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   583篇
  免费   23篇
耳鼻咽喉   2篇
儿科学   14篇
妇产科学   5篇
基础医学   46篇
口腔科学   12篇
临床医学   58篇
内科学   67篇
皮肤病学   3篇
神经病学   42篇
特种医学   114篇
外科学   141篇
综合类   10篇
预防医学   38篇
眼科学   3篇
药学   31篇
肿瘤学   20篇
  2022年   2篇
  2021年   6篇
  2019年   2篇
  2018年   7篇
  2017年   5篇
  2016年   2篇
  2015年   10篇
  2014年   13篇
  2013年   12篇
  2012年   20篇
  2011年   21篇
  2010年   22篇
  2009年   6篇
  2008年   47篇
  2007年   18篇
  2006年   22篇
  2005年   26篇
  2004年   41篇
  2003年   44篇
  2002年   27篇
  2001年   16篇
  2000年   10篇
  1999年   7篇
  1998年   16篇
  1997年   10篇
  1996年   11篇
  1995年   9篇
  1994年   13篇
  1993年   9篇
  1992年   7篇
  1991年   6篇
  1990年   7篇
  1989年   9篇
  1988年   12篇
  1987年   9篇
  1986年   11篇
  1985年   12篇
  1984年   5篇
  1983年   10篇
  1982年   7篇
  1981年   5篇
  1980年   14篇
  1979年   4篇
  1978年   11篇
  1977年   8篇
  1976年   4篇
  1975年   2篇
  1973年   2篇
  1972年   2篇
  1936年   1篇
排序方式: 共有606条查询结果,搜索用时 0 毫秒
1.
2.
3.
Haughton  VM; Prost  R 《Radiology》1986,158(2):461-462
The effect of chemical shift on magnetic resonance (MR) imaging of the pituitary fossa was studied. Healthy volunteers underwent conventional MR imaging of the pituitary fossa and then imaging with the frequency-encoding gradient reversed or with the phase- and frequency-encoding gradients interchanged. Comparison of the image pairs in each subject showed that the thin, black stripe evident at the water-fat interface within the pituitary fossa was altered when the gradients were changed. Therefore, the low-intensity signal within the pituitary fossa is a chemical shift misregistration effect.  相似文献   
4.
5.
Anulus fibrosus in bulging intervertebral disks   总被引:1,自引:0,他引:1  
Yu  SW; Haughton  VM; Sether  LA; Wagner  M 《Radiology》1988,169(3):761-763
In this investigation the association of radial tears of the anulus fibrosus and bulging of the intervertebral disk was studied. An index of disk bulging was measured in sagittal anatomic sections in 149 lumbar disks from 31 cadavers. The indexes of disk bulging were correlated with stages of disk development and the presence of an annular tear. The largest disk-bulging indexes were always associated with radial tears of the anulus. Eighty-four percent of the disks with radial tears had disk-bulging indexes greater than 2.5 mm. Most normal adult disks had an index of less than 2.5 mm. The results challenge the concept that the anulus fibrosus is intact in bulging disks, although ruptured in herniated disks.  相似文献   
6.
It has been estimated that 26% of Americans are obese. A very small subset of this group can be categorized as morbidly obese, fulfilling the criteria of being 100 pounds, or 100%, over ideal body weight. The clinical records of seven morbidly obese burn patients treated over a 20-year period are reviewed. Particularly notable was a 43% incidence of fatal pulmonary embolism.  相似文献   
7.
BACKGROUND: Cancer pain is highly prevalent and commonly undertreated. This study was designed to determine whether dissemination of a clinical protocol for pain management would improve outcomes in community oncology practices. PATIENTS AND METHODS: A pain management protocol was developed based on accepted guidelines. After baseline assessment, oncology practices were randomly assigned to 'analgesic protocol' (AP) sites, where oncologists implemented the guidelines in a group of lung or prostate cancer patients, or to 'physician discretion' (PD) sites, where customary treatment was continued. Patients treated on protocol and a comparison group of patients with pain due to breast cancer or myeloma were monitored for change in pain using the Brief Pain Inventory, and for change in other symptoms or mood. RESULTS: The protocol terminated early because of poor accrual. We compared groups using proportions of patients who had no or mild pain at follow-up. Although measures of protocol adherence did not suggest the occurrence of major practice change, the proportion of lung or prostate cancer patients with no or mild pain increased significantly from baseline for those treated at AP sites compared with those treated at PD sites. There was no significant difference between the breast and myeloma patients treated at AP sites versus those treated at PD sites. CONCLUSION: A protocol for cancer pain management can improve pain control. Diffusion of these benefits to other patients was not confirmed. Given the small sample size, these findings require confirmation in a larger trial.  相似文献   
8.
9.
People undergoing medical procedures sometimes experience feelings that may influence the results. In this study, we explore the relationship between changes in mood state self-ratings and cerebral glucose metabolism during positron emission tomography (PET) in persons with age-associated memory impairment (mean age 59.4±9.8 years). Brain regions of interest involved in both mood and memory were examined. Mood ratings of increased boredom correlated significantly with mesial temporal and parietal asymmetry and decreased parietal metabolism. Mood ratings of increased fatigue correlated with basal ganglia asymmetry and the right basal ganglia and left mesial temporal metabolism. These findings suggest that subjective mood state changes during PET may influence metabolism in brain regions implicated in emotion and memory function in people with age-related memory complaints.  相似文献   
10.
Hemoglobin (Hb) solutions can cause vasoconstriction and activation of intravascular coagulation. Because the endothelium plays a major role in the regulation of vascular tone and hemostasis, a study was conducted of human umbilical vein endothelial cells (EC) incubated with various Hbs. Cell injury was evaluated by electron microscopy and the release of lactic dehydrogenase, H2O2, and procoagulant "tissue factor." Cell reaction was assessed by the measurement of 6-keto-prostaglandin F (PGF)1 alpha (metabolite of prostacyclin) and thromboxane B2 (metabolite of thromboxane A2). Incubation with unmodified bovine hemoglobin for 24 h caused no cell injury and a reaction characterized by 48.4 +/- 8.2% increase in 6-keto-PGF1 alpha production, accompanied by 40.2 +/- 9.4% reduction in thromboxane (Tx)B2 (compared with a control group of EC incubated with saline solution). Incubation with a nonpure Hb solution (Hb plus red blood cell membrane aminophospholipids; a-PLs) caused cell injury with significant release of tissue factor, plus a reaction characterized by 97.5 +/- 12.5% increase in TxB2 production accompanied by 25.3 +/- 3% reduction in 6-keto-PGF1 alpha. A second nonpure Hb [Hb plus bacterial environmental endotoxin (E)] caused cell injury, the release of tissue factor, and increased production of both prostaglandins, with greater release of TxB2 (197 +/- 17%) than of 6-keto-PGF1 alpha (112 +/- 8.3%). These data indicate that the endothelium reacts differently to pure and nonpure hemoglobins. The biocompatibility of Hb solutions, with regard to vasoconstriction and activation of intravascular coagulation, depends on the absence of stromal a-PLs and bacterial E.  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