1,556 research outputs found
Terahertz spin-orbital excitations in the paramagnetic state of multiferroic Sr2FeSi2O7
We studied the novel multiferroic material Sr2FeSi2O7 and found three absorption modes above the magnetic ordering transition temperature using time-domain terahertz spectroscopy. These absorption modes can be explained as the optical transitions between the spin-orbit coupling and crystal-field split 3d(6) Fe2+ ground-state term in this material. Consideration of the compressed tetrahedral environment of the Fe2+ site is crucial to understand the excitations. We point out, however, discrepancies between the single-site atomic picture and the experimental results.1133Ysciescopu
Inhibition of Nitric Oxide and Prostaglandin E2 Expression by Methanol Extract of Polyopes affinis in Lipopolysaccharide-stimulated BV2 Microglial Cells through Suppression of Akt-dependent NF-kB Activity and MAPK Pathway
Purpose: To determine whether the methanol extract of Polyopes affinis (MEPA) down-regulates the expression of pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated BV2 microglial cells.Methods: The production of nitric oxide (NO) and prostaglandin E2 (PGE2) was measured by the Griess reagents and enzyme-linked immunosorbent assay (ELISA), respectively. Expression levels of mRNA and protein in LPS-stimulated BV2 microglial cells were assessed by reverse transcription-polymerase (RT-PCR) and Western blot analysis. Activation of nuclear factor-êB (NF-êB) was detected by electrophoretic mobility shift assay (EMSA).Results: MEPA inhibited the expression of LPS-induced pro-inflammatory mediators, NO and PGE2, as well as their respective genes, iNOS and COX-2, at both protein and mRNA levels, without any accompanying cytotoxicity. Moreover, treatment with MEPA significantly suppressed the LPS-induced DNA-binding activity of NF-êB, which is known as a main transcription factor for the regulation of proinflammatory genes, as well as the nuclear translocation of its subunit p65 and p50, by degrading IêBá.MEPA increased Akt dephosphorylation which leads to suppression of the DNA-binding activity of NF-kB in LPS-stimulated BV2 microglial cells and suppressed phosphorylation of ERK and JNK, which are involved in the mitogen-activated protein kinase (MAPK) signaling pathway for regulating proinflammatory genes.Conclusion: Our results indicate that MEPA down-regulates pro-inflammatory mediators such as NO and PGE2 by suppressing Akt-dependent NF-êB activity as well as phosphorylation of ERK and JNK inLPS-stimulated BV2 microglial cells.Keywords: Polyopes affinis, Nitric oxide, Prostaglandin E2, Nuclear factor-k
Methanol Extract of Myelophycus caespitosus Inhibits the Inflammatory Response in Lipopolysaccharidestimulated BV2 Microglial Cells by Downregulating NF-kB via Inhibition of the Akt Signaling Pathway
Purpose: To determine whether the methanol extract of Myelophycus caespitosus (MEMC) downregulates the expression of pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated BV2 microglial cells.Methods: Reverse transcription-polymerase chain reaction (RT-PCR) together with Western blot analysis was used to evaluate the expression of pro-inflammatory mediators such as nitric oxide (NO) and prostaglandin E2(PGE2) as well as their regulatory genes such as inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), in LPS-stimulated BV2 microglial cells. The level of NO production was analyzed using Griess reaction.The release of PGE2 was determined using sandwich enzyme-linked immunosorbent assay. The DNA-binding activity of nuclear factor-êB (NF-êB) was measured by electrophoretic mobility shift assay.Results: MEMC inhibited LPS-induced pro-inflammatory mediators, NO and PGE2, as well as their respective genes, iNOS and COX-2, at both protein and mRNA levels, without any significant cytotoxicity. Treatment withMEMC also substantially reduced the LPS-induced DNA-binding activity of NF-êB and nuclear translocation of NF-êB subunits p65 and p50 via the inhibition of IêBá phosphorylation and degradation. MEMC promoteddephosphorylation of Akt that subsequently suppressed the DNA-binding activity of NF-êB in LPS-stimulated BV2 microglial cells.Conclusion: Collectively, these data suggest that MEMC attenuates expression of pro-inflammatory mediators such as NO and PGE2 by suppression of their regulatory genes through the inhibition of Aktmediated NF-êB activity.Keywords: Myelophycus caespitosus, Nitric oxide, Prostaglandin E2, Nuclear factor-êB
Association analysis of polymorphism in KIAA1717, HUMMLC2B, DECR1 and FTO genes with meat quality traits of the Berkshire breed
Single nucleotide polymorphisms (SNPs) in KIAA1717, HUMMLC2B, DECR1, and FTO genes have been found to be associated with some pork meat quality traits. In this study, we discovered that, in addition to meat quality traits reported previously, SNPs in these genes also are significantly associated with other meat quality traits in the Berkshire breed. A total of 323 Berkshire pigs bred under the same conditions were used for meat quality evaluation and polymerase chain reaction-amplified genes with restriction endonucleases (PCR-RFLP) genotyping analyses. The association analysis of RFLP genotyping with meat quality traits revealed that the SNPs in these 4 genes have novel associations with multiple meat quality traits (p < 0.01 or p < 0.05); a SNP in KIAA1717 was associated with meat color (CIE L), backfat thickness, drip loss, water-holding capacity, and pH24hr; a SNP in HUMMLC2B was associated with chemical composition (collagen), drip loss, shear force, and pH24hr; a SNP in DECR1 was associated with meat color (CIE a and b) and backfat thickness; and a SNP in FTO was associated with meat color (CIE L, a and b), protein content, drip loss, and water-holding capacity. Taken collectively, our results suggest that these 4 SNPs may be used for marker-assisted selection as a genetic marker for meat quality traits in Berkshire pigs.Key words: Berkshire, genetic markers, meat quality, SN
Magnetism and magnetoelectricity in the polar oxide α-Cu2V2O7
Single crystals of the orthorhombic polar oxide alpha-Cu2V2O7 with space group Fdd2 are synthesized and their physical properties are measured. Neutron powder diffraction is also performed on a polycrystal sample to extract the magnetic structure. The ground state is shown to be weakly ferromagnetic, that is, collinearly antiferromagnetic in the a-direction with a small remanent magnetization in the c-direction. When an external magnetic field is applied in the c-direction, further spin canting, accompanied by the induced electric polarization, occurs. It is demonstrated that the magnetoelectric effect in alpha-Cu2V2O7 is adequately described if spin-dependent p-d hybridization due to spin-orbit coupling as well as magnetic domain effects are simultaneously taken into account. We discuss the implication of the present result in the search for materials with multiferroicity and/or magnetoelectricity. Copyright (C) EPLA, 2016open11122sciescopu
A potential naphtho[2,1-b:3,4-b ']dithiophene-based polymer with large open circuit voltage for efficient use in organic solar cells
A novel copolymer, PNDT-BTN, based on naphtho[2,1-b:3,4-b'] dithiophene (NDT) and alkoxy naphthalene, was designed and synthesized by the Pd-catalyzed Stille-coupling method. The copolymer demonstrated good solubility and film-forming ability, along with good thermal stability. PNDT-BTN exhibited a broad absorption (from 300 to 600 nm), centered at 492 nm. HOMO and LUMO energy levels of the polymer were estimated to be -5.56 eV and -3.48 eV, respectively. The polymer solar cell fabricated from the blend of the polymer (donor) and PC71BM (acceptor) exhibited a high power conversion efficiency of 4.29% with a high V-OC of 0.98 V. To the best of our knowledge, this is among the highest V-OC values of PSCs based on NDT derivatives. This work demonstrates that the replacement of a vinylene group in a conjugated polymer with alkoxy naphthalene moieties is able to significantly lower HOMO energy levels, and therefore, increase the open circuit voltage of solar cells.open1198sciescopu
10-year nationwide trends of the incidence, prevalence, and adverse outcomes of non-valvular atrial fibrillation nationwide health insurance data covering the entire Korean population
Prior Mating Experience Modulates the Dispersal of Drosophila in Males More Than in Females
Cues from both an animal’s internal physiological state and its local environment may influence its decision to disperse. However, identifying and quantifying the causative factors underlying the initiation of dispersal is difficult in uncontrolled natural settings. In this study, we automatically monitored the movement of fruit flies and examined the influence of food availability, sex, and reproductive status on their dispersal between laboratory environments. In general, flies with mating experience behave as if they are hungrier than virgin flies, leaving at a greater rate when food is unavailable and staying longer when it is available. Males dispersed at a higher rate and were more active than females when food was unavailable, but tended to stay longer in environments containing food than did females. We found no significant relationship between weight and activity, suggesting the behavioral differences between males and females are caused by an intrinsic factor relating to the sex of a fly and not simply its body size. Finally, we observed a significant difference between the dispersal of the natural isolate used throughout this study and the widely-used laboratory strain, Canton-S, and show that the difference cannot be explained by allelic differences in the foraging gene
Signal transducer and activator of transcription 3-mediated CD133 up-regulation contributes to promotion of hepatocellular carcinoma
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Template Synthesis of Carbon Nanofibers Containing Linear Mesocage Arrays
Carbon nanofibers containing linear mesocage arrays were prepared via evaporation induced self-assembly method within AAO template with an average channel diameter of about 25 nm. The TEM results show that the mesocages have an elongated shape in the transversal direction. The results of N2 adsorption–desorption analysis indicate that the sample possesses a cage-like mesoporous structure and the average mesopore size of the sample is about 18 nm
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