2,377 research outputs found
Investigation of the SH3BP2 Gene Mutation in Cherubism
Cherubism is a rare developmental lesion of the jaw that is generally inherited as an autosomal dominant trait. Recent studies have revealed point mutations in the SH3BP2 gene in cherubism patients. In this study, we examined a 6-year-old Korean boy and his family. We found a Pro418Arg mutation in the SH3BP2 gene of the patient and his mother. A father and his 30-month-old younger brother had no mutations. Immunohistochemically, the multinucleated giant cells proved positive for CD68 and tartrate-resistant acid phosphatase (TRAP). Numerous spindle-shaped stromal cells expressed a ligand for receptor activator of nuclear factor kB (RANKL), but not in multinucleated giant cells. These results provide evidence that RANKL plays a critical role in the differentiation of osteoclast precursor cells to multinucleated giant cells in cherubism. Additionally, genetic analysis may be a useful method for differentiation of cherubism.</p
Test Platform Development of Vessel???s Power Management System Using Hardware- in-the-Loop-Simulation Technique
A PMS (Power Management System) controls vessel's power systems to improve the system efficiency and to protect a blackout condition. The PMS should be developed with considering the type and the capacity of the vessel???s power system. It is necessary to test the PMS functions developed for vessel???s safe operations under various sailing situations. Therefore, the function tests in cooperation with practical power systems are required in the PMS development. In this paper, a hardware-in-the-loop (HIL) simulator is developed for the purposes of the PMS function tests. The HIL simulator can be more cost-effective, more time-saved, easier to reproduce, and safer beyond the normal operating range than conventional off-line simulators, especially at early stages in development processes or during fault tests. Vessel's power system model is developed by using a MATLAB/SIMULINK software and by communicating between an OPAL-RT???s OP5600 simulator. The PMS uses a Modbus communication protocol implemented using LabVIEW software. Representative tests of the PMS functions are performed to verify the validity of the proposed HIL-based test platform
Nitrogen doping of carbon nanoelectrodes for enhanced control of DNA translocation dynamics
Controlling the dynamics of DNA translocation is a central issue in the
emerging nanopore-based DNA sequencing. To address the potential of heteroatom
doping of carbon nanostructures to achieve this goal, herein we carry out
atomistic molecular dynamics simulations for single-stranded DNAs translocating
between two pristine or doped carbon nanotube (CNT) electrodes. Specifically,
we consider the substitutional nitrogen doping of capped CNT (capCNT)
electrodes and perform two types of molecular dynamics simulations for the
entrapped and translocating single-stranded DNAs. We find that the
substitutional nitrogen doping of capCNTs stabilizes the edge-on nucleobase
configurations rather than the original face-on ones and slows down the DNA
translocation speed by establishing hydrogen bonds between the N dopant atoms
and nucleobases. Due to the enhanced interactions between DNAs and N-doped
capCNTs, the duration time of nucleobases within the nanogap was extended by up
to ~ 290 % and the fluctuation of the nucleobases was reduced by up to ~ 70 %.
Given the possibility to be combined with extrinsic light or gate voltage
modulation methods, the current work demonstrates that the substitutional
nitrogen doping is a promising direction for the control of DNA translocation
dynamics through a nanopore or nanogap based of carbon nanomaterials.Comment: 11 pages, 4 figure
Dynamical mean-field theory of Hubbard-Holstein model at half-filling: Zero temperature metal-insulator and insulator-insulator transitions
We study the Hubbard-Holstein model, which includes both the
electron-electron and electron-phonon interactions characterized by and
, respectively, employing the dynamical mean-field theory combined with
Wilson's numerical renormalization group technique. A zero temperature phase
diagram of metal-insulator and insulator-insulator transitions at half-filling
is mapped out which exhibits the interplay between and . As () is
increased, a metal to Mott-Hubbard insulator (bipolaron insulator) transition
occurs, and the two insulating states are distinct and can not be adiabatically
connected. The nature of and transitions between the three states are
discussed.Comment: 5 pages, 4 figures. Submitted to Physical Review Letter
Stability of hydrogenation states of graphene and conditions for hydrogen spillover
The hydrogen spillover mechanism has been discussed in the field of hydrogen storage and is believed to have particular advantage over the storage as metal or chemical hydrides. We investigate conditions for practicality realizing the hydrogen spillover mechanism onto carbon surfaces, using first-principles methods. Our results show that contrary to common belief, types of hydrogenation configurations of graphene (the aggregated all-paired configurations) can satisfy the thermodynamic requirement for room-temperature hydrogen storage. However, the peculiarity of the paired adsorption modes gives rise to a large kinetic barrier against hydrogen migration and desorption. It means that an extremely high pressure is required to induce the migration-derived hydrogenation. However, if mobile catalytic particles are present inside the graphitic interstitials, hydrogen migration channels can open and the spillover phenomena can be realized. We suggest a molecular model for such a mobile catalyst which can exchange hydrogen atoms with the wall of graphene.open151
Theory of magnetic field-induced metaelectric critical end point in BiMnO
A recent experiment on the multiferroic BiMnO compound under a strong
applied magnetic field revealed a rich phase diagram driven by the coupling of
magnetic and charge (dipolar) degrees of freedom. Based on the
exchange-striction mechanism, we propose here a theoretical model with the
intent to capture the interplay of the spin and dipolar moments in the presence
of a magnetic field in BiMnO. Experimentally observed behavior of the
dielectric constants, magnetic susceptibility, and the polarization is, for the
most part, reproduced by our model. The critical behavior observed near the
polarization reversal point in the phase diagram is interpreted as
arising from the proximity to the critical end point.Comment: Theory; relevant experiment uploaded as arXiv:0810.190
Frequent Users of Hospital Emergency Departments in Korea Characterized by Claims Data from the National Health Insurance: A Cross Sectional Study
The Korean National Health Insurance, which provides universal coverage for the entire Korean population, is now facing financial instability. Frequent emergency department (ED) users may represent a medically vulnerable population who could benefit from interventions that both improve care and lower costs. To understand the nature of frequent ED users in Korea, we analyzed claims data from a population-based national representative sample. We performed both bivariate and multivariable analyses to investigate the association between patient characteristics and frequent ED use (4+ ED visits in a year) using claims data of a 1% random sample of the Korean population, collected in 2009. Among 156,246 total ED users, 4,835 (3.1%) were frequent ED users. These patients accounted for 14% of 209,326 total ED visits and 17.2% of $76,253,784 total medical expenses generated from all ED visits in the 1% data sample. Frequent ED users tended to be older, male, and of lower socio-economic status compared with occasional ED users (p < 0.001 for each). Moreover, frequent ED users had longer stays in the hospital when admitted, higher probability of undergoing an operative procedure, and increased mortality. Among 8,425 primary diagnoses, alcohol-related complaints and schizophrenia showed the strongest positive correlation with the number of ED visits. Among the frequent ED users, mortality and annual outpatient department visits were significantly lower in the alcohol-related patient subgroup compared with other frequent ED users; furthermore, the rate was even lower than that for non-frequent ED users. Our findings suggest that expanding mental health and alcohol treatment programs may be a reasonable strategy to decrease the dependence of these patients on the ED
Tau functions as Widom constants
We define a tau function for a generic Riemann-Hilbert problem posed on a
union of non-intersecting smooth closed curves with jump matrices analytic in
their neighborhood. The tau function depends on parameters of the jumps and is
expressed as the Fredholm determinant of an integral operator with block
integrable kernel constructed in terms of elementary parametrices. Its
logarithmic derivatives with respect to parameters are given by contour
integrals involving these parametrices and the solution of the Riemann-Hilbert
problem. In the case of one circle, the tau function coincides with Widom's
determinant arising in the asymptotics of block Toeplitz matrices. Our
construction gives the Jimbo-Miwa-Ueno tau function for Riemann-Hilbert
problems of isomonodromic origin (Painlev\'e VI, V, III, Garnier system, etc)
and the Sato-Segal-Wilson tau function for integrable hierarchies such as
Gelfand-Dickey and Drinfeld-Sokolov.Comment: 26 pages, 6 figure
EXAGGERATED BLOOD PRESSURE RESPONSE TO EXERCISE IS RELATED WITH SUBCLINICAL MYOCARDIAL DYSFUNCTION IN NORMOTENSIVE SUBJECTS
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