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   6713篇
  免费   295篇
  国内免费   34篇
耳鼻咽喉   103篇
儿科学   139篇
妇产科学   82篇
基础医学   884篇
口腔科学   141篇
临床医学   361篇
内科学   1618篇
皮肤病学   222篇
神经病学   516篇
特种医学   252篇
外科学   1195篇
综合类   40篇
一般理论   1篇
预防医学   180篇
眼科学   142篇
药学   291篇
中国医学   11篇
肿瘤学   864篇
  2023年   28篇
  2022年   63篇
  2021年   119篇
  2020年   73篇
  2019年   87篇
  2018年   124篇
  2017年   101篇
  2016年   159篇
  2015年   180篇
  2014年   185篇
  2013年   279篇
  2012年   408篇
  2011年   471篇
  2010年   275篇
  2009年   206篇
  2008年   426篇
  2007年   424篇
  2006年   473篇
  2005年   456篇
  2004年   472篇
  2003年   481篇
  2002年   442篇
  2001年   66篇
  2000年   58篇
  1999年   87篇
  1998年   113篇
  1997年   110篇
  1996年   82篇
  1995年   81篇
  1994年   63篇
  1993年   54篇
  1992年   37篇
  1991年   38篇
  1990年   23篇
  1989年   27篇
  1988年   27篇
  1987年   21篇
  1986年   12篇
  1985年   11篇
  1984年   14篇
  1983年   16篇
  1982年   22篇
  1981年   24篇
  1980年   21篇
  1979年   14篇
  1978年   14篇
  1976年   9篇
  1975年   11篇
  1974年   7篇
  1971年   8篇
排序方式: 共有7042条查询结果,搜索用时 0 毫秒
141.
142.
Celiac disease (CD) is an immune-mediated, inflammatory disorder of the small intestines with a defined genetic etiological component associated with the expression of HLA-DQ2 and/or HLA-DQ8 haplotypes. The dietary consumption of gluten-rich cereals triggers a gluten-specific immune response in genetically susceptible individuals leading to a spectrum of clinical manifestations ranging from an inapparent subclinical disease, to overt enteropathy that can in some individuals progress to enteropathy-associated T cell lymphoma (EATL). The tissue-destructive pathologic process of CD is driven by activated NK-like intraepithelial CD8+ lymphocytes and the proinflammatory cytokine IL-15 has emerged to be pivotal in orchestrating this perpetual tissue destruction and inflammation. Moreover, transgenic mice that over-express human IL-15 from an enterocyte-specific promoter (T3b-hIL-15 Tg) recapitulate many of the disease-defining T and B cell-mediated pathologic features of CD, further supporting the evolving consensus that IL-15 represents a valuable target in devising therapeutic interventions against the form of the disease that is especially refractory to gluten-free diet. In the present study, we evaluated the potential efficacy of tofacitinib, a pan-JAK inhibitor that abrogates IL-15 signaling, as a therapeutic modality against CD using T3b-hIL-15 Tg mice. We demonstrate that tofacitinib therapy leads to a lasting reversal of pathologic manifestations in the treated mice, thereby highlighting the potential value of tofacitininb as a therapeutic modality against refractory CD for which no effective therapy exists currently. Additionally, the visceral adiposity observed in the tofacitinib-treated mice underscores the importance of continued evaluation of the drug’s impact on the lipid metabolism.  相似文献   
143.
Objective : The purpose of this study is to construct the cross-sectional head circumference growth curves, intended for clinical use, for the Japanese from birth to 18 years of age. Subjects and methods : Two sets of the national survey data on head circumference and height were utilized for the study: (1) The 1990 data collected by the Japanese Ministry of Health and Welfare on children below 7 years of age ( n = 16 621, 8511 males, 8110 females). (2) The 1992-1994 data collected by the Research Institute of Human Engineering for Quality Life on children from 7 to 18 years of age ( n = 10 183, 5610 males, 4573 females). We used the LMS method to obtain the 3rd, 10th, 25th, 50th, 75th, 90th and 97th percentile values for each age and gender. Results and conclusions : The results showed a persistent positive secular trend in head circumference in Japanese children of both genders. Comparison of these data with those of recent Caucasian studies revealed ethnic difference in head circumference, with Japanese having relatively larger head circumference for height as compared with Caucasians.  相似文献   
144.
A case of gastric undifferentiated carcinoma with diffuse c-kit overexpression and focal neuroendocrine differentiation is described. A 76-year-old man presented appetite loss for 1 month. Gastric endoscopy showed an exophytic huge nodular mass with central ulceration at the gastric prepylorus. Distal gastrectomy was performed with lymph node dissection. Histology indicated anaplastic medium- to large-sized round tumor cells in discohesive sheets. Adenocarcinomatous areas forming tubular glands or with intracytoplasmic mucin on PAS and Alcian-blue staining were not found in any sections. Immunohistochemistry showed that the tumor cells were diffusely positive for cytokeratin, vimentin, c-kit and focally positive for chromogranin A and synaptophysin.  相似文献   
145.
Vesicles or micelles prepared from amphiphiles with azobenzene (Az) moieties and long alkyl chains have attracted much attention in drug delivery systems. To induce release behavior from smart carriers via transcis photoisomerization of the Az groups, UV light exposure is typically used, but it can damage DNA and hardly penetrates cells. In this paper, Az-containing phospholipids without long alkyl tails were designed and synthesized; in these compounds, the end group of the Az moiety was substituted with a –NO2 and –OCH3 group (abbreviated N6 and M6, respectively). N6 self-assembled into H-aggregates with an interdigitated bilayered structure in water through the antiparallel orientation due to π–π interactions of the Az group, the attractive van der Waals forces, and the interactions and bending behavior of the phosphocholine groups. Vesicles showing visible light stimuli-responsive behavior were obtained by mixing N6 and M6, and the release of encapsulated calcein was triggered by visible light.

A mixture of a nitro- and methoxy-substituted azo-containing phospholipids without long alkyl tails formed vesicles showing visible light stimuli-responsive behavior. Release of encapsulated calcein from the vesicles was triggered by visible light.  相似文献   
146.
147.
148.
149.
150.
Summary Between August 1985 and July 1992, at our center, 142 Japanese children had an extracardiac conduit operation to reconstruct the right ventricular outflow tract. The study group consisted of 22 of these 142 children who had a persistent fever and whose serum was positive for acute-phase reactants after the operation. We present the diagnostic findings for 10 children with infection of an extracardiac conduit that had been placed to restore the continuity of the right ventricle-pulmonary artery. They were part of the group of 22 children who were followed over the past 7 years with blood cultures, echocardiography, and67Ga imaging. All 10 developed a persistent fever and were seropositive for acute-phase reactants. Conduit infection was diagnosed in only 2 patients by the detection of vegetation on echocardiography and was diagnosed in 9 of the 10 patients by an abnormal67Ga uptake in the area of the artificial vessels used to reconstruct the pulmonary artery. The present study compared the use of blood cultures, echocardiography, and67Ga imaging in diagnosing an infection of the extracardiac conduit. The sensitivity of blood cultures in diagnosing an extracardiac conduit infection was 70% (7/10), and the specificity was 92% (1/12).67Ga imaging showed a higher sensitivity than echocardiography in diagnosing infection of an extracardiac conduit.  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