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   387篇
  免费   29篇
林业   22篇
农学   30篇
  42篇
综合类   33篇
农作物   53篇
水产渔业   56篇
畜牧兽医   151篇
园艺   3篇
植物保护   26篇
  2023年   2篇
  2022年   6篇
  2021年   21篇
  2020年   10篇
  2019年   14篇
  2018年   15篇
  2017年   3篇
  2016年   8篇
  2015年   13篇
  2014年   16篇
  2013年   18篇
  2012年   34篇
  2011年   34篇
  2010年   11篇
  2009年   28篇
  2008年   35篇
  2007年   16篇
  2006年   20篇
  2005年   16篇
  2004年   29篇
  2003年   13篇
  2002年   8篇
  2001年   5篇
  2000年   8篇
  1999年   1篇
  1998年   3篇
  1997年   3篇
  1996年   2篇
  1993年   1篇
  1992年   1篇
  1987年   1篇
  1985年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   5篇
  1978年   1篇
  1976年   1篇
  1970年   2篇
  1965年   1篇
  1964年   4篇
  1963年   3篇
排序方式: 共有416条查询结果,搜索用时 31 毫秒
351.
Paeoniflorin: an antihyperlipidemic agent from Paeonia lactiflora   总被引:4,自引:0,他引:4  
Yang HO  Ko WK  Kim JY  Ro HS 《Fitoterapia》2004,75(1):45-49
Paeoniflorin (1), isolated from the methanol extract of Paeonia lactiflora, showed a lowering effect on cholesterol level in the experimentally-induced hyperlipidemic rats. Paeoniflorin showed a significantly lowering effect of total cholesterol, LDL and triglyceride levels compared with the control group at the dose of 200 and 400 mg/kg, p.o. once a day for 4 weeks.  相似文献   
352.
An 8-year-old Yorkshire terrier was presented with tracheal collapse. Two intraluminal nitinol stents were implanted. The implanted stents were found to be fractured 4 weeks after implantation. The fractured stents were removed. To restore the collapsed trachea, ring prostheses were applied. However, the dog was euthanized because of a bad outcome following surgery.  相似文献   
353.
To assess the correlation between the nature of immunity induced by different types of immunogens and the establishment of latent infection by wild-type pseudorabies virus (PrV), we used a murine model immunized with different immunogens, the PrV modified live vaccine (MLV), inactivated vaccine (IAV), and commercial oil-adjuvant subunit vaccine (OSV), via either intranasal (i.n.) or intramuscular (i.m.) route. Both MLV and IAV induced a different nature of immunity biased to Th1- and Th2-type, respectively, as judged by the ratio of PrV-specific IgG isotypes (IgG2a/IgG1) and the profile of cytokine IL-2, IL-4, and IFN-gamma production. In contrast, the OSV induced a lower isotype IgG2a to IgG1 ratio and higher level of IL-2 production. The MLV (inducing Th1-type) provided more effective protection against a virulent wild-type PrV challenge than IAV and OSV (inducing Th2- and mixed type, respectively). In addition, the MLV impeded the establishment of a latent infection with wild-type PrV, and the decrease in the PrV latency load by immunization with the MLV appeared to be mediated by the immune T-cells. These results demonstrate the substantial role of the immune responses driven by preceding vaccination in modulating the establishment of PrV latency caused by the post-infection of a field virus.  相似文献   
354.
355.
356.
Platycodon grandiflorum (PG), a species of herbaceous flowering perennial plant of the family Campanulaceae, has been used as a traditional oriental medicine for bronchitis, asthma, pulmonary tuberculosis, diabetes, hepatic fibrosis, bone disorders and many others similar diseases and as a food supplement. For the primary profiling of PG gas chromatography coupled with high resolution – time of flight mass spectrometry (GC/HR-TOF MS) was used as an analytical tool. A comparison of optimal extraction of metabolites was carried out with a number of solvents [hexane, methylene chloride, methanol, ethanol, methanol: ethanol (70:30, v:v)]. In extracts with methanol: ethanol (70:30 v:v) were detected higher amounts of metabolites than with other solvents. Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) plots showed significant differences between the diploid and tetraploid metabolite profiles. Extracts of tetraploid showed higher amounts of amino acids, while extracts of diploid contained more organic acids and sugars.
Graphical Abstract ?
  相似文献   
357.
Journal of Crop Science and Biotechnology - Bellflower (P. grandiflorum) has been an important medicinal plant since the ancient time. In the present study, we aimed to determine the effects of...  相似文献   
358.
359.
Vibrio alginolyticus is one of the most serious causative agents of diseases in cultured marine fish and shellfish. However, the characteristics of virulence factors in pathogenic V. alginolyticus are poorly known. To gain insight into fish diseases caused by V. alginolyticus, we carried out two-dimensional gel electrophoresis (2-DE) combined with MALDI-TOF mass spectrometry to identify uniquely expressed proteins in the disease-causing V. alginolyticus. V. alginolyticus strains were isolated from marine environments and diseased fish obtained from southern Thailand. We identified seven unique proteins in the disease-causing V. alginolyticus strain. Among those, the outer membrane protein A (OmpA) had the strongest expression. Therefore, the function of this protein was further analysed. To investigate the role of OmpA protein, an in-frame deletion mutant of ompA was constructed using the homologous recombination method. Although the ompA mutant V. alginolyticus strain (ΔompA) grew normally, the mutant exhibited a significant defect in the swarming ability and the biofilm formation. Furthermore, Galleria mellonella larvae injected with the mutant bacteria had a significantly greater survival percentage than those injected with the wild-type strain, demonstrating that OmpA protein is required for the pathogenicity of V. alginolyticus. Together, this study suggests a potential target for vaccine development against pathogenic V. alginolyticus strain.  相似文献   
360.
Echinochrome A (Ech A, 7-ethyl-2,3,5,6,8-pentahydroxy-1,4-naphthoquinone) has been known to exhibit anti-oxidative and anti-inflammatory effects. However, no study has been carried out on the efficacy of Ech A against skin photoaging; this process is largely mediated by oxidative stress. Six-week-old male SKH-1 hairless mice (n = 36) were divided into five groups. Except for a group that were not treated (n = 4), all mice underwent ultraviolet-B (UVB) exposure for 8 weeks while applying phosphate-buffered saline or Ech A through intraperitoneal injection. UVB impaired skin barrier function, showing increased transepidermal water loss and decreased stratum corneum hydration. UVB induced dermal collagen degeneration and mast cell infiltration. Ech A injection was found to significantly lower transepidermal water loss while attenuating tissue inflammatory changes and collagen degeneration compared to the control. Furthermore, Ech A was found to decrease the relative expression of matrix metalloproteinase, tryptase, and chymase. Taken together, these results suggest that Ech A protects against UVB-induced photoaging in both functional and histologic aspects, causing a lowering of collagen degradation and inflammatory cell infiltration.  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