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   42520篇
  免费   3086篇
  国内免费   146篇
耳鼻咽喉   463篇
儿科学   1375篇
妇产科学   1171篇
基础医学   5878篇
口腔科学   491篇
临床医学   6248篇
内科学   8093篇
皮肤病学   712篇
神经病学   4335篇
特种医学   805篇
外国民族医学   1篇
外科学   3453篇
综合类   760篇
一般理论   42篇
预防医学   4920篇
眼科学   878篇
药学   2968篇
中国医学   79篇
肿瘤学   3080篇
  2023年   208篇
  2022年   197篇
  2021年   861篇
  2020年   478篇
  2019年   799篇
  2018年   931篇
  2017年   721篇
  2016年   803篇
  2015年   974篇
  2014年   1308篇
  2013年   1990篇
  2012年   3011篇
  2011年   3168篇
  2010年   1603篇
  2009年   1556篇
  2008年   2843篇
  2007年   3064篇
  2006年   3142篇
  2005年   3092篇
  2004年   3008篇
  2003年   2824篇
  2002年   2614篇
  2001年   371篇
  2000年   269篇
  1999年   371篇
  1998年   483篇
  1997年   417篇
  1996年   378篇
  1995年   361篇
  1994年   267篇
  1993年   297篇
  1992年   206篇
  1991年   204篇
  1990年   177篇
  1989年   176篇
  1988年   186篇
  1987年   150篇
  1986年   127篇
  1985年   147篇
  1984年   180篇
  1983年   182篇
  1982年   237篇
  1981年   170篇
  1980年   176篇
  1979年   109篇
  1978年   105篇
  1977年   109篇
  1976年   84篇
  1975年   70篇
  1974年   75篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
BACKGROUND AND OBJECTIVE: An observational case series to assess the value of positron emission tomography (PET) in staging ocular adnexal lymphomas and evaluating their response to therapy. PATIENTS AND METHODS: The clinical records of 16 consecutive patients with ocular adnexal lymphoma for whom pretreatment and posttreatment PET scans and corresponding computed tomography (CT) and magnetic resonance imaging (MRI) scans were available were compared. RESULTS: Pretreatment PET scans demonstrated fluorine 18-fluorodeoxyglucose (FDG) positive lesions in 15 orbits of 12 patients. In 1 patient with low-grade follicular lymphoma of the orbit, PET revealed an additional focus of lymphoma in the deltoid muscle that was missed on clinical examination and conventional radiography. All of the posttreatment PET scans showed complete resolution of FDG uptake, suggesting good response to therapy. However, posttreatment CT and MRI scans demonstrated residual masses in 3 patients. CONCLUSIONS: PET is valuable for initial staging of ocular adnexal lymphomas and may be a good adjunct to conventional imaging in evaluation of response to therapy.  相似文献   
105.
Relief of symptoms for patients and families throughout the illness trajectory requires that palliative care practitioners have knowledge and skill, both in assessment and use of pharmacologic and complementary therapies. This article presents the didactic content of symptom assessment and management, and the experiential experiences used in a nondrug laboratory within the End-of-Life Nursing Education Consortium (ELNEC) curriculum.  相似文献   
106.
Background: A new benzodiazepine derivative, CNS 7056, has been developed to permit a superior sedative profile to current agents, i.e., more predictable fast onset, short duration of sedative action, and rapid recovery profile. This goal has been achieved by rendering the compound susceptible to metabolism via esterases. The authors now report on the profile of CNS 7056 in vitro and in vivo.

Methods: The affinity of CNS 7056 and its carboxylic acid metabolite, CNS 7054, for benzodiazepine receptors and their selectivity profiles were evaluated using radioligand binding. The activity of CNS 7056 and midazolam at subtypes ([alpha]1[beta]2[gamma]2, [alpha]2[beta]2[gamma]2, [alpha]3[beta]2[gamma]2, [alpha]5[beta]2[gamma]2) of the [gamma]-aminobutyric acid type A (GABAA) receptor was evaluated using the whole cell patch clamp technique. The activity of CNS 7056 at brain benzodiazepine receptors in vivo was measured in rats using extracellular electrophysiology in the substantia nigra pars reticulata. The sedative profile was measured in rodents using the loss of righting reflex test.

Results: CNS 7056 bound to brain benzodiazepine sites with high affinity. The carboxylic acid metabolite, CNS 7054, showed around 300 times lower affinity. CNS 7056 and CNS 7054 (10 [mu]m) showed no affinity for a range of other receptors. CNS 7056 enhanced GABA currents in cells stably transfected with subtypes of the GABAA receptor. CNS 7056, like midazolam and other classic benzodiazepines, did not show clear selectivity between subtypes of the GABAA receptor. CNS 7056 (intravenous) caused a dose-dependent inhibition of substantia nigra pars reticulata neuronal firing and recovery to baseline firing rates was reached rapidly. CNS 7056 (intravenous) induced loss of the righting reflex in rodents. The duration of loss of righting reflex was short (< 10 min) and was inhibited by pretreatment with flumazenil.  相似文献   

107.
Background Processing multiple tissue sections in large Mohs cases is time consuming and labor intensive.
Objective To present innovative laboratory techniques to facilitate processing of large Mohs cases.
Methods A method for processing a large dermatofibrosarcoma protuberans Mohs case is outlined.
Results Modifications in tissue processing and equipment employed in a large Mohs case are presented.
Conclusion Innovative modifications to the standard Mohs laboratory technique can facilitate processing of large Mohs cases, resulting in high-quality, rapid frozen sections while optimizing efficiency.  相似文献   
108.
109.
The nursing profession is facing a serious shortage in all areas including BSN completion programs. The purpose of this study was to explore associate degree and diploma nurses' perceptions of the benefits and barriers to RN-BSN programs. In addition, factors that would facilitate degree completion in academia and work environments were examined.  相似文献   
110.
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