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   10188篇
  免费   484篇
  国内免费   63篇
耳鼻咽喉   123篇
儿科学   252篇
妇产科学   78篇
基础医学   1350篇
口腔科学   287篇
临床医学   697篇
内科学   2510篇
皮肤病学   262篇
神经病学   861篇
特种医学   326篇
外科学   2004篇
综合类   40篇
预防医学   271篇
眼科学   165篇
药学   599篇
中国医学   17篇
肿瘤学   893篇
  2023年   48篇
  2022年   82篇
  2021年   183篇
  2020年   100篇
  2019年   169篇
  2018年   210篇
  2017年   174篇
  2016年   189篇
  2015年   198篇
  2014年   245篇
  2013年   290篇
  2012年   506篇
  2011年   540篇
  2010年   287篇
  2009年   254篇
  2008年   413篇
  2007年   475篇
  2006年   408篇
  2005年   461篇
  2004年   456篇
  2003年   434篇
  2002年   464篇
  2001年   351篇
  2000年   386篇
  1999年   354篇
  1998年   134篇
  1997年   119篇
  1996年   104篇
  1995年   89篇
  1994年   68篇
  1993年   60篇
  1992年   238篇
  1991年   227篇
  1990年   202篇
  1989年   191篇
  1988年   159篇
  1987年   182篇
  1986年   155篇
  1985年   146篇
  1984年   104篇
  1983年   85篇
  1979年   86篇
  1978年   61篇
  1977年   55篇
  1971年   57篇
  1970年   40篇
  1969年   44篇
  1968年   53篇
  1967年   43篇
  1966年   44篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Elderly patients (aged greater than or equal to 65 years) with non-Hodgkin's lymphoma were treated either with CHOP or COP-BLAM therapy, and the effectiveness and reverse effects of COP-BLAM therapy were compared with those of CHOP therapy. Thirty-three patients (aged greater than or equal to 65 years) with previously untreated non-Hodgkin's lymphoma were entered either on CHOP or COP-BLAM regimen between September, 1979 and February 1990. To CHOP therapy was performed in 15 patients (median age; 70 years). Eight of them had diffuse large cell type lymphoma (large), five had diffuse medium-sized cell type (medium) and two had diffuse mixed cell type (mixed). As to clinical stage, there were patients in stage II, 4 in stage III and 9 in stage IV in CHOP group. Of 18 patients (median age; 68 years), who were treated with COP-BLAM therapy, 8 had of large lymphoma and 10 medium lymphomas in histopathological classification. In terms of clinical stage, there were 5 patients in stage II, 4 in stage III and 9 in stage IV. CHOP therapy and COP-BLAM therapy were performed according to the method reported by McKelvey et al, and by Laurence et al., respectively, using the full doses of drugs without consideration the age. Complete remission (CR) was achieved in seven (46.7%) of 15 patients treated with CHOP therapy. In this group, five (38.5%) of 13 patients in advanced stages (stage III or IV) entered CR. Of 18 patients subjected to COP-BLAM therapy, 15 (83.3%) achieved CR. Among 13 patients in advanced stage treated with COP-BLAM therapy, CR was achieved in 11 (84.6%).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
22.
Thoracic outlet syndrome is a disorder caused by neurovascular compression of the brachial nerve plexus and the subclavian artery or vein by bones and muscles. We report the MR angiographic findings of a patient with thoracic outlet syndrome.  相似文献   
23.
24.
25.
Sequential contrast-enhanced MR imaging of the penis   总被引:1,自引:0,他引:1  
Kaneko  K; De Mouy  EH; Lee  BE 《Radiology》1994,191(1):75
  相似文献   
26.
27.
A 52 year-old woman noticed general fatigue, polyarthralgia, and muscle weakness of lower extremities in October 2001. In December, she felt difficulty in walking due to muscle weakness. In January 2002, she admitted another hospital because of dyspnea on exertion and edema of lower extremities. Laboratory test revealed leukocytopenia, the elevation of creatine kinase and positive anti-U1-RNP antibodies. Her chest computed tomography (CT) showed severe interstitial pneumonia. Cardiac echogram revealed that she had pericardial effusion and pulmonary hypertension. Then she was transferred to Keio University Hospital and she was diagnosed as having mixed connective tissue disease (MCTD) manifestating myositis, interstitial pneumonia, pulmonary hypertension and pericarditis. Prednisolone (PSL) 60mg daily following to methylprednisolone (mPSL) pulse therapy was begun and her symptoms were gradually improved. In middle of February, she complained of high fever over 39.0 degrees C. Bacterial culture tests were negative and laboratory data indicated pancytopenia and a high level of serum ferritin. Bone marrow aspiration revealed hemophagocytosis in bone marrow specimens and she was diagnosed as having hemophagocytic syndrome associated with MCTD. mPSL pulse therapy was not effective and intermittent cyclophosphamide pulse therapy (IV-CY) was performed resulting in improvement of the symptoms. This case suggested the effectiveness of IV-CY therapy in patients with corticosteroid-resistant HPS associated with connective tissue diseases.  相似文献   
28.
Inhibition of HIV-1 infectivity with curdlan sulfate in vitro   总被引:5,自引:0,他引:5  
Polymethoxylated flavones and C-glycosyl derivatives isolated from medicinal plants besides other flavonoid compounds were studied for their influence on lipid peroxidation induced by FeSO4+ cysteine in rat liver microsomes. A number of hydroxyflavones (e.g. luteolin); C-glycosyl-flavones (e.g. orientin); methoxyflavones (e.g. gardenin D) and flavonols (e.g. datiscetin), as well as the flavanol leucocyanidol and the biflavone amentoflavone behaved as inhibitors of non-enzymic lipid peroxidation. Structure-activity relationships were established and it was observed that the structural features for active polyhydroxylated compounds were different from those of polymethoxylated flavones, antiperoxidative flavonoids possessing a high lipophilicity.  相似文献   
29.
Six heterogeneous common variable immunodeficiency (CVID) patients were analysed for germ-line DNA, DNA rearrangements, and RNA expressions of immunoglobulin (Ig) gene by Southern or northern blotting using appropriate probes. We detected no polymorphism in neutrophil DNA hybridized to a C mu and a C gamma probe. In three patients, both serum Ig and Ig-bearing cells were scarcely detected, and by northern hybridization methods, neither mu mRNA, gamma mRNA, alpha mRNA nor kappa mRNA was detected. However, one Epstein-Barr virus-transformed B lymphoblastoid cell line (LCL) of these three patients was different from the germ line in the region of JH, C gamma, and C kappa, and expressed mu mRNA at a higher level. The B cell defects of these three patients lay on the B cell maturation stage similar to X-linked agammaglobulinaemia (XLA). In two others among the six CVID patients, serum IgM and IgM-bearing cells were detected to a certain degree, and by northern hybridization, mu mRNA was detected at a lower level, but neither mu mRNA, alpha mRNA, nor kappa mRNA was detected. One LCL of these two patients could express mu mRNA at the normal level. In the last patient, the serum IgM was normal, serum IgG and IgA were somewhat low, Ig-bearing cells were normal, mu mRNA and kappa mRNA were detected at the normal level, and gamma mRNA and alpha mRNA were detected at a lower level. The defect of this patient affected the class switch stage. These results showed that primary B cell defects in CVID occurred at several B cell differentiation stages which could be classified by expression of the Ig gene, and at the degree of clonal diversity in the B cell repertoire. Furthermore, this study provides support for the idea that the CVID defect is related to a more generalized cellular function, such as regulating the proliferation and/or clonal expansion of cells of the B lymphoid lineage.  相似文献   
30.
The relation between smoking and risk of asthma has been well-examined; however little attention has been paid to the correlation between smoking and asthma symptoms. The aims of this study were to examine respiratory symptoms in asthmatics with a highly prevalent use of inhaled corticosteroid (ICS) and to assess the effects of smoking and its cessation. A cross-sectional study of pulmonologist-based 3197 asthmatics (men 45.2%, ages 20-97) was performed using a questionnaire about smoking habits, the incidence and frequency of symptoms (sputum, cough and wheezing, night symptoms, and shortness of breath), physical activity interference, and medication. Although 81.4% of the patients used ICS according to the international guideline, 14.9% had activity interference, and daily symptoms remained in 43.3%. At the time of the questionnaire, 21.6% were current and 25.1% were ex-smokers. In multiple logistic regression analysis, the factors of significance (p < 0.0001) were (1) smoking; for all four symptoms, (2) age and duration of asthma; for shortness of breath. Current smokers were at a risk of sputum (age-adjusted odds ratio 2.32 [95% confidence interval 1.73-3.11]; 2.09 [1.57-2.79]), of cough and wheezing (2.38 [1.81-3.14]; 1.78 [1.35-2.36]), of night symptoms (1.95 [1.41-2.60]; 1.47 [1.09-1.98]), and of shortness of breath (1.70 [1.26-2.28]; 1.30 [0.97-1.75]) in men and women, respectively. These ratios in ex-smokers decreased to the level similar to nonsmokers. Although 81.4% of asthmatic patients used ICS, 43.3% complained of daily respiratory symptoms, especially sputum. It is suggested that the effects of ICS on asthma symptoms may be interfered with by smoking and therefore more emphasis should be placed on cessation of smoking.  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