铜绿假单胞菌生物膜肺部感染大鼠血清IgG抗体及肺部IFN-γ水平的变化

目的 了解人工铜绿假单胞菌(PA)生物膜肺部感染对机体免疫功能的影响.方法 由支气管内直接注入PA(菌种为PAO579)藻酸盐微粒1×109CFU/mL),建立慢性PA生物膜肺部感染大鼠模型,以支气管内注入生理盐水作为对照,2周后评估血清PA特异性抗体IgG水平、肺部IFN-γ反应的变化及其与肺组织病理学的相关性.结果...     

硬铝合金半连续铸造的裂纹缺陷分析

对凝固过程中流场、应力场、温度场及微观组织形态进行数值模拟,能帮助工艺设计人员分析不同时刻凝固过程的温度分布、金属流态、结晶晶粒大小、应力分布等重要物理参数,从而预测疏松、偏析、夹杂及热裂纹等缺陷。     

栽培条件对半夏叶片POD、SOD、CAT活性的影响

为了筛选能提高半夏叶片POD、SOD、CAT活性的栽培条件,用愈创木酚法、NBT光化还原抑制法和紫外分光光度法分别测定了不同基质不同施肥条件下半夏叶片中过氧化物酶（POD）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活性。结果表明：半夏叶片POD酶活性受基质影响不明显,但不同施肥处理对其活性影响极显著,其中施用1/2MS+K+P（KH2PO4 100 mg/L）的处理半夏叶片POD酶的活性最强;半夏叶片中SOD和CAT酶的活性受不同基质的影响比较明显,其中以珍珠岩为基质栽培的半夏叶片中两种酶的活性均显著高于以土壤为基质栽培的半夏;不同施肥处理对这两种酶的活性也有影响,其中施用1/2MS+K+P（KH2PO4 100 mg/L）的处理半夏叶片SOD酶的活性最强。栽培半夏以珍珠岩为基质、施用1/2MS+K+P（KH2PO4 100 mg/L）的处理对于提高半夏叶片中POD、SOD、CAT 3种同工酶的活性为佳。     

小鼠B7-H4原核表达载体的构建、表达及多克隆抗体的制备

目的探讨小鼠B7-H4原核表达载体的构建、表达及多克隆抗体的制备。方法采用特异性引物扩增小鼠B7-H4（mB7-H4）胞外功能区DNA,经酶切、拼接构建原核表达载体pET28a-mB7-H4。将构建的重组表达质粒转化入E.coliBL21（DE3）菌株,采用IPTG诱导表达、Ni-NTA柱亲和层析纯化目的蛋白、SDS-PAGE分析蛋白纯度。将纯化的目的蛋白免疫家兔制备多克隆抗体,并对其进行纯化及鉴定。结果序列测定证实了构建的pET28a-mB7-H4重组表达载体含有mB7-H4编码序列,其序列分析与GenBank中公布序列对比一致,质粒在E.coli中诱导表达相对分子质量（Mr）为26.5 KD的目的蛋白,SDS-PAGE分析表明纯化后的目的蛋白达到电泳纯。双向琼脂扩散法检测抗体效价为1∶16,ELISA法检测抗体效价为1∶12 800,Western blot分析显示抗体能特异性结合mB7-H4。结论成功制备了高表达重组mB7-H4蛋白的原核表达载体及高效价抗mB7-H4多克隆抗体,为进一步研究B7-H4的功能奠定了基础。     

Schisandra total lignin attenuates apoptosis of endoplasmic reticulum pathway to delay mouse brain aging

AIM:To investigate the role of schisandra total lignin (SCL) in anti-aging of the mouse brain. METHODS:A D-galactose induced mouse aging model was established. The following groups in this study were set up: control group, model group, SCL low dose group ［SCL (L)］, SCL moderate dose group ［SCL (M)］ and SCL high dose group ［SCL (H)］. Learning and memory abilities were measured by mouse jumping experiments. The expression of ubiquitin (Ub), glucose-regulated protein 78 （GRP78）, protein disulfide isomerase (PDI), CCAAT /enhancer-binding protein homologous protein (CHOP), Bcl-2 and Bax proteins was detected by Western blotting. In addition, the protein expression of Bcl-2 and Bax in the aging cerebral cortex was also observed by immunohistochemistry. RESULTS:In learning test, compared with control group, the number of errors within 5 min increased in model group (P<0.05). Compared with model group, the number of errors within 5 min decreased in SCL (L) group, SCL(M) group and SCL(H) group (P<0.05). In memory test, compared with control group, incubation period of the first jumping off the platform was shorter and the number of errors within 5 min increased in model grou(P<0.05). Compared with model group, the incubation period of the first jumping off the platform was longer and the number of errors within 5 min decreased in SCL (L) group , SCL(M) group and SCL(H) group (P<0.05). Compared with control group, the protein expression of Ub, GRP78, PDI, CHOP and Bax was increased (P<0.05), while Bcl-2 protein level and Bcl-2/Bax ratio were decreased in model group(P<0.05). Compared with model group, the protein expression of Ub, GRP78, PDI, CHOP and Bax was decreased in SCL (L) group, SCL(M) group and SCL(H) group (P<0.05), while Bcl-2 protein level and Bcl-2/Bax ratio were increased (P<0.05). In control group, neuronal morphology was normal, the protein expression of Bcl-2 was positive and Bax was negative in the cytoplasm. In model group, the neurons were degeneration, the protein expression of Bcl-2 was negative and Bax was positive in the cytoplasm. In SCL (L) group, SCL (M) group and SCL (H) group, the number of degenerative neurons decreased, the protein expression of Bcl-2 was positive and Bax was negative in the cytoplasm. CONCLUSION: SCL inhibit D-galactose-induced brain aging in mice by attenuating apoptosis of endoplasmic reticulum pathway.     

Response Surface Methodology for Ultrasound-Assisted Extraction of Astaxanthin from Haematococcus pluvialis

Astaxanthin is a novel carotenoid nutraceutical occurring in many crustaceans and red yeasts. It has exhibited various biological activities including prevention or amelioration of cardiovascular disease, gastric ulcer, hypertension, and diabetic nephropathy. In this study, ultrasound-assisted extraction was developed for the effective extraction of astaxanthin from Haematococcus pluvialis. Some parameters such as extraction solvent, liquid-to-solid ratio, extraction temperature, and extraction time were optimized by single-factor experiment and response surface methodology. The optimal extraction conditions were 48.0% ethanol in ethyl acetate, the liquid-to-solid ratio was 20:1 (mL/g), and extraction for 16.0 min at 41.1 °C under ultrasound irradiation of 200 W. Under optimal conditions, the yield of astaxanthin was 27.58 ± 0.40 mg/g. The results obtained are beneficial for the full utilization of Haematococcus pluvialis, which also indicated that ultrasound-assisted extraction is a very useful method for extracting astaxanthin from marine life.     

政策性农业保险试点绩效评估与实证研究——以湖南省为例

基于农业保险试点绩效的政策目标,运用关键绩效指标法,建立了包含财政补贴到位率、保险资金充足率、自主参保率、受保障度4项指标的评估体系和评分方法。选取湖南为范例,对其试点5年来的绩效进行评分,在肯定其绩效的同时指出在农民参保自主性、业务经营持续性、政府财政支持性等方面存在必须重视的问题,并提出相应的政策建议。评估结果可以作为实践考核与未来政策选择的依据。     

重新认识农民工——兼论农民工认识上的4大误区

当前农民工问题再次受到政府与社会的关注,这是一种进步的倾向。但也有一些值得注意的基本问题。其中之一,就是关于农民工的重新认识问题。初步的研究发现,对农民工的认识存在名称、内涵与外延、特征4大误区。     

Influence of hydrogen sulfide on ileal epithelial cell apoptosis in rats with intestinal ischemia-reperfusion injury

AIM: To investigate the influence of hydrogen sulfide (H₂S) on intestinal epithelial cell mitochondrial morphology and function and the expression of caspase-3, cleaved caspase-3, cytochrome C (Cyt C), Bcl-2 and Bax in rats with intestinal ischemia-reperfusion (I/R) injury. METHODS: Wistar rats (n=24) were randomly divided into 3 groups (8 in each group): sham group, I/R group and I/R+sodium hydrosulfide (NaHS) group. The animal model of intestinal I/R injury was established. The rats in I/R+NaHS group received NaHS (100 μmol/kg bolus +1 mg·kg^-1·h^-1 infusion) 10 min prior to the onset of reperfusion, whereas the rats in I/R group and sham group received equal volume of normal sodium. Ileum epithelial mitochondrial morphology and function were measured. Plasma H₂S was detected by sensitive sulfide electrode. The expression of Bcl-2 and Bax mRNA was studied by RT-PCR. The protein levels of caspase-3, cleaved caspase-3, cytochrome C (Cyt C), Bcl-2 and Bax were tested by Western blot.RESULTS: The area, volume density, maximum diameter, minimum diameter and equivalent diameter of mitochondria, and the expression of cleaved caspase-3, Cyt C and Bax in I/R group were significantly higher than those in I/R+NaHS and sham groups (P<0.01). The mitochondrial count, circumference, specific surface area, area density and population density, plasma H₂S, respiratory control rate (RCR), the ratio of P/O, R₃ , R₄, and the expression of Bcl-2 in I/R group were sharply lower than those in I/R+NaHS and sham groups (P<0.01). H₂S was negatively correlated with caspase-3, cleaved caspase-3, Cyt C and Bax (P<0.01), and was positively correlated with Bcl-2 (P<0.01). CONCLUSION: H₂S has a protective effect on mitochondrial morphology and function in rats with intestinal I/R injury by down-regulating cleaved caspase-3, Cyt C and Bax and up-regulating Bcl-2.     

新媒体在大学生思想政治工作中的创新应用

现代新媒体技术为思想政治教育创新提供了新的方法、手段和内容,同时也带来了一些不利影响。针对新情况和新问题,文章在阐述新媒体对大学生思想政治教育的优势和负面影响的基础上,提出了新媒体环境下加强大学生思想政治教育的创新。