全文获取类型
收费全文 | 968011篇 |
免费 | 70998篇 |
国内免费 | 3969篇 |
专业分类
耳鼻咽喉 | 13150篇 |
儿科学 | 24836篇 |
妇产科学 | 23769篇 |
基础医学 | 137474篇 |
口腔科学 | 28901篇 |
临床医学 | 85195篇 |
内科学 | 189256篇 |
皮肤病学 | 19558篇 |
神经病学 | 74386篇 |
特种医学 | 38053篇 |
外国民族医学 | 102篇 |
外科学 | 156133篇 |
综合类 | 23811篇 |
现状与发展 | 13篇 |
一般理论 | 237篇 |
预防医学 | 63945篇 |
眼科学 | 22252篇 |
药学 | 76409篇 |
18篇 | |
中国医学 | 4049篇 |
肿瘤学 | 61431篇 |
出版年
2021年 | 7247篇 |
2018年 | 10214篇 |
2017年 | 8187篇 |
2016年 | 8868篇 |
2015年 | 10582篇 |
2014年 | 14015篇 |
2013年 | 19273篇 |
2012年 | 26902篇 |
2011年 | 27986篇 |
2010年 | 16612篇 |
2009年 | 15706篇 |
2008年 | 26613篇 |
2007年 | 27717篇 |
2006年 | 28338篇 |
2005年 | 27368篇 |
2004年 | 25877篇 |
2003年 | 24872篇 |
2002年 | 24195篇 |
2001年 | 55518篇 |
2000年 | 57468篇 |
1999年 | 47946篇 |
1998年 | 11358篇 |
1997年 | 10133篇 |
1996年 | 10082篇 |
1995年 | 9394篇 |
1994年 | 8709篇 |
1993年 | 7882篇 |
1992年 | 35776篇 |
1991年 | 34215篇 |
1990年 | 32992篇 |
1989年 | 32101篇 |
1988年 | 29190篇 |
1987年 | 28439篇 |
1986年 | 26444篇 |
1985年 | 25255篇 |
1984年 | 17915篇 |
1983年 | 15213篇 |
1982年 | 7823篇 |
1979年 | 15811篇 |
1978年 | 10618篇 |
1977年 | 9069篇 |
1976年 | 7888篇 |
1975年 | 8636篇 |
1974年 | 10472篇 |
1973年 | 9866篇 |
1972年 | 9359篇 |
1971年 | 8857篇 |
1970年 | 8428篇 |
1969年 | 7926篇 |
1968年 | 7202篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Hassen Lena M. Albarrak Rana A. Albahlal Reem A. Alsaqabi Dimah K. Hassen Ikhlass M. Daghestani Maha H. Alqurtas Eman M. Alkhalaf Abdulaziz T. Bedaiwi Mohammed K. Omair Mohammed A. Almaghlouth Ibrahim A. 《Quality of life research》2022,31(11):3229-3239
Quality of Life Research - The COVID-19 pandemic might add to the stressors experienced by people living with rheumatic diseases. This study aimed to examine rheumatic patients’ functional... 相似文献
2.
3.
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
4.
Stepanova E. S. Makarenkova L. M. Chistyakov V. V. Rybakov Yu. L. Gukasov V. M. Fedotcheva T. A. Parshin V. A. Votyakov V. A. Shimanovskii N. L. 《Pharmaceutical Chemistry Journal》2019,52(12):1016-1020
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was... 相似文献
5.
6.
Elizabeth D. Krebs Robert B. Hawkins J. Hunter Mehaffey Clifford E. Fonner Alan M. Speir Mohammed A. Quader Jeffrey B. Rich Leora T. Yarboro Nicholas R. Teman Gorav Ailawadi 《The Journal of thoracic and cardiovascular surgery》2019,157(4):1533-1542.e2
Objectives
Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.Methods
Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.Results
A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.Conclusions
Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight. 相似文献7.
8.
9.
10.
Autoimmune comorbid diseases associated with lichen planus: a nationwide case–control study
下载免费PDF全文
![点击此处可从《Journal of the European Academy of Dermatology and Venereology》网站下载免费的PDF全文](/ch/ext_images/free.gif)