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   14216篇
  免费   653篇
  国内免费   235篇
耳鼻咽喉   265篇
儿科学   206篇
妇产科学   121篇
基础医学   1488篇
口腔科学   377篇
临床医学   1371篇
内科学   1230篇
皮肤病学   27篇
神经病学   1051篇
特种医学   1477篇
外科学   4232篇
综合类   1391篇
预防医学   233篇
眼科学   654篇
药学   579篇
  5篇
中国医学   109篇
肿瘤学   288篇
  2024年   10篇
  2023年   282篇
  2022年   426篇
  2021年   585篇
  2020年   518篇
  2019年   429篇
  2018年   514篇
  2017年   462篇
  2016年   466篇
  2015年   420篇
  2014年   870篇
  2013年   915篇
  2012年   722篇
  2011年   842篇
  2010年   637篇
  2009年   779篇
  2008年   801篇
  2007年   734篇
  2006年   617篇
  2005年   492篇
  2004年   423篇
  2003年   383篇
  2002年   247篇
  2001年   276篇
  2000年   221篇
  1999年   238篇
  1998年   196篇
  1997年   181篇
  1996年   157篇
  1995年   151篇
  1994年   144篇
  1993年   99篇
  1992年   116篇
  1991年   72篇
  1990年   67篇
  1989年   79篇
  1988年   63篇
  1987年   52篇
  1986年   64篇
  1985年   55篇
  1984年   56篇
  1983年   27篇
  1982年   37篇
  1981年   33篇
  1980年   33篇
  1979年   24篇
  1978年   21篇
  1977年   25篇
  1976年   17篇
  1973年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
目的:比较关节镜双后内入路与切开手术治疗急性单纯后交叉韧带胫骨止点撕脱骨折的疗效差异。方法:回顾性分析2016年6月至2020年6月经手术治疗的52例急性单纯性后交叉韧带胫骨止点撕脱骨折患者的临床资料,按手术方案不同分为两组,关节镜组27例患者行关节镜双后内入路手术治疗,其中男16例,女11例,年龄19~52(34.9±9.2)岁;切开复位组25例患者行膝关节后内侧切口手术治疗,其中男14例,女11例,年龄18~54(33.7±8.4)岁。观察并比较两组患者手术时间、切口长度、术中出血量、住院时间、住院费用、术后愈合情况、并发症以及术后12个月Lysholm、IKDC评分。结果:两组患者均顺利完成手术,无血管、神经损伤。52例均获得随访,时间6~24(15.0±1.7)个月。关节镜组手术时间、住院费用大于切开复位组(P<0.05);关节镜组术中出血量、切口长度、住院时间小于切开复位组(P<0.05);关节镜组和切开复位组术后12个月Lysholm评分分别为(95.9±1.7)分和(86.4±1.2)分,均较术前的(49.1±2.3)分和(48.9±1.1)分显著提高(P<0.05);关节镜组和切开复位组术后12个月IKDC总分分别为(96.9±1.5)分和(87.1±1.4)分,均较术前的(47.6±4.1)分和(48.1±3.9)分显著提高(P<0.05);关节镜组术后12个月膝关节Lysholm、IKDC评分均高于切开复位组(P<0.05)。结论:关节镜双后内入路治疗急性单纯后交叉韧带胫骨止点撕脱骨折,早期效果满意,疗效优于传统开放手术,具有创伤小、恢复快、操作简便等优点。  相似文献   
3.
PurposeTo test the following hypotheses: (a) balloon or stent assistance increases coil packing density (CPD) in the endovascular treatment of intracranial aneurysms, and (b) CPD correlates to ostium area (OA) and aneurysm volume (AV).Materials and MethodsThis retrospective study included 60 aneurysms (54 ruptured and 6 unruptured) treated with simple coiling (SC) (n = 18), balloon-assisted coiling (BAC) (n = 7), or stent-assisted coiling (SAC) (n = 35) at the authors’ institution between August 2017 and December 2019. AV and OA measurements were obtained from 3-dimensional digital subtraction angiography images using commercial software. Coil sizes were retrieved from patient files, and coil volume (CV) measurements were obtained from https://www.angiocalc.com/. Analysis of covariance, multivariate covariance analysis, and Pearson correlation analyses were performed.ResultsThe median value for AV, CV, CPD, and OA was 63.4 mm3 (range, 5.5–1,771.4 mm3), 23.13 mm3 (range, 2.03–296.95 mm3), 33.29% (range, 13.41%–81.02%), and 10.7 mm2 (range, 2.7–49.9 mm2), respectively. Multivariate analysis showed that the CPD values were not significantly different among the treatment groups, although OA significantly differed between the SC and SAC groups (P < .05). Pearson correlations showed that similar to AV, OA was negatively correlated with CPD (r = ?0.321, P < .05).ConclusionsThe CPD value in cerebral aneurysms treated with BAC or SAC did not differ from that in aneurysms treated with SC.  相似文献   
4.
PurposeTo evaluate in vivo parameters as biomarkers of limbal stem cell function and to establish an objective system that detects and stage limbal stem cell deficiency (LSCD).MethodsA total of 126 patients (172 eyes) with LSCD and 67 normal subjects (99 eyes) were included in this observational cross-sectional comparative study. Slit-lamp biomicroscopy, in vivo laser scanning confocal microscopy (IVCM), and anterior segment optical coherence tomography (AS-OCT) were performed to obtain the following: clinical score, cell morphology score, basal cell density (BCD), central corneal epithelial thickness (CET), limbal epithelial thickness (LET), total corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), and tortuosity coefficient. Their potential correlations with the severity of LSCD were investigated, and cutoff values were determined.ResultsAn increase clinical score correlated with a decrease in central cornea BCD, limbal BCD, CET, mean LET, maximum LET, CNFL, CNFD, CNBD, and tortuosity coefficient. Regression analyses showed that central cornea BCD, CET and CNFL were the best parameters to differentiate LSCD from normal eyes (Coef = 3.123, 3.379, and 2.223; all p < 0.05). The rank correlation analysis showed a similar outcome between the clinical scores and the central cornea BCD (ρ = 0.79), CET (ρ = 0.82), and CNFL (ρ = 0.71). A comprehensive LSCD grading formula based on a combination of these parameters was established.ConclusionsA comprehensive staging system combining clinical presentation, central cornea BCD, CET, and CNFL is established to accurately and objectively diagnose LSCD and stage its severity.  相似文献   
5.
6.
BackgroundAfter anterior cruciate ligament reconstruction (ACLR), the decision to allow a return to running is empirical, and the post-operative delay is the most-used criterion. The Quadriceps isokinetic-strength Limb Symmetry Index (Quadriceps LSI), with a cutoff of 60%, could be a useful criterion.ObjectiveTo determine the association between a Quadriceps LSI  60% and return to running after ACLR.MethodsOver a 10-year period, we retrospectively included 470 patients who underwent ACLR. Four months after ACLR, participants performed an isokinetic test; quadriceps concentric peak torque was used to calculate the Quadriceps LSI at 60?/s. With a Quadriceps LSI  60%, a return to running was suggested. At 6 months after ACLR, participants were clinically evaluated for a return to sport and post-operative middle-term complications. A multivariable predictive model was built to assess the efficiency diagnosis of this cutoff in order to consider cofounding factors. Quadriceps LSI cutoff  60% was assessed with sensitivity, specificity and the area under the receiver operating characteristic curve (AUC).ResultsAccording to our decision-making process with the 60% Quadriceps LSI cutoff at 60?/s, 285 patients were authorized to return to running at 4 months after ACLR and 185 were not, but 21% (n = 59) and 24% (n = 45), respectively, were not compliant with the recommendation. No iterative autograft rupture or meniscus pathology occurred at 6 months of follow-up. On multivariable logistic regression analysis, a return to running by using the 60% Quadriceps LSI cutoff was associated with undergoing the hamstring strand procedure (odds ratio 2.60, 95% confidence interval [CI] 1.75–3.84; P < 0.0001) and the absence of knee complications (1.18, 1.07–1.29; P = 0.001) at 4 months. The sensitivity and specificity of the 60% Quadriceps LSI cutoff were 83% and 70%, respectively. The AUC was 0.840 (95% CI 0.803–0.877).ConclusionsUsing the 60% cutoff of the isokinetic Quadriceps LSI at 4 months after ACLR could help in the decision to allow a return to running.  相似文献   
7.
BackgroundAnterior cruciate ligament (ACL) reconstruction is recommended in patients who intend to return to high-level sports. However, there is only a 55–80% return to pre-injury level of sports after ACL reconstruction, with a re-injury rate up to 20%. The aim of this study was to determine the percentage of patients passing the Back in Action (BIA) test 9 months after primary bone-patellar-tendon-bone (BPTB) ACL reconstruction, and evaluate the association between passing the BIA test and patient reported outcome measurements (PROMs).MethodsPatients underwent the BIA test 9 months after BPTB ACL reconstruction. In total 103 patients were included. Passing the BIA test (PASSED-group) was defined as a normal or higher score at all sub-tests with limb symmetry index (LSI) ≥90% for the dominant leg and LSI >80% for the non-dominant leg. Patients who did not meet these criteria were defined as the FAILED-group. PROMs included the International Knee Documentation Committee, Knee injury Osteoarthritis Outcome Score and Anterior Cruciate Ligament-Return to Sport after Injury.ResultsEighteen patients (17.5%) passed the BIA test 9 months after BPTB ACL reconstruction. PROMs were not statistically significant different between the PASSED- and FAILED-group.ConclusionLow percentage of patients passed the BIA test 9 months after BPTB ACL reconstruction. Although current PROMs cut-off values were met, the BIA test results show persistent functional deficits. Therefore, the BIA test could be of additional value in the decision-making process regarding return to sport (RTS). This study highlights the need for additional rehabilitation as RTS in a condition of incomplete recovery may increase the risk of re-injury.Level of evidenceII.  相似文献   
8.
ObjectivesAnalyse changes in knee laxity between 3, 6, 12 and 24 months after non-surgically treated ACL injury and to analyse associations between knee laxity and knee function, self-reported knee stability, ACL-Return to Sport after Injury (ACL-RSI), fear and confidence at different timepoints during recovery.DesignProspective cohort study.Participants125 patients (67 males, mean age 25.0 ± 7.0 years) with acute ACL injury.Main outcomeLaxity was measured using KT-1000 arthrometer. Self-reported knee function was assessed using the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF). Confidence and fear were assessed with questions from the ACL-RSI scale. Subjectively knee stability was assessed using SANE.ResultsKnee laxity increased bilaterally from 3 to 12 months, and in the non-involved knee from 3 to 24 months (p˂0.05), although mean change was below 1 mm. Side-to-side difference in knee laxity was correlated with IKDC-SKF (r = −0.283) and knee stability in rehabilitation/sport activities (r = −0.315) at 6 months, but not with confidence/fear.ConclusionKnee laxity increased bilaterally during the first year after non-surgically treated ACL injury, though, the mean change in knee laxity was below 1 mm and the clinical significance is unknown. Knee laxity was weakly associated with knee function and perceived knee stability.Level of evidenceLevel IITrial registrationNCT02931084  相似文献   
9.

Introduction

Left ventricular (LV) dysfunction is estimated to occur in 10%–25% of the general intensive care unit (ICU) population and is frequently seen as regional wall motion abnormalities (RWMAs). Although RWMA is mostly attributed to myocardial ischemia or infarction, some studies have suggested that nonischemic RWMA might also be prevalent. We sought to establish that RWMA can be seen in critically ill patients with normal coronary arteries and to explore reasons for RWMA in this population.

Methods

In this retrospective study, data from the hospital angiography register and the ICU register were collated between 2012 and 2019. Patients were identified who underwent angiography in conjunction with their ICU stay and had RWMA on echocardiography. Patients were divided into either those with non-obstructed or those with obstructed coronary arteries. Cardiac magnetic resonance imaging (cMRI) examinations were reviewed if they had been performed on patients with non-obstructed coronaries.

Results

We identified 53 patients with RWMA and non-obstructed coronary arteries and 204 patients with RWMA and obstructed coronary arteries. Patients with non-obstructed coronary arteries were more often female, younger, and had fewer cardiovascular risk factors. They less commonly had ST elevation, but more frequently had T-wave inversion or serious arrhythmias. Troponin levels were higher in patients with obstructed coronary arteries, but NT-proBNP was similar between the groups. There were no differences in risk-adjusted 90-day mortality between patients with non-obstructed versus obstructed coronary arteries (OR 1.21, [95% CI 0.56–2.64], p = .628). In those with non-obstructed coronary arteries, follow-up echocardiography was available for 38 patients, of whom 30 showed normalization of cardiac function. Of the 14 patients with non-obstructed coronary arteries on whom cMRI was performed, 7 had a tentative diagnosis of Takotsubo syndrome or myocardial stunning; 4 had a myocardial infarction (preexisting in 3 cases); 1 patient had acute myocarditis; 1 patient had post-myocarditis; and 1 patient was diagnosed with dilated cardiomyopathy.

Conclusion

RWMA can be seen to occur in critically ill patients in the absence of coronary artery obstruction. Several conditions can cause regional hypokinesia, and cMRI is useful to evaluate the underlying etiology.  相似文献   
10.
目的分析水痘-带状疱疹病毒(VZV)性角膜葡萄膜炎继发青光眼患者的临床表现,探讨其治疗方案。  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