569 research outputs found

    Cyclic Lorentzian Lie Groups

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    We consider Lie groups equipped with a left-invariant cyclic Lorentzian metric. As in the Riemannian case, in terms of homogeneous structures, such metrics can be considered as different as possible from bi-invariant metrics. We show that several results concerning cyclic Riemannian metrics do not extend to their Lorentzian analogues, and obtain a full classification of three- and four-dimensional cyclic Lorentzian metrics

    The histone deacetylase inhibitor ITF2357 targets oncogenic BRAF in human melanoma cells

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    ITF2357 (Givinostat) is a potent antineoplastic histone deacetylase inhibitor which is currently used in clinical trials for leukemias and myelomas and in the therapy for systemic juvenile idiopathic arthritis. Here evidence is provided that ITF2357 reduces the viability of human melanoma SK-Mel28 cells thereby inducing cell death. This compound was more efficacious than SAHA, another well known HDAC inhibitor belonging to the same class of hydroxamic acids. Moreover, we demonstrated for the first time that ITF2357 determines in SK-Mel28 cells a remarkable reduction in the level of oncogenic B-Raf, the product of the BRAF V600E mutated gene in melanoma. Western blot analysis showed that the decrease of oncogenic B-Raf induced by ITF2357 is dose and time dependent. This effect was accompanied with a decrease in the level of phosho-ERK confirming the blockage of the B-Raf mitogenic pathway. To potentiate the inhibition of this pathway, the MEK inhibitor UO126 was used in combination with ITF2357. The results indicated that this compound increases the effect of ITF2357 on cell death. Intriguingly, UO126 not only reduced ERK phosphorylation, as a confirmation of MEK inhibition, but also consistently reduced the level of B-Raf when combined with ITF2357. These preliminary results suggest that ITF2357, either alone or in combination with UO126, can be considered a good candidate in melanoma targeted therapy and ongoing studies will further clarify the mechanism of oncogenic B-Raf inhibition

    On the symmetries of Siklos spacetimes

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    We consider the large class of Siklos spacetimes and investigate their relevant symmetries (homothetic and affine vector fields, Ricci, curvature, Weyl and matter collineations). We prove some general results and obtain complete classifications for homogeneous Siklos spacetimes

    Three-dimensional curvature homogeneous hypersurfaces

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    summary:This paper is motivated by the open problem whether a three-dimensional curvature homogeneous hypersurface of a real space form is locally homogeneous or not. We give some partial positive answers

    Litchi chinensis as a Functional Food and a Source of Antitumor Compounds: An Overview and a Description of Biochemical Pathways

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    Litchi is a tasty fruit that is commercially grown for food consumption and nutritional benefits in various parts of the world. Due to its biological activities, the fruit is becoming increasingly known and deserves attention not only for its edible part, the pulp, but also for its peel and seed that contain beneficial substances with antioxidant, cancer preventive, antimicrobial, and anti-inflammatory functions. Although literature demonstrates the biological activity of Litchi components in reducing tumor cell viability in in vitro or in vivo models, data about the biochemical mechanisms responsible for these effects are quite fragmentary. This review specifically describes, in a comprehensive analysis, the antitumor properties of the different parts of Litchi and highlights the main biochemical mechanisms involved

    Multifaceted Health Benefits of Mangifera indica L. (Mango): The Inestimable Value of Orchards Recently Planted in Sicilian Rural Areas

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    Historically, Mangifera indica L. cultivations have been widely planted in tropical areas of India, Africa, Asia, and Central America. However, at least 20 years ago its spreading allowed the development of some cultivars in Sicily, an island to the south of Italy, where the favourable subtropical climate and adapted soils represent the perfect field to create new sources of production for the Sicilian agricultural supply chain. Currently, cultivations of Kensington Pride, Keitt, Glenn, Maya, and Tommy Atkins varieties are active in Sicily and their products meet the requirements of local and European markets. Mango plants produce fleshy stone fruits rich in phytochemicals with an undisputed nutritional value for its high content of polyphenolics and vitamins. This review provides an overview of the antioxidant, anti-inflammatory, and anticancer properties of mango, a fruit that should be included in everyone\u2019s diet for its multifaceted biochemical actions and health-enhancing properties

    Algebraic Properties of Curvature Operators in Lorentzian Manifolds with Large Isometry Groups

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    Together with spaces of constant sectional curvature and products of a real line with a manifold of constant curvature, the socalled Egorov spaces and ε-spaces exhaust the class of n-dimensional Lorentzian manifolds admitting a group of isometries of dimension at least 0.5n(n − 1) + 1, for almost all values of n [Patrangenaru V., Geom. Dedicata 102 (2003), 25–33]. We shall prove that the curvature tensor of these spaces satisfi several interesting algebraic properties. In particular, we will show that Egorov spaces are Ivanov–Petrova manifolds, curvature-Ricci commuting (indeed, semi-symmetric) and P-spaces, and that ε-spaces are Ivanov–Petrova and curvature-curvature commuting manifolds
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