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Kim JH, Kim KW, Gwon DI, Ko GY, Sung KB, Lee J, Shin YM, Song GW, Hwang S, Lee SG. Effect of splenic artery embolization for splenic artery steal syndrome in liver transplant recipients: estimation at computed tomography based on changes in caliber of related arteries. Transplant Proc 2011; 43:1790-3. [PMID: 21693280 DOI: 10.1016/j.transproceed.2011.02.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 02/07/2011] [Indexed: 12/30/2022]
Abstract
PURPOSE To estimate the effect of splenic artery embolization (SAE) on blood flow in orthotopic liver transplantation (OLT) recipients with splenic artery steal syndrome (SASS) based on changes in caliber of related arteries upon serial computed tomography (CT) scans. METHODS Between 2004 and 2007, nine OLT recipients with SASS underwent SAE. They had CT scans before and after SAE: short-, mid-, and long-term, ie, approximately 1 week, 1 month, and 1 year, respectively. The diameters of the celiac axis (CA), common hepatic artery (CHA), and splenic artery (SA) were measured with arterial phase of each CT scan and the ratios of SA to CHA diameter (SA/CHA) calculated to analyze their changes during the follow-up period. RESULTS The diameters of celiac axis, CHA, and SA and SA/CHA changed most rapidly during the short-term period. The CHA diameter significantly increased short-term post-SAE by CT and slightly decreased thereafter. However, the mid-term and long-term post-SAE CT values were still significantly greater than those on the pre-SAE CT. The SA diameter steadily decreased throughout the follow-up. The SA/CHA decreased until the mid-term. The SA diameter and SA/CHA were significantly smaller upon mid-term and long-term post-SAE CT compared with those at pre-SAE CT. CONCLUSIONS The effect of SAE to improve hepatic arterial flow in OLT recipients with SASS might be expected for at least approximately one year. The effect maximally occurred during the short-term after SAE on the basis of changes in the caliber of related arteries upon CT.
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So MW, Lee SG, Kim YG, Lee CK, Yoo B. Factors associated with acute gout attacks in normouricaemic gout patients receiving allopurinol: a retrospective study. Scand J Rheumatol 2011; 40:444-7. [DOI: 10.3109/03009742.2011.589033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Kim KH, Jung DH, Park KM, Lee YJ, Kim DY, Kim KM, Lee SG. Comparison of open and laparoscopic live donor left lateral sectionectomy. Br J Surg 2011; 98:1302-8. [PMID: 21717424 DOI: 10.1002/bjs.7601] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2011] [Indexed: 12/14/2022]
Abstract
BACKGROUND The present study was undertaken to determine whether laparoscopic live donor left lateral sectionectomy (LLS) in paediatric liver transplantation is a feasible, safe and reproducible procedure, compared with open live donor left lateral sectionectomy (OLS). METHODS A retrospective review was conducted of all consecutive live donor procedures for paediatric liver transplantation performed between May 2008 and October 2009. All live donor hepatectomies were carried out by a single surgeon. RESULTS A total of 26 live donor procedures for paediatric liver transplantation were performed, of which 11 were LLS and 11 OLS; four left hepatectomies were excluded. The LLS group had a significantly shorter hospital stay (mean(s.d.) 6·9(0·3) versus 9·8(0·9) days; P = 0·001) and time to oral diet (2·1(0·3) versus 2·7(0·4) days; P = 0·012). Duration of operation, blood loss, warm ischaemia time and out-of-pocket medical costs were comparable between groups. There was no death in either donor group and only one complication, a wound seroma, in the OLS group. CONCLUSION LLS seemed to be a safe, feasible and reproducible procedure, and was associated with reduced hospital stay.
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Bak JG, Lee SG, Kim HS. Diamagnetic loop measurement in Korea Superconducting Tokamak Advanced Research machine. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:063504. [PMID: 21721688 DOI: 10.1063/1.3600455] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Diamagnetic loop (DL), which consists of two poloidal loops inside the vacuum vessel, is used to measure the diamagnetic flux during a plasma discharge in the Korea Superconducting Tokamak Advanced Research (KSTAR) machine. The vacuum fluxes in the DL signal can be compensated up to 0.1 mWb by using the coefficients, which are obtained from experimental investigations, in the vacuum flux measurements during vacuum shots under same operational conditions of magnetic coils for plasma experiment in the KSTAR machine. The maximum error in the diamagnetic flux measurement due to the errors of the coefficients was estimated as ∼0.22 mWb. From the diamagnetic flux measurements for the ohmically heated circular plasmas in the KSTAR machine, the stored energy agrees well with the estimated kinetic energy within the discrepancy of 25%. When the electron cyclotron heating, the neutral beam injection, and the ion cyclotron resonance heating are added to the ohmically heated limiter plasmas, the additional heating effects can be clearly observed from the increase of the stored energy evaluated in the DL measurement.
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Hwang S, Kim KH, Song GW, Yu YD, Park GC, Kim KW, Choi NK, Park PJ, Choi YI, Jung DH, Ahn CS, Moon DB, Ha TY, Lee SG. Peritransplant monitoring of immune cell function in adult living donor liver transplantation. Transplant Proc 2011; 42:2567-71. [PMID: 20832545 DOI: 10.1016/j.transproceed.2010.04.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Accepted: 04/21/2010] [Indexed: 01/12/2023]
Abstract
PURPOSE We evaluated the clinical utility of peritransplant in vitro assays of immune cell function in adult living donor liver transplant (LDLT) recipients. METHODS In particular, we measured immune cell function, using the ImmuKnow assay, in 107 adult LDLT recipients and 200 potential living liver donors (control group) admitted to our center between July 2008 and January 2009. RESULTS In the control group, the mean proportion of T-helper/inducer cells was 36.8% ± 8.2%. The degree of immune response was strong in 12%, moderate in 77%, and low in 11%. In the study group, the degree of immune response within the first month was strong in 4.6%, moderate in 38.2%, and low in 57.2%, thus significantly lower than in the control group (P < .001). ImmuKnow results and tacrolimus levels did not show a significant correlation (r(2) = .002, P = .392). Although six patients showed biopsy-proven acute cellular rejection, none showed a strong immune response. Patients with overt infection showed a lower immune response. CONCLUSIONS These results indicate that peritransplant assessment of immune response using the ImmuKnow assay does not reliably predict the occurrence of acute rejection. Additional studies are necessary to accurately assess the clinical utility of immune response monitoring.
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Lee JY, Kim SB, Chang JW, Park SK, Kwon SW, Song KW, Hwang S, Lee SG. Comparison of the molecular adsorbent recirculating system and plasmapheresis for patients with graft dysfunction after liver transplantation. Transplant Proc 2011; 42:2625-30. [PMID: 20832557 DOI: 10.1016/j.transproceed.2010.04.070] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 01/04/2010] [Accepted: 04/08/2010] [Indexed: 12/22/2022]
Abstract
BACKGROUND Graft dysfunction after liver transplantation (OLT) is a life- threatening condition. Molecular adsorbent recirculating system (MARS) or plasmapheresis (PLP) may be effective supportive therapy of graft dysfunction for patients who cannot undergo retransplantation. The aim of this study was to compare the effects of MARS and PLP in patients with graft dysfunction after OLT. METHODS Between January 2002 and July 2007, 31 OLT recipients who experienced graft dysfunction, defined as hyperbilirubinemia (>10 mg/dL) without bile duct obstruction and/or presence of hepatic encephalopathy, were treated with MARS or PLP. Biochemical and hemodynamic data and survival were compared in MARS and PLP groups. RESULTS Fifteen patients were treated with 41 MARS sessions and 16 with 105 PLP sessions. After a single MARS session, patients showed significant reductions in creatinine, urea nitrogen, bilirubin, and ammonia. After a single PLP session, patients showed significant improvements in prothrombin time, bilirubin, alanine aminotransferase, alkaline phosphatase, and albumin. After the completion of treatment, Both MARS and PLP significantly improved bilirubin values. at 90 days there were no differences in overall survival rates; 53% in MARS versus 56% in PLP. CONCLUSION Both MARS and PLP are alternative supportive treatments for graft dysfunction after OLT.
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Hill KW, Bitter M, Delgado-Aparicio L, Johnson D, Feder R, Beiersdorfer P, Dunn J, Morris K, Wang E, Reinke M, Podpaly Y, Rice JE, Barnsley R, O'Mullane M, Lee SG. Development of a spatially resolving x-ray crystal spectrometer for measurement of ion-temperature (T(i)) and rotation-velocity (v) profiles in ITER. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:10E322. [PMID: 21034020 DOI: 10.1063/1.3492414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Imaging x-ray crystal spectrometer (XCS) arrays are being developed as a US-ITER activity for Doppler measurement of T(i) and v profiles of impurities (W, Kr, and Fe) with ∼7 cm (a/30) and 10-100 ms resolution in ITER. The imaging XCS, modeled after a prototype instrument on Alcator C-Mod, uses a spherically bent crystal and 2D x-ray detectors to achieve high spectral resolving power (E/dE>6000) horizontally and spatial imaging vertically. Two arrays will measure T(i) and both poloidal and toroidal rotation velocity profiles. The measurement of many spatial chords permits tomographic inversion for the inference of local parameters. The instrument design, predictions of performance, and results from C-Mod are presented.
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Lee SG, Bak JG, Nam UW, Moon MK, Shi Y, Bitter M, Hill K. The first experimental results from x-ray imaging crystal spectrometer for KSTAR. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:10E506. [PMID: 21034034 DOI: 10.1063/1.3478631] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The x-ray imaging crystal spectrometer (XICS) for the Korea Superconducting Tokamak Advanced Research has been first applied for the experimental campaign in 2009. The XICS was designed to provide measurements of the profiles of the ion and electron temperatures from the heliumlike argon (Ar XVII) spectra. The basic functions of the XICS are properly working although some satellites lines are not well matched with the expected theoretical values. The initial experimental results from the XICS are briefly described.
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Lee JH, Na HK, Lee SG, Bak JG, Seo DC, Seo SH, Oh ST, Ko WH, Chung J, Nam YU, Lee KD, Ka EM, Oh YK, Kwon M, Jeong SH. Diagnostics for first plasma and development plan on KSTAR. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:063502. [PMID: 20590236 DOI: 10.1063/1.3429942] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The first plasma with target values of the plasma current and the pulse duration was finally achieved on June 13, 2008 in the Korea Superconducting Tokamak Advanced Research (KSTAR). The diagnostic systems played an important role in achieving successful first plasma operation for the KSTAR tokamak. The employed plasma diagnostic systems for the KSTAR first plasma including the magnetic diagnostics, millimeter-wave interferometer, inspection illuminator, H(alpha), visible spectrometer, filterscope, and electron cyclotron emission (ECE) radiometer have provided the main plasma parameters, which are essential for the plasma generation, control, and physics understanding. Improvements to the first diagnostic systems and additional diagnostics including an x-ray imaging crystal spectrometer, reflectometer, ECE radiometer, resistive bolometer, and soft x-ray array are scheduled to be added for the next KSTAR experimental campaign in 2009.
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Jeong WK, Kim KW, Kim MY, Shin YM, Kim PN, Kim Y, Song GW, Ha TY, Hwang S, Lee SG. Increase of modified retrograde to antegrade flow ratio on doppler ultrasounds of the hepatic vein indicating tricuspid regurgitation during follow-up of liver transplantation: correlation with echocardiographic results. Transplant Proc 2009; 41:4238-42. [PMID: 20005376 DOI: 10.1016/j.transproceed.2009.07.110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Accepted: 07/28/2009] [Indexed: 11/15/2022]
Abstract
The purpose of this study was to explore the best parameter of hepatic vein (HV) Doppler ultrasounds (DUS) that correlated with echocardiographic findings of and particularly the optimal cutoff value for tricuspid regurgitation (TR) following liver transplantation (LT). Thirty-six patients underwent echocardiography and DUS after LT from January 2006 to July 2007. Echocardiographic records were searched for TR grade and peak velocity of TR flow. The HV DUS parameters included peak velocity of retrograde flow (R), peak velocity of antegrade flow (A), the difference between R and A (R-A), the ratio of R to A (R/A ratio), and a modified R/A ratio, namely, the product of the R/A ratio and the R/A duration ratio. Correlation tests and receiver-operator characteristic analyses explored their interrelations and to obtained cutoff values to diagnose moderate and severe TR. TR grade best correlated with the modified R/A ratio (rho = 0.585), followed by the R/A ratio (rho = 0.503) and R (rho = 0.455). The modified R/A ratio was the most accurate parameter for the diagnosis of moderate and severe TR (Az = 0.825 and 0.895, respectively); its cutoff value was > or =0.11 for moderate TR (sensitivity and specificity both 77.78%) and 0.13 for severe TR (sensitivity, 100%; specificity, 81.2%). The modified R/A ratio best correlated with echocardiographic results of TR, although the strength of correlation was only moderate. Additionally, the modified R/A ratio was an accurate DUS parameter to diagnose moderate and severe TR among patients following LT.
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Ryu GY, Lee SG, Lim SH, Kim GY, Kim YK, Shin DM. A non-doped organic light emitting diode with pure red emission using a new host emitter. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2009; 9:6983-6987. [PMID: 19908711 DOI: 10.1166/jnn.2009.1655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A red fluorescent material (2E,2'E)-3,3'-[4,4"-bis(dimethylamino)-1,1': 4',1 "-terphenyl-2',5'-diyl]bis[2-(2-thienyl)acrylonitrile] (ABCV-Th) was synthesized for use in organic light emitting diodes (OLEDs) as the host emissive material. It has been reported some green and blue host emissive materials used in OLEDs revealed high device performance but, owing to concentration quenching, comparable red light emitting materials are still rare in OLEDs application. Non-doped organic light emitting diodes, with the structure of ITO/NPB/ABCV-Th (30 nm and 50 nm)/BCP/Alq3/Liq/Al were fabricated using ABCV-Th as the host emitter. The peak wavelength and full width at half maximum (FWHM) of electroluminescence (EL) were 629.5 nm and 68.5 nm, respectively. The maximum brightness and turn on voltage of the device were measured to be 1330 cd/m2 at 14.6 V and 3.4 V, respectively. The device exhibited authentic red emission (Commission Internationale De L'Eclairage (CIE(xy)) = 0.65, 0.34) which is almost close to the standard red (CIE(xy) = 0.67, 0.33) demanded by the national television system committee (NTSC).
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Oh JS, Kim YG, Lee SG, Lee CK, Yoo B. Successful treatment of recurrent lupus enteritis with rituximab. Lupus 2009; 19:220-2. [PMID: 19880555 DOI: 10.1177/0961203309345787] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Oh JS, Heo HM, Kim YG, Lee SG, Lee CK, Yoo B. The effect of anti-tumor necrosis factor agents on sexual dysfunction in male patients with ankylosing spondylitis: a pilot study. Int J Impot Res 2009; 21:372-5. [PMID: 19759542 DOI: 10.1038/ijir.2009.44] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Sexual dysfunction is a common problem among patients with ankylosing spondylitis (AS). This study was an open-label study without placebo to assess sexual dysfunction in male patients with AS, and to determine whether sexual function might improve with the use of tumor necrosis factor (TNF)-alpha blockers. Twenty-two males with AS (age, 29-48 years) were treated for 3 months with TNF-alpha blockers. Before and after treatment, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) was measured, and all patients completed the International Index of Erectile Function (IIEF) questionnaire, a self-administered measure of sexual dysfunction with five domains: erectile function (EF), intercourse satisfaction (IS), orgasmic function (OF), sexual desire (SD) and overall satisfaction (OS). There were significant improvements in BASDAI after treatment with TNF-alpha blockers (P<0.001). Anti-TNF-alpha treated patients showed significant improvements in four out of the five IIEF domains (EF, P<0.001; IS, P<0.001; SD, P=0.006; OS, P=0.033). Among patients with erectile dysfunction, there were significant improvements in three IIEF domains (EF, P=0.006; IS, P=0.007; SD, P=0.018). Only IS domain of IIEF showed a significant correlation with BASDAI (partial correlation coefficient = -0.484, P=0.026). This study showed that anti-TNF-alpha therapy may improve sexual dysfunction in male AS patients, in addition to reducing disease activity.
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Kim JS, Kim KM, Ko JK, Lee YJ, Lee SG. Intrapulmonary shunt in the course of pediatric liver transplantation. Transplant Proc 2008; 40:2512-4. [PMID: 18929783 DOI: 10.1016/j.transproceed.2008.07.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The hepatopulmonary syndrome occurs when an intrapulmonary shunt (IPS) causes hypoxemia in patients with cirrhosis. Because IPS has not been clearly defined in children, we investigated the prevalence, clinical characteristics, and outcomes of IPS in children undergoing liver transplantation (OLT). Of the 107 pediatric OLT recipients between December 1994 and March 2005, 18 (16.8%) had IPS, as evaluated by contrast-enhanced echocardiography (CEE) at 9 months to 16 years of age. The degree of IPS was classified into five grades according to the extent of microbubbles in the left ventricle, with significant IPS defined as grade II or higher. Baseline characteristics, including serum total bilirubin, albumin, aminotransferase, and prothrombin time, did not differ in patients with or without IPS. The patients with IPS had significantly lower Pao2 and Sao2, longer duration of mechanical ventilation and hospital stay, and higher postoperative morbidity and mortality than patients without IPS (P < .05 each), but there were no other significant differences between the groups. The six patients with significant IPS (one grade II, three grade III, and two grade IV) showed a significantly greater morbidity and mortality than patients with grade I IPS (P < .05). Most of the positive CEE findings of IPS regressed within 6 months after OLT. These findings indicated that IPS is not uncommon among children undergoing OLT, but is reversible. Because severe IPS may increase patient morbidity and mortality, early assessment of IPS status using CEE is essential for pediatric OLT candidates.
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Ince-Cushman A, Rice JE, Bitter M, Reinke ML, Hill KW, Gu MF, Eikenberry E, Broennimann C, Scott S, Podpaly Y, Lee SG, Marmar ES. Spatially resolved high resolution x-ray spectroscopy for magnetically confined fusion plasmas (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:10E302. [PMID: 19044464 DOI: 10.1063/1.2968707] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The use of high resolution x-ray crystal spectrometers to diagnose fusion plasmas has been limited by the poor spatial localization associated with chord integrated measurements. Taking advantage of a new x-ray imaging spectrometer concept [M. Bitter et al., Rev. Sci. Instrum. 75, 3660 (2004)], and improvements in x-ray detector technology [Ch. Broennimann et al., J. Synchrotron Radiat. 13, 120 (2006)], a spatially resolving high resolution x-ray spectrometer has been built and installed on the Alcator C-Mod tokamak. This instrument utilizes a spherically bent quartz crystal and a set of two dimensional x-ray detectors arranged in the Johann configuration [H. H. Johann, Z. Phys. 69, 185 (1931)] to image the entire plasma cross section with a spatial resolution of about 1 cm. The spectrometer was designed to measure line emission from H-like and He-like argon in the wavelength range 3.7 and 4.0 A with a resolving power of approximately 10,000 at frame rates up to 200 Hz. Using spectral tomographic techniques [I. Condrea, Phys. Plasmas 11, 2427 (2004)] the line integrated spectra can be inverted to infer profiles of impurity emissivity, velocity, and temperature. From these quantities it is then possible to calculate impurity density and electron temperature profiles. An overview of the instrument, analysis techniques, and example profiles are presented.
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Ka EM, Lee SG, Bak JG, Son D. Performance test of the integrator system for magnetic diagnostics in KSTAR. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:10F119. [PMID: 19044603 DOI: 10.1063/1.2966396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Ten modules of the integrator system of the initial magnetic diagnostics for the first plasma operation have been simultaneously tested in the Korea superconducting tokamak advanced research device by measuring the magnetic flux density from various magnetic diagnostics sensors when a small current was applied to the superconducting poloidal field coils. The measured drifts from the integrators show between 1x10(-6) and 1x10(-5) Wb/s. The results from the field tests before the first plasma generation are described.
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Hill KW, Bitter ML, Scott SD, Ince-Cushman A, Reinke M, Rice JE, Beiersdorfer P, Gu MF, Lee SG, Broennimann C, Eikenberry EF. A spatially resolving x-ray crystal spectrometer for measurement of ion-temperature and rotation-velocity profiles on the Alcator C-Mod tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:10E320. [PMID: 19044482 DOI: 10.1063/1.2969080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A new spatially resolving x-ray crystal spectrometer capable of measuring continuous spatial profiles of high resolution spectra (lambda/d lambda>6000) of He-like and H-like Ar K alpha lines with good spatial (approximately 1 cm) and temporal (approximately 10 ms) resolutions has been installed on the Alcator C-Mod tokamak. Two spherically bent crystals image the spectra onto four two-dimensional Pilatus II pixel detectors. Tomographic inversion enables inference of local line emissivity, ion temperature (T(i)), and toroidal plasma rotation velocity (upsilon(phi)) from the line Doppler widths and shifts. The data analysis techniques, T(i) and upsilon(phi) profiles, analysis of fusion-neutron background, and predictions of performance on other tokamaks, including ITER, will be presented.
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Bak JG, Lee SG, Ka EM. Diamagnetic loop for the first plasma in the KSTAR machine. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:10F118. [PMID: 19044602 DOI: 10.1063/1.2956963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The diamagnetic loop (DL) is installed for the plasma diamagnetic measurement at the first plasma in the Korea superconducting tokamak advanced research (KSTAR) machine. Experimental results from the position measurement of the DL inside the KSTAR vacuum vessel and the vacuum flux measurement by using the DL for the evaluation of the geometrical data and the balance coefficient of the DL for the compensation of the vacuum flux in the diamagnetic measurement are described. In addition, a preliminary work of an instrument for a hardware compensation of the vacuum flux is presented.
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Lee SG, Bak JG, Ka EM, Kim JH, Hahn SH. Magnetic diagnostics for the first plasma operation in Korea Superconducting Tokamak Advanced Research. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:10F117. [PMID: 19044601 DOI: 10.1063/1.2953587] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Magnetic diagnostics for the first plasma operation in the Korea Superconducting Tokamak Advanced Research device are described. The main discussion is the feasibility studies from the magnetic flux and field measurements utilizing the superconducting poloidal field coils before the first plasma generation.
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Lee SG, Bak JG, Nam UW, Moon MK, Cheon JK, Bitter M, Hill K. Spectral resolution measurement of an x-ray imaging crystal spectrometer for KSTAR. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:10E317. [PMID: 19044479 DOI: 10.1063/1.2982416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A spectral resolution measurement of the x-ray imaging crystal spectrometer for the Korea Superconducting Tokamak Advanced Research machine utilizing a segmented position-sensitive detector and time-to-digital converter based delay-line readout electronics was performed by using an x-ray tube in a laboratory. The measured spectral resolution is about 12,600, which means the actual energy resolution is 0.32 eV for the x-ray tube's bremsstrahlung peak energy of 4 keV. The results from the spectral resolution measurement are described.
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Hong SH, Hwang YJ, Lee SG, Shin DM. Annihilation of photochemical reactivity of photo-alignment layer. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2008; 8:4611-4615. [PMID: 19049069 DOI: 10.1166/jnn.2008.ic34] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The gas-polymer and liquid-polymer interfacial reactions of photosensitive polyimide can annihilate photo-reactive carbon-carbon double bonds, which remain after photo-alignment process. The annihilation processes dramatically affect voltage holding ratio and reorientation of photo-active functional groups. Photochemical dimerizations were identified using UV-visible and FT-IR spectroscopy. Polyimide films containing cinnamate groups were irradiated by linear polarized ultra violet (LPUV) light. Schadt et al. claims that the photo-alignment results from the anisotropy depletion of the cinnamate side chains as a consequence of the (2+2) cycloaddition reactions. The photo-aligned polyimide induces the orientation of nematic liquid crystals perpendicular to the polarization axis. However, the un-reacted photo-sensitive functional groups generate problems such as image sticking and reduced contrast ratio. Voltage holding ratio and photo-fading observed from photo-alignment layer can be dramatically improved by annihilation process of remnant photoreactive groups.
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Park JS, Park DI, Park SK, Choi JS, Kim YH, Chang DK, Son HJ, Kim JE, Kim JO, Lee SH, Kim HS, Sin JE, Lee SG, Lee SY, Park SJ, Park CH, Baek IH, Jang BI, Jeen YT, Huh KC. Endoscopic evaluation of significant gastrointestinal lesions in patients with iron deficiency with and without anaemia: a Korean Association for the Study of Intestinal Disease study. Intern Med J 2008; 39:441-6. [PMID: 19220549 DOI: 10.1111/j.1445-5994.2008.01785.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Although endoscopy is recommended for patients with iron deficiency anaemia, there is, currently, no consensus on the role of endoscopy for iron-deficient patients without anaemia. The goal of this study was to determine the prevalence of serious gastrointestinal (GI) lesions, identified by endoscopy in patients with iron deficiency and anaemia compared with patients with iron deficiency without anaemia. METHODS One thousand five hundred and eighteen patients with a ferritin value of <or=50 ng/mL and a total iron-binding capacity >or=300 mg/dL were retrospectively investigated using oesophagogastroduodenoscopy and colonoscopy between January 2005 and September 2006. The lesions identified were classified as clinically important according to standard predetermined criteria. RESULTS Among the 1518 cases, 749 patients had anaemia and 769 had normal haemoglobin levels. Clinically important lesions were identified in 24.6% of the patients with anaemia and in 22.8% of the patients without anaemia (P > 0.05). The frequency of lower GI tract lesions (13.6 vs 11.4%, P > 0.05) and upper GI tract lesions (11.9 vs 12.5%, P > 0.05) was similar in the comparisons between the two groups. However, the frequency of malignant GI lesions was higher in the patients with anaemia (5.1 vs 0.7%, P < 0.01). In addition, the patients without anaemia were significantly more likely to have early-stage neoplasia (adenoma, early gastric cancer and Dukes' A and B colon cancer) than were the patients with anaemia (98.4 vs 52.5%, P < 0.01). CONCLUSION The results of this study suggest that patients with iron deficiency should undergo endoscopic evaluation of the GI tract, irrespective of whether they have anaemia. The endoscopic evaluation of the GI tract in patients with iron deficiency without anaemia could provide an opportunity for the detection of early-stage neoplasia at a curable stage.
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Kim IS, Lim YS, Lee HC, Suh DJ, Lee YJ, Lee SG. Pre-operative transarterial chemoembolization for resectable hepatocellular carcinoma adversely affects post-operative patient outcome. Aliment Pharmacol Ther 2008; 27:338-45. [PMID: 18047564 DOI: 10.1111/j.1365-2036.2007.03580.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND Long-term outcomes after hepatic resection for hepatocellular carcinoma are not satisfactory because of high recurrence rates. Aim To assess whether a single session of pre-operative transarterial chemoembolization affects post-operative outcome. METHODS We analysed outcomes retrospectively in 334 consecutive patients who underwent hepatic resection for hepatocellular carcinoma, initially judged resectable. Ninety-seven of these patients had each undergone a single session of pre-operative transarterial chemoembolization (transarterial chemoembolization + hepatic resection group), whereas 237 had not (hepatic resection group). RESULTS Most clinicopathological characteristics were similar in the two groups. The overall survival rate was significantly higher in the hepatic resection than in the transarterial chemoembolization + hepatic resection group (P = 0.011), whereas their disease-free survival rates were comparable (P = 0.67). The overall and disease-free survival rates of the transarterial chemoembolization + hepatic resection group with incomplete tumour necrosis were significantly lower than those of the hepatic resection group (P < 0.001 and P = 0.006, respectively). Multivariate analysis showed that pre-operative transarterial chemoembolization, serum alpha-fetoprotein elevation (>1000 ng/mL), tumour size (>5 cm) and vascular invasion were independent risk factors for poor overall survival after hepatic resection. CONCLUSIONS A single session of pre-operative transarterial chemoembolization for initially resectable hepatocellular carcinoma worsens overall survival rate. It may also increase the risk of tumour recurrence in patients who achieve incomplete tumour necrosis.
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Lee SG, Bak JG, Bitter M. Calibration of an imaging crystal spectrometer for low x-ray energies. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:013501. [PMID: 18248028 DOI: 10.1063/1.2829888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
An x-ray imaging crystal spectrometer was designed for the Hanbit magnetic mirror device to observe spectra of heliumlike neon at 13.4474 A. The spectrometer consists of a spherically bent mica crystal and an x-ray sensitive vacuum charge coupled device camera. This spectrometer can provide spatially resolved spectra, making it possible to obtain profiles of the ion charge state distribution from line ratios and profiles of the plasma rotation velocity from Doppler shift measurements. The paper describes measurements of spectral resolution of this instrument for low x-ray energies.
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Nam UW, Lee SG, Bak JG, Moon MK, Cheon JK, Lee CH. Data acquisition system for an advanced x-ray imaging crystal spectrometer using a segmented position-sensitive detector. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2007; 78:103504. [PMID: 17979416 DOI: 10.1063/1.2795650] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A versatile time-to-digital converter based data acquisition system for a segmented position-sensitive detector has been developed. This data acquisition system was successfully demonstrated to a two-segment position-sensitive detector. The data acquisition system will be developed further to support multisegmented position-sensitive detector to improve the photon count rate capability of the advanced x-ray imaging crystal spectrometer system.
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