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   157篇
  免费   1篇
  国内免费   2篇
林业   4篇
农学   1篇
  12篇
综合类   1篇
农作物   6篇
水产渔业   11篇
畜牧兽医   123篇
植物保护   2篇
  2022年   12篇
  2021年   20篇
  2017年   1篇
  2016年   4篇
  2015年   15篇
  2014年   13篇
  2013年   11篇
  2012年   2篇
  2011年   4篇
  2010年   8篇
  2009年   9篇
  2008年   6篇
  2007年   5篇
  2006年   12篇
  2005年   5篇
  2004年   12篇
  2003年   9篇
  2002年   7篇
  2001年   2篇
  2000年   1篇
  1999年   1篇
  1993年   1篇
排序方式: 共有160条查询结果,搜索用时 15 毫秒
131.
ABSTRACT:   Hatchery-reared black sea bream Acanthopagrus schlegeli juveniles averaging 0.05 g in body weight were fed either a control diet (commercial diet) or an experimental diet in which the commercial diet was fortified with 50 mg l -ascorbyl 2-monophosphate Mg (APM)/100 g diet for 50 days. Calcium ascorbate supplemented as a vitamin mixture in the control diet was completely destroyed during storage. Fortification with APM significantly increased the ascorbic acid levels in the muscle, liver, brain and eye. Although APM fortification did not influence growth, survival or fish body composition, adipocyte diameter in the intraperitoneal fat body (IPF) was significantly reduced. After the feeding experiment, the fish were kept for 39 days without feeding. Fortification with APM resulted in high survival, high muscle protein retention and low body weight loss. The results suggested the necessity of fortification with an adequate amount of ascorbate in the diet. While fatty acid compositions of the IPF, muscle and liver were not significantly influenced by APM fortification, characteristic changes in the fatty acid profile were found after starvation. Vitamin C and highly unsaturated fatty acids seemed crossly interactive in relation to lipolysis activity in black sea bream juveniles.  相似文献   
132.
To investigate the transition in concentration of porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) and antibody for these viruses in serum, serum samples were collected from 29 pigs on weaning day and at 7, 14, 21, 28, 53, 84, and 120 days after weaning. The concentration of circulated PRRSV and PCV2 in serum was measured by real-time RT-PCR and real-time PCR, respectively. The specific antibody for PRRSV and PCV2 was measured using ELISA. PRRSV was not detected on 0 days post-weaning (dpw). The specific antibody for PRRSV began to increase as the concentration of PRRSV in serum increased, and the level of PRRSV then tended to decrease. PCV2 was detected in 12 of 28 pigs on 0 dpw. The concentration of PCV2 and the specific antibody for PCV2 showed a similar tendency to those of PRRSV. The correlation analysis suggests that a decline in the daily weight gain coincided with an increase in the PRRSV concentration. Pigs with a higher antibody titer against PRRSV or PCV2 on 0 dpw showed the lower level of PRRSV or PCV2, respectively.  相似文献   
133.
The objective of this study was to develop an in‐straw dilution method suitable for direct transfer of vitrified bovine sexed embryos. Embryo sexing was performed by molecular diagnosis. Several sexed and vitrified‐warmed embryos were transferred after evaluation of morphologically embryonic survival at warming and in‐straw dilution (Evaluation group). The other embryos were immediately directly transferred to recipients without first being expelled from the straws after in‐straw dilution (Non‐evaluation group). The pregnancy rates of vitrified sexed embryos were 38.7% and 34.8% in the Evaluation group and Non‐evaluation group, respectively, which were not significantly different. The viability of lower quality embryos before vitrification tended to be lower (P = 0.087) than that of the higher quality embryos regardless of evaluating embryos after warming and in‐straw dilution. The abortion rates were similar, and there was no difference between the two groups (13.9% and 12.5%, respectively). These results demonstrate that vitrified bovine sexed embryos can be vitrified and diluted by the in‐straw method and that the vitrified and warmed sexed embryos can develop to term.  相似文献   
134.
Previous studies reported that diabetes alters the activities of hepatic cytochrome P450 (CYP) enzymes, which, in turn, affects the disposition of some drugs. We herein examined and compared the effects of the combination of dapagliflozin with a low insulin dose, a full dose of insulin alone, and dapagliflozin alone for 3 and 8 weeks on CYP activities in a diabetes type 1 rat model. We induced type 1 diabetes in rats using a single intraperitoneal injection of 60 mg/kg streptozotocin (STZ). Daily treatment with the full dose of insulin alone, dapagliflozin alone, or dapagliflozin in combination with a low dose of insulin was then initiated. STZ-induced rats developed marked hyperglycemia and altered CYP2E activities. Dapagliflozin in combination with a low dose of insulin stabilized hyperglycemia and CYP1A, 2D, 2E and 3A activities. However, dapagliflozin alone did not improve blood glucose levels or CYP activities. These results suggest that the effects of dapagliflozin in combination with a low dose of insulin are similar to those of a full dose of insulin, and stabilize CYP activities in type 1 diabetes.  相似文献   
135.
A 12-year-old neutered male Chihuahua was diagnosed with acute brain infarction in the right middle cerebral artery (MCA) territory. Transcranial Doppler ultrasonography (TCD) was performed to assess the local cerebral blood flow at the time of diagnosis and after 4 and 31 hr. Initially, the right MCA retained blood flow but with a lower cerebral blood flow velocity (CBFV; 14.9 cm/sec) than the left MCA (27.9 cm/sec). The TCD vascular resistance variables were higher in the right than in the left MCA. An increase in the CBFV and a decrease in TCD vascular resistance variables were observed, consistent with improvements in neurological symptoms. TCD can be a non-invasive, and easy-to-use modality for bedside monitoring of cerebral edema and infarction.  相似文献   
136.
Seventeen soybean cultivars were screened to discern differences in aluminum (Al) sensitivity. The Sowon (Al-tolerant) and Poongsan (Al-sensitive) cultivars were selected for further study by simple growth measurement. Aluminum-induced root growth inhibition was significantly higher in the Poongsan cultivar than in the Sowon cultivar, although the differences depended on the Al concentration (0, 25, 50, 75 or 100 μmol L–1) and the amount of exposure (0, 3, 6, 12 or 24 h). Damage occurred preferentially in the root apex. High-sensitivity growth measurements using India ink implicated the central elongation zone located 2–3 mm from the root apex. The Al content was lower 0–5 mm from the root apices in the Sowon cultivar than in the apices of the Poongsan cultivar when exposed to 50 μmol L–1 Al for 12 h. Furthermore, the citric acid exudation rate was more than twofold higher in the Sowon cultivar. Protein production of plasma membrane (PM) H+-ATPase from the root apices (0–5 mm) was upregulated in the presence of Al for 24 h in both cultivars. This activity, however, decreased in both cultivars treated with Al and the Poongsan cultivar was more severely affected. We propose that Al-induced growth inhibition is correlated with changes in PM H+-ATPase activity, which is linked to the exudation of citric acid in the root apex.  相似文献   
137.
Porphyromonas gulae is considered to be associated with canine periodontitis. We have previously reported that the P. gulae American Type Culture Collection (ATCC) 51700 comprised 41-kDa fimbriae. The purpose of the present study was to demonstrate the roles of 41-kDa fimbrial protein in periodontal disease. In this study, we examined the involvement of the 41-kDa fimbrial protein in osteoclast differentiation and cytokine production in murine macrophages. Furthermore, alveolar bone resorption induced by P. gulae infection in rats was evaluated. To estimate osteoclast differentiation, bone marrow cells and MC3T3-G2/PA6 cells were cultured with or without the 41-kDa fimbrial protein for 7 days. BALB/c mouse peritoneal macrophages were stimulated with the 41-kDa fimbrial protein, and the levels of interleukin (IL)-1β and tumor necrosis factor (TNF)-α production were determined by enzyme-linked immunosorbent assay. Osteoclast differentiation was significantly enhanced by treatment with the 41-kDa fimbrial protein in a dose-dependent manner. The total area of pits formed on the dentine slices with osteoclasts incubated with the 41-kDa fimbrial protein was significantly greater than that of the control. The purified 41-kDa fimbrial protein induced IL-1β and TNF-α production in BALB/c mouse peritoneal macrophages after 6 hr of incubation in a dose-dependent manner. The bone loss level in rats infected with P. gulae was significantly higher than that of the sham-infected rats. These results suggest that P. gulae 41-kDa fimbriae play important roles in the pathogenesis of periodontal disease.  相似文献   
138.
The structure and functions of placentas were examined in 3 species of rorqual whales, common minke (Balaenoptera acutorostrata), Bryde’s (B. brydei) and sei (B. borealis) whales, with the aim of confirming the structural characteristics of the chorion, including the presence of the areolar part, and clarifying steroidogenic activities and fetomaternal interactions in the placentas of these whales. Placentas were collected from the second phase of the Japanese Whale Research Program under Special Permit in the North Pacific (JARPN II). Histological and ultrastructural examinations revealed that these whale placentas were epitheliochorial placentas with the interdigitation of chorionic villi lined by monolayer uninucleate cells (trophoblast cells) and endometrial crypts as well as folded placentation by fold-like chorionic villi. Moreover, well-developed pouch-like areolae were observed in the placentas, and active absorption was suggested in the chorionic epithelial cells of the areolar part (areolar trophoblast cells). Berlin blue staining showed the presence of ferric ions (Fe3+) in the uterine glandular epithelial cells and within the stroma of chorionic villi in the areolar part. An immunohistochemical examination revealed tartrate-resistant acid phosphatase (TRAP; known as uteroferrin in uteri) in the cytoplasm of glandular cells and areolar trophoblast cells. This result suggested that, in cetaceans, uteroferrin is used to supply iron to the fetus. Furthermore, immunoreactivity for P450scc and P450arom was detected in trophoblast cells, but not in areolar trophoblast cells, suggesting that trophoblast cells synthesize estrogen in whale placentas. Therefore, we herein immunohistochemically revealed the localization of aromatase and uteroferrin in cetacean placentas during pregnancy for the first time.  相似文献   
139.
140.
This review presents a brief overview on the mechanism of insulin action on glucose metabolism at the molecular basis in ruminants. For ruminants, an exact mechanism of insulin on glucose metabolism is still rudimentary, but it is clear that originally, if not all, the mechanism of insulin action in ruminants was the same as in other species. Like non‐ruminants, the insulin‐sensitive glucose transporter GLUT 4 is thought to be a key‐protein in the control of glucose uptake and metabolism in ruminants, and insulin regulates glucose transport by stimulating the translocation of GLUT 4 from an intracellular membrane pool to the plasma membrane in adipocytes and muscles. Moreover, insulin‐induced GLUT 4 translocation is activated through the common intracellular signaling pathway of insulin phosphatidylinositol 3‐kinase (PI3‐kinase) signaling pathway rather than the mitogen activated protein kinase (MAP kinase)‐dependent signaling pathway. However, GLUT 4 mRNA and protein, and insulin‐induced GLUT 4 translocation on adipocytes and muscles in ruminants are lower than those in rodents and human subjects. Furthermore, insulin‐induced PI3‐kinase activation is reduced concomitantly with the lower content of insulin receptor substrate‐1 (IRS‐1) in ruminants. In spite of normal status, a resistance to the stimulatory action of insulin on glucose metabolism in ruminants as compared to non‐ruminants may be due to, at least in part, the lower content of GLUT 4 and the lower capacity of insulin signal transduction, resulting to the lower glucose transport activity.  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