Double neutron star (DNS) merger events are promising candidates of short gamma-ray burst (sGRB) progenitors as well as high-frequency gravitational wave (GW) emitters. On August 17, 2017, such a ...coinciding event was detected by both the LIGO-Virgo gravitational wave detector network as GW170817 and Gamma-Ray Monitor on board NASA's Fermi Space Telescope as GRB 170817A. Here, we show that the fluence and spectral peak energy of this sGRB fall into the lower portion of the distributions of known sGRBs. Its peak isotropic luminosity is abnormally low. The estimated event rate density above this luminosity is at least Formula: see text Gpc
yr
, which is close to but still below the DNS merger event rate density. This event likely originates from a structured jet viewed from a large viewing angle. There are similar faint soft GRBs in the Fermi archival data, a small fraction of which might belong to this new population of nearby, low-luminosity sGRBs.
Cancer stem cells (CSCs) are inherently resistant to chemotherapy, and CSCs in chemotherapy-failed recurrent tumors are enriched; however, the cellular origin of chemotherapy-induced CSC enrichment ...remains unclear. Communication with stromal fibroblasts may induce cancer cell dedifferentiation into CSCs through secreted factors. We recently demonstrated that fibroblast-derived exosomes promote chemoresistance in colorectal cancer (CRC). Here, we report that fibroblasts confer CRC chemoresistance via exosome-induced reprogramming (dedifferentiation) of bulk CRC cells to phenotypic and functional CSCs. At the molecular level, we provided evidence that the major reprogramming regulators in fibroblast-exosomes are Wnts. Exosomal Wnts were found to increase Wnt activity and drug resistance in differentiated CRC cells, and inhibiting Wnt release diminished this effect in vitro and in vivo. Together, our results indicate that exosomal Wnts derived from fibroblasts could induce the dedifferentiation of cancer cells to promote chemoresistance in CRC, and suggest that interfering with exosomal Wnt signaling may help to improve chemosensitivity and the therapeutic window.
Although fish consumption may have an influence on specific mortality of major chronic diseases, the relationship between fish consumption and all-cause mortality remains inconsistent.
We performed a ...systematic search of publications using PubMed and Web of science up to 31 December 2014. Summary relative risk (RR) for the highest versus lowest category of fish consumption on risk of all-cause mortality was calculated by using a random effects model. Potential nonlinear relation was tested by modeling fish intake using restricted cubic splines with three knots at fixed percentiles of the distribution.
Twelve prospective cohort studies with 672,389 participants and 57,641 deaths were included in this meta-analysis. Compared with the lowest category, the highest category of fish intake was associated with about a 6% significantly lower risk of all-cause mortality (RR=0.94, 95% confidence interval (CI): 0.90, 0.98; I(2)=39.1%, P=0.06). The dose-response analysis indicated a nonlinear relationship between fish consumption and all-cause mortality. Compared with never consumers, consumption of 60 g of fish per day was associated with a 12% reduction (RR=0.88, 95% CI: 0.83, 0.93) in risk of total death.
These results imply that fish consumption was associated with a reduced risk of all-cause mortality.
ABSTRACT
High time resolution and accuracy are of critical importance in the studies of timing analysis and time delay localization of gamma-ray bursts (GRBs), soft gamma-ray repeaters (SGRs) and ...pulsars. The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) consisting of two micro-satellites, GECAM-A and GECAM-B, launched on 2020 December 10, is aimed at monitoring and locating X-ray and GRBs all over the sky. To achieve its scientific goals, GECAM is designed to have the highest time resolution (0.1 $\mu {\rm s}$) among all GRB detectors ever flown. Here, we make a comprehensive time calibration campaign including both on-ground and on-orbit tests to derive not only the relative time accuracy of GECAM satellites and detectors, but also the absolute time accuracy of GECAM-B. Using the on-ground calibration with a $\rm ^{22}Na$ radioactive source, we find that the relative time accuracy between GECAM-A and GECAM-B is about 0.15 $\mu {\rm s}$ (1σ). To measure the relative time accuracy between all detectors of a single GECAM satellite, cosmic-ray events detected on orbit are utilized since they could produce many secondary particles simultaneously record by multiple detectors. We find that the relative time accuracy among all detectors onboard GECAM-B is about 0.12 $\mu {\rm s}$ (1σ). Finally, we use the novel Li-CCF method to perform the absolute time calibration with Crab pulsar and SGR J1935+2154, both of which were jointly observed by GECAM-B and Fermi/GBM, and obtain that the time difference between GECAM-B and Fermi/GBM is 3.06 ± 6.04 $\mu {\rm s}$ (1σ).
The role of autotransplantation in end-stage hepatic alveolar echinococcosis (AE) is unclear. We aimed to present our 15-case experience and propose selection criteria for autotransplantation. All ...patients were considered to have unresectable hepatic AE by conventional resection due to critical invasion to retrohepatic vena cava, hepatocaval region along with three hepatic veins, and the tertiary portal and arterial branches. All patients successfully underwent ex vivo extended right hepatectomy and autotransplantation without intraoperative mortality. The median autograft weight was 706 g (380–1000 g); operative time was 15.5 hours (11.5–20.5 hours); and anhepatic time was 283.8 minutes (180–435 min). Postoperative hospital stay was 32.3 days (12–60 days). Postoperative complication Clavien–Dindo grade IIIa or higher occurred in three patients including one death that occurred 12 days after the surgery due to acute liver failure. One patient was lost to follow-up after the sixth month. Thirteen patients were followed for a median of 21.6 months with no relapse. This is the largest reported series of patients with end-stage hepatic AE treated with liver autotransplantation. The technique requires neither organ donor nor postoperative immunosuppressant. The early postoperative mortality was low with acceptable morbidity. Preoperative precise assessment and strict patient selection are of utmost importance.
MicroRNAs are a class of small, non‐coding RNAs that can negatively regulate protein‐coding genes, and are associated with almost all known physiological and pathological processes, especially ...cancer. The number of studies documenting miRNA expression patterns in malignancy continues to expand rapidly, with continuously gained critical information regarding how aberrantly expressed miRNAs may contribute to carcinogenesis. miRNAs can influence cancer pathogenesis, playing a potential role as either oncogenes or tumour suppressors. Recently, several miRNAs have been reported to exert different regulatory functions in oesophageal cancer – the carcinoma typically arising from the epithelial lining of the oesophagus. These miRNAs also have potential clinical applications towards developing biomarkers or targets for possible use in diagnosis or therapy in oesophageal cancer. In this review, we have summarized the two (oncogenic or tumour suppressive) roles of miRNAs here, and their applications as potential biomarkers or therapeutic targets, which may illuminate future treatment for oesophageal cancer.
Energy consumption in machining contributes a significant part of manufacturing cost and produces a great environmental impact. This paper provides a critical assessment on energy consumption in a ...machining system. Energy consumption is classified at the process, machine, and system levels. Machine tool power demand at different machine states by different components is also discussed. Then predictive methods of energy consumption at different levels are summarized. Finally, energy consumption reduction strategies are discussed to achieve sustainable manufacturing.
•Energy consumption is classified at the process, machine, and system levels.•The concept of net cutting energy is established.•Empirical and analytical models of energy consumption are critically analyzed.•The strategies for reducing energy consumption are recommended.
Abstract
We report on analysis of observations of the bright transient X-ray pulsar Swift J0243.6+6124 obtained during its 2017-2018 giant outburst with Insight-HXMT, NuSTAR, and Swift observatories. ...We focus on the discovery of a sharp state transition of the timing and spectral properties of the source at super-Eddington accretion rates, which we associate with the transition of the accretion disk to a radiation pressure dominated (RPD) state, the first ever directly observed for magnetized neutron star. This transition occurs at slightly higher luminosity compared to already reported transition of the source from sub- to super-critical accretion regime associate with onset of an accretion column. We argue that this scenario can only be realized for comparatively weakly magnetized neutron star, not dissimilar to other ultra-luminous X-ray pulsars (ULPs), which accrete at similar rates. Further evidence for this conclusion is provided by the non-detection of the transition to the propeller state in quiescence which strongly implies compact magnetosphere and thus rules out magnetar-like fields.
The cross section of the e+e−→Λc+Λ¯c− process is measured with unprecedented precision using data collected with the BESIII detector at /¯s=4574.5, 4580.0, 4590.0 and 4599.5 MeV. The nonzero cross ...section near the Λc+Λ¯c− production threshold is cleared. At center-of-mass energies /¯s=4574.5 and 4599.5 MeV, the higher statistics data enable us to measure the Λc polar angle distributions. From these, the Λc electric over magnetic form-factor ratios (|GE/GM|) are measured for the first time. They are found to be 1.14±0.14±0.07 and 1.23±0.05±0.03, respectively, where the first uncertainties are statistical and the second are systematic.
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