1,721,078 research outputs found
A computational physiological model of acute respiratory distress syndrome patients for positive end-expiratory pressure titration
No full textBackground and objective: Patients with acute respiratory distress syndrome (ARDS) experience alveolar collapse,
leading to reduced ventilation and blood oxygenation. Clinical treatment with mechanical ventilation involves
the use of positive end-expiratory pressure (PEEP) to recruit collapsed alveoli. The identification of an optimal
PEEP level has remained a subject of debate in critical care for over 50 years. This work proposes a 0D car
diopulmonary computational physiological model (CPM) to investigate the issue of PEEP titration by studying
the impact of PEEP on the cardiopulmonary system of ARDS patients.
Methods: The 0D cardiopulmonary CPM presented in this work was implemented using Mathworks® Simulink. In
the respiratory system model, the lung was divided into aerated alveoli and collapsed alveoli, allowing the latter
to open when the pressure exceeds the recruitment threshold. Conversely, when the pressure falls below the
collapse threshold, the recruited alveoli close. In the circulatory system model, the lung was divided into non-
perfused (zone 1), partially perfused (zone 2), and perfused alveoli (zone 3), depending on the increased alve
olar pressure caused by PEEP. Pulmonary ventilation and perfusion were combined using gas exchange equations
to determine blood oxygenation. The model was tested on a dataset of 1000 synthetic patients generated from
ARDS patient input data reported in the literature.
Results: A statistical validation of the 0D cardiopulmonary CPM was conducted by calculating the Wasserstein
distance between the distributions of the model’s calculated outputs and the reference output distributions. The
Wasserstein distance values obtained were 0.15, 0.43, 0.78, and 0.63 respectively for the outputs of the gas
exchange equations, the respiratory system model, the circulatory system model, and the complete model.
Conclusions: The 0D cardiopulmonary CPM developed in this study integrates a novel alveolar recruitment and
collapse mechanism, the simulation of pulmonary capillary disengagement, and gas exchange equations to
predict the impact of PEEP on blood oxygenation. The model demonstrates potential applicability for PEEP
titration in clinical practice, providing the ability to replicate ARDS patient conditions using clinical data,
combined with high reliability and low computational cost
Formaggio a pasta dura a basso contenuto di sale
No full textL’eccessiva assunzione di sodio con la dieta è stata
documentata recentemente, su basi scientifiche, come
tra i fattori di rischio per le patologie cardiovascolari. Il
Regno Unito è tra i principali Paesi che stanno adottando
diverse strategie per la riduzione di sodio negli alimenti
a più largo consumo. Tuttavia la riduzione di sale
comporta inevitabilmente un effetto sfavorevole sulle
qualità organolettiche e sul sapore. Anche nei formaggi
a pasta dura e a lunga stagionatura il sale gioca un
ruolo importante oltre che nella conservazione anche
e soprattutto nel determinare le caratteristiche legate
alla gradevolezza. In questo studio vengono riportate
le analisi effettuate su campioni di formaggio a pasta
dura (GranSpeciale) con un contenuto di sale normale
e campioni dello stesso formaggio a contenuto ridotto
(-35%). L’impiego di un Sistema Artificiale Olfattivo (SOA)
ha permesso di verificare che il profilo aromatico dei
campioni presi in esame risulta pressoché sovrapponibile
(livello di discriminazione del 62,1%)
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
Phantom-based lumbar spine experimental investigation and validation of a multibody model
Get PDFThe study of the biomechanics of the human spine is not yet developed extensively. Recent developments in this field have heightened the need for observing the spine from a comprehensive perspective to understand the complex biomechanical patterns, which underlie the kinematic and dynamic responses of this multiple-joint column. Within this frame of exigence, a joint study embracing experimental tests and multibody modelling was designed. This study provides novel insights to the segmental contribution profiles in flexion and extension, analysing different forms of sagittal-plane angles. Moreover, the validation of the multibody model contributes to defining the key aspects for a consistent spine modelling as well as it introduces the basis for simulating pathological conditions and post-orthopaedic surgical outcomes
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
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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