全文获取类型
收费全文 | 147897篇 |
免费 | 14184篇 |
国内免费 | 10170篇 |
专业分类
耳鼻咽喉 | 1280篇 |
儿科学 | 2102篇 |
妇产科学 | 1671篇 |
基础医学 | 15599篇 |
口腔科学 | 2398篇 |
临床医学 | 19293篇 |
内科学 | 20413篇 |
皮肤病学 | 1461篇 |
神经病学 | 7114篇 |
特种医学 | 5241篇 |
外国民族医学 | 85篇 |
外科学 | 14509篇 |
综合类 | 27518篇 |
现状与发展 | 31篇 |
一般理论 | 12篇 |
预防医学 | 10793篇 |
眼科学 | 3758篇 |
药学 | 16916篇 |
118篇 | |
中国医学 | 9911篇 |
肿瘤学 | 12028篇 |
出版年
2024年 | 474篇 |
2023年 | 1911篇 |
2022年 | 4957篇 |
2021年 | 6977篇 |
2020年 | 5680篇 |
2019年 | 4486篇 |
2018年 | 4882篇 |
2017年 | 4813篇 |
2016年 | 4369篇 |
2015年 | 6991篇 |
2014年 | 8656篇 |
2013年 | 8098篇 |
2012年 | 12204篇 |
2011年 | 13098篇 |
2010年 | 9058篇 |
2009年 | 7362篇 |
2008年 | 8776篇 |
2007年 | 8362篇 |
2006年 | 7879篇 |
2005年 | 7373篇 |
2004年 | 4985篇 |
2003年 | 4628篇 |
2002年 | 3758篇 |
2001年 | 3065篇 |
2000年 | 3001篇 |
1999年 | 2991篇 |
1998年 | 1773篇 |
1997年 | 1778篇 |
1996年 | 1353篇 |
1995年 | 1247篇 |
1994年 | 1033篇 |
1993年 | 736篇 |
1992年 | 844篇 |
1991年 | 805篇 |
1990年 | 637篇 |
1989年 | 554篇 |
1988年 | 503篇 |
1987年 | 483篇 |
1986年 | 363篇 |
1985年 | 285篇 |
1984年 | 219篇 |
1983年 | 139篇 |
1982年 | 86篇 |
1981年 | 106篇 |
1980年 | 72篇 |
1979年 | 89篇 |
1978年 | 62篇 |
1977年 | 46篇 |
1976年 | 38篇 |
1973年 | 30篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
1.
2.
目的分析细棒、PEEK棒固定对寰枢关节稳定性的影响。方法采用6具新鲜成人枕骨(occipital bone,Oc)~颈椎C4节段进行测试,模拟以下手术及固定状态:①完整状态;②损伤状态:枢椎齿状突II型骨折;③坚强固定:寰枢椎均采用普通椎弓根螺钉固定,直径3.5 mm钛棒连接;④PEEK棒:直径3.5 mm的PEEK棒连接;⑤细棒:直径2.0 mm钛棒连接。采用重复测量实验设计,在完整、损伤和不同的固定状态下,通过脊柱试验机对标本分别施加1.5 N·m的前屈/后伸、左/右侧弯和左/右轴向旋转的纯力偶矩。采用Optotrak三维运动测量系统连续采集标本运动,分析寰枢椎之间角度运动范围和中性区。结果采用直径3.5 mm的钛棒,2.0 mm的细棒以及3.5 mm的PEEK棒固定后,在前屈、后伸、侧弯和旋转方向上均显著减小了固定节段的运动范围(P<0.05)。直径3.5 mm和2.0 mm的棒固定后的运动范围,在各个方向上无显著性差异。PEEK棒固定的运动范围仅在侧弯方向上大于坚强固定(P=0.005),其他方向无显著性差异。3种固定方式在屈伸、侧弯和旋转方向上均显著减小了固定节段的中性区(P<0.05)。各种固定方式之间相比较,无显著性差异(P>0.05)。结论在寰枢关节采用直径2.0 mm的细棒固定,与坚强固定的稳定性相当。采用直径3.5 mm的PEEK棒固定,在前屈、后伸、旋转方向上与坚强固定的稳定性相当,在侧弯方向上弱于坚强固定。 相似文献
3.
Ludefu Su Yu Liu Yanhong Tang Mingmin Zhou Liang Xiong Congxin Huang 《International journal of clinical and experimental pathology》2021,14(4):408
Background and objective: Myocardial infarction (MI) is a common critical disease of the cardiovascular system. The process of MI is often accompanied by the excessive activation of cardiac sympathetic nerves, which leads to arrhythmia. Resiniferatoxin (RTX) is a transient receptor potential vanilloid 1 (TRPV1), involved in the cardiac sympathetic afferent reflex. However, whether RTX can reduce the occurrence of arrhythmia and exert a cardioprotective effect by inhibiting the sympathetic reflex during MI is still unknown. Methods: The left anterior descending artery of cardiac was clamped to construct a model of MI. RTX (50 μg/ml) was used by epicardial application in MI rats. Ventricular electrophysiologic properties were continuously monitored by a body surface ECG. Yrosine hydroxylase (TH) and growth associated protein 43 (GAP43) were detected by Immunofluorescence staining. Connexin43 and transforming growth factor beta receptor 1 (TGF-β1) were detected by western blot. Norepinephrine (NE) and BNP levels in blood and tissue were determined by ELISA. Cardiac function was assessed by echocardiography. Results: The ERP, APD90, QRS, QT and the Tend-Tpeak intervals in MI rats were all prolonged, but decreased after RTX treatment (n = 3, P<0.05). In contrast, the RR interval was shortened in the MI group, but prolonged in the MI+RTX group (n = 3, P<0.05). RTX treatment significantly reduced ventricular arrhythmias after MI. TH- and GAP43-positive nerve densities and TGF-β1, and cx-43 protein expression were up-regulated in the MI group compared to the sham group, and they were decreased in the MI+RTX group compared to the MI group (n = 3, P<0.05). RTX can decrease serum and tissue NE and BNP levels (n = 3, P<0.05). RTX pretreatment significantly decreased heart rate, HW/BW ratio and LVIDS, and increased LVEF andLVFS values (n = 3, P<0.05). Conclusion: RTX improved cardiac dysfunction, ventricular electrophysiologic properties, and sympathetic nerve remodeling in rats with MI by inhibiting the excessive cardiac sympathetic drive. 相似文献
4.
Yuxiang Ma Wenfeng Fang Hongyun Zhao Sai Praneeth Bathena Amol Tendolkar Jennifer Sheng Li Zhang 《The oncologist》2021,26(4):e549-e566
Lessons Learned
- The overall safety profiles of ipilimumab 3 mg/kg and 10 mg/kg administered every 3 weeks, were consistent between Chinese patients with solid tumors in the current study and patients from previous U.S. ipilimumab monotherapy studies. No new safety signals were identified.
- The mean systemic exposures to ipilimumab (assessed by first dose area under the curve during the dosing interval and maximum serum concentration) were numerically lower in the Chinese patient population than in U.S. patients for both 3 mg/kg and 10 mg/kg doses; however, the range of serum concentrations in the Chinese and U.S. populations overlapped (3 mg/kg and 10 mg/kg), suggesting that ipilimumab pharmacokinetics was ethnically insensitive in this study.
5.
Kara S. Tanaka MD Veronica R. Andaya BA Steven W. Thorpe MD Kenneth R. Gundle MD James B. Hayden MD Yee-Cheen Duong MD Raffi S. Avedian MD David G. Mohler MD Lee J. Morse MD Melissa N. Zimel MD Richard J. O'Donnell MD Andrew Fang MD Robert Lor Randall MD Tina H. Tran BS Christin New BA Rosanna L. Wustrack MD other members of Study Group FORCE 《Journal of surgical oncology》2023,127(1):148-158
6.
7.
目的探究面肌痉挛患者微血管减压术(MVD)中异常肌反应(AMR)的变化特点与术后疗效的关系。方法回顾性分析73例MVD术中采用AMR全程定量化监测患者的AMR变化特点,减压操作前AMR阈值较基础阈值升高≥1倍为A1组、1倍为A2组,手术结束时AMR完全消失为B1组、未消失为B2组,B2组中AMR阈值较基础阈值升高≥1倍为B2a组、1倍为B2b组,对各组的术后疗效进行对比分析。结果 A1组21例中,19例立即治愈,1例延迟治愈,1例未愈; A2组52例中,35例立即治愈,9例延迟治愈,8例未愈。A1组较A2组疗效好(P=0. 046)。B1组50例中,42例立即治愈,5例延迟治愈,3例未愈; B2组23例中,12例立即治愈,5例延迟治愈,6例未愈。B1组较B2组疗效好(P=0. 003)。B2 a组的治愈比例较B2 b组高(分别为14/16、3/7),差异有统计学意义(P=0. 045)。结论 AMR在术中的变化特点对术者有重要参考意义,AMR在减压前升高、在手术结束时完全消失、未消失但升高较基础阈值≥1倍者术后疗效相对较好。 相似文献
8.
9.
Wang-Shu Zhu Si-Ya Shi Ze-Hong Yang Chao Song Jun Shen 《World journal of gastroenterology : WJG》2020,26(11):1208-1220
BACKGROUND Postoperative liver failure is the most severe complication in cirrhotic patients with hepatocellular carcinoma(HCC) after major hepatectomy. Current available clinical indexes predicting postoperative residual liver function are not sufficiently accurate.AIM To determine a radiomics model based on preoperative gadoxetic acid-enhanced magnetic resonance imaging for predicting liver failure in cirrhotic patients with HCC after major hepatectomy.METHODS For this retrospective study, a radiomics-based model was developed based on preoperative hepatobiliary phase gadoxetic acid-enhanced magnetic resonance images in 101 patients with HCC between June 2012 and June 2018. Sixty-one radiomic features were extracted from hepatobiliary phase images and selected by the least absolute shrinkage and selection operator method to construct a radiomics signature. A clinical prediction model, and radiomics-based model incorporating significant clinical indexes and radiomics signature were built using multivariable logistic regression analysis. The integrated radiomics-based model was presented as a radiomics nomogram. The performances of clinical prediction model, radiomics signature, and radiomics-based model for predicting post-operative liver failure were determined using receiver operating characteristics curve, calibration curve, and decision curve analyses.RESULTS Five radiomics features from hepatobiliary phase images were selected to construct the radiomics signature. The clinical prediction model, radiomics signature, and radiomics-based model incorporating indocyanine green clearance rate at 15 min and radiomics signature showed favorable performance for predicting postoperative liver failure(area under the curve: 0.809-0.894). The radiomics-based model achieved the highest performance for predicting liver failure(area under the curve: 0.894; 95%CI: 0.823-0.964). The integrated discrimination improvement analysis showed a significant improvement in the accuracy of liver failure prediction when radiomics signature was added to the clinical prediction model(integrated discrimination improvement = 0.117, P =0.002). The calibration curve and an insignificant Hosmer-Lemeshow test statistic(P = 0.841) demonstrated good calibration of the radiomics-based model. The decision curve analysis showed that patients would benefit more from a radiomics-based prediction model than from a clinical prediction model and radiomics signature alone.CONCLUSION A radiomics-based model of preoperative gadoxetic acid–enhanced MRI can be used to predict liver failure in cirrhotic patients with HCC after major hepatectomy. 相似文献
10.