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   116861篇
  免费   8734篇
  国内免费   392篇
耳鼻咽喉   1259篇
儿科学   3066篇
妇产科学   2069篇
基础医学   16684篇
口腔科学   2575篇
临床医学   11851篇
内科学   24605篇
皮肤病学   2350篇
神经病学   12334篇
特种医学   4808篇
外国民族医学   6篇
外科学   16195篇
综合类   1416篇
一般理论   80篇
预防医学   9196篇
眼科学   1920篇
药学   7855篇
中国医学   132篇
肿瘤学   7586篇
  2023年   627篇
  2022年   1202篇
  2021年   2348篇
  2020年   1466篇
  2019年   2205篇
  2018年   2698篇
  2017年   2029篇
  2016年   2404篇
  2015年   2764篇
  2014年   3617篇
  2013年   4838篇
  2012年   7398篇
  2011年   7548篇
  2010年   4376篇
  2009年   4022篇
  2008年   6603篇
  2007年   7036篇
  2006年   6596篇
  2005年   6496篇
  2004年   6091篇
  2003年   5450篇
  2002年   5352篇
  2001年   2356篇
  2000年   2258篇
  1999年   2140篇
  1998年   1409篇
  1997年   1158篇
  1996年   945篇
  1995年   957篇
  1994年   851篇
  1993年   760篇
  1992年   1457篇
  1991年   1391篇
  1990年   1283篇
  1989年   1266篇
  1988年   1138篇
  1987年   1028篇
  1986年   1029篇
  1985年   1011篇
  1984年   837篇
  1983年   720篇
  1982年   633篇
  1981年   548篇
  1980年   461篇
  1979年   626篇
  1978年   500篇
  1977年   463篇
  1975年   427篇
  1974年   472篇
  1973年   426篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
The loss of available iodine from povidone-iodine solution stored in contact with two different polyetherpolyurethane foams was monitored as a function of time and temperature. Statistical evaluation of the results for the four temperatures studied [ambient (25 degrees), 30, 45 and 55 degrees C] indicated the chemical equivalence of the two foams as storage and delivery systems for povidone-iodine solution in terms of solution stability. In addition, application of a first-order kinetic model to the data produced an acceptable fit. An Arrhenius-type evaluation of the resulting rate constants yielded a linear relationship which was shown to be useful for predicting loss of available iodine under ambient temperature conditions of storage.  相似文献   
93.
94.
Abstract: We describe the use of restriction analysis on PCR-amplified DNA for detecting all B*27 subtypes except B*2710 and B*2711 (i.e. from B*2701 to B*2709). After detecting B*27 by Sty I, double digestions consisting of Sty I plus another informative enzyme led to subtype assignment. We used mismatched primers to create restriction sites when necessary. The method avoids group-specific amplifications and other laborious optimization procedures. It was successfully tested on a panel of well characterized cell lines covering different B*27 subtypes. Then, we studied a group of 57 ankylosing spondyiitis patients and 746 controls from the south of Spain. B*27 showed a very strong association with the disease (OR=211.27, P=\0˜7). B*2702 and B*2705 distribution in controls (20% and 77.1%, respectively) differed from previously reported data in the Spanish population. We unexpectedly found the B*2707 allele in our population (one control).  相似文献   
95.
Bony fusions involving the carpus have a much higher prevalence in blacks relative to whites. This article describes a case of lunotriquetral coalition fracture-dislocation in an African American. This lesion is best treated through open reduction and pin fixation.  相似文献   
96.
The anticancer agent temozolomide labeled with 13C (8-Carbamoyl-3-13C-methylimidazo-[5,1-d]-1,2,3,5-tetrazin-4-(3H)-one), was noninvasively detected in subcutaneous RIF-1 tumors by a selective cross polarization 13C NMR method, at a field strength of 9.4T. Pharmacokinetics of the drug, at a dose of 150 mg/kg, were determined for intravenous and intraperitoneal modes of administration (three animals per mode). The half-life of the drug in the tumors was approximately 60 min. The uptake and clearance of the drug, however, varied significantly between individual hosts, for both modes of administration. These results demonstrate the feasibility of obtaining pharmacokinetics of anticancer agents for individual tumors without the need for a label that might modify drug activity (e.g., fluorine). The variability of the in vivo measurements, even within the same tumor model, demonstrates the necessity of directly monitoring the tumor to evaluate drug pharmacokinetics.  相似文献   
97.
98.
In child and youth care in the Netherlands, systematic planning of treatment is more and more considered to be a condition for effective and well founded treatment. Although workers are convinced of the benefits of treatment plans, treatment planning is not yet a natural and integrated part of residential care. There are several pressure points. In this article a model of treatment planning will be presented that contributes to an answer to these pressure points. The theoretical bases and the practical implications of this model will be discussed.  相似文献   
99.
100.
G12 monoclonal antibody (mAb), one of a library of constructed mAb directed against human sperm proteins, was found by immunoperoxidase staining to label the post-acrosomal and neck regions of fixed human cauda epididymal and ejaculated spermatozoa. Epithelium and fluid of caput epididymis were strongly labelled while there was no staining on testis and efferent ducts. Western lot analysis revealed that G12 antibody reacted with proteins of 17.5, 18 and 19 kDa in human spermatozoa. This pattern seems to be specific for mature human spermatozoa, as it has not been observed either in other human tissues tested, or in spermatozoa from different animals. SOB2, the corresponding protein, was isolated from NP40-extracted human spermatozoa by using preparative electrophoresis, followed by isoelectrofocusing according to its isoelectric point of 6.4 G12 Fab fragments strongly inhibited binding of human spermatozoa to zona-free hamster oocytes (up to 86% inhibition at 200 micrograms/ml). Impairment of binding was dependent on the concentration of purified G12 immunoglobulin (Ig)G1, and significant even at 10 micrograms/ml. There was no inhibitory effect of G12 antibody on sperm motility parameters or triggering of the acrosome reaction and it did not inhibit binding to human zona pellucida. These results indicate that SOB2 is likely to participate in membrane oocyte binding, and my be potential candidate for the development of a contraceptive vaccine.   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