1,720,998 research outputs found
Imaging of soft-tissue tumors.
No full textSOFT TISSUE arises from the mesenchyme, which
during development differentiates into fat, skeletal
muscles, peripheral nerves, blood vessels, and fibrous
tissue (1). Soft-tissue tumors are histologically classified
on the basis of the soft-tissue component that
presents the lesion, but this does not imply that the
tumor develops from that tissue (1).
Although imaging cannot always be used to characterize
soft-tissue lesion, clinical history (ie, information
about recent traumas, fluctuating mass size,
malignancies or familial syndromes) and physical examination
(ie, superficial/deep mass, fixity to surrounding
tissue) can help identify lesions that need
biopsy to exclude malignancy (2). Wu and Hochman
(2) report the basic sequences employed to evaluate a
soft-tissue mass; we usually refer to the sequences
reported in Table 1.
Soft-tissue sarcomas are generally larger than 5 cm
and more likely to outgrow their vascular supply with
subsequent infarction and necrosis and heterogeneous
signal intensity on T2-weighted (T2w) images (3).
They respect fascial borders and remain within anatomic
compartments without infiltrating adjacent
structures until late in their development (3,4).
Computed tomography (CT) and magnetic resonance
imaging (MRI) are the current state of art in the proper
staging, evaluation of locoregional involvement, presence
of necrotic areas, infiltration and surrounding tissue,
and surgical and bioptical planning (5–8). Since distant
dissemination principally involves lungs, liver, and bone,
CT of the abdomen and the chest is necessary to evaluate
for retroperitoneal lymphadenopathy and metastasis:
CT is more sensitive in the detection of bone cortical
thinning and cortical invasion, while MRI is useful to
evaluate compartmentality, intraarticular tumor extension,
and for the depiction of bone marrow edema (5–9).
Our group has undertaken a review of some of the
almost 200 cases of soft-tissue lesions that we have
diagnosed in the last 5 years and that have been collected
in the MIRC database (10). A literature review
was performed using PubMed as well as cited references
within previously published articles and textbooks
for all published studies related to imaging of soft-tissue
tumors, with particular attention to ultrasonography
(US) and MRI findings
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
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
Détection ultra-sensible d'hydrocarbures aromatiques polycycliques adsorbés à la surface des suies par désorption laser/ionisation laser/spectrométrie de masse à temps de vol : une approche pour étudier les processus de croissance des suies dans les flammes
No full textPrésent dès les premiers instants de la combustion, les Hydrocarbures Aromatiques Polycycliques (HAP) jouent un rôle prépondérant dans la formation des suies avant d’être adsorbés par les particules ainsi formées. Les HAP influencent ainsi la quantité, la composition et la morphologie des suies émises pendant la combustion. L'étude de l'évolution de la phase adsorbée de ces particules au sein de la flamme doit permettre de mieux comprendre leur mécanisme de formation ainsi que leur impact sur la santé et l’environnement. Une expérience originale dédiée à une telle étude et basée sur le couplage des techniques de Désorption Laser, Ionisation Laser et Spectrométrie de Masse a été développée pendant cette thèse. Des suies collectées dans des flammes sont irradiées par un laser à 532 nm permettant ainsi la libération des HAP adsorbés. Les HAP sont ionisés par un deuxième laser à 266 nm avant d'être finalement analysés dans un spectromètre de masse à temps de vol. L’interprétation des spectres ainsi obtenus a fait l’objet d’une analyse très approfondie afin de caractériser les étapes de désorption et d’ionisation. Les analyses, réalisées dans différents types de flammes permettent d’identifier les HAP présents à la surface des suies à différents stades de leur formation, l’étendue des spectres variant fortement dans la zone de nucléation des suies. Afin de distinguer les HAP gazeux de ceux adsorbés, une nouvelle méthode de collecte basée sur le dépôt des suies et des HAP gazeux sur des substrats différents a été développée. Par ce biais, l’implication de réactions hétérogènes entre les HAP gazeux et les suies dans la croissance de ces dernières a pu être mise en évidence.Polycyclic Aromatic Hydrocarbons (PAH) are important precursors of carbonaceous soot particles, thus influence the quantity and morphology of particulate emission of combustion processes. Furthermore the PAH adsorbed on the surface of the soot particles contribute to the carcinogenicity of the particles, so there is scientific interest in characterising and quantifying those species to provide key information on the mechanism of soot formation and to understand their impact on environment and human health. An original setup based on the coupling of Laser Desorption, Laser Ionisation and Time-Of-Flight Mass Spectrometry techniques has been dedicated to the analysis of PAH desorbed from soot. Briefly, soot is sampled from flames using an extractive vacuum probe and deposed on porous filters. The samples are irradiated with a 532 nm laser beam to promote the desorption of neutral molecules. The ejecta are then ionised with a 266 nm laser beam, and the positive ions produced this way are mass analysed in a TOF-MS. The complete characterisation of the desorption and ionisation process has been the first goal of this work. The acquired expertise allowed investigations on different flames in which the PAH have been identified and studied at different level of their formation. Particularly, relevant differences in the mass spectra have been detected in the soot inception region. A new method based on the deposition of soot on different substrates is proposed in order to distinguish the PAH belonging to the gas-phase during the sampling from those adsorbed on soot particles, hence the role of the heterogeneous reactions between gaseous PAH and soot particles has been highlighted
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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