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   1763986篇
  免费   132301篇
  国内免费   2581篇
耳鼻咽喉   22703篇
儿科学   59109篇
妇产科学   49058篇
基础医学   242932篇
口腔科学   48641篇
临床医学   152208篇
内科学   343081篇
皮肤病学   34708篇
神经病学   145213篇
特种医学   73057篇
外国民族医学   474篇
外科学   270542篇
综合类   41967篇
现状与发展   3篇
一般理论   544篇
预防医学   139523篇
眼科学   39100篇
药学   130000篇
  3篇
中国医学   3598篇
肿瘤学   102404篇
  2018年   35170篇
  2017年   27800篇
  2016年   31026篇
  2015年   15851篇
  2014年   21351篇
  2013年   32010篇
  2012年   48960篇
  2011年   64293篇
  2010年   43802篇
  2009年   36032篇
  2008年   61113篇
  2007年   65359篇
  2006年   46456篇
  2005年   46604篇
  2004年   47182篇
  2003年   46163篇
  2002年   43535篇
  2001年   75908篇
  2000年   78702篇
  1999年   66525篇
  1998年   17911篇
  1997年   16512篇
  1996年   16379篇
  1995年   16101篇
  1994年   15156篇
  1993年   14269篇
  1992年   55450篇
  1991年   53851篇
  1990年   52673篇
  1989年   50888篇
  1988年   47264篇
  1987年   46589篇
  1986年   44303篇
  1985年   42865篇
  1984年   32049篇
  1983年   27584篇
  1982年   16166篇
  1981年   14436篇
  1979年   30462篇
  1978年   21071篇
  1977年   17766篇
  1976年   16701篇
  1975年   17579篇
  1974年   21505篇
  1973年   20673篇
  1972年   18853篇
  1971年   17770篇
  1970年   16307篇
  1969年   15287篇
  1968年   13964篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
993.
994.
995.
996.
Several case reports have implicated Ginkgo biloba in clinically adverse bleeding disorders. Ginkgo biloba has been reported to increase pain-free walking distance among patients with peripheral artery disease (PAD). Standard PAD therapy includes 325 mg/day aspirin. The objective of this study was to examine potential adverse effects of concomitant aspirin and Ginkgo biloba on platelet function. Ginkgo biloba (EGb 761, 300 mg/day) was compared with placebo for effects on measures of platelet aggregation among adults consuming 325 mg/day aspirin in a randomized, double-blind, placebo-controlled, parallel design trial of 4-week duration. Participants were adults, age 69 +/- 10 years, with PAD or risk factors for cardiovascular disease. Outcome measures included platelet function analysis (PFA-100 analyzer) using ADP as an agonist (n = 26 placebo; n = 29 ginkgo), and platelet aggregation using ADP, epinephrine, collagen and ristocetin as agonists (n = 21 placebo; n = 23 ginkgo). Participants kept daily logs of bleeding or bruising episodes. There were no clinically or statistically significant differences between treatment groups for any agonists, for either PFA-100 analysis or platelet aggregation. Reports of bleeding or bruising were infrequent and similar for both study groups. In conclusion, in older adults with PAD or cardiovascular disease risk, a relatively high dose of Ginkgo biloba combined with 325 mg/day daily aspirin did not have a clinically or statistically detectable impact on indices of coagulation examined over 4 weeks, compared with the effect of aspirin alone. No adverse bleeding events were observed, although the trial was limited to a small sample size.  相似文献   
997.
BRING ADDICTION TREATMENT OUT OF THE CLOSET   总被引:1,自引:1,他引:0  
  相似文献   
998.
The co-existence of fungal elements in allergic nasal Polyposis, has given rise to a distinct clinical entity known as ‘Allergic fungal sinusitis ’ (AF’S). Many a time, these fungal elements may not be diagnosed pre-operatively by routine diagnostic nasal endoscopy or CT scan of paranasal sinuses, due to the florid presentation of nasal polyps, which usually obscure the underlying fungal pathology. The diagnosis is often made intra-operatively. The post-operative confirmation of AFS is by histopathology, fungal smear, fungal culture, allergic murin study and fungal specific IgE titres. We report a series often such cases done in our institution, which highlight that AFS should be considered as a differential diagnosis in Sinonasal Polyposis cases, for their effective management.  相似文献   
999.
Hepatic encephalopathy is a reversible state of altered cognition that may occur in patients with acute or chronic liver disease or porto-systemic shunt, and in which known neurological or psychiatric signs may develop. Nitrogenated substances from intestinal digestion reach the brain without being cleared by their passage through the liver due to the presence of porto-systemic shunt. We report two cases of patients with porto-systemic shunt diagnosed with recurrent chronic hepatic encephalopathy refractory to conventional medical treatment. They were satisfactorily treated with shunt embolization using interventionist radiology techniques.  相似文献   
1000.
BACKGROUND CONTEXT: The effectiveness of spinal surgery as a treatment option is currently evaluated through the assessment of patient-reported outcomes (PROs). The minimum clinically important difference (MCID) represents the smallest improvement considered worthwhile by a patient. The concept of an MCID is offered as the new standard for determining effectiveness of a given treatment and describing patient satisfaction in reference to that treatment. PURPOSE: Our goal is to review the various definitions of MCID and the methods available to determine MCID. STUDY DESIGN: The primary means of determining the MCID for a specific treatment are divided into anchor-based and distribution-based methods. Each method is further subdivided and examined in detail. METHODS: The overall limitations of the MCID concept are first identified. The basic assumptions, statistical biases, and shortcomings of each method are examined in detail. RESULTS: Each method of determining the MCID has specific shortcomings. Three general limitations in the accurate determination of an MCID have been identified: the multiplicity of MCID determinations, the loss of the patient's perspective, and the relationship between pretreatment baseline and posttreatment change scores. CONCLUSIONS: An ideal means of determining the MCID for a given intervention is yet to be determined. It is possible to develop a useful method provided that the assumptions and methodology are initially declared. Our efforts toward the establishment of a MCID will rely on the establishment of specific external criteria based on the symptoms of the patient and treatment intervention being evaluated.  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