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   11799篇
  免费   501篇
  国内免费   91篇
耳鼻咽喉   98篇
儿科学   215篇
妇产科学   201篇
基础医学   1258篇
口腔科学   247篇
临床医学   806篇
内科学   2846篇
皮肤病学   351篇
神经病学   727篇
特种医学   471篇
外科学   2430篇
综合类   33篇
一般理论   2篇
预防医学   285篇
眼科学   310篇
药学   763篇
中国医学   18篇
肿瘤学   1330篇
  2023年   76篇
  2022年   151篇
  2021年   284篇
  2020年   161篇
  2019年   175篇
  2018年   270篇
  2017年   204篇
  2016年   216篇
  2015年   262篇
  2014年   327篇
  2013年   414篇
  2012年   690篇
  2011年   818篇
  2010年   437篇
  2009年   386篇
  2008年   663篇
  2007年   701篇
  2006年   637篇
  2005年   660篇
  2004年   609篇
  2003年   626篇
  2002年   554篇
  2001年   220篇
  2000年   227篇
  1999年   214篇
  1998年   152篇
  1997年   97篇
  1996年   99篇
  1995年   86篇
  1994年   84篇
  1993年   68篇
  1992年   163篇
  1991年   143篇
  1990年   140篇
  1989年   152篇
  1988年   135篇
  1987年   130篇
  1986年   108篇
  1985年   149篇
  1984年   77篇
  1983年   59篇
  1982年   34篇
  1979年   45篇
  1978年   44篇
  1977年   37篇
  1975年   38篇
  1974年   41篇
  1973年   36篇
  1972年   47篇
  1969年   36篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
neurogenetics - Mediator (MED) is a key regulator of protein-coding gene expression, and mutations in MED subunits are associated with a broad spectrum of diseases. Because mutations in MED17...  相似文献   
3.
4.
Recently an essential role of interstitial cells of Cajal (ICC) within myenteric plexus (ICC-MY) was suggested in ascending contraction and descending relaxation in the mouse ileum. The role of ICC in these neural reflexes was examined in the distal colonic segments prepared from the wild type and c-kit mutant, W/W(V) mice, in the present study. Localized distension of the segments from the wild type mice by using a small balloon resulted in ascending contraction and descending relaxation. In the segments from the mutant mice, localized distension also induced these neural reflexes similar to those observed in the wild type mice. Immunohistochemical examination demonstrated that ICC-MY and ICC present in muscle layers (ICC-IM) were severely disrupted in the mutant mouse, but only ICC, present within submucosal plexus (ICC-SMP), remained unchanged. In the small strips with ICC-SMP absent prepared from the mutant mouse, electrical field stimulation induced contraction or relaxation in the absence or presence of atropine, respectively. It was suggested that ICC have no important role in the ascending and descending neural reflexes in the mouse distal colon, this is in direct contrast to the role of ICC-MY in the ileum.  相似文献   
5.
5-Fluorouracil (5-FU) in combination with leucovorin (LV) is nowadays the standard treatment in colon cancer and would be a candidate to be delivered orally to the colon. Eudragit P-4135F or Eudragit RS100 were used separately to prepare microspheres by an oil/oil emulsification process trapping 5-FU and LV simultaneously. Scanning electron microscopy permitted a structural analysis, process parameters were analyzed and drug loading and release profiles were recorded. Particle size varied between 123 (RS100) and 146 microm (P-4135F). Generally, higher encapsulation rates were found with RS100 (5-FU, 60.3+/-9.7%; LV, 81.4+/-8.6%) compared to P-4135F (5-FU, 48.3+/-2.0%; LV, 55.4+/-2.7%). Microparticles made from Eudragit RS100 released the incorporated drug combination within 8 h not exhibiting general differences between the kinetics of both drugs. P-4135F was found to maintain the undesired 5-FU release at pH 6.8 lower than 25% within 4 h while at pH 7.4, a nearly immediate release (within 15 min) was observed. Although the release was similar at pH 7.4, at pH 6.8 LV showed a distinct initial drug loss of about 60% and a complete release within 2 h. SEM analyses revealed a substantial presence of LV crystals on the particle surface provoking a distinct burst effect of LV. These observations were concluded to be related to the high lipophilicity of P-4135F provoking a separation between P-4135F and LV during the preparation process.  相似文献   
6.
7.
Minimum incision endoscopic nephrectomy for giant hydronephrosis   总被引:1,自引:0,他引:1  
Five consecutive patients with symptomatic giant hydronephrosis underwent minimum incision endoscopic nephrectomy. The originally huge renal specimen was retroperitoneally mobilized using both of endoscopy and direct vision, without the use of trocar ports or gas insufflation, via a single minimum incision that narrowly permitted extraction of the specimen. The specimen was successfully extracted from the incision in all patients. Technically, proper deflation of the hydronephrotic sac facilitates mobilization and enables extraction of the specimen. Median (range) size of incision, operative time, and estimated blood loss were 4 cm (3-5), 205 min (156-222), and 210 mL (110-350), respectively. No patient required blood transfusion or encountered operative complications. Postoperative convalescence was short and uneventful; all patients resumed oral intake and ambulance on the day following surgery, and were physically dischargeable from hospital after 2-3 postoperative days. Thus, this technique is a feasible, minimally invasive and safe procedure for symptomatic giant hydronephrosis.  相似文献   
8.
Renal cell carcinoma (RCC) causes many kinds of symptoms such as hypercalcemia, hypertension, polycythemia and fever. Here we describe a rare case of RCC presenting with a persistent cough. After radical nephrectomy, the obstinate cough disappeared. When the tumor recurred locally, the cough also recurred. Furthermore, the cough disappeared completely again after the removal of the recurrent tumor. Although all the clinical findings suggested that the RCC caused the cough, we could not identify a specific humoral substance responsible for the cough.  相似文献   
9.
Since 1998, we have performed minimum incision endoscopic surgery (MIES) for renal cell carcinoma (RCC). For seven dialysis patients with bilateral RCC, we have performed sequential bilateral MIES radical nephrectomy. It was carried out by retroperitoneal approach through a single minimum incision that narrowly permitted extraction of the specimen using endoscopy and direct stereovision, without trocar ports, without gas insufflation and without the insertion of the hands of operators into the operative field. Although six of the seven patients had multiple complications in addition to chronic renal failure (CRF), bilateral kidneys were successfully removed by sequential MIES radical nephrectomy without major operative complication. Postoperative recovery was prompt with all patients resuming oral feeding and walking by the second postoperative day. Sequential bilateral MIES radical nephrectomy, leaving the peritoneal cavity intact and without imposing circulatory stress caused by gas insufflation, is a feasible treatment for bilateral RCCs in dialysis patients.  相似文献   
10.
Late-onset chylothorax occurred 49 days after right lower lobectomy for lung cancer in a 76-year-old man. Chylothorax was successfully managed by conservative treatment with chest tube drainage and an enteral low-fat diet. Chylothorax may occur in the late period after pulmonary resection and systematic mediastinal lymph node dissection for lung cancer, for which conservative management is the treatment of choice.  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