1,721,364 research outputs found
Cartilage mechanical tests: Evolution of current standards for cartilage repair and tissue engineering. A literature review
No full textBackground: Repair procedures and tissue engineering are solutions available in the clinical practice for the treatment of damaged articular cartilage. Regulatory bodies defined the requirements that any products, intended to regenerate cartilage, should have to be applied. In order to verify these requirements, the Food and Drug Administration (FDA, USA) and the International Standard Organization (ISO) indicated some Standard tests, which allow evaluating, in a reproducible way, the performances of scaffolds/treatments for cartilage tissue regeneration. Methods: A review of the literature about cartilage mechanical characterization found 394 studies, from 1970 to date. They were classified by material (simulated/animal/human cartilage) and method (theoretical/applied; static/dynamic; standard/non-standard study), and analyzed by nation and year of publication. Findings: While Standard methods for cartilage mechanical characterization still refer to studies developed in the eighties, expertise and interest on cartilage mechanics research are evolving continuously and internationally, with studies both in vitro – on human and animal tissues – and in silico, dealing with tissue function and modelling, using static and dynamic loading conditions. Interpretation: there is a consensus on the importance of mechanical characterization that should be considered to evaluate cartilage treatments. Still, relative Standards need to be updated to describe advanced constructs and procedures for cartilage regeneration in a more exhaustive way. The use of the more complex, fibre-reinforced biphasic model, instead of the standard simple biphasic model, to describe cartilage response to loading, and the standardisation of dynamic tests can represent a first step in this direction
Sintesi e carbossilazione elettrochimica di N-enoilossazolidinoni chirali. Uno studio preliminare
No full textGoing 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
Indagini preliminari su bacilli sporigeni associati ad adulti di Punteruolo rosso e loro possibili impieghi in lotta biologica.
No full textE’ stata condotta un’indagine per isolare batteri sporigeni associati ad adulti morti di Rhynchophorus ferrugineus. La carica microbica riscontrata, sia quella superficiale che endogena, risulta essere elevata (107 UFC/gr). Gli isolati sono riconducibili al genere Bacillus. La produzione di cristalli parasporali, potenziali δ-endotossine, è stata utilizzata come parametro fondamentale per lo screening delle colture. All’attualità su un totale di 126 isolati solo 8, presentanti elevata produzione di esostrutture, sono stati sottoposti a caratterizzazione tassonomica. Gli isolati GC33 e GC76, identificati presuntivamente come Bacillus thuringiensis, sono stati saggiati alla concentrazione di 106 UFC/ml su uova di R.f. producendo una mortalità del 15% del totale delle uova. Altrettanto bassa è risultata la tossicità di GC11 Bacillus sphericus e di GC57 Bacillus megaterium
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
Polymerization of methylmethacrylate through ionizing radiation in CO2 based dense systems
No full textHerein, we report the use of ionizing radiation to induce a dispersion polymerization reaction in dense CO2. As a model system, the polymerization of methyl methacrylate in the presence of poly(dimethylsiloxane) stabilizers was investigated. It was demonstrated that the dose plays the key role in the progress of the reaction and in the morphology of the resulting polymer. Dispersion polymerization carried out in the presence of mono- and bifunctionalized surfactants gave differently structured polymers. The polymers obtained have been characterized by scanning electron microscopy, solubility tests, and gel permeation chromatography, and the molecular structure has been related to dynamic mechanical behavior in the melt state
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