170,206 research outputs found
Energetics of quadruplex-drug recognition in anticancer therapy
No full textImmortality of tumour cells is strictly correlated to telomerase activity. Telomerase is overexpressed in about 85% of tumour cells and maintains telomere length contributing to cell immortalisation, whereas in somatic cells telomeres progressively shorten until cell death occurs by apoptosis. Different drugs can promote telomeric G-rich overhangs which fold into quadruplex structures that inhibit telomerase activity. Detailed studies on drug-quadruplex complexes are essential to understand quadruplex recognition and address drug design. This review will discuss the energetic aspects of quadruplex-drug interactions with a particular attention to physico-chemical methodologies
The vertical and intertemporal structure of educational inequalities in Italy
No full textThis paper aims to analyse the joint impact that individual and ascriptive variables (gender, family background, migratory background) and contextual variables (socio-economic and cultural context, school composition and tracking, territorial differentiation) exert on the academic performance of Italian students. The aim is to investigate the mechanisms operating at both macro and micro levels and their interplay (Coleman, 1990), which shape individual choices and how the combination of these produces collective effects (micro-macro). We investigate these goals using OECD PISA data for the years 2018 and 2022. While many studies analyse the impact of factors such as students’ family background and tracking on performance (Panichella and Triventi, 2019; Bernardi and Triventi, 2020; Giancola and Salmieri, 2022), showing the multilevel and territorial structure of these inequalities from a diachronic perspective is a relatively new topic in the Italian context.
Educational inequalities at the upper secondary level arise from various factors, one of which is the territorial and school level. In our research, the territorial level, specifically geographical macro-areas, represents the highest level of aggregation for inequality factors. Individual schools represent the intermediate level. Several studies have showed the role played by the social composition of individual schools in different territories (Benadusi et al, 2010; Argentin et al, 2017). The social background of students in Italian schools plays a determining role in the level of segregation observed (Giancola and Salmieri, 2020). In Italy, schools and students' families are intertwined with diverse territorial contexts. These contexts are characterized by different socio-economic and cultural combinations, which are shaped by a range of factors, including institutions, politics, and the local environment. If this relates to the "vertical" dimension of the stratification of inequalities, then we must also consider the temporal dimension, which includes the effects of the Covid-19 pandemic such as school closures, social isolation, and the subsequent phenomena of learning loss.
The study investigates these objectives using the data collected by OECD in PISA 2018 and 2022 (OECD-PISA, 2019; 2023) and refers to performance differences in Reading among Italian upper secondary students. In the first part, the study analyses the configuration of educational inequalities within and among the five macro-territorial areas considered in the PISA survey. In this section, a multilevel regression sets (Bottoni, G., 2022) will be used to construct an interpretative model of the vertical structuring (macro-area, school, individual) of inequalities. Following this phase, we analyse the data from 2018 to 2022 to investigate whether and how school performance has changed over time in the five territorial areas. We use a pseudo-counterfactual approach and apply the Difference-In-Difference technique (Morgan, S., L. and Winship, C., 2015)
Incontri di Parole. Dal sapere al comprendere, al sentire e viceversa.
No full textIl Coordinamento Napoletano Donne nella Scienza con il Convegno Inter/Azioni tra i Linguaggi della Scienza. La valorizzazione delle differenze è giunto al VI anno delle proprie attività di divulgazione dei saperi e dei contributi offerti da docenti, ricercatrici, dirigenti di ricerca che operano in campi e discipline diversi. In particolare il 2012, è stato dedicato al ciclo di seminari Incontri di Parole. Dal sapere al comprendere promosso dalle colleghe di area umanistica R. Valenti e V. Viparelli per avviare una riflessione sul tema del rapporto, ormai ineludibile, tra discipline e saperi diversi. Al centro della questione è l???inedito intreccio di umanesimo e scienza, persona e corpo, natura e storia (e/o artificio). Oltre la lingua ed i linguaggi e la loro mutevolezza, nella crescita culturale complessiva di una Comunità, svolge un ruolo significativo la Comunicazione, ovvero la trasmissione del sapere e della conoscenza sia di uno stesso campo scientifico che di saperi differenti. I risultati perseguiti con il VI Convegno possono essere riassunti nelle diverse modalità operative che la comunicazione attua per il trasferimento delle informazioni tra i codici della lingua, della biologia, della fisica, della politica fino all???economia. L???analisi del pensiero femminista degli studi economici, infatti, in relazione alla crisi ambientale, sociale ed economica in atto e determinata dal modello socio-economico del turbo-capitalismo liberista, è coerente all???analisi che indaga il rapporto tra scienza e genere ed è in continuità culturale per quanto riguarda le proposte alternative alle forti criticità che si stanno verificando a livello globale. La scienza non deve rinunciare a promuovere lo sviluppo umano sul Pianeta purché per esso si intenda l???integrazione tra il benessere spirituale e materiale individuale con l???equità sociale collettiva e con la salvaguardia di ogni forma di vita e dell???ambiente. Mai come in questa data epoca storica la sfera scientifica non può essere separata dalla sfera economica e sociale. Il contributo di genere può essere un???ulteriore alternativa per ribaltare le gerarchie ed i rapporti di dominio su cui è fondato il sistema economico capitalista attualmente in disgregazione. Ricomporre l???unità del processo storico di formazione dei saperi umanistici e scientifici è uno dei due aspetti fondamentali dell???esigenza di costituire un Coordinamento scientifico trasversale a tutte le componenti dei mondi del sapere nella nostra realtà territoriale; l???altro aspetto è percorrere ed indagare i territori inesplorati e di margine tra una disciplina e l???altra, tra un sapere e un altro, cioè trarre spunti e nuova linfa vitale tra i punti al tempo stesso di separazione e di contatto tra mondi diversi. Lo spazio o il campo, sconosciuto o conosciuto sono comunque le fonti della conoscenza e se si intende valorizzare la differenza di genere si deve indicare la rotta del cammino, si deve tracciare la strada da percorrere, si devono chiarire gli obiettivi da perseguire per raggiungere l???unico vero scopo della Scienza: affrancare gli esseri umani dalla sofferenza, dal dolore, dalla schiavitù, dalla segregazione, dalla violenza, in senso globale e non di una sola parte. Non esiste progresso scientifico se i benefici non hanno ricaduta sull???intera Comunità umana. Non esiste avanzamento della conoscenza se altre specie viventi sono poste in condizione di rischio di estinzione. L???approccio di genere deve vincere questa sfida, ancora tutta da pianificare, da mettere in campo, ancora al nastro di partenza. Non è un caso che le scienziate sono ancora troppo poche, soprattutto nei ruoli delle decisioni e dei programmi
Applications of Isothermal Titration Calorimetry in BiophysicalStudies of G-quadruplexes
No full textG-quadruplexes are higher-order nucleic acids structures formed by G-rich sequences that are stabilized by tetrads of hydrogen-bonded guanine bases. Recently, there has been growing interest in the study of G-quadruplexes because of their possible involvement in many biological processes. Isothermal titration calorimetry (ITC) has been proven to be a useful tool to study the energetic aspects of G-quadruplex interactions. Particularly, ITC has been applied many times to determine the thermodynamic properties of drug-quadruplex interactions to screening among various drugs and to address drug design. In the present review, we will focus on the ITC studies of G-quadruplex structures and their interaction with proteins and drugs and the most significant results will be discussed
Dilution Enthalpies of Alkanols in Concentrated Aqueous Solutions of Urea at 25° C
No full textEnthalpies of dilution of some aliphatic alcohols were determined at 25°C in aqueous 7M urea solutions by flow microcalorimetry. The excess enthalpies were expressed as power expansion series in molalities referred to 1 kg of constant composition urea-water mixture. This urea-water mixture was utilized throughout as a mixed solvent. The values of the second enthalpic virial coefficients were all found to be positive and generally lower than the corresponding values in water. Large differences were encountered, as in water, by comparing normal and branched isomeric propanols and butanols. For one system it was possible to measure the third coefficients, which were also positive. The second enthalpic coefficients were found to increase with the molecular weight of the alkanols. These facts suggest that in the presence of a large concentration of urea, the excess enthalpies are mainly determined by apolar interactions. This is surprising and potentially rich in consequences for a better understanding of the interactions among amino acid residues distantly situated in the primary sequences but topologically near in the loops of globular proteins. An analysis, carried out using the Savage-Wood additivity group method, shows that the enthalpic contributions (that appear to play a crucial role in water in making the polar interaction to be favorable) become essentially unfavorable in urea-water solvent. The hypothesis that the peptide-peptide interactions are prevented by the preferential solvation of urea is also discussed
Structural characterization of N-acetylglycyl-L-prolinamide: an X-ray and thermodynamic study
No full textEnthalpies and entropies of fusion of some substituted dipeptides
No full textEnthalpies and temperatures of fusion or transition for four substituted dipeptides (Nacetylamides of glycyl-L-alanine (NAGAA),L-alanyl-L-alanine (NAA2A),L-prolyl-glycine (NAPGA) andL-leucyl-L-proline monohydrate (NALPA·H2O)) were determined by differential scanning calorimetry and the entropies of fusion derived. The results obtained have been compared with those of the corresponding substituted aminoacids and some of their racemic crystalline mixtures. The enthalpies and entropies of fusion of some substituted aminoacids have been redetermined. The results are discussed in comparison with crystal structural data, which has been reported in the literature or determined recently by some of the authors. Rationalization of the fusion parameters was attempted mainly on the basis of the number of intramolecular hydrogen bonds and the packing densities in the crystals
THERMODYNAMICS OF G-QUADRUPLEXES
No full textGuanosine and its derivatives have a high potential for self-recognition and self-assembly, as well as the recognition ability for other biologically important molecules. This book explores in detail these properties with the goal of increasing knowledge of the basic principles of guanosine-assembly, synthesis of new optimised materials and exploration of their electronic and optical properties. Following the work of COST Action MP0802, the aim is to design novel reproducible and well ordered supramolecular structures to serve as molecular-scale architectures for new hybrid molecular electronics. Coverage includes synthesis, characterisation and optimisation, theoretical modelling and prediction, biochemical and biorecognition properties and applications in nanotechnology especially in molecular electronics. Appealing to researchers working in the field ranging from chemists, biologists and material scientists, this title will be a welcome addition to the inter-disciplinary literature providing direction for future research and ideas for industrial applications
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