28,582 research outputs found
3-Amminoisotiazol diossidi come efficienti dienofili in reazioni di cicloaddizione di Diels Alder
No full text3-Amminoisotiazol diossidi come efficienti dienofili in reazioni di cicloaddizione di Diels AlderLe reazioni di Diels-Alder rappresentano uno dei mezzi più efficaci per la costruzione di sistemi carbociclici od eterociclici esatomici ed offrono la possibilità di realizzare processi sintetici stereocontrollati. Sulla base di questa considerazione e del nostro interesse nei confronti dei sistemi isotiazolici,1 abbiamo studiato le potenzialità del sistema 3-amminoisotiazol S-ossido in reazioni di Diels-Alder, valutando la sua efficienza come dienofilo e l’efficacia del gruppo sulfinilico come induttore di stereoselettività. Per la realizzazione delle cicloaddizioni sono state studiate metodologie eco-compatibili.2 In particolare, abbiamo utilizzato due approcci: 1) eliminazione del solvente; 2) sostituzione con solventi a basso impatto ambientale.
Il gruppo SO induce la formazione esclusiva dell’addotto endo e, a seconda delle condizioni adottate, è possibile osservare una variazione nel rapporto percentuale tra i due addotti endo sin ed endo anti.
1. F. Clerici, “Thiazole and Thiadiazole S-oxides” Advances in Heterocyclic Chemistry, A. R. Katritzky ed., Pergamon Press, vol. 83, 72-116, 2002
2.G.Imperato, B. Koenig, A. Sala. Sweet Solutions – Low melting mixtures of carbohydrates and inorganic salts as new media for organic reaction, German, Degussa, January 200
Higgs and flavour as doors to new physics
No full textA natural solution to the hierarchy problem of the Fermi scale motivates signals of New Physics at current and near-future experiments. After a critical synthesis of this general motivation, we concentrate our attention on the interplay between LHC searches for new resonances, and precision measurements of both Higgs couplings and flavour violating observables. We do so for i) the Higgs sectors of the NMSSM and MSSM, as paradigmatic examples of theories providing extra scalars, and for ii) CKM-like flavour symmetries, with a focus on (Formula presented.). This article is mainly based on several papers by the author, but it also reviews other recent related results. Its goal is to provide a synthetic, yet comprehensive, orientation on these subjects, at the dawn of several (ATLAS and CMS, LHCb, NA62, etc.) forthcoming experimental results
Chapter 22 - Surgery of brainstem lesions
No full textDuring the past 20 years, surgery of the brainstem has continued to represent a challenge in neurosurgery. During the 1990s a more rational and constructive approach to the surgical management of neoplastic and vascular brainstem lesions emerged. This trend has continued into the new millennium, thanks also to technological innovations such as fiber tracking, neuronavigation, intraoperative magnetic resonance imaging (MRI), and refined skull base approaches. Since 2001, when the first edition of this book was published, the field of intraoperative neurophysiological monitoring (ION) has also dramatically evolved. Yet, in those years, the cornerstone of brainstem ION techniques such as mapping of the floor of the fourth ventricle or corticobulbar motor-evoked potentials were already part of the clinical practice in some of the most experienced neurosurgical centers. During the past two decades, these techniques have become more common at many more institutions, and the cumulative experience has allowed us to better define the value and the limitations of these techniques. In this new edition, we have largely maintained all the relevant information on the functional neuroanatomy of the brainstem, which remains invaluable for a modern approach to brainstem surgery, and on the main surgical approaches to the midbrain, pons, and medulla. While the various ION techniques that are used in brainstem surgery are described elsewhere in this book, at the end of this chapter, we will shortly review their impact in our practice based on a 20-year experience with using ION-guided brainstem surgery
Considerations on an integrated biochronological scale of Italian Quaternary Mammals
No full textViene analizzato il lavoro di MASINI e SALA (2007) sull’approccio integrato della distribuzione dei grandi e piccoli mammiferi dell’Italia continentale del tardo Pliocene e del Pleistocene, tenendo conto della nuova definizione del Quaternario, mettendo in risalto i punti di forza e quelli deboli della scala proposta. Vengono inoltre aggiunti nuovi dati sulla biocronologia a mammiferi del Pleistocene Superiore.The paper of MASINI and SALA (2007) regarding an integrated approach on the stratigraphic distribution patterns of large and small mammals in the late Pliocene and Pleistocene of the Italian peninsula is analysed, showing the weak and strong points. New data are presented on the mammal biochronology of the Late Pleistocen
Introduction to Public ethics for real people
No full textThis book develops an innovative paradigm of public ethics that provides a unique insight into three central themes - recognition, social conflicts and democratic distortions - while critically celebrating the work of Anna Elisabetta Galeotti. In honor of her seventieth birthday, this edited collection brings together leading scholars in the field of normative political philosophy to reason upon the main strands of her research. The volume envisages a general paradigm of public ethics to deal with social conflicts that involve structural dynamics and deliberative deficits. While addressing diverse yet interrelated topics, all the contributors demonstrate a commitment to the ideal that, in the construction and reform of social and political institutions, respect for individuals as the makers of their own lives should act as the guiding principle. Against this backdrop, this volume strikes a difficult-to-reach balance between refined theorizing over classical themes of the liberal tradition and the ability to open these classic themes to new strands of research. The collection deals with crucial contemporary challenges to the democratic order, such as democratic backsliding and the breach of social trust, legal and democratic fights over free speech, multicultural clashes in highly diverse societies, and reparation for historical wrongs
Zważyć stratę. Z Tomaszem Bąkiem rozmawia Zuzanna Sala
No full textIn her interview with Tomasz Bąk, author of several books of poetry, Zuzanna Sala talks, among other things, about his latest books, ways of thinking about the future, the post-pandemic era and the climate crisis.Z Tomaszem Bąkiem, autorem książek poetyckich, Zuzanna Sala rozmawia między innymi o jego najnowszych książkach, sposobach myślenia o przyszłości, czasie popandemicznym i kryzysie klimatycznym
Higgs boson properties (theory)
No full textWe provide an overview of the theory motivations for extra Higgs bosons, focussing on models that address the hierarchy problem (Twin Higgs, the MSSM and the NMSSM), and on the reasons why new Higgses could be the first particles seen in these models. We then discuss a phenomenological framework to describe the phenomenology of extra Higgs doublets and/or singlets, that easily maps on the above and other models, and that allows to set a strategy to perform experimental searches. We finally summarise the LHC8 status of these searches, as well as their prospects at the next runs of the LHC. In particular we describe the interplay of the following measurements: i) SM Higgs couplings to other SM particles, ii) SM Higgs self coupling, iii) direct searches for extra Higgses
A light dimuon resonance in B decays?
No full textThe observed deviations from the Standard Model in several processes can be explained in terms of a new vector boson produced on-shell in B meson decays. A mass of 2.5-3 GeV and a total width of 10-20% allow to hide the associated dimuon bump in the poorly known charmonium region, and the large invisible decay width can be interpreted in terms of Dark Matter. This proposal predicts a contribution to the muon anomalous magnetic moment, that could explain the long-standing tension with the Standard Model. It also predicts sizeable invisible decays and a peculiar -dependence of the lepton flavor universality ratios and , that could be tested at the LHCb and Belle-II. This proceeding is based on arXiv:1704.06188, and slightly extends it with comments about Dark Matter
In SUSY with a U(2)3 flavour symmetry
No full textA U(2)^3 flavour symmetry acting on the first two generations of quarks partially explains the hierarchies of the yukawa couplings, and provides a natural embedding for Supersymmetry with heavier first two generations, where collider constraints are not in conflict with the requirement of naturalness and the SUSY CP problem is solved. Within this context a specific pattern of flavour symmetry breaking is considered. The K, Bd and Bs mixing amplitudes show a definite correlation that can resolve existing tensions in the CKM fit, pointing in this way to sbottom and gluino masses below about 1.5 TeV. Potentially sizeable contributions to both indirect and direct CP violation in B decays are allowed, even in the absence of flavour-blind phases. In case some effects are observed, the peculiar pattern in ΔF = 2 and ΔB = 1 observables may allow to distinguish between this and other models
- …
