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   1228篇
  免费   105篇
  国内免费   6篇
耳鼻咽喉   10篇
儿科学   36篇
妇产科学   21篇
基础医学   175篇
口腔科学   45篇
临床医学   143篇
内科学   191篇
皮肤病学   20篇
神经病学   111篇
特种医学   48篇
外科学   250篇
综合类   57篇
一般理论   8篇
预防医学   95篇
眼科学   25篇
药学   59篇
中国医学   7篇
肿瘤学   38篇
  2021年   18篇
  2019年   8篇
  2018年   12篇
  2017年   13篇
  2016年   16篇
  2015年   23篇
  2014年   27篇
  2013年   30篇
  2012年   38篇
  2011年   51篇
  2010年   41篇
  2009年   26篇
  2008年   35篇
  2007年   50篇
  2006年   56篇
  2005年   47篇
  2004年   54篇
  2003年   59篇
  2002年   37篇
  2001年   57篇
  2000年   54篇
  1999年   33篇
  1998年   21篇
  1997年   26篇
  1996年   30篇
  1995年   22篇
  1994年   10篇
  1993年   10篇
  1992年   39篇
  1991年   23篇
  1990年   30篇
  1989年   34篇
  1988年   22篇
  1987年   22篇
  1986年   18篇
  1985年   22篇
  1984年   17篇
  1983年   12篇
  1982年   10篇
  1981年   11篇
  1980年   13篇
  1979年   15篇
  1978年   15篇
  1977年   13篇
  1976年   7篇
  1975年   8篇
  1974年   7篇
  1973年   8篇
  1972年   8篇
  1969年   10篇
排序方式: 共有1339条查询结果,搜索用时 437 毫秒
1.
The discovery of an inducible isoform of cyclooxygenase (COX-2) requires a refinement of the theory that inhibition of cyclooxygenase activity is responsible for both therapeutic and side-effects of nonsteroidal anti-inflammatory drugs (NSAIDs). Pharmacological results with developmental compounds suggest that COX-2 is the relevant target for the therapeutic (i.e. anti-inflammatory) effects of NSAIDs, whereas gastric and renal side-effects are related to inhibition of constitutive COX-1. However a role of COX-1 in inflammation cannot be excluded. Furthermore, more research effort is needed to investigate the functional relevance of COX-2 in normal tissue.  相似文献   
2.
The condition of newborn infants with anencephaly, a neural tube defect, is incurable and uniformly fatal. Although physicians reached a consensus two decades ago on the appropriateness of using these infants' organs, ethical and legal questioning has since challenged the grounds on which medical authorities justified transplantation. Advocates have proposed three conceptual strategies to warrant procuring anencephalics' organs: redefining death, excluding the infants from possessing personhood, and intubating and ventilating them while keeping a vigil for brain death. Each of these conceptual schemes has arguable shortcomings in its construction, however; as such, the case for using anencephalic infants as sources of organs has yet to be conclusively demonstrated.  相似文献   
3.
Book reviewed in this article: The Needs of Strangers . By Michael Ignatieff. The Health Economy . By Victor Fuchs. Just Health Care . By Norman Daniels  相似文献   
4.
5.
6.
Radiologic diagnosis of an intra-abdominal abscess. Do multiple tests help?   总被引:2,自引:0,他引:2  
A review was made of the charts of 94 patients who underwent ultrasonography (US), computed tomography (CT), and gallium citrate Ga 67 (Gall) scan to rule out intra-abdominal abscesses. Of all the clinical and laboratory data, only the presence of pain and tenderness differentiated patients with and without abscesses. A review of radiologic data showed that CT was superior to US, and that US was superior to Gall scan with regard to sensitivity, specificity, accuracy, and positive and negative predictive values. When multiple radiologic tests were performed, results agreed in 72% of cases; therefore, the additional tests were essentially redundant. When radiologic test results disagreed, accuracy rates were CT, 0.86; US, 0.00; and Gall scan, 0.44. These findings suggest that, except to rule out pelvic abscesses in the presence of pelvic inflammatory disease, CT is usually the only special radiologic test that should be performed to localize a suspected intra-abdominal abscess.  相似文献   
7.
Three field-adapted methods for the quantification of the antimalarial drug chloroquine are described. Two of the methods are modifications of the Haskins test and are based on ion-pair formation between chloroquine and methyl orange in either dichloromethane or chloroform. Absorbance values measured at 420 nm with a hand-held, battery-operated filter photometer were linearly related to chloroquine concentrations in urine up to 100 μmol/l (32 μg/ml) for both methods. The contribution of the desethylchloroquine metabolite to the measured absorbance for both methods is less than that of chloroquine; the relative sensitivity for this metabolite is about 50% of that of chloroquine for both methods. The detection limit for modification I is 1 μmol/l (0.3 μg/ml), while that for modification II is 3 μmol/l (1 μg/ml). A single dose of chloroquine diphosphate (300 mg as base) administered to each of three volunteers yielded detectable levels by modification I of chloroquine in the urine for 28 days after dosing. Results for the colorimetric methods correlated well with the liquid chromatographic reference method used. The related thin-layer chromatographic method confirmed the presence of chloroquine and desethylchloroquine in the urine and permitted independent estimation of the concentration of these two compounds if desired. The two colorimetric methods may be used in remote locations where no electricity is available.  相似文献   
8.
This double blind, randomized, parallel, placebo-controlled study investigates whether clonazepam accelerates and/ or increases the overall response in patients with obsessive compulsive disorder (OCD) who are treated with sertraline. Thirty-seven patients were randomized with 20 in the sertraline and clonazepam group and 17 in the sertraline and placebo groups. Male and female outpatients, age 18-65 years, met criteria for a primary diagnosis of obsessive compulsive disorder according to DSM-IV, as determined by the structured clinical MINI interview. Appropriate safety and efficacy parameters were measured throughout the study. The determination of efficacy was based primarily on changes from baseline to the last observation taken through week 12. Analysis revealed no significant difference between groups at endpoint on the main scale.  相似文献   
9.
10.
Air breathing is used to lessen hyperbaric oxygen (HBO2) toxicity. Hypoxemia could occur during hyperbaric air breathing in patients with lung dysfunction, although this has not been previously reported. We report two cases of hypoxemia during air breathing with two patients treated with the US Navy Table 6. Patient 1 was an 11-year-old male with cerebral gas embolism (during cardiac transplantation), patient 2 was a 66-year-old female with cerebral gas embolism from a central venous catheter accident. Both were mechanically ventilated. We monitored arterial blood gas (ABG) during therapy. In both patients, ABG measurements showed hypoxia during the first air breathing period at 1.9 atm abs (192.5 kPa). If patients require > or = 40% inspired oxygen before HBO2 therapy, oxygenation monitoring is advisable during air breathing periods, especially at lower chamber pressures (< or = 2.0 atm abs).  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