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   2333篇
  免费   223篇
  国内免费   4篇
耳鼻咽喉   43篇
儿科学   69篇
妇产科学   55篇
基础医学   303篇
口腔科学   38篇
临床医学   161篇
内科学   412篇
皮肤病学   70篇
神经病学   282篇
特种医学   80篇
外国民族医学   1篇
外科学   358篇
综合类   56篇
一般理论   1篇
预防医学   118篇
眼科学   72篇
药学   196篇
中国医学   9篇
肿瘤学   236篇
  2023年   13篇
  2022年   42篇
  2021年   73篇
  2020年   53篇
  2019年   70篇
  2018年   95篇
  2017年   60篇
  2016年   52篇
  2015年   64篇
  2014年   74篇
  2013年   90篇
  2012年   136篇
  2011年   172篇
  2010年   77篇
  2009年   54篇
  2008年   134篇
  2007年   147篇
  2006年   138篇
  2005年   96篇
  2004年   102篇
  2003年   88篇
  2002年   83篇
  2001年   61篇
  2000年   63篇
  1999年   41篇
  1998年   14篇
  1997年   14篇
  1996年   13篇
  1995年   17篇
  1994年   14篇
  1993年   8篇
  1992年   32篇
  1991年   46篇
  1990年   41篇
  1989年   32篇
  1988年   29篇
  1987年   29篇
  1986年   22篇
  1985年   17篇
  1984年   19篇
  1983年   9篇
  1981年   13篇
  1980年   10篇
  1979年   10篇
  1978年   9篇
  1977年   11篇
  1976年   7篇
  1975年   8篇
  1970年   7篇
  1968年   7篇
排序方式: 共有2560条查询结果,搜索用时 15 毫秒
41.
42.
Blunt abdominal trauma mostly results from motor vehicle accidents, recreational accidents, falls or assaults with commonly injured internal organs being the spleen, liver, retroperitoneum, small bowel, kidneys, bladder, colorectal, diaphragm and pancreas. Gastric rupture is quite uncommon. Isolated gastric perforations following blunt trauma to the abdomen are mostly seen in paediatric patients. It is uncommon in adult patients and even rarer is the occurrence of double gastric perforations. We report here with a case of isolated double gastric perforation in a 24-year-old male patient following vehicular accident.  相似文献   
43.
44.
The outcome of randomized controlled trials can vary depending on the eligibility criteria of the patients entering into the trial, as well as the heterogeneity of the eligible population and/or the interventions. If the subject population and/or interventions are heterogeneous, the final outcome of the trial depends on the degree of concordance of effects of the subgroups of interventions on the subgroups of the subject population. The considerations that go into the calculation of sample size and determination of the study stopping rules also would affect the nature of the outcome of the study. In this paper we try to examine these phenomena with respect to the recent trials on endovascular therapy in acute ischemic stroke.  相似文献   
45.
Gall bladder Carcinoma (GBC) is the fifth most common cancer of the digestive tract and frequently diagnosed in late stage of disease. Estimation of circulating free DNA (cfDNA) in serum has been applied as a “liquid biopsy” in several deep seated malignancies. Its value in diagnosis of gall bladder carcinoma has not been studied. The present study was designed to assess the role of cfDNA in the diagnosis of GBC and correlate levels with the TNM stage. Serum was collected from 34 patients with GBC and 39 age and sex matched controls including 22 cholecystitis and 17 healthy individuals. Serum cfDNA levels were measured through quantitative polymerase chain reaction (qPCR) by amplification of β-globin gene. Performance of the assay was calculated through the receiver operating characteristic (ROC) curve. The cfDNA level was significantly lower in healthy controls and cholecystitis (89.32 ± 59.76 ng/ml, 174.21 ± 99.93 ng/ml) compared to GBC (1245.91 ± 892.46 ng/ml, p = <0.001). The cfDNA level was significantly associated with TNM stage, lymph node involvement and jaundice (0.002, 0.027, and 0.041, respectively). Area under curve of ROC analysis for cancer group versus healthy and cholecystitis group was 1.00 and 0.983 with sensitivity of 100 %, 88.24 % and specificity of 100 % respectively. Quantitative analysis of cfDNA may distinguish cholecystitis and gall bladder carcinoma and may serve as new diagnostic, noninvasive marker adjunct to imaging for the diagnosis of GBC.  相似文献   
46.
A high frequency of mutations at the PTEN locus has been noticed in carcinoma of oral. However, the role of PTEN alternations and its association with outcome variables in the genesis of oral carcinoma is not understood fully. The purpose of our study was to examine the impact of PTEN and Bcl2 in the genesis of Squamous cell carcinoma of oral. Total numbers of 60 histopathologically confirmed cases of Squamous Cell Carcinoma and 15 cases of inflammatory lesion of oral specimens were studied. We assessed PTEN and bcl2 overexpression by the use of anti-PTEN and anti-bcl2 antibody through immunohistochemistry as directed by the manufacturer. There was progressive loss of PTEN expression from inflammatory lesion to OSCC (p<0.05). Significant differences were found for PTEN expression between inflammatory lesion and OSCC. The difference in expression pattern of PTEN in gender did not reach statistical significance (p>0.05). The expression of bcl2 was found to be restricted to tumor cells in well and moderately differentiated tumors. The intense expression of bcl2 was observed throughout the tumor cell in poorly differentiated tumors.The Overexpression of bcl2 and loss of PTEN expression were correlated to poor differentiation, lymph node involvement and late stages. Thus, alteration of PTEN and bcl2 is likely an important molecular event in pathogenesis and carcinogenesis of oral carcinoma.  相似文献   
47.
Lymphomatoid papulosis (LyP) is a paraneoplastic primary cutaneous CD30+ lymphoproliferative disorder (LPD) that has been associated with malignant lymphomas, most commonly mycosis fungoides (MF). We observed 10 patients with MF who developed severe inflammation after using nitrogen-mustard (NM) gel from 1 to 8 months and who developed LyP. We hypothesized that NM gel produced local inflammation, which induced CD30 expression in malignant T cells in situ leading to the appearance of LyP papules. The high frequency of induction of LyP lesions in patients with severe inflammation while on treatment with NM gel suggests an association between inflammatory stimuli and development of LyP. Our observation provides insight into the pathogenesis of CD30+ LPD.  相似文献   
48.
49.
50.
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