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La scintigrafia miocardica con 111In Antimiosina nella valutazione della cardiotossicità da antracicline
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La medicina nucleare nella diagnostica integrata della patologia da affaticamento
No full textNuclear medicine applications deal with the functional and dynamic study of organs and apparatuses in each diagnostic protocol. Bone scintigraphy (diagnostic accuracy: 80%) plays an important role in the differential diagnosis of the various musculoskeletal conditions in sports, mainly in the so-called "stress syndrome". The method is rather simple, including three steps: 1) study of radioactivity in the ROI; 2) capillary phase, with early imaging; 3) bone phase, with a static image 5 hours after injection. Slight differences in marker uptake, with fusiform and elongated marker accumulation areas, can be seen in the tibial stress syndrome, which exhibits no increase in the vascular phase, while in stress fractures, mainly in the late stages, increased activity can be seen in the arteriolar and capillary phases. Stress fractures are divided into 5 stages, from stage 1 = 80% bone involvement. The advantages of 3-phase bone..
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
Significato ed utilità della SPET con 99mTc-HMPAO nella diagnostica dell’emicrania con aura
No full textIt is generally agreed upon that the attacks of migraine with aura are indicative of abnormal cerebral perfusion, while the permanence of such perfusion abnormalities during the pain-free intervals of migraine remains debated. This study was aimed at assessing: 1) the presence of cerebral perfusion abnormalities also during the interictal phase and 2) the role of SPET with 99mTc HM-PAO to diagnose migraine. Twenty-eight patients (22 women and 6 men), diagnosed as having migraine with aura according to the International Headache Society (Headache Classification Committee criteria), were submitted to SPET studies, within 10 days of the last attack. 99mTc HM-PAO was used as perfusion tracer and a single head rotating gamma camera equipped with a high-resolution collimator was used for data acquisition. The qualitative analysis of SPET images showed slight hypoperfusion areas in 22 of 28 patients (79%). In 12 of 22 patients (55%) a regional correlation was observed between hypoperfusion ar..
Subcellular distribution of technetium-99m-N-NOEt in rat myocardium
No full textThe aim of this study was to determine the subcellular distribution of bis(N-ethoxy N-ethyl)dithiocarbamato nitrido technetium(V) (99mTcN-NOEt) in rat heart by differential centrifugation techniques. Extraction of the activity from homogenized rat heart tissue was also performed to assess whether myocardial retention might induce changes in the chemical identity of the complex. Methods: Anesthetized rats were intravenously injected with 99mTcN-NOEt, the heart tissue was extracted and homogenized and tissue fractions were obtained by differential centrifugation. The efficiency of organelle separation was determined by assay of each centrifugal fraction using enzyme markers. Lactate dehydrogenase (LDH), acid phosphatase (ACP), alkaline phosphatase (ALP) and 5'-nucleotidase (5'ND) activities were assayed using standard spectrophotometric methods. Succinic dehydrogenase (SDH) activity was determined using a p-iodonitrotetrazolium-linked assay. Severe cell membrane and organelle disruption were induced by prolonging the homogenization time and their effect on the subcellular distribution of 99mTcN-NOEt was studied. The activity from homogenized heart tissue was extracted using the Folch technique and analyzed by TLC and HPLC. Results: Most of the 99mTcN-NOEt activity was found to be associated with the hydrophobic components of the cell. No evidence of specific association of activity with the cytosolic and mitochondrial components was observed. Organelle and membrane cleavage did not cause release of activity into the cytosol. Approximately 90% of 99mTcN-NOEt activity was extracted from ventricular tissue and the chemical nature of 99mTcN-NOEt was not altered by uptake by myocardium. Conclusion: Cell membranes are the most apparent site of localization of 99mTcN-NOEt in heart tissue
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