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   1407篇
  免费   79篇
  国内免费   5篇
耳鼻咽喉   17篇
儿科学   50篇
妇产科学   18篇
基础医学   123篇
口腔科学   42篇
临床医学   138篇
内科学   267篇
皮肤病学   11篇
神经病学   48篇
特种医学   334篇
外科学   136篇
综合类   29篇
预防医学   137篇
眼科学   18篇
药学   70篇
  1篇
中国医学   8篇
肿瘤学   44篇
  2021年   20篇
  2020年   9篇
  2018年   21篇
  2017年   9篇
  2016年   20篇
  2015年   22篇
  2014年   16篇
  2013年   50篇
  2012年   51篇
  2011年   55篇
  2010年   45篇
  2009年   44篇
  2008年   37篇
  2007年   39篇
  2006年   46篇
  2005年   34篇
  2004年   22篇
  2003年   43篇
  2002年   32篇
  2001年   29篇
  2000年   36篇
  1999年   34篇
  1998年   44篇
  1997年   37篇
  1996年   39篇
  1995年   48篇
  1994年   39篇
  1993年   37篇
  1992年   20篇
  1991年   7篇
  1990年   23篇
  1989年   46篇
  1988年   30篇
  1987年   30篇
  1986年   41篇
  1985年   32篇
  1984年   24篇
  1983年   18篇
  1982年   17篇
  1981年   25篇
  1980年   21篇
  1979年   13篇
  1978年   24篇
  1977年   20篇
  1976年   16篇
  1975年   17篇
  1972年   11篇
  1971年   8篇
  1967年   8篇
  1966年   10篇
排序方式: 共有1491条查询结果,搜索用时 11 毫秒
41.
Endometrial adenocarcinoma is the most common malignancy of the gynaecologic tract, and therefore one of the most commonly encountered surgical pathology specimens. Accurate diagnosis, grading and staging are necessary to direct therapy for this common disease. Evaluation of these cases is usually straightforward. Some cases, however, may be complicated by a variety of issues such as difficulty assessing depth of invasion; difficulty assessing cervical involvement; possibility of synchronous ovarian primaries; evaluation of lymphovascular space invasion; difficulties with FIGO grade (especially in the company of altered differentiation); and subtle patterns of myoinvasion. The purpose of this review is to emphasize these problematic areas and offer straightforward guidelines to apply when these situations are encountered. Proper recognition of these diagnostic challenges will hopefully improve grading and staging accuracy, and subsequently therapy, for the multitudes of women affected by this disease.  相似文献   
42.
PURPOSE: Saccharomyces cerevisiae, a nonpathogenic yeast, has been used previously as a vehicle to elicit immune responses to foreign antigens, and tumor-associated antigens, and has been shown to reduce tumor burden in mice. Studies were designed to determine if vaccination of human carcinoembryonic antigen (CEA)-transgenic (CEA-Tg) mice (where CEA is a self-antigen) with a recombinant S. cerevisiae construct expressing human CEA (yeast-CEA) elicits CEA-specific T-cell responses and antitumor activity. EXPERIMENTAL DESIGN: CEA-Tg mice were vaccinated with yeast-CEA, and CD4(+) and CD8(+) T-cell responses were assessed after one and multiple administrations or vaccinations at multiple sites per administration. Antitumor activity was determined by tumor growth and overall survival in both pulmonary metastasis and s.c. pancreatic tumor models. RESULTS: These studies demonstrate that recombinant yeast can break tolerance and that (a) yeast-CEA constructs elicit both CEA-specific CD4(+) and CD8(+) T-cell responses; (b) repeated yeast-CEA administration causes increased antigen-specific T-cell responses after each vaccination; (c) vaccination with yeast-CEA at multiple sites induces a greater T-cell response than the same dose given at a single site; and (d) tumor-bearing mice vaccinated with yeast-CEA show a reduction in tumor burden and increased overall survival compared to mock-treated or control yeast-vaccinated mice in both pulmonary metastasis and s.c. pancreatic tumor models. CONCLUSIONS: Vaccination with a heat-killed recombinant yeast expressing the tumor-associated antigen CEA induces CEA-specific immune responses, reduces tumor burden, and extends overall survival in CEA-Tg mice. These studies thus form the rationale for the incorporation of recombinant yeast-CEA and other recombinant yeast constructs in cancer immunotherapy protocols.  相似文献   
43.
BACKGROUND: Tumour necrosis factor-alpha (TNF-alpha) is an important regulator of the chronic inflammation contributing to tumour progression. Infliximab, an anti-TNF-alpha monoclonal antibody was investigated in this trial of patients with advanced cancer. The primary objectives were to determine the safety profile and biological response of infliximab in a cancer population. Clinical response was a secondary objective. PATIENTS AND METHODS: Forty-one patients received infliximab at 5 mg/kg (n = 21) or 10 mg/kg (n = 20) i.v. at 0 and 2 weeks and then every 4 weeks. Post-treatment samples were measured for changes in plasma and serum TNF-alpha, CCL2, IL-6 and C-reactive protein (CRP). RESULTS: Infliximab was well tolerated with no dose-limiting toxic effects. At both doses of infliximab, neutralisation of serum TNF-alpha was observed after 1 h while plasma CCL2, IL-6 and serum CRP were decreased 24 and 48 h following infliximab administration. Seven patients experienced disease stablisation (range 10-50+ weeks). There was no evidence of disease acceleration in any patient. CONCLUSIONS: Infliximab treatment was safe and well tolerated in patients with advanced cancer. There was evidence of biological activity with baseline TNF-alpha and CCL2 being correlated with infliximab response.  相似文献   
44.
45.
Dietary intake during diarrhea in children less than three years of age was estimated from information recorded on illustrated dietary forms used by children's caretakers during the first week of illness in a prospective community-based study of diarrheal diseases in Lima, Peru. The frequency of consumption and the amount consumed of food groups and selected commonly consumed foods were analyzed by the final duration of the diarrheal episode. Cereals were less frequently consumed during the acute phase of diarrheal episodes that ultimately became persistent (>14 days'duration), apparently shortening the duration of the episode by one day (median duration of four days in children not consuming vs three days in children consuming cereals during diarrhea, p <0.02 Kaplan-Meier logrank test). Only roots and tubers (mainly potatoes) were consumed in greater quantity during episodes that became persistent. There was no evidence that consumption of breast milk or non-maternal milk was associated with an alteration in diarrheal duration. This study provides further evidence of the beneficial effects of continuing feeding during diarrhea using foods available at the home level, especially cereals, which are commonly used in the diet of young children.  相似文献   
46.
47.
Brain arteriovenous malformation (BAVM) resection can result in an acute increase in cerebral blood flow (CBF) of unclear etiology. This observational study investigated the relationship between changes in CBF and cardiac output (CO) in patients undergoing microsurgical resection of BAVMs. In 20 patients undergoing a BAVM resection during an isoflurane-based anesthesia, we measured CBF and systemic cardiovascular parameters immediately before and after BAVM resection. CBF was measured on the hemisphere ipsilateral to the lesions and on the contralateral side, using intravenous cold 133Xe washout. Cardiac output was measured using thermodilution technique via a pulmonary artery catheter. There was an increase in global CBF after resection (25 +/- 8 versus 31 +/- 13 mL/100 g/min, preresection versus postresection, mean +/- SD, P =.002), ipsilateral CBF (25 +/- 8 versus 31 +/- 13 mL/100 g/min, P =.002), and contralateral CBF (24 +/- 7 versus 30 +/- 13 mL/100 g/min, P =.003). There was no change in CO, mean systemic arterial pressure, central venous pressure, or pulmonary artery diastolic pressure. The change in CBFGLOBAL was not correlated with changes in CO (r =.154, P =.517). BAVM resection resulted in global increases in CBF that was not substantially related to changes in CO or other systemic parameters.  相似文献   
48.

Background  

There is evidence that certain mutations in the double-strand break repair pathway ataxia-telangiectasia mutated gene act in a dominant-negative manner to increase the risk of breast cancer. There are also some reports to suggest that the amino acid substitution variants T2119C Ser707Pro and C3161G Pro1054Arg may be associated with breast cancer risk. We investigate the breast cancer risk associated with these two nonconservative amino acid substitution variants using a large Australian population-based case–control study.  相似文献   
49.
50.
Monascus purpureus is a fungus that has been tradi-tionally used in China for thousands of years to produce ricewine . Traditionally the fungus is used to ferment non-gluti-nous cooking of rice ,to produce a kind of famous red ricewine .Its main traditional indications consist of disordersdue to the accumulation of fats (nosologically linked withthe problems of stasis of circulation in traditional Chinesemedicine) ,liver disorders and some forms of tumor as ithelps i mprove the circulation of …  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