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

Microscopic Theory of Rashba Interaction in Magnetic Metal

Theory of Rashba spin-orbit coupling in magnetic metals is worked out from microscopic Hamiltonian describing d-orbitals. When structural inversion symmetry is broken, electron hopping between $d$-orbitals generates chiral ordering of orbital angular momentum, which combines with atomic spin-orbit coupling to result in the Rashba interaction. Rashba parameter characterizing the interaction is band-specific, even reversing its sign from band to band. Large enhancement of the Rashba parameter found in recent experiments is attributed to the orbital mixing of 3d magnetic atoms with non-magnetic heavy elements as we demonstrate by first-principles and tight-binding calculations.Comment: 5 pages, 2 figure

Export of recombinant proteins in Escherichia coli using ABC transporter with an attached lipase ABC transporter recognition domain (LARD)

<p>Abstract</p> <p>Background</p> <p>ATP binding cassette (ABC) transporter secretes the protein through inner and outer membranes simultaneously in gram negative bacteria. Thermostable lipase (TliA) of <it>Pseudomonas fluorescens </it>SIK W1 is secreted through the ABC transporter. TliA has four glycine-rich repeats (GGXGXD) in its C-terminus, which appear in many ABC transporter-secreted proteins. From a homology model of TliA derived from the structure of <it>P. aeruginosa </it>alkaline protease (AprA), lipase ABC transporter domains (LARDs) were designed for the secretion of fusion proteins.</p> <p>Results</p> <p>The LARDs included four glycine-rich repeats comprising a β-roll structure, and were added to the C-terminus of test proteins. Either Pro-Gly linker or Factor Xa site was added between fusion proteins and LARDs. We attached different length of LARDs such as LARD0, LARD1 or whole TliA (the longest LARD) to three types of proteins; green fluorescent protein (GFP), epidermal growth factor (EGF) and cytoplasmic transduction peptide (CTP). These fusion proteins were expressed in <it>Escherichia coli </it>together with ABC transporter of either <it>P. fluorescens </it>or <it>Erwinia chrysanthemi</it>. Export of fusion proteins with the whole TliA through the ABC transporter was evident on the basis of lipase enzymatic activity. Upon supplementation of <it>E. coli </it>with ABC transporter, GFP-LARDs and EGF-LARDs were excreted into the culture supernatant.</p> <p>Conclusion</p> <p>The LARDs or whole TliA were attached to C-termini of model proteins and enabled the export of the model proteins such as GFP and EGF in <it>E. coli </it>supplemented with ABC transporter. These results open the possibility for the extracellular production of recombinant proteins in <it>Pseudomonas </it>using LARDs or TliA as a C-terminal signal sequence.</p