非吸烟烟草对BALB/3T3 A31—1—13细胞的转化活性

用体外细胞转化系统对嚼烟与含烟抽提物的转化活性进行了研究,发现两种烟草的抽提物均可使 BALB/3T3细胞发生形态学转化。酸化后的含烟抽提物和亚硝化后的嚼烟抽提物的转化活性高于未酸化或未亚硝化者。从转化集落分离出来的细胞具有肿瘤转化的某些特征,如细胞生长的接触抑制消失,饱和密度增高,获得锚独立性,细胞能在软琼脂上生长,形成克隆。本研究结果提示非吸烟烟草对使用者可能具有致癌危害作用.     

煤尘抽提物诱发BALB/3T3A31-1-13细胞系形态转化的研究

本文用 BALB/3T3 A31-1-13细胞系研究了煤尘抽提物的转化活性。亚硝化和未亚硝化的煤尘抽提物都能诱发细胞发生转化且有剂量反应关系.但亚硝化煤尘抽提物的转化活性比未亚硝化者高。从转化集落分离出来的细胞具有赘生转化的一些特征,如细胞生长迅速、接触抑制消失和停泊不依赖性生长等.本文结果看来支持煤矿工胃癌高发原因的煤尘假说。     

保元汤对巨噬细胞功能影响的实验观察

本文观察了补益元气之代表方——保元汤对巨噬细胞功能的调整作用,发现保元汤在内毒素血症时或胰岛素性低血糖时有加快小白鼠网状内皮系统对胶体炭的清除、增强巨噬细胞的吞噬能力、促进其对靶细胞的细胞毒作用。     

PFOS致SH-SY5Y细胞凋亡及可能机制

目的探讨全氟辛烷磺酸盐(PFOS)对成人神经母瘤细胞(SH-SY5Y)的凋亡效应及可能的机制。方法实验中PFOS剂量设置为200、150、100、50、10、1μmol/L和DMSO(对照组)。体外培养SH-SY5Y细胞,以不同浓度PFOS(1、10、50、100、150、200μmol/L)处理细胞。染毒24 h和48 h后用CCK8法检测SH-SY5Y细胞活性,应用Annexin-V FITC/PI双染法结合流式细胞术检测细胞凋亡,紫外和荧光分光光度法检测SH-SY5Y细胞超氧化物歧化酶(SOD)、谷胱甘肽还原酶(GSH)、总活性氧(ROS)和丙二醛(MDA)的影响。结果 PFOS暴露降低了SH-SY5Y细胞活性,并呈明显的剂量效应关系;PFOS导致SH-SY5Y细胞凋亡;紫外和荧光分光光度法结果显示PFOS引起SH-SY5Y细胞中SOD和GSH水平下降,与对照组相比,最高剂量组PFOS引起GSH含量从8.00±0.12 nmol/mg蛋白降至5.89±0.90 nmol/mg蛋白;同时引起总活性氧(ROS)和丙二醛(MDA)水平上升,与对照组相比,最高剂量组PFOS引起MDA含量从1.92±0.17 nmol/mg蛋白显著上升至6.95±0.26 nmol/mg蛋白。结论PFOS可能通过对SH-SY5Y细胞产生氧化应激损伤从而对SH-SY5Y细胞产生毒性效应。     

肝脏缺血激活PI3K/p⁃Akt2信号通路并促进库普弗细胞向M1型巨噬细胞转化

目的：研究肝脏库普弗细胞（Kupffer cells,KCs）在肝脏缺血及再灌注过程中的转化转归及其在肝脏缺血再灌注损伤中的作用。方法：制作小鼠肝脏不同缺血时间的模型,用流式细胞术分析缺血后KCs数量,体外培养中用实时荧光定量PCR（qPCR）技术分析炎性细胞因子的表达及巨噬细胞表面标记物的表达水平,免疫印迹（Western blot）技术分析磷脂酰肌醇3?激酶/磷酸化蛋白激酶B?2（PI3K/p?Akt2）信号通路的表达情况。使用qPCR技术分析Akt2抑制剂对KCs炎性细胞因子的表达及其表面标记物表达的影响,另外小鼠肝脏缺血后再灌注6 h,通过肝脏切片HE染色及血清丙氨酸氨基转移酶（alanine aminotransferase,ALT）水平等指标分析肝脏损伤情况。结果：肝脏缺血后KCs数量减少,而存活细胞在体外培养中,脂多糖（lipopolysaccharide,LPS）刺激后促炎性细胞因子的表达明显高于对照组（P < 0.05）,且M1型巨噬细胞的表面标记物诱导型一氧化氮合酶（iNOS）表达水平也高于对照组（P < 0.05）,其细胞内的PI3K/p?Akt2通路被激活,促进KCs向M1型巨噬细胞转化,而Akt2抑制剂可阻断细胞转化过程,减轻肝脏缺血再灌注损伤。结论：小鼠肝脏缺血能激活KCs内PI3K/p?Akt2信号通路,从而在炎性刺激下促进其向M1型巨噬细胞转化,并加重肝脏缺血再灌注损伤。     

Oral microbiota in the oral-genitourinary axis:identifying periodontitis as a potential risk of genitourinary cancers

Periodontitis has been proposed as a novel risk factor of genitourinary cancers:although periodontitis and genitourinary cancers are two totally distinct types ...     

Study on the Design,Preparation, and Performance Evaluation of Heat-Resistant Interlayer-Polyimide-Resin-Based Neutron-Shielding Materials

Polymers have an excellent effect in terms of moderating fast neutrons with rich hydrogen and carbon, which plays an indispensable role in shielding devices. As the shielding of neutrons is typically accompanied by the generation of γ-rays, shielding materials are developed from monomers to multi-component composites, multi-layer structures, and even complex structures. In this paper, based on the typical multilayer structure, the integrated design of the shield component structure and the preparation and performance evaluation of the materials is carried out based on the design sample of the heat-resistant lightweight polymer-based interlayer. Through calculation, the component structure of the polymer-based materials and the three-layer thickness of the shield are obtained. The mass fraction of boron carbide accounts for 11% of the polymer-based material. Since the polymer-based material is the weak link of heat resistance of the multilayer shield, in terms of material selection and modification, the B₄C/TiO₂/polyimide molded plate was prepared by the hot-pressing method, and characterization analysis was conducted for its structure and properties. The results show that the ball milling method can mix the materials well and realize the uniform dispersion of B₄C and TiO₂ in the polyimide matrices. Boron carbide particles are evenly distributed in the material. Except for Ti, the other elemental content of the selected areas for mapping is in good agreement with the theoretical values of the elemental content of the system. The prepared B₄C/TiO₂/polyimide molded plate presents excellent thermal properties, and its glass transition temperature and initial thermal decomposition temperature are as high as 363.6 °C and 572.8 °C, respectively. In addition, the molded plate has good toughness performs well in compression resistance, shock resistance, and thermal aging resistance, which allows it to be used for a long time under 300 °C. Finally, the prepared materials are tested experimentally on an americium beryllium neutron source. The experimental results match the simulation results well.     

Dioscin Ameliorates Hyperuricemia-Induced Atherosclerosis by Modulating of Cholesterol Metabolism through FXR-Signaling Pathway

Hyperuricemia is one of the independent risk factors for atherosclerotic cardiovascular disease. Herein, we investigate the association between uric acid and cholesterol metabolism and the effect of dioscin on the prevention of hyperuricemia-induced atherosclerosis. In the potassium oxonate-treated ApoE^{−/−−/−} mice, atherosclerosis was accelerated along with elevated serum cholesterol levels in the hyperuricemic state, which can be ameliorated by dioscin. Together with the in vitro assays, we found that the effect of dioscin was at least partially through the regulation of the farnesoid X receptor (FXR) -small heterodimer partner (SHP) -7α-hydroxylase (CYP7A1) signaling pathway in the liver. Tigogenin (a metabolite of dioscin) suppressed FXR activation and increased CYP7A1, resulting in an increased conversion rate of cholesterols into bile acids. Further clinical study revealed that treatment with a dioscin-enriched preparation decreased serum cholesterol levels in individuals with hyperuricemia. In summary, this study demonstrated a slowdown effect of dioscin on the progression of hyperuricemia-induced atherosclerosis.     

The Influence of Precipitate Morphology on the Growth of Austenite Grain in Nb-Ti-Al Microalloyed Steels

The present study investigates the morphological evolution of carbonitrides and the effect of these precipitates on grain boundary pinning during pseudo-carburizing a Nb-Ti-Al microalloyed steel. The result indicated that three kinds of complex precipitates with different morphologies containing Nb, Ti, and Al respectively were observed in samples austenitized at different temperatures and times. The NbC and TiN precipitates played an important role in pinning grain boundaries and suppressing the growth of austenite grains, relying on the high thermal stability of TiN precipitates and small size of NbC precipitates. The precipitate characteristics affected the size of austenite grain. Based on the Zener pinning model, the effect of precipitate characteristic on austenite grain size was quantitatively analyzed. It is found that the existence of NbC and TiN precipitated at high temperature makes austenite grain growth difficult when austenite grain boundaries were pinned by fine and diffused precipitates.