1
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Hunter A, Beck S, Cappelli E, Margot F, Straub M, Alexanian Y, Gatti G, Watson MD, Kim TK, Cacho C, Plumb NC, Shi M, Radović M, Sokolov DA, Mackenzie AP, Zingl M, Mravlje J, Georges A, Baumberger F, Tamai A. Fate of Quasiparticles at High Temperature in the Correlated Metal Sr_{2}RuO_{4}. Phys Rev Lett 2023; 131:236502. [PMID: 38134803 DOI: 10.1103/physrevlett.131.236502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 11/08/2023] [Indexed: 12/24/2023]
Abstract
We study the temperature evolution of quasiparticles in the correlated metal Sr_{2}RuO_{4}. Our angle resolved photoemission data show that quasiparticles persist up to temperatures above 200 K, far beyond the Fermi liquid regime. Extracting the quasiparticle self-energy, we demonstrate that the quasiparticle residue Z increases with increasing temperature. Quasiparticles eventually disappear on approaching the bad metal state of Sr_{2}RuO_{4} not by losing weight but via excessive broadening from super-Planckian scattering. We further show that the Fermi surface of Sr_{2}RuO_{4}-defined as the loci where the spectral function peaks-deflates with increasing temperature. These findings are in semiquantitative agreement with dynamical mean field theory calculations.
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Affiliation(s)
- A Hunter
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - S Beck
- Center for Computational Quantum Physics, Flatiron Institute, 162 Fifth Avenue, New York, New York 10010, USA
| | - E Cappelli
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - F Margot
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - M Straub
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Y Alexanian
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - G Gatti
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - M D Watson
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, United Kingdom
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, United Kingdom
| | - C Cacho
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, United Kingdom
| | - N C Plumb
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M Shi
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M Radović
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - D A Sokolov
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - A P Mackenzie
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - M Zingl
- Center for Computational Quantum Physics, Flatiron Institute, 162 Fifth Avenue, New York, New York 10010, USA
| | - J Mravlje
- Department of Theoretical Physics, Institute Jozef Stefan, Jamova 39, SI-1001 Ljubljana, Slovenia
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000 Ljubljana
| | - A Georges
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
- Center for Computational Quantum Physics, Flatiron Institute, 162 Fifth Avenue, New York, New York 10010, USA
- Collège de France, 11 Place Marcelin Berthelot, 75005 Paris, France
- Centre de Physique Théorique, Ecole Polytechnique, CNRS, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
| | - F Baumberger
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - A Tamai
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
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2
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Honma A, Takane D, Souma S, Yamauchi K, Wang Y, Nakayama K, Sugawara K, Kitamura M, Horiba K, Kumigashira H, Tanaka K, Kim TK, Cacho C, Oguchi T, Takahashi T, Ando Y, Sato T. Antiferromagnetic topological insulator with selectively gapped Dirac cones. Nat Commun 2023; 14:7396. [PMID: 37978297 PMCID: PMC10656484 DOI: 10.1038/s41467-023-42782-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 10/20/2023] [Indexed: 11/19/2023] Open
Abstract
Antiferromagnetic (AF) topological materials offer a fertile ground to explore a variety of quantum phenomena such as axion magnetoelectric dynamics and chiral Majorana fermions. To realize such intriguing states, it is essential to establish a direct link between electronic states and topology in the AF phase, whereas this has been challenging because of the lack of a suitable materials platform. Here we report the experimental realization of the AF topological-insulator phase in NdBi. By using micro-focused angle-resolved photoemission spectroscopy, we discovered contrasting surface electronic states for two types of AF domains; the surface having the out-of-plane component in the AF-ordering vector displays Dirac-cone states with a gigantic energy gap, whereas the surface parallel to the AF-ordering vector hosts gapless Dirac states despite the time-reversal-symmetry breaking. The present results establish an essential role of combined symmetry to protect massless Dirac fermions under the presence of AF order and widen opportunities to realize exotic phenomena utilizing AF topological materials.
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Affiliation(s)
- A Honma
- Department of Physics, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan
| | - D Takane
- Department of Physics, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan
| | - S Souma
- Center for Science and Innovation in Spintronics (CSIS), Tohoku University, Sendai, 980-8577, Japan.
- Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai, 980-8577, Japan.
| | - K Yamauchi
- Center for Spintronics Research Network (CSRN), Osaka University, Toyonaka, Osaka, 560-8531, Japan
| | - Y Wang
- Institute of Physics II, University of Cologne, Köln, 50937, Germany
| | - K Nakayama
- Department of Physics, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Tokyo, 102-0076, Japan
| | - K Sugawara
- Department of Physics, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan
- Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai, 980-8577, Japan
| | - M Kitamura
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, 305-0801, Japan
- National Institutes for Quantum Science and Technology (QST), Sendai, 980-8579, Japan
| | - K Horiba
- National Institutes for Quantum Science and Technology (QST), Sendai, 980-8579, Japan
| | - H Kumigashira
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai, 980-8577, Japan
| | - K Tanaka
- UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki, 444-8585, Japan
| | - T K Kim
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0QX, UK
| | - C Cacho
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0QX, UK
| | - T Oguchi
- Center for Spintronics Research Network (CSRN), Osaka University, Toyonaka, Osaka, 560-8531, Japan
| | - T Takahashi
- Department of Physics, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan
- Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai, 980-8577, Japan
| | - Yoichi Ando
- Institute of Physics II, University of Cologne, Köln, 50937, Germany
| | - T Sato
- Department of Physics, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan.
- Center for Science and Innovation in Spintronics (CSIS), Tohoku University, Sendai, 980-8577, Japan.
- Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai, 980-8577, Japan.
- International Center for Synchrotron Radiation Innov1ation Smart (SRIS), Tohoku University, Sendai, 980-8577, Japan.
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3
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Gatti G, Issing J, Rademaker L, Margot F, de Jong TA, van der Molen SJ, Teyssier J, Kim TK, Watson MD, Cacho C, Dudin P, Avila J, Edwards KC, Paruch P, Ubrig N, Gutiérrez-Lezama I, Morpurgo AF, Tamai A, Baumberger F. Flat Γ Moiré Bands in Twisted Bilayer WSe_{2}. Phys Rev Lett 2023; 131:046401. [PMID: 37566843 DOI: 10.1103/physrevlett.131.046401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 06/26/2023] [Indexed: 08/13/2023]
Abstract
The recent observation of correlated phases in transition metal dichalcogenide moiré systems at integer and fractional filling promises new insight into metal-insulator transitions and the unusual states of matter that can emerge near such transitions. Here, we combine real- and momentum-space mapping techniques to study moiré superlattice effects in 57.4° twisted WSe_{2} (tWSe_{2}). Our data reveal a split-off flat band that derives from the monolayer Γ states. Using advanced data analysis, we directly quantify the moiré potential from our data. We further demonstrate that the global valence band maximum in tWSe_{2} is close in energy to this flat band but derives from the monolayer K states which show weaker superlattice effects. These results constrain theoretical models and open the perspective that Γ-valley flat bands might be involved in the correlated physics of twisted WSe_{2}.
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Affiliation(s)
- G Gatti
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - J Issing
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - L Rademaker
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
- Department of Theoretical Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - F Margot
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - T A de Jong
- Huygens-Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, Leiden, The Netherlands
| | - S J van der Molen
- Huygens-Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, Leiden, The Netherlands
| | - J Teyssier
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, United Kingdom
| | - M D Watson
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, United Kingdom
| | - C Cacho
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, United Kingdom
| | - P Dudin
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin-BP 48, 91192 Gif sur Yvette Cedex, France
| | - J Avila
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin-BP 48, 91192 Gif sur Yvette Cedex, France
| | - K Cordero Edwards
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - P Paruch
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - N Ubrig
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
- Department of Applied Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - I Gutiérrez-Lezama
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
- Department of Applied Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - A F Morpurgo
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
- Department of Applied Physics, University of Geneva, 24 Quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - A Tamai
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
| | - F Baumberger
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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4
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Lee S, Kim HJ, Kim JH, Kim TK, Kang CN, Lee JH, Cho JH, Kim SH, Moon SH. Evaluation of the efficacy and safety of NVP-1203 and aceclofenac in patients with acute low back pain and muscle spasm: A randomized, double-blind, active-controlled, parallel, multicenter, phase 3 clinical trial. Eur Rev Med Pharmacol Sci 2023; 27:315-324. [PMID: 36647880 DOI: 10.26355/eurrev_202301_30878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
OBJECTIVE Acute low back pain (LBP) is a common condition that can be chronic if not properly treated. Aceclofenac and eperisone hydrochloride are commonly prescribed drugs for acute LBP and muscle spasms. Therefore, NVP-1203, a fixed-dose combination of 100 mg aceclofenac and 75 mg eperisone hydrochloride, is being developed. This study aimed to evaluate the efficacy and safety of NVP-1203 compared to those of a single administration of 100 mg aceclofenac in patients with acute LBP and muscle spasms. PATIENTS AND METHODS Overall, 455 patients with acute LBP and muscle spasms were enrolled. The patients were assigned to NVP-1203 or Airtal group (aceclofenac 100 mg). The primary efficacy endpoint was the mean change in the 100 mm pain movement and resting visual analog scale (VAS) scores on treatment day 7. RESULTS The mean change in the 100 mm pain movement/resting VAS scores from baseline to day 7 was -49.7 ± 21.5/-41.0 ± 19.4 mm and -38.8 ± 18.9/-33.8 ± 18.0 mm for the NVP-1203 and Airtal groups, respectively. The differences between the two groups were statistically significant (movement, p < 0.0001; resting, p = 0.0002). Differences in least-square (LS) mean change of the 100 mm pain movement/resting VAS score between the two groups using the analysis of covariance (ANCOVA) model was -10.2/-7.4 mm, and the upper limit of the 95% confidence interval was -6.44/-4.16 mm. CONCLUSIONS NVP-1203 is more effective in reducing pain than the 100 mg aceclofenac alone. However, the two drugs have similar safety profiles in patients with acute LBP and muscle spasms.
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Affiliation(s)
- S Lee
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Gyeonggi-do, Republic of Korea.
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Noguchi R, Takahashi T, Kuroda K, Ochi M, Shirasawa T, Sakano M, Bareille C, Nakayama M, Watson MD, Yaji K, Harasawa A, Iwasawa H, Dudin P, Kim TK, Hoesch M, Kandyba V, Giampietri A, Barinov A, Shin S, Arita R, Sasagawa T, Kondo T. Publisher Correction: A weak topological insulator state in quasi-one-dimensional bismuth iodide. Nature 2020; 584:E4. [PMID: 32690939 DOI: 10.1038/s41586-020-2392-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Affiliation(s)
- Ryo Noguchi
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - T Takahashi
- Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama, Japan
| | - K Kuroda
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - M Ochi
- Department of Physics, Osaka University, Toyonaka, Japan
| | - T Shirasawa
- National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | - M Sakano
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan.,Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo, Japan
| | - C Bareille
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - M Nakayama
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - M D Watson
- Diamond Light Source, Harwell Campus, Didcot, UK
| | - K Yaji
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - A Harasawa
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - H Iwasawa
- Diamond Light Source, Harwell Campus, Didcot, UK.,Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan
| | - P Dudin
- Diamond Light Source, Harwell Campus, Didcot, UK
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot, UK
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot, UK.,DESY Photon Science, Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - V Kandyba
- Elettra - Sincrotrone Trieste, Basovizza, Italy
| | | | - A Barinov
- Elettra - Sincrotrone Trieste, Basovizza, Italy
| | - S Shin
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan
| | - R Arita
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
| | - T Sasagawa
- Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama, Japan.
| | - Takeshi Kondo
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Japan.
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6
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Cucchi I, Marrazzo A, Cappelli E, Riccò S, Bruno FY, Lisi S, Hoesch M, Kim TK, Cacho C, Besnard C, Giannini E, Marzari N, Gibertini M, Baumberger F, Tamai A. Bulk and Surface Electronic Structure of the Dual-Topology Semimetal Pt_{2}HgSe_{3}. Phys Rev Lett 2020; 124:106402. [PMID: 32216410 DOI: 10.1103/physrevlett.124.106402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 02/14/2020] [Indexed: 06/10/2023]
Abstract
We report high-resolution angle-resolved photoemission measurements on single crystals of Pt_{2}HgSe_{3} grown by high-pressure synthesis. Our data reveal a gapped Dirac nodal line whose (001) projection separates the surface Brillouin zone in topological and trivial areas. In the nontrivial k-space range, we find surface states with multiple saddle points in the dispersion, resulting in two van Hove singularities in the surface density of states. Based on density-functional theory calculations, we identify these surface states as signatures of a topological crystalline state, which coexists with a weak topological phase.
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Affiliation(s)
- I Cucchi
- Department of Quantum Matter Physics, University of Geneva, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - A Marrazzo
- Theory and Simulation of Materials (THEOS), and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - E Cappelli
- Department of Quantum Matter Physics, University of Geneva, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - S Riccò
- Department of Quantum Matter Physics, University of Geneva, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - F Y Bruno
- Department of Quantum Matter Physics, University of Geneva, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
- GFMC, Departamento de Física de Materiales, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - S Lisi
- Department of Quantum Matter Physics, University of Geneva, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
- Deutsches Elektronen-Synchrotron DESY, Photon Science, 22607 Hamburg, Germany
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - C Cacho
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - C Besnard
- Department of Quantum Matter Physics, University of Geneva, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - E Giannini
- Department of Quantum Matter Physics, University of Geneva, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
| | - N Marzari
- Theory and Simulation of Materials (THEOS), and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - M Gibertini
- Department of Quantum Matter Physics, University of Geneva, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
- Theory and Simulation of Materials (THEOS), and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - F Baumberger
- Department of Quantum Matter Physics, University of Geneva, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
- Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - A Tamai
- Department of Quantum Matter Physics, University of Geneva, 24 quai Ernest Ansermet, CH-1211 Geneva, Switzerland
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7
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Kim HJ, Oh SY, Won SY, Kim HJ, Kim TK, Ko BC, Woo SY, Park EC. Associations between earplug use and hearing loss in ROK military personnel. BMJ Mil Health 2020; 167:398-401. [PMID: 32139412 PMCID: PMC8639962 DOI: 10.1136/jramc-2019-001378] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/14/2019] [Accepted: 12/17/2019] [Indexed: 12/05/2022]
Abstract
Introduction The easiest way to prevent noise-induced hearing loss (NIHL) is to wear earplugs. The Republic of Korea (ROK) Ministry of National Defense (MND) is supplying earplugs to prevent NIHL, but many patients still suffer from this. We speculated that earplugs would have a high NIHL rate, depending on the rate of use of earplugs, regardless of the rate of supply. Therefore, we conducted this study to investigate the relationship between the use of earplugs and hearing loss by ROK military personnel. Methods The study used data from the Military Health Survey conducted in 2014–2015, which included 13 470 questionnaires completed by ROK military personnel. Hearing loss and earplug use were self-reported. Logistic regression analysis was used to assess associations between earplug use and hearing loss. Results The study sample included 13 470 ROK military personnel (response rate of 71.2%) (Army, 8330 (61.8%); Navy/Marines, 2236 (16.6%); and Air Force, 2904 (21.6%)). Overall, 18.8% of Korean military personnel reported that they always wore earplugs, and 2.8% reported hearing loss. In logistic regression analysis, there were significant differences in the rates of hearing loss associated with wearing earplugs sometimes (OR=1.48, 95% CI 1.07 to 2.05) and never wearing earplugs (OR=1.53, 95% CI 1.12 to 2.10). In subgroup analysis, in Air Force, non-combat branch, forward area and long-term military service personnel increased hearing loss was associated with not wearing earplugs. Conclusion Our study confirmed that within the ROK military, there is an association between hearing loss and lack of earplug use. In the ROK MND, Army, Navy/Marines and Air Force headquarters must provide guidelines for the use of earplugs during field training to protect military personnel’s hearings and, if necessary, need to be regulated or institutionalised.
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Affiliation(s)
- Hwi Jun Kim
- Department of Public Health, Graduate School, Yonsei University, Seodaemun-gu, Seoul, Republic of Korea
| | - S Y Oh
- Department of Public Health, Graduate School, Yonsei University, Seodaemun-gu, Seoul, Republic of Korea
| | - S Y Won
- Division of Management Logistics, Korea Ministry of National Defense, Seoul, Republic of Korea
| | - H J Kim
- Division of Medical Corps, Second Operational Command, Daegu, Republic of Korea
| | - T K Kim
- Secretary's office, Armed Forces Medical Command, Seongnam, Republic of Korea
| | - B C Ko
- Department of Operation, 7th Division Medical Detachment, Seoul, Republic of Korea
| | - S Y Woo
- Department of Nursing, Yonsei University, Seodaemun-gu, Seoul, Republic of Korea
| | - E-C Park
- Department of Preventive Medicine, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Republic of Korea
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8
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Clark OJ, Neat MJ, Okawa K, Bawden L, Marković I, Mazzola F, Feng J, Sunko V, Riley JM, Meevasana W, Fujii J, Vobornik I, Kim TK, Hoesch M, Sasagawa T, Wahl P, Bahramy MS, King PDC. Fermiology and Superconductivity of Topological Surface States in PdTe_{2}. Phys Rev Lett 2018; 120:156401. [PMID: 29756894 DOI: 10.1103/physrevlett.120.156401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/17/2018] [Indexed: 05/12/2023]
Abstract
We study the low-energy surface electronic structure of the transition-metal dichalcogenide superconductor PdTe_{2} by spin- and angle-resolved photoemission, scanning tunneling microscopy, and density-functional theory-based supercell calculations. Comparing PdTe_{2} with its sister compound PtSe_{2}, we demonstrate how enhanced interlayer hopping in the Te-based material drives a band inversion within the antibonding p-orbital manifold well above the Fermi level. We show how this mediates spin-polarized topological surface states which form rich multivalley Fermi surfaces with complex spin textures. Scanning tunneling spectroscopy reveals type-II superconductivity at the surface, and moreover shows no evidence for an unconventional component of its superconducting order parameter, despite the presence of topological surface states.
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Affiliation(s)
- O J Clark
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - M J Neat
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - K Okawa
- Materials and Structures Laboratory, Tokyo Institute of Technology, Kanagawa 226-8503, Japan
| | - L Bawden
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - I Marković
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - F Mazzola
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - J Feng
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
- Suzhou Institute of Nano-Tech. and Nanobionics (SINANO), CAS, 398 Ruoshui Road, SEID, SIP, Suzhou 215123, China
| | - V Sunko
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - J M Riley
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - W Meevasana
- School of Physics and Center of Excellence on Advanced Functional Materials, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand
- ThEP, Commission of Higher Education, Bangkok 10400, Thailand
| | - J Fujii
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - I Vobornik
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - T Sasagawa
- Materials and Structures Laboratory, Tokyo Institute of Technology, Kanagawa 226-8503, Japan
| | - P Wahl
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - M S Bahramy
- Quantum-Phase Electronics Center and Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
- RIKEN center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - P D C King
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
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9
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Sunko V, Rosner H, Kushwaha P, Khim S, Mazzola F, Bawden L, Clark OJ, Riley JM, Kasinathan D, Haverkort MW, Kim TK, Hoesch M, Fujii J, Vobornik I, Mackenzie AP, King PDC. Maximal Rashba-like spin splitting via kinetic-energy-coupled inversion-symmetry breaking. Nature 2018; 549:492-496. [PMID: 28959958 DOI: 10.1038/nature23898] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 07/26/2017] [Indexed: 11/09/2022]
Abstract
Engineering and enhancing the breaking of inversion symmetry in solids-that is, allowing electrons to differentiate between 'up' and 'down'-is a key goal in condensed-matter physics and materials science because it can be used to stabilize states that are of fundamental interest and also have potential practical applications. Examples include improved ferroelectrics for memory devices and materials that host Majorana zero modes for quantum computing. Although inversion symmetry is naturally broken in several crystalline environments, such as at surfaces and interfaces, maximizing the influence of this effect on the electronic states of interest remains a challenge. Here we present a mechanism for realizing a much larger coupling of inversion-symmetry breaking to itinerant surface electrons than is typically achieved. The key element is a pronounced asymmetry of surface hopping energies-that is, a kinetic-energy-coupled inversion-symmetry breaking, the energy scale of which is a substantial fraction of the bandwidth. Using spin- and angle-resolved photoemission spectroscopy, we demonstrate that such a strong inversion-symmetry breaking, when combined with spin-orbit interactions, can mediate Rashba-like spin splittings that are much larger than would typically be expected. The energy scale of the inversion-symmetry breaking that we achieve is so large that the spin splitting in the CoO2- and RhO2-derived surface states of delafossite oxides becomes controlled by the full atomic spin-orbit coupling of the 3d and 4d transition metals, resulting in some of the largest known Rashba-like spin splittings. The core structural building blocks that facilitate the bandwidth-scaled inversion-symmetry breaking are common to numerous materials. Our findings therefore provide opportunities for creating spin-textured states and suggest routes to interfacial control of inversion-symmetry breaking in designer heterostructures of oxides and other material classes.
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Affiliation(s)
- Veronika Sunko
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK.,Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - H Rosner
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - P Kushwaha
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - S Khim
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - F Mazzola
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - L Bawden
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - O J Clark
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - J M Riley
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK.,Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - D Kasinathan
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - M W Haverkort
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany.,Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, 69120 Heidelberg, Germany
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - J Fujii
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S.14, Km 163.5, 34149 Trieste, Italy
| | - I Vobornik
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S.14, Km 163.5, 34149 Trieste, Italy
| | - A P Mackenzie
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK.,Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - P D C King
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
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10
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Bahramy MS, Clark OJ, Yang BJ, Feng J, Bawden L, Riley JM, Marković I, Mazzola F, Sunko V, Biswas D, Cooil SP, Jorge M, Wells JW, Leandersson M, Balasubramanian T, Fujii J, Vobornik I, Rault JE, Kim TK, Hoesch M, Okawa K, Asakawa M, Sasagawa T, Eknapakul T, Meevasana W, King PDC. Ubiquitous formation of bulk Dirac cones and topological surface states from a single orbital manifold in transition-metal dichalcogenides. Nat Mater 2018; 17:21-28. [PMID: 29180775 DOI: 10.1038/nmat5031] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 10/13/2017] [Indexed: 05/12/2023]
Abstract
Transition-metal dichalcogenides (TMDs) are renowned for their rich and varied bulk properties, while their single-layer variants have become one of the most prominent examples of two-dimensional materials beyond graphene. Their disparate ground states largely depend on transition metal d-electron-derived electronic states, on which the vast majority of attention has been concentrated to date. Here, we focus on the chalcogen-derived states. From density-functional theory calculations together with spin- and angle-resolved photoemission, we find that these generically host a co-existence of type-I and type-II three-dimensional bulk Dirac fermions as well as ladders of topological surface states and surface resonances. We demonstrate how these naturally arise within a single p-orbital manifold as a general consequence of a trigonal crystal field, and as such can be expected across a large number of compounds. Already, we demonstrate their existence in six separate TMDs, opening routes to tune, and ultimately exploit, their topological physics.
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Affiliation(s)
- M S Bahramy
- Quantum-Phase Electronics Center and Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
- RIKEN center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - O J Clark
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
| | - B-J Yang
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Korea
- Center for Theoretical Physics (CTP), Seoul National University, Seoul 08826, Korea
| | - J Feng
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
- Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO) CAS, 398 Ruoshi Road, SEID, SIP, Suzhou 215123, China
| | - L Bawden
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
| | - J M Riley
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - I Marković
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - F Mazzola
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
| | - V Sunko
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - D Biswas
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
| | - S P Cooil
- Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - M Jorge
- Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - J W Wells
- Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - M Leandersson
- MAX IV Laboratory, Lund University, PO Box 118, 221 00 Lund, Sweden
| | | | - J Fujii
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - I Vobornik
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - J E Rault
- Synchrotron SOLEIL, CNRS-CEA, L'Orme des Merisiers, Saint-Aubin-BP48, 91192 Gif-sur-Yvette, France
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - K Okawa
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Kanagawa 226-8503, Japan
| | - M Asakawa
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Kanagawa 226-8503, Japan
| | - T Sasagawa
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Kanagawa 226-8503, Japan
| | - T Eknapakul
- School of Physics and Center of Excellence on Advanced Functional Materials, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - W Meevasana
- School of Physics and Center of Excellence on Advanced Functional Materials, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
- ThEP, Commission of Higher Education, Bangkok 10400, Thailand
| | - P D C King
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
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11
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Kim M, Lee EJ, Shin HM, Jung HS, Kim TK, Kim TN, Kwon MJ, Lee SH, Rhee BD, Park JH. The effect of PPARγ agonist on SGLT2 and glucagon expressions in alpha cells under hyperglycemia. J Endocrinol Invest 2017; 40:1069-1076. [PMID: 28391584 DOI: 10.1007/s40618-017-0659-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 03/17/2017] [Indexed: 12/28/2022]
Abstract
BACKGROUND Although sodium glucose cotransporter 2 (SGLT2) inhibitors have many beneficial effects for type 2 diabetes, including decreased cardiovascular death, recent reports that they increased glucagon through SGLT2 inhibition raised some concern. Troglitazone, Peroxisome proliferator-activated receptor γ (PPAR-γ) agonist, was reported to increase SGLT2 in renal proximal tubule cells, but its role on pancreatic alpha cells have not been reported. We investigated the effect of troglitazone on SGLT2 expression in alpha cells and subsequent glucagon regulation in hyperglycemia. METHODS An Alpha TC1-6 cell line was cultured in control (5 mM) or hyperglycemia (HG, 15 mM) for 72 h. We applied troglitazone with or without PPARγ antagonist (GW9662 10 μM). To investigate the involvement of PI3K/Akt pathway, we applied troglitazone with or without Wortmanin. We measured sodium glucose transporter 2 (SGLT2) and glucagon (GCG) mRNA and protein expression. PPAR gamma, PI3K and Akt protein were also measured. RESULTS Exposure of alpha TC cells to HG for 72 h increased glucagon mRNA and protein expression. HG decreased SGLT2 mRNA and protein expression. Troglitazone significantly reversed HG-induced reduction of SGLT2 expression and increase of glucagon secretion. PPARγ antagonist (GW9662 10 μM) decreased the expression of SGLT2 and increased glucagon as HG did. Hyperglycemia increased PI3K and pAkt expression in alpha cells. Wortmanin (PI3K inhibitor, 1 μM) reversed HG-induced SGLT2 decrease and glucagon increase. Troglitazone treatment decreased PI3K and pAkt expression in HG. CONCLUSION In conclusion, PPARγ agonist, troglitazone improved glucose transport SGLT2 dysfunction and subsequent glucagon dysregulation in alpha cell under hyperglycemia. Those effects were through the involvement of PI3K/pAkt signaling pathway. This study may add one more reason for the ideal combination of PPARγ agonist and SGLT2 inhibitor in clinical practice.
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Affiliation(s)
- M Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, 875, Hauendae-ro, Hauendae-gu, Busan, 612-862, South Korea.
- Molecular Therapy Lab, Paik Institute for Clinical Research, Inje University, Busan, South Korea.
| | - E J Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, 875, Hauendae-ro, Hauendae-gu, Busan, 612-862, South Korea
| | - H M Shin
- Molecular Therapy Lab, Paik Institute for Clinical Research, Inje University, Busan, South Korea
| | - H S Jung
- Molecular Therapy Lab, Paik Institute for Clinical Research, Inje University, Busan, South Korea
| | - T K Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, 875, Hauendae-ro, Hauendae-gu, Busan, 612-862, South Korea
| | - T N Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, 875, Hauendae-ro, Hauendae-gu, Busan, 612-862, South Korea
| | - M J Kwon
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, 875, Hauendae-ro, Hauendae-gu, Busan, 612-862, South Korea
| | - S H Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, 875, Hauendae-ro, Hauendae-gu, Busan, 612-862, South Korea
| | - B D Rhee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, 875, Hauendae-ro, Hauendae-gu, Busan, 612-862, South Korea
| | - J H Park
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, 875, Hauendae-ro, Hauendae-gu, Busan, 612-862, South Korea
- Molecular Therapy Lab, Paik Institute for Clinical Research, Inje University, Busan, South Korea
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12
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Cho YJ, Jo WY, Oh H, Koo CH, Oh J, Cho JY, Yu KS, Jeon Y, Kim TK. Performance of the Minto model for the target-controlled infusion of remifentanil during cardiopulmonary bypass. Anaesthesia 2017; 72:1196-1205. [PMID: 28891056 DOI: 10.1111/anae.14019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2017] [Indexed: 02/05/2023]
Abstract
We studied the predictive performance of the Minto pharmacokinetic model during cardiopulmonary bypass in patients undergoing cardiac surgery. Patients received remifentanil target-controlled infusion using the Minto model during total intravenous anaesthesia with propofol. From 56 patients, 275 arterial blood samples were drawn before, during and after bypass to determine the plasma concentration of remifentanil, and the predicted concentrations were recorded at each time. For pooled data, the median prediction error and median absolute prediction error were 21.3% and 21.8%, respectively, and 22.1% and 22.3% during bypass. Both were 148.4% during hypothermic circulatory arrest and measured concentrations were more than three times greater than predicted (26.9 (17.0) vs. 7.1 (1.6) ng.ml-1 ). The Minto model showed considerable bias but overall acceptable precision during bypass. The target concentration of remifentanil should be reduced when using the Minto model during hypothermic circulatory arrest.
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Affiliation(s)
- Y J Cho
- Department of Anaesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, South Korea
| | - W Y Jo
- Department of Anaesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, South Korea
| | - H Oh
- Department of Anaesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, South Korea
| | - C-H Koo
- CHA Bundang Medical Centre, Department of Anaesthesiology and Pain Medicine, Seongnam-si, South Korea
| | - J Oh
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, South Korea
| | - J-Y Cho
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, South Korea
| | - K-S Yu
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, South Korea
| | - Y Jeon
- Department of Anaesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, South Korea
| | - T K Kim
- Department of Anaesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, South Korea
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13
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Sharma G, Liu D, Malhotra R, Zhou YX, Akagi M, Kim TK. Availability of Additional Mediolateral Implant Option During Total Knee Arthroplasty Improves Femoral Component Fit Across Ethnicities: Results of a Multicenter Study. JB JS Open Access 2017; 2:e0014. [PMID: 30229215 PMCID: PMC6132471 DOI: 10.2106/jbjs.oa.16.00014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Background: Anatomical variation may represent a challenge in achieving a close fit between a prosthesis and a patient’s osseous geometry in total knee arthroplasty (TKA). The purposes of this study were to determine whether the shape of the distal part of the femur differs among ethnicities, whether these differences affect the fit of the femoral component of a standard prosthesis, and whether the additional availability of a femoral component with a reduced mediolateral dimension for the same anteroposterior dimension improves femoral component fit across ethnicities. Methods: Femoral dimensions were measured intraoperatively during 967 TKAs performed using the same type of prosthesis in patients of 5 different ethnicities. Aspect ratios were calculated to determine whether the shapes of the femora differed among ethnicities. The component fit (“perfect,” overhang, or underhang) when only standard prostheses were available was compared with the fit when both standard and narrow prostheses were available in all ethnic groups. This enabled us to determine whether the femoral component fit was improved by the additional availability of the narrow version. Results: Wide variations in shape were found among ethnicities as were variations among individuals of the same ethnicity. Differences in shape among ethnicities influenced the rate of overhang. However, overhang was more frequent at the trochlear than at the condylar level across all ethnicities. The availability of both the standard and the narrow femoral components improved the rate of a perfect fit in women in 3 of the 5 ethnic groups and reduced the overhang rate in women in all 5 of the ethnic groups. In contrast, only modest improvements in femoral component fit, which were not statistically significant, were seen in men. Conclusions: The shape of the distal part of the femur varies not only among ethnicities but also within ethnic groups, leading to a high prevalence of overhang when only standard prostheses are available. The additional availability of a femoral component with a reduced mediolateral dimension for the same anteroposterior size can reduce overhang and improve component fit across ethnicities.
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Affiliation(s)
- Gaurav Sharma
- Joint Reconstruction Center, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Republic of Korea
| | - David Liu
- Gold Coast Centre for Bone and Joint Surgery, John Flynn Private Hospital, Gold Coast, Queensland, Australia
| | - Rajesh Malhotra
- Department of Orthopaedics, All India Institute of Medical Sciences, New Delhi, India
| | - Yi Xin Zhou
- Department of Orthopaedic Surgery, Beijing Jishuitan Hospital, Fourth Clinical College of Peking University, Beijing, China
| | - Masao Akagi
- Department of Orthopaedic Surgery, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
| | - T K Kim
- Joint Reconstruction Center, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Republic of Korea
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14
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Sutter D, Fatuzzo CG, Moser S, Kim M, Fittipaldi R, Vecchione A, Granata V, Sassa Y, Cossalter F, Gatti G, Grioni M, Rønnow HM, Plumb NC, Matt CE, Shi M, Hoesch M, Kim TK, Chang TR, Jeng HT, Jozwiak C, Bostwick A, Rotenberg E, Georges A, Neupert T, Chang J. Hallmarks of Hunds coupling in the Mott insulator Ca 2RuO 4. Nat Commun 2017; 8:15176. [PMID: 28474681 PMCID: PMC5424259 DOI: 10.1038/ncomms15176] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 03/03/2017] [Indexed: 11/20/2022] Open
Abstract
A paradigmatic case of multi-band Mott physics including spin-orbit and Hund's coupling is realized in Ca2RuO4. Progress in understanding the nature of this Mott insulating phase has been impeded by the lack of knowledge about the low-energy electronic structure. Here we provide—using angle-resolved photoemission electron spectroscopy—the band structure of the paramagnetic insulating phase of Ca2RuO4 and show how it features several distinct energy scales. Comparison to a simple analysis of atomic multiplets provides a quantitative estimate of the Hund's coupling J=0.4 eV. Furthermore, the experimental spectra are in good agreement with electronic structure calculations performed with Dynamical Mean-Field Theory. The crystal field stabilization of the dxy orbital due to c-axis contraction is shown to be essential to explain the insulating phase. These results underscore the importance of multi-band physics, Coulomb interaction and Hund's coupling that together generate the Mott insulating state of Ca2RuO4. Detailed knowledge of the low-energy electronic structure is required to understand the Mott insulating phase of Ca2RuO4. Here, Sutter et al. provide directly the experimental band structure of the paramagnetic insulating phase of Ca2RuO4 and unveil the electronic origin of its Mott phase.
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Affiliation(s)
- D Sutter
- Physik-Institut, Universität Zürich, Winterthurerstrasse 190, Zürich CH-8057, Switzerland
| | - C G Fatuzzo
- Institute of Physics, École Polytechnique Fedérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - S Moser
- Advanced Light Source (ALS), Berkeley, California 94720, USA
| | - M Kim
- College de France, Paris Cedex 05 75231, France.,Centre de Physique Théorique, Ecole Polytechnique, CNRS, Univ Paris-Saclay, Palaiseau 91128, France
| | - R Fittipaldi
- CNR-SPIN, Fisciano, Salerno I-84084, Italy.,Dipartimento di Fisica 'E.R. Caianiello', Università di Salerno, Fisciano, Salerno I-84084, Italy
| | - A Vecchione
- CNR-SPIN, Fisciano, Salerno I-84084, Italy.,Dipartimento di Fisica 'E.R. Caianiello', Università di Salerno, Fisciano, Salerno I-84084, Italy
| | - V Granata
- CNR-SPIN, Fisciano, Salerno I-84084, Italy.,Dipartimento di Fisica 'E.R. Caianiello', Università di Salerno, Fisciano, Salerno I-84084, Italy
| | - Y Sassa
- Department of Physics and Astronomy, Uppsala University, Uppsala S-75121, Sweden
| | - F Cossalter
- Physik-Institut, Universität Zürich, Winterthurerstrasse 190, Zürich CH-8057, Switzerland
| | - G Gatti
- Institute of Physics, École Polytechnique Fedérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - M Grioni
- Institute of Physics, École Polytechnique Fedérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - H M Rønnow
- Institute of Physics, École Polytechnique Fedérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - N C Plumb
- Swiss Light Source, Paul Scherrer Institut, Villigen PSI CH-5232, Switzerland
| | - C E Matt
- Swiss Light Source, Paul Scherrer Institut, Villigen PSI CH-5232, Switzerland
| | - M Shi
- Swiss Light Source, Paul Scherrer Institut, Villigen PSI CH-5232, Switzerland
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - T-R Chang
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan.,Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - H-T Jeng
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan.,Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - C Jozwiak
- Advanced Light Source (ALS), Berkeley, California 94720, USA
| | - A Bostwick
- Advanced Light Source (ALS), Berkeley, California 94720, USA
| | - E Rotenberg
- Advanced Light Source (ALS), Berkeley, California 94720, USA
| | - A Georges
- College de France, Paris Cedex 05 75231, France.,Centre de Physique Théorique, Ecole Polytechnique, CNRS, Univ Paris-Saclay, Palaiseau 91128, France.,Department of Quantum Matter Physics, University of Geneva, Geneva 4 1211, Switzerland
| | - T Neupert
- Physik-Institut, Universität Zürich, Winterthurerstrasse 190, Zürich CH-8057, Switzerland
| | - J Chang
- Physik-Institut, Universität Zürich, Winterthurerstrasse 190, Zürich CH-8057, Switzerland
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15
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Kim J, Lee HH, Kang Y, Kim TK, Lee SW, So Y, Lee WW. Maximum standardised uptake value of quantitative bone SPECT/CT in patients with medial compartment osteoarthritis of the knee. Clin Radiol 2017; 72:580-589. [PMID: 28400059 DOI: 10.1016/j.crad.2017.03.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/08/2017] [Accepted: 03/14/2017] [Indexed: 11/16/2022]
Abstract
AIM To evaluate the correlation between the maximum standardised uptake value (SUVmax) from bone single-photon-emission computed tomography/computed tomography (SPECT/CT) and other imaging parameters for medial compartment osteoarthritis (OA) of the knee. MATERIALS AND METHODS Patients (n=26; male:female=2:24; age, 55.3±5.8 years) underwent quantitative knee SPECT/CT using technetium-99m (Tc-99m) hydroxymethylene diphosphonate (HDP) before surgical operation for medial OA of the knee. SUVmax was calculated using dedicated quantitative software. Visual grades of tracer uptake on bone SPECT/CT and Kellgren-Lawrence (KL) OA scores on plain radiographs were assessed using a five-point scale. Magnetic resonance imaging (MRI) scores (n=22) and patient symptom scores were also assessed. RESULTS The operated knees (n=34) had a greater SUVmax than the non-operated knees (n=18) in the medial compartment (14.1±6.1 versus 5.3±4.4, p<0.0001). In the medial compartment, the SUVmax was significantly correlated with SPECT/CT visual grades (rho=0.794, p<0.0001), KL scores (rho=0.703, p<0.0001), and MRI scores (rho=0.714-0.808, p≤0.0002); however, SUVmax and other imaging parameters were not correlated with patient symptom scores (p>0.05). CONCLUSIONS The SUVmax of quantitative bone SPECT/CT was highly correlated with traditional imaging parameters for medial compartment OA severity of the knee. Quantitative bone SPECT/CT is a promising imaging technique for the objective assessment of knee OA.
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Affiliation(s)
- J Kim
- Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - H-H Lee
- Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Y Kang
- Department of Radiology, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - T K Kim
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - S W Lee
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Y So
- Department of Nuclear Medicine, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - W W Lee
- Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea; Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Republic of Korea.
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16
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Hoesch M, Kim TK, Dudin P, Wang H, Scott S, Harris P, Patel S, Matthews M, Hawkins D, Alcock SG, Richter T, Mudd JJ, Basham M, Pratt L, Leicester P, Longhi EC, Tamai A, Baumberger F. A facility for the analysis of the electronic structures of solids and their surfaces by synchrotron radiation photoelectron spectroscopy. Rev Sci Instrum 2017; 88:013106. [PMID: 28147670 DOI: 10.1063/1.4973562] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A synchrotron radiation beamline in the photon energy range of 18-240 eV and an electron spectroscopy end station have been constructed at the 3 GeV Diamond Light Source storage ring. The instrument features a variable polarisation undulator, a high resolution monochromator, a re-focussing system to form a beam spot of 50 × 50 μm2, and an end station for angle-resolved photoelectron spectroscopy (ARPES) including a 6-degrees-of-freedom cryogenic sample manipulator. The beamline design and its performance allow for a highly productive and precise use of the ARPES technique at an energy resolution of 10-15 meV for fast k-space mapping studies with a photon flux up to 2 ⋅ 1013 ph/s and well below 3 meV for high resolution spectra.
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Affiliation(s)
- M Hoesch
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - T K Kim
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - P Dudin
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - H Wang
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - S Scott
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - P Harris
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - S Patel
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - M Matthews
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - D Hawkins
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - S G Alcock
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - T Richter
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - J J Mudd
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - M Basham
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - L Pratt
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - P Leicester
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - E C Longhi
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - A Tamai
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - F Baumberger
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
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17
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Wang Z, McKeown Walker S, Tamai A, Wang Y, Ristic Z, Bruno FY, de la Torre A, Riccò S, Plumb NC, Shi M, Hlawenka P, Sánchez-Barriga J, Varykhalov A, Kim TK, Hoesch M, King PDC, Meevasana W, Diebold U, Mesot J, Moritz B, Devereaux TP, Radovic M, Baumberger F. Tailoring the nature and strength of electron-phonon interactions in the SrTiO3(001) 2D electron liquid. Nat Mater 2016; 15:835-839. [PMID: 27064529 DOI: 10.1038/nmat4623] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 03/10/2016] [Indexed: 06/05/2023]
Abstract
Surfaces and interfaces offer new possibilities for tailoring the many-body interactions that dominate the electrical and thermal properties of transition metal oxides. Here, we use the prototypical two-dimensional electron liquid (2DEL) at the SrTiO3(001) surface to reveal a remarkably complex evolution of electron-phonon coupling with the tunable carrier density of this system. At low density, where superconductivity is found in the analogous 2DEL at the LaAlO3/SrTiO3 interface, our angle-resolved photoemission data show replica bands separated by 100 meV from the main bands. This is a hallmark of a coherent polaronic liquid and implies long-range coupling to a single longitudinal optical phonon branch. In the overdoped regime the preferential coupling to this branch decreases and the 2DEL undergoes a crossover to a more conventional metallic state with weaker short-range electron-phonon interaction. These results place constraints on the theoretical description of superconductivity and allow a unified understanding of the transport properties in SrTiO3-based 2DELs.
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Affiliation(s)
- Z Wang
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - S McKeown Walker
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - A Tamai
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Y Wang
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - Z Ristic
- Institute of Condensed Matter Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - F Y Bruno
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - A de la Torre
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - S Riccò
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - N C Plumb
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M Shi
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - P Hlawenka
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY-II, 12489 Berlin, Germany
| | - J Sánchez-Barriga
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY-II, 12489 Berlin, Germany
| | - A Varykhalov
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY-II, 12489 Berlin, Germany
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - P D C King
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
| | - W Meevasana
- School of Physics and NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - U Diebold
- Institute of Applied Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10/134, A-1040 Vienna, Austria
| | - J Mesot
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Institute of Condensed Matter Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Laboratory for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - B Moritz
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - T P Devereaux
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA
| | - M Radovic
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- SwissFEL, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - F Baumberger
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
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18
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Lee W, Park HK, Lee DJ, Nam YU, Leem J, Kim TK. Design of a collective scattering system for small scale turbulence study in Korea Superconducting Tokamak Advanced Research. Rev Sci Instrum 2016; 87:043501. [PMID: 27131668 DOI: 10.1063/1.4944834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The design characteristics of a multi-channel collective (or coherent) scattering system for small scale turbulence study in Korea Superconducting Tokamak Advanced Research (KSTAR), which is planned to be installed in 2017, are given in this paper. A few critical issues are discussed in depth such as the Faraday and Cotton-Mouton effects on the beam polarization, radial spatial resolution, probe beam frequency, polarization, and power. A proper and feasible optics with the 300 GHz probe beam, which was designed based on these issues, provides a simultaneous measurement of electron density fluctuations at four discrete poloidal wavenumbers up to 24 cm(-1). The upper limit corresponds to the normalized wavenumber kθρe of ∼0.15 in nominal KSTAR plasmas. To detect the scattered beam power and extract phase information, a quadrature detection system consisting of four-channel antenna/detector array and electronics will be employed.
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Affiliation(s)
- W Lee
- Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea
| | - H K Park
- Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea
| | - D J Lee
- Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea
| | - Y U Nam
- National Fusion Research Institute, Daejeon 34133, South Korea
| | - J Leem
- Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, South Korea
| | - T K Kim
- Kyunpook National University, Daegu 41566, South Korea
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19
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Oh CY, Kim DY, Jin SM, Kim TK, Kim JP, Jeong ED, Hyun MH, Sim EK, Lee YC, Jin JS. Self-Assembled Silica Nanostructures: Simultaneous Discrimination of Handedness, Pitch and Diameter of Helical Silica Nanotubes. J Nanosci Nanotechnol 2016; 16:1988-1992. [PMID: 27433714 DOI: 10.1166/jnn.2016.11956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The left- and right-handed helical silica nanostructures were obtained with the aid of organic templates, the formation of the nanostructures might follow a co-operation self-assembly mechanism. The chirality of the organogel self-assemblies was successfully transcribed in to the silica. The helical pitch and pore size of the silica nanotubes sensitively depended on the optical purity of the neutral gelator in the reaction mixtures.
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20
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Park CS, Kim TK, Kim HG, Kim YJ, Jeoung MH, Lee WR, Go NK, Heo K, Lee S. Therapeutic targeting of tetraspanin8 in epithelial ovarian cancer invasion and metastasis. Oncogene 2016; 35:4540-8. [PMID: 26804173 DOI: 10.1038/onc.2015.520] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 10/27/2015] [Accepted: 11/12/2015] [Indexed: 11/09/2022]
Abstract
Epithelial ovarian cancer (EOC) invasion and metastasis are complex phenomena that result from the coordinated action of many metastatic regulators and must be overcome to improve clinical outcomes for patients with these cancers. The identification of novel therapeutic targets is critical because of the limited success of current treatment regimens, particularly in advanced-stage ovarian cancers. In this study, we found that tetraspanin 8 (TSPAN8) is overexpressed in about 52% (14/27) of EOC tissues and correlates with poor survival. Using small interfering RNA-mediated TSPAN8 knockdown and a competition assay with purified TSPAN8 large extracellular loop (TSPAN8-LEL) protein, we identified TSPAN8-LEL as a key regulator of EOC cell invasion. Furthermore, monotherapy with TSPAN8-blocking antibody we developed shows that antibody-based modulation of TSPAN8-LEL can significantly reduce the incidence of EOC metastasis without severe toxicity in vivo. Finally, we demonstrated that the TSPAN8-blocking antibody promotes the internalization and concomitant downregulation of cell surface TSPAN8. Collectively, our data suggest TSPAN8 as a potential novel therapeutic target in EOCs and antibody targeting of TSPAN8 as an effective strategy for inhibiting invasion and metastasis of TSPAN8-expressing EOCs.
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Affiliation(s)
- C S Park
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea
| | - T-K Kim
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea
| | - H G Kim
- New Experimental Therapeutics Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - Y-J Kim
- Specific Organs Cancer Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - M H Jeoung
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea
| | - W R Lee
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea
| | - N K Go
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea
| | - K Heo
- New Experimental Therapeutics Branch, Research Institute, National Cancer Center, Goyang-si, Korea
| | - S Lee
- Laboratory of Molecular Cancer Therapeutics, Scripps Korea Antibody Institute,, Chuncheon-si, Korea
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21
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Riley JM, Meevasana W, Bawden L, Asakawa M, Takayama T, Eknapakul T, Kim TK, Hoesch M, Mo SK, Takagi H, Sasagawa T, Bahramy MS, King PDC. Negative electronic compressibility and tunable spin splitting in WSe2. Nat Nanotechnol 2015; 10:1043-1047. [PMID: 26389661 DOI: 10.1038/nnano.2015.217] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 08/20/2015] [Indexed: 06/05/2023]
Abstract
Tunable bandgaps, extraordinarily large exciton-binding energies, strong light-matter coupling and a locking of the electron spin with layer and valley pseudospins have established transition-metal dichalcogenides (TMDs) as a unique class of two-dimensional (2D) semiconductors with wide-ranging practical applications. Using angle-resolved photoemission (ARPES), we show here that doping electrons at the surface of the prototypical strong spin-orbit TMD WSe2, akin to applying a gate voltage in a transistor-type device, induces a counterintuitive lowering of the surface chemical potential concomitant with the formation of a multivalley 2D electron gas (2DEG). These measurements provide a direct spectroscopic signature of negative electronic compressibility (NEC), a result of electron-electron interactions, which we find persists to carrier densities approximately three orders of magnitude higher than in typical semiconductor 2DEGs that exhibit this effect. An accompanying tunable spin splitting of the valence bands further reveals a complex interplay between single-particle band-structure evolution and many-body interactions in electrostatically doped TMDs. Understanding and exploiting this will open up new opportunities for advanced electronic and quantum-logic devices.
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Affiliation(s)
- J M Riley
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - W Meevasana
- School of Physics, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
- NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - L Bawden
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
| | - M Asakawa
- Materials and Structures Laboratory, Tokyo Institute of Technology, Kanagawa 226-8503, Japan
| | - T Takayama
- Department of Physics, University of Tokyo, Hongo, Tokyo 113-0033, Japan
- Max Planck Institute for Solid State Research, Stuttgart 70569, Germany
| | - T Eknapakul
- School of Physics, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, UK
| | - S-K Mo
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley California 94720, USA
| | - H Takagi
- Department of Physics, University of Tokyo, Hongo, Tokyo 113-0033, Japan
- Max Planck Institute for Solid State Research, Stuttgart 70569, Germany
| | - T Sasagawa
- Materials and Structures Laboratory, Tokyo Institute of Technology, Kanagawa 226-8503, Japan
| | - M S Bahramy
- Quantum-Phase Electronics Center and Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - P D C King
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK
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22
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de la Torre A, McKeown Walker S, Bruno FY, Riccó S, Wang Z, Gutierrez Lezama I, Scheerer G, Giriat G, Jaccard D, Berthod C, Kim TK, Hoesch M, Hunter EC, Perry RS, Tamai A, Baumberger F. Collapse of the Mott Gap and Emergence of a Nodal Liquid in Lightly Doped Sr(2)IrO(4). Phys Rev Lett 2015; 115:176402. [PMID: 26551128 DOI: 10.1103/physrevlett.115.176402] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Indexed: 06/05/2023]
Abstract
We report angle resolved photoemission experiments on the electron doped Heisenberg antiferromagnet (Sr(1-x)La(x))(2)IrO(4). For a doping level of x=0.05, we find an unusual metallic state with coherent nodal excitations and an antinodal pseudogap bearing strong similarities with underdoped cuprates. This state emerges from a rapid collapse of the Mott gap with doping resulting in a large underlying Fermi surface that is backfolded by a (π,π) reciprocal lattice vector which we attribute to the intrinsic structural distortion of Sr(2)IrO(4).
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Affiliation(s)
- A de la Torre
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - S McKeown Walker
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - F Y Bruno
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - S Riccó
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Z Wang
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - I Gutierrez Lezama
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - G Scheerer
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - G Giriat
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - D Jaccard
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - C Berthod
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - E C Hunter
- School of Physics and Astronomy, The University of Edinburgh, James Clerk Maxwell Building, Mayfield Road, Edinburgh EH9 2TT, United Kingdom
| | - R S Perry
- London Centre for Nanotechnology and UCL Centre for Materials Discovery, University College London, London WC1E 6BT, United Kingdom
| | - A Tamai
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - F Baumberger
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews, Fife KY16 9SS, United Kingdom
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23
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Jiang J, Tang F, Pan XC, Liu HM, Niu XH, Wang YX, Xu DF, Yang HF, Xie BP, Song FQ, Dudin P, Kim TK, Hoesch M, Das PK, Vobornik I, Wan XG, Feng DL. Signature of Strong Spin-Orbital Coupling in the Large Nonsaturating Magnetoresistance Material WTe2. Phys Rev Lett 2015; 115:166601. [PMID: 26550888 DOI: 10.1103/physrevlett.115.166601] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Indexed: 06/05/2023]
Abstract
We report the detailed electronic structure of WTe2 by high resolution angle-resolved photoemission spectroscopy. We resolved a rather complicated Fermi surface of WTe2. Specifically, there are in total nine Fermi pockets, including one hole pocket at the Brillouin zone center Γ, and two hole pockets and two electron pockets on each side of Γ along the Γ-X direction. Remarkably, we have observed circular dichroism in our photoemission spectra, which suggests that the orbital angular momentum exhibits a rich texture at various sections of the Fermi surface. This is further confirmed by our density-functional-theory calculations, where the spin texture is qualitatively reproduced as the conjugate consequence of spin-orbital coupling. Since the spin texture would forbid backscatterings that are directly involved in the resistivity, our data suggest that the spin-orbit coupling and the related spin and orbital angular momentum textures may play an important role in the anomalously large magnetoresistance of WTe2. Furthermore, the large differences among spin textures calculated for magnetic fields along the in-plane and out-of-plane directions also provide a natural explanation of the large field-direction dependence on the magnetoresistance.
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Affiliation(s)
- J Jiang
- State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - F Tang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and College of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - X C Pan
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and College of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - H M Liu
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and College of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - X H Niu
- State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - Y X Wang
- State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - D F Xu
- State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - H F Yang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050, China
| | - B P Xie
- State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - F Q Song
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and College of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - P Dudin
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - P Kumar Das
- CNR-IOM, TASC Laboratory AREA Science Park-Basovizza, 34149 Trieste, Italy
- International Centre for Theoretical Physics, Strada Costiera 11, 34100 Trieste, Italy
| | - I Vobornik
- CNR-IOM, TASC Laboratory AREA Science Park-Basovizza, 34149 Trieste, Italy
| | - X G Wan
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and College of Physics, Nanjing University, Nanjing 210093, People's Republic of China
| | - D L Feng
- State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
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Radulović ŽM, Porter LM, Kim TK, Bakshi M, Mulenga A. Amblyomma americanum tick saliva insulin-like growth factor binding protein-related protein 1 binds insulin but not insulin-like growth factors. Insect Mol Biol 2015; 24:539-550. [PMID: 26108887 PMCID: PMC4560673 DOI: 10.1111/imb.12180] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Silencing Amblyomma americanum insulin-like growth factor binding protein-related protein 1 (AamIGFBP-rP1) mRNA prevented ticks from feeding to repletion. In this study, we used recombinant (r)AamIGFBP-rP1 in a series of assays to obtain further insight into the role(s) of this protein in tick feeding regulation. Our results suggest that AamIGFBP-1 is an antigenic protein that is apparently exclusively expressed in salivary glands. We found that both males and females secrete AamIGFBP-rP1 into the host during feeding and confirmed that female ticks secrete this protein from within 24-48 h after attachment. Our data suggest that native AamIGFBP-rP1 is a functional insulin binding protein in that both yeast- and insect cell-expressed rAamIGFBP-rP1 bound insulin, but not insulin-like growth factors. When subjected to anti-blood clotting and platelet aggregation assays, rAamIGFBP-rP1 did not have any effect. Unlike human IGFBP-rP1, which is controlled by trypsinization, rAamIGFBP-rP1 is resistant to digestion, suggesting that the tick protein may not be under mammalian host control at the tick feeding site. The majority of tick-borne pathogens are transmitted 48 h after the tick has attached. Thus, the demonstrated antigenicity and secretion into the host within 24-48 h of the tick starting to feed makes AamIGFBP-rP1 an attractive target for antitick vaccine development.
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Affiliation(s)
- Ž M Radulović
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
| | - L M Porter
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
| | - T K Kim
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
| | - M Bakshi
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
| | - A Mulenga
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
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25
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He Y, Chevillet JR, Liu G, Kim TK, Wang K. The effects of microRNA on the absorption, distribution, metabolism and excretion of drugs. Br J Pharmacol 2015; 172:2733-47. [PMID: 25296724 PMCID: PMC4439871 DOI: 10.1111/bph.12968] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 09/18/2014] [Accepted: 09/26/2014] [Indexed: 12/17/2022] Open
Abstract
The importance of genetic factors (e.g. sequence variation) in the absorption, distribution, metabolism, excretion (ADME) and overall efficacy of therapeutic agents is well established. Our ability to identify, interpret and utilize these factors is the subject of much clinical investigation and therapeutic development. However, drug ADME and efficacy are also heavily influenced by epigenetic factors such as DNA/histone methylation and non-coding RNAs [especially microRNAs (miRNAs)]. Results from studies using tools, such as in silico miRNA target prediction, in vitro functional assays, nucleic acid profiling/sequencing and high-throughput proteomics, are rapidly expanding our knowledge of these factors and their effects on drug metabolism. Although these studies reveal a complex regulation of drug ADME, an increased understanding of the molecular interplay between the genome, epigenome and transcriptome has the potential to provide practically useful strategies to facilitate drug development, optimize therapeutic efficacy, circumvent adverse effects, yield novel diagnostics and ultimately become an integral component of personalized medicine.
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Affiliation(s)
- Y He
- Institute of Medical Systems Biology, Guangdong Medical CollegeDongguan, Guangdong, China
| | | | - G Liu
- Department of Chemistry and Biochemistry, North Dakota State UniversityFargo, ND, USA
| | - T K Kim
- Institute for Systems BiologySeattle, WA, USA
| | - K Wang
- Institute for Systems BiologySeattle, WA, USA
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26
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Min JJ, Kim HJ, Jung SY, Kim BG, Kwon K, Jung HJ, Kim TK, Hong DM, Park BJ, Jeon Y. Effects of Palonosetron on Perioperative Cardiovascular Complications in Patients Undergoing Noncardiac Surgery With General Anesthesia: A Retrospective Cohort Study. Clin Pharmacol Ther 2015; 98:96-106. [PMID: 25786663 DOI: 10.1002/cpt.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 01/19/2015] [Accepted: 03/13/2015] [Indexed: 11/10/2022]
Abstract
We retrospectively investigated whether palonosetron administered during the induction of general anesthesia is associated with an increased risk of perioperative cardiovascular complications in a single tertiary center cohort consisting of 4,517 palonosetron-exposed patients and 4,517 propensity score-matched patients without palonosetron exposure. The primary endpoint was a composite of perioperative cardiovascular complications, including intraoperative cardiac arrhythmia, intraoperative cardiac death, and myocardial injury within the first postoperative week, and there was no significant difference between the groups (odds ratio [OR] = 1.04; 95% confidence interval [CI] = 0.92-1.19). As secondary endpoints, intraoperative cardioversion, cardiac compression, use of cardiovascular drugs, postoperative hospital stay, and in-hospital mortality showed no differences between the groups. However, the palonosetron group showed decreased intraoperative hypotension (OR = 0.88; 95% CI = 0.79-0.97) and length of postoperative intensive care unit (ICU) stay (4.26 ± 9.86 vs. 6.14 ± 16.75; P = 0.026). Palonosetron did not increase the rate of perioperative cardiovascular complications, and can therefore be used safely during anesthetic induction.
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Affiliation(s)
- J J Min
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - H J Kim
- Department of Anesthesiology and Pain Medicine, Severance Hospital, Seoul, Republic of Korea
| | - S-Y Jung
- Korea Institute of Drug Safety and Risk Management (KIDS), Seoul, Republic of Korea
| | - B G Kim
- Korea Institute of Drug Safety and Risk Management (KIDS), Seoul, Republic of Korea
| | - K Kwon
- Korea Institute of Drug Safety and Risk Management (KIDS), Seoul, Republic of Korea
| | - H-J Jung
- Korea Institute of Drug Safety and Risk Management (KIDS), Seoul, Republic of Korea
| | - T K Kim
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - D M Hong
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - B-J Park
- Korea Institute of Drug Safety and Risk Management (KIDS), Seoul, Republic of Korea.,Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Y Jeon
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea
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27
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Lee KM, Chang CB, Park MS, Kang SB, Kim TK, Chung CY. Changes of knee joint and ankle joint orientations after high tibial osteotomy. Osteoarthritis Cartilage 2015; 23:232-8. [PMID: 25450843 DOI: 10.1016/j.joca.2014.11.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 10/04/2014] [Accepted: 11/02/2014] [Indexed: 02/06/2023]
Abstract
OBJECTIVE We sought to determine (1) whether change in the tibial plateau inclination (TPI) after high tibial osteotomy (HTO) is different from change in the knee joint line orientation (KJLO) relative to the ground; (2) whether, in varus knee OA patients before and after HTO, these radiographic measures are different from those in normal control; and (3) whether the postoperative values of the TPI and KJLO relative to the ground are associated with short term clinical outcome scores after HTO. DESIGN Fifty patients who underwent HTO and 75 normal controls were assessed with four radiographic measures. We compared the measures before HTO with those after HTO and with those of the normal controls, then examined associations between the postoperative radiographic measures and clinical outcome scores 1-year after HTO. RESULTS After HTO, TPI increased 9.0°, whereas KJLO relative to the ground only increased 4.1°, with a compensatory change of the ankle joint line orientation. However, the postoperative KJLO relative to the ground in the HTO group was significantly different from that of the normal controls (mean difference, 4.9°; P < 0.001). In the multiple regression analyses, the postoperative radiographic measures were not associated with outcome clinical scores 1 year after HTO. CONCLUSION After HTO the relative KJLO changed significantly less than did the anatomical geometry of the proximal tibia. Although the KJLO after the HTO was still significantly different from that of normal knees, its value did not adversely affect clinical outcome scores 1 year after HTO.
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Affiliation(s)
- K M Lee
- Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seongnam-si, South Korea
| | - C B Chang
- Department of Orthopaedic Surgery, SMG-SNU Boramae Medical Center, Seoul, South Korea; Department of Orthopaedic Surgery, Seoul National University College of Medicine, South Korea.
| | - M S Park
- Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seongnam-si, South Korea
| | - S-B Kang
- Department of Orthopaedic Surgery, SMG-SNU Boramae Medical Center, Seoul, South Korea; Department of Orthopaedic Surgery, Seoul National University College of Medicine, South Korea
| | - T K Kim
- Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seongnam-si, South Korea; Department of Orthopaedic Surgery, Seoul National University College of Medicine, South Korea
| | - C Y Chung
- Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seongnam-si, South Korea; Department of Orthopaedic Surgery, Seoul National University College of Medicine, South Korea
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28
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de la Torre A, Hunter EC, Subedi A, McKeown Walker S, Tamai A, Kim TK, Hoesch M, Perry RS, Georges A, Baumberger F. Coherent quasiparticles with a small fermi surface in lightly doped Sr(3)Ir(2)O(7). Phys Rev Lett 2014; 113:256402. [PMID: 25554897 DOI: 10.1103/physrevlett.113.256402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Indexed: 06/04/2023]
Abstract
We characterize the electron doping evolution of (Sr_{1-x}La_{x})_{3}Ir_{2}O_{7} by means of angle-resolved photoemission. Concomitant with the metal insulator transition around x≈0.05 we find the emergence of coherent quasiparticle states forming a closed small Fermi surface of volume 3x/2, where x is the independently measured La concentration. The quasiparticle weight Z remains large along the entire Fermi surface, consistent with the moderate renormalization of the low-energy dispersion, and no pseudogap is observed. This indicates a conventional, weakly correlated Fermi liquid state with a momentum independent residue Z≈0.5 in lightly doped Sr_{3}Ir_{2}O_{7}.
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Affiliation(s)
- A de la Torre
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - E C Hunter
- School of Physics and Astronomy, The University of Edinburgh, James Clerk Maxwell Building, Mayfield Road, Edinburgh EH9 2TT, United Kingdom
| | - A Subedi
- Centre de Physique Théorique, École Polytechnique, CNRS, 91128 Palaiseau Cedex, France
| | - S McKeown Walker
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - A Tamai
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - R S Perry
- London Centre for Nanotechnology and UCL Centre for Materials Discovery, University College London, London WC1E 6BT, United Kingdom
| | - A Georges
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland and Centre de Physique Théorique, École Polytechnique, CNRS, 91128 Palaiseau Cedex, France and Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
| | - F Baumberger
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland and Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland and SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, United Kingdom
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29
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Slominski A, Kim TK, Brożyna AA, Janjetovic Z, Brooks DLP, Schwab LP, Skobowiat C, Jóźwicki W, Seagroves TN. The role of melanogenesis in regulation of melanoma behavior: melanogenesis leads to stimulation of HIF-1α expression and HIF-dependent attendant pathways. Arch Biochem Biophys 2014; 563:79-93. [PMID: 24997364 PMCID: PMC4221528 DOI: 10.1016/j.abb.2014.06.030] [Citation(s) in RCA: 162] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/30/2014] [Accepted: 06/24/2014] [Indexed: 12/20/2022]
Abstract
To study the effect of melanogenesis on HIF-1α expression and attendant pathways, we used stable human and hamster melanoma cell lines in which the amelanotic vs. melanotic phenotypes are dependent upon the concentration of melanogenesis precursors in the culture media. The induction of melanin pigmentation led to significant up-regulation of HIF-1α, but not HIF-2α, protein in melanized cells for both lines. Similar upregulation of nuclear HIF-1α was observed in excisions of advanced melanotic vs. amelanotic melanomas. In cultured cells, melanogenesis also significantly stimulated expression of classical HIF-1-dependent target genes involved in angiogenesis and cellular metabolism, including glucose metabolism and stimulation of activity of key enzymes in the glycolytic pathway. Several other stress related genes containing putative HRE consensus sites were also upregulated by melanogenesis, concurrently with modulation of expression of HIF-1-independent genes encoding for steroidogenic enzymes, cytokines and growth factors. Immunohistochemical studies using a large panel of pigmented lesions revealed that higher levels of HIF-1α and GLUT-1 were detected in advanced melanomas in comparison to melanocytic nevi or thin melanomas localized to the skin. However, the effects on overall or disease free survival in melanoma patients were modest or absent for GLUT-1 or for HIF-1α, respectively. In conclusion, induction of the melanogenic pathway leads to robust upregulation of HIF-1-dependent and independent pathways in cultured melanoma cells, suggesting a key role for melanogenesis in regulation of cellular metabolism.
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Affiliation(s)
- A Slominski
- Department of Pathology and Laboratory Medicine, University of Tennessee HSC, Memphis, TN, USA; Department of Medicine, Division of Rheumatology, University of Tennessee HSC, Memphis, TN, USA; Center for Cancer Research, University of Tennessee HSC, Memphis, TN, USA.
| | - T-K Kim
- Department of Pathology and Laboratory Medicine, University of Tennessee HSC, Memphis, TN, USA; Center for Cancer Research, University of Tennessee HSC, Memphis, TN, USA
| | - A A Brożyna
- Department of Tumor Pathology and Pathomorphology, Oncology Centre - Prof. Franciszek Łukaszczyk Memorial Hospital, The Ludwik Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - Z Janjetovic
- Department of Pathology and Laboratory Medicine, University of Tennessee HSC, Memphis, TN, USA; Center for Cancer Research, University of Tennessee HSC, Memphis, TN, USA
| | - D L P Brooks
- Department of Pathology and Laboratory Medicine, University of Tennessee HSC, Memphis, TN, USA; Center for Cancer Research, University of Tennessee HSC, Memphis, TN, USA
| | - L P Schwab
- Department of Pathology and Laboratory Medicine, University of Tennessee HSC, Memphis, TN, USA; Center for Cancer Research, University of Tennessee HSC, Memphis, TN, USA
| | - C Skobowiat
- Department of Pathology and Laboratory Medicine, University of Tennessee HSC, Memphis, TN, USA; Center for Cancer Research, University of Tennessee HSC, Memphis, TN, USA
| | - W Jóźwicki
- Department of Tumor Pathology and Pathomorphology, Oncology Centre - Prof. Franciszek Łukaszczyk Memorial Hospital, The Ludwik Rydygier Collegium Medicum, Nicolaus Copernicus University, Bydgoszcz, Poland
| | - T N Seagroves
- Department of Pathology and Laboratory Medicine, University of Tennessee HSC, Memphis, TN, USA; Center for Cancer Research, University of Tennessee HSC, Memphis, TN, USA
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30
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Walker SM, de la Torre A, Bruno FY, Tamai A, Kim TK, Hoesch M, Shi M, Bahramy MS, King PDC, Baumberger F. Control of a two-dimensional electron gas on SrTiO₃(111) by atomic oxygen. Phys Rev Lett 2014; 113:177601. [PMID: 25379937 DOI: 10.1103/physrevlett.113.177601] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Indexed: 06/04/2023]
Abstract
We report on the formation of a two-dimensional electron gas (2DEG) at the bare surface of (111) oriented SrTiO3. Angle resolved photoemission experiments reveal highly itinerant carriers with a sixfold symmetric Fermi surface and strongly anisotropic effective masses. The electronic structure of the 2DEG is in good agreement with self-consistent tight-binding supercell calculations that incorporate a confinement potential due to surface band bending. We further demonstrate that alternate exposure of the surface to ultraviolet light and atomic oxygen allows tuning of the carrier density and the complete suppression of the 2DEG.
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Affiliation(s)
- S McKeown Walker
- Département de Physique de la Matière Condensée, Universitée de Genève, 24 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland
| | - A de la Torre
- Département de Physique de la Matière Condensée, Universitée de Genève, 24 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland
| | - F Y Bruno
- Département de Physique de la Matière Condensée, Universitée de Genève, 24 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland
| | - A Tamai
- Département de Physique de la Matière Condensée, Universitée de Genève, 24 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland
| | - T K Kim
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - M Hoesch
- Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - M Shi
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M S Bahramy
- Quantum-Phase Electronics Center, Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan and RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - P D C King
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, United Kingdom
| | - F Baumberger
- Département de Physique de la Matière Condensée, Universitée de Genève, 24 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland and Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland and SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, United Kingdom
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31
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Kim TK, Ji YS, Park MH, Kim CH. Determination of SK3497 in rat plasma and its application in a pharmacokinetic study of SK3497. Drug Res (Stuttg) 2014; 64:647-50. [PMID: 24918347 DOI: 10.1055/s-0034-1376996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
In this study, a sensitive and reliable method for the quantitation of SK3497 in rat plasma was developed and validated using high performance liquid chromatography. The plasma samples were prepared by deproteinization, and sildenafil was used as an internal standard. Chromatographic separation was achieved using a reversed-phase (C18) column. The mobile phase, 0.02 M ammonium acetate buffer:acetonitrile (45:55, v/v), was run at a flow rate of 1.0 mL/min, and the column eluent was monitored using an ultraviolet detector at 254 nm at room temperature. The retention times of sildenafil (an internal standard), and SK3497 were approximately 5.6 and 8.3 min, respectively. The detection limit of SK3497 in rat plasma was 0.03 μg/mL. Pharmacokinetic parameters of SK3497 was evaluated after intravenous (i. v.; at doses of 15 mg/kg) and oral (p.o.; at doses of 30 mg/kg) administration of SK3497 in rats. After p.o. administration (30 mg/kg) of SK3497, F-value was approximately 53.0%. The protein binding of SK3497 to 4% human serum albumin were also described.
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Affiliation(s)
- T K Kim
- College of Science & Engineering, Jungwon University, Chungbuk, South Korea
| | - Y S Ji
- College of Science & Engineering, Jungwon University, Chungbuk, South Korea
| | - M H Park
- College of Science & Engineering, Jungwon University, Chungbuk, South Korea
| | - C H Kim
- College of Science & Engineering, Jungwon University, Chungbuk, South Korea
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32
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Min JJ, Nam K, Kim TK, Kim HJ, Seo JH, Hwang HY, Kim KB, Murkin JM, Hong DM, Jeon Y. Relationship between early postoperative C-reactive protein elevation and long-term postoperative major adverse cardiovascular and cerebral events in patients undergoing off-pump coronary artery bypass graft surgery: a retrospective study. Br J Anaesth 2014; 113:391-401. [PMID: 24829443 DOI: 10.1093/bja/aeu099] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Inflammation plays a key role in the pathogenesis of vascular occlusive diseases, such as myocardial infarction and stroke. Additionally, these conditions are predicted by C-reactive protein (CRP), a general inflammation marker. We hypothesized that the inflammation induced by surgery itself augments vascular occlusive disease. We retrospectively evaluated the relationship between postoperative CRP elevation and postoperative major adverse cardiovascular and cerebral events (MACCE) in patients undergoing off-pump coronary artery bypass surgery (OPCAB). METHODS The electronic medical records of 1046 patients who underwent OPCAB were reviewed retrospectively. The relationship between postoperative serum CRP and long-term postoperative MACCE (median follow-up 28 months) was investigated. RESULTS Patients were divided into quartiles according to maximum postoperative CRP levels (<18, 18-22, 22-27, ≥27 mg dl(-1)). The adjusted hazard ratios (HRs) were 2.15, 2.45, and 2.81, respectively (P=0.004), compared with the lowest quartile (<18 mg dl(-1)). In the multivariate analysis, the postoperative CRP quartile (HR 2.81; P=0.004), postoperative non-use of statins (HR 1.86; P=0.003), and postoperative maximum troponin I (HR 1.02; P<0.001) independently predicted postoperative MACCE, while preoperative CRP did not (P=0.203). Several parameters were correlated with postoperative maximum CRP level: body temperature (P=0.001) and heart rate (P<0.001) at the end of surgery; intraoperative last lactate (P<0.001) and base excess (P<0.001); and red blood cell transfusion (P=0.019). CONCLUSIONS Postoperative CRP elevation was associated with long-term postoperative MACCE in OPCAB patients. This was mitigated by postoperative statin medication. Furthermore, postoperative CRP elevation was associated with intraoperative parameters reflecting hypoperfusion and inflammation.
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Affiliation(s)
- J J Min
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - K Nam
- Department of Anesthesiology and Pain Medicine, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - T K Kim
- Department of Anesthesiology and Pain Medicine, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - H J Kim
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - J H Seo
- Department of Anesthesiology and Pain Medicine, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - H Y Hwang
- Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Daehakro 101, Jongno-gu 110-744, Seoul, Republic of Korea
| | - K B Kim
- Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Daehakro 101, Jongno-gu 110-744, Seoul, Republic of Korea
| | - J M Murkin
- Department of Anesthesiology and Perioperative Medicine, Schulich School of Medicine, University of Western Ontario, London, ON, Canada
| | - D M Hong
- Department of Anesthesiology and Pain Medicine, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Y Jeon
- Department of Anesthesiology and Pain Medicine, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
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Abstract
Osteophyte excision is a mainstay of treatment for mucous cyst combined with Heberden's node in a distal interphalangeal joint or in an interphalangeal joint of the thumb. The aim of this study was to evaluate the results of osteophyte excision without cyst excision for the treatment of a mucous cyst combined with Heberden's node. The medical records of 37 patients (42 cases) with a mucous cyst with Heberden's node were retrospectively reviewed. Thirty-eight of 40 cases with available pre-operative simple radiographs showed evidence of joint arthrosis. A T-shaped skin incision of the joint capsule between the extensor tendon and lateral collateral ligament was used. Osteophyte excision without cyst excision was performed. All cysts, except one, regressed without recurrence or a skin complication after osteophyte excision, but eight cases showed post-operative pain and loss of range of motion. Osteophyte excision without cyst excision may be a good treatment choice for mucous cyst of the finger.
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Affiliation(s)
- H-J Lee
- 1Department of Orthopaedic Surgery, Kyungpook National University Hospital, Daegu, Republic of Korea
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34
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Liew NC, Chang YH, Choi G, Chu PH, Gao X, Gibbs H, Ho CO, Ibrahim H, Kim TK, Kritpracha B, Lee LH, Lee L, Lee WY, Li YJ, Nicolaides AN, Oh D, Pratama D, Ramakrishnan N, Robless PA, Villarama-Alemany G, Wong R. Asian venous thromboembolism guidelines: prevention of venous thromboembolism. INT ANGIOL 2012; 31:501-516. [PMID: 23222928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Venous thromboembolism (VTE) prophylaxis is under-utilized in Asia because of the misconception that its incidence is lower in Asians as compared to the Caucasians. The available data on VTE in Asia is limited due to the lack of well-designed multicenter randomized controlled trials as well as non-standardized research designs, making data comparison difficult. Emerging data indicates that the VTE incidence is not low in Asia, and is comparable to that reported in the Western literature in some instances. There is also a trend towards increasing incidence of VTE, as demonstrated by a number of hospital-based studies in Asia. This could be attributed to lifestyle changes, ageing population, increasing awareness of VTE and wider availability of Duplex ultrasound. The risk of VTE in hospitalized patients remain the same in Asians and Caucasians, even though there may be factors that are inherent to patients in Asia that influence the slight variation in incidence. The utilization rate of VTE prophylaxis remains suboptimal in Asia. The Asian Venous Thrombosis Forum (AVTF) comprises participants from various countries such as China, Hong Kong, India, Indonesia, Korea, Malaysia, Philippines, Singapore, Taiwan, Thailand and experts from Australia and Europe. The forum evaluated the available data on VTE from the Asian region and formulated guidelines tailored to meet the needs of the region. We recommend that serious considerations are given to VTE prophylaxis especially in the at-risk group and a formal hospital policy be established to facilitate the implementation. On admission to the hospital, we recommend assessing the patients for both VTE and bleeding risk. We recommend mechanical prophylaxis for patients at increased risk of bleeding and utilizing it as an adjunctive measure in combination with pharmacological prophylaxis in patients with high risk of VTE. For patients undergoing general or gynecological surgery and with moderate risk for VTE, we recommend prophylaxis with one of the following: low dose unfractionated heparin (LDUH), low molecular weight heparin (LMWH), fondaparinux or intermittent pneumatic compression (IPC). For the same group of patients at high risk of VTE, we recommend pharmacological or combination of pharmacological and mechanical prophylaxis. For patients undergoing major orthopedic surgeries like total hip replacement, total knee replacement and proximal hip fracture surgery, we recommend using one of the following: LMWH, fondaparinux, rivaroxaban, apixaban, edoxaban, dabigatran, warfarin or aspirin with IPC. For patients admitted to the hospital with acute medical illness and has moderate risk of VTE, we recommend prophylaxis with LDUH, LMWH or Fondaparinux. For the same group at high risk of VTE, we recommend combination of pharmacological and mechanical prophylaxis.
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Affiliation(s)
- N C Liew
- Department of Surgery, University Putra Malaysia, General Hospital, Kuala Lumpur, Malaysia.
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Abstract
OBJECTIVE A prospective study to compare the power of the Logistic Organ Dysfunction System (LODS) and the Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring systems to predict survival, in patients admitted to the neurological intensive care unit (NICU). METHODS Clinical data from 521 consecutive NICU patients were collected during the first 24 h of admission and were used to compare the predictive power of both scoring systems. RESULTS The observed mortality rate was 10.0% compared with predicted mortality rates of 7.2% and 4.8% according to LODS and APACHE II, respectively. Both scoring systems had excellent discrimination but LODS had superior calibration. CONCLUSION The LODS scoring system was more stable than the APACHE II scoring system in the NICU setting.
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Affiliation(s)
- T K Kim
- Department of Anaesthesia and Pain Medicine, Bucheon St Mary's Hospital, The Catholic University of Korea, Bucheon, Republic of Korea
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Song JK, Stebbins CL, Kim TK, Kim HB, Kang HJ, Chai JH. Effects of 12 weeks of aerobic exercise on body composition and vascular compliance in obese boys. J Sports Med Phys Fitness 2012; 52:522-529. [PMID: 22976739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
AIM This study tested the hypothesis that 12 weeks of air board exercise would enhance cardiorespiratory fitness and vascular compliance and reduce % body fat in obese Korean boys. METHODS Twenty-two obese boys (>30% body fat) were studied. They were divided into 2 groups- an aerobic exercise group (N.=12), which trained 3 days/week, 50 min/day for 12 weeks, and a control group (N.=10). Control subjects only performed activities involved in their physical education classes. Body composition, cardiovascular fitness (20 m multistage endurance test performance) and vascular compliance were assessed before and after the completion of exercise training. RESULTS The % changes in body fat (-4.6±0.9 vs. -1.5±1.0%), fat mass (-5.4±1.5 vs. -0.1±1.6%) and performance on the cardiovascular fitness test (14.3±2.5 vs. 3.7±1.6%) were greater in the exercise group than in the controls Compared to controls, % increases in vascular compliance were greater in the arms and legs of the exercise group (left arm: 2.8±0.5 vs. 2.0±2.9%; left leg: 2.6±1.2 vs. -0.5±2.0%; right arm: 2.9±0.9 vs. 0.3±2.9%; right leg: 4.8±1.8 vs. 1.5±2.0%). CONCLUSION Results suggest that exercise training can reduce % body fat and enhance vascular compliance in obese male adolescents; changes that may reduce the risk for later development of cardiovascular disease.
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Affiliation(s)
- J K Song
- Department of Taekwondo, College of Physical Education, Kyung Hee University, Yongin City, Republic of South Korea
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Kim TK, Yoo HH, Kim EJ, Sa JH, Lee BY, Park JH. Comparative protein binding of taxotere and SID530, a new docetaxel formulation with hydroxypropyl-beta-cyclodextrin, in human plasma in vitro. Pharmazie 2012; 67:789-791. [PMID: 23016452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The purpose of this study was to evaluate the plasma-protein binding of docetaxel in two different formulations, Taxotere and SID530, a new docetaxel formulation with hydroxypropyl-beta-cyclodextrin (HP-beta-CD), in human plasma in vitro, using equilibrium dialysis. Unbound docetaxel concentration in the human plasma was determined by LC-MS/MS analysis. SID530 showed a plasma-protein binding profile comparable to that of Taxotere in the clinically relevant concentration range of docetaxel. In both formulations, the unbound fraction of docetaxel increased in a concentration-dependent biphasic manner. The resulting data indicate that the excipient used in SID530, HP-beta-CD, generates similar effects as polysorbate 80 of Taxotere in terms of plasma-protein binding of docetaxel.
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Affiliation(s)
- T K Kim
- College of Pharmacy, Seoul National University, Seoul, Republic of Korea
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Kim TK, Yoo HH, Park JH. Validated LC-MS/MS method for the determination of mirodenafil in rat plasma and its application to a comparative pharmacokinetic study of the free base and hydrochloride salt forms of mirodenafil. Arzneimittelforschung 2012; 62:351-354. [PMID: 22692776 DOI: 10.1055/s-0032-1312665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In this study, the pharmacokinetics of 2 forms of mirodenafil, namely the base form and the hydrochloride salt form, were investigated in rats. The 2 forms were orally administered to rats and the plasma concentrations of mirodenafil were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The mirodenafil base and hydrochloride salt forms showed similar pharmacokinetic profiles in terms of their maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC). The time to peak concentration (Tmax) of the base form was slightly greater than that of the salt form, but this difference was not statistically significant. These results suggest that the mirodenafil base and hydrochloride forms are pharmacokinetically equivalent in rats, and thus the base form could be used in various mirodenafil formulations as a substitute for the existing mirodenafil hydrochloride form.
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Affiliation(s)
- T K Kim
- College of Pharmacy, Seoul National University, Seoul, Republic of Korea
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Varykhalov A, Marchenko D, Scholz MR, Rienks EDL, Kim TK, Bihlmayer G, Sánchez-Barriga J, Rader O. Ir(111) surface state with giant Rashba splitting persists under graphene in air. Phys Rev Lett 2012; 108:066804. [PMID: 22401103 DOI: 10.1103/physrevlett.108.066804] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Indexed: 05/31/2023]
Abstract
We reveal a giant Rashba effect (α(R)≈1.3 eV Å) on a surface state of Ir(111) by angle-resolved photoemission and by density functional theory. It is demonstrated that the existence of the surface state, its spin polarization, and the size of its Rashba-type spin-orbit splitting remain unaffected when Ir is covered with graphene. The graphene protection is, in turn, sufficient for the spin-split surface state to survive in ambient atmosphere. We discuss this result along with indications for a topological protection of the surface state.
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Affiliation(s)
- A Varykhalov
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Berlin, Germany
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Trinckauf J, Hänke T, Zabolotnyy V, Ritschel T, Apostu MO, Suryanarayanan R, Revcolevschi A, Koepernik K, Kim TK, Zimmermann MV, Borisenko SV, Knupfer M, Büchner B, Geck J. Electronic confinement and ordering instabilities in colossal magnetoresistive bilayer manganites. Phys Rev Lett 2012; 108:016403. [PMID: 22304275 DOI: 10.1103/physrevlett.108.016403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2011] [Revised: 09/16/2011] [Indexed: 05/31/2023]
Abstract
We present angle-resolved photoemission studies of (La{1-z}Pr{z}){2-2x}Sr{1+2x}Mn{2}O{7} with x=0.4 and z=0.1, 0.2, and 0.4 along with density functional theory calculations and x-ray scattering data. Our results show that the bilayer splitting in the ferromagnetic metallic phase of these materials is small, if not completely absent. The charge carriers are therefore confined to a single MnO{2} layer, which in turn results in a strongly nested Fermi surface. In addition to this, the spectral function also displays clear signatures of an electronic ordering instability well below the Fermi level. The increase of the corresponding interaction strength with z and its magnitude of ∼400 meV make the coupling to a bare phonon highly unlikely. Instead we conclude that fluctuating order, involving electronic and lattice degrees of freedom, causes the observed renormalization of the spectral features.
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Affiliation(s)
- J Trinckauf
- Leibniz Institute for Solid State and Materials Research IFW Dresden, Helmholtzstraße 20, 01069 Dresden, Germany
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Janjetovic Z, Brozyna AA, Tuckey RC, Kim TK, Nguyen MN, Jozwicki W, Pfeffer SR, Pfeffer LM, Slominski AT. High basal NF-κB activity in nonpigmented melanoma cells is associated with an enhanced sensitivity to vitamin D3 derivatives. Br J Cancer 2011; 105:1874-84. [PMID: 22095230 PMCID: PMC3251881 DOI: 10.1038/bjc.2011.458] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background: Melanoma is highly resistant to current modalities of therapy, with the extent of pigmentation playing an important role in therapeutic resistance. Nuclear factor-κB (NF-κB) is constitutively activated in melanoma and can serve as a molecular target for cancer therapy and steroid/secosteroid action. Methods: Cultured melanoma cells were used for mechanistic studies on NF-κB activity, utilising immunofluorescence, western blotting, EMSA, ELISA, gene reporter, and estimated DNA synthesis assays. Formalin-fixed, paraffin-embedded specimens from melanoma patients were used for immunocytochemical analysis of NF-κB activity in situ. Results: Novel 20-hydroxyvitamin (20(OH)D3) and classical 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) secosteroids inhibited melanoma cell proliferation. Active forms of vitamin D were found to inhibit NF-κB activity in nonpigmented cells, while having no effect on pigmented cells. Treatment of nonpigmented cells with vitamin D3 derivatives inhibited NF-κB DNA binding and NF-κB-dependent reporter assays, as well as inhibited the nuclear translocation of the p65 NF-κB subunit and its accumulation in the cytoplasm. Moreover, analysis of biopsies of melanoma patients showed that nonpigmented and slightly pigmented melanomas displayed higher nuclear NF-κB p65 expression than highly pigmented melanomas. Conclusion: Classical 1,25(OH)2D3 and novel 20(OH)D3 hydroxyderivatives of vitamin D3 can target NF-κB and regulate melanoma progression in nonpigmented melanoma cells. Melanin pigmentation is associated with the resistance of melanomas to 20(OH)D3 and 1,25(OH)2D3 treatment.
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Affiliation(s)
- Z Janjetovic
- Department of Pathology and Laboratory Medicine, Center for Cancer Research, University of Tennessee Health Science Center, 930 Madison Avenue, Memphis, TN 38163, USA
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Vyalikh DV, Danzenbächer S, Kucherenko Y, Kummer K, Krellner C, Geibel C, Holder MG, Kim TK, Laubschat C, Shi M, Patthey L, Follath R, Molodtsov SL. k Dependence of the crystal-field splittings of 4f states in rare-earth systems. Phys Rev Lett 2010; 105:237601. [PMID: 21231502 DOI: 10.1103/physrevlett.105.237601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2010] [Revised: 10/19/2010] [Indexed: 05/30/2023]
Abstract
The occupation, energy separation, and order of the crystal-field-split 4f states are crucial for the understanding of the magnetic properties of rare-earth systems. We provide the experimental evidence that crystal-field-split 4f states exhibit energy dispersion in momentum space leading to variations of energy spacings between them and even of their energy sequence across the Brillouin zone. These observations were made by performing angle-resolved photoemission experiments on YbRh(2)Si(2) and properly simulated within a simple model based on results obtained by inelastic neutron scattering experiments and band structure calculations. Our findings should be generally applicable to rare-earth systems and have considerable impact on the understanding of magnetism and related phenomena.
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Affiliation(s)
- D V Vyalikh
- Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden, Germany
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Borisenko SV, Zabolotnyy VB, Evtushinsky DV, Kim TK, Morozov IV, Yaresko AN, Kordyuk AA, Behr G, Vasiliev A, Follath R, Büchner B. Superconductivity without nesting in LiFeAs. Phys Rev Lett 2010; 105:067002. [PMID: 20867999 DOI: 10.1103/physrevlett.105.067002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Indexed: 05/29/2023]
Abstract
We have studied the electronic structure of the nonmagnetic LiFeAs (T(c)∼18 K) superconductor using angle-resolved photoemission spectroscopy. We find a notable absence of the Fermi surface nesting, strong renormalization of the conduction bands by a factor of 3, high density of states at the Fermi level caused by a van Hove singularity, and no evidence for either a static or a fluctuating order except superconductivity with in-plane isotropic energy gaps. Our observations suggest that these electronic properties capture the majority of ingredients necessary for the superconductivity in iron pnictides.
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Affiliation(s)
- S V Borisenko
- Leibniz-Institute for Solid State Research, IFW-Dresden, D-01171 Dresden, Germany
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Inosov DS, White JS, Evtushinsky DV, Morozov IV, Cameron A, Stockert U, Zabolotnyy VB, Kim TK, Kordyuk AA, Borisenko SV, Forgan EM, Klingeler R, Park JT, Wurmehl S, Vasiliev AN, Behr G, Dewhurst CD, Hinkov V. Weak superconducting pairing and a single isotropic energy gap in stoichiometric LiFeAs. Phys Rev Lett 2010; 104:187001. [PMID: 20482200 DOI: 10.1103/physrevlett.104.187001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2010] [Indexed: 05/29/2023]
Abstract
We report superconducting (SC) properties of stoichiometric LiFeAs (T(c)=17 K) studied by small-angle neutron scattering (SANS) and angle-resolved photoemission (ARPES). Although the vortex lattice exhibits no long-range order, well-defined SANS rocking curves indicate better ordering than in chemically doped 122 compounds. The London penetration depth lambda(ab)(0)=210+/-20 nm, determined from the magnetic field dependence of the form factor, is compared to that calculated from the ARPES band structure with no adjustable parameters. The temperature dependence of lambda(ab) is best described by a single isotropic SC gap Delta(0)=3.0+/-0.2 meV, which agrees with the ARPES value of Delta(0)(ARPES)=3.1+/-0.3 meV and corresponds to the ratio 2Delta/k(B)T(c)=4.1+/-0.3, approaching the weak-coupling limit predicted by the BCS theory. This classifies LiFeAs as a weakly coupled single-gap superconductor.
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Affiliation(s)
- D S Inosov
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
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Chang CB, Choi JY, Koh IJ, Seo ES, Seong SC, Kim TK. What should be considered in using standard knee radiographs to estimate mechanical alignment of the knee? Osteoarthritis Cartilage 2010; 18:530-8. [PMID: 20060951 DOI: 10.1016/j.joca.2009.12.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 11/17/2009] [Accepted: 12/01/2009] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Anatomical tibiofemoral angle (anatomical TFA) of the knee measured on standard knee radiographs is still widely used as proxy for mechanical tibiofemoral angle (mechanical TFA), because of the practical and economic limitations in using full-limb radiographs. However, reported differences between anatomical and mechanical TFAs show wide variations. The first aim of this study was to determine whether gender, the presence of advanced osteoarthritis (OA), and history of total knee arthroplasty (TKA) influence the differences between anatomical and mechanical TFAs. The second aim was to identify anatomical features that cause divergences between anatomical and mechanical TFAs, and the final aim was to determine whether anatomical TFA measured using reference points more distant from the knee provides more accurate estimates of mechanical TFA. DESIGN In 102 knees with advanced OA before and after TKAs and 99 control knees with no/minimal OA, we assessed the differences between two anatomical TFAs, namely, anatomical TFA1 and anatomical TFA2, which were based on conventional or more distant proximal and distal reference points on standard knee radiographs, respectively, and the mechanical TFA measured on full-limb radiographs. These differences were investigated for women vs men, no/minimal OA vs advanced OA, and for knees before vs after TKA. Regression analyses were performed to determine associations between femoral and tibial anatomical characteristics and the differences between mechanical and anatomical TFAs. RESULTS The OA group showed significantly greater differences between mechanical and anatomical TFAs than the control group for both genders. In OA and TKA group, women were more likely to have greater mean differences between mechanical and anatomical TFAs than men. However, TKA did not significantly affect these differences. Femoral and tibial bowing angles, particularly of the femur, were found to be the major contributors to divergences between mechanical and two anatomical TFAs. Furthermore, anatomical TFA2 was found to provide more accurate estimates of mechanical TFA. CONCLUSIONS We found that the differences between mechanical and anatomical TFAs depend on gender and the presence of advanced OA, but not on a history of TKA. These findings indicate that prediction of mechanical TFA based on anatomical TFA is dependent on study population characteristics. This study also shows that the presence of lateral bowing of the femur is a major cause of mechanical TFA to anatomical TFA variations associated with gender and advanced OA. To reduce the adverse effects of anatomical variations on estimations of mechanical TFA based on an anatomical TFA method, more distant proximal and distal reference points are recommended to determine anatomical TFA value on standard knee radiographs.
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Affiliation(s)
- C B Chang
- Joint Reconstruction Center, Seoul National University Bundang Hospital, Seongnamsi, South Korea
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Holder MG, Jesche A, Lombardo P, Hayn R, Vyalikh DV, Danzenbächer S, Kummer K, Krellner C, Geibel C, Kucherenko Y, Kim TK, Follath R, Molodtsov SL, Laubschat C. CeFePO: f-d hybridization and quenching of superconductivity. Phys Rev Lett 2010; 104:096402. [PMID: 20366999 DOI: 10.1103/physrevlett.104.096402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Indexed: 05/29/2023]
Abstract
As a homologue to the new, Fe-based type of high-temperature superconductors, the electronic structure of the heavy-fermion compound CeFePO was studied by means of angle-resolved resonant photoemission. It was experimentally found-and later on confirmed by local-density approximation (LDA) as well as dynamical mean-field theory (DMFT) calculations-that the Ce 4f states hybridize to the Fe 3d states of d{3z{2}-r{2}} symmetry near the Fermi level that discloses their participation in the occurring electron-correlation phenomena and provides insight into mechanism of superconductivity in oxopnictides.
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Affiliation(s)
- M G Holder
- Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden, Germany
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Abstract
BACKGROUND Infraorbital dark circles are a cosmetic concern for a large number of individuals. However, the exact definition and precise cause has not been elucidated clearly. In our experience infraorbital dark circles due to thin and translucent lower eyelid skin overlying the orbicularis oculi muscle can be treated successfully with autologous fat transplantation. OBJECTIVES This study was conducted to clarify the nature of dark circles under the eyes and determine the efficacy of autologous fat transplantation. PATIENTS AND METHODS Ten patients with dark circles due to increased vascularity and translucency of the skin were included. They received at least one autologous fat transplantation and follow-up evaluations were conducted at least 3 months after the last treatment. RESULTS An average of 1.6 autologous fat transplantations were done in both infraorbital areas. Patients showed an average of 78% improvement (average grading scale: 2.6 out of 4). Most of the patients showed improvement in the infraorbital darkening and contour of the lower eyelids. CONCLUSIONS Autologous fat transplantation is an effective method for the treatment of infraorbital dark circles due to thin and translucent lower eyelid skin overlying the orbicularis oculi muscle.
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Affiliation(s)
- M R Roh
- Department of Dermatology, Yonsei University College of Medicine, Seoul, Korea
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Chang CB, Seong SC, Kim TK. Evaluations of radiographic joint space--do they adequately predict cartilage conditions in the patellofemoral joint of the patients undergoing total knee arthroplasty for advanced knee osteoarthritis? Osteoarthritis Cartilage 2008; 16:1160-6. [PMID: 18387318 DOI: 10.1016/j.joca.2008.02.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Accepted: 02/17/2008] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine whether assessments of patellofemoral (PF) joint space reliably predict the cartilage conditions in the PF joint of the patients undergoing total knee arthroplasty (TKA) for advanced knee osteoarthritis. METHODS Radiographic joint spaces and gross cartilage conditions in the PF joint were assessed in 151 osteoarthritic knees undergoing TKA. Minimum joint space widths (MJSWs) in the medial and lateral compartments of the PF joint were measured separately on Merchant radiographs. Degrees of joint space were graded as normal, narrowed and obliterated, and expected locations of significant cartilage lesions were classified as medial, lateral, and global. Cartilage lesions were grossly assessed in terms of their severity (depth and size) and location. Cross-table analyses and kappa statistics were used to determine the level of agreements between radiographic and gross assessments and the diagnostic accuracies of the radiographic assessments. RESULTS The agreements between the radiographic assessments and the gross assessments on the lesion severities and locations were only fair [kappa coefficient (k)=0.288 and 0.211, respectively]. The cross-table analyses demonstrated that 45 (47.4%) of 95 knees with a normal radiographic joint space had moderate or severe cartilage degeneration of the PF joint identified with gross assessments. In the radiographic assessments, the lateral compartment of the PF joint was the most frequent location of joint space narrowing (71.4%) whereas in the gross assessments, the medial compartment of the PF joint was the most frequent location of significant cartilage lesion (48.1%). Diagnostic accuracies on the lesion severities and locations were generally poor. CONCLUSION This study demonstrates that prediction of the cartilage conditions of the PF joint by the radiographic joint space can be inaccurate.
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Affiliation(s)
- C B Chang
- Joint Reconstruction Center, Seoul National University Bundang Hospital, Seongnamsi, Republic of Korea
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Lueck GJ, Kim TK, Burns PN, Martel AL. Hepatic perfusion imaging using factor analysis of contrast enhanced ultrasound. IEEE Trans Med Imaging 2008; 27:1449-1457. [PMID: 18815097 DOI: 10.1109/tmi.2008.922695] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Contrast enhanced ultrasound imaging provides a real-time tool for evaluating vasculature in the liver. Primary liver cancer is known to be perfused exclusively by blood from the hepatic artery, whereas normal liver is also supplied by the portal vein. Visual separation of two different phases of enhancement from the independent feeding vessels is important for diagnosis but remains a challenge. This paper presents a method of using factor analysis for extracting distinct time-intensity curves. A key component to this extraction is the clustering of measured bolus curves and their projection onto a positivity domain to obtain nonnegative curves. This technique provides complementary images representing spatial loadings on each curve. As little as 1% of the data is required to contain unmixed signals to extract time-intensity curves that correlate well with true curves. A method of combining this information to display a regional hepatic perfusion image is proposed, and results are tested on a set of 10 patients. Region of interest analysis suggests it is possible to detect changes in the hepatic perfusion index of liver lesions relative to normal liver parenchyma using contrast ultrasound.
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Affiliation(s)
- G J Lueck
- University of Toronto, Sunnybrook Research Institute, 2075 BayviewAve., Toronto, ON M4N3M5, Canada.
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Lee KG, Ahn KJ, Kihm HW, Ahn JS, Kim TK, Hong S, Kim ZH, Kim DS. Surface plasmon polariton detection discriminating the polarization reversal image dipole effects. Opt Express 2008; 16:10641-10649. [PMID: 18607478 DOI: 10.1364/oe.16.010641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Image dipole effects are highly dependent on the polarization direction, constructive (destructive) interference between real and image dipoles for the vertically (horizontally) aligned one in the vicinity of metal surfaces, respectively. This polarization-reversal of the image dipole effects is quantitatively investigated by using a gold nanoparticle functionalized tip as a local dipolar scatterer and a propagating surface plasmon polariton as an excitation source of dipoles. The polarization-resolved detection technique is applied to separate the radiations of the vertical and the horizontal dipoles from each other. In our study, the image dipole effects on the far-field detected signals are fully explained by the Fabry-Perot like interference between the radiations from the real and the image dipoles, and by considering the finite size effects of the gold nanoparticle.
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Affiliation(s)
- K G Lee
- Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea
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