1,721,039 research outputs found
Studio dell'ottenimento di un materiale fotoelettrochimico da selenocianato ammoniacato.
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Electrolytic oxidation of thiocyanate and selenocyanate salts and photoelectrochemical effect.
No full textEvaluation of TBT toxicity on murine macrophages
No full textSeveral classes of environmental contaminants are considered to be prototypical immunotoxic agents. These include the polycylic aromatic hydrocarbons, halogenated aromated hydrocarbons and various organometallic compounds such as the organotins. Immunotoxicity following exposure to planar aromatic hydrocarbons is associated with a distinct genetic locus for a cytosolic receptor known as the aryl-hydrocarbon receptor. Of the organotin, tributyltin (TBT), a biocidal organotin historically used as an antifungal agent and in marine antifouling paints, has received a great deal of attention in toxicological studies due to the likelihood of exposure to human through seafood consumption and dry-dock application procedures. No known genetic loci is associated with TBT toxicity and the exact mecanisms of toxicity are unknown. Nevertheless, an important target for tributyltin (TBT) toxicity, at least in rodents, is the immune system, with thymic atrophy serving as a hallmark feature of exposure. Moreover, it is known that TBT is able to induce both cytoskeletal alterations and apoptosis in mammalian thymocytes.
In order to explain the molecular mechanism which is responsible for the effects observed in whole organisms, in this study we have evaluated the effects of TBT in cultures of murine peritoneal macrophages.
After 24 h exposure at increasing doses of TBT, the MTT test showed a dose-dependent cytotoxicity with an IC50 value of about 3 μM. Since the inhibition of mitochondrial activity by TBT is well known, our investigations were focused on lysosomes prepared from the same murine peritoneal macrophages in which the toxicity has been evalued. By means of a probe for the measurement of internal pH by acridine orange, it was observed that TBT inhibits the lysosomal acidification. A possible explanation of these results is that TBT behaves as uncoupler in both mitochondria and lysosomes
Photoelectrochemical effect of the anodic deposit obtained on platinum from selenocyanate ammoniate.
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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
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