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   303篇
  免费   15篇
  国内免费   11篇
耳鼻咽喉   34篇
儿科学   1篇
基础医学   30篇
口腔科学   1篇
临床医学   26篇
内科学   6篇
神经病学   42篇
特种医学   35篇
外科学   80篇
综合类   20篇
预防医学   2篇
药学   4篇
肿瘤学   48篇
  2023年   1篇
  2022年   9篇
  2021年   12篇
  2020年   12篇
  2019年   9篇
  2018年   11篇
  2017年   7篇
  2016年   8篇
  2015年   8篇
  2014年   11篇
  2013年   15篇
  2012年   9篇
  2011年   20篇
  2010年   9篇
  2009年   33篇
  2008年   13篇
  2007年   19篇
  2006年   13篇
  2005年   12篇
  2004年   9篇
  2003年   9篇
  2002年   6篇
  2001年   7篇
  2000年   6篇
  1999年   6篇
  1998年   3篇
  1997年   5篇
  1996年   4篇
  1995年   6篇
  1994年   5篇
  1993年   3篇
  1992年   1篇
  1991年   3篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1987年   3篇
  1986年   5篇
  1985年   2篇
  1983年   2篇
  1982年   2篇
  1981年   3篇
  1980年   1篇
  1976年   2篇
  1973年   1篇
排序方式: 共有329条查询结果,搜索用时 15 毫秒
1.
目的构建脊索瘤患者的预测模型并进行验证。方法从SEER数据库(2004~2015年)中鉴定和收集597例脊索瘤患者。Nomogram是基于建模组420例拥有完整数据的患者建立的。C指数(C-index)和校正曲线确定Nomogram的预测精度和判别能力。结果建立了基于年龄、种族、原发部位及数量、肿瘤分期(TNM)、手术方式、是否放疗、肿瘤转移和肿瘤大小等预后因素的预测模型,C指数为0.778。确定生存概率的校准曲线表明,Nomogram预测结果与实际观测结果吻合较好。年龄>60岁(P<0.001,HR 5.723,95%CI 1.988~16.474)、M1(P<0.001,HR 4.121,95%CI 1.834~9.257)、手术方式(全切除,P<0.01,HR0.416,95%CI 0.236~0.732;根治性扩大切除,P<0.0001,HR 0.251,95%CI 0.143~0.442)是独立预后因素。结论 Nomogram为脊柱脊索瘤患者提供了更准确的预后预测。本研究结果显示,年龄>60岁肿瘤分期M1和不进行手术是显著缩短脊索瘤患者生存时间的独立危险因素。  相似文献   
2.
AimsThe outcome of chordoma patients with local or distant failure after proton therapy is not well established. We assessed the disease-specific (DSS) and overall survival of patients recurring after proton therapy and evaluated the prognostic factors affecting DSS.Materials and methodsA retrospective analysis was carried out of 71 recurring skull base (n = 36) and extracranial (n = 35) chordoma patients who received adjuvant proton therapy at initial presentation (n = 42; 59%) or after post-surgical recurrence (n = 29; 41%). The median proton therapy dose delivered was 74 GyRBE (range 62–76). The mean age was 55 ± 14.2 years and the male/female ratio was about one.ResultsThe median time to first failure after proton therapy was 30.8 months (range 3–152). Most patients (n = 59; 83%) presented with locoregional failure only. There were only 12 (17%) distant failures, either with (n = 5) or without (n = 7) synchronous local failure. Eight patients (11%) received no salvage therapy for their treatment failure after proton therapy. Salvage treatments after proton therapy failure included surgery, systemic therapy and additional radiotherapy in 45 (63%), 20 (28%) and eight (11%) patients, respectively. Fifty-three patients (75%) died, most often from disease progression (47 of 53 patients; 89%). The median DSS and overall survival after failure was 3.9 (95% confidence interval 3.1–5.1) and 3.4 (95% confidence interval 2.5–4.4) years, respectively. On multivariate analysis, extracranial location and late failure (≥31 months after proton therapy) were independent favourable prognostic factors for DSS.ConclusionThe survival of chordoma patients after a treatment failure following proton therapy is poor, particularly for patients who relapse early or recur in the skull base. Although salvage treatment is administered to most patients with uncontrolled disease, they will ultimately die as a result of disease progression in most cases.  相似文献   
3.
4.
目的对治疗前原发性骶尾部脊索瘤(PSC)CT图像分型,并分析其CT征象,为诊断和个性化治疗提供依据。方法回顾性分析101例PSC患者治疗前的CT图像,包括肿瘤的部位、范围、大小、密度、肿瘤与邻近结构的关系。按照肿瘤的部位由上及下分为Ⅰ~Ⅳ型,并根据肿瘤侵犯的范围从小到大分为a^d亚型。采用Kruskal-Wallis H检验比较PSC各亚型的占比,并对各亚型之间进行两两比较。采用R×C列联表精确概率检验比较分型和亚型肿瘤钙化的发生率。采用单因素方差分析及LSD-t检验对各分型和亚型肿瘤的大小和密度进行分析、比较。结果101例PSC中,Ⅰ~Ⅳ型的发生率分别为17.8%、30.7%、36.6%、14.9%,a^d亚型的占比分别为9.9%、25.7%、58.4%、5.9%。各亚型的占比差异具有统计学意义(P=0.012)。c亚型明显高于a亚型(P=0.039),d亚型明显低于a亚型(P=0.036),其余各型之间无明显差异。各分型肿瘤内钙化的差异无统计学意义(P=0.233);各亚型肿瘤内钙化的差异有统计学意义(P=0.003),a^d亚型肿瘤钙化的比率逐渐增加。Ⅰ型肿瘤的左右径及上下径明显大于Ⅱ~Ⅳ型(P<0.05)。a亚型与b亚型肿瘤之间前后径的差异无统计学意义(P=0.102),b^d亚型之间前后径的差异均有统计学意义(P<0.05);不同亚型肿瘤之间的左右径、上下径之间的差异均有统计学意义(P<0.05),a亚型径线最小,d亚型径线最大。结论101例PSC中,Ⅱ、Ⅲ型最多见,肿瘤较少累及第一骶骨;各亚型中,a型较少见,c亚型最多见,d亚型最少见。肿瘤的密度与分型无关,肿瘤内钙化与亚型有关。Ⅰ型肿瘤侵犯的范围较Ⅱ~Ⅳ型广泛,a^d亚型肿瘤的径线逐渐增大,CT分型有利于判断肿瘤的范围。PSC诊断延迟现象比较明显,但很少发生远处侵犯和转移。CT图像可对治疗前PSC分型,为诊断和个性化治疗提供依据。  相似文献   
5.
目的探讨神经内镜经鼻蝶入路切除颅底脊索瘤的手术策略、临床疗效及其影响因素。方法回顾性分析2004年1月至2021年3月首都医科大学附属北京天坛医院神经外科采用神经内镜经鼻蝶入路切除的颅底脊索瘤患者的临床资料,共纳入373例患者(共行500例次手术)。其中2004—2019年为早期手术组,采用以肿瘤为中心的手术策略;2020—2021年为近期手术组,依据肿瘤的起源部位及其沿着颅底骨缝、神经和大血管孔道延伸生长的特点进行顺序探查和切除(探查顺序形似"龟背")。比较两种手术策略切除肿瘤程度的差异。随访患者的无进展生存期(PFS)和总生存期(OS),采用Kaplan-Meier法生存分析,采用log-rank检验分析不同临床特征患者间PFS和OS的差异。结果500例次手术中,413例次为早期手术组,肿瘤的全切除率、次全切除率、部分切除率分别为35.1%(145例次)、36.6%(151例次)、28.3%(117例次);87例次为近期手术组,肿瘤的全切除率、次全切除率、部分切除率分别为52.9%(46例次)、37.9%(33例次)、9.2%(8例次),两组肿瘤的切除率差异有统计学意义(P<0.001)。500例次手术,脑脊液漏的发生率为4.6%(23例次)。373例患者中,术后1例(0.3%)死亡,1例(0.3%)发生大面积脑梗死;共325例(87.1%)患者获得完整的随访资料,中位随访时间为31个月(3~193个月)。182例(56.0%)复发,估计总体患者的中位PFS为24个月(95%CI:17.5~30.5);85例(26.2%)死亡,估计总体患者的中位OS为106个月。生存分析显示,与原发性肿瘤、肿瘤体积小、肿瘤全切除、病理学类型为经典型或软骨型肿瘤及术后放疗的患者比较,复发性肿瘤、肿瘤体积大、肿瘤非全切除、病理学类型为去分化或差分化或肉瘤样型肿瘤及术后未行放疗患者的PFS和OS均短,差异均有统计学意义(均P<0.05)。结论依据颅底脊索瘤生长侵袭特点,采用"龟背"形顺序探查、切除肿瘤的手术策略有利于提高肿瘤的切除程度。肿瘤是否原发、体积大小、切除程度、病理学类型、术后是否放疗可能与颅底脊索瘤患者术后的PFS和OS有关。  相似文献   
6.
7.
Chordoma is a locally aggressive malignant tumor that generally occurs in the clivus, mobile spine and sacrum. While en bloc resection with wide margins has been advocated as the only cure for chordomas, tumor characteristics and violation of critical anatomical boundaries may preclude pursuing this treatment option in the cervical spine. We present a C2 chordoma in a 35-year-old man with epidural and prevertebral extension that was treated with a single stage anterior–posterior total C2 spondylectomy with novel reconstruction using an expandable cage with integrated fixation followed by stereotactic radiosurgery. Single stage intralesional total C2 spondylectomy via anterior transoral and posterior approaches was performed. The anterior column was reconstructed using an expandable cage with integrated fixation from the clivus to C3. The patient maintained his intact neurological status at 6 month follow-up with full resumption of activities of daily living without any significant morbidity.  相似文献   
8.
Chordomas are tumors arising from remnants of the embryological notochord, most commonly found in the spheno-occipital, spinal, or sacro-coccygeal areas. They are rare tumors in the pediatric population and are challenging to manage due to their difficult accessibility, proximity to important anatomy and extension into adjacent structures. We report a series of 10 children treated for chordoma at The Hospital for Sick Children focusing on their surgery, adjuvant therapy and long-term outcomes. A retrospective review involving patient charts, radiographic imaging, and pathology slides was performed for 10 chordoma patients during the period from 1987–2015. Important variables, including patient demographics, chordoma location, presentation, imaging characteristics, pathology subtype, treatment options, and long-term outcome were analysed. The series consists of seven girls and three boys with cranial or upper cervical spine chordomas. One patient presented with an extradural left cerebellopontine angle chordoma demonstrating aggressive and dedifferentiated features, which, to our knowledge, has not been previously described in the literature. All patients received surgical resection followed by photon or proton radiotherapy. Four patients with chondroid or atypical pathology also received chemotherapeutic adjuvants. All patients with classical pathology achieved favourable outcome, while the four patients with atypical pathology progressed quickly despite aggressive therapy, suggesting that pathology subtype is a crucial prognostic factor. This study summarizes 30 years of surgical and adjuvant therapy experience in a large academic center for pediatric chordoma patients. Patient outcomes were dependent on pathology subtype, and a multidisciplinary approach involving surgery, radiotherapy, and chemotherapy can be considered on an individual basis.  相似文献   
9.
10.
脊索瘤是临床少见的原发性低度恶性骨肿瘤,源自残留的胚胎脊索或迷走的脊索组织,好发于中轴骨,具有局部侵袭性、复发率高、预后差,以及对放射治疗和药物化疗不敏感等特点,使其临床治疗存在巨大挑战。位于活动节段的脊柱脊索瘤由于脊柱特有的解剖学特点而具有其独特特点,本文通过回顾近年国内外相关文献,对脊索瘤生物学行为特点进行概述,以期为脊索瘤治疗提供新的思路。  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