The second-order dynamic phase transition and Lee--Yang zeros in Eggers urn model

A second-order dynamic phase transition in a non-equilibrium Eggers urn model for the separation of sand is studied. The order parameter, the susceptibility and the stationary probability distribution have been calculated. By applying the Lee-Yang zeros method of equilibrium phase transitions, we study the distributions of the effective partition function zeros and obtain the same result for the model. Thus, the Lee-Yang theory can be applied to a more general non-equilibrium system.     

转化生长因子-β1对大鼠腹膜间皮细胞炎症因子及细胞外基质表达的影响

目的 研究转化生长因子-β1（TGF-β1）对大鼠腹膜间皮细胞炎症因子表达和细胞外基质（ECM）积聚的影响。方法 体外培养SD 大鼠原代腹膜间皮细胞,静止24h 后,采用RT-PCR 检测TGF-β1（10ng/ml）刺激后0、3、6、12、24、48h 单核细胞趋化蛋白-1（MCP-1）、白介素-6（IL-6）、Ⅰ型胶原（CollagenⅠ）、纤溶酶原激活物抑制物-1（PAI-1）mRNA 的表达情况;Western blot 检测TGF-β1（10ng/ml）刺激后0、4、12、24、48h CollagenⅠ和PAI-1 表达情况;ELISA 法检测MCP-1 和IL-6 表达情况。结果 TGF-β1处理6h 后MCP-1、IL-6 和PAI-1mRNA 即开始逐渐升高,与0h 组的差异均有统计学意义（均P＜0.05）,24h 后显著升高（均P＜0.01）;TGF-β1 处理12h 后CollagenⅠmRNA 表达开始明显升高,与0h 比较差异有统计学意义（P＜0.05）,24h 后有显著升高（P＜0.01）;TGF-β1 处理4h 后IL-6 表达水平升高（P＜0.05）,24h 后显著升高（P＜0.01）;处理12h 后MCP-1 和PAI-1 表达水平较0h 明显升高（P＜0.05）,处理24h 后CollagenⅠ表达水平显著升高（P＜0.05）;TGF-β1 显著增加MCP-1、IL-6、CollagenⅠ、PAI-1 及其mRNA 的表达上调。结论 TGF-β1可能通过诱导大鼠腹膜间皮细胞炎症因子上调表达和ECM积聚导致腹膜纤维化。     

初发系统性红斑狼疮患者调节性T细胞和Th17细胞的检测及意义

目的：观察初发系统性红斑狼疮（SLE）患者外周血调节性T细胞（Treg）和Th17细胞的变化,探讨其临床意义。方法检测15例初发SLE患者（活动组11例,非活动组5例）及10例健康对照者（对照组）的外周血CD4＋CD25highTreg、Th17细胞占CD4＋的比例,分析两种细胞的比率与疾病活动指数（SLEDAI）的相关性。结果初发SLE患者外周血CD4＋CD25highTreg和Th17细胞的比例与对照组相比,差异无统计学意义（P＞0.05）,与SLEDAI无相关性（均P＞0.05）。CD4＋CD25highT细胞与Th17细胞的比率在活动组患者下降尤为明显（P＜0.05）,且与SLEDAI呈明显的负相关（P＜0.05）。结论初发的活动性SLE患者外周血Treg与Th17细胞的比率明显下降,并与疾病活动密切相关,两群细胞的失衡可能在SLE发病机制中起重要的作用。     

The effects of the Dzyaloshinskii-Moriya interaction on the ground-state properties of the XY chain in a transverse field

The effects of the Dzyaloshinski-Moriya (DM) interaction on the ground-state properties of the anisotropic XY chain in a transverse field have been studied by means of correlation functions and entanglement. Different from the case without the DM interaction, the excitation spectra εk of this model are not symmetrical in the momentum space and are not always positive. As a result, besides the ferromagnetic (FM) and the paramagnetic (PM) phases, a gapless chiral phase is induced. In the chiral phase, the von Neumann entropy is proportional to log2L (L is the length of a subchain) with the coefficient A ≈ 1/3, which is the same as that of the XY chain in a transverse field without the DM interaction for γ = 0 and 0 h ≤ 1. And in the vicinity of the critical point between the chiral phase and the FM (or PM) phase, the behaviors of the nearest-neighbor concurrence and its derivative are like those for the anisotropy transition.