全文获取类型
收费全文 | 9058篇 |
免费 | 2674篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 142篇 |
儿科学 | 166篇 |
妇产科学 | 252篇 |
基础医学 | 290篇 |
口腔科学 | 337篇 |
临床医学 | 3377篇 |
内科学 | 1758篇 |
皮肤病学 | 242篇 |
神经病学 | 974篇 |
特种医学 | 323篇 |
外科学 | 1546篇 |
综合类 | 100篇 |
预防医学 | 1232篇 |
眼科学 | 412篇 |
药学 | 125篇 |
1篇 | |
肿瘤学 | 509篇 |
出版年
2024年 | 51篇 |
2023年 | 479篇 |
2022年 | 82篇 |
2021年 | 214篇 |
2020年 | 363篇 |
2019年 | 144篇 |
2018年 | 639篇 |
2017年 | 711篇 |
2016年 | 651篇 |
2015年 | 677篇 |
2014年 | 785篇 |
2013年 | 803篇 |
2012年 | 247篇 |
2011年 | 259篇 |
2010年 | 500篇 |
2009年 | 667篇 |
2008年 | 242篇 |
2007年 | 177篇 |
2006年 | 217篇 |
2005年 | 145篇 |
2004年 | 100篇 |
2003年 | 92篇 |
2002年 | 98篇 |
2001年 | 205篇 |
2000年 | 92篇 |
1999年 | 194篇 |
1998年 | 284篇 |
1997年 | 296篇 |
1996年 | 348篇 |
1995年 | 246篇 |
1994年 | 250篇 |
1993年 | 204篇 |
1992年 | 166篇 |
1991年 | 128篇 |
1990年 | 90篇 |
1989年 | 97篇 |
1988年 | 91篇 |
1987年 | 90篇 |
1986年 | 80篇 |
1985年 | 67篇 |
1984年 | 61篇 |
1983年 | 63篇 |
1982年 | 54篇 |
1981年 | 38篇 |
1980年 | 35篇 |
1979年 | 34篇 |
1978年 | 27篇 |
1977年 | 25篇 |
1975年 | 32篇 |
1971年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
R. Langevin PhD R. Lang PhD R. Reynolds PhD P. Wright MA D. Garrels MA V. Marchese BSc L. Handy G. Pugh PhD R. Frenzel BSc 《Sexual abuse : a journal of research and treatment》1988,1(1):13-32
Test properties of the Millon Clinical Multiaxial Inventory (MCMI) were examined in a sample of 419 sex offenders and controls in three different settings. The offender group included sexual aggressives, pedophiles, incest perpetrators and miscellaneous cases. Nineteen of the 20 scales of the MCMI had alpha reliability over 0.60 and for 13 scales it was over 0.80. The scales showed satisfactory discriminant validity from age but 9 scales showed a moderate influence of intelligence scores and education. Criminal history did not influence scale results. The scales unfortunately did show significant correlations with MMPI validity scales. Although the scales were not susceptible to naive lying, they were influenced by social desirability especially. Four factors were extracted in principal axes factor analysis that accounted for 91.2% of the total variance. The first factor explained 58.2% of the variance and was labeled general psychopathology. The other three factors suggested psychotic tendencies, extraversion and the bipolar dependency-antisocial tendencies. When the groups were compared, almost all scales significantly differentiated them. When the MMPI F-K Scale was forced to enter a stepwise discriminant analysis first, five scales still were significant; Narcissistic, Schizoid-Asocial, Alcohol Abuse, Paranoid, & Dependent-Submissive scales. The MCMI taps important dimensions in sex offenders but suffers from validity problems. 相似文献
62.
63.
64.
65.
Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm). 相似文献
66.
The authors report the clinical and laboratory findings of a patient who had severe immune hemolytic anemia due to hydrochlorothiazide (HCTZ). In this case, the HCTZ antibody reacted not only with other thiazide and thiazide-like drugs, but also with a chemically unrelated diuretic, ethacrynic acid. These results indicate that HCTZ antibody activity is not restricted solely to the thiazides and imply that therapy with any of the reactive drugs would be contraindicated for this patient. The serologic screening for drug reactivity may be useful for selecting alternative therapy for patients with drug-induced immune hemolytic anemia. 相似文献
67.
68.
Gender differences in informal caring 总被引:1,自引:0,他引:1
Men have hitherto largely been invisible in research on informal care. This paper examines gender differences in informal caring, focusing on gender differences according to the relationship between the carer and care-recipient and the location of caring. The paper uses secondary analysis of the 1990–91 General Household Survey, which identified over 2700 adults as informal carers. Four per cent of men and women provide care for someone living in the same household. More women than men, 13% compared with 10%, provide care for someone living in another household. Men carers are less involved in care provision than women, providing fewer hours of care each week, and are less likely to be the main carer. However, gender differences are most marked among married carers, apart from those caring for their spouse, and least among unmarried carers. Married men can often rely on their wives to perform caring roles rather than performing them personally. Women carers are more likely to provide personal care than men carers, but the gender difference is least among those caring for their spouse or for disabled children. Cross-sex personal care is performed within the marital relationship and by parents caring for disabled children, but seldom by adult children caring for their parents or in more distant caring relationships. Evidence of cross-sex taboos in giving personal care is largely restricted to care provided in another household. Since the majority of elderly people in need of care are women, such cultural taboos may reinforce the pressure on mid-life women to care for mothers and mothers-in-law. 相似文献
69.
Balloon dilatation of the aortic valve was attempted 16 times in 15 patients with severe aortic stenosis. None died but one had a transient stroke after the procedure. At dilatation the gradient across the aortic valve was reduced by greater than 30% in 69% of patients and the Gorlin valve area (calculated in 7/15 patients) increased by 30% in half. But a comparison of Doppler gradients measured before and one to two days after dilatation in 11 patients showed a greater than 30% reduction in the simultaneously measured gradient in only four. Doppler gradient was the most accurate predictor of symptomatic benefit and a fall in Doppler gradient persisted mainly in patients whose peak to peak gradient fell by at least 40% at the time of the procedure. Balloon dilatation of the aortic valve is a relatively safe procedure but it is less successful than previous reports suggest, perhaps because of early restenosis. Some forms of aortic stenosis may be more amenable to this procedure than others. 相似文献
70.
U.M. Hodges BSc Hons MBBS FRCA S. Berg BSc MBBS FRCA S.K. Naik FRCS S. Bower MBChB PhD A. Lloyd-Thomas MBBS FRCA M. Elliot MD FRCS 《Journal of cardiothoracic and vascular anesthesia》1994,8(6)
Modified ultrafiltration after cardiopulmonary bypass in children has been shown to be associated with an increase in arterial blood pressure. As part of a series of studies to investigate the possible causes of this blood pressure elevation, the hypothesis that if filtration was removing a significant amount of fentanyl, then the increase in blood pressure might be due to pain was proposed. Ten children, aged between 0.5 and 9.3 years (median 3.8 years), weighing 5.9 to 25..5 kg (median 15.7 kg), underwent corrective cardiac surgery (incorporating modified ultrafiltration). A standard anesthetic protocol was followed, with up to 78 μg/kg of fentanyl given prebypass for analgesia. After completion of cardiopulmonary bypass, modified ultrafiltration was commenced at 100 mL/min until a hematocrit of 35% was reached. Samples were taken of arterial blood (prefiltration, 3, 10, and 20 minutes postfiltration), the venous reservoir blood (prefiltration) and the filtrate (5 and 10 minutes into filtration). Hemodynamic data were recorded both prefiltration and postfiltration. The hemodynamic data showed the expected rise in both systemic arterial pressure and cardiac index after ultrafiltration. The plasma fentanyl concentrations did not significantly change after ultrafiltration: 1.59 to 12.39 ng/mL (median 6.27 ng/mL) prefiltration and 2.05 to 15.59 ng/mL (6.29 ng/mL) at 3 minutes, 2.22 to 12.64 ng/mL (6.87 ng/mL) at 10 minutes, and 1.83 to 11.52 ng/mL (5.85 ng/mL) at 20 minutes postfiltration. The concentration of fentanyl in the venous reservoir, 2.06 to 11.64 ng/mL (7.04 ng/mL), was not significantly different from the plasma levels. The level of fentanyl in the filtrate was significantly less than the plasma levels, 0.243 to 1.87 ng/mL (0.894 ng/mL) at 5 minutes and 0.385 to 1.688 ng / mL (0.952 ng / mL) at 10 minutes into filtration; (P < 0.02 by the Wilcoxon signed-rank method). The data show that the plasma fentanyl concentration was not significantly reduced by modified ultrafiltration. The fentanyl levels found prefiltration were maintained postfiltration, and the observed changes in systemic arterial pressure were not due to an acute fall in the plasma concentration of analgesic drug. 相似文献