The Influence of Structure on the Molecular Mobility and Rheology of Amorphous Macromolecular Systems

1962 ◽  
Author(s):  
T. G. Fox ◽  
V. Allen
Author(s):  
E. Baer

The most advanced macromolecular materials are found in plants and animals, and certainly the connective tissues in mammals are amongst the most advanced macromolecular composites known to mankind. The efficient use of collagen, a fibrous protein, in the design of both soft and hard connective tissues is worthy of comment. Very crudely, in bone collagen serves as a highly efficient binder for the inorganic hydroxyappatite which stiffens the structure. The interactions between the organic fiber of collagen and the inorganic material seem to occur at the nano (scale) level of organization. Epitatic crystallization of the inorganic phase on the fibers has been reported to give a highly anisotropic, stress responsive, structure. Soft connective tissues also have sophisticated oriented hierarchical structures. The collagen fibers are “glued” together by a highly hydrated gel-like proteoglycan matrix. One of the simplest structures of this type is tendon which functions primarily in uniaxial tension as a reinforced elastomeric cable between muscle and bone.


Author(s):  
A.M. Magerramov ◽  
◽  
N.I. Kurbanova ◽  
M.N. Bayramov ◽  
N.A. Alimirzoyeva ◽  
...  

Using radiothermoluminescence (RTL), the molecular mobility features in the temperature range of 77-300 K were studied for the polypropylene (PP)/ethylene propylene diene elastomer SKEPT-4044 with NiO, Cu2O and Fe3O4 nanoparticles (NPs) based on ABS-acrylonitrile butadiene or SCS-divinyl styrene matrices. It has been shown that the introduction of nanofillers in PP significantly affects the nature and temperature of γ- and β-relaxation processes, while the region of manifestation of the β-process noticeably shifts to the region of low temperatures. Composites with Cu2O NPs have a higher β-transition temperature Tβ than composites with other NPs. It was found that PP/SKEPT-4044 composites with Cu2O NPs with a dispersion of 11-15 nm and acrylonitrile butadiene thermoplastics have optimal frost resistance compared to other compositions.


2019 ◽  
Vol 25 (7) ◽  
pp. 750-773 ◽  
Author(s):  
Pabitra Narayan Samanta ◽  
Supratik Kar ◽  
Jerzy Leszczynski

The rapid advancement of computer architectures and development of mathematical algorithms offer a unique opportunity to leverage the simulation of macromolecular systems at physiologically relevant timescales. Herein, we discuss the impact of diverse structure-based and ligand-based molecular modeling techniques in designing potent and selective antagonists against each adenosine receptor (AR) subtype that constitutes multitude of drug targets. The efficiency and robustness of high-throughput empirical scoring function-based approaches for hit discovery and lead optimization in the AR family are assessed with the help of illustrative examples that have led to nanomolar to sub-micromolar inhibition activities. Recent progress in computer-aided drug discovery through homology modeling, quantitative structure-activity relation, pharmacophore models, and molecular docking coupled with more accurate free energy calculation methods are reported and critically analyzed within the framework of structure-based virtual screening of AR antagonists. Later, the potency and applicability of integrated molecular dynamics (MD) methods are addressed in the context of diligent inspection of intricated AR-antagonist binding processes. MD simulations are exposed to be competent for studying the role of the membrane as well as the receptor flexibility toward the precise evaluation of the biological activities of antagonistbound AR complexes such as ligand binding modes, inhibition affinity, and associated thermodynamic and kinetic parameters.


2021 ◽  
Vol 12 (9) ◽  
pp. 2370-2375
Author(s):  
Huan Wang ◽  
Tian Huang ◽  
Steve Granick

RSC Advances ◽  
2021 ◽  
Vol 11 (30) ◽  
pp. 18685-18692
Author(s):  
Hiroki Masuda ◽  
Yoshinori Arisaka ◽  
Masahiro Hakariya ◽  
Takanori Iwata ◽  
Tetsuya Yoda ◽  
...  

Molecular mobility of polyrotaxane surfaces promoted mineralization in a co-culture system of mesenchymal stem cells and endothelial cells.


2021 ◽  
Author(s):  
Ruriko Sekiya-Aoyama ◽  
Yoshinori Arisaka ◽  
Masahiro Hakariya ◽  
Hiroki Masuda ◽  
Takanori Iwata ◽  
...  

Mesenchymal stem cells on polyrotaxane surfaces underwent enhanced osteoblast and adipocyte differentiation. Two independent parameters, high molecular mobility and negative charge on the surfaces, may not offset the effect to promote both differentiation.


Author(s):  
Natalia V. Karimova ◽  
Michael R Alves ◽  
Man Luo ◽  
Vicki Grassian ◽  
Robert Benny Gerber

Water systems often contain complex macromolecular systems that absorb light. In marine environments, these light absorbing components are often at the air-water interface and can participate in the chemistry of...


Sign in / Sign up

Export Citation Format

Share Document