全文获取类型
收费全文 | 37035篇 |
免费 | 2672篇 |
国内免费 | 228篇 |
专业分类
耳鼻咽喉 | 503篇 |
儿科学 | 1011篇 |
妇产科学 | 904篇 |
基础医学 | 4979篇 |
口腔科学 | 822篇 |
临床医学 | 3686篇 |
内科学 | 7799篇 |
皮肤病学 | 894篇 |
神经病学 | 2735篇 |
特种医学 | 1444篇 |
外国民族医学 | 1篇 |
外科学 | 4518篇 |
综合类 | 1022篇 |
现状与发展 | 1篇 |
一般理论 | 40篇 |
预防医学 | 2541篇 |
眼科学 | 1150篇 |
药学 | 2637篇 |
中国医学 | 218篇 |
肿瘤学 | 3030篇 |
出版年
2023年 | 311篇 |
2022年 | 552篇 |
2021年 | 1278篇 |
2020年 | 772篇 |
2019年 | 1043篇 |
2018年 | 1196篇 |
2017年 | 897篇 |
2016年 | 1063篇 |
2015年 | 1314篇 |
2014年 | 1655篇 |
2013年 | 1909篇 |
2012年 | 2932篇 |
2011年 | 2936篇 |
2010年 | 1663篇 |
2009年 | 1498篇 |
2008年 | 2169篇 |
2007年 | 2258篇 |
2006年 | 2086篇 |
2005年 | 1973篇 |
2004年 | 1679篇 |
2003年 | 1488篇 |
2002年 | 1287篇 |
2001年 | 702篇 |
2000年 | 694篇 |
1999年 | 559篇 |
1998年 | 272篇 |
1997年 | 215篇 |
1996年 | 168篇 |
1995年 | 178篇 |
1994年 | 155篇 |
1993年 | 135篇 |
1992年 | 245篇 |
1991年 | 256篇 |
1990年 | 242篇 |
1989年 | 201篇 |
1988年 | 190篇 |
1987年 | 211篇 |
1986年 | 163篇 |
1985年 | 174篇 |
1984年 | 129篇 |
1983年 | 114篇 |
1982年 | 79篇 |
1981年 | 66篇 |
1980年 | 67篇 |
1979年 | 94篇 |
1978年 | 72篇 |
1977年 | 69篇 |
1975年 | 56篇 |
1974年 | 57篇 |
1973年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
51.
52.
Infective conjunctivitis and corneal scarring in three brothers with sex linked hypogammaglobulinaemia (Bruton''s disease). 下载免费PDF全文
T T Hansel D P O''Neill M L Yee J M Gibson R A Thompson 《The British journal of ophthalmology》1990,74(2):118-120
The ocular findings in three brothers with Bruton's disease are reported. All three boys had purulent conjunctivitis, but the two older brothers also developed marked corneal scarring with visual impairment. Haemophilus influenzae was cultured from conjunctival swabs; it was resistant to neomycin but sensitive to chloramphenicol. Tear analysis showed that the three subjects had normal levels of lysozyme but no detectable IgA. 相似文献
53.
OBJECTIVE: Many patients with haemorrhoids are investigated because of the fear of missing colorectal cancer (CRC). The aim of this study was to determine whether a primarily clinical approach regarding the need for investigation was safe and did not miss patients with CRC. PATIENTS AND METHODS: Data was collected prospectively on 589 consecutive patients with the principle diagnosis of haemorrhoids at first clinic visit. All had clinical assessment including rigid sigmoidoscopy and were treated by phenol injection or banding. They were categorized for (1) no review unless symptoms persisted -'One Stop SOS' (2) outpatient review or (3) investigation. To check for the development of CRC they were contacted by postal questionnaire or telephone interview with a minimum of one year from diagnosis and treatment. All 589 patients were cross-referenced with the Pathology database and the Hospital Information Services System. RESULTS: Four hundred and sixty-nine (80%) answered the questionnaire; 352 patients (60% of the total group) fell in the 'one stop SOS' outpatient category; 95 (16%) patients were followed up to review response to treatment for large haemorrhoids; 105 (18%) were investigated with barium enema (12%), flexible sigmoidoscopy (4%), colonoscopy (1%) and miscellaneous (1%); 37 (6%) patients were either given a haemorrhoidectomy date or referred on with a different diagnosis. No patients selected for 'one-stop' treatment developed CRC. Five (0.8%) patients were diagnosed with CRC after appropriate investigation was instituted for suspicious symptoms. One patient with distal transverse colon cancer had a delayed diagnosis as she was investigated initially by flexible sigmoidoscopy. CONCLUSION: Most patients with the primary diagnosis of symptomatic haemorrhoids do not need investigation. 相似文献
54.
55.
Prevalence of silent myocardial ischemia in asymptomatic individuals with subclinical atherosclerosis detected by electron beam tomography 总被引:3,自引:0,他引:3
Anand D. Vijay Lim Eric Raval Usha Lipkin David Lahiri Avijit 《Journal of nuclear cardiology》2004,11(4):450-457
BACKGROUND: Electron beam tomography coronary calcium imaging is an evolving technique for the early detection of coronary atherosclerosis, and recent studies have established its prognostic value in asymptomatic individuals. The relationship of coronary artery calcium scores (CAC) to obstructive coronary artery disease (CAD) has been poorly studied but is clinically relevant because it determines which individuals are likely to benefit from revascularization procedures. Hence, we prospectively evaluated the prevalence of myocardial ischemia in asymptomatic patients with cardiovascular risk factors and subclinical atherosclerosis. METHODS AND RESULTS: We studied 864 asymptomatic patients with no previous CAD but with cardiovascular risk factors, referred for electron beam tomography coronary calcium imaging to our institution over an 18-month period. From this group, 220 consecutive patients (85% men; mean age, 61 +/- 9 years; age range, 31-84 years) with moderate to severe atherosclerotic disease (coronary calcium score > or =100 Agatston units) were prospectively evaluated by technetium 99m sestamibi single photon emission computed tomography (SPECT). Patients were followed up (mean follow-up, 14 months) and data regarding their subsequent clinical management recorded. Of the 220 patients, 119 had moderate atherosclerosis (CAC score of 100-400 Agatston units) and 101 had severe atherosclerosis (CAC score > or =400 Agatston units). Abnormal SPECT findings were seen in 18% of patients with moderate atherosclerosis (n = 21) and 45% of patients with severe atherosclerosis (n = 45). Increasing severity of atherosclerosis was related to increasing ischemic burden (summed difference score = 1 +/- 0.2 for CAC score of 100-400 Agatston units and 3.2 +/- 0.5 for CAC score > or =400 Agatston units). In a multivariate linear regression model incorporating risk factors, CAC was the only predictor of silent ischemia. CONCLUSION: In comparison to previously published data, we detected a higher prevalence of silent ischemia even in patients with moderate coronary atherosclerosis (18%). This may reflect the differing risk factor profile of our patient population. When coronary calcium screening is used to preselect asymptomatic patients with cardiovascular risk factors for myocardial perfusion imaging, the optimum coronary calcium score threshold will depend on the population prevalence of risk factors and asymptomatic obstructive CAD. 相似文献
56.
57.
Although antibiotics are widely used in an attempt to decrease the incidence of infections after facial fractures, no systematic prospective study of their efficacy has been performed. In this study, all adult patients with facial fractures who had not received antibiotics were asked to participate in a clinical trial. There were 101 patients with facial fractures enrolled into the study and randomized prospectively into two groups. One group received no antibiotics. The other group received cefazolin sodium, 1 g intravenously, one hour prior to the surgical procedure, and a similar dose eight hours later. Of the 101 patients enrolled in the study, 79 had mandibular fractures, 18 had zygoma fractures, and four had Le Fort fractures. When all facial fractures were considered, perioperative intravenous cefazolin reduced the incidence of postoperative infections; 42.2% in the no-antibiotic group became infected, and 8.9% in the antibiotic group became infected. On the basis of this study, we conclude that cefazolin, used perioperatively, diminished the incidence of postoperative infections in facial fractures. 相似文献
58.
59.