全文获取类型
收费全文 | 87484篇 |
免费 | 5842篇 |
国内免费 | 2443篇 |
专业分类
耳鼻咽喉 | 4160篇 |
儿科学 | 1107篇 |
妇产科学 | 1537篇 |
基础医学 | 2515篇 |
口腔科学 | 4050篇 |
临床医学 | 8444篇 |
内科学 | 11047篇 |
皮肤病学 | 727篇 |
神经病学 | 3378篇 |
特种医学 | 1751篇 |
外国民族医学 | 20篇 |
外科学 | 27510篇 |
综合类 | 11718篇 |
一般理论 | 2篇 |
预防医学 | 2794篇 |
眼科学 | 4642篇 |
药学 | 3485篇 |
171篇 | |
中国医学 | 956篇 |
肿瘤学 | 5755篇 |
出版年
2024年 | 45篇 |
2023年 | 2326篇 |
2022年 | 2814篇 |
2021年 | 4192篇 |
2020年 | 4670篇 |
2019年 | 3763篇 |
2018年 | 3472篇 |
2017年 | 3257篇 |
2016年 | 3190篇 |
2015年 | 3327篇 |
2014年 | 6809篇 |
2013年 | 6274篇 |
2012年 | 5124篇 |
2011年 | 5403篇 |
2010年 | 4322篇 |
2009年 | 4070篇 |
2008年 | 4025篇 |
2007年 | 4035篇 |
2006年 | 3487篇 |
2005年 | 3067篇 |
2004年 | 2633篇 |
2003年 | 2096篇 |
2002年 | 1666篇 |
2001年 | 1605篇 |
2000年 | 1373篇 |
1999年 | 1234篇 |
1998年 | 971篇 |
1997年 | 912篇 |
1996年 | 699篇 |
1995年 | 623篇 |
1994年 | 554篇 |
1993年 | 453篇 |
1992年 | 397篇 |
1991年 | 383篇 |
1990年 | 277篇 |
1989年 | 281篇 |
1988年 | 267篇 |
1987年 | 264篇 |
1986年 | 216篇 |
1985年 | 231篇 |
1984年 | 206篇 |
1983年 | 141篇 |
1982年 | 153篇 |
1981年 | 129篇 |
1980年 | 102篇 |
1979年 | 61篇 |
1978年 | 46篇 |
1977年 | 46篇 |
1976年 | 31篇 |
1975年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
《Pancreatology》2022,22(6):698-705
BackgroundThe functional and morphological recovery following an episode of acute pancreatitis (AP) in children still remains ill understood as research exploring this is limited. We aimed to characterize the morphological and functional changes in pancreas following AP and ARP (acute recurrent pancreatitis) in children.MethodsChildren with AP were followed prospectively and assessed at two time points at least 3 months apart, with the first assessment at least 3 months after the AP episode. Exocrine and endocrine functions were measured using fecal elastase and fasting blood sugar/HbA1c levels respectively. Morphological assessment was done using endoscopic ultrasound (EUS) and magnetic resonance imaging and cholangiopancreatography (MRI/MRCP).ResultsSeventy-three children (boys:59%; mean age:8.4 ± 3.2years) were studied and 21 of them (29%) progressed to ARP. Altered glucose homeostasis was seen in 19 (26%) at first and 16 (22%) at second assessment and it was significantly more in ARP group than the AP group at first (42.8%vs19.2%; p = 0.03) as well as second assessment (38.1%vs15.3%; p = 0.03). Twenty-one children (28.7%) at first and 24 (32.8%) at second assessment developed biochemical exocrine pancreatic insufficiency. EUS detected indeterminate and suggestive changes of chronic pancreatitis in 21% at first (n = 38) and 27.6% at second assessment (n = 58). On MRCP, main pancreatic duct and side branch dilatation were seen in 15 (20.5%) and 2 (2.7%) children respectively.ConclusionsMore than one-quarter of children have evidence of altered glucose homeostasis and biochemical exocrine pancreatic insufficiency following an episode of AP. Similarly, morphological features of chronicity seen in some of the children suggest that a fraction of subjects may develop chronic pancreatitis on longer follow-up. 相似文献
3.
目的 研究内镜超声检查术(endoscopic ultrasound,EUS)判断早期胃癌浸润深度的准确性及影响因素。方法 回顾性分析2014年1月—2020年8月于北京友谊医院就诊、行EUS且EUS分期为T1的早期胃癌患者的资料。比较EUS与术后病理浸润深度的一致性,计算EUS判断早期胃癌浸润深度的准确率、灵敏度及特异度,并探究影响EUS准确性的相关因素。单因素及多因素分析均采用Logistic回归模型。结果 共纳入380处病变,EUS发现黏膜内(T1a)病变301处,黏膜下层(T1b)病变79处;术后病理实际浸润深度为T1a病变320处,T1b病变60处。EUS判断早期胃癌浸润深度的准确率为77.1%(293/380),灵敏度为83.4%(267/320),特异度为43.3%(26/60)。多因素分析提示,病变位于胃上1/3部(OR=2.272,95%CI:1.266~4.080,P=0.006)、病变长径≥20 mm(OR=2.013,95%CI:1.200~3.377,P=0.008)及低分化癌(OR=2.090,95%CI:1.018~4.294,P=0.045)是影响EUS分期准确性的独立危险因素。低分化癌(OR=4.046,95%CI:1.737~9.425,P=0.001)是EUS过度分期的危险因素。结论 EUS对于早期胃癌浸润深度的判断具有一定的临床应用价值,影响EUS分期准确性的因素包括病变位于胃上1/3部、病变长径≥20 mm及低分化癌,其中低分化癌是EUS过度分期的危险因素。 相似文献
4.
Kevin Kyung Ho Choi Santosh Sanagapalli 《World journal of gastrointestinal oncology》2022,14(3):568-586
Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC). Progression to cancer typically occurs in a stepwise fashion through worsening dysplasia and ultimately, invasive neoplasia. Established EAC with deep involvement of the esophageal wall and/or metastatic disease is invariably associated with poor long-term survival rates. This guides the rationale of surveillance of Barrett’s in an attempt to treat lesions at an earlier, and potentially curative stage. The last two decades have seen a paradigm shift in management of Barrett’s with rapid expansion in the role of endoscopic eradication therapy (EET) for management of dysplastic and early neoplastic BE, and there have been substantial changes to international consensus guidelines for management of early BE based on evolving evidence. This review aims to assist the physician in the therapeutic decision-making process with patients by comprehensive review and summary of literature surrounding natural history of Barrett’s by histological stage, and the effectiveness of interventions in attenuating the risk posed by its natural history. Key findings were as follows. Non-dysplastic Barrett’s is associated with extremely low risk of progression, and interventions cannot be justified. The annual risk of cancer progression in low grade dysplasia is between 1%-3%; EET can be offered though evidence for its benefit remains confined to highly select settings. High-grade dysplasia progresses to cancer in 5%-10% per year; EET is similarly effective to and less morbid than surgery and should be routinely performed for this indication. Risk of nodal metastases in intramucosal cancer is 2%-4%, which is comparable to operative mortality rate, so EET is usually preferred. Submucosal cancer is associated with nodal metastases in 14%-41% hence surgery remains standard of care, except for select situations. 相似文献
5.
6.
The scope of computerized simulation in competency-based maxillofacial training: a systematic review
《International journal of oral and maxillofacial surgery》2022,51(8):1101-1110
Oral and maxillofacial surgery (OMS) teaching is set to undergo a paradigm shift towards competency-based training. With increasing focus on resident skill development and patient safety, computerized simulators are likely to play a more mainstream role in OMS training. A systematic review of the available literature was conducted, in accordance with the PRISMA guidelines, to highlight the scope of computerized simulation in OMS teaching. A PubMed search was performed by two independent reviewers, and 35 articles published in English between 2010 and 2021 that reported the use of computerized simulation for teaching maxillofacial procedures were included in the analysis. Eight articles on minor oral surgery, seven on orthognathic surgery, five on maxillofacial trauma, five on cleft lip and palate surgery, three articles each on nerve block techniques, endoscopic procedures, and reconstructive surgery, and one article on fibre-optic intubation reported the use of computerized simulation that can be applied to OMS training. Ten randomized controlled trials were identified in the search. However there was marked heterogeneity among the studies. Simulator training for skill acquisition mentored by an expert OMS educator could offer holistic resident training; however more studies that test common themes of resident training such as knowledge acquisition and skill development are necessary. 相似文献
7.
《The British journal of oral & maxillofacial surgery》2022,60(4):470-474
Traditionally, surgical management of zygomaticomaxillary complex (ZMC) and orbital fractures occurs within two to three weeks of the injury, followed by an overnight admission to allow for extended eye observations. This is due to the risk of postoperative retrobulbar haemorrhage (RBH) or orbital compartment syndrome (OCS), a rapidly progressive and sight threatening emergency that requires immediate intervention. In September 2016 the oral and maxillofacial surgery (OMFS) department at Leeds Teaching Hospitals redesigned their trauma service with a full-time trauma consultant, a dedicated clinic, and a weekly morning elective trauma theatre list. This allowed for standardisation of the management of patients with OMFS injuries. Furthermore, a formal day-case ZMC and orbital fracture pathway was developed to allow patients to undergo surgical management of such fractures with a same-day discharge. This has since been identified as an area of excellence by the Getting It Right First Time (GIRFT) programme, and is in line with the addition of ZMC and orbital fractures to the procedural list written by the British Association of Day Case Surgery (BADS). Unbeknown to the unit, the volume of day-case procedures was the highest within the UK, demonstrating the importance of GIRFT in highlighting areas of good or unique practice. The aim of this study was to determine the impact of our day-case pathway and designated OMFS trauma service on compliance with recent recommendations by GIRFT and BADS. Secondly, it was to determine the safety of same-day discharge with regards to postoperative complications. 相似文献
8.
9.
10.