26 research outputs found

    Dimensions and refractive index estimates of deeply buried optical waveguides in Lithium Fluoride

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    A recursive procedure is applied to the measured near-field profiles of buried optical waveguides recorded in a lithium fluoride (LiF) crystal by femtosecond laser pulses in order to estimate the core dimensions and the refractive index increase. Albeit the waveguides transversal section geometry is quite complex it is possible to obtain the horizontal and vertical widths and the average refractive index maximum increase assuming a simplified rectangular transversal section in the simulation. The procedure is validated by comparing the simulated results with the experimental near-field profiles and the maximum refractive index values of two commercial optical fibers. Typical dimensions of ~(8x10)µm² and refractive index changes of ~(2-10)x10-4 were obtained for the LiF waveguides at several wavelengths

    Confocal fluorescence microscopy and confocal raman microspectroscopy of X-ray irradiated LIF crystals

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    Radiation-induced color centers locally produced in lithium fluoride (LiF) are successfully used for radiation detectors. LiF detectors for extreme ultraviolet radiation, soft and hard X-rays, based on photoluminescence from aggregate electronic defects, are currently under development for imaging applications with laboratory radiation sources, as well as large-scale facilities. Among the peculiarities of LiF-based detectors, noteworthy ones are their very high intrinsic spatial resolution across a large field of view, wide dynamic range, and versatility. LiF crystals irradiated with a monochromatic 8 keV X-ray beam at KIT synchrotron light source (Karlsruhe, Germany) and with the broadband white beam spectrum of the synchrotron bending magnet have been investigated by optical spectroscopy, laser scanning confocal microscopy in fluorescence mode, and confocal Raman micro-spectroscopy. The 3D reconstruction of the distributions of the color centers induced by the X-rays has been performed with both confocal techniques. The combination of the LiF crystal capability to register volumetric X-ray mapping with the optical sectioning operations of the confocal techniques has allowed performing 3D reconstructions of the X-ray colored volumes and it could provide advanced tools for 3D X-ray detection

    Paraoxonase Activity and Genotype Predispose to Successful Aging

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    The paraoxonase 1 codon 192 R allele has been previously reported to have a role in successful aging. The relationship between PON1 genotypes, enzymatic activity, and mass concentration was evaluated in a group of 229 participants from 22 to 104 years of age, focusing our attention on nonagenarian/centenarian participants. We found a genetic control for paraoxonase activity that is maintained throughout life, also in the nonagenarians/centenarians. This activity decreases significantly during aging and shows different mean values among R and M carriers, where R+ and M− carriers have the significant highest paraoxonase activity. Results from the multinomial regression logistic model show that paraoxonase activity as well as R+ and M− carriers contribute significantly to the explanation of the longevity phenotype. In conclusion, we show that genetic variability at the PON1 locus is related to paraoxonase activity throughout life, and suggest that both parameters affect survival at extreme advanced ag

    Shadow monochromatic backlighting: Large-field high resolution X-ray shadowgraphy with improved spectral tunability

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    The shadow monochromatic backlighting (SMB) scheme, a modification of the well-known soft X-ray monochromatic backlighting scheme, is proposed. It is based on a spherical crystal as the dispersive element and extends the traditional scheme by allowing one to work with a wide range of Bragg angles and thus in a wide spectral range. The advantages of the new scheme are demonstrated experimentally and supported numerically by ray-tracing simulations. In the experiments, the X-ray backlighter source is a laser-produced plasma, created by the interaction of an ultrashort pulse, Ti:Sapphire laser (120 fs, 3–5 mJ, 1016 W/cm2 on target) or a short wavelength XeCl laser (10 ns, 1–2 J, 1013 W/cm2 on target) with various solid targets (Dy, Ni + Cr, BaF2). In both experiments, the X-ray sources are well localized spatially (∼20 μm) and are spectrally tunable in a relatively wide wavelength range (λ = 8–15 Å). High quality monochromatic (δλ/λ ∼ 10−5–10−3) images with high spatial resolution (up to ∼4 μm) over a large field of view (a few square millimeters) were obtained. Utilization of spherically bent crystals to obtain high-resolution, large field, monochromatic images in a wide range of Bragg angles (35° < Θ < 90°) is demonstrated for the first time

    NMR-Based Metabolomic Approach Tracks Potential Serum Biomarkers of Disease Progression in Patients with Type 2 Diabetes Mellitus

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    Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by chronic hyperglycemia associated with alterations in carbohydrate, lipid, and protein metabolism. The prognosis of T2DM patients is highly dependent on the development of complications, and therefore the identification of biomarkers of T2DM progression, with minimally invasive techniques, is a huge need. In the present study, we applied a H-1-Nuclear Magnetic Resonance (H-1-NMR)-based metabolomic approach coupled with multivariate data analysis to identify serum metabolite profiles associated with T2DM development and progression. To perform this, we compared the serum metabolome of non-diabetic subjects, treatment-naive non-complicated T2DM patients, and T2DM patients with complications in insulin monotherapy. Our analysis revealed a significant reduction of alanine, glutamine, glutamate, leucine, lysine, methionine, tyrosine, and phenylalanine in T2DM patients with respect to non-diabetic subjects. Moreover, isoleucine, leucine, lysine, tyrosine, and valine levels distinguished complicated patients from patients without complications. Overall, the metabolic pathway analysis suggested that branched-chain amino acid (BCAA) metabolism is significantly compromised in T2DM patients with complications, while perturbation in the metabolism of gluconeogenic amino acids other than BCAAs characterizes both early and advanced T2DM stages. In conclusion, we identified a metabolic serum signature associated with T2DM stages. These data could be integrated with clinical characteristics to build a composite T2DM/complications risk score to be validated in a prospective cohort

    Circulating miR-320b and miR-483-5p levels are associated with COVID-19 in-hospital mortality

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    none28noThe stratification of mortality risk in COVID-19 patients remains extremely challenging for physicians, especially in older patients. Innovative minimally invasive molecular biomarkers are needed to improve the prediction of mortality risk and better customize patient management. In this study, aimed at identifying circulating miRNAs associated with the risk of COVID-19 in-hospital mortality, we analyzed serum samples of 12 COVID-19 patients by small RNA-seq and validated the findings in an independent cohort of 116 COVID-19 patients by qRT-PCR. Thirty-four significantly deregulated miRNAs, 25 downregulated and 9 upregulated in deceased COVID-19 patients compared to survivors, were identified in the discovery cohort. Based on the highest fold-changes and on the highest expression levels, 5 of these 34 miRNAs were selected for the analysis in the validation cohort. MiR-320b and miR-483-5p were confirmed to be significantly hyper-expressed in deceased patients compared to survived ones. Kaplan-Meier and Cox regression models, adjusted for relevant confounders, confirmed that patients with the 20% highest miR-320b and miR-483-5p serum levels had three-fold increased risk to die during in-hospital stay for COVID-19. In conclusion, high levels of circulating miR-320b and miR-483-5p can be useful as minimally invasive biomarkers to stratify older COVID-19 patients with an increased risk of in-hospital mortality.restrictedGiuliani, Angelica; Matacchione, Giulia; Ramini, Deborah; Di Rosa, Mirko; Bonfigli, Anna Rita; Sabbatinelli, Jacopo; Monsurrò, Vladia; Recchioni, Rina; Marcheselli, Fiorella; Marchegiani, Francesca; Piacenza, Francesco; Cardelli, Maurizio; Galeazzi, Roberta; Pomponio, Giovanni; Ferrarini, Alessia; Gabrielli, Armando; Baroni, Silvia Svegliati; Moretti, Marco; Sarzani, Riccardo; Giordano, Piero; Cherubini, Antonio; Corsonello, Andrea; Antonicelli, Roberto; Procopio, Antonio Domenico; Ferracin, Manuela; Bonafè, Massimiliano; Lattanzio, Fabrizia; Olivieri, FabiolaGiuliani, Angelica; Matacchione, Giulia; Ramini, Deborah; Di Rosa, Mirko; Bonfigli, Anna Rita; Sabbatinelli, Jacopo; Monsurrò, Vladia; Recchioni, Rina; Marcheselli, Fiorella; Marchegiani, Francesca; Piacenza, Francesco; Cardelli, Maurizio; Galeazzi, Roberta; Pomponio, Giovanni; Ferrarini, Alessia; Gabrielli, Armando; Baroni, Silvia Svegliati; Moretti, Marco; Sarzani, Riccardo; Giordano, Piero; Cherubini, Antonio; Corsonello, Andrea; Antonicelli, Roberto; Procopio, Antonio Domenico; Ferracin, Manuela; Bonafè, Massimiliano; Lattanzio, Fabrizia; Olivieri, Fabiol

    Mitochondrial DNA Backgrounds Might Modulate Diabetes Complications Rather than T2DM as a Whole

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    Mitochondrial dysfunction has been implicated in rare and common forms of type 2 diabetes (T2DM). Additionally, rare mitochondrial DNA (mtDNA) mutations have been shown to be causal for T2DM pathogenesis. So far, many studies have investigated the possibility that mtDNA variation might affect the risk of T2DM, however, when found, haplogroup association has been rarely replicated, even in related populations, possibly due to an inadequate level of haplogroup resolution. Effects of mtDNA variation on diabetes complications have also been proposed. However, additional studies evaluating the mitochondrial role on both T2DM and related complications are badly needed. To test the hypothesis of a mitochondrial genome effect on diabetes and its complications, we genotyped the mtDNAs of 466 T2DM patients and 438 controls from a regional population of central Italy (Marche). Based on the most updated mtDNA phylogeny, all 904 samples were classified into 57 different mitochondrial sub-haplogroups, thus reaching an unprecedented level of resolution. We then evaluated whether the susceptibility of developing T2DM or its complications differed among the identified haplogroups, considering also the potential effects of phenotypical and clinical variables. MtDNA backgrounds, even when based on a refined haplogroup classification, do not appear to play a role in developing T2DM despite a possible protective effect for the common European haplogroup H1, which harbors the G3010A transition in the MTRNR2 gene. In contrast, our data indicate that different mitochondrial haplogroups are significantly associated with an increased risk of specific diabetes complications: H (the most frequent European haplogroup) with retinopathy, H3 with neuropathy, U3 with nephropathy, and V with renal failure

    Energy, comfort and environmental assessment of different building envelope techniques in a Mediterranean climate with a hot dry summer

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    The EU regulations on energy saving have been implemented in Italy with the adoption of the North-European super-insulated model that led to the construction of buildings not much related to their climatic context. The European Directives 2010/31/EU and 2012/27/EU highlighted the importance to consider the specific climate but the development of a technical culture suitable for a temperate climate stillremains an open question. The aim of the paper is to quantify the effect on energy consumptions, comfort levels, environmental sustainability of the adoption of 3 energy efficient envelopes recently introduced in Mediterranean area and characterized by different thermal inertia (masonry, wood–cement, wood). In order to achieve this goal, a multidisciplinary approach was adopted involving: the study of the energy performance in winter and summer using analytical models both in semi-stationary and dynamic conditions (Termo and EnergyPlus programs) and the detailed analysis of thermal bridges (Therm software); the analysis of the annual comfort through dynamic analysis with Fanger’s PMV and adaptive comfort models; the quantification of environmental–economic impacts through LCA analysis (SimaPro software) with Eco-indicator 99, CED, EPS 2000 and IPCC 2001 GWP methods and LCC considering financial and environmental costs. The results made it possible to stress the differences between the various adopted methods and demonstrate that in such energy efficient envelopes the thermal mass has low influence on energy saving while it has a great effect on comfort levels and environmental burdens, with a conflicting incidence on these two aspects

    Evaluating the Conservation State of Naturally Aged Paper with Raman and Luminescence Spectral Mapping: Toward a Non-Destructive Diagnostic Protocol

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    Micro-Raman and luminescence spectroscopy were combined with morphological analysis to study the conservation state of differently degraded paper samples, dated from 1873 to 2021. The aim of the work reported in this paper was to obtain ageing markers based on variations of Raman and fluorescence spectral features. Raman and luminescence spectra were acquired by scanning non-printed areas of books, and Raman and fluorescence maps were built by contrasting spectral parameters point by point, obtaining a micron-scale space resolved imaging of the degradation pattern. Complementary information on paper morphology and surface compactness were obtained by high-resolution scanning electron and atomic force microscopy. The proposed non-destructive procedure is particularly interesting for precious and ancient samples to analyze their degradation processes and to evaluate the performance and effectiveness of restoration treatments
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