1359 research outputs found
Sort by
Unique gene expression profiles of microglia and astrocytes following innate immune activation
Get PDFBoth astrocytes and microglia are often activated in association with diseases of the central nervous system (CNS), including virus-induced neurological disease. Understanding how activation alters the transcriptome of these cells may offer valuable insight in regards to how activated cells mediate neurological damage. Furthermore, identifying common and unique pathways of gene expression during activation may provide new insight into the distinct roles these cells have in the CNS during infection and inflammation. In the current study, we utilized microarray analysis to examine the response of astrocyte and microglia to specific innate immune stimuli. Since virus infections often induce activation of toll-like receptor 7 (TLR7), we used the TLR7 agonist imiquimod that has been shown to induce activation of both microglia and astrocytes in vivo and in vitro. We found that microglia generate a much stronger response to TLR7 activation than astrocytes, with the upregulation and downregulation of substantially more genes in microglia than that observed in astrocytes. We identified genes that were uniquely upregulated by each cell type and examined these genes for upregulation by other factors including virus infection. These data provide new insights into innate immune activation of astrocytes and microglia that will be useful in characterizing the cellular responses of these genes during infection or insult of the CNS
Novel technologies for microalgae cultivation and subsequent lipid extraction
Get PDFWorld economy is strictly linked to the availability of fossil fuels, which nowadays meet the world’s growing energy demand. However, the intensive exploitation of fossil fuels as main source of energy is currently recognized to be not sustainable due to the continuous depletion of available resources as well as to their contribution to environmental pollution and greenhouse gases emissions (Ahmad et al., 2011). Moreover global warming (GW) induced by increasing concentrations of greenhouse gases (GHG) in the atmosphere has become today an important environmental concern. The major anthropogenic sources of GHG are transportations, energy sectors and agriculture which are responsible in European Union (EU) for more than 20%, 60% and 9% of emissions, respectively (EEA 2004, 2007).
A worldwide problem has become the depletion of petrochemical fuels and the continuous rise in oil prize that call us to make a global effort in order to find alternative energetic sources.
Currently, many options are being studied and implemented in practice to meet the sustainability goals agreed under the Kyoto Protocol (1992) with different degrees of success. Wind, geothermal, solar (either thermal or photovoltaic), hydroelectric, ocean wave, carbon sequestration and bio fuels energy are been developed as more sustainable alternative energy sources compared with the combustion of fossil fuels (Dewily and Van Langenhove, 2006; Schiermeier et al., 2008).
The use of fossil fuels is now widely accepted as unsustainable, due to depleting resources and the accumulation of GHG in the environment that have already exceeded dangerously high thresholds. For this reason, the production of renewable sources of energy such as biofuels is recognized to be critical to fulfill a sustainable economy and face global climate changes (Cheng and Timilsina, 2011). Therefore, biofuels deriving from feedstocks such as plants, organic wastes or algae could help to reduce the world’s oil dependence (Naik et al., 2010).
In fact, biomass feedstocks are intrinsically renewable since they are produced through a natural process, i.e. photosynthesis that is continuously replenished by sunlight. Moreover, biofuels would mitigate global warming problems since all the CO2 emitted during their burning can be fixed by plants used as biomass feedstock, through photosynthetic mechanisms. On the other hand, first and second generation biofuels are characterized by several drawbacks which can limit their exploitation as alternative source of energy.
One important goal for the gradual replacement of fossil fuels by renewable energy sources, as a measure for transportation emissions reduction, is the use of biofuels which are seen as real contributors to reach those goals, particularly in the short term.
Today the most common biofuels are biodiesel and bio-ethanol, which can replace diesel and gasoline, respectively. In EU biodiesel represent 82% of total biofuels production (Bozbas, 2008) and is still growing in Europe, South America and United States, based on political and economic objectives.
The first generation biofuel production systems (starch- and sugar-based ethanol production crops) demonstrated the feasibility of generating liquid transportation fuels from renewable sources, but at initially low energy-conversion efficiencies and high cost. However since vegetable oil produced by crops of first generation may also be used for human consumption, this can lead to an increase in price of food-grade oils, causing the cost of biodiesel to increase and preventing its usage. Plants that produce high levels of cellulose and hemicellulose biomass (which can be converted into sugars using advanced enzyme catalysts) are being developed as second generation biofuel production systems. These biofuel crops do not compete directly with food production, require less agronomic inputs and have lower environmental impacts than first generation biofuels.
Morevor the use of biodiesel from second generation crops may also be advantageous since they do not require arable lands and do not affect biodiversity deriving from the cutting of existing forests and the use of potential invasive crops that may disrupt the biological integrity of local ecosystems and important ecological areas (Scarlat et al., 2008; RFA, 2008). However the main drawback of second generation biofuels is that they cannot be produced at a rate which coud meet the growing energy demand of the transopration sector. This is due to the fact that they are produced from feedstocks such as wastes or agricultural residues whose production is constrained by the original productive process from which they come. Morevoer second generation biofuels process have not still attained the economic sustainability.
Although biofuels are still more expensive than fossil fuels their production is increasing in countries around the world also encouraged by policy measures and biofuels targets for transport (COM, 2006).
A transition to a third generation biofuels, such as microalgae, is than needed since low-cost and profitable biodiesel should be produced from low-cost feedstocks in order not to compete with edible vegetable oils and should have lower environmental
impacts. Thus transition can also contribute to a reduction in land requirements due to their higher energy yields per hectare as well as to their non-requirement of agricultural land.
Concerning potential feedstock microalage are among the more interesting possibilities currently being investigated and implemented at pilot scale or even at industrial scale.
Their use as a possible solution to the problem of GW is desirable since this group of fast-growing unicellular organisms shows several advantages which make them one of the most promising and attractive renewable sources for a fully sustainable and low-carbon economy portfolio. Between their advantages: widespread availability, absent (or very reduced) competition with agricultural land, utilization of cheap and abundant nutrient sources (sunlight, carbon dioxide, water), high oil and biomass yields, high quality and versatility of the by-products, generation of biomass for biofuel production with concomitant CO2 sequestration and suitability for wastewater treatments and other industrial plants (Vilchez et al., 1997; Olguín, 2003; Mulbry et al., 2008; EABA, 2012).
The high potentiality of algae based biofuels is confirmed by the number of recent papers available in the literature related to the use of microalgae in the energy sector (Usui and Ikenouchi, 1997; Borowitzka, 1999; Kargi and Ozmihçi, 2004; Chisti, 2007), by the growing investments of private companies (Solazyme, Ocean Nutrition Canada, Cellana, AlgaeLink) and governments (US Dep. Energy, 2010) in algae-related research activity as well as by the increasing number of filed patents (Burton and Cleeland, 2008; Wu and Xiong, 2009; Cao and Concas, 2010; Parsheh et al., 2010; Rispoli et al., 2011).
Despite this growing interest, the current microalgae-based technology is still not widespread since it is affected by technical and economic constraints that hinder its full scale-up (Chen et al., 2011). Therefore, great R&D efforts are currently undertaken to produce biodiesel at competitive costs and with the required quality starting from microalgae feedstock. In particular given the potential benefits of microalgae, their cultivation should be studied and optimized to make them competitive as fuel producing systems in the global market (Debska et al., 2010).
The main technical barriers are related to the fact that photosynthetic efficiency, growth rate and lipid content of microalgae are still low if compared to the rate of fuel demand of the transportation market.
In order to overcome such drawback, scientific community is moving on three main directions. The first one is the identification of cultivation conditions and photobioreactors configurations that maximize lipid productivity and CO2 fixation by means of a reduced number of known microalgae (Yoo et al., 2010; Yeh et al., 2011). Another research line is targeted to the identification of new microalgae strains which are intrinsically characterized by high growth rates and high lipid content (de la Vega et al., 2011). A futher attractive scientific challenge to face this problem is the genetic manipulation of existing strains in order to increase their photosynthetic efficiency and/or to regulate their metabolism in order to achieve an abundant production of lipids coupled with high biomass accumulation (León-Bañares et al., 2004). Finally the identification of novel techniques to improve lipid extraction from microalgae is one of the main target to be achieved in order to make the technology economically sustainable.
Along these lines the present PhD activity has been focused on two different lines of research which share the common target of identifying suitable strategies to increase the lipid productivity of the current microalgal technology. Specifically, in the first line of activity, a novel cell disruption technique for the enhancement of lipid extraction yields from C. Vulgaris is proposed. In the second line of activity the exploitation of iron-based strategies to increase lipid synthesis in C. Vulgaris, is investigate
Tra l’umano e il divino: la divinazione in Giamblico. Un commentario al terzo libro del De mysteriis.
Get PDFDivination is the leitmotif of this essay. I tried to analyze this subjet that the main
thinkers and philosophers point out as the key-subject of the neoplatonic sage
Giambilico's Treatise On the Mysteries of Egyptians. It is a ten books work and the third
one was totally focused on Divination by the Author. Here he refutes and debates
Porfirio's objections about the nature, the shapes and the teurgic aims the divination
art can have. This essay follows the studying method already used in the Comment of
the Book III of the Treatise On the Mysteries of Egyptians: in this way i tried to show up
and present a fresco about the wide variety of theories, doctrines and contradictions
about this subject and describe an original complete critic structure, that you cannot
find in other essays about this theme. The core-subject of this debate is the
dissertation of Portirio's theory that we can read in the Letter to Anebo: here the
philosopher describes the divination origin as a complete natural origin, based on
psyco-physiological mood and inclinations of a typical soothsayer. Giambilico opposes
his idea to Portirios's, and he elevates the role of the medium from the soothsayer
attitude to the Supernatural, far from a mixture based on the human level and
existence
Sul paragone delle arti nella rivista "Civiltà delle macchine". La direzione di Leonardo Sinisgalli (1953-1958)
Get PDFThis thesis concerns the journal «Civiltà delle macchine», published by the industrial group Finmeccanica, specifically during the editorial years of the poet and engineer Leonardo Sinisgalli, between 1953 and 1958. Shaped by overcoming the dichotomy between scientific knowledge and liberal arts, «Civiltà delle macchine» goes beyond the traditional boundaries of an house organ, coming up as a significant cultural project and innovative publishing product: the articles, that can often be considered as real essays, debate a wide spectrum of topics. Our research, looking further into the magazine «Pirelli», that had also resulted from the professional partnership between Sinisgalli and the manager Giuseppe Eugenio Luraghi, assumes that the dialogue between science and the humanities meets in «Civiltà delle macchine» the presence of literature and art. Our attention focuses on the articles related to literature and visual arts as well as on the relationship between written texts and images. The multidisciplinary and interdisciplinary nature of «Civiltà delle macchine» and the specific perspective chosen for our analysis required us to use flexible and composite methodological approaches, in order to develop the in-depth investigations and the contributions that the thesis aims to offer to the specialized studies. At the heart of the first chapter we develop themes concerning the aegis of Leonardo da Vinci and the occurrences of analogy in the journal; connected to the analogy is the matter of the Baroque, in the second chapter. This second chapter is mainly devoted to some key moments of Sinisgalli’s intellectual life preceding «Civiltà delle macchine» ‒ the consequences of which are reflected in the editorial line of the journal ‒ from the acquisition of the poetics of Hermeticism to the advertising language designed for Olivetti company. The third chapter talks over the editorial line of the journal, by referring to an idea of polytechnic e inclusive literature; the fourth one, through the systematic interpretation of written texts, images and their relationship, deal with the fundamental topics in «Civiltà delle macchine»: machines, machines and human beings, factories, as they are represented and interpreted by writers and artists. We do deduce critical considerations on the poetics and aesthetics involved with mechanical civilization in the Fifties and on the links with the historical avant-garde, particularly with Futurism
Extended cognition, dynamics, and algorithms. A turing machine based approach to the study of arithmetical skills
Get PDFThe fields of philosophy of mind and cognitive science have been characterized, in the last few
decades, by a growing interest for explanations of mind's activity in terms of interaction between
brains, bodies and the world. Embodiment, embeddedness, situatededness are key words that most
often can be found in contemporary cognitive studies. However, some cognitive activities seem
recalcitrant to this kind of treatment. Mathematical thinking is one of them. Explanations of human
computational competencies, indeed, focus typically on representational issues, while giving less
importance to the role of mind/body/environment interaction for the performance and development
of algorithmic skills, namely, those capacities which are essential in order to operate with numbers
and carry out symbolic transformation.
The significance of these skills for a general understanding of computational activities is explicitely
recognized in Alan Turing's theory of computation, which is focused on the construction of
idealized models of the mechanisms at work in a real cognitive system, namely the one consisting
of a man performing calculations with paper and pencil. In the present thesis I take seriously Marco
Giunti's proposal to use a Turing machine (TM)-based computational architecture, namely the
Bidimensional Turing Machine (BTM), in order to study human algorithmic skills.
This work consists of two main parts. The first part, philosophically-oriented, deals with Andrew
Wells' ecological interpretation of the TM's architecture and its relations with a set of philosophical
and psychological positions such as classic computationalism, the extended-mind hypothesis and
the dynamical approach to cognition; the second, more technical part, sets up a theoretical and
methodological framework for the development and justification of BTM-based models of human
algorithmic skills
Dall’azione di annullamento all’azione di adempimento: il codice del processo amministrativo
Get PDFThe code of the administrative process represents the last stage of the long and constant evolution which has concerned the administrative justice during the twentieth century.
The present study provides an overview of the historical factors that have influenced the change of the administrative judgement progressively oriented towards a full protection of citizens' interests against public powers.
The issue analyzes the evolution of the Italian doctrine, which since the years 60’s had brought to urge the introduction of a legal instrument similar to the german verpflichtungsklage.
In addition, the study highlights the comparison with the french law related to the recours pour excès de pouvoir.
Particular attention is given to the decree n. 104/2010 including the code of the administrative process and especially the importance of the articles 30 and 34.
The final part is an analysis of the code regulations related to the use of information technology in order to ensure judgements within a reasonable time and enhance efficiency of administrative justice
Food, place, territorialization. From territory appreciation to successful businesses
Get PDFDuring the last decades, the awareness of the bond between food and its territory of origin has grown, and food perceived to be local and traditional increased in its attractiveness. Aware of this scenario, the purpose of this dissertation is to explore in depth the phenomenon of place-based food: firstly, it aims for a better understanding of the concept of place-based food; secondly, the purpose is to study the territorial orientation of food companies, trying to understand how local and global food companies could interpret and employ in their strategy the link with territory.
This dissertation is composed of three essays, each with specific purposes. In Essay 1, we intend to improve the comprehension of place-based food concept, answering to the following central questions: What are the main characteristics of place-based foods? What reasons drive people to increase their attention to territoriality? What meanings do consumers attach to territorial food consumption? To pursue this threefold objective, we review the extant multidisciplinary literature related to food and place.
After this in-depth analysis of place-based food concept, in Essay 2 and 3 we investigate the territorial facet of food companies, thus exploring the relationship between food and place in an organizational point of view. Specifically, in Essay 2 we focus on local companies in order to verify the possibility to shift from the concept of terroir products to the concept of terroir organization. In particular, the research questions are as follows: How a local food company which serves typical and traditional products manages its linkage with the territory? What are the implications of the fact that the company itself shows a strong link with the territory of origin of the food products offered? To what extent does the connection among firm, food and territory influence the firm’s strategy? In contrast to Essay 2, in Essay 3 the purpose is to investigate how global companies have progressively changed their offer, paying increasing attention to the territorial dimension. What are the main factors that determine the new face of transnational companies? To what extent does the link between food and place influence their chosen strategies?
To explore these issues, both in Essay 2 and 3 we examine a case study based on qualitative inductive techniques. Specifically, in Essay 2 we analyze the case of MeC Puddu’s, a Sardinian restaurant deeply embedded in its territory of origin, which offers Sardinian traditional dishes in an
unusual fast-food way. In opposition, in Essay 3 we consider the case of McDonald’s that, over the past four years, has undertaken on the Italian market a process of developing Italian products by launching a new line of products based on Italian recipes and produced with certified Italian ingredients. These two cases illustrate two different ways to use territorial links in the firm strategy. Furthermore, they underline two reverse implications of the territorial orientation related to the mix between local and global elements. In this reference, MeC Puddu’s desire to become a global promoter of traditional products of its land can be considered as the opposite of the McDonald’s attempt to approach the Italian market via the McItaly line. Just as McDonald’s tries to replicate its corporate philosophy and symbols, while simultaneously catering for Italian preferences for food produced locally and nationally, MeC Puddu’s aims to reverse this process. The Sardinian fast-food aims to transmit and communicate the cultural and traditional aspect of its products and its place of provenance overcoming the regional boundaries.
The implications of this dissertation are both theoretical and practical. On a theoretical level, it contributes to a better understanding of the concept of place-based food, showing at the same time the need for further research to better understand the place-based food consumer. Additionally, the current work enlarges the study of the relationship between food and territory, by considering it in an organizational point of view, and contributes to the development of the glocalization literature, by underlining a new element to be considered in the balance between global and local forces. On a practical level, the dissertation offers valid support to marketing strategies to be implemented in the food sector, also emphasizing the potentiality of the adoption of a territorial orientation in firms’ strategies
Printed log-periodic feeds for radar applications
Get PDFRadar systems are well known since the end of world war II and are widespread.
The basic concept of radar is relatively simple: the system uses the propagation characteristics of electromagnetic waves and works by radiating electromagnetic energy in the space and detecting the echo reflected by the objects (named “target”). The information related to the target is available in the echo signal: the range, or distance, to the target is found from the time it takes for the radiated
energy to travel to the target and back; the angular location is detected using narrow beam width directive antennas (i.e. reflector antennas). The ability to discern about the nature and size of the target depends on the radar resolution which is related to the bandwidth and to the electrical size of the antenna.
The physical principles of radar are suitable also to the weather radars, used to detect the precipitations at long distance, where the "object of interest” (the target) are the particles of rain and clouds. The detection of these objects involves radar operating at multiple frequencies located in S and C bands, where the wavelength (from 15 to 3.75 centimeters) is comparable to the size of
hydrometeors.
Radar systems use directive antennas, such as mechanically steered parabolic reflector antennas and planar phased arrays. Aim of these antennas is to concentrate the energy in a narrow beam width of about 1° or 2°. This characteristic not only concentrates the energy on the target itself, but also permits a measure of its direction.
In this work we have studied the substitution of reflector horn feeds with printed log-periodic planar feeds in order to obtain the same performance of the horn antennas, but with considerable advantages in terms of weight and cost. The design of log-periodic feeds has been focused on the
feed antenna network, and their possible improvements with respect to the state-of-the-art.
In the first chapter, a general description of radar systems is given, introducing the Probert-Jones
equation for meteorological target. The second and third chapter provide a brief description of antennas concepts and an introduction to reflector antennas.
The chapter four is fully dedicated to reflector horn antennas and printed microstrip feed with a brief description of the state-of-art.
Finally, in chapter five, three printed log-periodic feed for reflector antennas are presented. The first
structure is a printed log-periodic array (LPDA) operating over the C, X and Ku bands. The antenna feeding structure consist of two coaxial cables, in order to realize an infinite balun which provides the required broadband input matching. The second coaxial cable mirrors the first one, connected to the antenna input, and is capable of both stabilizing the antenna phase center and improving the
radiation pattern. Both the simulated and measured results have show that the LPDA can be successfully user as a wide band feed for reflector antennas.
The second feed consists of a LPDA operating between 3 and 6 GHz, and fed with a coplanar waveguide. The structure has been designed starting from Carrel’s theory, optimized using CST MICROWAVE STUDIO 2012 and then realized. The comparison between simulated and measured results shows that the proposed antenna can be used as feed for reflector broadband applications in the whole operating frequency band, with a very good input matching and a satisfactory endfire radiation pattern.
The results obtained with these two printed LPDA provided the starting point for the design of a
high gain “V-shaped” log-periodic feed for weather radar applications, operating in S and C band and fed by the dual coaxial cable configuration. The developed feed provides very good input matching and a symmetric radiation pattern both in E-plane and H-plane, with a reasonable gain
over the whole operating bandwidth. This feed may be recommended for usage in weather radar systems having a transmitting power less than 400 KW, allowing a discrete operational range
Effetto pro-ossidante e pro-infiammatorio degli ossisteroli in cellule intestinali: attività modulatoria della frazione fenolica del vino
Get PDFBecause the intestine sits at the interface between the organism and its luminal environment, it represents a critical defense barrier against luminal toxic agents. Thus, in addition to being exposed to luminal nutrients, the intestinal mucosa is constantly challenged by diet-derived oxidants, mutagens, and carcinogens as well as by endogenously generated reactive oxygen species. Among the oxidizing agents cholesterol oxidation products, oxysterols, are particularly relevant; besides being generated endogenously, they may be introduced with the diet. Oxysterols are involved in physiological processes, but they also exert several detrimental effects including cytotoxicity, induction of cell death, carcinogenicity and pro-oxidative and pro-inflammatory activities. These compounds have recently been suggested to be associated with the pathogenesis of inflammatory bowel diseases (IBD), and with a high risk of developing colorectal cancer. There is an increasing interest in the mechanisms of response of the intestinal epithelium to oxidative stress and in the capability of nutritional antioxidants to strengthen endogenous antioxidant defenses. Among dietary-derived antioxidants, phenolic compounds have been described to have a wide range of biological activities and many reports have illustrated their promising role as preventive tools in several acute and chronic disorders. Phenolic compounds are absorbed and extensively metabolized in vivo: however, the percentage of absorption does not exceed a few percent of the ingested dose. It is assumed that dietary polyphenols may display their first antioxidant defense in the digestive tract, where they concentrate, both through their “conventional“ antioxidant capacity, limiting ROS formation and scavenging them, and by an “indirect” antioxidant effect, inducing endogenous protective enzymes and/or regulating cellular process such as inflammation. Wine accounts for a very high proportion of phenolic compounds intake in the Mediterranean diet; typically a glass of red wine contains about 100 mg of compounds generally called polyphenols.
We investigated the ability of two wine phenolic extracts, obtained from grape varieties grown in Sardinia, Cannonau (red) and Vermentino (white), to exert a protective action against the pro-oxidative and pro-inflammatory effect of oxysterols in Caco-2 cells, a cell line
with enterocyte-like features, as a model system that mimics the insult of dietary oxidized lipids on the intestinal mucosa. Oxidative damage was induced by treating cells with a dietary-representative oxysterols mixture (7-ketocholesterol, 5α,6α-epoxycholesterol, 5β,6β-epoxycholesterol, 7α-hydroxycholesterol and 7β-hydroxycholesterol); malondialdehyde (MDA) production was evaluated as marker of oxidative damage, together with cell death. Changes in the cellular redox state were evaluated determining the glutathione peroxidase (GPx) activity, the variation of GSH concentration, NADPH oxidase 1 (NOX1) activation and ROS generation. Twenty-four hours exposure to oxysterols induced cell death and MDA production, together with a significant loss of GSH, just after 30 min of incubation. An increase in the GPx activity was observed 18 hours after treatment. Pretreatment with both the wine phenolic extracts protected Caco-2 cells from oxidative damage and the level of GSH was preserved; a further increase of the GPx activity was observed in cells pretreated with wine fenolic extracts in agreement with previous studies. Oxysterols oxidizing action was due, at least in part, to the generation of intracellular ROS, as demonstrated by the use of a fluorescent probe. Since the increase of ROS levels by oxysterols in Caco-2 cells has been reported to involve modulation of NOX1, we also measured the activation of this enzyme; oxysterols treatment significantly enhanced the activity of NOX1. Wine phenolic extracts pretreatment reduced ROS formation, probably by a scavenging direct action, but also through the modulation of NOX1 activity, which was significantly inhibited by the extracts. In view of recent studies reporting that oxysterols may induce an increase of ROS production through an enhanced expression of NOX1 in Caco-2 cells in association with an increase of inflammatory cytokine production (IL-6 and IL-8), we investigated the antinflammatory effect of the wine phenolic extracts, by measuring the release of IL-6 and IL-8 by Caco-2 cells treated with the oxysterols mixture. Differentiated Caco-2 cells in fact have been reported to be also an excellent in vitro model of intestinal inflammation, responding to different inflammatory stimuli. Cannonau phenolic extract exerted a significant antinflammatory activity, inhibiting the release of the two interleukins.
Finally, we evaluated the signaling pathways modulated by oxysterols and wine phenolic extracts with the aim of clarifying the molecular mechanism involved in the antioxidant and
antinflammatory activity. For this purpose the possible modulation of the MAPKs cascade was analyzed in Caco-2 treated with oxysterols. These kinases have been reported to be activated by various stress stimuli, and they have been also implicated in oxysterols induced cytokine secretion and apoptosis. Under our experimental conditions, the oxysterols mixture was not able to modulate ERK phosphorilation, but induced p38 and JNK pathways activation. Pretreatment with both the wine phenolic extracts significantly inhibited p38 and JNK phosphorilation. The results of this study support a potential role for wine phenolic compounds in preventing oxysterols induced oxidative damage and inflammatory cytokine production in Caco-2 cells. We suggest that wine phenolic compounds exerted such a preventive effect through a mechanism involving a direct scavenging of ROS and/or an inhibition of NOX1, which in turn affected ROS production and redox sensitive MAPKs, p38 and JNK, expression and interleukins release. Although further studies are needed, our results point out for the first time a direct antioxidant and antinflammatory action of the phenolic fraction from the red wine Cannonau and the white wine Vermentino on enterocytes exposed to oxidizing species. These data have an interesting biological significance, suggesting the possibility that, together with their metabolites, wine polyphenols may significantly contribute to preserve the integrity of intestinal mucosa against oxidative damage and inflammation related disorders. Our data also support the opinion that total phenolic content, as well as wine’s color, are not essential for the antioxidant activity of a wine extract; although the extract obtained from the red wine Cannonau was effective at lower concentrations and in all the experimental conditions, the extract obtained from the white wine Vermentino showed basically a comparable efficacy
Black brane solutions of Einstein-scalar-Maxwell gravity and their holographic applications
Get PDFBlack hole solutions of Einstein (and Einstein-Maxwell) gravity coupled to scalar fields have acquired a growing interest and importance in recent years.
This interest is motivated both by more \classical" issues, as the problem of the uniqueness of classical black holes solutions (and related \no-hair" theorems), and mainly by recent applications of the AdS/CFT correspondence,
an holographic duality which allows to describe, starting from a gravitational theory, strongly coupled quantum field theories.
In this thesis, we treat this topic both from a pure gravitational point of view and from the holographic perspective. In particular, we propose a general method for exactly solving, in some cases, the field equations of
Einstein-scalar-Maxwell gravity, and present some new analytical and numerical solutions (we mainly focus on black brane solutions, i.e. solutions with a planar event horizon). Moreover, we discuss hyperscaling violation,
a particular scaling behavior of free energy and entropy (as functions of the temperature), typical of some phase transitions of real condensed matter systems.
Hyperscaling violation can be described, via AdS/CFT, starting from a gravitational solution with a particular symmetry.
Finally, we perform some interesting results about the mass spectrum and stability of black brane solutions in a wide class of gravitational models.
In particular, the thermodynamics of some solutions of these models provides important information about the possible existence of physicallyrelevant phase transitions in the dual field theories