146 research outputs found

    Developing fast laboratory screening platform for sulfate dioxide in food by surface-enhanced Raman spectroscopy

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    基于表面增强拉曼光谱(SERS)的指纹图谱的高能量分辨率,以位于~630; cm~(-1)亚硫酸根的特征峰为定性和定量依据,本文开展了食品中滥用和非法添加二氧化硫的直接检测研究:一种检测流程实现了不同食品基质中二氧化硫的; 高灵敏检测,最低检出浓度达1 mg; kg~(-1)的水平.针对实际样本的传统蒸馏法前处理流程的一些不足以及SERS检测的指纹图谱优势,本文进行了三方面显著改进:; (1)碳酸钙和沸石取代氮气以提高二氧化硫的挥发提取效率; (2)草酸取代盐酸酸化蒸馏溶液,以有效避免挥发性强酸对操作环境的危害;; (3)氢氧化钠溶液代替乙酸铅溶液作为吸收液,以防止二次污染.环境友好、灵敏度高和不受基质干扰等特点使得本方法有望取代经典蒸馏法和比色法,用于食品; 中非法添加二氧化硫类添加剂的快速高效筛查.The direct detection of sulphur dioxide has been realized in various; food matrixes with high sensitivity and high selectivity, on the basis; of the integration of the high energy resolution of the finger-print; spectrum of surface-enhanced Raman spectroscopy and the universal but; easy-on-going pretreatment procedure. The characteristic peak of sulphur; dioxide at ~630 cm~(-1) was applied as the qualitative and quantitative; standard, which displayed a lowest detectable concentration at the 1 mg; kg~(-1) level for the spiked food samples. The key point of the high; sensitivity and selectivity is the effective pretreatment born out of; the standard distillation one, which has been improved in the three; parts. (1) Using CaCO_3 and Zeolite instead of N_2 gas as the bubbling; reagent. (2) Using oxalic acid as the acidic distillation solution to; eliminate the hazards from acid volatilization, such as hydrochloric; acid. (3) Using diluted sodium hydroxide solution as the absorption; reagent instead of lead acetate solution to avoid the secondary; pollution. With the three distinguished advantages of environment; friendly, high sensitivity and free of matrix interference, the proposed; method has great potential to replace the traditional ones for the fast; screening of the illegal or abused sulphur dioxide in food.国家自然科学基金; 福建省高校产学合作项目; 中央高校基本科研业务费专项资

    类泛素蛋白及其中文命名

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    泛素家族包括泛素及类泛素蛋白,约20种成员蛋白.近年来,泛素家族领域取得了迅猛发展,并已与生物学及医学研究的各个领域相互交叉.泛素家族介导的蛋白质降解和细胞自噬机制的发现分别于2004和2016年获得诺贝尔奖.但是,类泛素蛋白并没有统一规范的中文译名. 2018年4月9日在苏州召开的《泛素家族介导的蛋白质降解和细胞自噬》专著的编委会上,部分作者讨论了类泛素蛋白的中文命名问题,并在随后的\"泛素家族、自噬与疾病\"(Ubiquitinfamily,autophagy anddiseases)苏州会议上提出了类泛素蛋白中文翻译草案,此草案在参加该会议的国内学者及海外华人学者间取得了高度共识.冷泉港亚洲\"泛素家族、自噬与疾病\"苏州会议是由美国冷泉港实验室主办、两年一度、面向全球的英文会议.该会议在海内外华人学者中具有广泛影响,因此,参会华人学者的意见具有一定的代表性.本文介绍了10个类别的类泛素蛋白的中文命名,系统总结了它们的结构特点,并比较了参与各种类泛素化修饰的酶和它们的生物学功能.文章由45名从事该领域研究的专家合作撰写,其中包括中国工程院院士1名,相关学者4名,长江学者3名,国家杰出青年科学基金获得者18名和美国知名高校华人教授4名.他们绝大多数是参加编写即将由科学出版社出版的专著《泛素家族介导的蛋白质降解和细胞自噬》的专家

    人工调控基因表达

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    The Optimization of Method for Determination of β-carotene from Spirulina Powder

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    采用可见分光光度法测定螺旋藻藻粉中β-胡萝卜素含量,并对测定过程中有关β-胡萝卜素的提取工艺进行了优化,确定了最佳工艺参数为:提取剂为V(正庚烷):V(丙酮):V(无水乙醇):V(甲苯)=10:7:6:7,提取剂体积为30 mL,浸提时间为12 h,浸提温度为35℃.在该工艺下测得螺旋藻藻粉的β-胡萝卜素含量为134.15 mg/100 g

    盐渍化棉田全程栽培管理方法

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    本发明涉及一种盐渍化棉田全程栽培管理方法,该方法为高密度栽培即高密度种植(理论株数1.6-2.4万株/亩);五早管理技术即采用早熟品种(生育期115~125天)适时早播、早中耕多中耕、早放苗定苗,早防蓟马;三促技术即前期促苗早发稳长、中期促蕾保铃、后期促早熟吐絮;三防技术即苗期防立枯病、蕾期防蚜虫、花铃期防棉铃虫;化控技术即根据棉花品种、苗情和农艺措施轻重不一多次化控;施肥技术即有机-无机结合提高土壤肥力,减轻盐分为害;通过实践证明:采用该方法能提高盐渍化低产棉田棉花产量高,克服棉花前期生长缓慢,易发生苗期病害,棉株发育的相对矮小,后期往往贪青晚熟甚至棉桃不能正常开裂吐絮等问题

    荆州碘泡虫粘体动物门碘泡虫科重描述及其基于18srdna系统发育关系分析

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    本实验利用现行主流分类衍征,重新对荆州碘泡虫(Myxobolus kinchowensis)进行了详细描述,其分类特征如下:包囊圆形,寄生于鲫肌肉与肾脏,肌肉包囊大小(126.7±1.8)μm,肾脏包囊直径为94.2μm;两寄生部位各形态参数无显著差异,成熟孢子正面观呈梨形,缝面观呈纺锤形,含一大一小两梨形极囊;无明显囊间突起,孢子后端无褶皱,无粘液膜。组织病理显示在两寄生部位均未引起严重的炎性反应,且感染强度不高,推测该种对宿主无显著影响。基于18S r DNA进化分析发现荆州碘泡虫与寄生在肌肉部位的碘泡虫属种类聚为一个大枝,然后该大枝又根据地理位置远近分为北美枝、欧洲枝以及亚洲枝。通过形态比较研究以及分子分析可确定荆州碘泡虫为有效种,其寄主为鲫,寄生部位为肌纤维间和肾小囊。此外,两组织差异明显的寄生部位出现说明荆州碘泡虫相应的放射孢子虫在宿主鲫体内存在不同的发育与移行途径,而肌肉可能为其常规寄生部位,肾脏为其异常寄生部位,这种寄生部位的转移与宿主转变可能是粘孢子虫物种多样性形成的机制

    Bioactivity of Reducing Blood Sugar and Elements Speciation Analysis of the Extract from Cyclocarya paliurus (Batal.) Iljinsk Leaves

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    为了从青钱柳(CP)中提取降血糖功能活性物质,并获得其中多种降血糖相关性微量元素的化学形态信息.本研究通过四氧嘧啶糖尿病小鼠模型进行青钱柳提取物生物活性验证,用流动注射 电感耦合等离子体质谱法(FIA ICP MS)对功能提取物中的相关元素进行表征.结果表明:青钱柳提取物具有显著的降血糖活性,提取物在IR光谱中显示典型的多糖吸收特征,得率为9.6%.连续四周腹腔注射青钱柳提取物后,小鼠血糖值比糖尿病模型组降低了41.3%.多糖复合物中降血糖相关性元素以可溶态为主.在可溶态元素中,镁主要以无机形态存在,而锰、铜和锌主要以有机形态分布.A hyperglycemia animal model was successfully established by treating normal Kunming mice with alloxan(iv).These mice were orally administrated by the extract from Cyclocarya paliurus (Batal.) Iljinsk(CP). It was demonstrated that the extract is complex polysaccharide, which is able to significantly reduce the fasting serum glucose in alloxan diabetic mice. The extract is brown with the yield of 9.6%. The elements in the functional extract were fractionated into four fractions: the soluble, particulate, organic and inorganic using 0.45 μm membrane filter and C18 bonded silica gel column (Waters), respectively. Various metal species in each fraction were measured by online FIAICPMS system. Most elements in CP extract existed as soluble species. The CP extract is visioned as a kind of complex solution, in which various elemental species stay in equilibration, which is mainly including inorganicmagnesium, organicmanganese, organiccopper, inorganicnickle, and organozinc.福建省青年科技人才创新项目(2001J063);; 江西省自然科学基金(0120018)资助项

    黄河尾闾及近岸沉积物中重金属的含量分布及生态风险评价

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    为了解黄河尾闾及近岸沉积物中重金属的污染特征,采用电感耦合等离子体质谱仪(ICP-MS)测定了黄河河道和河口48个样品中Cr、Cu、Zn、Cd、Pb和As等6种重金属的含量,并对其分布和生态风险进行了评价。结果表明,黄河尾闾及近岸重金属的总含量沿河道至河口方向呈现先增加后降低再增加的趋势,至近岸B断面,As、Pb、Cd和Zn含量呈明显增加趋势,Cu和Cr含量增加幅度较小;黄河河口沉积物中重金属浓度明显高于河道沉积物中重金属的浓度。与我国其他流域相比,研究区域重金属含量处于较低水平。潜在生态风险评价结果表明,黄河尾闾及近岸沉积物6种重金属潜在生态风险系数从高到低依次为:Cd>As>Pb>Zn>C..
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