全文获取类型
收费全文 | 2446篇 |
免费 | 211篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 46篇 |
妇产科学 | 22篇 |
基础医学 | 158篇 |
口腔科学 | 29篇 |
临床医学 | 209篇 |
内科学 | 204篇 |
皮肤病学 | 39篇 |
神经病学 | 43篇 |
特种医学 | 44篇 |
外科学 | 157篇 |
综合类 | 497篇 |
预防医学 | 633篇 |
眼科学 | 24篇 |
药学 | 407篇 |
4篇 | |
中国医学 | 124篇 |
肿瘤学 | 36篇 |
出版年
2024年 | 5篇 |
2023年 | 29篇 |
2022年 | 71篇 |
2021年 | 118篇 |
2020年 | 113篇 |
2019年 | 92篇 |
2018年 | 65篇 |
2017年 | 80篇 |
2016年 | 85篇 |
2015年 | 95篇 |
2014年 | 172篇 |
2013年 | 196篇 |
2012年 | 235篇 |
2011年 | 239篇 |
2010年 | 141篇 |
2009年 | 112篇 |
2008年 | 115篇 |
2007年 | 151篇 |
2006年 | 104篇 |
2005年 | 82篇 |
2004年 | 61篇 |
2003年 | 56篇 |
2002年 | 47篇 |
2001年 | 25篇 |
2000年 | 31篇 |
1999年 | 25篇 |
1998年 | 17篇 |
1997年 | 19篇 |
1996年 | 10篇 |
1995年 | 12篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 7篇 |
1981年 | 3篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
排序方式: 共有2691条查询结果,搜索用时 31 毫秒
1.
2.
3.
《The Journal of thoracic and cardiovascular surgery》2023,165(2):449-459.e4
ObjectiveThe objective of this study was to investigate the association between morphological variation and postsurgical pulmonary vein (PV) stenosis (PPVS) in patients with cardiac total anomalous pulmonary venous connection (TAPVC).MethodsThis single-center, retrospective study included 168 pediatric patients who underwent surgical repair of cardiac TAPVC from 2013 to 2019 (connection to the coronary sinus [CS], n = 136; connection directly to the right atrium [RA], n = 32). Three-dimensional computed tomography modeling and geometric analysis were performed to investigate the morphological features; their relevance to the PPVS was examined.ResultsThe connection type had no association with PPVS (CS type: 18% vs right atrial type: 19%; P = .89) but there was a higher incidence of PPVS in patients with a single PV orifice than > 1 orifice (P < .001). Confluence-to-total PV area ratio (hazard ratio, 4.78, 95% CI, 1.86-12.32; P = .001) and length of drainage route (hazard ratio, 1.22; 95% CI, 1.14-1.31; P < .001) had a 4- and 1-fold increase in the risk for PPVS in the CS type after adjustment for age and preoperative pulmonary venous obstruction. In the right atrial type, those with anomalous PV return to the RA roof were more likely to develop PPVS than to the posterior wall of the RA (P < .001).ConclusionsThe number of inter-junction PV orifice correlated with PPVS development in cardiac TAPVC. The confluence-to-total PV ratio, length of drainage route, and anomalous PV return to the RA roof are important predictors for PPVS. Morphological subcategorization in this clinical setting can potentially assist in surgical decision-making. 相似文献
4.
多囊卵巢综合征是一种生殖功能障碍与糖代谢异常并存的内分泌紊乱综合征。是目前青中年妇女发病率较高的内分泌系统疾病,此病可由多方面因素诱发引起下丘脑-垂体-卵巢功能轴紊乱。是育龄期妇女月经不调,不孕等疾病的主要诱因。 相似文献
5.
Objective
To determine the association between provider training level and postplacental intrauterine device (IUD) outcomes following insertion instruction by email only.Study design
We conducted a single-center chart review of demographics, insertion and clinical outcomes within 6 months of delivery for 116 patients who underwent postplacental levonorgestrel 52?mg IUD placement from October 1, 2016, to March 31, 2017.Results
We confirmed IUD retention, removal or expulsion in 87 of 116 (75.0%) patients by 6 months after delivery. Complete expulsion or removal for malposition occurred in 20 (23.0%) patients and more frequently after vaginal than cesarean delivery (30.2% vs. 4.2%, OR 9.93 [95% CI 1.25–78.96]) and when a postgraduate year (PGY) 1 physician placed the IUD compared to a PGY 2–4 or attending physician (37.5% vs. 14.5%, OR 3.52 [95% CI 1.25–9.94]).Conclusion
Postplacental levonorgestrel 52?mg IUD expulsion rates are associated with provider training level as well as delivery route, though the individual association of each of these factors is difficult to ascertain given the high degree of collinearity between these two variables in our study. 相似文献6.
M.-D.-M. Amador F. Muratet E. Teyssou S. Boillée S. Millecamps 《Revue neurologique》2021,177(5):524-535
Due to novel gene therapy opportunities, genetic screening is no longer restricted to familial cases of ALS (FALS) cases but also aplies to the sporadic populations (SALS). Screening of four main genes (C9orf72, SOD1, TARDBP and FUS) identified the causes in 15% of Amyotrophic Lateral Sclerosis (ALS) patients (two third of the familial cases and 8% of the sporadic ones) but their respective contribution to ALS phenotype varies according the age of disease onset. The genetic overlap between ALS and other diseases is expanding and includes frontotemporal dementia, Paget's Disease of Bone, myopathy for adult cases, HSP and CMT for young cases highlighing the importance of retrieving the exhaustive familial history for each indivdual with ALS. Incomplete disease penetrance, diversity of the possible phenotypes, as well as the lack of confidence concerning the pathogenicity of most identified variants and/or possible oligogenic inheritance are burdens of ALS genetic counseling to be delivered to patients and at risk individuals. The multitude of rare ALS genetic causes identifed seems to converge to similar cellular pathways leading to inapropriate response to stress emphacising new potential therapeutic options for the disease. 相似文献
7.
The sortilin-related receptor 1 (SORL1) gene has been the subject of many studies focusing on frequent polymorphisms, which is associated with increased risk for Alzheimer’s Disease (AD). By whole-exome sequencing (WES), we identified two pathogenic missense mutations c.579C > G (p.F193L) and c.1397A > G (p.N466S) in SORL1. The two mutations were located in the same protein domain, and the two unrelated probands both had an onset of memory problems at less than 65 years of age, but their clinical manifestations and cranial imaging are different. The protein structure and function affected by these mutations were predicted using bioinformatics analysis, which suggested they were pathogenic. 3D protein structural analysis revealed that these amino acid substitutions might result in instability of protein structure and adverse intramolecular interactions. These findings suggest that both F193L and N466S should be thought as potential causative mutations in early-onset Alzheimer’s disease (EOAD) patients. Further functional studies are warranted to evaluate their roles in the pathogenesis of AD. 相似文献
8.
目的分析口腔感染患者病原菌分布及药敏情况,为临床合理用药提供参考。方法选取口腔感染患者86例作为研究对象,收集口腔分泌物进行病原菌培养,并行药敏实验。结果本组86例患者中,≤15岁、≥56岁口腔感染患者比例较高,分别占30.2%、40.7%。共检出病原菌351株,其中厌氧菌236株,占67.2%,其在厌氧菌中黑色素普氏菌比例最高(50.4%),其次为口腔链球菌(16.5%);需氧菌115株,占32.8%。对苯唑西林、头孢唑肟、庆大霉素、环丙沙星的耐药较高,分别为49.2%、46.6%、42.0%、40.2%;对万古霉素、四环素、头孢曲松的敏感性较高,分别为98.3%、95.8%、93.6%。结论厌氧菌是口腔感染较为常见的菌种,可选用万古霉素、四环素、头孢曲松等敏感性高的药物治疗。 相似文献
9.
10.
Adeline Tarantini Sylvie Huet Gérard Jarry Rachelle Lanceleur Martine Poul Ana Tavares Nádia Vital Henriqueta Louro Maria João Silva Valérie Fessard 《Environmental and molecular mutagenesis》2015,56(2):218-227
Synthetic amorphous silica (SAS) in its nanosized form is now used in food applications although the potential risks for human health have not been evaluated. In this study, genotoxicity and oxidative DNA damage of two pyrogenic (NM‐202 and 203) and two precipitated (NM‐200 and ‐201) nanosized SAS were investigated in vivo in rats following oral exposure. Male Sprague Dawley rats were exposed to 5, 10, or 20 mg/kg b.w./day for three days by gavage. DNA strand breaks and oxidative DNA damage were investigated in seven tissues (blood, bone marrow from femur, liver, spleen, kidney, duodenum, and colon) with the alkaline and the (Fpg)‐modified comet assays, respectively. Concomitantly, chromosomal damage was investigated in bone marrow and in colon with the micronucleus assay. Additionally, malondialdehyde (MDA), a lipid peroxidation marker, was measured in plasma. When required, a histopathological examination was also conducted. The results showed neither obvious DNA strand breaks nor oxidative damage with the comet assay, irrespective of the dose and the organ investigated. Similarly, no increases in chromosome damage in bone marrow or lipid peroxidation in plasma were detected. However, although the response was not dose‐dependent, a weak increase in the percentage of micronucleated cells was observed in the colon of rats treated with the two pyrogenic SAS at the lowest dose (5 mg/kg b.w./day). Additional data are required to confirm this result, considering in particular, the role of agglomeration/aggregation of SAS NMs in their uptake by intestinal cells. Environ. Mol. Mutagen. 56:218–227, 2015. © 2014 Wiley Periodicals, Inc. 相似文献