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   91篇
  免费   7篇
  98篇
  2024年   2篇
  2021年   2篇
  2020年   2篇
  2019年   5篇
  2018年   1篇
  2016年   2篇
  2015年   2篇
  2014年   6篇
  2013年   7篇
  2012年   4篇
  2011年   5篇
  2010年   6篇
  2009年   5篇
  2008年   8篇
  2007年   7篇
  2006年   2篇
  2005年   5篇
  2004年   3篇
  2003年   1篇
  2002年   1篇
  2001年   1篇
  2000年   2篇
  1999年   3篇
  1998年   3篇
  1997年   2篇
  1996年   1篇
  1994年   1篇
  1992年   3篇
  1989年   1篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1977年   1篇
排序方式: 共有98条查询结果,搜索用时 0 毫秒
1.
Changes in peroxidases and glycosidases activities in cytoplasmic and ionically wall-bound fraction of developing seed of Hibiscus esculentum were studied. In both fractions, the activity of peroxiases assayed with ferulic acid and caffeic acid as a hydrogen donors, showed inverse correlation with the cell enlargement (sink size development phase). Activities of glycosidases, on the other hand, showed positive correlation with the sink development and sink filling period of the developing seed. The role of both the enzymes, glycosidases and peoxidase in seed development is discussed.  相似文献   
2.
Naive CD4+ T cells use L-selectin (CD62L) expression to facilitate immune surveillance. However, the reasons for its expression on a subset of memory CD4+ T cells are unknown. We show that memory CD4+ T cells expressing CD62L were smaller, proliferated well in response to tetanus toxoid, had longer telomeres, and expressed genes and proteins consistent with immune surveillance function. Conversely, memory CD4+ T cells lacking CD62L expression were larger, proliferated poorly in response to tetanus toxoid, had shorter telomeres, and expressed genes and proteins consistent with effector function. These findings suggest that CD62L expression facilitates immune surveillance by programming CD4+ T cell blood and lymph node recirculation, irrespective of naive or memory CD4+ T cell phenotype.  相似文献   
3.
Halieutopsis bathyoreos Bradbury, 1988 (Lophiiformes: Ogcocephalidae), previously described only on the basis of the holotype (62.6mm in standard length) from the central North Pacific, is redescribed on the basis of the holotype and six additional specimens (41.2–68.7mm in standard length) collected from the western South Pacific, off Papua New Guinea, and the western North Pacific, including the Japanese Archipelago. Halieutopsis bathyoreos is distinguished from its congeners by having a shelflike rostrum extending anteriorly well beyond the mouth, a dorsal escal lobe slightly bisected ventrally, an illicial cavity square in outline and completely visible in ventral view, and lacking tubercles on the ventral surface of the disk. The following characters are newly added to the diagnoses of this species: rostrum width 21–29% of head length, tubercles on the dorsal surface of the disk about half the diameter of those on the lateral margin, and 13–15 large lateral-line scales on the tail.  相似文献   
4.
5.
The role of endogenous GA3 and its application to seed development in two cotton genotypes Hybrid-6 (H-6) (big seeds) and Gujarat cotton 13 (G. Cot) (small seeds) was studied. Kernel and seed coat were subjected to growth analysis in terms of dry weight, water amount, and rates of dry matter accumulation and water uptake. H-6 kernel had manifold higher dry weight and water amount than G. Cot. Seed coat of both genotypes had similar dry weight at maturity, but the maximum rates of dry matter accumulation and water uptake were distinctly higher in H-6. According to growth analysis, development of seed kernel and coat was subdivided into four phases, i.e., cell division, cell elongation, dry matter accumulation and maturation. Endogenous GA3 level was estimated in kernel and seed coat by indirect ELISA using antibodies raised against GA3. GA3 amount per seed components was higher in the seed kernel of H-6 than of G. Cot, except 33 and 36 days after anthesis in kernel. H-6 seed coat had the higher amount of GA3 during cell division phase than that of G. Cot. Close correlation between in vivo GA3 level and water amount was recorded in both seed components. With GA3 or GA3 + NAA treatments in ovule culture, higher promotion in dry weight, water amount and seed size was noted in G. Cot than in H-6 suggesting that G. Cot is more deficient in endogenous GA3. The greatest stimulation of parameters studied was obtained in ovule culture with GA3 + NAA. When GA3 or GA3 + NAA was applied, initial significant difference in water amount and seed size was nullified. Data presented in this study indicated that GA3 regulates cell expansion through the water uptake by cotton seed.  相似文献   
6.
The N-terminus of V-ATPase subunit E has been shown to associate with the subunits C, G and H, respectively. To understand the assembly of E with its neighboring subunits as well as its N-terminal structure, the N-terminal region, E(1-69), of the Saccharomyces cerevisiae V-ATPase subunit E was expressed and purified. The solution structure of E(1-69) was determined by NMR spectroscopy. The protein is 90.3?? in length and forms an á-helix between the residues 12-68. The molecule is amphipathic with hydrophobic residues at the N-terminus, predicted to interact with subunit C. The polar epitopes of E(1-69) are discussed as areas interacting with subunits G and H.  相似文献   
7.
8.
Advances in schizophrenia   总被引:18,自引:0,他引:18  
Recent studies into the etiology of schizophrenia have yielded both promising leads and disappointing dead ends, indicating the multifactored and complex nature of the disorder. The focus has subsequently shifted back to refining the phenotype and identifying clinical and biological subtypes. Recent technological breakthroughs in genomics and proteomics hold promise for advancing our understanding of the molecular pathophysiology of schizophrenia.  相似文献   
9.
    
This paper presents the work conducted on thechemical constituents of some common and widely distributedhalophyte taxa from Cyprus with the aim that these studies willhelp in the evaluation of halophytes for different economicalpurposes. The plant species of Crithmum maritimum L., Limbardacrithmoides (L.) Dumort, Atriplex portulacoides L., Salsola kali L.,Atriplex halimus L., Limonium oleifolium Mill., L. meyeri (Boiss.)Kuntze; and Tetraena alba (L.f.) Beier & Thulin were collectedin the middle of July. The shoot tissue and leaf samples werecollected from the natural habitats and left for drying under aircirculation followed by placing them in oven at 60 °C for 96hours. The material was crushed using mortar and pestle andsubjected to an analysis of macro- and micro-nutrients andbiochemical compounds. K+/Na+ in the leaf tissues of the dicotspecies showed relatively high values depicting their behavioras Na+ includes but very low Cl- levels were recorded. Out ofthe species investigated here in 4 TFAA content was rather high.Values ranging from 0.5% to 1% dry weight were exhibited in onespecies. However, only 3 species showed very low TFAA values.Later may be due to low nitrogen availability in their environment.The phenetic analyses of eight halophyte species performed onthe data matrix using Ntsys-pc program version 2.1 revealedthat, cluster analysis of the overall results obtained here leads to2 clusters. This discrimination appears to be as a result of theirdifferent abilities to accumulate either proline or glycine betaine.  相似文献   
10.
The anti-Fusarium oxysporum f. sp cicer (FOC) and anti-Alternaria porri (A. porri) effects were evaluated for 75 different essential oils. The most active essential oils found were those of lemongrass, clove, cinnamon bark, cinnamon leaf, cassia, fennel, basil and evening primrose. However, the effectiveness of these essential oils with both the tested fungi showed different responses. The level of inhibition was compared with Hexaconazole. GC–MS analysis for five oils amongst the 75 essential oils tested was performed. The potential of these essential oils as an ecofriendly and economic approach as a fungicide for FOC and A. porri is discussed.  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