6,596 results on '"Hyun Sung"'
Search Results
2. Role of subcutaneous closed suction drain in the prevention of incisional surgical site infection after loop ileostomy reversal with purse-string skin closure: a retrospective observational study
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You Seok Jeong, Sung Hwan Cho, Byung-Soo Park, Gyung Mo Son, and Hyun Sung Kim
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Ileostomy reversal ,Subcutaneous closed suction drain ,Purse-string skin closure ,Surgical site infection ,Surgery ,RD1-811 - Abstract
Abstract Background Surgical site infection (SSI) is not rare after loop ileostomy reversal. This study assessed the effects of a subcutaneous closed suction drain on reducing SSIs after loop ileostomy reversal with purse-string skin closure. Methods This retrospective study included 229 patients who underwent loop ileostomy reversal with purse-string closure at the Pusan National University Yangsan Hospital between January 2017 and December 2021. We divided the patients into those with a subcutaneous drain (SD group) and those without it (ND group). We analyzed variables that affected SSI occurrence in both groups. Results The SD and ND groups included 109 and 120 patients, respectively. The number of incisional SSIs was significantly lower in the SD than in the ND group (0 vs. 7 events). An average of 35.7 mL of fluid was collected in the drainage bulb during hospitalization. The C-reactive protein level on postoperative day 4 was significantly lower in the SD group than in the ND group. The insertion of a subcutaneous drain was the only factor associated with a reduced incidence of SSIs (p = 0.015). Conclusions Subcutaneous closed suction drain with purse-string skin closure in loop ileostomy reversal can reduce incisional SSI occurrence.
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- 2024
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3. Compartmentalized regulation of organelle integrity in neurodegenerative diseases: lessons from the Drosophila motor neuron
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Hyun Sung
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Neurology. Diseases of the nervous system ,RC346-429 - Published
- 2025
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4. Cigarette smoke impairs the hematopoietic supportive property of mesenchymal stem cells via the production of reactive oxygen species and NLRP3 activation
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Hyun Sung Park, Byung-Chul Lee, Dong-Hoon Chae, Aaron Yu, Jae Han Park, Jiyoung Heo, Myoung Hee Han, Keonwoo Cho, Joong Won Lee, Ji-Won Jung, Cynthia E. Dunbar, Mi-Kyung Oh, and Kyung-Rok Yu
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Cigarette smoking extract ,Mesenchymal stem cells ,Reactive oxygen species ,NLRP3 ,Bone marrow niche ,Medicine (General) ,R5-920 ,Biochemistry ,QD415-436 - Abstract
Abstract Background Mesenchymal stem cells (MSCs) play important roles in tissue homeostasis by providing a supportive microenvironmental niche for the hematopoietic system. Cigarette smoking induces systemic abnormalities, including an impeded recovery process after hematopoietic stem cell transplantation. However, the role of cigarette smoking-mediated alterations in MSC niche function have not been investigated. Methods In the present study, we investigated whether exposure to cigarette smoking extract (CSE) disrupts the hematopoietic niche function of MSCs, and pathways impacted. To investigate the effects on bone marrow (BM)-derived MSCs and support of hematopoietic stem and progenitor cells (HSPCs), mice were repeatedly infused with the CSE named 3R4F, and hematopoietic stem and progenitor cells (HSPCs) supporting function was determined. The impact of 3R4F on MSCs at cellular level were screened by bulk-RNA sequencing and subsequently validated through qRT-PCR. Specific inhibitors were treated to verify the ROS or NLRP3-specific effects, and the cells were then transplanted into the animal model or subjected to coculture with HSPCs. Results Both direct ex vivo and systemic in vivo MSC exposure to 3R4F resulted in impaired engraftment in a humanized mouse model. Furthermore, transcriptomic profile analysis showed significantly upregulated signaling pathways related to reactive oxygen species (ROS), inflammation, and aging in 3R4F-treated MSCs. Notably, ingenuity pathway analysis revealed the activation of NLRP3 inflammasome signaling pathway in 3R4F-treated MSCs, and pretreatment with the NLRP3 inhibitor MCC950 rescued the HSPC-supporting ability of 3R4F-treated MSCs. Conclusion In conclusion, these findings indicate that exposure to CSE reduces HSPCs supportive function of MSCs by inducing robust ROS production and subsequent NLRP3 activation.
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- 2024
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5. Association between arterial stiffness and autonomic dysfunction in participants underwent treadmill exercise testing: a cross-sectional analysis
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Sungjoon Park, Hack-Lyoung Kim, Kyung-Taek Park, Hyun Sung Joh, Woo-Hyun Lim, Jae-Bin Seo, Sang-Hyun Kim, and Myung-A Kim
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arterial stiffness ,autonomic function ,heart rate recovery ,pulse wave velocity ,treadmill exercise test ,Medicine ,Science - Abstract
Abstract Data on the impact of arterial stiffness on autonomic function are limited. We sought to investigate whether heart rate recovery (HRR), a predictor of autonomic function, is impaired in patients with increased arterial stiffness. A total of 475 participants (mean age 55.8 ± 11.1 years, 34.3% women) who underwent a treadmill exercise test (TET) for the evaluation of chest pain were retrospectively analyzed. All patients underwent brachial-ankle pulse wave velocity (baPWV) measurement on the same day. HRR was defined as the difference in heart rate from maximal exercise to 1 min of recovery. Participants with the lowest HRR tertile were older and had more cardiovascular risk factors than those with the highest HRR tertile. Simple correlation analysis showed that baPWV was negatively correlated with HRR (r = − 0.327, P
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- 2024
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6. Association between invasively measured central aortic pulse pressure and diameter of ascending aorta
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Hack-Lyoung Kim, Hyun Sung Joh, Woo-Hyun Lim, Jae-Bin Seo, Sang-Hyun Kim, Joo-Hee Zo, and Myung-A Kim
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Medicine ,Science - Abstract
Abstract Data on the relationship between arterial pulsatile hemodynamics and aortic root geometry, using invasive hemodynamic measurement, has been scarce. Thus, this study aimed to assess the relationship between invasively measured aortic pulse pressure (aPP) and the diameter of ascending aorta (AoD). We analyzed 665 subjects (64.3 ± 11.0 years; 34.6% female) who underwent elective invasive coronary angiography (ICA) for the evaluation of coronary artery disease. Transthoracic echocardiography was performed on the same day, and AoD was measured at the level of 1 cm above the sinotubular junction at the end-diastole. Body surface area (BSA)-adjusted AoD (AoD/BSA) was used for the analysis. A pig-tail catheter was used to measure aortic pressures at a level approximately 3 cm above the aortic valve just before ICA. aPP was calculated as the difference between systolic and diastolic pressures of the aorta. In multiple linear regression analyses, aPP (β = 0.259; P
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- 2023
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7. Effect of high-dose intravenous iron injection on hepatic function in a rat model of cirrhosis
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Ji-Hye Kwon, RyungA Kang, Sangmin Maria Lee, Tae Soo Hahm, Hyun Sung Cho, Gayoung Jin, and Justin Sangwook Ko
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Medicine (General) ,R5-920 - Abstract
Objective To investigate the hepatic effects of high-dose intravenous (IV) iron, including those on liver function and the degree of fibrosis, in a rat model of cirrhosis. Methods We evenly allocated 25 Sprague–Dawley rats into five groups: normal rats (control group), cirrhotic rats receiving IV normal saline (liver cirrhosis [LC] group), and cirrhotic rats receiving 20, 40, or 80 mg/kg IV ferric carboxymaltose (LC-iron20, LC-iron40, and LC-iron80 group, respectively). Biochemical parameters were compared at 0, 7, 14, 21, and 28 days. The degrees of hepatic fibrosis and iron deposition were evaluated. Inflammatory and oxidative stress markers were also compared. Results There were no significant differences in the 28-day serum alanine aminotransferase levels among the LC-iron20, LC-iron40, and LC-iron80 groups (69 ± 7, 1003 ± 127, 1064 ± 309, 919 ± 346, and 820 ± 195 IU/L in the control, LC, LC-iron20, LC-iron40, and LC-iron80 groups, respectively). Hepatic iron accumulation increased in a dose-dependent manner, but the degree of hepatic fibrosis was comparable among the groups. The inflammatory and oxidative stress marker levels did not differ significantly according to the IV iron dose. Conclusions Administration of IV iron at various high doses appears safe in our rat model of cirrhosis.
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- 2024
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8. Preoperative C-reactive protein/albumin ratio and mortality of off-pump coronary artery bypass graft
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Ah Ran Oh, Ji-Hye Kwon, Jungchan Park, Jeong-Jin Min, Jong-Hwan Lee, Seung Yeon Yoo, Dong Jae Lee, Wooksung Kim, Hyun Sung Cho, Chung Su Kim, and Sangmin Maria Lee
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albumin ,biomarker ,coronary artery bypass ,C-reactive protein ,mortality ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
BackgroundWe sought to investigate the prognostic value of preoperative C-reactive protein (CRP)-to-albumin ratio (CAR) for the prediction of mortality in patients undergoing off-pump coronary artery bypass grafting (OPCAB).MethodsFrom January 2010 to August 2016, adult patients undergoing OPCAB were analyzed retrospectively. In a total of 2,082 patients, preoperative inflammatory markers including CAR, CRP, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio were recorded. Receiver operating characteristic (ROC) curves were used to determine the optimal threshold and compare the predictive values of the markers. The patients were divided into two groups according to the cut-off value of CAR, and then the outcomes were compared. The primary end point was 1-year mortality.ResultsDuring the 1-year follow-up period, 25 patients (1.2%) died after OPCAB. The area under the curve of CAR for 1-year mortality was 0.767, which was significantly higher than other inflammatory markers. According to the calculated cut-off value of 1.326, the patients were divided into two groups: 1,580 (75.9%) patients were placed in the low CAR group vs. 502 (24.1%) patients in the high CAR group. After adjustment with inverse probability weighting, high CAR was significantly associated with increased risk of 1-year mortality after OPCAB (Hazard ratio, 5.01; 95% Confidence interval, 2.01–12.50; p
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- 2024
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9. Discovery biomarker to optimize obeticholic acid treatment for non-alcoholic fatty liver disease
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Seung Min Lee, Dae Won Jun, Eileen Laurel Yoon, Ju Hee Oh, Yoon Jin Roh, Eun Jeoung Lee, Ji-Hee Shin, Young-Do Nam, and Hyun Sung Kim
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Non-alcoholic fatty liver ,Obeticholic acid ,Bile acid ,Alternative pathway ,Biomarker ,Microbiome ,Biology (General) ,QH301-705.5 - Abstract
Abstract The response rate to obeticholic acid (OCA), a potential therapeutic agent for non-alcoholic fatty liver disease, is limited. This study demonstrated that upregulation of the alternative bile acid synthesis pathway increases the OCA treatment response rate. The hepatic transcriptome and bile acid metabolite profile analyses revealed that the alternative bile acid synthesis pathway (Cyp7b1 and muricholic acid) in the OCA-responder group were upregulated compared with those in the OCA-non-responder group. Intestinal microbiome analysis also revealed that the abundances of Bacteroidaceae, Parabacteroides, and Bacteroides, which were positively correlated with the alternative bile acid synthesis pathway, were higher in the OCA-responder group than in the non-responder group. Pre-study hepatic mRNA levels of Cyp8b1 (classic pathway) were downregulated in the OCA-responder group. The OCA response rate increased up to 80% in cases with a hepatic Cyp7b1/Cyp8b1 ratio ≥ 5.0. Therefore, the OCA therapeutic response can be evaluated based on the Cyp7b1/Cyp8b1 ratio or the alternative/classic bile acid synthesis pathway activity.
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- 2023
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10. Non-Hermitian chiral degeneracy of gated graphene metasurfaces
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Soojeong Baek, Sang Hyun Park, Donghak Oh, Kanghee Lee, Sangha Lee, Hosub Lim, Taewoo Ha, Hyun Sung Park, Shuang Zhang, Lan Yang, Bumki Min, and Teun-Teun Kim
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Applied optics. Photonics ,TA1501-1820 ,Optics. Light ,QC350-467 - Abstract
We report the precise real-time probing of chiral exceptional points with an electrical and spectral method and the consequences of chiral mode collapsing by an active platform of hybridised non-Hermitian metasurfaces with gated graphene microribbons.
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- 2023
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11. Arterial stiffness and its associations with left ventricular diastolic function according to heart failure types
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Hack-Lyoung Kim, Jaehoon Chung, Seokmoon Han, Hyun Sung Joh, Woo-Hyun Lim, Jae-Bin Seo, Sang-Hyun Kim, Joo-Hee Zo, and Myung-A Kim
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Vascular stiffness ,Diastolic function ,Heart failure ,Pulse wave analysis ,Medicine ,Internal medicine ,RC31-1245 - Abstract
Abstract Background Little is known about the characteristics of arterial stiffness in heart failure (HF). This study was performed to compare the degree of arterial stiffness and its association with left ventricular (LV) diastolic function among three groups: control subjects, patients with HF with reduced ejection fraction (HFrEF), and patients with HF with preserved ejection fraction (HFpEF). Methods A total of 83 patients with HFrEF, 68 patients with HFpEF, and 84 control subjects were analyzed. All HF patients had a history of hospitalization for HF treatment. Brachial-ankle pulse wave velocity (baPWV) measurement and transthoracic echocardiography were performed at the same day in a stable condition. Results The baPWV was significantly higher in patients with both HFrEF and HFpEF compared to control subjects (1,661 ± 390, 1,909 ± 466, and 1,477 ± 296 cm/sec, respectively; P
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- 2023
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12. Days alive and out of hospital at 30 days and outcomes of off-pump coronary artery bypass grafting
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Ah Ran Oh, Seung-Hwa Lee, Jungchan Park, Jeong-Jin Min, Jong-Hwan Lee, Seung Yeon Yoo, Ji-Hye Kwon, Dan-Cheong Choi, Wooksung Kim, and Hyun Sung Cho
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Medicine ,Science - Abstract
Abstract Days alive and out of hospital (DAOH) is a simple estimator based on the number of days not in hospital within a defined period. In cases of mortality within the period, DAOH is regarded as zero. It has not been validated solely in off-pump coronary artery bypass grafting (OPCAB). This study aimed to demonstrate a correlation between DAOH and outcome of OPCAB. We identified 2211 OPCAB performed from January 2010 to August 2016. We calculated DAOH at 30 and 60 days. We generated a receiver-operating curve and compared outcomes. The median duration of hospital stay after OPCAB was 6 days. The median DAOH values at 30 and 60 days were 24 and 54 days. The estimated thresholds for 3-year mortality for DAOH at 30 and 60 days were 20 and 50 days. Three-year mortality was higher for short DAOH (1.2% vs. 5.7% and 1.1% vs. 5.6% DAOH at 30 and 60 days). After adjustment, the short DAOH 30 group showed significantly higher mortality during 3-year follow-up (hazard ratio 3.07; 95% confidence interval 1.45–6.52; p = 0.004). DAOH at 30 days after OPCAB showed a correlation with 3-year outcomes. DAOH 30 might be a reliable long-term outcome measure that can be obtained within 30 days after surgery.
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- 2023
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13. Impact of Esterification with Octenyl Succinic Anhydride on the Structural Characteristics and Glucose Response in Mice of Wheat Starch
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Hyun Sung Lee, Gyeong A Jeong, Seokwon Lim, and Chang Joo Lee
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octenyl succinic anhydride ,esterification ,resistant starch ,glucose response ,low calorie ,Chemical technology ,TP1-1185 - Abstract
In this study, we investigated the structural properties and digestibility of wheat starch treated with octenyl succinic anhydride (OSA). For the experiment, the samples were reacted with 2, 4, 6, 8, and 10% OSA (pH 8.5–9.0) for 2 h. A light micrograph showed that there was no difference in the morphology and Maltese cross between native and OSA-treated starch. The X-ray diffraction (XRD) patterns of the native and OSA-treated starches showed typical A-type diffraction. In addition, the Fourier transform infrared (FT-IR) spectrum showed a distinct carbonyl peak at approximately 1730 cm−1, indicating the stretching vibration of the C=O bond of the ester group. The degree of substitution (DS) and content of resistant starch (RS) increased with increasing concentrations of treated OSA because of the increase in ester bonds. In particular, RS was thermostable compared to the RS content in uncooked and cooked starch. Blood glucose levels and response in vivo decreased as the OSA concentration increased. Treatment of wheat starch with 8% OSA concentration produced 35.6% heat-stable resistant starch. These results suggest that starch modified with OSA can be used to produce functional foods for diabetes.
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- 2024
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14. Combined procedure with radial probe and convex probe endobronchial ultrasound
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Hyun Sung Chung, Kyoungjune Pak, Geewon Lee, and Jung Seop Eom
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bronchoscopy ,diagnosis ,lung neoplasms ,lymph nodes ,ultrasound ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Concurrent bronchoscopy using radial probe and convex endobronchial ultrasound (RP‐ and CP‐EBUS) is used to simultaneously evaluate both peripheral lung lesions for the histological diagnosis of the primary tumor and mediastinal lymph nodes for mediastinal staging. So far, little is known about the combined procedure with RP‐ and CP‐EBUS. Methods Between January 2020 and March 2021, the bronchoscopy database was reviewed to identify the clinical outcomes of the combined procedure with RP‐ and CP‐EBUS. Patients who underwent transbronchial biopsy using RP‐EBUS alone were classified as the RP‐EBUS group, while those who underwent a combined procedure with RP‐ and CP‐EBUS were classified as the combination group. Results The overall diagnostic yield of the bronchoscopic procedure in the combination group was significantly higher than the RP‐EBUS group (90.7% vs. 70.0%, p
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- 2022
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15. Gene expression analysis in recurrent benign paroxysmal positional vertigo: a preliminary study
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Eun Hye Oh, Jin-Ok Lee, Hyun Sung Kim, Ji-Yun Park, Seo Young Choi, Kwang-Dong Choi, Ji-Soo Kim, and Jae-Hwan Choi
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benign paroxysmal positional vertigo (BPPV) ,gene expression profiling (GEP) ,bioinformatics analysis ,oxidative stress ,immune system ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
ObjectivesThis study aimed to determine the pathophysiology of recurrent benign paroxysmal positional vertigo (BPPV) in young patients using gene expression profiling combined with bioinformatics analysis.MethodsTotal RNA was extracted from the whole blood of four young patients with recurrent BPPV and four controls. The differentially expressed genes (DEGs) between the groups were screened using a microarray analysis based on the cutoff criteria of |log2 fold change| > 1 and an adjusted p-value of < 0.05. Functional enrichment analysis of DEGs was performed using Gene Ontology analysis, and the protein–protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of the Interacting Genes database.ResultsA total of 39 DEGs were detected between the BPPV and control samples, comprising 33 upregulated DEGs and six downregulated DEGs in the BPPV group. Functional enrichment analysis indicated that the upregulated DEGs were significantly enriched in terms related to metabolic processes and the immune system. Two main pathways were extracted from the PPI network: one was associated with oxidative phosphorylation and stress and the other with the adaptive immune system and extracellular matrix degradation.ConclusionThe findings of our bioinformatics analysis indicated that oxidative stress or extracellular matrix degradation due to immune-mediated inflammatory responses may contribute to the development of recurrent BPPV in young patients.
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- 2023
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16. Verifying the relationships of defect site and enhanced photocatalytic properties of modified ZrO2 nanoparticles evaluated by in-situ spectroscopy and STEM-EELS
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Hyun Sung Kim, Ye-Jin Kim, Ye Rim Son, Vy Ngoc Pham, Ki-jeong Kim, Chang Woo Kim, Young-Sang Youn, Oh-Hoon Kwon, and Hangil Lee
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Medicine ,Science - Abstract
Abstract Base treatment and metal doping were evaluated as means of enhancing the photocatalytic activity of ZrO2 nanoparticles (NPs) via the generation of oxygen vacancies (OvS), and the sites responsible for this enhancement were identified and characterized by spectroscopic and microscopic techniques. We confirmed that OvS produced by base treatment engaged in photocatalytic activity for organic pollutant degradation, whereas surface defects introduced by Cr-ion doping engaged in oxidative catalysis of molecules. Moreover, we verified that base-treated ZrO2 NPs outperformed their Cr-ion doped counterparts as photocatalysts using in situ X-ray photoelectron spectroscopy and scanning transmission electron microscopy coupled with electron energy loss spectroscopy (STEM-EELS). Thus, our study provides valuable information on the origin of the enhanced photocatalytic activity of modified ZrO2 NPs and demonstrates the practicality of in situ spectroscopy and STEM-EELS for the evaluation of highly efficient metal oxide photocatalysts.
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- 2022
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17. Vasoactive inotropic score as a predictor of long-term mortality in patients after off-pump coronary artery bypass grafting
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Ji-Hye Kwon, Seung Yeon Yoo, Seonwoo Kim, Hojeong Won, Wooksung Kim, Sukyoung Her, Yu Jeong Bang, Jungchan Park, Jong-Hwan Lee, Hyun Sung Cho, and Jeong-Jin Min
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Medicine ,Science - Abstract
Abstract Increased vasoactive-inotropic score (VIS) is a reliable predictor of mortality and morbidity after cardiac surgery. Here, we retrospectively evaluated the association between VIS and adverse outcomes in adult patients after off-pump coronary artery bypass grafting (OPCAB). We included 2149 patients who underwent OPCAB. The maximal VIS was calculated for the initial 48 postoperative hours using standard formulae. The primary outcome was 1-year death. The composite adverse outcome was death, resuscitation or mechanical support, myocardial infarction, revascularization, new-onset atrial fibrillation, infection requiring antibacterial therapy, acute kidney injury, and stroke. Path-analysis was conducted using lactate and prognostic nutritional index (PNI). VIS was associated with 1-year death (odds ratio [OR] 1.07 [1.04–1.10], p
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- 2022
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18. Multidisciplinary treatment strategy for early rectal cancer: A review
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Gyung Mo Son, In Young Lee, Sung Hwan Cho, Byung-Soo Park, Hyun Sung Kim, Su Bum Park, Hyung Wook Kim, Sang Bo Oh, Tae Un Kim, and Dong Hoon Shin
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colonoscopy ,neoadjuvant therapy ,organ preservation ,rectal neoplasms ,transanal endoscopic surgery ,Medicine - Abstract
The early rectal cancer (ERC) has increased with the national cancer screening project for early detection of colorectal cancer. The gold standard treatment for low rectal cancer is low anterior resection (LAR) based on total mesorectal excision. However, radical resection results in a high mortality and complication rate, and the deterioration of quality of life due to LAR syndrome, genitourinary dysfunction, and possible permanent stoma. Local excision with chemoradiation therapy could be one of the alternative therapeutic strategies for the organ preservation and a cure of cancer. To decide the treatment strategies, it is important to establish sophisticated indications that can maximize the therapeutic effect. ERC has heterogeneous pathological features, including aggressive behavior and occult lymph node metastasis, with different responses to chemoradiotherapy. Therefore, radiologic, endoscopic and pathologic evaluation to predict the risk of lymph node metastasis and local recurrence has been evolving to determine the optimal treatment strategy in the patient-tailored medicine. Recently, the long-term outcomes of prospective randomized clinical trials provide new hope for organ preservation in patients with ERC. In this paper, we aim to review various risk factors related to local recurrence and discuss the optimal treatment strategy for ERC.
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- 2022
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19. Discriminative Role of Invasive Left Heart Catheterization in Patients Suspected of Heart Failure With Preserved Ejection Fraction
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Ki Hong Choi, Jeong Hoon Yang, Jeong Hun Seo, David Hong, Taeho Youn, Hyun Sung Joh, Seung Hun Lee, Darae Kim, Taek Kyu Park, Joo Myung Lee, Young Bin Song, Jin‐Oh Choi, Joo‐Yong Hahn, Seung‐Hyuk Choi, Hyeon‐Cheol Gwon, and Eun‐Seok Jeon
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heart failure with preserved ejection fraction ,HFA‐PEFF score ,left ventricular end‐diastolic pressure ,let heart catheterization ,prognosis ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Background Recently, diastolic stress testing and invasive hemodynamic measurements have been emphasized for diagnosis of heart failure with preserved ejection fraction (HFpEF) because when determined using noninvasive parameters it can fall into a nondiagnostic intermediate range. The current study evaluated the discriminative and prognostic roles of invasive measured left ventricular end‐diastolic pressure in the population with suspected HFpEF, particularly for patients with intermediate Heart Failure Association Pre‐test Assessment, Echocardiography & Natriuretic Peptide, Functional Testing, Final Etiology (HFA‐PEFF) score. Methods and Results A total of 404 patients with symptoms or signs of HF and preserved left ventricular systolic function were enrolled. All subjects underwent left heart catheterization with left ventricular end‐diastolic pressure measurement for confirmation of HFpEF (≥16 mm Hg). The primary outcome was all‐cause death or readmission due to HF within 10 years. Among the study population, 324 patients (80.2%) were diagnosed as invasively confirmed HFpEF, and 80 patients (19.8%) were as noncardiac dyspnea. The patients with HFpEF showed a significantly higher HFA‐PEFF score than the patients with noncardiac dyspnea (3.8±1.8 versus 2.6±1.5, P
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- 2023
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20. Provably Secure Pseudo-Identity Three-Factor Authentication Protocol Based on Extended Chaotic-Maps for Lightweight Mobile Devices
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Devanapalli Suresh, Vanga Odelu, Alavalapati Goutham Reddy, Kolloju Phaneendra, and Hyun Sung Kim
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Security ,privacy ,three-factor ,authentication ,key agreement ,chaotic-maps ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Authentication and key agreement (AKA) play a major role in an open network environment to communicate between two or more participants securely. Authentication and key agreement protocols should protect sensitive data from a malevolent adversary by offering a several of services, such as user credential privacy and authentication when a user’s or server’s private key is revealed or a smart card is lost/stolen. Unfortunately, the majority of offered authentication and key agreement protocols suggested in the literature are vulnerable to many attacks. In this research, we present a pseudo-identity-based secure mutual authentication protocol that protects privacy. The suggested protocol resists replay attacks, de-synchronization attacks, eavesdropping attacks, denial of service attacks, insider attacks, known session-specific temporary information attacks, and man-in-the-middle attacks efficiently and also provides forward security. In order to offer privacy and prevent traceability, our protocol employs the pseudo-identity mechanism. We present a comprehensive security analysis, which includes formal verification with the Scyther tool; a BAN logic proof; and an informal discussion of various attacks, demonstrating that the proposed protocol is secure against all well-known attacks. Additionally, we give a performance study and a comparison to similar existing protocols.
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- 2022
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21. Prognostic Impact of Cardiac Diastolic Function and Coronary Microvascular Function on Cardiovascular Death
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David Hong, Seung Hun Lee, Doosup Shin, Ki Hong Choi, Hyun Kuk Kim, Sang Jin Ha, Hyun Sung Joh, Taek Kyu Park, Jeong Hoon Yang, Young Bin Song, Joo‐Yong Hahn, Seung‐Hyuk Choi, Hyeon‐Cheol Gwon, and Joo Myung Lee
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cardiac diastolic dysfunction ,coronary flow reserve ,coronary microvascular dysfunction ,index of microcirculatory resistance ,prognosis ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Background Coronary microvascular dysfunction (CMD) has been considered as a possible cause of cardiac diastolic dysfunction. The current study evaluated the association between cardiac diastolic dysfunction and CMD, and their prognostic implications in patients without significant left ventricular systolic dysfunction and epicardial coronary stenosis. Methods and Results A total of 330 patients without left ventricular systolic dysfunction (ejection fraction ≥50%) and significant epicardial coronary stenosis (fractional flow reserve >0.80) were analyzed. Cardiac diastolic dysfunction was defined by echocardiographic parameters (early diastolic transmitral flow velocity/early diastolic mitral annular velocity, e' velocity, tricuspid regurgitation velocity, and left atrial volume index). Overt CMD was defined as coronary flow reserve
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- 2023
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22. Associations of Estimated Pulse Wave Velocity with Body Mass Index and Waist Circumference among General Korean Adults
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Hack-Lyoung Kim, Hyun Sung Joh, Woo-Hyun Lim, Jae-Bin Seo, Sang-Hyun Kim, Joo-Hee Zo, and Myung-A Kim
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arterial stiffness ,body mass index ,pulse wave velocity ,obesity ,waist circumference ,Microbiology ,QR1-502 - Abstract
The correlation between body fat parameters and arterial stiffness is still under debate. This study aimed to examine the associations of body mass index (BMI) and waist circumference (WC) with estimated pulse wave velocity (ePWV). We utilized data from 14,228 subjects (mean age 53.4 ± 16.8 years; 56.9% were female) from the Korean National Health and Nutrition Examination Survey. The ePWV was calculated using a formula based on age and blood pressure. Simple linear correlation analyses revealed significant associations between both BMI and ePWV (r = 0.098; p < 0.001) and WC and ePWV (r = 0.291; p < 0.001), with a stronger correlation observed between WC and ePWV. Multiple linear regression analysis demonstrated that WC remained significantly associated with ePWV after adjusting for potential confounders (β = 0.020; p = 0.001). However, a statistically significant association was not found between BMI and ePWV (β = 0.011; p = 0.076). Multiple binary logistic regression analysis further indicated that both higher BMI and WC were independently associated with higher ePWV, but the association was more pronounced between WC and ePWV than between BMI and ePWV. These findings underscore a stronger correlation between visceral obesity (as indicated by WC) and arterial stiffness (as indicated by ePWV) compared to overall obesity (as indicated by BMI). This highlights the potential significance of abdominal obesity in assessing cardiovascular risk.
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- 2023
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23. Cerebello-brainstem dominant form of X-linked adrenoleukodystrophy with intrafamilial phenotypic variability
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Jae-Hwan Choi, Hyun Sung Kim, Eun Hye Oh, Jae Hyeok Lee, and Chong Kun Cheon
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adrenoleukodystrophy ,ABCD1 ,cerebellar ataxia ,very long-chain fatty acids ,phenotype ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
ObjectivesThis study aimed to describe the clinical and radiological characteristics of a cerebello-brainstem dominant form of X-linked adrenoleukodystrophy (X-ALD).MethodsThree affected members from a family with cerebellar ataxia received full neurological, laboratory and radiological examinations. Genetic diagnoses were confirmed using whole-exome sequencing and protein structural modeling.ResultsAll affected members presented with slurred speech, ataxia, and spasticity, but showed obvious differences in phenotypic severity and radiological findings. The levels of very long-chain fatty acids (VLCFA) were elevated in each member, while only one had adrenal dysfunction. Genetic analysis identified a hemizygous missense mutation (c.887A>G, p.Tyr296Cys) of the ATP-binding cassette subfamily D member 1 gene (ABCD1) in all affected members, which is likely to destabilize the overall structure of the ABCD1 protein.ConclusionsWe report a cerebello-dominant form of X-ALD caused by a missense variant in ABCD1. This report highlights intrafamilial phenotypic variability in X-ALD.
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- 2022
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24. Peripheral blood mononuclear cell mitochondrial copy number and adenosine triphosphate inhibition test in NAFLD
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A-Hyeon Lee, Ju Hee Oh, Hyun Sung Kim, Jeong-Hun Shin, Eileen L. Yoon, and Dae Won Jun
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NAFLD ,mitochondrial dysfunction ,mitochondria copy number ,ATP ,biomarker ,Diseases of the endocrine glands. Clinical endocrinology ,RC648-665 - Abstract
Background and aimNon-alcoholic fatty liver disease (NAFLD) is associated with mitochondrial dysfunction. This study aims to develop biomarkers for assessing mitochondrial dysfunction in patients with NAFLD.MethodsMitochondrion-associated transcriptome analysis was performed. Peripheral blood mononuclear cells obtained from patients with NAFLD (69) and healthy controls (19) were used to determine the mitochondrial DNA (mtDNA) copy number. A mitochondrial inhibition substrate test (ATP assay) was performed in HepG2 cells using the patient serum.ResultsHepatic mRNA transcriptome analysis showed that the gene expression related to mitochondrial functions (mitochondrial fusion, apoptotic signal, and mitochondrial envelope) increased in patients with steatohepatitis, but not in those with NAFL. Gene set enrichment analysis revealed that the upregulated expression of genes is related to the pathways of the tricarboxylic (TCA) cycle and deoxyribonucleic acid (DNA) replication in patients with steatohepatitis, but not in healthy controls. The mtDNA copy number in the peripheral blood mononuclear cells was 1.28-fold lower in patients with NAFLD than that in healthy controls (P
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- 2022
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25. Tumor grade 2 as the independent predictor for lymph node metastasis in 10–20 mm sized rectal neuroendocrine tumor
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Byung-Soo Park, Sung Hwan Cho, Gyung Mo Son, Hyun Sung Kim, Su Jin Kim, Su Bum Park, Cheol Woong Choi, Hyung Wook Kim, and Dong Hoon Shin
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neuroendocrine tumors ,rectum ,lymphatic metastasis ,grade ,endoscopy ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 ,Surgery ,RD1-811 - Abstract
Purpose Rectal neuroendocrine tumors (NETs)
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- 2021
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26. Absent or impaired rectoanal inhibitory reflex as a diagnostic factor for high-grade (grade III–V) rectal prolapse: a retrospective study
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Byung-Soo Park, Sung Hwan Cho, Gyung Mo Son, Hyun Sung Kim, Yong-Hoon Cho, Dae Gon Ryu, Su Jin Kim, Su Bum Park, Cheol Woong Choi, Hyung Wook Kim, Tae Un Kim, Dong Soo Suh, Myunghee Yoon, and Hong Jae Jo
- Subjects
Rectal prolapse ,Rectoanal inhibitory reflex ,Diagnosis ,Manometry ,Defecography ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Abstract Background Clinically diagnosing high-grade (III–V) rectal prolapse might be difficult, and the prolapse can often be overlooked. Even though defecography is the significant diagnostic tool for rectal prolapse, it is noticed that rectoanal inhibitory reflex (RAIR) can be associated with rectal prolapse. This study investigated whether RAIR can be used as a diagnostic factor for rectal prolapse. Methods In this retrospective study, we evaluated 107 patients who underwent both anorectal manometry and defecography between July 2012 and December 2019. Rectal prolapse was classified in accordance with the Oxford Rectal Prolapse Grading System. Patients in the high-grade (III–V) rectal prolapse (high-grade group, n = 30), and patients with no rectal prolapse or low-grade (I, II) rectal prolapse (low-grade group, n = 77) were analyzed. Clinical variables, including symptoms such as fecal incontinence, feeling of prolapse, and history were collected. Symptoms were assessed using yes/no surveys answered by the patients. The manometric results were also evaluated. Results Frequencies of fecal incontinence (p = 0.002) and feeling of prolapse (p
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- 2021
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27. Prognostic Impact of Coronary Flow Reserve in Patients With Reduced Left Ventricular Ejection Fraction
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Hyun Sung Joh, Doosup Shin, Joo Myung Lee, Seung Hun Lee, David Hong, Ki Hong Choi, Doyeon Hwang, Coen K. M. Boerhout, Guus A. de Waard, Ji‐Hyun Jung, Hernan Mejia‐Renteria, Masahiro Hoshino, Mauro Echavarria‐Pinto, Martijn Meuwissen, Hitoshi Matsuo, Maribel Madera‐Cambero, Ashkan Eftekhari, Mohamed A. Effat, Tadashi Murai, Koen Marques, Joon‐Hyung Doh, Evald H. Christiansen, Rupak Banerjee, Hyun Kuk Kim, Chang‐Wook Nam, Giampaolo Niccoli, Masafumi Nakayama, Nobuhiro Tanaka, Eun‐Seok Shin, Steven A. J. Chamuleau, Niels van Royen, Paul Knaapen, Bon Kwon Koo, Tsunekazu Kakuta, Javier Escaned, Jan J. Piek, and Tim P. van de Hoef
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coronary flow reserve ,coronary physiology ,left ventricular ejection fraction ,prognosis ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Background Intracoronary physiologic indexes such as coronary flow reserve (CFR) and left ventricular ejection fraction (LVEF) have been regarded as prognostic indicators in patients with coronary artery disease. The current study evaluated the association between intracoronary physiologic indexes and LVEF and their differential prognostic implications in patients with coronary artery disease. Methods and Results A total of 1889 patients with 2492 vessels with available CFR and LVEF were selected from an international multicenter prospective registry. Baseline physiologic indexes were measured by thermodilution or Doppler methods and LVEF was recorded at the index procedure. The primary outcome was target vessel failure, which was a composite of cardiac death, target vessel myocardial infarction, or clinically driven target vessel revascularization over 5 years of follow‐up. Patients with reduced LVEF
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- 2022
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28. Transcriptional Down-Regulation of Major Histocompatibility Complex as a Possible Pathogenesis for Meniere's Disease
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Kwang-Dong Choi, Eun Hye Oh, Hyun Sung Kim, Hyang-Sook Kim, Ji-Yun Park, Seo Young Choi, and Jae-Hwan Choi
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Meniere's disease ,transcriptome analysis ,immune system ,MHC protein ,differentially expressed gene ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
ObjectivesThis study aimed to determine the underlying pathogenesis of Meniere's disease (MD) using transcriptome analysis.MethodsTotal RNA was extracted from the peripheral blood mononuclear cells of 39 patients with MD and 39 controls. Through microarray analysis for nine patients and controls, the differentially expressed genes (DEGs) of those two groups were screened based on cut-off criteria (|fold changes| > 2.0 and adjusted p-value < 0.05). The functional enrichment analysis of DEGs was performed using Gene Ontology (GO).ResultsThere were 996 DEGs identified in the MD group: 415 were upregulated and 581 were downregulated. A functional enrichment analysis indicated that the downregulated DEGs were significantly enriched in terms related to immune system processes. Among them, 17 genes were enriched in terms for the major histocompatibility complex (MHC) protein complex, and the relative messenger RNA (mRNA) levels of three markedly downregulated DEGs [fold changes < −5: human leukocyte antigen (HLA)-DMA, HLA-DRB1, and HLA-DPB1] were significantly decreased in another 30 patients with MD compared with normal controls by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). However, there were no correlations between the expression levels of these three genes and clinical data, such as age, onset age, time course, or hearing threshold.ConclusionsOur transcriptome analysis showed that the downregulated DEGs in MD were mainly associated with the immune system pathways including the MHC protein complex in MD. Remarkably, a breakdown in immunological tolerance mediated by MHC class II may contribute to the MD development, which has implications for targeted treatment.
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- 2022
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29. Semi-Automatic Framework for Traffic Landmark Annotation
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Won Hee Lee, Kyungboo Jung, Chulwoo Kang, and Hyun Sung Chang
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Detection algorithms ,image databases ,image registration ,intelligent vehicles ,sensor systems ,Transportation engineering ,TA1001-1280 ,Transportation and communications ,HE1-9990 - Abstract
We present a semi-automatic annotation method to build a large dataset for traffic landmark detection, where traffic landmarks include traffic signs, traffic lights as well as road markings. Labor-intensive bounding box tagging is a huge challenge to generate a large dataset for detection algorithms. To mitigate the labor, we adopt a high-definition (HD) map and a positioning system. We propose a process to align the HD map and images semi-automatically. Through the registration, the annotations of the HD map can be directly tagged onto traffic landmarks in the images. To make full use of the HD map for the dataset generation, we annotate the traffic landmarks with reference points, following the way that they are represented in the HD map, instead of the bounding boxes. The proposed semi-automatic method speeds up the annotation by a factor of 3.19, as compared to the manual annotation. Our dataset consists of about 150,000 images and includes about 470,000 annotated traffic landmarks. We train a deep neural network on our dataset to detect the traffic landmarks, and its performance is evaluated using a novel evaluation metric. Moreover, we show that the pretrained traffic landmark detection network is effective in detecting traffic landmarks in other countries using the bounding box by fine-tuning.
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- 2021
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30. Unsupervised Training of Diffusion Models for Feasible Solution Generation in Neural Combinatorial Optimization
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Hong, Seong-Hyun, Kim, Hyun-Sung, Jang, Zian, Yoon, Deunsol, Hong, Sunghoon, and Lee, Byung-Jun
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Computer Science - Artificial Intelligence ,Computer Science - Machine Learning ,Mathematics - Optimization and Control - Abstract
Recent advancements in neural combinatorial optimization (NCO) methods have shown promising results in generating near-optimal solutions without the need for expert-crafted heuristics. However, high performance of these approaches often rely on problem-specific human-expertise-based search after generating candidate solutions, limiting their applicability to commonly solved CO problems such as Traveling Salesman Problem (TSP). In this paper, we present IC/DC, an unsupervised CO framework that directly trains a diffusion model from scratch. We train our model in a self-supervised way to minimize the cost of the solution while adhering to the problem-specific constraints. IC/DC is specialized in addressing CO problems involving two distinct sets of items, and it does not need problem-specific search processes to generate valid solutions. IC/DC employs a novel architecture capable of capturing the intricate relationships between items, and thereby enabling effective optimization in challenging CO scenarios. IC/DC achieves state-of-the-art performance relative to existing NCO methods on the Parallel Machine Scheduling Problem (PMSP) and Asymmetric Traveling Salesman Problem (ATSP).
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- 2024
31. Perianal extragastrointestinal stromal tumor
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Ayoung Kang, Sung Hwan Cho, Byung-Soo Park, Gyung Mo Son, Hyun Sung Kim, Jae-Joon Kim, Su Jin Kim, Dong Hoon Shin, and Tae Un Kim
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extragastrointestinal stromal tumor ,gastrointestinal stromal tumor ,perianal neoplasm ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 ,Surgery ,RD1-811 - Abstract
An extragastrointestinal stromal tumor (EGIST) is a gastrointestinal stromal tumor that arises outside of the gastrointestinal tract. Most EGISTs are located in the omentum, mesentery, and retroperitoneum. The occurrence of an EGIST at the perianal region is very rare. Herein, we report our experience with EGISTs in the perianal area and review the literature. A 70-year-old man presented to our hospital with a 2-year history of anal discomfort. A pelvic magnetic resonance imaging scan showed a homogenous, well-defined, soft tissue density mass. The patient underwent mass excision, and the pathological examination confirmed that the mass was an EGIST. The size of the tumor was 4.3×3.2 cm, and the mitotic count was 1 per 50 high-power fields. The tumor cells were immunohistochemically positive for KIT and CD34 but were negative for S-100 and alpha-smooth muscle actin. There were no other abnormal findings in the gastrointestinal tract; upon pathological review, this case was confirmed as perianal EGIST. Therefore, EGIST should be considered as a differential diagnosis of perianal masses.
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- 2020
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32. Sequential Organ Failure Assessment score as a predictor of mortality in ventilated patients with multidrug-resistant bacteremia
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Yeseul Oh, Jiyeon Roh, Jaemin Lee, Hyun Sung Chung, Kwangha Lee, and Min Ki Lee
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bacteremia ,intensive care unit ,prognosis ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Background The occurrence of multidrug-resistant (MDR) bacteremia in ventilated patients may be associated with a high mortality rate. We evaluated whether Sequential Organ Failure Assessment (SOFA) score on the day of bacteremia could predict 90-day mortality in these patients. Methods Data were obtained retrospectively from 202 patients (male, 60.4%; median age, 64 years) hospitalized at a single university-affiliated tertiary care hospital. All adult patients who had were ventilated and had one of the following six MDR bacteremias between March 2011 and February 2018 were enrolled: methicillin-resistant Staphylococcus aureus, extended-spectrum β-lactamase-producing Gram-negative bacteria (Escherichia coli and Klebsiella pneumonia), carbapenem-resistant Gram-negative rods (Acinetobacter baumannii and Pseudomonas aeruginosa), or vancomycin-resistant Enterococcus faecium. Results The overall 90-day mortality rate after the day of bacteremia was 59.9%. The areas under the receiver operating characteristic curves for the SOFA and Acute Physiology and Chronic Health Evaluation (APACHE) II scores were 0.732 (95% confidence interval [CI], 0.666 to 0.792; P
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- 2020
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33. TRPV4 disrupts mitochondrial transport and causes axonal degeneration via a CaMKII-dependent elevation of intracellular Ca2+
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Brian M. Woolums, Brett A. McCray, Hyun Sung, Masashi Tabuchi, Jeremy M. Sullivan, Kendra Takle Ruppell, Yunpeng Yang, Catherine Mamah, William H. Aisenberg, Pamela C. Saavedra-Rivera, Bryan S. Larin, Alexander R. Lau, Douglas N. Robinson, Yang Xiang, Mark N. Wu, Charlotte J. Sumner, and Thomas E. Lloyd
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Science - Abstract
Mutations in the TRPV4 channel cause inherited neurodegeneration syndromes, but the molecular mechanisms are unknown. Here the authors reveal that TRPV4 activation causes dose-dependent, CaMKII-mediated neuronal dysfunction and axonal degeneration via disruption of mitochondrial axonal transport.
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- 2020
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34. A SMAD4‐modulated gene profile predicts disease‐free survival in stage II and III colorectal cancer
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Bryan C. Szeglin, Chao Wu, Michael R. Marco, Hyun Sung Park, Zeda Zhang, Bing Zhang, Julio Garcia‐Aguilar, R. Daniel Beauchamp, X. Steven Chen, and J. Joshua Smith
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cancer biology ,colorectal cancer ,gene expression profile ,SMAD4 ,tumor suppressor genes ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Colorectal cancer is the second‐leading cause of cancer‐related mortality in the United States and a leading cause of cancer‐related mortality worldwide. Loss of SMAD4, a critical tumor suppressor and the central node of the transforming growth factor‐beta superfamily, is associated with worse outcomes for colorectal cancer patients; however, it is unknown whether an RNA‐based profile associated with SMAD4 expression could be used to better identify high‐risk colorectal cancer patients. Aim Identify a gene expression‐based SMAD4‐modulated profile and test its association with patient outcome. Methods and results Using a discovery dataset of 250 colorectal cancer patients, we analyzed expression of BMP/Wnt target genes for association with SMAD4 expression. Promoters of the BMP/Wnt genes were interrogated for SMAD‐binding elements. Fifteen genes were implicated and three tested for modulation by SMAD4 in patient‐derived colorectal cancer tumoroids. Expression of the 15 genes was used for unsupervised hierarchical clustering of a training dataset and two resulting clusters modeled in a centroid model. This model was applied to an independent validation dataset of stage II and III patients. Disease‐free survival was analyzed by the Kaplan‐Meier method. In vitro analysis of three genes identified in the SMAD4‐modulated profile (JAG1, TCF7, and MYC) revealed modulation by SMAD4 consistent with the trend observed in the profile. In the training dataset (n = 553), the profile was not associated with outcome. However, among stage II and III patients (n = 461), distinct clusters were identified by unsupervised hierarchical clustering that were associated with disease‐free survival (p = .02, log‐rank test). The main model was applied to a validation dataset of stage II/III CRC patients (n = 257) which confirmed the association of clustering with disease‐free survival (p = .013, log‐rank test). Conclusions A SMAD4‐modulated gene expression profile identified high‐risk stage II and III colorectal cancer patients, can predict disease‐free survival, and has prognostic potential for stage II and III colorectal cancer patients.
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- 2022
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35. Bronchoscopic management of solitary bronchial myelolipoma: a case report
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Hyun Sung Chung, Kyu Min Lee, Jung Seop Eom, Insu Kim, Seyeon Park, Jihyun Ahn, Ahrong Kim, Chang Hun Lee, Geewon Lee, and Min Ki Lee
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Myelolipoma ,Bronchoscopy ,Pulmonary atelectasis ,Lung neoplasms ,Diseases of the respiratory system ,RC705-779 - Abstract
Abstract Background Myelolipoma is a rare benign tumor composed of mature adipose and hematopoietic tissues. Most myelolipomas are found in the adrenal glands, whereas intrathoracic myelolipoma is extremely rare. In particular, bronchial myelolipoma without the involvement of lung parenchyma has never been reported. Case presentation A previously healthy 38-year-old male developed dyspnea and a productive cough. Computed tomography revealed an endobronchial mass at the right bronchus intermedius and subsequent atelectasis of the right middle and lower lobes. Flexible bronchoscopy found a total obstruction of the right bronchus intermedius due to an endobronchial tumor. Using a rigid bronchoscope, the endobronchial tumor was resected and the base of the tumor was additionally ablated with a diode laser to prevent recurrence. The removed endobronchial tumor was a 13 mm × 20 mm-sized oval-shaped mass and was pathologically diagnosed as bronchial myelolipoma. Chest radiographs, obtained on the day following the procedure, showed an improvement of atelectasis, and accompanying symptoms were immediately improved. Follow-up bronchoscopy performed after 12 months evidenced no recurrence of the bronchial myelolipoma. Conclusions We used bronchoscopic intervention in patients with solitary bronchial myelolipoma and there was no evidence of recurrence.
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- 2019
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36. Democratizing Digital Microfluidics by a Cloud-based Design and Manufacturing Platform
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Wang, Qining Leo, Cho, Hyun-Sung Eric, Li, Jia, Huang, Hsin-Chuan, Kin, Sarath, Piao, Yuhao, Xu, Lin, Tang, Kenneth, Kuiry, Shounak, He, Zifan, Yu, Danning, Cheng, Brian, Wu, Chang-Chi, Choi, Connor, Shin, Kwanwoo, Ho, Tsung-Yi, and Kim, Chang-Jin
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Engineering ,Electrical Engineering ,Chemical Sciences ,Analytical Chemistry ,Chemical sciences - Abstract
Akin to the impact that digital microelectronics had on electronic devices for information technology, digital microfluidics (DMF) was anticipated to transform fluidic devices for lab-on-a-chip (LoC) applications. However, despite a wealth of research and publications, electrowetting-on-dielectric (EWOD) DMF has not achieved the anticipated wide adoption, and commercialization has been painfully slow. By identifying the technological and resource hurdles in developing DMF chip and control systems as the culprit, we envision democratizing DMF by building a standardized design and manufacturing platform. To achieve this vision, we introduce a proof-of-concept cloud platform that empowers any user to design, obtain, and operate DMF chips (https://edroplets.org). For chip design, we establish a web-based EWOD chip design platform with layout rules and automated wire routing. For chip manufacturing, we build a web-based EWOD chip manufacturing platform and fabricate four types of EWOD chips (i.e., glass, paper, PCB, and TFT) to demonstrate the foundry service workflow. For chip control, we introduce a compact EWOD control system along with web-based operating software. Although industrial fabrication services are beyond the scope of this work, we hope this perspective will inspire academic and commercial stakeholders to join the initiative toward a DMF ecosystem for the masses.
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- 2024
37. Synchronous Quadruple Colon Cancer With Two Lesions Previously Obscured by Ischemic Colitis, Plus Bladder Cancer and Thymoma: A Case Report
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Byung-Soo Park, Sung Hwan Cho, Su Jin Kim, Tae Un Kim, Dong Il Kim, Gyung Mo Son, and Hyun Sung Kim
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colorectal neoplasms ,quadruple ,ischemic colitis ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Synchronous quadruple colorectal cancer (CRC) is extremely rare without genetic alterations. We present a case of synchronous quadruple CRC with 2 lesions previously obscured by ischemic colitis. A 73-year-old woman was admitted to our emergency department. An abdominal computed tomography revealed ischemic colitis and irregular wall thickening of the sigmoid colon and sigmoid-descending junction, suspicious of 2 colon cancers. A colonoscopy examination revealed a fungating mass 20 cm from the anal verge, as well as ischemic colitis spanning the mucosa from the sigmoid colon to the transverse colon. The patient underwent laparoscopic Hartmann procedure. Pathologic examination confirmed both lesions as adenocarcinomas with microsatellite stable. Seven months postoperatively, instead of a laparoscopic Hartmann reversal, a laparoscopic total colectomy was performed due to the continued presence of severe ischemic colitis. The pathologic report suggested the presence of 2 distinct invasive adenocarcinomas in the descending colon without genetic alterations such as microsatellite instability.
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- 2021
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38. Enhanced photo-decomposition of methylene blue and toluene with (Ag,Na)-TiO2/Sr4All4O25:Eu,Dy heterojunction photocatalyst synthesized by coprecipitation method
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Kang, Hyun-sung, Cho, Bumrae, and Kim, Jung-Sik
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- 2025
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39. Thermal-quench behavior of non-insulated high-temperature superconducting (HTS) racetrack pancake coil with cooling channels through the epoxy surface
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Mtangi Mohamed Mussa, Hyun Sung Noh, Dawool Kwon, Yunyeol Ryu, Yeon Suk Choi, and Haigun Lee
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HTS racetrack pancake coil ,No-insulation coil ,Stycast 2850 FT ,Epoxy impregnation ,Cooling channels ,MQE ,Physics ,QC1-999 - Abstract
The high-temperature superconducting (HTS) racetrack pancake (RP) coil is recommended to be used as a field coil in rotating machines such as generators and motors. Epoxy impregnation is normally required in the field coil to protect it against mechanical stresses due to the variation in the magnetic field and to enhance its mechanical stability to withstand rotor vibrations. However, the thermal conductivity of epoxy is very low compared with that of HTS. Consequently, when quenching is induced in an epoxy-impregnated coil, the Joule heating is poorly dissipated outward because of the absence of thermal drain to dissipate the heat in liquid nitrogen (LN2), which damages the coil through heat accumulation. We designed cooling channels (pores) through the surface of an epoxy-impregnated coil to boost the circulation of LN2 in the coil during the cooling process and to improve the operation of the coil during quenching. In this study, cooling-down and quench tests were performed on the epoxy-impregnated RP coils to investigate the effect of cooling channel on the thermal-quench characteristics of the RP coils. Moreover, the minimum quench energy and normal-zone propagation velocity of the hotspot induced in the coils were discussed on the basis of the quench-test results.
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- 2021
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40. Effects of Heat Treatment on Tribological Behaviour of Al–Si Coated 22MnB5 and SKD61 Tool Steels in Hot Stamping
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Ji, Min-Ki, Son, Hyun Sung, Oh, Jin Keun, Kim, Seong Woo, Alkelae, Fathia, and Jun, Tea-Sung
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- 2024
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41. Qualitative differences in the mindsets associated with dual nature of normative commitment.
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Hyun Sung Oh and Sukanlaya Sawang
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Medicine ,Science - Abstract
This study aims to o uncover how employees' normative commitment (sense of obligation) to their organization is experienced in terms of dual normative commitment (moral imperative or indebted obligation) and to describe the potential for different mindsets arising through the dynamic combination of the various components in the commitment profile. Semi-structured interviews were conducted with 16 participants. The interviews were designed to identify the respondents' perceptions of obligation to their organisation, and their underlying motivational mindset associating with dual nature of normative commitment The interview findings for the affective-normative commitment dominant and the continuance commitment dominant participants were consistent with normative commitment experienced as either moral imperative or an indebted obligation, depending on the relative levels of affective and continuance commitment. All participants irrespective of their commitment profile noted that they had commitment to multiple foci, however, the alignment between commitment to these various foci differed by commitment profile. The qualitative differences among the commitment profiles indicated that the interaction of the commitment components is more complex than current commitment profile propositions suggest and that further theory development beyond the mindsets associated with continuance commitment and affective-normative commitment dominant profiles is required.
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- 2021
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42. Unexpected exposure to Mycobacterium tuberculosis during bronchoscopy using radial probe endobronchial ultrasound.
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Hyun Sung Chung, Soohyun Bae, Insu Kim, Hyo Yeong Ahn, and Jung Seop Eom
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Medicine ,Science - Abstract
BackgroundBronchoscopy using radial probe endobronchial ultrasound (EBUS) is performed when a peripheral lung lesion (PLL) is suspected to be malignant. However, pulmonary tuberculosis is diagnosed in some patients, and healthcare workers could therefore be exposed to tuberculosis if sufficient precautions are not taken. In this study, we examined the proportion of and factors associated with unexpected exposure to Mycobacterium tuberculosis during bronchoscopy using radial probe EBUS.MethodsThis retrospective study included 970 patients who received bronchoscopy using radial probe EBUS between December 2015 and November 2018. Clinical, histological, radiological, and microbiological data were reviewed.ResultsPulmonary tuberculosis was diagnosed in 31 patients (3.2%) during bronchoscopy using radial probe EBUS. Patients with a lower age were significantly more likely to be diagnosed with tuberculosis than elderly patients (odds ratio [OR], 0.951; 95% confidence interval [CI], 0.924-0.978; P = 0.001). Among the various CT findings, a low HUs difference between pre- and post-enhanced CT (OR, 0.976; 95% CI, 0.955-0.996; P = 0.022), the presence of concentric cavitation (OR, 5.211; 95% CI, 1.447-18.759; P = 0.012), and the presence of satellite centrilobular nodules (OR, 22.925; 95% CI, 10.556-49.785; P < 0.001) were independently associated with diagnosis of tuberculosis.ConclusionsThe proportion of unexpected exposure to Mycobacterium tuberculosis during bronchoscopy using radial probe EBUS was 3.2%. A higher risk was independently associated with a younger age and CT findings of a small difference in HUs between pre- and post-enhancement images, concentric cavitation, and the presence of a satellite centrilobular nodule.
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- 2021
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43. TFEB/Mitf links impaired nuclear import to autophagolysosomal dysfunction in C9-ALS
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Kathleen M Cunningham, Kirstin Maulding, Kai Ruan, Mumine Senturk, Jonathan C Grima, Hyun Sung, Zhongyuan Zuo, Helen Song, Junli Gao, Sandeep Dubey, Jeffrey D Rothstein, Ke Zhang, Hugo J Bellen, and Thomas E Lloyd
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autophagy ,nuclear pore ,c9orf72 ,amyotrophic lateral sclerosis ,lysosome ,nucleocytoplasmic transport ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Disrupted nucleocytoplasmic transport (NCT) has been implicated in neurodegenerative disease pathogenesis; however, the mechanisms by which disrupted NCT causes neurodegeneration remain unclear. In a Drosophila screen, we identified ref(2)P/p62, a key regulator of autophagy, as a potent suppressor of neurodegeneration caused by the GGGGCC hexanucleotide repeat expansion (G4C2 HRE) in C9orf72 that causes amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). We found that p62 is increased and forms ubiquitinated aggregates due to decreased autophagic cargo degradation. Immunofluorescence and electron microscopy of Drosophila tissues demonstrate an accumulation of lysosome-like organelles that precedes neurodegeneration. These phenotypes are partially caused by cytoplasmic mislocalization of Mitf/TFEB, a key transcriptional regulator of autophagolysosomal function. Additionally, TFEB is mislocalized and downregulated in human cells expressing GGGGCC repeats and in C9-ALS patient motor cortex. Our data suggest that the C9orf72-HRE impairs Mitf/TFEB nuclear import, thereby disrupting autophagy and exacerbating proteostasis defects in C9-ALS/FTD.
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- 2020
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44. Appendiceal intussusception requiring an ileocecectomy: a case report and comment on the optimal surgery
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Byung-Soo Park, Dong Hoon Shin, Dong-il Kim, Gyung Mo Son, and Hyun Sung Kim
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Intussusception ,Appendix ,Appendiceal neoplasm ,Ileocecectomy ,Laparoscopic surgery ,Surgery ,RD1-811 - Abstract
Abstract Background Appendiceal intussusception is very rare condition with an estimated incidence of 0.01%. Therefore, it is likely to be overlooked. In addition, making the diagnosis before or during surgery is very difficult. Case presentation A 60-year-old male who was referred to our gastroenterology center with cecal inflammation found during a colonoscopy. An abdominal computed tomography (CT) following endoscopy revealed a 5 × 2.5 × 4 cm mass-like lesion in the cecum around the ileocolic (IC) valve and appendiceal orifice. The main lesion seemed to be an inflammatory mass rather than a malignancy because it appeared to be an extraluminal or extramucosal lesion. Ultrasonography revealed diffuse wall thickening of the cecum around the appendiceal orifice that was suspicious for an inflammatory mass or a benign mass. A diagnosis was uncertain. The differential diagnosis included chronic appendicitis, appendiceal neoplasm such as appendiceal mucocele, low grade appendiceal mucinous neoplasm. The patient underwent a laparoscopic partial cecectomy. In the surgical field, there was a large mass in the appendiceal orifice. The cecum was partially resected, with care taken to preserve the IC valve. Final histopathological analysis of the surgical specimen revealed an appendiceal intussusception without any mucosal lesion of the appendix. Narrowing of the terminal ileum with a small bowel obstruction and stenosis of the IC valve occurred postoperatively. Therefore, ileocecectomy was performed via a laparoscopic approach. The patient was discharged 11 days after the second surgery without another significant postoperative complication. Conclusions We report a rare case of appendiceal intussusception that required reoperation due to ileocolic valve stenosis. If the correct diagnosis of appendiceal intussusception is made, we can select an appropriate surgical treatment based on the classification of appendiceal intussusceptions.
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- 2018
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45. Rapid and accurate diagnosis of infection by real-time polymerase chain reaction
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Pil Hun Song, Jung Hwa Min, You Sun Kim, Soo Yeon Jo, Eun Jin Kim, Kyung Jin Lee, Jeonghun Lee, Hyun Sung, Jeong Seop Moon, and Dong Hee Whang
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infection ,Polymerase chain reaction ,Diagnostic method ,Medicine ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Background/AimsThe incidence and severity of Clostridium difficile infection (CDI) have increased worldwide, resulting in a need for rapid and accurate diagnostic methods.MethodsA retrospective study was conducted to compare CDI diagnosis methods between January 2014 and December 2014. The stool samples, which were obtained in presumptive CDI patients, were compared for their diagnostic accuracy and rapidity, including real-time polymerase chain reaction (PCR) of toxin genes, C. difficile toxin assay, and culture for C. difficile.ResultsA total of 207 cases from 116 patients were enrolled in this study and 117 cases (56.5%) were diagnosed as having CDI. Among the 117 cases, the sensitivities of real-time PCR, C. difficile toxin assay, and culture for C. difficile were 87.2% (102 cases; 95% CI, 80.7%–92.8%), 48.7% (57 cases; 95% CI, 41.0%–59.8%), and 65.0% (76 cases; 95% CI, 60.2%–78.5%), respectively (P
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- 2018
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46. A case of ruptured hepatic angiomyolipoma in a young male
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Sun Hwa Kim, Tae Wook Kang, Kyunghee Lim, Hyun Sung Joh, Jiseok Kang, and Dong Hyun Sinn
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Angiomyolipoma ,Liver ,Spontaneous rupture ,Human melanoma black-45 ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
A 31-year-old male visited a local hospital due to sudden-onset severe abdominal pain. Abdominal computed tomography revealed a solid cystic mass with a size of approximately 12 cm and exhibiting both hemorrhage and fluid collection in the pelvic cavity. Emergency angiography and embolization were performed, and a large hepatic tumor was subsequently surgically resected. The tumor cells stained positive for human melanoma black-45 and smooth-muscle actin, and the pathologic diagnosis was hepatic angiomyolipoma. This case report also discusses the spontaneous rupture of a hepatic angiomyolipoma.
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- 2017
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47. Perineal squamous cell carcinoma arising from an epidermal cyst: a case report
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Byung-Soo Park, Dong Hoon Shin, Soo-Hong Kim, Hyuk Jae Jung, Gyung Mo Son, and Hyun Sung Kim
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Squamous cell carcinoma ,Epidermal cyst ,Malignant transformation ,Perineum ,Excision ,Surgery ,RD1-811 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Epidermal cysts and squamous cell carcinomas (SCCs) are common skin lesions. However, a malignant change in an epidermal cyst is very rare. The incidence of a malignant change from an epidermal cyst to cutaneous SCC is 0.011–0.045%. In particular, malignant transformation of an epidermal cyst in the perineum is extremely rare. To date, three cases have been reported in the English literature. Case presentation We report a case of 51-year-old male with an approximately 15-cm perineal mass. This mass started to grow suddenly 4 months previously and caused great discomfort in the perineum due to the large size. The patient underwent excision of the mass with a negative margin. Histopathological analysis confirmed a microinvasive SCC arising from a proliferating epidermoid cyst. Conclusions Even if benign tumors are suspected, a change in size, pain, ulceration, or discharge should indicate the need for surgical resection due to the possibility of a malignant change.
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- 2018
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48. Organizational Commitment Profiles and Turnover Intention: Using a Person-Centered Approach in the Korean Context
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Hyun Sung Oh
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organizational commitment ,latent profiles ,person-centered ,mixture model ,turnover intention ,Psychology ,BF1-990 - Abstract
Extensive research on organizational commitment (OC) profiles has been conducted as researchers recognized that individuals can concurrently experience various levels of OC. Although there is a growing body of research on commitment profiles (CPs) within the past decade, existing empirical research has focused on Western cultural contexts and paid little attention to CPs arising in Asian cultural contexts. The present study utilized a person-centered analytic method (latent profile analysis) to examine the types of CPs among a sample of employees from South Korea (n = 510). From the results emerged six distinct CPs of South Korean employees, and these six profiles exemplified the differing impact of CPs on turnover intentions. Finally, the implications of these results for commitment theory, practice, and future research are discussed.
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- 2019
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49. Carcinoembryonic antigen-positive circulating epithelial cells as a biomarker for the diagnosis and prognosis of colorectal cancer
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Jeon, Hong Jae, Seo, Jin hyuk, Jeong, Euna, Son, Chae Yeon, Rawding, Piper A., Hwang, Yuri, Bang, Seha, Jang, Tae min, Kubiatowicz, Luke J., Hyun, Sung Hee, Hong, Seungpyo, Song, Ik-Chan, Lee, Tae Hee, Bu, Jiyoon, and Eun, Hyuk Soo
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- 2024
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50. Learning with Noisy Labels: Interconnection of Two Expectation-Maximizations
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Kim, Heewon, Chang, Hyun Sung, Cho, Kiho, Lee, Jaeyun, and Han, Bohyung
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Computer Science - Computer Vision and Pattern Recognition - Abstract
Labor-intensive labeling becomes a bottleneck in developing computer vision algorithms based on deep learning. For this reason, dealing with imperfect labels has increasingly gained attention and has become an active field of study. We address learning with noisy labels (LNL) problem, which is formalized as a task of finding a structured manifold in the midst of noisy data. In this framework, we provide a proper objective function and an optimization algorithm based on two expectation-maximization (EM) cycles. The separate networks associated with the two EM cycles collaborate to optimize the objective function, where one model is for distinguishing clean labels from corrupted ones while the other is for refurbishing the corrupted labels. This approach results in a non-collapsing LNL-flywheel model in the end. Experiments show that our algorithm achieves state-of-the-art performance in multiple standard benchmarks with substantial margins under various types of label noise.
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- 2024
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