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   82篇
  免费   0篇
  国内免费   1篇
农学   2篇
  11篇
综合类   6篇
农作物   2篇
水产渔业   9篇
畜牧兽医   44篇
植物保护   9篇
  2022年   5篇
  2021年   8篇
  2016年   2篇
  2015年   7篇
  2014年   9篇
  2013年   6篇
  2012年   2篇
  2011年   2篇
  2010年   2篇
  2009年   3篇
  2008年   7篇
  2007年   2篇
  2006年   4篇
  2005年   1篇
  2004年   2篇
  2003年   6篇
  2002年   4篇
  2001年   1篇
  2000年   2篇
  1993年   2篇
  1958年   3篇
  1957年   2篇
  1951年   1篇
排序方式: 共有83条查询结果,搜索用时 31 毫秒
21.
The pituitary is an important endocrine tissue of the vertebrate that produces and secretes many hormones. Accumulating data suggest that several types of cells compose the pituitary, and there is growing interest in elucidating the origin of these cell types and their roles in pituitary organogenesis. Therein, the histogenous cell line is an extremely valuable experimental tool for investigating the function of derived tissue. In this study, we compared gene expression profiles by microarray analysis and real-time PCR for murine pituitary tumor-derived non-hormone-producing cell lines TtT/GF, Tpit/F1 and Tpit/E. Several genes are characteristically expressed in each cell line: Abcg2, Nestin, Prrx1, Prrx2, CD34, Eng, Cspg4 (Ng2), S100β and nNos in TtT/GF; Cxcl12, Raldh1, Msx1 and Twist1 in Tpit/F1; and Cxadr, Sox9, Cdh1, EpCAM and Krt8 in Tpit/E. Ultimately, we came to the following conclusions: TtT/GF cells show the most differentiated state, and may have some properties of the pituitary vascular endothelial cell and/or pericyte. Tpit/F1 cells show the epithelial and mesenchymal phenotypes with stemness still in a transiting state. Tpit/E cells have a phenotype of epithelial cells and are the most immature cells in the progression of differentiation or in the initial endothelial-mesenchymal transition (EMT). Thus, these three cell lines must be useful model cell lines for investigating pituitary stem/progenitor cells as well as organogenesis.  相似文献   
22.
23.
24.
以云南稻种耐冷性资源昆明小白谷及弱耐冷性的日本品种十和田配制的杂交F2代为材料,采用159个RFLP及SSR分子标记构建的连锁图和STATISTIC等分析软件,以单株结实率作为耐冷性评价指标.分析结果显示单株结实率与单株特定颖花结实率之间的相关系数(r)为0.8364;与耐冷性(以单株结实率为指标)相关的分子标记有43个,分布在8条染色体  相似文献   
25.
Tomomi  NIKI  Yuko  KATO  Hisanori  NOZAWA  Nobuo  SEKI 《Fisheries Science》2002,68(3):688-693
ABSTRACT: The low salt extract from scallop striated adductor muscle contained extra proteins in addition to sarcoplasmic proteins and was turned into a gel upon standing or immediately by the addition of Ca2+. The amount of extra protein, which was composed of a large amount of actin and a small amount of myosin, decreased with a decrease in adenosine triphosphate (ATP) content in the muscle during storage at 5°C. Actin was easily extracted from scallop myofibrils in low salt solution with ATP at 1 mM or above. Furthermore, ATP was required to induce the gelation of the low salt extract. A visual observation of the gelation of low salt extract is therefore a simple and easy method to inspect prerigor state of scallop adductor muscle.  相似文献   
26.
It has been suspected that in comparison with glucose or fatty acids, the levels of amino acids may readily change with different forms of exercise. In the present study, we measured the concentrations of amino acids, glucose, triglycerides, total protein and total cholesterol in the blood and/or cerebrospinal fluid (CSF) of rats subjected to forced running exercise on a treadmill, and voluntary running exercise using a wheel, with a constant running distance of 440 m. Rats that performed no running and rats subjected to immobilization stress were used as controls. We observed a few significant changes in the levels of plasma glucose, triglycerides, total protein and total cholesterol in all groups. Whereas, plasma amino acid levels were significantly changed by exercise and stress, especially during the light period. The plasma levels of many amino acids were specifically increased by forced running; some were decreased by immobilization stress. Few amino acids showed similar changes in their levels as a result of voluntary running. In addition, there was a significant difference in the degree of amino acid imbalance between blood and CSF. These results provide the first information on changes in levels of amino acids in plasma and CSF resulting from forced and voluntary exercises.  相似文献   
27.
28.
29.
人工合成甘蓝型油菜的繁育特性与试管繁殖   总被引:5,自引:0,他引:5  
通过甘蓝品种(2n=18,CC)与白菜品种(2n=20,AA)杂交并借助胚珠培养和染色体加倍,获得一系列人工甘蓝型油菜新品系。对18个人工合成甘蓝型油菜新品系的花粉育性、自交结实性、异交结实性等研究表明,人工油菜品系花期自交不结实或结实率很低。蕾期自交一朵花平均获3.6粒种子,平均结角率为19.7%。但是,人工甘蓝型油菜无论作父本还是作母本与天然甘蓝型油菜杂交的结实率都较高。以人工油菜作父本与天然油菜杂交。42个组合平均杂交一朵花获得10.3粒杂交种子;以人工油菜作母本与天然油菜杂交,15个组合平均杂交一朵花获得8.5粒杂交种子。分析结果表明。本试验的人工油菜品系具有很强的自交不亲和性,蕾期自交结实率也较低,但对异交结实影响不大,因此可以直接用于杂种生产。试验对自交结实特别困难的5个人工甘蓝型油菜新品系进行了试管繁殖,采取子叶、下胚轴和茎尖联合培养方式。22株无菌苗经过2个月快繁,获得260株苗。平均繁殖系数为12.4。不同基因型繁殖系数差异较大。变幅为3.3~21.0。  相似文献   
30.
Evaluation of a new chemiluminescent enzyme immunoassay, the PATHFAST assay system (PATHFAST), for measurement of circulating progesterone in mares was performed. Five mares at the mid-luteal stage were administrated a single i.m. injection of prostaglandin F2α analog (PGF2α; cloprostenol 250 μg/ml), and then blood samples were collected from the jugular vein at 0, 15, 30 and 45 min, at one-hour intervals until 24 and at 48 hr via a catheter in the jugular vein. To monitor the physiological changes in circulating progesterone in mares after induced luteolysis, concentrations of progesterone in whole blood and serum samples were measured by PATHFAST. In addition, concentrations of progesterone in serum samples measured by PATHFAST were compared with those measured by radioimmunoassay (RIA) and enzyme immunoassay (EIA). Using PATHFAST, the serum concentrations of progesterone in mares correlated highly with those of whole blood samples (r=0.9672, n=88). The serum concentrations of progesterone as measured by PATHFAST correlated well with RIA (r=0.9654, n=88) and EIA (r=0.9323, n=112). An abrupt decline in circulating progesterone in whole blood samples was observed within 2 hr (50%), followed by a gradual decline until 48 hr later. The results for progesterone in whole blood samples correlated highly with those in serum samples, and the declining pattern paralleled that of the serum samples. These results demonstrated that PATHFAST is useful in the equine clinic as an accurate diagnostic tool for rapid assay of progesterone within 26 min, using unextracted whole blood.  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