1,111 research outputs found
Photon orbits and phase transition for Non-Linear charged Anti-de Sitter black holes
In this work, we investigate the relationship between the photon sphere
radius and the first-order phase transition for the charged EPYM AdS black
hole. Through the analysis, we find with a certain condition there exist the
non-monotonic behaviors between the photon sphere radius, the impact parameter,
the non-linear YM charge parameter, temperature, and pressure. And both the
changes of photon sphere radius and impact parameter before and after phase
transition can be regarded as the order parameter, their critical exponents
near the critical point are equal to the same value , just like the
ordinary thermal systems. These indicate that there maybe exists a universal
relationship of gravity nearby the critical point for a black hole
thermodynamical system. Furthermore, the effect of impact parameter on the
deflect angle is also investigated
(N,N-Diethyldithiocarbamato-κ2 S,S′)iodido(1,10-phenanthroline-κ2 N,N′)copper(II)
The copper(II) atom in the title compound, [Cu(C5H10NS2)I(C12H8N2)], is chelated by the N-heterocycle and the dithiocarbamate anion in a slightly distorted tetragonal coordination. The tetragonal-pyramidal coorination is completed by the iodine atom in the apical position. One ethyl group is disordered over two positions with site occupancies of 0.31 (2) and 0.69 (2)
2,2′-(Butane-1,4-diyl)diisoquinolinium tetrachloridozincate(II)
The crystal of the title compound, (C22H22N2)[ZnCl4], consists of 2,2′-(butane-1,4-diyl)diisoquinolinium organic cations and [ZnCl4]2− complex anions. The cation is located across a twofold axis and the ZnII atom of the anion is located on the other twofold axis. The centroid–centroid distance between parallel pyridine rings of neighboring molecules is 3.699 (3) Å, but the face-to-face separation of 3.601 (3) Å suggests there is no significant π–π stacking in the crystal structure
An Exposure Meter of Lijiang Fiber-fed High-Resolution Spectrograph
In 2016, an exposure meter was installed on the Lijiang Fiber-fed
High-Resolution Spectrograph to monitor the coupling of starlight to the
science fiber during observations. Based on it, we investigated a method to
estimate the exposure flux of the CCD in real time by using the counts of the
photomultiplier tubes (PMT) of the exposure meter, and developed a piece of
software to optimize the control of the exposure time. First, by using
flat-field lamp observations, we determined that there is a linear and
proportional relationship between the total counts of the PMT and the exposure
flux of the CCD. Second, using historical observations of different spectral
types, the corresponding relational conversion factors were determined and
obtained separately. Third, the method was validated using actual observation
data, which showed that all values of the coefficient of determination were
greater than 0.92. Finally, software was developed to display the counts of the
PMT and the estimated exposure flux of the CCD in real-time during the
observation, providing a visual reference for optimizing the exposure time
control.Comment: Published in Research in Astronomy and Astrophysic
p38b Mitogen-Activated Protein Kinase Signaling Mediates Exenatide-Stimulated Microglial b-Endorphin Expression
ABSTRACT Recent discoveries established that activation of glucagon-like peptide-1 receptors (GLP-1Rs) mediates neuroprotection and antinociception through microglial b-endorphin expression. This study aimed to explore the underlying signaling mechanisms of microglial b-endorphin. GLP-1Rs and b-endorphin were coexpressed in primary cultures of microglia. Treatment with the GLP-1R agonist exenatide concentration-dependently stimulated microglial expression of the b-endorphin precursor gene proopiomelanocortin (POMC) and peptides, with EC 50 values of 4.1 and 7.5 nM, respectively. Exenatide also significantly increased intracellular cAMP levels and expression of pprotein kinase A (PKA), p-p38, and p-cAMP response element binding protein (CREB) in cultured primary microglia. Furthermore, exenatide-induced microglial expression of POMC was completely blocked by reagents that specifically inhibit adenylyl cyclase and activation of PKA, p38, and CREB. In addition, knockdown of p38b (but not p38a) using short interfering RNA (siRNA) eliminated exenatide-induced microglial p38 phosphorylation and POMC expression. In contrast, lipopolysaccharide increased microglial activation of p38, and knockdown of p38a (but not p38b) partially suppressed expression of proinflammatory factors (including tumor necrosis factor-a, interleukin-1b, and interleukin-6). Exenatideinduced phosphorylation of p38 and CREB was also totally blocked by the PKA inhibitor and siRNA/p38b, but not by siRNA/p38a. Seven-day intrathecal injections of siRNA/p38b (but not siRNA/p38a) completely blocked exenatide-induced spinal p38 activation, b-endorphin expression, and mechanical antiallodynia in rats with established neuropathy, although siRNA/p38b and siRNA/p38a were not antiallodynic. To our knowledge, our results are the first to show a causal relationship between the PKA-dependent p38b mitogen-activated protein kinase/CREB signal cascade and GLP-1R agonismmediated microglial b-endorphin expression. The differential role of p38a and p38b activation in inflammation and nociception was also highlighted
2,2′-(Hexane-1,6-diyl)diisoquinolinium tetrachloridozincate(II)
The asymmetric unit of the title compound, (C24H26N2)[ZnCl4], consists of two 2,2′-(hexane-1,6-diyl)diisoquinolinium cations and two [ZnCl4]2− complex anions. The [ZnCl4]2− anions have a distorted tetrahedral geometry. The dihedral angles between the isoquinoline rings of the two cations are nearly equal [16.1 (2) and 16.3 (2)°]. In the crystal structure, the ordered linear formation is aggregated by weak intermolecular π–π stacking interactions between neighboring isoquinoline pyridine rings with a centroid–centroid distance of 3.779 (4) Å
Zhi-Bai-Di-Huang-Wan, a classic Chinese medicinal formula in relieving menopausal symptoms: A multi-centre and controlled trial from UK and China
Background: To explore the effects of Zhi-Bai-Di-Huang-Wan (ZBDHW), a classic formula of Chinese medicinal herbs in relieving menopausal symptoms in British and Chinese women.Methods and Materials: Between May 2011 and May 2013, 224 Chinese and British women were divided into a ZBDHW group with 115 cases and a control group with 109 cases. The clinical menopausal symptoms were assessed by the modified Kupperman Index Scale. The serum levels of follicle stimulating hormone (FSH) and estradiol (E2) were respectively detected before and after the treatment. Results: After 12 weeks of treatment, both groups’ Kupperman index scores markedly decreased (P<0.05) and no significant difference existed between them (P>0.05). The serum levels of FSH did not change significantly after the treatment (P>0.05) and no significant difference existed between them (P>0.05). The serum levels of E2 significantly increased in both of the two groups (P<0.05) and it increased more in the comparison group (P<0.05). No side-effect of the treatment was reported in both of the two groups during the period of the treatment.Conclusion: The classic Chinese medicinal formula, ZBDHW, showed promise in relieving menopausal symptoms.Key words: Chinese medicinal herb; Zhi-Bai-Di-Huang-Wan (ZBDHW); menopausal symptom
- …