1,721,011 research outputs found
Inusuale aspetto ecotomografico di una raccolta post-traumatica nello spazio perivescicale sottoperitoneale.
No full textDisruption of cytoskeleton by methylmercury in cultured CHO cells
No full textThe effect of methylmercury (MM) on three main cytoskeletal components [i.e. microtubules (MT), microfilaments (MF) and intermediate filaments (IF)] and on specific biochemical parameters (i.e. glutathione transferase (GST), glutathione reductase (RED), glutathione peroxidase (GSH-Px), glyoxalase 1 (GLY 1) and total -SH groups (TSH) of the cytosolic fraction) was studied in cultured Chinese hamster ovary (CHO) cells. The experiments were conducted with increasing doses of MM (i.e. 1, 4 and 8 Î1⁄4m), using an exposure time of 16 hr; and with a fixed dose of MM (2 Î1⁄4m), using increasing exposure periods (i.e. 0-24 hr). The morphological changes observed by immunofluorescence seemed to indicate that MF were damaged as much as (if not more than) MT after 16 hr of exposure to 4 Î1⁄4m-MM. At a concentration of 1 Î1⁄4m, MM only affected MF. The time-course experiments revealed that IF as well as MF and MT were severely disorganized after 3 and 6 hr of incubation in the presence of 2 Î1⁄4m-MM. However, an obvious reorganization was observed after 24 hr of exposure. In experiments using increasing MM doses, changes in the enzymatic activities were less noticeable than those observed in the morphology; only a modest decrease in TSH and RED activities (<30%) was recorded at the highest dose of MM used (i.e. 8 Î1⁄4m). In contrast, increasing the time of exposure to MM induced changes in both the cytoskeletal structures and the biochemical parameters: the lowest RED activity and TSH were observed after 3-6 hr exposure; control values were obtained after an exposure period of 24 hr. Ultrastructural observations on cells treated with increasing doses of MM showed changes in plasmamembrane profile, cytoskeleton organization and mitochondrion structure. The results confirm that MM causes non-specific damage to CHO cells and suggest that a functional interaction may exist between GSH-dependent enzymes and cytoskeletal structures. © 1992
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
La colestasi intraepatica progressiva familiare: due casi.
No full textLa colestasi intraepatica progressiva familiare o malattia
di Byler si colloca tra le colestasi intraepatiche da difetto
funzionale primitivo e riconosce una ereditarietà di tipo
autosomico recessivo . È stata descritta per la prima volta
da Clayton nel 1965 in 7 bambini Amish; attualmente
esistono in letteratura a nostra conoscenza circa una quarantina di segnalazioni in soggetti di gruppi etnici diversi
The structure and the fate of the test cuticle during the fusion-non fusion reaction in colonies of Botryllus schlosseri (Tunicata)
Full text linkElectron microscopy observations show that in contacting colonies of B. schlosseri a fusion and then a dissolution of cuticles occur resulting in the confluence of the tunics. This
occurs occasionally with both genetically
compatible and incompatible colonies
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