1,720,957 research outputs found
Development of an innovative instrument for the online characterization of high-frequency percussive ventilators
No full textA portable instrument for the volume measurement of high-frequency percussive ventilators
No full textIn vitro measurement of respiratory mechanics during HFPV using a mechanical lung model
No full textHigh-frequency percussive ventilation (HFPV) may be defined as flow-regulated time-cycled ventilation that creates controlled pressure and delivers a series of high-frequency subtidal volumes in combination with low-frequency breathing cycles. In recent years, the usefulness of HFPV has been clinically assessed as an alternative to conventional mechanical ventilation. In the clinical practice, HFPV is not an intuitive ventilatory modality and the absence of real-time delivered volume monitoring produces disaffection among the physicians. For this purpose, it would be useful to develop a monitor able to realize a complete online characterization of high-frequency percussive ventilators and to identify the best combination of their parameters according to the specific pathological situation. This paper describes an innovative acquisition and elaboration system based on the use of new generation pressure transducers presenting high sensitivity and fast response. Such a system is compact and inexpensive, and it allows the user to carry out a more correct online characterization of high-frequency percussive ventilators. This output allowed best real-time ventilatory setting, minimizing the potential baro-volutrauma hazard
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
Caratterizzazione del ventilatore percussivo
No full text2009/2010The thesis describes the study on the characterization of the percussive ventilator; the activities have been carried out in cooperation with the “D.A.I. di Medicina Perioperatoria, Terapia Intensiva ed Emergenza - UCO di Anestesia, Rianimazione e Terapia Antalgica dell'Azienda Mista Universitaria - Ospedaliera di Trieste”. The first chapter describes the physiology of the respiratory system and the classical models presented in literature, the second chapter illustrates the main modes of mechanical ventilation, particularly in the percussive ventilation. The third chapter describes the classical laboratory equipment for the measurement of breathing. The fourth chapter examines the state of the art of methods and instruments for the analysis of respiratory parameters. The fifth chapter discusses the instruments for measuring respiratory parameters, developed in the biomedical laboratory of the DEEI of University of Trieste. The sixth chapter contains a detailed study on the characterization of the percussive ventilator: the model, the method for estimating parameters, the system tests and the results. Particularly, the ability to monitor respiratory parameters by using the instrument developed avoids the volutrauma (alveolar-capillary permeability increase owing to excessive distension of the lung) during controlled ventilation. The instrument also allows to accurately estimate the lung elastance, determining factor of the volume distribution in the used model. At the conclusion of the work, the seventh chapter summarizes the results from the study of the volumes distribution in the two-compartment model of the lung conditioned to percussive ventilation.XXIII Ciclo196
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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