5,139 research outputs found
Towards phenotyping stroke: Leveraging data from a large-scale epidemiological study to detect stroke diagnosis
Optimal Early Clinical Endpoints for Long-Term Functional Outcome Prediction After Thrombectomy
Maximum IV tPA Dose for Obese Patients is Associated with Greater Likelihood of Hemorrhagic Conversion and Worse Functional Outcome at Discharge
Delocalization Transition in Colloidal Crystals
Sublattice melting is the loss of order of one lattice component in binary or
ternary ionic crystals upon increase in temperature. A related transition has
been predicted in colloidal crystals. To understand the nature of this
transition, we study delocalization in self-assembled, size asymmetric binary
colloidal crystals using a generalized molecular dynamics model. Focusing on
BCC lattices, we observe a smooth change from localized-to-delocalized
interstitial particles for a variety of interaction strengths. Thermodynamic
arguments, mainly the absence of a discontinuity in the heat capacity, suggest
that the passage from localization-to-delocalization is continuous and not a
phase transition. This change is enhanced by lattice vibrations, and the
temperature of the onset of delocalization can be tuned by the strength of the
interaction between the colloid species. Therefore, the localized and
delocalized regimes of the sublattice are dominated by enthalpic and entropic
driving forces, respectively. This work sets the stage for future studies of
sublattice melting in colloidal systems with different stoichiometries and
lattice types, and it provides insights into superionic materials, which have
potential for application in energy storage technologies.Comment: Hector Lopez-Rios and Ali Ehlen contributed equall
Metallization of colloidal crystals
Colloidal crystals formed by size-asymmetric binary particles co-assemble
into a wide variety of colloidal compounds with lattices akin to ionic
crystals. Recently, a transition from a compound phase with a sublattice of
small particles to a metal-like phase in which the small particles are
delocalized has been predicted computationally and observed experimentally. In
this colloidal metallic phase, the small particles roam the crystal maintaining
the integrity of the lattice of large particles, as electrons do in metals. A
similar transition also occurs in superionic crystals, termed sublattice
melting. Here, we use energetic principles and a generalized molecular dynamics
model of a binary system of functionalized nanoparticles to analyze the
transition to sublattice delocalization in different co-assembled crystal
phases as a function of T, number of grafted chains on the small particles, and
number ratio between the small and large particles :. We find that
: is the primary determinant of crystal type due to energetic
interactions and interstitial site filling, while the number of grafted chains
per small particle determines the stability of these crystals. We observe
first-order sublattice delocalization transitions as T increases, in which the
host lattice transforms from low- to high-symmetry crystal structures,
including A20 to BCT to BCC, Ad to BCT to BCC, and BCC to BCC/FCC to FCC
transitions and lattices. Analogous sublattice transitions driven primarily by
lattice vibrations have been seen in some atomic materials exhibiting an
insulator-metal transition also referred to as metallization. We also find
minima in the lattice vibrations and diffusion coefficient of small particles
as a function of :, indicating enhanced stability of certain crystal
structures for : values that form compounds.Comment: AE and HL-R contributed equally to this wor
Cancer nurses, are we really contributing to reduce burden via cancer prevention?
From the wisdom of experience and years, our grandparents used to say: 'Prevention is better than cure'. Nurses also want to prevent rather than cure cancer and follow that old said. Cancer is one of the leading causes of mortality in the world and the incidence is expected to keep increasing every year[1]. And while there is an improvement in cancer survival due to developments on treatments; the diagnosis, treatment and survivorship entails a high burden for patients, for communities and for health systems
On the Dirac delta as initial condition for nonlinear Schr\"odinger equations
In this article we will study the initial value problem for some
Schr\"odinger equations with Diraclike initial data and therefore with infinite
L2 mass, obtaining positive results for subcritical nonlinearities. In the
critical case and in one dimension we prove that after some renormalization the
corresponding solution has finite energy. This allows us to conclude a
stability result in the defocusing setting. These problems are related to the
existence of a singular dynamics for Schr\"odinger maps through the so called
Hasimoto transformation.Comment: 17 pages, to appear in in AnIHP Ann Non Li
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