全文获取类型
收费全文 | 1376篇 |
免费 | 115篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 87篇 |
妇产科学 | 18篇 |
基础医学 | 178篇 |
口腔科学 | 63篇 |
临床医学 | 113篇 |
内科学 | 345篇 |
皮肤病学 | 21篇 |
神经病学 | 87篇 |
特种医学 | 161篇 |
外科学 | 147篇 |
综合类 | 51篇 |
一般理论 | 1篇 |
预防医学 | 40篇 |
眼科学 | 54篇 |
药学 | 75篇 |
中国医学 | 1篇 |
肿瘤学 | 43篇 |
出版年
2023年 | 6篇 |
2021年 | 19篇 |
2020年 | 17篇 |
2019年 | 14篇 |
2018年 | 39篇 |
2017年 | 22篇 |
2016年 | 36篇 |
2015年 | 36篇 |
2014年 | 46篇 |
2013年 | 61篇 |
2012年 | 59篇 |
2011年 | 64篇 |
2010年 | 63篇 |
2009年 | 67篇 |
2008年 | 57篇 |
2007年 | 65篇 |
2006年 | 46篇 |
2005年 | 55篇 |
2004年 | 39篇 |
2003年 | 41篇 |
2002年 | 29篇 |
2001年 | 21篇 |
2000年 | 16篇 |
1999年 | 17篇 |
1998年 | 47篇 |
1997年 | 44篇 |
1996年 | 46篇 |
1995年 | 40篇 |
1994年 | 24篇 |
1993年 | 29篇 |
1992年 | 15篇 |
1991年 | 26篇 |
1990年 | 11篇 |
1989年 | 24篇 |
1988年 | 27篇 |
1987年 | 18篇 |
1986年 | 20篇 |
1985年 | 23篇 |
1984年 | 13篇 |
1983年 | 17篇 |
1982年 | 7篇 |
1981年 | 16篇 |
1980年 | 11篇 |
1979年 | 11篇 |
1978年 | 7篇 |
1977年 | 11篇 |
1976年 | 15篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1971年 | 6篇 |
排序方式: 共有1500条查询结果,搜索用时 15 毫秒
11.
Variations of the origin of the artery of the sinoatrial node in normal human hearts 总被引:8,自引:0,他引:8
Summary The artery of the sino-atrial node was studied in 100 normal human hearts after injection of each coronary artery with coloured gelatine containing a radiopaque substance. The hearts belonged to 69 males and 31 females, being 64 Caucasians and 36 non-Caucasians (Negroes and Mulattoes) whose age ranged from 7 to 80 years. Since the individuals had committed suicide or were victims of accidents, their hearts, after pathologists' evaluation, were considered normal. The sinoatrial node of the normal human heart is supplied by the right coronary artery more frequently (58%±4.9% of the cases) than by the left (42%±4.9). The right anterior medial atrial artery, originating from the right coronary at the level of the medial third of the right anterior quadrant of the atrial dome, is most frequently (50%±5) responsible for the blood supply of the sinoatrial node. Among the branches of the left coronary artery, the left anterior medial atrial artery, originating at the level of the medial third of the left. anterior quadrant of the atrial cupola, was the most frequent blood supplier (25%±4.3) of the sinoatrial node. The origin of the artery of the sinoatrial node from the proximal portion or trunk of the left coronary artery was less frequent (12%±3.2) than the origin from the circumflex artery (30%±4.5). Neither sex nor race influenced the variations of the origin of the sino-atrial node.
Variations d'origine de l'artère du noeud sinu-atrial du coeur humain normal
Résumé L'a. du noeud sinu-atrial a été étudiée sur 100 coeurs humains normaux après injection de chaque a. coronaire à la gélatine colorée additionnée d'une substance radio-opaque. Les coeurs provenaient de 69 hommes et 31 femmes, 64 caucasiens et 36 non caucasiens (nègres et mulâtres) âgés de 7 à 80 ans. Ces sujets étant décédés par suicide ou des suites d'accidents, leurs coeurs ont été considérés comme normaux après examen anatomo-pathologique. Le noeud sinu-atrial du coeur humain est vascularisé par l'a. coronaire droite plus fréquemment (58 %±4,9) que par l'a. coronaire gauche (42 %±4). L'a. atriale antéro-médiale droite, issue de l'a. coronaire droite au niveau du tiers médial du quadrant antérieur droit du dôme atrial est l'artère la plus fréquemment en cause (50 %±5) dans la vascularisation du noeud sinuatrial. Parmi les branches de l'a. coronaire gauche, l'a. atriale antéro-médiale gauche, née au niveau du tiers médial du quadrant antérieur gauche du dôme atrial, était la branche la plus fréquemment en cause (25 %±4,3) dans la vascularisation du noeud sinu-atrial. La naissance de l'a. du noeud sinu-atrial à partir de la partie proximale ou du tronc de l'a. coronaire gauche était moins fréquente (12 %±3,2) que son origine à partir du rameau circonflexe (30 %±4,5). Les variations d'origine de l'a. du noeud sinu-atrial n'apparaissaient pas influencées par le sexe ou la race.相似文献
12.
13.
14.
One of the hallmark characteristics of chronic diabetic wounds is the presence of biofilm‐forming bacteria. Bacteria encapsulated in a biofilm may coexist as a polymicrobial community and communicate with each other through a phenomenon termed quorum sensing (QS). Here, we describe the QS circuits of bacterial species commonly found in chronic diabetic wounds. QS relies on diffusion of signaling molecules and the local concentration changes of these molecules that bacteria experience in wounds. These biochemical signaling pathways play a role not only in biofilm formation and virulence but also in wound healing. They are, therefore, key to understanding the distinctive nature of these infections. While several in vivo and in vitro models exist to study QS in wounds, there has been limited progress in understanding the interplay between QS molecules and host factors that contribute to wound healing. Lastly, we examine the potential of targeting QS for both diagnosis and therapeutic intervention purposes. 相似文献
15.
To find out the efficacy of sucralfate in preventing gastrointestinal side effects of non-steroidal anti-inflammatory drugs (NSAIDs) a prospective, randomised single blind study was conducted from 1989 to 1992. Patients with osteoarthritis, rheumatoid arthritis and other long standing painful conditions, who were expected to receive NSAIDs for over three months, were recruited into the study. All medicines were discontinued for a period of 10–15 days prior to initial endoscopic assessment. NSAID therapy was started and the patients were randomised to receive either placebo (group A) or sucralfate (group B) in addition. Patient were reassessed clinically every week and an endoscopic examination was repeated after 6–8 weeks of follow-up. A total of 176 patients were studied in group A (n=91) and group B (n=85). At the end of 8 weeks gastrointestinal symptoms were present in 30.6% and 26.4% patients of group A and B respectively. Endoscopic assessment showed superficial lesions in 36.5% and 18.7% while endoscopic ulcer in 2.4% and 1.1% patients of groups A and B respectively. Thus in patients receiving chronic NSAID therapy, simultaneous administration of sucralfate reduces the incidence of superficial gastric lesions but has no significant effect on symptoms or ulcer formation.KEY WORDS: Gastropathy, Sucralfate, Nonsteroidal anti-inflammatory drugs 相似文献
16.
PURPOSE: To evaluate differences in central corneal thickness (CCT) before and after vitrectomy with injection of silicone oil as vitreous substitution material in order to determine whether silicone oil causes more frequent and/or pronounced corneal decompensation than other substitution materials. METHODS: CCT was measured by ultrasonic pachometry in 42 eyes. 25 eyes received injection of silicone oil and 17 eyes C3F8, atmospheric air or saline. Measurements were performed 24 hours pre operatively, during anaesthesia pre operatively and 24 hours, 48 hours and five months post operatively. RESULTS: A progressive central corneal thickening could be demonstrated in both groups. Eyes which received silicone oil showed maximum CCT increase of 0.083 mm (14.1%) 48 hours post operatively. At follow-up CCT had decreased to baseline value in both groups. Silicone oil did not induce CCT changes that were significantly different from those induced by other substitution materials. CONCLUSION: Silicone oil injection in detachment surgery induces reversible corneal decompensation to the same degree as other substitution materials within the first five months post operatively. 相似文献
17.
Indications and results of skin flaps in painful digital neuroma 总被引:1,自引:0,他引:1
G Foucher D Sammut P Greant F M Braun S Ehrler N Buch 《The Journal of hand surgery, European volume》1991,16(1):25-29
Of the many procedures for treating painful neuromas, resection and proximal translocation are the most usual techniques, but these can decrease distal sensibility increasing deafferentation pain. In cases of intricate pain (nociception plus deafferentation), certain types of flaps allow the treatment of both components of the pain. We have used 30 such flaps in 28 patients: local flaps (exchange, advancement or lasso island flaps) and distant flaps (free "custom-made" toe flaps). The results of the different techniques provides 86.6% excellent or good results. 相似文献
18.
JP Bound PW Harvey BJ Francis F Awwad AC Gatrell 《Archives of disease in childhood》1997,76(2):107-112
OBJECTIVE: To analyse the prevalence of neural tube defects in small geographical areas and seek to explain any spatial variations with reference to environmental lead and deprivation. SETTING: The Fylde of Lancashire in the north west of England. DESIGN: Cases were ascertained as part of a prospective survey of major congenital malformations in babies born in the Fylde to residents there between 1957 and 1981. A matched case-control analysis used infants with cardiovascular system, alimentary tract, and urinary system malformations as controls. Conditional logistic regression was used to assess the effects of more than 10 micrograms/l lead in drinking water and the Townsend deprivation score. RESULTS: The prevalence of neural tube defects in 1957-73 was higher in Blackpool, Fleetwood, and North Fylde, whereas the three control groups showed no significant spatial variation. In 1957-81 mothers living in electoral wards with either a higher proportion of houses with more than 10 micrograms/l lead in the water or a higher deprivation score had a greater risk of having a baby with a neural tube defect. For spina bifida and cranium bifidum alone, this was also true. For anencephaly, deprivation was less important although the effect of lead was still seen. In some neural tube defects, lead may act independently of other possible factors associated with deprivation. It seemed unlikely that lead levels changed significantly during the survey. The percentage of houses with 10 micrograms/l or more of lead in the water in 1984-5 was similar to that found in Great Britain 10 years previously. CONCLUSION: There is evidence to suggest that lead is one cause of neural tube defects, especially anencephaly. This could link the known preventive actions of hard water and folic acid. Calcium is a toxicological antagonist of lead. One cause of a deficiency of folic acid is impaired absorption secondary to zinc deficiency, which may be produced or exacerbated by lead. 相似文献
19.
FJ O'Callaghan AC Clarke H Joffe B Keeton R Martin A Salmon RD Thomas JP Osborne 《Archives of disease in childhood》1998,78(2):159-162
This report highlights the association between tuberous sclerosis and Wolff-Parkinson-White syndrome. Ten patients with concurrent diagnoses of Wolff-Parkinson-White syndrome and tuberous sclerosis were identified. Wolff-Parkinson-White syndrome presented early in life, nine cases being diagnosed in the first year. Eight of the 10 cases were male. In eight cases, the syndrome was associated with supraventricular tachycardias, and in nine with cardiac rhabdomyomata. One child died from cardiac failure secondary to obstruction of the left ventricular outflow tract by a rhabdomyoma. Five of nine survivors showed resolution of Wolff-Parkinson-White syndrome on follow up. The accessory pathway was localised in nine patients from surface electrocardiograms: six children had left sided pathways and three had right sided pathways. 相似文献
20.
David AC Leggett Kenneth A Miles Benjamin B Kelley 《Journal of Medical Imaging and Radiation Oncology》1998,42(4):335-340
Five cases of cerebral glioma are presented here that illustrate the benefit of functional CT imaging of blood-brain barrier permeability and cerebral blood volume. Functional CT uses Patlak analysis of a single location dynamic sequence to extract physiological information that is useful clinically in the assessment of cerebral gliomas. Functional CT offers distinct advantages over other functional modalities including clearer delineation of tumour, tumour grading, measurement of tumour activity and monitoring response to therapy. 相似文献