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   31803篇
  免费   1597篇
  国内免费   145篇
耳鼻咽喉   413篇
儿科学   568篇
妇产科学   567篇
基础医学   4223篇
口腔科学   1172篇
临床医学   2483篇
内科学   7504篇
皮肤病学   793篇
神经病学   2375篇
特种医学   1262篇
外科学   5247篇
综合类   206篇
一般理论   2篇
预防医学   987篇
眼科学   499篇
药学   2168篇
中国医学   46篇
肿瘤学   3030篇
  2021年   529篇
  2020年   277篇
  2019年   418篇
  2018年   592篇
  2017年   421篇
  2016年   467篇
  2015年   552篇
  2014年   732篇
  2013年   807篇
  2012年   1276篇
  2011年   1376篇
  2010年   759篇
  2009年   712篇
  2008年   1260篇
  2007年   1320篇
  2006年   1355篇
  2005年   1391篇
  2004年   1350篇
  2003年   1290篇
  2002年   1303篇
  2001年   1211篇
  2000年   1381篇
  1999年   1185篇
  1998年   362篇
  1997年   271篇
  1996年   275篇
  1995年   279篇
  1994年   238篇
  1993年   224篇
  1992年   793篇
  1991年   753篇
  1990年   688篇
  1989年   698篇
  1988年   674篇
  1987年   661篇
  1986年   672篇
  1985年   594篇
  1984年   428篇
  1983年   350篇
  1979年   339篇
  1978年   235篇
  1977年   200篇
  1975年   199篇
  1974年   228篇
  1973年   208篇
  1972年   197篇
  1971年   209篇
  1970年   203篇
  1969年   224篇
  1968年   175篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Portal venous gas is occasionally encountered in children with intestinal pneumatosis, identified on real‐time ultrasound imaging as hyperechoic foci with quick movement. The origin of the portal venous gas can be identified by following the hyperechoic foci along the branches of the portal vein, providing an estimate of the location of intestinal pneumatosis. This approach may be useful for predicting the patient's prognosis. Our report describes 2 cases of portal venous gas while estimating the area of intestinal pneumatosis, which were evaluated with real‐time ultrasound.  相似文献   
5.
Systemic sclerosis‐associated interstitial lung disease (SSc‐ILD) is the most frequent cause of death for SSc but there is still no sufficient treatment available. Although cyclophosphamide (CYC) therapy is a common treatment which has shown statistical efficacy against SSc‐ILD to date, its effects are temporary and not enough. Rituximab (RTX), the anti‐CD20 monoclonal antibody, has recently shown efficacy in many autoimmune diseases. In SSc‐ILD, RTX is also considered to be one of the novel treatment candidates. However, studies of SSc‐ILD in Japanese treated with RTX have only a few case reports. Therefore, in this study, we retrospectively compared nine patients treated with RTX and 30 patients treated with CYC to investigate the efficacy of RTX treatment for Japanese anti‐topoisomerase I‐positive SSc‐ILD patients. At the 24‐month evaluation, the improvement rates of percent predicted of forced vital capacity and percent predicted of diffusing capacity of the lung carbon monoxide in the RTX‐treated group were significantly higher than those in the CYC‐treated group (20.6 ± 8.8% vs 1.1 ± 3.9%; P < 0.05 and 34.0 ± 6.0% vs ?1.5 ± 2.8%; P < 0.01, respectively). In addition, skin thickness scores also showed a marked improvement from 13.5 points before the start of treatment to 5.8 points after 24 months by RTX therapy (P < 0.05). These results suggest that RTX treatment is more effective for Japanese SSc‐ILD patients than CYC treatment. In the future, it is expected that large‐scale clinical trials will show the usefulness of RTX treatment for SSc‐ILD.  相似文献   
6.
The carcinogenesis and development of prostate cancer are mediated by enhanced Ca2+ signaling. In the present study, the pharmacological profile of the Ca2+-sensing receptor (CaSR) antagonists (calcilytics) was examined in human prostate cancer PC-3 cells. NPS2143 and Calhex 231 blocked extracellular Ca2+-induced increases in cytosolic [Ca2+]. NPS2143 and Calhex 231 inhibited cell proliferation (IC50 = 7.4 and 10.3 μM, respectively) and migration. The exposure to NPS2143 or Calhex 231 down-regulated CaSR protein expression. These results demonstrated that calcilytics inhibited cell proliferation/migration and down-regulated CaSR expression in human prostate cancer cells, suggesting their potential as novel therapeutic drugs for prostate cancer.  相似文献   
7.
8.
9.
The efficacy of azacitidine (AZA) on survival of lower risk (LR) ‐ myelodysplastic syndromes (MDS) is controversial. To address this issue, we retrospectively evaluated the long‐term survival benefit of AZA for patients with LR‐MDS defined by International Prognostic Scoring System (IPSS). Using data from 489 patients with LR‐MDS in Nagasaki, hematologic responses according to International Working Group 2006 and overall survival (OS) were compared among patients that received best supportive care (BSC), immunosuppressive therapy (IST), erythropoiesis‐stimulating agents (ESA), and AZA. Patients treated with AZA showed complete remission (CR) rate at 11.3%, marrow CR at 1.9%, and any hematologic improvement at 34.0%, with transfusion independence (TI) of red blood cells in 27.3% of patients. and platelet in 20% of patients, respectively. Median OS for patients received IST, ESA, BSC, and AZA (not reached, 91 months, 58 months, and 29 months, respectively) differed significantly (P < .001). Infection‐related severe adverse events were observed in more than 20% of patients treated with AZA. Multivariate analysis showed age, sex, IPSS score at diagnosis, and transfusion dependence were significant for OS, but AZA treatment was not, which maintained even response to AZA, and IPSS risk status at AZA administration was added as factors. We could not find significant survival benefit of AZA treatment for LR‐MDS patients.  相似文献   
10.
The benefit of rituximab (RTX) for systemic sclerosis-associated interstitial lung disease (SSc-ILD) has been shown in previous clinical trials. However, predictors of RTX efficacy have not been clarified. We investigated whether B-cell responsiveness to RTX is related to therapeutic effect. Ten SSc-ILD patients treated with RTX in an independent clinical trial (Japan Registry of Clinical Trials, jRCTs031180373) were included in this analysis. Peripheral B-cell counts were examined retrospectively before RTX administration (baseline) and at 2, 4, 12, and 24 weeks after the first RTX administration, along with percent-predicted forced vital capacity (%FVC) before and 24 weeks after RTX treatment. Relative to baseline, the percentage of residual peripheral blood B cells at 2 weeks after RTX was negatively correlated with the %FVC improvement at the 24-week assessment (r = ?0.41, p = 0.04). In the subgroup with less than 5% B-cell persistence at week 2, %FVC at the 24-week assessment was significantly improved compared to baseline (p = 0.02). In another subgroup with more than 5% residual B cells, %FVC was not significantly different after 24 weeks compared to baseline (p = 0.41). In conclusion, the removal rate of B cells after 2 weeks of RTX treatment may be a useful surrogate marker of subsequent SSc-ILD improvement.  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