Revisiting Lepton Flavour Universality in B Decays

Lepton flavour universality (LFU) in B-decays is revisited by considering a class of semileptonic operators defined at a scale Lambda above the electroweak scale v. The importance of quantum effects, so far neglected in the literature, is emphasised. We construct the low-energy effective Lagrangian taking into account the running effects from Lambda down to v through the one-loop renormalization group equations (RGE) in the limit of exact electroweak symmetry and QED RGEs from v down to the 1 GeV scale. The most important quantum effects turn out to be the modification of the leptonic couplings of the vector boson Z and the generation of a purely leptonic effective Lagrangian. Large LFU breaking effects in Z and tau decays and visible lepton flavour violating (LFV) effects in the processes tau -> mu ll, tau -> mu rho, tau -> mu pi and tau -> mu eta^(') are induced.Comment: 5 pages, 2 figures. V2: Minor text improvements. Published PRL versio

On the Importance of Electroweak Corrections for B Anomalies

The growing experimental indication of Lepton Flavour Universality Violation (LFUV) both in charged- and neutral-current semileptonic B-decays, has triggered many theoretical interpretations of such non-standard phenomena. Focusing on popular scenarios where the explanation of these anomalies requires New Physics at the TeV scale, we emphasise the importance of including electroweak corrections to obtain trustable predictions for the models in question. We find that the most important quantum effects are the modifications of the leptonic couplings of the W and Z vector bosons and the generation of a purely leptonic effective Lagrangian. As a result, the tight experimental bounds on Z-pole observables and tau decays challenge an explanation of the current non-standard data. We illustrate how these effects arise, by providing a detailed discussion of the running and matching procedure which is necessary to derive the low-energy effective Lagrangian.Comment: 38 pages, 7 figures. V2: Text improvments. Published versio

Lepton Flavour Violation in Composite Higgs Models

We discuss in detail the constraints on partial compositeness coming from flavour and CP violation in the leptonic sector. In a first part we present a formulation of partial compositeness in terms of a flavour symmetry group and a set of spurions, whose background values specify the symmetry breaking pattern. In such a framework we construct the complete set of dimension-six operators describing lepton flavour violation and CP violation. By exploiting the existing bounds, we derive limits on the compositeness scale in different scenarios, characterised by increasing restrictions on the spurion properties. We confirm that in the most general case the compositeness scale should lie well-above 10 TeV. However, if in the composite sector mass parameters and Yukawa couplings are universal, such a bound can be significantly lowered, without necessarily reproducing the case of minimal flavour violation. The most sensitive processes are decays of charged leptons either of radiative type or into three charged leptons, muon to electron conversion in nuclei and the electric dipole moment of the electron. In a second part we explicitly compute the Wilson coefficients of the relevant dimension-six operators in the so-called two-site model, embodying the symmetry breaking pattern discussed in our first part, and we compare the results with those of the general spurion analysis.Comment: 42 pages, 9 figures; text improved, some corrections in appendix B and C, results unchange

The Perils of a Defective Medical Communication: Fatal Neglected Squamous Cell Carcinoma Arising in Perineal Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a recurrent suppurative disease characterized by inflammatory nodules, abscesses, fistulas, and scarring. We report a case of squamous cell carcinoma arising in chronic HS. In our case the asymptomatic lesion was neglected by the patient for a long time, allowing the occurrence of advanced disease before treatment was sought, which resulted in a terminal outcome. In the context of HS, a painful lump or ulcer could easily be mistaken for an inflammatory lesion, and therefore a low threshold for biopsy is warranted

Topical tacrolimus and 50% zinc oxide paste for Hailey-Hailey disease: less is more.

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Large Eddy Simulations (LES) towards a comprehensive understanding of Ducted Fuel Injection concept in non-reacting conditions

The diesel combustion research is increasingly focused on Ducted Fuel Injection (DFI), a promising concept to abate engine-out soot emissions in Compression-Ignition engines. A large set of experiments and numerical simulations, at medium-low computational cost, showed that the duct adop- tion in front of the injector nozzle activates several soot mitigation mechanisms, leading to quasi-zero soot formation in several engine-like operating conditions. However, although the simplified CFD mod- elling so far played a crucial role for the preliminary understanding of DFI technology, a more accurate turbulence description approach, combined with a large set of numerical experiments for statistical pur- poses, is of paramount importance for a robust knowledge on the DFI physical behavior. In this context, the present work exploits the potential of Large Eddy Simulations (LES) to analyze the non-reacting spray of DFI configuration compared with the unconstrained spray. For this purpose, a previously developed spray model, calibrated and validated in the RANS framework against an exten- sive amount of experimental data related to both free spray and DFI, has been employed. This high- fidelity simulation model has been adapted for LES, firstly selecting the best grid settings, and then carrying out several numerical experiments for both spray configurations until achieving a satisfying statistical convergence. With this aim, the number of independent samples for the averaging procedure has been increased exploiting the axial symmetry characteristics of the present case study. The relia- bility of this methodology has been herein proven, highlighting an impressive runtime saving without any remarkable worsening of the accuracy level. Thanks to this approach, a detailed description of the main DFI-enabled soot mitigation mechanisms has been achieved, bridging the still open knowledge gap in the physical understanding of the impact of spray-duct interaction

Anandamide regulates keratinocyte differentiation by inducing DNA methylation in a CB1 receptor-dependent manner.

Anandamide (arachidonoylethanolamide, AEA) belongs to an important class of endogenous lipids including amides and esters of long chain polyunsaturated fatty acids, collectively termed "endocannabinoids." Recently we have shown that AEA inhibits differentiation of human keratinocytes, by binding to type-1 cannabinoid receptors (CB1R). To further characterize the molecular mechanisms responsible for this effect, we investigated the expression of epidermal differentiation-related genes after AEA treatment. We observed that keratin 1 and 10, transglutaminase 5 and involucrin are transcriptionally down-regulated by AEA. Most importantly, we found that AEA is able to decrease differentiating gene expression by increasing DNA methylation in human keratinocytes, through a p38, and to a lesser extent p42/44, mitogen-activated protein kinase-dependent pathway triggered by CB1R. An effect of AEA on DNA methylation because of CB1R-mediated increase of methyltransferase activity is described here for the first time, and we believe that the importance of this effect clearly extends beyond the regulation of skin differentiation. In fact, the modulation of DNA methylation by endocannabinoids may affect the expression of a number of genes that regulate many cell functions in response to these substances

Amyloid Oligomer Neurotoxicity, Calcium Dysregulation, and Lipid Rafts

Amyloid proteins constitute a chemically heterogeneous group of proteins, which share some biophysical and biological characteristics, the principal of which are the high propensity to acquire an incorrect folding and the tendency to aggregate. A number of diseases are associated with misfolding and aggregation of proteins, although only in some of them—most notably Alzheimer's disease (AD) and transmissible spongiform encephalopathies (TSEs)—a pathogenetic link with misfolded proteins is now widely recognized. Lipid rafts (LRs) have been involved in the pathophysiology of diseases associated with protein misfolding at several levels, including aggregation of misfolded proteins, amyloidogenic processing, and neurotoxicity. Among the pathogenic misfolded proteins, the AD-related protein amyloid β (Aβ) is by far the most studied protein, and a large body of evidence has been gathered on the role played by LRs in Aβ pathogenicity. However, significant amount of data has also been collected for several other amyloid proteins, so that their ability to interact with LRs can be considered an additional, shared feature characterizing the amyloid protein family. In this paper, we will review the evidence on the role of LRs in the neurotoxicity of huntingtin, α-synuclein, prion protein, and calcitonin

Comparison Between Different Hydrogen Fuelled Powertrains for Urban Busses

In the compelling need for the decarbonization of the transport sector, hydrogen could play a crucial role, especially in heavy duty applications where the limited specific energy of chemical batteries can significantly reduce either the payload or the operative range. Moreover, the possibility to use Hydrogen not only within Fuel Cells (FCs) systems but also as a fuel in Internal Combustion Engines (ICEs) makes it even more attractive for future sustainable transport systems. In such a framework, this work aims to compare, through numerical simulation, different hydrogen powertrain configurations designed for an urban bus application. In particular, a series hybrid architecture was chosen as a reference considering three different technologies for its Auxiliary Power Unit: two internal combustion engines fuelled with Diesel and Hydrogen respectively, and a Fuel Cell featuring almost the same power level of the internal combustion engines. The study was carried out in real world driving condition and it showed the benefits of both hydrogen powertrains on the vehicle fuel economy. Finally, in order to provide a more comprehensive overview, an analysis of the Total Cost of Ownership (TCO) was performed demonstrating that the H2-engine could achieve a significant improvement of the powertrain efficiency with investments and operating costs closer to the Diesel configuration

New water-soluble carbamate ester derivatives of resveratrol

Low bioavailability severely hinders exploitation of the biomedical potential of resveratrol. Extensive phase-II metabolism and poor water solubility contribute to lowering the concentrations of resveratrol in the bloodstream after oral administration. Prodrugs may provide a solution—protection of the phenolic functions hinders conjugative metabolism and can be exploited to modulate the physicochemical properties of the compound. We report here the synthesis and characterization of carbamate ester derivatives of resveratrol bearing on each nitrogen atom a methyl group and either a methoxy-poly(ethylene glycol)-350 (mPEG-350) or a butyl-glucosyl promoiety conferring high water solubility. Ex vivo absorption studies revealed that the butyl-glucosyl conjugate, unlike the mPEG-350 one, is able to permeate the intestinal wall. In vivo pharmacokinetics confirmed absorption after oral administration and showed that no hydrolysis of the carbamate groups takes place. Thus, sugar groups can be attached to resveratrol to obtain soluble derivatives maintaining to some degree the ability to permeate biomembranes, perhaps by facilitated or active transport