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Kim YN, Shim Y, Lee JY, Lee ST, Seo J, Lee Y, Shin S, Kim S, Choi J, Kim S. 757P Investigation of PARP inhibitor resistance through the analysis of serially collected circulating tumor DNA (ctDNA) in ovarian cancer patients. Ann Oncol 2021. [DOI: 10.1016/j.annonc.2021.08.1199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Lee IS, Park SH, Choi SJ, Shim Y, Ahn SJ, Kim KW, Kim KK, Jeong YM, Choe YH. Diagnostic Performance of Multidetector Computerized Tomography in the Detection of Abdominal Complications Early and Late After Liver Transplantation: A 10-Year Experience. Transplant Proc 2018; 50:3673-3680. [PMID: 30577254 DOI: 10.1016/j.transproceed.2018.09.016] [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] [Received: 05/19/2018] [Revised: 08/15/2018] [Accepted: 09/05/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND Multidetector computerized tomography (MDCT) is considered to be a fast noninvasive diagnostic technique for the evaluation of postoperative complications in patients with liver transplantation (LT). However, its role has not been fully established in the diagnosis for detecting complications after liver transplantation. The aim of this work was to evaluate the diagnostic performance of MDCT for detecting abdominal complications in the early and late periods after LT. METHODS We retrospectively enrolled 75 patients who had undergone LT from March 2006 to January 2010, followed by MDCT from March 2006 to November 2017. Patients were divided into 2 groups according to the timing after LT: within the first 3 months (early period) or ≥3 months after LT (late period). We evaluated vascular, biliary, and other complications on MDCT. Angiography, endoscopic retrograde cholangiography, and percutaneous transhepatic cholangiography were used as reference standards. RESULTS We initially found 77 complications in 45 patients (60.0%) with the use of MDCT. After comparison with the reference standards, 83 complications were diagnosed in 49 patients (65.3%). Forty-seven complications (34 vascular, 10 biliary, 3 other complications) were diagnosed in 33 patients (44.0%) during the early period, and 36 complications (6 vascular, 20 biliary, 10 other complications) were detected in 27 patients (36.0%) in the late period. The sensitivity, specificity, and diagnostic accuracy of MDCT for diagnosing overall complications were, respectively, 93.6%, 90.2%, and 92.0% in the early period (for vascular complications: 97.1%, 92.6%, and 94.3%,; for biliary complications: 80.0%, 100%, and 97.7%) and 77.8%, 98.1%, and 89.8% in the late period (for vascular complications: 83.3%, 100%, and 98.9%; for biliary complications: 65.0%, 98.6%, and 90.9%). CONCLUSIONS Although MDCT in the late period should be interpreted with caution in patients with suspected biliary complication, MDCT is a reliable diagnostic technique for the identification of early and late abdominal complications after LT.
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Affiliation(s)
- I S Lee
- Department of Radiology, Gil Medical Center, Gachon University, Incheon, Korea
| | - S H Park
- Department of Radiology, Gil Medical Center, Gachon University, Incheon, Korea.
| | - S J Choi
- Department of Radiology, Gil Medical Center, Gachon University, Incheon, Korea
| | - Y Shim
- Department of Radiology, Gil Medical Center, Gachon University, Incheon, Korea
| | - S-J Ahn
- Department of Radiology, Gil Medical Center, Gachon University, Incheon, Korea
| | - K W Kim
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - K K Kim
- Department of Surgery, Gil Medical Center, Gachon University, Incheon, Korea
| | - Y M Jeong
- Department of Radiology, Gil Medical Center, Gachon University, Incheon, Korea
| | - Y H Choe
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Kim SY, Cho JY, Lee J, Hwang SI, Moon MH, Lee EJ, Hong SS, Kim CK, Kim KA, Park SB, Sung DJ, Kim Y, Kim YM, Jung SI, Rha SE, Kim DW, Lee H, Shim Y, Hwang I, Woo S, Choi HJ. Low-Tube-Voltage CT Urography Using Low-Concentration-Iodine Contrast Media and Iterative Reconstruction: A Multi-Institutional Randomized Controlled Trial for Comparison with Conventional CT Urography. Korean J Radiol 2018; 19:1119-1129. [PMID: 30386143 PMCID: PMC6201985 DOI: 10.3348/kjr.2018.19.6.1119] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 06/07/2018] [Indexed: 01/29/2023] Open
Abstract
Objective To compare the image quality of low-tube-voltage and low-iodine-concentration-contrast-medium (LVLC) computed tomography urography (CTU) with iterative reconstruction (IR) with that of conventional CTU. Materials and Methods This prospective, multi-institutional, randomized controlled trial was performed at 16 hospitals using CT scanners from various vendors. Patients were randomly assigned to the following groups: 1) the LVLC-CTU (80 kVp and 240 mgI/mL) with IR group and 2) the conventional CTU (120 kVp and 350 mgI/mL) with filtered-back projection group. The overall diagnostic acceptability, sharpness, and noise were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) in the urinary tract were evaluated. Results The study included 299 patients (LVLC-CTU group: 150 patients; conventional CTU group: 149 patients). The LVLC-CTU group had a significantly lower effective radiation dose (5.73 ± 4.04 vs. 8.43 ± 4.38 mSv) compared to the conventional CTU group. LVLC-CTU showed at least standard diagnostic acceptability (score ≥ 3), but it was non-inferior when compared to conventional CTU. The mean attenuation value, mean SNR, CNR, and FOM in all pre-defined segments of the urinary tract were significantly higher in the LVLC-CTU group than in the conventional CTU group. Conclusion The diagnostic acceptability and quantitative image quality of LVLC-CTU with IR are not inferior to those of conventional CTU. Additionally, LVLC-CTU with IR is beneficial because both radiation exposure and total iodine load are reduced.
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Affiliation(s)
- Sang Youn Kim
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Jeong Yeon Cho
- Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea.,Institute of Radiation Medicine and Kidney Research Institute, Seoul National University, Seoul 03080, Korea
| | - Joongyub Lee
- Medical Research Collaborating Center, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Sung Il Hwang
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam 13621, Korea
| | - Min Hoan Moon
- Department of Radiology, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul 07061, Korea
| | - Eun Ju Lee
- Department of Radiology, Ajou University Hospital, Ajou University School of Medicine, Suwon 16499, Korea
| | - Seong Sook Hong
- Department of Radiology, Soonchunhyang University Seoul Hospital, Seoul 04401, Korea
| | - Chan Kyo Kim
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
| | - Kyeong Ah Kim
- Department of Radiology, Korea University Guro Hospital, Korea University College of Medicine, Seoul 08308, Korea
| | - Sung Bin Park
- Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul 06973, Korea
| | - Deuk Jae Sung
- Department of Radiology, Korea University Anam Hospital, Korea University College of Medicine, Seoul 02841, Korea
| | - Yongsoo Kim
- Department of Radiology, Hanyang University Guri Hospital, Guri 11923, Korea
| | - You Me Kim
- Department of Radiology, Dankook University Hospital, Dankook University College of Medicine, Cheonan 31116, Korea
| | - Sung Il Jung
- Department of Radiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul 05030, Korea
| | - Sung Eun Rha
- Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
| | - Dong Won Kim
- Department of Radiology, Dong-A University College of Medicine, Busan 49201, Korea
| | - Hyun Lee
- Department of Radiology, Hallym University Sacred Heart Hospital, Anyang 14068, Korea
| | - Youngsup Shim
- Department of Radiology, Gachon University, Gil Medical Center, Incheon 21565, Korea
| | - Inpyeong Hwang
- Department of Radiology, Cheongyang-gun Health Center and County Hospital, Cheongyang 33324, Korea
| | - Sungmin Woo
- Department of Radiology, Armed Forces Daejeon Hospital, Daejeon 34059, Korea
| | - Hyuck Jae Choi
- Department of Radiology, Sheikh Khalifa Specialty Hospital, Ras al Khaimah, UAE
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Lee H, Shim Y, Jeong H, Kwon E, Hwang J. The Association between Bone Age Advancement and Insulin Resistance in Prepubertal Obese Children. Exp Clin Endocrinol Diabetes 2015; 123:604-7. [DOI: 10.1055/s-0035-1559795] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- H. Lee
- Department of Pediatrics, Ajou University School of Medicine, Ajou University Hospital, Suwon, Korea
| | - Y. Shim
- Department of Pediatrics, Hallym University School of Medicine, Dongtan Sacred Heart Hospital, Dongtan, Korea
| | - H. Jeong
- Department of Pediatrics, Ajou University School of Medicine, Ajou University Hospital, Suwon, Korea
| | - E. Kwon
- Department of Pediatrics, Ajou University School of Medicine, Ajou University Hospital, Suwon, Korea
| | - J. Hwang
- Department of Pediatrics, Ajou University School of Medicine, Ajou University Hospital, Suwon, Korea
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Hyun DK, Shim Y, Oh S. Proposed Mechanism for Central Retinal Artery Occlusion Following Neurointervention Other Than Thromboembolism: Iodine Contrast. Skull Base Surg 2014. [DOI: 10.1055/s-0034-1384159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Uhm J, Hong J, Choi M, Kim K, Han J, Kim J, Shim Y, Kwon O, Ahn J, Ahn M, Park K. External validation of proposals for the revision of the TNM stage groupings by the IASLC lung cancer staging project in Korean non-small cell lung cancer patients. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.22140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Shim Y, Nishimoto Y, Okada W, Wakita K, Mamedov N. Temperature-dependent spectro-ellipsometric studies of optical transitions near absorption edge of TlInS2. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/pssc.200777758] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lee JH, Kaplan B, Shim Y, Tylenda C. Adverse Birth Outcomes and Exposures to Air Pollutants Assessed by Spatial and Temporal Modeling in Incheon, Republic of Korea. Epidemiology 2006. [DOI: 10.1097/00001648-200611001-00321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Lee K, Shim Y, Lee S, Cho M, Mun Y, Seong C, Lee S. Prognostic significance of CD44s expression in bile duct carcinomas. J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.14071] [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: 11/20/2022] Open
Abstract
14071 Background: CD44 is a surface glycoprotein and has a key role for surface hyaluronan receptor, which is associated with adhesion and metastasis in many solid tumors. There are CD44 standard isoform (CD44s) and ten variant isoforms (CD44v1–10). CD44s and CD44 variant 6 (CD44v6) were evaluated to clarify the applicable prognostic factor in patients with bile duct carcinomas. Methods: A retrospective study was performed in bile duct carcinomas. Immunohistochemical stain was done with primary antibodies for CD44 (Novocastra, Newcastle upon Tyne, UK) and CD44v6 (Novocastra) using automated machine (Vision Biosystems, Mount Waverley, VIC, Australia) and bond polymer detection system with counterstain (Vision Biosystems) in paraffin embedded tissues. The extent of staining categorized as 0% (none), <10% (weak), 10%-50% (moderate), and >50% (strong). Clinical characteristics including age, sex, stage, grade and overall survival were reviewed. Results: Ninety six patients (M:F=35:61) were evaluated and the median age of these patients was 64 years old (37∼86). The rate of overexpression (>10%) of CD44s was 50% and the rate of CD44v6 expression was 16.9%. With median 34.2 months of follow up, the overall survival of total 96 patients was 12.2 months. The Cox proportional hazards test identified CD44s overexpression. (HR:2.379, 95% CI:1.195–4.736, p=0.014) and the stage as prognostic factors. But the expression of CD44v6 (weak vs. moderate to strong, HR:3.983, 95%CI:0.295–1.588, p=0.377) showed no prognostic significance on overall survival. Conclusion: CD44s overexpression can be a poor prognostic marker in bile duct carcinomas. And there is a potential to apply postoperative investigational or aggressive therapy in this poor prognostic group. No significant financial relationships to disclose.
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Affiliation(s)
- K. Lee
- Ewha Womans University Hospital, Seoul, Republic of Korea
| | - Y. Shim
- Ewha Womans University Hospital, Seoul, Republic of Korea
| | - S. Lee
- Ewha Womans University Hospital, Seoul, Republic of Korea
| | - M. Cho
- Ewha Womans University Hospital, Seoul, Republic of Korea
| | - Y. Mun
- Ewha Womans University Hospital, Seoul, Republic of Korea
| | - C. Seong
- Ewha Womans University Hospital, Seoul, Republic of Korea
| | - S. Lee
- Ewha Womans University Hospital, Seoul, Republic of Korea
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Na I, Kang H, Park Y, Koh J, Cho S, Lee B, Lee Y, Shim Y, Ryoo B, Yang S. EGFR mutations and human papillomavirus in squamous cell carcinoma of tongue and tonsil. J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.10027] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
10027 Background: Some studies reported the presence of somatic mutation of EGFR in head and neck cancer. Human papillomavirus (HPV) was associated with some types of head and neck cancer. We performed this study to determine clinical significance of EGFR mutation and its association with HPV infection in patients with tongue and tonsil cancer. Methods: We sequenced exons 18–21 of EGFR TK domain and HPV typing was performed using the HPV DNA chip in tissues of patients with tongue and tonsil cancer. Univariate and multivariate analysis was performed. Results: Eighty-one patients were included. We detected EGFR mutation in 10 (12%) patients. Mutation was significantly frequent in never-smoker (21% versus 5%; P = 0.031). The mutation frequency did not differ between tongue and tonsil cancer (12% vs. 13%, respectively; P = 0.978). There was no difference between female and male (12% vs. 14%, respectively; P = 0.754). Eleven of 81 (14%) patients were HPV positive. HPV positivity was more common in young (<60 years) than older (≥60 years) patients (20% vs. 3%, respectively; P = 0.039). Patients with tonsil cancer showed more frequent HPV positivity than tongue cancer (42% vs. 2%, respectively; P < 0.001). There was no association between HPV positivity and EGFR mutation. In terms of disease-free survival, patients with EGFR mutation had better survival independently of stage and primary site (hazard ratio, 0.246; 95% CI, 0.075 to 0.802). Conclusions: We did not find association between EGFR mutation and HPV positivity. Patients with EGFR mutation showed better outcome in tongue and tonsil cancer. These results suggest that EGFR mutation may be a prognostic factor in patients with head and neck cancer. No significant financial relationships to disclose.
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Affiliation(s)
- I. Na
- Korea Cancer Center Hospital, Seoul, Republic of Korea
| | - H. Kang
- Korea Cancer Center Hospital, Seoul, Republic of Korea
| | - Y. Park
- Korea Cancer Center Hospital, Seoul, Republic of Korea
| | - J. Koh
- Korea Cancer Center Hospital, Seoul, Republic of Korea
| | - S. Cho
- Korea Cancer Center Hospital, Seoul, Republic of Korea
| | - B. Lee
- Korea Cancer Center Hospital, Seoul, Republic of Korea
| | - Y. Lee
- Korea Cancer Center Hospital, Seoul, Republic of Korea
| | - Y. Shim
- Korea Cancer Center Hospital, Seoul, Republic of Korea
| | - B. Ryoo
- Korea Cancer Center Hospital, Seoul, Republic of Korea
| | - S. Yang
- Korea Cancer Center Hospital, Seoul, Republic of Korea
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Choi Y, Choi H, Lee J, Son D, Song I, Lim Y, Kim K, Shim Y, Kim J. P-021 Prognostic significance of matrix metalloproteinase-2 activity incuratively resected stage I non-small cell lung cancer. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)80515-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Lim T, Lee J, Park J, Kang J, Han J, Shim Y, Kim J, Kwon O, Kim H, Park K. P-626 Clinical features and treatment outcome of bronchioloalveolarlung cancer. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)81119-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hoseok I, Lee J, Nam D, Ahn Y, Shim Y, Kim K, Choi Y, Kim J. P-880 Surgical treatment of non-small cell lung carcinoma with isolatedsynchronous brain metastases. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)81373-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Kim S, Lee J, Park J, Kang J, Han J, Shim Y, Kim J, Kwon O, Kim H, Park K. P-660 Clinical and histologic correlation of thymic epithelial tumors(TETs) in Korea. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)81153-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lee C, Oh J, Kwon S, Lee J, Lee S, Yim J, Yoo C, Kim Y, Han S, Shim Y. P-258 Natural history and clinical significance of solitary ground glass opacity (GGO) lesion detected by chest CT(HRCT). Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)80752-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Hahn TW, Lohakare J, Shim Y, Han K, Won H, Park Y, Chae B. The effects of vitamin C-polyethylene glycol
complex on growth performance and immunity in
broiler chickens. J Anim Feed Sci 2005. [DOI: 10.22358/jafs/66973/2005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Shim Y, Choi MY, Kim HJ. A molecular dynamics computer simulation study of room-temperature ionic liquids. I. Equilibrium solvation structure and free energetics. J Chem Phys 2005; 122:44510. [PMID: 15740270 DOI: 10.1063/1.1819317] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Solvation in 1-ethyl-3-methylmidazolium chloride and in 1-ethyl-3-methylimidazolium hexafluorophosphate near equilibrium is investigated via molecular dynamics computer simulations with diatomic and benzenelike molecules employed as probe solutes. It is found that electrostriction plays an important role in both solvation structure and free energetics. The angular and radial distributions of cations and anions become more structured and their densities near the solute become enhanced as the solute charge separation grows. Due to the enhancement in structural rigidity induced by electrostriction, the force constant associated with solvent configuration fluctuations relevant to charge shift and transfer processes is also found to increase. The effective polarity and reorganization free energies of these ionic liquids are analyzed and compared with those of highly polar acetonitrile. Their screening behavior of electric charges is also investigated.
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Affiliation(s)
- Y Shim
- Department of Physics, Seoul National University, Seoul 151-747, Korea
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Shim Y, Choi MY, Kim HJ. A molecular dynamics computer simulation study of room-temperature ionic liquids. II. Equilibrium and nonequilibrium solvation dynamics. J Chem Phys 2005; 122:44511. [PMID: 15740271 DOI: 10.1063/1.1819318] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The molecular dynamics (MD) simulation study of solvation structure and free energetics in 1-ethyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium hexafluorophosphate using a probe solute in the preceding article [Y. Shim, M. Y. Choi and H. J. Kim, J. Chem. Phys. 122, 044510 (2005)] is extended to investigate dynamic properties of these liquids. Solvent fluctuation dynamics near equilibrium are studied via MD and associated time-dependent friction is analyzed via the generalized Langevin equation. Nonequilibrium solvent relaxation following an instantaneous change in the solute charge distribution and accompanying solvent structure reorganization are also investigated. Both equilibrium and nonequilibrium solvation dynamics are characterized by at least two vastly different time scales--a subpicosecond inertial regime followed by a slow diffusive regime. Solvent regions contributing to the subpicosecond nonequilibrium relaxation are found to vary significantly with initial solvation configurations, especially near the solute. If the solvent density near the solute is sufficiently high at the outset of the relaxation, subpicosecond dynamics are mainly governed by the motions of a few ions close to the solute. By contrast, in the case of a low local density, solvent ions located not only close to but also relatively far from the solute participate in the subpicosecond relaxation. Despite this difference, linear response holds reasonably well in both ionic liquids.
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Affiliation(s)
- Y Shim
- Department of Physics, Seoul National University, Seoul 151-747, Korea
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Shim Y, Levine LE, Thomson R. Critical behavior of a strain percolation model for metals. Phys Rev E Stat Nonlin Soft Matter Phys 2002; 65:046146. [PMID: 12005965 DOI: 10.1103/physreve.65.046146] [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: 05/08/2001] [Indexed: 05/23/2023]
Abstract
Extensive simulations of a strain percolation model for a deforming metal have been performed to examine its strain behavior. We find that the total strain exhibits critical power-law behavior that is well explained by two-dimensional percolation theory. Near the critical point, most of the strained cells organize themselves around a state having the minimum or at least marginally stable strain regardless of the initial conditions. A strain much greater than the minimum stable strain generally decays to a lower value when transmitted to an unstrained cell. The universal behavior of the total strain in the system is a consequence of the self-organizing character of the strain in the critical cluster. Although the probability distributions for the total strain and cluster size appear to exhibit nonuniversal behavior, this may merely represent a transient response before crossover to a true asymptotic, universal behavior occurs. Other critical aspects of the model are also discussed.
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Affiliation(s)
- Y Shim
- Center for Simulational Physics, University of Georgia, Athens, Georgia 30602, USA
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Shim Y, Hong H, Choi MY. Noise-enhanced temporal association in neural networks. Phys Rev E Stat Nonlin Soft Matter Phys 2002; 65:036114. [PMID: 11909172 DOI: 10.1103/physreve.65.036114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2001] [Revised: 11/02/2001] [Indexed: 05/23/2023]
Abstract
We consider a network of globally coupled neuronal oscillators subject to random force, and investigate numerically dynamic responses to external periodic driving. The order parameter, which measures the overlap between the configuration of the system and embedded patterns, is found to exhibit stochastic resonance behavior, as manifested by the signal-to-noise ratio (SNR). The optimal noise level at which the SNR reaches its maximum is found to depend on the driving frequency. On the other hand, as the randomness in the driving amplitude is increased, the system undergoes a transition from the memory-retrieval state to the mixed-memory one. The noise effects on the temporal-association state in the absence of external periodic driving are also investigated, revealing similar noise-enhanced resonance.
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Affiliation(s)
- Y Shim
- Department of Physics and Center for Theoretical Physics, Seoul National University, Seoul 151-747, Korea
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Abstract
OBJECTIVE This study compares consumers' self-perceived diet quality with calculated diet quality to assess the degree of consumer misperception regarding one's own diet quality and to identify factors associated with such misperception. DESIGN The perceived diet quality was measured by consumers' self-perception of the overall healthfulness of their diet. The calculated diet quality was measured by the Healthy Eating Index, a 10-component indicator of overall diet quality developed from 3 consecutive days of 1-day 24-hour dietary recall and 2-day diet record. SUBJECTS/SETTINGS Measures of perceived and calculated diet quality were obtained for a sample of 2862 household meal planners/preparers from the 1989-90 Continuing Survey of Food Intake by Individuals and the Diet and Health Knowledge Survey. OUTCOME Dietary misperception was assessed by classifying respondents based on categories of perceived and calculated diet quality into three groups: optimists, realists, and pessimists. STATISTICAL ANALYSES Bivariate statistical tests and multivariate logistic regression were used for comparing the characteristics of optimists with the other two groups. RESULTS An estimated 40% of the population of household meal planner/preparers were optimists who perceived the quality of their diets to be better than their calculated diet quality. In multivariate analysis, household size, gender, education, smoking status, perceived health status, importance of nutrition in grocery shopping, and belief about the need for dietary change were found to be significant predictors of being optimistic about diet quality. Nutritionists and health professionals need to be aware of this misperception and alert dietary optimists about their false perceptions of diet quality.
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Affiliation(s)
- J N Variyam
- Economic Research Service, U.S. Department of Agriculture, Washington, DC 20036-5831, USA.
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Shim Y, Landau DP. Dynamic finite-size scaling of the normalized height distribution in kinetic surface roughening. Phys Rev E Stat Nonlin Soft Matter Phys 2001; 64:036110. [PMID: 11580397 DOI: 10.1103/physreve.64.036110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2000] [Revised: 04/03/2001] [Indexed: 05/23/2023]
Abstract
Using well-known simple growth models, we have studied the dynamic finite-size scaling theory for the normalized height distribution of a growing surface. We find a simple functional form that explains size-dependent behavior of the skewness and kurtosis in the transient regime, and obtain the transient- and long-time values of the skewness and kurtosis for the models. Scaled distributions of the models are obtained, and the shape of each distribution is discussed in terms of the interfacial width, skewness, and kurtosis, and compared with those for other models. Exponents eta(+) and eta(-), which characterize the form of the distribution, are determined from an exponential fitting of scaling functions. Our detailed results reveal that eta(+)+eta(-) approximately 4 for a model obeying usual scaling in contrast to eta(+)+eta(-)<4 with eta(-)=1 for a model exhibiting anomalous scaling as well as multiscaling. Since we obtain eta(+)+eta(-) approximately 4 for a model exhibiting anomalous scaling but no multiscaling, we conclude that the deviation from eta(+)+eta(-) approximately 4 is due to the presence of multiscaling behavior in a model.
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Affiliation(s)
- Y Shim
- Center for Simulational Physics, University of Georgia, Athens, Georgia 30602, USA.
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Pae HH, Lee JH, Yoo CG, Lee CT, Chung HS, Kim YW, Han SK, Shim Y. Study for Clinical Characteristics of Nontuberculous Mycobacterial Pulmonary Diseases. Tuberc Respir Dis (Seoul) 1999. [DOI: 10.4046/trd.1999.47.6.735] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- H H Pae
- Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, Korea
| | - J H Lee
- Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, Korea
| | - C G Yoo
- Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, Korea
| | - C T Lee
- Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, Korea
| | - H S Chung
- Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Y W Kim
- Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, Korea
| | - S K Han
- Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Y Shim
- Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, Seoul, Korea
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Lee SJ, Kim GS, Lee JC, Yoo CG, Kim YW, Han SK, Shim Y. The first case of summer-type hypersensitivity pneumonitis in Korea. Tuberc Respir Dis (Seoul) 1996. [DOI: 10.4046/trd.1996.43.2.280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Seung Joon Lee
- Department of Internal Medicine, College of Medicine, Seoul National University, Korea
| | - Gye Soo Kim
- Department of Internal Medicine, College of Medicine, Seoul National University, Korea
| | - Jae Cheol Lee
- Department of Internal Medicine, College of Medicine, Seoul National University, Korea
| | - Churl Gyoo Yoo
- Department of Internal Medicine, College of Medicine, Seoul National University, Korea
| | - Young Whan Kim
- Department of Internal Medicine, College of Medicine, Seoul National University, Korea
| | - Sung Koo Han
- Department of Internal Medicine, College of Medicine, Seoul National University, Korea
| | - Y Shim
- Department of Internal Medicine, College of Medicine, Seoul National University, Korea
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Shim Y, Kim H, Chang M, Kim C. Map dynamic ranges versus duration of hearing loss in cochlear implantees. Ann Otol Rhinol Laryngol Suppl 1995; 166:178-80. [PMID: 7668625] [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: 01/26/2023]
Abstract
In order to assess the relationship of factors such as age, cause of deafness, use of hearing aids, duration of hearing loss, and age at onset of hearing loss, with the size of map dynamic ranges (DRs), 34 postlingually and 8 prelingually deaf users of the Nucleus cochlear implant system were analyzed according to the sizes of map DRs. Lack of auditory stimulation for a longer period than 10 years might be one of the most important factors associated with a reduced map DR. Use of hearing aids was associated with larger map DRs. Small map DRs were found across a range of age, age at onset, and duration of hearing loss. Cause of deafness did not appear to be related to map DRs.
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Affiliation(s)
- Y Shim
- Department of Otorhinolaryngology-Head and Neck Surgery, Yonsei University, College of Medicine, Seoul, Korea
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Shim Y, Pasipoularides A, Straley CA, Hampton TG, Soto PF, Owen CH, Davis JW, Glower DD. Arterial windkessel parameter estimation: a new time-domain method. Ann Biomed Eng 1994; 22:66-77. [PMID: 8060028 DOI: 10.1007/bf02368223] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [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] [Indexed: 01/28/2023]
Abstract
We developed and validated a new, more accurate, and easily applied method for calculating the parameters of the three-element Windkessel to quantitate arterial properties and to investigate ventriculoarterial coupling. This method is based on integrating the governing differential equation of the three-element Windkessel and solving for arterial compliance. It accounts for the interaction between characteristic impedance and compliance, an important phenomenon that has been ignored by previously implemented methods. The new integral method was compared with four previously published methods as well as a new independent linear least-squares analysis, using ascending aortic micromanometric and volumetric flow measurements from eight dogs. The parameters calculated by the new integral method were found to be significantly different from those obtained by the previous methods but did not differ significantly from maximum likelihood estimators obtained by a linear least-squares approach. To assess the accuracy of parameter estimation, pressure and flow waveforms were reconstructed in the time domain by numerically solving the governing differential equation of the three-element Windkessel model. Standard deviations of reconstructed waveforms from the experimental ensemble-averaged waveforms, which solely reflect the relative accuracy of the Windkessel parameters given by the various methods, were calculated. The new integral method invariably yielded the smallest error. These results demonstrate the improved accuracy of our new integral method in estimating arterial parameters of the three-element Windkessel.
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Affiliation(s)
- Y Shim
- Department of Biomedical Engineering, Duke University, Durham, NC 27706
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Shim Y, Hampton TG, Straley CA, Harrison JK, Spero LA, Bashore TM, Pasipoularides AD. Ejection load changes in aortic stenosis. Observations made after balloon aortic valvuloplasty. Circ Res 1992; 71:1174-84. [PMID: 1394879 DOI: 10.1161/01.res.71.5.1174] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
To investigate complementarity and competitiveness between the intrinsic and extrinsic components of the total left ventricular systolic load, hemodynamic data from 18 elderly subjects with severe aortic stenosis were analyzed before and after balloon dilation of the stenosed aortic valve. Multisensor micromanometric pressure measurements allowed calculation (simplified Bernoulli equation) of the ejection velocity and aortic input impedance spectra. Despite a 32% increase in the aortic valve area (from 0.56 +/- 0.04 to 0.74 +/- 0.05 cm2 [mean +/- SEM], p < 0.01), the peak left ventricular systolic pressure fell by only 12% (from 189 +/- 10 to 167 +/- 8 mm Hg, p < 0.01). This was accompanied by an increase in the impedance at the same cardiac output. In a subset of patients (n = 9) in whom the peak aortic systolic pressure rose after valvuloplasty (from 115 +/- 10 to 128 +/- 12 mm Hg, p < 0.01), a 40% increase in the aortic valve area was accompanied by a marked increase in the aortic input impedance. In this subset, the steady component of the aortic input impedance increased by 24% (from 960 +/- 96 to 1,188 +/- 134 dyne.sec/ml, p < 0.05), and the characteristic impedance increased by 25% (from 106 +/- 13 to 132 +/- 19 dyne.sec/ml, p < 0.05). Because of an increased aortic impedance acutely following the procedure, the total left ventricular systolic load after balloon dilation of the stenotic valve was only slightly decreased despite a significant increase in aortic valve area. This represents an example of complementarity and competitiveness between the intrinsic and extrinsic components of the total systolic ventricular load. It may explain why improvement in left ventricular performance may be modest acutely following balloon aortic valvuloplasty.
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Affiliation(s)
- Y Shim
- Department of Biomedical Engineering, Duke University, Durham, NC 27706
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