收费全文 | 9103篇 |
免费 | 727篇 |
国内免费 | 31篇 |
耳鼻咽喉 | 117篇 |
儿科学 | 288篇 |
妇产科学 | 292篇 |
基础医学 | 1281篇 |
口腔科学 | 223篇 |
临床医学 | 994篇 |
内科学 | 1566篇 |
皮肤病学 | 138篇 |
神经病学 | 1062篇 |
特种医学 | 243篇 |
外科学 | 1104篇 |
综合类 | 60篇 |
一般理论 | 11篇 |
预防医学 | 935篇 |
眼科学 | 170篇 |
药学 | 543篇 |
中国医学 | 33篇 |
肿瘤学 | 801篇 |
2023年 | 59篇 |
2022年 | 45篇 |
2021年 | 234篇 |
2020年 | 179篇 |
2019年 | 233篇 |
2018年 | 235篇 |
2017年 | 177篇 |
2016年 | 225篇 |
2015年 | 232篇 |
2014年 | 328篇 |
2013年 | 436篇 |
2012年 | 687篇 |
2011年 | 658篇 |
2010年 | 393篇 |
2009年 | 387篇 |
2008年 | 604篇 |
2007年 | 566篇 |
2006年 | 546篇 |
2005年 | 509篇 |
2004年 | 533篇 |
2003年 | 498篇 |
2002年 | 449篇 |
2001年 | 112篇 |
2000年 | 75篇 |
1999年 | 105篇 |
1998年 | 112篇 |
1997年 | 84篇 |
1996年 | 62篇 |
1995年 | 74篇 |
1994年 | 74篇 |
1993年 | 63篇 |
1992年 | 91篇 |
1991年 | 71篇 |
1990年 | 61篇 |
1989年 | 48篇 |
1988年 | 41篇 |
1987年 | 38篇 |
1986年 | 35篇 |
1985年 | 45篇 |
1984年 | 42篇 |
1983年 | 31篇 |
1982年 | 37篇 |
1981年 | 30篇 |
1979年 | 23篇 |
1978年 | 26篇 |
1975年 | 23篇 |
1974年 | 22篇 |
1973年 | 30篇 |
1972年 | 28篇 |
1971年 | 19篇 |
Objective
Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.Methods
Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.Results
In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.Conclusions
Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection. 相似文献Methods: Patients were divided into two groups: Group A (22 patients) who underwent ACL reconstruction performed with an All-Inside graft-link technique; Group B (22 patients) who underwent ACL reconstruction with an Out-In technique and DGST graft. At a mean follow-up of 13 months, quadriceps and hamstring isokinetic peak torque deficits were recorded.
Results: In group A, the mean side to side peak torque flexion difference between the operated and non-operated limbs was ?3% and the mean torque at 30° was ?7.5% at high angular velocity (180°/sec); the mean peak flexion torque was 7.2% and the mean torque at 30° was 3.1% at low angular velocity (60°/sec).
In group B, the mean side to side peak flexion torque was ?3.5% and the mean torque at 30° was ?7.6% at high angular velocity (180°/sec); the mean peak flexion torque was ?7.2% and the mean torque at 30° was ?11% at low angular velocity (60°/sec).
A statistically significant difference was found between the two groups at lower angular velocity both for the mean peak flexion torque and the mean torque at 30° (p = 0.009), with better results in the study group.
Discussion/conclusion: Gracilis sparing technique is a minimally invasive technique for ACL reconstruction and yielded a significantly better flexion strength recovery at lower angular velocity compared to a full tibial tunnel technique with DGST for ACL reconstruction. 相似文献