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   14631篇
  免费   795篇
  国内免费   63篇
耳鼻咽喉   230篇
儿科学   503篇
妇产科学   357篇
基础医学   2501篇
口腔科学   406篇
临床医学   1109篇
内科学   2353篇
皮肤病学   394篇
神经病学   1380篇
特种医学   477篇
外科学   2189篇
综合类   161篇
一般理论   2篇
预防医学   1134篇
眼科学   303篇
药学   1342篇
中国医学   80篇
肿瘤学   568篇
  2023年   122篇
  2022年   126篇
  2021年   281篇
  2020年   207篇
  2019年   316篇
  2018年   566篇
  2017年   418篇
  2016年   521篇
  2015年   510篇
  2014年   709篇
  2013年   1061篇
  2012年   1288篇
  2011年   1357篇
  2010年   836篇
  2009年   467篇
  2008年   454篇
  2007年   471篇
  2006年   437篇
  2005年   375篇
  2004年   390篇
  2003年   385篇
  2002年   330篇
  2001年   269篇
  2000年   360篇
  1999年   292篇
  1998年   149篇
  1997年   155篇
  1996年   116篇
  1995年   114篇
  1994年   77篇
  1993年   60篇
  1992年   115篇
  1991年   103篇
  1990年   110篇
  1989年   103篇
  1988年   95篇
  1987年   70篇
  1986年   72篇
  1985年   82篇
  1984年   87篇
  1983年   78篇
  1982年   76篇
  1981年   64篇
  1980年   58篇
  1979年   64篇
  1978年   63篇
  1977年   67篇
  1976年   61篇
  1975年   69篇
  1972年   59篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
The relationship between the immunoglobulin kappa light chain allotypes and autoantibodies was studied in a series of seven human monoclonal kappa-bearing IgM antibodies with Rheumatoid Factor (RF) activity, two IgM anti-low density lipoprotein (LDL) antibodies, and one IgM anti-intermediate filament (IF) antibody. Residues at amino acid positions 153 and 191 related to the Km allotypes in human kappa chains were determined by an HPLC tryptic fingerprint and corroborated by amino acid sequence analysis. All the autoantibodies shared similar variable regions derived from the V kappa IIIb gene(s). The seven RF and the anti-IF were associated with the Km(3) constant region allotype whereas the two anti-LDL were associated with the Km(1,2) allotype. Thus, monoclonal autoantibodies showed the same Km allotypic distribution as the normal population. However, although the number of samples is small, it seems likely that a preferential association may exist between particular V kappa genes and Km alleles in the generation of autoantibodies with different specificities.  相似文献   
14.
15.
16.
Several cases of relapsing attacks during which the ear becomes red and patients experience a burning sensation have been reported in the literature. This combination of symptoms has been described as ‘red ear syndrome’ (RES). We report on a 7‐year‐old boy who had episodes of reddening, swelling and a burning sensation in one ear with local hyperthermia persisting for 3 years. The differential diagnosis included RES and erythromelalgia, as isolated auricular variants of erythromelalgia have been described and the symptoms are difficult to distinguish from RES. In this report, we discuss the similarities and differences between RES and erythromelalgia.  相似文献   
17.

Background  

Reports on childhood cancer survivors estimated cumulative probability of developing secondary neoplasms vary from 3,3% to 25% at 25 years from diagnosis, and the risk of developing another cancer to several times greater than in the general population.  相似文献   
18.
With 1–1.5 million cases reported every year cutaneous leishmaniasis represents an increasing health problem. The course of cutaneous leishmaniasis varies from a single self‐healing ulcer to a persistent ulcer or progressive mucosal disease with nasopharyngeal destruction. An enormous array of topical and systemic treatment modalities has been endorsed. The response to treatment depends on the species of parasite as well as the host's immunological and genetic status. Species‐specific treatment guidelines based on evidence from controlled studies are highly desirable. We present two cases of cutaneous leishmaniasis, one in a child and one during pregnancy, reviewing various diagnostic and therapeutic measures with special attention to problems in young and pregnant patients.  相似文献   
19.
It is well known that there might be an epidemiological association between Helicobacter pylori infection and extraintestinal diseases. This study aimed at determining H. pylori infection in epileptic patients. Forty-seven cryptogenic epileptic patients (Group 1) and 35 healthy people (Group 2) participated in this study. Presence of H. pylori infection was examined by H. pylori stool antigen (HpSA), H. pylori IgG, and IgM. HpSA was detected in 21 participants (44.6%) in Group 1 and in 3 participants (8.5%) in Group 2. H. pylori IgM was positive in 27 participants (57.4%) in Group 1 and in 8 participants (22.8%) in Group 2. H. pylori IgG was positive in 37 participants (78.7%) in Group 1 and in 13 participants (38%) in Group 2. The difference of rates of HpSA, H. pylori IgM and IgG in Groups 1 and 2 were found statistically significant (chi2=4.18, p=0.04; chi2=9.18, p=0.0017; chi2=14.58, p<0.001, respectively). We also compared presence of H. pylori infection between the epileptic patients with poor and good prognosis; HpSA positivity was detected in 15 (62.5%) of 24 and 6 (26%) of 23, respectively, and the differences were statistically significant (chi2=6.30, p=0.012). H. pylori IgM positivity was detected in 16 (66%) of 24 patients with poor prognosis and 11 (47.8%) of 23 patients with good prognosis (p>0.05). H. pylori IgG positivity was detected in 18 (75%) of 24 patients with poor prognosis and 19 (82.6%) of 23 patients with good prognosis. The differences of H. pylori IgM and IgG positivity rates in epileptic patients with poor and good prognosis were not found statistically significant (p>0.05). These results suggest a probable association between the acute H. pylori infection and epilepsy, especially with poor prognosis.  相似文献   
20.
Teeth with white spot lesions (WSL) might be more prone to enamel loss during bracket debonding. This in vitro study compared enamel loss from teeth with (n = 14) and without (n = 14) WSL after polishing with low-speed finishing burs or disks (Sof-Lex, 3M ESPE, St Paul, Minn). Debonded surfaces were analyzed with a contact stylus profilometer, and digitized data were compared with baseline readings by using AnSur NT software (Regents, University of Minnesota, Minneapolis, Minn). Specimen surfaces were also examined with a scanning electron microscope. Two-way analysis of variance was performed to analyze the data. In teeth without WSL, the volume losses were 0.16 mm(3) for the bur group and 0.10 mm(3) for the disk group; the mean maximum depths were 47.7 microm for the bur group and 54.3 microm for the disk group. In teeth with WSL, the volume losses were 0.06 and 0.17 mm(3), and the mean maximum depths were 35.1 and 48.7 microm for the bur and disk groups, respectively. There were no significant differences in enamel loss between the 2 groups of teeth without WSL (P =.12). However, in teeth with WSL, the burs removed less enamel than the disks (P = 0.006). Scanning electron microscope examination showed that any damage on the enamel surface was usually located in the cervical third of the teeth. On most specimens, even though tooth surfaces appeared resin-free to the naked eye, there were remnants of it. The differences between groups were so small that they might be clinically insignificant.  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