首页 > 最新文献

中国地球物理学会年刊最新文献

英文 中文
Assessment of educational modules based on the "How people learn" framework delivered to biotechnology learners at two universities 基于“人们如何学习”框架对两所大学生物技术学习者的教育模块进行评估
Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1053469
T. Giorgio, S. Brophy, G. Birol, A. McKenna, H. Smith
New modular materials and methods for teaching biotechnology have been developed based on the 'How People Learn' (HPL) framework and classroom tested in a STAR Legacy sequence. Domain-specific questions targeting each of the learning objectives were used in a pre/post assessment strategy that seeks to measure the change in learner capabilities. One such pre/post assessment revealed a statistically significant increase in learner performance following intervention using HPL and modular materials. The same pre/post assessment yielded no increase in learner performance on control learning objectives not addressed in the classroom. Our results suggest that this approach can produce satisfactory interrater correlation and is a sensitive measure of learner performance.
基于“人们如何学习”(HPL)框架和STAR Legacy序列的课堂测试,开发了新的模块化生物技术教学材料和方法。针对每个学习目标的领域特定问题被用于前/后评估策略,旨在衡量学习者能力的变化。一项这样的前/后评估显示,在使用HPL和模块化材料进行干预后,学习者的表现在统计学上有显著提高。同样的前/后评估并没有提高学习者在课堂上没有解决的控制性学习目标上的表现。我们的研究结果表明,这种方法可以产生令人满意的相互关联,是学习者表现的敏感指标。
{"title":"Assessment of educational modules based on the \"How people learn\" framework delivered to biotechnology learners at two universities","authors":"T. Giorgio, S. Brophy, G. Birol, A. McKenna, H. Smith","doi":"10.1109/IEMBS.2002.1053469","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1053469","url":null,"abstract":"New modular materials and methods for teaching biotechnology have been developed based on the 'How People Learn' (HPL) framework and classroom tested in a STAR Legacy sequence. Domain-specific questions targeting each of the learning objectives were used in a pre/post assessment strategy that seeks to measure the change in learner capabilities. One such pre/post assessment revealed a statistically significant increase in learner performance following intervention using HPL and modular materials. The same pre/post assessment yielded no increase in learner performance on control learning objectives not addressed in the classroom. Our results suggest that this approach can produce satisfactory interrater correlation and is a sensitive measure of learner performance.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83216576","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: 10
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
Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1136841
Jonathan N. Sachs, Thomas B. Woolf
We have performed molecular dynamics (MD) simulations of NaCl solution separated by two charged plates. In order to establish its applicability to future simulations of the transmembrane electrochemical gradient, we have employed the EW3DC technique for calculations of long range electrostatics. EW3DC allows for different salt concentrations on the two sides of the plates. Hence, the system mimics a transmembrane concentration gradient, a phenomena not previously simulated via MD. Molecular-level ordering of oxygens, hydrogens and salt ions produced oscillations in the electrostatic potential profile.
本文采用分子动力学(MD)方法模拟了被两片带电板分离的NaCl溶液。为了建立其对未来跨膜电化学梯度模拟的适用性,我们采用了EW3DC技术来计算远程静电。EW3DC允许在板的两侧有不同的盐浓度。因此,该系统模拟了跨膜浓度梯度,这是一种以前没有通过MD模拟过的现象。氧、氢和盐离子的分子水平排序在静电电位分布中产生振荡。
{"title":"Molecular dynamics simulations of charged plates and electrolyte in a bilayer-like geometry: molecular ordering and electrostatic potential","authors":"Jonathan N. Sachs, Thomas B. Woolf","doi":"10.1109/IEMBS.2002.1136841","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1136841","url":null,"abstract":"We have performed molecular dynamics (MD) simulations of NaCl solution separated by two charged plates. In order to establish its applicability to future simulations of the transmembrane electrochemical gradient, we have employed the EW3DC technique for calculations of long range electrostatics. EW3DC allows for different salt concentrations on the two sides of the plates. Hence, the system mimics a transmembrane concentration gradient, a phenomena not previously simulated via MD. Molecular-level ordering of oxygens, hydrogens and salt ions produced oscillations in the electrostatic potential profile.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85167886","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
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
Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1053151
L. Cimponeriu, S. Tong, Anastasios Bezerianos, N. Thakor
The high frequency of neurological dysfunction after cardiac arrest emphasizes the need for new approaches able to provide an early evaluation of the amount of initial injury as well as the presence of ongoing injury. In the present paper, we apply two synchronization measures to the study of EEG data, namely phase synchronization and mutual information, and evaluate their potential usefulness in the assessment of the degree of brain injury following the cardiac arrest injury. Our preliminary results reveal that phase synchronization in the theta frequency range and the patterns of information flow across the cerebral cortex changes during the one hour after the cardiac arrest event. Therefore, measures of synchronization applied on the brain's electrical signaling can provide a new quantitative assessment of the brain response to injury, as well as the recovery process of neurological function after cardiac arrest.
心脏骤停后神经功能障碍的高频率强调了对新方法的需求,这些新方法能够提供早期评估初始损伤的数量以及持续损伤的存在。本文采用相同步和互信息两种同步方法对脑电数据进行研究,并评价其在心脏骤停损伤后脑损伤程度评估中的潜在价值。我们的初步结果表明,在心脏骤停事件发生后的一小时内,θ波频率范围的相位同步和大脑皮层的信息流模式发生了变化。因此,同步测量脑电信号可以为脑损伤反应以及心脏骤停后神经功能的恢复过程提供新的定量评估。
{"title":"Synchronization and information processing across the cerebral cortex following cardiac arrest injury","authors":"L. Cimponeriu, S. Tong, Anastasios Bezerianos, N. Thakor","doi":"10.1109/IEMBS.2002.1053151","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1053151","url":null,"abstract":"The high frequency of neurological dysfunction after cardiac arrest emphasizes the need for new approaches able to provide an early evaluation of the amount of initial injury as well as the presence of ongoing injury. In the present paper, we apply two synchronization measures to the study of EEG data, namely phase synchronization and mutual information, and evaluate their potential usefulness in the assessment of the degree of brain injury following the cardiac arrest injury. Our preliminary results reveal that phase synchronization in the theta frequency range and the patterns of information flow across the cerebral cortex changes during the one hour after the cardiac arrest event. Therefore, measures of synchronization applied on the brain's electrical signaling can provide a new quantitative assessment of the brain response to injury, as well as the recovery process of neurological function after cardiac arrest.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78743736","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: 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
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
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.
在发生动脉粥样硬化的Yucatan迷你葡萄酒模型中,评估了壁运动的区域变化、归一化壁剪切振幅(NWSA)和动脉粥样硬化病变组成之间的关系。我们通过内皮细胞剥落诱导血管病变。这些动物被喂食高胆固醇饮食8周,以形成早期动脉粥样硬化病变。在8周结束时,我们获得了去角质股动脉和对照股动脉的血流动力学和血管内超声(IVUS)图像数据。根据成像数据重建血管段的几何形状,并结合从图像中获得的血管壁运动数据作为移动边界条件,对每个段进行CFD分析。NWSA与血管壁运动和病变组成相关。分析6条正常动脉和4条病变动脉的数据。结果表明,与健康区域相比,动脉粥样硬化动脉段的壁运动和NWSA增加。然而,与健康节段相对均匀的分布相比,病变节段的壁运动表现出区域变异性。本研究表明,与健康节段相比,早期动脉粥样硬化存在时血管节段壁运动和NWSA的区域差异。
{"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":null,"pages":null},"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
Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1053283
S. Jacques, P. Bargo, T. Goodell, R. Sleven, G. Kovall, G. Blair
Photodynamic Therapy (PDT) uses light to activate photosensitive drug to yield oxidative injury to targeted tissues such as cancer. The ability of treatment light to penetrate a tissue and activate the drug that has accumulated in a target tissue depends on the tissue optical properties, especially the blood perfusion. An endoscopic spectroscopic probe was developed for monitoring esophageal and lung tissues and tested in patients in a pilot clinical study.
光动力疗法(PDT)利用光激活光敏药物,对肿瘤等目标组织产生氧化损伤。治疗光穿透组织并激活已积聚在目标组织中的药物的能力取决于组织的光学特性,特别是血液灌注。开发了一种内窥镜光谱探针,用于监测食管和肺组织,并在一项试点临床研究中对患者进行了测试。
{"title":"Variability of tissue optical properties in cancer patients receiving photodynamic therapy","authors":"S. Jacques, P. Bargo, T. Goodell, R. Sleven, G. Kovall, G. Blair","doi":"10.1109/IEMBS.2002.1053283","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1053283","url":null,"abstract":"Photodynamic Therapy (PDT) uses light to activate photosensitive drug to yield oxidative injury to targeted tissues such as cancer. The ability of treatment light to penetrate a tissue and activate the drug that has accumulated in a target tissue depends on the tissue optical properties, especially the blood perfusion. An endoscopic spectroscopic probe was developed for monitoring esophageal and lung tissues and tested in patients in a pilot clinical study.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86019494","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
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
Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1137112
M. Neidert, J. Wille, R. Tranquillo
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.
组织工程瓣膜作为替代瓣膜具有相当大的前景,可以避免当前替代瓣膜技术中存在的许多问题。此外,这些瓣膜作为一个活体结构,能够在体内生长和重塑。我们已经开发出一种基于双支架生物聚合物支架的瓣膜等效物,它具有正确的几何形状和潜在的胶原纤维排列。然而,与健康的天然阀门相比,这些阀门的机械性能明显较差(就极限拉伸应力和切线模量而言)。此外,与初始胶原支架相当的瓣膜显示很少的成分重塑,留下以胶原为主的瓣膜,很少有天然瓣膜中存在的弹性蛋白和蛋白聚糖含量。我们在此提出的工作旨在通过使用纤维蛋白(而不是胶原)支架与TGF-/spl β /和胰岛素培养的化学信号和VE在生物反应器中培养的机械信号的组合来改善瓣膜当量(VEs)的组成和机械性能。
{"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":null,"pages":null},"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
Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1106283
G. Adams, G. Vick, C. Ballantyne, W. Insull, J. Morrisett
Accurate quantitation of arterial lumen and wall volumes in the carotid arteries is possible using magnetic resonance imaging. Semi-automated algorithms reduce the time required to make the measurements and increase their reproducibility. An algorithm using active contours to aid in localizing the lumen and outer wall boundary of the artery and an automated algorithm to estimate the plaque burden was developed. The algorithm was tested on twenty MRI image sets from ten patients who had undergone unilateral carotid endarterectomy. The algorithm significantly decreases operator time for quantifying arterial volumes and provides very reproducible results.
使用磁共振成像可以精确定量颈动脉的管腔和壁体积。半自动算法减少了测量所需的时间,并提高了测量结果的可重复性。提出了一种利用活动轮廓线辅助定位动脉管腔和外壁边界的算法,以及一种估计斑块负荷的自动算法。该算法在10例单侧颈动脉内膜切除术患者的20组MRI图像集上进行了测试。该算法显著减少了量化动脉体积的操作时间,并提供了非常可重复性的结果。
{"title":"Estimation of carotid atherosclerotic plaque volume from in vivo magnetic resonance images","authors":"G. Adams, G. Vick, C. Ballantyne, W. Insull, J. Morrisett","doi":"10.1109/IEMBS.2002.1106283","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1106283","url":null,"abstract":"Accurate quantitation of arterial lumen and wall volumes in the carotid arteries is possible using magnetic resonance imaging. Semi-automated algorithms reduce the time required to make the measurements and increase their reproducibility. An algorithm using active contours to aid in localizing the lumen and outer wall boundary of the artery and an automated algorithm to estimate the plaque burden was developed. The algorithm was tested on twenty MRI image sets from ten patients who had undergone unilateral carotid endarterectomy. The algorithm significantly decreases operator time for quantifying arterial volumes and provides very reproducible results.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84093642","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: 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
Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1053211
E. C. Huang, J. Heys, V. Barocas
Primary angle-closure glaucoma features a narrow anterior chamber angle in which the anteriorly positioned iris blocks aqueous humor outflow through the trabecular meshwork, subsequently increasing the intraocular pressure. A mathematical model is used to investigate the aqueous humor-iris interaction in synechial angle closure. The model predicted increased intraocular pressure as the anterior chamber angle decreased and a plateau iris configuration in synechial angle closure - consistent with clinical observations.
原发性闭角型青光眼的特点是前房角狭窄,位于前侧的虹膜阻断房水通过小梁网流出,导致眼压升高。采用数学模型研究了体液-虹膜在协同角闭合过程中的相互作用。该模型预测,随着前房角的减小和虹膜平台的闭合,眼压升高,这与临床观察一致。
{"title":"Aqueous humor and iris mechanics in synechial closure in primary angle-closure glaucoma","authors":"E. C. Huang, J. Heys, V. Barocas","doi":"10.1109/IEMBS.2002.1053211","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1053211","url":null,"abstract":"Primary angle-closure glaucoma features a narrow anterior chamber angle in which the anteriorly positioned iris blocks aqueous humor outflow through the trabecular meshwork, subsequently increasing the intraocular pressure. A mathematical model is used to investigate the aqueous humor-iris interaction in synechial angle closure. The model predicted increased intraocular pressure as the anterior chamber angle decreased and a plateau iris configuration in synechial angle closure - consistent with clinical observations.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82875545","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
Model for microtubule chemotaxis 微管趋化模型
Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1137039
D.J. Oddel
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".
微管(MT)细胞骨架的戏剧性重组是包括有丝分裂和轴突起始在内的许多细胞过程的基础。体内的MT组装由MT组装调节剂调节,而MT组装调节剂本身通常由拮抗的激酶/磷酸酶对调节,这样磷酸化的形式是活跃的,而去磷酸化的形式是不活跃的。如果拮抗活性在细胞中是空间分离的,那么应该存在一个稳定的梯度来有效地促进MT在一个区域的组装和/或抑制另一个区域的组装。这一机制被用来解释mt在有丝分裂期间是如何被募集到染色体上的。目前尚不清楚的是,在什么条件下这种梯度可以预期存在于细胞中。为了定量预测这种梯度,开发了激酶/磷酸酶反应的反应-扩散模型。利用典型的反应速率常数和扩散系数,预测在10 /spl mu/m距离内,浓度变化将达到10倍。这样的梯度预计会对MT组装动力学产生重大影响,有效地将微管招募到细胞的特定亚区。这种招募机制与细菌趋化性相似,所以我称之为“微管趋化”。
{"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":null,"pages":null},"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
Pub Date : 2002-12-01 DOI: 10.1109/IEMBS.2002.1106340
M. Anastasio, D. Shi, Xiaochuan Pane, C. Pelizzari
Radiation therapy is one of the most important procedures for treating cancer. When delivering the treatment, it is critically important that the position and orientation of the tumor volume and radiation sensitive structures that surround it are consistent with those assumed when designing the treatment plan. In this work, we investigate the potential of cone-beam local tomography for imaging tumor volumes using projection data that correspond to X-rays passing only through or near the tumor volume. The effect of projection truncation on the Feldkamp cone-beam reconstruction algorithm is also investigated.
放射治疗是治疗癌症最重要的方法之一。在进行治疗时,至关重要的是肿瘤的位置和方向,体积和周围的辐射敏感结构与设计治疗计划时假设的一致。在这项工作中,我们研究了锥束局部断层扫描成像肿瘤体积的潜力,使用的投影数据对应于仅通过或接近肿瘤体积的x射线。研究了投影截断对费尔德坎普锥束重建算法的影响。
{"title":"A preliminary investigation of local cone-beam tomography for MV CT imaging of tumor volumes in radiation therapy","authors":"M. Anastasio, D. Shi, Xiaochuan Pane, C. Pelizzari","doi":"10.1109/IEMBS.2002.1106340","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1106340","url":null,"abstract":"Radiation therapy is one of the most important procedures for treating cancer. When delivering the treatment, it is critically important that the position and orientation of the tumor volume and radiation sensitive structures that surround it are consistent with those assumed when designing the treatment plan. In this work, we investigate the potential of cone-beam local tomography for imaging tumor volumes using projection data that correspond to X-rays passing only through or near the tumor volume. The effect of projection truncation on the Feldkamp cone-beam reconstruction algorithm is also investigated.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90869252","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
期刊
中国地球物理学会年刊
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1