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The preparation of nonaqueous microemulsions using food-acceptable components is reported. The effect of oil on the formation of microemulsions stabilized by lecithin (Epikuron 200) and containing propylene glycol as immiscible solvent was investigated. When the triglycerides were used as oil, three types of phase behavior were noted, namely, a two-phase cloudy region (occurring at low lecithin concentrations), a liquid crystalline (LC) phase (occurring at high surfactant and low oil concentrations), and a clear monophasic microemulsion region. The extent of this clear one-phase region was found to be dependent upon the molecular volume of the oil being solubilized. Large molecular volume oils, such as soybean and sunflower oils, produced a small microemulsion region, whereas the smallest molecular volume triglyceride, tributyrin, produced a large, clear monophasic region. Use of the ethyl ester, ethyl oleate, as oil produced a clear, monophasic region of a size comparable to that seen with tributyrin. Substitution of some of the propylene glycol with water greatly reduced the extent of the clear one-phase region and increased the extent of the liquid crystalline region. In contrast, ethanol enhanced the clear, monophasic region by decreasing the LC phase. Replacement of some of the lecithin with the micelle-forming nonionic surfactant Tween 80 to produce mixed lecithin/Tween 80 mixtures of weight ratios (Km) 1:2 and 1:3 did not significantly alter the phase behavior, although there was a marginal increase in the area of the two-phase, cloudy region of the phase diagram. The use of the lower phosphatidylcholine content lecithin, Epikuron 170, in place of Epikuron 200 resulted in a reduction in the LC region for all of the systems investigated. In conclusion, these studies show that it is possible to prepare one-phase, clear lecithin-based microemulsions over a wide range of compositions using components that are food-acceptable. 相似文献
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The inhibitory effect of mimosine on polyphenoloxidase (PPO) from the cephalothorax of Pacific white shrimp (Litopenaeus vannamei) was studied. Mimosine showed inhibitory activity toward PPO from white shrimp with an apparent molecular weight of 210 kDa as evidenced by the decrease in the activity staining band, as compared to the control. An inhibition kinetic study revealed that mimosine exhibited the mixed type reversible inhibition on PPO from white shrimp with a Ki value of 3.7 mM. Mimosine showed copper (Cu2+) reduction and chelating capacity in a dose dependent manner. Mimosine could react with the intermediate browning product, thereby rendering lower red-brown color formation. Therefore, mimosine could inhibit PPO by different modes of inhibition and could be used to prevent melanosis formation in Pacific white shrimp. 相似文献
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绿茶被认为具有多种生理功效,但临床实验和流行病学研究仍存有争议。绿茶儿茶素类生物标记物检测方法的建立是为了从代谢物水平研究绿茶及其提取物对人体的生理效用,有助于阐释绿茶生理功效的作用机理,并避免或减轻由于摄入样品化学组成差异和生物个体差异对实验结果的影响。儿茶素类化合物EGCG、EGC、EC和ECG及其派生物是常用的绿茶儿茶素类生物标记物,主要检测方法有高效液相色谱-电化学检测法、液相色谱-串联质谱法等。本文综述了绿茶儿茶素类生物标记物的种类、备样方法和检测手段,分析、讨论了基于绿茶儿茶素类生物标记物开展的绿茶生物利用率研究,以及临床实验和流行病学研究结果,提出在后续研究中应进一步完善和规范人体中儿茶素类生物标记物的备样和检测方法,并可尝试寻找在生物体内比较稳定的、更能反映绿茶及其提取物摄入水平的新型生物标记物。 相似文献
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The present work was undertaken to investigate clonal fidelity of banana (Musa acuminata cv. Grand Naine) regenerants from six different in vitro subculture generations and in the explant suckers by using ISSR and REMAP molecular markers. Both types of markers revealed high degree of monomorphism. Very low variation was observed up to the eighth subculture generation with polymorphic bands being low in both ISSR (0.96%) and REMAP (0.95%) markers. Epigenetic stability was studied by DNA methylation analysis of the eighth subculture generation samples. Single 570 bp methylation sensitive band was absent in two of the fifteen MspI predigested samples, while it was present in HpaII predigested and undigested samples. The results of the investigation confirmed that the micropropagation of banana up to the eighth subculture generation show low variation. 相似文献
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Nilesh N. Maharaj Eugene M. Miyao R. Michael Davis Stéphane Uroz Johan H. J. Leveau 《European journal of plant pathology / European Foundation for Plant Pathology》2018,152(4):855-868
We report the results of a 3-year study in which we collected and analyzed soil and yield data from experimental plots in six commercial processing tomato fields in Yolo and Solano counties in California. Our objective was to assess the effect of soil chemistry and soil-delivered nutrients and fungicides on tomato plant health and fruit yield at harvest. Marketable yield, leaf necrosis, and fruit loss due to sunburn differed significantly between individual fields, with averages ranging from 81.2–138.5 Mg ha?1, 32–72% leaf necrosis and 1.9 to 8.8% sunburnt fruit, respectively. Higher-yielding fields showed significantly lower levels of leaf necrosis and sunburn damage and a positive correlation with pre-plant soil parameters such as potassium concentration and cation exchange capacity (CEC). Interestingly, soil amendments of composted poultry manure or other nutrient supplements in low-CEC fields, but not high-CEC fields, resulted in higher fruit yield and less leaf necrosis. While all fields showed symptoms typical of Verticillium wilt and some fields showed symptoms of Fusarium wilt, Fusarium crown and root rot, corky root, and root knot nematode, none of our soil amendments, including chemical and biological fungicides, significantly or consistently reduced incidence or severity of these diseases. We discuss our findings in the context of premature vine decline of tomato, an emerging phenomenon in production fields in the Sacramento Valley, which is characterized by the loss of plant vigor and canopy cover at the onset of fruit ripening and for which causative agent(s) and management options in California remain elusive. (247 words). 相似文献
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ABSTRACT For landscape level conservation and rural sustenance, forests outside of protected areas are becoming increasingly important. Since most outside forests in the lowlands of Nepal are under government control and utilized as open access resources, their feasibility to achieve these objectives is questionable. We compared forests inside (with three decades of strict protection) and outside of protected areas (under government control and proposed as community forests) to assess the ecological sustainability of outside forests and to provide baseline data on structure of outside forests so that effectiveness of community forestry (after implementation) can be evaluated in the future. Our results indicate that outside forests were in a degraded condition with low tree, sapling and seedling densities and lower species diversity. Trees in lower dbh (diameter at breast height) classes were absent in these forests. Although the canopy layer was not significantly different, the ordination of plots and species showed that species composition of understory and the ground layer were different than protected forests. The present condition of outside forests is not only ecologically unsustainable but also cannot fulfill the demands for forest products of local people. The inefficiency of government to monitor against exploitation has been responsible for present conditions. We recommend that community forestry programs, which are successful in improving conditions of degraded forests in the mountains of Nepal, should be widely implemented in lowland areas (Terai) and proposed community forests should be handed over to local communities as soon as it is practicable. 相似文献
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Emblica officinalis G. dried fruit tannin was extracted and applied as a natural mordant alone and in combination with metal mordant namely copper
sulphate for dyeing on cotton and silk fabrics using natural dyes. The color strength, color-coordinates, wash and light fastness
were also evaluated for cotton and silk fabrics with and without mordanting. The pre-mordanted cotton and silk fabrics on
dyeing gave better color strength, wash and light fastness than those dyeing obtained without mordanting. The total phenolic
content of the extract was calculated. Cotton and silk fabrics resulted in good antibacterial activity using the Emblica officinalis G. mordant. When mordant was used along with 0.5 and 1 % copper sulphate mordant and the activity enhanced and was active up
to 20 washes. 相似文献
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Ghosh Arkendu Dey Koyel Hassan Md. Abu Bauri Fatik Kumar Das Bikash Chandra Bhowmick Nilesh Dey Amarendra Nath Das Soumitra Sahu Pradip Kumar 《Genetic Resources and Crop Evolution》2022,69(7):2585-2604
Genetic Resources and Crop Evolution - Semecarpus anacardium L. is a potential underutilized edible, highly nutritious fruit crop with ample medicinal properties grown in some localized pockets of... 相似文献
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水稻产量及其相关性状的数量性状位点(QTL)鉴定(英文) 总被引：2，自引：0，他引：2
Deshmukh Rupesh Sonah Humira Tiwari Anshuman Mahatman Krityanand Jadhav Srikrishna Kadam Suhas Kesawat Mahipal Reddy Niranjan Deshmukh Nilesh Verulkar Satish 《广西农业科学》2008,39(5)
由于大部分水稻育种的最终目标是获得高产、稳产,因此对于育种工作者来说．水稻产量及其构成因素 是重要的性状。在大田试验中,采用随机区组设计,设两个重复,对CT9993-5-10-1-M × IR62266-42-6-2杂交而得 的144份水稻品系DH群体的产量及其主要农艺性状的数量性状位点(QTLs)进行定位。采用MAPMAKER/QTL 1．1软件进行区间定位并估计每个QTL的表型方差的百分比,以LOD阈值>2．4来确定一个QTL的有无.试验鉴 定出与6个水稻农艺性状如千粒重、单株产量、株高、穗长、粒宽、粒长宽比有关的23个QTLs,这些QTLs将有助于 提高水稻产量,并有利于了解水稻产量性状的遗传调控. 相似文献
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