178 research outputs found
Uniform families of minimal rational curves on Fano manifolds
It is a well-known fact that families of minimal rational curves on rational
homogeneous manifolds of Picard number one are uniform, in the sense that the
tangent bundle to the manifold has the same splitting type on each curve of the
family. In this note we prove that certain --stronger-- uniformity conditions
on a family of minimal rational curves on a Fano manifold of Picard number one
allow to prove that the manifold is homogeneous
Nestings of rational homogeneous varieties
In this paper we study the existence of sections of universal bundles on
rational homogeneous varieties -- called nestings -- classifying them
completely in the case in which the Lie algebra of the automorphism group of
the variety is simple of classical type. In particular we show that, under this
hypothesis, nestings do not exist unless there exists a proper algebraic
subgroup of the automorphism group acting transitively on the base variety.Comment: Major revision of the exposition. To appear in Tranformation Group
Rank two Fano bundles on G(1,4)
We classify rank two Fano bundles over the Grassmannian of lines \G(1,4).
In particular we show that the only non-split rank two Fano bundle over
\G(1,4) is, up to a twist, the universal quotient bundle \cQ. This
completes the classification of rank two Fano bundles over Grassmannians of
lines
LivHeart: A Multi Organ-on-Chip Platform to Study Off-Target Cardiotoxicity of Drugs Upon Liver Metabolism
The drug discovery and development process is still long, costly, and highly risky. The principal attrition factor is undetected toxicity, with hepatic and cardiac toxicities playing a critical role and being the main responsible of safety-related drug withdrawals from the market. Multi Organs-on-Chip (MOoC) represent a disruptive solution to study drug-related effects on several organs simultaneously and to efficiently predict drug toxicity in preclinical trials. Specifically focusing on drug safety, different technological features are applied here to develop versatile MOoC platforms encompassing two culture chambers for generating and controlling the type of communication between a metabolically competent liver model and a functional 3D heart model. The administration of the drug Terfenadine, a cardiotoxic compound liver-metabolized into the noncardiotoxic Fexofenadine, proved that liver metabolism and a fine control over drug diffusion are fundamental to elicit a physio-pathological cardiac response. From these results, an optimized LivHeart platform is developed to house a liver model and a cardiac construct that can be mechanically trained to achieve a beating microtissue, whose electrophysiology can be directly recorded in vitro. The platform is proved able to predict off-target cardiotoxicity of Terfenadine after liver metabolism both in terms of cell viability and functionality
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