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   942篇
  免费   91篇
  国内免费   19篇
耳鼻咽喉   4篇
儿科学   40篇
妇产科学   13篇
基础医学   75篇
口腔科学   25篇
临床医学   145篇
内科学   234篇
皮肤病学   24篇
神经病学   55篇
特种医学   139篇
外科学   90篇
综合类   27篇
预防医学   87篇
眼科学   6篇
药学   38篇
中国医学   3篇
肿瘤学   47篇
  2021年   19篇
  2020年   6篇
  2018年   13篇
  2017年   11篇
  2016年   17篇
  2015年   16篇
  2014年   26篇
  2013年   37篇
  2012年   25篇
  2011年   26篇
  2010年   30篇
  2009年   41篇
  2008年   27篇
  2007年   55篇
  2006年   33篇
  2005年   29篇
  2004年   32篇
  2003年   25篇
  2002年   13篇
  2001年   22篇
  2000年   12篇
  1999年   22篇
  1998年   57篇
  1997年   52篇
  1996年   30篇
  1995年   24篇
  1994年   17篇
  1993年   18篇
  1992年   11篇
  1991年   17篇
  1990年   18篇
  1989年   22篇
  1988年   21篇
  1987年   25篇
  1986年   16篇
  1985年   28篇
  1984年   19篇
  1983年   24篇
  1982年   6篇
  1981年   8篇
  1980年   10篇
  1979年   9篇
  1977年   4篇
  1975年   6篇
  1974年   4篇
  1971年   7篇
  1970年   4篇
  1969年   4篇
  1968年   5篇
  1964年   4篇
排序方式: 共有1052条查询结果,搜索用时 15 毫秒
1.
Changing attentional demands in left hemispatial neglect.   总被引:1,自引:0,他引:1  
Seven variations of a letter cancellation test were used to examine how varying attentional demands affect hemispatial neglect in patients with right hemisphere lesions. While the 14 targets always remained in the same location, the number of distractors (zero, nine, 28, or 82) as well as their complexity (one letter or nine different letters) were varied. The percentage of targets canceled in the left hemispace was linearly related to the number of distractors. There were no differences between the complexity conditions. In a second study, the same 14 targets were presented but the distractors (zero, 14, or 41) were all placed on the right. Increasing the number of distractors on the right increased neglect on both sides of the space. Taken together, these results suggest that, while the limited attentional resources of the left hemisphere are biased toward the right hemispace, the absence of contralateral attentional demands allows these resources to be directed ipsilaterally.  相似文献   
2.
In 1995, the National League for Nursing commissioned a Panel on Interdisciplinary/Transdisciplinary Education. The focus of the Panel's work was to examine educational issues that transcend the health professions and to make recommendations for future implementation of an interdisciplinary approach to addressing them. This article is being simultaneously published by several professional journals. The goal is to seek as much feedback as possible.  相似文献   
3.
The World Wide Web creates new challenges and opportunities for medical educators. Prominent among these are the lack of consistent standards by which to evaluate web-based educational tools. We present the instrument that was used to review web-based innovations in medical education submissions to the 2003 Society of General Internal Medicine (SGIM) national meeting, and discuss the process used by the SGIM web-based clinical curriculum interest group to develop the instrument. The 5 highest-ranked submissions are summarized with commentary from the reviewers.  相似文献   
4.
Haemophilus ducreyi infection in south Florida: a rare disease on the rise?   总被引:2,自引:0,他引:2  
Increased numbers of patients with genital ulcers sought medical attention in the Palm Beach County, Florida, Sexually Transmitted Disease clinics from Aug 1, 1982 to Aug 31, 1983. We established that a small proportion of subsequent cases of genital ulcers were caused by Haemophilus ducreyi, the etiologic agent associated with chancroid. We also set up a surveillance system to monitor this sexually transmitted infection, and have illuminated several recent cases of chancroid occurring in that area. This outbreak of chancroid suggest that clinicians practicing in south Florida consider chancroid (generally a rare disease in the United States) in their differential diagnoses of genital ulcers.  相似文献   
5.
BACKGROUND: There are obvious advantages to increasing donor retention. However, for reasons of blood safety, certain donors may, in fact, be more desirable to retain than others. “Safe” donors are defined as those who provided a blood donation that was negative on all laboratory screening tests and who subsequently reported no behavioral risks in response to an anonymous survey. This study identifies the most important factors affecting the intention of “safe” donors to provide another donation. STUDY DESIGN AND METHODS: An anonymous survey asking about donation history, sexual history, injecting drug use, and recent donation experience was mailed to 50,162 randomly selected allogeneic donors (including directed donors) who gave blood from April through July or from October through December 1993 at one of the five United States blood centers participating in the Retrovirus Epidemiology Donor Study. Before mailing, questionnaires were coded to designate donors with nonreactive laboratory screening tests at their most recent donation. RESULTS: A total of 34,726 donors (69%) responded, with substantially higher response among repeat donors. According to reported intentions only, the vast majority of “safe” donors indicated a high likelihood of donating again within the next 12 months. Only 3.4 percent reported a low likelihood of donating again. A comparison of those likely to return and those unlikely to return reveals significant differences in demographics and in ratings of the donation experience. A higher proportion of those unlikely to return were first-time donors, minority-group donors, and donors with less education. The highest projected loss among “safe” donors was seen for those who gave a fair to poor assessment of their treatment by blood center staff or of their physical well-being during or after donating. CONCLUSION: These data suggest that efforts to improve donors' perceptions of their donation experience, as well as attention to the physical effects of blood donation, may aid in the retention of both repeat and first-time donors.  相似文献   
6.
7.
Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture.  相似文献   
8.
The authors investigated the effects of transient, mild hemorrhagic hypotension after fluid-percussion traumatic brain injury on intracranial pressure, cerebral blood flow (CBF), cerebral oxygen delivery (CBF x arterial O2 content), and electroencephalographic (EEG) activity. Adult mongrel cats were anesthetized with 1.6% isoflurane in N2O:O2 (70:30) and prepared for trauma and for radioactive microsphere CBF measurement. Isoflurane concentration was decreased to 0.8%, and the cats were randomly assigned to one of four control groups or to an experimental group. Animals in the four control groups underwent either mild hemorrhage (18 ml.kg-1) immediately followed by resuscitation with equal volumes of 10% Hetastarch (eight cats), mild hemorrhage followed by replacement of shed blood (six cats), isovolemic hemodilution with 18 ml.kg-1 of Hetastarch (six cats), or moderate (2.2 atm) trauma alone (eight cats). The experimental group received a combination of trauma and mild hemorrhage followed by resuscitation with Hetastarch (eight cats). Mild hemorrhage produced no significant changes in CBF, renal blood flow, or cardiac output. Following resuscitation from mild hemorrhage, mean arterial blood pressure, cardiac output, renal blood flow, and CBF were not significantly different from baseline; cardiac output and renal blood flow did not differ significantly from baseline 2 hours after Hetastarch resuscitation. Neither hemorrhage nor trauma alone produced significant decreases in CBF or in EEG activity, but trauma followed by hemorrhage and resuscitation produced significant (p less than 0.01) decreases in CBF, cerebral oxygen delivery, and EEG score. These data demonstrate that, following traumatic brain injury, even mild hemorrhagic hypotension is associated with significant deficits in cerebral oxygen availability and neurological function.  相似文献   
9.
Intestinal schistosomiasis japonica: CT-pathologic correlation   总被引:1,自引:0,他引:1  
  相似文献   
10.
Vascular complications of pancreatic transplantation: MR evaluation   总被引:8,自引:0,他引:8  
Krebs  TL; Daly  B; Wong  JJ; Chow  CC; Bartlett  ST 《Radiology》1995,196(3):793
  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