全文获取类型
收费全文 | 47368篇 |
免费 | 4482篇 |
国内免费 | 3609篇 |
专业分类
耳鼻咽喉 | 298篇 |
儿科学 | 426篇 |
妇产科学 | 482篇 |
基础医学 | 5622篇 |
口腔科学 | 740篇 |
临床医学 | 6876篇 |
内科学 | 7390篇 |
皮肤病学 | 585篇 |
神经病学 | 2591篇 |
特种医学 | 1917篇 |
外国民族医学 | 23篇 |
外科学 | 4326篇 |
综合类 | 7670篇 |
现状与发展 | 15篇 |
一般理论 | 7篇 |
预防医学 | 2870篇 |
眼科学 | 1463篇 |
药学 | 5004篇 |
81篇 | |
中国医学 | 2832篇 |
肿瘤学 | 4241篇 |
出版年
2024年 | 124篇 |
2023年 | 768篇 |
2022年 | 1967篇 |
2021年 | 2602篇 |
2020年 | 1949篇 |
2019年 | 1646篇 |
2018年 | 1752篇 |
2017年 | 1510篇 |
2016年 | 1449篇 |
2015年 | 2159篇 |
2014年 | 2629篇 |
2013年 | 2330篇 |
2012年 | 3453篇 |
2011年 | 3879篇 |
2010年 | 2355篇 |
2009年 | 1848篇 |
2008年 | 2473篇 |
2007年 | 2540篇 |
2006年 | 2470篇 |
2005年 | 2564篇 |
2004年 | 1482篇 |
2003年 | 1329篇 |
2002年 | 1106篇 |
2001年 | 1098篇 |
2000年 | 1146篇 |
1999年 | 1205篇 |
1998年 | 781篇 |
1997年 | 795篇 |
1996年 | 618篇 |
1995年 | 568篇 |
1994年 | 515篇 |
1993年 | 300篇 |
1992年 | 378篇 |
1991年 | 308篇 |
1990年 | 282篇 |
1989年 | 242篇 |
1988年 | 230篇 |
1987年 | 203篇 |
1986年 | 151篇 |
1985年 | 110篇 |
1984年 | 50篇 |
1983年 | 38篇 |
1982年 | 19篇 |
1981年 | 12篇 |
1980年 | 13篇 |
1979年 | 12篇 |
1966年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
12.
13.
14.
15.
16.
目的分析早发型子痫前期应用低分子肝素期待治疗的临床效果。方法回顾分析2017-01—2018-12间在郑州大学第一附属医院产科终止妊娠的95例早发型子痫前期患者的临床资料。按终止妊娠前是否应用低分子肝素分为2组。对照组(47例)给予降压、解痉等治疗;观察组(48例)在对照组基础上加用低分子肝素。结果2组分娩孕周、妊娠延长时间、妊娠并发症发生率、新生儿出生体质量、新生儿窒息及胎儿宫内窘迫发生率、新生儿Apgar评分等,差异均无统计学意义(P>0.05)。结论对早发型子痫前期患者在常规治疗基础上短期应用低分子肝素,不能延长妊娠时间,不改善母婴结局。 相似文献
17.
随着腔镜技术的进一步发展以及微创理念应用于结直肠外科疾病的诊治中,结直肠相关疾病的诊治发生了翻天覆地的变化。由传统的经腹手术到腹腔镜手术、经自然腔道手术,再到经自然腔道取标本手术(NOSES),结直肠疾病的外科诊治在微创领域取得了巨大成果。NOSES技术是目前结直肠外科在微创领域前沿的手术方式之一,它通过经直肠、阴道取标本来避免了腹壁的辅助取标本切口,从而将结直肠外科手术进一步微创化。NOSES技术集传统腹腔镜手术的优势与现代微创外科的理念于一体,它在确保手术效果的基础上集中体现了微创、加速康复外科、功能外科、"无疤"等理念的特点。本文主要就国内外各中心开展NOSES技术在结直肠外科诊治开展中的相关经验、心得和体会进行综述。 相似文献
18.
By means of the ultrasonic surface impact (amplitude of 30 μm, strike number of 48,000 times/mm2), nanograins have been achieved in the surfaces of both Ti6Al4V(TC4) and Ti3Zr2Sn3Mo25Nb(TLM) titanium alloys, mainly because of the dislocation motion. Many mechanical properties are improved, such as hardness, residual stress, and roughness. The rotating–bending fatigue limits of TC4 and TLM subjected to ultrasonic impact are improved by 13.1% and 23.7%, separately. Because of the bending fatigue behavior, which is sensitive to the surface condition, cracks usually initiate from the surface defects under high stress amplitude. By means of an ultrasonic impact tip with the size of 8 mm, most of the inner cracks present at the zone with a depth range of 100~250 μm in the high life region. The inner crack core to TC4 usually appears as a deformed long and narrow α-phase, while the cracks in TLM specimens prefer to initiate at the triple grain boundary junctions. This zone crosses the grain refined layer and the deformed coarse grain layer. With the gradient change of elastic parameters, the model shows an increase of normal stress at this zone. Combined with the loss of plasticity and toughness, it is easy to understand these fatigue behaviors. 相似文献
19.
Xiaojie Wu Leyan Zhang Jiadi Zhou Luying Liu Qiang Fu Aili Fu Xiaoying Feng Rui Xin Hongrui Liu Yong Gao Jiangnan Xue 《Current problems in cancer》2019,43(1):18-26
Aim
Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is an immune inhibitory receptor which is expressed within most types of hematopoietic cells and negatively regulates immune responses. Recently, we found LAIR-1 expression to be present within tumors of nonhematopoietic lineages. However, the roles of LAIR-1 in hepatocellular carcinoma (HCC) have yet to be examined. The purpose of this study was to investigate the expression of LAIR-1 in HCC tissue and assess its clinical significance at this site.Materials and methods
Expression levels of LAIR-1 within HCC samples collected from 90 patients and compared with that of slides of normal liver tissue collected from 9 non-HCC patients were measured by immunohistochemistry using tissue microarrays. A semiquantitative score was assigned, as was based on staining intensity and percent of positive cells and a Spearman Rank correlation test was used to assess any potential significant correlations between LAIR-1 expression and clinicopathological factors. Overall survival analysis was performed using the Kaplan-Meier and Log Rank statistical test.Results
LAIR-1 expression was detected in cancer tissue and adjacent tumor tissue, but not in normal liver tissue. The percent of LAIR-1-positive expression in cancer tissue of HCC samples was 97.78% (88/90) while that in adjacent tumor tissue was 96.67% (87/90). Significantly greater expression levels of LAIR-1 were obtained from cancer tissue (Mean?±?SD?=?5.722?±?2.145) than that in adjacent tumor tissue (4.141?±?1.486). In addition, LAIR-1 expression was found to be significantly correlated with pathological grade of HCC, T stage, and age. Expression levels of LAIR-1 were related with worse overall survival rates of HCC patients, especially in HCC patients with hepatic cirrhosis.Conclusion
Results of this study show that LAIR-1 is expressed in HCC tissues and that high levels of LAIR-1 expression are associated with the poor cancer differentiation. In addition, overexpression of LAIR-1 was significantly associated with worse overall survival in the patients with HCC. These data suggest that LAIR-1 may be an independent predictor for clinical outcomes in patients with HCC. 相似文献20.