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Oh CH, Cho SB, Lee HJ, Kwon H, Hwang YG. Migration of double-J ureteral stent in patients with ureteroileal anastomosis stricture undergoing radical cystectomy and orthotopic neobladder: Analysis risk factors of stent migration. Medicine (Baltimore) 2024; 103:e37765. [PMID: 38640312 PMCID: PMC11030022 DOI: 10.1097/md.0000000000037765] [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] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 02/29/2024] [Accepted: 03/08/2024] [Indexed: 04/21/2024] Open
Abstract
The objective was to evaluate the incidence and degree of double-J ureteral stent (DJUS) migration. Additionally, we aimed to investigate the risk factors associated with stent migration in the orthotopic neobladder group. In this retrospective study, 61 consecutive patients were included; 35 patients (45 DJUS placements) underwent radical cystectomy with orthotopic neobladder and 26 patients (35 DJUS placements) underwent urinary bladder without cystectomy between July 2021 and March 2023. All the patients were treated with a DJUS for ureteric strictures. The technical success rate was 100% in each group. The DJUS migration was significantly higher in the orthotopic neobladder group, with 22 of 45 cases (48.9%), compared to the urinary bladder group, which had 4 of 35 cases (11.4%) (P ≤ .001). Among the patients in the orthotopic neobladder group who experienced DJUS migration, stent dysfunction occurred in 18 cases (81.8%), which was statistically significant (P = .003). Multivariate logistic regression analysis revealed that only the size of the DJUS was significantly and positively associated with migration (odds ratio:10.214, P = .010). DJUS migration can easily occur in patients undergoing radical cystectomy and orthotopic neobladder, and smaller stent sizes are associated with a higher incidence of migration.
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Affiliation(s)
- Chang Hoon Oh
- Department of Radiology, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Soo Buem Cho
- Department of Radiology, Ewha Womans University Seoul Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Hyo Jeong Lee
- Department of Radiology, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Hyeyoung Kwon
- Department of Radiology, Chungnam National University Hospital, Chungnam National Uvinersity School of Medicine, Daejeon, Republic of Korea
| | - Yeok Gu Hwang
- Department of Orthopedic Surgery, Ewha Womans University Seoul Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
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Choi YS, Oh CH. Successful Removal of a Fractured Desilets-Hoffman Sheath in a Patient With a Loop Arteriovenous Graft: Balloon-Supported Retrieval Technique. Vasc Endovascular Surg 2024; 58:448-451. [PMID: 37978848 DOI: 10.1177/15385744231217617] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
INTRODUCTION While a Desilets-Hoffman sheath rarely fractures, when it does, the presence of an intravenous foreign body can cause various complications. CASE PRESENTATION A 74-year-old woman receiving hemodialysis for end-stage renal disease via a left forearm arteriovenous graft (AVG) was referred to the interventional radiology department following thrombotic occlusion of the AVG. A corrective procedure was initiated, and the 7F Desilets-Hoffman sheath fractured after the purse-string suture. A .035-inch guidewire was passed through the fractured sheath, and a 3.0-mm x 60-mm balloon catheter was inflated, allowing for the successful removal of the sheath fragment without complications. CONCLUSION The fractured Desilets-Hoffman sheath was successfully removed in a patient with a loop arteriovenous graft using balloon-supported retrieval technique.
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Affiliation(s)
- Yoon Seo Choi
- Department of Radiology, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Chang Hoon Oh
- Department of Radiology, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
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Lim Choi S, Il Gwon D, Ha Kim G, Won Kim S, Oh CH, Ko GY. Safety and efficacy of large-bore uncovered stents for treating malignant superior vena cava syndrome. Eur J Radiol 2024; 175:111446. [PMID: 38581861 DOI: 10.1016/j.ejrad.2024.111446] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 03/04/2024] [Accepted: 03/24/2024] [Indexed: 04/08/2024]
Abstract
PURPOSE To investigate the safety and efficacy of large-bore uncovered stents for treating malignant superior vena cava syndrome. METHODS This retrospective study included 115 patients (89 men, 26 women; mean age 63.2 years; range 21-83 years) who underwent endovascular large-bore (≥18 mm in diameter) uncovered stent placement between August 2015 and July 2022. One patient was lost to follow-up. Therefore, 114 patients were available for follow-up. RESULTS Stent placement was technically successful in all 115 patients. Minor procedure-related complications occurred in nine (7.8 %) patients. One hundred eight (93.9 %) patients experienced complete or marked symptomatic relief (Kishi score ≤ 2) at a mean of 3 days after procedure. The cumulative stent patency rates were 98.2 %, 95 %, 93.7 %, 91.5 %, 83.5 %, and 83.5 % at 1, 3, 6, 12, 18, and 24 months, respectively. Stent occlusion occurred in ten (8.8 %) of 114 patients at a mean of 215 days (range 1-732 days) due to thrombosis (n = 7) and tumor ingrowth (n = 3). Stent occlusion did not occur in 21 patients who underwent subsequent central venous catheter insertion. The median patient survival time was 159 days (95 % confidence interval 102-216 days). Univariate and multivariate Cox regression analysis revealed adjuvant anticancer treatment (p = 0.001) and tumor response (p < 0.001) as independent predictors of patient survival. CONCLUSIONS Endovascular placement of large-bore uncovered stents was a safe and effective treatment for malignant superior vena cava syndrome. Large-bore stent placement can effectively prevent stent occlusion by tumor ingrowth in most cases, and it can provide a sufficient diameter for subsequent insertion of central venous catheters.
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Affiliation(s)
- Sang Lim Choi
- Department of Radiology, Chung-Ang University Gwangmyeong Hospital, Chung-Ang University College of Medicine, Gwangmyeong, Korea
| | - Dong Il Gwon
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
| | - Gun Ha Kim
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Sung Won Kim
- Department of Radiology, Youngin Severance Hospital, Yonsei University College of Medicine, Youngin, Korea
| | - Chang Hoon Oh
- Department of Radiology, Ewha Womans University Mokdong Hospital, Ewha Womans University College of Medicine, Seoul, Korea
| | - Gi-Young Ko
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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Lim YW, Oh CH, Lee HJ, Cho SB, Kim MS. Technical feasibility and safety of the alternative snare technique using a 0.018-inch guide wire and 5-French catheter for double-J ureteral stent removal. Medicine (Baltimore) 2024; 103:e37525. [PMID: 38489740 PMCID: PMC10939643 DOI: 10.1097/md.0000000000037525] [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] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 01/05/2024] [Accepted: 02/14/2024] [Indexed: 03/17/2024] Open
Abstract
To evaluate the technical feasibility of the alternative snare technique using a 0.018-inch guide wire and 5-French (Fr) catheter for double-J ureteral stent (DJUS) removal. In this retrospective study, 11 DJUS were removed in 9 consecutive patients between July 2023 and October 2023. We evaluated patient characteristics, DJUS characteristics, and procedure characteristics. Out of 11 cases, 8 (72.7%) were successful in removing the DJUS using the alternative snare technique without major complications. The average time between DJUS insertion and removal was 47.4 ± 50.0 days. The most common DJUS size was an 8-Fr, with proximal tips predominantly in the proximal ureter and renal pelvis. The mean procedure time for successful cases was 15.2 ± 16.8 minutes. Three failed cases, attributed to obstructions like debris, were later successfully addressed using the ALN inferior vena cava filter removal kit, forceps, and modified snare technique. The alternative snare technique using a 0.018-inch guidewire and Fr catheter is safe and effective in cases of DJUS removal.
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Affiliation(s)
- Ye Won Lim
- Department of Radiology, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Chang Hoon Oh
- Department of Radiology, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Hyo Jeong Lee
- Department of Radiology, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Soo Buem Cho
- Department of Radiology, Ewha Womans University Seoul Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Myung Soo Kim
- Department of Urology, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
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Lee HJ, Cho SB, Lee JK, Kim JS, Oh CH, Kim HJ, Yoon H, Ahn HK, Kim M, Hwang YG, Kwon HY, Hwang MJ. The feasibility of MR elastography with transpelvic vibration for localization of focal prostate lesion. Sci Rep 2024; 14:3864. [PMID: 38366042 PMCID: PMC10873507 DOI: 10.1038/s41598-024-54341-0] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 02/12/2024] [Indexed: 02/18/2024] Open
Abstract
We aimed to evaluate the feasibility of MR elastography (MRE) using a transpelvic approach. Thirty-one patients who underwent prostate MRE and had a pathological diagnosis were included in this study. MRE was obtained using a passive driver placed at the umbilicus and iliac crests. The shear stiffness, clinical data, and conventional imaging findings of prostate cancer and benign prostatic hyperplasia (BPH) were compared. Inter-reader agreements were evaluated using the intraclass coefficient class (ICC). Prostate MRE was successfully performed for all patients (100% technical success rate). Nineteen cancer and 10 BPH lesions were visualized on MRE. The mean shear stiffness of cancer was significantly higher than that of BPH (5.99 ± 1.46 kPa vs. 4.67 ± 1.54 kPa, p = 0.045). One cancer was detected on MRE but not on conventional sequences. Six tiny cancer lesions were not visualized on MRE. The mean size of cancers that were not detected on MRE was smaller than that of cancers that were visible on MRE (0.8 ± 0.3 cm vs. 2.3 ± 1.8 cm, p = 0.001). The inter-reader agreement for interpreting MRE was excellent (ICC = 0.95). Prostate MRE with transpelvic vibration is feasible without intracavitary actuators. Transpelvic prostate MRE is reliable for detecting focal lesions, including clinically significant prostate cancer and BPH.
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Affiliation(s)
- Hyo Jeong Lee
- Department of Radiology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Soo Buem Cho
- Department of Radiology, Ewha Womans University College of Medicine, Seoul, South Korea.
| | - Jeong Kyong Lee
- Department of Radiology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Jin Sil Kim
- Department of Radiology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Chang Hoon Oh
- Department of Radiology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Hyun Jin Kim
- Department of Radiology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Hana Yoon
- Department of Urology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Hyun Kyu Ahn
- Department of Urology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Myong Kim
- Department of Urology, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Yeok Gu Hwang
- Department of Orthopedic Surgery, Ewha Womans University College of Medicine, Seoul, South Korea
| | - Hye Young Kwon
- Department of Radiology, Chungnam National University College of Medicine, Daejeon, South Korea
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Oh CH, Cho SB, Kwon H. Evaluating Image Quality and Radiation Dose in Low-Dose Thoraco-Abdominal CT Angiography with a Tin Filter for Patients with Aortic Disease. J Clin Med 2024; 13:996. [PMID: 38398309 PMCID: PMC10889810 DOI: 10.3390/jcm13040996] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 01/31/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
Background: We aimed to compared radiation exposure and image quality between tin-filter-based and standard dose thoraco-abdominal computed tomography angiography (TACTA) protocols, aiming to address a gap in the existing literature. Methods: In this retrospective study, ninety consecutive patients undergoing TACTA were included. Of these, 45 followed a routine standard-dose protocol (ST100kV), and 45 underwent a low-dose protocol with a tin filter (TF100kV). Radiation metrics were compared. The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) were calculated for the thoracic and abdominal aorta and right common iliac artery. Two independent readers assessed the image noise, image contrast, sharpness, and subjective image quality. Results: The mean dose for the TF100kV group was significantly lower (DLP 128.25 ± 18.18 mGy*cm vs. 662.75 ± 181.29, p < 0.001; CTDIvol 1.83 ± 0.25 mGy vs. 9.28 ± 2.17, p = 0.001), with an effective dose close to 2.3 mSv (2.31 ± 0.33 mSv; p < 0.001). The TF100kV group demonstrated greater dose efficiency (FOM, thoracic aorta: 36.70 ± 22.77 vs. 13.96 ± 13.18 mSv-1, p < 0.001) compared to the ST100kV group. Conclusions: Dedicated low-dose TACTA using a tin filter can significantly reduce the radiation dose while maintaining sufficient diagnostic image quality.
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Affiliation(s)
- Chang Hoon Oh
- Department of Radiology, Ewha Womans Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul 07985, Republic of Korea;
| | - Soo Buem Cho
- Department of Radiology, Ewha Womans Seoul Hospital, College of Medicine, Ewha Womans University, Seoul 07804, Republic of Korea
| | - Hyeyoung Kwon
- Department of Radiology, Chungnam University Hospital, School of Medicine, Chungnam University, Daejeon 35015, Republic of Korea;
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Oh CH, Gwon DI, Chu HH, Ko GY, Kim GH, Choi SL, Kim SW. Percutaneous insertion of long-covered biliary stents in patients with malignant duodenobiliary stricture. Eur Radiol 2024; 34:538-547. [PMID: 37540317 DOI: 10.1007/s00330-023-10024-4] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 06/11/2023] [Accepted: 06/13/2023] [Indexed: 08/05/2023]
Abstract
OBJECTIVE To investigate the technical feasibility, safety, and efficacy of a long-covered biliary stent in patients with malignant duodenobiliary stricture. METHODS This retrospective study enrolled 57 consecutive patients (34 men, 23 women; mean age, 64 years; range, 32-85 years) who presented with malignant duodenobiliary stricture between February 2019 and November 2020. All patients were treated with a long (18 or 23 cm)-covered biliary stent. RESULTS The biliary stent deployment was technically successful in all 57 patients. The overall adverse event rate was 17.5% (10 of 57 patients). Successful internal drainage was achieved in 55 (96.5%) of 57 patients. The median patient survival and stent patency times were 99 days (95% confidence interval [CI], 58-140 days) and 73 days (95% CI, 60-86 days), respectively. Fourteen (25.5%) of the fifty-five patients presented with biliary stent dysfunction due to sludge (n = 11), tumor overgrowth (n = 1), collapse of the long biliary stent by a subsequently inserted additional duodenal stent (n = 1), or rapidly progressed duodenal cancer (n = 1). A univariate Cox proportional hazards model did not reveal any independent predictor of biliary stent patency. CONCLUSIONS Percutaneous insertion of a subsequent biliary stent was technically feasible after duodenal stent insertion. Percutaneous insertion of a long-covered biliary stent was safe and effective in patients with malignant duodenobiliary stricture. CLINICAL RELEVANCE STATEMENT In patients with malignant duodenobiliary stricture, percutaneous insertion of a long-covered biliary stent was safe and effective regardless of duodenal stent placement. KEY POINTS • Percutaneous insertion of long-covered biliary stents in patients with malignant duodenobiliary stricture is a safe and effective procedure. • Biliary stent deployment was technically successful in all 57 patients and successful internal drainage was achieved in 55 (96.5%) of 57 patients. • The median patient survival and stent patency times were 99 days and 73 days, respectively, after placement of a long-covered biliary stent in patients with duodenobiliary stricture.
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Affiliation(s)
- Chang Hoon Oh
- Department of Radiology, Ewha Womans Mokdong Hospital, Ewha Womans University School of Medicine, Seoul, Korea
| | - Dong Il Gwon
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-Ro 43-Gil, Songpa-Gu, Seoul, 05505, Korea.
| | - Hee Ho Chu
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-Ro 43-Gil, Songpa-Gu, Seoul, 05505, Korea
| | - Gi-Young Ko
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-Ro 43-Gil, Songpa-Gu, Seoul, 05505, Korea
| | - Gun Ha Kim
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-Ro 43-Gil, Songpa-Gu, Seoul, 05505, Korea
| | - Sang Lim Choi
- Department of Radiology, Chung-Ang University Gwangmyeong Hospital, Gwangmyeong, Korea
| | - Sung Won Kim
- Department of Radiology, Research Institute of Radiological Science, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, Korea
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Kim Y, Oh CH, Choi SL, Kim S. Percutaneous Ureteral Stent Insertion in Patients with Benign Uretero-Ileal Anastomosis Strictures Who Underwent Radical Cystectomy: Assessing Risk Factors for Stent Patency. J Clin Med 2023; 12:7721. [PMID: 38137790 PMCID: PMC10744104 DOI: 10.3390/jcm12247721] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/08/2023] [Accepted: 12/15/2023] [Indexed: 12/24/2023] Open
Abstract
We aimed to investigate the risk factors of early double-J ureteral stent (DJUS) dysfunction rates and the long-term patency of DJUSs inserted via a percutaneous approach in patients with benign uretero-ileal anastomosis stricture (UIAS) who had undergone radical cystectomy. In this retrospective study, 63 DJUS placements were placed via a percutaneous nephrostomy tract in 42 consecutive patients between May 2020 and March 2023. The technical success rate was 100% in all patients without major complications. The early dysfunction rate and long-term patency rate were 38.1% (24/63) and 84.2% (32/38), respectively. The blood clot retention grade, balloon dilatation, and length of the ureteral stricture exhibited a significant correlation with early DJUS dysfunction (blood clot retention grade: odds ratio (OR) 6.922 in grade two, p = 0.009; balloon dilatation: OR 0.186, p = 0.017; length of ureteral stricture: OR 8.715, p = 0.035 in moderate stenosis, and 7.646, p = 0.028 in severe stenosis). A multivariate Cox's proportional hazard analysis revealed that blood clot retention grade and length of ureteral stricture were independent predictors of long-term DJUS patency. Percutaneous insertion of the DJUSs was safe and effective in patients with benign UIAS.
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Affiliation(s)
- Yebin Kim
- Department of Radiology, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul 07985, Republic of Korea;
| | - Chang Hoon Oh
- Department of Radiology, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul 07985, Republic of Korea;
| | - Sang Lim Choi
- Department of Radiology, Chung-Ang University Gwangmyeong Hospital, Gwangmyeong 14353, Republic of Korea;
| | - Sungwon Kim
- Department of Radiology, Research Institute of Radiological Science, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin 03186, Republic of Korea;
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Oh CH. Clinical efficacy and safety of percutaneous drainage for post-operative fluid collection in patients with bladder cancer undergoing radical cystectomy and urinary diversion. Medicine (Baltimore) 2023; 102:e36488. [PMID: 38065871 PMCID: PMC10713095 DOI: 10.1097/md.0000000000036488] [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] [MESH Headings] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Accepted: 11/15/2023] [Indexed: 12/18/2023] Open
Abstract
To evaluate the success rates of percutaneous drainage for fluid collection after radical cystectomy, with emphasis on factors affecting the clinical success, including lesion, patient, and procedure characteristics. In this retrospective study, 31 percutaneous drainage catheters were placed in 29 consecutive patients between January 2021 and September 2023. Most fluid collections formed near the uretero-ileal anastomosis site in the right pelvic cavity (80.6%). The technical success rate was 100%. The primary and final clinical success was 80.6% and 96.9%, respectively. Lymphoceles notably increased the primary clinical failure risk (odds ratio and 95% confidential interval: 22.667 (1.839-279.366), P = .015). Significant differences were observed between transabdominal and transgluteal approaches in terms of fluoroscopic time, dose, and location. Leakage indications on computed tomography prompted differing interventions, but all achieved final clinical success. Percutaneous drainage for post-operative fluid collection is safe and effective in patients with radical cystectomy and urinary diversion.
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Affiliation(s)
- Chang Hoon Oh
- Department of Radiology, Ewha Womans University Mokdong Hospital, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
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Park JY, Muaid R, Lew YK, Oh CH. Exploring the role of organisational learning and leadership in developing dynamic capabilities. EJIM 2023. [DOI: 10.1504/ejim.2023.127231] [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: 12/03/2022]
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Oh CH, Oetzel J. Multinational enterprises and natural disasters: Challenges and opportunities for IB research. J Int Bus Stud 2022; 53:231-254. [PMID: 35034991 PMCID: PMC8741579 DOI: 10.1057/s41267-021-00483-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/20/2021] [Accepted: 09/07/2021] [Indexed: 06/14/2023]
Abstract
The purpose of this paper is to encourage and to extend research on natural disasters and international business (IB). More specifically, we review the characteristics of natural disasters and the unique challenges they pose to the business environment and examine how they differ from other types of disasters/crises often researched in the IB literature. Next, we investigate the applicability and challenges of core IB theories to the study of natural disasters. By extending new internalization theory (NIT) to overcome challenges of bounded rationality and reliability, we identify effective strategies for managing the threat of natural disasters through establishing multi-sector partnerships and alternative supply chains. Integrating research on the characteristics of natural disasters and the insights from NIT, we propose natural disaster management strategies for multinational enterprises (MNEs) based on varying degrees of geographic scope of natural disasters and MNEs. This paper concludes with proposing new research opportunities for IB scholars in disaster preparedness, cross-organizational collaborations, and supply chain management.
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Affiliation(s)
- Chang Hoon Oh
- School of Business, University of Kansas, 1654 Naismith Dr, Lawrence, KS 66045 USA
| | - Jennifer Oetzel
- Management Department, Kogod School of Business, American University, 4400 Massachusetts Ave., Washington, D.C., NW 20016 USA
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Oh CH, Shin J, Oetzel J. How does experience change firms' foreign investment decisions to non-market events? Journal of International Management 2021. [DOI: 10.1016/j.intman.2020.100802] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Oh CH, Kim Y, Cho BS, Yi KS. Successful transcatheter arterial embolization for massive hemorrhage from acquired uterine arteriovenous malformation which occurred as a complication of hysterectomy: A case report. Medicine (Baltimore) 2021; 100:e24052. [PMID: 33466159 PMCID: PMC7808482 DOI: 10.1097/md.0000000000024052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 12/07/2020] [Indexed: 01/05/2023] Open
Abstract
RATIONALE Uterine arteriovenous malformation (UVM), which can be congenital or acquired, is a relatively rare disorder that can cause life-threatening hemorrhage. Acquired UVM occurs predominantly after previous uterine procedures; rarely, it may occur after a hysterectomy. Although the best treatment option for UVM remains controversial, transcatheter arterial embolization (TAE) has recently been introduced as a safe and effective treatment. PATIENT CONCERNS A 34-year-old woman who underwent hysterectomy for uncontrolled postpartum bleeding continued to have hemoperitoneum. DIAGNOSIS Two days after surgery, massive hemoperitoneum was identified on computed tomography scan, and acquired UVM was diagnosed by angiography. INTERVENTIONS The patient was successfully treated using TAE with an n-Butyl cyanoacrylate. OUTCOMES After embolization, hemodynamic stability was achieved. A day after embolization, hemoglobin was 10.2 g/dL, and the patient was discharged from the hospital 4 days thereafter. LESSONS Although the overall incidence of acquired UVM after hysterectomy is low, bleeding from acquired UVM should be considered as one of the differential diagnoses in the immediate postpartum period, especially when the clinical symptoms do not correlate with the amount of blood loss. A high index of suspicion, prompt diagnosis and intervention, and a multidisciplinary approach in the management were the elements of a successful outcome in this case.
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Affiliation(s)
| | | | | | - Kyung Sik Yi
- Department of Neurosurgery, Chungbuk National University Hospital, Cheongju, Republic of Korea
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Oh CH, Kim Y, Lee JH, Kim HR, Go SJ. Successful superselective embolization with n-butyl cyanoacrylate for hemorrhage from superficial femoral artery branches following blunt trauma: Three case reports. Medicine (Baltimore) 2020; 99:e20467. [PMID: 32629630 PMCID: PMC7337482 DOI: 10.1097/md.0000000000020467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
INTRODUCTION In blunt traumatic superficial femoral arterial (SFA) injuries, hemorrhage from the branches without injury to the main artery is rare, but can lead to serious complications, such as compartment syndrome affecting the clinical outcomes. Although open surgical repair has been the standard approach to peripheral vascular injuries, endovascular treatment has become more refined and is now an alternative to open surgery, which potentially involves lower morbidity and mortality rates. However, management of arterial injuries, especially when they involve simple bleeding from small branches of the main artery, can be challenging, and the best treatment options for such injuries remains controversial. PATIENT CONCERNS Three cases suffered blunt trauma that resulted in hemorrhage from branches of the SFA. DIAGNOSIS All patients underwent selective angiography, which demonstrated active extravasation from branches of the SFA. INTERVENTIONS All patients were treated using embolization with n-butyl cyanoacrylate (NBCA). OUTCOMES A post-embolization angiography demonstrated successful hemostasis, with no complications. CONCLUSION Superselective catheterization using a coaxial technique with a 5-F curved catheter and the smallest caliber microcatheter, and using a permanent liquid embolic agent, such as NBCA, increases the success rate of embolization for cases of hemorrhage from SFA branches.
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Affiliation(s)
| | | | | | - Hong Rye Kim
- Department of Neurosurgery, Chungbuk National University Hospital
| | - Seung Je Go
- Department of Surgery, Trauma Center, Eulji University Hospital, Cheongju, Republic of Korea
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Kim JH, Son YD, Kim JM, Kim HK, Kim YB, Lee C, Oh CH. Interregional correlations of glucose metabolism between the basal ganglia and different cortical areas: an ultra-high resolution PET/MRI fusion study using 18F-FDG. ACTA ACUST UNITED AC 2017; 51:e6724. [PMID: 29160415 PMCID: PMC5685063 DOI: 10.1590/1414-431x20176724] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 09/12/2017] [Indexed: 11/29/2022]
Abstract
Basal ganglia have complex functional connections with the cerebral cortex and are involved in motor control, executive functions of the forebrain, such as the planning of movement, and cognitive behaviors based on their connections. The aim of this study was to provide detailed functional correlation patterns between the basal ganglia and cerebral cortex by conducting an interregional correlation analysis of the 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) data based on precise structural information. Fifteen participants were scanned with 7-Tesla magnetic resonance imaging (MRI) and high resolution research tomography (HRRT)-PET fusion system using 18F-FDG. For detailed interregional correlation analysis, 24 subregions of the basal ganglia including pre-commissural dorsal caudate, post-commissural caudate, pre-commissural dorsal putamen, post-commissural putamen, internal globus pallidus, and external globus pallidus and 80 cerebral regions were selected as regions of interest on the MRI image and their glucose metabolism were calculated from the PET images. Pearson's product-moment correlation analysis was conducted for the interregional correlation analysis of the basal ganglia. Functional correlation patterns between the basal ganglia and cerebral cortex were not only consistent with the findings of previous studies, but also showed new functional correlation between the dorsal striatum (i.e., caudate nucleus and putamen) and insula. In this study, we established the detailed basal ganglia subregional functional correlation patterns using 18F-FDG PET/MRI fusion imaging. Our methods and results could potentially be an important resource for investigating basal ganglia dysfunction as well as for conducting functional studies in the context of movement and psychiatric disorders.
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Affiliation(s)
- J H Kim
- Research Institute for Advanced Industrial Technology, College of Science and Technology, Korea University, Sejong, South Korea
| | - Y D Son
- Department of Biomedical Engineering, College of Health Science, Gachon University, Incheon, South Korea
| | - J M Kim
- Department of Electronics and Information Engineering, College of Science and Technology, Korea University, Sejong, South Korea
| | - H K Kim
- Department of Biomedical Engineering, College of Health Science, Gachon University, Incheon, South Korea
| | - Y B Kim
- Department of Neurosurgery, Gachon University Gil Medical Center, Gachon University School of Medicine, Incheon, South Korea
| | - C Lee
- Bioimaging Research Team, Korea Basic Science Institute, Cheongju, South Korea
| | - C H Oh
- Department of Electronics and Information Engineering, College of Science and Technology, Korea University, Sejong, South Korea
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Wang F, Feng X, Oh CH. Optical bistability and multistability via quantum coherence in chiral molecules. Opt Express 2016; 24:13702-13713. [PMID: 27410534 DOI: 10.1364/oe.24.013702] [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 optical bistability (OB) and multistability (OM) in chiral molecules are investigated by placing the sample into a unidirectional ring cavity. Because of broken mirror symmetry of the effective potential, the chiral molecules have a cyclic three-level Δ-configuration structure, in which one- and two-photon transitions can coexist. We find that the OB is achievable in this system on exact one-, two- and three-photon resonance conditions but absent in the three-level Λ-type system under the two-photon resonance. Moreover, the OM and the switching between OB and OM are also realized by choosing parameters properly. Interestingly, the left- and right-handed chiral molecules exhibit different bistable and multistable behaviors. It is shown that the threshold intensity of OB is strongly dependent on the percentage of the two enantiomers in the mixture. This provides an effective approach to probe molecular chirality and to determine enantiomer excess, which may find potential application in organic chemistry, pharmacology, biochemistry, etc..
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Yang WL, An JH, Zhang CJ, Chen CY, Oh CH. Dynamics of quantum correlation between separated nitrogen-vacancy centers embedded in plasmonic waveguide. Sci Rep 2015; 5:15513. [PMID: 26493045 PMCID: PMC4616030 DOI: 10.1038/srep15513] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 09/28/2015] [Indexed: 11/24/2022] Open
Abstract
We investigate the dynamics of quantum correlation between two separated nitrogen vacancy centers (NVCs) placed near a one-dimensional plasmonic waveguide. As a common medium of the radiation field of NVCs propagating, the plasmonic waveguide can dynamically induce quantum correlation between the two NVCs. It is interesting to find that such dynamically induced quantum correlation can be preserved in the long-time steady state by locally applying individual driving on the two NVCs. In particular, we also show that a large degree of quantum correlation can be established by this scheme even when the distance between the NVCs is much larger than their operating wavelength. This feature may open new perspectives for devising active decoherence-immune solid-state optical devices and long-distance NVC-based quantum networks in the context of plasmonic quantum electrodynamics.
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Affiliation(s)
- Wan-li Yang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,Centre for Quantum Technologies, National University of Singapore, Singapore 117543, Singapore
| | - Jun-Hong An
- Center for Interdisciplinary Studies &Key Laboratory for Magnetism and Magnetic Materials of the MoE, Lanzhou University, Lanzhou 730000, China.,Centre for Quantum Technologies, National University of Singapore, Singapore 117543, Singapore
| | - Cheng-jie Zhang
- Centre for Quantum Technologies, National University of Singapore, Singapore 117543, Singapore
| | - Chang-yong Chen
- Department of Physics, Shaoguan University, Shaoguan, Guangdong 512005, China
| | - C H Oh
- Centre for Quantum Technologies, National University of Singapore, Singapore 117543, Singapore
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Oh CH, Sohl T, Rugman AM. Regional and product diversification and the performance of retail multinationals. Journal of International Management 2015. [DOI: 10.1016/j.intman.2015.04.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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You JB, Shao XQ, Tong QJ, Chan AH, Oh CH, Vedral V. Majorana transport in superconducting nanowire with Rashba and Dresselhaus spin-orbit couplings. J Phys Condens Matter 2015; 27:225302. [PMID: 25984649 DOI: 10.1088/0953-8984/27/22/225302] [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] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The tunneling experiment is a key technique for detecting Majorana fermion (MF) in solid state systems. We use Keldysh non-equilibrium Green function method to study two-lead tunneling in superconducting nanowire with Rashba and Dresselhaus spin-orbit couplings. A zero-bias dc conductance peak appears in our setup which signifies the existence of MF and is in accordance with previous experimental results on InSb nanowire. Interestingly, due to the exotic property of MF, there exists a hole transmission channel which makes the currents asymmetric at the left and right leads. The ac current response mediated by MF is also studied here. To discuss the impacts of Coulomb interaction and disorder on the transport property of Majorana nanowire, we use the renormalization group method to study the phase diagram of the wire. It is found that there is a topological phase transition under the interplay of superconductivity and disorder. We find that the Majorana transport is preserved in the superconducting-dominated topological phase and destroyed in the disorder-dominated non-topological insulator phase.
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Affiliation(s)
- Jia-Bin You
- Centre for Quantum Technologies, National University of Singapore, 117543, Singapore
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Park GY, Im S, Oh CH, Lee SJ, Pae CU. The association between the severity of poststroke depression and clinical outcomes after first-onset stroke in Korean patients. Gen Hosp Psychiatry 2015; 37:245-50. [PMID: 25817322 DOI: 10.1016/j.genhosppsych.2015.02.009] [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] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 02/26/2015] [Accepted: 02/27/2015] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The purpose of the present study is to evaluate the association between poststroke depression (PSD) and clinical outcomes in first-onset stroke patients who are undergoing a rehabilitation program. METHODS The present study included 180 inpatients that were recruited consecutively and followed up over a 6-month observational period. Poststroke depression was diagnosed using the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Symptoms of depression and clinical outcomes were assessed using the Beck Depression Inventory, the modified Barthel Index (MBI) and the Mini Mental State Examination (MMSE). All patients were assessed at baseline and at the end of the 6-month observational period. RESULTS Of the 180 patients, 127 (70.6%) were diagnosed with minimal-to-mild depression (MMD), and 53 (29.4%) were diagnosed with moderate-to-severe depression (MSD). The mean change in MBI scores from baseline to 6 months was significantly higher (P=.029) in the MMD group (23.8) than in the MSD group (8.6). The odds ratio for an unfavorable outcome (MBI score <60) in patients with MSD was approximately 3.5 in relation to patients with MMD. The mean change in MMSE score (4.4 versus 7.4) was not significantly different between the MMD and MSD groups. CONCLUSION The present findings suggest that the severity of PSD may be associated with clinical outcomes in Korean patients 6 months after a first-onset stroke. Our data agree with previous findings, which indicate that clinicians should carefully evaluate symptoms of depression in stroke patients during routine clinical practice. The methodological shortcomings of the present study may require further studies with adequate power and improved design to clarify the association between PSD and clinical outcomes following stroke.
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Affiliation(s)
- Geun-Young Park
- Department of Rehabilitation Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sun Im
- Department of Rehabilitation Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Chang Hoon Oh
- Department of Rehabilitation Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Soo-Jung Lee
- Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Chi-Un Pae
- Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea; Department of Psychiatry and Behavioural Sciences, Duke University Medical Center, Durham, NC, USA.
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Kim HG, Chung ME, Song DH, Kim JY, Sul BM, Oh CH, Park NS. Determination of injection site in flexor digitorum longus for effective and safe botulinum toxin injection. Ann Rehabil Med 2015; 39:32-8. [PMID: 25750869 PMCID: PMC4351492 DOI: 10.5535/arm.2015.39.1.32] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [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: 05/29/2014] [Accepted: 09/02/2014] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To determine the optimal injection site in the flexor digitorum longus (FDL) muscle for effective botulinum toxin injection. METHODS Fourteen specimens from eight adult Korean cadavers were used in this study. The most proximal medial point of the tibia plateau was defined as the proximal reference point; the most distal tip of the medial malleolus was defined as the distal reference point. The distance of a line connecting the proximal and distal reference points was defined as the reference length. The X-coordinate was the distance from the proximal reference point to the intramuscular motor endpoint (IME), or motor entry point (MEP) on the reference line, and the Y-coordinate was the distance from the nearest point from MEP on the medial border of the tibia to the MEP. IME and MEP distances from the proximal reference point were evaluated using the raw value and the X-coordinate to reference length ratio was determined as a percentage. RESULTS The majority of IMEs were located within 30%-60% of the reference length from the proximal reference point. The majority of the MEPs were located within 40%-60% of the reference length from the proximal reference point. CONCLUSION We recommend the anatomical site for a botulinum toxin injection in the FDL to be within a region 30%-60% of the reference length from the proximal reference point.
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Affiliation(s)
- Hong Geum Kim
- Department of Rehabilitation Medicine, St. Paul's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Myung Eun Chung
- Department of Rehabilitation Medicine, St. Paul's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Dae Heon Song
- Department of Rehabilitation Medicine, St. Paul's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Ju Yong Kim
- Department of Rehabilitation Medicine, St. Paul's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Bo Mi Sul
- Department of Rehabilitation Medicine, St. Paul's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Chang Hoon Oh
- Department of Rehabilitation Medicine, St. Paul's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Nam Su Park
- Department of Rehabilitation Medicine, St. Paul's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
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Oh CH, Park NS, Kim JM, Kim MW. Determination of an ideal stimulation site of the medial antebrachial cutaneous nerve using ultrasound and investigation of the efficiency. Ann Rehabil Med 2015; 38:836-42. [PMID: 25566484 PMCID: PMC4280381 DOI: 10.5535/arm.2014.38.6.836] [Citation(s) in RCA: 7] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 08/01/2014] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To determine an ideal stimulation site of the medial antebrachial cutaneous nerve (MACN) using ultrasound measurement and to compare the efficiency of the new stimulation site with the conventional stimulation site on the nerve conduction study. METHODS Both arms of 15 healthy participants were measured using ultrasound. The MACN was identified in the transverse view at each 0, 2, 4, 6, and 8 cm proximal sites from the medial epicondyle, and the distances to the median nerve and to the skin from the MACN were measured. The ideal stimulation site should be located at the level which can give the shortest distance from the skin and the longest distance from the median nerve in terms of volume conduction. To confirm the efficiency of the ideal site, we measured the amplitude of the MACN conduction study at the ideal site against one at the 4 cm proximal to the medial epicondyle (conventional site). RESULTS The ultrasound showed the ideal stimulation site for the MACN could be the elbow crease line. However, the nerve conduction study revealed that the amplitudes of the MACN were significantly larger at the 4 cm proximal to the medial epicondyle compared with ones at the ideal site. CONCLUSION The ideal stimulation site based on the ultrasound did not permit better stimulation site for the nerve conduction study of the MACN compared with the conventional site. Careful adjustment of the stimulation site on the basis of this study would contribute to an accurate conduction study of the MACN.
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Affiliation(s)
- Chang Hoon Oh
- Department of Rehabilitation Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Nam Su Park
- Department of Rehabilitation Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Jae Min Kim
- Department of Rehabilitation Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Min Wook Kim
- Department of Rehabilitation Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
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Baek YS, Jeon J, Kim JH, Oh CH. Severity of acute and chronic urticaria correlates with D-dimer level, but not C-reactive protein or total IgE. Clin Exp Dermatol 2014; 39:795-800. [PMID: 25196271 DOI: 10.1111/ced.12413] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2013] [Indexed: 11/29/2022]
Abstract
BACKGROUND Although various scoring systems for measuring urticaria severity have been introduced, most rely on subjective criteria. Therefore, additional objective criteria such as laboratory markers would be helpful adjuncts in making this assessment. AIM To evaluate the usefulness of three laboratory markers [D-dimer, C-reactive protein (CRP), and total IgE] in assessing disease severity of both acute urticaria (AU) and chronic urticaria (CU). METHODS We conducted a retrospective analysis of 94 patients with urticaria. Correlations between the aforementioned laboratory markers and the Urticaria Activity Score (UAS) were calculated. RESULTS A substantial proportion of patients with urticaria (acute 43.5%; chronic 39.6%) had an increased D-dimer level. Additionally, there was a significant correlation between D-dimer level and UAS (AU r = 0.60, P < 0.001; CU r = 0.37, P < 0.05). However, there was no significant correlation between UAS and either CRP or total IgE. CONCLUSIONS D-dimer level could be used as a marker of disease severity for both AU and CU. However, CRP and total IgE are not as reliable in predicting disease severity.
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Affiliation(s)
- Y S Baek
- Department of Dermatology, College of Medicine, Korea University, Seoul, Korea
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Hyun HJ, Oh CH, Paik Y. Impact of nationality composition in foreign subsidiary on its performance: a case of Korean companies. The International Journal of Human Resource Management 2014. [DOI: 10.1080/09585192.2014.949819] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Yang CJ, An JH, Luo HG, Li Y, Oh CH. Canonical versus noncanonical equilibration dynamics of open quantum systems. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 90:022122. [PMID: 25215704 DOI: 10.1103/physreve.90.022122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Indexed: 06/03/2023]
Abstract
In statistical mechanics, any quantum system in equilibrium with its weakly coupled reservoir is described by a canonical state at the same temperature as the reservoir. Here, by studying the equilibration dynamics of a harmonic oscillator interacting with a reservoir, we evaluate microscopically the condition under which the equilibration to a canonical state is valid. It is revealed that the non-Markovian effect and the availability of a stationary state of the total system play a profound role in the equilibration. In the Markovian limit, the conventional canonical state can be recovered. In the non-Markovian regime, when the stationary state is absent, the system equilibrates to a generalized canonical state at an effective temperature; whenever the stationary state is present, the equilibrium state of the system cannot be described by any canonical state anymore. Our finding of the physical condition on such noncanonical equilibration might have significant impact on statistical physics. A physical scheme based on circuit QED is proposed to test our results.
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Affiliation(s)
- Chun-Jie Yang
- Center for Interdisciplinary Studies, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China and Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology in China Aerospace Science and Technology Corporation, Beijing 100094, China
| | - Jun-Hong An
- Center for Interdisciplinary Studies, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China and Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore
| | - Hong-Gang Luo
- Center for Interdisciplinary Studies, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China and Beijing Computational Science Research Center, Beijing 100084, China
| | - Yading Li
- Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology in China Aerospace Science and Technology Corporation, Beijing 100094, China
| | - C H Oh
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore
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Kim MW, Oh CH, Kim J. No. 45 Determination of an Ideal Stimulation Site of the Medial Antebrachial Cutaneous Nerve Using Ultrasound and Investigation of the Effectiveness. PM R 2014. [DOI: 10.1016/j.pmrj.2014.08.276] [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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Oetzel JM, Oh CH. Learning to Carry the Cat by the Tail: Firm Experience, Disasters, and Multinational Subsidiary Entry and Expansion. Organization Science 2014. [DOI: 10.1287/orsc.2013.0860] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
In this Letter we propose a set of conditions on the joint probabilities as a test of genuine multipartite nonlocality without inequality. Our test is failed by all nonsignaling local models in which even nonlocal correlations among some observables (not all) are allowed as long as these correlations respect the nonsignaling principle. A pass of our test by a state therefore indicates that this state cannot be simulated by any nonsignaling local models; i.e., the state exhibits genuine multipartite nonlocality. It turns out that all entangled symmetric n-qubit (n≥3) states pass our test and therefore are n-way nonlocal. Also we construct two Bell-type inequalities from our proposed test whose violations indicate genuine multipartite nonlocal correlations.
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Affiliation(s)
- Qing Chen
- Centre for quantum technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore
| | - Sixia Yu
- Centre for quantum technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore and Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Chengjie Zhang
- Centre for quantum technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore
| | - C H Lai
- Centre for quantum technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore and Physics department, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore
| | - C H Oh
- Centre for quantum technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore and Physics department, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore
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Wu C, Chen JL, Ye XJ, Su HY, Deng DL, Wang Z, Oh CH. Test of Einstein-Podolsky-Rosen steering based on the all-versus-nothing proof. Sci Rep 2014; 4:4291. [PMID: 24598858 PMCID: PMC3944728 DOI: 10.1038/srep04291] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 02/13/2014] [Indexed: 11/09/2022] Open
Abstract
In comparison with entanglement and Bell nonlocality, Einstein-Podolsky-Rosen steering is a newly emerged research topic and in its incipient stage. Although Einstein-Podolsky-Rosen steering has been explored via violations of steering inequalities both theoretically and experimentally, the known inequalities in the literatures are far from well-developed. As a result, it is not yet possible to observe Einstein-Podolsky-Rosen steering for some steerable mixed states. Recently, a simple approach was presented to identify Einstein-Podolsky-Rosen steering based on all-versus-nothing argument, offering a strong condition to witness the steerability of a family of two-qubit (pure or mixed) entangled states. In this work, we show that the all-versus-nothing proof of Einstein-Podolsky-Rosen steering can be tested by measuring the projective probabilities. Through the bound of probabilities imposed by local-hidden-state model, the proposed test shows that steering can be detected by the all-versus-nothing argument experimentally even in the presence of imprecision and errors. Our test can be implemented in many physical systems and we discuss the possible realizations of our scheme with non-Abelian anyons and trapped ions.
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Affiliation(s)
- Chunfeng Wu
- 1] Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 [2] Pillar of Engineering Product Development, Singapore University of Technology and Design, 20 Dover Drive, Singapore 138682
| | - Jing-Ling Chen
- 1] Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 [2] Theoretical Physics Division, Chern Institute of Mathematics, Nankai University, Tianjin 300071, People's Republic of China
| | - Xiang-Jun Ye
- 1] Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 [2] Theoretical Physics Division, Chern Institute of Mathematics, Nankai University, Tianjin 300071, People's Republic of China
| | - Hong-Yi Su
- 1] Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 [2] Theoretical Physics Division, Chern Institute of Mathematics, Nankai University, Tianjin 300071, People's Republic of China
| | - Dong-Ling Deng
- Department of Physics and Michigan Center for Theoretical Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Zhenghan Wang
- Microsoft Research, Station Q, University of California, Santa Barbara, CA 93106, USA
| | - C H Oh
- 1] Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 [2] Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551
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Seo YJ, Im S, Oh CH, Park GY, Ko SB, Lee YJ. Recovery from a Complicated Case of Central Pontine and Extrapontine Myelinolysis by Dopaminergic Treatment: One-Year Follow-up: A Case Report. Brain Neurorehabil 2014. [DOI: 10.12786/bn.2014.7.2.126] [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: 11/08/2022] Open
Affiliation(s)
- Yu Jung Seo
- Department of Rehabilitation Medicine, College of Medicine, The Catholic University of Korea, Korea
| | - Sun Im
- Department of Rehabilitation Medicine, College of Medicine, The Catholic University of Korea, Korea
| | - Chang Hoon Oh
- Department of Rehabilitation Medicine, College of Medicine, The Catholic University of Korea, Korea
| | - Geun Young Park
- Department of Rehabilitation Medicine, College of Medicine, The Catholic University of Korea, Korea
| | - Sae Byuk Ko
- Department of Rehabilitation Medicine, College of Medicine, The Catholic University of Korea, Korea
| | - Yu Jin Lee
- Department of Rehabilitation Medicine, College of Medicine, The Catholic University of Korea, Korea
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Zhang C, Yu S, Chen Q, Oh CH. Detecting and estimating continuous-variable entanglement by local orthogonal observables. Phys Rev Lett 2013; 111:190501. [PMID: 24266463 DOI: 10.1103/physrevlett.111.190501] [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: 08/22/2013] [Indexed: 06/02/2023]
Abstract
Entanglement detection and estimation are fundamental problems in quantum information science. Compared with discrete-variable states, for which lots of efficient entanglement detection criteria and lower bounds of entanglement measures have been proposed, the continuous-variable entanglement is much less understood. Here we shall present a family of entanglement witnesses based on continuous-variable local orthogonal observables (CVLOOs) to detect and estimate entanglement of Gaussian and non-Gaussian states, especially for bound entangled states. By choosing an optimal set of CVLOOs, our entanglement witness is equivalent to the realignment criterion and can be used to detect bound entanglement of a class of 2+2 mode Gaussian states. Via our entanglement witness, lower bounds of two typical entanglement measures for arbitrary two-mode continuous-variable states are provided.
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Affiliation(s)
- Chengjie Zhang
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore
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Zhang Q, Gong J, Oh CH. Intrinsic dynamical fluctuation assisted symmetry breaking in adiabatic following. Phys Rev Lett 2013; 110:130402. [PMID: 23581298 DOI: 10.1103/physrevlett.110.130402] [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: 09/06/2012] [Indexed: 06/02/2023]
Abstract
Classical adiabatic invariants in actual adiabatic processes possess intrinsic dynamical fluctuations. The magnitude of such intrinsic fluctuations is often thought to be negligible. This widely believed physical picture is contested here. For adiabatic following of a moving stable fixed-point solution facing a pitchfork bifurcation, we show that intrinsic dynamical fluctuations in an adiabatic process can assist in a deterministic selection between two symmetry-connected fixed-point solutions, with the outcome independent of the duration of the adiabatic process. Using a classical model Hamiltonian also relevant to a two-mode quantum system, we further demonstrate the formation of an adiabatic hysteresis loop in purely Hamiltonian mechanics and the generation of a Berry phase via changing one single-valued parameter only.
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Affiliation(s)
- Qi Zhang
- Laboratory of Condensed Matter Theory and Computational Materials, Zhengzhou University, Zhengzhou 450001, People's Republic of China
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Tang W, Yu S, Oh CH. Greenberger-Horne-Zeilinger paradoxes from qudit graph states. Phys Rev Lett 2013; 110:100403. [PMID: 23521234 DOI: 10.1103/physrevlett.110.100403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 11/24/2012] [Indexed: 06/01/2023]
Abstract
One fascinating way of revealing quantum nonlocality is the all-versus-nothing test due to Greenberger, Horne, and Zeilinger (GHZ) known as the GHZ paradox. So far genuine multipartite and multilevel GHZ paradoxes are known to exist only in systems containing an odd number of particles. Here we shall construct GHZ paradoxes for an arbitrary number (greater than 3) of particles with the help of qudit graph states on a special kind of graphs, called GHZ graphs. Furthermore, based on the GHZ paradox arising from a GHZ graph, we derive a Bell inequality with two d-outcome observables for each observer, whose maximal violation attained by the corresponding graph state, and a Kochen-Specker inequality testing the quantum contextuality in a state-independent fashion.
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Affiliation(s)
- Weidong Tang
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics of University of Science and Technology of China, Hefei 230026, People's Republic of China
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Abstract
We show that a single Bell's inequality with two dichotomic observables for each observer, which originates from Hardy's nonlocality proof without inequalities, is violated by all entangled pure states of a given number of particles, each of which may have a different number of energy levels. Thus Gisin's theorem is proved in its most general form from which it follows that for pure states Bell's nonlocality and quantum entanglement are equivalent.
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Affiliation(s)
- Sixia Yu
- Centre for Quantum Technologies, National University of Singapore, Singapore
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Oh CH, Contractor FJ. The role of territorial coverage and product diversification in the multinationality-performance relationship. Global Strategy Journal 2012. [DOI: 10.1002/gsj.1031] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Sun H, Fan SL, Feng XL, Wu CF, Gong SQ, Huang GX, Oh CH. Strongly interacting photons in asymmetric quantum well via resonant tunneling. Opt Express 2012; 20:8485-8495. [PMID: 22513556 DOI: 10.1364/oe.20.008485] [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] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We propose an asymmetric quantum well structure to realize strong interaction between two slow optical pulses. The essential idea is the combination of the advantages of inverted-Y type scheme and resonant tunneling. We analytically demonstrate that giant cross-Kerr nonlinearity can be achieved with vanishing absorptions. Owing to resonant tunneling, the contributions of the probe and signal cross-Kerr nonlinearities to total nonlinear phase shift vary from destructive to constrictive, leading to nonlinear phase shift on order of π at low light level. In this structure, the scheme is inherent symmetric for the probe and signal pulses. Consequently, the condition of group velocity matching can be fulfilled with appropriate initial electron distribution.
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Affiliation(s)
- H Sun
- School of Physics and Information Technology, Shaanxi Normal University, Xi’an 710062, China
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Abstract
Quantum contextuality, as proved by Kochen and Specker, and also by Bell, should manifest itself in any state in any system with more than two distinguishable states and recently has been experimentally verified. However, for the simplest system capable of exhibiting contextuality, a qutrit, the quantum contextuality is verified only state dependently in experiment because too many (at least 31) observables are involved in all the known state-independent tests. Here we report an experimentally testable inequality involving only 13 observables that is satisfied by all noncontextual realistic models while being violated by all qutrit states. Thus our inequality facilitates a state-independent test of the quantum contextuality for an indivisible quantum system. We also provide a record-breaking state-independent proof of the Kochen-Specker theorem with 13 directions determined by 26 points on the surface of a magic cube.
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Affiliation(s)
- Sixia Yu
- Centre for quantum technologies and Physics department, National University of Singapore, 3 Science Drive 2, Singapore 117543
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Deng DL, Wu C, Chen JL, Oh CH. Fault-tolerant Greenberger-Horne-Zeilinger paradox based on non-Abelian anyons. Phys Rev Lett 2010; 105:060402. [PMID: 20867962 DOI: 10.1103/physrevlett.105.060402] [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: 04/07/2010] [Indexed: 05/29/2023]
Abstract
We propose a scheme to test the Greenberger-Horne-Zeilinger paradox based on braidings of non-Abelian anyons, which are exotic quasiparticle excitations of topological states of matter. Because topological ordered states are robust against local perturbations, this scheme is in some sense "fault-tolerant" and might close the detection inefficiency loophole problem in previous experimental tests of the Greenberger-Horne-Zeilinger paradox. In turn, the construction of the Greenberger-Horne-Zeilinger paradox reveals the nonlocal property of non-Abelian anyons. Our results indicate that the non-Abelian fractional statistics is a pure quantum effect and cannot be described by local realistic theories. Finally, we present a possible experimental implementation of the scheme based on the anyonic interferometry technologies.
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Affiliation(s)
- Dong-Ling Deng
- Theoretical Physics Division, Chern Institute of Mathematics, Nankai University, Tianjin 300071, People's Republic of China
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Oh JH, Kim SH, Kim JH, Shin YH, Yoon JP, Oh CH. The level of vitamin D in the serum correlates with fatty degeneration of the muscles of the rotator cuff. ACTA ACUST UNITED AC 2010; 91:1587-93. [PMID: 19949122 DOI: 10.1302/0301-620x.91b12.22481] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This study examined the role of vitamin D as a factor accounting for fatty degeneration and muscle function in the rotator cuff. There were 366 patients with disorders of the shoulder. A total of 228 patients had a full-thickness tear (group 1) and 138 patients had no tear (group 2). All underwent magnetic resonance arthrography and an isokinetic muscle performance test. The serum concentrations of vitamin D (25(OH)D(3)) were measured. In general, a lower serum level of vitamin D was related to higher fatty degeneration in the muscles of the cuff. Spearman's correlation coefficients were 0.173 (p = 0.001), -0.181 (p = 0.001), and -0.117 (p = 0.026) for supraspinatus, infraspinatus and subscapularis, respectively. In group 1, multivariate linear regression analysis revealed that the serum level of vitamin D was an independent variable for fatty degeneration of the supraspinatus and infraspinatus. The serum vitamin D level has a significant negative correlation with the fatty degeneration of the cuff muscle and a positive correlation with isokinetic muscle torque.
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Affiliation(s)
- J H Oh
- Department of Orthopaedic Surgery, Seoul National University, College of Medicine, Seoul National University Bundang Hospital, Bundang-gu, Seongnam, Korea
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Feng XL, Wu C, Sun H, Oh CH. Geometric entangling gates in decoherence-free subspaces with minimal requirements. Phys Rev Lett 2009; 103:200501. [PMID: 20365968 DOI: 10.1103/physrevlett.103.200501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Indexed: 05/29/2023]
Abstract
We introduce a new strongly driven dispersive atom-cavity interaction and develop a new scheme for implementing the nontrivial entangling gates for two logical qubits in decoherence-free subspaces (DFSs). Our scheme combines the robust advantages of DFS and the geometric phase. Moreover, only two neighboring physical qubits, which encode a logical qubit, are required to undergo the collective dephasing in our scheme.
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Affiliation(s)
- Xun-Li Feng
- Department of Physics and Centre for Quantum Technologies, National University of Singapore, 2 Science Drive 3, Singapore 117542
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Oh YS, Lee JH, Yoon SH, Oh CH, Choi DS, Choe E, Jung MY. Characterization and quantification of anthocyanins in grape juices obtained from the grapes cultivated in Korea by HPLC/DAD, HPLC/MS, and HPLC/MS/MS. J Food Sci 2008; 73:C378-89. [PMID: 18576983 DOI: 10.1111/j.1750-3841.2008.00756.x] [Citation(s) in RCA: 55] [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] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The characterization and quantification of anthocyanins in grape cultivars of Oll-Meoru (Vitis coignetiaexVitis labrusca), Neut-Meoru (Vitis coignetiaexVitis labrusca), Muscal Bailey A. (Vitis labruscana), and Campbell Early (Vitis labruscaxV. vinifera) cultivated in Korea were carried out by partial purification through XAD-7 column chromatography followed by C-18 HPLC/diode array detector (DAD), HPLC/MS, and HPLC/MS/MS analyses. The column oven temperature during the reverse phase C-18 HPLC greatly affected the separation of individual anthocyanins. The result showed that the optimum column oven temperature was 35 degrees C. Sixteen different anthocyanins (11 nonacylated and 5 acylated anthocyanins) were identified in the grape juices. Oll-Meoru, Neut-Meoru, and Muscat Bailey A (MBA) grape juices contained only nonacylated anthocyanins. Oll-Meoru and Neut-Meoru grape juices had same anthocyanins, but their proportions were considerably different. Peonidin 3,5-diglucoside and malvidin 3,5-diglucoside were the major anthocyanins in Oll-Meoru grape juice. Delphinidin 3-glucoside was, however, the major anthocyanin in Neut-Meoru grape juice. Peonidin 3-glucoside and malvidin 3-glucoside were the most abundant anthocyanins in Muscal Bailey A grape juice. Campbell Early grape juice contained both nonacylated and acylated anthocyanins. Cyanidin 3-(p-coumaroyl)glucoside-5-glucoside and peonidin 3-(p-coumaroyl)glucoside-5-glucoside were the most abundant anthocyanins in Campbell Early grape juice. Total anthocyanin contents were greatly different in different grape jucies, with the highest in Neut-Meoru juice (1043.5 microg/mL), followed by Oll-Meoru (997.7 microg/mL), MBA (390.2 microg/mL), and Campbell Early (183.9 microg/mL) juices. The total anthocyanin content in Neut-Meoru grape juice was 5.67 times higher than that in Campbell Early grape juice. This represents the 1st report on the systematic characterization and quantification of anthocyanins in the juices of these grapes cultivated in Korea.
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Affiliation(s)
- Y S Oh
- Department of Bioscience and Biotechnology in Graduate School, Woosuk University, Samrea-Up, Wanju-Kun, Jeonbuk Province 565-701, Republic of Korea
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Abstract
We report the first nonadditive quantum error-correcting code, namely, a ((9, 12, 3)) code which is a 12-dimensional subspace within a 9-qubit Hilbert space, that outperforms the optimal stabilizer code of the same length by encoding more levels while correcting arbitrary single-qubit errors. Taking advantage of the graph states, we construct explicitly a complete encoding-decoding circuit for the proposed nonadditive error-correcting code.
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Affiliation(s)
- Sixia Yu
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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Shim JH, Kim SE, Woo DH, Kim SK, Oh CH, McKay R, Kim JH. Directed differentiation of human embryonic stem cells towards a pancreatic cell fate. Diabetologia 2007; 50:1228-38. [PMID: 17457565 DOI: 10.1007/s00125-007-0634-z] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Accepted: 01/15/2007] [Indexed: 12/13/2022]
Abstract
AIMS/HYPOTHESIS The relative lack of successful pancreatic differentiation of human embryonic stem cells (hESCs) may suggest that directed differentiation of hESCs into definitive endoderm and subsequent commitment towards a pancreatic fate are not readily achieved. The aim of this study was to investigate whether sequential exposure of hESCs to epigenetic signals that mimic in vivo pancreatic development can efficiently generate pancreatic endodermal cells, and whether these cells can be further matured and reverse hyperglycaemia upon transplantation. MATERIALS AND METHODS The hESCs were sequentially treated with serum, activin and retinoic acid (RA) during embryoid body formation. The patterns of gene expression and protein production associated with embryonic germ layers and pancreatic endoderm were analysed by RT-PCR and immunostaining. The developmental competence and function of hESC-derived PDX1-positive cells were evaluated after in vivo transplantation. RESULTS Sequential treatment with serum, activin and RA highly upregulated the expression of the genes encoding forkhead box protein A2 (FOXA2), SRY-box containing gene 17 (SOX17), pancreatic and duodenal homeobox 1 (PDX1) and homeobox HB9 (HLXB9). The population of pancreatic endodermal cells that produced PDX1 was significantly increased at the expense of ectodermal differentiation, and a subset of the PDX1-positive cells also produced FOXA2, caudal-type homeobox transcription factor 2 (CDX2), and nestin (NES). After transplantation, the PDX1-positive cells further differentiated into mature cell types producing insulin and glucagon, resulting in amelioration of hyperglycaemia and weight loss in streptozotocin-treated diabetic mice. CONCLUSIONS/INTERPRETATION Our strategy allows the progressive differentiation of hESCs into pancreatic endoderm capable of generating mature pancreatic cell types that function in vivo. These findings may establish the basis of further investigations for the purification of transplantable islet progenitors derived from hESCs.
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Affiliation(s)
- J H Shim
- Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University, West Building/Room 304, Science Campus, 1 Anam-dong 5-ga, Sungbuk-goo, Seoul 136-713, Republic of Korea
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Tong DM, Singh K, Kwek LC, Oh CH. Sufficiency criterion for the validity of the adiabatic approximation. Phys Rev Lett 2007; 98:150402. [PMID: 17501324 DOI: 10.1103/physrevlett.98.150402] [Citation(s) in RCA: 9] [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: 11/24/2006] [Indexed: 05/15/2023]
Abstract
We examine the quantitative condition which has been widely used as a criterion for the adiabatic approximation but was recently found insufficient. Our results indicate that the usual quantitative condition is sufficient for a special class of quantum mechanical systems. For general systems, it may not be sufficient, but it, along with additional conditions, is sufficient. The usual quantitative condition and the additional conditions constitute a general criterion for the validity of the adiabatic approximation, which is applicable to all N-dimensional quantum systems. Moreover, we illustrate the use of the general quantitative criterion in some physical models.
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Affiliation(s)
- D M Tong
- Department of Physics, National University of Singapore, 10 Kent Ridge Crescent, Singapore.
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Abstract
We propose an optical means to realize the spin-Hall effect (SHE) in a neutral atomic system by coupling the internal spin states of atoms to radiation. The interaction between the external optical fields and the atoms creates effective magnetic fields that act in opposite directions on "electrically" neutral atoms with opposite spin polarizations. This effect leads to a Landau level structure for each spin orientation in direct analogy with the familiar SHE in semiconductors. The conservation and topological properties of the spin current, and the creation of a pure spin current are discussed.
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Affiliation(s)
- Xiong-Jun Liu
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore.
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Koh SB, Suh SI, Lee DH, Kim AR, Oh CH, Yoon JS, Weon BM, Seol SK, Pyun AR, Je JH, Hwu Y, Margaritondo G. Phase contrast radiography of Lewy bodies in Parkinson disease. Neuroimage 2006; 32:566-9. [PMID: 16766209 DOI: 10.1016/j.neuroimage.2006.04.217] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2005] [Revised: 02/23/2006] [Accepted: 04/05/2006] [Indexed: 11/24/2022] Open
Abstract
Parkinson's disease (PD), defined as a neurodegenerative disorder, is characterized by the loss of dopaminergic neurons and the presence of Lewy bodies in neurons. Morphological study of Lewy bodies is important to identify the causes and the processes of PD. Here, we investigate a possibility of phase contrast radiography using coherent synchrotron X-rays to explore the microscopic details of Lewy bodies in thick (approximately 3 mm) midbrain tissues. Autopsied midbrain tissues of a PD patient were sliced in 3 mm thickness and then examined using synchrotron X-rays from the 7B2 beamline of the Pohang Light Source. Refraction-enhanced phase contrast radiography and microtomography were adopted to identify dark core and dim edge of Lewy bodies in neurons. The morphology of Lewy bodies was clearly revealed by the phase contrast radiography in very thick (3 mm) midbrain tissues without any staining treatment. Three-dimensional volume rendered microtomography of the autopsied midbrain tissues demonstrates striking evidence that several Lewy bodies are agglomerated by dim edges in a neuron. We suggest that the phase contrast radiography could be a useful tool to morphologically investigate the causes or the processes in PD.
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Affiliation(s)
- S B Koh
- Department of Neurology, Korea University College of Medicine, Korea.
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