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   742篇
  免费   48篇
  国内免费   24篇
儿科学   26篇
妇产科学   8篇
基础医学   84篇
口腔科学   10篇
临床医学   50篇
内科学   380篇
皮肤病学   30篇
神经病学   17篇
特种医学   68篇
外科学   19篇
综合类   22篇
预防医学   9篇
药学   69篇
肿瘤学   22篇
  2023年   3篇
  2021年   4篇
  2020年   2篇
  2019年   12篇
  2018年   11篇
  2017年   3篇
  2016年   4篇
  2015年   13篇
  2014年   13篇
  2013年   24篇
  2012年   33篇
  2011年   17篇
  2010年   20篇
  2009年   25篇
  2008年   37篇
  2007年   67篇
  2006年   39篇
  2005年   39篇
  2004年   35篇
  2003年   28篇
  2002年   24篇
  2001年   22篇
  2000年   21篇
  1999年   25篇
  1998年   25篇
  1997年   19篇
  1996年   30篇
  1995年   13篇
  1994年   18篇
  1993年   14篇
  1992年   10篇
  1991年   12篇
  1990年   20篇
  1989年   15篇
  1988年   20篇
  1987年   11篇
  1986年   13篇
  1985年   12篇
  1984年   7篇
  1983年   7篇
  1982年   7篇
  1981年   7篇
  1980年   5篇
  1979年   3篇
  1978年   3篇
  1977年   4篇
  1976年   6篇
  1975年   3篇
  1972年   3篇
  1967年   2篇
排序方式: 共有814条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
COLAL-PRED (prednisolone sodium metasulfobenzoate), which is targeted to the colon by COLAL colonic drug delivery technology, is being developed by Alizyme for the potential treatment of inflammatory bowel disease. Alizyme expect to initiate a phase III trial in 2005.  相似文献   
45.
Aminosalicylate therapy for ulcerative colitis remains a foundational strategy for the induction and maintenance of remission for mild to moderate disease. Although it seems clear that topical mesalazine (mesalamine) is the most efficacious approach to distal ulcerative colitis, recent trials with orally delivered azo conjugates suggest that there may be an advantage over pH-released mesalazine as a first-line approach to active disease. No such comparisons are available for azo products and the prolonged-release formulation, Pentasa. However, recent meta-analyses have demonstrated that, although there is little difference in systemic exposure between marketed products, luminal concentrations may vary. In maintenance therapy, aminosalicylates remain the standard approach after aminosalicylate-induced remission. A number of gaps remain in the evidence base with regard to the optimal dosing of oral mesalazine as a maintenance agent, whether oral mesalazine can maintain remissions after rectal mesalazine induction, and the dose-response and efficacy of aminosalicylates after steroid- or ciclosporin-induced remissions. Although aminosalicylates have been advocated for several decades in Crohn's disease, a number of controversies have evolved since the original trials with sulfasalazine in active Crohn's disease. The original trials demonstrated benefits for sulfasalazine in colonic involvement, but controlled trial evidence for the role of sulfasalazine as maintenance therapy has not been as firmly established. In addition, although oral mesalazine has been demonstrated in controlled trials to be superior to placebo in mild to moderate disease, it is less efficacious than corticosteroids at inducing remissions. The maintenance benefits of mesalazine appear to be limited to patients 'induced into remission' with mesalazine and in some post-operative settings.  相似文献   
46.
BACKGROUND: Repifermin (keratinocyte growth factor-2) has been shown to reduce inflammation in animal models of colitis. AIM: To evaluate repifermin for the treatment of active ulcerative colitis. METHODS: Eighty-eight patients with active ulcerative colitis were enrolled in a 6-week, double-blind trial. Patients were randomized to receive treatment for five consecutive days with intravenous repifermin at a dose of 1, 5, 10, 25 or 50 microg/kg, or placebo. The primary objective of the study was to evaluate the safety of repifermin. The primary efficacy outcome was clinical remission at week 4, defined as a score of zero on the endoscopic appearance and stool blood components of the Mayo score and a score of zero or unity on the stool frequency and physician's global assessment components. RESULTS: At week 4, the rates of clinical remission in the 1, 5, 10, 25 and 50 microg/kg repifermin groups were 19%, 9%, 0%, 0% and 0%, respectively, and 11% for the placebo group (P = 0.32 for repifermin vs. placebo). The frequencies of commonly occurring adverse events and severe adverse events were similar in both groups. CONCLUSIONS: Intravenous repifermin at a dose of 1-50 microg/kg was very well tolerated, but there was no evidence that repifermin was effective for the treatment of active ulcerative colitis at these doses. An additional study to determine the efficacy of repifermin at doses of > 50 microg/kg or for a longer treatment duration may be warranted, as the maximally tolerated dose was not reached in the present study.  相似文献   
47.
OBJECTIVE: Lactoferrin is a glycoprotein expressed by activated neutrophils. The aim of this study was to determine the sensitivity and specificity of fecal lactoferrin concentrations for inflammatory bowel disease (IBD) or irritable bowel syndrome (IBS) versus healthy controls. METHODS: Fresh stool samples were collected from outpatients with ulcerative colitis (UC), Crohn's disease (CD), or IBS. Clinical disease activity for IBD was assessed using a modified Harvey-Bradshaw Activity Index. Fecal lactoferrin concentrations were determined using a polyclonal antibody-based enzyme linked immunoassay. Mean fecal lactoferrin concentrations for each group and sensitivity and specificity of the assay were determined. RESULTS: One hundred-four CD patients, 80 UC patients, 31 IBS patients, and 56 healthy controls were recruited. The mean +/- SE fecal lactoferrin concentration (microg/g fecal weight) was 440 +/- 128 for CD patients, 1125 +/- 498 for UC patients, 1.27 +/- 0.29 for IBS patients, and 1.45 +/- 0.4 for healthy controls. Fecal lactoferrin was 90% specific for identifying inflammation in patients with active IBD. Elevated fecal lactoferrin was 100% specific in ruling out IBS. CONCLUSIONS: Fecal lactoferrin is sensitive and specific for detecting inflammation in chronic IBD. This noninvasive test may prove useful in screening for inflammation in patients presenting with abdominal pain and diarrhea.  相似文献   
48.
Smoking and inflammatory bowel disease   总被引:4,自引:0,他引:4  
It is well established that smoking cigarettes is associated with Crohn's disease (CD) and that non-smoking is associated with ulcerative colitis (UC). Furthermore, there is convincing evidence that smoking cigarettes has a negative effect on the course of CD, and that smoking cigarettes may improve the disease severity or have a 'protective' effect in some patients with UC. Despite these well-described associations, the mechanism by which cigarette smoking affects CD and UC is not known. Researchers have studied the systemic effects, cellular and humoral immune effects, mucosal changes, and the intestinal permeability changes with inflammatory bowel disease (IBD) and smoking. To date, none of these studies adequately explains the observed clinical patterns. It has been assumed that nicotine is the active agent in these associations, but clinical trials of nicotine chewing gum and transdermal nicotine in UC have shown limited benefit, and have been complicated by significant side-effects. Topical delivery systems for nicotine therapy are currently under development and await future clinical trials.  相似文献   
49.
50.

Purpose

To perform Preimplantation Genetic Diagnosis (PGD) on a paternal Brca2 unknown mutation carrier with early-onset breast cancer, whose paternal grandmother and mother had breast cancer at 60s.

Method

Elucidating the linkage via single sperm haplotyping on patient''s carrier brother, and identifying the genomic deletion via BLAST followed by PCR screening. PGD was subsequently conducted.

Result

The mutant allele was found by using 4 microsatellite and 2 intragenic SNP markers. Recombination was detected in 8 % of sperms. BLAST was utilized to locate putative hairpin structure(s), followed by PCR screening with seven sets of primers. A novel 2,596 bp deletion containing exon 15 ~ 16 was identified. Due to the severity of phenotype and the integrity of exon 11 encoding RAD51 binding domain, and the fact that the patient''s mother also had breast cancer at her 60s, we speculate a possible coexistence of maternal breast cancer risk allele(s). Embryo biopsy was performed on day 3. Unaffected morula and blastocyst were replaced on day 5, resulting in a singleton livebirth. A breast lump appeared in the patient after delivery without the presence of malignant cells.

Conclusion

Concerning the assisted reproductive option for breast cancer patients, the possibility of coexistence of multiple familial risk alleles and the significance of each mutation to the phenotype should be evaluated. To eliminate misdiagnosis resulting from recombination and/or allelic drop-out, both direct mutation detection and linkage analysis approaches may be necessary. BLAST is a very useful and cost-effective tool for identifying large genomic deletion.  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