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   2060篇
  免费   140篇
  2200篇
  2024年   3篇
  2023年   16篇
  2022年   44篇
  2021年   59篇
  2020年   32篇
  2019年   66篇
  2018年   71篇
  2017年   54篇
  2016年   78篇
  2015年   116篇
  2014年   119篇
  2013年   131篇
  2012年   196篇
  2011年   187篇
  2010年   101篇
  2009年   94篇
  2008年   138篇
  2007年   118篇
  2006年   113篇
  2005年   84篇
  2004年   79篇
  2003年   63篇
  2002年   52篇
  2001年   11篇
  2000年   9篇
  1999年   9篇
  1998年   14篇
  1997年   5篇
  1996年   16篇
  1995年   14篇
  1994年   6篇
  1993年   9篇
  1992年   13篇
  1991年   4篇
  1990年   2篇
  1989年   6篇
  1988年   4篇
  1987年   6篇
  1986年   5篇
  1985年   8篇
  1984年   4篇
  1982年   11篇
  1981年   4篇
  1979年   5篇
  1978年   6篇
  1977年   4篇
  1976年   3篇
  1968年   2篇
  1966年   1篇
  1964年   1篇
排序方式: 共有2200条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
A series of 65 cases of different histological types of breast carcinoma was investigated for the immunohistochemical location of the estrogen receptor-related, 29 kD phosphoprotein using the ER-D5 monoclonal antibody. The ER-D5 response is heterogeneous in relation to some therapeutic limitations and is correlated with histopathological features of the tumors and survival. The main parameters for evaluation of breast cancers are reviewed, both those that are statistically correlated and those that are not apparently always correlated but are known to have considerable biological meaning, such as the ER-status of tumors.  相似文献   
5.
The qualitative fungal composition of Turin 's atmospheric environment was surveyed, carrying out a twelve-month study and collecting with a single stage volumetric sieve sampler on Dermasel agar supplemented with 0.4 g l–1 cycloheximide and 0.05 g l–1 chloramphenicol. We isolated 165 species and 2 varieties of mesophilic fungi from 58 genera and 26 thermotolerant species from 12 genera. Penicillium, Aspergillus, Acremonium, Chrysosporium, Scopulariopsis, Malbranchea, Paecilomyces, Phialophora and Cladosporium were in sequence the genera most rich in mesophilic species; Aspergillus, Penicillium, Chrysosporium and Scopulariopsis the most rich in thermotolerant species. Many of the species isolated are rarely or never recorded in the atmospheric environment. Cycloheximide can thus be said to select among airborne fungi, giving a characteristic picture.Abbreviation CH Cycloheximide - cfu colony forming unit  相似文献   
6.
7.
A hybrid hybridoma secreting a bispecific hybrid mAb (bsmAb), which recognizes both the epidermal growth factor receptor (EGF-R) and the drug doxorubicin, was produced by somatic hybridization of two hybridomas. The bsmAb obtained was able to retarget doxorubicin cytotoxicity in vitro specifically on EGF-R-positive cells exerting at the same time an antidotal effect on cells that did not overexpress the EGF-R. Distribution studies in mice indicate that the bsmAb selectively delivers the drug to tumour cells and modifies doxorubicin biodistribution with a statistically significant decrease of drug concentration in the intestine, which is the main target of early anthracycline toxicity. In keeping with this finding is the remarkable antidotal activity exerted by bsmAb in mice treated with doxorubiein, which is proved by retardation in loss of body weight and mortality. The effectiveness on tumour growth of the mAb followed by the administration of doxorubicin appears to be equal to that of the drug alone; however, the bsmAb exerts a remarkable antidotal activity.  相似文献   
8.
Abstract Three phyletic groups of Borrelia associated with Lyme disease, B. burgdorferi, B. garinii and group VS461 can be distinguished from each other and other species of Borrelia by Bfa I restriction site polymorphisms in PCR amplified 16S rRNA genes. One strain isolated from an Ixodes pacificus tick in California that was previously unclassifiable was distinguishable from B. burgdorferi by an Mnl I restriction site polymorphism.  相似文献   
9.
Rainbow lizards (Agama agama) are common in suburban areas throughout Africa, and have an opportunistic foraging strategy, with arthropods being the main prey source. In a coastal resort in southern Togo, West Africa, several individuals in a population were observed while feeding regularly upon non-natural human-made food (pizza) and showing a clear preference for a given type of food versus others that were offered (‘four cheeses’ being the preferred one). The fact that all monitored individuals fed upon a same type of pizza suggests that they may have some chemical cues attracting them.  相似文献   
10.
Activation of splenic lymphocytes with Con A leads to the formation of suppressor cells capable of interfering with the activity of several polyclonal B-cell-activating substances. Thus, these suppressor cells, or their products, most probably act directly on B cells. Suppressor cells could be recovered from the effluent cell population of nylon wool columns, and they were absent from the spleens of athymic nude mice. Furthermore, they were absent from the thymus of normal as well as cortison-treated mice. Cortisone treatment did not abolish the formation of Con A-induced suppressor cells in the spleen. Treatment of activated suppressor cells with antisera specific for distinct products of the H-2 I region revealed that they carried I-J cell surface antigens. We conclude that the suppressor cells in our test system, which unlike other Con A-induced suppressor cell populations have a direct effect on B cells, had antigenic characteristics similar to those previously described for I-J carrying suppressor cells.  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