中国地球物理学会年刊最新文献_第5页

Engineering cell motility via substrate incorporation of poly(ethylene glycol) 通过底物掺入聚乙二醇来工程细胞运动

中国地球物理学会年刊 Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1137060

R. Sharma, J. Kohn, P. Moghe

{"title":"Engineering cell motility via substrate incorporation of poly(ethylene glycol)","authors":"R. Sharma, J. Kohn, P. Moghe","doi":"10.1109/IEMBS.2002.1137060","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1137060","url":null,"abstract":"This study examined the modulation of cell migratory responsiveness to protein-adsorbed poly(ethylene glycol) (PEG) variant copolymers. To this end, fibronectin was adsorbed to equivalent levels on copolymers based on a family of tyrosine/PEG derived polycarbonates. Atomic force microscopy (AFM) revealed unique protein distributions for each copolymer system, indicating that although equal amounts of ligand are presented, the concentration of PEG in the underlying substrate can effect the adsorbed ligand. Consequently, quantitation of fibronectin RGD-binding sites on the protein-adsorbed copolymers revealed that cell-binding sites were maximized at intermediate concentrations of PEG. Our migration studies demonstrated that increasing PEG in the copolymer increased cell speed monotonically up to an intermediate PEG level where a maximum speed was reached. After incubating cells on ligand adsorbed copolymers, higher PEG levels elicited equivalent number of cell-binding sites relative to those on intermediate levels of PEG. Integrin inhibition studies showed that /spl alpha//sub 5//spl beta//sub 1/ was critical in modulating the number of RGD sites. Our AFM data suggests that rearrangement at higher PEG levels was facilitated by electrostatic repulsion, effecting fibronectin slippage at the polymer surface as well as conformational rearrangement revealing addition al RGD binding sites. Overall, we report on the finding that cell migratory responsiveness to a given ligand concentration can be further manipulated via systematic ligand changes due to the substrate PEG composition.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"47 1","pages":"765-766 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88246215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Molecular dynamics simulations of charged plates and electrolyte in a bilayer-like geometry: molecular ordering and electrostatic potential 双层状几何结构中带电板和电解质的分子动力学模拟:分子有序和静电势

中国地球物理学会年刊 Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1136841

Jonathan N. Sachs, Thomas B. Woolf

引用次数: 0

Synchronization and information processing across the cerebral cortex following cardiac arrest injury 心脏骤停损伤后大脑皮层的同步和信息处理

中国地球物理学会年刊 Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1053151

L. Cimponeriu, S. Tong, Anastasios Bezerianos, N. Thakor

引用次数: 4

Alteration in fluid mechanics in femoral arteries with atheroma development 股动脉粥样硬化形成时流体力学的改变

中国地球物理学会年刊 Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1106391

Y. Liu, A. Nagaraj, A. Hamilton, K. Liu, Lijing L. Yan, D. McPherson, K. Chandran

{"title":"Alteration in fluid mechanics in femoral arteries with atheroma development","authors":"Y. Liu, A. Nagaraj, A. Hamilton, K. Liu, Lijing L. Yan, D. McPherson, K. Chandran","doi":"10.1109/IEMBS.2002.1106391","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1106391","url":null,"abstract":"The relationship between regional alterations in wall motion, normalized wall shear amplitude (NWSA), and atheromatic lesion composition was evaluated in the Yucatan miniswine model with developing atherosclerosis. We induced vascular lesions by endothelial cell denudation. The animals were fed a high cholesterol diet for 8 weeks to develop early atherosclerotic lesions. At the end of the 8 weeks, hemodynamic and intravascular ultrasound (IVUS) image data were obtained in both the denuded and control femoral arteries. The vascular segment geometry was reconstructed from the imaging data and the CFD analysis performed in each segment incorporating the vascular wall motion data obtained from the images as a moving boundary condition. NWSA was correlated with vessel wall motion and lesion composition. Data from 6 control and 4 diseased arteries were analyzed. Results demonstrate that wall motion and NWSA increased in an arterial segment with atheroma compared to those in healthy regions, as determined from histology. However, the wall motion in the diseased segments demonstrated regional variability compared to relatively uniform distribution in the healthy segments. This study demonstrates the regional variability in the wall motion and NWSA in vascular segments in the presence of early atheroma compared to those in healthy segments.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"37 1","pages":"1287-1288 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85993533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Variability of tissue optical properties in cancer patients receiving photodynamic therapy 接受光动力治疗的癌症患者组织光学特性的变异性

中国地球物理学会年刊 Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1053283

S. Jacques, P. Bargo, T. Goodell, R. Sleven, G. Kovall, G. Blair

引用次数: 2

Development and characterization of improved tissue engineered valve-equivalents using chemical and mechanical signaling 利用化学和机械信号技术开发和表征改良的组织工程等效阀

中国地球物理学会年刊 Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1137112

M. Neidert, J. Wille, R. Tranquillo

{"title":"Development and characterization of improved tissue engineered valve-equivalents using chemical and mechanical signaling","authors":"M. Neidert, J. Wille, R. Tranquillo","doi":"10.1109/IEMBS.2002.1137112","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1137112","url":null,"abstract":"Tissue engineered valves hold considerable promise as replacement valves that avoid many of the problems present in current replacement valve technology. Furthermore, these valves, as a living construct, would be able to grow and remodel in vivo. We have developed a bileaflet biopolymer-scaffold based valve equivalent that possesses the correct geometry and underlying collagen fibril alignment. These valve-equivalents, however, have significantly worse mechanical properties as compared to healthy, native valves (in terms of ultimate tensile stress and tangent modulus). Furthermore, valve equivalents with initial collagen scaffolds show very little compositional remodeling leaving a predominantly collagen valve with little of the elastin and proteoglycan content present in native valves. We present work here aimed at improving the compositional and mechanical properties of valve-equivalents (VEs) by using a combination of chemical signaling by using a fibrin (as opposed to collagen) scaffold incubated with TGF-/spl beta/ and insulin and mechanical signaling achieved by VE incubation in a bioreactor.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"85 1","pages":"858-859 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88643382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Estimation of carotid atherosclerotic plaque volume from in vivo magnetic resonance images 从活体磁共振图像估计颈动脉粥样硬化斑块体积

中国地球物理学会年刊 Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1106283

G. Adams, G. Vick, C. Ballantyne, W. Insull, J. Morrisett

引用次数: 4

Aqueous humor and iris mechanics in synechial closure in primary angle-closure glaucoma 原发性闭角型青光眼的虹膜力学与房水力学

中国地球物理学会年刊 Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1053211

E. C. Huang, J. Heys, V. Barocas

引用次数: 0

Model for microtubule chemotaxis 微管趋化模型

中国地球物理学会年刊 Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1137039

D.J. Oddel

{"title":"Model for microtubule chemotaxis","authors":"D.J. Oddel","doi":"10.1109/IEMBS.2002.1137039","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1137039","url":null,"abstract":"Dramatic reorganization of the microtubule (MT) cytoskeleton underlies a number of cellular processes including mitosis and axon initiation. MT assembly in vivo is regulated by MT assembly modulators, which are themselves regulated, often by antagonistic kinase/phosphatase pairs such that the phosphorylated form is active while the dephosphorylated form is inactive. If the antagonistic activities are spatially segregated in the cell, then a stable gradient should exist to effectively promote MT assembly in one region and/or inhibit assembly in another region. This mechanism has been invoked to explain how MTs are recruited to chromosomes during mitosis. What is not known is under what conditions such gradients can be expected to exist in the cell. To quantitatively predict such gradients, a reaction-diffusion model of the kinase/phosphatase reactions was developed. Using typical reaction rate constants and diffusion coefficients, it was predicted that a 10-fold concentration change should exist over a 10 /spl mu/m distance. Such a gradient would be expected to exert a substantial Influence over MT assembly dynamics, effectively recruiting microtubules to a particular subregion of the cell. The recruitment mechanism is reminiscent of and analogous to bacterial chemotaxis, so I call it \"microtubule chemotaxis\".","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"9 1","pages":"726-727 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90864935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A preliminary investigation of local cone-beam tomography for MV CT imaging of tumor volumes in radiation therapy 局部锥束断层扫描在MV CT放射治疗中肿瘤体积成像的初步研究

中国地球物理学会年刊 Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1106340

M. Anastasio, D. Shi, Xiaochuan Pane, C. Pelizzari

引用次数: 0