A kilonova associated with GRB 070809

For on-axis typical short gamma-ray bursts (sGRBs), the forward shock emission is usually so bright that renders the identification of kilonovae (also known as macronovae) in the early afterglow ($t<0.5$ d) phase rather challenging. This is why previously no thermal-like kilonova component has been identified at such early time except in the off-axis dim GRB 170817A associated with GW170817. Here we report the identification of an unusual optical radiation component in GRB 070809 at $t\sim 0.47$ d, thanks plausibly to the very-weak/subdominant forward shock emission. The optical emission with a very red spectrum is well in excess of the extrapolation of the X-ray emission that is distinguished by an unusually hard spectrum, which is at odds with the forward shock afterglow prediction but can be naturally interpreted as a kilonova. Our finding supports the speculation that kilonovae are ubiquitous , and demonstrates the possibility of revealing the neutron star merger origin with the early afterglow data of some typical sGRBs that take place well beyond the sensitive radius of the advanced gravitational wave detectors and hence the opportunity of organizing dedicated follow-up observations for events of interest.Comment: 20 pages, 5 figures, published in Nature Astronom

PinX1 regulation of telomerase activity and apoptosis in nasopharyngeal carcinoma cells

<p>Abstract</p> <p>Background</p> <p>Human interacting protein X1 (PinX1) has been identified as a critical telomerase inhibitor and proposed to be a putative tumor suppressor gene. Loss of PinX1 has been found in a large variety of malignancies, however, its function in inhibiting telomerase activity of tumor cells is not well documented. Here we show that PinX1 is essential for down-regulation telomerase activity of nasopharyngeal carcinoma.</p> <p>Methods</p> <p>Expression vectors of human PinX1 (pEGFP-C3-PinX1) and its small interfering RNA (PinX1-FAM-siRNA) were constructed and transfected into NPC. Their effects on mRNA of telomerase catalytic subunit (hTERT), telomerase activity, cell proliferation, cell migration, wound healing, cell cycles and apoptosis were examined using semi-quantitative RT-PCR, stretch PCR, MTT assay, Transwell, scratch assay and flow cytometry, respectively.</p> <p>Results</p> <p>Transfection of pEGFP-C3-PinX1 and PinX1-FAM-siRNA increased and reduced PinX1 mRNA by 1.6-fold and 70%, respectively. Over-expression of PinX1 decreased hTERT mRNA by 21%, reduced telomerase activity, inhibited cell growth, migration and wound healing ability, arrested cells in G0/G1 phase, and increased apoptotic index. In contrast, down-regulation of PinX1 did not alter the above characteristics.</p> <p>Conclusions</p> <p>PinX1 may play important roles in NPC proliferation, migration and apoptosis and has application potential in tumor-targeted gene therapy.</p

New constraints on the Cretaceous geodynamics of paleo-Pacific plate subduction: Insights from the Xiaojiang–Beizhang granitoids, Zhejiang Province, southeast China

The relationship between the evolution of Cretaceous magmatism along the southeastern margin of Eurasia and subduction of the paleo-Pacific plate remains controversial. Here we investigate the petrogenesis of the Xiaojiang–Beizhang ferroan and magnesian granitoids, melanocratic microgranular enclaves (MME) that are found within the granitoids, and an associated mafic dyke exposed in southeast China to provide new constraints on the geodynamics of paleo-Pacific plate subduction. Zircon U–Pb ages indicate that the ferroan and magnesian granitoids were emplaced in the Cretaceous (ca. 120 and 110 Ma, respectively), and that the MME and mafic dyke are coeval with their host granitoids. Geochemical characteristics imply that the granitoids were produced by partial melting of crustal rocks and mixed with mantle-derived magmas. The MME are derivatives of the mafic magmas that intruded the silicic magmas. Two phases of mafic magmatism are evident. Stage 1 mafic rocks (the ca. 120 Ma MME) were derived mainly from the subcontinental lithospheric mantle (SCLM) with some contribution from asthenospheric mantle. The parental mafic magmas for Stage 2 (the ca. 110 Ma MME and mafic dykes) were derived from interaction and metasomatism of the SCLM and asthenosphere with slab-derived fluids. Iron enrichment or depletion in the granitoids was controlled mainly by oxygen fugacity and pressure. Our new data, combined with previously published data from Cretaceous igneous rocks in southeastern China, reveal major geochemical changes at 136 and 118 Ma, respectively. The 132–119 Ma igneous rocks record the minimal addition of slab-derived components to their source, and provide strong evidence for an abrupt change in the direction of motion of the paleo-Pacific plate from southwest to northwest at ca. 125–122 Ma

Construction of Non-Biaryl Atropisomeric Amide Scaffolds Bearing a C&ndash;N Axis via Enantioselective Catalysis

The significant scaffold offered by atropisomeric amides with a C&ndash;N chiral axis has been extensively utilized for pharmaceuticals, agricultural science, and organic syntheses. As a result, the field of atropisomer synthesis has attracted considerable interest within chemistry communities. To date, a range of catalytic atroposelective approaches has been reported for the efficient construction of these challenging scaffolds. However, greatly concise and highly useful methodologies for the synthesis of these atropisomeric compounds, focusing on transition-metal, chiral amine, and phosphoric acid catalysis reactions, etc., are still desirable. Hence, it is indispensable to succinctly and systematically present all such reports by means of disclosing the mechanistic analysis and application, as well as the challenges and issues associated with the establishment of these atropisomers. In this review, we summarize the development of catalytic asymmetric synthetic strategies to access non-biaryl atropisomers rotating around a C&ndash;N chiral axis, including the reaction methods, mechanism, late-stage transformations, and applications

Concurrent chemotherapy for T4 classification nasopharyngeal carcinoma in the era of intensity-modulated radiotherapy.

OBJECTIVE:To evaluate concurrent chemotherapy for T4 classification nasopharyngeal carcinoma (NPC) treated by intensity-modulated radiotherapy (IMRT). METHODS:From July 2004 to June 2011, 180 non-metastatic T4 classification NPC patients were retrospectively analyzed. Of these patients, 117 patients were treated by concurrent chemoradiotherapy (CCRT) using IMRT and 63 cases were treated by IMRT alone. RESULTS:The median follow-up time was 58.97 months (range, 2.79-114.92) months. For all the patients, the 1, 3 and 5-year local failure-free survival (LFFS) rates were 97.7%, 89.2% and 85.9%, regional failure free survival (RFFS) rates were 98.9%, 94.4% and 94.4%, distant failure-free survival (DFFS) rates were 89.7%, 79.9% and 76.2%, and overall survival (OS) rates were 92.7%, 78.9% and 65.3%, respectively. No statistically significant difference was observed in LFFS, RFFS, DFFS and OS between the CCRT group and the IMRT alone group. No statistically significant difference was observed in acute toxicity except leukopenia (p = 0.000) during IMRT between the CCRT group and the IMRT alone group. CONCLUSION:IMRT alone for T4 classification NPC achieved similar treatment outcomes in terms of disease local control and overall survival as compared to concurrent chemotherapy plus IMRT. However, this is a retrospective study with a limited number of patients, such results need further investigation in a prospective randomized clinical trial

Epidemiology of Cryptosporidium infection in cattle in China: a review

The present review discusses the findings of cryptosporidiosis research conducted in cattle in China and highlights the currently available information on Cryptosporidium epidemiology, genetic diversity, and distribution in China, which is critical to understanding the economic and public health importance of cryptosporidiosis transmission in cattle. To date, 10 Cryptosporidium species have been detected in cattle in China, with an overall infection rate of 11.9%. The highest rate of infection (19.5%) was observed in preweaned calves, followed by that in juveniles (10.69%), postweaned juveniles (9.0%), and adult cattle (4.94%). The dominant species were C. parvum in preweaned calves and C. andersoni in postweaned, juvenile, and adult cattle. Zoonotic Cryptosporidium species (C. parvum and C. hominis) were found in cattle, indicating the possibility of transmission between humans and cattle. Different cattle breeds had significant differences in the prevalence rate and species of Cryptosporidium. This review demonstrates an age-associated, breed-associated, and geographic-related occurrence of Cryptosporidium and provides references for further understanding of the epidemiological characteristics, and for preventing and controlling the disease

Epidemiology of

The present review discusses the findings of cryptosporidiosis research conducted in cattle in China and highlights the currently available information on Cryptosporidium epidemiology, genetic diversity, and distribution in China, which is critical to understanding the economic and public health importance of cryptosporidiosis transmission in cattle. To date, 10 Cryptosporidium species have been detected in cattle in China, with an overall infection rate of 11.9%. The highest rate of infection (19.5%) was observed in preweaned calves, followed by that in juveniles (10.69%), postweaned juveniles (9.0%), and adult cattle (4.94%). The dominant species were C. parvum in preweaned calves and C. andersoni in postweaned, juvenile, and adult cattle. Zoonotic Cryptosporidium species (C. parvum and C. hominis) were found in cattle, indicating the possibility of transmission between humans and cattle. Different cattle breeds had significant differences in the prevalence rate and species of Cryptosporidium. This review demonstrates an age-associated, breed-associated, and geographic-related occurrence of Cryptosporidium and provides references for further understanding of the epidemiological characteristics, and for preventing and controlling the disease

Kaplan-Meier curve showing OS, LRRS, RFFS and DFFS of patients with T4 classification NPC treated with IMRT alone or CCRT in the study.

<p>Kaplan-Meier curve showing OS, LRRS, RFFS and DFFS of patients with T4 classification NPC treated with IMRT alone or CCRT in the study.</p

Frequency of acute toxicity during IMRT.

<p>Frequency of acute toxicity during IMRT.</p