Mitral Loop Cerclage Annuloplasty for Secondary Mitral Regurgitation

Park, Y.H.,Chon, M.K.,Lederman, R.J.,Sung, S.C.,Je, H.G.,Choo, K.S.,Lee, S.H.,Shin, E.S.,Kim, J.S.,Hwang, K.W.,Lee, S.Y.,Chun, K.J.,Kim, C.M.,Kim, J.H. Elsevier 2017 JACC. Cardiovascular interventions Vol.10 No.6

<P>OBJECTIVES This is an early feasibility clinical test of mitral loop cerclage annuloplasty to treat secondary mitral valve regurgitation. BACKGROUND Secondary mitral regurgitation is characterized by cardiomyopathy, mitral annular enlargement, and leaflet traction contributing to malcoaptation. Transcatheter mitral loop cerclage applies circumferential compression to the mitral annulus by creating a loop through the coronary sinus across the interventricular septum, protecting entrapped coronary arteries from compression, and interactive annular reduction under echocardiographic guidance. This is the first human test of mitral loop annuloplasty. METHODS Five subjects with severe symptomatic secondary mitral regurgitation underwent mitral loop cerclage, with echocardiographic and computed tomography follow-up over 6 months. RESULTS Mitral loop cerclage was successful in 4 of 5 subjects and aborted in 1 of the 5 because of unsuitable septal coronary vein anatomy. Immediately and over 6 months, measures of both mitral valve regurgitation (effective orifice area and regurgitation fraction) and chamber dimensions (left atrial and left ventricular volumes) were reduced progressively and ejection fractions increased. Two with persistent and permanent atrial fibrillation spontaneously reverted to sinus rhythm during follow-up. One subject experienced a small myocardial infarction from an unrecognized small branch coronary occlusion. Another, experiencing cardiogenic shock at baseline, died of intractable heart failure after 6 weeks. CONCLUSIONS In this first human test, mitral loop cerclage annuloplasty was successful in 4 of 5 attempts, caused reverse remodeling (reduction in secondary mitral regurgitation and heart chamber volumes), and suggested electrical remodeling (reversion of atrial fibrillation). Further evaluation is warranted. (C) 2017 by the American College of Cardiology Foundation. Published by Elsevier. All rights reserved.</P>

Orbital hybridization mechanism for the enhanced photoluminescence in edge-functionalized sp² carbon clusters

Kang, B.,Choi, Y.,Kim, B.S.,Youn, I.S.,Lee, G. Pergamon Press ; Elsevier Science Ltd 2016 Carbon Vol.109 No.-

<P>Using the first principles methods, we performed systematic study on the effect of edge-functional groups on the electronic energy levels and the optical properties of sp(2) carbon clusters. It is found that the intrinsic pi and pi* orbitals are weakly altered by oxygen-bearing functional groups, but it is significantly disrupted by pyrrolic groups. Thereby the oscillator strength of the lowest-energy transition is found to be much stronger for the pyrrolic group functionalized cluster than for the carboxyl group. From our results being consistent with the experimental reports, we suggest that the photoluminescence enhancement is caused by a perturbation of the intrinsic, frontier molecular orbitals by edge groups. (C) 2016 Elsevier. Ltd. All rights reserved.</P>

Integration of graphs from different data sources using crowdsourcing

Kim, Y.,Jung, W.,Shim, K. Elsevier science 2017 Information sciences Vol.385 No.-

<P>In this paper, we present an efficient algorithm to integrate two graphs collected from different sources using crowdsourcing systems. Given two graphs, we repeatedly select a query node from a graph and request a human annotator to find its matching node from the other graph, which is considered to be the one indicating the same entity as the query node. The proposed method is to choose the query nodes that would increase the precision the most if it is labeled. By experiments with both the simulated answers and the labels collected by real crowdsourcing, we show that our algorithm finds more accurate graph matches with a smaller cost for crowdsourcing than the baseline algorithms. (C) 2017 Elsevier Inc. All rights reserved.</P>

Direct infusion of nitrite into meat batter by atmospheric pressure plasma treatment

Jung, S.,Lee, J.,Lim, Y.,Choe, W.,Yong, H.I.,Jo, C. Elsevier Science 2017 Innovative food science & emerging technologies Vol.39 No.-

<P>This study investigated the influence of direct atmospheric pressure plasma (APP) treatment on nitrite levels and physiochemical quality of meat batter during the mixing process. A compact APP system was developed for installation on top of a food mixer. Meat batter composed of pork, water and sodium Chloride (80:20:1, w/w/w) was treated with APP during mixing. Plasma treatment gradually increased the temperature of meat batter over 60 min from 0.2 degrees C to 20 degrees C. Total aerobic bacterial count of meat batter was not influenced by plasma treatment for 30 min (p > 0.05). The nitrite level in meat batter increased steadily with increasing plasma treatment duration (p < 0.05), reaching 65.96 ppm at 30 min. Consequently, the CIE a*- and b*-values of cooked meat batter gradually increased and decreased, respectively, as the time of plasma treatment increased. According to the results, direct APP treatment can replace nitrite addition in cured meat processing. (C) 2016 Elsevier Ltd. All rights reserved.</P>

The unique spliceosome signature of human pluripotent stem cells is mediated by SNRPA1, SNRPD1, and PNN

Kim, Y.D.,Lee, J.,Kim, H.S.,Lee, M.O.,Son, M.Y.,Yoo, C.H.,Choi, J.K.,Lee, S.C.,Cho, Y.S. Elsevier 2017 Stem cell research Vol.22 No.-

<P>Spliceosomes are the core host of pre-mRNA splicing, allowing multiple protein isoforms to be produced from a single gene. Herein, we reveal that spliceosomes are more abundant in human pluripotent stem cells (hPSs), including human embryonic stem cells (hESs) and human induced pluripotent stem cells (hiPSs), than non-hPSs, and their presence is associated with high transcriptional activity. Supportively, spliceosomal components involved in the catalytically active pre-mRNA splicing step were mainly co-localized with hPS spliceosomes. By profiling the gene expression of 342 selected splicing factors, we found that 71 genes were significantly altered during the reprogramming of human somatic cells into hiPSs. Among them, SNRPA1, SNRPD1, and PNNwere significantly up-regulated during the early stage of reprogramming, identified as hub genes by interaction network and cluster analysis. SNRPA1, SNRPD1, or PNNdepletion led to a pronounced loss of pluripotency and significantly blocked hiPS generation. SNRPA1, SNRPD1, and PNN co-localized with the hPS spliceosomes, physically interacted with each other, and positively influenced the appearance of hPS spliceosomes. Our data suggest that SNRPA1, SNRPD1, and PNN are key players in the regulation of pluripotency-specific spliceosome assembly and the acquisition and maintenance of pluripotency. (C) 2017 The Authors. Published by Elsevier B.V.</P>

Evaluation of steady-state characteristics for solid oxide carbon fuel cell short-stacks

Mushtaq, Usman,Mehran, Muhammad Taqi,Kim, Sun-Kyoung,Lim, Tak-Hyoung,Naqvi, Syed Asad Ali,Lee, Jong-Won,Lee, Seung-Bok,Park, Seok-Joo,Song, Rak-Hyun ELSEVIER 2017 APPLIED ENERGY -BARKING THEN OXFORD- Vol.187 No.-

<P>Solid oxide based carbon fuel cells (SO-CFCs) offer clean and efficient utilization of carbon based fuels for energy conversion. In this work, we have realized and operated 100 and 200 W-class solid oxide carbon fuel cell (SO-CFC) short stacks to investigate the fuel supply, electrochemical performance, continuous operation, long-term stability, and scale-up characteristics for SO-CFC based power generation systems. Different configurations for 100 and 200 W class short stacks were employed for integrated Boudouard gasification and carbon fuel supply at the stack level. For the 100 W class SO-CFC short stack, maximum stack power of 80.4, 93.5, and 111.5 W was achieved at 700, 750, and 800 degrees C, respectively, while the 200 W class SO-CFC short stack produced maximum power of 224.4 W at 750 degrees C when operated on carbon fuel. Both SO-CFC short stacks were operated continuously at galvanostatic conditions to study the fuel supply conditions and long-term degradation behavior of the tubular cells in the short stacks. A postmortem analysis of the SO-CFC anode was also performed by SEM and XRD to elucidate the reasons for stack performance degradation during relatively longer operation with carbon fuels. Through a detailed analysis of the dry gasification in the integrated gasifier, the electrochemical performance of the SO-CFC stacks, and the post operation diagnosis of the cells, this study provides details on the important challenges in scaling-up SO-CFC technology from a single-cell to a several hundred watt power generation system. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Estimation of the transverse dispersion coefficient for two-dimensional models of mixing in natural streams

Baek, K.O.,Seo, I.W. ELSEVIER SCIENCE B.V; AMSTERDAM 2017 JOURNAL OF HYDROENVIRONMENT RESEARCH Vol.15 No.-

<P>The results of the classification flow chart showed that, at the first step, in the cases where secondary currents data were available for natural streams, the theoretical equation by Baek and Seo (2011) could be used to estimate the transverse dispersion coefficient. At the second step, in the case of large value of P, i.e., P> 0.04, the equation by Baek and Seo (2013) was suitable to estimate the transverse dispersion coefficient, while in the case of a small value of P, equations by Yotukura and Sayer (1976) and Baek and Seo (2013), could be used with little differences. At the third step, for the narrow streams with <50, those proposed by Bansal (1971) and Deng et al. (2001) were preferable to estimate the transverse dispersion coefficient for two-dimensional mixing models. In wide streams with W/h > 50, the results of Jeon et al. (2007) showed much better agreement with the observed values than the others. (C) 2017 International Association for Hydro-environment Engineering and Research, Asia Pacific Division. Published by Elsevier B.V. All rights reserved.</P>

Laser ignition and controlled explosion of nanoenergetic materials: The role of multi-walled carbon nanotubes

Kim, Ji Hoon,Cho, Myung Hoon,Kim, Kyung Ju,Kim, Soo Hyung Elsevier 2017 Carbon Vol.118 No.-

<P>Laser irradiation permits the remote ignition of nanoenergetic materials (nEMs). To reliably ignite nEMs with lower-power laser irradiation, light-sensitive materials could be added to the nEMs matrix. In this study, we investigated the effects of multi-walled carbon nanotubes (MWCNTs) on the combustion and explosion characteristics of laser irradiation-ignited nEMs. The threshold power and delay time of ignition gradually decreased with increases in the MWCNT contents of Al nanoparticle (NP)/CuO NP-based nEMs. The threshold power and delay time of MWCNT (10 wt%)/Al NP/CuO NP ignition were reduced to similar to 40% and similar to 50%, respectively, of those of MWCNT (10 wt%)/Al NP/CuO NP. This suggests that the MWCNTs act as effective optical igniters by absorbing irradiated laser beams and subsequently generating heat by the photo-thermal effect, promoting nEMs ignition. The optimal addition of <= 2 wt% MWCNTs in the nEMs matrix enhanced the pressurization rate, flame propagation speed, and pressure wave speed of nEMs because the MWCNTs rapidly transferred heat energy from nEMs combustion. However, adding excess MWCNTs suppressed the combustion and explosion characteristics of the Al NP/CuO NP-based nEMs matrix by heat dissipation and thermochemical interventions. This suggests that MWCNTs can potentially control the combustion and explosion characteristics of Al NP/CuO NP-based nEMs. (C) 2017 Elsevier Ltd. All rights reserved.</P>

Heavily aluminated graphene nanoplatelets as an efficient flame-retardant

Jeon, In-Yup,Shin, Sun-Hee,Choi, Hyun-Jung,Yu, Soo-Young,Jung, Sun-Min,Baek, Jong-Beom Elsevier 2017 Carbon Vol.116 No.-

<P>Substantial amounts of aluminum (Al), which is one of the most abundant elements and period III post transition metals, can be incorporated into graphene nanoplatelets (GnPs) by ball-milling graphite in the presence of solid Al beads. After thoroughly etching away any unreacted Al residues, the structure and properties of the resultant aluminated GnPs (AIGnPs) were characterized using various analytical techniques including transmission electron microscopy (TEM) and time-of-flight secondary ion mass spectroscopy (TOF-SIMS). The results indicate that AIGnPs contain a considerable amount of Al (30.9 wt%, by TEM energy dispersive X-ray spectrum) and display good dispersibility in various solvents, including water. Next, composite films from aqueous AIGnP/poly(vinyl alcohol) (1/4, wt/wt) solutions were cast and tested for flame retardation. The results indicate that AIGnPs could serve as an outstanding flame retardant that operates by both chemical (condensation) and physical (cooling and blocking) mechanisms. This suggests that AIGnPs may provide a promising option for a new, cost-effective, eco-friendly, yet efficient flame retardant. (C) 2017 Elsevier Ltd. All rights reserved.</P>

Flexible transparent electrodes made of core-shell-structured carbon/metal hybrid nanofiber mesh films fabricated via electrospinning and electroplating

Huh, J.W.,Jeon, H.J.,Ahn, C.W. ELSEVIER 2017 CURRENT APPLIED PHYSICS Vol.17 No.11

<P>The development of practical flexible transparent electrodes is one of the major core technology fields for future nanoscale optoelectronics. Despite the many efforts to replace the indium tin oxide (ITO) electrode, preparing practical alternatives that satisfy the essential requirements of flexible transparent electrodes remains a challenge. In this work, core-shell-structured carbon/metal hybrid mesh (CS-CMHM) films, comprised of a metal layer coated onto conductive carbon nanofiber network structures, were fabricated using electrospinning and electroplating and demonstrated potential for use as flexible transparent electrodes. In contrast to previously described techniques that use conventional polymer fibers as sacrificial structures, the conductive carbon nanofibers used in the current technique that we developed provided bi-functionality: they formed conductive core channels and artificial supports of the metal structures. The CS-CMHM films displayed superior optoelectrical, mechanical, and thermal properties: they transmitted similar to 91% of visible light, showed a low sheet resistance of similar to 2.7 Omega/sq, and displayed excellent mechanical stability even after 10000 cycles of bending the films to a radius of 5 mm; also, applying a voltage of only 3 V to a transparent heater based on CS-CMHM films resulted in the temperature of the film surface increasing very rapidly in the first 20 s, and soon thereafter reaching similar to 280 degrees C. Based on these results, we believe that the use of CS-CMHM films and the process we developed to fabricate them open up great opportunities for high-performance flexible transparent electronics. (C) 2017 Elsevier B.V. All rights reserved.</P>