全文获取类型
收费全文 | 2361篇 |
免费 | 93篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 63篇 |
妇产科学 | 50篇 |
基础医学 | 223篇 |
口腔科学 | 24篇 |
临床医学 | 302篇 |
内科学 | 334篇 |
皮肤病学 | 45篇 |
神经病学 | 133篇 |
特种医学 | 193篇 |
外科学 | 193篇 |
综合类 | 309篇 |
预防医学 | 211篇 |
眼科学 | 32篇 |
药学 | 212篇 |
3篇 | |
中国医学 | 99篇 |
肿瘤学 | 59篇 |
出版年
2023年 | 12篇 |
2022年 | 23篇 |
2021年 | 37篇 |
2020年 | 38篇 |
2019年 | 20篇 |
2018年 | 15篇 |
2017年 | 32篇 |
2016年 | 26篇 |
2015年 | 39篇 |
2014年 | 55篇 |
2013年 | 68篇 |
2012年 | 111篇 |
2011年 | 102篇 |
2010年 | 95篇 |
2009年 | 98篇 |
2008年 | 124篇 |
2007年 | 120篇 |
2006年 | 113篇 |
2005年 | 96篇 |
2004年 | 52篇 |
2003年 | 39篇 |
2002年 | 36篇 |
2001年 | 54篇 |
2000年 | 45篇 |
1999年 | 34篇 |
1998年 | 38篇 |
1997年 | 47篇 |
1996年 | 53篇 |
1995年 | 44篇 |
1994年 | 46篇 |
1993年 | 32篇 |
1992年 | 14篇 |
1991年 | 31篇 |
1990年 | 26篇 |
1989年 | 28篇 |
1988年 | 28篇 |
1987年 | 25篇 |
1986年 | 17篇 |
1985年 | 29篇 |
1984年 | 28篇 |
1983年 | 14篇 |
1980年 | 12篇 |
1977年 | 11篇 |
1959年 | 41篇 |
1958年 | 66篇 |
1957年 | 75篇 |
1956年 | 73篇 |
1955年 | 83篇 |
1954年 | 51篇 |
1948年 | 11篇 |
排序方式: 共有2506条查询结果,搜索用时 15 毫秒
151.
美国近距离放射治疗学会(ABS)关于
食管癌近距离放疗的应用指南 总被引:1,自引:0,他引:1
152.
In a prospective study, 121 consecutive patients with a clinical diagnosis of deep venous thrombosis of the leg were examined with real-time ultrasonography. The findings were correlated with the results of venography. The common femoral vein and the popliteal vein were evaluated for intraluminal echoes and compressibility, and the common femoral vein was also evaluated for an increase in diameter in response to the Valsalva maneuver. The superficial femoral vein and the calf veins were not evaluated. The results indicate that compressibility of the common femoral and popliteal veins is the best indication of deep venous thrombosis, with a sensitivity of 96% and a specificity of 97%. The accuracy of detection was not improved by including data from thrombus visualization or the response of the common femoral vein to the Valsalva maneuver. 相似文献
153.
154.
155.
W G Van Gorp P Satz M E Kiersch R Henry 《Journal of clinical and experimental neuropsychology》1986,8(6):702-705
The 60-item Boston Naming Test was administered to a group of 78 normal, bright, and independently living older adults in five age groupings from 59 to 80+ in an attempt to generate normative data for an older population. Results indicated that naming abilities decline only slightly with advancing age (r = -.33), although consistent with prior research, more variation in performance was found in the higher age groups. 相似文献
156.
Among 600 infants examined with ultrasound for vomiting, seven (mean age, 3 months) had distinctive features that can be considered diagnostic of gastric ulcer. The findings are thickening of the mucosa (greater than 4 mm) in the antropyloric region, elongation of the antropyloric canal, persistent spasm, and delayed gastric emptying. Two of the infants had slight thickening of the pyloric muscle. Gastrointestinal series or endoscopy demonstrated thickened gastric mucosa and a deformed gastric antrum in all infants, as well as actual ulceration in five. 相似文献
157.
Abstract— Great variations reported in the frequency distribution of buffer capacity values may partly be due to methodological differences in saliva sampling. In this study we wanted to see to what extent these variations are due to repetition and prestimulation. 9-yr-old schoolchildren ( n : 41, 23 girls and 18 boys), who had never had saliva samples taken before, participated in the present study. The repetition tests were carried out between 9 and 11 a.m. on three subsequent days. The effect of prestimulation was tested 4 days later with the same subjects. The buffer capacity of the samples was determined electrometrically immediately after sampling using the commercial Dentobuff-test. The intraindividual analysis revealed a significant increase in flow rate but not in buffer capacity along with repetition of the sampling. The analysis further showed that the buffer capacity of children accustomed to saliva sampling increased significantly through prestimulation of 1 min. The use of prestimulation resulted in substantial changes also in the frequency distribution of the buffer capacity values. Our results emphasize the importance of proper sampling conditions in saliva collection when screening children for high caries risk. 相似文献
158.
159.
K.H. LE QUAN-SANG M. DAVID-DUFILHO P. KERTH M.G. PERNOLLET M. FRISK-HOLMBERT P. MEYER and M.A. DEVYNCK 《Fundamental & clinical pharmacology》1987,1(2):125-134
Summary— Cell Na+ and Ca2+ concentrations control each other by various mechanisms. In excitable cells from various origins, Ca2+ extrusion from the cell and its entry are dependent for a large part on the activity of the Na+, Ca2+ -countertransport system. Cytosolic free Ca2+ concentration is also controlled by the Na+–H+ exchange activity. To analyze the changes in cytosolic Ca2+ concentration accompanying the reduction of the membrane Na+ gradient, cytosolic free Ca2+ concentration ([Ca2+ ]i ) was measured by fluorescent dyes in platelets and erythrocytes from healthy subjects, before and during digoxin treatment (0.25 mg/day for 6 days). [Ca2+ ]i was increased in platelets from 169±30 to 321±61 nmol/l ( n = 7, P <0.02) and unchanged in erythrocytes (121±6 and 104±7 nmol/l). This increase in platelet [Ca2+ ]i was not accompanied by a change in serotonin content (5.43±0.67 vs 5.49±0.61 10−7 mol per 1011 cells) and could not be reproduced by in vitro addition of 10−4 mol/l ouabain (198±33 vs 186±73 nmol/l). The enhanced [Ca2+ ]i in platelets is thus not a short-term consequence of a reduced membrane Na+ gradient, but reflects either the overload of intracellular Ca2+ stores or an enhanced in vivo stimulation by hormones or neurotransmitters. 相似文献
160.
Hand preference in homosexual men 总被引:1,自引:0,他引:1
P Satz E N Miller O Selnes W Van Gorp L F D'Elia B Visscher 《Cortex; a journal devoted to the study of the nervous system and behavior》1991,27(2):295-306
The present study examined the distribution of hand preference and its relationship to immune system functioning and performance on neuropsychological tests in a sample of 993 homosexual men from the Multicenter AIDS Cohort Study comprising 502 HIV-1 seronegatives, 436 asymptomatic HIV-1 seropositives, and 55 men with diagnoses of AIDS or AIDS Related Complex. The prevalence of left-handedness in all of the groups (13.1-14.5%) was consistent with prior published reports of prevalent left-handedness in the general population. The distribution of hand preference scores (on a 5-item self-report questionnaire) was J-shaped and shifted to the right as in the general population. There were no differences between right- and left-handers in the immune system parameter of CD4 counts, nor was there any increase of self-reported allergies among the left-handers. We found a significantly larger number of 'outliers' on the neuropsychological measures for left-handers than for right-handers, both for HIV-1 seronegatives and seropositives. These results failed to replicate Lindesay's (1987) report of a leftward shift in manual preference among homosexual men, and failed to support Geschwind and Galaburda's (1985b) hypothesis of a link between homosexuality, handedness and autoimmune disorder. The differences between right- and left-handers on neuropsychological measures, independent of HIV-1 serostatus, are discussed in terms of Satz's (1972) model of pathological left-handedness. 相似文献