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   46817篇
  免费   4673篇
  国内免费   3681篇
耳鼻咽喉   392篇
儿科学   492篇
妇产科学   625篇
基础医学   5576篇
口腔科学   1019篇
临床医学   6102篇
内科学   6953篇
皮肤病学   530篇
神经病学   2395篇
特种医学   1782篇
外国民族医学   23篇
外科学   4808篇
综合类   8053篇
现状与发展   15篇
一般理论   6篇
预防医学   3179篇
眼科学   1222篇
药学   4844篇
  36篇
中国医学   3071篇
肿瘤学   4048篇
  2024年   176篇
  2023年   733篇
  2022年   1928篇
  2021年   2438篇
  2020年   1840篇
  2019年   1543篇
  2018年   1693篇
  2017年   1525篇
  2016年   1400篇
  2015年   2087篇
  2014年   2641篇
  2013年   2242篇
  2012年   3269篇
  2011年   3572篇
  2010年   2192篇
  2009年   1782篇
  2008年   2294篇
  2007年   2356篇
  2006年   2328篇
  2005年   2096篇
  2004年   1728篇
  2003年   1846篇
  2002年   1675篇
  2001年   1413篇
  2000年   1256篇
  1999年   1354篇
  1998年   902篇
  1997年   836篇
  1996年   658篇
  1995年   597篇
  1994年   521篇
  1993年   267篇
  1992年   359篇
  1991年   297篇
  1990年   282篇
  1989年   230篇
  1988年   221篇
  1987年   179篇
  1986年   151篇
  1985年   96篇
  1984年   76篇
  1983年   33篇
  1982年   18篇
  1981年   15篇
  1980年   14篇
  1979年   6篇
  1978年   2篇
  1970年   1篇
  1969年   1篇
  1964年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
想起吃饭,奶猪有时候高兴.有时候不高兴。 老头儿猪对她说过.挨饿的时候他总惦记自杀,因为他见到那势头,总觉得躲不过去。之所以后来还活着.是因为他想到要是不死,保不准哪天还能吃上碗红烧肉,死了可就板上定钉永远也吃不上了。老头儿猪因为这个崇高的信念咬牙切齿地养大了肉猪他爸肉猪他爸又养大了肉猪。肉猪是奶猪的男朋友,肉猪他爸和老头儿猪把肉猪叫肉猪,肉猪把奶猪叫奶猪,肉猪说:“这样好,听起来就胖乎乎香喷喷的”。  相似文献   
3.
Intractable tinnitus can lead to serious consequences. Study evidence indicates that the central nervous system is involved in generation and maintenance of chronic tinnitus and that tinnitus and other neurologic symptoms such as chronic pain may share similar mechanisms. Brain ablation and stimulation are used to treat chronic pain with success. Recent studies showed that ablation and stimulation in non-auditory areas resulted in tinnitus improvement. Deep brain stimulation (DBS) may be an alternative treatment for intractable tinnitus and deserves further study.  相似文献   
4.
1. We previously reported that angiotensin II release from the mesenteric arteries of Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) increased in a time-dependent manner as a result of the isolation of the arteries and perfusion. This phenomenon appeared to be due to the withdrawal of circulating angiotensin II (AII). 2. The purpose of the present study was to test the hypothesis that vascular AII generation may be negatively regulated by circulating AII in WKY and SHR, and to clarify the role of this vascular angiotensin II in the sustained hypertension of SHR following nephrectomy. 3. The mesenteric arteries from kidney-intact and nephrectomized WKY and SHR were perfused and the amount of AII released into the perfusate was measured. The effects of the angiotensin converting enzyme inhibitor, captopril, and the effects of supplementation of renal renin and circulating angiotensins to nephrectomized rats, by blood exchange between kidney-intact and nephrectomized rats, on AII release were examined to clarify the pathway of vascular AII generation after nephrectomy. 4. Nephrectomy caused augmentation of vascular AII release both in WKY and SHR in spite of the abolishment of circulating renin. Captopril reduced this enhanced release of AII, but blood exchange did not affect it. There was no significant difference in these responses between WKY and SHR. 5. These results suggest that WKY and SHR have in common a potent pathway for production of vascular AII in response to the withdrawal of circulating AII, although this pathway is not responsible for the sustained hypertension of SHR after nephrectomy. The precise pathophysiological role of this pathway remains to be elucidated.  相似文献   
5.
6.
7.
Poly (3-phenylthiophene) (P3PhT) films have been electrochemically synthesized by direct oxidation of 3-phenylthiophene in the electrolyte of pure boron trifluoride diethyl etherate (BFEE). The oxidation potential of the monomer was measured to be 1.29 V (vs. SCE), and about 0.15 V lower than that measured in a neutral medium of acetonitrile. Free-standing P3PhT film with tensile strength of 32–40 MPa has been obtained for the first time. The morphology and the structure of the polymer film have been studied by scanning electron microscopy, infrared and Raman spectroscopies. Raman spectral results demonstrated that the doping level of the P3PhT film increased with film thickness during electrochemical growth process.  相似文献   
8.
Stem cells and periodontal regeneration   总被引:10,自引:0,他引:10  
  相似文献   
9.
The present study was designed to detect three single nucleotide polymorphisms (SNPs) located on 22q11 that was thought as being of particularly importance for genetic research into schizophrenia. We recruited a total of 176 Chinese family trios of Han descent, consisting of mothers, fathers and affected offspring with schizophrenia for the genetic analysis. The transmission disequilibrium test (TDT) showed that of three SNPs, rs10314 in the 3'-untranslated region of the CLDN5 locus was associated with schizophrenia (chi(2) = 4.75, P = 0.029). The other two SNPs, rs1548359 present in the CDC45L locus centromeric of rs10314 and rs739371 in the 5'-flanking region of the CLDN5 locus, did not show such an association. The global chi-square (chi(2)) test showed that the 3-SNP haplotype system was not associated with schizophrenia although the 1-df test for individual haplotypes showed that the rs1548359(C)-rs10314(G)-rs739371(C) haplotype was excessively non-transmitted (chi(2) = 5.32, P = 0.02). Because the claudin proteins are a major component for barrier-forming tight junctions that could play a crucial role in response to changing natural, physiological and pathological conditions, the CLDN5 association with schizophrenia may be an important clue leading to look into a meeting point of genetic and environmental factors.  相似文献   
10.
In order to investigate the antagonistic effect of Glycyrrhiza Uralensis Fish (GUF) and Chelidonium maJus L (CML) on gastrccarcinogenesis induced by MNNG in Wastar rats, we treated the rats with MNNG alone (group 1) and with MNNG plus GUF and CML (group 2 and 3) respectively. The incidence of infiltrating adenocarcinoma of the glandular stomach and duodenum in group 2 was significantly lower than that in group 1 (26.7% vs. 67.8%). The differentiation and aggressivenees of carcinomas occured in group 2 were much better and mild than those in group 1. Present study also demonstrated that the inhibitory effect of CML on proliferation of human stomach carcinoma cell line MGC-803 was very remarkable; in addition, GUF and CML were able to antagonise the mutagenic activation of MNNG. These results suggest that GUF and CML may be empoyed in prevention of gastric carcinoma.  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