中国东北末次冰期松原黄土的释光测年及其古气候意义初探

本文以中国东北松原黄土为研究对象,通过光释光测年建立其末次冰期年代标尺,并探讨磁化率和平均粒径这两个黄土研究中常用的气候替代性指标的可能指示意义。采用成熟的细颗粒石英单片再生(SAR)光释光(OSL)测年技术获得了松原剖面顶部5.5 m年代6个,并获得了2 cm间距的低频磁化率和平均粒径这两个常规参数。石英OSL测年相关检验证实了该技术测量松原黄土的可靠性。测年结果表明,松原剖面顶部5.5 m主要沉积于末次冰期的中晚期,即约5.5 - 1.8 m((52.18 &plusmn; 3.47) - (27.76 &plusmn; 1.77) ka)主要堆积于深海氧同位素阶段(MIS)3中晚期,而顶部1.8 - 0.4 m((27.76 &plusmn; 1.77) - (20.61&plusmn; 1.31) ka)堆积于MIS2早期。磁化率自52.18 &plusmn; 3.47 ka到27.76 &plusmn; 1.77 ka经历了先小幅降低又小幅升高,波动幅度较小,而自27.76 &plusmn; 1.77 ka以后,磁化率值呈整体下降并呈现大幅度摆动。平均粒径则自52.18 &plusmn; 3.47 ka到46.80 &plusmn; 3.13 ka呈明显变小趋势,自46.80 &plusmn; 3.13 ka到约20 ka变化不大,自约20 ka以后,平均粒径由约40 &mu;m陡然增加至约140 &mu;m,并在之后稳定在这一水平。测试结果对比显示,磁化率和粒度的变化不具有明显的相位关系,且同黄土高原渭南剖面末次冰期磁化率和平均粒径的变化也表现出明显的不一致现象。因此,在对松原黄土剖面的研究中,将磁化率和平均粒径分别作为东亚夏季风和冬季风的替代性指标使用时要慎重。</p

双特异性磷酸酶 2 在肝细胞癌组织中的表达及临床意义

背景与目的：近年来研究发现，双特异性磷酸酶2（DUSP2）在多种恶性肿瘤中发挥了肿瘤抑制因子的作用。然而，DUSP2在肝细胞癌（HCC）中的表达情况及作用仍不清楚，因此，本研究探讨HCC患者癌组织中DUSP2的表达及临床意义。 方法：收集2010年1—2014年12月间104例HCC患者手术标本及临床资料，免疫组化检测HCC组织中DUSP2表达，分析DUSP2的表达与患者临床病理特征及预后的关系，采用Cox比例风险模型分析影响HCC患者无瘤生存率和总生存率的危险因素。 结果：104例患者的组织标本中，DUSP2高表达占59.6%（62/104），DUSP2低表达占40.4%（42/104）。DUSP2的表达与年龄、性别和肿瘤大小无关（均P>0.05），而与肿瘤分化程度（P=0.018）、肿瘤数目（P=0.048）、远处转移（P=0.001）、血清HBV浓度（P=0.018）明显有关。Kaplan-Meier生存分析显示，DUSP2低表达患者3年无瘤生存率及3年总生存率均明显低于DUSP2高表达患者（25.2% vs. 63.3%，P=0.004；42.5% vs. 85.5%，P=0.002）。Cox比例风险模型分析显示，低分化程度、远处转移、DUSP2低表达是影响HCC患者无瘤生存率与总生存率的独立危险因素（均P0.05), while it was significantly associated with the degree of tumor differentiation (P=0.018), number of tumors (P=0.048), distant metastases (P=0.001) and serum HBV level (P=0.018). Kaplan Meier survival analysis showed that both 3-year disease-free survival rate and 3-year overall survival rate of patients with low DUSP2 expression were significantly lower than those of patients with high DUSP2 expression (25.2% vs. 63.3%, P=0.004; 42.5% vs. 85.5%, P=0.002). Cox proportional hazard model analysis showed that low differentiation degree, distant metastasis and low DUSP2 expression were the independent risk factors for both tumor-free survival rate and overall survival rate of HCC patients (all P<0.05). Conclusion: The DUSP2 expression in the tumor tissue is closely associate with the tumor differentiation, number of tumor and metastasis as well as the prognosis of HCC patients. DUSP2 can be used as a molecular marker to predict the prognosis of HCC patients and those with low DUSP2 expression may have a poor prognosis. © 2020 by the Author(s)

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^