6,165 research outputs found
A novel fractional memristor-based Grassi-Miller map: Hyperchaotic behavior and coexistence of attractors
No full textReferring to fractional memristor-based discrete systems, this paper contributes to the field by presenting a new fourth-dimensional (4D) hyperchaotic memristor-based fractional map. The conceived system, obtained by combining a non-integer order discrete memristor with the Grassi-Miller map, is characterized by some special features, which include the absence of equilibrium point and the coexistence of various chaotic and hypechaotic attractors. Numerical techniques including phase plots, Lyapunov exponents and bifurcation diagrams are used to highlight the complex dynamic behavior of the suggested 4D fractional memristor-based Grassi-Miller map
I perché dell'italiano
No full textUna rubrica bimestrale, curata da Roberta Grassi ed Enrico Serena, che si rivolge in primo luogo ad insegnanti di italiano come lingua seconda, straniera o materna, ma che può essere interessante anche per studenti, curiosi e appassionati della nostra lingua. La rubrica, che contiene di volta in volta interventi di specialisti diversi, si propone di offrire chiarimenti scientificamente fondati su peculiarità dell’uso e delle strutture dell’italiano. Perché nessuna curiosità è troppo piccola da meritare di essere trascurata, e anzi a volte sono proprio le piccole eccezioni, le anomalie, le particolarità del sistema a illuminare forze profonde o risvolti trasversali a più lingue
Los mundos lejanos de Ángela Grassi: historia, leyenda y moral
No full textThis study sets out to uncover the ideological and formal keys of the literary work published by Ángela Grassi (1823-1883) in the form of press articles. Of her extensive production, which appeared in various magazines of her time, particularly women’s magazines, we have annotated over fifty articles published in El Correo de la Moda, the magazine to which Grassi contributed most assiduously from 1866 onwards, and which she ran from 1867 until her death. Her work, romantic in nature, escapes the reality of her age in historical or legendary times in which she looks for useful models for moral education; all wrapped in a rich literary style.El presente estudio se propone descubrir las claves ideológicas y formales en que se funda la obra literaria publicada por Ángela Grassi (1823-1883) bajo la forma de artículos en prensa. De su extensa producción, aparecida en las diversas revistas de su tiempo, en especial en las femeninas, hemos acotado más de medio centenar de artículos publicados en El Correo de la Moda, la revista en que la autora colaboró más asiduamente desde 1866 y que dirigió desde 1867 hasta su muerte. Su obra, de estirpe romántica, se aleja de la realidad de su época para huir hacia tiempos históricos o legendarios en los que busca modelos útiles para una enseñanza moral; todo ello revestido de una gran riqueza literaria
Grassi e antiossidanti
No full textI grassi (o lipidi) che introduciamo con la dieta possono essere di origine animale o vegetale e sono rappresentati prevalentemente dai trigliceridi. Gli acidi grassi sono una
famiglia numerosa di molecole che differiscono per lunghezza della catena, presenza di doppi legami e insaturazione cis o trans. I grassi sono metabolicamente importanti e oltre a costituire un’importante fonte di energia, facilitano l’assorbimento di molecole liposolubili presenti nella dieta quali le vitamine liposolubili (vitamina A, D, K, E).
Inoltre grassi e oli contribuiscono in modo sostanziale a fornire all’organismo acidi grassi essenziali.
Il colesterolo è il principale rappresentante degli steroli e lo possiamo considerare la molecola della vita. Nell’organismo umano esso svolge diversi ruoli fisiologici: è componente
delle membrane cellulari e delle lipoproteine plasmatiche, è precursore degli ormoni steroidei, della vitamina D3 e degli acidi biliari. Negli ultimi anni è emersa una rilevanza nutrizionale dei fistosteroli e fitostanoli, molecole presenti negli alimenti di origine vegetale. Numerosi studi hanno dimostrato che la loro assunzione contribuisce
a ridurre i livelli di colesterolo plasmatico riducendone il riassorbimento a livello intestinale.
- Una delle modificazioni composizionali a cui vanno incontro i lipidi sia dell’organismo sia degli alimenti è la perossidazione lipidica in presenza di radicali liberi dell’ossigeno (ROS). La perossidazione lipidica modifica la struttura dei lipidi con conseguenze sulle loro funzioni. I principali substrati della perossidazione lipidica sono gli acidi grassi mono e polinsaturi. La dieta ha un ruolo chiave nella modulazione della perossidazione lipidica in quanto fonte di sostanze con proprietà antiossidanti. Gli antiossidanti includono
sistemi di difesa enzimatica e non enzimatica
Entry in the Italian banking: an empirical analysis
No full textThis paper presents an analysis of the Italian banking market. We concentrate our study on the choice by banks to open new branches, considering both new entrant banks and incumbents. We first show the evolution of the branches in the Italian market in the period 2000-2007, and then propose a model to study the reasons which drive banks to their strategic choice. We emphasize the role of concentration of the market, functional distance and exogenous demand factors, as population density and pro-capita income
La Fine del Potere Ottomano. L’ultimo sultano, l’ultimo califfo, gli ultimi gran visir
No full textContrariamente alla fine dell’Impero zarista, dell’Impero asburgico e di quello germanico, la fine dell’Impero ottomano sopravvenne dopo lunga e tortuosa agonia, prodotta principalmente dalle confliggenti ambizioni delle potenze che avevano vinto la Grande Guerra. A cento anni dall’abolizione del califfato (3 marzo 1924), Fabio L. Grassi ripercorre la storia ben poco conosciuta degli uomini che ressero e rappresentarono l’impero in quegli anni. L’autore ne illustra la vita, la carriera, le propensioni politiche, l’opera, le posizioni di volta in volta assunte, la loro sorte successiva, oltre che la loro dimensione culturale, morale e psicologica. Ciò che fecero e non fecero l’ultimo sultano, l’ultimo califfo e gli ultimi gran visir, ovvero i massimi rappresentanti della «Turchia legale», nelle loro relazioni da una parte con gli Alleati dall’altra con la «Turchia ribelle», costituisce un insieme complesso, ambiguo e in parte ancora misterioso.Contrary to the end of the Tsarist Empire, of the Habsburg Empire and of the Germanic, Empire, the end of the Ottoman Empire came after a long and torturous agony, caused mainly by the conflicting ambitions of the powers that had won the Great War. One hundred years after the abolition of the caliphate (3 March 1924), Fabio L. Grassi traces the scarcely story
known of the men who ruled and represented the empire in those years. The author illustrates their life, career and political propensities policies, their acts, the positions taken from time to time, theirs subsequent fate, as well as their cultural, psychological and moral dimension. What the last sultan, the last caliph and the last grand viziers, i.e. the highest representatives of «legal Türkiye», did and did not do, in their relations on the one hand with the AlliedPowers on the other with "rebel Türkiye", constitutes a
complex, ambiguous and partly still mysterious whole
Pseudo-pneumoretroperitoneum secondary to lumbar emphysema: CT demonstration in two cases
No full textBV formalism and partition functions
No full textThe BV formalism is a well-established method for analyzing symmetries and quantizing field theories. In this paper, we use BV formalism to derive partition functions and the space of gauge invariant operators implementing the equations of motions and their redundancies for selected theories. We discuss various interpretations of the results, some dualities, and relation to the first quantized models
Improving drug efficacy and specificity by innovative drug delivery approaches
No full textThe limited efficacy of current therapeutic approaches for a number of socially relevant human diseases requires the exploration of alternative and more effective therapeutic strategies. In this regard, the researchers have pursued on one hand the identification of novel and more effective therapeutic molecules and on the other the optimization of drug delivery systems.
So far, many therapeutic molecules, especially those used as anticancer drugs, are plagued by a low therapeutic index being the efficacious dose very close to the lethal one; moreover, they often lack any specificity of action. This aspect can be improved by the use of drug delivery systems composed of different drug carriers including lipids and polymers. The carriers, often in the shape of nanoparticles , can be loaded by the therapeutic molecule and directed against the target cells via the presence of targeting moieties allocated on the nanoparticle surface.
The specificity of the complex carrier/drug can be further improved by the use of therapeutic molecules preferentially/exclusively active on the target diseased cells. Molecules active against diseased-associated target (oncogenes etc) may hit the diseased cells leaving healthy cells substantially unaffected. In this regard, in the last three decades, nucleic acid based drugs (NABDs) have emerged as an attractive and novel alternative with great therapeutic potential. NABDs, which include antisense oligonucleotides, decoys, aptamers, triple helix forming oligonucleotides, DNAzymes, Ribozymes and small interfering RNAs, have been shown to be able to efficiently and specifically counteract pathological gene expression in many different experimental systems. Notably as they can be engineered to hit virtually any cell target, their potential applicability is very broad.
Despite NABD broad potential applicability, their use in the clinic is limited by the lack of optimal delivery systems. Due to their hydrophilic nature, NABDs cannot efficiently cross cellular membrane for which appropriate carriers are needed. Moreover, their instability in serum requires a proper protection to prevent a fast degradation which would invariably lead to the abrogation of any significant therapeutic effect.
The present special issue will be focused on the critical description of some aspects related to the optimization of drug delivery with a particular emphasis on NABD; despite this, a discussion about the possibility to use/adapt NABD developed delivery systems for more conventional drugs, is also present.
The papers of Chan et al., of Marrache et al, of Schaffert et al., Jung et al. and Grassi et al. describe different delivery approaches for NABD and other commonly used therapeutic molecules for several pathological conditions. In the paper of Chan et al. attention is given to liposome and polymeric based delivery systems with regard to DNA enzymes; the described studies offer perspectives on future methodologies for improved DNAzyme delivery and utility as novel drugs. Marrache et al. describe the use of nanoparticles (made by polymer, liposome and other delivery agents), as delivery devices which can be engineered to load multiple drugs with varied physicochemical properties, contrast agents, and cellular or intracellular component targeting moieties. Schaffert et al draw their attention on the description of delivery systems based on the polycation linear polyethylenimine, where peptide based ligands are attached to the polycation via heterobifunctional polyethylene glycol linker molecules. Conjugate synthesis, in vitro testing and in vivo cancer models in rodents are discussed. Jung et al describe the employment of the thermo sensitive pluronic-based core/shell nanoparticles, formed using various strategies such as self-assembly and temperature induced-phase transition. Particular emphasis is given to the use of the nanoparticles for tumor targeting, stimulated release of proteins, and cancer imaging capabilities. Grassi et al, beside discussing the above mentioned delivery systems, for most of the different types of NABDs, draw their attention on the complex situation of NABD delivery to the arteries describing the advantages and dis-advantages of three different administration routes i.e. systemic, perivascular and intravascular.
The papers of Lico et al, Pagliari et al and Castronovo et al report the use of “living delivery systems” and describe the influences of nano-systems on NABD. Lico et al. focus their attention on the use of a different approach for NABD delivery based on plant viruses which have a size particularly suitable for nanoscale applications and can offer several advantages being structurally uniform, robust, biodegradable and easy to produce. Pagliari et al. continue the description of “living vector” reporting the possible and very innovative use of stem cells as delivery devices for therapeutic molecules to the injured myocardium. Finally, in the paper of Castronovo et al., a completely innovative point of view about NABD complexation in nano-carriers is provided. The author show that the functionality of NABD in nano-systems is highly dependent upon the local density, molecular flexibility and network of weak interactions between adjacent molecules. The understanding of these properties can enable the development of powerful molecular tools for nano-medicine.
In conclusion, whereas the developmental process of many delivery systems is still at the beginning, other delivery strategies are closer to possible applications. Regardless of the fact that the delivery systems are used for NABD or clinically available drugs, we believe the target tissue will mainly determine the nature of the optimal strategy. Despite the delivery issue can and should be further optimized, the encouraging results displayed so far in different experimental models using NABD or clinically used drugs, fully justify further economic and scientific efforts
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