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   12009篇
  免费   913篇
  国内免费   175篇
耳鼻咽喉   200篇
儿科学   217篇
妇产科学   169篇
基础医学   2090篇
口腔科学   120篇
临床医学   1119篇
内科学   2298篇
皮肤病学   714篇
神经病学   858篇
特种医学   855篇
外科学   1201篇
综合类   51篇
现状与发展   1篇
一般理论   2篇
预防医学   500篇
眼科学   312篇
药学   1175篇
中国医学   193篇
肿瘤学   1022篇
  2024年   7篇
  2023年   98篇
  2022年   394篇
  2021年   569篇
  2020年   298篇
  2019年   379篇
  2018年   418篇
  2017年   384篇
  2016年   590篇
  2015年   758篇
  2014年   862篇
  2013年   906篇
  2012年   1271篇
  2011年   1169篇
  2010年   712篇
  2009年   582篇
  2008年   699篇
  2007年   659篇
  2006年   509篇
  2005年   473篇
  2004年   358篇
  2003年   302篇
  2002年   238篇
  2001年   54篇
  2000年   41篇
  1999年   30篇
  1998年   45篇
  1997年   39篇
  1996年   37篇
  1995年   27篇
  1994年   31篇
  1993年   12篇
  1992年   7篇
  1991年   17篇
  1990年   15篇
  1989年   18篇
  1988年   13篇
  1987年   8篇
  1986年   9篇
  1985年   12篇
  1984年   9篇
  1982年   2篇
  1981年   3篇
  1980年   4篇
  1979年   6篇
  1978年   4篇
  1977年   12篇
  1976年   3篇
  1970年   1篇
  1962年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
This paper reports a novel method for reconstructing the posterolateral structures [lateral collateral ligament (LCL), popliteus tendon, popliteofibular ligament] based on an anatomical study of a cadaveric dissection. The popliteus tendon was found to always be attached to the anterior–inferior portion of the femoral attachment site of the LCL, and the average distance from the origin of the popliteal tendon in the femoral side to that of the LCL was 18.5 mm (17–20). The insertion site of the LCL in the fibular side was located anterior–inferior-superficially and the popliteofibular ligament was inserted into the posterior–superior-deep portion around the styloid process. Two femoral tunnels and one fibular head tunnel were made at the proximal and distal portion of the anatomical insertion sites.  相似文献   
92.
Objectives  A paucity of data exists on actual pathology of the contemporary patients strictly categorized as having low-risk prostate cancer. We tried to identify useful preoperative predictors of Gleason score upgrading in patients who underwent radical retropubic prostatectomy (RRP) for low-risk prostate cancer diagnosed via multi-core prostate biopsy. Methods  A total of 203 patients who underwent radical RRP for low-risk prostate cancer, as defined by D’Amico et al.'s classification (clinical stage ≤T2a, biopsy Gleason sum ≤6, and PSA ≤10 ng/ml), detected via multi (≥12)-core prostate biopsy were enrolled. We reviewed patients preoperative and pathological data. Results  Among all subjects, 81 (39.9%) were upgraded to Gleason score ≥7 after RRP, whereas no downgrading was observed. In multivariate analysis, only preoperative PSA level (= 0.024) and number of positive cores (P = 0.027) were observed to be independent predictors of Gleason score upgrading following RRP. Also, Gleason core upgrading was observed to be significantly associated with extraprostatic extension of tumor (P < 0.001) and positive surgical margin (P = 0.002). Conclusions  A significant proportion of patients with low-risk prostate cancer as defined by D’Amico et al.’s classification diagnosed via multi-core prostate biopsy in contemporary period may have Gleason score upgrading following RRP. For patients with low-risk prostate cancer, preoperative PSA level and number of positive cores may be useful predictors of Gleason score upgrading, which was observed to significantly associated with other adverse pathologic features.  相似文献   
93.

Objective:

To evaluate the diagnostic accuracy of three-dimensional (3D) enhanced T1 high-resolution isotropic volume excitation (eTHRIVE) shoulder MR for variable shoulder pathology such as rotator cuff tear, labral injury and synovial pathology in comparison with two-dimensional enhanced fast spin echo T1 fat saturation (2D T1 FS) sequences MR.

Methods:

This retrospective study included 86 patients who underwent MRI of the shoulder using eTHRIVE technique. Two radiologists evaluated anatomic identification of the supraspinatus, glenoid labrum and acromioclavicular joint (AC joint) on routine MRI sequences (2D T1 FS) and compared them with the reformatted eTHRIVE images. Subjective scoring of the images was performed with a four-point scale that rated the degree of discrimination of the shape of the supraspinatus, glenoid labrum and AC joint. The diagnostic accuracy of eTHRIVE compared with routine MR images was evaluated in terms of rotator cuff pathology, labral pathology and synovial pathology.

Results:

Anatomic identification scores of the supraspinatus tendon and labrum were significantly lower for eTHRIVE than for 2D T1 FS. There were no significant differences between eTHRIVE and 2D T1 FS in anatomic identification of the AC joint. There were no significant differences between eTHRIVE and 2D T1 FS in diagnosing the three disease categories.

Conclusion:

eTHRIVE had comparable diagnostic accuracy to 2D T1 FS imaging in the evaluation of rotator cuff tears, labral injury and synovial pathology, but anatomic identification was inferior to that of 2D T1 FS.

Advances in knowledge:

The accuracy of 3D eTHRIVE imaging is comparable to that of 2D T1 FS for the diagnosis of rotator cuff tears, labral injury and synovial pathology.  相似文献   
94.

Background

To investigate the prognostic significance of altered breast cancer susceptibility gene 1 (BRCA1) and p53 expression in triple-negative breast cancer (TNBC).

Methods

Immunohistochemical expression of BRCA1 and p53 was examined in the tumor tissues of 465 TNBC cases and relations were sought with clinicopathological features and patient survival.

Results

Loss of BRCA1 expression was found in 29.5% (137/465) of TNBCs. Positive expression of p53 was observed in 49.9% (232/465). Patients with loss of BRCA1 expression had a tendency to have higher rate of lymph node metastasis (p = 0.075). An association between p53 expression and high histological grade was observed (p = 0.039). TNBC patients with loss of BRCA1 expression had a tendency to have poorer overall survival (OS) than those positive for BRCA1 (p = 0.09). TNBC patients with positive p53 expression showed better OS than those with p53 negativity (p = 0.001). In terms of combined expression patterns, significantly poorer overall survival (OS) was observed for BRCA1-negative/p53-negative TNBCs and best OS for BRCA1-positive/p53-positive TNBCs (p = 0.005).

Conclusions

Combined expression patterns of BRCA1 and p53 could serve as useful prognostic markers in TNBC.
  相似文献   
95.

Background

The development of pedicle screw-based posterior spinal instrumentation is recognized as one of the major surgical treatment methods for thoracolumbar burst fractures. However, the appropriate level in posterior segment instrumentation is still a point of debate. To assesses the long-term results of two-level and three-level posterior fixations of thoracolumbar burst fractures that have load-sharing scores of 7 and 8 points.

Methods

From January 1998 to May 2009, we retrospectively analyzed clinical and radiologic outcomes of 45 patients with thoracolumbar burst fractures of 7 and 8 points in load-sharing classification who were operated on using two-level posterior fixation (one segment above and one segment below: 28 patients, group I) or three-level posterior fixation (two segments above and one segment below: 17 patients, group II). Clinical results included the grade of the fracture using the Frankel classification, and the visual analog score was used to evaluate pain before surgery, immediately after surgery, and during follow-up period. We also evaluated pain and work status at the final follow-up using the Denis pain scale.

Results

In all cases, non-union or loosening of implants was not observed. There were two screw breakages in two-level posterior fixation group, but bony union was obtained at the final follow-up. There were no significant differences in loss of anterior vertebral body height, correction loss, or change in adjacent discs. Also, in clinical evaluation, there was no significant difference in the neurological deficit of any patient during the follow-up period.

Conclusions

In our study, two-level posterior fixation could be used successfully in selected cases of thoracolumbar burst fractures of 7 and 8 points in the load-sharing classification.  相似文献   
96.
Anterior translocation of the pulmonary root was used as a new approach to the staged repair of Taussig-Bing anomaly with an interrupted aortic arch. It was performed to construct the right ventricle outflow tract with intraventricular baffling of the left ventricle to the aorta as the second stage operation after repair of the interrupted arch and pulmonary artery banding. This technique allows minimization of pulmonary regurgitation and has the major theoretical advantage for growth potential, which could diminish the need for reoperation.  相似文献   
97.
This study examined the kinematics of a cruciate-retaining (CR) total knee arthroplasty (TKA) component that attempts to enhance knee flexion by improving posterior tibiofemoral articular contact at high-flexion angles. Using an in vitro robotic experimental setup, medial and lateral femoral translations of this CR design were compared with that of a conventional CR TKA design and intact knee under a combined quadriceps and hamstring muscle load. Both CR TKA designs showed similar kinematics throughout the range of flexion (0 degrees -150 degrees ). The TKAs restored nearly 80% of the posterior femoral translation of the intact knee at 150 degrees . The posterior cruciate ligament (PCL) forces measured for the high-flexion CR TKA component indicate that the PCL is important in the mid-flexion range but has little effect on knee kinematics at high flexion.  相似文献   
98.

OBJECTIVE

To evaluate the long‐term results and predictive risk factors for efficacy after the tension‐free vaginal tape (TVT) procedure for treating female stress urinary incontinence (SUI).

PATIENTS AND METHODS

Inall, 306 women (mean age 50.7 years, sd 8.7) who had a TVT procedure for SUI were selected and followed ≥7 years (mean 92.3 months, range 84–110) after surgery. We analysed the long‐term results, the variables predictive of cure rates, and patient satisfaction.

RESULTS

The overall 7‐year cure rate was 84.6%, with a satisfaction rate of 69.3%. The cure rates were lower in patients with high‐grade SUI (50% in grade III, 82.8% in grade II and 90.7% in grade I; P < 0.001). On multivariate analysis, there were no independent risk factors related to cure rate, and urgency was the only factor independently associated with patient satisfaction (P = 0.008; odds ratio 2.47). Seventy‐one patients (23.2%) had complications at the 1‐month follow‐up after surgery, but only eight (2.6%) had complications at the 7‐year follow‐up, including mesh exposure in six and de novo urgency in two.

CONCLUSION

The absence of long‐term adverse events associated with the TVT procedure, and high subjective and objective 7‐year success rates with no independent predictive factors affecting the long‐term cure rate, make the TVT procedure a recommendable surgical treatment for female SUI.  相似文献   
99.
Lee T  Suh HJ  Lee HJ  Lee JE 《The Journal of urology》2005,174(3):1084-1087
PURPOSE: We prospectively evaluated the efficacy of a combination of desmopressin and oxybutynin for treating children with nocturnal enuresis, compared to the single drugs imipramine and desmopressin. MATERIALS AND METHODS: We enrolled 158 patients from 2003 to 2004. Children were randomly assigned to 1 of 3 groups and treated with desmopressin, imipramine or a combination of desmopressin plus oxybutynin. Of these patients 145 (100 boys and 45 girls, mean age 7.8 +/- 2.5 years, range 5 to 15) were followed for more than 6 months. Efficacy was measured at 1, 3 and 6 months in terms of average enuretic frequency, 5-scale response based on change in nocturnal enuretic frequency after treatment and posttreatment enuretic frequency as a percentage of pretreatment baseline frequency. The latter efficacy was classified according to daytime voiding symptoms. Statistical evaluation was performed using chi-square tests and ANOVA. RESULTS: Of the 145 children followed 48 received combination therapy, 49 received desmopressin and 48 received imipramine. A total of 68 patients (47%) had monosymptomatic enuresis and 77 (53%) had polysymptomatic enuresis. Combination therapy produced the best and most rapid results regardless of whether the children had monosymptomatic or polysymptomatic enuresis. CONCLUSIONS: Combination therapy with desmopressin plus oxybutynin for the treatment of pediatric nocturnal enuresis was well tolerated, and gave significantly faster and more cost-effective results than single drug therapy using either desmopressin or imipramine.  相似文献   
100.

Purpose

The purpose of this study was to investigate the usefulness of metabolic-volumetric indices of 18F- fluorodeoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) for the evaluation of neoadjuvant chemotherapy outcomes in breast cancer.

Methods

Twenty-four patients with locally advanced breast cancer were enrolled in the study. They underwent baseline 18F-FDG PET/CT scan and received four or six cycles of neoadjuvant chemotherapy, interim 18F-FDG PET/CT was done after second cycle of chemotherapy. Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary lesions were calculated. Reduction rates of these parameters were obtained between baseline and interim 18F-FDG PET/CT. Chemotherapy outcomes were assessed using tumor size reduction rate and histological grading system (Miller and Payne system). Reduction rates of SUVmax, MTV, and TLG correlated with chemotherapy outcomes.

Results

MTV and TLG reduction rates showed significant correlation with tumor size reduction rate (R = 0.68, P = 0.0004; R = 0.62, P = 0.002, respectively). However, SUVmax reduction rate showed no significant correlation. MTV and TLG reduction rates were significantly higher in responders than nonresponders, as determined by Miller and Payne system (P < 0.0007, P < 0.002). However, SUVmax reduction rate showed no significant difference. On ROC analysis, the area under the MTV and TLG curves was 0.886, and that of SUVmax was 0.743. Sensitivity, specificity, positive predictive value, and negative predictive value to predict histopathologic response were the same for MTV and TLG, and the values were 100 %, 85.7 %, 83.3 %, and 100 %, respectively (at the reduction rate of 93.2 % for MTV, and 95.8 % for TLG).

Conclusion

Changes of metabolic–volumetric indices successfully reflected the neoadjuvant chemotherapy outcomes. MTV and TLG could be robust indices in discriminating pathologic responder as SUVmax, after neoadjuvant chemotherapy.  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