843 research outputs found

    Ultrafast Relaxation Dynamics of Photoexcited Dirac Fermion in The Three Dimensional Dirac Semimetal Cadmium Arsenide

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    Three dimensional (3D) Dirac semimetals which can be seen as 3D analogues of graphene have attracted enormous interests in research recently. In order to apply these ultrahigh-mobility materials in future electronic/optoelectronic devices, it is crucial to understand the relaxation dynamics of photoexcited carriers and their coupling with lattice. In this work, we report ultrafast transient reflection measurements of the photoexcited carrier dynamics in cadmium arsenide (Cd3As2), which is one of the most stable Dirac semimetals that have been confirmed experimentally. By using low energy probe photon of 0.3 eV, we probed the dynamics of the photoexcited carriers that are Dirac-Fermi-like approaching the Dirac point. We systematically studied the transient reflection on bulk and nanoplate samples that have different doping intensities by tuning the probe wavelength, pump power and lattice temperature, and find that the dynamical evolution of carrier distributions can be retrieved qualitatively by using a two-temperature model. This result is very similar to that of graphene, but the carrier cooling through the optical phonon couplings is slower and lasts over larger electron temperature range because the optical phonon energies in Cd3As2 are much lower than those in graphene

    A Lattice Study of (Dˉ1D)±(\bar{D}_1 D^{*})^\pm Near-threshold Scattering

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    In this exploratory lattice study, low-energy near threshold scattering of the (Dˉ1D)±(\bar{D}_1 D^{*})^\pm meson system is analyzed using lattice QCD with Nf=2N_f=2 twisted mass fermion configurations. Both s-wave (JP=0J^P=0^-) and p-wave (JP=1+J^P=1^+) channels are investigated. It is found that the interaction between the two charmed mesons is attractive near the threshold in both channels. This calculation provides some hints in the searching of resonances or bound states around the threshold of (Dˉ1D)±(\bar{D}_1 D^{*})^\pm system.Comment: 20 pages, 15 figures, matches the version on PR

    Efficient routing on scale-free networks based on local information

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    In this letter, we propose a new routing strategy with a single free parameter α\alpha only based on local information of network topology. In order to maximize the packets handling capacity of underlying structure that can be measured by the critical point of continuous phase transition from free flow to congestion, the optimal value of α\alpha is sought out. By investigating the distributions of queue length on each node in free state, we give an explanation why the delivering capacity of the network can be enhanced by choosing the optimal α\alpha. Furthermore, dynamic properties right after the critical point are also studied. Interestingly, it is found that although the system enters the congestion state, it still possesses partial delivering capability which do not depend on α\alpha. This phenomenon suggests that the capacity of the network can be enhanced by increasing the forwarding ability of small important nodes which bear severe congestion.Comment: 4 pages, 7 figure

    Increased CD4+CD25+ regulatory T cells correlate with poor short-term outcomes in hepatitis B virus-related acute-on-chronic liver failure patients

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    BackgroundThe roles of CD4+CD25+ regulatory T cells (Treg) in chronicity of hepatitis B virus (HBV) infection have been confirmed. We aimed to explore alteration of Treg in patients with HBV-related acute-on-chronic liver failure (ACLF).MethodsThirty-two HBV-related ACLF patients, 44 chronic hepatitis B patients, and 41 healthy controls were recruited. We detected frequencies of peripheral Treg and intrahepatic forkhead winged helix transcription factor (Foxp3)+ cells. Inhibitory activity of Treg was assessed by functional suppression assays. Serum interferon-γ and interleukin-10 were also determined.ResultsPeripheral Treg and intrahepatic Foxp3+ cells were more markedly increased in ACLF than chronic hepatitis B and controls (all p < 0.001), and the Foxp3+ cells located predominantly in the portal areas. The Treg frequency was positively correlated with HBV DNA load, international normalized ratio, model of end stage liver disease score, and serum interleukin-10 level in ACLF patients. Functional assays in vitro demonstrated that ACLF patients exhibited higher suppressive effects of Treg on proliferations of autologous CD4+CD25− T cells than controls. On logistic regression, prolonged international normalized ratio and higher peripheral Treg frequency predicted 30-day survival of ACLF.ConclusionThe patients with HBV-related ACLF exhibit increased amounts of Treg, of which redistribution from periphery to liver seems to modulate liver inflammation. Higher Treg amounts are associated with more severe liver disease in ACLF, and its level in combination with international normalized ratio may assist prediction of short-term outcomes of HBV-related ACLF

    Genetic variation analysis of reemerging porcine epidemic diarrhea virus prevailing in central China from 2010 to 2011

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    Porcine epidemic diarrhea has re-emerged with devastating impact in central China since October 2010. To investigate and analyze the reason of this outbreak, the M and ORF3 genes of 15 porcine epidemic diarrhea viruses (PEDV), which were collected from different areas of central China during October 2010 and December 2011, were amplified by reverse transcriptase polymerase chain reaction, cloned, sequenced, and analyzed. Sequence analyses showed that the nucleotides and amino acids were changed at some sites in the M and ORF3 genes of the 15 PEDV strains compared with those genes of CV777 reference strain. Based on the phylogenetic analyses, PEDVs in central China and reference strains could be separated into three groups: G1, G2, and G3. The 15 PEDV strains belonged to G3 group and showed a close relationship with Korean strains (2007), Thai strains (2007–2008), and partial other Chinese strains (2010–2011), but differed genetically from European strains (Br1/87) and the vaccine strain (CV777 vs) being used in China. Furthermore, all 15 PEDV strains from central China and some other isolates in China from 2003 to 2007 (LJB-03, QH, and LZC) belonged to different group. Therefore, PEDV exhibits rapid variation and genetic evolution, and the currently prevailing PEDV strains in central China are a new genotype

    Redetermination of tris­(N,N-diethyl­dithio­carbamato)anti­mony(III)

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    The title compound, [Sb(C5H10NS2)3], was synthesized from Sb2O3, diethyl­amine, carbon dis­ulfide, hydro­chloric acid and sodium hydroxide. The structure has been published previously but H atoms were not included in the model [Raston & White (1976 ▶). Chem. Soc. Dalton Trans. p. 791]. The current determination has significantly higher precision than the original work. The complex has three ligands. The Sb atom is coordinated by three bidentate diethyl­dithio­carbamate groups, two in an almost planar fashion and the third perpendicular to that plane with a dihedral angle of 86.429 (13)°. One ethyl group is disordered over two positions of equal occupancy

    Effects of Herb-Partitioned Moxibustion on the miRNA Expression Profiles in Colon from Rats with DSS-Induced Ulcerative Colitis

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    Objective. This study explored the mechanism of herb-partitioned moxibustion (HM) on dextran sulfate sodium- (DSS-) induced ulcerative colitis (UC) from the miRNA perspective. Methods. Rats were randomly divided into 3 groups [normal control (NC) group, UC model (UC) group, and herb-partitioned moxibustion (UCHM) group]. The UC and UCHM groups were administered 4% DSS for 7 days. The UCHM group received HM at the Tianshu (bilateral, ST25). The effect of HM on UC was observed and the miRNA expression profile in the colon tissues was analyzed. Results. Compared with the UC group, the body weights were significantly higher in the UCHM group on day 14 (P<0.001); the macroscopic colon injury scores and microscopic histopathology scores in the UCHM group decreased (P<0.05); and there were 15 differentially expressed miRNAs in the UCHM group. The changes in miR-184 and miR-490-5p expression levels on the UC were reversed by HM intervention. Validation using qRT-PCR showed that two miRNAs expression trend was consistent with the sequencing results. Conclusion. HM at ST25 might regulate miR-184 and miR-490-5p expression, act on the transcription of their target genes to regulate inflammatory signaling pathways, and attenuate inflammation and tissue injury in the colons of rats with DSS-induced UC

    The Effect of Baduanjin on Promoting the Physical Fitness and Health of Adults

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    The purpose of study was to assess the efficacy of a 16-week Baduanjin qigong training intervention in promoting physical fitness and health for adults. An experimental design was adopted, and subjects were assigned randomly into an experimental group ( = 55) and a control group ( = 55). In the intervention group comprised of adults, there were no significant variations in blood glucose, blood lipid, blood pressure, heart rate variability, and vital capacity indices. The body weight and body mass index (BMI) dropped in the intervention group. Compared with the control group, the skinfold thicknesses decreased at lower corner of scapula, triceps brachii, and abdomen, with a statistical significance ( &lt; 0.001; = 0.005; = 0.003). By comparing the physical fitness indices, it was found that the increase of the results of sit-and-reach test in the intervention group had statistical significance ( = 0.001). In conclusion, it was found by our trial that Baduanjin exercise could significantly improve the physical flexibility and subcutaneous adipose accumulation in the healthy adults

    The Effect of Baduanjin on Promoting the Physical Fitness and Health of Adults

    Get PDF
    The purpose of study was to assess the efficacy of a 16-week Baduanjin qigong training intervention in promoting physical fitness and health for adults. An experimental design was adopted, and subjects were assigned randomly into an experimental group (n=55) and a control group (n=55). In the intervention group comprised of adults, there were no significant variations in blood glucose, blood lipid, blood pressure, heart rate variability, and vital capacity indices. The body weight and body mass index (BMI) dropped in the intervention group. Compared with the control group, the skinfold thicknesses decreased at lower corner of scapula, triceps brachii, and abdomen, with a statistical significance (P<0.001; P=0.005; P=0.003). By comparing the physical fitness indices, it was found that the increase of the results of sit-and-reach test in the intervention group had statistical significance (P=0.001). In conclusion, it was found by our trial that Baduanjin exercise could significantly improve the physical flexibility and subcutaneous adipose accumulation in the healthy adults
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