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   2010篇
  免费   710篇
  国内免费   113篇
耳鼻咽喉   19篇
儿科学   39篇
妇产科学   28篇
基础医学   174篇
口腔科学   27篇
临床医学   302篇
内科学   327篇
皮肤病学   47篇
神经病学   136篇
特种医学   153篇
外科学   299篇
综合类   225篇
现状与发展   1篇
预防医学   408篇
眼科学   153篇
药学   149篇
  5篇
中国医学   174篇
肿瘤学   167篇
  2024年   61篇
  2023年   123篇
  2022年   312篇
  2021年   409篇
  2020年   308篇
  2019年   225篇
  2018年   199篇
  2017年   198篇
  2016年   169篇
  2015年   239篇
  2014年   274篇
  2013年   36篇
  2012年   23篇
  2011年   31篇
  2010年   25篇
  2009年   15篇
  2008年   26篇
  2007年   32篇
  2006年   22篇
  2005年   17篇
  2004年   12篇
  2003年   10篇
  2002年   16篇
  2001年   8篇
  2000年   9篇
  1999年   12篇
  1998年   2篇
  1997年   9篇
  1992年   3篇
  1991年   3篇
  1989年   1篇
  1987年   1篇
  1986年   1篇
  1974年   2篇
排序方式: 共有2833条查询结果,搜索用时 15 毫秒
11.
目的:通过光学相干断层成像(OCT)检测高度近视合并青光眼患者视神经纤维层厚度的变化规律。方法:选取2017-01/12于我院进行治疗的高度近视合并青光眼患者80例160眼作为观察组,并选择同期于我院进行体检的健康志愿者60例120眼作为对照组。采用OCT分析所有受检者视神经纤维层厚度。结果:与对照组受检者相比,观察组患者鼻侧、颞上、鼻下、鼻上、颞下及全周平均视神经纤维层厚度均降低,而颞侧视神经纤维层厚度升高(P<0.05),且观察组中屈光度-10.00^-11.00D的患者鼻侧、颞上、鼻下、鼻上、颞下及全周平均视神经纤维层厚度均显著高于屈光度≥-12.00D的患者(P<0.05)。Spearman相关分析结果显示,观察组患者屈光度的绝对值与鼻侧、颞上、鼻下、颞下及全周平均厚度视神经纤维层厚度呈负相关,与颞侧视神经纤维层厚度呈正相关。结论:高度近视合并青光眼患者除颞侧外各象限视神经纤维层变薄。  相似文献   
12.
关于电离辐射是否可诱发非霍奇金淋巴瘤(NHL),目前的研究结果尚未获得一致结论。笔者报道了河南“4.26” 60Co源辐射事故中1例中度骨髓型急性放射病患者受照后第13年患NHL的病例,结合患者的受照史、病史特点、诊断及国际多项大型研究,从流行病学资料和影响因素两方面分析了患者“天”患非霍奇金淋巴瘤与电离辐射的关系,为电离辐射致NHL提供辐射流行病学依据。  相似文献   
13.
ObjectiveTo synthesize data quality (DQ) dimensions and assessment methods of real-world data, especially electronic health records, through a systematic scoping review and to assess the practice of DQ assessment in the national Patient-centered Clinical Research Network (PCORnet).Materials and MethodsWe started with 3 widely cited DQ literature—2 reviews from Chan et al (2010) and Weiskopf et al (2013a) and 1 DQ framework from Kahn et al (2016)—and expanded our review systematically to cover relevant articles published up to February 2020. We extracted DQ dimensions and assessment methods from these studies, mapped their relationships, and organized a synthesized summarization of existing DQ dimensions and assessment methods. We reviewed the data checks employed by the PCORnet and mapped them to the synthesized DQ dimensions and methods.ResultsWe analyzed a total of 3 reviews, 20 DQ frameworks, and 226 DQ studies and extracted 14 DQ dimensions and 10 assessment methods. We found that completeness, concordance, and correctness/accuracy were commonly assessed. Element presence, validity check, and conformance were commonly used DQ assessment methods and were the main focuses of the PCORnet data checks.DiscussionDefinitions of DQ dimensions and methods were not consistent in the literature, and the DQ assessment practice was not evenly distributed (eg, usability and ease-of-use were rarely discussed). Challenges in DQ assessments, given the complex and heterogeneous nature of real-world data, exist.ConclusionThe practice of DQ assessment is still limited in scope. Future work is warranted to generate understandable, executable, and reusable DQ measures.  相似文献   
14.
目的 通过与传统诊断方法的对比分析,探讨髂耻足三联试验在骶髂关节功能障碍诊断中的效果及临床意义。方法 选择2018年6月至2019年3月门诊骶髂关节功能障碍患者(病例组)30例和正常对照组30例,分别采用髂耻足三联试验和传统诊断方法进行骶髂关节功能障碍相关检查,最后以骶髂关节注射术来确定诊断。对比两种诊断方法对骶髂关节功能障碍诊断的敏感度、特异度、受试者工作特征曲线(receiver operating characteristic,ROC)曲线下面积以及敏感度差异。结果 病例组患者和对照组受试者比较,性别(χ2=0.287,P=0.592)、年龄(t=0.400,P=0.691)差异无统计学意义。传统方法诊断骶髂关节功能障碍的敏感度为33.3%,特异度96.7%,ROC曲线下面积为0.650(P=0.046);髂耻足三联试验诊断骶髂关节功能障碍的敏感性为76.7%,特异性为96.7%,ROC曲线下面积为0.867(P<0.001)。两种诊断方法的诊断敏感度差异有统计学意义(χ2=11.38,P=0.001)。结论 骶髂关节功能障碍的髂耻足三联试验,具有更高的诊断敏感性,对于怀疑骶髂关节功能障碍的腰腿痛患者应进行全面的专科体格检查,早期诊断,避免漏诊,降低腰椎术后失败综合征的发生风险。  相似文献   
15.
16.
Chen  Kaiwen  Nie  Cong  Song  Huan  Zhu  Yu  Lyu  Feizhou  Jiang  Jianyuan  Zheng  Chaojun 《European spine journal》2023,32(2):608-616
Purpose

To investigate the impact of early versus delayed surgery on sensory abnormalities in acute traumatic central cord syndrome (ATCCS).

Methods

Pressure pain threshold (PPT), temporal summation (TS), conditioned pain modulation (CPM) and pain assessments were performed in 72 ATCCS patients (early vs. delayed surgical treatment: 32 vs. 40) and 72 healthy subjects in this ambispective cohort study. These examinations, along with mechanical detection threshold (MDT) and disabilities of arm, shoulder and hand (DASH), were assessed at 2 years postoperatively.

Results

Preoperatively, more delayed surgical patients had neuropathic pain below level compared with early surgical patients (P < 0.05). Both early and delayed surgical patients showed reduced PPT in common painful areas and increased TS, while reduced CPM only existed in the latter (P < 0.05). Reduced PPT in all tested areas, along with abnormalities in TS and CPM, was observed in patients with durations over 3 months. Both incidences and intensities of pain and pain sensitivities in common painful areas were reduced in both treatment groups postoperatively, but only early surgical treatment improved the CPM and TS. Follow-up analysis demonstrated a higher MDT and lower PPT in hand, greater TS, greater DASH, lower pain intensities and higher incidence of dissatisfaction involving sensory symptoms in delayed surgical patients than in early surgical patients (P < 0.05).

Conclusions

Central hypersensitivity may be involved in the persistence of sensory symptoms in ATCCS, and this augmented central processing may commence in the early stage. Early surgical treatment may reverse dysfunction of endogenous pain modulation, thus reducing the risk of central sensitization and alleviating sensory symptoms.

  相似文献   
17.
Lyu RK  Chen CJ  Tang LM  Chen ST 《Neurosurgery》2002,51(2):509-12; discussion 512
OBJECTIVE AND IMPORTANCE: We describe a case of a posterior spinal epidural abscess that was successfully treated with percutaneous, computed tomography-guided, needle aspiration and parenteral antibiotic therapy. CLINICAL PRESENTATION: A 48-year-old man experienced acute pain in the paralumbar region for 1 week, followed by gait disturbance and micturition difficulty. Laboratory studies demonstrated leukocytosis and hyperglycemia. Blood cultures yielded Staphylococcus aureus. Magnetic resonance imaging scans of the thoracolumbar spine revealed a posterior spinal epidural abscess located between L2 and the lower cervical spine. INTERVENTION: The patient's low back pain persisted despite 10 days of antibiotic therapy. Therefore, percutaneous, computed tomography-guided, needle aspiration was performed. The low back pain was relieved dramatically and immediately after the procedure. The spinal epidural abscess completely resolved after 6 weeks of antibiotic treatment. CONCLUSION: Surgical decompression and antibiotic therapy are the treatments of choice for patients with spinal epidural abscesses. Selected patients may be treated nonsurgically. Rarely, percutaneous drainage of the abscess has been reported to be helpful. Our case suggests that percutaneous, computed tomography-guided, needle aspiration might be a rational alternative to surgical decompression for treatment of spinal epidural abscesses.  相似文献   
18.
正Rh(D)阴性血型较为罕见,仅占我国汉族人群的0. 2%~0. 4%~([1])。因此,Rh(D)阴性供者、血源非常稀缺,对这类血型患者施行肝移植将面对巨大的免疫风险~([2-3])。肝移植是目前治疗终末期肝病及肝脏恶性肿瘤最有效的方式,很多器官移植中心都报道过ABO血型不合肝移植术,但Rh(D)血型不合且成功实施器官移植的报道并不多见。  相似文献   
19.
目的探讨经后路椎体次全切治疗胸腰段椎体成形术椎再骨折的疗效。方法回顾性分析2017年6月至2019年10月河南省人民医院脊柱外科收治的28例胸腰段椎体成形术椎再骨折患者资料。男7例,女21例;年龄61~76岁,平均62.4岁;骨折椎体:T115例,T129例,L111例,L23例;既往手术方法:经皮椎体成形术治疗17例,经皮椎体后凸成形术治疗11例。手术方法:后路切除棘突、椎板,经侧方切除关节突、横突,部分切除椎体、骨水泥及上下椎间盘,神经减压,椎体间人工椎体固定,后路钉棒矫形固定。记录手术时间及术中出血量,比较患者术前和末次随访时后凸cobb角评价矫形效果;比较患者术前和末次随访时疼痛视觉模拟评分(VAS)、日本骨科协会(JOA)评分评价脊柱功能改善情况。结果本组患者手术时间平均为182.1 min,术中出血量平均为996.2 mL。28例患者术后随访8~29个月(平均19.8个月),无明显神经功能损伤及其他严重并发症发生。cobb角由术前的41.3°±10.3°改善为末次随访时的6.4°±2.5°,VAS评分由术前的(7.3±1.8)分改善为末次随访时的(2.5±1.0)分,JOA评分由术前的(8.4±2.3)分改善为末次随访时的(21.3±2.5)分,以上比较差异均有统计学意义(P<0.05)。结论经后路椎体次全切治疗胸腰段椎体成形术椎再骨折,可一期进行骨水泥清除、椎管减压、椎间植骨融合,重建脊柱稳定性,有很好的疗效。  相似文献   
20.
C J Chen  R K Lyu  S T Lee  Y C Wong  L J Wang 《Radiology》2001,221(3):789-794
PURPOSE: To examine whether the different appearances of intramedullary high signal intensity (SI) on T2-weighted MR images in cervical spondylotic myelopathy are related to differences in surgical prognosis. MATERIALS AND METHODS: The magnetic resonance (MR) findings and Japanese Orthopedic Association (JOA) score of 64 cervical spondylotic myelopathy patients, who underwent decompression surgery, were evaluated. SIs were classified as type 0 if no intramedullary high SI on T2-weighted MR images was noted, type 1 if a predominantly (>50%) faint and fuzzy border of high SI was noted, or type 2 if a predominantly (>50%) intense and well-defined border of high SI was noted. Postoperative JOA scoring and MR imaging were also performed 6 months after surgery. Recovery ratios were calculated. RESULTS: There were 20 type 0, 23 type 1, and 21 type 2 cases. Statistical analyses showed no significant difference in age, sex, cervical curvature, and preoperative JOA score between the three groups. Statistical analyses of the recovery ratio showed significantly poor prognosis of type 2 compared with type 1 (P < .001) and type 0 (P =.001), but no difference between types 0 and 1 (P = .317). After controlling for factors of age, sex, preoperative JOA score, cervical curvature, and cord compression ratio, analysis of covariance showed the same result. CONCLUSION: Type 1 intramedullary high SI on T2-weighted MR images indicates a better surgical outcome than does type 2.  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