1,137 research outputs found

    Star-related lipid transfer protein 10 (STARD10): a novel key player in alcohol-induced breast cancer progression

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    Ethanol abuse promotes breast cancer development, metastasis and recurrence stimulating mammary tumorigenesis by mechanisms that remain unclear. Normally, 35% of breast cancer is receptor tyrosine-protein kinase (ERBB2)-positive that predisposes to poor prognosis and relapse, while ethanol drinking leads to invasion of their positive cells triggering the phosphorylation status of mitogen-activated protein kinase. StAR-related lipid transfer protein 10 (STARD10) is a lipid transporter of phosphatidylcholine and phosphatidylethanolamine; their changes on membrane composition occur before the morphological tumorigenic events. Interestingly, STARD10 has been described to be highly expressed in 35-40% of ERBB2-positive breast cancers. In this study, we demonstrate that ethanol administration promotes STARD10 and ERBB2 expression that is significantly associated with increased cell malignancy and aggressiveness. Consistently, ERBB2 overexpression causes an increase in STARD10 expression, while overexpression of ERBB2’s downstream targets, p65, c-MYC, c-FOS or c-JUN induces STARD10 promoter activity, correlative of enhanced ERBB2 function STARD10-mediated cellular membrane fluidity and intracellular calcium concentration impacts ERBB2 signaling pathway as evaluated by enhancedp65 nuclear translocation and binding to both ERBB2 and STARD10 promoters. Basically, we proved that STARD10 and ERBB2 positively regulate each other’s expression and function. Taken together, our data demonstrate that ethanol can modulate ERBB2’s function in breast cancer via a novel interplay with STARD10

    The cGAS Paradox:Contrasting Roles for cGAS-STING Pathway in Chromosomal Instability

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    Chromosomal instability (CIN) is an intricate phenomenon that is often found in human cancer, characterized by persisting errors in chromosome segregation. This ongoing chromosome mis-segregation results in structural and numerical chromosomal abnormalities that have been widely described to promote tumor evolution. In addition to being a driver of tumor evolution, recent evidence demonstrates CIN to be the central node of the crosstalk between a tumor and its surrounding microenvironment, as mediated by the cGAS-STING pathway. The role that cGAS-STING signaling exerts on CIN tumors is both complex and paradoxical. On one hand, the cGAS-STING axis promotes the clearance of CIN tumors through recruitment of immune cells, thus suppressing tumor progression. On the other hand, the cGAS-STING pathway has been described to be the major regulator in the promotion of metastasis of CIN tumors. Here, we review this dual role of the cGAS-STING pathway in the context of chromosomal instability and discuss the potential therapeutic implications of cGAS-STING signaling for targeting CIN tumors

    Localized Polycentric Orbital Basis Set for Quantum Monte Carlo Calculations Derived from the Decomposition of Kohn-Sham Optimized Orbitals

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    In this work, we present a simple decomposition scheme of the Kohn-Sham optimized orbitals which is able to provide a reduced basis set, made of localized polycentric orbitals, specifically designed for Quantum Monte Carlo. The decomposition follows a standard Density functional theory (DFT) calculation and is based on atomic connectivity and shell structure. The new orbitals are used to construct a compact correlated wave function of the Slater–Jastrow form which is optimized at the Variational Monte Carlo level and then used as the trial wave function for a final Diffusion Monte Carlo accurate energy calculation. We are able, in this way, to capture the basic information on the real system brought by the Kohn-Sham orbitals and use it for the calculation of the ground state energy within a strictly variational method. Here, we show test calculations performed on some small selected systems to assess the validity of the proposed approach in a molecular fragmentation, in the calculation of a barrier height of a chemical reaction and in the determination of intermolecular potentials. The final Diffusion Monte Carlo energies are in very good agreement with the best literature data within chemical accuracy

    Thermoelasticity of Fe2+-bearing bridgmanite

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    We present LDA+U calculations of high temperature elastic properties of bridgmanite with composition (Mg(1−x)_{(1-x)}Fex2+_{x}^{2+})SiO3_3 for 0≤x≤0.1250\le{x}\le0.125. Results of elastic moduli and acoustic velocities for the Mg-end member (x=0) agree very well with the latest high pressure and high temperature experimental measurements. In the iron-bearing system, we focus particularly on the change in thermoelastic parameters across the state change that occurs in ferrous iron above ∼\sim30 GPa, often attributed to a high-spin (HS) to intermediate spin (IS) crossover but explained by first principles calculations as a lateral displacement of substitutional iron in the perovskite cage. We show that the measured effect of this change on the equation of state of this system can be explained by the lateral displacement of substitutional iron, not by the HS to IS crossover. The calculated elastic properties of (Mg0.875_{0.875}Fe0.1252+_{0.125}^{2+})SiO3_3 along an adiabatic mantle geotherm, somewhat overestimate longitudinal velocities but produce densities and shear velocities quite consistent with Preliminary Reference Earth Model data throughout most of the lower mantle.Comment: Accepted for Geophysical Research Letters (DOI: 10.1002/2014GL062888

    Energy Management and Control System Design of an Integrated Flywheel Energy Storage System for Residential Users

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    This paper presents the energy management and control system design of an integrated flywheel energy storage system (FESS) for residential users. The proposed FESS is able to draw/deliver 8 kWh at 8 kW, and relies on a large-airgap surface-mounted permanent magnet synchronous machine, the inner rotor of which integrates a carbon-fiber flywheel, leading to a compact and efficient FESS. The proposed energy management system is based on four different operating modes, which are defined and can be selected in accordance with FESS speed and/or user’s preference, while FESS control system is devoted to power/current tracking at both machine- and grid-side converters. The effectiveness of the proposed solutions, as well as the overall energy performance of the proposed FESS, are verified by real-time simulations, which regard different operating conditions and/or realistic scenarios

    Integration of Sodium Metal Halide Energy Storage Systems in Telecommunication Microgrids: Performance Analysis of DC-DC Converter Topologies

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    The present paper proposes an integrated method for modelling and designing Energy Storage Systems (ESSs) based on Sodium Metal Halide Batteries (SMHBs). The implementation of the proposed methodology for designing an SMHB-ESS used for supporting telecommunication DC microgrids is presented. The motivation concerning this specific case study is the role assumed by battery technology in improving the reliability and robustness of telecommunication DC microgrids. In this context, the SMHBs, due to their operative temperature, dynamic power response and robustness against cell breakdown, represent one of the most suitable technologies, mainly when challenging environmental conditions occur. The motivation for implementing an integrated design approach is the non-linear behaviour of SMHBs, which requires a high accuracy in battery modelling and in managing DC-DC interfacing for full SMHB capacity exploitation. To highlight the advantages of this novel approach, a comparison between the SMHB- ESS designs considering, as the DC-DC converter, a buck–boost topology actually implemented in the commercial systems and a Dual-Active-Bridge (DAB) converter, specifically developed for this kind of battery, was investigated. Considering different operating conditions in a specific DC telecommunication microgrid, the designed configurations of SMHB ESSs were simulated. Finally, a comparison of simulation results is presented and discussed, highlighting that DABs, despite their greater complexity compared to buck–boost converters, present advantages in terms of flexibility, dynamic performances and efficiency, increasing the available SMHB capacity by 10%

    Magnetic Energy Landscape of Dimolybdenum Tetraacetate on a Bulk Insulator Surface

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    The magnetic states and the magnetic anisotropy barrier of a transition metal molecular complex, dimolybdenum tetraacetate, are investigated via density functional theory (DFT). Calculations are performed in the gas phase and on a calcite (10.4) bulk insulating surface, using the Generalized-Gradient Approximation (GGA)-PBE and the Hubbard-corrected DFT + U and DFT + U + V functionals. The molecular complex (denoted MoMo) contains two central metallic molybdenum atoms, embedded in a square cage of acetate groups. Recently, MoMo was observed to form locally regular networks of immobile molecules on calcite (10.4), at room conditions. As this is the first example of a metal-coordinated molecule strongly anchored to an insulator surface at room temperature, we explore here its magnetic properties with the aim to understand whether the system could be assigned features of a single molecule magnet (SMM) and could represent the basis to realize stable magnetic networks on insulators. After an introductory review on SMMs, we show that, while the uncorrected GGA-PBE functional stabilizes MoMo in a nonmagnetic state, the DFT + U and DFT + U + V approaches stabilize an antiferromagnetic ground state and several meta-stable ferromagnetic and ferrimagnetic states. Importantly, the energy landscape of magnetic states remains almost unaltered on the insulating surface. Finally, via a noncollinear magnetic formalism and a newly introduced algorithm, we calculate the magnetic anisotropy barrier, whose value indicates the stability of the molecule’s magnetic moment

    Methods for Evaluating the Effectiveness of Home Oral Hygiene Measures—A Narrative Review of Dental Biofilm Indices

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    Dental plaque is a biofilm structured in an extracellular matrix of polymers of host and microbial origin; the microorganisms can coexist in harmony with the host, thus guarantying oral health. Environmental modifications can lead to dysbiosis and onset of oral diseases; in fact, plaque is the etiological agent both of periodontal disease and dental decay. The use of an effective oral hygiene index should be considered as a relevant goal for the clinicians and the researchers, and consequently, numerous plaque indices have been proposed during the years. The present literature review aims primarily to obtain a complete summary of these scores to assess plaque deposits. It is useful because the clinician/researcher will select the right scoring method for the specific situation only if he knows the available options and if he is aware of both their strengths and weaknesses. This review applies a basic classification of plaque indices that distinguishes the ones that use non-quantitative methods from the ones that use quantitative methods. Non-quantitative methods are more subjective because they are based on the ability of the clinician to point out the presence or the entity of deposits, while quantitative methods introduce objectifiable means to measure plaque deposits

    Design of a High-Speed Ferrite-based Brushless DC Machine for Electric Vehicles

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    In the present paper an analytic procedure for the preliminary design of a High-Speed ferrite-based Brushless DC Machine (HS-BLDC) has been proposed. In particular, mechanical and electromagnetic modeling have been developed in order to take into account their mutual influence in the definition of the geometry of the electrical machine. In addition, suitable design targets have been imposed in accordance with electric vehicle application requirements. Hence, several mechanical and electromagnetic constraints have been introduced in order to comply with high-speed operation, preventing demagnetization issues of ferrite magnets as well. Subsequently, an HS-BLDC characterized by an inner rotor configuration has been designed in accordance with the proposed methodology. The analytical procedure and the corresponding results have been reported and validated by means of Finite Element Analyses (FEAs), highlighting the effectiveness of the proposed configuration and design solutions
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