聚合酶链式反应技术检测化妆品中的铜绿假单胞菌

利用聚合酶链式反应(PCR)技术建立了一种快速检测化妆品中铜绿假单胞菌的方法。根据已报道的铜绿假单胞菌特异性基因ETA设计引物,确定引物的特异性和灵敏度;对染菌化妆品样品进行增菌检测。琼脂糖凝胶电泳检测PCR产物结果显示,仅在含有铜绿假单胞菌基因组的样品中得到条带;对染菌样品的扩增结果显示,可以在原样品的活菌浓度为6 cfu.mL-1时通过增菌12 h后检出。     

铜绿假单胞菌在水体的生长特性研究及其在不同温度下生长预测模型的建立

目的:为了更好的了解铜绿假单胞菌在水体中的生长特性,并预测铜绿假单胞菌在不同温度水体中的生长情况,从而有效降低环境中潜在的铜绿假单胞菌污染风险。方法:本实验研究了铜绿假单胞菌标准菌株在不同温度下的生长情况,之后使用Richards模型、MMF模型、Gompertz模型和Logistic模型进行数据拟合,构建不同温度下的最佳模型。结果:MMF模型适用于15℃、25℃和35℃下水体环境中的铜绿假单胞菌生长模型的构建。Logistic模型可以用来模拟5℃下铜绿假单胞菌的生长模型。结论:该模型能够较好的描述铜绿假单胞菌在不同温度下的生长规律和变化特征,能够为铜绿假单胞菌在水体环境中的生长提供较为准确地预测数据。     

长江下游某地区饮用水中铜绿假单胞菌的赋存特征

针对长江下游某地区饮用水中铜绿假单胞菌的含量进行排摸,比较2020年1月—2022年12月铜绿假单胞菌的检测平均值,水源地Q取水与输水中铜绿假单胞菌的含量明显高于水源地C。水源地Q取水中铜绿假单胞菌平均含量达420.5MPN/(100 mL),输水中达242.0 MPN/(100 mL);水源地C取水中铜绿假单胞菌平均含量达201.4 MPN/(100 mL),输水中达82.5MPN/(100 mL)。水源地Q相关联水厂N进水铜绿假单胞菌均值含量远高于水源地C相关联水厂T进水的含量,其检测结果分别为232.1、2.1 MPN/(100 mL);水厂N进水铜绿假单胞菌的检出率达58.3%(7/12)、水厂T进水铜绿假单胞菌的检出率达50%(6/12),与水源地输水铜绿假单胞菌含量和检出率相比,显著降低。进水经给水厂处理后,水厂N、水厂T出水铜绿假单胞菌均未检出。与其他季节相比,在气温较高时(每年7月—10月),水源地铜绿假单胞菌含量显著增高,并有逐年最高值递增的趋势,当气温较高时,进水中铜绿假单胞菌含量也存在高值,建议在高温时期对铜绿假单胞菌进行持续监测。     

D-异抗坏血酸苯甲酸酯的合成及其抗氧化和抗菌性能

通过酰氯法由苯甲酰氯和D-异抗坏血酸合成了标题化合物,产物的结构经过FT-IR和1HNMR得以确认。用POV法评价了产物在茶籽油中的抗氧化性能,用MTT法测试了产物对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌和铜绿假单胞菌的抗菌作用。结果表明,标题化合物具有明显的抗氧化效果,对大肠杆菌、枯草芽孢杆菌和铜绿假单胞菌的生长有明显的拟制作用。     

铜绿假单胞菌与秀丽隐杆线虫互作研究进展

铜绿假单胞菌（Pseudomonas aeruginosa）属于革兰氏阴性杆菌,对人和动物具有潜在致病性。秀丽隐杆线虫（Caenorhabditis elegans）是一种以大肠杆菌为食的微小模式生物。铜绿假单胞菌与秀丽隐杆线虫互作模型常用于研究铜绿假单胞菌对宿主损害机制及宿主应对铜绿假单胞菌侵染的策略。本文从铜绿假单胞菌对秀丽隐杆线虫侵染和宿主应对策略这两个角度进行综述,以期为研究铜绿假单胞菌致病机制及筛选治疗其引发疾病的治疗思路提供参考。     

酶底物法检测包装饮用水中铜绿假单胞菌方法比对

滤膜法为现行包装饮用水中铜绿假单胞菌测定的国家标准方法，酶底物法测定包装饮用水中铜绿假单胞菌已通过国内外多个标准认证。采用酶底物法与滤膜法对包装饮用水中铜绿假单胞菌进行检测。通过标准菌株加标试验，酶底物法检测包装饮用水中铜绿假单胞菌的方法精密度相对标准偏差为0.8%～9.0%,定量质控样品测定的所有结果均在真值范围内，且方法的相对误差为0.8%。对两种方法检测结果进行统计学分析发现：两种方法在统计学上无显著性差异。与滤膜法相比，酶底物法具有操作简单、结果准确性高、稳定性好等特点，酶底物法可作为评价包装饮用水中铜绿假单胞菌污染的补充方法。     

荞麦七提取物的体外抑菌活性研究

以铜绿假单胞菌、大肠杆菌、金黄色葡萄球菌及枯草芽孢杆菌为受试菌,通过最小抑菌浓度测定、抑菌圈的判断、生长曲线的绘制及菌液电导率的测定等方法,研究了荞麦七的4种提取物(水提物、蒽醌、鞣质、黄酮)的体外抑菌活性。结果表明:荞麦七水提物对枯草芽孢杆菌及铜绿假单胞菌抑制作用较强;荞麦七蒽醌对金黄色葡萄球菌及铜绿假单胞菌抑制作用较强;荞麦七鞣质对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌抑制作用较强;荞麦七黄酮对大肠杆菌抑制作用最强。     

假单胞菌代谢尼古丁研究进展

假单胞菌和节杆菌是两种最重要的尼古丁降解菌,目前节杆菌降解尼古丁的代谢途径、代谢相关基因和酶学机制都已经研究清楚,但是对假单胞菌降解尼古丁的研究尚不完善。本文将主要针对假单胞菌,从目前分离到的假单胞菌属微生物的菌株种类、代谢途径、代谢相关基因和酶学机制等方面阐述假单胞菌属微生物降解尼古丁的研究进展。     

苯佐卡因缩芳醛席夫碱的合成及其抑菌活性

以苯佐卡因和芳醛为原料合成了3种标题化合物,用IR、1HNMR和元素分析对产物的结构进行了确证。采用滤纸片法测试了3种标题化合物对大肠杆菌、金黄色葡萄球菌及铜绿假单胞菌的抑菌性能。实验结果表明,标题化合物对所试3种细菌均有一定的抑菌活性能。其中,苯佐卡因缩水杨醛席夫碱对铜绿假单胞菌的抑菌效果最好,其抑菌圈直径达16.8 mm。     

荧光光电法检测化妆品中致病菌的研究

建立了一种利用荧光光电技术快速检测化妆品中致病菌的方法。分别对化妆品中的大肠杆菌、铜绿假单胞菌和金黄色葡萄球菌进行检测。结果显示此方法检测大肠杆菌、铜绿假单胞菌和金黄色葡萄球菌的特异性良好,检测菌液和人工污染爽肤水及乳液样品的灵敏度均达到100cfu·mL-1,总检测时间可控制在14 h以内。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。