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   19224篇
  免费   932篇
  国内免费   556篇
耳鼻咽喉   40篇
儿科学   132篇
妇产科学   20篇
基础医学   1207篇
口腔科学   551篇
临床医学   1563篇
内科学   755篇
皮肤病学   21篇
神经病学   403篇
特种医学   1244篇
外科学   9514篇
综合类   2910篇
预防医学   518篇
眼科学   70篇
药学   1068篇
  20篇
中国医学   472篇
肿瘤学   204篇
  2024年   56篇
  2023年   277篇
  2022年   626篇
  2021年   829篇
  2020年   734篇
  2019年   611篇
  2018年   612篇
  2017年   709篇
  2016年   772篇
  2015年   704篇
  2014年   1669篇
  2013年   1525篇
  2012年   1395篇
  2011年   1471篇
  2010年   1143篇
  2009年   1160篇
  2008年   890篇
  2007年   937篇
  2006年   834篇
  2005年   764篇
  2004年   550篇
  2003年   415篇
  2002年   344篇
  2001年   262篇
  2000年   223篇
  1999年   185篇
  1998年   124篇
  1997年   95篇
  1996年   87篇
  1995年   69篇
  1994年   75篇
  1993年   64篇
  1992年   55篇
  1991年   45篇
  1990年   42篇
  1989年   30篇
  1988年   36篇
  1987年   31篇
  1986年   23篇
  1985年   27篇
  1984年   25篇
  1983年   23篇
  1982年   36篇
  1981年   29篇
  1980年   22篇
  1979年   16篇
  1978年   18篇
  1977年   9篇
  1976年   16篇
  1975年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
We report on a consanguineous Brazilian couple whose 2 children had tibial aplasia-ectrodactyly. Femoral bifurcation was present in one of the affected children. The relationship of tibial aplasia-ectrodactyly to the Gollop-Wolfgang complex is discussed. Clinical and genetic aspects of the conditions involving tibial aplasia and femoral bifurcation are discussed.  相似文献   
22.
The effects of external and internal tibial rotation on patellar motion were investigated using a magnetic 3Space® tracker system (Polhemus, Colchester, VT 05446, USA). Seven fresh-frozen adult cadaver knees were used in this study. The muscle alignment of each quadriceps muscle was measured to determine the direction of loading forces. Three loading patterns were used to simulate the unresisted knee extension during sitting, standing from squatting and the stance phase of walking, with different weights applied to each quadriceps muscle at each knee flexion angle. The position of the patella, along with patellar shift, tilt and rotation was measured and compared to external or internal tibial rotation and neutral rotation. In the sitting and squatting simulations the patella showed at the terminal extension of the knee more lateral shift and a more lateral tilt with tibial external rotation than in a neutral position (P < 0.05). In walking simulation, the patella showed more external rotation with external rotation of the tibia than with a neutral one, at the 0, 72 and 90% of the stance phase of walking (P < 0.05). These results demonstrate the importance of external tibial rotation as a factor in the development of patellar dislocations or subluxations, especially in athletes.  相似文献   
23.
The effectiveness of external fixation in the stabilisation of pelvic ring fractures was studied in a laboratory cadaveric series. Shearing displacements occurring at sacroiliac joint and symphysis pubis dislocation sites, due to simplified longitudinal loading of the sacrum in an Instron unit, were monitored using variable-impedence transducers. The rigidity of fixation was compared for the Slätis and the Bonnel single anterior frames, for coupled and uncoupled double anterior frames, and for combined anterior-plus-posterior fixation achieved with separate transfixation pin clusters, with through-and-through pin clusters, or with a posterior screw plate. The data showed that the use of posterior fixation provided greatly enhanced stabilisation compared to that achieved with anterior fixation alone. The complex double anterior frames performed only slightly better than did the simpler single anterior frames. In no case, however, was it possible to recover rigidity levels approaching those of the intact pelvis. The results suggest that the transfixation pin arrangement is the most important determinant of pelvic fixation stability, and that further investigation of posterior screw-plate fixation is warranted.  相似文献   
24.
25.
IntroductionThe repair of a deltoid ligament injury, following an ankle fracture with involvement of the syndesmosis, has no univocal consensus. Also the surgical strategies in case of a subsequent chronic instability are still under debate. In this work the result of a double bundle anatomic reconstruction of deltoid ligament with ipsilateral autologous gracilis muscle tendon is presented.Case reportA 50 year old active male patient came to our attention with a catastrophic medial ankle instability, a severe pronation of the hindfoot and disabling ankle pain. He reported a Weber type B fracture of the left ankle with a lesion of the syndesmosis treated with anatomic plate and screws and a transyndesmotic screw 8 months before. The imaging showed a complete deltoid ligament lesion. Due to the impossibility of a direct repair of the ligament, we performed the reconstruction of the medial ligamentous complex with an autologous gracilis tendon graft. 10 months after the medial ligamentous complex reconstruction, the patient showed an excellent recovery of walking ability, disappearance of pain under load and resumed an active lifestyle.DiscussionThe deltoid ligament has a key role in ankle joint stability and its integrity promotes the recovery after ankle fractures. However, its lesion is often left untreated in the acute setting. The result of a chronic untreated deltoid ligament injury could be extremely disabling and the ligament reconstruction, when an optimal native deltoid ligament repair is not achievable, is the choice to restore ankle function and stability.ConclusionIn the delayed treatment of a deltoid ligament rupture the described double bundle anatomic reconstruction with autologous tendon graft can be an effective and suitable option.  相似文献   
26.
PurposeAssessing surgical accuracy and patient-recorded outcome measures for patients fitted with either the OPTY-LINE intramedullary realignment system or the Tomofix plate for medial opening wedge high tibial osteotomy (HTO).Patients and methodsTwo matched case series of patients with symptomatic medial compartment osteoarthritis without other significant knee pathology. One group comprised of 19 patients receiving the Tomofix plate, whereas another comprised of 12 patients receiving the OPTY-LINE intramedullary nail. Patella-centred long leg alignment radiographs were assessed to calculate surgical accuracy in all cases. Patients completed knee injury osteoarthritis outcome scores (KOOS) and osteotomy surgery patient satisfaction questionnaires pre-operatively and at 24 months post-surgery.ResultsAbsolute surgical accuracy at 2 years post-surgery was a mean 4.2 [standard deviation 3.7] for OPTY-LINE versus 9.2 [SD 7.8] for Tomofix (p = 0.11, Mann–Whitney U test). On average, patients in either the OPTY-LINE or Tomofix cohort reported at least a minimal perceptible clinical improvement—minimum average improvement of 15—for all five KOOS themes. No significant difference in change of KOOS scores over time or patient satisfaction levels were observed between the two cohorts.ConclusionThe OPTY-LINE device for HTO performs to a similar level as the Tomofix device. Surgical accuracy data are promising for OPTY-LINE, but does not seem to readily translate into difference in patient-reported outcomes compared to Tomofix. Even longer follow-up periods, to measure survival rates, and true randomised trials on larger samples can elucidate if there is a benefit for using one device over the other.  相似文献   
27.
28.
29.
PurposeCompletely displaced distal radius fractures in children have been traditionally reduced and immobilized with a cast or pin fixed. Cast immobilization leaving the fracture displaced in the bayonet position has been recently suggested as a non-invasive and effective treatment alternative. This is a pilot comparative study between reduction and no reduction.MethodsWe assessed subjective, functional and radiographic outcome after a minimum 2.5-year follow-up in 12 children under ten years of age who had sustained a completely displaced metaphyseal radius fracture, which had been immobilized leaving the fracture in an overriding position (shortening 3 mm to 9 mm). A total of 12 age-matched patients, whose similar fractures were reduced and pin fixed, were chosen for controls. ResultsAt follow-up none of the 24 patients had visible forearm deformity and the maximal angulation in radiographs was 5° Forearm and wrist movement was restored (< 10° of discrepancy) in all 24 patients. Grip strength ratio was normal in all but three surgically treated patients. All patients had returned to their previous activities. One operatively treated boy who was re-operated on reported of pain (visual analogue scale 2).ConclusionThe results of this study do not demonstrate the superiority of reduction and pin fixation over cast immobilization in the bayonet position of closed overriding distal metaphyseal radius fractures in children under ten years with normal neurovascular findings.Level of evidenceIII  相似文献   
30.
BackgroudCurrent evidence supports the use of cemented hemiarthroplasty for treatment of intracapsular femoral neck fractures since it is associated with a lower risk of implant-related complications. However, many medical centers employ the cementless technique for the frail elderly population because it is faster and has lower cardiovascular risks and perioperative mortality. This observational study reports the outcomes of cementless bipolar hemiarthroplasty for intracapsular femoral neck fractures in patients aged 80 years and older.MethodsA total of 424 patients (female, 77.1%) with a mean age of 86.9 years were operated for intracapsular femoral neck fractures between January 2009 and December 2017. Of those, 66.7% had an American Society of Anaesthesiologists (ASA) score of 3 or more. All operations were performed with the posterolateral surgical approach and all patients received a cementless stem. Intraoperative and perioperative values and in-hospital outcomes were evaluated, and clinical and radiographical follow-up was done at 40 days, 90 days, and when possible between 5 months and 12 months postoperatively. Multivariate analysis was performed to evaluate if there were factors affecting mortality.ResultsThe mean operative time was 50 minutes. There were no deaths intraoperatively. Intraoperative periprosthetic fractures occurred in 2.1% of the cases with 66.7% of them fixed through cerclage wires intraoperatively. The median length of hospitalization was 11 days (interquartile range, 8.75–15) and 2.4% of patients died while in hospital after surgery. Approximately 91.5% of patients presented with perioperative anemia. Only 1.9% of the complications were related to the implant, 62.5% of which were dislocations. More than 90% of patients were ambulatory either autonomously or with support at each follow-up assessment. Age, male sex, and higher ASA score were related to increased mortality.ConclusionsDespite some limitations, this observational study underlines that a cementless femoral stem of modern design can give good clinical outcomes, thus being an appropriate solution especially for the frail elderly.  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