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   6755篇
  免费   403篇
  国内免费   40篇
耳鼻咽喉   141篇
儿科学   205篇
妇产科学   67篇
基础医学   824篇
口腔科学   80篇
临床医学   625篇
内科学   1900篇
皮肤病学   91篇
神经病学   582篇
特种医学   228篇
外国民族医学   7篇
外科学   1131篇
综合类   36篇
预防医学   360篇
眼科学   63篇
药学   413篇
中国医学   6篇
肿瘤学   439篇
  2023年   36篇
  2022年   55篇
  2021年   132篇
  2020年   74篇
  2019年   134篇
  2018年   175篇
  2017年   119篇
  2016年   136篇
  2015年   172篇
  2014年   216篇
  2013年   279篇
  2012年   439篇
  2011年   434篇
  2010年   228篇
  2009年   232篇
  2008年   368篇
  2007年   364篇
  2006年   422篇
  2005年   384篇
  2004年   328篇
  2003年   343篇
  2002年   304篇
  2001年   134篇
  2000年   143篇
  1999年   126篇
  1998年   78篇
  1997年   52篇
  1996年   60篇
  1995年   41篇
  1994年   39篇
  1993年   36篇
  1992年   101篇
  1991年   91篇
  1990年   67篇
  1989年   73篇
  1988年   56篇
  1987年   83篇
  1986年   65篇
  1985年   72篇
  1984年   46篇
  1983年   44篇
  1982年   25篇
  1981年   22篇
  1979年   45篇
  1977年   22篇
  1976年   25篇
  1974年   28篇
  1973年   28篇
  1972年   21篇
  1971年   34篇
排序方式: 共有7198条查询结果,搜索用时 15 毫秒
71.
Provocative tests for coronary spasm were performed in a groupof 131 patients (124 men and 7 women) with recent (<6 weeks)transmural myocardial infarction. Coronary arteriography wasperformed 27±9 days after the onset of the infarction.The provocative test was performed using a single IV bolus of0.4 mg of ergometrine. Aortic pressure, ECG and arteriogramsof the two coronary vessels were repeated 3 and 5 min later.Provoked spasm was observed in 27 (21%) of the patients. In13 (48%) the coronary spasm occurred in a vessel presumed tobe responsible for the myocardial infarction, while it was observedin coronary artery unrelated to the area of the infarct in 14(52% of the cases with spasm). Thus, this study demonstratesa high degree of reactivity of the coronary tree of patientswith recent transmural myocardial infarction suggesting thelikelihood of a role for spasm in the infarction process andoffering some explanation for subsequent recurrent ischemicevents.  相似文献   
72.
A patient operated upon 20 years ago for myocardial revascularization with two Vineberg procedures and one coronary artery bypass graft (CABG) on the right coronary artery had a recurrence of unstable angina due to the thrombosis of the left internal mammary artery (IMA) and the right CABG. The right IMA was patent but stenosed distally. Reoperation was performed with a direct end to side anastomosis of the patent right IMA onto the left anterior descending artery and a saphenous vein graft as a CABG on the marginal branch. We comment on the choice of this "second hand" IMA graft and the pathological appearances of the patent IMA.  相似文献   
73.
OBJECTIVES: To compare the results of the BTA Trak test with voided urine cytology (VUC) in the diagnosis and follow-up of bladder tumors. PATIENTS AND METHODS: Urine samples were obtained from 53 patients with bladder tumor (77 samples) and 53 patients treated for bladder tumor with no evidence of disease on the basis of cystoscopic evaluation (88 samples). Urine samples were collected prior to cystoscopy. The BTA assay was performed by the BTA Trak test according to the manufacturer's recommendations. A value >14 U/ml was considered abnormal. RESULTS: There was a statistically significant increase in median BTA value with increasing stage of tumor: 11.9, 57.9 and 391.0 U/ml respectively for stages pTa, pT1 and pT2/3 (p<0.0001, Kruskal-Wallis test). There was also a correlation between increasing grade and median BTA values measured at 6.9, 13.1 and 235.0 U/ml in grades 1, 2 and 3 tumors respectively (p<0.0001, Kruskall-Wallis test). The overall sensitivity of the BTA Trak test was 58.4% compared to 46.7% for VUC, a difference of 11.7%, which was statistically significant (McNemar test, p<0.005). The sensitivity of both tests combined was 63.6%. The specificity of the VUC (94.3%) was significantly higher than that of the BTA Traktrade mark (75.0%) (p<0.005, McNemar test). The accuracy of the Bard Trak test (67.3%) was similar to that of VUC (66.9%). CONCLUSION: The BTA Trak test is more sensitive than urinary cytology in the detection of bladder tumors but the improvement involved is insufficient to consider decreasing the frequency of endoscopic examinations in the follow-up of superficial bladder tumor.  相似文献   
74.
75.
OBJECTIVE: To assess the impact of introducing clinical practice guidelines on acute coronary syndrome without persistent ST segment elevation (ACS) on patient initial assessment. DESIGN: Prospective before-after evaluation over a 3-month period. SETTING: The emergency ward of a tertiary teaching hospital. PATIENTS: All consecutive patients with ACS evaluated in the emergency ward over the two 3-month periods. INTERVENTION: Implementation of the practice guidelines, and the addition of a cardiology consultant to the emergency team. MAIN OUTCOME MEASURES: Diagnosis, electrocardiogram interpretation, and risk stratification after the initial evaluation. RESULTS: The clinical characteristics of the 328 and 364 patients evaluated in the emergency ward for suspicion of ACS before and after guideline implementation were similar. Significantly more patients were classified as suffering from atypical chest pain (39.6% versus 47.0%; P = 0.006) after guideline implementation. Guidelines availability was associated with significantly more formal diagnoses (79.9% versus 92.9%; P < 0.0001) and risk stratification (53.7% versus 65.4%, P < 0.0001) at the end of initial assessment. CONCLUSION: Guidelines implementation, along with availability of a cardiology consultant in the emergency room had a positive impact on initial assessment of patients evaluated for suspicion of ACS. It led to increased confidence in diagnosis and stratification by risk, which are the first steps in initiating effective treatment for this common condition.  相似文献   
76.
77.
78.
The first EORTC (European Organization of Research and Treatment of Cancer) acute myeloblastic leukemia (AML) pilot study (58872) was conducted between January 1988 and December 1991. Out of 108 patients, 78% achieved complete remission (CR), and event-free survival (EFS) and survival rates (s.e., %) at 7 years were 40 (5) and 51% (6%), respectively. It indicated that mitoxantrone could be substituted for conventional anthracyclines in the treatment of childhood AML without inducing cardiotoxicity. The aim of the next EORTC 58921 trial was to compare the efficacy and toxicity of idarubicin vs mitoxantrone in initial chemotherapy courses, further therapy consisting of allogeneic bone marrow transplantation (alloBMT) in patients with an HLA-compatible sibling donor or chemotherapy in patients without a donor. Out of 177 patients, recruited between October 1992 and December 2002, 81% reached CR. Overall 7-year EFS and survival rates were 49 (4) and 62% (4%), respectively. Out of 145 patients who received the first intensification, 39 had a sibling donor. In patients with or without a donor, the 7-year disease-free survival (DFS) rate was 63 (8) and 57% (5%) and the 7-year survival rate was 78 (7) and 65% (5%), respectively. Patients with favorable, intermediate and unfavorable cytogenetic features had a 5-year EFS rate of 57, 45 and 45% and a 5-year survival rate of 89, 67 and 53%, respectively.  相似文献   
79.
State-of-the-art therapeutics: diffuse large B-cell lymphoma.   总被引:3,自引:0,他引:3  
This article is a review of the improvement in the treatment of patients with diffuse large B-cell lymphoma made during the last 10 years. Patients with diffuse large B-cell lymphoma now have a better outcome with longer survival because of two major developments: (1) increasing the dose of active drugs with shortening the time between cycles, resulting in dose-dense and/or dose-intense regimens; and (2) combining rituximab with chemotherapy. Both strategies were associated with higher response rates, lower relapse rates, longer event-free survival, longer time to progression, and longer overall survival, particularly in patients without adverse prognostic parameters. A combination of dose-dense, dose-intense regimens plus rituximab is currently being tested for poor-risk patients with diffuse large B-cell lymphoma. However, much work has to be done for patients with high-risk lymphoma. It may come with a better definition of genetic abnormalities specifically associated with refractoriness to chemotherapy.  相似文献   
80.
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