全文获取类型
收费全文 | 4242篇 |
免费 | 302篇 |
国内免费 | 80篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 20篇 |
妇产科学 | 26篇 |
基础医学 | 454篇 |
口腔科学 | 30篇 |
临床医学 | 284篇 |
内科学 | 507篇 |
皮肤病学 | 5篇 |
神经病学 | 203篇 |
特种医学 | 114篇 |
外科学 | 943篇 |
综合类 | 810篇 |
预防医学 | 121篇 |
眼科学 | 614篇 |
药学 | 335篇 |
5篇 | |
中国医学 | 95篇 |
肿瘤学 | 35篇 |
出版年
2024年 | 13篇 |
2023年 | 75篇 |
2022年 | 105篇 |
2021年 | 166篇 |
2020年 | 183篇 |
2019年 | 142篇 |
2018年 | 159篇 |
2017年 | 177篇 |
2016年 | 203篇 |
2015年 | 184篇 |
2014年 | 363篇 |
2013年 | 310篇 |
2012年 | 278篇 |
2011年 | 251篇 |
2010年 | 196篇 |
2009年 | 214篇 |
2008年 | 159篇 |
2007年 | 159篇 |
2006年 | 154篇 |
2005年 | 127篇 |
2004年 | 118篇 |
2003年 | 118篇 |
2002年 | 85篇 |
2001年 | 80篇 |
2000年 | 58篇 |
1999年 | 54篇 |
1998年 | 46篇 |
1997年 | 46篇 |
1996年 | 43篇 |
1995年 | 48篇 |
1994年 | 32篇 |
1993年 | 30篇 |
1992年 | 24篇 |
1991年 | 19篇 |
1990年 | 11篇 |
1989年 | 8篇 |
1988年 | 15篇 |
1987年 | 20篇 |
1986年 | 15篇 |
1985年 | 25篇 |
1984年 | 24篇 |
1983年 | 17篇 |
1982年 | 15篇 |
1981年 | 10篇 |
1980年 | 19篇 |
1979年 | 10篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1969年 | 1篇 |
排序方式: 共有4624条查询结果,搜索用时 26 毫秒
1.
ObjectiveEach pulmonary segment is an anatomical and functional unit. However, it is fundamentally difficult to precisely distinguish every pulmonary segment using the conventional pulmonary intersegmental planes from computed tomography images. Building arteriopulmonary segments is likely to be an effective way to identify pulmonary segments.MethodsThe thoracic computed tomography images of 40 patients were collected. The anatomic structures of interest were extracted in the transverse, sagittal, and coronal planes using the semi-automated segmentation tools provided by Amira software. The intrapulmonary vessels were subsequently segmented and reconstructed. The distributions of the pulmonary arteries, veins, and bronchi were observed. In patients with pulmonary masses, the mass was also reconstructed.ResultsThe three-dimensional reconstructed images showed the branches of the pulmonary artery ramified up to their eighth order covering the entire lung as well as evident intersegmental gaps without pulmonary arteries. The segmental artery was closely accompanied by the segmental bronchi in 486 pulmonary segments (90% of total number of segments). The size and spatial location of the pulmonary mass within a pulmonary segment were also clearly visible.ConclusionsDemarcation of arteriopulmonary segments can be used to precisely distinguish every pulmonary segment and provide its detailed anatomical structure before pulmonary segmentectomy. 相似文献
2.
3.
《Journal of bodywork and movement therapies》2019,23(4):818-824
BackgroundThere is paucity in the literature regarding the role of interoceptive accuracy (IAc) at predicting the effectiveness of osteopathic techniques which increase spinal mobility when directed specifically at the thoracolumbar junction (TLJ).AimsThe study aimed to explore whether a high velocity, low amplitude (HVLA) thrust of the TLJ would increase spinal mobility (measured through Range of Motion; ROM) and change IAc. Also, whether baseline IAc correlated with the post-ROM measures and change in ROM.Method21 asymptomatic participants were allocated into three conditions in a randomised order. These were; (1) a high velocity low amplitude manipulation of the TLJ; (2) sham (basic touch); and (3) a control (laying supine on a plinth). Before and following each intervention, the participants’ spinal ROM was measured using an Acumar digital inclinometer. In addition to this an ECG was used to measure their pre and post condition IAc.ResultsThere were significant increases in ROM for all condition, however, the HVLA thrust led to a significantly greater increase in ROM (p < 0.001) when compared to the control and sham. Baseline IAc was inversely associated with post-ROM but there was no association with change in ROM. The HVLA thrust did not significantly change IAc scores from pre to post intervention. Conclusions. HVLA thrust over the TLJ is a useful intervention for increasing spinal ROM. IAc maybe a useful predictor for intervention effectiveness of this technique and spinal area which could in the future be utilised by osteopaths as part of their diagnostics. 相似文献
4.
Anna C. Rienmüller Sandro M. Krieg Franziska A. Schmidt Elias L. Meyer Bernhard Meyer 《The spine journal》2019,19(1):113-120
Background Context
The concept of dynamic stabilization (DS) of the lumbar spine for treatment of degenerative instability has been introduced almost two decades ago. Dynamic stabilization follows the principle of controlling movement in the coronal plane by providing load transfer of the spinal segment without fusion and, at the same time, reducing side effects such as adjacent segment disease (ASD). So far, only little is known about revision rates after DS due to ASD and screw loosening (SL).Purpose
The present study aimed to evaluate the longitudinal revision rates following dynamic pedicle screw stabilization in the lumbar spine and to determine specific risk factors predictive for ASD, SL, and overall reoperation in a large cohort with considerable follow-up.Design
We carried out a post hoc analysis of a prospectively collected database in a level I spine center.Patients Example
The patient sample comprised 283 (151 female/132 male) consecutive patients suffering from painful degenerative lumbar segmental instability with or without spinal stenosis who underwent DS of the lumbar spine (Ulrich Cosmic, Ulrich Medical, Ulm, Germany) between January 2008 and December 2011.Outcome Measures
Longitudinal reoperation rate and risk factors predictive for revision surgery were evaluated.Methods
We analyzed the longitudinal reoperation rate due to ASD and SL and overall reoperation. Risk factors such as age, gender, body mass index, lumbar lordosis (LL), number of segments, and number of previous surgeries were taken into account. Regular and mixed model logistic regressions were performed to determine risk factors for revision surgery on a patient and on a screw level.Results
The mean age was 65.7±10.2 years (range 31–88). One hundred thirty-two patients were stabilized in 1 segment, 134 in 2 segments, 15 in 3 segments, and 2 patients in 4 segments. Reoperation rate for ASD and SL after 1 year was 7.4 %, after 2 years was 15.0%, and after a mean follow-up of 51.4±15 months was 22.6%. Reasons for revision were SL in 19 cases (6.6%), ASD in 39 cases (13.7%), SL and ASD in 6 cases, hematoma in 2 cases (0.7%), cerebrospinal fluid fistulae in 3 cases (1.1%), infection in 6 cases (2.1%), and implant failure in 1 case (0.4%). The patients' age, the number of stabilized segments, and the number of previous surgeries and postoperative LL had a significant influence on the probability for revision surgery.Conclusions
Reoperation rates after DS of the lumbar spine are comparable with rigid fixations. The younger the patient and the more segments are involved, the lower the LL and the more previous surgeries were found, the higher was the risk of revision. Risk of revision was almost twice as high in men compared with women. We therefore conclude that for clear clinical indication and careful evaluation of preoperative imaging data, DS using the Cosmic system seems to be a possible option. The presented data will help to further tailor indication and patient selection. 相似文献5.
经皮椎弓根技术治疗胸腰椎骨折的临床探讨 总被引:2,自引:0,他引:2
目的:探讨微创经皮椎弓根螺钉内固定手术治疗胸腰椎骨折的可行性及其疗效。方法:20例胸腰椎骨折病例,男13例,女7例;年龄28~65岁,平均48·2岁。其中16例损伤平面以下无神经功能损害、无双下肢和大小便障碍;4例有不同程度的脊髓损伤,按Frankel分级:C级1例,D级3例。在C形臂X线的定位下确定需要固定的椎弓根根部,做4个1·5cm长的切口,固定与复位均在4个小切口内完成。结果:所有病例均获随访,时间9~18个月,平均15个月。术后患者椎体高度均有不同程度恢复,椎体后凸畸形获得不同程度矫正。手术时间约1·5h,出血量约80ml。结论:微创经皮椎弓根螺钉内固定手术操作简便、安全可靠,具有创伤小、出血少、疼痛轻、恢复快、住院时间短等优点。 相似文献
6.
腰椎融合术后邻近节段退变的诊断与治疗 总被引:10,自引:0,他引:10
目的:探讨腰椎融合术后邻近节段退变的特点及再手术治疗的术式与疗效.方法:回顾性分析2002年1月至2004年12月间收治的10例因腰椎管狭窄症或腰椎滑脱症曾行后路减压、植骨及椎弓根内固定术,术后12~132个月(平均41.6个月)出现新的腰腿痛症状的病例.对所有患者进行影像学检查,与术前资料比较,并行手术治疗.结果:X线片显示融合的上方(1个节段7例,2个节段1例)或下方(1个节段2例)邻近节段出现了退变,首次术前及术后上述邻近节段均未见退变征象.8例MRI显示邻近节段出现了新的椎管狭窄,且有明显的神经压迫.采用后路术式,将减压及固定融合范围向邻近退变节段延伸.经7~36个月平均12.1个月的随访,优良率80%.结论:腰椎融合术后邻近节段退变是术后症状复发的原因之一,应仔细鉴别症状复发的原因.对于有明显神经压迫者,再手术治疗仍可取得较好的疗效. 相似文献
7.
8.
本文报告了作者研制的改良哈氏棒治疗胸腰段脊柱不稳定骨折的临床效果。1991年1月~1994年10月,治疗26例,伤椎椎体前缘高度从41.91%,恢复至95.57%,椎体后缘高度从81.03%恢复至100%,后凸畸形(Cobb氏法)从26°恢复至5°,有5例恢复前凸8°~10°,神经功能恢复1.8级(Frankel分级)。作者认为回复生理前凸的纵轴上纵向撑开力,更有助于胸腰段脊柱骨折的解剖复位。 相似文献
9.
Pedicle screw fixation with translaminar facet joint screws for the treatment of thoracolumbar fracture 总被引:4,自引:0,他引:4
Objective:To evaluate the efficacy of Cotrel-Dubeusset (CD) instrumentation combined with translaminar facet joint screw ( TLS ) in the treatment of thoracolumbar fracture. Methods: A total of six L2-L4 spines were used to establish unstable fracture model with three-dimensional range of motion ( ROM ) of the spines measured. Fixation with CD and fixation with CD combined with translaminar facet joint screw were achieved to compare their stability. Thirty cases of thoracolumbar fracture, in whom the anterior edge of vertebral body was compressed to 59% and the posterior edge compressed to 88%, were treated by pedicle screw fixation combined with TLS. Among them, 19 received posterolateral or anterior-posterior bone grafting Results- There was significant difference in ROM between the two techniques except that in extension. In Group CD TLS, ROM was 5.38% lower, lateral bending 4.91% lower and axial rotation 11.85 % lower than those in Group CD respectively. In the clinical group, the average anterior edge restored to 97 % and posterior edge to 98%. The duration of follow-up was 5-24 months (mean, 10 months). The rate of correction loss on the anterior edge was 4.5%. Among the 19 cases of bone grafting, all of them achieved bony fusion (mean fusion time, 4.3 month) with a correction loss rate of 3.4%. Conclusions:In the treatment of thoracolumbar fracture, pedicle screw fixation combined with TLS can strengthen the stability of pedicle screws, especially antirotation stability and enhance fusion rate and reduce correction loss. 相似文献
10.
Jhoji Tanabe Hirohiko Nakazato Hisayoshi Tanabe Hidetoshi Hanasaki Kazuo Kawasaki Daizo Yonemura 《Documenta ophthalmologica. Advances in ophthalmology》1986,63(2):165-171
The spectral response curve (amplitude versus wavelength) of the R2 of the early receptor potential (ERP) was studied in normal, protan, and deutan subjects. The R2 amplitude peaked at 520nm in most normal subjects. The R2 at long wavelengths was smaller than normal in protans and larger than normal in deutans when the maximum amplitudes were normalized to 100% at the peak. The ratio of the R2 amplitude at 460 nm to that at 600 nm clearly differed between protans and deutans. The ERP and the rapid off-response, which is mainly due to the cessation of the late receptor potential, were recorded in the same subjects. The ratio of the sensitivity of the rapid off-response at 500 nm to that at 600 nm was correlated with the ratio of the R2 amplitude at 460 nm to that at 600nm (correlation coefficient, 0.823, p < 0.001). This study, in conjunction with our previous study, indicates that the abnormality is in the outer segments of the cones in protans and deutans. 相似文献