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   1303851篇
  免费   95009篇
  国内免费   2054篇
耳鼻咽喉   18471篇
儿科学   43140篇
妇产科学   38425篇
基础医学   190474篇
口腔科学   36032篇
临床医学   111352篇
内科学   256661篇
皮肤病学   26702篇
神经病学   101805篇
特种医学   50922篇
外国民族医学   366篇
外科学   201647篇
综合类   26908篇
现状与发展   1篇
一般理论   320篇
预防医学   95676篇
眼科学   29590篇
药学   99526篇
  1篇
中国医学   2519篇
肿瘤学   70376篇
  2018年   12298篇
  2016年   10470篇
  2015年   12085篇
  2014年   16749篇
  2013年   25514篇
  2012年   35122篇
  2011年   37551篇
  2010年   22105篇
  2009年   20828篇
  2008年   36469篇
  2007年   39603篇
  2006年   40098篇
  2005年   39387篇
  2004年   37929篇
  2003年   36842篇
  2002年   36316篇
  2001年   58546篇
  2000年   60036篇
  1999年   51120篇
  1998年   14573篇
  1997年   13084篇
  1996年   13322篇
  1995年   12601篇
  1994年   12019篇
  1993年   11110篇
  1992年   41334篇
  1991年   40631篇
  1990年   40177篇
  1989年   38998篇
  1988年   36376篇
  1987年   35597篇
  1986年   34000篇
  1985年   32392篇
  1984年   24173篇
  1983年   21065篇
  1982年   12580篇
  1981年   11145篇
  1979年   22856篇
  1978年   16083篇
  1977年   13861篇
  1976年   13122篇
  1975年   14341篇
  1974年   16805篇
  1973年   16222篇
  1972年   15446篇
  1971年   14355篇
  1970年   13329篇
  1969年   12824篇
  1968年   12075篇
  1967年   10557篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Pulmonary valve insertion during reoperation for tetralogy of Fallot   总被引:1,自引:0,他引:1  
Our experience with pulmonary valve insertion during reoperation for residual lesions after initial open repair of tetralogy of Fallot in 15 patients is reported. Preoperatively, 14 patients were in moderate to severe congestive heart failure, and all 15 had decreased right ventricular (RV) function at cardiac catheterization. All 15 patients had pulmonary insufficiency but not as an isolated finding. The most common residual lesions encountered were ventricular septal defect in 9, tricuspid insufficiency in 11, and peripheral pulmonary arterial stenosis in 6. Tissue valves were inserted in all patients. Mean peak RV-left ventricular pressure ratio measured in the operating room decreased from 0.61 +/- 0.10 (+/- the standard deviation) to 0.47 +/- 0.17 (p less than 0.05). There were no operative deaths. At follow-up (mean, 33 months), all but 1 patient were in New York Heart Association Class I or II. Pulmonary valve insertion should be considered during reoperation for tetralogy of Fallot when pulmonary insufficiency and RV failure are present.  相似文献   
82.
83.
Median cervical cysts are congenital anomalies arising from remaining thyroglossal duct epithelium. A major problem in the surgical treatment of these cysts is the high frequency of recurrence. Embryonic considerations indicate an important causal role for the hyoid bone in these recurrences. We studied the relationship between operative techniques and the number of recurrences in 36 patients treated in our hospital. Fourteen patients sent from other hospitals had a recurrent fistula; in thirteen cases the hyoid bone was still in place. All patients who had the central part of the hyoid bone excised were cured. In 14 patients without adequate excisions of the hyoid bone we found four recurrences. To prevent recurrence a total excision of thyroglossal duct epithelium is necessary.  相似文献   
84.
Eighty-eight patients with blunt renal trauma were examined sonographically. Rupture of the kidney was diagnosed in 41 patients and contusion of the kidney in 45. The correlation between operative findings, sonography and urography showed positive sonographic findings to be correct in all patients with rupture of the kidney. In 4 patients with normal sonograms, the diagnosis of a contusion was based on the urographic results. Three patients underwent angiography. An intimal lesion was seen in 2 and a tear of the renal artery in 1. The results of our investigation suggest that sonography should be applied in the first place in the evaluation of blunt renal trauma. It is the investigation of choice during follow-up after surgical as well as conservative therapy.  相似文献   
85.
86.
87.
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   
88.
89.
90.
Concanavalin A-induced lymphocyte proliferation was studied in 25 patients with alcoholic hepatitis or compensated alcoholic cirrhosis. Nine alcoholics without evidence of liver disease were also evaluated. A nonlinear correlation equation, which was natural logarithmic, was applied to individual dose-response proliferation curves and permitted comparisons between patient groups and controls. The proliferative response in all patient groups was significantly lower when compared to healthy controls and was independent of the presence or absence of liver disease. This suggests that some changes in immune function observed in alcoholics may be linked to the direct effects of alcohol on the immune system rather than to the associated liver disease.  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