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   5663篇
  免费   293篇
  国内免费   39篇
耳鼻咽喉   120篇
儿科学   175篇
妇产科学   136篇
基础医学   894篇
口腔科学   559篇
临床医学   391篇
内科学   1122篇
皮肤病学   139篇
神经病学   448篇
特种医学   104篇
外科学   495篇
综合类   25篇
一般理论   3篇
预防医学   553篇
眼科学   70篇
药学   409篇
中国医学   27篇
肿瘤学   325篇
  2024年   5篇
  2023年   48篇
  2022年   141篇
  2021年   233篇
  2020年   164篇
  2019年   190篇
  2018年   209篇
  2017年   129篇
  2016年   185篇
  2015年   226篇
  2014年   262篇
  2013年   336篇
  2012年   451篇
  2011年   532篇
  2010年   292篇
  2009年   251篇
  2008年   342篇
  2007年   365篇
  2006年   337篇
  2005年   309篇
  2004年   261篇
  2003年   197篇
  2002年   178篇
  2001年   34篇
  2000年   21篇
  1999年   24篇
  1998年   20篇
  1997年   25篇
  1996年   18篇
  1995年   14篇
  1994年   6篇
  1993年   14篇
  1992年   8篇
  1991年   7篇
  1990年   4篇
  1989年   8篇
  1988年   11篇
  1987年   12篇
  1986年   9篇
  1985年   12篇
  1983年   11篇
  1982年   5篇
  1981年   4篇
  1980年   5篇
  1979年   8篇
  1977年   12篇
  1975年   15篇
  1974年   4篇
  1972年   6篇
  1971年   4篇
排序方式: 共有5995条查询结果,搜索用时 0 毫秒
1.
An in vitro expression of delayed-type hypersensitivity to tuberculin was tested in Mantoux positive and Mantoux negative persons. Their lymphocytes and monocytes were isolated from venous blood and incubated in vaseline chambers with or without tuberculin. In the presence of tuberculin, a substantially lower percentage of monocytes from Mantoux positive persons spread, than monocytes from Mantoux negative persons. This antigen-induced inhibition of monocyte spreading seems to be a reliable measure of tuberculin hypersensitivity, since it occurs only in Mantoux positive persons and correlates well with the intensity of the tuberculin skin reaction. Reproducibility of the test and the speed with which it is performed could constitute a basis for the use of monocyte spreading inhibition in clinical studies of cell-mediated immune reactions.  相似文献   
2.
Four different tests for detection of rubella-specific IgM antibodies were compared: two Ig separation methods (centrifugation and chromatography) with subsequent haemagglutination inhibition test and two commercially available ELISA tests. The 114 sera tested had been sent to the diagnostic laboratory, mostly with insufficient clinical histories. Agreement between the centrifugation method and one of the ELISA tests was good (2 divergent results with 107 sera tested), while the other ELISA test yielded more positive (partly perhaps non-specific) results. The chromatographic method did not separate the Ig classes as reliably as the centrifugation method, but because of its simplicity it may be useful, if adequate test controls are performed. The divergent results are discussed. It is postulated that in cases with pending induced abortion, two independent tests should be performed.  相似文献   
3.
Acute coronary syndromes (ACS), including unstable angina (UA) and acute myocardial infarction (MI), are clinical manifestations of a progressive atherosclerotic process. Antibodies (Ab) to heat shock proteins (hsp) have been reported to be associated with atherosclerosis. Blood samples from 35 patients with ACS and 20 healthy volunteers were tested for Ab to human hsp60 by an enzyme-linked immunosorbent assay (ELISA). Levels of specific serum Ab against hsp60 were significantly elevated in patients with ACS when compared to clinically healthy subjects. To determine the antigenic determinants recognized by these Ab, antibody binding to seven peptides, selected from the hydrophilic and acrophilic regions of the human hsp60 molecule, was assessed. Despite the individual variation in the immune response among patients, one immunodominant region was revealed corresponding to the hsp60 (409-424) peptide. The identification of this epitope may be important for understanding the function of this protein in the atherosclerotic process.  相似文献   
4.
Psyllium is a hydrophilic agent found in many bulk laxative preparations. We report the occurrence of an anaphylactic reaction in a patient after ingestion of a psyllium-containing laxative. IgE mediation of the reaction was suggested by a positive immediate skin test to psyllium, positive passive transfer skin test, lack of skin response during passive transfer with heat treated serum, and an elevated IgE (RAST) to psyllium seed.  相似文献   
5.
Implanted biomaterials trigger acute and chronic inflammatory responses directly correlated to the central role of phagocytic cells at the host-implant interface. This study was designed to evaluate specific humoral immune responses following repeated intraperitoneal implantations of collagen-impregnated polyester (Dacron) prosthetic segments into LEWIS rats. Serum antibody detection was performed by enzyme immunoassay with the prosthetic segments as a target. Cutoff values for antibody positivity were greater than or equal to the 99th percentile for control rats. Polymer immunoglobiulin G (IgG) antibodies were significantly increased (p < 0.05) by repeated implantation and were subsequently followed until experimental day 293. Antibody formation was significantly enhanced through the application of complete Freund's adjuvant in combination with the first implantation. All rats within this group were antibody-positive on day 53, but only 6 of 10 animals that received the prosthesis without the adjuvant were. After preincubation of sera with bovine collagen type I (solid phase adsorbed or in solution), polymer antibody binding was discovered not to be diminished, indicating that the IgG antibodies detected were not directed against the prosthesis impregnation. Furthermore, a significant correlation was obtained between polymer antibody binding to collagen-impregnated and nonimpregnated prostheses (r(s) = 0.797, p < 0.001). There was no substantiated correlation between antibody binding to polyester and to an irrelevant polymer (Tecoflex EG 80). We conclude that specific polymer antibodies may indeed provide an additional parameter for biocompatibility testing as well as a possible serological marker of an inflammatory response to implants.  相似文献   
6.
Isolated human peripheral lymphocytes were treated in vitro with styrene-7, 8-oxide (SO) and the kinetics of the repair of induced DNA damage was assessed by comet assay during further incubation of lymphocytes. Using a modified assay we measured simultaneously the number of single strand breaks in DNA (SSBs) and the sites sensitive to endonuclease III (endo III) that most probably represent abasic sites in DNA molecules. SO induced DNA damage in a dose-dependent manner and both SSBs and endo III sites were removed from the DNA by a repair process with a half time about 2-4 hours. The damage was repaired completely within 12 hours after the treatment.  相似文献   
7.
8.
Lasers in Medical Science - This study compared the effects of LED therapy associated with occlusal splint (OS) on the signs and symptoms of temporomandibular disorder (TMD). In this randomized,...  相似文献   
9.
10.
BACKGROUND: Androgenetic alopecia (AGA) is a common, genetically predisposed condition that begins after puberty and whose frequency increases with age; although biologically benign, AGA can impact patients both psychologically and socially, contributing to an impairment on their quality of life. OBJECTIVE: We sought to evaluate the psychological, social, and quality of life impairments inherent in women with AGA using 5% minoxidil daily for at least six months. DESIGN: Thirty-one women with diffuse central hair thinning and shaft miniaturization who were using 5% minoxidil daily for at least six months responded to a clinical questionnaire and underwent trichoscopy. RESULTS: 83.9 percent (n=26) of the participants reported they were satisfied with the 5% minoxidil treatment and its convenience. Hair loss influenced social life in 54.8 percent (n=17) of the respondents and choice of hair cut/hairstyle in 87.1 percent (n=27) of respondents. For 51.6 percent (n=16) hair loss was slightly increased, although it did not increase after beginning treatment. A frontoparietal pattern (74.2%, n=23), very low capillary density (61.3%, n=19), trichodynia (32.3%, n=10), and negative traction test (100%, n=31) were also observed. Miniaturization occurred in 100 percent (n=31) of patients, frontal/occipital hair thickness was reduced in 83.9 percent (n=26), and more than 10 percent of velus hair in the frontal area was observed in 83.9 percent (n=26) of patients. The number of hair shafts per follicular unit was reduced in 67.7 percent (n=21), and a higher frontal to occipital ratio of follicular units with one hair shaft was seen in 74.2 percent (n=23) of patients. Empty follicles, large numbers of peripillar brownish halo, scalp pigmentation, mild Ludwig''s baldness degree, and quality of life scores of 4±3.5 points were observed. CONCLUSION: Our results indicate that patient satisfaction and quality of life of women with AGA on 5% topical minoxidil are high, although hair loss influences daily habits and social life.  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