自然和人工生境被子植物枝木质部结构与功能差异

水是植物生存与生长的基础条件, 水分有效性影响植物木质部解剖结构、水力功能, 使之形成特定的适应特征。因此, 对比自然与人工生境中同一植物的水力功能与解剖结构差异, 有助于理解植物对水分环境的适应机理。该研究以湿润区三角槭(Acer buergerianum)、青冈(Cyclobalanopsis glauca)和女贞(Ligustrum lucidum)为研究材料, 对比分析了自然和人工生境中各物种的栓塞抗性(导水率损失50%时的水势(P₅₀))、输水效率(比导率(K_s))和解剖结构(导管直径(D)、导管壁厚(T)、导管密度(N)、木质部密度(WD)、厚度跨度比(t/b)²)特征, 探究了同生境种内与跨生境、跨物种水平的效率-安全权衡关系, 量化分析了水力功能与解剖结构的关系。结果发现: 1) 3种被子植物在自然生境中K_s更大, P₅₀更小, 与其更大的D、更小的(t/b)²有关。2)同生境种内K_s与P₅₀不存在权衡。3)功能性状和解剖结构相关分析表明: 同生境种内D与P₅₀不存在显著的相关关系; 除自然生境女贞外, T、(t/b)²均与P₅₀正相关。相对于人工生境, 在水分有效性低或无额外浇灌的自然生境中, 植物通过增大导管直径显著提高其输水效率, 从而避免水势下降、降低潜在栓塞风险。     

香茅精油的抑菌和抗氧化活性研究

选用产自福建厦门的香茅(Cymbopogon nardus),测定香茅精油对白色粘性沙雷氏菌、红色粘性沙雷氏菌、大肠杆菌、金黄葡萄球菌、铜绿假单胞菌和紫色杆菌等6种菌的抑菌活性,并利用ABTS^.+自由基清除法以及超氧阴离子清除法研究香茅精油的抗氧化活性。结果表明,新鲜香茅精油的平均提取率为0.29,对6种供试菌种都有较高的抑制作用,其中对紫色杆菌的抑制活性最强,且香茅精油有极高的清除ABTS^.+自由基以及超氧阴离子自由基的能力,证明香茅精油具有广谱抑菌活性及强抗氧化活性。     

生防菌株HG18基因组信息分析与抗菌功能基因挖掘

贝莱斯芽胞杆菌（Bacillus velezensis）HG18是1株低温生防菌株,能够分泌抗菌物质。为挖掘和利用其抗菌功能基因,服务农业生产,采用二、三代相结合测序技术,对其进行全基因组测序,获得菌株完整基因组序列。基因组全长4 461 844 bp,包含一个染色体和一个质粒,GC含量44.06%,编码4 643个基因,编码基因总长度3 893 994 bp,占基因组87.27%。发现6个几丁质降解相关基因,2个葡聚糖酶基因和1个壳聚糖酶基因,2个脂肽类抗菌物质芬芥素与表面活性素合成基因簇,2个细菌素subtilin和bacillolysin合成基因。研究为提高抗菌物质产量的菌株定向遗传改造以及植物抗病育种提供基因资源。     

爪哇棒束孢侵染美国白蛾过程及抗氧化酶活性变化

[目的]爪哇棒束孢Isaria javanica是一种重要的虫生真菌,已广泛应用于多种害虫的防治.本研究从美国白蛾Hyphantria cunea僵虫尸体中分离出对美国白蛾具有致病作用的爪哇棒束孢BE01菌株,为了解该菌株对美国白蛾的侵染过程,并通过研究宿主体内抗氧化酶系对爪哇棒束孢BE01菌株入侵的响应,评价该菌的杀虫作用,为爪哇棒束孢BE01防治美国白蛾提供依据.[方法]采用扫描电镜技术,观察爪哇棒束孢BE01分生孢子侵染的美国白蛾3龄幼虫,并测定美国白蛾接菌后体内超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)含量的变化.[结果]爪哇棒束孢对美国白蛾侵染过程包括:分生孢子粘附在美国白蛾的角质层上,接种后6h孢子开始萌发,24h产生附着胞,48 h菌丝在体表继续生长,96h菌丝从虫体内长出并产分身孢子,120 h菌丝覆盖整个虫体.在受到爪哇棒束孢BE01侵染后,美国白蛾幼虫体内的3种抗氧化酶SOD、POD、CAT酶活性明显升高,并在侵染48 h时达到峰值.随着侵染时间的增加,48 h后3种酶的活性开始下降, 60 h后酶活性均低于对照组.[结论]爪哇棒束孢BE01孢子活力高、萌发速率快,导致美国白蛾体内的保护酶系难以发挥保护作用.爪哇棒束孢BE01菌株能够快速侵染美国白蛾幼虫,具有开发成新的高效生物防治菌株的潜能.     

胃食管反流病患者自我管理行为依从性及其影响因素调查

目的：调查分析胃食管反流病患者自我管理行为依从性情况及其影响因素。方法：选取2010年2月-2012年6月来我院就诊治疗的胃食管反流患者150例,利用自我行为管理量表、自我效能量表、焦虑自评量表（SAs）及抑郁自评量表（SDS）进行调查,并采用单因素分析及多因素分析法分析其影响因素。结果：所有150例患者的自我行为管理平均得分为37．12＋4．95分,处于中下游水平,其中治疗依从性较好而疾病知识认知方面较差;而从单因素及多因素分析中得知,胃食管反流病患者自我行为依从性的影响因素主要为自我效能、工作学习压力及文化程度（偏回顾系数=0．301、-2．264、1．403）。结论：胃食管返流病患者的自我管理行为依从性较差,这与其文化程度较低、工作学习压力较大有关,医务人员应指导患者减轻工作学习压力,改善生活方式以提高其自我管理行为依从性。     

一条新的柱层析纯化路径对HBsAg免疫原性的影响

摘要目的：建立一条新的毕赤酵母表达乙肝表面抗原（HepatitisBantigen,HBsAg）柱层析纯化方法,保持HBsAg结构完整性和提高免疫原性。方法：毕赤酵母发酵料液经过菌体破碎、聚乙二醇沉淀、疏水层析、超滤和凝胶分子筛精纯,收集HBsAg合格样品液适当稀释后加入铝佐荆吸附,制成乙肝疫苗半成品免疫BALB／c小鼠。结果：纯化产物经SDS-PAGE银染鉴定得单一条带,分子量在23kD左右,凝胶成像软件分析纯度超过95％;该纯化方法得到的HBsAg颗粒电镜观察得平均直径为22nm病毒样颗粒,结构较均一完整;自制疫苗免疫小鼠后,其血清抗体水平高于葛兰素史克生产的Engerix—B（安在时）,存在显著性差异（P〈0．05）。结论：通过该方法纯化的HBsAg结构完整性良好,疫苗免疫效果优于酵母表达的Engerix—B,纯化路径简单高效,易于放大用于工业化生产。     

新生隐球菌生物膜动物感染模型的构建及其活性的检测

目的 构建一种简便易行的新生隐球菌生物膜感染动物模型.方法 采用大鼠皮下置管法构建新生隐球菌生物膜感染动物模型,并使用电子扫描显微镜观察新生隐球菌体内形成生物膜的结构;采用MTT法对获得的体内生物膜结构进行活性的检测.结果 成功构建了新生隐球菌生物膜大鼠感染模型;MTT法检测体内生物膜活性表明,随着体内培养时间的延长,生物膜活性增强,与直接镜检和电镜观察结果一致.结论 新生隐球菌生物膜大鼠模型简单易行,便于操作,对于研究新生隐球菌生物膜体内活性的研究具有一定的实际应用价值.     

Prevalence of HIV Infection and Associated Risk Factors among Men Who Have Sex with Men (MSM) in Harbin,P. R. China

Objective

To assess the prevalence of HIV infection and characteristically risk of factors which associated with HIV infection among MSM in Harbin, China.

Methods

A face-to-face questionnaire interview was conducted among 463 Men Who Have Sex with Men (MSM) who were recruited by the snowball sampling in Harbin from April, 2011 to July, 2011. The questionnaire mainly included demographics, AIDS knowledge, homosexual behavior and the status of intervention in MSM. Blood specimens were obtained and tested for the diagnoses of HIV, syphilis and hepatitis C virus (HCV). Associations between above exposed factors and HIV infection were analyzed using a univariate analysis and forward stepwise logistic regression.

Results

The prevalence of HIV and syphilis was 9.5 and 14.3%. The awareness rate of AIDS was 86.8%. The rate of unprotected sexual behavior was 57.6% of MSM during the past 6 months. The univariate analysis identified that the age (age≥35 years old), cohabitation, more than 10 years of homosexual behavior and more than 10 homosexual partners were risk factors which associated with the HIV infection, and that protected sex during the past 6 months was a protective factor for the HIV infection. The multivariate analysis identified that the duration of homosexual behavior and commercial sexual behavior were independent risk factors which associated with the HIV infection, and the protected sex during the past 6 months was a protective factor for the HIV infection.

Conclusion

The prevalence of HIV among MSM in Harbin has been rapidly increasing in the past few years. Targeted, tailored, and comprehensive interventions are urgently needed to prevent the HIV infection from MSM.     

TLR4 signaling-induced heme oxygenase upregulation in the acute lung injury: role in hemorrhagic shock and two-hit induced lung inflammation

Resuscitated hemorrhagic shock is believed to promote the development of acute lung injury (ALI) by priming the immune system for an exaggerated inflammatory response to a second trivial stimulus. This work explored effects of TLR4 on hemorrhage-induced ALI and “second-hit” responses, and further explore the mechanisms involved in “second-hit” responses. Expression of HO-1, IL-10, lung W/D and MPO markedly increased at nearly all time-points examined in HSR/LPS group as compared with sham/LPS group in WT mice. In HSR/LPS mice, the induced amount of IL-10 and the expressions of HO-1 of WT mice were significantly higher compared with TLR-4d/d. This study provides in vivo evidence that pulmonary infections after LPS instillation contribute to local tissue release of pro-inflammatory mediators after HSR systemic. Activation of TLR4 might induce HO-1 expression and HO-1 modulates proinflammatory responses that are triggered via TLR4 signaling.