全文获取类型
收费全文 | 2230篇 |
免费 | 168篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 46篇 |
妇产科学 | 21篇 |
基础医学 | 436篇 |
口腔科学 | 69篇 |
临床医学 | 246篇 |
内科学 | 607篇 |
皮肤病学 | 19篇 |
神经病学 | 137篇 |
特种医学 | 90篇 |
外国民族医学 | 1篇 |
外科学 | 265篇 |
综合类 | 7篇 |
预防医学 | 170篇 |
眼科学 | 5篇 |
药学 | 159篇 |
肿瘤学 | 107篇 |
出版年
2023年 | 16篇 |
2022年 | 15篇 |
2021年 | 49篇 |
2020年 | 27篇 |
2019年 | 36篇 |
2018年 | 48篇 |
2017年 | 43篇 |
2016年 | 51篇 |
2015年 | 58篇 |
2014年 | 63篇 |
2013年 | 92篇 |
2012年 | 106篇 |
2011年 | 124篇 |
2010年 | 78篇 |
2009年 | 75篇 |
2008年 | 103篇 |
2007年 | 114篇 |
2006年 | 105篇 |
2005年 | 92篇 |
2004年 | 86篇 |
2003年 | 85篇 |
2002年 | 70篇 |
2001年 | 65篇 |
2000年 | 80篇 |
1999年 | 58篇 |
1998年 | 37篇 |
1997年 | 18篇 |
1996年 | 28篇 |
1995年 | 25篇 |
1994年 | 21篇 |
1993年 | 22篇 |
1992年 | 59篇 |
1991年 | 42篇 |
1990年 | 50篇 |
1989年 | 31篇 |
1988年 | 45篇 |
1987年 | 44篇 |
1986年 | 32篇 |
1985年 | 25篇 |
1984年 | 15篇 |
1983年 | 20篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1979年 | 14篇 |
1978年 | 17篇 |
1977年 | 8篇 |
1975年 | 14篇 |
1973年 | 10篇 |
1972年 | 12篇 |
1971年 | 14篇 |
排序方式: 共有2400条查询结果,搜索用时 31 毫秒
81.
Pepersack T Rotsaert P Benoit F Willems D Fuss M Bourdoux P Duchateau J 《Archives of gerontology and geriatrics》2001,33(3):243-253
Zinc is an essential trace element, and constituent of many metallo-enzymes required for normal metabolism. Age may be associated with altered metallothionein metabolism related to changes in zinc metabolism. The objectives of this study were: (i) to assess the prevalence of zinc deficiency among hospitalised elderly patients; (ii) to define the social, functional, pathological and nutritional characteristics of zinc deficient elderly hospitalised patients; and (iii) to assess the relationship between the zinc status and humoral immune function among hospitalised elderly patients. Fifty consecutive patients underwent comprehensive geriatric assessments included evaluations of the medical (index of the severity of the disease(s)), psychiatric (Geriatric depression scale (GDS)), therapeutic, social, functional (Katz's scale), and nutritional problems (Mini Nutritional Assessment (MNA) and biochemical markers (zinc, albumin, prealbumin (PAB), cholesterol) before their discharge. Fourteen patients (28%) presented a zinc concentrations lower than 10.7 micromol/l, this value is usually considered as the cut-off level below which a zinc deficient status is possible. Higher proportions of respiratory infections, cardiac failure, and depression were observed among zinc deficient patients as compared with the group of patients with normal zinc status. The other parameters of comprehensive geriatric assessment did not allow to discriminate the zinc deficient patients. The only slight differences (which remained unsignificant) concerned the prealbumin levels which tended to be higher in the group of patients presenting normal zinc status than in the group with poor zinc status (0.208+/-0.062 versus 0.171+/-0.068 g/l respectively, P=0.06), and the IgG2 levels which tended to be lower in the group of patients with normal zinc status than in the group presenting poor zinc status (2.77+/-1.91 versus 4.06+/-2.56, respectively, P=0.057). A negative correlation was observed between the Zn concentrations and the IgG2 levels (Spearman R=-0.311, P=0.028). To the best of our knowledge, this is the first study presenting zinc status according to a comprehensive geriatric assessment among European hospitalised geriatric patients. We decided to perform this study to known whom of our patients needed to be supplemented with zinc administration. Considering the low energy intake of hospitalised patients (confirmed here in regards of the nutritional assessment), and the insufficient trace element density in European foods, the relevance of providing medical supplements or enriched foods to this population has to be evaluated. Although most of the current diseases may be relevant to long-term interactions between nutrition and ageing, certain states observed in the elderly, like impaired immune and cognitive functions, could still benefit from an appropriate nutritional supplementation. 相似文献
82.
Enzymatic assessment of myocardial necrosis after cardiac surgery: differentiation from skeletal muscle damage, hemolysis, and liver injury 总被引:1,自引:0,他引:1
G M Willems F H van der Veen H A Huysmans W Flameng R de Meyere A van der Laarse G J van der Vusse W T Hermens 《American heart journal》1985,109(6):1243-1252
Plasma activities of various (iso)enzymes were measured in patients after cardiac surgery (n = 114) and after acute myocardial infarction (n = 40). From these activities, the cumulative release of enzymes in plasma was calculated with a two-compartment circulatory model. This model was adapted to transient postoperative changes in plasma volume and similar changes in the transcapillary escape rate of proteins, observed after cardiac surgery and verified in dogs after cardiopulmonary bypass (CPB). Comparison of cumulative release of enzymes with the enzyme content of myocardium, skeletal muscle, and blood cells allows identification of the various sources of enzyme release. Cardiac injury after uncomplicated bypass surgery is only 1.5 +/- 1.5 (mean +/- SD) gram equivalents (gmEq) of myocardium, compared to a loss of 31 +/- 13 gmEq of myocardium after AMI. Peroperative hemolysis is estimated at 68 +/- 15 ml of blood. Total loss of skeletal muscle amounts to 13 +/- 10 gmEq. Some hepatic enzyme release is observed after AMI but not after surgery. Large differences in time course exist between the release of enzymes from myocardium and skeletal muscle and also between myocardial release in the surgery group and in the AMI group. The accuracy of estimations is discussed and indicated as a function of the extent of cardiac injury. 相似文献
83.
84.
Ian J Majewski Lorenza Mittempergher Nadia M Davidson Astrid Bosma Stefan M Willems Hugo M Horlings Iris de Rink Liliana Greger Gerrit KJ Hooijer Dennis Peters Petra M Nederlof Ingrid Hofland Jeroen de Jong Jelle Wesseling Roelof JC Kluin Wim Brugman Ron Kerkhoven Frank Nieboer Paul Roepman Annegien Broeks Thomas R Muley Jacek Jassem Jacek Niklinski Nico van Zandwijk Alvis Brazma Alicia Oshlack Michel van den Heuvel René Bernards 《The Journal of pathology》2013,230(3):270-276
85.
Janie Houle Marjolaine Gascon-Depatie Gabrielle Bélanger-Dumontier Charles Cardinal 《Patient education and counseling》2013
Objective
To systematically review empirical evidence regarding the efficacy of depression self-management support (SMS) interventions for improving depression symptomatology and preventing relapse.Methods
Pubmed and PsycINFO databases were searched for relevant articles on depression SMS interventions. Scanning of references in the articles and relevant reviews and communications with field experts yielded additional articles. Two independent reviewers analyzed the articles for inclusion and data was extracted from the selected articles.Results
13 papers met the inclusion criteria and reported the results of six separate studies, including three pilot studies. The results were mostly positive. A majority of the trials assessing depression severity changes found SMS to be superior to care as usual. SMS interventions were found to improve self-management behaviors and self-efficacy. Mixed results were found concerning relapse rates. Promising results were found on assessments of functional status. Based on the findings, cost-effectiveness remains unclear.Conclusion
SMS has been mostly examined through pilot studies with insufficient power. The results are promising, but larger randomized controlled trials are needed.Practice implications
SMS interventions can be administered by non-physician professionals and are well accepted by patients, but more research is needed before we can recommend implementing specific depression SMS approaches in primary care. 相似文献86.
87.
Pierre Lahoud Mostafa EzEldeen Thomas Beznik Holger Willems André Leite Adriaan Van Gerven Reinhilde Jacobs 《Journal of endodontics》2021,47(5):827-835
IntroductionTooth segmentation on cone-beam computed tomographic (CBCT) imaging is a labor-intensive task considering the limited contrast resolution and potential disturbance by various artifacts. Fully automated tooth segmentation cannot be achieved by merely relying on CBCT intensity variations. This study aimed to develop and validate an artificial intelligence (AI)-driven tool for automated tooth segmentation on CBCT imaging.MethodsA total of 433 Digital Imaging and Communications in Medicine images of single- and double-rooted teeth randomly selected from 314 anonymized CBCT scans were imported and manually segmented. An AI-driven tooth segmentation algorithm based on a feature pyramid network was developed to automatically detect and segment teeth, replacing manual user contour placement. The AI-driven tool was evaluated based on volume comparison, intersection over union, the Dice score coefficient, morphologic surface deviation, and total segmentation time.ResultsOverall, AI-driven and clinical reference segmentations resulted in very similar segmentation volumes. The mean intersection over union for full-tooth segmentation was 0.87 (±0.03) and 0.88 (±0.03) for semiautomated (SA) (clinical reference) versus fully automated AI-driven (F-AI) and refined AI-driven (R-AI) tooth segmentation, respectively. R-AI and F-AI segmentation showed an average median surface deviation from SA segmentation of 9.96 μm (±59.33 μm) and 7.85 μm (±69.55 μm), respectively. SA segmentations of single- and double-rooted teeth had a mean total time of 6.6 minutes (±76.15 seconds), F-AI segmentation of 0.5 minutes (±8.64 seconds, 12 times faster), and R-AI segmentation of 1.2 minutes (±33.02 seconds, 6 times faster).ConclusionsThis study showed a unique fast and accurate approach for AI-driven automated tooth segmentation on CBCT imaging. These results may open doors for AI-driven applications in surgical and treatment planning in oral health care. 相似文献
88.
89.
90.
Stella Riedemann Germán Reinhardt Jaime Jara Richard Rios María Soledad Wenzel Paul Willems Hans L Bock 《International journal of infectious diseases》2002,6(3):215-222
OBJECTIVES: To determine the immunogenicity and reactogenicity of a combined DTPw-HBV/Hib vaccine, in comparison with DTPw-HBV and Hib vaccines given as separate concomitant injections. METHODS: In an open, randomized study, healthy infants were injected with either DTPw-HBV/Hib vaccine or separate DTPw-HBV and Hib vaccines at 2, 4 and 6 months of age, with a booster at 18 months. RESULTS: Both vaccination regimens were immunogenic, with seropositivity rates of 100% after the booster vaccination for all vaccine components. Even as early as 2 months after the second dose of the primary vaccination, most patients had seroprotective antibody titers, the proportion of seropositive subjects approaching 100% for tetanus, hepatitis B, and Hib. Post-primary and post-booster geometric mean titers (GMTs) were well above seroprotective thresholds for each vaccine antigen in both groups, with no clinically relevant differences in the groups. The separate and combined administrations showed comparable reactogenicity profiles, and neither showed a significant increase in reactogenicity with successive doses. CONCLUSIONS: The results of this study support the combination of Hib and DTPw-HBV vaccination in routine infant immunization at 2, 4 and 6 months of age with a booster at 18 months. Maximum benefit is obtained from compliance with the full course, but substantial benefit is likely to be achieved even in partially compliant patients, provided they receive at least two doses. Furthermore, these results demonstrate the tolerability of a fourth (booster) administration, where the addition of the Hib vaccine to DTPw-HBV did not lead to an increase in the overall reactogenicity. 相似文献