1,720,984 research outputs found
Effetto carcinogenico delle polveri di legno: riparo del DNA e mutazioni EGFR/HRAS
No full textSulla base di studi epidemiologici, le polveri di legno, con particolare riferimento a quelle di legno
duro, sono classificate dallo IARC come cancerogene certe per l’uomo. E’ stato ipotizzato che una
lunga permanenza delle polveri di legno inspirate e depositate nei vari tratti dell’apparato
respiratorio possa innescare meccanismi infiammatori e tossici che, a lungo termine, potrebbero
predisporre la cellula ad una trasformazione maligna. Ad oggi, i meccanismi molecolari alla base
della cancerogenicità delle polveri di legno sono ancora sconosciuti.
Obiettivo dello studio è investigare il potenziale cancerogeno di due polveri di legno duro (Rovere,
Padouk) e due polveri di legno morbido (Abete, Pino). I risultati ottenuti mostrano che le polveri
agiscono inducendo un danno ossidativo mediato da ROS che provoca l’accumulo di basi puriniche
e pirimidiche ossidate. Le lesioni accumulate sono associate ad un cambiamento fenotipico della
cellula che acquista la capacità di crescere in maniera ancoraggio-indipendente. Le cellule
trasformate dalla lunga esposizione alle diverse polveri presentano un’alterazione mitocondriale ed
un aumentato numero di autofagosomi, nonché un’aumentata capacità replicativa. La principale
caratteristica delle cellule trasformate è una sottoespressione del gene dell’OGG1 che impedisce il
riparo della principale base mutagenica (siti FPG) prodotta dai ROS. La cancerogenicità delle
polveri di legno sembra coinvolgere anche la via metabolica dell’EGFR: tutte le cellule trasformate
presentano una delezione nell’esone 19 del gene dell’EGFR (c.2236_2250del15) ed una
sostituzione nell’esone 1 del gene dell’HRAS (35G>A).
Sebbene la magnitudo dell’effetto prodotto sia differente, i risultati ottenuti mostrano che le diverse
polveri di legno agiscano con meccanismi comuni di cancerogenicità, indistintamente dalla loro
classificazione come legno duro o morbido
American options with acceleration clauses
Full text linkAcceleration clauses shorten the residual life of an option when an acceleration condition is met. Acceleration clauses are frequent in warrants, American call options on traded stocks. In warrants with the acceleration clause, if an index (e.g. the average underlying stock) triggers an acceleration threshold, the American call option can be exercised on a much shorter maturity (e.g. 30 days). The actual time-to-maturity of an American option with an acceleration condition is therefore stochastic. In order to evaluate these contracts we first reduce the generic American option with stochastic time-to-maturity to a compound American option with constant maturity, and provide estimates for their prices. Finally we propose an efficient algorithm to price American call options with the acceleration clause in a binomial setting
Marcatori epigenetici in combinazione con la mesotelina nella diagnosi precoce del mesotelioma maligno della pleura.
No full textEpigenic in the early detection of tumours associated with occupational exposure: miR-126 and mesothelin as biomarkers of the malignant pleural mesothelioma
No full textExperimental evaluation of cross-infection risk during spirometric tests using different types of mouthpieces
No full text
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
Effect of ascorbic acid-rich diet on in vivo-induced oxidative stress.
No full textUsing hyperbaric oxygen (HBO) therapy as an in vivo oxidation model, we investigated the effect of a diet enriched in ascorbic acid (AA) on HBO-induced oxidative stress. Volunteers (n 46) were allocated to the AA-rich diet group or the control group. Blood samples were collected at the basal time, after the 1-week diet before and immediately after the HBO treatment, and 1 week after the HBO treatment. AA level, total antioxidant status (TAS), hydroperoxides (HP), lymphocyte DNA oxidation and DNA repair capacity were assessed. The expression of genes involved in oxidative stress was evaluated in lymphocytes and the protein activity of the modulated genes was determined in the plasma. The AA level and the antioxidant status of plasma were increased by AA-rich food consumption. HBO exposure did not affect the AA levels or TAS, but induced HP formation in the control group. The lymphocytes isolated from dietary-supplemented subjects were resistant to ex vivo DNA oxidation, showing an increased DNA repair capacity compared with controls. A difference in gene expression pattern was observed between the groups. AA-rich foods provide dual protection against oxidative stress, enhancing plasma antioxidant levels and stimulating genes involved in cell detoxification
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