高脂肪日粮和产甲烷菌抑制剂对C57BL/6J小鼠盲肠微生物及脂肪代谢的影响

摘要:【目的】本文旨在研究产甲烷菌抑制剂溴氯甲烷(BCM)对采食高、低脂肪水平日粮小鼠的肠道微生物以及脂肪代谢的影响。【方法】选取32只21日龄的雌性C57BL/6J小,随机分成4组:对照低脂日粮组、对照低脂日粮加BCM组、高脂日粮组及高脂日粮加BCM组,每组8个重复,BCM通过饮水添加。饲养周期为6周,试验期结束,采集小鼠血液样品,用于生化指标分析;采集小鼠盲肠内容物,用变性梯度凝胶电泳(DGGE)和real-time PCR技术分析其菌群;气相色谱法分析粪样中短链脂肪酸含量;real-time PCR技术分析 肝脏中脂肪代谢相关基因表达。【结果】高脂日粮和BCM处理对小鼠体增重均无显著影响;DGGE图谱中低脂日粮组和高脂日粮组样品聚于不同簇,但对各组总细菌、产甲烷菌和硫还原菌数量无显著影响。高脂日粮组粪样中乙酸占总挥发酸比例显著降低(P＜0.05);BCM处理显著增加小鼠粪样丙酸比例(P＜0.05);高脂日粮处理显著影响高密度脂蛋白胆固醇、低密度脂蛋白胆固醇和总胆固醇含量(P＜0.05);高脂日粮处理促进了甘油三酯水解酶表达(P＜0.05)。【结论】高脂日粮对小鼠肠道菌群结构以及脂肪代谢有明显影响,而BCM处理影响较小。     

Reduced Graphene Oxide Thin Films as Ultrabarriers for Organic Electronics

Encapsulation of electronic devices based on organic materials that are prone to degradation even under normal atmospheric conditions with hermetic barriers is crucial for increasing their lifetime. A challenge is to develop ultrabarriers that are impermeable, flexible, and preferably transparent. Another important requirement is that they must be compatible with organic electronics fabrication schemes (i.e., must be solution processable, deposited at room temperature and be chemically inert). Here, a lifetime increase of 1300 h for poly(3‐hexylthiophene) (P3HT) films encapsulated by uniform and continuous thin (≈10 nm) films of reduced graphene oxide (rGO) is reported. This level of protection against oxygen/water vapor diffusion is substantially better than conventional polymeric barriers such as Cytop, which degrades after only 350 h despite being 400 nm thick. Analysis using atomic force microscopy, X‐ray photoelectron spectroscopy, and high‐resolution transmission electron microscopy suggest that the superior oxygen gas/moisture barrier property of rGO is due to the close interlayer distance packing and absence of pinholes within the impermeable sheets. These material properties can be correlated to the enhanced lag time of 500 h. The results provide new insight for the design of high‐performance and solution‐processable transparent ultrabarriers for a wide range of encapsulation applications.     

A comprehensive study on neurobehavior, neurotransmitters and lymphocyte subsets alteration of Chinese manganese welding workers

The neurotoxicity of manganese has been demonstrated by many researches. But few reports have been found on its immunotoxicity in manganese-exposed workers. Here we selected welding workers (aged 34 years) as Mn-exposed subjects. They have been exposed to manganese for 16 years. The control group was from a flour plant. The average concentrations of Mn, Cd, Fe and Ni in work place were 138.40 +/- 11.60 microg/m3, 581.40 +/- 45.32 microg/m3, 3.84 +/- 0.53 microg/m3 and 12.64 +/- 2.80 ng/m3, respectively. Blood Mn (4.84 mug/dl) of welding workers was higher than that of the control group (1.92 microg/dl). Neurobehavioral core test battery (NCTB) recommended by WHO was conducted on the subjects and found that the scores of negative emotions, such as confusion-bewilderment, depression-dejection, fatigue-inertia, and tension-anxiety, were higher in welding workers. Visual simple reaction time and the fast simple reaction time were shorter than that of the control group. The numbers of digital span, forward digital span, backward digital span and digital symbol decreased in welding workers compared with control group. Monoamine neurotransmitters and their metabolism substances in urine were tested by HPLC-ultraviolet. NE, E, MHPG, HVA, DA, DOPAC and 5-HT in the urine of Mn-exposed group had no significant changes while 5-HIAA in Mn-exposed group had significantly decreased compared with that of the control group. Lymphocyte subsets of the subjects were determined by Flow Cytometer. CD3+ T cell, CD4+CD8- T cell, CD4-CD8+ T cell, CD4+CD45RO- "virgin" lymphocytes, CD4+CD45RO+ "memory" lymphocytes, and CD3-CD19+ B cell had no significant changes compared with the control group. The results showed that long-term exposure to manganese in welding might have adverse effects on mood state, neurobehavior, and peripheral neurotransmitters. However, they had no effects on lymphocyte subsets parameters.     

盐酸埃托啡在亚洲象全身麻醉中的应用

正盐酸埃托啡(etorphine hydrochloride)属于阿片受体激动剂,是人工合成的作用于中枢神经系统的化学保定剂,由英国人于1963年研发,其属强效镇痛类药,精神依赖多见,故一般不用于人体麻醉,而在动物尤其是食草动物的麻醉保定中被广泛使用(Nielsen,1999)。盐酸埃托啡可与马来酸乙酰丙嗪(acepromazine maleate)复合使用,乙酰丙嗪具有中枢镇静作用,能加强中枢抑制药的效应(刘焕奇等,2003;段俊堂,2015)。M99是以盐酸埃托啡为主要成分的动物麻醉剂。大动物保定灵是以盐酸埃托啡和马来酸乙酰丙嗪为主要成分的动物麻醉剂。盐酸     

一种溶菌酶样蛋白对肺炎链球菌毒力及荚膜多糖合成的影响

摘要：【目的】为了研究肺炎链球菌（Streptococcus pneumoniae, S.pn）的一种假想的溶菌酶样蛋白在细菌生物学性状及其致病中的作用。【方法】利用长臂同源PCR对该基因进行敲出,并同时构建带有拯救质粒的缺失菌株,观察D39野生菌、缺失菌与带有拯救质粒的缺失菌株在相关生物学性状及其致病力改变,从而鉴定这种假想溶菌酶样蛋白的功能。【结果】缺失菌与野生菌相比,细菌生长减缓,毒力下降,荚膜多糖合成明显减少。而将拯救质粒转入缺失菌株后,该溶菌酶样蛋白的mRNA表达水平较野生菌高,其毒力及荚膜合成