1,721,062 research outputs found
Sunscreen and 25-Hydroxyvitamin D Levels: Friends or Foes? A Systematic Review and Meta-Analysis
No full textObjective: To evaluate the impact of sunscreen use on 25-hydroxyvitamin D (25(OH)D) levels, addressing conflicting findings from observational and interventional studies. Methods: Potentially eligible studies were identified from the PubMed/MEDLINE, Scopus, and Web of Science databases from inception to November 2024, utilizing a search strategy incorporating terms related to "sunscreen" and "vitamin D." The studies eligible addressed the questions define based on the Population, Intervention, Comparator, Outcome framework: What are 25(OH)D levels in patients exposing to sun applying or not sunscreen? This review followed Preferred Reported Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality assessment and the risk of bias were analyzed using Quality Assessment of Diagnostic Accuracy Studies version 2. Results: We included 22 studies in the qualitative synthesis, and 7 in the quantitative one, encompassing a total of 9470 participants. In vitro studies consistently showed that sunscreen blocks UV-B radiation, crucial for vitamin D3 production, while population-based studies reported mixed findings. Some studies linked sunscreen use to lower 25(OH)D levels, particularly in individuals with limited sun exposure, while others observed no significant impact. Meta-analysis showed that the adoption of sunscreen is associated to a reduction of 25(OH)D serum concentration (standardized mean difference = -2 ng/mL, 95% confidence interval -3, -1) with a not important heterogeneity across studies (I-square = 37%, P = .15). Conclusion: The existing evidence supports that sunscreen can impair vitamin D3 synthesis, and as a result decrease serum 25(OH)D levels, but further research is necessary to determine the broader health implications and guide public health recommendations
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
'Double layer' frozen elephant trunk with balloon endoclamping: A technique to simplify the 2-stage open repair of thoraco-abdominal aortic aneurysms
Get PDFStaged replacement of the aortic arch and thoraco-abdominal aorta (TAA) with a frozen elephant trunk followed by TAA repair is a valuable treatment for patients with chronic TAA dissection. However, in patients with an unclampable descending thoracic aorta, the retrieval of the trunk can be problematic and the proximal stent graft-to-graft anastomosis technically challenging. Here we present our 'double layer' frozen elephant trunk technique to treat patients with TAA dissection
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Bartolomeo della Gatta e i suoi allievi. L'arte aretina da Piero della Francesca a Marcillat e Vasari
No full textLa presente tesi ha l’obiettivo di indagare lo status dell’arte ad Arezzo a cavallo tra XV e XVI secolo attraverso l’analisi dell’opera pittorica di Bartolomeo della Gatta, al secolo Piero Dei, e dell’attività degli allievi della sua bottega cittadina.
Dopo un excursus che analizza la produzione artistica di Bartolomeo della Gatta, relativa in particolare alla città di Arezzo, e la successiva analisi dell’ opera pittorica dei suoi collaboratori e allievi, che fino al secondo decennio del XVI secolo continuarono a livello locale i suoi modi pittorici, la tesi ha sviluppato una ricerca personale che si prefiggeva come obiettivo l’attribuzione di un affresco raffigurante un’Annunciazione, ora conservato nella chiesa aretina di San Francesco, che ha finora avuto una lunga e dibattuta storia critica e che per lungo tempo è stato ricondotto all’attività giovanile di Luca Signorelli. Sulla base del confronto con le precedenti attribuzioni, con l’opera pittorica di Signorelli e di quella di Della Gatta e in seguito a personali indagini riguardanti gli elementi stilistici dell’opera e la probabile committenza, la ricerca svolta ha portato alla conclusione che l’affresco possa essere riferito all’attività di Bartolomeo della Gatta e del suo entourage artistico aretino, andando così ad arricchire il già cospicuo corpus di opere realizzate dall’artista in ambito cittadino.
Il lavoro si è infine concluso con la trattazione di alcune particolarità e innovazioni di carattere iconografico rilevate in seguito ad un’indagine più approfondita delle opere maggiormente significative del pittore, con il risultato di riuscire ad individuare in Bartolomeo della Gatta, anche a livello iconografico, la personalità artistica più rilevante in Arezzo nel periodo che va da Piero della Francesca a Guillaume de Marcillat e Giorgio Vasari e, più in generale, uno dei migliori interpreti della pittura rinascimentale coeva e del panorama artistico toscano della seconda metà del XV secolo
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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