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   1047篇
  免费   92篇
耳鼻咽喉   6篇
儿科学   89篇
妇产科学   1篇
基础医学   167篇
口腔科学   21篇
临床医学   87篇
内科学   225篇
皮肤病学   22篇
神经病学   211篇
特种医学   12篇
外科学   114篇
综合类   2篇
预防医学   100篇
眼科学   2篇
药学   60篇
中国医学   5篇
肿瘤学   15篇
  2021年   8篇
  2020年   7篇
  2018年   9篇
  2017年   12篇
  2016年   12篇
  2015年   10篇
  2014年   12篇
  2013年   20篇
  2012年   44篇
  2011年   34篇
  2010年   31篇
  2009年   45篇
  2008年   37篇
  2007年   46篇
  2006年   52篇
  2005年   53篇
  2004年   60篇
  2003年   51篇
  2002年   50篇
  2001年   53篇
  2000年   40篇
  1999年   37篇
  1998年   20篇
  1997年   20篇
  1996年   15篇
  1995年   8篇
  1994年   5篇
  1992年   17篇
  1991年   31篇
  1990年   31篇
  1989年   34篇
  1988年   26篇
  1987年   12篇
  1986年   8篇
  1985年   20篇
  1984年   12篇
  1983年   7篇
  1981年   5篇
  1980年   5篇
  1979年   9篇
  1975年   9篇
  1974年   11篇
  1973年   6篇
  1972年   14篇
  1970年   4篇
  1969年   10篇
  1968年   8篇
  1967年   6篇
  1966年   8篇
  1960年   4篇
排序方式: 共有1139条查询结果,搜索用时 31 毫秒
1.
Background The incidence rate of incisional hernias after open surgery has been reported to be higher than that of port site hernias after laparoscopic surgery. No studies have compared the costs for the health care system in treating those two types of hernia. Methods A systematic review was conducted to obtain the baseline data, and a decision analysis model was created to simulate the occurrence and recurrence of incisional and port site hernias. Results The overall risk of having incisional hernias was eight-times higher than that of having port site hernias (7.4% vs 0.9%). A cost savings of £93 per patient can be generated for the health care system in the UK. Similar results were obtained for Germany, Italy and France. Conclusions The additional treatment costs for incisional hernia should be taken into account when the costs of a surgery performed by open approach are compared with by laparoscopy.  相似文献   
2.
Using 2D and M-Mode transesophageal short axis cross sections, right ventricular systolic wall motion was quantified in 15 normal patients. A further group of 39 patients with right ventricular infarction was investigated. In the normal group fractional shortening of the septum was -19.6% (-45 to 8%), that of the lateral wall 51.6% (37 to 73%), of the posterior wall 33.9% (5 to 50%) and of the anterior wall 42.7% (18 to 57%). Right ventricular infarction (RVI) was associated in 33 patients with posterior left ventricular infarction (85%) and in three patients with anterior infarction. In two cases only an isolated RVI was found. Right ventricular dilation occurred in 24 patients (61%). Hemodynamic criteria were fulfilled in eleven out of 21 patients (53%). RVI was confirmed in one patient by surgery and in ten patients by autopsy. Recognition of regional wall motion abnormalities by transesophageal echocardiography permits an accurate bedside identification of RVI. 2D and M-Mode registration of the short axis improves RVI assessment. Wall motion analyses offer the possibility to determine the extent of right ventricular infarction.  相似文献   
3.
Rabies virus was isolated by cell culture from the brains of 104 confirmed rabies cases diagnosed by the fluorescent-antibody staining technique in the United States during 1974-1984. Eighty-seven isolates were obtained from wild-life species, 10 from humans, and seven from domestic animals. These isolates were tested in virus neutralization and immunofluorescence assays using a panel of 34 monoclonal antibodies specific for rabies virus nucleocapsid protein, 44 monoclonal antibodies specific for rabies virus glycoprotein, and two monoclonal antibodies specific for rabies virus nucleocapsid-associated phosphoprotein. Using discriminant analysis, a distinctly different reactivity pattern was revealed between virus isolates from terrestrial (raccoon, skunk) and nonterrestrial (bat) reservoir hosts. The usefulness of this approach for studying the epidemiology of rabies and for predicting the source of infection when this information is unknown is discussed.  相似文献   
4.
5.
6.
7.
8.
Interleukin 1 (IL-1) and tumor necrosis factor alpha are thought to contribute to the inflammatory response associated with autoimmune diseases. Transforming growth factor beta 1 (TGF-beta 1) counteracts many effects of these cytokines and has various immunosuppressive properties. In the present study, it is shown that microgram amounts of TGF-beta 1, injected daily for 1-2 weeks, protect against collagen-induced arthritis (CIA) and relapsing experimental allergic encephalomyelitis (REAE), the animal models for rheumatoid arthritis and multiple sclerosis, respectively. When administered during induction of the disease, TGF-beta 1 prevents CIA but only delays the onset of REAE by 2-3 days. However, when administered during a remission. TGF-beta 1 prevents the occurrence of relapses in REAE. The results suggest that TGF-beta 1 has powerful anti-inflammatory effects, mimicking in some respects the beneficial effects of immunosuppressive drugs in these experimental models of autoimmune disease, but without discernable adverse effects.  相似文献   
9.
Background Cosmetic changes are to be expected after radiotherapy for skin tumours. Objectives This study aimed to answer the questions: How frequent are cosmetic changes after soft X‐ray therapy? Do treatment parameters, tumour thickness, localization and size of the irradiated field have a major influence? Were patients irritated by the visual appearance of the irradiated field? Methods In total, 2474 examinations of 1149 irradiated fields were performed. Results Hypopigmentation was found in 64.7% of examinations more than 90 days after therapy, teleangiectases in 43.1%, erythema in 24.8%, and hyperpigmentation in 16.8%. The frequency of hypopigmentation, teleangiectases and hyperpigmentation increased with time from X‐ray exposure; more than 4 years after therapy hypopigmentation was diagnosed in 91.8% and teleangiectases in 82.2% of examinations. Total dose, the time–dose–fractionation factor (TDF), field size and dose per fraction were significantly related to the frequency of cosmetic changes. Incidence rates of cosmetic changes differed by less than 15% if different treatment conditions were compared: thicker vs. thinner tumours, larger vs. smaller fields, higher vs. lower total doses, doses per fraction, and TDF. Frequencies of hypopigmentation, teleangiectases, erythema and hyperpigmentation differed by more than 15% between some localizations on the head. Women reported irritation by the visual appearance of the irradiated field in 12.6% of 1116 interviews, and men in 4.4% of 1284 interviews. Conclusions Cosmetic changes after soft X‐ray therapy are relatively frequent. Treatment parameters, tumour thickness and field size have only a minor influence. Few patients, but more women than men, were irritated by the visual appearance of the irradiated field.  相似文献   
10.
Zusammenfassung Während die Argumente für einen peripheren Ursprung der Nachbewegung (Nb.) der Kritik nicht standhalten, läßt sich die Erscheinung auf das Überdauern einer zentralen (subkortikalen) Erregung, die von der längeren Willküranstrengung herstammt, zurückführen. Die Nb. bietet weitgehende Ähnlichkeit mit der auf einem Bestehen unterschwelliger Dauererregungen beruhenden Zunahme der Reflextätigkeit des Froschrückenmarkes nach funktioneller Beanspruchung. Der rhythmische Verlauf der Nb., ihr Umschlag in ein Schwererwerden der angestrengten Extremität, sowie eine Reihe von Summationserscheinungen und die willkürliche Hemmbarkeit, endlich die Tatsache der Beeinflussung entsprechender nicht angespannter Muskeln der andern Körperhälfte stützen den Beweis. Die subjektive Seite der Nb. ist, wie der Novocainversuch zeigt, im wesentlichen peripher bedingt zu denken.  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