全文获取类型
收费全文 | 8324篇 |
免费 | 25篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 1029篇 |
妇产科学 | 315篇 |
基础医学 | 669篇 |
口腔科学 | 267篇 |
临床医学 | 309篇 |
内科学 | 1936篇 |
皮肤病学 | 300篇 |
神经病学 | 289篇 |
特种医学 | 210篇 |
外科学 | 2051篇 |
综合类 | 35篇 |
预防医学 | 188篇 |
眼科学 | 208篇 |
药学 | 254篇 |
中国医学 | 49篇 |
肿瘤学 | 208篇 |
出版年
2023年 | 14篇 |
2022年 | 10篇 |
2021年 | 139篇 |
2020年 | 14篇 |
2019年 | 1159篇 |
2018年 | 901篇 |
2017年 | 505篇 |
2016年 | 8篇 |
2015年 | 16篇 |
2014年 | 45篇 |
2013年 | 38篇 |
2012年 | 20篇 |
2011年 | 31篇 |
2010年 | 23篇 |
2009年 | 34篇 |
2008年 | 19篇 |
2007年 | 24篇 |
2006年 | 27篇 |
2005年 | 24篇 |
2004年 | 24篇 |
2003年 | 15篇 |
2002年 | 19篇 |
2001年 | 18篇 |
2000年 | 20篇 |
1999年 | 20篇 |
1998年 | 13篇 |
1997年 | 14篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1991年 | 5篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 438篇 |
1984年 | 632篇 |
1983年 | 326篇 |
1982年 | 512篇 |
1981年 | 427篇 |
1980年 | 356篇 |
1979年 | 409篇 |
1978年 | 329篇 |
1977年 | 341篇 |
1976年 | 403篇 |
1975年 | 340篇 |
1974年 | 301篇 |
1973年 | 303篇 |
1972年 | 4篇 |
排序方式: 共有8354条查询结果,搜索用时 78 毫秒
101.
Arterial pulse wave velocities, pulse wave contours, and systolic time intervals were recorded in thirty-nine diabetic children and were compared with recordings taken in twenty-seven normal children. Systolic time intervals were similar in the two groups of subjects. However, brachial and aortic pulse wave velocities were significantly greater in the diabetic than in the normal children (p < 0.025 and < 0.005, respectively). Also, in the diabetic children the time interval from the incisura to the midpoint of the dicrotic wave (I-D) was significantly shortened in both the brachial (p < 0.005) and carotid (p < 0.05) pulse waves as compared to the normal children. These changes in pulse wave velocity and contour are associated with increased wall stiffness that occurs with aging and suggest that the large arteries of diabetic children may exhibit acceleration of the aging process. The severity of these changes bore no direct correlation with the degree of carbohydrate intolerance as judged by insulin requirement. 相似文献
102.
Echocardiographic findings from 10 patients without clinical indications of aortic root dissection or aortic valve disease from 1 patient with angiographic confirmation of aortic root dissection are reported and compared. Previously reported echocardiographic findings were confirmed in the patient with aortic root dissection. These include (1) a widened posterior or anterior aortic wall, or both; (2) parallel motion of the separated margins of the aortic walls; and (3) aortic root dilatation (42 mm or more at end-systole). However, all three findings were also noted in 5 of the 10 patients without clinical indications of aortic root dissection or aortic valve disease, and at least two of the three findings were noted in the remaining 5 patients. Echocardiographic detection of aortic root dissection appears to be most reliable when clinical indications of the anomaly are present. 相似文献
103.
Isometric handgrip (IHG) imposes an acutely increased afterload on the left ventricle. Utilizing systolic time intervals, we studied various responses to IHG, measured as changes from resting values with near-maximum IHG, in old normal (ON) subjects, young normal (YN) subjects, and old patients with hypertensive heart disease (HHD) and patients with coronary artery disease (CAD). There were no differences in responses to IHG between ON and patients with HHD or patients with CAD. However, there were clear differences between the responses of ON and YN subjects. Increase in heart rate (HR) was much more prominent in YN (ON vs. YN = +11.6 +/- 2.6 vs. +15.6 +/- 5.7 beats per minute p less than 0.001). Pre-ejection period (PEP) end isovolumic contraction time (IVCT) increased in ON but decreased in YN (PEP + 6.2 +/- 1.7 vs. -11.0 +/- 3.7 msec., p less than 0.001; IVCT +8.1 +/- 2.2 vs. -13.8 +/- 3.4 msec., p less than 0.001. Shortening of LVET was much more marked in YN (-6.5 +/- 4.1 VS. -63.3 +/- 9.9 msec. p less than 0.001), but this was entirely due to the HR differences since there was no difference in ejection time index (+ 5.1 +/- 3.4 vs. -0.4 +/- 7.3 msec. p greater than 0.5). IHG produced no significant differences between ON and YN in the timing of the "mitral" component of the first heart sound (q-Im), in the ratio PEP/LVET, or in pulse transmission time (PTT). By contrast, resting control PTT was markedly short in ON, especially those with CAD. Resting PTT in ON was 27.1 +/- 2.6 msec.; in YN 43.7 +/- 1.4 msec.; in CAD patients 20.7 +/- 1.3 msec. We conclude that even near-maximal IHG does not seem to be an adequate noninvasive screening test for cardiovascular disease in that age alone seems to have the most significant influence on the responses. 相似文献
104.
R Ruffy P Smith M Laseter R Lal S S Kim 《Journal of the American College of Cardiology》1985,6(2):482-485
A 42 year old man who survived sudden cardiac death was treated with an automatic implantable cardioverter/defibrillator. After a 5 month symptom-free interval, the patient received two internal discharges in the conscious state while wearing an ambulatory electrocardiographic recorder. Analysis of the tape revealed that both discharges were activated by two bursts of polymorphous ventricular tachycardia, the first one occurring at the end and the second at the onset of episodes of slow, hemodynamically stable monomorphous ventricular tachycardia. This case illustrates the reliability of the automatic implantable cardioverter/defibrillator as an antiventricular tachycardia device and the problem posed by its exposure to nonsustained ventricular tachycardia. 相似文献
105.
106.
107.
108.
109.
110.
Mariana Ciobanu Abdul S. Abbasi Marty Allen Alan Hermer Richard Spellberg 《The American journal of cardiology》1982,49(2):339-343
Detection and estimation of the degree of chronic aortic insufficiency with pulsed Doppler echocardiography was attempted in 27 patients documented to have aortic insufficiency on aortography. Twenty-five patients had associated aortic stenosis or mitral valve disease, or both. A disturbed diastolic flow within the left ventricular outflow tract was recorded in all but one patient (Doppler sensitivity 96 percent). Aortic insufficiency was clinically undetected In three patients (clinical sensitivity 89 percent). In a small number of patients Doppler echocardiography also appeared to be highly specific for this disorder. The Doppler technique estimated the degree of aortic Insufficiency by assessing the distribution of diastolic flow within the outflow tract and the body of the left ventricle. A significant correlation between the Doppler method and the angiographic estimation of aortic insufficiency was found (r = 0.88, p < 0.01). 相似文献