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排序方式: 共有1223条查询结果,搜索用时 31 毫秒
91.
Deny Hartono Xinyan Bi Kun‐Lin Yang Lin‐Yue Lanry Yung 《Advanced functional materials》2008,18(19):2938-2945
A new air‐supported liquid crystal (LC) system for analyzing interfacial phenomena that occur based on the molecular interaction between LCs and adsorbed molecules of interest at the aqueous/LC interface is reported. Compared with existing LC‐based detection systems, the miniature system reported here requires less sample and involves simpler preparation. Using this system, the enzymatic hydrolysis of various phospholipases such as phospholipase A2 (PLA2), phospholipase C (PLC) and phospholipase D (PLD) are characterized. The hydrolysis of phospholipid monolayers self‐assembled at aqueous/LC interface induces an orientational response from the LCs. As a result, an optical signal that reflects the spatial and temporal distribution of phospholipids during the enzymatic reaction can be generated in a real‐time manner. When well‐known phospholipase inhibitors are introduced together with respective phospholipases, no orientational response of LCs is observed. In the case of inhibitors MJ33 and compound 48/80, cross‐inhibitions among phospholipases are also observed. This work demonstrates that the air‐supported LC system provides a facile label‐free assay for characterizing phospholipase activities and for screening enzyme inhibitors. It could potentially be useful for different high throughput and cost‐effective enzyme screening assays. 相似文献
92.
Zakir Hossain Kenji Fukunaga Masatoshi Tanouchi Koretaro Takahashi 《European Journal of Lipid Science and Technology》2009,111(9):877-883
An animal experiment was conducted to assess the antitumor effects of chitosan‐coated liposomes on myeloma SP2. The animal experimental groups designed for myeloma SP2 tumor‐bearing BALB/c mice were provided with five different drinks: (I) control (double‐distilled water); (II) squid phospholipid liposomes alone 1.0 mg/mL; (III) chitosan alone 5.0 mg/mL; (IV) squid phospholipid liposomes 1.0 mg/mL with chitosan 5.0 mg/mL in the form of a simple mixture; and (V) squid phospholipid liposomes 1.0 mg/mL coated with chitosan 5.0 mg/mL. At 20 days after implantation of the myeloma SP2 cells into mice, oral administration of the experimental drinks was provided for 35 days. There was significant suppression of tumor growth when chitosan and squid phospholipids were administered simultaneously in a simple mixture or as chitosan‐coated liposomes. Matrix metalloproteinase (MMP)‐2 and MMP‐9 activity was significantly less in the serum of mice that consumed chitosan‐coated liposomes than in control mice. We found that decreased tumor burden was related to MMP secretion. Therefore, chitosan‐coated marine phospholipid liposomes might be useful as potential agents for the treatment of myeloma SP2. 相似文献
93.
Fractionation of soybean phospholipids by high-performance liquid chromatography with an evaporative light-scattering detector 总被引:4,自引:0,他引:4
Tong Wang Earl G. Hammond James L. Cornette Walter R. Fehr 《Journal of the American Oil Chemists' Society》1999,76(11):1313-1321
Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) from 23 soybean lines with a wide range of fatty acid compositions
were resolved into seven fractions by high-performance liquid chromatography (HPLC). Fraction identities were assigned from
fatty acid compositions determined by gas chromatography (GC). A mass detector, i.e., an evaporative light-scattering detector,
was used for HPLC quantification. The detector response was a power function of PC and PE concentrations. Various correction
methods were applied to the detector response to obtain the best agreement between phospholipid (PL) fatty acid compositions
determined by GC and that calculated from the corrected HPLC fraction percentages. The corrected HPLC fraction composition
also was compared with that calculated from stereospecific distribution data using a 1-random-2-random hypothesis. Correlation
between PL-fatty acid and HPLC-fraction percentages showed that genetic modification of soybean oil composition caused changes
in PL species, which alter physical properties and may alter the physiological functions of PL in biomembranes. 相似文献
94.
Michał Krempski-Smejda Jan Stawczyk Krzysztof Śmigielski Renata Prusinowska 《Drying Technology》2015,33(13):1671-1677
A new product from a low temperature drying method that reduces the loss of highly volatile essential oils is presented. The proposed drying method consists of evaporation/sublimation of water and aromatic substances in a dryer with a closed drying agent cycle. In parallel, the evaporated compounds are continuously condensed in a heat exchanger. As a result of the drying process, high-quality dried plants and Fluidolat as liquid phase containing water and volatile organic compounds are obtained. The aim of presented investigations was to optimize the developed technology for the herb lavender. 相似文献
95.
两条不等宽的道路相对接时,如果中线是缓和曲线,特别是在内边线加宽的情况下,边线平滑连接涉及复杂的曲线解算。本文就此问题阐述解决的思路和方法。 相似文献
96.
The aim of this research was to exploit the chemical properties of natural products to control the incidence and extent of mould growth in houses. The screening of antimould activities of seven essential oil extracts showed that most of the extracts completely inhibited the growth of all three test mould at the concentration of 1% w/v on nutrient medium, whereas, different fractions of manuka oil showed varied activity. Subsequently, using both mycological and scanning electron microscopy, the testing of selected extracts on two different types of gypsum board finished with either paint or wall-paper, confirmed the antimould activity of eugenol, thymol and cinnamaldehyde against Penicillium corylophilum. This study identified certain essential oil extract as a potential mould inhibitor for panel products which is one of the most common mould habitats in the building environment. Mould growth in residential houses is a major concern and chemical fungicides commonly used to control the growth of mould are not often appropriate for indoor applications. Natural alternatives such as essential oils are desirable for this application. Knowledge gained through this research should lead to new niche panel product development to create healthier housing. 相似文献
97.
98.
超临界CO_2萃取香料精油的研究 总被引:16,自引:0,他引:16
本文对熏衣草、百里香、野百里香和迷迭香4种香料单独或两种香料混合超临界CO2萃取和分级分离香料精油的工艺可行性,以及采用GC,GC-MC对萃取物的主要成分分析进行了初步研究。从两种香料混合物中革取所获产率等于从每种香料所获产率之平均值,混合萃取明显提高精油和树脂两种产品的分离效率,两种香料混合物的萃取物所含的主要成分与两种香料单独萃取的成分相同,但浓度有明显差别。 相似文献
99.
Smoke-dried beef was pre-processed with water or by pressure cooking, weight losses were 50 and 54% respectively, with the rate of drying faster in the latter. There was a greater loss of total lipid and triglycerides in pressure cooked samples but the reverse was true for the phospholipids. The proportions of saturated and monoenoic fatty acids were slightly higher in the water cooked products although total unsaturation was slightly lower, the values being 37 and 39%, respectively. The fatty acid composition of the phospholipids was similar for both treatments except that the levels of polyenoic fatty acids were 16.4 and 14.43%, respectively in water and pressure cooked samples. Of the polyenes C20:4 accounted for about 75% of the fatty acids in the water cooked samples, compared with 40% with pressure cooking. After 60 weeks of storage at room temperature, pressure cooked samples were found to be more stable oxidatively: malonaldehyde was the principal oxidative by-product in both treatments. 相似文献
100.
Pamidighantam Prabhakara Rao Allani Nagender Lingamallu Jaganmohan Rao Dubasi Govardhana Rao 《European Food Research and Technology》2007,224(6):791-795
Garlic cloves in the form of bits were dried in a cabinet tray dryer and a microwave dryer, and pulverized to obtain free
flowing powder. The volatile oil was obtained by hydro-steam distillation method. Fresh cloves and the powders resulting from
the two drying methods were used for obtaining the volatile oil, which was analyzed by GC-MS. The studies were mainly restricted
to comparing the effect of drying methods on the volatile oil composition of the powders. Although the drying time was reduced
considerably from 8 h in a cabinet dryer to 0.25 h in a microwave dryer, essential oil yield and color values were lower,
and flavor quality varied considerably. The relative concentrations of major peaks such as diallyl disulfide, diallyl tetrasulfide
increased in both the drying methods, and it was more so in microwave-dried samples. However, the concentrations of the other
two major peaks, diallyl trisulfide and allyl methyl trisulfide, decreased in both drying methods, and they were lower in
microwave-dried samples. Hunter values of L and b were lower for samples obtained by microwave drying as compared to those of cabinet-dried samples. 相似文献