1,721,169 research outputs found
Tutorial on microarray gene expression experiments - An introduction
No full textObjectives: With the collection of articles presented in this special issue, we aim at educating interested statisticians and biometricians on the one hand as well as biologists and medical researchers on the other with respect to basic necessities in planning, conducting and analyzing microarray gene expression experiments. The reader should get comprehensive directions to understand both the overall structure of this approach as well as the decisive details, which enable - or thwart - a meaningful data analysis. Methods: For a one-day workshop with tutorial character we brought together experts in design, conduct and analysis of microarray gene expression experiments who prepared a series of comprehensive lessons. These contributions were then reworked into a series of introductory articles and bundled in form and content as a Special Topic. Results: It was possible to present a tutorial overview of the field. The interested reader was able to learn the basic necessities and was referred to further references for details on the possible alternatives. A recipe style all-embracing plan, covering all eventualities and possibilities was not only beyond the scope of an introductory tutorial-like presentation, but was also not yet agreed upon by the scientific society. Conclusions: It proved feasible to find a framework for integrating the interdisciplinary approaches to the challenging field of gene expression analysis with microarrays, hopefully contributing to a rapid and comprehensive introduction for novices
Tutorial on microarray gene expression experiments - An introduction
No full textObjectives: With the collection of articles presented in this special issue, we aim at educating interested statisticians and biometricians on the one hand as well as biologists and medical researchers on the other with respect to basic necessities in planning, conducting and analyzing microarray gene expression experiments. The reader should get comprehensive directions to understand both the overall structure of this approach as well as the decisive details, which enable - or thwart - a meaningful data analysis. Methods: For a one-day workshop with tutorial character we brought together experts in design, conduct and analysis of microarray gene expression experiments who prepared a series of comprehensive lessons. These contributions were then reworked into a series of introductory articles and bundled in form and content as a Special Topic. Results: It was possible to present a tutorial overview of the field. The interested reader was able to learn the basic necessities and was referred to further references for details on the possible alternatives. A recipe style all-embracing plan, covering all eventualities and possibilities was not only beyond the scope of an introductory tutorial-like presentation, but was also not yet agreed upon by the scientific society. Conclusions: It proved feasible to find a framework for integrating the interdisciplinary approaches to the challenging field of gene expression analysis with microarrays, hopefully contributing to a rapid and comprehensive introduction for novices
Inflammatory response after acute ischemic stroke
No full textBackground and purpose: This study aimed to characterize the time course of inflammatory parameters after acute ischemic stroke. Methods: We serially determined high sensitivity C-reactive protein (CRP), fibrinogen, and leukocyte counts at 10 time points between days I and 90 after ischemic stroke and in control subjects. Results: CRP did not significantly change, whereas fibrinogen increased after stroke. At all time points, CRP and fibrinogen were higher than in healthy control subjects, but not risk factor control subjects. The leukocyte count declined after stroke and was significantly elevated as compared to both control groups only on day 1 but not later. NIHSS levels were positively correlated with CRP and fibrinogen at all time points. Larger infarcts were associated with a higher CRP and leukocyte counts on day 90. Treatment with aspirin was associated with lower values for all three inflammatory parameters in the subacute phase after ischemia. Conclusions: The course after stroke was different between the parameters of inflammation. Only the leukocytes followed the paradigm of an acute phase response. (c) 2005 Elsevier B.V. All rights reserved
A prospective randomized study to assess the efficacy of a surgical sealant to treat air leaks in lung surgery
No full textOBIETTIVO: Studio prospettico, randomizzato per valutare l’efficacia e la sicurezza dell’uso di un sigillante polimerico (Coseal, Baxter Healthcare, Deerfield, IL) per ridurre le perdite aeree e migliorare l’esito postoperatorio in pazienti sottoposti a resezione polmonare. METODI: tra Novembre 2005 e Febbraio 2008, 203 pazienti (128 M, 75 F) che mostravano perdite aeree di grado moderato/severo dopo lobectomie standard/bi-lobectomie/ lobectomie con resezione bronchiale a manicotto (110) o resezioni minori (segmentectomie/atipiche) (83), sono stati prospettivamente arruolati e sottoposti in cieco ad una delle seguenti strategie di gestione intraoperatoria: sutura manuale/meccanica (101 pazienti- gruppo di trattamento standard) o sutura manuale/meccanica con aggiunta del sigillante Coseal (102 pazienti-gruppo Coseal). Per valutare l’efficacia del sigillante , sono stati registrati i seguenti dati e poi confrontati tra i due gruppi: numero di pazienti con arresto della perdita aerea intraoperatoria, numero dei pazienti senza perdita aerea a 24 e 48 ore, durata della perdita aerea, degenza ospedaliera. RISULTATI: Non si è verificato nessun evento avverso riconducibile all’uso del sigillante. Il tasso di arresto della perdita aerea intraoperatoria è stato più alto nel gruppo trattato con il Coseal con una differenza statistica significativa (85.3% vs 59.4%; p<0.001). Il tasso di perdite aeree a 24 e 48 ore è risultato significativamente più basso nel gruppo di trattamento con il Coseal (19.6% vs 40.6%; p=0.001 a 24h e 23.5% vs 41.6%; p=0.006 a 48h). La durata delle perdite aeree è risultata significativamente più breve nel gruppo di trattamento con Coseal (p=0.01). La degenza ospedaliera è stata più breve nel gruppo di trattamento con Coseal (media: 5.7+/-2.3 giorni vs 6.2+/-2.5 giorni). Tuttavia, questa differenza non ha raggiunto significatività statistica dovuta a molti fattori clinici noti. CONCLUSIONI: L’uso del sigillante Coseal ha dimostrato sicurezza ed efficacia nella riduzione delle perdite aeree durante resezioni polmonari, riducendo la durata della perdita aerea postoperatoria con tendenza verso una degenza postoperatoria più breve
Estimating the common distribution of two potential treatment responses given a biomarker and right censoring censored event times
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
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