1,720,999 research outputs found
Indium-111 pentetreotide scintigrapy in the detection of insulinomas: importance of SPECT imaging
No full textJ Nucl Med. 2000 Mar;41(3):459-62.
111In-pentetreotide scintigraphy in the detection of insulinomas: importance of SPECT imaging.
Schillaci O, Massa R, Scopinaro F.
SourceDepartment of Sciences and Biomedical Technologies, University of L'Aquila, Rome, Italy.
Abstract
The aim of this study was to determine whether the systematic use of SPECT can increase the reported low sensitivity of somatostatin receptor scintigraphy (SRS) in detecting insulinomas.
METHODS: Fourteen patients were evaluated. After 111In-pentetreotide injection (approximately 250 MBq intravenously), abdominal SPECT images were obtained at 4 h and multiple planar images were obtained at 4 and 24 h. MRI and CT were performed within 1 mo of SRS. Sixteen tumors were histologically verified after surgery in 14 patients.
RESULTS: SPECT revealed 14 lesions in 12 patients (sensitivity, 87.5%), both planar SRS and MRI revealed 7 tumors in 7 patients (sensitivity, 43.8%), and CT revealed only 5 lesions in 4 patients (sensitivity, 31.3%). Moreover, in 4 patients SPECT was the only examination with positive findings.
CONCLUSION: SPECT at 4 h is mandatory for preoperative detection of insulinomas using SRS because the images are more sensitive than planar images and are superior to images from other conventional methods.
PMID:10716319[PubMed - indexed for MEDLINE] Free full tex
Occupational exposure to electromagnetic fields: risk assessment of operators performing Transcranial Magnetic Stimulation (TMS) treatments
Full text linkThe assessment of the risk from occupational exposure to electromagnetic fields (EMF) has attracted the attention of those involved in safety in the workplace, in particular after the updating of European legislation, with the publication for EMFs, of Directive 2013/35/EU1 of the European Parliament and of the Council, which made the risk assessment mandatory for this type of physical agents. The issue is made even more relevant by the proliferation of industrial and health applications using EMF even of considerable intensity. However, the rapid technological development has not always been accompanied by adequate growth in the culture of prevention and safety. Many devices expose both operators and persons of the general public to significant risks, but often, these risks are not adequately reported by the manufacturer, nor mentioned in the instruction manual, as would be expressly required by the harmonized standards.
In this general framework is placed this Ph.D. research project, whose aim is to analyze possible conditions of risk in the workplace, considering only the environment where the EMF sources potentially expose the operator to risk. The research project involves a joint collaboration between two Institutions: the National Institute for Insurance against Accidents at Work - INAIL and of course Sapienza University of Rome.
The project is developed in a multidisciplinary manner, providing experimental and numerical investigations to achieve the required goals, also considering the literature review and comparison for a more realistic analysis of the risk, in terms of human exposure to EMF. The work is based on a multiphysics approach to obtain a complete evaluation of the risk in the workplace, with the prospective to improve the current approach in the assessment of the risk and eventually suggest some indications to the operator for better use of the device under test.
Therefore, the starting point has been a review of the workplaces to identify any gaps and critical issues in relation to the risk assessment and therefore for which it is considered necessary to deepen the protectionist issues. A literature analysis of the state of the art on the risk in the workplace is first carried out.
This has been followed by numerical and accurate modeling of the device under test as well as the workers in a real reproduced work condition of exposure. Of paramount importance is the understanding of all the parameters that can affect the distribution of the induced EM quantities, which are essential for the risk assessment and the verification of compliance with the regulations system. To do this, it was necessary to study human exposure in-depth, also using different human body models available for dosimetric analysis on dedicated software.
All the research has traveled on two parallel tracks, on the one hand, the need to fill the scientific gaps in the research area of exposure assessment of workers and on the other one to take into account the regulatory aspects, essential for a correct evaluation of professional exposure. Therefore, as a last step of the overall work, a possible new protocol of risk assessment analysis is proposed to move forward on the improvement of safety and security in the workplace
Experimental set-up for dynamic evaluation of optical parameters of liquid samples exposed to microwave radiation
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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
Scientific review for the identification of occupational scenarios where electromagnetic fields exposure can exceed exposure limits
No full textIn this paper a scientific review is presented, aimed to the identification of occupational scenarios where the exposure to stray electromagnetic fields (EMFs) can exceed the exposure limit values (ELVs) defined in Directive 2013/35/EU and in the Italian law. A total number of 56 papers was examined
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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