Search results for "CAG"

Intramolecular caging in polybutadiene due to rotational barriers

2003

We present molecular dynamics simulations of a chemically realistic model of 1,4-polybutadiene and a freely rotating chain model derived from the first model by neglecting all dihedral potentials. We show that the presence of energy barriers hindering dihedral rotation leads to an intermediate plateau regime in the tagged particle mean-squared displacement reminiscent of the cage effect underlying the mode-coupling description of the liquid-glass transition. This intramolecular caging, however, occurs already at temperatures well above the glass transition regime. Because of its different physical origin, it also does not comply with the theoretical predictions of the mode-coupling theory. …

The role of GLP-1 receptor agonists during COVID-19 pandemia: a hypothetical molecular mechanism

2021

ABSTRACT Introduction A number of anti-diabetic treatments have been favored during the continuing spread of the current SARS-CoV-2 pandemic. Glucagon like peptide-1 receptor agonists (GLP1-RAs) are a group of antidiabetic drugs, the glucose reducing effect of which is founded on augmenting glucose-dependent insulin secretion with concomitant reduction of glucagon secretion and delayed gastric emptying. Apart from their glucose lowering effects, GLP1-RAs also exert a plethora of pleiotropic activities in the form of anti-inflammatory, anti-thrombotic and anti-obesogenic properties, with beneficial cardiovascular and renal impact. All these make this class of drugs a preferred option for man…

Molecular-dynamics simulation of a glassy polymer melt: Incoherent scattering function

1999

We report results of molecular-dynamics simulations for a glassy polymer melt consisting of short, linear bead-spring chains. It was shown in previous work that this onset of the glassy slowing down is compatible with the predictions of the mode coupling theory. The physical process of `caging' of a monomer by its spatial neighbors leads to a distinct two step behavior in the particle mean square displacements. In this work we analyze the effects of this caging process on the Rouse description of the melt's dynamics. We show that the Rouse theory is applicable for length and time scales above the typical scales for the caging process. Futhermore, the monomer displacement is compared with si…

Dynamics of a supercooled polymer melt above the mode-coupling critical temperature: cage versus polymer-specific effects

2000

This paper reports results of molecular dynamics simulations for a glassy polymer melt consisting of short, non-entangled chains. The temperature region studied covers the supercooled state of the melt above the mode-coupling critical temperature. The analysis focuses on the interplay of simple-liquid and polymer-specific effects. One can clearly distinguish two regimes: a regime of small and one of large monomer displacements. The first regime corresponds to motion of a monomer in its local environment. It is dominated by the cage effect and well described by the idealized mode-coupling theory. The second regime is governed by the late-β/early-α process. In this regime the connectivity of …

1,2-Bis(methylsulfanyl)-1,2-dicarba-closo-dodecaborane(12)

2004

3 pages, 1 figure, 2 tables

Frontispiece: An Octanuclear Metallosupramolecular Cage Designed To Exhibit Spin-Crossover Behavior

2017

Innentitelbild: A Self-Assembled M8L6 Cubic Cage that Selectively Encapsulates Large Aromatic Guests (Angew. Chem. 15/2011)

2011

Cellular cytotoxicity against autologous hepatocytes in children with different forms of chronic hepatitis B.

1990

Cell-mediated immune reactions play the most important role in the pathogenesis of chronic viral and auto-immune hepatitis. Cellular cytotoxicity (CC) of peripheral blood lymphocytes against autologous hepatocytes isolated from liver biopsies was studied in 29 children with different types of hepatitis B surface antigen (HBsAg)-positive hepatitis. Children with chronic hepatitis B showed higher cytotoxicity than control patients. However, a correlation of cytotoxicity to serum amino-transferases, HBeAg-/Anti-HBe-status, and hepatitis B virus DNA in serum could not be found. Children with a higher percentage of hepatitis B core antigen (HBcAg) expression in their liver tissue presented lower…

Association of hepatitis Be antigen (HBeAg) with the core of the hepatitis B virus (HBcAg).

2008

— Three substances (pronase E, sodium dodecylsulfate (SDS) and guanidine hydrochloride) with different chemical actions partially convert HBcAg to HBeAg. This process retains the integrity of the HBcAg particle, which was not different between HBcAg subpopulations, and does not generate HBcAg or HBeAg sub-units. DNA polymerase activity was destroyed by SDS and guanidine hydrochloride, but not by pronase E. Serum HBeAg could not be converted into HBcAg, suggesting that this might be an irreversible process. The data are consistent with the assumption that HBcAg and HBeAg are coded for by the same gene (C gene of the HBV-DNA).

Infection with cagA -Positive and cagA -Negative Types of Helicobacter pylori Among Children and Adolescents with Gastrointestinal Symptoms in Latvia

2003

In order to determine the prevalence of concomitant cagA-positive and cagA-negative Helicobacter pylori genotypes in individual subjects, a group of 56 symptomatic patients (aged 8-18 years) was studied. Among 31 patients culture-positive for Helicobacter pylori, only cagA-positive colonies were isolated from 18 patients, both cagA-positive and cagA-negative genotypes were isolated from 4 patients, and in 9 patients all of the individual colonies isolated were cagA-negative, but in seven of them a pool of colonies was positive for cagA. Thus, the presence of both cagA-positive and cagA-negative genotypes in the same individual was identified in 11 of the 31 culture-positive patients tested,…