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   1513篇
  免费   142篇
  国内免费   9篇
耳鼻咽喉   13篇
儿科学   108篇
妇产科学   20篇
基础医学   142篇
口腔科学   73篇
临床医学   151篇
内科学   427篇
皮肤病学   22篇
神经病学   35篇
特种医学   248篇
外国民族医学   1篇
外科学   103篇
综合类   69篇
预防医学   104篇
眼科学   21篇
药学   63篇
中国医学   9篇
肿瘤学   55篇
  2020年   9篇
  2019年   16篇
  2018年   14篇
  2017年   14篇
  2016年   12篇
  2015年   27篇
  2014年   44篇
  2013年   74篇
  2012年   40篇
  2011年   51篇
  2010年   55篇
  2009年   67篇
  2008年   49篇
  2007年   68篇
  2006年   43篇
  2005年   39篇
  2004年   35篇
  2003年   30篇
  2002年   30篇
  2001年   27篇
  2000年   24篇
  1999年   25篇
  1998年   83篇
  1997年   57篇
  1996年   65篇
  1995年   44篇
  1994年   51篇
  1993年   45篇
  1992年   25篇
  1991年   13篇
  1990年   27篇
  1989年   51篇
  1988年   46篇
  1987年   35篇
  1986年   30篇
  1985年   26篇
  1984年   30篇
  1983年   24篇
  1982年   18篇
  1981年   24篇
  1980年   18篇
  1979年   12篇
  1978年   12篇
  1977年   19篇
  1976年   10篇
  1975年   13篇
  1972年   8篇
  1970年   11篇
  1969年   11篇
  1966年   8篇
排序方式: 共有1664条查询结果,搜索用时 31 毫秒
1.
A clinical performance examination was developed for basic baccalaureate nursing students and used to validate the clinical skills of registered nurses entering a baccalaureate degree program. With few exceptions, RNs returning to school demonstrated clinical competence in the secondary care area as measured by this examination. Therefore, another means of validating RN clinical skills was developed based on the evaluation criteria used for the clinical performance examination. Using employer and colleague validation, students individually documented competence in the area of practice. There was a decrease in student stress, an increase in self-esteem, conservation of the time and energy of students and faculty, and more effective use of program resources.  相似文献   
2.
目的 探讨创伤后迟发性脑肿胀的临床特点、发病机制与治疗。方法 回顾性分析1998年1月~2005年6月年收治的17例迟发性脑肿胀患者的临床特点和救治情况。结果 所有颅脑损伤患者采用保守治疗后均有好转,但于伤后5-10d出现恶化,CT复查有脑肿胀,经加强综合脱水等治疗后16例治愈,1例死亡。结论 迟发性脑肿胀好发于对冲性额、颞叶挫裂伤伴明显蛛网膜下腔出血、硬膜下薄层血肿及早期CT有脑肿胀者。其发病机制可能与创伤后的迟发性脑血管痉挛、微循环障碍、静脉回流障碍及甘露醇作用下降等因素有关。此类患者病情隐蔽性强,应加强观察、积极行CT复查,如能早期明确诊断,保守治疗多数效果良好。  相似文献   
3.
Retrorenal colon: implications for percutaneous diskectomy   总被引:1,自引:0,他引:1  
Helms  CA; Munk  PL; Witt  WS; Davis  GW; Morris  J; Onik  G 《Radiology》1989,171(3):864-865
It has been recommended that computed tomography (CT) with the patient prone be performed in every patient undergoing percutaneous diskectomy; this would enable detection of a retrorenal location of the colon, which could interfere with the percutaneous procedure. In this evaluation of 346 prone CT studies, only one patient (0.29%) was found to have retrorenal or retropsoas bowel that would have been perforated at diskectomy. Because of this extremely low prevalence, the performance of prone CT in every patient undergoing percutaneous lumbar diskectomy is not believed to be necessary.  相似文献   
4.
5.
6.
7.
采用间接ELISA检测23名肾移植受者血清巨细胞病毒(CMV)抗体,共检出18名(78%)活动性CMV感染,其中10名(44%)为原发性感染。结果证实CMV-IgE和-IgA具有较好的血清学诊断价值,优于CMV-IgM。  相似文献   
8.
Time series data were collected twice daily for 62 days from 10 individuals on three variables related to smoking habit strength: number of cigarettes smoked, salivary cotinine, and carbon monoxide. The two purposes of this study were: (a) to evaluate which time series model(s) best fits each of the measures; and (b) to determine which model of nicotine regulation is consistent with the data. Three models of nicotine regulation were considered: (a) nicotine fixed effect; (b) nicotine regulation; and (c) multiple regulation. These models provide different predictions about the size and direction of the lag-one autocorrelation. Each measure was described in terms of one of a family of time series models represented mathematically as ARIMA (p, d, q). Models varied by individual, but a single model described the majority of subjects for all three variables. The clearest model identification was for the number of cigarettes smoked where an ARIMA (1, 0, 0) model with a moderate to strong negative dependency fit the majority of the subjects. This provided strong support for the multiple regulation model. An appendix provides a brief review of time series methodology.  相似文献   
9.
The beta-amyloid (Abeta) precursor protein (APP) is cleaved sequentially by beta-site of APP-cleaving enzyme (BACE) and gamma-secretase to release the Abeta peptides that accumulate in plaques in Alzheimer's disease (AD). GGA1, a member of the Golgi-localized gamma-ear-containing ARF-binding (GGA) protein family, interacts with BACE and influences its subcellular distribution. We now report that overexpression of GGA1 in cells increased the APP C-terminal fragment resulting from beta-cleavage but surprisingly reduced Abeta. GGA1 confined APP to the Golgi, in which fluorescence resonance energy transfer analyses suggest that the proteins come into close proximity. GGA1 blunted only APP but not notch intracellular domain release. These results suggest that GGA1 prevented APP beta-cleavage products from becoming substrates for gamma-secretase. Direct binding of GGA1 to BACE was not required for these effects, but the integrity of the GAT (GGA1 and TOM) domain of GGA1 was. GGA1 may act as a specific spatial switch influencing APP trafficking and processing, so that APP-GGA1 interactions may have pathophysiological relevance in AD.  相似文献   
10.
AIM: The aim of this pilot study was an investigation on photodynamic therapy (PDT) whether it is a good alternative for treating periungual and subungual warts of the hands. STUDY DESIGN: Twenty patients (mean age: 30.5 years) with a total of 40 periungual and subungual warts were treated with PDT. A photosensitizer, 20%delta-aminolevulinic acid was applied on the warts. After a mean incubation time of 4.6 h (SD: 1.2), the warts were irradiated with the VersaLight for 5-30 min (15.2 +/- 4.3 min). RESULTS: After a mean of 4.5 treatments a mean clearance of 100% was achieved in 90% of the patients. One patient (5%) showed a clearance of 50% and another showed no improvement. The subungual or periungual location of the wart had no influence on the number of treatments or end result (P > 0.05). There were two recurrences during the mean follow-up period of 5.9 months (SD: 7.6). Besides mainly pain and hyperpigmentation, most treatments had no side-effects. CONCLUSION: PDT can offer a good alternative for treating periungual warts of the hands. Larger studies are indicated.  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