全文获取类型
收费全文 | 645篇 |
免费 | 40篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 6篇 |
妇产科学 | 9篇 |
基础医学 | 122篇 |
口腔科学 | 23篇 |
临床医学 | 64篇 |
内科学 | 124篇 |
皮肤病学 | 5篇 |
神经病学 | 65篇 |
特种医学 | 51篇 |
外科学 | 74篇 |
综合类 | 17篇 |
一般理论 | 1篇 |
预防医学 | 38篇 |
眼科学 | 5篇 |
药学 | 53篇 |
肿瘤学 | 33篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 15篇 |
2021年 | 27篇 |
2020年 | 16篇 |
2019年 | 13篇 |
2018年 | 19篇 |
2017年 | 14篇 |
2016年 | 25篇 |
2015年 | 25篇 |
2014年 | 28篇 |
2013年 | 34篇 |
2012年 | 53篇 |
2011年 | 43篇 |
2010年 | 34篇 |
2009年 | 26篇 |
2008年 | 44篇 |
2007年 | 45篇 |
2006年 | 43篇 |
2005年 | 34篇 |
2004年 | 31篇 |
2003年 | 27篇 |
2002年 | 23篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1971年 | 1篇 |
1970年 | 3篇 |
1968年 | 3篇 |
1965年 | 1篇 |
排序方式: 共有692条查询结果,搜索用时 865 毫秒
81.
Tina Becic Darko Kero Katarina Vukojevic Snjezana Mardesic Mirna Saraga-Babic 《Acta histochemica》2018,120(3):205-214
82.
Ivana Kantardžić Darko Vasiljević Ognjan Lužanin Tatjana Maravić Larisa Blažić 《Medical & biological engineering & computing》2018,56(10):1875-1886
In order to investigate the influence of cusp reduction, cavity isthmus width, and restorative material on stress values in premolar with mesio-occlusal-distal (MOD) cavity, numerical simulations were done on three-dimensional (3D) models of a maxillary second premolar designed using computerized tomography (CT) scan images. The use of four restorative materials (direct resin composite, direct resin composite with resin-modified glass-ionomer cement as the base, indirect resin composite, ceramic), three cavity preparation designs (without cusp coverage, 2-mm palatal cusp coverage, 2-mm palatal and buccal cusp coverage), and two cavity isthmus widths (1/2 and 2/3 intercuspal width) were simulated. After applying a static load of 200 N on the occlusal surface of the tooth, von Mises stresses in the enamel, dentin, and restoration were calculated using finite element analysis (FEA). Stress values in the enamel were primarily influenced by cavity preparation design, while restorative material showed higher contribution in dentin. The lowest stress values were obtained in models with cusp coverage and indirect restorations. Cavity isthmus width had minimal influence on stress values in tooth structures. None of the investigated factors determined stress values in the restoration. In conclusion, the use of ceramic restoration covering both palatal and buccal cusp provided the most favourable stress distribution of premolars with MOD cavity. 相似文献
83.
Petar Bezinovi? Darko Rovi? Nena Ron?evi? Lovorka Bilajac 《Croatian medical journal》2015,56(3):297-305
Aim
To examine associations between different forms of internet use and a number of psychological variables related to mental health in adolescents.Methods
A cross-sectional survey was carried out on a representative sample of students (N = 1539) from all high schools in the region of Istria in Croatia (14-19 years). The associations between four factors of internet use and nine mental health indicators were analyzed using canonical correlation analysis.Results
The four canonical functions suggested a significant association between different types of internet use and specific indicators of mental health (P < 0.001). Problematic internet use, more typical among boys, was associated with general aggressive behavior and substance abuse (P < 0.001). Experiences of harassment, more typical among girls, were associated with health complaints, symptoms of depression, loneliness, and fear of negative evaluation (P < 0.001). Using the internet for communication and entertainment was associated with better relationships with peers (P < 0.001), while use of the internet for academic purposes was associated with conscientiousness (P < 0.001).Conclusion
The results suggest that different patterns of internet use are significantly associated with specific sets of positive and negative mental health indicators. The data support the assumption that internet use can have both positive and adverse effects on the mental health of youth.New technologies, and especially the use of computers and the internet, are part of the everyday lives of young people and have a significant impact on their psychological development. Indeed, this mass use of new media technologies presents parents and society with a challenge to protect and support the positive development of children and youth. To date, a number of studies have examined the positive and negative aspects of using internet technologies.Literature points to several positive aspects of internet use (1,2): for information acquiring, communication, and social networking, entertainment, and online shopping. More specifically, adolescents use the internet as a useful source of information about school assignments, daily events, interests and hobbies, or health and sexuality concerns. In these instances, online activities aimed at connecting with peers have a significant place. Visiting social networking sites and using communication tools such as email, chat, forums, and discussion groups enables the creation of friendships and social groups and contributes to the development of personal identity (3). The use of computers and the internet (cyberspace) has also been argued to provide opportunities for new and faster learning, exercising one''s self-control, considering different opinions, expressing one''s attitudes and tolerance, and developing skills in critical thinking and decision-making (4). Best et al (5) found that use of online communication technologies contributed to increased self-confidence, better perception of social support, greater social capital, positive experimenting with one’s own identity, and greater opportunities for open self-disclosure. Conversely, adolescents who do not use the internet might trail behind in the development of such positive attitudes and traits and risk being rejected by their peers (6). Finally, Livingstone et al (7) found that a certain amount of risk exposure was useful in building resilience.In contrast to these positive influences of internet use, harmful effects of internet abuse range from exposure to inappropriate sexual content, pornography, and violence (2,7) to humiliation and cyber-bullying (6,8-10) and internet addiction (11,12). Research has confirmed the link between internet abuse and social isolation, depression and, anxiety (1,5,13,14), alcohol and drug abuse and gambling (15), and problems with physical health (16). Ybarra and Mitchell (17) found a connection between experiences of threats or humiliation in the virtual world and absences from school, lower school achievement, substance use disorders, delinquency and depression. Fekkes et al (18) point to the association between victimizing experiences and a number of physical, emotional, and behavioral problems, such as headaches, tension, fatigue, loss of appetite, enuresis, and sleeping problems. Slonje and Smith (19) define such experiences as a product of cyber-bullying and argue that this can be viewed as another form of aggressive behavior. Gender has emerged as a significant predictor of the manner in which the internet is used. Specifically, girls tend to experience victimizing experiences, while boys more frequently demonstrate antisocial behavior (20,21).Although many studies have identified both positive and negative correlates of internet use, there have been only a few studies using complex multivariate analyses to identify broader patterns of internet use and adolescent mental health (22,23). Less is known about how adolescents exhibiting different personalities and different emotional and behavioral patterns engage in internet use and what might be the consequences of this engagement. The aim of this study was to determine the specific patterns of internet use and mental health among adolescents. The following hypotheses were tested:H1: Problematic internet use is associated with externalized symptoms and other negative indicators of mental health. Exposure to victimizing and disturbing content on the internet is associated with internalized symptoms and negative indicators of mental health.H2: Prosocial internet use (aimed at connecting with peers and entertainment) and internet use for school purposes are associated with positive aspects of mental health.H3: Problematic internet use is present more often in young men, while exposure to disturbing content on the internet is more frequently experienced by young women. 相似文献84.
85.
Brnić Z Blašković D Klasić B Ramač JP Flegarić-Bradić M Stimac D Lubina IZ Brnić V Faj D 《European journal of radiology》2012,81(4):e478-e485
Purpose
The study was aimed to provide objective evidence about the mammographic image quality in Croatia, to compare it between different types of MG facilities and to identify the most common deficiencies and possible reasons as well as the steps needed to improve image quality.Materials and methods
A total of 420 mammographic examinations collected from 84 mammographic units participating in the Croatian nationwide breast cancer screening program were reviewed in terms of four image quality categories: identification of patient and examination, breast positioning and compression, exposure and contrast, and artifacts. Those were rated using image evaluating system based on American College of Radiology and European Commission proposals. The results were compared among different types of mammographic units, and common image quality deficiencies were identified.Results
Total image quality scores of 12.8, 16.1, 13.0 and 13.7 were found for general hospitals, university hospitals, private clinics and public healthcare centres, respectively. Average score for all mammographic units was 13.5 (out of 25 points). University hospitals were significantly better than all other mammography units in overall image quality, which was mostly contributed by better breast positioning practices. Private clinics showed the worst results in identification, exposure, contrast and artifacts.Conclusions
Serious deficiencies in identification and breast positioning, which might compromise breast cancer screening outcome, were detected in our material. They occur mainly due to subjective reasons and could be corrected through additional staff training and improvement of working discipline. 相似文献86.
87.
The increase in human plasma antioxidant capacity after red wine consumption is due to both plasma urate and wine polyphenols 总被引:1,自引:0,他引:1
Modun D Music I Vukovic J Brizic I Katalinic V Obad A Palada I Dujic Z Boban M 《Atherosclerosis》2008,197(1):250-256
By using red wine, dealcoholized red wine, polyphenols-stripped red wine, ethanol-water solution and water, the role of wine polyphenols and induction of plasma urate elevation on plasma antioxidant capacity was examined in humans (n=9 per beverage). Healthy males randomly consumed each beverage in a cross-over design. Plasma antioxidant capacity (measured by ferric reducing antioxidant power, FRAP), ethanol, catechin and urate concentrations were determined before and 30, 60, 90, 120 and 180 min after beverage intake. Dealcoholized red wine and polyphenols-stripped red wine induced similar increase in FRAP values which represented nearly half the effect of the original red wine. This indicates that consumption of red wine involves two separate mechanisms in elevation of plasma FRAP values and both wine phenols and plasma urate contribute to that effect. 相似文献
88.
D A Darko A Dornhorst G Kennedy R C Mandeno M Seed 《Diabetes research and clinical practice》2001,54(3):157-164
AIMS: To compare the effect of a fixed combination of an oestrogen (17-beta oestradiol) with a cyclical progestagen (norethisterone) on glycaemic control, plasma lipoproteins and haemostatic factors in women with Type 2 diabetes. METHODS: Oral and transdermal hormone replacement therapy (HRT) were compared to no HRT treatment in 33 postmenopausal women with Type 2 diabetes, in a 12-week randomised prospective open parallel group study. RESULTS: In the 11 women who received 12 weeks of oral HRT, there was a significant fall in total cholesterol (5.9+/-1.0 (S.D.) to 4.7+/-1.0 mmol l(-1), P=0.005), low density lipoprotein cholesterol (3.44+/-0.89 to 2.77+/-0.92 mmol l(-1), P=0.005) and triglyceride values (median (range)), (2.46 (0.96-5.52) to 2.29 (1.00-3.87) mmol l(-1), P<0.05). Oral HRT improved glycated haemoglobin (HbA(1c)) (7.4+/-1.4 to 6.8+/-1.2%, P< or =0.005). Oral HRT additionally reduced the cell adhesion factor E-selectin (82+/-33 to 60+/-20 microg l(-1), P<0.01) and factor VII (143+/-25 to 109+/-24% pooled plasma activity, P<0.01). No improvement in any of these parameters, except E-selectin (65+/-19 to 58+/-18 microg l(-1), P<0.01), occurred in the nine women receiving transdermal HRT, and no improvement occurred in the 13 controls randomised to no treatment. CONCLUSION: In women with Type 2 diabetes, cyclical oestrogen and progestagen taken orally for 12 weeks significantly improved glycaemic control and lipoprotein concentrations. These metabolic benefits were not apparent when a similar HRT preparation was administered transdermally. 相似文献
89.
Hanzel G Balon H Wong O Soffer D Lee DT Safian RD 《The American journal of cardiology》2005,96(9):1322-1327
Sixty-six patients with atherosclerotic renal artery stenosis (RAS) and serum creatinine < or =2.0 mg/dl were treated with antihypertensive therapy, a statin, and aspirin. Renal stenting was reserved for patients with injuries to the heart, brain, or kidneys. The primary end point was stenotic kidney glomerular filtration rate (GFR) at 21 months; secondary end points included major adverse clinical events, serum creatinine, total GFR, and blood pressure (BP). After baseline evaluation, 26 of 66 patients underwent renal stenting because of injuries to the heart, brain, or kidneys. After 21 months, 6 medical patients required renal stenting, and 5 patients experienced late clinical events (2 medical patients, 3 stent patients). There was no difference in final BP between groups. Whereas medical patients experienced 6% and 8% decreases in total and stenotic kidney GFR, stent patients experienced 7% and 11% increases in total kidney (p = 0.006) and stenotic kidney (p = 0.02) GFR. There was no difference in final serum creatinine. In conclusion, patients with atherosclerotic RAS and baseline creatinine < or =2.0 mg/dl can be safely managed with aggressive medical therapy, with a small decrease in GFR. For patients who develop injuries to the heart, brain, or kidneys, renal artery stenting may further reduce hypertension and improve renal function. 相似文献
90.
C. Christine Lee Steven M. Haffner Lynne E. Wagenknecht Carlos Lorenzo Jill M. Norris Richard N. Bergman Darko Stefanovski Andrea M. Anderson Jerome I. Rotter Mark O. Goodarzi Anthony J. Hanley 《Diabetes care》2013,36(4):901-907