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>

Synthesis of Cr-doped SnO₂ quantum dots and its enhanced photocatalytic activity

Reddy, Ch.Venkata,Babu, B.,Shim, Jaesool Elsevier Sequoia 2017 Materials Science and Engineering B Vol. No.

<P>Chromium (Cr)-doped SnO2 quantum dots (QDs) with various doping concentration have been successfully synthesized using a simple combustion method. The QDs have been characterized by using various techniques. The X-ray diffraction patterns revealed that the prepared QDs have monophasic tetragonal rutile-type crystallite structure with an average crystallite size of similar to 3 nm. The optical band gap energies of QDs increased with increasing the Cr ion concentration. The XPS spectra reveal the presence of Sn4+, Cr3+, and O respectively. Cr (0.03 mol%)-doped SnO2 QDs are exhibited the greater photocatalytic activity compared with other photocatalysts, which is attributed mainly due to quantum confinement effect and an increase in specific surface area. The existence of a Cr3+ as shown from XPS spectra, act as an electron acceptor and/or hole donor, which enhancing longer survived charge carrier separation in Cr-doped SnO2 QDs as confirmed by PL spectroscopy. (C) 2017 Elsevier B.V. All rights reserved.</P>

Pb(Zr,Ti)O₃-Pb(Mn_1/3Nb_2/3)O₃ piezoelectric thick films by aerosol deposition

Ryu, J.,Choi, J.J.,Hahn, B.D.,Yoon, W.H.,Lee, B.K.,Choi, J.H.,Park, D.S. Elsevier Sequoia 2010 Materials Science and Engineering B Vol. No.

<P>Piezoelectric thick films of Pb(Zr,Ti)O-3-Pb(Mn1/3Nb2/3)O-3 (PZT-PMnN) with Zr:Ti ratios ranging from 0.45:0.55 to 0.60:0.40 were fabricated on a platinized silicon wafer by aerosol deposition (AD). All the films were deposited with a thickness of 10 mu m with high density. By adding PMnN to 57:43 PZT, a dielectric constant as low as similar to 660 was achieved while the effective piezoelectric constant was over 140 pC/N. PZT-PMnN with a Zr:Ti ratio of 57:43 thus showed a maximum piezoelectric voltage constant (g(33)) of 23.8 x 10(-3) Vm/N and is a good candidate for high quality thick films for application to high-energy density or high sensitivity, piezoelectric energy harvesters and sensors. (C) 2010 Elsevier B.V. All rights reserved.</P>

Controlled synthesis of highly spherical nano-PbO2 particles and their characterization

Kannan, K.,Muthuraman, G.,Moon, Il Shik Elsevier 2014 Materials letters Vol.123 No.-

This letter describes the chemical synthesis of highly mono-dispersed spherical nano-PbO2. In the first step, sodium borohydride in the presence of TritonX-100 was used to reduce Pb(NO3)(2) to highly spherical nano-Pb, and the second NaOCI was used to oxidize nano-Pb to nano-PbO2 (both reactions were performed at room temperature). TEM, SEM, XRD, and XPS surface analyses showed that the prepared Pb and PbO2 particles were spherical, 95% were mono-dispersed and of the size of 30 nm. In addition, electrochemical active surface area studies confirmed the nano-particulate nature of the prepared PbO2 particles. The developed procedure is straightforward, rapid, performed at room temperature, and scalable to the industrial level. (C) 2014 Elsevier B.V. All rights reserved.

Enhanced efficiency in dye-sensitized solar cells based on mesoporous titanium phosphate photoanode

Park, K.H.,Mondal, S.,Ghosh, S.,Das, S.,Bhaumik, A. Elsevier 2016 Microporous and mesoporous materials Vol.225 No.-

<P>A new bilayer-nanostructured photoanode with mesoporous titanium phosphate (MTP1) as overlayer and titanium dioxide (TiO2) as underlayer has been fabricated. Mesoporous titanium phosphate material with high surface area (442 m(2) g(-1)) has been synthesized hydrothermally by using a new tailor made gemini surfactant under acidic pH conditions. HR TEM and N-2 sorption analysis revealed the presence of disordered mesopores of dimension ca. 4.50 nm in MTP1 material. Open-circuit voltage decay (OCVD) spectroscopy is used to investigate the kinetic process of electron transport and recombination within TiO2/TiO2, MTP1/TiO2, or MTP1/MTP1 based DSSCs, revealing a faster electron transport rate and a lower recombination rate in the MTP1/TiO2 photoanode. The energy conversion efficiency of dye-sensitized solar cells (DSSCs) based on such a MTP1/TiO2 photoelectrode shows a significant enhancement (6.0%) compared to TiO2/TiO2 photoelectrode (5.5%) with similar thickness (similar to 7 mu m), suggesting the favorable electron transport rate in former. (C) 2016 Elsevier Inc. All rights reserved.</P>

Preparation of randomly distributed micro-lens arrays fabricated from porous polymer film and their application as a light extraction component

Suh, M.C.,Pyo, B.,Lim, B.W.,Kim, N.S. ELSEVIER 2016 ORGANIC ELECTRONICS Vol.38 No.-

<P>We fabricated a randomly distributed micro-lens array (RDMLA) to improve the external quantum efficiency of organic light emitting diodes (OLED). We,prepared three different types of RDMLA with different size distribution (L1 pattern: 0.3-0.5 mu m, L2 pattern: 1.0-1.2 mu m, L3 pattern: 3.0-5.0 mu m). To control the average size of RDMLA, we prepared porous polymer film with an average pore size similar to that of RDMLA to utilize it as a template for simple imprinting technology. Especially, the RDMLA having L2 structure showed the best external quantum efficiency which was improved by 28.5% compared to that without RDMLA. (C) 2016 Elsevier EV. All rights reserved.</P>

Prognostic value of nutritional and hematologic markers in head and neck squamous cell carcinoma treated by chemoradiotherapy

Moon, H.,Roh, J.L.,Lee, S.w.,Kim, S.B.,Choi, S.H.,Nam, S.Y.,Kim, S.Y. Elsevier Science Publishers 2016 Radiotherapy and oncology Vol.118 No.2

<P>Purpose: Malnutrition and systemic lymphopenia are common in many cancers and are associated with tumor progression. The purpose of this study was to investigate the prognostic values of nutritional and hematologic markers in patients with head and neck squamous cell carcinoma (HNSCC). Methods: This prospective study included 153 patients with treatment-naive HNSCC who underwent definitive chemoradiotherapy. Body weight, serologic and hematologic parameters were measured at baseline and after 2 months of treatment. Univariate and multivariate analyses using Cox proportional hazards model were used to identify predictors of progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS). Results: Body weight, body mass index (BMI), serum albumin, total serum proteins, hemoglobin, and circulating neutrophil, lymphocyte, monocyte, and platelet counts significantly decreased, but neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) significantly increased after 2 months of treatment (P < 0.05 each). Multivariate analyses showed that pretreatment hypoalbuminemia and high NLR were independent predictors of PFS (P < 0.01 each). ECOG performance status, BMI < 18.5 kg/m(2) and NLR were independent predictors of CSS and OS (P < 0.01 each). Conclusions: Our data support the evidence that several nutritional and hematologic markers are associated with the prognosis of HNSCC. (C) 2015 Elsevier Ireland Ltd. All rights reserved.</P>

Optical anisotropy and diamagnetic energy shifts in InP-GaP lateral quantum wells

Shin, Y.H.,Kim, Yongmin,Song, J.D.,Lee, Y.T.,Saito, H.,Nakamura, D.,Matsuda, Y.H.,Takeyama, S. Elsevier 2014 Journal of luminescence Vol.151 No.-

Linearly polarized photoluminescence (PL) measurements were made from InP-GaP lateral multiple quantum wells induced by composition modulation along the lateral direction. At B=0, two prominent emission peaks emerged, which are identified as transitions from In-rich well and Ga-rich barrier. regions. Both transitions are strongly linear polarized parallel to the [110] crystal direction. While rotating PL orientation from [110] to [1-10] direction, the well and barrier transitions show red- and blue-shifts, respectively, due to the different valence states. In high magnetic fields, the two peaks exhibit different diamagnetic energy shifts mainly because of the effective-mass difference in the In-rich and Ga-rich alternate regions along the lateral direction. (C) 2014 Elsevier B.V. All rights reserved.

Micro-ultrasonic welding using thermoplastic-elastomeric composite film

Chan, W.X.,Ng, S.H.,Li, K.H.H.,Park, W.T.,Yoon, Y.J. Elsevier 2016 Journal of materials processing technology Vol. No.

<P>A composite film of PMMA microspheres in PDMS is used as the fusion layer to avoid trapped air and to restrict the flow of the melted polymer during welding. The matrix material selection and distribution of PMMA microspheres is determined by the 1-D theoretical model. The theoretical work reveals that the difference in dynamic modulus between the matrix material and PMMA is the most significant contribution to the viability of this composite ultrasonic welding film. The experiment is conducted with PDMS as the matrix material to determine effect of the concentration of PMMA microspheres as micro energy directors on the welding strength and quality of the proposed methodology with the chosen composite. While there are no visible signs of trapped air in all specimens, the resultant welding strength in this methodology is limited by the particle size range of the PMMA microspheres. For ultrasonic energy input of 1 kJ on a 32 mm x 32 mm sample, the optimum concentration of PMMA microspheres is found to be 0.24. (C) 2016 Elsevier B.V. All rights reserved.</P>