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   17729篇
  免费   609篇
  国内免费   75篇
耳鼻咽喉   123篇
儿科学   325篇
妇产科学   213篇
基础医学   2125篇
口腔科学   663篇
临床医学   1119篇
内科学   4029篇
皮肤病学   484篇
神经病学   1556篇
特种医学   786篇
外科学   2569篇
综合类   72篇
现状与发展   1篇
预防医学   706篇
眼科学   434篇
药学   1396篇
  2篇
中国医学   33篇
肿瘤学   1777篇
  2024年   78篇
  2023年   137篇
  2022年   207篇
  2021年   353篇
  2020年   222篇
  2019年   294篇
  2018年   334篇
  2017年   275篇
  2016年   361篇
  2015年   334篇
  2014年   476篇
  2013年   571篇
  2012年   914篇
  2011年   1051篇
  2010年   585篇
  2009年   477篇
  2008年   878篇
  2007年   913篇
  2006年   896篇
  2005年   916篇
  2004年   883篇
  2003年   811篇
  2002年   813篇
  2001年   459篇
  2000年   512篇
  1999年   493篇
  1998年   209篇
  1997年   160篇
  1996年   149篇
  1995年   128篇
  1994年   122篇
  1993年   93篇
  1992年   254篇
  1991年   259篇
  1990年   263篇
  1989年   259篇
  1988年   223篇
  1987年   246篇
  1986年   237篇
  1985年   224篇
  1984年   158篇
  1983年   109篇
  1980年   59篇
  1979年   115篇
  1978年   89篇
  1977年   85篇
  1974年   67篇
  1973年   68篇
  1972年   58篇
  1969年   63篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
The issue of medical practice guidelines has attracted the attention of doctors and health care professionals in Western countries since the middle 1980s. Such guidelines aim to assist in clinical decision-making in order to reduce variations in care and unnecessary costs for delivered health care service, and to improve the outcomes of medical care. Strangely, however, there is no interest or attention given to this topic in the medical and health care fields in Japan. As the president of the 71st Japanese Gastric Cancer Association, the author hopes to generate interest in this topic by opening a symposium at the annual meeting of the JGCA this year. As an introduction to this session, the present paper provides a short review of medical practice guidelines, their development cycle, and their advantages and disadvantages.  相似文献   
993.
The monoclonal antibody PC10 is used for immunohistochemical staining of the proliferating cell nuclear antigen (PCNA). The percentage of PC10-positive cancer cells is defined as the PC10 index. We evaluated the relationship between the PC10 index in pretreatment endoscopic biopsies and the prognoses of 47 patients with Stage II-III oesophageal squamous cell carcinoma treated with radiotherapy. The patients with a PC10 index > 40% had significantly poorer prognoses than the other patients (p = 0.0007). Proportional hazards model analysis indicated that only the PC10 index was a prognostic factor (p = 0.0009). The patient group of complete responders showed significantly lower PC10 indices compared to patients with a partial response or no change (p = 0.049). The PC10 index can be a good predictive indicator of the prognosis in patients with Stage II-III oesophageal cancer treated with radiotherapy.  相似文献   
994.
To determine the biological role of caudal-like homeobox gene CDX2, we constructed knockout mice in which its mouse homologue Cdx2 was inactivated by homologous recombination, placing a bacterial lacZ gene under the control of the Cdx2 promoter. Although the homozygous mutants died in utero around implantation, the heterozygotes were viable and fertile and expressed lacZ in the caudal region in early embryos and in the gut tissues in adults. The heterozygotes developed cecal and colonic villi by anteriorization and formed hamartomatous polyps in the proximal colon. The hamartoma started to develop at 11.5 days of gestation as an outpocket of the gut epithelium, which ceased to express the remaining Cdx2 allele. The outpocket then expanded as a partially duplicated gut but was contained as a hamartoma after birth. In adult mice, these hamartomas grew very slowly and took a benign course. None of them progressed into invasive adenocarcinomas, even at 1.5 years of age. Whereas the cecal and colonic villi expressed lacZ, the hamartoma epithelium did not, nor did it express Cdx2 mRNA from the wild-type allele. However, genomic DNA analysis of the polyp epithelium did not show a loss of heterozygosity of the Cdx2 gene, suggesting a mechanism of biallelic Cdx2 inactivation other than loss of heterozygosity. These results indicate that the Cdx2 haploin-sufficiency caused cecal and colonic villi, whereas the biallelic inactivation of Cdx2 triggered anomalous duplications of the embryonic gut epithelium, which were contained as hamartomas after birth.  相似文献   
995.
996.
997.
BACKGROUND AND OBJECTIVES: The adhesive tumor cell culture system (ATCCS) is known to produce high colony-forming efficiency. We, therefore, studied the feasibility of ATCCS for gastric cancer by use of biopsy specimens and the relationship between the results of ATCCS and histological effects of anticancer drugs. METHODS: Tumor specimens extracted by gastroendoscopic biopsy were sufficient for obtaining the result of sensitivity to at least one drug in 24 out of 30 (80%) patients. Twenty patients were administered 5-fluorouracil (5-FU) for 14 days prior to surgery, and the results of ATCCS were compared with histological changes of the resected specimens. RESULTS: The histological response rate was found to be 100% (4/4) when the 90% inhibition concentration (IC90) of 5-FU was less than 0.24 microg/ml (sensitive) and was 0% (0/3) when IC90 was greater than 0.40 microg/ml (resistant). CONCLUSIONS: Although lacking in statistical significance, the results suggest that the drug to which the tumor revealed sensitivity in the ATCCS would produce histological effects and the drug to which the tumor was resistant would have no histological effect.  相似文献   
998.
999.
1000.
A 4⅓-year-old girl with congenital thyrotrophin-releasing hormone (TRH) deficiency is described. Oral TRH administration led to normal thyroid hormone and TRH levels in the blood; favourable growth and development was achieved.  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