全文获取类型
收费全文 | 37134篇 |
免费 | 1874篇 |
国内免费 | 170篇 |
专业分类
耳鼻咽喉 | 533篇 |
儿科学 | 683篇 |
妇产科学 | 425篇 |
基础医学 | 4626篇 |
口腔科学 | 1165篇 |
临床医学 | 2538篇 |
内科学 | 8497篇 |
皮肤病学 | 770篇 |
神经病学 | 3671篇 |
特种医学 | 1871篇 |
外国民族医学 | 1篇 |
外科学 | 5781篇 |
综合类 | 128篇 |
一般理论 | 6篇 |
预防医学 | 1138篇 |
眼科学 | 763篇 |
药学 | 2371篇 |
中国医学 | 71篇 |
肿瘤学 | 4140篇 |
出版年
2023年 | 188篇 |
2022年 | 298篇 |
2021年 | 669篇 |
2020年 | 379篇 |
2019年 | 513篇 |
2018年 | 655篇 |
2017年 | 526篇 |
2016年 | 682篇 |
2015年 | 643篇 |
2014年 | 821篇 |
2013年 | 1011篇 |
2012年 | 1659篇 |
2011年 | 1694篇 |
2010年 | 1038篇 |
2009年 | 886篇 |
2008年 | 1527篇 |
2007年 | 1752篇 |
2006年 | 1650篇 |
2005年 | 1597篇 |
2004年 | 1591篇 |
2003年 | 1530篇 |
2002年 | 1533篇 |
2001年 | 1328篇 |
2000年 | 1447篇 |
1999年 | 1289篇 |
1998年 | 508篇 |
1997年 | 400篇 |
1996年 | 384篇 |
1995年 | 315篇 |
1994年 | 319篇 |
1993年 | 297篇 |
1992年 | 996篇 |
1991年 | 862篇 |
1990年 | 817篇 |
1989年 | 815篇 |
1988年 | 762篇 |
1987年 | 761篇 |
1986年 | 676篇 |
1985年 | 638篇 |
1984年 | 444篇 |
1983年 | 349篇 |
1982年 | 157篇 |
1979年 | 299篇 |
1978年 | 200篇 |
1977年 | 180篇 |
1974年 | 195篇 |
1973年 | 162篇 |
1972年 | 164篇 |
1971年 | 183篇 |
1969年 | 179篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
901.
902.
T Fujikane S Fujiuchi Y Yamazaki H Matsumoto M Takahashi Y Fujita T Shimizu K Kikuchi 《The international journal of tuberculosis and lung disease》2004,8(1):39-44
SETTING: The incidence of tuberculosis in Japan has fallen rapidly in the past 50 years, to 27.9 cases per 100,000 population in 2001. OBJECTIVE: To assess the molecular epidemiology of tuberculosis in the north Hokkaido district, Japan. DESIGN: Restriction fragment length polymorphism analysis was consecutively performed on Mycobacterium tuberculosis strains from patients with pulmonary tuberculosis from April 1999 to March 2002. RESULTS: Of 229 patients, strains from 227 (99.1%) were available for analysis. The mean age of the patients analysed was 69.4 years. There was one immigrant patient. Two hundred and seven patients had six or more copies of IS6110. Of these, 16 (7.7%) in eight clusters had identical patterns, 120 (58.0%) belonged to five groups that had similar patterns (Dice coefficient >0.7) and 80 (38.6%) belonged to the 35 groups with the most common patterns (Dice coefficient >0.9). CONCLUSION: These results may reflect the epidemiological characteristics, age and migration of the residents and the incidence of tuberculosis of the area, and also those of Japan: many elderly patients were infected in the past, when the incidence of tuberculosis was very high. 相似文献
903.
Srinivasan R Chakrabarti S Walsh T Igarashi T Takahashi Y Kleiner D Donohue T Shalabi R Carvallo C Barrett AJ Geller N Childs R 《British journal of haematology》2004,124(6):777-786
Approximately 15% of patients undergoing non-myeloablative allogeneic haematopoietical cell transplantation (NMHCT) develop steroid-refractory acute-graft versus host disease (aGVHD), a usually fatal complication. We encountered 18 cases of steroid-refractory aGVHD in 146 patients, undergoing NMHCT from a related human leucocyte antigen-compatible donor following cyclophosphamide/fludarabine-based conditioning. Our initial cohort of steroid-refractory aGVHD patients treated with antithymocyte globulin (ATG) and mycophenolate mofetil (regimen-1: n = 6) had high GVHD-related mortality. Therefore, we investigated an alternative strategy for subsequent patients developing this complication (regimen-2: n = 12), consisting of daclizumab (alone or combined with infliximab/ATG) and targeted broad spectrum antibacterial and aspergillus prophylaxis in conjunction with rapid tapering of steroids to minimize opportunistic infections. In a retrospective analysis, patients receiving regimen-2 were significantly more likely to have complete resolution of GVHD compared with those receiving regimen-1 [12/12 (100%) vs. 1/6 (17%); P < 0.001]. When compared with those receiving regimen-1, regimen-2 patients also had a higher probability of survival at day 100 (100% vs. 50%) and day 200 (73% vs. 17%) post-transplant, and improved overall survival (median 453 d vs. 42 d from aGVHD onset; P < 0.0001). GVHD-related mortality was 89% for regimen-1 patients vs. 17% for regimen-2 patients (P < 0.0001). These data suggest that a co-ordinated approach using immunoregulatory monoclonal antibodies, pre-emptive antimicrobial therapy and judicious steroid withdrawal can dramatically improve outcome in steroid-refractory aGVHD. 相似文献
904.
Furumoto K Arii S Mori A Furuyama H Gorrin Rivas MJ Nakao T Isobe N Murata T Takahashi C Noda M Imamura M 《Hepatology (Baltimore, Md.)》2001,33(1):189-195
The RECK (reversion-inducing-cysteine-rich protein with Kazal motifs) gene was initially isolated as a transformation suppressor gene. It encodes a membrane-anchored glycoprotein with multiple serine protease inhibitor-like domains. The RECK gene is expressed widely in normal organs but is undetectable in many tumor-derived cell lines. When artificially expressed in such cell lines, RECK suppresses their invasive and metastatic activities. Clinical implications of these findings, however, remained undefined because of the lack of studies using fresh human tumor samples. In the present study, we have addressed this issue by analyzing the levels of RECK gene expression in hepatocellular carcinoma (HCC). RECK mRNA was detectable by RNA blot hybridization in all the tumorous and contiguous nontumorous tissues obtained from 64 patients with HCC. In 26 cases, the RECK expression in tumorous tissues was higher than that in nontumorous tissues. The expression of RECK protein in these tissues could also be demonstrated by immunohistochemistry. Patients with high RECK mRNA expression in tumorous tissues tended to show better survival (P =.02), and such tumors had a tendency to be less invasive. Univariate and multivariate analysis revealed that the RECK mRNA expression is a novel and independent variable affecting overall survival (P =.01). These findings support the hypothesis that RECK has negative effects on the invasiveness of HCC cells and suggest the feasibility of RECK mRNA as a promising prognostic molecular marker for HCC. 相似文献
905.
Masatoshi Murata Asako Ooe Tomonori Izumi Michihiro Nakagawa Shigeki Takahashi Masaaki Ishikawa Kazuo Mori & Akitada Ichinose 《British journal of haematology》1997,99(2):301-303
Dysplasminogenaemia has been reported in patients with retinochoroidal vascular disorders. The precise genetic defects of these cases, however, remain unclear because of the limitations of conventional diagnostic techniques. In this study, three patients with these diseases were investigated at the DNA level for the first time to define the molecular bases of these disorders. Polymerase chain reaction–restriction fragment length polymorphism analysis revealed that all three cases carried the same Ala601-Thr mutation. This defect may also play a role in the pathogenesis of circulation disorders in small local vessels because of reduced fibrinolytic activity due to decreased functional plasminogen levels. 相似文献
906.
907.
Incidence of human parvovirus B19 DNA detection in blood donors 总被引:2,自引:0,他引:2
Yuko Yoto Tooru Kudoh Keiji Haseyama Nobuhiro Suzuki Takanori Oda Toshiaki Katoh Tsuneo Takahashi Sadami Sekiguchi Shunzo Chiba 《British journal of haematology》1995,91(4):1017-1018
Summary. 1000 serum samples from blood donors were tested for human parvovirus B19 (B19) DNA by a nested PCR assay: six samples were positive for B19 DNA. The frequency was 1/167 (0-6%), considerably higher than previous surveys (0-004-0-03%). Five of the six samples were also positive for anti-B19 IgM, indicating an acute phase of infection. It is recommended to screen for B19 DNA in blood products to prevent transfusion mediated viral infection for those susceptible such as immunocompromised patients and pregnant women. 相似文献
908.
909.
Masafumi Takahashi Hiromichi Sekiguchi Hideyuki Fujikawa Hideaki Mito Masato Eto Yukihiro Hojo Yoshizo Chiba Satoshi Kitamura Kazuyuki Shimada 《Catheterization and cardiovascular interventions》1994,31(4):290-292
Bilateral coronary artery fistula constitutes an uncommon subgroup of coronary artery fistulas that may have a distinct embryologic origin. Coronary artery fistulas usually show a tortuous arrangement upon coronary angiography, but aneurysmal dilatation is rare. We report here an extremely rare case of coronary artery fistula originating from both coronary arteries, which showed multicystic aneurysmal dilatation. 相似文献
910.
A 56-year-old Japanese man with hypertension presented with a 10 days history of high fever, right and left upper quadrant tenderness. An abdominal ultrasonography and computerized tomographic scan revealed a large collection in the right lobe of the liver that was consistent with an abscess. A drainage catheter was placed and purulent fluid was drained. Cultures of the fluid and blood were positive for a strain of ampicillin-resistant Klebsiella pneumoniae. Six days after admission, paraplegia and urinary retention were found. On the neurological examination, deep tendon reflexes of the lower extremities were absent bilaterally. Magnetic resonance imaging scan detected thoracic spinal epidural abscess and paraspinal abscess. He received the emergent decompressive laminectomy. Culture of surgical specimen grew ampicillin-resistant K. pneumoniae. The patient was treated with biapenem intravenously. Thereafter, clinical symptoms improved gradually and he was removed to the professional hospital to continue rehabilitation for gait disturbance on hospital day 147. 相似文献