The Effect of the Structure of Polychlorinated Biphenyls on their Hydroxylation, Oxidation,and Glutathionyl Conjugation Reactions

Objective To compare the nature of the metabolites formed from the phase I metabolism （hydroxylation and oxidation） and phase II metabolism （glutathionyl conjugation） of PCBs that have different chlorine substitution patterns. To discuss the structure-activity relationships and metabolic mechanisms of PCBs. Methods 4-CI-biphenyl （PCB3）, 4,4＇-CI-biphenyl （PCB15）, 3,4,3＇,4＇-Cl-biphenyl （PCB77） were used for in vitro metabolic study. LC/MS and UV-Vis studies were performed for metabolites identification. Results The cytochrome P-450 catalyzed hydroxylation rate decreased as the number of chlorine substitutions increased. In this reaction, PCB3 was fully metabolized, approximately half of the PCB15 was metabolized and PCB77 was not metabolized at all. The oxidation rate of PCB15-HQ was higher than that of PCB3-HO. under various oxidation conditions. The LC/MS and UV-Vis data suggest that in the conjugation reaction of PCB15-Q and GSH, the Michael addition reaction occurs preferentially over the displacement reaction. Conclusion The metabolic profiles of polychlorinated biphenyls （PCBs） are dramatically affected by chlorine substitution patterns. It is suggested that the metabolic profiles of PCBs are related to their chlorine substitution patterns, which may have implications for the toxicity of PCB exposure.

Application of an acrylic vessel supported by a stainless-steel truss for the JUNO central detector

After the success of the Daya Bay experiment, the Jiangmen Underground Neutrino Observatory （JUNO） was launched to measure neutrino-mass hierarchy and oscillation parameters and to study other neutrino physics. Its central detector is set for antineutrinos from reactors, the Earth, the atmosphere, and the Sun. The main requirements of the central detector are con- tainment of 20 kt of liquid scintillator, as the target mass, and 3% energy resolution. It is about a ball-shape detector of 38.5 m with -75% coverage of PMT on its inner surface. The design of such a huge detector is a big challenge because it must meet the requirements for several different types of physics measurement and possess the feasibility and reliability in its structure and engineering, all at reasonable time and cost. One option for the JUNO central detector is a hyper-scale acrylic ball sub- merged in the water to shield the background. This paper proposes a structural scheme for such an acrylic ball that is supported by a stainless-steel truss, inspired by point-supported glass-curtain walls in civil engineering. The preliminary design of the scheme is completed and verified by finite element （FE） method using ABAQUS. FE analysis shows that the scheme can con- trol the stress level of the acrylic ball within the limit of 5 to 10 MPa, in accordance with the demand of the design objective of the central detector. The scheme is of outstanding global stability and allows various chocces on local connections. We prove that the scheme is of good feasibility and should be a reasonable option for the central detector.

SH2B1在非小细胞肺癌中的表达水平及与临床病理参数和预后的关系

目的观察SH2B衔接因子蛋白1(SH2B1)在非小细胞肺癌组织中表达情况,并探讨SH2B1与临床病理特征及预后的关系。方法选取2013年9月-2015年6月在青海省第五人民医院进行手术治疗的51例非小细胞肺癌患者的癌组织标本为非小细胞肺癌组织组,另选取距癌组织边缘≥5 cm的癌旁组织作为癌旁组织组。分别采用荧光实时定量聚合酶链反应法(qRT-PCR)与免疫印迹法(Western blot)检测SH2B1 mRNA、SH2B1蛋白相对表达情况;应用免疫组织化学法(SP)检测SH2B1蛋白表达;分析SH2B1与临床病理参数的关系,采用Kaplan-Meier对非小细胞肺癌患者3年生存情况进行分析;并对影响非小细胞肺癌预后的因素进行COX回归分析。结果与癌旁组织相比,非小细胞肺癌组织中SH2B1 mRNA、SH2B1蛋白表达水平显著升高(P<0.05),SH2B1蛋白阳性率显著高于癌旁组织(62.7%vs.31.4%)(P<0.05)。SH2B1在有淋巴结转移、分化程度低、TNM分期为Ⅲ~Ⅳ期患者癌组织中表达量高于无淋巴结转移、分化程度中高、TNM分期为Ⅰ~Ⅱ期患者(P<0.05)。Kaplan-Meier分析结果显示SH2B1高表达组三年内存活率低于SH2B1低表达组(18.8%vs.63.2%)(P<0.05);多因素COX回归分析结果显示SH2B1阳性表达是影响非小细胞癌不良预后的独立危险因素。结论SH2B1基因在非小细胞肺癌组织中高表达,其异常表达与患者临床病理指标及预后不良密切相关,推测SH2B1可能参与非小细胞肺癌的癌变过程。