Search results for "Macromolecule"
showing 10 items of 235 documents
Artificial multiple criticality and phase equilibria: an investigation of the PC-SAFT approach
2005
The perturbed-chain statistical associating fluid theory (PC-SAFT) is studied for a wide range of temperature, T, pressure, p, and (effective) chain length, m, to establish the generic phase diagram of polymers according to this theory. In addition to the expected gas-liquid coexistence, two additional phase separations are found, termed "gas-gas" equilibrium (at very low densities) and "liquid-liquid" equilibrium (at densities where the system is expected to be solid already). These phase separations imply that in one-component polymer systems three critical points occur, as well as equilibria of three fluid phases at triple points. However, Monte Carlo simulations of the corresponding sys…
Identification of 2-(thiophen-2-yl)acetic Acid-Based Lead Compound for mPGES-1 Inhibition.
2021
We report the implementation of our in silico/synthesis pipeline by targeting the glutathione-dependent enzyme mPGES-1, a valuable macromolecular target in both cancer therapy and inflammation therapy. Specifically, by using a virtual fragment screening approach of aromatic bromides, straightforwardly modifiable by the Suzuki-Miyaura reaction, we identified 3-phenylpropanoic acid and 2-(thiophen-2-yl)acetic acid to be suitable chemical platforms to develop tighter mPGES-1 inhibitors. Among these, compounds 1c and 2c showed selective inhibitory activity against mPGES-1 in the low micromolar range in accordance with molecular modeling calculations. Moreover, 1c and 2c exhibited interesting IC…
Synthese von makromolekeln einheitlicher größe.
1953
Es werden die Wege zur Herstellung von Makromolekeln einheitlicher Grose diskutiert, namlich die schrittweise Synthese, die Trennung polymerhomologer Gemische und das Duplikationsverfahren. Nach dem zuletzt genannten Verfahren werden mit Hilfe von Diisocyanaten und Diolen in 3 Stufen Oligo-urethane einheitlicher Molekelgrose bis zum Molgewicht ca. 2000 hergestellt und durch Derivate charakterisiert. The methods by which macromolecules of uniform molecular size can be prepared are discussed. These are the synthesis step by step, the separation of polymerhomologue mixtures and the method of duplication. According to the last-named method Oligourethanes of a uniform molecular weight of about 2…
Photon scattering as a probe of microviscosity and channel size in gels such as sickle haemoglobin.
1983
The aggregation of sickle-cell haemoglobin (HbS) is one of the most physiologically important and widely studied macromolecular gelation processes. Both the thermodynamics and kinetics of the process are important in determining the pathological consequences of deoxygenation of the red cells (and both must be understood if a rational strategy is to be developed for pharmacological intervention). We describe here a new and versatile technique for the study of the structure and formation of the HbS aggregates, that should be widely applicable to gel systems generally. We use laser autocorrelation spectroscopy to observe the diffusion of monodisperse polystyrene latex spheres in the interstice…
Structure and biological evaluation of amino-functionalized PVP nanogels for fast cellular internalization
2013
Abstract Aminopropyl methacrylamide chloride-graft-poly(N-vinyl pyrrolidone) nanogels (NGs) were designed to exploit the favorable properties of poly(N-vinyl pyrrolidone) (PVP), such as its high affinity to water and complexation ability of ions, molecules and macromolecules, with the availability of primary amino groups for bioconjugation reactions. A thorough structural characterization of the nanoscalar networks was performed via 1 H NMR and solid state 13 C NMR spectroscopies, while solid state NMR relaxation time measurements completed the NGs description in terms of polymer network density. Information on the hydrodynamic size and surface charge densities were sought via dynamic light…
Advanced Functional Structures Based on Interpolyelectrolyte Complexes
2013
This review considers interpolyelectrolyte complexes, with a particular emphasis on advanced macromolecular co-assemblies based on polyionic species with nonlinear topology and on polymer–inorganic hybrids formed by interpolyelectrolyte complexes containing metal ions and/or metal nanoparticles.
Anomalous Slowdown of Polymer Detachment Dynamics on Carbon Nanotubes
2019
The "wrapping" of polymer chains on the surface of carbon nanotubes allows one to obtain multifunctional hybrid materials with unique properties for a wide range of applications in biomedicine, electronics, nanocomposites, biosensors, and solar cell technologies. We study by means of molecular dynamics simulations the force-assisted desorption kinetics of a polymer from the surface of a carbon nanotube. We find that, due to the geometric coupling between the adsorbing surface and the conformation of the macromolecule, the process of desorption slows down dramatically upon increasing the windings around the nanotube. This behavior can be rationalized in terms of an overdamped dynamics with a…
Conformational changes in acetylcholine binding protein investigated by temperature accelerated molecular dynamics.
2014
Despite the large number of studies available on nicotinic acetylcholine receptors, a complete account of the mechanistic aspects of their gating transition in response to ligand binding still remains elusive. As a first step toward dissecting the transition mechanism by accelerated sampling techniques, we study the ligand-induced conformational changes of the acetylcholine binding protein (AChBP), a widely accepted model for the full receptor extracellular domain. Using unbiased Molecular Dynamics (MD) and Temperature Accelerated Molecular Dynamics (TAMD) simulations we investigate the AChBP transition between the apo and the agonist-bound state. In long standard MD simulations, both confo…
Heparin–polynitroxides: Synthesis and preliminary evaluation as cardiovascular EPR/MR imaging probes and extracellular space-targeted antioxidants
2011
We report here the synthesis of heparin-polynitroxide derivatives (HPNs) in which nitroxide moieties are linked either to uronic acid or glycosamine residues of the heparin macromolecule. HPNs have low anticoagulant activity, possess superoxide scavenging properties, bind to the vascular endothelium/extra-cellular matrix and can be detected by EPR and MRI techniques. As the vascular wall-targeted redox-active paramagnetic compounds, HPNs may have both diagnostic (molecular MRI) and therapeutic (ecSOD mimics) applications.
Integrated Linear and Nonlinear Optics with Novel Macromolecular Systems
1992
ABSTRACTThis paper deals with the application of some recently developed evanescent waveoptical techniques for the characterization of novel macromolecular host-guest systems. In particular, surface plasmon- and guided optical wave-spectroscopies and -microscopies are used to determine the linear and nonlinear optical properties of these materials in thin film form.