178 research outputs found

    Study on extraction technology of volatile oil from cortex phellodendri by supercritical carbon dioxide

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    使用超临界二氧化碳技术对经过超声-微波处理过的黄柏中的挥发油进行萃取,并对萃取工艺进行响应面优化。在单因素预实验的基础上,以萃取压力、萃取温度、萃取时间为响应因素,黄柏挥发油的萃取量为响应值,根据中心组合(bOX-bEHnkEn)实验设计原理,采用三因素三水平的响应面分析法,确定各工艺条件对萃取量的影响,并用扫描电子显微镜(SEM)对萃取前、未超声-微波处理超临界萃取后及超声-微波处理超临界萃取后的黄柏进行比较观察,对萃取效果进行了微观解释。结果表明,经过超声-微波处理过的黄柏中的挥发油超临界二氧化碳萃取最佳工艺条件为:萃取压力为34MPA,萃取温度为41℃,萃取时间为66MIn,萃取率达6.03%。The supercritical carbon dioxide extraction of volatile oil from processed cortex phellodendri was optimized by response surface methodology(RSM).According to the principle of Box-Behnken central composite design,extraction pressure,extraction temperature,extraction time were chosen as response factors,extraction mass was chosen as response value,and a three-factor and three level central composite design was adopted to determine the influence of various technological conditions.Using SEM observed the cortex phellodendri before and after extraction,and explained the extraction effects from microcosmic aspect.The results showed that the optimum extraction conditions were as follows:extraction pressure 34MPa,extraction temperature 41℃,extraction time 66min,extraction yield was 6.03%.湖南省科技厅重大专项(2008FJ1007);2010年吉首大学大学生研究性学习与创新性实验计划项目(JSU-CX-2010-49

    Research on Salt Tolerance of Rice Transformed by mangrin Gene

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    以转MAngrIn基因水稻的阳性植株(11#,59#,86#)和阴性植株为材料,在0,100,150,200 MMOl/l的nACl溶液中经盐胁迫7 d后,测定叶片相对含水量、质膜透性、超氧化物歧化酶(SOd)活性和脯氨酸含量4项耐盐指标。结果表明:盐胁迫下,转基因植株的叶片相对含水量、脯氨酸含量、SOd活性明显高于阴性植株,叶片电导率则低于阴性植株。对转基因植株和阴性植株的耐盐性综合评定结果是11#>59#>86#>阴性植株。Plants transformed by mangrin gene(11#,59#,86#) and negatives were tested using several salt tolerance indices,including related water content,cell membrane permeability,SOD activity and proline content,which were conducted under the NaCl concentration of 0,100,150,200 mmol/L after 7 days.The results indicated that the transgenic rice plants accumulated more RWC,proline content and SOD activity than ck under salt stress conditions,yet cell membrane permeability decreased less than ck.According to physiological target in synthetically evaluation,the result is 11#> 59#> 86#> Negatives.福建省青年人才基金项目(2006F3022);福建省自然科学基金项目(2007J0250

    Retinoic acid receptor β is required for anti-activator protein-1 activity by retinoic acid in gastric cancer cells

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    Objective To investigate the role of retinoic acid receptor β (RARβ) in mediating inhibitory effect of all-trans retinoic acid (ATRA) on activator protein-1 (AP-1) activity in gastric cancer cells. Methods Transient transfection and chloramphenicol acetyltransferase (CAT) assay, Northern blot, gene transfection, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, and anchorage-independent growth assay were used.Results Transient transfection of RARβ expression vector into MKN-45...theNationalOutstandingYouthScienceFoundationofChina (No 3982 5 5 0 2 )andtheNationalNaturalScienceFoundationofChina (No 39880 0 15

    结合电子设计竞赛的“电力电子技术”课程教学改革实践

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    电子设计竞赛是提高学生动手能力、加强创新设计能力、增进团队合作等能力的有效手段,同时也能促进高校相关课程的改革。\"电力电子技术\"课程涉及电子技术、控制技术和电力技术,主要内容包括电力电子器件、整流电路、逆变电路、直流-直流变换、交流-交流变频、PWM控制技术及软开关等,课程实践性和工程性都很强。根据\"电力电子技术\"课程特点及存在的问题,提出相应的课程教学改革思路并加以实践,包括将\"电力电子技术\"课程与电子设计竞赛结合,把电赛题目带进课堂,通过案例式教学讲授知识点,积极动员学生参与电子设计竞赛,积累好的作品反馈于课程教学等。结果表明:结合电子设计竞赛的\"电力电子技术\"课程选课学生数有明显提升,参与电子设计竞赛的学生人数和获奖比例有一定提高

    布鲁菌病44例临床特征分析

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    目的分析大庆地区44例布鲁菌病患者临床表现及实验室相关指标的变化,为临床诊治提供依据。方法回顾性分析大庆油田总医院2014年2月-2018年8月44例布鲁菌病患者的临床特征。结果大庆地区布鲁菌病患者以农牧民(25例,56.8%)和30岁以上患者(31~69岁,93.2%)为主,临床主要表现为贫血30例(68.2%)、发热23例(52.3%)、胆囊疾病9例(20.5%)、脾肿大9例(20.5%)、胃炎7例(15.9%)、关节炎关节痛6例(13.6%)、睾丸附睾炎4例(9.1%)、心包积液4例(9.1%)、全血细胞减少2例(4.5%)、胸壁脓肿1例(2.3%)。实验室相关指标中,降钙素原(PCT)升高31例(31/32,96.9%),C反应蛋白(CRP)升高33例(33/35,94.3%),红细胞沉降率(ESR)增快11例(11/13,84.6%),44患者中白蛋白减少37例(84.1%),肝功能异常27例(61.4%),单核细胞增多23例(52.3%),白细胞升高10例(22.7%),血小板减少7例(15.9%)。结论布鲁菌病随受累器官不同临床表现多样,除常见症状外,胆囊病变也是其可能出现的临床特征;在实验室相关指标中,可出现单核细胞增多及血小板减少,PCT普遍升高且以轻度升高为主。临床医师应加强对该病的认识,以做到早期诊断和治疗

    纳米Co_3O_4的制备及其在富氢气氛下CO选择氧化反应中的催化性能

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    过渡金属氧化物四氧化三钴(Co3O4)在CO氧化反应中展示了较好的低温活性.Co3O4催化剂用于富氢气氛下CO选择氧化反应已引起了人们极大的关注,具有潜在的应用前景.采用液相沉淀-热解氧化方法制备了2种不同形貌的纳米Co3O4.用X射线衍射(XRD)、扫描电子显微镜(SEM)等技术考察了包括沉淀剂种类、老化时间、焙烧温度等合成条件对生成Co3O4形貌、晶粒尺度的影响.制备的Co3O4的外形与沉淀前驱物外形直接相关.焙烧温度越高,Co3O4的颗粒越大.研究了制得的Co3O4在富氢气氛下CO选择氧化反应中的催化性能.对比以上方法制备的Co3O4的催化性能发现,催化剂的粒径和比表面积与催化剂的活性存在关联.使用尿素沉淀法并经250~300℃空气热解氧化制得的Co3O4具有较好的催化活性

    Bacterial community and its relation to environmental variables in a subtropical stratified reservoir for drinking water supply in autumn

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    水库在我国东南沿海地区是重要的饮用水水源地,对地区经济发展和社会稳定起到重要作用。选择亚热带地区典型的热分层水库——福建莆田东圳水库,于2011年秋季稳定分层期,以水体温度的垂直变化特征为依据进行分层采样。应用PCrdggE和克隆测序的方法研究浮游细菌群落的垂直分布特征,利用多元统计分析揭示细菌群落与热分层水体理化指标之间的关系。结果显示:溶解氧、电导率、叶绿素A、总氮、氨氮及硝氮在上下层水体中的分布有显著差异,下层缺氧区细菌的SHAnnOnWIEnEr指数和dggE条带数明显高于上层好氧区,表明东圳水库热分层水体中存在明显的物理、化学及生物分层现象。测序结果表明β-变形菌可能是东圳水库中占优势的细菌类群,统计结果提示溶解氧是显著影响细菌群落组成的环境因子。热分层水体的物理化学分层与水体细菌群落结构密切相关,提示水库生态学研究应对水体热分层给予重视。Fujian reservoirs in southeast China are important water resources for economic and social sustainable development,although few have been studied previously.Dongzhen Reservoir,a typical subtropical stratified reservoir in Fujian,was chosen for investigation of bacterial distribution,composition and diversity in autumn 2011.As the only built large reservoir in Putian City,it plays an important role in irrigation,flood control,hydroelectric power,and water supply.Dongzhen Reservoir shows an obvious phenomenon of water thermal stratification during summer and autumn,thus creates a unique gradient of environmental variables along the water column.We investigated the bacterial community and its relation to environmental variables in this study for a better understanding of vertical distribution of bacterial community and theprimary environmental drivers in a stratified reservoir.Five water samples were collected from five different depths according to the vertical changes of temperature.Both PCR-DGGE and sequencing were used to investigate the bacterial community and diversity.Moreover,physical and chemical parameters were measured according to the national standard methods.Multivariate statistical techniques were used to examine the relationship between bacterial community and environmental variables.Principal component analysis( PCA) clearly showed that water temperature,dissolved oxygen( DO),chlorophyll a( Chl a),total nitrogen( TN),ammonia nitrogen( NH4-N),nitrite / nitrate nitrogen( NOx-N) and electric conductivity of the upper aerobic zone were differed from those of the deeper anoxic zone.Both the number of DGGE bands and the Shannon-Wiener index of the deeper anoxic zone were higher than those of the upper aerobic zone.Further,two groups were distinguished by the cluster analysis of bacterial communities based on the Bray-Curtis similarity.Thus,Dongzhen Reservoir presented an obviously physical,chemical,and biological stratified phenomenon.Seven bands that common to all sampling depths were extracted and sequenced,and among which four were identified as Betaproteobacteria,indicating that Betaproteobacteria were the most dominant taxa in Dongzhen Reservoir in autumn.Bacterial community composition and diversity differed greatly among different sampling depths,and these differences were closely related to the physical and chemical stratification of the water body.Redundancy analysis( RDA) demonstrated DO was the significant environmental variable that shaping the bacterial community and diversity( P < 0.01).Therefore,we should pay more attention to DO and thermal stratification of reservoirs for sustainable reservoir management.国家重大科学研究计划(2012CB956103); 中国科学院知识创新工程方向项目(KZCX2-YW-QN401); 国家自然科学基金面上项目(31172114); 福建省杰出青年科学基金项目(2012J06009

    重组人类T淋巴细胞白血病病毒抗原及双抗原夹心法ELISA抗体诊断试剂盒的研制

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    为研制灵敏、特异的抗人类T淋巴细胞白血病病毒(HTLV)抗体诊断试剂,将一段HTLV Ⅰ和HTLV Ⅱenv区嵌合基因在大肠杆菌中表达,获得的重组抗原具有良好活性。将该抗原作为酶标记抗原建立双抗原夹心法ELISA(dsELISA),对31份HTLV Ⅰ型血清和19份HTLV Ⅱ型血清均能100%检出,而在5065份各种阴性血清中特异度为99 94%。用dsELISA试剂与进口间接法试剂(GeneLabs试剂)平行检测18份HTLV Ⅰ参比血清、17份HTLV Ⅱ参比血清和1024份献血员血清,结果dsELISA试剂正确率为100%,对HTLV Ⅰ型血清和HTLV Ⅱ型血清的反应性基本相同,平均s/co值显著高于GeneLabs试剂。而GeneLabs试剂对HTLV Ⅱ型血清的反应性显著弱于Ⅰ型,并有2份BBI参比血清中的Ⅱ型血清漏检。另外,GeneLabs试剂在献血员血清中出现9例假阳性,特异性显著低于dsELISA试剂。这些结果表明:所研制的dsELISA试剂可用于HTLV Ⅰ型和Ⅱ型血清的检测,其灵敏度和特异度均优于进口间接法诊断试剂

    庚型肝炎病毒基因在大肠杆菌中表达的初步研究

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    利用原核表达载体 pRSET或 (和 )pGEX在大肠杆菌内表达了覆盖庚型肝炎病毒 (HGV)C NS3和NS5区的多段基因。CE1、E2、NS3、NS5及NS3 NS5嵌合基因等的 8段基因均有高效表达 ,各重组蛋白产量与菌体总蛋白之比在 10 %~ 35 %之间。对以上重组蛋白进行免疫学筛选 ,证实其中 7个重组蛋白均具免疫学活性 ,在一定程度上确定了重组HGV抗原表位的分布 ,为HGV的血清学和免疫学诊断试剂的研究奠定了坚实基

    Proteomic Analysis of Rice Cultivar Jiafuzhan in the Responses to Xanthomonas campestris pv.oryzicola Infection

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    作者简介: 陈芳育(1978-) , 男, 讲师。E-mail : cfy307@ sohu. com * 通讯作者(Corresponding author) : 陈亮( 1963-) , 男, 教授, 博士生导师, 研究方向: 细胞与分子生物学。E-mail: chenlg@ xmu. edu. cn[中文文摘]运用双向电泳分析高抗水稻品种“佳辐占”受强毒力细菌性条斑病病原菌侵染2d后的叶片蛋白质组变化,共发现38个蛋白质发生差异表达,其中32个上调,5个下调,1个新增。用MALDI-TOF-MS分析和数据库检索鉴定出其中的33个差异表达蛋白质,并将它们分为4个功能类群,即信号转导相关蛋白、防卫相关蛋白、代谢相关蛋白和蛋白质稳定相关蛋白。这些蛋白分别参与了信号识别、信号传递、抗氧化、糖代谢、细胞壁加固、植保素合成等抗病生理反应。研究表明,水稻对细菌性条斑病病原菌的侵染存在着一个复杂的抗病信号应答和代谢调控网络,其作用机理可以通过差异表达的蛋白质(酶)反映出来,其中差异表达的8个R蛋白和3个PR蛋白可能与水稻对细菌性条斑病的抗病性密切相关。本研究为进一步揭示水稻对细菌性条斑病的抗性机理及相关抗病基因的功能克隆提供了依据。[英文文摘]Rice bacterial leaf streak( BLS) caused by the pathogen Xanthomonas oryzae pv. oryzicola ( Xooc) is one of the major rice diseases in South China. Here we focus on proteomics as a tool for the discovery of differentially expressed proteins closely related to the disease resistance. The leaves of rice cultivar Jiafuzhan (Oryzae sativa L. ) highly resistant to the disease, were infected by"89773-1- 1" strain of the Xooc with strong pathogenicity. Total proteins were extracted from the leaves sampled at two days after inoculation, and separated by two- dimensional electrophoresis. It was found that there were thirty- eight proteins expressed differentially, of which thirty-two were up-regulated, five down-regulated and one was "new". Of the thirty- eight responsive proteins, thirty-three were identified by MALD-I TOF-MS and database searching.Based on the predicted function, we grouped them into four clusters: signal transduction, defensive responses, substance metabolism and protein stabilization, which were involved in many resistant physiological react ions, including signal recognition and transduction, antioxidant react ion, carbonhydrate metabolism, cel-l wall reinforcement and phytoalexin biosythesis. In turn a complex signal transduct ion and metabolic regulative network in the resistant responses to the infection of Xooc was outlined in this work, and the molecular mechanism was revealed by differentially expressed protein/enzyme patterns during Xooc infection. In this study, eight R proteins and three pathogenesis- related(PR) proteins which might relate closely to the disease-resistance were found. This result provides us the basic information to further reveal the resistant mechanism and conduct functional cloning of the resistan-t related genes in rice to BLS.生物农药与化学生物学教育部重点实验室( 福建农林大学) 开放课题基金项目( KF0411
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