326 research outputs found

    Characterization of a wheat HSP70 gene and its expression in response to stripe rust infection and abiotic stresses

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    Members of the family of 70-kD heat shock proteins (HSP70 s) play various stress-protective roles in plants. In this study, a wheat HSP70 gene was isolated from a suppression subtractive hybridization (SSH) cDNA library of wheat leaves infected by Puccinia striiformis f. sp. tritici. The gene, that was designated as TaHSC70, was predicted to encode a protein of 690 amino acids, with a molecular mass of 73.54 KDa and a pI of 5.01. Further analysis revealed the presence of a conserved signature that is characteristic for HSP70s and phylogenetic analysis demonstrated that TaHSC70 is a homolog of chloroplast HSP70s. TaHSC70 mRNA was present in leaves of both green and etiolated wheat seedlings and in stems and roots. The transcript level in roots was approximately threefold less than in leaves but light–dark treatment did not charge TaHSC70 expression. Following heat shock of wheat seedlings at 40°C, TaHSC70 expression increased in leaves of etiolated seedlings but remained stable at the same level in green seedlings. In addition, TaHSC70 was differentially expressed during an incompatible and compatible interaction with wheat-stripe rust, and there was a transient increase in expression upon treatment with methyl jasmonate (MeJA) treatment. Salicylic acid (SA), ethylene (ET) and abscisic acid (ABA) treatments had no influence on TaHSC70 expression. These results suggest that TaHSC70 plays a role in stress-related responses, and in defense responses elicited by infection with stripe rust fungus and does so via a JA-dependent signal transduction pathway

    Short Fatigue Crack Behavior of LZ50 Axle Steel under Rotating-Bending Cyclic Loading

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    The short fatigue short crack replica tests using LZ50 axle steel hourglass-shaped specimens of were carried out under rotating-bending cyclic load. Seven sets of effective test data were obtained. The analysis demonstrated that short fatigue cracks generally originate in ferrite grains or on their boundaries, and then short cracks start propagating, which is strongly influenced by the microstructure of the material. The crack growth rate increases serratically, followed by its decrease double-fold because of the limit of ferrite grain boundaries and the banded pearlite structure. Based on the three principles of the best fit, which include the overall fitting effect, correlation with fatigue physics, and safety of residual strength prediction, the statistical evolution of the dominant effective short fatigue crack length and life share were analyzed. The statistical results show that the minimum value distribution exhibit the best fit of the dominant effective fatigue short crack length and the life share. The short fatigue crack growth model, which includes various microstructure barriers, provides a good fitting result and reflects the cyclic effect of the microstructure on the short fatigue crack behaviorВыполнены испытания на репликах короткой усталостной трещины с использованием образцов осевой стали LZ50 в форме песочных часов в условиях циклического нагружения при изгибе с вращением. Выполнены семь серий испытаний. Показано, что короткие усталостные трещины возникают в ферритных зернах или на их границах, затем они начинают расти под влиянием микроструктуры материала. Скорость роста трещин увеличивается скачкообразно, затем снижается вдвое за счет барьера, создаваемого границами ферритных зерен и полосчатой структурой перлита. Проанализированы статистическая эволюция длины доминирующей эффективной короткой усталостной трещины и доля остаточного ресурса на основании трех принципов наилучшего соответствия, включающих общий эффект соответствия, соответствие принципам физики усталости и надежность прогнозирования остаточной прочности. Установлено, что статистическое распределение минимальных величин выявляет наилучшее соответствие для длины доминирующей эффективной короткой усталостной трещины и доли остаточного ресурса. Модель роста короткой усталостной трещины, включающая различные барьеры в микроструктуре, обеспечивает хороший результат подгонки и отражает циклическое влияние микроструктуры на ее поведение

    High expression of cell adhesion molecule 2 unfavorably impacts survival in non-small cell lung cancer patients with brain metastases

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    Background: Lung cancer is one kind of malignant tumor with a high risk for morbidity and mortality compared to other solid organ malignancies. Brain metastases occur in 30-55% of non-small cell lung cancer (NSCLC) patients. Prognosis of NSCLC patients with brain metastases is very poor. Our previous study showed that cell adhesion molecule 2 (CADM2) could regulate the development of brain metastasis in NSCLC cells. Therefore, the objective of the study is to evaluate the effect of CADM2 on the prognosis of NSCLC patients with brain metastases.Methods: The expression of CADM2 was detected by quantitative real-time polymerase chain reaction (qRT-PCR) in the tissue of the primary tumor. Patients were followed up and overall survival (OS) was calculated. The relationships between CADM2 and clinicopathological features were analyzed using the chi-square test. Kaplan-Meier analysis was carried out to demonstrate the influence of CADM2 on the OS of patients. Univariate and multivariate Cox analyses were used to determine the prognosis of NSCLC patients with brain metastases.Results: A total of 139 NSCLC patients with brain metastases from the Affiliated Cancer Hospital & Institute of Guangzhou Medical University, treated between January 2015 and December 2017 were evaluated retrospectively. The expression level of CADM2 in patients ranged from 1 to 17.2677, with a median of 6.0772. Chi-square analysis showed that CADM2 gene expression level was not significantly associated with gender, age, tumor location, histological subtype, tumor T stage, extracranial metastasis, or smoking status. However, CADM2 expression was notably associated with risk for lymph node metastasis. The results of the Kaplan-Meier analysis showed that high expression [CADM2 messenger RNA (mRNA) >= 6.0772] of CADM2 was markedly associated with poor prognosis. Univariate and multivariate Cox analyses demonstrated that CADM2 was an independent risk factor for survival in NSCLC patients with brain metastases (P<0.05).Conclusions: CADM2 expression is up-regulated and closely associated with disease progression and poor prognosis in NSCLC patients with brain metastases. CADM2 expression warrants special consideration given its potential prognostic significance that might help inform clinical decision making.Pathogenesis and treatment of chronic pulmonary disease

    A Measurement of Psi(2S) Resonance Parameters

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    Cross sections for e+e- to hadons, pi+pi- J/Psi, and mu+mu- have been measured in the vicinity of the Psi(2S) resonance using the BESII detector operated at the BEPC. The Psi(2S) total width; partial widths to hadrons, pi+pi- J/Psi, muons; and corresponding branching fractions have been determined to be Gamma(total)= (264+-27) keV; Gamma(hadron)= (258+-26) keV, Gamma(mu)= (2.44+-0.21) keV, and Gamma(pi+pi- J/Psi)= (85+-8.7) keV; and Br(hadron)= (97.79+-0.15)%, Br(pi+pi- J/Psi)= (32+-1.4)%, Br(mu)= (0.93+-0.08)%, respectively.Comment: 8 pages, 6 figure

    Direct Measurements of the Branching Fractions for D0Ke+νeD^0 \to K^-e^+\nu_e and D0πe+νeD^0 \to \pi^-e^+\nu_e and Determinations of the Form Factors f+K(0)f_{+}^{K}(0) and f+π(0)f^{\pi}_{+}(0)

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    The absolute branching fractions for the decays D0Ke+νeD^0 \to K^-e ^+\nu_e and D0πe+νeD^0 \to \pi^-e^+\nu_e are determined using 7584±198±3417584\pm 198 \pm 341 singly tagged Dˉ0\bar D^0 sample from the data collected around 3.773 GeV with the BES-II detector at the BEPC. In the system recoiling against the singly tagged Dˉ0\bar D^0 meson, 104.0±10.9104.0\pm 10.9 events for D0Ke+νeD^0 \to K^-e ^+\nu_e and 9.0±3.69.0 \pm 3.6 events for D0πe+νeD^0 \to \pi^-e^+\nu_e decays are observed. Those yield the absolute branching fractions to be BF(D0Ke+νe)=(3.82±0.40±0.27)BF(D^0 \to K^-e^+\nu_e)=(3.82 \pm 0.40\pm 0.27)% and BF(D0πe+νe)=(0.33±0.13±0.03)BF(D^0 \to \pi^-e^+\nu_e)=(0.33 \pm 0.13\pm 0.03)%. The vector form factors are determined to be f+K(0)=0.78±0.04±0.03|f^K_+(0)| = 0.78 \pm 0.04 \pm 0.03 and f+π(0)=0.73±0.14±0.06|f^{\pi}_+(0)| = 0.73 \pm 0.14 \pm 0.06. The ratio of the two form factors is measured to be f+π(0)/f+K(0)=0.93±0.19±0.07|f^{\pi}_+(0)/f^K_+(0)|= 0.93 \pm 0.19 \pm 0.07.Comment: 6 pages, 5 figure

    Measurements of J/psi Decays into 2(pi+pi-)eta and 3(pi+pi-)eta

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    Based on a sample of 5.8X 10^7 J/psi events taken with the BESII detector, the branching fractions of J/psi--> 2(pi+pi-)eta and J/psi-->3(pi+pi-)eta are measured for the first time to be (2.26+-0.08+-0.27)X10^{-3} and (7.24+-0.96+-1.11)X10^{-4}, respectively.Comment: 11 pages, 6 figure

    BESII Detector Simulation

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    A Monte Carlo program based on Geant3 has been developed for BESII detector simulation. The organization of the program is outlined, and the digitization procedure for simulating the response of various sub-detectors is described. Comparisons with data show that the performance of the program is generally satisfactory.Comment: 17 pages, 14 figures, uses elsart.cls, to be submitted to NIM

    Measurement of branching fractions for the inclusive Cabibbo-favored ~K*0(892) and Cabibbo-suppressed K*0(892) decays of neutral and charged D mesons

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    The branching fractions for the inclusive Cabibbo-favored ~K*0 and Cabibbo-suppressed K*0 decays of D mesons are measured based on a data sample of 33 pb-1 collected at and around the center-of-mass energy of 3.773 GeV with the BES-II detector at the BEPC collider. The branching fractions for the decays D+(0) -> ~K*0(892)X and D0 -> K*0(892)X are determined to be BF(D0 -> \~K*0X) = (8.7 +/- 4.0 +/- 1.2)%, BF(D+ -> ~K*0X) = (23.2 +/- 4.5 +/- 3.0)% and BF(D0 -> K*0X) = (2.8 +/- 1.2 +/- 0.4)%. An upper limit on the branching fraction at 90% C.L. for the decay D+ -> K*0(892)X is set to be BF(D+ -> K*0X) < 6.6%

    Measurements of the Mass and Full-Width of the ηc\eta_c Meson

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    In a sample of 58 million J/ψJ/\psi events collected with the BES II detector, the process J/ψγηc\psi\to\gamma\eta_c is observed in five different decay channels: γK+Kπ+π\gamma K^+K^-\pi^+\pi^-, γπ+ππ+π\gamma\pi^+\pi^-\pi^+\pi^-, γK±KS0π\gamma K^\pm K^0_S \pi^\mp (with KS0π+πK^0_S\to\pi^+\pi^-), γϕϕ\gamma \phi\phi (with ϕK+K\phi\to K^+K^-) and γppˉ\gamma p\bar{p}. From a combined fit of all five channels, we determine the mass and full-width of ηc\eta_c to be mηc=2977.5±1.0(stat.)±1.2(syst.)m_{\eta_c}=2977.5\pm1.0 ({stat.})\pm1.2 ({syst.}) MeV/c2c^2 and Γηc=17.0±3.7(stat.)±7.4(syst.)\Gamma_{\eta_c} = 17.0\pm3.7 ({stat.})\pm7.4 ({syst.}) MeV/c2c^2.Comment: 9 pages, 2 figures and 4 table. Submitted to Phys. Lett.
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