首页 | 官方网站   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   176455篇
  免费   1122篇
  国内免费   12篇
医药卫生   177589篇
  2023年   21篇
  2021年   86篇
  2020年   57篇
  2019年   78篇
  2018年   22001篇
  2017年   17411篇
  2016年   19565篇
  2015年   947篇
  2014年   876篇
  2013年   817篇
  2012年   7019篇
  2011年   21068篇
  2010年   18846篇
  2009年   11562篇
  2008年   19521篇
  2007年   21734篇
  2006年   567篇
  2005年   2205篇
  2004年   3393篇
  2003年   4336篇
  2002年   2496篇
  2001年   321篇
  2000年   448篇
  1999年   208篇
  1998年   206篇
  1997年   205篇
  1996年   96篇
  1995年   108篇
  1994年   101篇
  1993年   69篇
  1992年   54篇
  1991年   105篇
  1990年   137篇
  1989年   90篇
  1988年   64篇
  1987年   55篇
  1986年   38篇
  1985年   37篇
  1984年   24篇
  1983年   28篇
  1982年   36篇
  1980年   42篇
  1974年   21篇
  1970年   22篇
  1938年   60篇
  1937年   25篇
  1935年   22篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
The specific characteristics of genetic data lead to ethical-legal conflicts in the framework of genetic diagnosis. Several international organisations, including UNESCO and the Council of Europe, have enacted rules referring to the use of genetic information. This paper discusses possible legal and ethical criteria that could be used in genetic testing.  相似文献   
42.
43.

Introduction  

This paper presents the results of a study on the psychometric properties of an authorized Spanish version of the McMaster Family Assessment Device, a self-report measure of family functioning.  相似文献   
44.
45.
46.

Introduction  

Although ependymoma is the third most common pediatric brain tumor, we know little about the genetic/epigenetic basis of its initiation, maintenance, or progression. This is due in part to the heterogeneity of the disease, as well as the small sample size of the cohorts analyzed in most studies.  相似文献   
47.
48.
A benign esophageal leiomyoma with abnormally increased fluorine-18-fluorodeoxyglucose uptake on positron emission tomography (PET) was resected thoracoscopically. The tumor, of which the maximum standardized uptake value of the lesion was 4.7, was well defined and 38 mm in diameter. Neither mitotic activity nor degeneration was found histologically; and immunoreactivity for CD34, CD117, MIB-1, and glucose transporter-1 was negative immunohistochemically. A diagnosis of gastrointestinal stromal tumor was ruled out by an oncogenic kinase gene mutation study. This case cautions against PET-dependent evaluation for malignant potential of esophageal submucosal tumors.  相似文献   
49.
50.
Some investigators have suggested that preoperative chemotherapy for hepatic colorectal metastases may cause hepatic injury and increase perioperative morbidity and mortality. The objective of the current study was to examine whether treatment with preoperative chemotherapy was associated with hepatic injury of the nontumorous liver and whether such injury, if present, was associated with increased morbidity or mortality after hepatic resection. Two-hundred and twelve eligible patients who underwent hepatic resection for colorectal liver metastases between January 1999 and December 2005 were identified. Data on demographics, clinicopathologic characteristics, and preoperative chemotherapy details were collected and analyzed. The majority of patients received preoperative chemotherapy (n = 153; 72.2%). Chemotherapy consisted of fluoropyrimidine-based regimens: 5-FU monotherapy, 31.6%; irinotecan, 25.9%; and oxaliplatin, 14.6%. Among those patients who received chemotherapy, the type of chemotherapy regimen predicted distinct patterns of liver injury. Oxaliplatin was associated with increased likelihood of grade 3 sinusoidal dilatation (p = 0.017). Steatosis >30% was associated with irinotecan (27.3%) compared with no chemotherapy, 5-FU monotherapy, and oxaliplatin (all p < 0.05). Irinotecan also was associated with steatohepatitis, as two of the three patients with steatohepatitis had received irinotecan preoperatively. Overall, the perioperative complication rate was similar between the no-chemotherapy group (30.5%) and the chemotherapy group (35.3%) (p = 0.79). Preoperative chemotherapy was also not associated with 60-day mortality. In patients with hepatic colorectal metastases, preoperative chemotherapy is associated with hepatic injury in about 20 to 30% of patients. Furthermore, the type of hepatic injury after preoperative chemotherapy was regimen-specific. Presented at the American Hepato-Pancreato-Biliary Association 2006 Annual Meeting, March 11, Miami, Florida.  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-23

京公网安备 11010802026262号