全文获取类型
收费全文 | 23515篇 |
免费 | 1850篇 |
国内免费 | 106篇 |
专业分类
耳鼻咽喉 | 259篇 |
儿科学 | 704篇 |
妇产科学 | 425篇 |
基础医学 | 2918篇 |
口腔科学 | 292篇 |
临床医学 | 2978篇 |
内科学 | 5523篇 |
皮肤病学 | 398篇 |
神经病学 | 1878篇 |
特种医学 | 744篇 |
外科学 | 3373篇 |
综合类 | 324篇 |
一般理论 | 17篇 |
预防医学 | 1921篇 |
眼科学 | 724篇 |
药学 | 1380篇 |
中国医学 | 52篇 |
肿瘤学 | 1561篇 |
出版年
2023年 | 131篇 |
2022年 | 157篇 |
2021年 | 469篇 |
2020年 | 265篇 |
2019年 | 522篇 |
2018年 | 555篇 |
2017年 | 429篇 |
2016年 | 454篇 |
2015年 | 483篇 |
2014年 | 715篇 |
2013年 | 1089篇 |
2012年 | 1497篇 |
2011年 | 1470篇 |
2010年 | 863篇 |
2009年 | 842篇 |
2008年 | 1412篇 |
2007年 | 1501篇 |
2006年 | 1505篇 |
2005年 | 1469篇 |
2004年 | 1400篇 |
2003年 | 1334篇 |
2002年 | 1205篇 |
2001年 | 340篇 |
2000年 | 320篇 |
1999年 | 291篇 |
1998年 | 253篇 |
1997年 | 233篇 |
1996年 | 176篇 |
1995年 | 237篇 |
1994年 | 175篇 |
1993年 | 140篇 |
1992年 | 218篇 |
1991年 | 177篇 |
1990年 | 180篇 |
1989年 | 165篇 |
1988年 | 175篇 |
1987年 | 174篇 |
1986年 | 149篇 |
1985年 | 136篇 |
1984年 | 134篇 |
1983年 | 143篇 |
1982年 | 141篇 |
1981年 | 125篇 |
1980年 | 119篇 |
1979年 | 100篇 |
1978年 | 99篇 |
1977年 | 110篇 |
1976年 | 87篇 |
1975年 | 62篇 |
1974年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 406 毫秒
1.
Dongbing Lai Emma C. Johnson Sarah Colbert Gayathri Pandey Grace Chan Lance Bauer Meredith W. Francis Victor Hesselbrock Chella Kamarajan John Kramer Weipeng Kuang Sally Kuo Samuel Kuperman Yunlong Liu Vivia McCutcheon Zhiping Pang Martin H. Plawecki Marc Schuckit Jay Tischfield Leah Wetherill Yong Zang Howard J. Edenberg Bernice Porjesz Arpana Agrawal Tatiana Foroud 《Alcoholism, clinical and experimental research》2022,46(3):374-383
2.
Anela Stanic Denis Rybin Francis Cannata Carole Hohl Jennifer Brody Jessie Gaeta 《AIDS care》2021,33(1):1-9
ABSTRACT The lack of stable housing can impair access and continuity of care for patients living with human immunodeficiency virus (HIV). This study investigated the relationship between housing status assessed at multiple time points and several core HIV-related outcomes within the same group of HIV patients experiencing homelessness. Patients with consistently stable housing (CSH) during the year were compared to patients who lacked CSH (non-CSH group). The study outcomes included HIV viral load (VL), CD4 counts, and health care utilization. Multivariable and propensity weighted analyses were used to assess outcomes adjusting for potential group differences. Of 208 patients, 88 (42%) had CSH and 120 (58%) were non-CSH. Patients with CSH had significantly higher proportion of VL suppression and higher mean CD4 counts. The frequency of nurse visits in the CSH group was less than a half of that in the non-CSH group. Patients with CSH were less likely to be admitted to the medical respite facility, and if admitted, their length of stay was about a half of that for the non-CSH group. Our study findings show that patients with CSH had significantly better HIV virologic control and immune status as well as improved health care utilization. 相似文献
3.
Dynamic LVOT Obstruction and Aortic Stenosis in the Same Patient: A Case of Challenging Doppler Hemodynamics 下载免费PDF全文
Matthew W. Parker M.D. Francis J. Kiernan M.D. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(6):1030-1032
We present a patient with both dynamic left ventricular outflow tract obstruction and valvular aortic stenosis. The aortic valve was calcified, and velocities and gradients measured by continuous‐wave Doppler met standard criteria for severe aortic stenosis. The increased subvalvular velocities invalidated assumptions of the simplified Bernoulli equation; correction using the longer form of the Bernoulli equation suggested a lower but still significant gradient. The complex shape of the subvalvular spectral Doppler envelope indicated supranormal systolic function and dynamic left ventricular outflow obstruction. Left heart catheterization with an end‐hole catheter was required to determine the subvalvular and valvular components of the obstruction. 相似文献
4.
5.
6.
7.
Victoria A. Chang Dawn M. Meyer Brett C. Meyer 《Journal of stroke and cerebrovascular diseases》2019,28(1):163-166
Background
Acute stroke codes may be activated for anisocoria, but how often these codes lead to a final stroke diagnosis or alteplase treatment is unknown. The purpose of this study was to assess the frequency of anisocoria in stroke codes that ultimately resulted in alteplase administration.Methods
We retrospectively assessed consecutive alteplase-treated patients from a prospectively-collected stroke registry between February 2015 and July 2018. Based on the stroke code exam, patients were categorized as having isolated anisocoria [A+(only)], anisocoria with other findings [A+(other)], or no anisocoria [A?]. Baseline demographics, stroke severity, alteplase time metrics, and outcomes were also collected.Results
Ninety-six patients received alteplase during the study period. Of the 94 who met inclusion criteria, there were 0 cases of A+(only). There were 9 cases of A+(other) (9.6%). A+(other) exhibited higher baseline National Institutes of Health (NIH) Stroke Scale scores compared to A? (17 versus 7; P?=?.0003), and no additional differences in demographics or alteplase time metrics. Final stroke diagnosis and other outcome measures were no different between A+(other) and A?. Of the A+ patients without pre-existing anisocoria, 5 of 6 (83%) had posterior circulation events or diffuse subarachnoid hemorrhage.Conclusions
In this exploratory analysis, zero patients with isolated anisocoria received alteplase treatment. Anisocoria as a part of the neurologic presentation occurred in 10% of alteplase patients, and was strongly associated with a posterior circulation event. Therefore, we conclude that anisocoria has a higher likelihood of leading to alteplase treatment when identified in the presence of other neurologic deficits. 相似文献8.
Bernard Natukunda Grace Ndeezi Lay See Er Francis Bajunirwe Gayle Teramura Meghan Delaney 《ISBT科学丛刊》2019,14(4):366-373
9.
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
10.