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   1283034篇
  免费   98075篇
  国内免费   1995篇
耳鼻咽喉   18498篇
儿科学   44526篇
妇产科学   35121篇
基础医学   182944篇
口腔科学   33669篇
临床医学   111579篇
内科学   258918篇
皮肤病学   28190篇
神经病学   100715篇
特种医学   51366篇
外国民族医学   660篇
外科学   197221篇
综合类   27066篇
现状与发展   1篇
一般理论   377篇
预防医学   95992篇
眼科学   27985篇
药学   94959篇
  2篇
中国医学   2422篇
肿瘤学   70893篇
  2018年   13247篇
  2017年   10038篇
  2016年   10952篇
  2015年   12438篇
  2014年   17332篇
  2013年   26572篇
  2012年   36191篇
  2011年   38248篇
  2010年   23059篇
  2009年   22161篇
  2008年   36817篇
  2007年   39415篇
  2006年   39672篇
  2005年   38550篇
  2004年   37717篇
  2003年   36528篇
  2002年   35877篇
  2001年   64106篇
  2000年   66609篇
  1999年   56529篇
  1998年   15242篇
  1997年   13871篇
  1996年   14289篇
  1995年   13535篇
  1994年   12847篇
  1993年   11858篇
  1992年   44597篇
  1991年   43508篇
  1990年   42264篇
  1989年   40161篇
  1988年   36928篇
  1987年   36286篇
  1986年   33654篇
  1985年   32317篇
  1984年   24178篇
  1983年   20307篇
  1982年   11762篇
  1981年   10734篇
  1980年   9540篇
  1979年   21370篇
  1978年   14849篇
  1977年   12564篇
  1976年   11717篇
  1975年   12632篇
  1974年   14680篇
  1973年   14134篇
  1972年   12953篇
  1971年   11738篇
  1970年   11061篇
  1969年   10031篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
Clinical versus ultrasonographic evaluation of scrotal disorders   总被引:1,自引:0,他引:1  
Clinical and ultrasonographic examinations of scrotal disorders were compared in 166 patients in order to determine their ability to distinguish between those diseases requiring surgery and those requiring clinical follow-up only. Ultrasound examinations were efficient in discriminating between normal and pathological findings. Extra-testicular lesions were readily differentiated from testicular ones. Although both clinical and ultrasonographic examinations had high sensitivity (90%) in detecting testicular cancer, the number of false positive findings was smaller after ultrasound examination. This gave a predictive value of a positive test of 53% after ultrasound examination but only 33% after clinical examination. Ultrasound examination may, therefore, reduce the number of surgical explorations in the scrotum and should be performed in patients with suspected testicular pathology based on history and palpatory findings.  相似文献   
72.
Multiple trauma is often associated with blunt thoracic injuries. Especially lung contusion can result in respiratory insufficiency and therefore a higher mortality rate. In our prospective study comparing 8 multiple trauma patients with and without associated lung contusion, we found that respiratory function was already significantly disturbed (decrease of paO2/FiO2 and increase of AaDO2, a rise in extravascular lung water (EVLW) both early after trauma and also with a second peak following the 4th day. This group (LK) developed significantly more cases of respiratory distress (ARDS). The disturbance of respiratory function seen initially was interpreted as a consequence of the direct mechanical impact, leading to the formation of interstitial fluid and hematoma. The frequent development of ARDS in the LK-group probably results from a pronounced activation of cellular and humoral mechanisms and therefore an enforced injury of the pulmonary capillary bed. A significant increase of pulmonary infections or the development of sepsis was not seen in the LK-group and is probably not responsible for the higher ARDS-rate in this group.  相似文献   
73.
Ten years experience with acute peritoneal dialysis in 39 preterm-, newborn and small infants shows advantage and low risk of surgically implanted single dacron cuffed silicone catheters compared to trocar catheters.  相似文献   
74.
The present study demonstrates that alcohol-induced memory impairment can be attenuated by pretreatment with an oral tryptophan supplementation. These results provide support for the role of a brain serotonin deficit in this impairment and highlight the impact a dietary manipulation can have on a complex behavioral process.  相似文献   
75.
The Dundee Memory Clinic was established in 1991. This paper reviews the diagnosis of the first 150 attenders and compares the findings with those of other memory clinics.  相似文献   
76.
Macrophage NRAMP1 and its role in resistance to microbial infections   总被引:12,自引:0,他引:12  
  相似文献   
77.
78.
79.
With pulsed X-ray cinematography we have analysed the angular excursions of the distal hindlimb joints (proximal interphalangeal, PIP; metatarsophalangeal, MTP; ankle) in cats walking on a treadmill. These distal joints transmit the body weight and the dynamic forces onto the ground. We have included the knee and hip joints in the analysis to relate the angular excursions of the proximal and distal joints and to verify the data previously obtained with external markers on the kinematics of the proximal joints. At the beginning of the stance phase the PIP joints flexed rapidly, the MTP joints extended slowly and the ankle and knee yielded under body weight. Whereas the PIP joints maintained a rather constant angular position of −75° throughout the stance phase, extension continued in the MTP joints from −230° at touch-down to −270° at the end of the stance phase. Around 50 ms before lift-off the MTP joints flexed rapidly. Early (−30 ms) after lift-off this flexion changed into a slow extension. The PIP joints extended swiftly at the stance-swing transition and moderately at the end of the swing phase. During the middle part of the swing phase they flexed slowly. Small rotatory movements around the long axis of the foot took place in the last 100 ms of the swing phase. The results of this study on the distal joints are discussed in relation to the placing of the paw, to the translation of forward propulsion into a MTP movement and to the lifting of the paw (conventionally described as toe curling). They show a differentiated mechanical interaction between the different distal limb joints during these different phases, which must be known in detail to interpret the corresponding electromyographic data and to understand how the hip is moved forward over the MTP joints which serve as the final pivot during stance.  相似文献   
80.
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