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   1633篇
  免费   114篇
  国内免费   5篇
耳鼻咽喉   6篇
儿科学   89篇
妇产科学   13篇
基础医学   220篇
口腔科学   72篇
临床医学   163篇
内科学   259篇
皮肤病学   12篇
神经病学   288篇
特种医学   203篇
外科学   103篇
综合类   78篇
预防医学   114篇
眼科学   10篇
药学   65篇
中国医学   24篇
肿瘤学   33篇
  2022年   16篇
  2020年   17篇
  2019年   11篇
  2018年   24篇
  2017年   28篇
  2016年   31篇
  2015年   33篇
  2014年   46篇
  2013年   83篇
  2012年   71篇
  2011年   86篇
  2010年   70篇
  2009年   71篇
  2008年   79篇
  2007年   104篇
  2006年   69篇
  2005年   57篇
  2004年   45篇
  2003年   19篇
  2002年   27篇
  2001年   29篇
  2000年   34篇
  1999年   28篇
  1998年   66篇
  1997年   55篇
  1996年   36篇
  1995年   27篇
  1994年   31篇
  1993年   25篇
  1992年   20篇
  1991年   11篇
  1990年   17篇
  1989年   28篇
  1988年   31篇
  1987年   28篇
  1986年   27篇
  1985年   34篇
  1984年   16篇
  1983年   23篇
  1982年   21篇
  1981年   13篇
  1980年   19篇
  1979年   14篇
  1978年   10篇
  1977年   15篇
  1976年   12篇
  1975年   9篇
  1974年   8篇
  1973年   12篇
  1972年   19篇
排序方式: 共有1752条查询结果,搜索用时 15 毫秒
21.
Pediatric obsessive-compulsive disorder (OCD) is a chronic neuropsychiatric condition associated with broad impairments in functioning. This paper outlines current etiological theories of OCD, providing a review of neuroanatomical, neurochemical, neuroimmunological, and cognitive–behavioral explanations. Subsequently, first-line treatment modalities are discussed (serotonin reuptake inhibitors [SRIs] and cognitive–behavioral therapy [CBT] with exposure and response prevention [E/RP]) in the context of recent pharmacological, CBT, and combined trials.  相似文献   
22.
 目的 探讨数字化导航模板辅助全膝关节置换的准确性和可行性。方法 取成年尸体下肢标本 20具,随机分为导航模板组和传统方法组,每组 10具 20个膝关节。导航模板组术前行下肢全长 CT扫描,利用逆向工程软件对 CT数据进行处理,设计与股骨远端和胫骨近端匹配的可定位截骨平面和外旋轴的导航模板,通过快速成型机制作模板实物用于尸体标本的全膝关节置换手术操作。传统方法组按常规全膝关节置换手术操作。术后通过 CT扫描比较两种方法定位的截骨准确性。结果 导航模板与股骨髁和胫骨平台贴合紧密,无明显移动。导航模板组 18个膝关节的股骨远端和胫骨近端截骨面与下肢机械轴垂直,2个膝关节内翻; 17个膝关节后髁截骨面与通髁轴完全平行,3个膝关节有成角。传统方法组 20个膝关节均出现下肢机械轴内外翻,其中 5个膝关节大于 5°; 20个膝关节均出现后髁截骨面与通髁轴成角,其中 10个膝关节大于 3°。结论 导航模板法的股骨远端、胫骨近端和股骨外旋截骨准确性均高于传统手术方法。  相似文献   
23.
经胸乳径路腔镜甲状腺手术180例的临床研究   总被引:1,自引:0,他引:1  
目的探讨经胸乳径路腔镜甲状腺手术技巧及其并发症的防治。方法回顾分析2005年3月至2009年12月经胸乳径路腔镜甲状腺手术180例患者的临床资料。结果本组178例腔镜甲状腺手术顺利完成,2例中转开放手术,其中1例为结节性甲状腺肿,因甲状腺体积大,空间狭小中转开放手术,另1例为原发性甲状腺功能亢进,因粘连严重、创面广泛渗血中转开放手术。全组手术时间70~190 min,平均110 min。术中出血量5~75 ml。术后出现皮肤瘀斑2例,抽搐1例,均于2周后恢复正常。声音嘶哑1例,1个月后恢复正常。住院时间3~6 d,平均4.5 d。结论经胸乳径路腔镜甲状腺手术是一种极富技巧性的手术,甲状旁腺损伤和喉返神经损伤是其严重并发症,规范手术操作能有效减少并发症的发生。  相似文献   
24.
Background Endoscopic ultrasound-guided fine-needle aspiration (EUS FNA) has a high accuracy in the evaluation of mediastinal lesions. The use of a core biopsy needle for EUS guided biopsy (EUS TCB) may further improve the yield of EUS. The aims of this study are to evaluate the safety of EUS TCB in thoracic lesions and to compare the diagnostic accuracy of TCB with FNA and FNA + TCB. Methods A single-center retrospective study. All patients underwent EUS-FNA and TCB. A cytopathologist was not present during the procedure. EUS FNA, TCB and FNA + TCB diagnostic accuracy were compared. Results A total of 48 patients were included. The lesions sampled included 41 lymph nodes (six aorto-pulmonary window, 32 subcarinal, two right paratracheal, one paraesophageal ATS station 8), five lung masses, and two esophageal masses. Twenty-nine patients had malignant disease and 19 had benign disorders. The overall diagnostic accuracy of FNA, TCB and FNA + TCB was 79%, 79% and 98% respectively (p = 0.007). TCB changed the diagnosis in nine cases missed by FNA. EUS TCB was better than FNA for benign diseases (89% vs. 63%, p = 0.04). All eight patients with a prior failed biopsy had a correct diagnosis established by EUS. No patient required mediastinoscopy or thoracoscopy after EUS. Conclusion The combination of TCB and FNA is superior to FNA alone. EUS-guided TCB should be considered in patients with benign disorders of the mediastinum when other modalities fail to yield a diagnosis.  相似文献   
25.

Introduction

The retrojugular approach for carotid endarterectomy (CEA) has been reported to have the advantages of shorter operative time and ease of dissection, especially in high carotid lesions. Controversial opinion exists with regard to its safety and benefits over the conventional antejugular approach.

Methods

A systematic review of electronic information sources was conducted to identify studies comparing outcomes of CEA performed with the retrojugular and antejugular approach. Synthesis of summary statistics was undertaken and fixed or random effects models were applied to combine outcome data.

Findings

A total of 6 studies reporting on a total of 740 CEAs (retrojugular approach: 333 patients; antejugular approach: 407 patients) entered our meta-analysis models. The retrojugular approach was found to be associated with a higher incidence of laryngeal nerve damage (odds ratio [OR]: 3.21, 95% confidence interval [CI]: 1.46–7.07). No significant differences in the incidence of hypoglossal or accessory nerve damage were identified between the retrojugular and antejugular approach groups (OR: 1.09 and 11.51, 95% CI: 0.31–3.80 and 0.59–225.43). Cranial nerve damage persisting during the follow-up period was similar between the groups (OR: 2.96, 95% CI: 0.79–11.13). Perioperative stroke and mortality rates did not differ in patients treated with the retrojugular or antejugular approach (OR: 1.26 and 1.28, 95% CI: 0.31–5.21 and 0.25–6.50).

Conclusions

Currently, there is no conclusive evidence to favour one approach over the other. Proof from a well designed randomised trial would help determine the role and benefits of the retrojugular approach in CEA.  相似文献   
26.
Parkinson’s disease (PD) is the most common age-related movement disorder and characterized by slowly progressive neurodegeneration resulting in motor symptoms, such as bradykinesia, rigidity, tremor and postural instability. Moreover, non-motor symptoms, such as hyposmia, anxiety and depression reduce the quality of life in PD. Motor symptoms are associated with a distinct striatal dopaminergic deficit resulting from axonal dysfunction and neuronal loss in the substantia nigra (SN). Recent progress in stem cell technology allows the optimization of cellular transplantation strategies in order to alleviate the motor deficit, which potentially leads to a reactivation of this therapeutic strategy. Besides neurodegenerative processes impaired adult neurogenesis and consequentially reduced endogenous cellular plasticity may play an important role in PD. This article discusses the notion that non-motor symptoms in PD may partly be explained by reduced adult neurogenesis in the olfactory bulb and hippocampus.  相似文献   
27.
28.
Plow  EF; Marguerie  GA; Ginsberg  MH 《Blood》1985,66(1):26-32
Plasma fibronectin binds in a specific and saturable manner to thrombin- stimulated platelets. gamma-Thrombin stimulated 80% as much fibronectin binding to platelets as alpha-thrombin with conversion of less than or equal to 1% of platelet fibrinogen to fibrin. Afibrinogenemic and normal platelets bound similar quantities of fibronectin in the presence of calcium or magnesium-ethylene glycol tetra-acetic acid (EGTA). These observations indicate that fibronectin can interact with platelets without involvement of fibrin or fibrinogen. Nevertheless, two different effects of fibrin(ogen) on fibronectin binding were observed. First, exogenous fibrinogen inhibited fibronectin binding to thrombin-stimulated platelets. This inhibition was unidirectional, as fibronectin did not inhibit fibrinogen binding to ADP or thrombin- stimulated cells. Second, formaldehyde-fixed cells with surface- associated fibrin bound significant quantities of fibronectin. This interaction required calcium and did not occur on fixed cells with or without surface-bound fibrinogen. A portion of the ligand bound to fixed cells with surface-associated fibrin was modified to form a derivative with a molecular weight identical to that of the fibronectin subunit cross-linked to the alpha-chain of fibrin. This high mol wt derivative was also observed to a variable extent with living cells in the presence of magnesium or calcium but not in the presence of magnesium-EGTA. Thus, fibronectin binds to platelets by at least two mechanisms: (1) a fibrin(ogen)-independent pathway that requires divalent ions and is inhibited by exogenous fibrinogen; and (2) a fibrin-dependent pathway with an absolute calcium requirement. With nonaggregated, thrombin-stimulated platelets, the former pathway appears to predominate.  相似文献   
29.
Our purposes were to determine the incidence of BK viruria, viremia or nephropathy with tacrolimus (FK506) versus cyclosporine (CyA) and whether intensive monitoring and discontinuation of mycophenolate (MMF) or azathioprine (AZA), upon detection of BK viremia, could prevent BK nephropathy. We randomized 200 adult renal transplant recipients to FK506 (n = 134) or CyA (n = 66). Urine and blood were collected weekly for 16 weeks and at months 5, 6, 9 and 12 and analyzed for BK by polymerase chain reaction (PCR). By 1 year, 70 patients (35%) developed viruria and 23 (11.5%) viremia; neither were affected independently by FK506, CyA, MMF or AZA. Viruria was highest with FK506-MMF (46%) and lowest with CyA-MMF (13%), p = 0.005. Viruria >/= 9.5 log(10) copies/mL was associated with a 3-fold increased risk of viremia and a 13-fold increased risk of sustained viremia. After reduction of immunosuppression, viremia resolved in 95%, without increased acute rejection, allograft dysfunction or graft loss. No BK nephropathy was observed. Choice of calcineurin inhibitor or adjuvant immunosuppression, independently, did not affect BK viruria or viremia. Viruria was highest with FK506-MMF and lowest with CyA-MMF. Monitoring and preemptive withdrawal of immunosuppression were associated with resolution of viremia and absence of BK nephropathy without acute rejection or graft loss.  相似文献   
30.
目的 对比分析单纯后路内固定+一期经腰椎间孔病椎间病灶清除(TLIF)与经典的前后联合手术在布氏杆菌性脊柱炎患者中的临床疗效及安全性。 方法 对我院2015年1月至2017年12月收治的93例布病性脊柱炎患者的临床资料进行分析。按手术方式分为观察组(45例)和对照组(48例)。对两组患者的基础数据、临床指标、术前术后各项指标水平以及术后并发症、植骨治愈情况。 结果 观察组与对照组基础数据比较,差异无统计学意义(P>0.05)。观察组患者的手术时间、住院天数、术中出血量及术后下床时间均明显低于对照组(P<0.01)。两组患者术后3个月的ODI、VAS、CRP、ESR及Cobb角均明显低于术前(P<0.05);术后3个月,观察组患者的ODI、VAS、CRP、ESR及Cobb角均明显低于对照组(P<0.05)。观察组术后并发症发生率(4.4%)明显低于对照组(25.0%)(Χ2=7.674,P<0.01)。 结论 TLIF治疗布氏杆菌性脊柱炎患者的临床疗效突出,安全性较好,更有利于患者术后身体的恢复。  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