1,720,995 research outputs found
Magnetic Nanoparticle-Guided Blind-Focusing in Microwave Hyperthermia: Numerical Assessment in the Case of Neck Tumors
No full textThis paper concerns with a recently proposed approach of blind focused microwave hyperthermia, exploiting magnetic nanoparticles as contrast agents, and aims at numerically assessing the approach in the clinically relevant case of the treatment of neck tumors. To this respect, a realistic scheme, inspired by the prototypal system called Hypercollar, has been adopted. The well-known Zubal phantom has been exploited as human model. The numerical results show that the proposed approach works well also in a realistic and complex situations like the one considered in this study
Magnetic Nanoparticle-Guided Blind Focusing in Microwave Hyperthermia of Neck Tumors
No full textThis paper aims to assess a recently proposed approach for microwave hyperthermia, exploiting magnetic nanoparticles as modulable contrast agents in order to blindly focus on the tumor the electric field radiated by an antenna array. The approach has been improved and numerically assessed in the realistic and clinically relevant case of the treatment of neck tumors. To this end, a realistic system, whose layout is inspired to an existing one, currently under clinical testing, has been considered. The Zubal phantom has been exploited to carry out the simulations. The numerical results show that the proposed blind focusing approach works properly even in realistic and complex situations like the one considered in this paper. Moreover, the results compare very well with those obtained through not-blind focusing approaches, based on the knowledge of geometry, positioning, and electric properties of the irradiated tissues. The robustness of approach against the measurement noise has been also analyzed, in order to identify the requirements that the measurement apparatuses must satisfy and the minimum amount of magnetic nanoparticles to be administered to the patient in order to make the approach feasible. The performed thermal analysis confirmed the ability of the approach to selectively heat the tumor. The proposed approach could be a valid alternative to achieve an effective field focusing without any a priori information on the electric and geometrical properties of the anatomical region to be treated. Moreover, it could be employed in combination with magnetic hyperthermia to improve the effectiveness of the therapy
On the optimal synthesis of sum or difference patterns of centrosymmetric arrays under arbitrary sidelobe constraints
No full textThis paper deals with the optimal synthesis of sum or difference patterns radiated by an array of fixed geometry. The aim is to establish the most general class of arrays for which such synthesis can be reduced to a linear programming problem, extending and completing previous results regarding uniformly spaced (linear and planar) arrays. It is shown that such a class consists of the centrosymmetric arrays, whose element patterns are either equal or Hermitian symmetric with respect to the center of symmetry. The optimal solutions are also Hermitian symmetric and the corresponding patterns are real. Furthermore, it is shown that the above class of arrays coincides with that of the arrays capable of radiating real patterns. Some numerical examples are provided to give an idea of the geometries and the synthesis problems to which the achieved result successfully applies and of the achievable computational advantage
A Compact Antipodal Vivaldi Antenna for Food Investigation
No full textIn food industry, the analysis of the integrity of packaging and the quality of the food inside it is becoming increasingly important. Thus, the food industry is looking for a low-cost solution for the inspection of food during the production and packaging process, in order to detect any small foreign body. This is the aim of this work, i.e., to develop a microwave device capable of inspecting foodstuffs, directly on the production line. The solution proposed for this work is a microwave imaging system that detects fragments in homogenous food packaged in circular plastic/glass jars. The system relies on a particular Antipodal Vivaldi antenna which, due to its ultra-wideband characteristics, can carry out the detection of various types of food, thus avoiding the need to use multiple antennas working at different frequencies to inspect foods with different characteristics. Numerical analysis of the designed antenna shows Ultrawideband behavior (1-15GHz), suitable for applications in food quality control. Additionally, its detection capabilities are numerically proved
[Prehospital fibrinolysis: from the experience of Alta Irpinia to Campania region's network]
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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
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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