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   2343篇
  免费   155篇
  国内免费   1篇
  2023年   19篇
  2022年   45篇
  2021年   70篇
  2020年   49篇
  2019年   43篇
  2018年   72篇
  2017年   61篇
  2016年   70篇
  2015年   98篇
  2014年   137篇
  2013年   148篇
  2012年   174篇
  2011年   142篇
  2010年   95篇
  2009年   77篇
  2008年   114篇
  2007年   104篇
  2006年   87篇
  2005年   73篇
  2004年   77篇
  2003年   59篇
  2002年   67篇
  2001年   53篇
  2000年   68篇
  1999年   54篇
  1998年   25篇
  1997年   16篇
  1996年   14篇
  1995年   9篇
  1994年   17篇
  1993年   17篇
  1992年   29篇
  1991年   33篇
  1990年   32篇
  1989年   32篇
  1988年   22篇
  1987年   17篇
  1986年   12篇
  1985年   12篇
  1984年   13篇
  1983年   8篇
  1982年   15篇
  1980年   7篇
  1979年   11篇
  1977年   11篇
  1976年   7篇
  1975年   7篇
  1974年   13篇
  1973年   9篇
  1971年   9篇
排序方式: 共有2499条查询结果,搜索用时 62 毫秒
81.
The role of endogenous indole-3-acetic acid (IAA), soluble proteins and RNA in the development of tea (Camellia sinensis (L). O. Kuntze) seeds was investigated in the present study. The state of continuum even at full maturity and lack of a clear end point to seed development as indicated by the persistence of appreciable contents of proteins at full maturity in all the seed parts further confirmed the ‘recalcitrant nature’ of the tea seeds. Unlike the orthodox seeds, the level of free IAA in tea embryos also remained high even at full maturity. The total RNA content remained high in the stages with high moisture content but declined with progressive decline in moisture content.  相似文献   
82.
83.
84.
People of all ages are suffering from periodontal disease. It causes indirect damage in the oral cavity. It is of interest to evaluate the efficacy of xanthan-based chlorhexidine gel (Xan-CHX) in patients with mild-severe chronic periodontitis. Five patients with 60 sites were divided in two groups. Group A (treated with SRP) and group B (treated with Chlosite i.e., SRP + CHL). The recorded clinical parameters were Plaque index (PI), Gingival index (GI), Bleeding index (BI), and Clinical attachment Level (CAL) with sub gingival plaque subjected to microbial analysis. Significant reduction was observed in both groups. However, group B (treated with Chlosite i.e., SRP + CHL) showed statistically significant improvement on above mentioned parameters as compared to group A. Data suggest that in the treatment of periodontal disease (viz. PI, GI, BI and CAL) combination of SRP and Chlosite showed added benefits over only SRP.  相似文献   
85.
86.
Elevated intraocular pressure (IOP) is a risk factor in glaucoma, a group of irreversible blinding diseases. Endogenous lipids may be involved in regulation of IOP homeostasis. We present comparative fold analysis of phospholipids and sphingolipids of aqueous humour and trabecular meshwork from human control vs primary open-angle glaucoma and mouse control (normotensive) vs ocular hypertensive state. The fold analysis in control vs disease state was based on ratiometric mass spectrometric data for above classes of lipids. We standardized in vitro assays for rapid characterization of lipids undergoing significant diminishment in disease state. Evaluation of lipids using in vitro assays helped select a finite number of lipids that may potentially expand cellular interstitial space embedded in an artificial matrix or increase fluid flow across a layer of cells. These assays reduced a number of lipids for initial evaluation using a mouse model, DBA/2J with spontaneous IOP elevation. These lipids were then used in other mouse models for confirmation of IOP lowering potential of a few lipids that were found promising in previous assessments. Our results provide selected lipid molecules that can be pursued for further evaluation and studies that may provide insight into their function.  相似文献   
87.
Abstract

The study recommends the Artemisia nilagirica (Clarke) Pamp. essential oil (ANEO) as plant-based shelf-life enhancer of millets against fungal, aflatoxin B1 (AFB1) contamination and lipid peroxidation with favourable safety profile. Chemical characterisation of ANEO through GC-MS, recorded 1,5-heptadiene-4-one,3,3,6-trimethyl (32.72%)as the main compound, followed by Artemisia alcohol (13.40%), alpha lonone (4.55%), benzene, methyl (1-methylethyl) (2.97%) and 1-cyclohexene-1-carboxaldehyde,4-(1-methylethyenyl) (2.23%). The mycoflora analysis of millet samples showed Aspergillus flavus strain[LHP(R)-5] as the most AFB1 secreting strain. The ANEO inhibited growth and AFB1 production by the toxigenic strain at 1.4 and 1.0?µL?mL?1, respectively, and also possess broad fungitoxic spectrum. The decrement in membrane ergosterol content, enhanced leakage of cellular Ca2+, K+ and Mg2+ ions along with SEM and TEM study of ANEO-treated cell denotes plasma membrane as antifungal site of action. The ANEO also showed strong antioxidant activity as determined by DPPH? and ABTS?+ assays having IC50 value 2.51 and 1.07?µL?mL?1, respectively. More than 70.78% protection of Ragi samples from fungal contamination was observed during in situ trial. The ANEO showed favourable safety profile with high LD50 value (7528.10?µL?kg?1) for male mice and also exhibited non-phytotoxicity for Ragi seeds germination.  相似文献   
88.
89.
90.
Physiology and Molecular Biology of Plants - The present study investigates the genetic diversity and population structure among 42 diverse pomegranate genotypes using a set of twenty one class I...  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