Tanmay Lele^1,1, Philmo Oh^1,1, Jeffrey A. Nickerson^1,1,2,2, Donald E. Ingber^1,1,3,3

Molecular & Cellular Biomechanics, Vol.1, No.3, pp. 181-190, 2004, DOI:10.3970/mcb.2004.001.181

Abstract The estimation of binding constants and diffusion coefficients of molecules that associate with insoluble molecular scaffolds inside living cells and nuclei has been facilitated by the use of Fluorescence Recovery after Photobleaching (FRAP) in conjunction with mathematical modeling. A critical feature unique to FRAP experiments that has been overlooked by past mathematical treatments is the existence of an `equilibrium constraint': local dynamic equilibrium is not disturbed because photobleaching does not functionally destroy molecules, and hence binding-unbinding proceeds at equilibrium rates. Here we describe an improved mathematical formulation under the equilibrium constraint which provides a more accurate estimate of molecular reaction… More >

Marziyeh Eftekhari¹, Omid Vahidi^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.2, pp. 153-171, 2018, DOI:10.3970/cmes.2018.114.153

Abstract Various drugs are used to maintain normoglycemia in subjects with type 2 diabetes mellitus. The combination of the drugs from different classes in one single tablet may enhance the effectiveness of the anti-diabetic drugs. To investigate the impact of combining drugs on the glucose regulation of subjects with type 2 diabetes, we propose a pharmacokinetic/pharmacodynamics (PK/PD) mathematical modeling approach for a combination of metformin and vildagliptin drugs. In the proposed modeling approach, two separate PK models representing oral administration of metformin and vildagliptin for diabetic subjects are interconnected to a PD model comprising a detailed compartmental physiological model representing the… More >

Rama Bansil¹, Minghai Li¹, Yongsheng Liu¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.4, pp. 75-76, 2009, DOI:10.3970/icces.2009.013.075

Abstract Block copolymers are known to form micelles of different shapes in selective solvents that preferentially dissolve one of the constituent blocks. These micellar fluids exhibit various ordered and disordered phases. To gain microscopic insight into the mechanisms involved in the transformation between different phases we use synchrotron-based time-resolved small angle x-ray scattering (SAXS) and coarse-grained discrete Brownian Dynamics simulations. In this talk I will focus on the kinetics of the transformation from the hexagonal packed cylinder (HEX) phase to cubic phases (FCC or BCC). SAXS data was interpreted with a geometrical model for the transformation from cylinders to spheres. Brownian… More >

Sergei Bronnikov¹, Sergei Kostromin, Vyacheslav Zuev

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.4, pp. 207-214, 2009, DOI:10.3970/icces.2009.009.207

Abstract Kinetics of the ordered phase growth in a melted multi-component liquid crystalline mixture subjected to a deep cooling was studied using polarizing optical microscopy. The droplets of the ordered phase revealed in the optical images across the phase transition were segmented and treated statistically. In the resulting histograms, two overlapping statistical ensembles related to two main components of the mixture were recognized. These ensembles were successfully described using principles of irreversible thermodynamics and the mean droplet diameters within both ensembles were determined. Analysis of the mean droplet diameter as a function of time allowed recognition of two regimes involved in… More >

O. Gil-Castell¹, J. D. Badia^1,2, A. Ribes-Greus^1,*

Journal of Renewable Materials, Vol.6, No.4, pp. 370-382, 2018, DOI:10.7569/JRM.2017.634170

Abstract A blending strategy of virgin and reprocessed polylactide may be postulated as an alternative to reduce the material cost at industrial level, and as a valorization route to plastic waste management of production scraps. The performance of blends prepared from virgin polylactide and polylactide mechanically reprocessed up to two cycles (PLA-V/R) was assessed in terms of thermo-oxidative stability, morphology, viscoelasticity and thermal kinetics for energetic valorization. PLA-V/R blends showed appropriate thermo-oxidative stability. The amorphous nature of polylactide was preserved after blending. The viscoelastic properties showed an increment of the mechanical blend effectiveness, which suggested the feasibility of using PLA-V/R blends… More >

Bernal Sibaja^1,2,3, Camila Pereira Matheus^1,2, Ricardo Ballestero Mendez^1,2, J. R. Vega-Baudrit³, Maria L. Auad^*,1,2

Journal of Renewable Materials, Vol.5, No.3-4, pp. 231-240, 2017, DOI:10.7569/JRM.2017.634113

Abstract Interpenetrating polymer networks (IPNs) using an epoxy phase synthesized from chemically modified α-resorcylic acid, and an acrylate phase employing acrylated soybean oil are the main focus of this study. Part 1 details the epoxidation of α-resorcylic acid with epichlorohydrin in alkaline medium, as well as the study of the polymerization and network formation of the generated epoxy-acrylate interpenetrated systems. The epoxy content of the epoxidized α-resorcylic acid was measured by means of a titration using HBr in acetic acid solution, and the functionalization was studied by FTIR. From the obtained results, mainly calorimetry and gel time determination, it was clear… More >

S.K. Pankaj¹, C. Bueno-Ferrer¹, N.N. Misra¹, L. O’Neill², Paula Bourke¹, P.J. Cullen^3*

Journal of Renewable Materials, Vol.5, No.1, pp. 14-20, 2017, DOI:10.7569/JRM.2016.634105

Abstract This work aims to analyze the effects of cold atmospheric air plasma treatment of antimicrobial chitosan film with different levels of thymol. Optical characterization of the dielectric barrier discharge showed the generation of reactive nitrogen and oxygen species by the system. A significant increase (p < 0.05) in the surface roughness was observed after cold plasma treatment of the films. No significant difference (p > 0.05) was observed in the thermal profile of the plasma-treated films. A significant increase (p < 0.05) in the thymol diffusion coefficient was observed after the plasma treatment for all the active films. More >

Dilson E. Rassier^*

Molecular & Cellular Biomechanics, Vol.6, No.4, pp. 229-242, 2009, DOI:10.3970/mcb.2009.006.229

Abstract When activated skeletal muscles are stretched at slow velocities, force increases in two phases: (i) a fast increase, and (ii) a slow increase. The transition between these phases is commonly associated with the mechanical detachment of cross-bridges from actin. This phenomenon is referred to asforce enhancement during stretch. After the stretch, force decreases and reaches steady-state at levels that are higher than the force produced at the corresponding length during purely isometric contractions. This phenomenon is referred to asresidual force enhancement.The mechanisms behind the increase in force during and after stretch are still a matter of debate, and have physiological… More >

Meghan H. Hoskins^*, Cheng Dong^∗,†

Molecular & Cellular Biomechanics, Vol.3, No.2, pp. 79-88, 2006, DOI:10.3970/mcb.2006.003.079

Abstract It has been determined previously that polymorphonuclear leukocytes, or PMNs, can facilitate melanoma cell extravasation through the endothelium under shear conditions [1,2]. The interactions between melanoma cells and PMNs are mediated by the β₂-integrins expressed by PMNs and intercellular adhesion molecules (ICAM-1) expressed on melanoma cells. In this study, the kinetics of these interactions was studied using a parallel plate flow chamber. The dissociation rates were calculated under low force conditions for ICAM-1 interactions with both β₂-integrins, LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18), together and separately by using functional blocking antibodies on PMNs. The kinetics of PMNs stimulated with IL-8 was… More >

Cheng Zhu¹, Rodger P. McEver²

Molecular & Cellular Biomechanics, Vol.2, No.3, pp. 91-104, 2005, DOI:10.3970/mcb.2005.002.091

Abstract Force can shorten the lifetimes of receptor-ligand bonds by accelerating their dissociation. Perhaps paradoxical at first glance, bond lifetimes can also be prolonged by force. This counterintuitive behavior was named catch bonds, which is in contrast to the ordinary slip bonds that describe the intuitive behavior of lifetimes being shortened by force. Fifteen years after their theoretical proposal, catch bonds have finally been observed. In this article we review recently published data that have demonstrated catch bonds in the selectin system and suggested catch bonds in other systems, the theoretical models for their explanations, and their function as a mechanism… More >