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   2428篇
  免费   154篇
  国内免费   2篇
  2022年   20篇
  2021年   32篇
  2020年   18篇
  2019年   19篇
  2018年   35篇
  2017年   32篇
  2016年   58篇
  2015年   67篇
  2014年   83篇
  2013年   175篇
  2012年   138篇
  2011年   168篇
  2010年   96篇
  2009年   80篇
  2008年   127篇
  2007年   132篇
  2006年   127篇
  2005年   136篇
  2004年   111篇
  2003年   115篇
  2002年   106篇
  2001年   62篇
  2000年   57篇
  1999年   66篇
  1998年   23篇
  1997年   27篇
  1996年   12篇
  1995年   21篇
  1994年   21篇
  1993年   11篇
  1992年   33篇
  1991年   32篇
  1990年   38篇
  1989年   28篇
  1988年   34篇
  1987年   31篇
  1986年   30篇
  1985年   19篇
  1984年   13篇
  1983年   9篇
  1982年   21篇
  1980年   12篇
  1979年   15篇
  1977年   9篇
  1975年   6篇
  1974年   8篇
  1970年   9篇
  1969年   8篇
  1968年   14篇
  1967年   8篇
排序方式: 共有2584条查询结果,搜索用时 140 毫秒
61.
Attempts were made to isolate and identify the unit chemical structure essential for manifestation of the immunoadjuvant activities characteristic of bacterial cell walls. The N-acetylmuramyl-peptide subunit monomers, Nalpha-(N-acetylmuramyl-L-alanyl-D-isoglutaminyl)-Nepsilon-(glycylglycyl)-L-lysyl-D-alanine from the cell walls of Staphylococcus aureus (FDA 209P) and N-acetylmuramyl-L-alanyl-D-isoglutaminyl-meso-diaminopimelic acid and/or N-acetylmuramyl-L-alanyl-D-isoglutaminyl-meso-diaminopimelyl-D-alanine from those of Lactobacillus plantarum (ATCC 8014), were shown to be unit chemical entities with definite adjuvant activity both in stimulation of antibody production and in induction of delayed-type hypersensitivity to ovalbumin when administered to guinea-pigs as water-in-oil emulsions.  相似文献   
62.
63.
Plasmonics - Detection and monitoring of SO2 is important because it is a representative toxic gas in the atmospheric environment that is emitted from industrial and natural processes. Localized...  相似文献   
64.
Journal of Plant Research - Cysteine biosynthesis is directed by the successive commitments of serine acetyltransferase, and O-acetylserine (thiol) lyase (OASTL) compounds, which subsequently frame...  相似文献   
65.
66.
Primates - In the original publication of the article, the coauthor “Takashi Hayakawa” was wrongly assigned as co-corresponding author.  相似文献   
67.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing the global coronavirus disease 2019 (COVID-19) pandemic. Because complete elimination of SARS-CoV-2 appears difficult, decreasing the risk of transmission is important. Treatment with 0.1 and 0.05 ppm ozone gas for 10 and 20 hr, respectively, decreased SARS-CoV-2 infectivity by about 95%. The magnitude of the effect was dependent on humidity. Treatment with 1 and 2 mg/L ozone water for 10 s reduced SARS-CoV-2 infectivity by about 2 and 3 logs, respectively. Our results suggest that low-dose ozone, in the form of gas and water, is effective against SARS-CoV-2.  相似文献   
68.
69.
Abstract

The molecular and crystal structure of neplanocin C(3), C11H13N5O4 M.W. = 279.26, has been determined by X-ray anlys?s. The space group is P21 with a=16.381(2), b=8.210(1), c=9.127(1) Å, β=105.31(1)° and z=4. The structure was solved by direct method, and least-squares refinement using 2093 reflections with |Fo|>3σ(F) led to the final R value of 0.0772. The sugar puckering of the two crystal-lographically independent molecules is C(2′)-exo-C(3′)-endo, and the torsion angles about the N(9)-C(1′) bond are 22.8(6) and 28.7(6)°, respectively (anti conformation).  相似文献   
70.
We established three lines of transgenic medaka, a heat‐shock element (HSE) monitor line (hse‐GFP line), heat‐inducible driver lines (hse‐cre lines), and effector lines (gapdh‐loxP[DsRed]‐GFP lines). We employed these to comprehensively analyze gene induction at different time points in various tissues. These analyses demonstrate a good response of synthetic HSEs by heat treatment during embryogenesis and the mosaic gene induction by cre/loxP‐mediated recombination, thus providing practical information regarding the feasibility of a heat‐inducible cre/loxP‐mediated system in medaka. We also activated recombination by local heat‐treatment using a metal probe and an infrared laser. Our results collectively indicate that these lines allow us to perform lineage tracing and mosaic analysis and provide the platform to investigate gene functions at later developmental stage and adult. genesis 51:59–67, 2013. © 2012 Wiley Periodicals, Inc.  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