2,844 research outputs found
Libretto di sala - 2006 - Omaggio ad Aribert Reimann
No full textValentina Valente, sopranoErik Battaglia, pianoforteSergio Delmastro, clarinett
Biogenic amines as regulators of mitochondrial functions: Roles of Agmatine
No full textAgmatine is a dicationic amine at physiological pH, formed by decarboxylation of arginine catalyzed by arginine decarboxylase. It acts on polyamine metabolism by inhibiting nitric oxyde synthase and activating spermidine/spermine acetyltransferase as well as the antizyme of ornithine decarboxylase. Agmatine is metabolized by agmatinase to form urea and putrescine, suggesting that it is a polyamine precursor. Agmatine is transported to organs by an energydependent mechanism, whereas increased cellular concentrations promotes apoptosis. Agmatine and its metabolic enzymes arginine decarboxylase and agmatinase have also been recognized in mitochondria, as well as imidazoline I2 receptor. These observations and the results obtained in these years, during my work, evidence a close relationship between agmatine and mitochondria. The aim of this work is to study the action of agmatine as regulator of mitochondrial functions, compared with the effect of polyamines (i.e. spermine), in isolated rat mitochondria from different organs: liver, brain and kidney. The first part of the work focuses on agmatine uptake by mitochondria with characterization of the transport system. A comparison among the agmatine transport mechanism in mitochondria isolated from different organs is reported. In the second part is reported the action of this amine on mitochondrial permeability transition induction, again with the above mentioned comparison but together the effects of spermine. The amine exhibits protective effects against the phenomenon in kidney and brain mitochondria, whereas in liver mitochondria it exhibits double behavior, that is, induction at low concentrations and protection at high concentrations. The possible explanation is the presence of a specific amino oxidase in liver mitochondria. Finally, in the third part, the synthesis of agmatine using an alternative reaction to that of arginine decarboxylase is reported. The presence of an amidinotransferase reaction has been found in rat kidney mitochondria and in a proximal tubule cell line as the results of a first purification step. This observation could correlate the synthesis of agmatine with a regulation mechanism of polyamine concentration in cells. In conclusions the results obtained with this study put in evidence agmatine as a physiological regulator of polyamine content in the cell, rather than a simple polyamine precursor, as proposed by some authors. Moreover, this investigation point out the important physiological role of mitochondria activity as mediators of this process. Indeed, the action of this amine in mitochondrial permeability transition of isolated mitochondria explains its effect on cell proliferation and apoptosis.L’agmatina è un’amina è formata dalla decarbossilazione dell’arginina in una reazione catalizzata dall’arginina decarbossilasi ed è caratterizzata dalla presenza di due cariche a pH fisiologico. L’agmatina agisce sul metabolismo delle poliamine inibendo la ossido nitrico sintasi e attivando la spermidina/spermina acetiltransferasi e l’antizima dell’ornitina decarbossilasi. L’agmatina viene metabolizzata dall’agmatinasi formando urea e putrescina, suggerendo che sia un precursore delle poliamine. Viene trasportata agli organi da un meccanismo energia-dipendente e, un aumento della sua concentrazione, promuove l’induzione dell’apoptosi. L’agmatina e gli enzimi del suo metabolismo, arginina decarbossilasi e agmatinasi, così come i recettori imidazolinici I2, ai quali l’amina si lega, sono stati ritrovati nei mitocondri. Queste osservazioni e i risultati ottenuti in questi anni, durante il mio lavoro, evidenziano una stretta relazione tra agmatina e mitocondri. Lo scopo di questa ricerca è studiare l’azione dell’agmatina come regolatore delle funzioni mitocondriali e confrontarne gli effetti con quelli delle poliamine (ad esempio spermina), in mitocondri isolati da organi differenti di ratto: fegato, cervello e rene. La prima parte del lavoro riporta il trasporto dell’agmatina all’interno dei mitocondri e la caratterizzazione del sistema di trasporto. Vengono comparati i meccanismi di trasporto dell’agmatina nei mitocondri isolati dai diversi organi. Nella seconda parte viene riportata l’azione di quest’amina sull’induzione della transizione di permeabilità mitocondriale, di nuovo comparando gli effetti nei diversi organi ma anche con la spermina. L’amina ha un effetto protettivo contro il fenomeno in rene e cervello, mentre nel fegato il suo comportamento è duplice: induce a basse concentrazioni e protegge ad alte. Per spiegare tale differenza, si ipotizza la presenza di una specifica amino ossidasi nei mitocondri di fegato. Infine, nella terza parte, viene studiata la sintesi di agmatina tramite una reazione alternativa all’arginina decarbossilasi. La presenza di una reazione amidinotransferasica è stata riscontrata in mitocondri di rene di ratto e in un linea cellulare di tubulo prossimale. Vengono riportati anche i risultati relativi ad un primo step di purificazione. Queste osservazioni potrebbero correlare la sintesi di agmatina con un meccanismo per la regolazione della concentrazione di poliamine nelle cellule. In conclusione, i risultati ottenuti mettono in evidenza come l’agmatina agisca da regolatore fisiologico del contenuto di poliamine nella cellula piuttosto che comportarsi come un semplice precursore delle poliamine, come viene considerata da alcuni autori. Questa ricerca dimostra, inoltre, come i mitocondri siano importanti mediatori fisiologici di questo processo. Infatti, l’azione di quest’amina sulla transizione di permeabilità mitocondriale spiega i suoi effetti sulla proliferazione cellulare e sull’apoptosi
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
Fluid flow along faults in carbonate rocks
No full textThe study of fluid flow in fractured rocks plays a key role in reservoir management, including CO2 sequestration
and waste isolation. We present a mathematical model of fluid flow in a fault zone, based on field data acquired
in Majella Mountain, in the Central Apennines (Italy). The Majella is a thrust related, asymmetric, box shaped
anticline. The mountain carbonate outcrops are part of a lower Cretaceous-Miocene succession, covered by a
siliciclastic sequence of lower Pliocene age.
We study a fault zone located in the Bolognano Formation (Oligo-Miocene age) and exposed in the Roman
Valley Quarry near the town of Lettomanoppello, in the northern sector of the Majella Mountain. This is
one of the best places in the Apennines to investigate a fault zone and has been the subject of numerous field
studies. Faults are mechanical and permeability heterogeneities in the upper crust, so they strongly influence fluid
flow. The distribution of the main components (core, damage zone) can lead a fault zone to act as a conduit, a
barrier or a combined conduit-barrier system. We integrated existing and our own structural surveys of the area to
better identify the major fault features (e.g., kind of fractures, statistical properties, geometry and pertrophysical
characteristics).
Our analytical model describe the Bolognano Formation using a dual porosity/dual permeability model:
global flow occurs through the fracture network only, while rock matrix contain the majority of fluid storage and
provide fluid drainage to the fractures. Pressure behavior is analyzed by examining the pressure drawdown curves,
the derivative plots and the effects of the characteristic parameters. The analytical model has been calibrated
against published data on fluid flow and pressure distribution in the Bolognano Formation
Oxidative stress is responsible for mitochondrial permeability transition induction by salicylate in liver mitochondria
No full textThe interaction of salicylate with the respiratory chain of liver mitochondria generates hydrogen peroxide and, most probably, other reactive oxygen species, which in turn oxidize thiol groups and glutathione. This oxidative stress, confirmed by the prevention of action by antioxidant agents, leads to the induction of the mitochondrial permeability transition in the presence of Ca2+. This phenomenon induces further increase of oxidative damage resulting in impairment of oxidative phosphorylation and beta-oxidation, cardinal features of Reye's syndrome in the liver. Mitochondrial permeability transition induction also induces the release of cytochrome c and apoptotic inducing factor from mitochondria, suggesting that salicylate also behaves as a pro-apoptotic agent. The reactive group of salicylate for inducing oxidative stress is the hydroxyl group which, by interacting with a Fe-S cluster of mitochondrial Complex I, the so-called N-2(Fe-S) center, produces reactive oxygen species
Arts in Italy: development through experiential marketing. Some empirical evidences
No full textGrowing competitive pressure, increasingly demanding clients and financial instability are forcing cultural organizations to look for innovative management tools to remain successful in the market. The experiential approach and/or experiential marketing seem to offer an answer to the new challenges.
This paper explores how experiential marketing is used by cultural organizations to retain and develop their audience base. Experiential methods and tools used by these organizations are studied through observation of the internet sites of 20 organizations in the cultural domain. The paper offers a picture of the experiential positioning of cultural organizations in the analyzed sectors. Comparisons within each sector and intra-sectors provide evolutionary cue
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
‐cutinase highlights the key role of residue 243
No full textEnzymatic degradation of poly(ethylene terephthalate) (PET) is becoming a reality because of the identification of novel PET-hydrolysing enzymes (PHEs) and the engineering of evolved enzyme variants. Here, improved variants of leaf-branch compost cutinase (LCC), a thermostable enzyme isolated by a metagenomic approach, were generated by a semi-rational protein engineering approach. Starting from a deleted LCC form lacking the secretion signal (Delta LCC), single and double variants possessing a higher activity on PET were isolated. The single-point F243T Delta LCC variant partially (similar to 67%) depolymerized amorphous PET film producing similar to 21.9 mm of products after 27 h of reaction at 72 degrees C. The S101N/F243T Delta LCC double variant reached a further increase in activity on PET. Notably, for both single and double variants the highest conversion yield was obtained at 55 degrees C. Kinetics studies and molecular dynamics simulations support that a slight decreased affinity for PET is responsible for the superior degradation performance of the S101N/F243T variant and that this stems from a slightly higher flexibility of the active site region close to position 243. Furthermore, our findings question the need for a high reaction temperature for PET degradation, at least for LCC: at >= 70 degrees C, the conversion of amorphous PET into a more crystalline polymer, resistant to enzymatic hydrolysis, is favoured. The evolved S101N/F243T Delta LCC variant is able to depolymerize fully 1.3 g of untreated postconsumer PET waste in <= 3 days at 55 degrees C (using 1.25 mg of enzyme only), this making PET enzymatic degradation by engineering LCC a more ecofriendly and sustainable process
Assessing the health researchâs social impact: a systematic review
No full textIn recent year, a growing attention is dedicated to the assessment of researchâs social impact. While prior research has often dealt with results of research, the last decade has begun to generate knowledge on the assessment of health researchâs social impact. However, this knowledge is scattered across different disciplines, research communities, and journals. Therefore, this paper analyzes the heterogeneous picture research has drawn within the past years with a focus on the health researchâs social impact on different stakeholders through an interdisciplinary, systematic review. By consulting major research databases, we have analyzed 53 key journal articles bibliographically and thematically. We argued that the adoption of a multi-stakeholder could be an evolution of the existing methods used to assess impact of research. After presenting a model to assess the health researchâs social impact with a multi stakeholder perspective, we suggest the implementation in the research process of three practice: a multi-stakeholder workshop on research agenda; a multi stakeholder supervisory board; a multi-stakeholder review process
La battaglia di Solferino e San Martino (24 giugno 1859): la traumatologia bellica nei crani dell'ossario di San Martino (BS).
No full textL’obiettivo della tesi è verificare la tipologia di lesioni riscontrate su un campione selezionato di crani conservati presso l’ossario di San Martino (BS), caduti nella battaglia di Solferino e San Martino del 1859. Nella trattazione verranno riportati anche i dati antropologici ricavati dall’analisi dei crani, le analisi paleopatologiche e lo studio sulle lesioni individuate e la possibile correlazione con le armi e le munizioni in uso in quell’epoca. Infine saranno verificate le ipotesi sulla presenza e tipologia delle lesioni riscontrate, in concordanza con le armi in uso, le tattiche militari del periodo e lo svolgimento della battaglia
- …
