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   3184篇
  免费   373篇
  国内免费   281篇
耳鼻咽喉   25篇
儿科学   55篇
妇产科学   58篇
基础医学   330篇
口腔科学   50篇
临床医学   445篇
内科学   473篇
皮肤病学   54篇
神经病学   177篇
特种医学   93篇
外国民族医学   2篇
外科学   297篇
综合类   397篇
预防医学   254篇
眼科学   118篇
药学   506篇
  6篇
中国医学   179篇
肿瘤学   319篇
  2024年   10篇
  2023年   43篇
  2022年   98篇
  2021年   175篇
  2020年   111篇
  2019年   115篇
  2018年   128篇
  2017年   85篇
  2016年   114篇
  2015年   161篇
  2014年   179篇
  2013年   166篇
  2012年   216篇
  2011年   252篇
  2010年   169篇
  2009年   138篇
  2008年   176篇
  2007年   248篇
  2006年   168篇
  2005年   164篇
  2004年   115篇
  2003年   89篇
  2002年   76篇
  2001年   76篇
  2000年   72篇
  1999年   55篇
  1998年   52篇
  1997年   51篇
  1996年   49篇
  1995年   29篇
  1994年   40篇
  1993年   34篇
  1992年   28篇
  1991年   33篇
  1990年   24篇
  1989年   20篇
  1988年   16篇
  1987年   14篇
  1986年   14篇
  1985年   5篇
  1984年   2篇
  1983年   6篇
  1981年   2篇
  1980年   4篇
  1979年   3篇
  1978年   3篇
  1977年   3篇
  1969年   1篇
  1964年   1篇
  1963年   1篇
排序方式: 共有3838条查询结果,搜索用时 187 毫秒
11.
12.
(吴永平)(车东媛)(张婉蓉),(李文英)RoleofthePericytesofIntra-acinarPulmonaryArteryintheStructuralRemodelingofPulmonaryVessels¥WUYong-ping;C...  相似文献   
13.
Background: The overexpression of p53 has been found to be correlated with prognosis of some carcinomas, including gastric cancer, but no studies have reported on its relationship to the location of gastric cancer. In the present study, we compared the p53 expression of proximal and distal gastric cancer concerning histopathology and prognosis. Methods: A total of 170 tumors in the patients with proximal (80 cases) and distal (90 cases) gastric cancer were studied by immunohistochemical methods. Results: p53 immunopositivity was detected in 28.8% of all tumors. The p53-positive expression in proximal gastric cancer was higher than in distal gastric cancer (38.8% vs. 20.0%, p<0.05). A 5-year survival analysis showed that there is no significant difference between tumors that are p53 positive and p53 negative. No correlation was found between p53 expression and histopathology of gastric cancer. Conclusion: p53 nuclear staining is not useful as a prognostic indicator or as a parameter in gastric cancer.  相似文献   
14.
作者于1987年2月16日~1988年2月15日在四川五个点211 639人群中监测急性病毒性肝炎。其发病率为167.74/10万,其中甲型肝炎占24.51%;乙型肝炎占38.31%;非甲非乙型肝炎占24.51%,EB病毒和巨细胞病毒所致肝炎各占3.38%;混合感染占5.92%。病毒性肝炎中有14.93%重叠感染。发病高峰在春季。发病率,男:女=1.75:1。甲型肝炎20岁以下年龄组、乙型肝炎20~39岁年龄组的发病率明显高于其他年龄组,非甲非乙型较分散,5~19岁相对多一些,其他型别年龄组间无明显差异。355例急性病毒性肝炎患者中43.9%有接触史,36.6%有注射史。  相似文献   
15.
Summary The monocrofaline-induced structural changes of small pulmonary arteries in rat and their relationship with pulmonary hypertension and right ventricular hypertrophy were observed by determining the right ventricular systolic pressure, and by light and electron microscope and morphometry. One to 38 days after last injection of monocrotaline (MCT), a medial thickening and lumen marrrowing of the circular muscular arteries (CMA), accompanying terminal (TB) and respiratory bronchioles (RB), were found. And there after the lumen of CMA, accompanying TB, became dilated, and its medial thickness (MT) decreased, whereas the histopathologic changes of the partially muscular arteries (PMA), accompanying RB, became severe, their MT increased continuously, and finally reached the peak value on Day 50. At the first day after last MCT treatment, inflammation and muscularization were found in PMA and nonmuscular arteries (NMA), and became more severe with the cause of disease. Therefore, the intra-acinar pulmonary arteries, both CMA and PMA, increased in number while the NMA decreased in number significantly because of the structural remodeling. Four days after MCT treatment, the right ventricular systolic pressure began to rise, and reached its peak value on Day 50. Eight days after MCT injection, right ventricular hypertrophy developed, and became most significant from Day 23 to Day 30. The results suggest that structural remodeling, i.e. muscularization, of intra-acinar pulmonary arteries plays an important role in the development of pulmonary hypertension and right ventricular hypertrophy.  相似文献   
16.
应用改进的AdEasy系统制备重组腺病毒   总被引:13,自引:2,他引:11  
目的 改进AdEasy系统,使之更简便、高效、快捷。方法 pAdtrack经酶切线性化后,转化经氯化钙处理的感受态AdEasier-1细菌,获得重组腺病毒质粒。最后将线性化的重组腺病毒质粒转染293细胞包装获得重组腺病毒。荧光显微镜下细胞中重组腺病毒观察绿色荧光蛋白的表达。结果 应用氯化钙法由pAdtrack转化AdEasier-1细菌,可获得极高比例的(20/20)阳性重组腺病毒克隆。结论 应用改进后的AdEasy系统构建腺病毒相比于传统AdEasy系统,方法更简便、成功率更高、实验周期更短、对实验室的条件要求低。  相似文献   
17.
OBJECTIVE: To prepare and identify monoclonal antibodies (mAbs) against Penicillium marneffei. METHODS: Recombinant mannoprotein1 (MP1) of Penicillium marneffei was used to immunize BALB/c mice, and anti-MP1 mAbs were obtained by means of hybridoma. Screening and identification of the mAbs were subsequently performed with indirect enzyme-linked immunosorbent assay and Western blotting, respectively. RESULTS: Four hybridomas producing antibodies against Penicillium marneffei were obtained, and the IgG isotypes of the 4 mAbs were identified as IgG1 with affinity constants (K) of 8.2x10(-9), 4.7x10(-9), 6.5x10(-9) and 2.7x10(-9), respectively. Western blotting demonstrated specific recognition of Aspergillus fumigatus MP1 by the obtained mAbs. CONCLUSION: The 4 hybridomas producing anti-MP1 mAbs with high specificity and affinity can be of significant value in the diagnosis of Penicilliosis marneffei infections.  相似文献   
18.
OBJECTIVE: The aim was to establish the potential efficacy, tolerabilityand side-effect profile of electromagnetic therapy as an adjunctto conventional dressings in the treatment of venous leg ulcers. METHOD: A prospective, randomized, double blind controlled clinicaltrial was carried out in a dedicated leg ulcer clinic basedin one urban general practice. Nineteen patients with leg ulcersof confirmed venous aetiology were assessed. The main outcomemeasures were rate and scale of venous leg ulcer healing, changesin patient-reported pain levels, quality of life, degree ofmobility, side effect profile and acceptability to patientsand staff. RESULTS: Sixty-eight per cent of patients attending this dedicated clinicachieved improvements in the size of their ulcer (4, 21%, healedfully) and in reduced pain levels (P < 0.05) during the trial,despite the chronicity of ulcer histories. Patients treatedwith electromagnetic therapy at 800 Hz were found at day 50to have significantly greater healing (P < 0.05) and paincontrol (P < 0.05) than placebo therapy or treatment with600 Hz. All patients reported improved mobility at the end ofthe study. The electromagnetic therapy was well tolerated bypatients, with no differences between groups in reporting adverseevents, and proved acceptable to staff. CONCLUSION: Despite the small numbers in this pilot study, electromagnetictherapy provided significant gains in the healing of venousleg ulcers and reduction in pain. Keywords. Electromagnetic therapy, RCT, leg ulcers, primary care.  相似文献   
19.
Intestinal schistosomiasis japonica: CT-pathologic correlation   总被引:1,自引:0,他引:1  
  相似文献   
20.
(席思川)(车东媛)(张婉蓉)TheInhibitoryEffectofRadixSalviaeMiltiorrhizaeonHypoxicStructuralRemodelingofIntra-acinarPulmonaryArteries¥XISi-c...  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