全文获取类型
收费全文 | 18722篇 |
免费 | 1184篇 |
国内免费 | 234篇 |
专业分类
耳鼻咽喉 | 227篇 |
儿科学 | 263篇 |
妇产科学 | 292篇 |
基础医学 | 2880篇 |
口腔科学 | 267篇 |
临床医学 | 1497篇 |
内科学 | 3811篇 |
皮肤病学 | 485篇 |
神经病学 | 1316篇 |
特种医学 | 1489篇 |
外科学 | 2525篇 |
综合类 | 54篇 |
一般理论 | 1篇 |
预防医学 | 607篇 |
眼科学 | 444篇 |
药学 | 1905篇 |
中国医学 | 306篇 |
肿瘤学 | 1771篇 |
出版年
2023年 | 95篇 |
2022年 | 418篇 |
2021年 | 675篇 |
2020年 | 333篇 |
2019年 | 491篇 |
2018年 | 531篇 |
2017年 | 485篇 |
2016年 | 711篇 |
2015年 | 965篇 |
2014年 | 1128篇 |
2013年 | 1287篇 |
2012年 | 1812篇 |
2011年 | 1756篇 |
2010年 | 1152篇 |
2009年 | 886篇 |
2008年 | 1193篇 |
2007年 | 1094篇 |
2006年 | 941篇 |
2005年 | 954篇 |
2004年 | 749篇 |
2003年 | 655篇 |
2002年 | 501篇 |
2001年 | 185篇 |
2000年 | 194篇 |
1999年 | 150篇 |
1998年 | 114篇 |
1997年 | 77篇 |
1996年 | 64篇 |
1995年 | 47篇 |
1994年 | 29篇 |
1993年 | 28篇 |
1992年 | 48篇 |
1991年 | 48篇 |
1990年 | 36篇 |
1989年 | 36篇 |
1988年 | 28篇 |
1987年 | 33篇 |
1986年 | 26篇 |
1985年 | 26篇 |
1984年 | 16篇 |
1983年 | 17篇 |
1982年 | 14篇 |
1981年 | 8篇 |
1980年 | 8篇 |
1979年 | 10篇 |
1978年 | 9篇 |
1976年 | 8篇 |
1973年 | 10篇 |
1971年 | 10篇 |
1968年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
1.
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
2.
3.
Moderate sedatives have been increasingly used to improve patient comfort during flexible bronchoscopy (FB). However, routine use of moderate sedation during FB is controversial because its efficacy and safety are not well established.This study aims to evaluate the efficacy and safety of moderate sedation during FB.A search was made of Medline, EMBASE, and the Cochrane Library to May 2014.Randomized controlled trials (RCTs) and quasi-RCTs were included.The main analysis was designed to examine the efficacy of moderate sedation during FB in sedation than no-sedation.The willingness to repeat FB was significantly more in sedation than no-sedation (odds ratio [OR] 2.30; 95% confidence interval [CI] 1.11–4.73; P = 0.02; I2 = 22.5). The duration of FB was shorter in sedation group than no-sedation group (standardized mean difference [SMD] −0.21; 95% CI −0.38 to −0.03; P = 0.02; I2 = 78.3%). Event of hypoxia was not significantly different between sedation and no-sedation groups (OR 0.86; 95% CI 0.42–1.73; P = 0.67; I2 = 0%). The SpO2 during procedure was not different between sedation and no-sedation groups (SMD −0.14; 95% CI −0.37 to 0.08; P = 0.21; I2 = 49.9%). However, in subgroup analysis without supplemental oxygen, the SpO2 was significantly lower in sedation than no-sedation group (SMD −0.45; 95% CI −0.78 to −0.11; P = 0.01; I2 = 0.0%).According to this meta-analysis, moderate sedation in FB would be useful in patients who will require repeated bronchoscopies as well as safe in respiratory depression. To our knowledge, although the various sedative drugs are already used in the real field, this analysis was the first attempt to quantify objective results. We anticipate more definite and studies designed to elucidate standardized outcomes for moderate sedation in FB. 相似文献
4.
5.
6.
Paul Tetteh Asare Nadeeka Bandara Tae-Yong Jeong Sangryeol Ryu Jochen Klumpp Kwang-Pyo Kim 《Archives of virology》2015,160(10):2647-2650
7.
Hae June Lee Yeonghoon Son Minyoung Lee Changjong Moon Sung Ho Kim In Sik Shin Miyoung Yang Sangwoo Bae Joong Sun Kim 《中国神经再生研究》2019,(9)
Sodium butyrate is a histone deacetylase inhibitor that affects various types of brain damages. To investigate the effects of sodium butyrate on hippocampal dysfunction that occurs after whole-brain irradiation in animal models and the effect of sodium butyrate on radiation exposure-induced cognitive impairments,adult C57BL/6 mice were intraperitoneally treated with 0.6 g/kg sodium butyrate before exposure to 10 Gy cranial irradiation. Cognitive impairment in adult C57BL/6 mice was evaluated via an object recognition test 30 days after irradiation. We also detected the expression levels of neurogenic cell markers(doublecortin)and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor. Radiation-exposed mice had decreased cognitive function and hippocampal doublecortin and phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression. Sodium butyrate pretreatment reversed these changes. These findings suggest that sodium butyrate can improve radiation-induced cognitive dysfunction through inhibiting the decrease in hippocampal phosphorylated cAMP response element binding protein/brain-derived neurotrophic factor expression. The study procedures were approved by the Institutional Animal Care and Use Committee of Korea Institute of Radiological Medical Sciences(approval No. KIRAMS16-0002) on December 30, 2016. 相似文献
8.
9.
10.