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   2035篇
  免费   79篇
  国内免费   42篇
耳鼻咽喉   31篇
儿科学   96篇
妇产科学   47篇
基础医学   165篇
口腔科学   35篇
临床医学   187篇
内科学   518篇
皮肤病学   135篇
神经病学   107篇
特种医学   239篇
外科学   310篇
综合类   42篇
预防医学   86篇
眼科学   8篇
药学   56篇
中国医学   3篇
肿瘤学   91篇
  2021年   24篇
  2020年   12篇
  2019年   19篇
  2018年   21篇
  2017年   27篇
  2016年   37篇
  2015年   48篇
  2014年   53篇
  2013年   108篇
  2012年   67篇
  2011年   68篇
  2010年   86篇
  2009年   91篇
  2008年   80篇
  2007年   106篇
  2006年   76篇
  2005年   79篇
  2004年   56篇
  2003年   38篇
  2002年   51篇
  2001年   38篇
  2000年   17篇
  1999年   30篇
  1998年   86篇
  1997年   76篇
  1996年   81篇
  1995年   52篇
  1994年   63篇
  1993年   53篇
  1992年   18篇
  1991年   23篇
  1990年   22篇
  1989年   41篇
  1988年   42篇
  1987年   33篇
  1986年   26篇
  1985年   27篇
  1984年   24篇
  1983年   14篇
  1982年   22篇
  1981年   18篇
  1980年   13篇
  1979年   17篇
  1978年   14篇
  1977年   17篇
  1976年   16篇
  1975年   12篇
  1973年   14篇
  1972年   9篇
  1957年   7篇
排序方式: 共有2156条查询结果,搜索用时 3 毫秒
991.
本文介绍用乳化—冻凝技术制备甲氨蝶吟—明胶微球的方法。实验结果证实,包裹在微球内的MTX对~(60)钻幅射、温度和光照射是稳定的。微球的体外溶出试验、明胶微球在介质中不同时间的溶胀度试验也在文中介绍。微球肝动脉栓塞实验治疗用大鼠移植性肝癌进行,结果表明MTX微球治疗组的大鼠在肿瘤抑制率、促使肿瘤坏死程度以及延长荷瘤动物存活期方面比肝动脉灌注生理盐水、MTX溶液和明胶微球为佳.由于MTX微球具有阻断肿瘤血供和在其局部缓释化疗药物等双重功用,故治疗肝癌的效果明显优于动脉化疗或单纯栓塞方法。  相似文献   
992.
Recently cholinergic stimulation of the lower esophageal sphincter (LES) with bethanechol has been shown to be effective in the treatment of chronic gastroesophageal reflux. Since chronic reflux and esophagitis also occur in patients with vagotomy and antrectomy, we studied the effect of bethanechol on sphincter pressure in 10 patients who had had vagotomy and antrectomy. Both subcutaneous (0.08 mg/kg) and oral (25 mg) administration of bethanechol caused significant increases in LES pressure in these patients. In addition, both subcutaneous and oral administration of bethanechol elevated hypotensive sphincter pressures to normal levels. Orally administered bethanechol produced a sustained increase in LES pressure throughout a 90-min study period. These studies suggest that cholinergic stimulation of the LES with bethanechol may be of therapeutic benefit in vagotomized and antrectomized patients with gastroesophageal reflux.  相似文献   
993.
In the past 20 years few reports of transrectal drainage of pelvic abscesses have been published in the English language other than brief discussions in standard textbooks. During the past five years nine patients with pelvic abscesses have been treated successfully by this method. There were no deaths and morbidity was minimal. These cases are reviewed and the indications and techniques of operation discussed. Read at the meeting of the South Texas Chapter of the American College of Surgeons, Houston, Texas, February 3, 1978.  相似文献   
994.
995.
The role of DNA repair in initiation, promotion, and progression of malignancy suggests that variations in DNA repair genes confer altered cancer risk. Accordingly, DNA repair gene variants have been studied extensively in the context of cancer predisposition. Single nucleotide polymorphisms (SNPs) are the most common genetic variations in the human genome. A fraction of SNPs are located within the genes, which are likely to alter the gene expression and function. SNPs that change the encoded amino acid sequence of the proteins (non-synonymous; nsSNPs) are potentially genetic disease determinant variations. However, as not all amino acid substitutions are supposed to lead to a change in protein function, it will be necessary to have a priori prediction and determination of the functional consequences of amino acid substitutions per se, and then together with other genetic and environmental factors to study their possible association with a trait. Here we report the analysis of nsSNPs in 88 DNA repair genes and their functional evaluation based on the conservation of amino acids among the protein family members. Our analysis demonstrated that >30% of variants of DNA repair proteins are highly likely to affect the function of the proteins drastically. In this study, we have shown that three nsSNPs, which were predicted to have functional consequences (XRCC1-R399Q, XRCC3-T241M, XRCC1-R280H), were already found to be associated with cancer risk. The strategy developed and applied in this study has the potential to identify functional protein variants of DNA repair pathway that may be associated with cancer predisposition.  相似文献   
996.
Children with milk allergy have higher incidence of other food allergies, especially egg allergy. The objective of this study was to ascertain the accuracy of the prick test in children with IgE-mediated milk allergy for diagnosing egg allergy. Children under the age of 1 yr who came consecutively to Allergy Department 2003–05, and were diagnosed with IgE-mediated milk allergy were selected for this study. Egg introduction was completely avoided until the age of 14 months when clinical history, skin prick tests (SPT), specific-IgE antibodies determination and egg challenge test were performed. One hundred and four milk-allergic children were included. At least one positive prick test to any egg allergen was found in 65 out of the 104 (62.5%). Thirty-eight (36.5%) were allergic to egg proteins as well. Prick tests with egg white and ovomucoid (OVM) had the best diagnostic performances showing the largest areas under the receiver operating characteristic curve. The optimal diagnosis cut-off point was 6 mm for egg white and 5 mm for OVM. The positive likelihood ratios for these cut-off points were: 2.95 (95% CI: 1.74–4.99) for egg white prick test, and 20 (95% CI: 2.9–143.7) for OVM prick test. Children with specific IgE-mediated cow's milk allergy must be closely followed as a risk group for egg allergy. Early diagnosis is necessary and the SPT has shown itself to be a very useful tool for diagnosing immediate IgE reactions to egg on first known exposure.  相似文献   
997.
998.
999.
1000.
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