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   7810篇
  免费   702篇
  国内免费   20篇
耳鼻咽喉   53篇
儿科学   176篇
妇产科学   215篇
基础医学   1186篇
口腔科学   107篇
临床医学   1030篇
内科学   1582篇
皮肤病学   88篇
神经病学   616篇
特种医学   332篇
外科学   1033篇
综合类   210篇
一般理论   2篇
预防医学   908篇
眼科学   63篇
药学   549篇
中国医学   1篇
肿瘤学   381篇
  2022年   44篇
  2021年   112篇
  2020年   83篇
  2019年   109篇
  2018年   133篇
  2017年   123篇
  2016年   92篇
  2015年   121篇
  2014年   173篇
  2013年   261篇
  2012年   386篇
  2011年   431篇
  2010年   211篇
  2009年   187篇
  2008年   358篇
  2007年   325篇
  2006年   318篇
  2005年   297篇
  2004年   343篇
  2003年   320篇
  2002年   290篇
  2001年   298篇
  2000年   278篇
  1999年   260篇
  1998年   94篇
  1997年   86篇
  1996年   86篇
  1995年   86篇
  1994年   76篇
  1993年   66篇
  1992年   208篇
  1991年   200篇
  1990年   209篇
  1989年   160篇
  1988年   146篇
  1987年   135篇
  1986年   142篇
  1985年   131篇
  1984年   115篇
  1983年   86篇
  1982年   62篇
  1981年   50篇
  1979年   82篇
  1978年   59篇
  1977年   48篇
  1974年   69篇
  1973年   47篇
  1972年   47篇
  1971年   45篇
  1970年   53篇
排序方式: 共有8532条查询结果,搜索用时 15 毫秒
1.
Gonadoblastoma, a rare gonadal neoplasm, presents most frequently in phenotypic female or phenotypically male patients with dysgenetic gonads or undescended testes. To date, only 2 cases of gonadoblastoma have been reported in anatomically normal male patients with scrotal testes. Both of these patients presented with testicular masses and germ cell tumors. We report a case of a genotypically and phenotypically normal, fertile man with descended testes who on evaluation for chronic orchialgia had a gonadoblastoma unaccompanied by a germ cell neoplasm. The tumor was nonpalpable and was initially discovered on scrotal ultrasound.  相似文献   
2.
The acting or interim leadership position has been neglected in terms of selection, role identification, and status. Individuals, programs, and organizations are paying a price for this inattention.  相似文献   
3.
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   
4.
Colonoscopy and bacteraemia: an experience in 50 patients   总被引:1,自引:0,他引:1  
There is little consensus concerning the incidence of bacteraemia during colonoscopy and the need for antibiotic prophylaxis in susceptible patients. Hepatic abscesses in one patient which may have been related to prior colonoscopic examinations led the authors to carry out a prospective study of 50 patients undergoing colonoscopy. Multiple blood cultures were carried out to maximise the positive yield of transient bacteraemia and to attempt to determine the time when bacteraemia is most likely to occur. Five patients had positive blood cultures. In two patients S epidermidis was isolated, but only from the precolonoscopic blood sample. In three subjects enteric organisms were cultured from blood samples obtained during the procedure. In one of these three the same organism was cultured from the preendoscopic blood sample so that in only two patients (4%) could the bacteraemia be attributed to the colonoscopy. These results would suggest that the risk of bacteraemia during colonoscopy is low.  相似文献   
5.
6.
A manic depressive illness is diagnosed in many women of childbearing age; thus they are candidates for lithium therapy. Since lithium has the most clearly documented teratogenic effect of all the psychotropic drugs, special care must be taken by the physician and patient when considering its use during this period of life. A review of the literature is presented and suggested guidelines are given for the use of lithium in this at-risk population.  相似文献   
7.
8.
9.
Extensive search of the literature reveals the extreme rarity of true diverticulum of the gallbladder. Its frequency varies from 0.0008% of all resected gallbladders at the Mayo Clinic to 0.06% of a series of congenital anomalies of the gallbladder collected from the world literature. We are presenting a case of a true diverticulum of the gallbladder with sonographic demonstration and focal malignant alterations, neither one of which has been reported previously. The difference between true and false diverticula of the gallbladder is discussed.  相似文献   
10.
Neurons in the primary visual cortex of higher mammals are arranged in columns, and the neurons in each column respond best to light-dark borders of particular orientations. The basis of cortical cell orientation selectivity is not known. One possible mechanism would be for cortical cells to receive input from several lateral geniculate nucleus (LGN) neurons with receptive fields that are aligned in the visual field (Hubel and Wiesel, 1962). We have investigated the relationship between the arrangement of the receptive fields of geniculocortical afferents and the orientation preferences of cortical cells in the orientation columns to which the afferents provide visual input. Radial microelectrode penetrations were made into primary visual cortex of anesthetized adult sable ferrets. Cortical cells were recorded throughout the depth of the cortex, and their orientation preferences were determined. Cortical cell responses were then eliminated by superfusion of the cortex with either kainic acid (Zahs and Stryker, 1988) or muscimol. After the drug treatment, responses from many single units with distinct receptive fields were recorded. These responses were presumed to be those of geniculocortical afferents, because they had the response properties characteristic of LGN neurons, and because they could be recorded only in cortical layers that receive geniculate input. In 16 of 18 cases, the afferent receptive fields recorded in a single penetration covered an elongated region of visual space. In these penetrations, the best-fit line through the centers of the afferent receptive fields generally paralleled the preferred orientation of cortical cells recorded at the same site in cortex. These results are consistent with the Hubel and Wiesel (1962) model for the construction of oriented visual cortical receptive fields from geniculate inputs with aligned receptive fields.  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