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   8781篇
  免费   437篇
  国内免费   41篇
耳鼻咽喉   85篇
儿科学   180篇
妇产科学   120篇
基础医学   1210篇
口腔科学   214篇
临床医学   962篇
内科学   2073篇
皮肤病学   222篇
神经病学   782篇
特种医学   378篇
外科学   1289篇
综合类   75篇
一般理论   2篇
预防医学   528篇
眼科学   82篇
药学   606篇
中国医学   7篇
肿瘤学   444篇
  2023年   45篇
  2022年   68篇
  2021年   135篇
  2020年   104篇
  2019年   160篇
  2018年   217篇
  2017年   170篇
  2016年   200篇
  2015年   163篇
  2014年   248篇
  2013年   372篇
  2012年   513篇
  2011年   527篇
  2010年   336篇
  2009年   294篇
  2008年   468篇
  2007年   528篇
  2006年   499篇
  2005年   474篇
  2004年   427篇
  2003年   431篇
  2002年   385篇
  2001年   154篇
  2000年   154篇
  1999年   145篇
  1998年   98篇
  1997年   82篇
  1996年   70篇
  1995年   52篇
  1994年   71篇
  1993年   52篇
  1992年   97篇
  1991年   95篇
  1990年   90篇
  1989年   82篇
  1988年   80篇
  1987年   76篇
  1986年   62篇
  1985年   74篇
  1984年   77篇
  1983年   56篇
  1982年   54篇
  1981年   44篇
  1980年   40篇
  1979年   47篇
  1978年   60篇
  1977年   44篇
  1975年   34篇
  1974年   29篇
  1972年   28篇
排序方式: 共有9259条查询结果,搜索用时 15 毫秒
101.
Complications of plate fixation in metacarpal fractures   总被引:6,自引:0,他引:6  
BACKGROUND: The objective of this study is to assess the complications after open reduction and plate fixation of extra-articular metacarpal fractures. METHODS: We retrospectively reviewed the clinical and radiologic records of 129 consecutive patients with 157 metacarpal fractures treated by open reduction and internal fixation with plates between 1993 and 1999. Intra-articular fractures and fractures of the thumb metacarpal were excluded. Eighty-one patients (64 men and 17 women) with 104 fractures were available for review, at an average follow-up of 13.6 months (range, 6-27 months). RESULTS: Twenty-eight patients (35%) and 33 fractures (32%) had one or more complications, including difficulty with fracture healing (12 patients [15%]), stiffness (eight patients [10%]), plate loosening or breakage (seven patients [8%]), complex regional pain syndrome (two patients), and one patient who developed a deep infection. CONCLUSION: Despite technical advances in implant material, design, and instrumentation, plate fixation of metacarpal fractures remains fraught with complications and unsatisfactory results.  相似文献   
102.
Examination is a cornerstone in the manual procedures leading to mobilisation/manipulation of the low back. The observer variation of the more specific segmental tests remains to be investigated. Two skilled specialists in manual medicine examined the segmental changes in the lumbar spine. The patients were unknown to the examiners and no information of the case history was given. All test results were recorded by an observer present in the room who ensured that no conversation was allowed during the examination. The primary outcome measures were the kappa values for each test. The matching was defined as acceptable (acc) within two neighbouring levels and perfect (per) on the same level. Intra-observer variation (tested in 33 patients and 10 subjects without low-back pain): The agreement between first and second segmental diagnosis examination was 70% (per) and 82% (per + acc). Kappa values were: segmental diagnosis 0.60 (per) and 0.70 (per + acc), multifidus test 0.51 (per) and 0.60 (per + acc), sideflexion 0.57 (per) and 0.69 (per + acc), and ventral flexion 0.31 (per) and 0.45 (per + acc). Inter-observer variation (tested in 60 patients): The agreement for segmental diagnosis between the examiner A and B was 42% (per) and 75% (per + acc). Kappa values were: segmental diagnosis 0.21 (per) and 0.57 (acc), multifidus test 0.12 (per) and 0.48 (acc), sideflexion 0.22 (per) and 0.45 (acc), and ventralflexion 0.22 (per) and 0.44 (acc). By manual tests, skilled examiners seem to be able to diagnose segmental dysfunctions in the low back. The clinical implication of these dysfunctions remains to be clarified.  相似文献   
103.
BACKGROUND: Operative treatment of stage II posterior tibial tendon insufficiency (PTTI) is controversial. Many soft-tissue and bony procedures and various combinations of the two have been reported for treatment of stage II PTTI. Orthopaedists recognize the lateral column lengthening component of the procedure as a successful reconstructive technique. The use of cortical allograft for lateral column lengthening in the correction of pes planus in the pediatric patient population has been routine. In the adult population, however, tricortical iliac crest autograft has been the bone graft of choice. Harvest of this autograft can precipitate significant morbidity and cost. Therefore, we undertook this randomized controlled trial to compare graft incorporation and healing of allograft and autograft in the lateral column lengthening component of adult flatfoot reconstruction. METHODS: Lateral column lengthening was done as a component of operative correction for stage II PTTI in adult patients (older than 18 years) by two surgeons using similar procedures. The patients were randomized to either the allograft or autograft procedures. The primary endpoint was graft incorporation and healing as assessed by radiographs. RESULTS: The study included 33 randomized feet in 31 patients. We followed 18 feet in the allograft group and 15 in the autograft group to the point of union. There were 21 women and 10 men. There were no delayed unions, nonunions, or hardware failures. All patients in both groups achieved bony union by the 12-week followup evaluation. Two superficial foot infections were successfully treated with oral antibiotics. Two patients in the autograft group continued to have hip donor site pain at 3 months. CONCLUSIONS: This study suggests that union rates of allograft and autograft (iliac crest bone graft) are equal. The use of allograft in the lateral column lengthening component of operative correction of adult stage II PTTI appears to be a viable alternative to the use of iliac crest autograft and eliminates the morbidity and increased cost associated with autograft harvest.  相似文献   
104.

Background  

Rheumatoid arthritis (RA) is a chronic, inflammatory and systemic disease which affects the musculoskeletal system. Exercise programmes are reported to improve physical functioning in patients with RA. Tai Chi is a traditional Chinese martial art which combines slow and gentle movements with mental focus. The purpose of this study was to study in which way Tai Chi group exercise impacted on disease activity, physical function, health status and experience in RA patients, applying quantitative and qualitative methods.  相似文献   
105.
106.
Full‐thickness 5 mm punch biopsy wounds were made lateral to the sacrum in 48 smokers and 30 never smokers. After 1 week, the wounds were excised and fixed. The smokers were then randomized to continuous smoking or abstinence with a transdermal nicotine patch or a placebo patch. The sequence of wounding and excision was repeated after 4, 8, and 12 weeks. All excised tissue was stained with hematoxylin–eosin and immunohistochemically for macrophages (CD68), procollagen 1 N‐terminal propeptide (PINP) in fibroblasts, and endothelial cells (CD31). The cellularity was assessed and scored by two independent histopathologists, and for the analysis, proportional odds models and random effect models for repeated measurements were applied. Macrophages and PINP‐stained fibroblasts were reduced in the smokers' wounds (0.28 [0.14–0.58] [OR, 95%CI]; p=0.01 and 0.37[0.19–0.70]; p<0.01, respectively, when compared with never smokers' wounds). Inflammation scores were marginally affected. Following smoking cessation, inflammatory cell infiltration and macrophages in the wounds increased. PINP‐stained fibroblasts were unaffected. Neovascularization was not affected by smoking or abstinence. Wound inflammation and fibroblast proliferation were attenuated in smokers, suggesting delayed healing. Abstinence from smoking restores inflammation, but does not affect proliferation. These findings suggest a pathophysiologic mechanism for postoperative wound infection and dehiscence in smokers and why smoking cessation appears to reduce wound infection but not dehiscence.  相似文献   
107.
The normal development of tibial torsion   总被引:2,自引:1,他引:2  
Objective: Pathological rotation of the leg is a well-known problem in paediatric orthopaedics. In this study the normal development of tibial torsion during growth was evaluated by computed tomography (CT). Design: Seventy-eight normal individuals (52 children, 26 adults) aged 3–51 years were examined with CT. In axial scans the angle between a line tangential to the posterior part of the femoral condyles and the intermalleolar line, a line through the centre of the lateral and medial malleolus, was measured. The radiation exposure was evaluated and accepted by The National Department for Radiation and the Regional Committee for Ethics in Science. Results: CT showed that the average lateral torsion of the leg at the age of 4 years was 28° with an individual variation of 20°–37°. Later the increase in tibial torsion was on average 1°/year until 10 years of age and, thereafter, 4° until maturity when the mean lateral torsion was 38° (18°–47°). Conclusion: Tibial torsion in children mainly develops during the first 4 years of life. After this the increase was of less clinical significance. Received: 13 November 2000 Revision requested: 26 February 2001 Revision received: 19 March 2001 Accepted: 18 April 2001  相似文献   
108.
Between 1979 and 1998, 152 patients with a soft-tissue sarcoma arising in the thigh were surgically treated in the Sarcoma Center in Aarhus, Denmark. We studied clinicopathologic factors prognostic for local recurrence and survival. 27 patients (18%) had a low-grade tumor, 26 (17%) an intermediate-grade and 99 (65%) a high-grade tumor.

27 patients (18%) were amputated and 125 (82%) had a local resection. 21 (14%) underwent a marginal resection, 82 (54%) a wide resection and 49 (32%) a compartmental resection. 32 patients were also given radiotherapy, 11 of these had a marginal resection.

The 5-year local recurrence-free rate was 91%. Multivariate analysis selected marginal resection and histological high grade as unfavorable prognostic factors for local recurrence. The 5-year survival rate was 68%. High age and histological high grade were unfavorable prognostic factors for survival in a multivariate analysis. Surgical margin influenced local recurrence, but not the overall survival.  相似文献   
109.
Genetic testing for RET germline mutations affords rapid identification of germline carriers, offering the prospect of cure before C-cell hyperplasia (CCH) has progressed to medullary thyroid carcinoma (MTC). Although nonindex RET mutation carriers have a better prognosis than do the index patients, it remains to be ascertained whether age represents a risk factor for MTC when screening patients. The current institutional study (October 1994 through June 1999) was set up to compare asymptomatic nonindex patients who were grouped by age: < 20 years and ≥ 20 years. Inclusion criteria were confirmed RET mutations in the germline, with no MTC being more advanced than pT1pN1M0. Adult patients (≥ 20 years) had MTC significantly more often (84% vs. 43%), significantly larger tumors (5 mm vs. 3 mm), and significantly higher basal calcitonin levels preoperatively (78.0 vs. 9.7 pg/ml) than their pediatric/adolescent counterparts (< 20 years). There was a close correlation between pT1 MTC and an elevated basal serum calcitonin level (r= 0.67; Spearman's rho). All three patients with lymph node metastases from MTC had elevated basal calcitonin levels. The two groups did not differ in terms of multifocality of MTC (pT1b), lymph node involvement (pN1) or bilateral lymph node metastasis (pN1b), or preoperative stimulated and postoperative basal and stimulated serum calcitonin. Prophylactic thyroidectomy should not be postponed beyond the age of 20, and it should be performed before basal serum calcitonin has turned positive. Pathologic conversion of stimulated serum calcitonin obviously marks the time in carriers of RET germline mutations when surgery should be scheduled at the latest to be prophylactic.  相似文献   
110.
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