1,757 research outputs found
Characterization Of Enzymes For The Food Industry And Active Packaging
No full textI vantaggi dell’utilizzo di enzimi al posto di reagenti chimici nei processi industriali e le loro applicazioni ad ampio spettro sono oggi comunemente noti, ma negli ultimi decenni si assiste ad un passaggio dall’uso di enzimi liberi in soluzione a quello di enzimi immobilizzati. In particolare, nell’industria alimentare, un enzima immobilizzato si trova spesso come agente funzionale nel cosiddetto “imballaggio attivo”. Tra gli enzimi utilizzati per scopi industriali, la laccasi (E.C. 1.10.3.2.) è certamente uno dei più sfruttati e versatili, grazie alla sua larga specificità per substrati ed al suo potenziale ossido-riduttivo modulabile in diverse condizioni di lavoro. E’ stato riportato per esempio che una laccasi da fungo è in grado di degradare alcune micotossine. In questo lavoro di dottorato, sono stati condotti studi su enzimi da utilizzare per applicazioni nel campo degli imballaggi alimentari. Una isoforma fungina di laccasi ricombinante, espressa in lievito, è stata immobilizzata in forma attiva su membrane di idrogel. Sono stati condotti studi funzionali in vitro e su matrice alimentare. I risultati hanno mostrato che l’enzima ricombinante, accoppiato ad un opportuno mediatore, è efficace nel degradare micotossine altamente diffuse e pericolose come l’aflatossina M1 e l’aflatossina B1. Un’altra laccasi fungina è stata espressa in batteri, ma la purificazione non ha dato un prodotto funzionale. Come seconda soluzione per imballaggi alimentari, il lisozima è stato scelto quale agente antimicrobico nella sua forma cristallina, ovvero cristalli di proteina sono stati fatti crescere su materiali avanzati composti da strati di idrogel su supporto di membrana idrofobica (membrane-idrogel composite). Test in vitro hanno dimostrato che l’attività antimicrobica di questa nuova soluzione di imballaggio risulta essere più efficiente dell’attività dell’enzima libero. Ad oggi questo è il primo studio riguardante l’applicazione di enzimi cristallizzati in imballaggi alimentari.The advantages of using enzymes instead of chemicals in the industrial processes and their wide range applications are nowadays of common knowledge, but over the last few decades we are experiencing a shift from the use of enzymes free in solution to the use of immobilized enzymes. In particular, in the food industry, an immobilized enzyme is often found as the functional agent in the so called “active packaging”. Among the enzymes used for industrial applications, laccase (E.C. 1.10.3.2) is certainly one of the most exploited and versatile, thanks to its broad substrate-specificity and tuneable redox potential at different working conditions. It has been reported for example that fungal laccase can degrade some mycotoxins. In this PhD work, studies were carried out on enzymes to be used for food packaging applications. A recombinant fungal laccase isoform overexpressed in yeast has been successfully immobilized in its active form into hydrogel films. Functional studies were carried out both in vitro and on food matrix. Results showed that the recombinant enzyme, coupled with a proper laccase-mediator system, was effective in degrading widespread and very hazardous mycotoxins such as aflatoxin M1 and aflatoxin B1. Another laccase fungal isoform was successfully overexpressed in bacteria, but purification did not give a functional product. As a second solution for food packaging, lysozyme was chosen as antimicrobial agent in the crystal form, as protein crystals were grown on advanced materials composed by hydrogel layers coated on hydrophobic membranes (hydrogel composite membranes). Tests in vitro showed that the antimicrobial activity of this new packaging solution resulted to be more efficient than the one of the enzyme free in solution. To our knowledge this is the first study concerning the application of crystallized enzymes on food packaging
Schermi. Immagini, corpi, condivisioni
No full textIn this book the author investigates the digital image proliferation of our times from an interdisciplinary point of view. Starting from the Visual Culture theoretical frame, Valentina Mignano explores the ways in which we interact with the screen, dealing with the "screen experience" in the first years of the network societ
ENTREPRENEURSHIP AND FEMALE ENTREPRENEURSHIP IN MARAMURES COUNTY
No full textInitiating and developing a business involves a considerable risk and a sustained effort in order to defeat the inertia against what is new. The person initiating a business, assuming the responsibility and risk of its development and benefiting from theentrepreneurship, female entrepreneurship, profit, businesses
The use of initial tocolysis and maintenance tocolysis in preterm birth : guideline-based approach or off-label use - a survey on the current application in Switzerland
No full textAuthor Valentina Schedl, BscMasterarbeit Universität Linz 202
Guido Crepax – Valentina – The Shape of Her Time
No full textThe paper will focus on the analysis of Guido Crepax revolutionary comic book character Valentina that belongs to the golden age of the Italian comic-book genre fumetto. The aim is to explore whether Guido Crepax Valentina character was a "living doll" filling male fantasies of her creator or she was a woman empowered by her author struggling for many of the values of the women's culture that feminists today are trying to introduce into the mainstream. It also addresses research questions that focus on comic books and gender and empowerment at the decade of sexual liberation.Through Valentina case study the present paper is going to study an approach on the concept of woman in comics, and touch the border of female empowerment issue in contemporary world taking in consideration that her revolutionary strong and independent figure was born in a society where women have been frequently viewed as passive and represented as inferior to men and where questions of sexuality were considered taboo. Despite the fact that she angered some feminists by the way she was portrayed as an object of male gaze or a damsel in distress, there is nothing anti-feminist about Valentina. The aim here is to uncover feminist themes in the stories of Valentina and to explore what empowered her and made her a contemporary icon of style and symbol of liberated women
Analysis of the interplay of the Orai1 Ca2+ Ion channel and different Ca2+ sensing proteins
No full textAuthor Valentina Hopl, MScDissertation Johannes Kepler Universität Linz 2024Arbeit nach Ablauf der Sperre auf den öffentlichen PCs in den Bibliotheken der JKU+Medizin abrufba
Lezioni d'autore, lezioni d'attore: Un ciclo di incontri con i protagonisti dello spettacolo, a cura di Valentina Garavaglia in collaborazione con il Teatro Franco Parenti di Milano Il lavoro dell'attore e la drammaturgia contemporanea
No full textMassimo Carlotto usa il noir come genere capace di raccontare le trasformazioni, anche nascoste, della società. I suoi libri sono tradotti in molte lingue e ha vinto numerosi premi sia in Italia che all'estero. Niente più niente al mondo è il monologo oggetto della ricerca del regista Fabio Cherstich interprete di un nuovo teatro di narrazione.Massimo Carlotto uses crime fiction to examine the oft-concealed transformations of society. His books have been translated in many languages and he has won numerous prizes, in Italy and abroad. No more nothing in the world is the monologue adapted by the director Fabio Cherstich, author of a new narrative theater
Is a Semantic Web Agent a Knowledge-Savvy Agent?
No full textThe issue of knowledge sharing has permeated the field of distributed AI and in particular, its successor, multiagent systems. Through the years, many research and engineering efforts have tackled the problem of encoding and sharing knowledge without the need for a single, centralized knowledge base. However, the emergence of modern computing paradigms such as distributed, open systems have highlighted the importance of sharing distributed and heterogeneous knowledge at a larger scale—possibly at the scale of the Internet. The very characteristics that define the Semantic Web—that is, dynamic, distributed, incomplete, and uncertain knowledge—suggest the need for autonomy in distributed software systems. Semantic Web research promises more than mere management of ontologies and data through the definition of machine-understandable languages. The openness and decentralization introduced by multiagent systems and service-oriented architectures give rise to new knowledge management models, for which we can’t make a priori assumptions about the type of interaction an agent or a service may be engaged in, and likewise about the message protocols and vocabulary used. We therefore discuss the problem of knowledge management for open multi-agent systems, and highlight a number of challenges relating to the exchange and evolution of knowledge in open environments, which pertinent to both the Semantic Web and Multi Agent System communities alike
Oxaliplatin Binding to Human Copper Chaperone Atox1 and Protein Dimerization
No full textCopper trafficking proteins have been implicated in the cellular response to platinum anticancer drugs. We investigated the reaction of the chaperone Atox1 with an activated form of oxaliplatin, the third platinum drug to reach worldwide approval. Unlike cisplatin, which contains monodentate ammines, oxaliplatin contains chelated 1,2-diaminocyclohexane (DACH), which is more resistant to displacement by nucleophiles. In solution, one or two Pt(DACH)2+ moieties bind to the conserved CXXC metal-binding motif of Atox1; in the latter case the two sulfur atoms likely bridging the two platinum units. At longer reaction times, a dimeric species is formed whose composition, Atox12·Pt2+2, indicates complete loss of the diamine ligands. Such a dimerization process is accompanied by partial unfolding of the protein. Crystallization experiments aiming at the characterization of the monomeric species have afforded, instead, a dimeric species resembling that already obtained by Boal and Rosenzweig in a similar reaction performed with cisplatin. However, while in the latter case there was only one Pt-binding site (0.4 occupancy) made of four sulfur atoms of the CXXC motifs of the two Atox1 chains in a tetrahedral arrangement, we found, in addition, a secondary Pt-binding site involving Cys41 of the B chain (0.25 occupancy). Moreover, both platinum atoms have lost their diamines. Thus, there appears to be little relationship between what is observed in solution and what is formed in the solid state. Since full occupancy of the tetrahedral cavity is a common feature of all Atox1 dimeric structures obtained with other metal ions (Cu+, Cd2+, and Hg2+), we propose that in the case of platinum, where the occupancy is only 0.4, the remaining cavities are occupied by Cu+ ions. Experimental evidence is reported in support of the latter hypothesis. Our proposal represents a meeting point between the initial proposal of Boal and Rosenzweig (0.4 Pt occupancy) and the reinterpretation of the original crystallographic data put forward by Shabalin et al. (1 Cu occupancy), and could apply to other cases
Multilateralismo, incertidumbre y reputación : las dispustas argentinas en la OMC
No full textThis article presents and analyzes trade disputes involving Argentina at the WTO. To do so, the author reviews Argentine participation at the WTO dispute settlement system since 1995 and examines both the economic local context and the WTO political circumstances.Fil: Delich, Valentina. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Derecho Internacional Público. Buenos Aires, ArgentinaFil: Delich, Valentina. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Propiedad Intelectual. Buenos Aires, ArgentinaFil: Delich, Valentina. FLACSO-Argentina. Buenos Aires, ArgentinaEl presente artículo presenta y analiza las controversias comerciales que involucran a la Argentina en la OMC. Para hacerlo, por un lado recorre la participación argentina en el sistema de solución de controversias desde 1995 a la fecha y por el otro examina tanto el contexto económico nacional como las circunstancias de la organización internacional donde ocurren
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