全文获取类型
收费全文 | 137286篇 |
免费 | 11563篇 |
国内免费 | 3620篇 |
专业分类
耳鼻咽喉 | 587篇 |
儿科学 | 4020篇 |
妇产科学 | 1383篇 |
基础医学 | 9421篇 |
口腔科学 | 1625篇 |
临床医学 | 19074篇 |
内科学 | 40995篇 |
皮肤病学 | 936篇 |
神经病学 | 3208篇 |
特种医学 | 3027篇 |
外国民族医学 | 2篇 |
外科学 | 14040篇 |
综合类 | 23639篇 |
现状与发展 | 16篇 |
一般理论 | 6篇 |
预防医学 | 6952篇 |
眼科学 | 507篇 |
药学 | 12279篇 |
130篇 | |
中国医学 | 8710篇 |
肿瘤学 | 1912篇 |
出版年
2024年 | 228篇 |
2023年 | 2352篇 |
2022年 | 2982篇 |
2021年 | 5731篇 |
2020年 | 5798篇 |
2019年 | 5196篇 |
2018年 | 4926篇 |
2017年 | 4938篇 |
2016年 | 5007篇 |
2015年 | 5185篇 |
2014年 | 9541篇 |
2013年 | 10393篇 |
2012年 | 7876篇 |
2011年 | 8781篇 |
2010年 | 6919篇 |
2009年 | 6631篇 |
2008年 | 6435篇 |
2007年 | 6587篇 |
2006年 | 5938篇 |
2005年 | 5403篇 |
2004年 | 4324篇 |
2003年 | 3713篇 |
2002年 | 3263篇 |
2001年 | 2931篇 |
2000年 | 2375篇 |
1999年 | 2178篇 |
1998年 | 1823篇 |
1997年 | 1769篇 |
1996年 | 1520篇 |
1995年 | 1426篇 |
1994年 | 1367篇 |
1993年 | 1026篇 |
1992年 | 959篇 |
1991年 | 877篇 |
1990年 | 702篇 |
1989年 | 680篇 |
1988年 | 594篇 |
1987年 | 517篇 |
1986年 | 469篇 |
1985年 | 567篇 |
1984年 | 462篇 |
1983年 | 294篇 |
1982年 | 333篇 |
1981年 | 322篇 |
1980年 | 237篇 |
1979年 | 197篇 |
1978年 | 178篇 |
1977年 | 141篇 |
1976年 | 133篇 |
1975年 | 76篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
92.
Nirmanmoh Bhatia Buddhadeb Dawn Tariq S. Siddiqui Marcus F. Stoddard 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》2015,42(1):16-24
Determining aortic stenosis (AS) severity is clinically important. Calculating aortic valve (AV) area by means of the continuity equation assumes a circular left ventricular outflow tract (LVOT). The full impact of this assumption in calculating AV area is unknown. Predictors of noncircular LVOT shape in patients with AS are undefined.In 109 adult patients with AS who underwent multiplanar transesophageal echocardiography, we calculated AV area by means of the standard continuity method and by a modified method involving planimetric LVOT area.We found 54 circular, 37 horizontal-oval, 8 vertical-oval, and 10 irregular LVOTs. Area derived by direct planimetry correlated better with the modified than the standard continuity method (r=0.89 vs r=0.85; both P=0.0001). Valve areas of patients with mild, moderate, or severe AS by planimetry were more often mischaracterized with use of the standard than modified method (29 vs 18; P <0.0001). Horizontal-oval AV area derived by planimetry (1.28 ± 0.55 cm2) was underestimated by the standard method (1.05 ± 0.47 cm2; P=0.001), but not by the modified method. Congenital AV morphology and low cardiac index were the only multivariate predictors of horizontal-oval shape. Low cardiac index was the only predictor of noncircular shape.More than half our patients with AS had noncircular LVOTs. Using the modified method reduces mischaracterizations of AS severity. Congenital AV morphology and low cardiac index predict horizontal-oval or noncircular shape. These data suggest the value of direct LVOT measurement to calculate AS severity in patients who have congenital AV or a low cardiac index. 相似文献
93.
Evaluation of training nurses to perform semi‐automated three‐dimensional left ventricular ejection fraction using a customised workstation‐based training protocol 下载免费PDF全文
94.
《Clinical therapeutics》2019,41(5):836-847
PurposeA role for the immune system in causing myalgic encephalopathy/chronic fatigue syndrome (ME/CFS) is long suspected, but few studies have looked for specific autoantibodies that might contribute to the symptoms. Our aim was to look for evidence of antibodies to neuronal proteins in patients with ME/CSF.MethodsSera samples from 50 patients and 50 healthy individuals were sent coded to the Neuroimmunology Laboratory in Oxford. Screening for antibody binding to neuronal tissue was performed on brain tissue and neuronal cultures. Specific serum antibodies were assessed by antigen-specific cell-based assays and radioimmunoassays. After antibody testing, the associations between seropositive status and clinical data were investigated.FindingsOverall, 8 patients and 11 participants were found to have some serum immunoreactivity toward neuronal or neuromuscular junction proteins, but only 1 patient and 2 participants had specific serum antibodies. Nevertheless, seropositive status in patients with ME was associated with shorter duration since onset and a more severe disease.ImplicationsThe results indicate no overall increased frequency of antibodies to neuronal proteins in ME/CSF and no evidence of a specific antibody that might be causative or contribute to clinical features in patients. However, the association of seropositive status with shorter duration of disease and more severe symptoms suggests a possible role of antibodies at onset in some patients and should be the focus of future studies. 相似文献
95.
96.
97.
《Journal of vascular and interventional radiology : JVIR》2019,30(6):781-789
Pelvic venous disorders (PeVDs) in women can present with chronic pelvic pain, lower-extremity and vulvar varicosities, lower-extremity swelling and pain, and left-flank pain and hematuria. Multiple evidence gaps exist related to PeVDs with the consequence that nonvascular specialists rarely consider the diagnosis. Recognizing this, the Society of Interventional Radiology Foundation funded a Research Consensus Panel to prioritize a research agenda to address these gaps. This paper presents the proceedings and recommendations from that Panel. 相似文献
98.
Paediatric palliative care and neurodisability are two relatively new, evolving paediatric sub-specialities that have increasing relevance in the current paediatric landscape. For many people palliative care has been synonymous with end of life care, but in paediatrics it encompasses much more and is for all children with life-threatening or life-limiting conditions, from the point of diagnosis. This breadth of focus is demonstrated well through the interface between paediatric palliative care and paediatric neurodisability. In this article we explore this unique interface through the three domains of complex symptom management, advanced care planning and end of life care. We describe the practicalities involved in all three areas and highlight the importance of early referral and the process of “dual” or “parallel” planning. We cover in more depth the specific management of the symptoms: dystonia/abnormalities of muscle tone, seizures, pain, agitation, secretions, respiratory failure, and gut failure. 相似文献
99.
目的研究人参、白术有效组分群对慢性萎缩性胃炎大鼠口腔、肠道菌群的影响。方法将大鼠随机分为空白组、模型组、给药(人参白术有效组分群)组,用主动免疫法复制慢性萎缩性胃炎模型。HE染色、扫描电子显微技术观察胃黏膜组织显微及超微结构,高通量测序技术检测肠道及口腔菌群,利用SPSS软件进行相关性分析。结果人参、白术有效组分群能改善慢性萎缩性胃炎大鼠胃组织病理形态(P<0.05);增加大鼠肠道、口腔菌群多样性及丰富度(P<0.05);减少肠道、口腔中致病菌群(普雷沃氏菌科_UCG-003、梭杆菌属)的数目(P<0.05)。其中,大鼠病理学评分与其口腔、肠道菌群的丰度、多样性以及门、属水平上的差异菌具有相关性(P<0.05)。结论人参、白术有效组分群对慢性萎缩性胃炎大鼠有良好的保护作用,缓解胃黏膜萎缩,其作用机制可能与改善肠道和口腔菌群有关。 相似文献
100.
目的:探究替米沙坦对冠心病合并糖尿病肾病患者疗效的影响情况。方法:56例探究目标对象均为某院接收的冠心病合并糖尿病肾病患者,挑选时间2018年6月~2019年6月。将"计算机表法"作为分组的参考,分配为参照组(n=28例)执行依那普利治疗,探究组(n=28例)执行替米沙坦治疗。结果:探究组的LVEF、LVEDd、肌酐、24h尿蛋白4项指标与参照组相比,差异有统计学意义(P<0.05);收缩压、舒张压、空腹血糖、餐后2h血糖4项指标与参照组相比,差异没有统计学意义(P>0.05)。结论:冠心病合并糖尿病肾病患者选择替米沙坦治疗后,心室功能的重构以及肾脏预后结局均得到改善,且临床效果比依那普利好,值得借鉴。 相似文献