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   285376篇
  免费   23058篇
  国内免费   9326篇
耳鼻咽喉   2394篇
儿科学   9375篇
妇产科学   1907篇
基础医学   24325篇
口腔科学   4665篇
临床医学   32045篇
内科学   73859篇
皮肤病学   3426篇
神经病学   28162篇
特种医学   8605篇
外国民族医学   14篇
外科学   22222篇
综合类   41450篇
现状与发展   41篇
一般理论   12篇
预防医学   21802篇
眼科学   2839篇
药学   20583篇
  234篇
中国医学   14084篇
肿瘤学   5716篇
  2024年   891篇
  2023年   5784篇
  2022年   10241篇
  2021年   14381篇
  2020年   13877篇
  2019年   10874篇
  2018年   10621篇
  2017年   10790篇
  2016年   11233篇
  2015年   10900篇
  2014年   19706篇
  2013年   21671篇
  2012年   16575篇
  2011年   17833篇
  2010年   14234篇
  2009年   13616篇
  2008年   13453篇
  2007年   13240篇
  2006年   11771篇
  2005年   9878篇
  2004年   8403篇
  2003年   7279篇
  2002年   6171篇
  2001年   5392篇
  2000年   4477篇
  1999年   3821篇
  1998年   3517篇
  1997年   3193篇
  1996年   2904篇
  1995年   2627篇
  1994年   2407篇
  1993年   1989篇
  1992年   1901篇
  1991年   1640篇
  1990年   1322篇
  1989年   1145篇
  1988年   1057篇
  1987年   946篇
  1986年   834篇
  1985年   1022篇
  1984年   840篇
  1983年   512篇
  1982年   600篇
  1981年   529篇
  1980年   392篇
  1979年   322篇
  1978年   246篇
  1977年   218篇
  1976年   186篇
  1975年   73篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
粉防己碱对野百合碱致大鼠肺动脉构形重建的逆转作用   总被引:2,自引:0,他引:2  
以野百合碱复制Wistar大鼠肺动脉高压模型,用特殊染色方法观察粉防已碱对野百合碱致大鼠肺动脉构形重建的逆转作用,结果表明粉防已碱可选择性的降低野百合碱诱导的大鼠肺动脉高压的作用,并明显地逆转肺血管及肺组织损伤,降低肺动脉高压和右心室肥大,对体循环压力无影响  相似文献   
102.
A new method for protecting intestinal anastomoses in patients at high risk of anastomotic dehiscence or fistula formation is described herein. This method involves raising a seromuscular flap on a pedicle from the stump of the intestine to be anastomosed. The anastomosis is performed, then covered with the seromuscular flap.  相似文献   
103.
To date, only 10 cases of distal penile gangrene in patients with chronic renal failure have been reported. This rare condition is believed to result from progressive vascular calcification due to secondary hyperparathyroidism in patients with chronic renal failure. We report an additional case of distal penile gangrene in a 41-year-old man who presented with chronic renal disease and pulmonary tuberculosis. Since some authors have emphasized that aggressive surgical treatment in such cases has a significant mortality rate, we took a more conservative approach to treatment.  相似文献   
104.
目的 评价单克隆IgH基因重排检测在恶性淋巴瘤 (B NHL)临床中的应用价值。方法 用半巢式PCR检测单克隆IgH基因重排。病例组为B NHL ,包括 6 9例石蜡包埋组织切片、治疗前 16例骨髓和 2 9例外周血、阳性者治疗后复查骨髓和外周血 ;对照组为 10例慢性淋巴结炎、3例T NHL和 2例HD。结果 对照组均阴性。病例组 :切片中单克隆IgH基因重排阳性率为 6 3.8% (44 / 6 9) ;骨髓和外周血阳性率分别为 43 .8%(7/ 16 )和 41.4% (12 / 2 9) ,细胞形态学检查未见异常细胞者阳性率分别为 33 .3% (3/ 9)和 31.3% (5 / 16 )。 16例同时采集骨髓和外周血者 ,阳性率分别为 43 .8% (7/ 16 )和 37.5 % (6 / 16 ) ,两者无统计学差异。治疗前单克隆IgH重排阳性者 ,6例完全缓解 (CR)后转阴 ,处于持续缓解状态 ,1例临床缓解后 13个月仍阳性 ,现在继续随访中 ,另 1例CR后持续阳性者 ,6个月后复发。结论 切片、骨髓和外周血中检测单克隆IgH基因重排可以作为B NHL诊断和随访微小残留病灶的辅助手段  相似文献   
105.
用酶联免疫吸附法对30例急性脑血管病(CVD)患者及32位正常人血清髓鞘碱性蛋白(MBP)含量进行检测。结果表明:急性CVD组患者血清MBP含量显著高于正常人组(P<0.01);血清MBP含量与急性CVD的严重程度相关。提示检测血清MBP含量对急性CVD诊断及预后判断有重要价值  相似文献   
106.
本实验复制了莱姆病实验家兔模型,对血液生化23项进行了动态观察。结果表明,血液中谷丙转氨酶、γ-谷氨酰转肽酶、乳酸脱氢酶、谷草转氨酶、β-羟丁酸脱氢酶、磷酸肌酸激酶、胆固醇、尿素氮随病情加重而升高。葡萄糖、尿酸、磷随病情加重而减低。  相似文献   
107.
Abstract Perioscan requires a plaque sample to detect the presence of enzymes capable of degrading N-benzoyl-DL-arginine-2-naphthylamide (BANA) from relatively few anaerobic periodontal pathogens. Periocheck assays the presence of neutral proteases in crevicular fluid. The aim of this study was to compare these test kits with traditional clinical methods of detecting periodontal disease and to monitor the ability of the kits to reflect the response to initial therapy. 19 patients with moderately severe chronic periodontitis were seen before and after a course of oral hygiene and root instrumentation consisting of 4 appointments. Clinical measurements and test assays were collected at 5 diseased sites and 2 healthy sites in each subject. Complete data from 125 sites were available for statistical analysis. At baseline Periocheck had a sensitivity of 88% and a specificity of 61% whereas Perioscan had a sensitivity of 99% and a specificity of 55%, when related to the clinical diagnosis. A composite clinical assessment, based on improvement or deterioration of one whole unit change of the subjective clinical indices and 2mm changes or greater in probing depth or probing attachment level, revealed 75 sites which improved following treatment, whereas 45 sites did not change and 5 sites deteriorated. The probability that the tests agreed with the clinical outcome after treatment, was calculated as 50.4% for Periocheck and 52% for Perioscan. The diagnostic kits did not reliably reflect the clinical assessment of periodontal disease in the cross sectional study, or the outcome following treatment.  相似文献   
108.
Data on 232 members of a single pedigree, descended from two pairs of original parents, were made available to the participants of Genetic Analysis Workshop 8 (GAW8). In addition to information concerning age and sex, measurements for 10 quantitative traits and genotypes at 22 polymorphic marker loci were also provided for a subset of 193 of these family members. © 1993 Wiley-Liss, Inc.  相似文献   
109.
OBJECTIVE: This study aimed to investigate the rate of occupational sensitization to horse hair in grooms and whether occupational exposure to horse hair increases respiratory and allergic symptoms and affects lung function in grooms or not. METHODS: This is a cross-sectional study. Two hundred grooms were randomly selected among 1000 grooms working in Veliefendi Hippodrome of Istanbul. One hundred and twenty-five subjects agreed to enter the study. Ninety-two workers who worked in the different parts of this hippodrome enrolled as the control group. A detailed questionnaire including respiratory and allergic symptoms was filled in, physical examination, skin prick tests and pulmonary function tests were performed. RESULTS: Sensitization to horse hair was 12.8% in grooms and 4.3% in controls. The difference was statistically significant (P = 0.0035). Asthma was found in 14.4% of the grooms and 5.4% of the controls, allergic rhinitis in 42.4% of the grooms and 18.4% of the controls, allergic conjunctivitis in 35.2% of the grooms and 15.2% of the controls, and allergic skin diseases in 32.8% of the grooms and 13% of the controls. The differences were statistically significant (P = 0.043, P = 0.0002, P = 0.001 and P = 0.0008, respectively). The means of FEV1, FEV1/FVC and FVC parameters were significantly lower in the groom group (P = 0.006, P = 0.001 and P = 0.003, respectively). In the multivariate analysis, being in the groom group and working years were found to be predictive factors for impairments of lung function (P < 0.001 and P = 0.002, respectively). CONCLUSION: Occupational exposure to horse increases the sensitization to horse hair, induces asthma and allergic symptoms and also impairs lung functions.  相似文献   
110.
Forty-one multiplex families, from published sources and new data from the National Cancer Institute, segregating for Hodgkin's disease and HLA, have been studied. A reanalysis of these data strongly suggests a recessive mode of inheritance for susceptibility to Hodgkin's disease. The HLA haplotype sharing data between affected relatives demonstrate that approximately 60% of cases in multiplex families are due to an HLA-linked susceptibility gene, the remaining 40% being due to other familial factors. The data clearly support the hypothesis of etiological heterogeneity for Hodgkin's disease, with both HLA-linked and HLA-unlinked factors being responsible. Finally, there is an increased concordance of histological types between affected relatives, but this concordance seems independent of HLA sharing.  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