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   109018篇
  免费   12232篇
  国内免费   5114篇
耳鼻咽喉   287篇
儿科学   697篇
妇产科学   389篇
基础医学   3967篇
口腔科学   619篇
临床医学   8073篇
内科学   9083篇
皮肤病学   1459篇
神经病学   2872篇
特种医学   1091篇
外国民族医学   13篇
外科学   3355篇
综合类   21516篇
现状与发展   12篇
一般理论   4篇
预防医学   5880篇
眼科学   943篇
药学   35062篇
  117篇
中国医学   26495篇
肿瘤学   4430篇
  2024年   772篇
  2023年   2157篇
  2022年   3615篇
  2021年   4803篇
  2020年   4856篇
  2019年   3871篇
  2018年   3502篇
  2017年   4584篇
  2016年   4517篇
  2015年   4359篇
  2014年   8574篇
  2013年   10384篇
  2012年   8534篇
  2011年   8582篇
  2010年   7083篇
  2009年   5680篇
  2008年   4931篇
  2007年   5269篇
  2006年   4433篇
  2005年   3901篇
  2004年   3198篇
  2003年   2841篇
  2002年   2271篇
  2001年   2110篇
  2000年   1685篇
  1999年   1329篇
  1998年   1083篇
  1997年   1049篇
  1996年   836篇
  1995年   745篇
  1994年   639篇
  1993年   500篇
  1992年   566篇
  1991年   485篇
  1990年   365篇
  1989年   297篇
  1988年   297篇
  1987年   274篇
  1986年   212篇
  1985年   223篇
  1984年   185篇
  1983年   131篇
  1982年   120篇
  1981年   92篇
  1980年   63篇
  1979年   64篇
  1978年   68篇
  1977年   50篇
  1976年   50篇
  1975年   50篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
101.
HK239: a P2 related temperate phage which excludes rII mutants of T4   总被引:7,自引:0,他引:7  
E K Dhillon  T S Dhillon 《Virology》1973,55(1):136-142
  相似文献   
102.
103.
An anticarbamazepine antibody was detected in the serum of a patient with severe carbamazepine-induced serum sickness. We found that the patient's T cells and IgG antibody recognized an epitope which appeared in subjects showing an allergic reaction, as well as that in subjects who showed no allergic reaction, after long-term carbamazepine therapy. These results show that an anti-carbamazepine immune response does not occur in the majority of subjects who undergo long-term carbamazepine therapy without developing allergic symptoms, although the immunodominant haptenic epitope of carbamazepine is present in their sera.  相似文献   
104.
105.
K. Kurashima    M. Fujimura    M. Saito    S. Sakamoto    Y. Miyake    K. Nishi  T. Matsuda 《Allergy》1990,45(4):249-253
Slow-reacting substance of anaphylaxis (SRS-A) is an important factor mediating bronchoconstriction in asthma. We developed a guinea pig model for SRS-A mediated bronchoconstriction induced by antigen inhalation. Using this model, we investigated the effect of inhaled WP871, a new anti-allergic drug, on bronchoconstriction. Aerosol WP871 (0.01 and 0.033%) to some extent inhibited the antigen-induced bronchoconstriction in a dose-dependent fashion, but high-dose WP871 (0.1%) inhalation itself produced a non-specific bronchoconstriction. However, aerosol WP871 (0.033%) showed no inhibitory effect on bronchoconstriction caused by direct inhalation of leukotriene C4, a component of SRS-A. These findings indicate that aerosol WP871 does not antagonize SRS-A, but inhibits synthesis and/or release of SRS-A and has some non-specific bronchoconstrictive effect in high concentration.  相似文献   
106.
The effects of treditional Chinese medlclne (Salrel-to) on experimental glomerulonephritls Induced In rats by monodonal antibody (mAb) 1–22–3 lnjectlon was examined. The level of proteinuria in the Sairel-to-treated group was significantly lower than that In the PBS treated group. This suppressive effect was caused by the major component of Sealer-to, Syo-salko-to but not by another component, Gorel-san. The suppressive effect of Syo-salko-to was Identified In Its components ( Bupleuri radix, Pindilae tuber and Zingibers rhizoma ), but not In the other combined components ( Ginseng radix and Zizyphl fructus ). Further study weeled that the suppressive effects of the combined components were mainly derived from Bupleuri radix . It was demonstrated that the actual active Ingredient is probably Salkosaponin-d. Light microscopy revealed that Sairel-to and Its effective components suppressed the proliferation of mesanglal cells and mesanglal matrix expansion. Semi quantitative morphological studies of glomerular lesions on the eighth day showed that Syo-salko-to and Its combined components ( Bupleuri radix, Zinglberis rhizoma and Pinelliae tuber ) suppressed mesanglal matrix expansion significantly compared with phosphate-buffered saline control groups (matrix score: 28.0±19.1 vs 102.3±14.1; 30.9±30.1 vs 102.3±14.1, p<0.005, respectively). It was concluded that Salkosaponln-d, as well as Bupleuri radix , Syo-salko-to and Sairel-to can suppress proteinurla and morphological changes In the rat glomerulonephritls model Induced by mAb 1–22–3.  相似文献   
107.
The HLA-DP genes (HLA-DPA1 and -DPB1) are encoded by the major histocompatibility complex (MHC) on human chromosome 6. They are involved in the presentation of antigen to CD4+ T cells as part of the class II antigen-presentation pathway. During a small study of Oriental subjects (11 Chinese and 26 Japanese subjects), one Chinese subject was identified as having numerous heterozygous sites within the second exon of both DPA1 and DPB1. These were further analysed using novel codon-specific primers. Sequencing analysis using these primers determined the subject to have DPA1*0103/*02015 and DPB1*0501/*8401; these new alleles have been submitted to GenBank and assigned the accession numbers AF098794 and AF077015, respectively.  相似文献   
108.
An interactive CD-ROM program designed to reduce adolescent substance use was developed and evaluated. The program uses video vignettes to teach refusal skills and socially acceptable responses to substance use situations, specifically offers of marijuana. In a randomized pretest-to-posttest experiment with 74 public school students from six classes in three high schools, significant changes were observed at posttest on (1) the adolescent's personal efficacy to refuse the offer of marijuana, (2) the adolescent's intention to refuse marijuana if offered, and (3) the adolescent's perceptions of the social norms associated with substance use and the importance of respecting another's decision to refuse a drug offer. In addition, adolescents in the treatment condition were able to recall approximately 50% of the portrayed refusal strategies. Findings are discussed with regard to the potential benefits of an interactive multimedia approach for conducting substance use interventions.  相似文献   
109.
110.
Biodegradation studies on periodate oxidized cellulose   总被引:1,自引:0,他引:1  
Sodium periodate oxidized cellulose was found to degrade into small molecules when implanted subcutaneously in rats. Thus the potentiality of using oxidized cellulose as a biodegradable drug carrier is envisaged.  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