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   1566篇
  免费   69篇
  国内免费   8篇
耳鼻咽喉   11篇
儿科学   22篇
妇产科学   12篇
基础医学   229篇
口腔科学   25篇
临床医学   99篇
内科学   414篇
皮肤病学   8篇
神经病学   40篇
特种医学   26篇
外科学   215篇
综合类   6篇
预防医学   33篇
眼科学   12篇
药学   126篇
中国医学   4篇
肿瘤学   361篇
  2023年   4篇
  2022年   20篇
  2021年   20篇
  2020年   15篇
  2019年   19篇
  2018年   25篇
  2017年   25篇
  2016年   15篇
  2015年   19篇
  2014年   29篇
  2013年   48篇
  2012年   54篇
  2011年   75篇
  2010年   39篇
  2009年   44篇
  2008年   68篇
  2007年   68篇
  2006年   65篇
  2005年   67篇
  2004年   65篇
  2003年   63篇
  2002年   71篇
  2001年   64篇
  2000年   67篇
  1999年   80篇
  1998年   28篇
  1997年   20篇
  1996年   23篇
  1995年   19篇
  1994年   14篇
  1993年   22篇
  1992年   41篇
  1991年   49篇
  1990年   52篇
  1989年   56篇
  1988年   38篇
  1987年   24篇
  1986年   27篇
  1985年   18篇
  1984年   15篇
  1983年   7篇
  1982年   8篇
  1981年   5篇
  1979年   6篇
  1975年   4篇
  1974年   5篇
  1973年   4篇
  1972年   4篇
  1971年   6篇
  1967年   3篇
排序方式: 共有1643条查询结果,搜索用时 31 毫秒
41.
42.
p53 point mutations in primary human gastric carcinomas   总被引:12,自引:0,他引:12  
Summary p53 point mutations in primary gastric carcinomas were analyzed by performing cDNA deoxynucleotide sequencing of the gene. Out of 16,9 (56.3%) primary gastric carcinoma cases, including early cancer, showed one or more p53 point mutations in their open-reading frame, and 4 out of 9 cases had a p53 point mutation within highly conserved domains. The characteristics of the p53 mutation spectrum observed in primary tumors were (a) frequent mutation at an A:T pair (50%, 7 out of 14 mutations), (b) high transversion incidence (29%, 4 out of 14 mutations), (c) no transition at CpG, and (d) no G:C to T:A transversion. Our results suggest that p53 mutation is a common event in gastric carcinoma occurring from the early stage of progression with its specific mutation spectrum.Abbreviation PCR-SSCP polymerase chain reaction single-strand conformation polymorphism  相似文献   
43.
44.
The molecular pathway of autonomous growth of the parathyroid glands in uremic patients is poorly understood. Loss of heterozygosity at the recently identified multiple endocrine neoplasia type 1 (MEN1) gene locus on chromosome 11q13 has been found in a subset of parathyroid glands from patients with refractory hyperparathyroidism. To clarify the role of the MEN1 gene in parathyroid tumorigenesis, we analyzed 81 parathyroid glands from 22 Japanese uremic patients for allelic loss on chromosomal arm 11q13 DNA using 3 flanking markers (PYGM, D11S4946, and D11S449) and for mutations of the MEN1-coding exons by PCR-based single strand conformation polymorphism analysis and sequencing. Allelic loss on 11q13 was observed in 6 glands (7%), and 1 of 6 demonstrated a previously unrecognized somatic frameshift deletion (331delG) of the MEN1 gene. This mutation would probably result in a nonfunctional menin protein, consistent with a tumor suppressor mechanism. Clinical and pathological characteristics of hyperparathyroidism were unrelated to the presence or absence of loss of heterozygosity on 11q13 and MEN1 gene mutations. These observations indicate that somatic inactivation of the MEN1 gene contributes to the pathogenesis of uremia-associated parathyroid tumors, but its role in this disease appears to be very limited.  相似文献   
45.
A 70-year-old man was admitted to the hospital in June 1994 because of cutaneous induration of the extremities. Eosinophilic fasciitis was diagnosed on the basis of the course and distribution of the cutaneous lesions. Cyclosporine (100 mg/day) was given. After 4 weeks of treatment, cutaneous induration and limited joint mobility improved. Liver dysfunction had been diagnosed 5 years before the onset of eosinophilic fasciitis. Primary biliary cirrhosis (PBC) was diagnosed on the basis of the elevated serum biliary-enzyme levels, strongly positive antimitochondrial antibody titer, and histologic features of the liver-biopsy specimens showed stage-3 PBC. These findings suggested that eosinophilic fasciitis developed in association with PBC. PBC is often accompanied by autoimmune diseases, such as Sjögren’s syndrome and Hashimoto’s disease. To our knowledge, eosinophilic fasciitis associated with PBC has not been reported previously. We believe this is the first time a case of eosinophilic fasciitis occurring in a patient with PBC is documented.  相似文献   
46.
47.
48.
BACKGROUND/AIMS: When a repeat hepatectomy is possible, it is the most effective treatment modality for recurrent colorectal liver metastasis. The aim of this study was to evaluate the surgical risks of repeat hepatectomy for liver metastasis from colorectal carcinoma. METHODOLOGY: Between 1986 and 1996, 60 patients with hepatic metastasis from colorectal carcinoma underwent surgery in the Department of Surgery I, Oita Medical University. Ten of them underwent a repeat hepatectomy. The cases of these 10 patients were studied retrospectively; in particular, postoperative complications and intraoperative blood loss were compared between the initial and second operation. RESULTS: During the second surgery, recurrence was detected adjacent to the hepatic stump in 9 of the 10 patients. During the initial surgery, 6 underwent non-anatomic resections, and 4 had anatomic resection, including 1 extended lobectomy, 1 lobectomy, and 2 segmentectomies. For the second surgery, 3 had anatomic resections, including 2 lobectomies, and 1 segmentectomy, and 7 underwent non-anatomic resections. There were no mortalities during the initial or second operation. There was no morbidity following the initial surgeries and 7 postoperative complications (intraabdominal abscess, 4 cases; biloma, 3 cases) following the second surgeries. Mean blood loss during the second operation (1044 mL) was significantly greater than during the initial operation (561 mL). CONCLUSIONS: The present results show that repeat hepatectomy for recurrent liver metastasis from colorectal carcinoma resulted in significantly greater intraoperative blood loss and postoperative complications than those of the initial surgeries. The blood loss and complications in the second operation, the one for the recurrence, were directly associated with the fact that the recurrence was so close to the hepatic stump. Since the resection line in the second surgery was adjacent to the hepatic hilus, resection of the lesion caused much more injury to the main bile duct and main portal vein than that caused by the.  相似文献   
49.
50.
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