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891.
本文介绍的联用分析系统是将超临界流体萃取(SFE)系统与超高效液相色谱(UHPLC)系统联用。使用在线SFE-UHPLC系统,可以完成对胡椒粉中胡椒碱成分的高速萃取和分析。整个分析过程包括萃取时间在内只需要7min。将此方法的萃取回收率与其他萃取方法进行比较,SFE方法得到的回收率与其他方法相当。这种在线SFE-UHPLC方法操作简单,分析速度快。这一方法对于分析固体样品中的化合物组分非常有用,可以有效避免繁琐的样品预处理过程。 相似文献
892.
In Japanese larch (Larix kaempferi (Lamb.) Carr.) calli, free sterol (FS), acylsterol (AS) and glycosylsterol, including the acylated type, were found in the proportion of 1.0:0.1:0.8. When the calli were cultured in the presence of 10 mM mevalonic acid (MVA), the content of AS, but not FS and glycosylsterol, was increased remarkably. The major component sterol in each sterol lipid class was usually sitosterol (more than 90%) with campesterol as a minor one. There were no differences on the sterol compositions between the calli cultured with or without MVA. When the calli cultured with 10 mM MVA for 6 weeks were transferred to the control medium without exogenous MVA, AS contents decreased to the level of the control calli. Thus, it was shown that sterol lipids, such as FS and glycosylsterols, with the structural functions was maintained in the constant content and the excess sterol biosynthesized from exogenous MVA was esterified to form AS for storage of sterol components. 相似文献
893.
We fabricated a multilayered medium by a laminating process with pressure-sensitive adhesives. It was possible to reduce the thickness variations of both photosensitive layers and transparent layers by applying laminating films. This method is easy to use to pile up many layers for a multilayered medium. We fabricated twenty recording layers and demonstrated the capability to record with significant reading results. The recorded data in each layer were read out without crosstalk. We evaluated the signal-to-noise ratio and crosstalk between neighboring layers. It was found that the signal-to-noise ratio of a multilayered medium was higher than 50 dB. 相似文献
894.
Tanaka K Yamaguchi N Baba T Amano N Nasu M 《International journal of food microbiology》2011,145(1):365-369
Aseptically prepared cold drinks based on tea have become popular worldwide. Contamination of these drinks with harmful microbes is a potential health problem because such drinks are kept free from preservatives to maximize aroma and flavour. Heat-tolerant conidia and ascospores of fungi can survive pasteurization, and need to be detected as quickly as possible. We were able to rapidly and accurately detect low numbers of conidia and ascospores in tea-based drinks using fluorescent staining followed by an automated counting system. Conidia or ascospores were inoculated into green tea and oolong tea, and samples were immediately filtered through nitrocellulose membranes (pore size: 0.8 μm) to concentrate fungal propagules. These were transferred onto potato dextrose agar and incubated for 23 h at 28 °C. Fungi germinating on the membranes were fluorescently stained for 30 min. The stained mycelia were counted selectively within 90 s using an automated counting system (MGS-10LD; Chuo Electric Works, Osaka, Japan). Very low numbers (1 CFU/100 ml) of conidia or ascospores could be rapidly counted, in contrast to traditional labour intensive techniques. All tested mould strains were detected within 24 h while conventional plate counting required 72 h for colony enumeration. Counts of slow-growing fungi (Cladosporium cladosporioides) obtained by automated counting and by conventional plate counting were close (r2 = 0.986). Our combination of methods enables counting of both fast- and slow-growing fungi, and should be useful for microbiological quality control of tea-based and also other drinks. 相似文献
895.
896.
Artificial Life and Robotics - Cross-view geo-localization is finding images containing the same geographic target in multi-views. For example, given a query image from UAV view, a proposed... 相似文献