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   4998篇
  免费   248篇
  国内免费   77篇
耳鼻咽喉   94篇
儿科学   32篇
妇产科学   47篇
基础医学   852篇
口腔科学   113篇
临床医学   494篇
内科学   959篇
皮肤病学   103篇
神经病学   455篇
特种医学   296篇
外科学   709篇
综合类   16篇
预防医学   201篇
眼科学   53篇
药学   442篇
中国医学   76篇
肿瘤学   381篇
  2024年   1篇
  2023年   44篇
  2022年   167篇
  2021年   240篇
  2020年   107篇
  2019年   121篇
  2018年   150篇
  2017年   121篇
  2016年   191篇
  2015年   333篇
  2014年   344篇
  2013年   378篇
  2012年   562篇
  2011年   535篇
  2010年   258篇
  2009年   234篇
  2008年   323篇
  2007年   281篇
  2006年   230篇
  2005年   155篇
  2004年   109篇
  2003年   96篇
  2002年   84篇
  2001年   74篇
  2000年   66篇
  1999年   41篇
  1998年   24篇
  1997年   6篇
  1996年   7篇
  1995年   7篇
  1994年   4篇
  1993年   7篇
  1992年   12篇
  1991年   2篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1987年   3篇
  1986年   2篇
  1977年   1篇
排序方式: 共有5323条查询结果,搜索用时 15 毫秒
51.
BackgroundOblique lateral interbody fusion (OLIF) at lumbosacral junction is typically performed on the central window between the bifurcations of iliac vessels. However, the central window of lumbosacral transitional vertebrae (LSTVs) is usually obstructed by the iliocaval venous structures. We aimed to describe the vascular anatomy and surgical approach in OLIF at LSTVs compared with those in OLIF at typical L5-S1 junction.MethodsSixty-eight consecutive patients who underwent OLIF at lumbosacral junction were included. Of these, 31 patients had LSTVs and 37 patients had typical L5-S1 junction. The position of the iliocaval junction and the configuration of the left common iliac vein were compared using the preoperative CT and MR images of the lumbar spine. The surgical approach and intraoperative vascular findings were analyzed.ResultsAlmost 70% of LSTVs had the iliocaval junction at low or very low position. Mobilization of left common iliac vein for central window was potentially difficult in almost 74% of OLIF at LSTVs while it was not required or was potentially easy in almost 80% of OLIF at typical L5-S1. Vascular injury was identified in 2 (6.5%) patients with OLIF at LSTVs and in 3 (8.1%) patients with OLIF at typical L5-S1 junction (P = 0.904).ConclusionsIn our series, OLIF at LSTVs was performed through lateral window in 93.5% of the cases. Preoperative evaluation of the iliocaval junction using CT/MR of lumbar spine was reliable and valid in the determination of OLIF approach at lumbosacral junction.  相似文献   
52.
ObjectiveTo report a case of vulvar epithelioid sarcoma, a rare type of tumor that has been reported in 37 cases in the English literature to date.Case reportWe report three cases of vulvar epithelioid sarcoma, proximal type. Wide excisions of the mass were performed with margins free of tumor in all three cases.ConclusionDue to its low incidence, there are no evidence-based diagnostic algorithms or published recommendations for treatment. Locoregional lymph node involvement, vascular invasion, tumor size larger than 2 cm, deep localization, presence of necrosis, and a high mitotic index are known as poor prognostic factors. Adjuvant radiotherapy is advisable in the presence of a high-grade tumor or positive margins. The beneficial effect of adjuvant chemotherapy is not well established. Treatment decisions should be made based on the individual case presentation and pathology evaluation.  相似文献   
53.
We present a case of developmental venous anomaly associated with arteriovenous fistula supplied by a single arterial feeder adjacent to a large acute intracerebral hemorrhage. The arteriovenous fistula was successfully obliterated by superselective embolization while completely preserving the developmental venous anomaly. Two similar cases, including superselective angiographic findings, have been reported in the literature; however, we describe herein superselective angiographic findings in more detail and demonstrate the arteriovenous shunt more clearly than the previous reports. In addition, a literature review was performed to discuss the association of a developmental venous anomaly with vascular lesions.  相似文献   
54.
Pulmonary sequestration is a rare cystic malformation composed of bronchopulmonary tissue that is discontinuous from the tracheobronchial tree and has an anomalous systemic blood supply. We present a case of a 40-y-old male who presented with an extralobar pulmonary sequestration and underwent a laparoscopic retroperitoneal mass excision. Preoperative imaging revealed a large 11.3-cm retroperitoneal tumor consisting of a multiloculated cystic lesion. The patient was discharged home, and at 3-mo follow-up no complaints were reported.  相似文献   
55.
56.
57.
58.
59.
The present study showed that silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), inhibited lipopolysaccharide (LPS)-induced morphological changes in the mouse RAW264.7 macrophage cell line. We also showed that silymarin inhibited the nuclear translocation and transactivation activities of nuclear factor-kappa B (NF-κB), which is important for macrophage activation-associated changes in cell morphology and gene expression of inflammatory cytokines. BAY-11-7085, an NF-κB inhibitor, abrogated LPS-induced morphological changes and NO production, similar to silymarin. Treatment of RAW264.7 cells with silymarin also inhibited LPS-stimulated activation of mitogen-activated protein kinases (MAPKs). Collectively, these experiments demonstrated that silymarin inhibited LPS-induced morphological changes in the RAW264.7 mouse macrophage cell line. Our findings indicated that the most likely mechanism underlying this biological effect involved inhibition of the MAPK pathway and NF-κB activity. Inhibition of these activities by silymarin is a potentially useful strategy for the treatment of inflammation because of the critical roles played by MAPK and NF-κB in mediating inflammatory responses in macrophages.  相似文献   
60.
This study was aimed at investigating the clinical feasibility of quantitative ultrasound (QUS) imaging in the evaluation of suspected hepatic steatosis through assessment of the reliability of measurements and its correlation with the controlled attenuation parameter (CAP). This retrospective study included 117 patients who underwent liver B-mode ultrasound (US) with QUS imaging with a clinical US machine (RS85, Samsung Medison, Seoul, Korea) and CAP measurements between December 2019 and March 2020. For QUS examination, tissue attenuation imaging (TAI) and tissue scatter-distribution imaging (TSI) parameters were obtained. Intra- and inter-examiner reliability were assessed using intra-class correlation coefficients (ICCs), and QUS imaging parameters were correlated with CAP measurements using Spearman's correlation analysis. TAI and TSI revealed excellent intra- and inter-examiner reliability with ICCs of 0.994 and 0.975 and 0.991 and 0.947, respectively. Both TAI and TSI were significantly positively correlated with CAP values. QUS imaging provided good intra-and inter-observer reliability and correlated well with CAP in assessing suspected hepatic steatosis.  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