A three-dimensional phase boundary model for diffusion processes involved in reactions of crosslinked polymeric amines with low molecular weight esters

1997 ◽  
Vol 109 (1) ◽  
pp. 39-48
Author(s):  
Desy P Koruthu ◽  
P M Madhusudanan ◽  
V N Rajasekharan Pillai
Keyword(s):  
Molecular Weight ◽  
Phase Boundary ◽  
Diffusion Processes ◽  
Three Dimensional ◽  
Low Molecular Weight ◽  
Boundary Model

A diffusion wake model for tracer ultrastructure-permeability studies in microvessels

1995 ◽  
Vol 269 (6) ◽  
pp. H2124-H2140 ◽  
Author(s):  
B. M. Fu ◽  
F. E. Curry ◽  
S. Weinbaum
Keyword(s):  
Molecular Weight ◽  
Three Dimensional ◽  
Threshold Concentration ◽  
Time Dependent ◽  
Surrounding Tissue ◽  
Low Molecular Weight ◽  
Electron Microscopic ◽  
Small Pore ◽  
Tissue Space ◽  
Transvascular Exchange

We developed a time-dependent diffusion model for analyzing the concentration profiles of low-molecular-weight tracers in the interendothelial clefts of the capillary wall that takes into account the three-dimensional time-dependent filling of the surrounding tissue space. The model provides a connecting link between two methods to investigate transvascular exchange: electron-microscopic experiments to study the time-dependent wake formed by low-molecular-weight tracers (such as lanthanum nitrate) on the tissue side of the junction strand discontinuities in the interendothelial cleft of frog mesentery capillaries (R. H. Adamson and C. C. Michel. J. Physiol. Lond. 466: 303-327, 1993) and confocal-microscopic experiments to measure the spread of low-molecular-weight fluorescent tracers in the tissue space surrounding these microvessels (R. H. Adamson, J. F. Lenz, and F. E. Curry, Microcirculation 1: 251-265, 1994). We show that the interpretation of the presence of tracer as an all-or-none indication of a pathway across the junctional strand is likely to be incorrect for small solutes. Large-pore pathways, in which the local tracer flux densities are high, reach a threshold concentration for detection and are likely to be detected after relatively short perfusion times, whereas distributed small-pore pathways may not be detected until the tissue concentrations surrounding the entire vessel approach threshold concentrations. The analysis using this approach supports the hypothesis advanced by Fu et al. (J. Biomech. Eng. 116: 502-513, 1994) that the principal pathways for water and solutes of < 1.0 nm diameter across the interendothelial cleft may be different and suggests new experiments to test this hypothesis.

Three dimensional heteroatom-doped carbon composite film for flexible solid-state supercapacitors

RSC Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 4483-4489 ◽  
Author(s):  
Ben-Xue Zou ◽  
You Gao ◽  
Bo Liu ◽  
Yongpeng Yu ◽  
Yanhua Lu
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
Composite Film ◽  
Active Carbon ◽  
Resin Composite ◽  
Three Dimensional ◽  
Carbon Composite ◽  
Low Molecular Weight ◽  
Supercapacitor Electrode ◽  
Flexible Supercapacitor

Three dimensional (3D) heteroatom-doped active carbon as a flexible supercapacitor electrode is explored with a starting material of silkworm fibers and low molecular weight phenol resin composite.

Interaction between Carbon Black and Polymer in Cured Elastomers

1951 ◽  
Vol 24 (3) ◽  
pp. 597-615
Author(s):  
R. S. Stearns ◽  
B. L. Johnson
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Chemical Bonding ◽  
Physical Adsorption ◽  
Three Dimensional ◽  
Physical Property ◽  
Carbon Black Particle ◽  
Low Molecular Weight ◽  
Carbon Blacks ◽  
Black Particle

Abstract This research was initiated to determine whether the interaction at the interface between the surface of finely divided solids, such as carbon black, and cured elastomers is primarily physical or chemical in nature. Further, it was desired to correlate some physical property of the reinforced stock with the surface properties of the solid pigment. Through an examination of the thermodynamic changes accompanying the deformation of loaded stocks it is shown that physical adsorption of the van der Waals type occurring at the interface between pigment and polymer is inadequate to account for the experimental observations. However, if chemical bonding occurs at the interface between polymer and pigment, then the entropy of deformation of the stock may be correlated with the extent of this bonding. By a calorimetric method it was demonstrated that the surface of a carbon black particle contains sites that react with bromine to liberate the same amount of heat as low molecular-weight olefins. It is, therefore, proposed that a carbon black particle be considered as a disordered agglomerate of polymeric benzenoid type molecules which contain around their perimeters various functional groups. The existence of olefinic-type unsaturation on the surface of carbon blacks suggests strongly that, in the case of carbon blacks, the polymer and pigment are combined chemically through pigment-sulfur-polymer bonds into a continuous three-dimensional cross-linked matrix.

scholarly journals The Effects of Three-Dimensional Ligand Immobilization on Kinetic Measurements in Biosensors

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 241
Author(s):  
Elisa Chiodi ◽  
Allison M. Marn ◽  
Monireh Bakhshpour ◽  
Nese Lortlar Ünlü ◽  
M. Selim Ünlü
Keyword(s):  
Molecular Weight ◽  
Three Dimensional ◽  
The Other ◽  
Low Molecular Weight ◽  
Surface Binding ◽  
Kinetic Measurements ◽  
Advantages And Disadvantages ◽  
Affinity Constants ◽  
Other Hand ◽  
The Impact

The field of biosensing is in constant evolution, propelled by the need for sensitive, reliable platforms that provide consistent results, especially in the drug development industry, where small molecule characterization is of uttermost relevance. Kinetic characterization of small biochemicals is particularly challenging, and has required sensor developers to find solutions to compensate for the lack of sensitivity of their instruments. In this regard, surface chemistry plays a crucial role. The ligands need to be efficiently immobilized on the sensor surface, and probe distribution, maintenance of their native structure and efficient diffusion of the analyte to the surface need to be optimized. In order to enhance the signal generated by low molecular weight targets, surface plasmon resonance sensors utilize a high density of probes on the surface by employing a thick dextran matrix, resulting in a three-dimensional, multilayer distribution of molecules. Despite increasing the binding signal, this method can generate artifacts, due to the diffusion dependence of surface binding, affecting the accuracy of measured affinity constants. On the other hand, when working with planar surface chemistries, an incredibly high sensitivity is required for low molecular weight analytes, and furthermore the standard method for immobilizing single layers of molecules based on self-assembled monolayers (SAM) of epoxysilane has been demonstrated to promote protein denaturation, thus being far from ideal. Here, we will give a concise overview of the impact of tridimensional immobilization of ligands on label-free biosensors, mostly focusing on the effect of diffusion on binding affinity constants measurements. We will comment on how multilayering of probes is certainly useful in terms of increasing the sensitivity of the sensor, but can cause steric hindrance, mass transport and other diffusion effects. On the other hand, probe monolayers on epoxysilane chemistries do not undergo diffusion effect but rather other artifacts can occur due to probe distortion. Finally, a combination of tridimensional polymeric chemistry and probe monolayer is presented and reviewed, showing advantages and disadvantages over the other two approaches.

scholarly journals Effects of matrix macromolecules on chondrocyte gene expression: synthesis of a low molecular weight collagen species by cells cultured within collagen gels.

1982 ◽  
Vol 93 (3) ◽  
pp. 767-774 ◽  
Author(s):  
G J Gibson ◽  
S L Schor ◽  
M E Grant
Keyword(s):  
Gene Expression ◽  
Molecular Weight ◽  
Three Dimensional ◽  
Molecular Size ◽  
Low Molecular Weight ◽  
Expression Data ◽  
Collagen Gels ◽  
Collagenous Matrix ◽  
Conventional Manner ◽  
Plastic Tissue Culture

Chick-embryo sternal chondrocytes have been cultured within three-dimensional collagen gels as part of a study concerned with the effects of extracellular matrix macromolecules on chondrocyte gene expression. Data are presented indicating that chondrocytes cultured within such a collagenous environment synthesize significantly more of an hitherto unidentified, low molecular weight collagen species than do cells grown on plastic tissue-culture dishes in the conventional manner. This low molecular weight collagen species contains noncollagenous domains (as indicated by its decreased molecular size after mild pepsin digestion), is distinct from the known collagen types (as judged by CNBr peptide analysis), and forms part of the insoluble collagenous matrix produced by the chondrocytes. Cells growing within the gel tend to form colonies consisting of a linear array of cells reminiscent of the cellular organization in growth cartilage.

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