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   219篇
  免费   2篇
  国内免费   1篇
林业   26篇
农学   17篇
  48篇
综合类   7篇
农作物   4篇
水产渔业   17篇
畜牧兽医   86篇
园艺   2篇
植物保护   15篇
  2022年   1篇
  2021年   4篇
  2020年   2篇
  2019年   4篇
  2018年   2篇
  2017年   3篇
  2016年   3篇
  2015年   8篇
  2014年   4篇
  2013年   29篇
  2012年   7篇
  2011年   17篇
  2010年   8篇
  2009年   4篇
  2008年   15篇
  2007年   8篇
  2006年   12篇
  2005年   9篇
  2004年   10篇
  2003年   12篇
  2002年   10篇
  2001年   6篇
  2000年   9篇
  1999年   6篇
  1998年   3篇
  1997年   3篇
  1996年   3篇
  1994年   1篇
  1993年   1篇
  1992年   2篇
  1990年   2篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   3篇
  1984年   2篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1967年   1篇
  1964年   1篇
  1962年   1篇
排序方式: 共有222条查询结果,搜索用时 15 毫秒
51.
Candida species in clinical urine samples were identified directly by the newly developed method of PCR analysis on 25S ribosomal DNA (rDNA). Two dogs were referred to the Animal Medical Center, Nihon University School of Veterinary Medicine, Fujisawa, Kanagawa, Japan for the examination of chronic cystitis. Microscopic examination of urine samples from these dogs revealed yeast cells. Urine culture on Sabouraud's dextrose agar at 27 degrees C for 5 days produced white to cream colored colonies. The isolates were identifical to Candida albicans and C. parapsilosis by mycological examination, respectively. The nucleotide sequences of 25S ribosomal DNA from these urine isolates showed 99% similarity to those of a reference strain of Candida albicans or C. parapsilosis. The nucleotide sequences of 25S rDNA obtained directly from urine samples were also identical to C. albicans and C. parapsilosis, respectively. Confirming the results on the isolates cultured from the same urine samples. This PCR analysis method could be available for the direct identification of Candida species in urine samples within 2 days.  相似文献   
52.
The inwardly rectifying K+ channels, Kir1.1, Kir2.3 and Kir4.1-Kir5.1, are the candidate chemosensory molecules for CO2/H+. We determined the mRNA expression and immunohistochemical localization of these channels in the medulla oblongata of the rat. RT-PCR analysis revealed mRNAs of Kir1.1, Kir2.3, Kir4.1 and Kir5.1 were detected in the medulla. The immunoreactivities for Kir1.1, Kir2.3, Kir4.1, and Kir5.1 were observed in the medulla, and immunolabeling pattern was varied by the subunit. Immunoreactivities for Kir1.1 and Kir2.3 were observed in the nerve cell bodies and glial cells both in the chemosensory areas [nucleus tractus solitarius (NTS), nucleus raphe obscurus (RO), pre-B?tzinger complex (PreB?tC)] and non-chemosensory area [hypoglossal nucleus (XII), inferior olive nucleus (IO)]. Kir4.1 immunoreactivity was observed in the glial cells and neuropil, especially in XII and IO. Kir5.1 immunoreactivity was observed in the nerve cell bodies in the XII, RO, and PreB?tC, but not in the NTS or IO. In the NTS, a dense network of varicose nerve fibers showed immunoreactivity for Kir5.1. Our findings suggest that Kir channels may not act specific to the central chemoreception, but regulate the ionic properties of cellular membranes in various neurons and glial cells.  相似文献   
53.
Classically, selection for superior genotypes in cacao has been based on the successive harvest records across a number of years. Little information on the minimum duration of these harvest periods is available in the literature. The repeatability coefficient (ρ) was used to estimate this period. Twenty five cacao genotypes were assayed in a randomized block design with four replications and 16-plant plots. The following yield components were studied: number of healthy fruits per plant, number of collected fruits per plant, weight of humid seeds per plant and per fruit, and percentage of diseased fruits per plant, over 5 years (1986–90). Repeatability estimates were higher than 0.84 for all components, except percentage of diseased fruits per plant (^ρ - 0.41). With such estimates, it is possible to select genotypes on the basis of only two years of successive harvests, with a determination coefficient of 90%. The advantages of applying the repeatability coefficient to the cacao breeding program are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
54.
The reduction of ferric chelate caused by various wood-rot fungi was analyzed. Ferric chelate reductive activity was detected in cell-free extracts of seven wood-rot fungi:Phanerochaete chrysosporium, P. sordida YK-624,Ganoderma sp. YK-505,Coriolus versicolor, Bjerkandera adusta, Tyromyces palustris, andGloeophyllum trabeum. These fungi produced NADPH- or NADH-dependent ferric chelate reductive enzymes (or both) of different molecular weight. In the liquid culture ofP. sordida YK-624 andC. versicolor, a positive correlation was observed between extracellular MnP activity and intracellular NADPH-dependent ferric chelate reductive activity.  相似文献   
55.
(1) Seven hydroxyanthraquinone pigments were separated from Sochiken soil 1 (Kuroboku soil). Chrysotalunin, chrysophanoi, chrysazin, and skyrln were identified by spectroscopy and co-chromatography with authentic compounds. The presence of oxyskyrin was presumed by spectroscopy and color reactions.

(2) A homologue of 4,9-dihydroxyperylene-3, 10-quinone was also detected.

(3) The amounts of hydroxyanthraqulnones in eight soils of different types were determined by colorimetry using chrysotalunin as a standard pigment. Their amounts varied from 3 to 11 ppm.

(4) The main pigment extracted from most soils was chrysotalunin, though it was not detected in Miyahara, Higashiyama, and Kisokoma soils.  相似文献   
56.
57.
58.
To determine the characters of receptors on target cells for avian rotaviruses, the receptors on MA104 cells for the pigeon rotavirus PO-13, the turkey rotaviruses Ty-1 and Ty-3, and the chicken rotavirus Ch-1 were analyzed. Pretreatment of MA104 cells with neuraminidase greatly reduced the infection by all of the four avian rotavirus strains. Binding of the cell-attachment protein, purified VP8 expressed in bacteria, of strain PO-13 to MA104 cells was also inhibited by pretreatment of cells with neuraminidase. These findings suggest that avian rotaviruses primarily utilize sialic acid-containing molecules as receptors on MA 104 cells.  相似文献   
59.
Differentiation of the histochemical characteristics of the olfactory receptor cells (ORC) was examined by immunohistochemistry for protein gene product 9.5 (PGP 9.5) and calretinin (CR) and lectin histochemistry for Phaseolus vulgaris agglutinin-L (PHA-L) in the developing olfactory epithelium (OE) of the barfin flounder. PGP 9.5 immunoreactivity was diffuse and CR immunoreactivity was restricted at day 7, but these immunoreactivities became intense in the OE toward day 91. Crypt cells were first identified at day 56. PHA-L staining was faint at day 28, but became intense toward day 91. These findings suggest that PGP 9.5-immunopositive cells, CR-immunopositive cells, crypt cells and PHA-L-reactive cells differentiate independently in the developing OE and constitute subsets of the ORC in the OE.  相似文献   
60.
Pulsed-field gel electrophoresis (PFGE) is a highly discriminating tool for molecular typing, but the conventional PFGE protocol is time consuming. This paper describes a rapid method of PFGE for Listeria monocytogenes that yields results within 2 days.  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