72 research outputs found

    The Theory and the Improvement Design of CH_4 Detection Instrument Based on Light Interference Technique

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    介绍光干涉式甲烷检测技术的基本测量原理,及在光电检测环节对系统所作的改进设计。这种改进体现在采用CCD或CMOS光电传感器,将视频信号输入嵌入式系统,进行数字图像处理,以合理的软件设计提高检测的速度与精度。In this paper,the methane detection technique based on laser light interference is discussed.At the same time,the improvement design in signal capturing is also focused on.The improvement design is that using CCD,CMOS photoelectricity sensor to get video signal,then the signal is send into embedded system.Digital image processing can give the concentration of methane,and an excellent program can improve the speed and precision of detection

    Influence of Different Enzyme Preparation on Premature Yeast Flocculation activity of PYF Factor from Malt

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    选取2种不同复合酶制剂,采用乙醇沉淀法提取出麦芽中PYF因子,通过模拟糖化条件及添加不同酶量来考察外加酶是否对PYF因子具有水解能力。结果发现,与对照组PYF活力值(F=78.79)相比,不同添加量的2种复合酶与PYF因子作用后PYF活力值没有发生显著变化(P>0.05),即PYF因子是一种结构特殊、复合酶不能水解的多糖大分子。Through simulating saccharification condition and adding different enzyme amount,the hydrolysis abilities of 2 different kinds of enzyme preparation on PYF factor,which was extracted from malt by ethanol precipitation, were measured and compared.The results showed that compared with the PYF activity value(F=78.79) of control group,PYF activity value didn't change significantly(P>0.05)after 2 kinds of enzyme with different adding amounts acted with PYF factor,namely that PYF factor was a kind of polysaccharide with a higher molecular weight and special structure and couldn't be hydrolyzed by enzyme

    利用表面增强拉曼光谱快速鉴别卷烟生产中烟用香精香料

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    烟用香精香料的配方是卷烟工业中的核心技术,也是构建不同特色卷烟产品的关键之一。然而,现有的香精香料质量评价手段主要是人工嗅香和测定某些特定的物性指标,如折光指数、相对密度、酸值、挥发份总量等。在实验室科研中还有使用色谱-质谱联用等方法。但是上述手段仍存在较多问题,比如受主观意识影响,操作繁琐,前处理耗时长,费用高,灵敏度低等。基于此,本文开发了一种利用表面增强拉曼光谱技术结合主成分分析算法来快速鉴别实际生产中不同种类、不同掺兑样的烟用香精香料的方法。本文利用该方法成功获取不同种类、同一种类不同生产批次及烟用香精香料不同掺兑量样品的增强拉曼谱图。经主成分分析表明不同种类以及不同掺兑量样品的散点分布在不同区域,直接区分度高;同一种类不同生产批次的香精香料谱图类似,在散点图中较为集中;说明不同生产批次的样品以及不同掺兑量的样品都可以与其他种类的香精香料标准样品进行有效区分。本文利用表面增强拉曼光谱结合主成分分析算法对烟用香精香料进行检测的方法操作简易,检测快捷,成本低廉,结果便于分析识别,适用于烟用香精香料实际生产中的质量控制。国家自然科学基金(No.21522508)浙江中烟工业有限责任公司科技项目(No.ZJZY2016C002

    改良的 Trizol 法提取小鼠皮肤 RNA 技术

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    【目的】由于皮肤组织韧性强且存在大量RNA酶,采用经典Trizol法提取的RNA存在易降解质量低等不足。因此,本研究旨在通过改良的Trizol法实现高质量的皮肤RNA提取。【方法】采用不同处理方式(Tri:Trizol包埋;Pro:RNA样本保护液包埋;Cry:先冷冻液氮再冷冻-80℃冰箱;LNG:液氮研磨;Cut:采用剪刀剪碎组织)提取的小鼠正常皮肤RNA为实验组;脊髓组织作为参照组,并以咪喹莫特(IMQ)诱导的小鼠银屑病模型皮肤组织作为保真性验证组。我们采用紫外分光光度法、琼脂凝胶电泳法、定量逆转录PCR法(qRT-PCR)等方法来检测经典Trizol法(1-Tri,Nor)和改良Trizol法(2-Tri,LNG-Tri,Tri-Cut,Pro)提取的RNA浓度、纯度和完整性以及IL-1β mRNA表达的差异性情况。【结果】①与脊髓组织相比,经典Trizol法(1-Tri)获得的正常皮肤组织总RNA量要低,DNA污染和5SRNA条带明显,IL-1β mRNA相对表达偏高,说明经典Trizol法在皮肤组织中提取RNA存在局限性,需要进行改良。②在不同小鼠皮肤样本处理组中,改良的2-Tri法和LNG-Tri法获得的RNA浓度更高,同时RNA降解、DNA污染更低,IL-1β mRNA表达更接近正常水平。更重要的是,在小鼠银屑病模型中,2-Tri法提取的RNA样本能真实反映出正常皮肤与银屑病变皮肤之间IL-1β mRNA的变化趋势。【结论】改良的2-Tri或LNG-Tri法分离的总RNA质量好,能可靠地反映生理或病理条件下的mRNA表达模式

    hrHPV DNA载量 分型和E6蛋白对宫颈癌前病变进展的预测作用

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    目的:探讨预测高危型人乳头瘤病毒(high risk human papillomavirus,hrHPV)阳性和宫颈上皮内瘤样病变1级(cervical in-traepithelial neoplasia grade 1,CIN1)妇女进展的生物学标志物。方法:2010年10月至2012年8月在山西省、河南省和江西省招募7 543名妇女,采用hrHPV DNA检测和E6蛋白检测(Onco E6)等方法进行宫颈癌筛查,任一结果阳性者转诊阴道镜并取活检,于1年后随访。纳入基线hrHPV阳性或病理诊断CIN1者。结果:共纳入794例满足条件妇女,1年后88例妇女病理级别发生进展。基线hrHPV DNA中高载量者进展的风险是低载量者的2.9倍(95%CI为1.8~4.8),hrHPV16/18/45、E6蛋白阳性者进展的风险分别是阴性者的2.4倍(95%CI为1.5~3.9)、2.9倍(95%CI为1.5~5.9),其进展至宫颈上皮内瘤样病变2级及以上(cervical intraepi-thelial neoplasia grade 2 or worse,CIN2+)的绝对风险分别为4.9%(95%CI为3.2~7.4)、9.0%(95%CI为5.5~14.3)、18.8%(95%CI为10.2~31.9)。hrHPV16/18/45中高载量且E6蛋白(Onco E6)阳性妇女进展的绝对风险高达32.4%(11/34)。结论:hrHPV DNA中高载量、hrHPV16/18/45分型以及E6蛋白(Onco E6)可作为妇女hrHPV阳性和CIN1进展的生物学标志物,特别是hrHPV中高载量且E6蛋白(Onco E6)阳性妇女,临床应给予密切随访。中国医学科学院医学与健康科技创新工程重大协同创新项目(编号:2016-I2M-1-019)资助~

    STUDY ON THE CONSTRUCTION AND IMMUNOLOGY CHARACTERISITCS of SIX-VA-LENT FUSION TOXIN of FOOD POISONING-BORNE BACTERIA

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    [目的]构建4种食源性致病菌融合毒素基因及重组表达载体,制备六联融合毒素的血清抗体。[方法]采用柔性lInkEr序列(g-g-g-g-S)对目的基因进行串联(HblA-VT1b-SEA-VT2b-bOnTAHC-SEb),构建重组表达质粒PET-22b(+)-f6并在E.COlI bl21中进行表达,将表达蛋白纯化后免疫豚鼠制备血清抗体,利用ElISA和琼脂扩散试验验证抗体的特异性与敏感性。[结果]成功构建了重组表达质粒PET-22b(+)-f6并在E.COlI bl21中成功表达,37℃表达蛋白主要以包涵体形式存在(表达量10.2%),基因序列全长3384bP,编码1127个氨基酸,蛋白分子量为127205,测序结果与设计序列一致性为100%。ElISA和琼脂扩散试验表明,融合毒素f6与4种食源性致病菌有良好的反应原性,与多种非目标菌不反应。[结论]成功构建了多联融合毒素基因的表达质粒及制备了抗血清,为利用融合毒素的方法检测食源性致病菌,进而建立食源性致病菌广谱、快速的检测方法奠定基础。[Objective] To construct toxin including fusion toxin gene from food poisoning bacteria and its recombinant expression vector,and then prepare serum antibody of Six-valent fusion toxin.[Methods] Six gene(HblA—VT1B—SEA— VT2B—BoNTaHc—SEB)fragments were connected by SOE-PCR via linker sequence encoding five amino acids(G-G-G-G-S),the recombination expression plasmid pET-22b(+)-F6 was constructed and expressed in E.coli BL21.The expression proteinum was purified,and the blood serum was prepared by the immune cobaya,The specificity and sensitivity of antibody were verified by the ELISA and agar diffusion reaction.[Results] The fusion gene F6(HblA—VT1B—SEA—VT2B—BoNTaHc—SEB)and re-combinant plasmid pET-22b(+)-F6 was successfully constructed.The most of the 37℃ expression proteinum showed to be cyt-orrhyctes(expreesion amounted to 10.2%).The sequence encoding the mature fusion protein of the F6 toxin gene was 3384bp,encoding 1127 amino acids.The molecular weight of recombinant fusion toxin protein was 127.205 ku.The result of sequencing was consistent with predicted gene sequences.The results of ELISA and agar diffusion reaction demonstrated that fusion gene F6 and other four kinds of food poisoning-born bacteria had favorable reactionogenicity and did not response to many other non-tar-get bacteria.[Conclusion] The expression plasmid of multi-valent fusion toxin was successful constructed and antiserum was prepared,which laid the foundation for establishing broad spectrum and rapid detection method for food poisoning bacteria by utilization of fusion toxin detection methods.国家自然基金资助项目(30671762);厦门市科技计划项目(3502Z20055009

    The development of CH_4 detection technique

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    甲烷的安全防爆是矿山开采中的一个重要问题,甲烷浓度实时准确的检测是问题的关键。本文重点阐述两类基于不同原理的甲烷检测技术:光纤吸收法、光干涉法。并对光纤吸收法中的差分检测技术、谐波检测技术进行比较,对各种方法检测甲烷的检测精度进行分析。CH4 is a kind of danger gas,how to detect it accurately and instantly is a very important project.This paper focuses on two different theoretical types of methane detection techniques which are fibre-optic absorption and light interference.It also illustrates the comparison between difference detection technique and frequency harmonic detection technique relate to fibre-optic absorption.At the same time,the detection precision of measures discussed in this paper are analysed

    水稻簇矮病——一种新的水稻病毒病

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    锯齿叶矮缩病在我国水稻上的发现

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    锯齿叶矮缩病在我国水稻上的发现

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