基于16srDNA序列分析冬樱花花期蜜囊细菌多样性

对昆明冬樱花花期东、西方蜜蜂蜜囊细菌进行分离、纯培养;并对分离菌株的16srDNA基因片段进行扩增和测序,序列比对后进行系统发育分析。结果表明:东方蜜蜂蜜囊细菌包括3个纲中的10个种,西方蜜蜂蜜囊细菌包括3个纲中的13个种,花蜜细菌包括4个纲中的6个种,所采集样品除Bacillus subtili相似以外,其余菌种差异较大。     

原油差温顺序输送停输初始状态及安全性

原油差温顺序输送管道不同停输初始状态对应不同的安全停输时间,停输安全性是该输送工艺的重要技术问题。为了获得停输初始状态对停输安全性的影响规律,定性分析了一个输送周期内不同时段的停输安全性特点,通过引入停输时机的概念和定义无量纲排空时间定量分析了不同停输初始状态的相对停输安全性。结果表明：高凝油油头到达进站口时停输最危险;不同停输时机的无量纲排空时间相差明显,即不同停输时机再启动的难易程度或停输安全性相差较大,且差异程度随停输时间延长而增大;对于存在停输危险的停输时机,无量纲排空时间总会在某一停输时间下趋于无穷大,表明该停输时间下,再启动不会成功。研究结果可为原油差温顺序输送管道合理安排停输检修计划或定性判断停输安全时间提供技术支持。（图4,表4,参13）     

脂肪细胞膜免疫对动物体脂含量的调控

降低动物体内脂肪含量,改善畜产品质量一直是动物研究人员研究的重点。近年发展起来的脂肪细胞膜免疫为降低动物体脂含量提供了一种安全而有效的方法。本文简要介绍了脂肪细胞膜免疫的两种免疫方法,并对其发展前景进行了展望。     

武汉市公园绿地植物的冠层雨水截留能力研究

公园绿地作为城市建设的重要组成部分,在协调雨洪管理方面具有重要作用 。研究植物冠层雨水截留能力的对 提高公园绿地雨洪功能具有重要意义 。本研究对武汉市公园绿地中常见的 80种植物进行了冠层雨水截留能力的测定与 分析 。结果表明: 同一种生活型的植物冠层雨水截留能力各有不同,具有强雨水截留能力的乔木有圆柏、枇杷、雪松、落羽 杉,灌木有绣球荚速、匍枝亮叶忍冬、杜鹃、木芙蓉,草本植物有麦冬、薏苡、香蒲、金门莎草 。不同生活型植物冠层截留能力 均值也存在较大的差异,针叶乔木的冠层雨水截留能力均值最高,而落叶阔叶乔木冠层雨水截留能力均值最低 。该研究可 为进一步筛选雨水截留能力高、适应武汉本土环境气候环境的公园绿地植物提供科学依据。     

阿苯达唑混悬剂的质量评价及其含量检测方法的建立

目的:对自制阿苯达唑混悬剂的质量进行评价,考察稳定性的影响因素,并建立混悬剂中阿苯达唑的含量测定方法.方法:利用沉降体积比和再分散性试验考察制剂的性状稳定性,利用粒度测定仪对粒径的大小和分布进行测定,利用高温、冷冻和光照试验研究阿苯达唑混悬剂的影响因素,利用高效液相色谱方法建立阿苯达唑的含量检测方法.结果:自制阿苯达唑...     

重组大肠杆菌不耐热肠毒素的表达及对小鼠胚胎稳定性的影响

为研究大肠杆菌不耐热肠毒素（LT）对小鼠胚胎稳定性的影响,运用大肠杆菌表达系统制备了具有生物活性的重组大肠杆菌LT,用重组LT通过腹腔注射处理妊娠小鼠,分析了LT对小鼠胚胎稳定性的影响。首先采用PCR方法从产毒大肠杆菌菌株44815基因组中扩增LT的A、B亚基基因,将其插入到pET-20b（＋）原核表达载体pelB信号肽的下游,分别构建成LTA和LTB分泌型表达载体;将载体分别转化大肠杆菌BL21（DE3）pLysS,在IPTG的诱导下进行表达,利用Ni-NTA琼脂糖凝胶从细菌周质释放液中提取和纯化重组LTA和LTB蛋白;利用细胞毒性试验检测重组蛋白的生物活性。然后用制备的重组LT注射妊娠6d的小鼠,连续注射3d后,统计小鼠的胚胎存活率。同时用ELISA方法检测小鼠血清中与胚胎稳定性密切相关的Th1型细胞因子（IFN-γ、IL-2）和Th2型细胞因子（IL-4、IL-10）及IL-β的表达水平。结果表明,采用分泌性表达策略实现了重组LT在大肠杆菌中的高效分泌表达,LTA和LTB的表达量分别达68、62mg/L。表达的重组LT具有明显的细胞毒性作用;用LT处理妊娠小鼠,胚胎的存活率为32%,明显低于对照组;小鼠血清中Th1型细胞因子IFN-γ和IL-2的含量明显高于对照组（P〈0.01）,分别为对照组的2、3倍。同时细胞因子IL-1β为对照组的2倍（P〈0.01）,而稳定胚胎发育的Th2型细胞因子IL-4、IL-10没有明显变化（P〉0.05）。据此推测,LT可能与大肠杆菌性肠炎引起妊娠家畜流产有关,LT对胚胎稳定性的影响除与LT的直接毒性有关外,可能还与LT介导的免疫调节异常有关。     

A cluster of two psittacosis cases among women farmers exposed to Chlamydia psittaci-infected domestic poultry in Zhejiang Province,China

A cluster of Chlamydia psittaci (C. psittaci) cases was reported in Zhejiang Province, China, 2019. This study evaluates the extent of the outbreak and determines the source of infection. Real-time PCR and sequencing of the ompA gene of C. psittaci were performed to identify the cases, the domesticated poultry and close contacts. The index patient was a 76-year-old woman with chronic vertigo, and Case 2 was a 64-year-old female farmer with herpes zoster. Both women bought psittaci-infected chickens or ducks from the same mobile street vendor and raised them for 10 days and 23 days before fever onset. There were no direct contact between the two women. C. psittaci test was positive for the two patients, one sick chicken, three healthy ducks and the vendor's chicken cage. Phylogenetic analysis showed that all seven C. psittaci positive samples carried identical ompA genotype A of C. psittaci. Of all of the patients' 148 close contacts, none tested positive for C. psittaci, or developed acute respiratory symptoms. Both patients were discharged after a 4-week hospital stay. In conclusion, the source of this cluster was the poultry infected with C. psittaci, which occasionally cause infections in farmers, but inter-human transmission seems unlikely.     

饲料粗蛋白质含量测定中试样快速分解新法——H2O2-H2SO4-混合催化剂法

H2O2-H2SO4-混合催化剂法可使饲料试样在35 min内即可分解完全,极大提高了饲料粗蛋白质检测效率.该法操作简单、快速.     

Role of PERK pathway in morphine-induced myocardial protection of H9c2 cells

AIM: To explore whether morphine protects oxidative stress-damaged myocardial cells by inhibiting the PERK pathway to reduce endoplasmic reticulum stress and prevent mitochondrial permeability transition pore (mPTP) opening. METHODS: Rat myocardial H9c2 cells were cultured to establish an oxidative stress model, and then randomly divided into control group, H₂O₂ group, H₂O₂+morphine group, H₂O₂+morphine+PERK pathway inhibitor GSK2656157 group, morphine group and GSK2656157 group. Immunohistochemical method was used to detect the effects of morphine on expression of glucose-regulated protein (GRP) 78 and GRP94 induced by oxidative stress. The protein levels of PERK signaling pathway-related molecules were determined by Western blot. Confocal microscopy was used to observe the effects of morphine on mPTP opening and endoplasmic reticulum induced by oxidative stress. Cellular toxicity was detected by lactate dehydrogenase (LDH) kit and cell viability was measured by MTT assay. RESULTS: Compared with control group, GRP78 and GRP94 proteins in H₂O₂ group were strongly expressed, and the brown-yellow particles were significantly increased, but morphine significantly inhibited this process. Compared with control group, the phosphorylation of PERK was significantly reduced with GSK2656157 treatment at different concentrations, among which 2 μmol/L had the most significant effect (P < 0.05). Oxidative stress significantly increased the protein levels of GRP78, GRP94, p-PERK and CHOP, but significantly decreased p-GSK-3β level. These changes were inhibited by morphine, and the effects of morphine were further enhanced by GSK2656157 (P < 0.05). Compared with control group, oxidative stress significantly reduced the fluorescence intensity of mitochondrial TMRE and ER-Tracker Red. Morphine significantly inhibited this effect even when mitochondrial membrane potential was reduced, mPTP was open, and endoplasmic reticulum was damaged, while GSK2656157 further enhanced the effect of morphine (P < 0.05). Compared with control group, H₂O₂ significantly increased cellular toxicity and decreased the cell viability. Morphine inhibited this effect and GSK2656157 significantly enhanced the effect of morphine (P < 0.05). CONCLUSION: Morphine protects cardiac H9c2 cells under oxidative condition by inhibiting endoplasmic reticulum stress through PERK pathway and preventing the mPTP opening via GSK-3β inactivation.