首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   15篇
  免费   0篇
  8篇
综合类   1篇
农作物   1篇
畜牧兽医   5篇
  2020年   1篇
  2016年   1篇
  2012年   1篇
  2010年   1篇
  2008年   2篇
  2007年   1篇
  2006年   1篇
  2004年   1篇
  2003年   1篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1988年   1篇
排序方式: 共有15条查询结果,搜索用时 15 毫秒
1.
Plant Foods for Human Nutrition - Grapes contain high contents of phenolics, which are known to possess health promoting properties. Exogenous application of phytoregulators, mainly methyl...  相似文献   
2.
Cryopreserved boar sperm is not used extensively for artificial insemination, owing to the poor fertility rates of the sperm after freezing and thawing. The sperm membrane is damaged as the cells are cooled from body temperature to 5°C (cold shock), as well as during the freeze–thaw process. Increasing the cholesterol content of boar sperm membranes could help them survive cryopreservation, similar to sperm from other species that are cold shock sensitive. The aim of this study was to determine the optimal cholesterol‐loaded cyclodextrin (CLC) concentration to use for boar sperm cryopreservation, and the influence of CLCs on the cryosurvival of sperm from boars classified as good or poor freezers. Treating boar sperm with 1 mg of CLC/120 × 106 sperm slightly improved (p < 0.05) the percentage of viable sperm after freezing–thawing. On the other hand, sperm, from both good and poor freezers, responded similarly to CLC treatment. Nevertheless, additional studies will be needed to study the effect of this treatment on other parameters of sperm quality.  相似文献   
3.
Pure (+)-methyl epijasmonate was isolated from lemon ( Citrus limon Burm.) for the first time. To that aim, two commercial essential oils and one homemade extract were included in the present paper. First, a study on the appropriate chromatographic conditions to avoid the epimerization from methyl epijasmonate to the more stable methyl jasmonate was accomplished. The results obtained are discussed. The presence of (+)-methyl epijasmonate in the three samples studied was initially established through the direct injection into GC-MS. However, the overlapping of (+)-methyl epijasmonate with other matrix components made it necessary to employ a multidimensional technique. RPLC-GC analysis via through-oven transfer adsorption-desorption (TOTAD) provided the selectivity and sensitivity required, reflecting that the homemade lemon extract was an adequate natural source to obtain pure (+)-methyl epijasmonate by means of the collection of the corresponding RPLC fraction.  相似文献   
4.
The vascular cell adhesion molecule 1 (VCAM1) has a strong influence on embryonic development and on the formation of the umbilical cord and placenta. These developmental processes are crucial to ensure the success of pregnancy. In this work, we have identified two T306A and C558T single nucleotide polymorphisms (SNP) at exons 2 and 3 of the pig VCAM1 locus, respectively. The T306A substitution involves a non conservative Asn to Lys replacement at amino acid position 102, whereas the C558T polymorphism is synonymous. An in silico prediction of the consequences of the Asn102→Lys102 mutation with the PolyPhen software revealed that it is not deleterious. The T306A SNP segregated in the Iberian, Piétrain, Duroc, Large White and Landrace breeds as well as in European wild boars. The C558T SNP also segregated and most of commercial standard breeds. The genotyping of the C558T SNP in an Iberian × Meishan intercross allowed to find a suggestive association (Bonferroni threshold, p < 0.004) between C558T genotype and time the newborn piglet needs to reach the udder (p = 0.013) as well as a significant one with time to make the first ingestion of colostrum (p = 0.003). The biological basis of these associations remains unclear and they should be interpreted with caution.  相似文献   
5.
Fundamental studies of enzyme-solvent interactions can be conducted with supercritical fluids because small changes in pressure or temperature may bring about great changes in the properties of a single solvent near its critical point. Cholesterol oxidase is active in supercritical carbon dioxide and supercritical carbon dioxide-cosolvent mixtures. Variations in solvent power caused by pressure changes or by the addition of dopants affected the rate of enzymatic oxidation of cholesterol by altering the structure of cholesterol aggregates.  相似文献   
6.
The enantiomeric distribution of filbertone was determined in unroasted and roasted hazelnut oils of different geographical origins by using solid-phase microextraction (SPME) and capillary gas chromatography. An optimization procedure including SPME fiber, extraction time, exposure temperature, and sample volume enabled the best conditions to be selected. Under the optimized conditions, detection limits were in the micrograms per liter level for both enantiomers of filbertone with relative standard deviation values of 7.1 and 4.9% for R-filbertone and S-filbertone, respectively. The proposed approach allowed the rapid determination of the enantiomeric composition of filbertone and demonstrated that its variability is an inherent property of the natural compound. Analysis of two batches of hazelnut oils obtained from either unroasted or roasted hazelnuts showed, in general, significantly higher amounts of filbertone in roasted hazelnut oils.  相似文献   
7.
The variation, in general, of the composition of the aromatic fraction and, in particular, of the enantiomeric composition of certain chiral volatile compounds of commercial Mentha pulegium L. powders caused by boiling water was evaluated. A comparison between the volatile profile of the studied herbs demonstrated that most M. pulegium L. samples contained high proportions of Mentha piperita L., even when this information was not specified on the label. Likewise, substantial changes in the volatile fraction of the infusions with respect to the composition of the original plant used in their preparation were found. The enantiomeric composition of some chiral compounds of the dried plant material, particularly limonene, was modified by adding hot water, whereas others were kept invariable. The results shown in this work reflect the need for the control of the composition of commercial powders and brews of M. pulegium L. to ensure their correct application.  相似文献   
8.
红色类胡萝卜素在蛋黄着色中的应用   总被引:5,自引:0,他引:5  
颜色在食物感觉中起重要的作用。明亮鲜艳的颜色会刺激食欲,增加人们对食品的喜好程度,并且也是一种视觉享受。据人们的一个基本经验就是适合食用的特定食品应有其特定的颜色fKlaui和Bauemfeind,1981)。蛋黄就是一个确切的例子,当家禽饲喂情况较差或受到疾病影响时,  相似文献   
9.
A new method is proposed to analyze the cholesterol-elevating cafestol and kahweol which allows their rapid and reliable determination in different coffee brews. The method involves the preseparation of the sample by high-performance liquid chromatography, the collection of the selected fraction, and its subsequent analysis by high-resolution gas chromatography using a programmed temperature vaporizer operated in the split mode as sampling system. Under the experimental conditions investigated, recoveries as high as 87% (cafestol) and 94% (kahweol) were achieved while detection limits equal to 0.06 and 0.04 ppm for cafestol and kahweol, respectively, were obtained. Examples are given comparing levels of cafestol and kahweol resulting from the same ground roasted coffee by different brewing methods, which show the lowest values for brews prepared from coffee bags.  相似文献   
10.
The aim of this study was to develop a simple and reproducible in vitro method for predicting the apparent energy digestibility of dry extruded dog foods. The proposed method is based on the two-step multienzymatic incubation assay described by [Boisen, S., 1991: In Vitro Digestion for Pigs and Poultry, M. F. Fuller (ed.). CAB International, Wallingford, 135-146], with some modifications adapted to dogs' digestion characteristics. The method consisted in two consecutives incubations, first one during 2 h with pepsin (10 mg/g of food sample) in acid pH and second one during 4 h with pancreatin (100 mg/g of food sample). The undigested residue obtained was collected in a filtration unit and then dried and ashed. The in vitro percentage of organic matter disappearance (in vitro dOM) of 54 dry extruded commercial dog foods was determined and used as predictor of the in vivo apparent organic matter (in vivo dOM) and energy digestibility (in vivo dE) and digestible energy (DE) content. There was a close linear relationship between the in vivo dOM and dE [r(2) = 0.95, residual standard deviation (RSD) = 1.05 and coefficient of variation (CV) = 1.2%] and also between the in vitro and in vivo dOM (r(2) = 0.92, RSD = 1.38 and CV = 1.6%), even if the in vitro dOM overestimated on average by 4% the in vivo dOM. When the in vitro dOM was used to predict the in vivo dE, the relationship between both variables was defined by the equation: in vivo dE (%) = -2.45 + 0.98 +/- 0.04x in vitro dOM (%), (r(2) = 0.92, RSD = 1.25 and CV = 1.5%). In addition, a close relationship between the in vivo and predicted DE (estimated dE x gross energy determined calorimetrically) was found (r(2) = 0.97, RSD = 0.26 and CV = 1.4%). The accuracy of DE content prediction using the proposed in vitro method was higher than that obtained when the DE content of the same set of samples was predicted by the equation proposed by the NRC (1985) (r(2) = 0.76, CV = 4.5%) and also slightly higher than that obtained when using the equation proposed by NRC (2006) (r(2) = 0.95, CV = 2.1%).  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号