酶底物法测定水中耐热大肠菌群的方法验证

目的验证酶底物法可用于生活饮用水、地表水、地下水中耐热大肠菌群的测定。方法通过6家实验单位对生活饮用水、地表水、地下水各30组水样分别用酶底物法和多管发酵法来做比对。结论酶底物法与多管发酵法检测数据存在相关性,且相关程度很高,具有一致性和稳定性。结果酶底物法可应用于生活饮用水、地表水、地下水中耐热大肠菌群的测定。     

酶底物法检测粪大肠菌群

文章对检测水中粪大肠菌群的方法进行了探讨。通过采集50种地表水和污水厂水样,分别用酶底物法和多管发酵法进行比较,从检测结果发现,两种方法的数据无明显差异,相关性好。相比之下,酶底物法更加高效、简便、快速、准确、二次污染少,是取代传统方法的发展趋势。     

酶底物法在总大肠菌群、粪大肠菌群和大肠埃希氏菌检测的适用性研究

为探讨酶底物法在三峡库区水质检测中的适用性,用酶底物法对库区地表水、污水厂出水中的总大肠菌群、粪大肠菌群和大肠埃希氏菌进行检测,测定结果 RSD<4%,测定标准菌株结果符合要求,用酶底物法和多管发酵法对不同样品进行比对,结果无统计学意义上的显著性差异(P>0.05),满足水质监测技术要求。     

酶底物光谱法与酶底物法检测水中大肠菌群的比较分析

采用新型酶底物光谱法和酶底物法对不同类型水样中总大肠菌群、大肠埃希氏菌及粪大肠菌群指标进行同步检测。两种方法各有优势,采用SPSS软件对检测结果处理后进行配对t检验,结果显示：两组总大肠菌群的数据P=0.057,相关系数r=0.904;两组大肠埃希氏菌的数据P=0.593,相关系数r=0.972;两组粪大肠菌群的数据P=0.136,相关系数r=0.986,表明两种检测方法具有相关性,且没有统计学意义上的显著性差异。采用酶底物光谱法检测有证质控样品,总大肠菌群、大肠埃希氏菌、粪大肠菌群的检测结果均在质控样真值范围内,证明该方法检测准确度符合要求。酶底物光谱法与酶底物法相比,反应原理类似,操作更加简便,具有仪器自动化和智能化快速检测、判读、存储、联网传输数据等优点,可满足实验室常规检测需求,在应急突发事件现场检测方面有较强的运用前景和优势。     

固定酶底物法与多管发酵法测定地表水耐热大肠菌群的综合效果比较

通过比较固定酶底物法与多管发酵法的检测效果,为监测站耐热大肠菌群的检测方法选择提供技术支持。2018年11月～2019年3月,选取广州市主要饮用水水源地和水源调查点采集的地表水为样本,用固定酶底物法与多管发酵法两种方法分别对51份水样中耐热大肠菌群进行比对试验检测。结果表明:固定酶底物法与多管发酵法相比,在检测一致性方面无统计学上的显著性差异,但固定酶底物法具有检测时间短、效率高、人力成本较低、结果更加精确、安全性较好等优势,既可作为地表水常规检测方法,又可用作应急、灾害时监测的快速筛查方法。     

环境水体中粪大肠菌群检测方法研究进展

粪大肠菌群作为水体粪便污染的指示菌,对地表水的水质监测评价具有重要作用。采取较为精确、快速的粪大肠菌群检测方法,对控制流行疾病的发生和传播有重要的科学意义。文章对检测粪大肠菌群发酵法、滤膜法、酶底物法、纸片法、聚合酶链式反应技术、荧光原位杂交技术等检测方法进行了综述。     

Research Progress on Detection Methods of Fecal Coliform

粪大肠菌群是水体粪便污染的指示菌。详细介绍了多管发酵法、滤膜法、纸片法、酶底物法及分子生物学方法检测粪大肠菌群的优缺点及主要应用实例。     

粪大肠菌群检测方法研究进展

粪大肠菌群是水体粪便污染的指示菌。详细介绍了多管发酵法、滤膜法、纸片法、酶底物法及分子生物学方法检测粪大肠菌群的优缺点及主要应用实例。     

酶底物法测定东莞市地下水、地表水、生活污水中粪大肠菌群、总大肠菌群的研究

酶底物法测定东莞市地下水、地表水、生活污水中粪大肠菌群、总大肠菌群,通过方法验证,酶底物法灵敏度高,操作简单,测定速率快,结果令人满意;东莞市地下水、地表水、生活污水中的粪大肠菌群、总大肠菌群测定结果表明:东莞市地下水、地表水和生活污水的水质较为理想。     

两种检测水中耐热大肠菌群方法的等效性比较

用多管发酵法和酶底物法检测水源水样本中耐热大肠菌群,比较了两者检测结果的等效性.结果表明,多管发酵法与酶底物法检测水中耐热大肠菌群的结果是等效的.酶底物法可以用作评价水中粪源性微生物污染的可替代方法.     

Stretchable Gold Tracks on Flat Polydimethylsiloxane (PDMS) Rubber Substrate

A process to fabricate stretchable gold tracks on silicone rubber substrates is studied by XPS, static water contact angle measurement, AFM, and SEM. The process involves several steps: removing uncured oligomers by hexane Soxhlet extraction; pre-stretching the substrate; activating the strained silicone surface by an oxygen plasma treatment; coating the strained substrate with 5 nm titanium and 80 nm gold layers; and finally releasing the sample. The plasma treatment creates a thin brittle silica-like layer that temporarily increases the substrate's surface energy. Indeed, the plasma treatment is followed by a hydrophobic recovery. As a consequence, the delay between plasma treatment and metal deposition has to be reduced as much as possible. The silica-like layer can be nicely observed after release. The entire process allows us to obtain stretchable metallized samples that remain conductive even after an excessive deformation leading to electrical failure.     

Stretchable Gold Tracks on Flat Polydimethylsiloxane (PDMS) Rubber Substrate

A process to fabricate stretchable gold tracks on silicone rubber substrates is studied by XPS, static water contact angle measurement, AFM, and SEM. The process involves several steps: removing uncured oligomers by hexane Soxhlet extraction; pre-stretching the substrate; activating the strained silicone surface by an oxygen plasma treatment; coating the strained substrate with 5 nm titanium and 80 nm gold layers; and finally releasing the sample. The plasma treatment creates a thin brittle silica-like layer that temporarily increases the substrate's surface energy. Indeed, the plasma treatment is followed by a hydrophobic recovery. As a consequence, the delay between plasma treatment and metal deposition has to be reduced as much as possible. The silica-like layer can be nicely observed after release. The entire process allows us to obtain stretchable metallized samples that remain conductive even after an excessive deformation leading to electrical failure.     

Pathways and Substrate Specificity of DMSP Catabolism in Marine Bacteria of the Roseobacter Clade

The volatiles released by Phaeobacter gallaeciensis, Oceanibulbus indolifex and Dinoroseobacter shibae have been investigated by GC‐MS, and several MeSH‐derived sulfur volatiles have been identified. An important sulfur source in the oceans is the algal metabolite dimethylsulfoniopropionate (DMSP). Labelled [²H₆]DMSP was fed to the bacteria to investigate the production of volatiles from this compound through the lysis pathway to [²H₆]dimethylsulfide or the demethylation pathway to [²H₃]‐3‐(methylmercapto)propionic acid and lysis to [²H₃]MeSH. [²H₆]DMSP was efficiently converted to [²H₃]MeSH by all three species. Several DMSP derivatives were synthesised and used in feeding experiments. Strong dealkylation activity was observed for the methylated ethyl methyl sulfoniopropionate and dimethylseleniopropionate, as indicated by the formation of EtSH‐ and MeSeH‐derived volatiles, whereas no volatiles were formed from dimethyltelluriopropionate. In contrast, the dealkylation activity for diethylsulfoniopropionate was strongly reduced, resulting in only small amounts of EtSH‐derived volatiles accompanied by diethyl sulfide in P. gallaeciensis and O. indolifex, while D. shibae produced the related oxidation product diethyl sulfone. The formation of diethyl sulfide and diethyl sulfone requires the lysis pathway, which is not active for [²H₆]DMSP. These observations can be explained by a shifted distribution between the two competing pathways due to a blocked dealkylation of ethylated substrates.     

Substrate Activity Screening (SAS) and Related Approaches in Medicinal Chemistry

Substrate activity screening (SAS) was presented a decade ago by Ellman and co‐workers as a straightforward methodology for the identification of fragment‐sized building blocks for enzyme inhibitors. Ever since, SAS and variations derived from it have been successfully applied to the discovery of inhibitors of various families of enzymatically active drug targets. This review covers key achievements and challenges of SAS and related methodologies, including the modified substrate activity screening (MSAS) approach. Special attention is given to the kinetic and thermodynamic aspects of these methodologies, as a thorough understanding thereof is crucial for successfully transforming the identified fragment‐sized hits into potent inhibitors.     

彩虹电子玻璃基板发展历程

玻璃基板是显示产业的关键性基础材料,长期受到国外技术封锁,属于平板显示产业链的"卡脖子"环节.我国电子玻璃产业发展起步较晚,彩虹人历经16年多艰苦卓绝、勠力同心,创造国内多个第一,目前,彩虹股份建成的两条国产G8.5溢流法玻璃基板生产线运行质量、效率均达到国际同行先进水平."十四五"期间,彩虹股份积极统筹布局产业规划,加速提高G8.5玻璃基板国产化率.     

细菌胞外多糖的研究和应用

综述了已经工业化生产的黄原胶、结冷胶和热凝多糖的历史与现状，重点介绍了三种多糖的应用情况，以及乳酸菌胞外多糖的应用和研究现状，进一步展望了未来细菌胞外多糖的发展趋势和应用前景。     

Biosorption Equilibrium and Kinetics of Au（Ⅲ） and Cu（Ⅱ） on Magnetotactic Bacteria

Magnetotactic bacteria （MTB） as biosorbents for the adsorption of Au（Ⅲ） and Cu（Ⅱ） ions from aqueous solution have been investigated. The optimum adsorption conditions for both metal ions were the initial pH scope of 1-5.5 for Au（Ⅲ） and 2.0-4.5 for Cu（Ⅱ）, room temperature, biomass concentration of 10.0g.L^-1 and sorotion du-ration more than 10 min. When the initial metal concentration were within 500mg.L^-1, the maximum biosorption capacity of 1.0g of MTB （dry mass basis） for Au（Ⅲ） and Cu（Ⅱ） were calculated as 505.2mg of Au（Ⅲ） and 493.1mg of.Cu（Ⅱ） by Langmuir model in single system, respectively. The isotherm equilibrium of Au（Ⅲ） and Cu（Ⅱ） ions in the Au-Cu binary system reflected a unique phenomenon that the adsorption of Au（Ⅲ） was rein-forced and that of Cu（Ⅱ） prohibited, compared respectively-with their performances in the single metal system.When the,concentration of-Au（Ⅲ） and Cu（Ⅱ）. were below 80mg.L^-1, the waste waterafter MTB treating, wasbelow 1.0mg.L^-1, which is in conformity with Environmental Performance Standards （EPS） of Canada. Besides, all the kinetic data were fitted well to the pseudo second-order kinetic model with a high correlation coefficient （R^2〉0.999）.     

Si(111)衬底上生长的ZnO薄膜的光学特性研究

利用等离子体分子束外延(P-MBE)设备在Si(111)衬底上制备了高质量的ZnO薄膜.通过扫描电镜观察了ZnO薄膜的表面形貌为的六角结构.X射线衍射谱显示ZnO薄膜为C轴择优取向的,ZnO(002)取向X射线衍射峰的最大半宽度仅0.18°.并通过室温和变温发光谱对ZnO薄膜的发光特性进行了研究.在低温下ZnO的发光以...     

Preparation of Superconducting Bi(Pb)-Sr-Ca-Cu-O Thick Films on Magnesia Substrate

Superconducting Bi(Pb)-Sr-Ca-Cu-O powders were prepared by the emulsion-drying method The powders consisting of the low- T _c phase (Bi(Pb)₂Sr₂Ca₁Cu₂O_y) and small amount of Ca₂PbO₄ were prepared by calcining under low oxygen partial pressure at 750°, 800°C. These calcined powders were used to prepare thick films on single-crystal MgO(100) substrates using a screen-printing technique to study the effect of the calcinations temperature and annealing procedure on the high-T_c phase (Bi(Pb)₂Sr₂Ca₂Cu₃O_y)formation. The formation of high-T_c phase was observed to be dependent on the calcinations conditions. The high- T_c phase formed very quickly (sintering at 840°C for 4 h), and the best films showed a sharp superconducting transition at about 105 K.