Mechanics & chemistry of biosystems : MCB最新文献

{"title":"Fixed electrical charges and mobile ions affect the measurable mechano-electrochemical properties of charged-hydrated biological tissues: the articular cartilage paradigm.","authors":"L. Wan, Chester Miller, X. Guo, V. Mow","doi":"10.3970/MCB.2004.001.081","DOIUrl":"https://doi.org/10.3970/MCB.2004.001.081","url":null,"abstract":"The triphasic constitutive law [Lai, Hou and Mow (1991)] has been shown in some special 1D cases to successfully model the deformational and transport behaviors of charged-hydrated, porous-permeable, soft biological tissues, as typified by articular cartilage. Due to nonlinearities and other mathematical complexities of these equations, few problems for the deformation of such materials have ever been solved analytically. Using a perturbation procedure, we have linearized the triphasic equations with respect to a small imposed axial compressive strain, and obtained an equilibrium solution, as well as a short-time boundary layer solution for the mechano-electrochemical (MEC) fields for such a material under a 2D unconfined compression test. The present results show that the key physical parameter determining the deformational behaviors is the ratio of the perturbation of osmotic pressure to elastic stress, which leads to changes of the measurable elastic coefficients. From the short-time boundary layer solution, both the lateral expansion and the applied load are found to decrease with the square root of time. The predicted deformations, flow fields and stresses are consistent with the analysis of the short time and equilibrium biphasic (i.e., the solid matrix has no attached electric charges) [Armstrong, Lai and Mow (1984)]. These results provide a better understanding of the manner in which fixed electric charges and mobile ions within the tissue contribute to the observed material responses.","PeriodicalId":87411,"journal":{"name":"Mechanics & chemistry of biosystems : MCB","volume":"1 1 1","pages":"81-99"},"PeriodicalIF":0.0,"publicationDate":"2004-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70238735","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}

{"title":"Yuan-Cheng Fung: A scientific giant and a kind man.","authors":"P. Tong","doi":"10.3970/MCB.2004.001.001","DOIUrl":"https://doi.org/10.3970/MCB.2004.001.001","url":null,"abstract":"","PeriodicalId":87411,"journal":{"name":"Mechanics & chemistry of biosystems : MCB","volume":"1 1 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2004-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70238968","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}

{"title":"Fixed electrical charges and mobile ions affect the measurable mechano-electrochemical properties of charged-hydrated biological tissues: the articular cartilage paradigm.","authors":"Leo Q Wan,&nbsp;Chester Miller,&nbsp;X Edward Guo,&nbsp;Van C Mow","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The triphasic constitutive law [Lai, Hou and Mow (1991)] has been shown in some special 1D cases to successfully model the deformational and transport behaviors of charged-hydrated, porous-permeable, soft biological tissues, as typified by articular cartilage. Due to nonlinearities and other mathematical complexities of these equations, few problems for the deformation of such materials have ever been solved analytically. Using a perturbation procedure, we have linearized the triphasic equations with respect to a small imposed axial compressive strain, and obtained an equilibrium solution, as well as a short-time boundary layer solution for the mechano-electrochemical (MEC) fields for such a material under a 2D unconfined compression test. The present results show that the key physical parameter determining the deformational behaviors is the ratio of the perturbation of osmotic pressure to elastic stress, which leads to changes of the measurable elastic coefficients. From the short-time boundary layer solution, both the lateral expansion and the applied load are found to decrease with the square root of time. The predicted deformations, flow fields and stresses are consistent with the analysis of the short time and equilibrium biphasic (i.e., the solid matrix has no attached electric charges) [Armstrong, Lai and Mow (1984)]. These results provide a better understanding of the manner in which fixed electric charges and mobile ions within the tissue contribute to the observed material responses.</p>","PeriodicalId":87411,"journal":{"name":"Mechanics & chemistry of biosystems : MCB","volume":"1 1","pages":"81-99"},"PeriodicalIF":0.0,"publicationDate":"2004-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2756514/pdf/nihms116746.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26095254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"System optimization for the development of ultrasensitive electronic biosensors using carbon nanotube nanoelectrode arrays.","authors":"J. Koehne, Jun Li, A. Cassell, Hua Chen, Q. Ye, Jie Han, M. Meyyappan","doi":"10.3970/MCB.2004.001.069","DOIUrl":"https://doi.org/10.3970/MCB.2004.001.069","url":null,"abstract":"Vertically aligned multi-walled carbon nanotubes (MWCNTs) have been reported in fabricating nanoelectrode arrays. Further studies on optimizing this system for the development of ultrasensitive DNA sensors are reported here. The mechanical stability of the as-grown MWCNT array can be improved by polymer coating or SiO2 encapsulation. The latter method provides excellent electronic and ionic insulation to the sidewall of MWCNTs and the underlying metal layer, which is investigated with electrochemical impedance spectroscopy. The insulation ensures well-defined nanoelectrode behavior. A method is developed for selectively functionalizing biomolecules at the open end of MWCNTs while keeping the SiO2 surface passivated, using the unique graphitic chemistry. An ultrahigh sensitivity approaching the limit of fluorescence techniques is obtained with this system for DNA detection.","PeriodicalId":87411,"journal":{"name":"Mechanics & chemistry of biosystems : MCB","volume":"1 1 1","pages":"69-80"},"PeriodicalIF":0.0,"publicationDate":"2004-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70238650","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}

{"title":"Flaw tolerant bulk and surface nanostructures of biological systems.","authors":"Huajian Gao, B. Ji, M. Buehler, H. Yao","doi":"10.3970/MCB.2004.001.037","DOIUrl":"https://doi.org/10.3970/MCB.2004.001.037","url":null,"abstract":"Bone-like biological materials have achieved superior mechanical properties through hierarchical composite structures of mineral and protein. Gecko and many insects have evolved hierarchical surface structures to achieve extraordinary adhesion capabilities. We show that the nanometer scale plays a key role in allowing these biological systems to achieve their superior properties. We suggest that the principle of flaw tolerance may have had an overarching influence on the evolution of the bulk nanostructure of bone-like materials and the surface nanostructure of gecko-like animal species. We demonstrate that the nanoscale sizes allow the mineral nanoparticles in bone to achieve optimum fracture strength and the spatula nanoprotrusions in Gecko to achieve optimum adhesion strength. In both systems, strength optimization is achieved by restricting the characteristic dimension of the basic structure components to nanometer scale so that crack-like flaws do not propagate to break the desired structural link. Continuum modeling and atomistic simulations have been conducted to verify the concept of flaw tolerance at nanoscale. A simple tension-shear chain model has been developed to model the stiffness and fracture energy of biocomposites. It is found that, while the problem of low toughness of mineral crystals is alleviated by restricting the crystal size to nanoscale, the problem of low modulus of protein has been solved by adopting a large aspect ratio for the mineral platelets. The fracture energy of biocomposites is found to be proportional to the effective shear strain and the effective shear stress in protein along its path of deformation to fracture. The bioengineered mineral-protein composites are ideally suited for fracture energy dissipation as the winding paths of protein domain unfolding and slipping along protein-mineral interfaces lead to very large effective strain before fracture. The usual entropic elasticity of biopolymers may involve relatively small effective stress and may not be able to ensure simultaneous domain unfolding and interface slipping. Cross-linking mechanisms such as Ca++ induced sacrificial bonds in bone can increase the shear stress in protein and along the protein-mineral interface, effectively converting the behavior of entropic elasticity to one that resembles metal plasticity. The sacrificial bond mechanism not only builds up a large effective stress in protein but also allows protein deformation and interface slipping to occur simultaneously under similar stress levels, making it possible to engineer a very long range of deformation under significant stress in order to maximize energy absorption. Optimization of mineral platelets near theoretical strength is found to be crucial for allowing a large effective stress to be built up in protein via cross-linking mechanisms such as Ca++ induced sacrificial bonds. Similarly, for gecko adhesion, the strength optimization of individual spatulas is found to play a critic","PeriodicalId":87411,"journal":{"name":"Mechanics & chemistry of biosystems : MCB","volume":"1 1 1","pages":"37-52"},"PeriodicalIF":0.0,"publicationDate":"2004-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70238863","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}

{"title":"The mechanochemical basis of cell and tissue regulation.","authors":"D. Ingber","doi":"10.3970/MCB.2004.001.053","DOIUrl":"https://doi.org/10.3970/MCB.2004.001.053","url":null,"abstract":"This article is a summary of a lecture presented at a symposium on \"Mechanics and Chemistry of Biosystems\" in honor of Professor Y.C. Fung that convened at the University of California, Irvine in February 2004. The article reviews work from our laboratory that focuses on the mechanism by which mechanical and chemical signals interplay to control how individual cells decide whether to grow, differentiate, move, or die, and thereby promote pattern formation during tissue morphogenesis. Pursuit of this challenge has required development and application of new microtechnologies, theoretical formulations, computational models and bioinformatics tools. These approaches have been used to apply controlled mechanical stresses to specific cell surface molecules and to measure mechanical and biochemical responses; to control cell shape independently of chemical factors; and to handle the structural, hierarchical and informational complexity of living cells. Results of these studies have changed our view of how cells and tissues control their shape and mechanical properties, and have led to the discovery that integrins and the cytoskeleton play a central role in cellular mechanotransduction. Recognition of these critical links between mechanics and cellular biochemistry should lead to novel strategies for the development of new drugs and engineered tissues, as well as biomimetic microdevices and nanotechnologies that more effectively function within the context of living tissues.","PeriodicalId":87411,"journal":{"name":"Mechanics & chemistry of biosystems : MCB","volume":"1 1 1","pages":"53-68"},"PeriodicalIF":0.0,"publicationDate":"2004-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70239016","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}

{"title":"The mechanochemical basis of cell and tissue regulation.","authors":"D E Ingber","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>This article is a summary of a lecture presented at a symposium on \"Mechanics and Chemistry of Biosystems\" in honor of Professor Y.C. Fung that convened at the University of California, Irvine in February 2004. The article reviews work from our laboratory that focuses on the mechanism by which mechanical and chemical signals interplay to control how individual cells decide whether to grow, differentiate, move, or die, and thereby promote pattern formation during tissue morphogenesis. Pursuit of this challenge has required development and application of new microtechnologies, theoretical formulations, computational models and bioinformatics tools. These approaches have been used to apply controlled mechanical stresses to specific cell surface molecules and to measure mechanical and biochemical responses; to control cell shape independently of chemical factors; and to handle the structural, hierarchical and informational complexity of living cells. Results of these studies have changed our view of how cells and tissues control their shape and mechanical properties, and have led to the discovery that integrins and the cytoskeleton play a central role in cellular mechanotransduction. Recognition of these critical links between mechanics and cellular biochemistry should lead to novel strategies for the development of new drugs and engineered tissues, as well as biomimetic microdevices and nanotechnologies that more effectively function within the context of living tissues.</p>","PeriodicalId":87411,"journal":{"name":"Mechanics & chemistry of biosystems : MCB","volume":"1 1","pages":"53-68"},"PeriodicalIF":0.0,"publicationDate":"2004-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26095252","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}

{"title":"System optimization for the development of ultrasensitive electronic biosensors using carbon nanotube nanoelectrode arrays.","authors":"Jessica E Koehne,&nbsp;Jun Li,&nbsp;Alan M Cassell,&nbsp;Hua Chen,&nbsp;Qi Ye,&nbsp;Jie Han,&nbsp;M Meyyappan","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Vertically aligned multi-walled carbon nanotubes (MWCNTs) have been reported in fabricating nanoelectrode arrays. Further studies on optimizing this system for the development of ultrasensitive DNA sensors are reported here. The mechanical stability of the as-grown MWCNT array can be improved by polymer coating or SiO2 encapsulation. The latter method provides excellent electronic and ionic insulation to the sidewall of MWCNTs and the underlying metal layer, which is investigated with electrochemical impedance spectroscopy. The insulation ensures well-defined nanoelectrode behavior. A method is developed for selectively functionalizing biomolecules at the open end of MWCNTs while keeping the SiO2 surface passivated, using the unique graphitic chemistry. An ultrahigh sensitivity approaching the limit of fluorescence techniques is obtained with this system for DNA detection.</p>","PeriodicalId":87411,"journal":{"name":"Mechanics & chemistry of biosystems : MCB","volume":"1 1","pages":"69-80"},"PeriodicalIF":0.0,"publicationDate":"2004-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26095253","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}

{"title":"Y.C. \"Bert\" Fung: the father of modern biomechanics.","authors":"G. Kassab","doi":"10.3970/MCB.2004.001.005","DOIUrl":"https://doi.org/10.3970/MCB.2004.001.005","url":null,"abstract":"It is a great fortune to have Professor Y.C. Fung as the Honorary Editor for the journal “Mechanics and Chemistry of Biosystems”. It is also my great fortune that Professor Satya Atluri (Editor-in-Chief) has asked me to write a tribute to Dr. Fung and his contributions to mechanics of biosystems or biomechanics. In casting off the first volume of the journal, this dedication is most appropriate since it is the intent of the Editors to publish articles that follow in the strong tradition of biomechanics set forth by Dr. Fung. Dr. Fung’s contributions span the fields of bio-fluid and bio-solid mechanics and have touched upon nearly every mechanical organ system in physiology. He has authored nearly 300 publications and 3 books, and is the editor of 6 additional books on biomechanics (see References). It is, of course, impossible to describe all of Dr. Fung’s contributions to the field of biomechanics in the allotted space. In this tribute, I will briefly describe some of the highlights of the past four golden decades.","PeriodicalId":87411,"journal":{"name":"Mechanics & chemistry of biosystems : MCB","volume":"1 1 1","pages":"5-22"},"PeriodicalIF":0.0,"publicationDate":"2004-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70239074","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}

{"title":"Engineering nanostructured probes for sensitive intracellular gene detection.","authors":"Gang Bao,&nbsp;Andrew Tsourkas,&nbsp;Philip J Santangelo","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The ability to detect, localize, quantify and monitor the expression of specific genes in living cells in real-time will offer unprecedented opportunities for advancement in molecular biology, disease pathophysiology, drug discovery, and medical diagnostics. However, current methods for quantifying gene expression employ either selective amplification (as in PCR) or saturation binding followed by removal of the excess probes (as in microarrays and in situ hybridization) to achieve specificity. Neither approach is applicable when detecting gene transcripts within living cells. Here we review the recent development in engineering nanostructured molecular probes for gene detection in vivo, describe probe design approaches and its structure-function relations, and discuss the critical issues and challenges in performing living cell gene detection with high specificity, sensitivity and signal-to-background ratio. The underlying biological and biochemical aspects are illustrated.</p>","PeriodicalId":87411,"journal":{"name":"Mechanics & chemistry of biosystems : MCB","volume":"1 1","pages":"23-36"},"PeriodicalIF":0.0,"publicationDate":"2004-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"26097516","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}