150,131 research outputs found

    Antidote application: an educational system for treatment of common toxin overdose

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    Poisonings account for almost 1% of emergency room visits each year. Time is a critical factor in dealing with a toxicologic emergency. Delay in dispensing the first antidote dose can lead to life-threatening sequelae. Current toxicological resources that support treatment decisions are broad in scope, time-consuming to read, or at times unavailable. Our review of current toxicological resources revealed a gap in their ability to provide expedient calculations and recommendations about appropriate course of treatment. To bridge the gap, we developed the Antidote Application (AA), a computational system that automatically provides patient-specific antidote treatment recommendations and individualized dose calculations. We implemented 27 algorithms that describe FDA (the US Food and Drug Administration) approved use and evidence-based practices found in primary literature for the treatment of common toxin exposure. The AA covers 29 antidotes recommended by Poison Control and toxicology experts, 19 poison classes and 31 poisons, which represent over 200 toxic entities. To the best of our knowledge, the AA is the first educational decision support system in toxicology that provides patient-specific treatment recommendations and drug dose calculations. The AA is publicly available at http://projects.met- hilab.org/antidote/

    Study of the ionic Peierls-Hubbard model using density matrix renormalization group methods

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    Density matrix renormalization group methods are used to investigate the quantum phase diagram of a one-dimensional half-filled ionic Hubbard model with bond-charge attraction, which can be mapped from the Su-Schrieffer-Heeger-type electron-phonon coupling at the antiadiabatic limit. A bond order wave (dimerized) phase which separates the band insulator from the Mott insulator always exists as long as electron-phonon coupling is present. This is qualitatively different from that at the adiabatic limit. Our results indicate that electron-electron interaction, ionic potential and quantum phonon fluctuations combine in the formation of the bond-order wave phase

    The State Equation of the Yang-Mills field Dark Energy Models

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    In this paper, we study the possibility of building Yang-Mills(YM) field dark energy models with equation of state (EoS) crossing -1, and find that it can not be realized by the single YM field models, no matter what kind of lagrangian or initial condition. But the states of −1<ω<0-1<\omega<0 and ω<−1\omega<-1 all can be naturally got in this kind of models. The former is like a quintessence field, and the latter is like a phantom field. This makes that one can build a model with two YM fields, in which one with the initial state of −1<ω<0-1<\omega<0, and the other with ω<−1\omega<-1. We give an example model of this kind, and find that its EoS is larger than -1 in the past and less than -1 at the present time. We also find that this change must be from ω>−1\omega>-1 to <−1<-1, and it will go to the critical state of ω=−1\omega=-1 with the expansion of the Universe, which character is same with the single YM field models, and the Big Rip is naturally avoided.Comment: 20 pages, 4 figures. minor typos correcte

    Dimerization in a half-filled one-dimensional extended Hubbard model

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    We use a density matrix renormalization group method to study quantitatively the phase diagram of a one-dimensional extended Hubbard model at half-filling by investigating the correlation functions and structure factors. We confirm the existence of a novel narrow region with long-rang bond-order-wave order which is highly controversial recently between the charge-density-wave phase and Mott insulator phase. We determined accurately the position of the tricritical point Ut≃7.2tU_t\simeq 7.2t, Vt≃3.746tV_t\simeq 3.746t which is quite different from previous studies

    Chiral superfluid states in hybrid graphene heterostructures

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    The use of high quality hexagonal boron nitride (hBN) as a dielectric material has made possible the realization of graphene devices with very high mobility. In addition hBN can be made as thin as few atomic layers and, as recently demonstrated experimentally, can be used to isolate electrically two graphene layers only few nanometers apart. The combined use of graphene and hBN has therefore opened the possibility to create novel electronic structures. In this work we study the "hybrid" heterostructure formed by one sheet of single layer graphene (SLG) and one sheet of bilayer graphene (BLG) separated by a thin film of hBN. In general it is expected that interlayer interactions can drive the system to a spontaneously broken symmetry state characterized by interlayer phase coherence. The peculiarity of the SLG-BLG heterostructure is that the electrons in the layers (SLG and BLG) have different chiralities. We find that the difference of chirality between electrons in the two layers causes the spontaneously broken symmetry state to be N-fold degenerate. Moreover, we find that some of the degenerate states are chiral superfluid states, topologically distinct from the usual layer-ferromagnetism. The chiral nature of the ground state opens the possibility to realize protected midgap states. The N-fold degeneracy of the ground state makes the physics of SLG-BLG hybrid systems analogous to the physics of helium-3, in particular given the recent discovery of chiral superfluid states in this system.Comment: 5 pages, 4 figure

    Stable Heteronuclear Few-Atom Bound States in Mixed Dimensions

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    We study few-body problems in mixed dimensions with N≥2N \ge 2 heavy atoms trapped individually in parallel one-dimensional tubes or two-dimensional disks, and a single light atom travels freely in three dimensions. By using the Born-Oppenheimer approximation, we find three- and four-body bound states for a broad region of heavy-light atom scattering length combinations. Specifically, the existence of trimer and tetramer states persist to negative scattering lengths regime, where no two-body bound state is present. These few-body bound states are analogous to the Efimov states in three dimensions, but are stable against three-body recombination due to geometric separation. In addition, we find that the binding energy of the ground trimer and tetramer state reaches its maximum value when the scattering lengths are comparable to the separation between the low-dimensional traps. This resonant behavior is a unique feature for the few-body bound states in mixed dimensions.Comment: Extended version with 14 pages and 14 figure
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