203 research outputs found

    Further understanding the nature of Ω(2012)\Omega(2012) within a chiral quark model

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    In our previous works, we have analyzed the two-body strong decays of the low-lying Ω\Omega baryon states within a chiral quark model. The results show that the Ω(2012)\Omega(2012) resonance favors the three-quark state with JP=3/2J^P=3/2^- classified in the quark model. With this assignment, in the present work we further study the three-body strong decay Ω(2012)Ξ(1530)KˉΞπKˉ\Omega(2012)\to \Xi^*(1530)\bar{K} \to \Xi\pi\bar{K} and coupled-channel effects on Ω(2012)\Omega(2012) from nearby channels ΞKˉ\Xi \bar{K}, Ωη\Omega\eta and Ξ(1530)Kˉ\Xi^*(1530)\bar{K} within the chiral quark model as well. It is found that the Ω(2012)\Omega(2012) resonance has a sizeable decay rate into the three-body final state ΞπKˉ\Xi\pi\bar{K}. The predicted ratio RΞKˉΞπKˉ=B[Ω(2012)Ξ(1530)KˉΞπKˉ]/B[Ω(2012)ΞKˉ]12%R_{\Xi\bar{K}}^{\Xi\pi\bar{K}}=\mathcal{B}[\Omega(2012)\to \Xi^*(1530)\bar{K}\to \Xi\pi\bar{K}]/\mathcal{B}[\Omega(2012)\to \Xi\bar{K}]\simeq 12\% is close to the up limit 11%11\% measured by the Belle Collaboration in 2019, however, our predicted ratio is too small to be comparable with the recent data 0.97±0.310.97\pm 0.31. Furthermore, our results show that the coupled-channel effects on the Ω(2012)\Omega(2012) is not large, its components should be dominated by the bare three-quark state, while the proportion of the molecular components is only 16%\sim 16\%. To clarify the nature of Ω(2012)\Omega(2012), the ratio RΞKˉΞπKˉR_{\Xi\bar{K}}^{\Xi\pi\bar{K}} is expected to be tested by other experiments.Comment: 7 pages, 3 figure

    Has Molecular Docking Ever Brought us a Medicine?

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    Molecular docking has been developed and improving for many years, but its ability to bring a medicine to the drug market effectively is still generally questioned. In this chapter, we introduce several successful cases including drugs for treatment of HIV, cancers, and other prevalent diseases. The technical details such as docking software, protein data bank (PDB) structures, and other computational methods employed are also collected and displayed. In most of the cases, the structures of drugs or drug candidates and the interacting residues on the target proteins are also presented. In addition, a few successful examples of drug repurposing using molecular docking are mentioned in this chapter. It should provide us with confidence that the docking will be extensively employed in the industry and basic research. Moreover, we should actively apply molecular docking and related technology to create new therapies for diseases

    Prognostic impact of H3K27me3 expression on locoregional progression after chemoradiotherapy in esophageal squamous cell carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Trimethylation of lysine 27 on histone H3 (H3K27me3) by enhancer of zeste homolog 2 (EZH2) is an epigenetic mark that mediates gene silencing. EZH2 is overexpressed and correlates with poor prognosis in many cancers. However, the clinical implication of H3K27me3 in human malignancies has not been well established. We wished to ascertain whether a correlation exists between the expression of H3K27me3 and clinical outcome in a group of patients with esophageal squamous cell carcinoma (ESCC) treated with definitive chemoradiotherapy (CRT).</p> <p>Methods</p> <p>The method of immunohistochemistry (IHC) was utilized to examine the protein expression of H3K27me3 in 98 pretreatment biopsy specimens of ESCC and in 30 samples of normal esophageal mucosa. The clinical/prognostic significance of H3K27me3 expression was statistically analyzed.</p> <p>Results</p> <p>The expression frequency and expression levels of H3K27me3 were significantly higher in ESCCs than in normal tissues. There was a positive correlation between H3K27me3 expression and WHO grade (<it>P </it>= 0.016), tumor size (<it>P </it>= 0.019), T status (<it>P </it>= 0.024), locoregional progression (<it>P </it>= 0.009) and EZH2 expression (<it>P </it>= 0.036). High H3K27me3 expression was associated with poor locoregional progression-free survival (LPFS) (<it>P </it>= 0.010) in ESCC. Further analysis demonstrated that H3K27me3 could stratify patient outcome in T2-3 (<it>P </it>= 0.048), N0 (<it>P </it>= 0.005) and M0 (<it>P </it>= 0.018) stages as well as in CRT effective group (<it>P </it>= 0.022).</p> <p>Conclusions</p> <p>Our data suggests that H3K27me3 expression examined by IHC might be useful for stratifying LPFS for different subsets of ESCC patients treated with definitive CRT.</p

    Epitaxial growth of heterogeneous metal nanocrystals: From gold nano-octahedra to palladium and silver nanocubes

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    通讯作者地址: Xie, ZX (通讯作者), Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen, Peoples R China 电子邮件地址: [email protected], [email protected] octahedral Au nanocrystals as seeds, highly monodisperse Au@Pd and Au@Ag core-shell nanocubes were synthesized by a two-step seed-mediated method in aqueous solution. Accordingly, we have preliminarily proposed a general rule that the atomic radius, bond dissociation energy, and electronegativity of the core and shell metals play key roles in determining the conformal epitaxial layered growth mode

    Proton-Boron Fusion Yield Increased by Orders of Magnitude with Foam Targets

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    A novel intense beam-driven scheme for high yield of the tri-alpha reaction 11B(p,{\alpha})2{\alpha} was investigated. We used a foam target made of cellulose triacetate (TAC, C_9H_{16}O_8) doped with boron. It was then heated volumetrically by soft X-ray radiation from a laser heated hohlraum and turned into a homogenous, and long living plasma. We employed a picosecond laser pulse to generate a high-intensity energetic proton beam via the well-known Target Normal Sheath Acceleration (TNSA) mechanism. We observed up to 10^{10}/sr {\alpha} particles per laser shot. This constitutes presently the highest yield value normalized to the laser energy on target. The measured fusion yield per proton exceeds the classical expectation of beam-target reactions by up to four orders of magnitude under high proton intensities. This enhancement is attributed to the strong electric fields and nonequilibrium thermonuclear fusion reactions as a result of the new method. Our approach shows opportunities to pursue ignition of aneutronic fusion

    Factors Influencing Chinese Male's Willingness to Undergo Circumcision: A Cross-Sectional Study in Western China

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    BACKGROUND: Male circumcision (MC) has been shown to reduce the risk of female to male transmission of HIV. The goal of this survey was to explore the acceptability of MC among the Chinese and to identify factors associated with circumcision preference. METHODS: A cross-sectional survey was conducted between September 2009 and December 2010. We interviewed 2,219 male community participants, from three high HIV prevalence provinces in western China. A structured questionnaire was used to collect data on MC knowledge, willingness to accept MC, reasons to accept or refuse MC, and sexual behaviors and health. For those who refused MC, a health education intervention providing information on the benefits of circumcision was conducted. We used multiple logistic regression models to identify factors associated with the acceptability of MC. RESULTS: Of the respondents (n = 2,219), 44.6% (989/2,219) reported they would accept MC for the following reasons: promotion of female partners' hygiene (60.3%), redundant foreskin (59.4%), prevention of penile cancer (50.2%), enhanced sexual pleasure (41.4%), and protection against HIV and STDs (34.2%). The multivariable logistic regression showed that five factors were associated with MC willingness: long foreskin (OR = 15.98), residing in Xinjiang province (OR = 3.69), being younger than 25 (OR = 1.60), knowing hazards of redundant foreskin (OR = 1.78), and having a friend who underwent circumcision (OR = 1.36). CONCLUSION: The acceptability of male circumcision was high among the general population in China. Our study elucidates the factors associated with circumcision preference and suggests that more health education campaigns about positive health effects are necessary to increase the MC rate in China

    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
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