DMEM (Dulbecco's Modified Eagle's Medium) for another 24 h as an OGD-reperfusion in this research. Furthermore, most PC 12 cells were in the state of apoptosis after OGD-reperfusion. (2) The viability of PC 12 cells preincubated with edaravone at high concentrations (1, 0.1, 0.01 μmol/L) increased significantly with edaravone protecting PC 12 cells from apoptosis after OGD-reperfusion injury. (3) Furthermore, edaravone attenuates the damage of OGD-reperfusion on mitochondria and regulated Bcl-2/Bax protein imbalance expression after OGD-reperfusion. Conclusion: Neuroprotective effects of edaravone on ischemic or other brain injuries may be partly mediated through inhibition of Bcl-2/Bax apoptotic pathways by recovering from the damage of mitochondria. 展开更多
关键词 EDARAVONE lschemia Apoptosis Rat pheochromocytoma (PC 12) cells MITOCHONDRIA Bax Bcl-2 Oxygen-glucose deprivation (OGD)
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Existence and Nonexistence of Global Solution for Quasilinear Parabolic Equation 被引量:1
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作者 宋锦萍 胡月 崔国忠 《Chinese Quarterly Journal of Mathematics》 CSCD 1998年第4期87-93, ,共7页
This paper deals with the existence and nonexistence of global positive solutions of the following quasilinear parabolic equations:u t=1m△u m-u n, x∈Ω,t>0 1m·u mv=u p,x∈Ω,t>0 u(x,0)=u 0(x)>0,x∈Ω-w... This paper deals with the existence and nonexistence of global positive solutions of the following quasilinear parabolic equations:u t=1m△u m-u n, x∈Ω,t>0 1m·u mv=u p,x∈Ω,t>0 u(x,0)=u 0(x)>0,x∈Ω-where Ω∈R N is a bounded domain with smooth boundary Ω,m,n,p are positive constants, γ is the outward normal vector. The necessary and sufficient conditions for the global existence of solutions are obtained. 展开更多
关键词 quasilinear parabolic equations nonlinear boundary conditions existence of global solutions
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Cell models and drug discovery for mitochondrial diseases 被引量:5
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作者 Shuang-yi HU Qian-qian ZHUANG +2 位作者 Yue QIU Xu-fen ZHU Qing-feng YAN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2019年第5期449-456,共8页
Mitochondrion is a semi-autonomous organelle,important for cell energy metabolism,apoptosis,the production of reactive oxygen species(ROS),and Ca2+homeostasis.Mitochondrial DNA(mtDNA)mutation is one of the primary fac... Mitochondrion is a semi-autonomous organelle,important for cell energy metabolism,apoptosis,the production of reactive oxygen species(ROS),and Ca2+homeostasis.Mitochondrial DNA(mtDNA)mutation is one of the primary factors in mitochondrial disorders.Though much progress has been made,there remain many difficulties in constructing cell models for mitochondrial diseases.This seriously restricts studies related to targeted drug discovery and the mechanism and therapy for such diseases.Here we summarize the characteristics of patient-specific immortalized lymphoblastoid cells,fibroblastoid cells,cytoplasmic hybrid(cybrid)cell lines,and induced pluripotent stem cells(iPSCs)-derived differentiation cells in the study of mitochondrial disorders,as well as offering discussion of roles and advances of these cell models,particularly in the screening of drugs. 展开更多
关键词 Mitochondrial diseases Mitochondrial DNA Cell model Drug discovery
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Simulation-based simplification of target-mediated drug disposition model of denosumab
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作者 Yu Fu Ye Yao +3 位作者 Peiming Ma Xuan Zhou Wei Lu Tianyan Zhou 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2018年第11期767-776,共10页
Target-mediated drug disposition (TMDD)model is one of the main modeling theories for studying nonlinear pharmacokinetics (PK)ofmonoclonal antibodies.However,there are too many parameters in full TMDD model to be esti... Target-mediated drug disposition (TMDD)model is one of the main modeling theories for studying nonlinear pharmacokinetics (PK)ofmonoclonal antibodies.However,there are too many parameters in full TMDD model to be estimated based on limited clinical data,leading to instability of the final model.In the present study,we analyzed the predictive ability and applicability of a simplified quasi-steady state (QSS)model with the assumption that the total target concentration was a constant parameter during treatment with monoelonal antibody in clinical data modeling.Based on the parameters of a published TMDD model of denosumab,simulations were performed at population and individual levels.Then,a simplified TMDD model,QSS model, was used to examine the effects of hypotheses,in which the total receptor concentration was constant or variable on model fit and stability of parameter estimation.Both simulations at the population level and model fit results of simulated individual data showed that at the therapeutic doses,the total receptor concentration had little influence on changes in drug concentration,and the model with constant total receptor concentration had the same predictive power.The validated hypothesis could be applied to clinical trial design and selection of the optimal PK model in the development of monoclonal antibodies. 展开更多
关键词 Target-mediated drug disposition model Monoclonal antibody Nonlinear pharmacokinetics DENOSUMAB SIMULATION
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