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Hyun K, Kim JJ, Choi WK, Kim YH, Han SC. Prediction of postoperative final degree and recurrence of pectus excavatum using machine learning algorithms. J Thorac Dis 2024; 16:311-320. [PMID: 38410566 PMCID: PMC10894412 DOI: 10.21037/jtd-23-1430] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 12/01/2023] [Indexed: 02/28/2024]
Abstract
Background Chest wall re-depression after bar removal (BR) in pectus excavatum (PE) is insufficiently investigated. However, it is not easy to investigate chest wall re-depression due to its multifactorial characteristics. Herein, we investigated chest wall re-depression after BR using machine learning algorithms. To the best of my knowledge, this is the first study of chest wall re-depression after BR using machine learning algorithms. Methods We retrospectively reviewed 199 consecutive subjects who underwent both minimally invasive repair of pectus excavatum (MIRPE) and BR at a single hospital from March 2012 to June 2020. We investigated attributes of chest wall re-depression and risk factors for recurrence after BR, predicted final degree and recurrence of PE after BR, and suggested the optimal age at the time of MIRPE based on recurrence. Data for the chest wall re-depression were analyzed to discover differences according to age group [<10 years (early repair group; EG) vs. ≥10 years (late repair group; LG)]. Results We observed no significant difference between the Haller index and radiographical pectus index (RPI) (P=0.431) and a significant correlation between Haller index and RPI (P<0.001). RPI significantly increased for the first 6 months after BR in both age groups (both P<0.001) and was maintained at 1 year after BR. RPI value of the LG were significantly higher than those of the EG for the entire period after MIRPE (P=0.041). Recurrence of PE in the LG was significantly more frequent than in the EG (P<0.001). RPI values before and after MIRPE and age group were identified as independent risk factors for recurrence after BR (P<0.001, P=0.007, and P=0.001, respectively). The linear regression model outperformed for final RPI with performance scores of mean squared error 0.198, root mean squared error 0.445, mean absolute error 0.336, and R2 0.415. In addition, the logistic regression model outperformed for predicting recurrence with performance scores of 0.865 the area under the curve, 0.884 accuracy, 0.859 F1, 0.865 precision, and 0.884 recall. Conclusions The present study shows that machine learning algorithms can provide good estimates for postoperative results in PE. An approach integrating machine learning models and readily available clinical data can be used to create other models in the thoracic surgery field.
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Affiliation(s)
- Kwanyong Hyun
- Department of Thoracic and Cardiovascular Surgery, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Gyeonggi-do, Republic of Korea
| | - Jae Jun Kim
- Department of Thoracic and Cardiovascular Surgery, Uijeongbu St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Gyeonggi-do, Republic of Korea
| | - Won Kyu Choi
- Department of Anesthesiology and Pain Medicine, Uijeongbu St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Gyeonggi-do, Republic of Korea
| | - Yoon Ho Kim
- Department of Anesthesiology and Pain Medicine, Uijeongbu St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Gyeonggi-do, Republic of Korea
| | - Sang Chul Han
- Department of Anesthesiology and Pain Medicine, Uijeongbu St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Gyeonggi-do, Republic of Korea
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Kim DK, Lim HS, Eun KM, Seo Y, Kim JK, Kim YS, Kim MK, Jin S, Han SC, Kim DW. Subepithelial neutrophil infiltration as a predictor of the surgical outcome of chronic rhinosinusitis with nasal polyps. Rhinology 2021; 59:173-180. [PMID: 33129200 DOI: 10.4193/rhin20.373] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Neutrophils present as major inflammatory cells in refractory chronic rhinosinusitis with nasal polyps (CRSwNP), regardless of the endotype. However, their role in the pathophysiology of CRSwNP remains poorly understood. We investigated factors predicting the surgical outcomes of CRSwNP patients with focus on neutrophilic localization. METHODS We employed machine-learning methods such as the decision tree and random forest models to predict the surgical outcomes of CRSwNP. Immunofluorescence analysis was conducted to detect human neutrophil elastase (HNE), Bcl-2, and Ki-67 in NP tissues. We counted the immunofluorescence-positive cells and divided them into three groups based on the infiltrated area, namely, epithelial, subepithelial, and perivascular groups. RESULTS On machine learning, the decision tree algorithm demonstrated that the number of subepithelial HNE-positive cells, Lund-Mackay (LM) scores, and endotype (eosinophilic or non-eosinophilic) were the most important predictors of surgical outcomes in CRSwNP patients. Additionally, the random forest algorithm showed that, after ranking the mean decrease in the Gini index or the accuracy of each factor, the top three ranking factors associated with surgical outcomes were the LM score, age, and number of subepithelial HNE-positive cells. In terms of cellular proliferation, immunofluorescence analysis revealed that Ki-67/HNE-double positive and Bcl-2/HNE-double positive cells were significantly increased in the subepithelial area in refractory CRSwNP. CONCLUSION Our machine-learning approach and immunofluorescence analysis demonstrated that subepithelial neutrophils in NP tissues had a high expression of Ki-67 and could serve as a cellular biomarker for predicting surgical outcomes in CRSwNP patients.
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Affiliation(s)
- D-K Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Chuncheon Sacred Heart Hospital and Institute of New Frontier Research, Hallym University College of Medicine, Chuncheon, Republic of Korea; Division of Big Data and Artificial Intelligence, Hallym University College of Medicine, Chuncheon, Republic of Korea
| | - H-S Lim
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - K M Eun
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Y Seo
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - J K Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Y S Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - M-K Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - S Jin
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - S C Han
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - D W Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul National University College of Medicine, Seoul, Republic of Korea
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Khaki M, Hendricks Franssen HJ, Han SC. Multi-mission satellite remote sensing data for improving land hydrological models via data assimilation. Sci Rep 2020; 10:18791. [PMID: 33139783 PMCID: PMC7608680 DOI: 10.1038/s41598-020-75710-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [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: 05/20/2020] [Accepted: 09/17/2020] [Indexed: 11/21/2022] Open
Abstract
Satellite remote sensing offers valuable tools to study Earth and hydrological processes and improve land surface models. This is essential to improve the quality of model predictions, which are affected by various factors such as erroneous input data, the uncertainty of model forcings, and parameter uncertainties. Abundant datasets from multi-mission satellite remote sensing during recent years have provided an opportunity to improve not only the model estimates but also model parameters through a parameter estimation process. This study utilises multiple datasets from satellite remote sensing including soil moisture from Soil Moisture and Ocean Salinity Mission and Advanced Microwave Scanning Radiometer Earth Observing System, terrestrial water storage from the Gravity Recovery And Climate Experiment, and leaf area index from Advanced Very-High-Resolution Radiometer to estimate model parameters. This is done using the recently proposed assimilation method, unsupervised weak constrained ensemble Kalman filter (UWCEnKF). UWCEnKF applies a dual scheme to separately update the state and parameters using two interactive EnKF filters followed by a water balance constraint enforcement. The performance of multivariate data assimilation is evaluated against various independent data over different time periods over two different basins including the Murray–Darling and Mississippi basins. Results indicate that simultaneous assimilation of multiple satellite products combined with parameter estimation strongly improves model predictions compared with single satellite products and/or state estimation alone. This improvement is achieved not only during the parameter estimation period (\documentclass[12pt]{minimal}
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Affiliation(s)
- M Khaki
- School of Engineering, University of Newcastle, Callaghan, NSW, Australia.
| | | | - S C Han
- School of Engineering, University of Newcastle, Callaghan, NSW, Australia
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Lee H, Kim YS, Cho HJ, Oh S, Shim J, Nam Y, Sohn SH, Jung YC, Han SC, Lee SY. Evaluation of Icephobic and Dissipation Performance on Coating Materials for Preventing Overhead Transmission Line from Ice/Snow Damages. pk 2020. [DOI: 10.7317/pk.2020.44.3.342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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He SL, Yu J, Gou YJ, Bai QZ, Ma JL, Han SC, Jin DC, Chen M. [Anterior mediastinal chondrosarcoma: a case report]. Zhonghua Zhong Liu Za Zhi 2019; 41:479-480. [PMID: 31216838 DOI: 10.3760/cma.j.issn.0253-3766.2019.06.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- S L He
- The First Department of Thoracic Surgery, Gansu Provincial Hospital, Lanzhou 730000, China
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Park DW, An JH, Han SC, Lee J, Lee HS, Seo JT. Effects of feminine cleanser Inclear on sperm motility: A prospective study. Clin Exp Reprod Med 2015; 41:165-7. [PMID: 25599039 PMCID: PMC4295943 DOI: 10.5653/cerm.2014.41.4.165] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 10/15/2014] [Accepted: 10/23/2014] [Indexed: 11/06/2022] Open
Abstract
Objective The objective of this study is to estimate the effects of Inclear, a feminine cleanser, on sperm motility. Methods Semen samples were obtained from infertile male patients. Following liquefaction, the raw semen samples were diluted with Ham's F-10 nutrient mixture medium containing 0.4% human serum albumin solution at a ratio of 1:3. The semen samples were subsequently centrifuged to separate the seminal plasma from the serum. The supernatant was discarded, and the pellet was resuspended. The sample was again centrifuged to remove cell debris, and the supernatant was removed. The final pellet was gently loosened by resuspension and incubated in medium alone as a control, and in a 10% solution of the medium plus Inclear. A sampling time of 30 minutes was selected on the basis of sperm transport studies. Sperm motility was evaluated with computer-assisted sperm analysis. Results A total of 20 samples were analyzed. The mean age of patients was 34.40±2.96 years. There was no difference in sperm concentration and motility in the two samples at 0 minute and 30 minutes of incubation. In both semen samples, the sperm concentration and motility decreased after an incubation period of 30 minutes. However, there was no statistical difference between the samples. Sperm concentration and motility were not significantly different between the control and Inclear samples after 0 minute and 30 minutes of incubation. Conclusion Inclear has no negative effects on sperm motility. This product can be recommended to pregnancy planners for vaginal hygiene and as a vaginal lubricant.
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Affiliation(s)
- Dong-Wook Park
- Laboratory of Reproductive Medicine, Cheil General Hospital and Women's Healthcare Center, Catholic Kwandong University College of Medicine, Seoul, Korea
| | - Jin Hee An
- Laboratory of Reproductive Medicine, Cheil General Hospital and Women's Healthcare Center, Catholic Kwandong University College of Medicine, Seoul, Korea
| | - Sang Chul Han
- Laboratory of Reproductive Medicine, Cheil General Hospital and Women's Healthcare Center, Catholic Kwandong University College of Medicine, Seoul, Korea
| | | | - Hyo Serk Lee
- Department of Urology, Cheil General Hospital and Women's Healthcare Center, Catholic Kwandong University College of Medicine, Seoul, Korea
| | - Ju Tae Seo
- Department of Urology, Cheil General Hospital and Women's Healthcare Center, Catholic Kwandong University College of Medicine, Seoul, Korea
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Kim SW, Han SC, Kim CY, Kim JT, Kim YH. Reconstruction of chronic osteomyelitis of the nose using a thin latissimus dorsi perforator flap. J Craniofac Surg 2014; 23:e617-9. [PMID: 23172498 DOI: 10.1097/scs.0b013e31826cf878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Osteomyelitis is an acute or chronic inflammatory process that occurs in bone. Although cranial bones are rarely involved, timely diagnosis and early treatment are mandatory because of its proximity to critical neurovascular structures and aesthetic considerations.A 57-year-old woman, who had a comminuted open nasal bone fracture 20 years ago, presented a firm, painful swelling nose. Whole-body bone scan images indicated increased uptake of the nasal bone, which was suspected to be osteomyelitis. After debridement, the nose was reconstructed with a thin latissimus dorsi perforator flap.In this article, we report a rare case of chronic osteomyelitis of the nose and provide a brief review of the literature. It is important for clinicians to consider osteomyelitis for early diagnosis and treatment.
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Affiliation(s)
- Sang-Wha Kim
- Department of Plastic and Reconstructive Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea
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Kim SW, Han SC, Hwang KT, Ahn BK, Kim JT, Kim YH. Reconstruction of infected abdominal wall defects using latissimus dorsi free flap. ANZ J Surg 2012; 83:948-53. [PMID: 23009209 DOI: 10.1111/j.1445-2197.2012.06286.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2012] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Infected abdominal defects are a challenge to surgeons. In this study, we describe 10 cases in which the latissimus dorsi myocutaneous flap was used for successful reconstruction of abdominal wall defects severely infected with methicillin-resistant Staphylococcus aureus (MRSA). METHODS Retrospective review of 10 patients with abdominal wall defects that were reconstructed using the latissimus dorsi myocutaneous flap between 2002 and 2010. All patients had abdominal defects with hernias, combined with MRSA infections. The sizes of the flaps ranged from 120 to 364 cm(2) . The deep inferior epigastric artery was the recipient vessel in nine patients and the internal mammary vessels were used for one patient. RESULTS There were no complications relating to the flaps, although there were other minor complications including wound dehiscence, haematoma and fluid correction. After reconstruction, there were no signs of infection during follow-up periods, and the patients were satisfied with the final results. CONCLUSION Reconstruction using the latissimus dorsi myocutaneous flap, including muscle fascia structures, is a potential treatment option for severely infected large abdominal wall defects.
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Affiliation(s)
- Sang Wha Kim
- Department of Plastic and Reconstructive Surgery, College of Medicine, Catholic University, Seoul, Korea
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Li JL, Han SC, Yoo ES, Shin S, Hong J, Cui Z, Li H, Jung JH. Anti-inflammatory amino acid derivatives from the ascidian Herdmania momus. J Nat Prod 2011; 74:1792-7. [PMID: 21770369 DOI: 10.1021/np200397g] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Four new amino acid derivatives, herdmanines A-D (1-4), were isolated from the marine ascidian Herdmania momus. Herdmanines A-C contain the unusual D-form of arginine. Compounds 3 and 4 had a moderate suppressive effect on the production of NO, with IC₅₀ values of 96 and 9 μM, respectively. These compounds were found to inhibit the mRNA expression of iNOS. The inhibitory activities on the production and mRNA expression of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6 were evaluated.
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Affiliation(s)
- Jian Lin Li
- College of Pharmacy, Pusan National University, Busan 609-735, Korea
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Youn JS, Cha SH, Park CW, Yang KM, Kim JY, Koong MK, Kang IS, Song IO, Han SC. Predictive value of sperm motility characteristics assessed by computer-assisted sperm analysis in intrauterine insemination with superovulation in couples with unexplained infertility. Clin Exp Reprod Med 2011; 38:47-52. [PMID: 22384418 PMCID: PMC3283051 DOI: 10.5653/cerm.2011.38.1.47] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 02/11/2011] [Accepted: 02/18/2011] [Indexed: 11/26/2022] Open
Abstract
Objective To determine whether characteristics of sperm motility obtained by computer-assisted sperm analysis (CASA) could predict pregnancy after intrauterine insemination (IUI) in couples with unexplained infertility. Methods Three hundred eighty-three cycles of intrauterine insemination with superovulation were retrospectively analyzed. Semen analysis was performed with CASA before and after swim-up and the parameters were compared between pregnant and non-pregnant women. Results The pregnancy rate per cycle was 14.1%. Pregnant and non-pregnant women were comparable in terms of age, infertility duration, the number of dominant follicles. While sperm concentration, motility, and parameters such as average path velocity (VAP) and percentage rapid (RAPID) before semen preparation were significantly different between the pregnancy and non-pregnancy groups, there were no differences in sperm parameters when comparing the two groups after preparation. Using a receiver operating characteristic curve to measure sensitivity and specificity, the optimal threshold value for the predictors of pregnancy was revealed to be a concentration of ≥111×106/mL, a motility of ≥51.4%, and RAPID ≥30.1% before preparation for IUI. Conclusion Sperm parameters including concentration, motility, and RAPID before sperm preparation could have predictive value for pregnancy outcome after intrauterine insemination with superovulation in couples with unexplained infertility, and would be helpful when counseling patients before they make the decision to proceed with IVF/ICSI-ET.
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Affiliation(s)
- Joung Sub Youn
- Department of Obstetrics and Gynecology, Clinic of Dr. Min, Cheongju, Korea
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Ogay V, Min F, Kim K, Kim J, Bae KH, Han SC, Soh KS. Observation of Coiled Blood Plexus in Rat Skin with Diffusive Light Illumination. J Acupunct Meridian Stud 2009; 2:56-65. [PMID: 20633475 DOI: 10.1016/s2005-2901(09)60016-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Accepted: 01/12/2009] [Indexed: 10/20/2022] Open
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Han SC, Choo KH, Choi SJ, Benjamin MM. Removal of manganese from water using combined chelation/membrane separation systems. Water Sci Technol 2005; 51:349-55. [PMID: 16003996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The addition of the chelating polymer polyacrylic acid (PAA) to assist in the removal of manganese from groundwater by membranes was investigated using membranes with different pore sizes under various operating conditions. Negligible manganese removal was achieved with the UF and NF membranes at acidic pH values, but removals exceeding 90% could be achieved at elevated pH (pH 9), presumably due to the formation of manganese hydroxides. Mn removal increased substantially when PAA was added to the feed solution, due to chelation of Mn by the PAA and rejection of the chelates by the membranes. The chelate could be broken at acidic pH, releasing free PAA that could then be separated from the Mn ions and reused. Smaller PAA molecules were lost in the first regeneration cycle, but negligible PAA was lost in subsequent cycles. In the systems with PAA, nitrate ions were rejected more efficiently than in the PAA-free systems, presumably because of electrical repulsion between nitrate ions and PAA sorbed on the membrane surface. With increasing PAA dose, the volumetric flux first decreased and then increased; the latter result was accompanied by a change in the physical-chemical form of the polymers, as indicated by an increase in turbidity.
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Affiliation(s)
- S C Han
- Department of Environmental Engineering, Kyungpook National University, Daegu 702-701, Korea
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Hyun MH, Lee GS, Han SC, Cho YJ. Liquid chromatographic resolution of biphenyl dimethyl dicarboxylate (DDB) and its analogues on a chiral stationary phase. Enantiomer 2002; 6:313-8. [PMID: 11762927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Racemic biphenyl dimethyl dicarboxylate (DDB) and its analogues have been successfully resolved on a commercial HPLC chiral column, (3R,4S)-Whelk-O 1. In general, cyclic amide analogues of DDB, which were derived from pyrrolidine or piperidine, showed greater enantioselectivity and greater retention than the corresponding N,N-dialkyl amide or N-alkyl amide or ester analogues. From these results, it was concluded that the carbonyl oxygen of the DDB analogues plays an important role as a hydrogen bond acceptor, though the steric bulkiness of the amide functionality of DDB analogues may be another factor governing chiral recognition. The conformational stability of the two enantiomers of DDB and its analogues was also found to be high enough for the two enantiomers to be resolvable on (3R,4S)-Whelk-O 1.
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Affiliation(s)
- M H Hyun
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Republic of Korea.
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Abstract
A new high-performance liquid chromatographic chiral stationary phase (CSP) was prepared from (S)-N-(3,5-dimethylbenzoyl)leucine N-phenyl N-allyl amide. The new CSP was applied for the resolution of N-(3,5-dinitrobenzoyl)-alpha-amino amides and esters and the chromatographic resolution results were compared with those on another CSP derived from (S)-N-(3,5-dimethoxylbenzoyl)leucine N-phenyl N-allyl amide. The new CSP was found to exert greater enantioselectivity than the other one. These results are contrary to what was expected from the reciprocity of chiral recognition. From these results it was concluded that the reciprocity of chiral recognition should be used with some degree of care in developing effective CSPs or in predicting chromatographic resolution behaviors.
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Affiliation(s)
- M H Hyun
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, South Korea.
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Hyun MH, Han SC, Lipshutz BH, Shin YJ, Welch CJ. New chiral crown ether stationary phase for the liquid chromatographic resolution of alpha-amino acid enantiomers. J Chromatogr A 2001; 910:359-65. [PMID: 11261730 DOI: 10.1016/s0021-9673(00)01230-9] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A new chiral stationary phase (CSP) for the liquid chromatographic separation of enantiomers was prepared by bonding a novel enantiopure (diphenyl-substituted 1,1'-binaphthyl) crown ether to 5 microm silica gel. The resulting CSP was applied to the separation of the enantiomers of various natural and unnatural alpha-amino acids. All alpha-amino acids tested were resolved very well on the new CSP, with the exception of proline, which does not contain a primary amino group. The resolution of alpha-amino acid enantiomers on this new CSP was found to be dependent on the type and amounts of organic and acidic modifiers, and on column temperature.
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Affiliation(s)
- M H Hyun
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, South Korea.
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Hyun MH, Koo HJ, Lee GS, Han SC. Effect of the double bond pi-conjugation of the aromatic group of racemic analytes on the liquid chromatographic separation of enantiomers. Enantiomer 2001; 5:499-503. [PMID: 11143813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Various arylcarbinol esters were resolved on a commercial chiral column, (S, S) Whelk-O1. Among others, the analytes in which the aryl group is in conjugation with the double bond(s) to the chiral center were resolved much better on (S, S) Whelk-O1 than the corresponding non-double bonded analytes. From these results, it was proposed that the double bond pi-conjugation of the aromatic group of racemic analytes is very important for the chiral recognition. In addition, the size of the acyl group of arylcarbinol esters has been demonstrated to be important for the chiral recognition. In general, the large acyl group such as pivaloyl group was very effective for the chiral recognition of arylcarbinol esters on (S, S) Whelk-O1.
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Affiliation(s)
- M H Hyun
- Department of Chemistry, Chemistry Institute for Functional Materials, Pusan National University, Pusan 609-735, Republic of Korea.
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Abstract
We propose a motion-compensated video coding system employing dense motion fields. The dense motion field is calculated at the transmitter, and the motion information is efficiently encoded and transmitted along with the residual frame. The motion estimation is performed by existing techniques in the literature, while we focus on the coding of the motion field and the displaced frame difference (DFD) frame. The dense motion field formulation leads to several novel and distinct advantages. The motion field is encoded in a lossy manner to make the motion rate manageable. The more accurate and precise motion description allows us to predict where the DFD energy will be significant, thus leading to a more efficient DFD encoder compared to applying traditional still-image coding techniques. Furthermore, the dense motion field framework allows us to refine and tailor the motion estimation process such that the resulting DFD frame is easier to encode. Simulations demonstrate superior performance against standard block-based coders, with greater advantages for sequences with more complex motion.
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Affiliation(s)
- S C Han
- C-Cube Microsystems, Milpitas, CA 95132, USA.
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Han SC, Kim DH, Higgins SA, Carcangiu ML, Kacinski BM. Chemoradiation as primary or adjuvant treatment for locally advanced carcinoma of the vulva. Int J Radiat Oncol Biol Phys 2000; 47:1235-44. [PMID: 10889377 DOI: 10.1016/s0360-3016(00)00569-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE To determine the impact of primary or adjuvant chemotherapy and radiation (CRT) on the survival rates of patients with locally advanced vulvar carcinoma. METHODS AND MATERIALS Between 1973 and 1998, 54 patients with vulvar cancer were treated with radiation therapy, among which 20 received CRT, while 34 patients received radiation therapy (RT) alone. Of the 20 patients, 14 were treated for primary or recurrent disease (pCRT), and 6 after radical vulvectomy for high-risk disease (aCRT). Of the 34 patients, 12 were treated primarily (pRT) and 22 received adjuvant treatment (aRT). Chemotherapy consisted of 2 courses of 5-fluorouracil (5-FU) and mitomycin C administered during RT. Six patients received cisplatin in place of mitomycin C. In CRT groups, radiation was administered to the vulva, pelvic, and inguinal lymph nodes to a median dose of 45 Gy with additional 6-17 Gy to gross disease. In RT groups, the median dose to the microscopic diseases was 45 Gy. Nine patients received external beam boost and 16 patients received supplementary brachytherapy in the forms of (226)Ra or (241)Am plaques to sites of macroscopic disease. RESULTS Overall survival was superior in the patients treated with pCRT versus pRT with statistical significance (p = 0.04). There was also a statistically significant improvement in disease-specific (p = 0.03) and relapse-free survival (p = 0.01) favoring pCRT. No statistically significant trends of improved survival rates favoring aCRT over aRT were observed. CONCLUSION Concurrent radiation therapy and chemotherapy decreases local relapse rate, improves disease-specific and overall survival over RT alone as primary treatment for locally advanced vulvar cancer.
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Affiliation(s)
- S C Han
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520-8040, USA
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Abstract
Enantiomers of racemic 2-hydroxycarboxylic acids have been resolved as their O-ethoxycarbonyl pi-basic anilide derivatives on a new chiral stationary phase (CSP) derived from N-(3,5-dinitrobenzoyl)leucine N-phenyl N-alkylamide and the resolution results have been compared with those on various commercial pi-acidic CSPs. The resolution results demonstrate that the new CSP derived from N-(3,5-dinitrobenzoyl)leucine N-phenyl N-alkylamide is most effective among the five CSPs tested for the resolution of 2-hydroxycarboxylic acid derivatives. In order to elucidate the chiral recognition mechanism exerted by the new CSP, the resolution of slightly differently modified derivatives of 2-hydroxycarboxylic acids on the new CSP has been investigated. Based on the resolution results, a chiral recognition mechanism utilizing three simultaneous interactions such as the face to face pi-pi interaction and the two hydrogen bonding interactions between the CSP and the more retained enantiomer of the analyte has been proposed.
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Affiliation(s)
- M H Hyun
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, South Korea
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Abstract
PURPOSE Epithelial permeability to fluorescein (Pdc) increases with closed-eye soft contact lens wear. Possible mechanisms responsible for this change include corneal hypoxia (and acidosis) during overnight wear and interference of the lens with normal tear exchange. In this study we used a local environmental chamber to examine the effects of hypoxia on Pdc. METHODS After baseline slit-lamp examination, autofluorescence, and central corneal thickness measurements, 35 subjects were fitted with a pair of airtight swimming goggles. One eye was exposed to a humidified gas mixture containing 95% nitrogen (N2) and 5% carbon dioxide (CO2), and the fellow (control) eye was exposed to air. The experimental eye and the eye measured first were assigned using a randomized block design. After the subjects wore the goggles for 1 hour, corneal thickness measurements were repeated and Pdc was assessed as previously described. A final slit-lamp examination was performed by a masked examiner to assess epithelial integrity. RESULTS There was no significant difference in the mean ln(Pdc) (95% confidence interval) for eyes exposed to N2/CO2 when compared with paired eyes exposed to air (-2.70 [-2.99, -2.41] vs -2.51 [-2.72, -2.30] ln[nm/sec], P = .272). Although there was also no substantial difference in the slit-lamp appearance of the experimental and control eyes, the mean (95% confidence interval) change in corneal thickness for the hypoxic eyes was 19.78 (15.72, 23.84) microm compared with 3.40 (-0.67, 7.47) microm (P < .0001) in the control eyes. CONCLUSION One hour of hypoxia caused a significant increase in corneal thickness with no apparent change in Pdc. This suggests that other factors, either alone or in combination with hypoxia, may be responsible for increased Pdc during closed-eye contact lens wear.
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Affiliation(s)
- N A McNamara
- Morton D. Sarver Laboratory for Cornea and Contact Lens Research, School of Optometry, University of California, Berkeley 94720-2020, USA.
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Abstract
BACKGROUND AND OBJECTIVES Myofascial pain syndrome (MPS) is a common condition often resulting in referral to a pain clinic. The epidemiology, pathogenesis, and various diagnostic tools are reviewed, and a variety of treatment methods are discussed. METHODS Extensive periodical literature and textbooks are reviewed, and selected manuscripts are critically analyzed. RESULTS The incidence of MPS with associated trigger points appears to vary between 30 and 85% of people presenting to pain clinics, and the condition is more prevalent in women than in men. Patients complain of regional persistent pain, ranging in intensity and most frequently found in the head, neck, shoulders, extremities, and low back. Muscle histologic abnormalities have been described in some studies. Similarly, electromyographic, thermographic, and pressure algometric studies have inconsistently identified abnormalities. A multidisciplinary approach to treatment appears to be most beneficial and may include such modalities as trigger-point injections, dry needling, stretch and spray, and transcutaneous electrical nerve stimulation. CONCLUSIONS The definitive pathogenesis of MPS is currently unknown, and no single diagnostic method is consistently positive. While trigger-point injection is the most widely employed method of treatment, other modes of therapy have also proved to be effective.
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Affiliation(s)
- S C Han
- Department of Anesthesiology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
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Han SC, Lieuze D, Mougin O. [Emergency situations in visceral surgery]. Rev Infirm 1996:25-30. [PMID: 8900656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Chao TY, Han SC, Nieh S, Lan GY, Lee SH. Diagnosis of primary cardiac lymphoma. Report of a case with cytologic examination of pericardial fluid and imprints of transvenously biopsied intracardiac tissue. Acta Cytol 1995; 39:955-9. [PMID: 7571977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Primary cardiac lymphoma (PCL) is a treatable disease when appropriately diagnosed. Therefore, a prompt, safe method with high diagnostic accuracy is prerequisite to successful therapy for PCL. CASE A 57-year-old male presented with exertional dyspnea and atrial fibrillations. A pericardial effusion (PE) and several tumor masses occupying both atria were found. Cytologic examinations of PE and of imprints of the tissues obtained by transvenous biopsy of the cardiac tumors revealed numerous small, round tumor cells and lymphoglandular bodies, suggestive of malignant lymphoma. This cytologic impression was confirmed by immunocytochemical studies on the same cytologic material. Histologic studies reaffirmed the diagnosis of B-cell lymphoma. The patient received eight courses of chemotherapy, with complete remission of the illness. CONCLUSION Cardiac lymphoma can be quickly and safely diagnosed by cytologic examination of PE or transvenously biopsied cardiac tissue, with confirmation by immunocytochemical studies. Exploratory thoracotomy for biopsy can be avoided.
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Affiliation(s)
- T Y Chao
- Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
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Rosenthal AF, Chodsky SV, Han SC. Diether phosphinate lecithin: chemical synthesis and effects on phospholipase C. Biochim Biophys Acta 1969; 187:385-92. [PMID: 4310716 DOI: 10.1016/0005-2760(69)90012-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Rosenthal AF, Han SC. A simple nonchromatographic determination of glycerophosphatide in serum. Clin Chem 1969; 15:197-203. [PMID: 4304286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Rosenthal AF, Han SC. Phosphorus determination in phosphoglycerides from thin-layer chromatograms. J Lipid Res 1969; 10:243-5. [PMID: 4305714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Phosphoglyceride phosphorus is readily determined directly on silica gel removed from thin-layer chromatograms, without elution, by a nondigestive procedure with a sulfuric-periodic acid reagent. The method is specific for hydrolyzable phosphoglyceride containing two acid-hydrolyzable groups. Cariolipin reacts only partially, while sphingomyelin, diether lecithin, and phosphonate cephalin fail completely to react.
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Pogodina VV, Han SC. [Study of the correlation between the pathogenicity of tick-borne encephalitis viruses for animals and peculiarities of their growth in the organism. 2. Demonstration by the fluorescent antibody method of noninfectious virus antigens in the organs of animals infected by the Malaya Langat (TP-21) virus]. Vopr Virusol 1965; 10:30-6. [PMID: 5325010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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