662 research outputs found

    Using Optical Coherence Tomography to Reveal the Hidden History of The Landsdowne Virgin of the Yarnwinder by Leonardo da Vinci and Studio

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    Optical Coherence Tomography (OCT) was used for non-invasive examination of a well-known, yet complex, painting from the studio of Leonardo da Vinci in combination with routine imaging in various bands of electromagnetic radiation. In contrast with these techniques, OCT provides depth-resolved information. Three post-processing modalities were explored: cross-sectional views, maps of scattering from given depths, and their 3D models. Some hidden alterations of the painting due to past restorations were traced: retouching and overpainting with their positioning within varnish layers as well as indications of a former transfer to canvas

    The PPARÎł2 P12A polymorphism is not associated with all-cause mortality in patients with type 2 diabetes mellitus

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    The high mortality risk of patients with type 2 diabetes mellitus may well be explained by the several comorbidities and/or complications. Also the intrinsic genetic component predisposing to diabetes might have a role in shaping the risk of diabetes-related mortality. Among type 2 diabetes mellitus SNPs, rs1801282 is of particular interest because (i) it is harbored by peroxisome proliferator-activated receptor-γ2 (PPARγ2), which is the target for thiazolidinediones which are used as antidiabetic drugs, decreasing all-cause mortality in type 2 diabetes mellitus, and (ii) it is associated with insulin resistance and related traits, risk factors for overall mortality in type 2 diabetes mellitus. We investigated the role of PPARγ2 P12A, according to a dominant model (PA + AA vs. PP individuals) on incident all-cause mortality in three cohorts of type 2 diabetes mellitus, comprising a total of 1672 patients (462 deaths) and then performed a meta-analysis of ours and all available published data. In the three cohorts pooled and analyzed together, no association between PPARγ2 P12A and all-cause mortality was observed (HR 1.02, 95 % CI 0.79–1.33). Similar results were observed after adjusting for age, sex, smoking habits, and BMI (HR 1.09, 95 % CI 0.83–1.43). In a meta-analysis of ours and all studies previously published (n = 3241 individuals; 666 events), no association was observed between PPARγ2 P12A and all-cause mortality (HR 1.07, 95 % CI 0.85–1.33). Results from our individual samples as well as from our meta-analysis suggest that the PPARγ2 P12A does not significantly affect all-cause mortality in patients with type 2 diabetes mellitus

    Spectral imaging and archival data in analyzing the Madonna of the Rabbit painting by Manet and Titian

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    A concise insight into the outputs provided by the latest prototype of visible-near infrared (VIS-NIR) multispectral scanner (National Research Council-National Institute of Optics, CNR-INO, Italy) is presented. The analytical data acquired on an oil painting Madonna of the Rabbit by É. Manet are described. In this work, the VIS-NIR was complemented with X-ray fluorescence (XRF) mapping for the chemical and spatial characterization of several pigments. The spatially registered VIS-NIR data facilitated their processing by spectral correlation mapping (SCM) and artificial neural network (ANN) algorithm respectively for pigment mapping and improved visibility of pentimenti and of underdrawing style. The data provided several key elements for the comparison with a homonymous original work by Titian studied within the ARCHive LABoratory (ARCHLAB) transnational access project

    Round Robin Test on Microplastic Counting and Identification Method

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    The aim of this work is to verify the quality, robustness, and accuracy of a standard analytical protocol for the determination of microplastics in aqueous textile matrices. In order to reach this objective, a round robin scale identification and quantification test program was conducted. In particular, this chapter describes the round robin test, an interlaboratory comparison test on standard microfilament suspensions initiated in November 2021 by an expression of interest open call. In total, 18 laboratories expressed their interest, and 13 participants sent their results. Each of these laboratories received a set of 10 samples, accompanied by a protocol. The 10 samples consisted of three replicates per type of three different synthetic yarns and a control sample. The data required were the number of microplastics per sample recognized as fibers or particles, microplastic fiber lengths and diameters, and identification of the polymer using vibrational spectroscopy (ÎĽ-FTIR and/or ÎĽ-Raman). The data collected were statistically elaborated. The results highlighted that the laboratories had different recovery rates directly related to their specific procedures and equipment. Although there were issues related to the correct use of the standard method and to the behavior of operators, the method proved to be valid for the determination of microplastics in aqueous matrices

    Preparation and Analysis of Standard Microplastics

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    Over 14 million tons of microplastic have been accumulated in water resources and they are increasing yearly. About 8% of European microplastic released into the water are from synthetic textiles. This kind of microplastic is generally in the form of microfilaments. They have a higher potential to enter the food chain due to their size and shape. Although microfilaments generate great concern, no precise guidelines for their quantification and qualification are yet available. Thus, in this chapter, the origin of microfilaments is fully investigated. After that, a novel approach for identifying and counting microplastic with fiber shape is presented. An accurate method for preparing microfilament standard suspensions is described to facilitate lab tests and have a reliable methodology for monitoring microplastic pollution

    Optical techniques for the characetrization of surface-subsurface defects in painted layers

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    3D optical techniques are proven to be useful for the study of the artwork's surface morphology because they allow noncontact and noninvasive measurements. Detailed topographic analysis of the surface including a quantitative evaluation of defects related to the painting layers can be performed by means of holographic conoscopy on a micron scale. Moreover, artwork surfaces can be examined with suitable 2D optical techniques in the IR range to investigate defects at a subsurface level. In particular, thermography in the Mid-IR band 3-5 micron allows the detection and spatial mapping at a suitable resolution of the delamination of painted layers. An integrated model of the surface-subsurface defect distribution can be obtained by superimposing the results of the two above techniques, for a more effective analysis and monitoring of the delamination decay typology according to the specific case study. The delamination of organic paint layers from inorganic support is a decay that affects many wall paintings based on both traditional (oil and tempera) and synthetic media (acrylic and vinyl copolymers). Defining the factors that cause delamination, finding out strategies to restore the adhesion between paint layers and support, and monitoring the restoration intervention are fundamental conservation objectives. This paper investigates the feasibility of a joint use of holographic conoscopy and IR thermography for exploring the delamination decay typology of ad hoc laboratory samples. Set up includes a scanning micro-profilometer, and a thermal PtSi camera with a controlled IR source to provide heating stimulation

    Rubens' painting as inspiration of a later tapestry: non-invasive analyses provide insight into artworks history.

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    The 17th century painting Madonna della Cesta by Rubens and its presumed textile reproduction created by Févère for the House of Medici were analysed in comparison. A number of non-invasive optical techniques were applied with the aim to identify similarities and differences between tapestry and painting, in order to shed light on a possible link between their respective authors. The use of a multi-analytical approach proved effective for the acquisition of iconographic, morphological, structural, and compositional information for a comprehensive characterization of the two artworks. While serving as relevant support for documentation and conservation purposes, data so obtained also provide evidence of the uncanny resemblance between the two artworks, and specifically suggest the use by Févère of the same large-scale preparatory drawing (carton) realized by Rubens for his oil painting.Fil: Dal Fovo, Alicia. No especifíca;Fil: Striova, Jana. No especifíca;Fil: Pampaloni, Enrico. No especifíca;Fil: Fedeli, Ana María. Università della Calabria; ItaliaFil: Morita, María Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Ópticas. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones Ópticas. Universidad Nacional de La Plata. Centro de Investigaciones Ópticas; ArgentinaFil: Amaya Robayo, Dafne Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Ópticas. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones Ópticas. Universidad Nacional de La Plata. Centro de Investigaciones Ópticas; ArgentinaFil: Grazzi, Francesco. Centre National de la Recherche Scientifique; FranciaFil: Cimò, Marta. No especifíca;Fil: Cirrincione, Claudia. No especifíca;Fil: Fontana, Raffaella. No especifíca

    Scaling relations of metallicity, stellar mass, and star formation rate in metal-poor starbursts: I. A fundamental plane

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    Most galaxies follow well-defined scaling relations of metallicity (O/H), star formation rate (SFR), and stellar mass. However, low-metallicity starbursts, rare in the Local Universe but more common at high redshift, deviate significantly from these scaling relations. On the "main sequence" of star formation, these galaxies have high SFR for a given M*; and on the mass-metallicity relation, they have excess M* for their low metallicity. In this paper, we characterize O/H, M*, and SFR for these deviant "low-metallicity starbursts", selected from a sample of ~1100 galaxies, spanning almost two orders of magnitude in metal abundance, a factor of ~10^6 in SFR, and of ~10^5 in stellar mass. Our sample includes quiescent star-forming galaxies and blue compact dwarfs at redshift 0, luminous compact galaxies at redshift 0.3, and Lyman Break galaxies at redshifts 1-3.4. Applying a Principal Component Analysis (PCA) to the galaxies in our sample with M*<10^{10} Msun gives a Fundamental Plane (FP) of scaling relations; SFR and stellar mass define the plane itself, and O/H its thickness. The dispersion for our sample in the edge-on view of the plane is 0.17 dex, independently of redshift and including the metal-poor starbursts. The same FP is followed by 55100 galaxies selected from the Sloan Digital Sky Survey, with a dispersion of 0.06dex. In a companion paper, we develop multi-phase chemical evolution models that successfully predict the observed scaling relations and the FP; the deviations from the main scaling relations are caused by a different (starburst or "active") mode of star formation. These scaling relations do not truly evolve, but rather are defined by the different galaxy populations dominant at different cosmological epochs.Comment: 14 pages, 7 figures, accepted for publication by MNRA
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