78 research outputs found

    Potential of Core-Collapse Supernova Neutrino Detection at JUNO

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    JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

    Detection of the Diffuse Supernova Neutrino Background with JUNO

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    As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

    Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

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    Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30M⊙M_{\odot} for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

    The bioactivities of the central segment of Zp2 polypeptide

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    HI-6-loaded PEGylated liposomes: an on-site first-aid strategy for acute organophosphorus agent poisoning

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    AbstractOrganophosphorus agents, also known as nerve agents, are very dangerous chemicals that were used as chemical warfare agents. HI-6 is one of the most promising reactivators which is effective in reactivating AChE inhibited by many nerve agents. However, the fast in-vivo clearance of HI-6 became a large barrier for first aid use under some sophisticated circumstances. In this study, PEGylated liposomes loading HI-6 were prepared and evaluated in vitro and in vivo. For PEG-LP-HI-6, the optimal formulation’s loading efficiency and encapsulation efficiency were 6.47 ± 0.10% and 71.2 ± 1.15%, respectively. According to the pharmacokinetic results, compared with free HI-6 and LP-HI-6, the intravenous injection of PEG-LP-HI-6 significantly extended t1/2 (1.47 ± 0.29 h), MRT (1.44 ± 0.07 h), and improved the AUC of HI-6 in vivo. Drug concentrations in the CNS also increased after the intravenous administration of PEG-LP-HI-6. For in vivo treatment study, twenty minutes after poison exposure, the survival rate of animals in saline, free HI-6, LP-HI-6 and PEG-LP-HI-6 groups were 0, 0, 30% and 70%, respectively. Compared with the non-PEGylated liposomes group and free HI-6, PEG-LP-HI-6 could prolong the survival time of experimental animals and alleviate the neurotoxic symptoms, which demonstrated great potential as a first-aid strategy for acute organophosphorus agent poisoning

    Diagenetic and metallogenic ages, and geological significance of the Fujiashan skarn-type(Cu-) W Deposit, southeastern Hubei Province

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    The Fujiashan(Cu-) W Deposit, which is discovered recently, is one of the typical skarn deposit in southeastern Hubei.The(Cu-) W mineralization is closely associated with the Fujiashan granodiorite porphyry.In order to accurately determine the diagenetic and metallogenic ages of the deposit, ages of the granodiorite porphyry and (Cu-) W mineralization are studied by using LA-ICP-MS zircon U-Pb and molybdenite Re-Os isotopic dating in this paper. In addition, the tectonic setting of diagenesis and mineralization is discussed based on the sedimentary strata, structural deformation, geophysical and geochemical evidences in the middle and lower reaches of the Yangtze River during the Late Mesozoic.The results show that the granodiorite porphyry yields a weighted average 206Pb/238U age of (144±3) Ma, whereas a Re-Os model age of molybdenite of (146±2) Ma is obtained for mineralization.These isotopic ages indicate that the granodiorite porphyry and(Cu-) W mineralization at Fujiashan both formed during Late Jurassic-Early Cretaceous.In addition, the diagenesis and mineralization ages of the Fujiashan(Cu-) W Deposit are also consistent with the time of large-scale magmatic and metallogenic events for skarn Fe-Cu-Au-Mo deposits in the middle and lower reaches of the Yangtze River.According to the history of tectonic evolution and the latest chronological data in the middle and lower reaches of the Yangtze River, including southeastern Hubei, it is considered that the Fujiashan(Cu-) W Deposit is likely to be formed in a tectonic setting of lithospheric extension and thinning.The discovery and determination of Late Jurassic-Early Cretaceous skarn(Cu-) W Deposits including the Fujiashan indicate that the ore concentration area in southeastern Hubei has a good explorational prospect for tungsten deposits

    SMAD4 and NF1 mutations as potential biomarkers for poor prognosis to cetuximab-based therapy in Chinese metastatic colorectal cancer patients

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    Abstract Background Cetuximab, an anti-EGFR monoclonal antibody, is used in combination with chemotherapy in clinic to enhance the outcome in metastatic colorectal cancer (mCRC) patients with only ~ 20% response rate. To date only activating mutations in KRAS and NRAS have been identified as poor prognosis biomarkers in cetuximab-based treatment, which makes an urgent need for identification of novel prognosis biomarkers to precisely predict patients’ response in order to maximize the benefit. Methods In this study, we analysed the mutation profiles of 33 Chinese mCRC patients using comprehensive next-generation sequencing (NGS) targeting 416 cancer-relevant genes before cetuximab treatment. Upon receiving cetuximab-based therapy, patients were evaluated for drug response, and the progression-free survival (PFS) was monitored. The association of specific genetic alterations and cetuximab efficacy was analyzed. Results Patients carrying SMAD4 mutations (SMAD4 mut, n = 8) or NF1 mutations (NF1 mut, n = 4) had significantly shorter PFS comparing to those carrying wildtype SMAD4 (SMAD4 wt, n = 25) (P = 0.0081) or wildtype NF1 (NF1 wt, n = 29) (P = 0.0028), respectively. None of the SMAD4 mut or NF1 mut patients showed response to cetuximab when assessed at 12-week post-treatment. Interestingly, two patients carrying both SMAD4 mut and NF1 mut showed the shortest PFS among all the patients. Conclusions Our results demonstrated that SMAD4 and NF1 mutations can serve as potential biomarkers for poor prognosis to cetuximab-based therapy in Chinese mCRC patients
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