Fano-Rashba effect in thermoelectricity of a double quantum dot molecular junction

We examine the relation between the phase-coherent processes and spin-dependent thermoelectric effects in an Aharonov-Bohm (AB) interferometer with a Rashba quantum dot (QD) in each of its arm by using the Green's function formalism and equation of motion (EOM) technique. Due to the interplay between quantum destructive interference and Rashba spin-orbit interaction (RSOI) in each QD, an asymmetrical transmission node splits into two spin-dependent asymmetrical transmission nodes in the transmission spectrum and, as a consequence, results in the enhancement of the spin-dependent thermoelectric effects near the spin-dependent asymmetrical transmission nodes. We also examine the evolution of spin-dependent thermoelectric effects from a symmetrical parallel geometry to a configuration in series. It is found that the spin-dependent thermoelectric effects can be enhanced by controlling the dot-electrode coupling strength. The simple analytical expressions are also derived to support our numerical results

Enhanced tunneling electroresistance in multiferroic tunnel junctions due to the reversible modulation of orbitals overlap

published_or_final_versio

RXRα acts as a carrier for TR3 nuclear export in a 9-cis retinoic acid-dependent manner in gastric cancer cells

Retinoid X receptor (RXR) plays a crucial role in the cross talk between retinoid receptors and other hormone receptors including the orphan receptor TR3, forming different heterodimers that transduce diverse steroid/thyroid hormone signaling. Here we show that RXRalpha exhibits nucleocytoplasmic shuttling in MGC80-3 gastric cancer cells and that RXRalpha, shuttling is energy-dependent through a nuclear pore complex (NPC)mediated pathway for its import and an intact DNA binding domain-mediated pathway for its export. In the presence of its ligand 9-cis retinoic acid, RXRalpha was almost exclusively located in the cytoplasm. More importantly, we also show that RXRalpha. acts as a carrier to assist translocation of TR3, which plays an important role in apoptosis. Both RXRalpha and TR3 colocalized in the nucleus; however, upon stimulation by 9-cis retinoic acid they cotranslocated to the cytoplasm and then localized in the mitochondria. TR3 export depends on RXRalpha as in living cells GFP-TR3 alone did not result in export from the nucleus even in the presence of 9-cis retinoic acid, whereas GFP-TR3 cotransfected with RXRalpha was exported out of the nucleus in response to 9-cis retinoic acid. Moreover, specific reduction of RXRalpha levels caused by anti-sense RXRalpha abolished TR3 nuclear export. In contrast, specific knockdown of TR3 by antisense-TR3 or TR3-siRNA did not affect RXRalpha shuttling. These results indicate that RXRalpha is responsible for TR3 nucleocytoplasmic translocation, which is facilitated by the RXRalpha ligand 9-cis retinoic acid. In addition, mitochondrial TR3, but not RXRalpha was critical for apoptosis, as TR3 mutants that were distributed in the mitochondria induced apoptosis in the presence or absence of 9-cis retinoic acid. These data reveal a novel aspect of RXRalpha function, in which it acts as a carrier for nucleocytoplasmic translocation of orphan receptors

Effects of L-arginine on intestinal development and endogenous arginine-synthesizing enzymes in neonatal pigs

This study aimed to investigate the effects of dietary L-arginine supplementation on the intestinal development of neonatal piglets and the underlying mechanisms. 36 neonatal piglets were randomly allocated into three diet groups: control group (supplemented with 0% L-arginine), 0.4 and 0.8% Larginine groups. When compared with the control, dietary supplementation with L-arginine decreased (P<0.05) blood urea nitrogen (BUN), and improved (P<0.05) serum T3 and insulin level of the piglets on day 11. Arginine and its metabolites (citrulline and ornithine) were elevated, additionally, dietary supplementation with 0.8% L-arginine markedly enhanced jejunal villus height, villus area on day 11 and D-xylose absorption rate on day 19. Dietary supplementation with 0.8% L-arginine increased (P<0.05) activities of maltose and lactose on day 18, respectively. This effect correlated with profound change in enzyme activities as inducible nitric oxide synthetase (iNOS), glutamine synthetase (GS) and ornithine decarboxylase (ODC) were elevated on day 18. The concentrations of spermine was increased (P<0.05) by L-arginine supplementation on day 18. These results collectively suggest that dietary  Larginine supplementation improves protein synthesis and intestinal development of the neonatal pigs, the underlying mechanism includes dietary L-arginine supplementation which regulated the productions of intestinal polyamine in jejunum, and stimulated endogenous arginine-synthesizing enzymes in neonatal piglets.Key words: Neonatal pig, L-arginine, intestinal development, arginine-synthetases

Thylakoid-bound ascorbate peroxidase increases resistance to salt stress and drought in Brassica napus

Reactive oxygen species (ROS) are cellular indicators of stress. In plants, they function as secondary messengers in response to environmental stress. Ascorbate peroxidase (APX) is an important enzyme directly involved in the scavenging of ROS. In this study, we aimed at identifying the function of the Brassica napus thylakoid APX (tAPX). Germination efficiencies of seeds of B. napus plants over expressing tAPX were higher than those of the seeds of the control plants; this was true both on Murashige and Skoog medium with 300 mM mannitol and with 150 mM NaCl. Further experiments showed that 40-day-old seedlings of the control plants turned yellow, withered, and subsequently died, when treated with 150 mM NaCl for 12 days. In contrast, transgenic plants over expressing tAPX survived this treatment and had at least three green leaves at the end of the experiment. When 40-dayold seedlings were withheld water for 10 days, followed by a 2 day recovery, the control plants exhibited smaller leaves and shorter stems in comparison to tAPX-over expressing plants. In addition, compared with control plants, tAPX-overexpressing plants show reduced hydrogen peroxide accumulation and increased APX relative activity. Our results demonstrate that tAPX plays an important role in resistance to salt stress and drought in plants.Key words: tAPX, transgenic lines, Brassica napus, salt stress, water deficiency

Effect of the Chinese herb Mesima Reishi UE-1 on invasion of human ovarian cancer cells in vitro

To study the effects of Mesima Reishi UE-1 on the metastatic phenotype of the human ovarian cancer cell line HO8910. HO8910 cells were pretreated with different concentration of Mesima Reishi UE-1 in vitro. Using cell proliferation assay, spreading and adhesion assay, cell migration and invasion assay, zymography, immunocytochemical staining and RT-PCR, we examined the effects of Mesima Reishi UE- 1 on cell proliferation, motility, adhesion and expression of MMP-2, 9 in vitro. Mesima Reishi UE-1 directly inhibited HO8910 cell proliferation in vitro. And pretreated with different concentrations of Mesima Reishi UE-1, HO8910 cells motility, adhesion and invasion were inhibited significantly. The activity of MMP-9 was inhibited in a dose-dependent manner. The protein and mRNA expression of MMP-2, 9 were also inhibited. Mesima Reishi UE-1 suppresses invasion of human ovarian cancer cells in vitro.Key words: Mesima Reishi UE-1, polysaccharides, human ovarian cancer, tumor invasion, matrix metalloproteinase

Fe(II)-EDTA chelate-induced aromatic hydroxylation of terephthalate as a new method for the evaluation of hydroxyl radical-scavenging ability

The investigation of Fe(ii)-EDTA chelate-induced aromatic hydroxylation of terephthalate in pH 7.4 phosphate buffer solution and a new method for the evaluation of hydroxyl radical-scavenging ability are reported. The method is based on attack of the hydroxyl radical on the terephthalate to produce highly fluorescent 2-hydroxyterephthalate, which is detected fluorimetrically. The formation of hydroxyl radical is believed to be the result of the reduction of molecular oxygen by Fe(ii)-EDTA to form superoxide radical, which in turn dismutates to hydrogen peroxide, and then Fe(ii)-EDTA catalyzes the decomposition of hydrogen peroxide to produce hydroxyl radical. The mechanism of the generation of hydroxyl radical in the proposed system was confirmed. This study established a simple and inexpensive method for the evaluation of the scavenging ability of some compounds on hydroxyl radicals

Investigation of the anthracene-nitroxide hybrid molecule as a probe for hydroxyl radicals

A new method for the determination of hydroxyl radicals is proposed. The method is based on the use of a hybrid molecule consisting of a fluorescent chromophore, anthracene, and a nitroxide radical. In the hybrid molecule, the nitroxide quenches the fluorescence of anthracene strongly. The reaction of hydroxyl radicals with dimethyl sulfoxide generates quantitatively methyl radicals, which then combine with the nitroxide moiety of the hybrid molecules to result in an increase in the fluorescence intensity. The fluorescence increase is proportional to the concentration of hydroxyl radicals. The proposed method is capable of detecting hydroxyl radicals generated in the Fenton system. It is a simple and sensitive technique for the determination of hydroxyl radicals

Arabidopsis thaliana VDAC2 involvement in salt stress response pathway

Soil salinity seriously affects plants distribution and yield, while salt stress induces SOS genes, and voltage-dependent anion channels (VDAC) and a mitochondrial porin, are induced too. In this paper, phenotypes of AtVDAC2 transgenic lines and wild type (RLD) were analyzed. It was found that AtVDAC2 over-expressing transgenic plants were more sensitive to NaCl, and produced more H2O2 in the NaCl treatment. Also, to find the inner reason, the salt overly sensitive gene 3 (SOS3) expression level was changed with the expression of AtVDAC2. So, it was conjectured that the signal of salt stress response was first sent to AtVDAC2, then AtVDAC2 expression improved, leading to the down-stream signals changes, such as accumulation of H2O2 and improved expression of SOS3. So, it was found that in the over-expression of transgenic lines with AtVDAC2 up-regulation, SOS3 expression increased significantly, and in the inhibited-expressing lines, it was vice versa. In summary, AtVDAC2 was involved in salt stress signaling pathway, and it regulated SOS3 gene expression.Key words: Arabidopsis thaliana, voltage-dependent anion channels (VDAC), salt stress, signaling pathway