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   220篇
  免费   12篇
  国内免费   2篇
耳鼻咽喉   1篇
儿科学   1篇
基础医学   37篇
临床医学   10篇
内科学   32篇
皮肤病学   38篇
神经病学   33篇
特种医学   19篇
外科学   37篇
预防医学   8篇
药学   6篇
肿瘤学   12篇
  2023年   1篇
  2022年   1篇
  2021年   11篇
  2020年   2篇
  2019年   6篇
  2018年   4篇
  2017年   3篇
  2016年   5篇
  2015年   1篇
  2014年   10篇
  2013年   18篇
  2012年   12篇
  2011年   10篇
  2010年   10篇
  2009年   5篇
  2008年   6篇
  2007年   9篇
  2006年   10篇
  2005年   9篇
  2004年   12篇
  2003年   12篇
  2002年   6篇
  2001年   9篇
  2000年   5篇
  1999年   3篇
  1998年   3篇
  1996年   3篇
  1995年   1篇
  1992年   6篇
  1991年   1篇
  1990年   5篇
  1989年   1篇
  1988年   5篇
  1987年   3篇
  1986年   5篇
  1985年   1篇
  1984年   2篇
  1983年   4篇
  1982年   1篇
  1979年   3篇
  1978年   3篇
  1935年   1篇
  1934年   1篇
  1933年   1篇
  1932年   1篇
  1931年   2篇
  1930年   1篇
排序方式: 共有234条查询结果,搜索用时 15 毫秒
1.
A human tumor xenograft (L56Br-X1) was established from a breast cancer axillary lymph node metastasis of a 53-year-old woman with a BRCA1 germ-line nonsense mutation (1806C>T; Q563X), and a cell line (L56Br-C1) was subsequently derived from the xenograft. The xenograft carries only the mutant BRCA1 allele and expresses mutant BRCA1 mRNA but no BRCA1 protein as determined by immunoprecipitation or Western blotting. The primary tumor, lymph node metastasis, and xenograft were hypodiploid by DNA flow cytometry, whereas the cell line displayed an aneuploidy apparently developed via polyploidization. Cytogenetic analysis, spectral karyotyping, and comparative genomic hybridization of the cell line revealed a highly complex karyotype with numerous unbalanced translocations. The xenograft and cell line had retained a somatic TP53 missense mutation (S215I) originating from the primary tumors, as well as a lack of immunohistochemically detectable expression of steroid hormone receptors, epidermal growth factor receptor, human epidermal growth factor receptor 2 (HER-2), and keratin 8. Global gene expression analysis by cDNA microarrays supported a correlation between the expression profiles of the primary tumor, lymph node metastasis, xenograft, and cell line. We conclude that L56Br-X1 and L56Br-C1 are useful model systems for studies of the pathogenesis and new therapeutic modalities of BRCA1-induced human breast cancer.  相似文献   
2.
3.
4.
5.
In vivo studies of intestinal carnitine absorption in rats   总被引:2,自引:0,他引:2  
We have studied small intestinal absorption of carnitine in vivo using a combination of segmental perfusion techniques and bolus intraluminal injection. We found evidence of a partially saturable absorption process (with Km values of 1035 and 1267 microM for jejunum and ileum calculated for the saturable component) that appeared to be separate from the imino acid transport system. Absorption was characterized by slow mucosal uptake, prolonged mucosal retention, and a very slow mucosal exit process with blood levels of [3H] carnitine still rising 8 h after intraluminal administration. We have also demonstrated the presence of carnitine acetyltransferase in intestinal mucosa and have shown that the intestine forms significant amounts of acetylcarnitine from exogenous carnitine.  相似文献   
6.
7.
AIM: To study if and how physicians use the irritable bowel syndrome (IBS) diagnostic criteria and to assess treatment strategies in IBS patients. METHODS: A questionnaire was sent to 191 physicians regarding IBS criteria, diagnostic methods and treatment. Furthermore, 94 patients who were diagnosed with IBS underwent telephone interview. RESULTS: A total of 80/191 (41.9%) physicians responded to the survey. Overall, 13 patients were diag-nosed monthly with IBS by specialists in gastroenterology (SGs) and 2.5 patients by general practitioners (GPs). All the SGs knew of the criteria to diagnose IBS, as did 46/70 (65.7%) GPs. Seventy-nine percent used the patient’s history, 38% used a physical examination, and 38% exclusion of other diseases to diagnose IBS. Only 18/80 (22.5%) physicians used specific IBS criteria. Of the patients interviewed, 59/94 (62.8%) knew they had experienced IBS. Two out of five patients knew IBS and had seen a physician because of IBS symptoms. Half of those received a diagnosis of IBS. A total of 13% were satisfied with treatment. IBS affected daily activities in 43% of cases. CONCLUSION: Half of the patients with IBS who consulted a physician received a diagnosis. Awareness and knowledge of diagnostic criteria for IBS differ between SGs and GPs.  相似文献   
8.

Context

Our aim was to present a summary of the Second International Consultation on Bladder Cancer recommendations on the diagnosis and treatment options for non–muscle-invasive urothelial cancer of the bladder (NMIBC) using an evidence-based approach.

Objective

To critically review the recent data on the management of NMIBC to arrive at a general consensus.

Evidence acquisition

A detailed Medline analysis was performed for original articles addressing the treatment of NMIBC with regard to diagnosis, surgery, intravesical chemotherapy, and follow-up. Proceedings from the last 5 yr of major conferences were also searched.

Evidence synthesis

The major findings are presented in an evidence-based fashion. We analyzed large retrospective and prospective studies.

Conclusions

Urothelial cancer of the bladder staged Ta, T1, and carcinoma in situ (CIS), also indicated as NMIBC, poses greatly varying but uniformly demanding challenges to urologic care. On the one hand, the high recurrence rate and low progression rate with Ta low-grade demand risk-adapted treatment and surveillance to provide thorough care while minimizing treatment-related burden. On the other hand, the propensity of Ta high-grade, T1, and CIS to progress demands intense care and timely consideration of radical cystectomy.  相似文献   
9.
There are very few previous reports of expression of native full-length maedi visna virus (MVV) Env gp150 protein in the literature. Therefore the use of different plasmid and viral expression vectors to obtain full-length gp150 was investigated. A mammalian expression plasmid, pN3-Env, was constructed containing the MVV env gene encoding the precursor protein gp150 Env. The functionality of the recombinant plasmid was tested for expression in HEK293 cells. A recombinant modified vaccinia Ankara virus, MVA-Env, with expression detected in avian cells was also made. The expression of the MVV gp150 Env precursor protein was shown for the first time upon transfection of the eukaryotic HEK293 cells by the pN3-Env plasmid DNA as demonstrated by Western blot analysis. These plasmid or viral expression vectors are of potential use in MVV vaccines.  相似文献   
10.
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