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   13548篇
  免费   1277篇
  国内免费   24篇
耳鼻咽喉   163篇
儿科学   411篇
妇产科学   421篇
基础医学   1896篇
口腔科学   227篇
临床医学   1841篇
内科学   2455篇
皮肤病学   217篇
神经病学   1386篇
特种医学   457篇
外国民族医学   1篇
外科学   1613篇
综合类   266篇
一般理论   12篇
预防医学   1447篇
眼科学   320篇
药学   887篇
中国医学   18篇
肿瘤学   811篇
  2022年   108篇
  2021年   235篇
  2020年   167篇
  2019年   219篇
  2018年   306篇
  2017年   229篇
  2016年   245篇
  2015年   245篇
  2014年   386篇
  2013年   557篇
  2012年   712篇
  2011年   684篇
  2010年   382篇
  2009年   373篇
  2008年   615篇
  2007年   606篇
  2006年   639篇
  2005年   628篇
  2004年   544篇
  2003年   510篇
  2002年   495篇
  2001年   343篇
  2000年   333篇
  1999年   317篇
  1998年   140篇
  1997年   140篇
  1996年   112篇
  1995年   111篇
  1994年   114篇
  1993年   92篇
  1992年   250篇
  1991年   245篇
  1990年   238篇
  1989年   205篇
  1988年   232篇
  1987年   226篇
  1986年   227篇
  1985年   199篇
  1984年   172篇
  1983年   172篇
  1982年   122篇
  1981年   126篇
  1980年   106篇
  1979年   180篇
  1978年   132篇
  1977年   103篇
  1976年   123篇
  1975年   120篇
  1974年   128篇
  1973年   94篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
The traditional role of the high school based community community health nurse has changed considerably over recent decades. This article describes a qualitative study, in which nine community health nurses from eight different high schools completed a diary of the interventions and events during the course of two working days in order to identify the dimensions of their role. A short demographic questionnaire was also completed by the nurses and included two open-ended questions concerning their main professional issues and concerns. The researchers sought verification of the interpretation of the data through a focus group interview with the high school nurses. Data analysis indicated that the role of the high school community health nurses (CHN) consisted of seven categories. These were provider of clinical care, counsellor/ mediator, advocacy and support, liaison/referral, health promotion/education and resource agent, and professional management and research role. The findings highlight the complex and demanding aspects of the role of the high school nurse and articulate the importance of describing the contribution of such practitioners in to the promotion of health among adolescents.  相似文献   
5.
Summary Aged common marmosets were treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 0.5–2.0 mg/kg/week i.p.) for 16 or 24 weeks, observed for a total of 30 weeks and then killed for measurement of biochemical pramaters in basal ganglia. The MPTP treatment induced a marked depletion in dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid levels in the caudate nucleus and putamen. In contrast, the concentrations of five neuropeptides: [Met5]-enkephalin, [Leu5]-enkephalin, cholecystokinin, substance P and neurotensin as measured by a combined HPLC/RIA method, remained unaltered in all basal ganglia regions examined. Enkephalin precursor levels, as reflected by cryptic [Met5]-enkephalin content, were increased in the putamen, but not in the caudate nucleus, as a consequence of MPTP administration. Cryptic [Leu5]-enkephalin content remained unchanged in the striatum of MPTP treated marmosets. Overall, these results suggest an increase in striatal [Met5]-enkephalin release following chronic MPTP treatment of aged marmosets. However, the chronic treatment of aged marmosets with MPTP does not reproduce the neuropeptide alterations characteristic of Parkinson's disease.  相似文献   
6.
IL2-PE40 is a chimeric protein composed of human interleukin-2 (IL2) genetically fused to a modified form of Pseudomonas exotoxin lacking the cell recognition domain. IL2-PE40 is cytotoxic for IL2 receptor-bearing lymphocytes in culture and can inhibit activation of T cells in vivo. IL2-PE40 can significantly diminish antigen-stimulated proliferation of lymphocytes sensitized to myelin basic protein. Intraperitoneal administration of IL2-PE40 not only markedly inhibits the clinical manifestations of adoptively transferred relapsing experimental allergic encephalomyelitis but also dramatically reduces both inflammation and demyelination characteristic of the disease.  相似文献   
7.
Reply     
  相似文献   
8.
In 1984, in addition to its standard traditional curriculum, Rush Medical College (Chicago, Ill) developed a Socratic problem-based method of teaching basic science material called the alternative curriculum. As part of an evaluation of this new curriculum, students in the two curricula were compared using three traditional measurements: (1) test scores from the National Board of Medical Examiners, Part I; (2) test scores from the National Board of Medical Examiners, Part II; and (3) performance on an oral examination. Alternative curriculum students did not differ significantly from their traditional curriculum classmates on National Board of Medical Examiners, Part I and Part II total scores, although their subset scores on Part I did tend to be lower, reaching significance in one subset area. Differences in performance favoring the traditional curriculum were primarily seen in the early years of the program. Alternative curriculum students in the class matriculated in 1987 scored significantly higher in three of five categories on the oral examination.  相似文献   
9.
Gestational age determination based on obstetric dating criteria, early pregnancy ultrasound scans, Dubowitz examinations, and ultrasound scans performed shortly before delivery were reviewed for 69 preterm infants requiring neonatal intensive care. The last ultrasound scans underestimated gestational age by a median of 8 days, and by 2 weeks or more in 20 of the 69 cases, as opposed to best dating criteria. Ultrasonic fetal weight estimation was more accurate, but erred by more than 20% in 10% of cases. When obstetric decisions regarding preterm neonates must be made without prior information regarding gestational age, late ultrasound findings must be applied with extreme care.  相似文献   
10.
In vivo electrochemical methods were employed to study the potassium (K+-evoked release of monoamines from the cerebellum of the chloral hydrate anesthetized rat. K+-evoked releases were elicited using micropipette-Nafion-coated graphite epoxy electrode arrays in the granule/Purkenje cell layer, molecular layer, and white matter. These recorded releases were generally found to be reversible, moderately dose-dependent, and reproducible. However, the temporal dynamics of the releases were different for the cell layer versus molecular layer records. Releases were infrequently observed in cerebellar white matter, an area which is relatively devoid of monoamine containing terminals. The signals recorded from the cell and molecular layers were significantly attenuated by pretreatment with nomifensine, a potent catecholamine reuptake blocker, significantly prolonged the K+-evoked signals observed in both the granule/Purkenje cell and molecular layers. These data, taken together with earlier reports on the electrophysiological responses to activation of cerebellar noradrenergic inputs, support the conjecture that in vivo electrochemical recording methods have the sensitivity and spatial resolution for studies of functional monoamine release from brain regions that have a diffuse or laminated monoamine innervation.  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