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   3007018篇
  免费   241717篇
  国内免费   6129篇
耳鼻咽喉   42960篇
儿科学   95770篇
妇产科学   81749篇
基础医学   426906篇
口腔科学   86968篇
临床医学   275345篇
内科学   583331篇
皮肤病学   63699篇
神经病学   249869篇
特种医学   119245篇
外国民族医学   1131篇
外科学   453355篇
综合类   72415篇
现状与发展   1篇
一般理论   1288篇
预防医学   243985篇
眼科学   71069篇
药学   223031篇
  7篇
中国医学   5724篇
肿瘤学   157016篇
  2018年   31102篇
  2016年   26725篇
  2015年   30059篇
  2014年   42980篇
  2013年   65793篇
  2012年   88009篇
  2011年   93019篇
  2010年   55160篇
  2009年   52527篇
  2008年   87978篇
  2007年   93644篇
  2006年   94662篇
  2005年   91939篇
  2004年   88958篇
  2003年   85745篇
  2002年   84048篇
  2001年   137820篇
  2000年   142638篇
  1999年   120365篇
  1998年   35042篇
  1997年   31771篇
  1996年   31400篇
  1995年   30445篇
  1994年   28580篇
  1993年   26542篇
  1992年   97296篇
  1991年   94316篇
  1990年   91398篇
  1989年   88120篇
  1988年   81419篇
  1987年   80583篇
  1986年   76148篇
  1985年   72983篇
  1984年   55334篇
  1983年   47204篇
  1982年   28798篇
  1981年   25670篇
  1980年   24052篇
  1979年   52011篇
  1978年   36751篇
  1977年   31076篇
  1976年   29296篇
  1975年   30777篇
  1974年   37917篇
  1973年   36082篇
  1972年   33674篇
  1971年   31269篇
  1970年   29218篇
  1969年   27234篇
  1968年   24886篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
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   
982.
APACHE II score and abdominal sepsis. A prospective study   总被引:7,自引:0,他引:7  
Therapeutic trials for intra-abdominal sepsis require pretreatment stratification; physiologic scoring has been recently proposed for this purpose. We have prospectively tested the validity of one such scoring system, namely, the Acute Physiology and Chronic Health Evaluation (APACHE II). As part of a larger database, we correlated APACHE II scores with mortality in 100 patients hospitalized for generalized peritonitis or abdominal abscess. Use of steroids was recorded because of our suspicion that steroids increase mortality but blunt the physiologic response to sepsis. Thirty-one patients died, including 12 of 19 patients receiving steroids. Stepwise discriminant analysis revealed that the APACHE II score and steroid use were each independently associated with the rate of mortality. We report a prospective validation of pretreatment APACHE II scoring in abdominal sepsis. Steroid use is an independent risk factor.  相似文献   
983.
Choledochal cyst is an unusual but serious condition which most commonly affects Oriental people. Recent experience of three patients with this condition in whom diagnosis was made by ultrasound examination is reported. Cholangiography (ERCP or PTC) was performed in two of the cases to define the anatomy. All three cases were successfully managed by cyst excision and biliary reconstruction by Roux-en-Y hepaticojejunostomy. The rationale for and importance of cyst excision are discussed.  相似文献   
984.
We report our experience of eight cases of isolated full thickness burns of the penis. Early excision of burns of the penile shaft and repair with a preputial flap or mesh split skin graft produces excellent results, with a reduction in complications and an early re-establishment of sexual function. Conservative treatment of burns of the glans, on the other hand, is appropriate and results in minimal scarring.  相似文献   
985.
The use of additional epidural sympathetic block during and after microvascular surgery in the lower extremities to prevent vasospasm is generally agreed on. However, a significant fall in the perfusion rate of the transplants was seen after application of bupivacaine (Marcain) via the epidural catheter. This effect has, to our knowledge, not been described before and is probably caused by the sympathectomy effect of this type of analgesia.  相似文献   
986.
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   
987.
In a randomised, double-blind study, 20 women with idiopathic detrusor instability and associated symptoms were treated with terodiline 25 mg bd, placebo, and emepronium bromide 200 mg tds--each drug being given for 3 weeks with placebo as wash-out period before cross-over. The results were evaluated according to drug preference, frequency charts and elimination of detrusor instability on cystometry. Serum levels of both drugs were monitored as control of tablet intake. The preference for terodiline to placebo was statistically significant: 14/3 women (P less than 0.05), and the majority of women (12/4) preferred terodiline to emepronium. Terodiline also gave a small but significant reduction in 24 h micturition frequency and eliminated detrusor instability in almost 50% of the patients (P less than 0.05). Side effects were frequent but mild in all three treatment periods. It was concluded that terodiline offers an alternative in the treatment of female detrusor instability.  相似文献   
988.
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   
989.
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   
990.
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   
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