Liver Divination in Cicero’s "De Divinatione"

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Uses of the Somatic Word "Hand" in Oath, Prayer, Supplication and Revenge Formulae in "Iliad" I

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Liver as a Life Symbol in Ancient Greek and Georgian World Vision

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Reprintable self-healing polymer networks

We report a versatile approach to designing printable, re-processable polymer networks with controllable mechanical properties. The approach involves epoxy-based oligomeric building blocks which are reversibly crosslinked within reversible networks. The reversible crosslinking was enabled by Diels-Alder (DA) reactions between furan moieties of the oligomeric precursor and maleimide moieties of a crosslinker agent. The polymer networks formed in ambient conditions by DA reaction reversibly dissociated at elevated temperatures via retro DA reaction. The low viscosity of dissociated networks between 80 and 145 oC facilitated re-processing of the materials via injection molding or 3D printing. Importantly, the presence of reversible chemical crosslinks between furan and maleimide moieties enabled fast curing of the polymer resin and improved interlayer adhesion at the interfaces between the deposited layers during fused deposition modelling. Using this approach, the same oligomeric precursor could be used with variable amount of a crosslinker for fabrication of a series of polymer networks with the glass transition temperatures precisely controlled between -10 and 30 oC. The polymer networks demonstrated programmable MPa-range elastic moduli, and fast self-healing behavior. Moreover, the materials were rendered stimuli responsive via covalent attachment of light-responsive dyes, whose photoisomerization was triggered by exposure to UV irradiation. These results suggest a new and promising pathway into development of versatile materials for additive manufacturing of multifunctional adaptable structures

Electrophoresis of a rod macroion under polyelectrolyte salt: Is mobility reversed for DNA?

By molecular dynamics simulation, we study the charge inversion phenomenon of a rod macroion in the presence of polyelectrolyte counterions. We simulate electrophoresis of the macroion under an applied electric field. When both counterions and coions are polyelectrolytes, charge inversion occurs if the line charge density of the counterions is larger than that of the coions. For the macroion of surface charge density equal to that of the DNA, the reversed mobility is realized either with adsorption of the multivalent counterion polyelectrolyte or the combination of electrostatics and other mechanisms including the short-range attraction potential or the mechanical twining of polyelectrolyte around the rod axis.Comment: 8 pages, 5 figures, Applied Statistical Physics of Molecular Engineering (Mexico, 2003). Journal of Physics: Condensed Matters, in press (2004). Journal of Physics: Condensed Matters, in press (2004

Organic-inorganic hybrid polymer coatings with controlled biofunctionality

Fluorinated polyphosphazenes (FPs) offer important advantages as biocompatible coatings for coronary stents and other biomedical devices. Recently, a new class of FPs has been introduced, which integrates carboxylic1,2 or sulfonic acid3 and fluorinated moieties into a single macromolecular structure. Assemblies of such fluorinated polyelectrolytes with polyelectrolytes or charged small functional molecules can offer efficient modulation of hydrophobicity, improved biocompatibility, as well as biofunctionality, such as modulated drug release. Here, we have explored aqueous multilayer polyelectrolyte deposition as a convenient route to nanofabrication of layered coatings built from ionic FPs (iFPs) and polyelectrolytes1,2 or small molecule partners. The resulting layer-by-layer (LbL) assemblies displayed controlled film growth, modulated hydrophobicity, swelling, and protein adsorption characteristics. Hydrophobic interactions largely contributed to the formation of LbL films of iFPs with polycations, leading to linear growth and extremely low water uptake. As shown in neutron reflectometry (NR) studies, films of fluorinated polyphospazenes demonstrated superior layering and persistence of such layering in salt solution as compared to control nonfluorinated polyphospha-zene/polycation films. Hydrophobicity-enhanced ionic pairing between iFP and linear polycations gave rise to large-amplitude oscillations in surface wettability as a function of capping layer. Importantly, hydrophobicity of iFP-capped LbL coatings could be further enhanced by using a highly porous polyester surgical felt rather than planar substrates for film deposition.2 Please click Additional Files below to see the full abstract

BioScape: A Modeling and Simulation Language for Bacteria-Materials Interactions

We design BioScape, a concurrent language for the stochastic simulation of biological and bio-materials processes in a reactive environment in 3D space. BioScape is based on the Stochastic Pi-Calculus, and it is motivated by the need for individual-based, continuous motion, and continuous space simulation in modeling complex bacteria-materials interactions. Our driving example is a bio-triggered drug delivery system for infection-resistant medical implants. Our models in BioScape will help in identifying biological targets and materials strategies to treat biomaterials associated bacterial infections. The novel aspects of BioScape include syntactic primitives to declare the scope in space where species can move, diffusion rate, shape, and reaction distance, and an operational semantics that deals with the specifics of 3D locations, verifying reaction distance, and featuring random movement. We define a translation from BioScape to 3π and prove its soundness with respect to the operational semantics.Fil: Compagnoni, Adriana. Stevens Institute of Technology; Estados UnidosFil: Sharma, Vishaka. Stevens Institute of Technology; Estados UnidosFil: Bao, Yifei. Stevens Institute of Technology; Estados UnidosFil: Libera, Matthew. Stevens Institute of Technology; Estados UnidosFil: Sukhishvili, Svetlana. Stevens Institute of Technology; Estados UnidosFil: Bidinger, Philippe. VERIMAG; FranciaFil: Boglio, Livio. Universita Di Torino; ItaliaFil: Bonelli, Eduardo Augusto. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Polymer reptation and nucleosome repositioning

We consider how beads can diffuse along a chain that wraps them, without becoming displaced from the chain; our proposed mechanism is analogous to the reptation of "stored length" in more familiar situations of polymer dynamics. The problem arises in the case of globular aggregates of proteins (histones) that are wound by DNA in the chromosomes of plants and animals; these beads (nucleosomes) are multiply wrapped and yet are able to reposition themselves over long distances, while remaining bound by the DNA chain.Comment: 9 pages, including 2 figures, to be published in Phys. Rev. Let