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21.
Lex van Velsen Thea van der Geest Rob Klaassen 《International journal of human-computer interaction》2013,29(7):670-698
A personalized system is one that generates unique output for each individual. As a result, personalization has transformed the interaction between the user and the system, and specific new usability issues have arisen. Methods used for evaluating personalized systems should be able to reveal the issues and problems specifically associated with personalization. Therefore this study evaluated three of the most common test methods used to detect usability problems in a personalized search engine. This was done by comparing the comments generated from thinking-aloud, questionnaires, and interviews. Questionnaires and interviews appear to be more useful for assessing specific usability issues for personalization, whereas thinking-aloud generates more comments on the usefulness of the system in the intended context of use and identifies the most critical and serious problems. Interviews, on the other hand, appear to yield a disproportionate number of positive comments. During the formative evaluation of a personalized system it is best to use a combination of thinking-aloud and questionnaires. This article concludes with a summary of implications for practitioners. 相似文献
22.
Dr. Phillip T. Lowe Dr. Sergio Dall'Angelo Dr. Thea Mulder-Krieger Prof. Adriaan P. IJzerman Prof. Matteo Zanda Prof. David O'Hagan 《Chembiochem : a European journal of chemical biology》2017,18(21):2156-2164
The A2A adenosine receptor belongs to a family of G-coupled protein receptors that have been subjected to extensive investigation over the last few decades. Due to their prominent role in the biological functions of the heart, lungs, CNS and brain, they have become a target for the treatment of illnesses ranging from cancer immunotherapy to Parkinson's disease. The imaging of such receptors by using positron emission tomography (PET) has also been of interest, potentially providing a valuable tool for analysing and diagnosing various myocardial and neurodegenerative disorders, as well as offering support to drug discovery trials. Reported herein are the design, synthesis and evaluation of two new 5′-fluorodeoxy-adenosine (FDA)-based receptor agonists (FDA-PP1 and FDA-PP2), each substituted at the C-2 position with a terminally functionalised ethynyl unit. The structures enable a synthesis of 18F-labelled analogues by direct, last-step radiosynthesis from chlorinated precursors using the fluorinase enzyme (5′-fluoro-5′-deoxyadenosine synthase), which catalyses a transhalogenation reaction. This delivers a new class of A2A adenosine receptor agonist that can be directly radiolabelled for exploration in PET studies. 相似文献
23.
Sinha R Cross A Curtin J Zimmerman T McNutt S Risch A Holden J 《Molecular nutrition & food research》2005,49(7):648-655
There is ample evidence from basic research and animal carcinogenicity studies that heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) are mutagens and carcinogens. However, there was a paucity of human data due to a lack of appropriate investigative tools. We developed the first validated cooked meat module within a food frequency questionnaire (FFQ) in the United States of America and created databases to be used in conjunction with this FFQ to estimate intake of HCAs and benzo[a]pyrene, a marker of PAHs. It became clear that other aspects of meat may also contribute to carcinogenesis; in particular, we are pursuing two additional areas: processed meat and iron exposure in relation to cancer risk. To investigate these hypotheses, we have expanded the cooked meat module to include detailed information on processed meats and fish. In addition, we are developing two databases, one for total iron and heme iron in cooked meat and the other for nitrite, nitrate, and N-nitroso compounds in processed meats. In this report, we will outline the methods used to develop the meat questionnaires, the databases, a software package for generating the intake values, and the methods used to generate nutritional data from nationally representative samples. 相似文献
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Thea van der Geest Hans van der Meij Carolina van Puffelen 《Universal Access in the Information Society》2014,13(2):161-174
The Internet can make available to people with a visual impairment information and services that are otherwise inaccessible. But do visually impaired users actually use common Internet applications and do they have the necessary skills? This article reports a two-part study addressing these questions. The first part was an interview study in which 73 young and 69 older Dutch people with a visual impairment were questioned about usage of applications such as e-mail, chat, and web forms, and their self-perceived competence. The young participants reported more frequent use of Internet applications and mentioned multiple goals (i.e., social and educational), compared to the older. Both groups considered themselves reasonably competent, with the young rating themselves higher. The second part was a case study with 20 young and 20 older participants from the first study, who performed common Internet tasks, using websites or applications that complied with accessibility guidelines. Task performance was analyzed in detail for demonstrated skills. Actual performance proved to be unrelated to self-rated competence. Moreover, the competence of both young and older participants fell far short of what active participation in society requires, especially for the more complex information and strategic skills. The success rate on the performance tasks was low. People with a visual impairment should receive extensive support for the acquisition of higher-level skills that are called upon when using Internet information and services in order to participate in society. 相似文献
27.
Stefania Zappia Arxel de León Marina Alloisio Eduardo Arias Giovanna Dellepiane Giovanni Petrillo Ivana Moggio Sergio Thea Carlos Gallardo-Vega Marlene Rodríguez 《Materials Chemistry and Physics》2014
A perylene cholesteryl-benzoateethynylene co-polymer was synthesized by Sonogashira reaction and characterized by NMR, UV–Vis, static and dynamic fluorescence spectroscopy and cyclic voltammetry. The optical and electrochemical properties in solution are consistent with photoinduced energy transfer from the electron donor conjugated backbone to the electron acceptor perylene substituent. Photovoltaic properties are indeed found, even if the performance of the solar cells is quite low due to the formation of aggregates. The incorporation of (6,6)-phenyl C61–butyric acid methyl ester (PCBM), however, increases by an order of magnitude the efficiency of the prototype (from 10−4 to 10−3%) due to both better phase mixing and improved electrical continuity as supported by Atomic Force Microscopy (AFM) and Electrical Force Microscopy (EFM) studies. 相似文献
28.
Savannah A. Lynn Flavie Soubigou Jennifer M. Dewing Amanda Smith Joanna Ballingall Thea Sass Isabela Nica Catrin Watkins Bhaskar Gupta Hussein Almuhtaseb Stephen C. Lash Ho Ming Yuen Angela Cree Tracey A. Newman Andrew J. Lotery J. Arjuna Ratnayaka 《International journal of molecular sciences》2022,23(23)
Matrix metalloproteinase-9 (MMP9) and total amyloid-beta (Aβ) are prospective biomarkers of ocular ageing and retinopathy. These were quantified by ELISA in the vitreous and blood from controls (n = 55) and in a subset of age-related macular degeneration (AMD) patients (n = 12) for insights and possible additional links between the ocular and systemic compartments. Vitreous MMP9 levels in control and AMD groups were 932.5 ± 240.9 pg/mL and 813.7 ± 157.6 pg/mL, whilst serum levels were 2228 ± 193 pg/mL and 2386.8 ± 449.4 pg/mL, respectively. Vitreous Aβ in control and AMD groups were 1173.5 ± 117.1 pg/mL and 1275.6 ± 332.9 pg/mL, whilst plasma Aβ were 574.3 ± 104.8 pg/mL and 542.2 ± 139.9 pg/mL, respectively. MMP9 and Aβ showed variable levels across the lifecourse, indicating no correlation to each other or with age nor AMD status, though the smaller AMD cohort was a limiting factor. Aβ and MMP9 levels in the vitreous and blood were unrelated to mean arterial pressure. Smoking, another modifiable risk, showed no association with vitreous Aβ. However, smoking may be linked with vitreous (p = 0.004) and serum (p = 0.005) MMP9 levels in control and AMD groups, though this did not reach our elevated (p = 0.001) significance. A bioinformatics analysis revealed promising MMP9 and APP/Aβ partners for further scrutiny, many of which are already linked with retinopathy. 相似文献
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Márcia Gonçalves Ventura Maria do Carmo Freitas Adriano Manuel Gomes Pacheco Thea van Meerten Hubert Theodore Wolterbeek 《European Food Research and Technology》2007,224(3):403-401
In the present study, selenium contents for some selected food items commonly consumed in Portugal are presented. Food items, i.e., meat, fish, eggs, dairy products, cereals, fruits and vegetables were sampled from two representative markets of two different regions of Portugal territory. The selenium concentrations in the various food items have been determined by using nuclear activation analysis (NAA) in both versions instrumental (INAA) and replicate sample (RSINAA) through the short-lived nuclide 77mSe that features a half-life time of 17.5 s. The highest values were found for meat, fish and eggs (87.6–737 μg kg−1); lower values were obtained for vegetables and fruits (1.7–24.9 μg kg−1). 相似文献