全文获取类型
收费全文 | 23096篇 |
免费 | 1992篇 |
国内免费 | 788篇 |
专业分类
耳鼻咽喉 | 197篇 |
儿科学 | 560篇 |
妇产科学 | 587篇 |
基础医学 | 1250篇 |
口腔科学 | 524篇 |
临床医学 | 3415篇 |
内科学 | 5526篇 |
皮肤病学 | 104篇 |
神经病学 | 866篇 |
特种医学 | 674篇 |
外国民族医学 | 7篇 |
外科学 | 2661篇 |
综合类 | 3328篇 |
现状与发展 | 2篇 |
预防医学 | 1419篇 |
眼科学 | 105篇 |
药学 | 2293篇 |
49篇 | |
中国医学 | 1177篇 |
肿瘤学 | 1132篇 |
出版年
2024年 | 87篇 |
2023年 | 528篇 |
2022年 | 911篇 |
2021年 | 1281篇 |
2020年 | 1116篇 |
2019年 | 1003篇 |
2018年 | 942篇 |
2017年 | 970篇 |
2016年 | 958篇 |
2015年 | 915篇 |
2014年 | 1675篇 |
2013年 | 1880篇 |
2012年 | 1347篇 |
2011年 | 1414篇 |
2010年 | 1166篇 |
2009年 | 1038篇 |
2008年 | 989篇 |
2007年 | 971篇 |
2006年 | 954篇 |
2005年 | 812篇 |
2004年 | 646篇 |
2003年 | 567篇 |
2002年 | 507篇 |
2001年 | 424篇 |
2000年 | 349篇 |
1999年 | 252篇 |
1998年 | 238篇 |
1997年 | 215篇 |
1996年 | 208篇 |
1995年 | 203篇 |
1994年 | 160篇 |
1993年 | 131篇 |
1992年 | 138篇 |
1991年 | 116篇 |
1990年 | 104篇 |
1989年 | 92篇 |
1988年 | 79篇 |
1987年 | 65篇 |
1986年 | 51篇 |
1985年 | 67篇 |
1984年 | 48篇 |
1983年 | 42篇 |
1982年 | 41篇 |
1981年 | 39篇 |
1980年 | 32篇 |
1979年 | 21篇 |
1978年 | 25篇 |
1977年 | 17篇 |
1976年 | 12篇 |
1974年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
人类微生物群是由寄生在人体上皮屏障的细菌和其他微生物组成的,其中大部分位于肠道内,与宿主之间形成共生的关系。机体肠道微生物的组成虽然受到年龄、饮食、生活方式等因素的影响,但在正常生理情况下是相对稳定的。近年来,肠道菌群与恶性肿瘤的关系越来越受到重视。肠道菌群不但能够维持局部稳态,还能调节机体代谢、炎症和免疫等生理过程。有研究表明,微生物群,特别是肠道菌群能够显著调节机体对癌症治疗的反应性以及机体对毒副反应的敏感性。检查肠道菌群中各菌种之间的比例可作为筛查恶性肿瘤的新方法。本文将综述微生物群具有影响肿瘤的发生发展、抗肿瘤治疗疗效以及药物不良反应的证据,以及其中所涉及的微生物种类,从而为恶性肿瘤精准治疗提供证据。 相似文献
13.
14.
Altayeb Abdalla Ahmed 《Medicine》2021,100(19)
Estimating stature based on body/limb parts can help define the characteristics of unidentified bodies. The most studied upper limb part is the hand, although few studies have examined whether stature can be estimated using fingers plus other hand dimensions. Moreover, there is paucity in anthropometric studies that determined whether bilateral whole limb parts (e.g., arms, forearms, and hands) are related to stature among the living subjects.This prospective cross-sectional study aimed to evaluate the relationship between different upper limb measurements and the stature of Saudi men. Furthermore, I assessed whether upper limb asymmetry was present, and developed regression models to estimate stature based on different available measurements. Stature and 13 upper limb parameters were measured for 100 right-handed Saudi men who were 18 to 24 years old.All measurements were positively correlated with stature (P < .001), and the best single predictor was the bilateral ulnar length. Asymmetry was more pronounced in the hand measurements. A multiparameter model provided reasonable predictive accuracy (±3.77–5.68 cm) and was more accurate than single-parameter models. Inclusion of the right-side fingers improved the model''s accuracy.This study developed potential models for estimating stature during the identification of bodies of Saudi men. 相似文献
15.
Kensuke Kudou Hiroshi Saeki Yuichiro Nakashima Shun Sasaki Tomoko Jogo Kosuke Hirose Qingjiang Hu Yasuo Tsuda Koichi Kimura Ryota Nakanishi Nobuhide Kubo Koji Ando Eiji Oki Tetsuo Ikeda Yoshihiko Maehara 《American journal of surgery》2019,217(4):757-763
Background
There were few studies assessed the postoperative sarcopenia in patients with cancers. The objective of present study was to assess whether postoperative development of sarcopenia could predict a poor prognosis in patients with adenocarcinoma of esophagogastric junction, (AEG) and upper gastric cancer (UGC).Methods
Patients with AEG and UGC who were judged as non-sarcopenic before surgery were reassessed the presence of postoperative development of sarcopenia 6 months after surgery. Patients were divided into the development group or non-development group, and clinicopathological factors and prognosis between these two groups were analyzed.Results
The 5-year overall survival rates were significantly poorer in the development group than non-development group (68.0% vs. 92.6%, P?=?0.0118). Multivariate analyses showed that postoperative development of sarcopenia was an independent prognostic factor for poor overall survival (P?=?0.0237).Conclusions
Postoperative development of sarcopenia was associated with a poor prognosis in patients with AEG and UGC. 相似文献16.
17.
18.
《JACC: Cardiovascular Interventions》2022,15(7):741-750
ObjectivesThe aim of this study was to report 1-year clinical outcomes following commercial transcatheter left atrial appendage occlusion (LAAO) in the United States.BackgroundThe National Cardiovascular Data Registry LAAO Registry was initiated to meet a condition of Medicare coverage and allow the assessment of clinical outcomes. The 1-year rates of thromboembolic events after transcatheter LAAO in such a large cohort of “real-world” patients have not been previously reported.MethodsPatients entered into the National Cardiovascular Data Registry LAAO Registry for a Watchman procedure between January 1, 2016, and December 31, 2018, were included. The primary endpoint was ischemic stroke. Key secondary endpoints included the rate of ischemic stroke or systemic embolism, mortality, and major bleeding. Major bleeding was defined as any bleeding requiring hospitalization, and/or causing a decrease in hemoglobin level > 2g/dL, and/or requiring blood transfusion that was not hemorrhagic stroke. The Kaplan-Meier method was used for 1-year estimates of cumulative event rates.ResultsThe study population consisted of 36,681 patients. The mean age was 76.0 ± 8.1 years, the mean CHA2DS2-VASc score was 4.8 ± 1.5, and the mean HAS-BLED score was 3.0 ± 1.1. Prior stroke was present in 25.5%, clinically relevant bleeding in 69.5%, and intracranial bleeding in 11.9%. Median follow-up was 374 days (IQR: 212-425 days). The Kaplan-Meier–estimated 1-year rate of ischemic stroke was 1.53% (95% CI: 1.39%-1.69%), the rate of ischemic stroke or systemic embolism was 2.19% (95% CI: 2.01%-2.38%), and the rate of mortality was 8.52% (95% CI: 8.19%-8.87%). The 1-year estimated rate of major bleeding was 6.93% (95% CI: 6.65%-7.21%). Most bleeding events occurred between discharge and 45 days following the procedure.ConclusionsThis study characterizes important outcomes in a national cohort of patients undergoing transcatheter LAAO in the United States. Clinicians and patients can integrate these data in shared decision making when considering this therapy. 相似文献
19.
Ramya C. Mosarla Muthiah Vaduganathan Arman Qamar Javid Moslehi Gregory Piazza Robert P. Giugliano 《Journal of the American College of Cardiology》2019,73(11):1336-1349
Patients with active cancer are at an increased risk of arterial and venous thromboembolism (VTE) and bleeding events. Historically, in patients with cancer, low molecular weight heparins have been preferred for treatment of VTE, whereas warfarin has been the standard anticoagulant for stroke prevention in patients with atrial fibrillation (AF). More recently, direct oral anticoagulants (DOACs) have been demonstrated to reduce the risk of venous and arterial thromboembolism in large randomized clinical trials of patients with VTE and AF, respectively, thus providing an attractive oral dosing option that does not require routine laboratory monitoring. In this review, we summarize available clinical trial data and guideline recommendations, and outline a practical approach to anticoagulation management of VTE and AF in cancer. 相似文献
20.
《Journal of pediatric surgery》2023,58(6):1090-1094
BackgroundThe purpose of this study was to assess diagnostic accuracy and neonatal outcomes in fetuses with a suspected proximal gastrointestinal obstruction (GIO).MethodsAfter IRB approval, a retrospective chart review was conducted on prenatally suspected and/or postnatally confirmed cases of proximal GIO at a tertiary care facility (2012–2022). Maternal-fetal records were queried for presence of a double bubble ± polyhydramnios, and neonatal outcomes were assessed to calculate the diagnostic accuracy of fetal sonography.ResultsAmong 56 confirmed cases, the median birthweight and gestational age at birth were 2550 g [interquartile range (IQR) 2028–3012] and 37 weeks (IQR 34–38), respectively. There was one (2%) false-positive and three (6%) false-negatives by ultrasound. Double bubble had a sensitivity, specificity, positive predictive value, and negative predictive value for proximal GIO of 85%, 98%, 98%, and 83%, respectively. Pathologies included 49 (88%) with duodenal obstruction/annular pancreas, three (5%) with malrotation, and three (5%) with jejunal atresia. The median postoperative length of stay was 27 days (IQR 19–42). Cardiac anomalies were associated with significantly higher complications (45% vs 17%, p = 0.030).ConclusionsIn this contemporary series, fetal sonography has high diagnostic accuracy for detecting proximal gastrointestinal obstruction. These data are informative for pediatric surgeons in prenatal counseling and preoperative discussions with families.Level of EvidenceDiagnostic Study, Level III. 相似文献