The Chinese-French SVOM mission for GRBs studies

We present the SVOM (Space-based multi-band astronomical Variable Objects Monitor) mission that the Chinese National Space Agency and the French Space Agency have decided to jointly implement. SVOM has been designed to detect all known types of gamma-ray bursts (GRBs), to provide fast and reliable GRB positions, to measure the broadband spectral shape and temporal properties of the GRB prompt emission, and to quickly identify the optical/near-infrared afterglows of detected GRBs, including high-redshift ones. Scheduled to be in orbit in the second half of the present decade, the SVOM satellite will carry a very innovative scientific payload combining for the first time a wide field X- and gamma-ray coded mask imager for GRB real-time localizations to few arcmin, a non-imaging gamma-ray monitor, and two narrow-field instruments for the study of the GRB early afterglow emission in the X-ray and visible bands. The SVOM payload is complemented by ground-based instruments including a wide-field camera to catch the GRB prompt emission in the visible band and two robotic telescopes to measure the photometric properties of the early afterglow. A particular attention is paid to the GRB follow-up in facilitating the observation of the SVOM detected GRB by the largest ground based telescopes.Comment: 13 pages, 3 figures. To appear in a special issue of Comptes Rendus Physique "GRB studies in the SVOM era", Eds. F. Daigne, G. Dubu

Genomic survey, characterization and expression profile analysis of the peptide transporter family in rice (Oryza sativa L.)

<p>Abstract</p> <p>Background</p> <p>Peptide transporter (PTR) family whose member can transport di-/tripeptides and nitrate is important for plant growth and development. Although the rice (<it>Oryza sativa </it>L.) genome has been sequenced for a few years, a genomic survey, characterization and expression profile analysis of the PTR family in this species has not been reported.</p> <p>Results</p> <p>In this study, we report a comprehensive identification, characterization, phylogenetic and evolutionary analysis of 84 PTR family members in rice (OsPTR) as well as their whole-life expression patterns. Chromosomal distribution and sequence analysis indicate that nearly 70% of OsPTR members are involved in the tandem and segmental duplication events. It suggests that genome duplication might be a major mechanism for expansion of this family. Highly conserved motifs were identified in most of the OsPTR members. Meanwhile, expression profile of <it>OsPTR </it>genes has been analyzed by using Affymetrix rice microarray and real-time PCR in two elite hybrid rice parents, Minghui 63 and Zhenshan 97. Seven genes are found to exhibit either preferential or tissue-specific expression during different development stages of rice. Under phytohormone (NAA, GA3 and KT) and light/dark treatments, 14 and 17 <it>OsPTR </it>genes are differentially expressed respectively. <it>Ka/Ks </it>analysis of the paralogous <it>OsPTR </it>genes indicates that purifying selection plays an important role in function maintenance of this family.</p> <p>Conclusion</p> <p>These investigations add to our understanding of the importance of OsPTR family members and provide useful reference for selecting candidate genes for functional validation studies of this family in rice.</p

Dexmedetomidine inhibits inflammation in microglia cells under stimulation of LPS and ATP by c-Fos/NLRP3/caspase-1 cascades

NOD-like receptor 3 (NLRP3) plays critical roles in the initiation of inflammasome-mediated inflammation in microglia, thus becomes an important therapeutic target of Alzheimer’s disease (AD). Dexmedetomidine (Dex), a new type of clinical anesthetic agent, shows anti-inflammatory properties and inhibits postoperative cognitive dysfunction in AD patients. The present study was aimed to investigate effect of Dex on NLRP3 activity in activated microglia and reveal the underlying mechanisms. The human microglia clone 3 (HMC3) cells were exposed to 100 ng/ml LPS and 5 mM ATP, in the presence and absence of doses of Dex. Data from ELISA and Western blot assays showed that Dex abrogated the promoting effects of LPS/ATP on the release of pro-inflammatory cytokines including IL-1ß and IL-18 in the cell medium and the expression of NLRP3 and its downstream target caspase-1 in HMC3 cells. Furthermore, the present study found that exposure of HMC3 cells to LPS/ATP increased nuclear protein levels of transcription factor c-Fos, but treatment with Dex reversed the increase in c-Fos, as indicated by Western blot and immunofluorescence measures. Luciferase reported assay revealed that c-Fos can bind to the promoter region of NLRP3 gene and positively regulate the expression. These results suggest that Dex inhibiting c-Fos nuclear protein levels promoted by LPS/ATP blocks the up-regulation of NLRP3. This suggestion is supported by co-immunoprecipitation and PCR studies, in which Dex decreased the amount of c-Fos that binds to NLRP3 under the stimulation of LPS/ATP. The present study revealed that Dex inhibits inflammation in microglia cells under stimulation of LPS and ATP by c-Fos/NLRP3/caspase-1 cascades, which adds new understanding of the anti-inflammatory mechanism of Dex

Perspectives on Gamma-Ray Burst Physics and Cosmology with Next Generation Facilities

High-redshift Gamma-Ray Bursts (GRBs) beyond redshift $\sim6$ are potentially powerful tools to probe the distant early Universe. Their detections in large numbers and at truly high redshifts call for the next generation of high-energy wide-field instruments with unprecedented sensitivity at least one order of magnitude higher than the ones currently in orbit. On the other hand, follow-up observations of the afterglows of high-redshift GRBs and identification of their host galaxies, which would be difficult for the currently operating telescopes, require new, extremely large facilities of at multi-wavelengths. This chapter describes future experiments that are expected to advance this exciting field, both being currently built and being proposed. The legacy of Swift will be continued by SVOM, which is equipped with a set of space-based multi-wavelength instruments as well as and a ground segment including a wide angle camera and two follow-up telescopes. The established Lobster-eye X-ray focusing optics provides a promising technology for the detection of faint GRBs at very large distances, based on which the {THESEUS}, {Einstein Probe} and other mission concepts have been proposed. Follow-up observations and exploration of the reionization era will be enabled by large facilities such as {SKA} in the radio, the 30m class telescopes in the optical/near-IR, and the space-borne {WFIRST} and {JWST} in the optical/near-IR/mid-IR. In addition, the X-ray and $\gamma$-ray polarization experiment POLAR is also introduced.Comment: accepted for publication in Space Science Review; reprinted as a chapter in a book of the Space Sciences Series of ISSI for the proceedings of the ISSI-Beijing workshop " Gamma-Ray Bursts: a Tool to Explore the Young Universe

Effect of dexmedetomidine on miR-144-3p expression and epithelial mesenchymal transition in gastric cancer cells

Purpose: To investigate the effect of dexmedetomidine (DEX) on epithelial mesenchymal transition (EMT) in gastric cancer cells, and the role of microRNA-144-3p (miR-144-3p) in the process.Methods: The effect of DEX on miRNA expression profile was analyzed using GEO database(https://www.ncbi.nlm.nih.gov/gds/). Human gastric cancer cells were cultured in vitro, and one group of cells was treated with saline for 48 h (control group). Cells treated with DEX at doses of 0.01, 0.1 and 1.0 μmol/L for 48 h were marked as low-, medium- and high-DEX concentration groups. The mRNA expression levels of miR-144-3p, ZEB1, E-cadherin and vimentin were determined using real-time quantitative polymerase chain reaction (RT-PCR), while the protein expressions of ZEB1, E-cadherin and vimentin were assayed with Western blotting. Cell proliferation was determined with CCK-8 assay, while metastasis was measured using Transwell assay.Results: The GEO database demonstrated that the expression of miR-144-3p in rat cardiomyocytes was significantly decreased after DEX treatment (p &lt; 0.05). The expression of miR-144-3p was decreased in all groups, when compared to the control group, but the expressions of ZEB1 and vimentin were increased, while that of E-cadherin was down-regulated (p &lt; 0.05). Cell proliferation in the high-DEX concentration group was decreased (p &lt; 0.05). The degrees of cell invasion and migration were increased in the medium- and high-DEX concentration groups (p &lt; 0.05).Conclusion: DEX promotes the metastasis of gastric cancer cells by regulation of epithelialmesenchymal transition (EMT) and the expression of miR-144-3p. This finding provides a new insight into the treatment of gastric cancer