514 research outputs found

    The Gasotransmitter Hydrogen Sulfide (H<sub>2</sub>S) Prevents Pathologic Calcification (PC) in Cartilage.

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    Pathologic calcification (PC) is a painful and disabling condition whereby calcium-containing crystals deposit in tissues that do not physiologically calcify: cartilage, tendons, muscle, vessels and skin. In cartilage, compression and inflammation triggered by PC leads to cartilage degradation typical of osteoarthritis (OA). The PC process is poorly understood and treatments able to target the underlying mechanisms of the disease are lacking. Here we show a crucial role of the gasotransmitter hydrogen sulfide (H &lt;sub&gt;2&lt;/sub&gt; S) and, in particular, of the H &lt;sub&gt;2&lt;/sub&gt; S-producing enzyme cystathionine γ-lyase (CSE), in regulating PC in cartilage. Cse deficiency (Cse KO mice) exacerbated calcification in both surgically-induced (menisectomy) and spontaneous (aging) murine models of cartilage PC, and augmented PC was closely associated with cartilage degradation (OA). On the contrary, Cse overexpression (Cse tg mice) protected from these features. In vitro, Cse KO chondrocytes showed increased calcification, potentially via enhanced alkaline phosphatase (Alpl) expression and activity and increased IL-6 production. The opposite results were obtained in Cse tg chondrocytes. In cartilage samples from patients with OA, CSE expression inversely correlated with the degree of tissue calcification and disease severity. Increased cartilage degradation in murine and human tissues lacking or expressing low CSE levels may be accounted for by dysregulated catabolism. We found higher levels of matrix-degrading metalloproteases Mmp-3 and -13 in Cse KO chondrocytes, whereas the opposite results were obtained in Cse tg cells. Finally, by high-throughput screening, we identified a novel small molecule CSE positive allosteric modulator (PAM), and demonstrated that it was able to increase cellular H &lt;sub&gt;2&lt;/sub&gt; S production, and decrease murine and human chondrocyte calcification and IL-6 secretion. Together, these data implicate impaired CSE-dependent H &lt;sub&gt;2&lt;/sub&gt; S production by chondrocytes in the etiology of cartilage PC and worsening of secondary outcomes (OA). In this context, enhancing CSE expression and/or activity in chondrocytes could represent a potential strategy to inhibit PC

    Tuning morphology and magnetism in epitaxial L10-FePt films

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    In this work, well-ordered epitaxial FePt thin ¿lms have been grown by RF sputtering on two different substrates (MgO (100) and SrTiO3 (100)) and the effect of different lattice parameters between the substrate and FePt ¿lm on morphology and magnetic behavior has been considered. Growth conditions have been optimized to obtain different morphologies and magnetic behaviors

    The protective role of the 3-mercaptopyruvate sulfurtransferase (3-MST)-hydrogen sulfide (H<sub>2</sub>S) pathway against experimental osteoarthritis.

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    Osteoarthritis (OA) is characterized by the formation and deposition of calcium-containing crystals in joint tissues, but the underlying mechanisms are poorly understood. The gasotransmitter hydrogen sulfide (H &lt;sub&gt;2&lt;/sub&gt; S) has been implicated in mineralization but has never been studied in OA. Here, we investigated the role of the H &lt;sub&gt;2&lt;/sub&gt; S-producing enzyme 3-mercaptopyruvate sulfurtransferase (3-MST) in cartilage calcification and OA development. 3-MST expression was analyzed in cartilage from patients with different OA degrees, and in cartilage stimulated with hydroxyapatite (HA) crystals. The modulation of 3-MST expression in vivo was studied in the meniscectomy (MNX) model of murine OA, by comparing sham-operated to MNX knee cartilage. The role of 3-MST was investigated by quantifying joint calcification and cartilage degradation in WT and 3-MST &lt;sup&gt;-/-&lt;/sup&gt; meniscectomized knees. Chondrocyte mineralization in vitro was measured in WT and 3-MST &lt;sup&gt;-/-&lt;/sup&gt; cells. Finally, the effect of oxidative stress on 3-MST expression and chondrocyte mineralization was investigated. 3-MST expression in human cartilage negatively correlated with calcification and OA severity, and diminished upon HA stimulation. In accordance, cartilage from menisectomized OA knees revealed decreased 3-MST if compared to sham-operated healthy knees. Moreover, 3-MST &lt;sup&gt;-/-&lt;/sup&gt; mice showed exacerbated joint calcification and OA severity if compared to WT mice. In vitro, genetic or pharmacologic inhibition of 3-MST in chondrocytes resulted in enhanced mineralization and IL-6 secretion. Finally, oxidative stress decreased 3-MST expression and increased chondrocyte mineralization, maybe via induction of pro-mineralizing genes. 3-MST-generated H &lt;sub&gt;2&lt;/sub&gt; S protects against joint calcification and experimental OA. Enhancing H &lt;sub&gt;2&lt;/sub&gt; S production in chondrocytes may represent a potential disease modifier to treat OA

    Critical Strain Region Evaluation of Self-Assembled Semiconductor Quantum Dots

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    A novel peak finding method to map the strain from high resolution transmission electron micrographs, known as the Peak Pairs method, has been applied to In(Ga) As/AlGaAs quantum dot (QD) samples, which present stacking faults emerging from the QD edges. Moreover, strain distribution has been simulated by the finite element method applying the elastic theory on a 3D QD model. The agreement existing between determined and simulated strain values reveals that these techniques are consistent enough to qualitatively characterize the strain distribution of nanostructured materials. The correct application of both methods allows the localization of critical strain zones in semiconductor QDs, predicting the nucleation of defects, and being a very useful tool for the design of semiconductor device

    Correction to: New eco-friendly low-cost binders for Li-ion anodes

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    The article New eco-friendly low-cost binders for Li-ion anodes, written by D. Versaci, R. Nasi, U. Zubair, J. Amici, M. Sgroi, M. A. Dumitrescu, C. Francia, S. Bodoardo and N. Penazzi, was originally published electronically on the publisher's internet portal (currently SpringerLink)

    Tungsten oxide nanowires grown on amorphous-like tungsten films

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    Tungsten oxide nanowires have been synthesized by vacuum annealing in the range 500-710 °C from amorphous-like tungsten films, deposited on a Si(100) substrate by pulsed laser deposition (PLD) in the presence of a He background pressure. The oxygen required for the nanowires formation is already adsorbed in the W matrix before annealing, its amount depending on deposition parameters. Nanowire crystalline phase and stoichiometry depend on annealing temperature, ranging from W18O49-Magneli phase to monoclinic WO3. Sufficiently long annealing induces the formation of micrometer-long nanowires, up to 3.6 μm with an aspect ratio up to 90. Oxide nanowire growth appears to be triggered by the crystallization of the underlying amorphous W film, promoting their synthesis at low temperatures

    Validation of an adapted Italian-language version of the Sociocultural Attitudes Toward Appearance Questionnaire-3 (SATAQ-3), within a female population: the Sociocultural Attitudes Toward Appearance Questionnaire - Social Media (SATAQ-SM)

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    Sociocultural Attitudes Towards Appearance Questionnaire-Social Media (SATAQ-SM) is a self-administered questionnaire for the evaluation of social media pressure and internalization of beauty standards. This study aims to validate the SATAQ-SM an adapted Italian version of the Sociocultural Attitudes Towards Appearance Questionnaire third version (SATAQ-3). Confirmatory factor analysis was used to investigate whether the empirical data fitted the four-factor structure of SATAQ-3. Assessment of goodness-of-fit was based on standard model fit criteria: relative chi(2) value (chi(2)/df), Root Mean-Squared Error of Approximation (RMSEA), Comparative Fit Index (CFI) and Tucker-Lewis Index (TLI). Internal consistency was assessed using McDonald's omega. Criterion validity was calculated by correlating the SATAQ-SM factors scores with the total score of the Rosenberg self-esteem scale (RSES) and Eating Attitudes Test (EAT-26). Four-hundred and eighty-five females agreed to participate in the study. The four-factor model appears to be confirmed by the fit indices: chi(2)/df = 3.73, RMSEA = 0.07, CFI = 0.99 and TLI = 0.99. All the items defining the four factors had a factor loading of &gt;= 0.40. McDonald's omega of the entire questionnaire was equal to 0.95 and for the four subscales it did not assume values lower than 0.81. The correlations between the factor score of SATAQ-SM and the RSES were all negative and statistically relevant (p &lt; 0.001); the correlations between the scores of the SATAQ-SM subscales and the total score of the EAT-26 are all positive and statistically significant. SATAQ-SM demonstrated good psychometric properties to assess the influence of social media on body image perception related to social media

    Testing intermediate-age stellar evolution models with VLT photometry of LMC clusters. I. The data

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    This is the first of a series of three papers devoted to the calibration of a few parameters of crucial importance in the modeling of the evolution of intermediate-mass stars, with special attention to the amount of convective core overshoot. To this end we acquired deep V and R photometry for three globular clusters of the Large Magellanic Cloud (LMC), namely NGC 2173, SL 556 and NGC 2155, in the age interval 1-3 Gyr. In this first paper, we describe the aim of the project, the VLT observations and data reduction, and we make preliminary comparisons of the color-magnitude diagrams with both Padova and Yonsei-Yale isochrones. Two following papers in this series present the results of a detailed analysis of these data, independently carried out by members of the Yale and Padova stellar evolution groups. This allows us to compare both sets of models and discuss their main differences, as well as the systematic effects that they would have to the determination of the ages and metallicities of intermediate-age single stellar populations.Comment: 27 pages with 10 figures. Accepted by the Astronomical Journa
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