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81.
Sesame seeds (Sesamum indicum L.) are unique because of potent and various physiological activities imparted by their bioactive lignans. This investigation studied the intestinal distribution and excretion of sesaminol in Sprague-Dawley (SD) rats. To investigate the distribution of sesaminol (per oral 220 mg/kg), the changes in concentration of sesaminol and its metabolites were determined in the intestines and plasma within the 24 h period after tube feeding of sesaminol to SD rats. Results show that the epimerization of sesaminol appeared to be catalyzed by acid in the simulated gastric fluids. The major sesaminol epimer was characterized as 2-episesaminol using 2D-NMR. These findings indicate that sesame sesaminol and its epimer are poorly absorbed prior to reaching the rectum and that substantial amounts pass from the small to the large intestine, where they are metabolized by the colonic microflora to tetrahydrofuranoid metabolites. Sesaminol in plasma was largely present as phase II conjugates, and the seven metabolites were detected as the 2-episesaminol, sesaminol-6-catechol, methylated sesaminol-catechol, R,R-hydroxymethylsesaminol-tetrahydrofuran, S,R-hydroxymethylsesaminol-tetrahydrofuran, enterolactone, and enterodiol. Excretions of sesaminol in urine and feces within the 24 h period were equivalent to 0.02 and 9.33% of the amount ingested, respectively.  相似文献   
82.
Summary Failure forms caused by axial ultimate compression stress in three softwood and nine hardwood species and in model specimens made of wood, paper and plastics are described. Three categories of failure forms are distinguished: 1. Wood characteristic failure forms are connected with the general anisotropic structure of the wood. 2. Failure forms specific to the species are modifications of the first category arising from predominant anatomical structures. 3. Modifications of the failure forms are also induced experimentally. The interdependence among the anatomical structure, strength characteristics and failure forms of the wood specimens are examined by statistical methods. The structure cipher introduced in this paper, as a numerical characteristic of the anatomical features of the wood species, is seen to be the most important influencing factor as regards the intensity and pattern of the fracture, followed in second and third place by the geometry of the specimen and its specific gravity. Specimen volume and other factors are shown to have only a marginal influence on the fracture morphology.The strength tests were carried out as part of a diploma thesis by K. Buchmüller. Also the assistance of E. Risi in measuring and evaluating is gratefully acknowledged  相似文献   
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刘库  谢应忠 《中国草地》2005,27(5):53-57
由于自然因素及人为因素的共同作用,使得我国植被退化日趋严重.综合前人不同的研究成果,探讨了不同改良措施对退化植被的影响。  相似文献   
86.
The objectives of this study were to determine effects of cyfluthrin and pyrethrin spray products, used in combination with cyfluthrin topical and ear tag applications, on bull reproductive parameters over 18 weeks. Angus or Angus x Simmental bulls were randomly assigned to one of three treatment groups: (i) no exposure to pyrethrins/cyfluthrin (CONT; n = 10), (ii) cyfluthrin ear tag and topical applications (ET; n = 10), or (iii) cyfluthrin ear tag, topical, premise spray and pyrethrin fog spray applications (ET+S; n = 8). Bull body weight was measured every 3 week, and body condition score and scrotal circumference were recorded on weeks 0, 9 and 18. Semen and serum were collected every 3 weeks for sperm evaluation and testosterone measurement, respectively. There was a treatment × week interaction (p < 0.01) for sperm with primary defects; bulls in CONT group had a greater (p = 0.01) percentage of sperm with primary defects than bulls treated with insecticides at week 18. Overall and progressive sperm motility, normal sperm morphology, secondary sperm defects and serum testosterone concentrations changed (p < 0.01) over time in all bulls; however, treatment did not affect (p ≥ 0.13) any of these parameters. There were also no treatment effects (p ≥ 0.08) on bull body weight, body condition score or scrotal circumference. The use of pyrethrin‐ and cyfluthrin‐based insecticides, regardless of application, did not negatively affect reproductive parameters in beef bulls when administered over 18 weeks.  相似文献   
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打结器是方草捆捡拾压捆机上的关键部件,为了分析捆绳打结嘴的材质及性能,对捆绳打结嘴进行了金相组织分析,并进行了硬度试验和拉力试验.为了验证材料具体成分含量,又进行了光谱分析.通过试验发现:打结嘴的材料成分为15cr,外表面的硬度为HRC46,芯部硬度为HRC25,热处理工艺采用了调质处理和表面镀铬.为了预测打结嘴的疲劳寿命,采用局部应力应变法对打结嘴进行了分析运算.  相似文献   
89.
方草捆捡拾压捆机打结器控制系统运动分析   总被引:1,自引:0,他引:1  
通过对方草捆捡拾压捆机上实现自动打结的控制系统进行研究,详细地分析了9JK-1.7型捡拾压捆机实现控制自动打结的动作过程,并利用Pro/E软件分析了穿针四杆机构的运动过程,不仅为打结器的调节和使用提供了理论指导,也为打结器的后续试验分析及研究打结器与穿针的运动关系进行了前期工作.  相似文献   
90.
Non‐pungent bell pepper (Capsicum annuum L.) lacks the cytoplasmic male sterility (CMS) nuclear restorer allele, Rf, and CMS cannot be employed in its F1 hybrid seed production. To demonstrate that the genic male sterility (GMS) system in non‐pungent bell pepper can be converted to the CMS male sterility system, the conversion of GMS to CMS for non‐pungent bell pepper line GC3 was conducted by introgression of S‐type cytoplasm and the Rf allele from tropical pungent donors. After morphological traits were evaluated, two lines from BC1F1 containing S‐type cytoplasm and four lines from BC2F2 containing Rf allele, phenotypically similar to GC3, were obtained and could be employed as CMS male sterile lines and restorer lines for non‐pungent bell pepper. Four molecular markers potentially linked to traits of interest were also evaluated in BC1F1 and BC1F2 populations. This is the first time that GMS has been successfully converted to CMS in bell pepper, a significant contribution for bell pepper hybrid seed production.  相似文献   
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