1,720,999 research outputs found
Da Mezzi di contrasto in ecografia - Testo atlante
No full textL’ecografia è, tra le metodiche di diagnostica per immagini, quella che più di ogni altra ha conosciuto una straordinaria ed ubiquitaria diffusione, coinvolgendo discipline ed operatori che vanno ben oltre l’ambito prettamente radiologico.
La continua evoluzione tecnologica e l’approntamento di sofisticate apparecchiature, oggi in grado di garantire un elevatissimo contenuto informativo, hanno permesso applicazioni sempre più estese dell’ultrasonografia, tali da consentire, in alcuni settori, il conseguimento di risultati diagnostici almeno sovrapponibili a quelli derivanti dall’impiego di metodiche convenzionalmente ritenute più affidabili, quali TC e RM.
L’introduzione, nella pratica clinica, degli agenti ecoamplificatori ha ulteriormente magnificato le potenzialità applicative dell’ultrasonografia, con conseguenti guadagni diagnostici sia in termini di sensibilità che di specificità: in particolare, è da segnalarne il producente utilizzo nella caratterizzazione delle lesioni focali, nella valutazione di efficacia della risposta biologica ai trattamenti terapeutici, nello studio del distretto cardiovascolare.
L’uso dei mezzi di contrasto ecografici impone l’adozione di strumentazioni adeguate e l’esercizio attento di specifiche ed elevate competenze professionali: tale considerazione si correla strettamente con la necessità di garantire la più alta qualità delle prestazioni, ottimizzando l’approccio tecnico-metodologico.
Ne deriva la responsabilità - che investe a pieno il ruolo delle società scientifiche e delle competenti istituzioni accademiche e sanitarie - di assicurare idonei percorsi formativi, capaci di sviluppare la diffusione delle conoscenze e di standardizzare le procedure di lavoro.
In questo contesto si inserisce l’opera che qui viene presentata: nell’esprimere agli autori — noti ed affermati cultori dell’ecografia nonché pionieri, a livello nazionale ed internazionale, degli studi sull’impiego dei mezzi di contrasto - il più vivo apprezzamento, è da sottolineare con compiacimento il valore scientifico e didattico del volume, che raccoglie le esperienze cliniche dei più attivi gruppi di lavoro dell’ecografia italiana.
La ricca e dimostrativa iconografia, abbinata all’essenzialità dei riferimenti testuali, conferisce alla pubblicazione un carattere eminentemente pratico, che rappresenta un utile ed insostituibile punto di riferimento per chi intenda approfondire le modalità d’impiego clinico degli agenti ecoamplificatori; in buona sostanza, uno strumento educazionale completo, aggiornato, altamente qualificato: un contributo esauriente alla definizione delle possibilità e dei limiti di questo innovativo ed affascinante ambito applicativo dell’ultrasonografia
Efficiency and environmental impacts of biogas vs. biomethane in combined heat and power applications
No full textThe increasing demand for low-carbon energy carriers is increasingly driven by the urgent need to address climate change and reduce the environmental impact of conventional energy systems. In this context, biogas and biomethane are emerging as key renewable solutions within the global energy transition. This study investigates a biogas plant located in northern Italy equipped with an Ingeniapatented system designed to reduce ammoniacal nitrogen and CO2, thereby improving biogas quality and enabling its upgrade to biomethane. A comparative energy and environmental analyses are carried out to evaluate the use of either biogas or biomethane as fuels in combined heat and power units having an electrical and thermal power output of 410 kW and 400 kW, respectively, focusing on primary energy requirements and greenhouse gas emissions comparison. Results show that biomethane, due to its higher lower heating value, requires less fuel consumption than biogas to produce the same useful energy output (both electrical and thermal), thereby improving overall system efficiency. Specifically, the lower primary energy demand of biomethane leads to annual savings of up to 1.35 GWh. Moreover, if biomethane production matches the volume of biogas needed to deliver the same useful energy, the excess biomethane, approximately 142,400 Sm3, can be injected into the gas grid, contributing to enhanced national energy self-sufficiency. From an environmental perspective, results show that biogas use achieves an annual emissions reduction of approximately 880 tCO2 equivalent, while biomethane slightly improves the performance, reaching about 900 tCO2 equivalent avoided per year. Overall, the study demonstrates that biomethane offers enhanced energy efficiency and climate benefits, confirming its role as a valuable option for integrated low-carbon energy systems
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
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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