全文获取类型
收费全文 | 670篇 |
免费 | 45篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 33篇 |
妇产科学 | 49篇 |
基础医学 | 54篇 |
口腔科学 | 5篇 |
临床医学 | 95篇 |
内科学 | 104篇 |
皮肤病学 | 8篇 |
神经病学 | 50篇 |
特种医学 | 64篇 |
外科学 | 100篇 |
综合类 | 14篇 |
预防医学 | 61篇 |
眼科学 | 5篇 |
药学 | 16篇 |
肿瘤学 | 54篇 |
出版年
2022年 | 7篇 |
2020年 | 4篇 |
2019年 | 11篇 |
2018年 | 10篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 23篇 |
2014年 | 13篇 |
2013年 | 33篇 |
2012年 | 36篇 |
2011年 | 36篇 |
2010年 | 23篇 |
2009年 | 18篇 |
2008年 | 35篇 |
2007年 | 38篇 |
2006年 | 32篇 |
2005年 | 28篇 |
2004年 | 21篇 |
2003年 | 14篇 |
2002年 | 24篇 |
2001年 | 23篇 |
2000年 | 23篇 |
1999年 | 19篇 |
1998年 | 13篇 |
1997年 | 15篇 |
1995年 | 5篇 |
1993年 | 3篇 |
1992年 | 8篇 |
1991年 | 11篇 |
1990年 | 14篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 15篇 |
1986年 | 11篇 |
1985年 | 12篇 |
1984年 | 6篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1979年 | 4篇 |
1977年 | 5篇 |
1975年 | 6篇 |
1974年 | 9篇 |
1973年 | 5篇 |
1971年 | 4篇 |
1970年 | 4篇 |
1969年 | 6篇 |
1968年 | 6篇 |
1967年 | 3篇 |
1966年 | 3篇 |
排序方式: 共有716条查询结果,搜索用时 15 毫秒
11.
M. M. Henrich K. Großmann W. Motz M. Vogt E. Vester M. Holschbach W. Hamkens G. Notohamiprodjo B. E. Strauer L. E. Feinendegen 《European journal of nuclear medicine and molecular imaging》1993,20(3):225-230
Radioiodine labelled 17-iodo-heptadecanoic acid (IHA) is used for non-invasive study of myocardial metabolism in coronary heart disease and cardiomyopathy. Yet in the interpretation of in vivo myocardial tracer kinetics, it is controversial whether the intracellular degradation of IHA or the removal of iodide across cellular membranes is the rate-limiting step in iodide release from the myocardium. In five patients undergoing coronary sinus catheterization, a mixture of about 40 kBq of [123I] NaI was injected into the left coronary artery. During the following 15-min period, frequent blood samples were taken from the aorta and the coronary sinus. In the aqueous phase of the venous blood, 14CO2 and inorganic 131I appeared nearly in parallel, with a peak time of 4–5 min. Moreover, as shown by the AV difference, there was no significant back diffusion of IHA and no significant non-specific deiodination detectable over the period of observation. There was myocardial retention of inorganic iodide (123I) injected into the left coronary artery. The data strongly support the premise that lipid turnover through -oxidation is the rate-limiting step in the externally measured release of iodide after IHA injection, provided that recirculating inorganic radioactive iodide is corrected for. In addition, 15 volunteers were studied using [11C]palmitic acid and [123I]IHA using PET and dynamic planar camera scintigraphy with iodide correction. There was no significant difference between the mean values of the elimination half-times, and also no significant correlation between half-times of both fatty acids for single individuals. 相似文献
12.
J Sherman W R Mitchell S W Martin J Thorsen D G Ingram 《Canadian journal of comparative medicine》1979,43(1):1-9
The outbreaks of upper respiratory tract infections in horses at Standardbred racetracks were investigated over a three year period. The most serious epidemics of respiratory disease occurred in the winter and spring seasons. Both influenza viruses and equine herpesvirus 1 were shown to be present in the horse population. The herpesvirus was associated with respiratory disease particularly in the winter but the equine influenza viruses apparently were responsible for the major epidemics of respiratory disease at these tracks. Younger horses, two or three years of age, were particularly susceptible to upper respiratory disease and showed the greatest rate of seroconversion to influenza viruses. Major outbreaks of respiratory disease occurred when the proportion of young horses which had not previously been exposed to epidemics of respiratory disease reached 30 to 40% of the population at the track. Most horses over four years of age appeared to develop resistance to the infections. 相似文献
13.
Monsma DJ Thorsen PT Vollendorf NW Crenshaw TD Marlett JA 《The Journal of nutrition》2000,130(3):585-593
This experiment evaluated three hypotheses: i) production of propionate is increased during fermentation of substrate containing oat bran (OB)(6); ii) production of butyrate is increased during fermentation of substrate containing wheat bran (WB) and iii) results of in vitro fermentations using physiological substrates and inocula agree with in vivo data. Ileal digesta collected from swine fed OB and WB were the substrates. Digesta was fermented for 0-96 h in an anaerobic in vitro system using inocula prepared from ceca of rats fed the same fiber sources. Carbohydrate and short-chain fatty acid (SCFA) contents in the fermentations were measured by gas chromatography. Fermentation of WB digesta did not produce more n-butyrate (P > 0.05) and was significantly slower (P < 0.05) than fermentation of OB digesta. OB digesta fermentation produced a significantly greater (P < 0.05) molar proportion of SCFA as propionate. Bacterial mass increased more and was maintained longer during fermentation of OB digesta than the WB digesta. Our results indicate that dilution of undigested WB fiber and not n-butyrate production is one mechanism by which WB may protect colonic mucosa; propionate production is increased during fermentation of beta-glucan in OB; and an in vitro system using physiological sources of inoculum and substrate containing WB and OB yields results that agree with in vivo findings in humans and rats. 相似文献
14.
Lene Thorsen Eva Skovlund Sigmund B Str?mme Kjersti Hornslien Alv A Dahl Sophie D Foss? 《Journal of clinical oncology》2005,23(10):2378-2388
PURPOSE: To evaluate the effectiveness of a supervised home-based flexible training program on cardiorespiratory fitness (CRF), mental distress, and health-related quality of life (HRQOL) parameters in young and middle-aged cancer patients shortly after curative chemotherapy. PATIENTS AND METHODS: One hundred eleven patients age 18 to 50 years who had received chemotherapy for lymphomas or breast, gynecologic, or testicular cancer completed the trial. These patients were randomly allocated to either an intervention group (n = 59), which underwent a 14-week training program, or a control group (n = 52) that received standard care. Primary outcome was change in CRF, as determined by Astrand-Rhyming indirect bicycle ergometer test (maximum oxygen uptake [VO(2max)]), between baseline (T0) and follow-up (T1). Secondary outcomes were mental distress, as assessed by the Hospital Anxiety and Depression Scale, and HRQOL, as assessed by the European Organisation for Research and Treatment of Cancer Core Quality of Life Questionnaire. Two-way analysis of covariance was used to analyze changes from T0 to T1. RESULTS: VO(2max) increased by 6.4 mL/kg(-1)/min(-1) in patients in the intervention group and by 3.1 mL/kg(-1)/min(-1) in patients in the control group (P < .01). The fatigue score decreased by 17.0 points in the control group compared with only 5.8 points in the intervention group (P < .01). There were no intergroup differences in mental distress or HRQOL. CONCLUSION: A supervised, home-based, flexible training program has significant effect on CRF in young and middle-aged cancer patients shortly after curative chemotherapy, but it has no favorable effect on patients' experience of fatigue, mental distress, or HRQOL. 相似文献
15.
16.
17.
Sannie Y. Tang Annette J. Browne Bill Mussell Victoria L. Smye Patricia Rodney 《Sociology of health & illness》2015,37(5):698-714
In this article, we draw on findings from an ethnographic study that explored experiences of healthcare access from the perspectives of Indigenous and non‐Indigenous patients seeking services at the non‐urgent division of an urban emergency department (ED) in Canada. Our aim is to critically examine the notion of ‘underclassism’ within the context of healthcare in urban centres. Specifically, we discuss some of the processes by which patients experiencing poverty and racialisation are constructed as ‘underclass’ patients, and how assumptions of those patients as social and economic Other (including being seen as ‘drug users’ and ‘welfare dependents’) subject them to marginalisation, discrimination, and inequitable treatment within the healthcare system. We contend that healthcare is not only a clinical space; it is also a social space in which unequal power relations along the intersecting axes of ‘race’ and class are negotiated. Given the largely invisible roles that healthcare plays in controlling access to resources and power for people who are marginalised, we argue that there is an urgent need to improve healthcare inequities by challenging the taken‐for‐granted assumption that healthcare is equally accessible for all Canadians irrespective of differences in social and economic positioning. 相似文献
18.
Katrine Grimstrup Joensen Susanne Schjrring Mette Rrbk Gantzhorn Camilla Thougaard Vester Hans Linde Nielsen Jrgen Harald Engberg Hanne Marie Holt Steen Ethelberg Luise Müller Gudrun Sand Eva Mller Nielsen 《Euro surveillance : bulletin européen sur les maladies transmissibles = European communicable disease bulletin》2021,26(22)
Background Campylobacter is one of the most frequent causes of bacterial gastroenteritis. Campylobacter outbreaks are rarely reported, which could be a reflection of a surveillance without routine molecular typing. We have previously shown that numerous small outbreak-like clusters can be detected when whole genome sequencing (WGS) data of clinical Campylobacter isolates was applied.AimTyping-based surveillance of Campylobacter infections was initiated in 2019 to enable detection of large clusters of clinical isolates and to match them to concurrent retail chicken isolates in order to react on ongoing outbreaks.MethodsWe performed WGS continuously on isolates from cases (n = 701) and chicken meat (n = 164) throughout 2019. Core genome multilocus sequence typing was used to detect clusters of clinical isolates and match them to isolates from chicken meat.ResultsSeventy-two clusters were detected, 58 small clusters (2–4 cases) and 14 large clusters (5–91 cases). One third of the clinical isolates matched isolates from chicken meat. One large cluster persisted throughout the whole year and represented 12% of all studied Campylobacter cases. This cluster type was detected in several chicken samples and was traced back to one slaughterhouse, where interventions were implemented to control the outbreak.ConclusionOur WGS-based surveillance has contributed to an improved understanding of the dynamics of the occurrence of Campylobacter strains in chicken meat and the correlation to clusters of human cases. 相似文献
19.
Michal Cohen‐Eliav Regina Golan‐Gerstl Zahava Siegfried Claus L Andersen Kasper Thorsen Torben F Ørntoft David Mu Rotem Karni 《The Journal of pathology》2013,229(4):630-639
An increasing body of evidence connects alterations in the process of alternative splicing with cancer development and progression. However, a direct role of splicing factors as drivers of cancer development is mostly unknown. We analysed the gene copy number of several splicing factors in colon and lung tumours, and found that the gene encoding for the splicing factor SRSF6 is amplified and over‐expressed in these cancers. Moreover, over‐expression of SRSF6 in immortal lung epithelial cells enhanced proliferation, protected them from chemotherapy‐induced cell death and converted them to be tumourigenic in mice. In contrast, knock‐down of SRSF6 in lung and colon cancer cell lines inhibited their tumourigenic abilities. SRSF6 up‐ or down‐regulation altered the splicing of several tumour suppressors and oncogenes to generate the oncogenic isoforms and reduce the tumour‐suppressive isoforms. Our data suggest that the splicing factor SRSF6 is an oncoprotein that regulates the proliferation and survival of lung and colon cancer cells. 相似文献
20.
Thorsen Morten Bilenberg Niels Thorsen Lena Michel Tanja Maria 《Journal of autism and developmental disorders》2022,52(1):275-282
Journal of Autism and Developmental Disorders - Oxidative stress has been proposed as being important in the pathophysiology of autism spectrum disorders (ASD), and heightened levels of oxidative... 相似文献