Russian Nonproliferation Policy and the Korean Peninsula

Efforts to resolve the threat posed to Northeast Asia\u27s security by North Korea\u27s nuclear proliferation through six-party negotiations are proceeding with great difficulty. As in any multilateral process, a major problem is understanding the goals and perspectives of each of the participants. This monograph focuses upon Moscow’s perspectives with regard to North Korea’s nuclear program and Russia’s own standing in Northeast Asia, as well as of the other participants in those negotiations, since their views unfortunately are not well-known or readily available in the United States.https://press.armywarcollege.edu/monographs/1701/thumbnail.jp

Optical properties of iron-based superconductor LiFeAs single crystal

We have measured the reflectivity spectra of the iron based superconductor LiFeAs (Tc = 17.6 K) in the temperature range from 4 to 300 K. In the superconducting state (T < Tc), the clear opening of the optical absorption gap was observed below 25 cm-1, indicating an isotropic full gap formation. In the normal state (T > Tc), the optical conductivity spectra display a typical metallic behavior with the Drude type spectra at low frequencies, but we found that the introduction of the two Drude components best fits the data, indicating the multiband nature of this superconductor. A theoretical analysis of the low temperature data (T=4K < Tc) also suggests that two superconducting gaps best fit the data and their values were estimated as {\Delta}1 = 1.59 meV and {\Delta}2 = 3.15 meV, respectively. Using the Ferrell-Glover-Tinkham (FGT) sum rule and dielectric function {\epsilon}1({\omega}), the superconducting plasma frequency ({\omega}ps) is consistently estimated to be 6,665 cm-1, implying that about 59 % of the free carriers in the normal state condenses into the SC condensate. To investigate the various interband transition processes (for {\omega} > 200 cm-1), we have also performed the local-density approximation (LDA) band calculation and calculated the optical spectra of the interband transitions. The theoretical results provided a qualitative agreement with the experimental data below 4000 cm-1Comment: 19 pages, 5 figures. This paper has been accepted for publication in New Journal of Physic

Evaluation of the brain activation induced by functional electrical stimulation and voluntary contraction using functional magnetic resonance imaging

BACKGROUND: To observe brain activation induced by functional electrical stimulation, voluntary contraction, and the combination of both using functional magnetic resonance imaging (fMRI). METHODS: Nineteen healthy young men were enrolled in the study. We employed a typical block design that consisted of three sessions: voluntary contraction only, functional electrical stimulation (FES)-induced wrist extension, and finally simultaneous voluntary and FES-induced movement. MRI acquisition was performed on a 3.0 T MR system. To investigate activation in each session, one-sample t-tests were performed after correcting for false discovery rate (FDR; p < 0.05). To compare FES-induced movement and combined contraction, a two-sample t-test was performed using a contrast map (p < 0.01). RESULTS: In the voluntary contraction alone condition, brain activation was observed in the contralateral primary motor cortex (MI), thalamus, bilateral supplementary motor area (SMA), primary sensory cortex (SI), secondary somatosensory motor cortex (SII), caudate, and cerebellum (mainly ipsilateral). During FES-induced wrist movement, brain activation was observed in the contralateral MI, SI, SMA, thalamus, ipsilateral SII, and cerebellum. During FES-induced movement combined with voluntary contraction, brain activation was found in the contralateral MI, anterior cingulate cortex (ACC), SMA, ipsilateral cerebellum, bilateral SII, and SI. The activated brain regions (number of voxels) of the MI, SI, cerebellum, and SMA were largest during voluntary contraction alone and smallest during FES alone. SII-activated brain regions were largest during voluntary contraction combined with FES and smallest during FES contraction alone. The brain activation extent (maximum t score) of the MI, SI, and SII was largest during voluntary contraction alone and smallest during FES alone. The brain activation extent of the cerebellum and SMA during voluntary contraction alone was similar during FES combined with voluntary contraction; however, cerebellum and SMA activation during FES movement alone was smaller than that of voluntary contraction alone or voluntary contraction combined with FES. Between FES movement alone and combined contraction, activated regions and extent due to combined contraction was significantly higher than that of FES movement alone in the ipsilateral cerebellum and the contralateral MI and SI. CONCLUSIONS: Voluntary contraction combined with FES may be more effective for brain activation than FES-only movements for rehabilitation therapy. In addition, voluntary effort is the most important factor in the therapeutic process

Efficacy of Abatacept Versus Tumor Necrosis Factor Inhibitors in Anti-citrullinated Protein Antibody-Positive Patients with Rheumatoid Arthritis: Results from a Korean Nationwide Biologics Registry

Abstract Introduction To compare the efficacy of abatacept and tumor necrosis factor inhibitor (TNFi) in patients with anti-citrullinated protein antibody (ACPA)-positive rheumatoid arthritis (RA) and identify those who benefit most from abatacept over TNFi. Methods This observational study identified RA patients who were ACPA-positive and initiated abatacept or TNFi from the Korean College of Rheumatology Biologics and Targeted therapy registry. Propensity score (PS) matching was performed to balance baseline confounding in abatacept- or TNFi-treated patients. The major endpoints were changes in Clinical Disease Activity Index (CDAI) and achievement of CDAI remission/low disease activity after 1year of treatment. Subgroup analysis was mainly performed stratified by prior biologics use. Results A total of 291 PS-matched, ACPA-positive RA patients who initiated abatacept (n = 97) and TNFi (n = 194) were included. From baseline CDAI scores of 26.52 in the abatacept group and 26.38 in the TNFi group, the mean changes after 1year were − 16.78 and − 13.61, respectively (difference − 3.17, p = 0.020). The proportion of patients achieving CDAI remission/low disease activity was 68.0% with abatacept and 52.6% with TNFi (p = 0.013). In the subgroup analysis, patients that were biologics-naïve had better improvement in CDAI after treatment with abatacept than TNFi (difference −3.35, p = 0.021). Conclusions This real-world study suggests that abatacept may have better clinical response compared to TNFi in patients with established ACPA-positive RA, especially in those that were biologics-naïve

Correlation of Swallowing Function With Bilateral Diaphragmatic Movement in Hemiplegic Stroke Patients

Objective To investigate difference in bilateral diaphragm movement of patients with tracheal aspiration according to post stroke residue severity and determine correlations of Penetration-Aspiration Scale (PAS), residue scale, and bilateral diaphragm movement. Methods A total of 47 patients diagnosed with hemiplegic stroke were enrolled in this study. PAS, severity of valleculae, and pyriform sinus retention during videofluoroscopic swallowing study (VFSS) were assessed. Bilateral fluoroscopic diaphragm movements during spontaneous breathing and forced breathing were measured. Results Patients with tracheal aspiration (PAS≥6) had significantly (p=0.035) lower ipsilateral diaphragm movement during spontaneous breathing. Post-swallow residue severity showed statistically significant (p=0.028) difference in patients with ipsilateral diaphragm movement during forced breathing. In linear regression analysis, PAS showed weak correlations with ipsilateral spontaneous diaphragm movement (r=0.397, p=0.006), ipsilateral forced diaphragm movement (r=0.384, p=0.008), and contralateral forced diaphragm movement (r=0.323, p=0.027). Weak correlation was also observed between post swallow residue severity and ipsilateral diaphragm movement during spontaneous breathing (r=0.331, p=0.023) and forced breathing (r=0.343, p=0.018). Conclusion We confirmed the relationship between swallowing function and bilateral diaphragm movement in this study. The severity of dysphagia after hemiplegic stroke was correlated with bilateral diaphragm movement. Further longitudinal studies are needed to assess the effect of breathing exercise on post-stroke dysphagia

Highly-Sensitive Textile Pressure Sensors Enabled by Suspended-Type All Carbon Nanotube Fiber Transistor Architecture.

Among various wearable health-monitoring electronics, electronic textiles (e-textiles) have been considered as an appropriate alternative for a convenient self-diagnosis approach. However, for the realization of the wearable e-textiles capable of detecting subtle human physiological signals, the low-sensing performances still remain as a challenge. In this study, a fiber transistor-type ultra-sensitive pressure sensor (FTPS) with a new architecture that is thread-like suspended dry-spun carbon nanotube (CNT) fiber source (S)/drain (D) electrodes is proposed as the first proof of concept for the detection of very low-pressure stimuli. As a result, the pressure sensor shows an ultra-high sensitivity of ~3050 Pa-1 and a response/recovery time of 258/114 ms in the very low-pressure range of <300 Pa as the fiber transistor was operated in the linear region (VDS = -0.1 V). Also, it was observed that the pressure-sensing characteristics are highly dependent on the contact pressure between the top CNT fiber S/D electrodes and the single-walled carbon nanotubes (SWCNTs) channel layer due to the air-gap made by the suspended S/D electrode fibers on the channel layers of fiber transistors. Furthermore, due to their remarkable sensitivity in the low-pressure range, an acoustic wave that has a very tiny pressure could be detected using the FTPS

Detection of Biomolecular Binding Through Enhancement of Localized Surface Plasmon Resonance (LSPR) by Gold Nanoparticles

To amplify the difference in localized surface plasmon resonance (LSPR) spectra of gold nano-islands due to intermolecular binding events, gold nanoparticles were used. LSPR-based optical biosensors consisting of gold nano-islands were readily made on glass substrates using evaporation and heat treatment. Streptavidin (STA) and biotinylated bovine serum albumin (Bio-BSA) were chosen as the model receptor and the model analyte, respectively, to demonstrate the effectiveness of this detection method. Using this model system, we were able to enhance the sensitivity in monitoring the binding of Bio-BSA to gold nano-island surfaces functionalized with STA through the addition of gold nanoparticle-STA conjugates. In addition, SU-8 well chips with gold nano-island surfaces were fabricated through a conventional UV patterning method and were then utilized for image detection using the attenuated total reflection mode. These results suggest that the gold nano-island well chip may have the potential to be used for multiple and simultaneous detection of various bio-substances