Search results for "Response"

Mitochondrial (dys)function - a factor underlying the variability of efavirenz-induced hepatotoxicity?

2015

Background and Purpose The non-nucleoside analogue reverse transcriptase inhibitor efavirenz is associated with hepatic toxicity and metabolic disturbances. Although the mechanisms involved are not clear, recent evidence has pinpointed a specific mitochondrial action of efavirenz accompanied by the induction of an endoplasmic reticulum (ER) stress/unfolded protein response in human hepatic cells. The aim of this study was to further investigate the involvement of this organelle by evaluating efavirenz's effects in cells lacking functional mitochondria (rho°) and comparing them with those of the typical mitotoxic agent rotenone, a standard complex I inhibitor, and the ER stress inducer thaps…

Differential effect of the enantiomers of phenprocoumon and warfarin on the vitamin K1-epoxide/vitamin K1 ratio in rat plasma.

1979

Synthesis of hexahydrocyclopenta[ij]isoquinolines as a new class of dopaminergic agents.

2014

In this study, we have described the synthesis of the tricyclic 1,2,3,7,8,8a-hexahydrocyclopenta [ij]isoquinoline (HCPIQ). Herein, six differently substituted 5,6-dioxygenated-7-phenyl-HCPIQs have been synthesized using a new methodology via (E)-1-styryl-THIQ by Friedel-Crafts cyclization with Eaton's reagent. Results showed that HCPIQs (3, 3a-e) displayed a moderate affinity for D1 dopamine receptors (DR) in the micromolar range, furthermore the catecholic HCPIQs 3a (NH), 3c (NCH3) and 3e (NCH2CHCH2) exhibited outstanding affinity and high selectivity towards D2 DR. Indeed, 3a, 3c and 3e showed Ki values of 29 nM, 13 nM and 18 nM, respectively, and HCPIQs 3a (NH) and 3c (NCH3) displayed a …

PPARα/HNF4α Interplay on Diversified Responsive Elements. Relevance in the Regulation of Liver Peroxisomal Fatty Acid Catabolism

2012

In mammals, the liver is the major organ of fatty acid catabolism. This pathway is involved in both mitochondria and peroxisome. While mitochondria breaks down fatty acids with short, medium and long carbon chains, peroxisomes are involved in the catabolism of very long and branched chain fatty acids, which are degraded by three enzymes: acyl-CoA oxidase, multifunctional enzyme and thiolase enzyme. The active pathway results mainly from a tight transcriptional control of these gene-encoding enzymes. Two major nuclear receptors that are highly expressed in this organ are involved in this control, e.g. PPARα (peroxisome proliferator-activated receptor, α isoform) and HNF4α (hepatic nuclear fa…

P1 and P2 receptors in the rat duodenal smooth muscle

1989

Sugar-induced stabilization of the monoolein Pn3m bicontinuous cubic phase during dehydration

2001

To explore the molecular mechanism of the protective function of sugars on cubic lipidic systems, the mesomorphic properties of the monoolein-water system, dehydrated in the presence of a series of sugars, have been studied by osmotic stress experiments. Two bicontinuous inverse cubic structures $(Pn3m$ and $\mathrm{Ia}3d)$ and a lamellar ${L}_{\ensuremath{\alpha}}$ phase form under dehydration in pure water. In sugar solutions, the $\mathrm{Pn}3m$ phase shows an extraordinary stability: as a function of sugar concentration, the lattice parameter decreases to very low values, but no phase transitions occur. Instead, the $\mathrm{Pn}3m$ to $\mathrm{Ia}3d$ phase transition is obtained by equi…

The Effect of Bias Field on Dielectric Response in Lead Ferrotantalate Ceramics

2011

Studies of dielectric properties of PbFe1/2Ta1/2O3 ceramics at low- and infra-low-frequencies under bias field over a wide range of temperatures are reported. Applied bias field is found to broaden the ϵ′(Т) maxima shifting positions Тm of the maximums to higher temperatures. Additional anomalies in the dielectric response are revealed at T<Тm. The anomalies in the vicinity of Тm are related to structural change at phase transition, while those observed at TТm – to magneto-electric interactions in PbFe1/2Ta1/2O3.

Dielectric properties of Pb(Fe1/2Ta1/2)O3ceramics over 70–300 K temperature range

2011

The studies of dielectric response in ferromagnetic lead ferrotantalate Pb(Fe1/2Ta1/2)O3 are reported over a wide range of temperature under the applied bias field. The features of dielectric nonlinearity deduced from behaviour of reverse e'(E=) curves at different temperatures, including regions of ferroelectric phase transition and vicinity of the Neel point, are examined. Obtained results indicate a substantial broadening of the ferroelectric phase transition. The results are discussed with respect to effects of ferroelectric ordering in relaxor materials of such kind.

Reversive Dielectric Response in xPZN-(1 − x) PSN Ceramics

2006

The effects of bias fields E= on dielectric response of xPbZn1/3Nb2/3O3-(1 − x)PbSc1/2 Nb1/2O3 ferroelectric solid solutions of x = 0, 0.05, 0.2, and 0.5 studied at temperatures of diffused phase transitions are reported. The thermal interval of the existence of a relaxor phase in the system is found to shrink with the concentration of PbZn1/3Nb2/3O3. The change of the ratio of zinc-lead and scandium-lead niobate components is deduced to change the features of the transition to polarised state from first-order to second-order transition.

Anisotropic carrier diffusion in single MAPbI(3) grains correlates to their twin domains

2020

Polycrystalline thin films and single crystals of hybrid perovskites – a material group successfully used for photovoltaic and optoelectronic applications – reportedly display heterogeneous charge carrier dynamics often attributed to grain boundaries or crystalline strain. Here, we locally resolved the carrier diffusion in large, isolated methylammonium lead iodide (MAPbI3) grains via spatial- and time-resolved photoluminescence microscopy. We found that the anisotropic carrier dynamics directly correlate with the arrangement of ferroelastic twin domains. Comparing diffusion constants parallel and perpendicular to the domains showed carriers diffuse around 50–60% faster along the parallel d…