Lepton Mixing from Delta (3 n^2) and Delta (6 n^2) and CP

We perform a detailed study of lepton mixing patterns arising from a scenario with three Majorana neutrinos in which a discrete flavor group Gf=Delta (3 n^2) or Gf=Delta(6 n^2) and a CP symmetry are broken to residual symmetries Ge=Z3 and Gnu=Z2 x CP in the charged lepton and neutrino sectors, respectively. While we consider all possible Z3 and Z2 generating elements, we focus on a certain set of CP transformations. The resulting lepton mixing depends on group theoretical indices and one continuous parameter. In order to study the mixing patterns comprehensively for all admitted Ge and Gnu, it is sufficient to discuss only three types of combinations. One of them requires as flavor group Delta (6 n^2). Two types of combinations lead to mixing patterns with a trimaximal column, while the third one allows for a much richer structure. For the first type of combinations the Dirac as well as one Majorana phase are trivial, whereas the other two ones predict in general all CP phases to be non-trivial and also non-maximal. Already for small values of the index n of the group, n <= 11, experimental data on lepton mixing can be accommodated well for particular choices of the parameters of the theory. We also comment on the relation of the used CP transformations to the automorphisms of Delta (3 n^2) and Delta (6 n^2).Comment: 60 pages, 12 tables and 10 figures. v2: typos corrected, references updated, some minor improvement of the text, matches version accepted for publication in Nuclear Physics

Two-zero Majorana textures in the light of the Planck results

The recent results of the Planck experiment put a stringent constraint on the sum of the light neutrino masses, m1+m2+m3 < 0.23 eV (95 % CL). On the other hand, two-zero Majorana mass matrix textures predict strong correlations among the atmospheric angle and the sum of the masses. We use the Planck result to show that, for the normal hierarchy case, the texture with vanishing (2,2) and (3,3) elements is ruled out at a high confidence level; in addition, we emphasize that a future measurement of the octant of the atmospheric mixing angle (or the one sigma determination of it based on recent fit to neutrino data) will put severe constraint on the possible structure of the Majorana mass matrix. The implication of the above mentioned correlations for neutrinoless double beta-decay are also discussed, for both normal and inverted orderings.Comment: 9 pages, 8 figure

METABOLIC EFFECTS OF DIETARY APPROACHES:KETONE BODIES &amp; KETOGENIC DIET

One of the dietary approach that has attracted particular attention in recent years is the \u201cketogenic diet\u201d (KD). This is a dietary program designed in the 1920s as a therapy for drug-resistant epilepsy, which then gained popularity in the 1970s as a weight-loss diet (Atkins). Indeed, many current diets are based on the KD model, and, recently, this model was proposed for a number of neurological disorders like Alzheimer\u2019s and Parkinson\u2019s diseases. The KD is a high-fat, low-carbohydrates diet planned to achieve ketosis, characterized by increased levels of circulating KB. Under normal conditions and with a balanced diet, KB are produced in small quantities, but, under a KD, their synthesis is induced as a result of a very low carbohydrate intake and high fat intake. The low glucose supply stimulates the catabolism of fats to obtain energy, leading to the accumulation of acetyl-CoA and synthesis of KB by the liver, which are sent to the peripheral tissues where they are oxidized to produce energy. The overall aim of the present Ph.D. thesis was to investigate the metabolic effects of KB and KD, through both in vitro and in vivo approaches. Thus, the research project has been subdivided in two different parts. In the first part we focused our attention on the vascular risk represented by KD-induced oxidative stress. We evaluated the effects of physiological levels of KB by measuring markers of oxidative stress using an in vitro model of endothelium. With this aim, we decided to investigate: a) the DNA oxidative damage by comet assay in order to study the genotoxicity due to KB; b) the ability of KB to modulate DNA susceptibility toward a secondary oxidative insult and c) the cell adaptive metabolic response to KB exposure, by activation of the Nrf2, which is a transcriptional factor involved in the cellular response to a stress, by western blot, immunofluorescence and real time PCR. The results obtained in this in vitro study demonstrate the activation of a cellular metabolic response caused by the effect of KB exposure. Ketones, by inducing moderate oxidative stress, activate the transcription factor Nrf2, which translocates into the nucleus. By binding to the ARE, Nrf2 activates the transcription of target genes, among which HO-1. As a consequence, the metabolic response caused by KB exposure makes cells more protected against a secondary insult, such as H2O2, leading to a reduction in DNA oxidative damage. Every time a KD is applied it should be considered that this diet could have an impact on cell metabolism in different tissue functions. The second part was devoted to verify the impact of the KD on human intestinal environment, by an in vivo study. This project was in collaboration with the Human Nutrition and Eating Disorder Research Center of the University of Pavia, where the subjects were recruited. After the collection of the samples, three different activities were scheduled: a) analysis of the composition of gut bacteria (NGS, qPCR) performed in collaboration with the Department of Health Sciences of University of Milan; b) assessment of markers of bacterial metabolism (SCFA) and c) evaluation of fecal water citotoxicity and genotoxicity (Trypan blue, Comet assay). We found that, first of all, the microbiota gut composition of patients affected by refractory epilepsy or GLUT1-DS undergoing a KD as a therapy, was significantly different than healthy control subjects, thus it is possible that KD may influence human gut. Moreover, KD group showed an intestinal dysbiosis, highlighted by reduced biodiversity and richness in microbial populations. In addition, we found an altered ratio Firmicutes/Bacteroidetes, due to a significant decrease of Bacteroidetes phylum in KD group, consistent with the status of dysbiosis. This study was the first to evaluate the SCFA concentrations in relation with the consumption of a ketogenic dietary protocol; we found lower levels of SCFA in KD group compared to CTR, but also analyzing the same subjects before and after the diet. These data underline how KD is able to affect gut health by altering microbiota composition and its metabolic activity. This can mainly be due to reduction in carbohydrates content, and in bacterial genera able to do fermentation, like Fecalibaterum prausnitzii and Bacteroides. Both citotoxicity and genototixicy of fecal water analyzes have shown that ketogenic treatment does not adversely affect human colon mucosa, as the results indicated medium level of toxicity, comparable with levels found in other studies of healthy population. In conclusion, this study allow us to conclude that KD has an impact on the human gut, highlighting the need for further research to avoid long-term effects and optimize the therapy. Considering our findings, it may be reasonable to suggest a supplementation of probiotics/prebiotics to potentially restore the microbiota stability

Fracture behaviour of single crystal silicon microstructures

The fracture behaviour of single crystal silicon (SCSi) microstructures is analysed based on microme-chanical torsional and tensile experiments. The uniaxial testpieces are characterised by the presence of sharp not-ches at the gauge length extremities. The critical loading conditions are reproduced in a finite element model in order to identify the analogies of the failure conditions in tension and torsion. The stress field in the vicinity of the notch tip (were cracks originate) is analyzed, and fracture mechanics parameters are determined. In the finite element model a crack, reproducing the failure process observed in the experiments, is included. The crack area is incrementally increased and the energy release rate for the critical loading conditions in tension and torsion is calculated. Based on these results a failure criterion is formulated along with a procedure for the mechanical integrity analysis of SCSi microstructures of arbitrary shape and loading condition

Performance of a large limited streamer tube cell in drift mode

The performance of a large (3x3 $cm^2$) streamer tube cell in drift mode is shown. The detector space resolution has been studied using cosmic muons crossing an high precision silicon telescope. The experimental results are compared with a GARFIELD simulation.Comment: 18 pages, 7 figures. Accepted by Nucl. Instr. and Methods

Synthesis of 2-substituted-6-hydroxy and 6-methoxy benzothiazoles from 1,4-benzoquinone

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Triply green polyaniline: UV irradiation-induced synthesis of highly porous PANI/TiO2 composite and its application in dye removal

An environmentally benign procedure for the preparation of polyaniline/TiO2 composites is presented. The UV irradiation-induced synthesis leads to materials with good crystallinity and tailored morphology, showing promising sorption and recycle properties in dye removal tests. A reaction mechanism is proposed on the basis of LC-MS and FT-IR investigations

Polyaniline/TiO2 composites: green photocatalysic synthesis and application in wastewater remediation

In recent years, polyaniline (PANI) composites and nanocomposites with metal and metal-oxide materials have received growing attention for electrochemical and photoelectrochemical applications (Gu 2013). Among them, PANI/TiO2 composites are probably the most interesting systems due to synergistic effects between the conductive polymer and the oxide photocatalyst in terms of photogenerated charge separation and photocatalytic efficiency (Bae 2011). Moreover, polyaniline has been reported to possess favourable sorption properties, which can be exploited for pollutant remediation (Alcaraz-Espinoza 2015, Janaki 2012). PANI/TiO2 composites are thus promising candidates for wastewater treatment combining different pollutant remediation approaches. Polyaniline is classically synthesised via oxidative polymerization (Tran 2011), which involves noxious reagents (aniline and peroxydisulfates) and leads to toxic and carcinogenic byproducts (such as benzidine and trans-azobenzidine). In recent years, greener alternatives have been reported, such as a synthetic process starting from aniline dimer ((4-aminophenil)aniline) and using Fe3+ as catalyst and H2O2 as oxidant (Della Pina 2018). Unfortunately, this alternative procedure does not offer any control over the polymer morphology, leading to compact materials with low surface area and, as a consequence, poor dye-sorption capability. Very recently, we proposed a new photocatalytically induced green synthesis leading to stable polyaniline/TiO2 composites with porous morphology, wide surface area, high crystallinity and, most important, excellent dye removal performance and reusability (Cionti 2018). The reaction is carried out in two steps: at first, the aniline dimer is dissolved in a HCl aqueous solution and TiO2 is added while starting UV irradiation. In the second step, H2O2 is added in the dark, leading to the final product. In this work, we shed light on the photocatalytic nature of the synthetic mechanism, highlighting the different roles of TiO2 and of H2O2 on the composite structural and morphological features as well as on the composite performance for pollutant abatement. The reaction mechanism was investigated by a combination of spectrometric techniques, radical scavenger tests, and surface characterizations (Fig.1). By sampling the reaction mixture at different irradiation times, we demonstrated that under UV irradiation the growth of the oligomers occurs at the TiO2 particle surfaces. The same experiment carried out without UV irradiation showed the intrinsic photocatalytic nature of the process: in the dark, only short oligomers without appropriate chain conjugation were produced. However, even after prolonged UV irradiation, the final green product could be obtained only upon addition of H2O2, showing that, while oligomer formation is initiated by radicals produced by TiO2 photocatalysis, small amounts of an oxidant (H2O2) are still needed for the polymer chain growth. The role of the H2O2 amount proved to be especially crucial with respect to the composite properties. Increasing the H2O2 amount together with that of TiO2 led to composites with low surface area and reduced dye removal capability (Fig.2 a) due to a faster polymerization step. On the other hand, when only the photocatalyst amount was increased, neither the product morphology, nor its dye-removal ability were affected. This enables to increase the TiO2 content within the composite with the aim of enhancing its photocatalytic performance. In this respect, the composite stability was tested in water under prolonged UV irradiation, showing that the material optical, structural and morphological properties remained unchanged. The composite was tested towards the removal of anionic azo dyes in aqueous solution, evaluating the effect of the matrix composition and the composite reusability (Fig.2 b), showing promising results