300 results on '"Myung, Woo"'
Search Results
2. Complexation of drug and hapten-conjugated aptamer with universal hapten antibody for pancreatic cancer treatment
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Sun Il Choi, Yu-Sun Lee, Yul Min Lee, Hyun Jung Kim, Won Jong Kim, Sungjin Jung, Ji Eun Im, Mi Rim Lee, Joon Ki Kim, A-Ra Jeon, Sang Myung Woo, Goo Taeg Oh, Kyun Heo, Yun-Hee Kim, and In-Hoo Kim
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Pharmaceutical Science - Published
- 2023
3. Neural message-passing for objective-based uncertainty quantification and optimal experimental design
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Qihua Chen, Xuejin Chen, Hyun-Myung Woo, and Byung-Jun Yoon
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FOS: Computer and information sciences ,Computer Science - Machine Learning ,Optimization and Control (math.OC) ,Artificial Intelligence ,Control and Systems Engineering ,FOS: Mathematics ,Electrical and Electronic Engineering ,Mathematics - Optimization and Control ,Machine Learning (cs.LG) - Abstract
Various real-world scientific applications involve the mathematical modeling of complex uncertain systems with numerous unknown parameters. Accurate parameter estimation is often practically infeasible in such systems, as the available training data may be insufficient and the cost of acquiring additional data may be high. In such cases, based on a Bayesian paradigm, we can design robust operators retaining the best overall performance across all possible models and design optimal experiments that can effectively reduce uncertainty to enhance the performance of such operators maximally. While objective-based uncertainty quantification (objective-UQ) based on MOCU (mean objective cost of uncertainty) provides an effective means for quantifying uncertainty in complex systems, the high computational cost of estimating MOCU has been a challenge in applying it to real-world scientific/engineering problems. In this work, we propose a novel scheme to reduce the computational cost for objective-UQ via MOCU based on a data-driven approach. We adopt a neural message-passing model for surrogate modeling, incorporating a novel axiomatic constraint loss that penalizes an increase in the estimated system uncertainty. As an illustrative example, we consider the optimal experimental design (OED) problem for uncertain Kuramoto models, where the goal is to predict the experiments that can most effectively enhance robust synchronization performance through uncertainty reduction. We show that our proposed approach can accelerate MOCU-based OED by four to five orders of magnitude, without any visible performance loss compared to the state-of-the-art. The proposed approach applies to general OED tasks, beyond the Kuramoto model., Comment: 14 pages, 5 figures, accepted by Engineering Applications of Artificial Intelligence
- Published
- 2023
4. DNA aptamer immobilized hydroxyapatite for enhancing angiogenesis and bone regeneration
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Heung-Myung Woo, Byung-Jae Kang, Hojeong Jeon, Youngmin Seo, Junhyung Kim, Jaewoo Son, Jangsun Hwang, Jonghoon Choi, Kyungwoo Lee, Ho Chang Kang, and Yonghyun Choi
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Male ,Vascular Endothelial Growth Factor A ,Bone Regeneration ,Angiogenesis ,Aptamer ,Static Electricity ,0206 medical engineering ,Immobilized Nucleic Acids ,Biomedical Engineering ,Neovascularization, Physiologic ,Biocompatible Materials ,02 engineering and technology ,Biochemistry ,Bone and Bones ,Biomaterials ,chemistry.chemical_compound ,Osteogenesis ,In vivo ,Spectroscopy, Fourier Transform Infrared ,Human Umbilical Vein Endothelial Cells ,medicine ,Animals ,Humans ,Bone regeneration ,Molecular Biology ,Cell Proliferation ,Bone mineral ,Osteoblasts ,X-Ray Microtomography ,General Medicine ,Aptamers, Nucleotide ,021001 nanoscience & nanotechnology ,020601 biomedical engineering ,Cell biology ,Vascular endothelial growth factor ,Cross-Linking Reagents ,Durapatite ,medicine.anatomical_structure ,Microscopy, Fluorescence ,chemistry ,Cortical bone ,Human umbilical vein endothelial cell ,Rabbits ,0210 nano-technology ,Signal Transduction ,Biotechnology - Abstract
In this study, we developed aptamer-conjugated hydroxyapatite (Apt-HA) that promotes bone regeneration and angiogenesis. The 3R02 bivalent aptamer specific to vascular endothelial growth factor (VEGF) was grafted to the hydroxyapatite (HA) surface. Apt-HA was tested for its VEGF protein capture ability to determine the optimal aptamer concentration immobilized on the HA. Apt-HA showed higher VEGF protein capture ability, and faster growth of human umbilical vein endothelial cell (HUVEC) compared to a neat HA with no cytotoxic effects on human osteoblasts. To examine in vivo angiogenesis and bone regeneration, Apt-HA and HA were bilaterally implanted into rabbit tibial metaphyseal defects and analyzed after eight weeks using micro-CT, histology, and histomorphometry. Apt-HA showed significantly increased the volume of new bones, the percentage of bone, and the density of bone mineral in cortical bone. Apt-HA also exhibited the enhanced bone formation at the cortical region in a histomorphometric analysis. Finally, Apt-HA showed significantly increased blood vessel number compared to a neat HA. In summary, the engineered Apt-HA has potential as a bone graft material that may simultaneously promote bone regeneration and angiogenesis. STATEMENT OF SIGNIFICANCE: This work presents a functional hydroxyapatite bone graft using a DNA-based aptamer which overcomes the limitations of existing bone graft materials, which use bound signaling peptides. DNA aptamer immobilized hydroxyapatite enhances the in vitro proliferation of human umbilical vascular endothelial cells as well as in vivo angiogenesis and bone regeneration. DNA aptamer immobilized hydroxyapatite shows no cytotoxic effect on human osteoblasts.
- Published
- 2019
5. Mechanical, electrical, and thermal reliability of Sn-58wt.%Bi solder joints with Ag-decorated MWCNT for LED package component during aging treatment
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Park, Bum-Geun, primary, Myung, Woo-Ram, additional, Lee, Choong-Jae, additional, and Jung, Seung-Boo, additional
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- 2020
- Full Text
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6. Sa1435 A PROSPECTIVE, MULTI-CENTER, COMPARATIVE STUDY TO EVALUATE A NEW NEEDLE (CLEARTIPTM) IN EUS-TS FOR PANCREATIC SOLID LESIONS
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Tae Hyeon Kim, Chang-Min Cho, Sang Hyub Lee, Park Changhwan, Eunae Cho, Jun-Ho Choi, Jae Hee Cho, Dong Wook Lee, Tae Jun Song, Sang Myung Woo, Kwang Hyuck Lee, Jong Jin Hyun, Se Woo Park, and Seong Hun Kim
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medicine.medical_specialty ,business.industry ,Gastroenterology ,medicine ,Radiology, Nuclear Medicine and imaging ,Center (algebra and category theory) ,Radiology ,business - Published
- 2020
7. Efficacy of pancreatic exocrine replacement therapy for patients with unresectable pancreatic cancer in a randomized trial
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Young Hwan Koh, Yun-Hee Kim, Tae Hyun Kim, Woojin Lee, Sang-Jae Park, Sung-Sik Han, Seung Hyun Chung, Jungnam Joo, Hae Moon, So Young Kim, Sang Myung Woo, and Eun Kyung Hong
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Adult ,Male ,medicine.medical_specialty ,Hormone Replacement Therapy ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Placebo ,Gastroenterology ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Double-Blind Method ,Randomized controlled trial ,Weight loss ,law ,Pancreatic cancer ,Pancrelipase ,Internal medicine ,Weight Loss ,medicine ,Clinical endpoint ,Humans ,Prospective Studies ,Prospective cohort study ,Aged ,Hepatology ,business.industry ,Body Weight ,Hormone replacement therapy (menopause) ,Middle Aged ,medicine.disease ,Survival Analysis ,Pancreas, Exocrine ,Pancreatic Neoplasms ,Treatment Outcome ,030220 oncology & carcinogenesis ,Pancreatin ,Quality of Life ,Female ,030211 gastroenterology & hepatology ,medicine.symptom ,business - Abstract
Background Weight loss in pancreatic cancer is associated with maldigestion due to pancreatic duct obstruction. Pancreatic exocrine replacement therapy (PERT) may significantly improve fat and protein absorption. Objectives This prospective, double-blind, randomized, placebo-controlled phase II trial assessed whether PERT could reduce or prevent weight loss in patients with unresectable pancreatic cancer. Methods Sixty seven patients with unresectable pancreatic cancer were randomized to receive enteric coated PERT, consisting of 6–9 capsules of pancreatin (457.7 mg/capsule), or placebo. Patients took two capsules each three times daily during main meals and one capsule each up to three times daily when having between-meal snacks. The primary endpoint was the percentage change in body weight at eight weeks. Results The mean percentage change in body weight (1.49% [1.12 kg] vs. 2.99% [1.63 kg], P = 0.381) and the mean percent change in Patient-Generated Subjective Global Assessment (PG-SGA) score (8.85% vs. 15.69%, p = 0.18) did not differ significantly between the PERT and placebo groups. There was no improvement in quality of life and overall survival did not differ significantly between the PERT and placebo groups (5.84 months vs 8.13 months, p = 0.744). Conclusions PERT did not reduce weight loss in patients with unresectable pancreatic cancer. Larger randomized trials are needed to identify those patients who may benefit from PERT. Trial registration : ClinicalTrials.gov Number NCT01587534.
- Published
- 2016
8. Morphology study on the depleted uranium as hydriding/dehydriding cycles
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Yun Hee Oh, Min Ho Chang, Hyun-Goo Kang, Dongyou Chung, Yoon Myung Woo, Sei-Hun Yun, and Kweon Ho Kang
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Materials science ,Hydrogen ,Scanning electron microscope ,Mechanical Engineering ,Metallurgy ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,Nuclear Energy and Engineering ,Glovebox ,Optical microscope ,chemistry ,law ,Getter ,Agglomerate ,0103 physical sciences ,Particle ,General Materials Science ,0210 nano-technology ,Porosity ,Civil and Structural Engineering - Abstract
Depleted Uranium (DU) is one of the strongest candidates as a getter material of hydrogen isotopes in the nuclear fusion reactor. In this work, small DU lump specimen with 99.8% purity was prepared for observation of morphology variation as hydriding/dehydriding cycles. Hydriding/dehydriding of DU was carried out more than 10 cycles for powder preparation. The pulverized DU specimen was safely handled in the glove box under Argon gas condition to minimize contact with oxygen and humidity. The morphology change according to hydriding/dehydriding cycles was observed by visual cell reactor, optical microscope and scanning electron microscope. The first hydriding of the small DU sample has progressed slowly with surface enlargement and volume expansion as time passes. After third hydriding/dehydriding cycles, most of DU was pulverized. The powder fineness of DU developed as hydriding/dehydriding cycle progresses. But the agglomerates of fine DU particles were observed. It was confirmed that the DU particles exist as porous agglomerates. And the particle agglomerate shows poor fluidity and even has the cohesive force.
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- 2016
9. Fabrication of dispersible graphene flakes using thermal plasma jet and their thin films for solar cells
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Myung Woo Lee, Ju-Han Kim, Hyun Young Kim, Hyeokjin Yoon, and Jung Sang Suh
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Auxiliary electrode ,Materials science ,Graphene ,Graphene foam ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Chemical engineering ,law ,Solar cell ,Electrode ,General Materials Science ,Thin film ,0210 nano-technology ,Graphene nanoribbons ,Graphene oxide paper - Abstract
Graphene has generated tremendous interest over the past decade because of its extraordinary properties and potential applications. In this work, dispersible graphene flakes were successfully fabricated via a one-step process using a thermal plasma jet system. The graphene flakes fabricated by injection of ethylene gas as a carbon source (500 sccm) were very pure, contained no oxygen, and were few layered. Although their average size was larger than 100 nm, they were well-dispersed in organic solvents by sonication. The production rate based on the collected amount was approximately 1.5 g/h. As a representative application, thin films of the graphene flakes were fabricated on fluorine-doped tin oxide (FTO) glass using three deposition techniques. The resulting dye-sensitized solar cell with a graphene flake/FTO counter electrode exhibited a power conversion efficiency of 9.03%, which was similar to the efficiency of the solar cell with a conventional Pt/FTO counter electrode. Therefore, our graphene flake/FTO electrode could be used as a substitute for the conventional Pt/FTO counter electrode for DSSCs as graphene flakes are much less expensive than Pt. In addition to this specific application, dispersible graphene could be used in the fabrication of composites as well as various energy storage, sensor, and electronic devices.
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- 2016
10. Su1510 THE EFFICACY OF A FULLY COVERED SELF-EXPANDABLE METAL STENT ANCHORED BY A PLASTIC STENT FOR ANTI-MIGRATION IN THE MANAGEMENT OF MALIGNANT BILIARY STRICTURE: A PROSPECTIVE RANDOMIZED CONTROLLED STUDY
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Byeong Jun Song, Yong-Tae Kim, Jung Won Chun, Sang Hyub Lee, Young Hoon Choi, Dong-Won Ahn, Ji Kon Ryu, Woo Hyun Paik, Sang Myung Woo, Yoon Suk Lee, and Woojin Lee
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medicine.medical_specialty ,Self expandable ,business.industry ,medicine.medical_treatment ,Gastroenterology ,Stent ,Surgery ,law.invention ,Randomized controlled trial ,law ,medicine ,Radiology, Nuclear Medicine and imaging ,Plastic stent ,business - Published
- 2020
11. Su1522 A RETROSPECTIVE MULTICENTER STUDY OF A SIDE-BY-SIDE PLASTIC STENT TO A FULLY COVERED SELF-EXPANDABLE METAL STENT IN DISTAL MALIGNANT BILIARY OBSTRUCTION
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Sang Hyub Lee, Jung Won Chun, Gunn Huh, Sang Myung Woo, Ji Kon Ryu, Woo Hyun Paik, Yong-Tae Kim, Woojin Lee, and Jae Ok Park
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medicine.medical_specialty ,Multicenter study ,Self expandable ,business.industry ,medicine.medical_treatment ,Gastroenterology ,medicine ,Stent ,Radiology, Nuclear Medicine and imaging ,Plastic stent ,business ,Surgery - Published
- 2020
12. Su1143 EFFICACY AND SAFETY OF PEMBROLIZUMAB FOR GEMCITABINE/CISPLATIN-REFRACTORY BILIARY TRACT CANCER: A MULTICENTER RETROSPECTIVE STUDY
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Sang-Hoon Lee, Sang Hyub Lee, Sang Myung Woo, Hee Seung Lee, Seungmin Bang, and Dong Uk Kim
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Oncology ,medicine.medical_specialty ,Biliary tract cancer ,Hepatology ,Refractory ,business.industry ,Internal medicine ,Gastroenterology ,medicine ,Gemcitabine/cisplatin ,Retrospective cohort study ,Pembrolizumab ,business - Published
- 2020
13. Acute interstitial nephritis induced by Solanum nigrum
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Yeong Jin Choi, Myung Woo Choi, A Young Cho, Mi Rim Choi, Jong Hwa Lee, In O Sun, Hyun Ju Yang, Kwang Young Lee, and Sung Sik Oh
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lcsh:Internal medicine ,medicine.medical_specialty ,lcsh:Specialties of internal medicine ,medicine.drug_class ,Urology ,030232 urology & nephrology ,Inflammation ,Solanum nigrum ,Solanum ,Gastroenterology ,03 medical and health sciences ,0302 clinical medicine ,lcsh:RC581-951 ,Internal medicine ,medicine ,Anticholinergic ,Corticosteroid ,Ingestion ,lcsh:RC31-1245 ,Acute interstitial nephritis ,biology ,business.industry ,Acute kidney injury ,food and beverages ,medicine.disease ,biology.organism_classification ,030205 complementary & alternative medicine ,Corticosteroid therapy ,Nephrology ,Immunology ,medicine.symptom ,business - Abstract
Acute interstitial nephritis (AIN) is an important cause of reversible acute kidney injury and pathologically characterized by inflammatory infiltrate in the renal interstitium. Solanum nigrum (S. nigrum) is a medicinal plant member of the Solanaceae family. Although S. nigrum has been traditionally used to treat various ailments such as pain, inflammation, and fever, it has also been reported to have a toxic effect, resulting in anticholinergic symptoms. However, there have been no reports of AIN caused by S. nigrum. Here, we report the first case of biopsy-confirmed AIN after ingestion of S. nigrum. The patient was successfully treated using corticosteroid therapy.
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- 2016
14. Per-node throughput and fairness analysis of IEEE 802.11 wireless networks with hidden nodes
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Gang Uk Hwang, Sumit Roy, and Myung Woo Lee
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Exponential backoff ,Hidden node problem ,Computer Networks and Communications ,Wireless ad hoc network ,Computer science ,business.industry ,Wireless network ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Distributed coordination function ,Computer Science::Performance ,Hardware and Architecture ,Modeling and Simulation ,Node (computer science) ,Computer Science::Networking and Internet Architecture ,business ,Throughput (business) ,Software ,Carrier sense multiple access with collision avoidance ,Computer network - Abstract
This work seeks to develop an analytical model for the per-node throughput analysis of IEEE 802.11 WLAN networks with hidden nodes by extending Bianchi's model. With the analytic model we derive the per-node throughput of each node and quantify the impact of hidden nodes on per-node throughput. Through our analysis, we find that nodes having more hidden nodes are likely to have worse throughput performance than nodes having less hidden nodes, so resulting in unfairness in per-node throughput.We next propose a new algorithm, called the fake collision algorithm, to solve the unfairness due to hidden nodes. The proposed fake collision algorithm allows nodes with poor throughput to acquire more transmission opportunities by slightly modifying the Binary Exponential Backoff algorithm of the IEEE 802.11 Distributed Coordination Function. To this end, the fake collision algorithm uses a new control parameter called the fake collision probability which can be obtained from a computation algorithm that we develop based on our analytic model. We show that the fairness in per-node throughput can be achieved with the fake collision probability for each node through simulation.
- Published
- 2015
15. Mo1382 – Successful Establishment of Pancreatic Cancer Patient-Derived Orthotopic Xenograft Models Using Eus-Guided Fine-Needle Biopsy Samples
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Sang-Jae Park, Kyong-Ah Yoon, Jun Hyuk Kang, Sun-Young Kong, Yun-Hee Kim, Sang Myung Woo, Eun Kyung Hong, Sun Il Choi, A-Ra Jeon, Tae Hyun Kim, Sung-Sik Han, Ju Hee Lee, and Woojin Lee
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medicine.medical_specialty ,Hepatology ,business.industry ,Pancreatic cancer ,Gastroenterology ,medicine ,Radiology ,business ,medicine.disease ,Fine needle biopsy - Published
- 2019
16. The optimal duration of preoperative biliary drainage for periampullary tumors that cause severe obstructive jaundice
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Sun Whe Kim, Yong Bum Yoon, Sang Myung Woo, Jai Young Cho, Ho-Seong Han, Woojin Lee, Jun Hyuk Son, Yong-Tae Kim, Ji Kon Ryu, Sang Hyub Lee, Jaihwan Kim, Jin-Young Jang, Sang-Jae Park, Yoo Seok Yoon, and Jin-Hyeok Hwang
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Adult ,Male ,Ampulla of Vater ,medicine.medical_specialty ,Time Factors ,Databases, Factual ,Common Bile Duct Neoplasms ,behavioral disciplines and activities ,Gastroenterology ,Pancreaticojejunostomy ,Internal medicine ,Republic of Korea ,Periampullary cancer ,Humans ,Medicine ,Aged ,Retrospective Studies ,R0 resection ,Cholangiopancreatography, Endoscopic Retrograde ,Biliary drainage ,Common bile duct ,business.industry ,Bilirubin ,Retrospective cohort study ,General Medicine ,Middle Aged ,Jaundice ,people.cause_of_death ,Surgery ,Biliary Tract Surgical Procedures ,Jaundice, Obstructive ,Treatment Outcome ,medicine.anatomical_structure ,Preoperative Period ,Drainage ,Female ,Obstructive jaundice ,medicine.symptom ,business ,people ,Cholangiography - Abstract
Despite routine preoperative biliary drainage (PBD) with periampullary cancer, its optimal duration has not been established. The objective of this study was to investigate PBD in severely jaundiced patients.A total of 120 patients with periampullary tumors who underwent surgery with intent to cure after PBD for severe obstructive jaundice were enrolled. According to the duration of PBD, 66 and 54 patients were classified into the long-term (≥2 weeks) and short-term (2 weeks) groups.PBD-related complications occurred in 6 (9.1%) and 14 (25.9%) patients in the short-term and long-term groups, respectively (P = .014). Rates of surgery-related complications and mortalities were not significantly different between the 2 groups. The R0 resection rate tended to be lower (P = .054) and the mean length of hospital stay was significantly longer (P = .039) in the long-term group.PBD duration2 weeks is more appropriate in severely jaundiced patients with periampullary cancer.
- Published
- 2013
17. The procyanidin trimer C1 inhibits LPS-induced MAPK and NF-κB signaling through TLR4 in macrophages
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Jae Hun Kim, Eui-Baek Byun, Nak-Yun Sung, Eui-Hong Byun, Ju-Woon Lee, Jong-Heum Park, Myung-Woo Byun, Du-Sup Song, Sanghyun Park, Jae-Kyung Kim, and Beom-Seok Song
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Lipopolysaccharides ,MAP Kinase Signaling System ,Immunology ,Inflammation ,Nitric Oxide ,Catechin ,Dinoprostone ,Cell Line ,Nitric oxide ,Mice ,chemistry.chemical_compound ,Antigens, CD ,medicine ,Animals ,Biflavonoids ,Immunology and Allergy ,Proanthocyanidins ,Protein kinase A ,Pharmacology ,Chemistry ,Macrophages ,Anti-Inflammatory Agents, Non-Steroidal ,NF-kappa B ,NF-κB ,Cell biology ,Toll-Like Receptor 4 ,Biochemistry ,Cyclooxygenase 2 ,TLR4 ,Tumor necrosis factor alpha ,medicine.symptom ,Signal transduction ,Procyanidin C1 - Abstract
Natural products and dietary components rich in polyphenols have been shown to reduce inflammation; however, the molecular mechanisms underlying this anti-inflammatory activity are not completely characterized, and many features remain to be elucidated. This research was carried out to clarify the potential role of procyanidin trimer C1 in the anti-inflammatory effect of polyphenols. Procyanidin C1 inhibited inducible nitric oxide synthase-mediated nitric oxide production and the release of pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor-α) in lipopolysaccharide (LPS)-induced macrophages. Treatment with procyanidin C1 resulted in a significant decrease in prostaglandin E2 and cyclooxygenase-2 levels, as well as the expression of cell surface molecules (CD80, CD86, and MHC class II), which was induced by LPS. Furthermore, our data demonstrated that the anti-inflammatory effect of procyanidin C1 occurs through inhibition of mitogen-activated protein kinase (p38 and c-Jun N-terminal kinase) and nuclear factor-κB signaling pathways. These 2 factors play a major role in controlling inflammation, through toll-like receptor 4, suggesting that procyanidin C1 plays a potent role in promoting anti-inflammatory activity in macrophages. These results represent a novel and effective therapeutic intervention for the treatment of inflammatory disease.
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- 2013
18. T-category reflects the histopathologic characteristics of gallbladder cancer
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Eun Kyung Hong, Sang Myung Woo, Sung Yong Cho, Sung Sik Han, Sung Heon Kim, Woojin Lee, Tae Hyun Kim, Sun Jin Park, and Yongsun Kim
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Adult ,Male ,medicine.medical_specialty ,Neoplasm, Residual ,medicine.medical_treatment ,Kaplan-Meier Estimate ,Severity of Illness Index ,Risk Factors ,Republic of Korea ,Biomarkers, Tumor ,Humans ,Medicine ,Cholecystectomy ,Neoplasm Invasiveness ,Gallbladder cancer ,Aged ,Neoplasm Staging ,Retrospective Studies ,Analysis of Variance ,business.industry ,Gallbladder ,Hazard ratio ,Cancer ,Retrospective cohort study ,General Medicine ,Middle Aged ,Prognosis ,medicine.disease ,Primary tumor ,medicine.anatomical_structure ,Oncology ,Chemotherapy, Adjuvant ,Lymphatic Metastasis ,Multivariate Analysis ,Female ,Gallbladder Neoplasms ,Surgery ,CA19-9 ,Radiology ,business - Abstract
Gallbladder (GB) cancer is a relatively uncommon gastrointestinal malignancy and is known to often result in unfavorable outcomes. Recent advances in aggressive surgical resection have improved the overall survival rate of patients with GB cancer. We aimed to evaluate the outcomes and prognostic factors of GB cancer following a surgical resection with curative intent.Between March 2001 and March 2009, 89 patients with GB cancer underwent surgical resection with curative intent at the National Cancer Center of Korea. We then conducted a retrospective analysis of clinicopathologic data.Nineteen patients underwent simple cholecystectomy and 70 patients underwent extended cholecystectomy. Tumor-free resection margins were obtained in 84 cases. The 1-, 3- and 5-year disease-specific survival rates in the 89 patients were 85.8%, 68.0% and 64.1%, respectively. By multivariate analysis, only the T-category was significant (p0.001). The T-category showed a close correlation with all of the other histopathologic factors which were significant in univariate analysis.The T-category of GB cancer represents not only the depth of the primary tumor but also the aggressiveness of its histopathologic nature.
- Published
- 2012
19. Phase II study of concurrent transarterial chemoembolization and sorafenib in patients with unresectable hepatocellular carcinoma
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Joong-Won Park, Young Hwan Koh, Joon-Il Choi, Byung-Ho Nam, Hyun Beom Kim, Sangbu An, Hwi Young Kim, and Sang Myung Woo
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Sorafenib ,medicine.medical_specialty ,Hepatology ,business.industry ,Phases of clinical research ,Common Terminology Criteria for Adverse Events ,medicine.disease ,Gastroenterology ,BCLC Stage ,Response Evaluation Criteria in Solid Tumors ,Internal medicine ,Hepatocellular carcinoma ,medicine ,Radiology ,Liver cancer ,business ,Survival rate ,medicine.drug - Abstract
Background & Aims Transarterial chemoembolization (TACE) is an important palliative treatment for unresectable hepatocellular carcinoma (HCC), but TACE-induced ischemic injury can upregulate angiogenic factors and is associated with poor prognosis. The aim of this study was to evaluate the safety and efficacy of concurrent conventional TACE and sorafenib in patients with unresectable HCC. Methods The primary objectives of this prospective, single-arm, phase II study were to evaluate safety and time to progression (TTP). Sorafenib was given 3days after TACE and was administered for up to 24weeks. Repeated TACE was performed on demand. Tumor response was assessed every 8weeks. Results Fifty patients were treated and followed from July 2009 to May 2011. All patients were in Barcelona Clinic Liver Cancer (BCLC) stage B (82%) or C (18%). The median time of follow-up was 14.9months and a median of 1 TACE session was given (range, 1–4). The median dose intensity of sorafenib was 68.7% (range, 37.3–100) of 800mg daily. The most common reasons for dose reduction were hand–foot syndrome and thrombocytopenia. Thirty patients completed the study and 17 patients discontinued sorafenib due to disease progression. The overall median TTP was 7.1months (95% confidence interval (CI), 4.8–7.5months): 7.3months in BCLC stage B; 5.0months in BCLC stage C. The 6-month progression-free survival rate was 52% (95% CI, 37.3–66.1). Conclusions Concurrent treatment of unresectable HCC with conventional TACE and sorafenib demonstrates a manageable safety profile and a possibility of promising efficacy.
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- 2012
20. Role of Adjuvant Chemoradiotherapy for Resected Extrahepatic Biliary Tract Cancer
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Seong Hoon Kim, Sang Soo Kim, Tae Yoo, Sang Myung Woo, Sang-Jae Park, Woo Jin Lee, Eun Kyung Hong, Sung-Sik Han, Tae Hyun Kim, Sung Ho Moon, Joong-Won Park, and Dae Yong Kim
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Adult ,Male ,Cancer Research ,medicine.medical_specialty ,CA-19-9 Antigen ,Perineural invasion ,Gastroenterology ,Disease-Free Survival ,Sex Factors ,Bile Ducts, Extrahepatic ,Internal medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Stage (cooking) ,Radiation Injuries ,Aged ,Neoplasm Staging ,Retrospective Studies ,Aged, 80 and over ,Analysis of Variance ,Univariate analysis ,Radiation ,business.industry ,Age Factors ,Cancer ,Chemoradiotherapy, Adjuvant ,Middle Aged ,Prognosis ,medicine.disease ,Tumor Burden ,Bile Duct Neoplasms ,Oncology ,Biliary tract ,Resection margin ,T-stage ,Female ,business ,Chemoradiotherapy - Abstract
Purpose To evaluate the effect of adjuvant chemoradiotherapy (CRT) on locoregional control (LRC), disease-free survival (DFS), and overall survival (OS) for patients with extrahepatic biliary tract cancer treated with curative resection. Methods and Materials The study involved 168 patients with extrahepatic biliary tract cancer undergoing curative resection between August 2001 and April 2009. Of the 168 patients, 115 received adjuvant CRT (CRT group) and 53 did not (no-CRT group). Gender, age, tumor size, histologic differentiation, pre- and postoperative carbohydrate antigen 19-9 level, resection margin, vascular invasion, perineural invasion, T stage, N stage, overall stage, and the use of adjuvant CRT were analyzed to identify the prognostic factors associated with LRC, DFS, and OS. Results For all patients, the 5-year LRC, DFS, and OS rate was 54.8%, 30.6%, and 33.9%, respectively. On univariate analysis, the 5-year LRC, DFS, and OS rates in the CRT group were significantly better than those in the no-CRT group (58.5% vs. 44.4%, p = .007; 32.1% vs. 26.1%, p = .041; 36.5% vs. 28.2%, p = .049, respectively). Multivariate analysis revealed that adjuvant CRT was a significant independent prognostic factor for LRC, DFS, and OS ( p .05). Conclusion Our results have suggested that adjuvant CRT helps achieve LRC and, consequently, improves DFS and OS in patients with extrahepatic biliary tract cancer.
- Published
- 2011
21. CA 19-9 Level as Indicator of Early Distant Metastasis and Therapeutic Selection in Resected Pancreatic Cancer
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Dae Yong Kim, Tae Hyun Kim, Joong-Won Park, Sang Myung Woo, Sung-Sik Han, Sung Ho Moon, Eun Kyung Hong, Tae Yoo, Sang-Jae Park, Woo Jin Lee, and Seong Hoon Kim
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Adult ,Male ,Cancer Research ,medicine.medical_specialty ,Multivariate analysis ,CA-19-9 Antigen ,Leucovorin ,Deoxycytidine ,Gastroenterology ,Capecitabine ,Pancreatic cancer ,Internal medicine ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Neoplasm Metastasis ,Aged ,Retrospective Studies ,Aged, 80 and over ,Analysis of Variance ,Radiation ,business.industry ,Radiotherapy Dosage ,Retrospective cohort study ,Chemoradiotherapy ,Middle Aged ,medicine.disease ,Surgery ,Pancreatic Neoplasms ,medicine.anatomical_structure ,Oncology ,Resection margin ,Female ,CA19-9 ,Fluorouracil ,Pancreas ,business ,medicine.drug - Abstract
Purpose In patients with pancreatic cancer treated with curative resection, we evaluated the effect of clinicopathologic parameters on early distant metastasis within 6 months (DM 6m ) to identify patients who might benefit from surgery. Methods and Materials The study involved 84 patients with pancreatic cancer who had undergone curative resection between August 2001 and April 2009. The parameters of gender, age, tumor size, histologic differentiation, T classification, N classification, pre- and postoperative carbohydrate antigen (CA) 19-9 level, resection margin, and adjuvant chemoradiotherapy were analyzed to identify the risk factors associated with DM 6m . Results Of the 84 patients, locoregional recurrence developed in 35 (41.7%) and distant metastasis in 58 (69%). Of the 58 patients with distant metastasis, DM 6m had developed in 27 (46.6%). Multivariate analysis showed that preoperative CA 19-9 level was significantly associated with DM 6m ( p 6m was observed in 9.1%, 50%, and 80% of those with a preoperative CA 19-9 level of ≤100 U/mL, 101–400 U/mL, and >400 U/mL, respectively ( p .001). Conclusions The preoperative CA 19-9 level might be a useful predictor of DM 6m and to identify those who would benefit from surgical resection.
- Published
- 2011
22. Changes in antigenicity of porcine serum albumin in gamma-irradiated sausage extract by treatment with pepsin and trypsin
- Author
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Koth-Bong-Woo-Ri Kim, Ju-Woon Lee, So-Young Lee, Eu-Jin Song, Myung-Woo Byun, Dong-Hyun Ahn, and Jin-Gyu Park
- Subjects
Gel electrophoresis ,Antigenicity ,Radiation ,Chromatography ,biology ,Chemistry ,Sodium ,Albumin ,chemistry.chemical_element ,Trypsin ,medicine.disease_cause ,Allergen ,Pepsin ,medicine ,biology.protein ,Irradiation ,medicine.drug - Abstract
Pork is known as an allergenic food with porcine serum albumin (PSA, 66 kDa) representing the major allergen. This study was conducted to investigate the change in antigenicity of PSA in gamma-irradiated sausage extract treated with pepsin and trypsin. Sausage products (A and B) were irradiated at 1, 3, 10, and 20 kGy. After irradiation, sausage proteins were extracted and digested with pepsin (1:200, 30 min) and trypsin (1:300, 5, 30, 60, 90, and 120 min). The binding ability of PSA in extracts of the irradiated sausages (A and B) decreased by over 3 kGy relative to the binding ability of PSA in extracts of intact sausages and showed no notable differences when the dose of radiation ranged from 3 to 20 kGy. After treatment with pepsin and trypsin, the binding ability of PSA in extracts of the irradiated sausages was decreased more relative to that of intact sausages and showed no significant differences when the period of trypsin treatment is increased or when the dose of irradiation is increased. The sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) results indicated that there was no visible change in the intensity of the PSA band in extracts of the irradiated sausages. After pepsin and trypsin treatment, the intensity of PSA band faded with increasing doses of irradiation. In conclusion, antigenicity of PSA in pork sausages could be reduced by gamma irradiation.
- Published
- 2011
23. Rapid laser fabrication of microlens array using colorless liquid photopolymer for AMOLED devices
- Author
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Kwang-Ryul Kim, Hanwook Jeong, Kong-Soo Lee, Myung-Woo Cho, Sung-Hak Cho, Byoungdeog Choi, Junsin Yi, and Jae-Chern Yoo
- Subjects
Microlens ,Scanner ,Materials science ,Fabrication ,business.industry ,Laser ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,Display device ,AMOLED ,Optics ,law ,OLED ,Optoelectronics ,Light emission ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,business - Abstract
Microlens array (MLA) is microfabricated using Ultra Violet (UV) laser for display device applications. A colorless liquid photopolymer, Norland Optical Adhesive (NOA) 60, is spin-coated and pre-cured via UV light for completing the laser process. The laser energy controlled by a galvano scanner is radiated on the surface of the NOA 60. A rapid thermal volume expansion inside the material creates microlens array when the Gaussian laser energy is absorbed. The fabrication process conditions for various shapes and densities of MLA using a non-contact surface profiler are investigated. Furthermore, we analyze the optical and display characteristics for the Organic Light Emitting Diode (OLED) devices. Optimized condition furnishes the OLED with the enhancement of light emission by 15%. We show that UV laser technique, which is installed with NOA 60 MLA layer, is eligible for improving the performance of the next generation display devices.
- Published
- 2011
24. Enhancement of anti-tumor activity of gamma-irradiated silk fibroin via immunomodulatory effects
- Author
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Eui Baek Byun, Ju Woon Lee, Jae-Hun Kim, Toshiro Matsui, Myung Woo Byun, Jong-il Choi, and Nak Yun Sung
- Subjects
CD4-Positive T-Lymphocytes ,Cell Survival ,medicine.medical_treatment ,Fibroin ,Antineoplastic Agents ,CD8-Positive T-Lymphocytes ,Toxicology ,Mice ,Immune system ,medicine ,Animals ,Humans ,Immunologic Factors ,Cytotoxicity ,Melanoma ,Cells, Cultured ,Antitumor activity ,Chemistry ,Macrophages ,General Medicine ,Bombyx ,Acquired immune system ,Cell biology ,Killer Cells, Natural ,Mice, Inbred C57BL ,SILK ,Cytokine ,Gamma Rays ,Immunology ,Cytokines ,Female ,Peritoneum ,Fibroins ,Spleen ,Ex vivo - Abstract
Silk fibers have proven to be effective in many clinical applications as well as for clothing. In addition to the substantial effect of silk fibers, the present study was conducted to explore its importance in a new dimension to reinforce the effects of its physiological function regarding anti-tumor activity and immune response with gamma-irradiated silk fibroin (GISF). The cytotoxicity results showed that pre-treatment of GISF in the mouse peritoneal macrophages (MPM) indicated a higher proliferative effect than that of non-irradiated silk fibroin (NISF) in a concentration-dependent manner. Based on the cytotoxicity result of MPM, GISF (50 and 150 kGy) was selected for an ex vivo study in an animal (C57BL6) system and evaluated about whether the non-specific immune response was also related to GISF. GISF (50 and 150 kGy) augmented immune responsiveness via activation of NK cells, T lymphocytes proliferation, NO production, and cytokine level, such as IL-6, IL-2, IL-12, IFN-gamma, TNF-alpha, as compared with NISF, which strongly suggested that GISF significantly augmented an important element of all aspects of the innate and adaptive immune system. Therefore, from these results, it seems likely that the GISF will play a potent role in eliciting the effect of the non-specific immune response and anti-tumor activity as a value-added product in the medical industry.
- Published
- 2010
25. Effect of gamma irradiation on Burkholderia thailandensis (Burkholderia pseudomallei surrogate) survival under combinations of pH and NaCl
- Author
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Myung-Woo Byun, Ju-Woon Lee, Jae-Hun Kim, Kyoung-Hee Choi, and Yohan Yoon
- Subjects
Radiation ,Ph level ,food.ingredient ,Burkholderia thailandensis ,biology ,Burkholderia pseudomallei ,Chemistry ,Low dose ,Cell ,biology.organism_classification ,Microbiology ,food ,medicine.anatomical_structure ,medicine ,Agar ,Bacteria ,Gamma irradiation - Abstract
This study evaluated the effect of gamma irradiation on Burkholderia thailandensis ( Burkholderia pseudomallei surrogate; potential bioterrorism agent) survival under different levels of NaCl and pH. B . thailandensis in Luria Bertani broth supplemented with NaCl (0–3%), and pH-adjusted to 4–7 was treated with gamma irradiation (0–0.5 kGy). Surviving cell counts of bacteria were then enumerated on tryptic soy agar. Data for the cell counts were also used to calculate D 10 values (the dose required to reduce 1 log CFU/mL of B . thailandensis ). Cell counts of B . thailandensis were decreased ( P P ≥0.05) in cell counts of the bacteria were observed among different levels of NaCl and pH. D 10 values ranged from 0.04 to 0.07 kGy, regardless of NaCl and pH level. These results indicate that low doses of gamma irradiation should be a useful treatment in decreasing the potential bioterrorism bacteria, which may possibly infect humans through foods.
- Published
- 2010
26. Anti-proliferative effects of Lethariella zahlbruckneri extracts in human HT-29 human colon cancer cells
- Author
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Kwon-Il Seo, Jae-Seoun Hur, Myung-Woo Byun, Chi-Nam Seong, Jae-Yong Kim, Mei Rong Ren, Il-Yun Jeong, Mi-Kyung Lee, Seong-Chan Park, and Kyoung-Wuk Park
- Subjects
Programmed cell death ,Lichens ,Cell Survival ,Blotting, Western ,Cell ,Apoptosis ,Biology ,Toxicology ,Acetone ,Bcl-2-associated X protein ,medicine ,Humans ,Cell Proliferation ,bcl-2-Associated X Protein ,Caspase 8 ,Plant Extracts ,Cell growth ,Methanol ,Apoptosis Inducing Factor ,DNA, Neoplasm ,General Medicine ,Cell cycle ,Antineoplastic Agents, Phytogenic ,Molecular biology ,Caspase 9 ,medicine.anatomical_structure ,Proto-Oncogene Proteins c-bcl-2 ,Biochemistry ,Cell culture ,Colonic Neoplasms ,biology.protein ,Apoptosis-inducing factor ,Drug Screening Assays, Antitumor ,HT29 Cells ,Food Science - Abstract
This study was performed to elucidate the anti-proliferative effects and the apoptotic mechanisms of extracts from Lethariella zahlbruckneri in HT-29 human colon cancer cells. Both the acetone extract (AEL) and methanolic extract (MEL) of L. zahlbruckneri decreased viable cell numbers in a dose- and time-dependent manner in HT-29 cells. The AEL showed stronger cytotoxicity than MEL. Cell death induced by AEL increased cell populations in the sub-G1 phase, as well as the formation of apoptotic bodies and nuclear condensation, whereas MEL did not. Therefore, the potential of AEL to induce apoptosis was examined. Apoptosis induced by AEL was associated with the activation of initiator caspases-8 and -9, as well as the effector caspase-3. AEL stimulated Bid cleavage. This indicated that the apoptotic action of caspase-8-mediated Bid cleavage leads to the activation of caspase-9. AEL increased the expression of the pro-apoptotic protein, Bax, and decreased the expression of the anti-apoptotic protein, Bcl-2. AEL also increased the expression of the caspase-independent mitochondrial apoptosis factor, AIF, in HT-29 cells. These results indicate that AEL inhibited HT-29 cell proliferation by inducing apoptosis, which might be mediated via both caspase-dependent and -independent pathways.
- Published
- 2009
27. A comparison of the Niti-D biliary uncovered stent and the uncovered Wallstent in malignant biliary obstruction
- Author
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Joo Kyung Park, Ji Kon Ryu, Sang Myung Woo, Yong-Tae Kim, Jeong Kyun Seo, Yong Bum Yoon, and Ki Young Yang
- Subjects
Male ,medicine.medical_specialty ,Biopsy ,medicine.medical_treatment ,Subgroup analysis ,Endoscopic management ,Prosthesis Design ,Stent occlusion ,Coated Materials, Biocompatible ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Retrospective Studies ,Cholangiopancreatography, Endoscopic Retrograde ,Cholestasis ,business.industry ,Gastroenterology ,Stent ,Retrospective cohort study ,Middle Aged ,medicine.disease ,Surgery ,Treatment Outcome ,Bile Duct Neoplasms ,Biliary tract ,Pancreatitis ,Female ,Stents ,Radiology ,Tomography, X-Ray Computed ,Complication ,business ,Follow-Up Studies - Abstract
Background The conformability of uncovered self-expandable metal stents (SEMSs) plays an important role in maintaining stent patency. However, whether increased conformability can prolong the duration of SEMS patency remains to be proved. Objective The aim of this study was to examine the efficacy and complication rates of the Niti-D biliary uncovered metal stent (NDS), which is more conformable than the uncovered Wallstent. Design Nonrandomized, retrospective study. Setting Tertiary-care academic medical center. Patients From March 2005 to July 2007, 101 patients received an NDS (41 cases) or a Wallstent (60 cases) for malignant biliary obstruction. Interventions SEMS placement. Results Stent occlusion occurred in 11 patients (26.8%) with the NDS and 17 patients (28.3%) with the Wallstent. The median duration of stent patency tended to be longer for the NDS group (153 days) than for the Wallstent group (124 days); however, the difference was not statistically significant ( P = .204). The median duration of overall survival of patients was 160 days for the NDS and 148 days for the Wallstent. The subgroup analysis showed that 27 patients had hilar obstruction (NDS 13, Wallstent 14). The median duration of stent patency was 249 days for the NDS group and 76 days for the Wallstent group; this difference was statistically significant ( P = .006). The complications included pancreatitis in 3 NDS cases and 5 Wallstent cases. Limitation The absence of prospective randomized recruitment. Conclusion The results of this study showed no significant differences between the NDS and the Wallstent for the palliative endoscopic management of malignant biliary obstruction. There were no significant differences in patency, complication rates, and patient survival between the more conformable NDS and the conventional Wallstent. However, the NDS, which has good conformability, may be preferred for hilar obstruction.
- Published
- 2009
28. Comparison of gamma ray and electron beam irradiation on extraction yield, morphological and antioxidant properties of polysaccharides from tamarind seed
- Author
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Ju Woon Lee, Myung Woo Byun, Periasamy Srinivasan, Hyun Jin Park, Jong-il Choi, Jae Kyung Kim, and Jae-Hun Kim
- Subjects
chemistry.chemical_classification ,endocrine system ,Radiation ,Antioxidant ,Molecular mass ,Chemistry ,Scanning electron microscope ,medicine.medical_treatment ,Radiochemistry ,Gamma ray ,virus diseases ,Tamarind seed ,Polysaccharide ,immune system diseases ,medicine ,Molar mass distribution ,Irradiation - Abstract
Tamarind (Tamarindus indica L) seed polysaccharide (TSP) is of great important due to its various biological activities. The present investigation was carried out to compare extraction yield, morphological characteristics, average molecular weights and antioxidant activities of TSP from gamma- and electron beam (EB)-irradiated tamarind kernel powder. The tamarind kernel powder was irradiated with 0, 5 and 10 kGy by gamma ray (GR) and electron beam, respectively. The extraction yield of TSP was increased significantly by EB and GR irradiation, but there was no significant difference between irradiation types. Morphological studies by scanning electron microscope showed that TSP from GR-irradiated tamarind seed had a fibrous structure, different from that of EB irradiated with a particle structures. The average molecular weight of TSP was decreased by the irradiation, and EB treatment degraded more severely than GR. Superoxide radical scavenging ability and total antioxidant capacity of EB-treated TSP showed higher than those of GR-treated TSP.
- Published
- 2009
29. Effect of γ-irradiation on the volatile compounds of medicinal herb, Paeoniae Radix
- Author
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Min-Seok Jung, Joong-Ho Kwon, Kyong Su Kim, Ju-Woon Lee, Hyun-Pa Song, Hee-Yeon Kim, Myung-Woo Byun, Sung-Lye Shim, Jae-Hun Kim, In-Min Hwang, Keun-Young Ryu, and Hye-Young Seo
- Subjects
chemistry.chemical_classification ,Radiation ,Chromatography ,Base (chemistry) ,Extraction (chemistry) ,law.invention ,Eugenol ,Steam distillation ,chemistry.chemical_compound ,chemistry ,law ,Medicinal herbs ,Selected ion monitoring ,Paeonol ,Methyl salicylate - Abstract
A study was carried out to find the effect of γ-irradiation on contents of volatile compounds from medicinal herb, Paeoniae Radix ( Paenia albiflora Pallas var. trichocarpa Bunge). The volatile compounds of control, 1, 3, 5 and 10 kGy irradiated samples were extracted by simultaneous steam distillation and extraction (SDE) method and analyzed by gas chromatograph-mass spectrometer. The major volatile compounds were paeonol, ( E )-carveol, ( E , E )-2,4-octadienal, methyl salicylate, myrtanol and eugenol acetate. Volatile compounds belonging to chemical classes of acids, alcohols, aldehydes, esters, hydrocarbons and miscellaneous were identified in all experimental samples. The types of volatile compounds in irradiated samples were similar to those of non-irradiated sample and the concentrations of these compounds differed between treatments. 1,3-Bis (1,1-dimethylethyl)-benzene was identified by using the selected ion monitoring (GC/MS-SIM) mode. The concentration of this compound increased with the increase of irradiation dose level. These results suggest that it could be used as the base data for the effect of γ-irradiation on medicinal herb.
- Published
- 2009
30. Gamma irradiation reduces the immunological toxicity of doxorubicin, anticancer drug
- Author
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Jong Il Choi, Myung-Woo Byun, Ju-Woon Lee, Young-Jeong Hwang, Beom-Seok Song, Yohan Yoon, Nak-Yun Sung, Young-Choon Yoo, Jae-Hun Kim, and H. Balaji Raghavendran
- Subjects
Chemotherapy ,Radiation ,Chemistry ,medicine.medical_treatment ,technology, industry, and agriculture ,Pharmacology ,Anticancer drug ,carbohydrates (lipids) ,In vivo ,Toxicity ,polycyclic compounds ,medicine ,Doxorubicin ,Cytotoxicity ,Macrophage proliferation ,medicine.drug ,Gamma irradiation - Abstract
Doxorubicin (DOX) is a widely used anticancer agent, but exhibits some immunological toxicity to patients during chemotherapy. The present study was conducted to evaluate the effect of gamma irradiation on the immunological response and the inhibition activity on in vivo tumor mass of DOX. The results showed that DOX irradiated at 10 and 20 kGy reduce the inhibition of mouse peritoneal macrophage proliferation and induce the release of cytokines (TNF-α and IL-6) when compared with non-irradiated DOX. The cytotoxicity against human breast (MCF-7), murine colon adenocarcinoma (Colon 26) and human monocytic (THP-1) tumor cell were not significantly different between non-irradiated and irradiated DOX ( P In vivo study on the tumor mass inhibition, gamma-irradiated DOX showed a considerable inhibition of tumor mass and this effect was statistically non-significant as compared with non-irradiated DOX. In conclusion, gamma irradiation could be regarded as a potential method for reducing the immunological toxicity of DOX. Further researches is needed to reveal the formation and activity of radiolysis products by gamma irradiation.
- Published
- 2009
31. Korean space food development: Ready-to-eat Kimchi, a traditional Korean fermented vegetable, sterilized with high-dose gamma irradiation
- Author
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Myung-Woo Byun, Beom-Seok Song, In-Jun Han, Jae-Hun Kim, Jong Il Choi, Jin-Gyu Park, Jae-Nam Park, and Ju-Woon Lee
- Subjects
Atmospheric Science ,Vitamin C ,Chemistry ,Aerospace Engineering ,Astronomy and Astrophysics ,Ready to eat ,Microscopic observation ,Ames test ,Geophysics ,Space food ,Space and Planetary Science ,General Earth and Planetary Sciences ,Fermentation ,Food science ,Gamma irradiation - Abstract
Addition of calcium lactate and vitamin C, a mild heating, deep-freezing, and gamma irradiation at 25 kGy were conducted to prepare Kimchi as a ready-to-eat space food. It was confirmed that the space food was sterilized by an irradiation at 25 kGy through incubation at 37 °C for 30 days. The hardness of the Space Kimchi (SK) was lower than the untreated Kimchi (CON), but higher than the irradiated Kimchi (IR). Also, this result was supported by the scanning electron microscopic observation. Sensory attributes of the SK were similar to CON, and maintained during preservation at 35 °C for 30 days. According to the Ames test, Kimchi sterilized with a high-dose irradiation exerted no mutagenic activity in the bacterial strains of Salmonella typhimurium . And, the SK was certificated for use in space flight conditions during 30 days by the Russian Institute of Biomedical Problems.
- Published
- 2009
32. SLM-based maskless lithography for TFT-LCD
- Author
-
Junsin Yi, Kwang-Ryul Kim, Namhyun Kang, Sung-Hak Cho, Byoungdeog Choi, Bo-Sung Shin, and Myung-Woo Cho
- Subjects
Microlens ,Liquid-crystal display ,Materials science ,business.industry ,General Physics and Astronomy ,Surfaces and Interfaces ,General Chemistry ,Grating ,Condensed Matter Physics ,Surfaces, Coatings and Films ,law.invention ,Optics ,Resist ,law ,Thin-film transistor ,Photomask ,business ,Lithography ,Maskless lithography - Abstract
Maskless photolithographic methods have been developed using digital micromirror devices (DMDs) and grating light valves (GLVs), which are spatial light modulators (SLMs), because liquid crystal display (LCD) panel industries spend huge amounts of money for the cost of TFT (thin film resist)-LCD photomasks. The technology has been developed for implementing 2 μm bitmap resolutions, which is a requirement for the lithographic process, though the process time is still slow for mass-production system. A DMD-based maskless exposure uses 405 nm-wavelength semiconductor lasers as an illumination source and optical engines that contain DMDs, micro lens arrays (MLAs), and projection lenses. A GLV-based system consists of UV lasers and optical write engines, which are constructed with the GLV, grating optics, and imaging lenses. Since many companies have been trying to overcome the time limitations, the maskless technology will be realized in the LCD industry in near future.
- Published
- 2009
33. Effect of gamma irradiation on the efficacy of β-glucan against acetaminophen induced toxicity in mice
- Author
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Hanumantha Rao Balaji Raghavendran, Ju-Woon Lee, Eui-Hong Byun, Myung-Gon Shin, Eui-Baek Byun, Nak-Yun Sung, Jong Il Choi, Myung-Woo Byun, and Jae-Hun Kim
- Subjects
medicine.medical_specialty ,Pathology ,beta-Glucans ,Renal glomerulus ,Inflammation ,Kidney ,Toxicology ,digestive system ,Mice ,Internal medicine ,Edema ,medicine ,Animals ,Lung ,Acetaminophen ,Mice, Inbred BALB C ,business.industry ,Centrilobular necrosis ,digestive, oral, and skin physiology ,Histology ,General Medicine ,Analgesics, Non-Narcotic ,digestive system diseases ,Endocrinology ,medicine.anatomical_structure ,Liver ,Gamma Rays ,Toxicity ,medicine.symptom ,business ,medicine.drug - Abstract
The present study was conducted to compare the efficacy of unirradiated beta-glucan (UBG) and gamma irradiated beta-glucan (GIBG) against acetaminophen (APAP) induced hepatotoxicity in mice. Mice of BALB/c strain were pretreated with UBG and GIBG (50mg/kg, p.o.) for 7 days and on the 8th day they received an overdose of APAP (500 mg/kg, i.p.). Eight hours after the APAP injection, the levels of serum aminotransferase (AST) and alanine aminotransferase (ALT) were measured and liver, kidney and lung tissue were examined for morphological changes. A significant elevation (p
- Published
- 2009
34. Role of gamma irradiation on the natural antioxidants in cumin seeds
- Author
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Ju Woon Lee, Young Jeong Hwang, Mee Hye Shin, Jae-Hun Kim, Hyun Jin Park, Periasamy Srinivasan, Myung Woo Byun, and Jae Kyung Kim
- Subjects
Radiation ,Antioxidant ,DPPH ,medicine.medical_treatment ,Linoleic acid ,Radical ,Radiochemistry ,law.invention ,chemistry.chemical_compound ,chemistry ,Polyphenol ,law ,medicine ,Ferric ,Food science ,Irradiation ,Electron paramagnetic resonance ,medicine.drug - Abstract
Antioxidants quench oxidation by transferring hydrogen atoms to free radicals. In the present investigation, the effect of gamma irradiation on the natural antioxidants of irradiated cumin was studied. Cumin samples were purchased from retailers and then irradiated in a cobalt-60 irradiator to 0, 1, 3, 5 and 10 kGy at ambient temperature. The effect of irradiation on the antioxidant properties of the cumin seed were investigated by evaluating the radical-scavenging effect on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, determination of ferric reducing antioxidant power (FRAP), total polyphenol content (TPC) and the antioxidant index by β-carotene/linoleic acid co-oxidation. Electron spin resonance (ESR) was performed to assess ionization of cumin seeds by gamma irradiation. Irradiation was found to nonsignificantly increase and/or maintain all antioxidant parameters, TPC and the ESR signal intensity was found to be increased in cumin seeds.
- Published
- 2009
35. Effect of gamma irradiation on microbial analysis, antioxidant activity, sugar content and color of ready-to-use tamarind juice during storage
- Author
-
Sang-Bae Han, Myung Woo Byun, Duk-Jin Kim, Jae Kyung Kim, Periasamy Srinivasan, Jae-Hun Kim, Jong Il Choi, and Ju Woon Lee
- Subjects
Antioxidant ,DPPH ,medicine.medical_treatment ,Pulp (paper) ,Food preservation ,Food storage ,engineering.material ,Sensory analysis ,chemistry.chemical_compound ,Distilled water ,chemistry ,medicine ,engineering ,Food science ,Sugar ,Food Science - Abstract
Gamma irradiation is highly effective in inactivating microorganisms in various foods and it offers a safe alternative method of food decontamination. In the present study, the effect of gamma irradiation on microbial analysis, antioxidant activity, sugar content, color and sensory evaluation of ready-to-use tamarind juice was investigated during storage. A fresh tamarind juice was prepared by dissolving 5 g of pulp/100 ml of deionized distilled water and irradiated at 0, 1, 3 and 5 kGy at room temperature. Microbiological assay of the fresh and stored ready-to-use tamarind juice showed better quality after gamma irradiation. Antioxidant ability was studied by using 1,1-diphenyl-2-picrylhydrazyl (DPPH), FRAP (ferric reducing/antioxidant power) and total phenolic contents, and gamma irradiation had a significant increase or maintenance on the antioxidant potential of the ready-to-use tamarind juice. Contents of glucose and fructose also showed minimal alterations both in the fresh and stored samples. There was a significant improvement in the Hunter color value in both the fresh and stored tamarind juice. To conclude, gamma irradiation improves the microbial decontamination and the antioxidants as well as the color of the ready-to-use tamarind juice without any adverse change in sensory qualities.
- Published
- 2009
36. Effect of electron beam irradiation on the viscosity of carboxymethylcellulose solution
- Author
-
Jae-Hun Kim, Young-Jin Chung, Jong-il Choi, Hee-Sub Lee, Myung-Woo Byun, Kwang Won Lee, and Ju-Woon Lee
- Subjects
musculoskeletal diseases ,chemistry.chemical_classification ,Nuclear and High Energy Physics ,Molar mass ,Chemistry ,technology, industry, and agriculture ,Analytical chemistry ,macromolecular substances ,Polymer ,Penetration (firestop) ,musculoskeletal system ,body regions ,Electron beam irradiation ,Polymer chemistry ,Irradiation ,Reduced viscosity ,Instrumentation - Abstract
In this study, the effects of an electron beam irradiation on the viscosity of a carboxymethylcellulose (CMC) solution were investigated. The viscosity of the CMC solution was decreased with an increase in the irradiation dose. Interestingly, the extent of the degradation of the CMC was found to decrease with an increase of the CMC concentration in the solution. The change of the average molar mass confirmed the decrease in the viscosity due to the degradation of the polymer. The energy of the electron beam also affected the degradation of the CMC. Lower degradation of the CMC was obtained with a decreasing electron beam energy due to its lower penetration. Addition of vitamin C as a radical scavenger to the solution and an irradiation at −70 °C were shown to be moderately effective in preventing a decrease in the viscosity of the solution by irradiation.
- Published
- 2008
37. Effects of gamma irradiation on the physical and structural properties of β-glucan
- Author
-
Myung Woo Byun, Eui Hong Byun, Nak Yun Sung, Kwang Hoon Kim, Jong-il Choi, Ju Woon Lee, Jae-Hun Kim, Hong Sun Yook, and Seong Taek Lim
- Subjects
Gel permeation chromatography ,chemistry.chemical_classification ,Radiation ,Chemistry ,Radiolysis ,Radiochemistry ,Irradiation ,Cobalt-60 ,Solubility ,Fourier transform infrared spectroscopy ,Isotopes of cobalt ,Glucan - Abstract
This study was carried out to evaluate the effect of gamma irradiation on the physical and structural properties of β- glucan. β- Glucan solution (10%, w/v) was exposed to a cobalt-60 source (10, 30, and 50 kGy). Gel permeation chromatography data showed that the average molecular weight of irradiated β- glucan significantly decreased as the irradiation dose increased. In addition, gamma irradiation improved the solubility and decreased the viscosity of β- glucan by the radiolysis of the glycosidic bonds, and this effect was dependent upon the absorbed dose. Fourier transform infrared spectroscopy results showed that the functional groups of β- glucan were not significantly affected by gamma irradiation. Scanning electron microscopy results showed that the irradiated β- glucan was deformed into smaller granules. Therefore, gamma irradiation could be used in commercial processes as an effective method to resolve the physical problems involved in the use of β- glucan with high viscosity and low solubility.
- Published
- 2008
38. The effect of irradiation temperature on the quality improvement of Kimchi, Korean fermented vegetables, for its shelf stability
- Author
-
Young-Duk Kim, Han-Joon Hwang, Jae-Hun Kim, Ju-Woon Lee, Wang-Geun Kim, Myung-Woo Byun, Jae-Nam Park, and Jin-Gyu Park
- Subjects
Radiation ,Combined treatment ,Materials science ,Dry ice ,Fermentation ,Food science ,Irradiation ,Liquid nitrogen ,Softening - Abstract
The present study was conducted to evaluate the effect of irradiation temperature on the shelf stability and quality of Kimchi during storage at 35 °C for 30 days. Kimchi samples were N 2 -packaged and heated at 60 °C and then gamma irradiated at 20 kGy under various temperatures (room temperature, ice, dry ice, and liquid nitrogen). In the results of microbial, pH, and acidity analysis, combination treatment of heating and irradiation was able to sterilize microbes in Kimchi regardless of irradiation temperature. When Kimchi was irradiated under frozen temperatures, especially dry ice, the softening of texture and the deterioration of sensory quality of Kimchi were reduced. Also, ESR signal intensities were weakened due to the decrease of irradiation dose and temperature.
- Published
- 2008
39. Effect of gamma irradiation on the physicochemical properties of a starch-based film
- Author
-
Myung Woo Byun, Jae Kyung Kim, Hyun Jin Park, and Cheorun Jo
- Subjects
chemistry.chemical_classification ,Materials science ,Starch ,General Chemical Engineering ,food and beverages ,General Chemistry ,Polysaccharide ,Polyvinyl alcohol ,chemistry.chemical_compound ,chemistry ,Biochemistry ,Enzymatic hydrolysis ,Ultimate tensile strength ,Glycerol ,Locust bean gum ,Irradiation ,Food Science ,Nuclear chemistry - Abstract
The influence of gamma irradiation and an addition of locust bean gum (LBG) on the properties of the starch-based films were investigated. The film casting solution including the corn starch, LBG (0%, 0.75%, and 1.5% w/v), polyvinyl alcohol, sucrose, and glycerol was irradiated at 0, 3, 6, 12, and 24 kGy. After irradiation, an intact and smooth film was formed by irradiation treatment. The presence of LBG increased the tensile strength of the films, but the appropriate irradiation dose should be determined to get the highest tensile strength. Application of LBG reduced the percent elongation of the films, but irradiation significantly increased the percent elongation. The enzymatic hydrolysis and water vapor permeability was shown to decrease with an increase in the irradiation dose. Results indicate that the irradiation technology can be a useful tool as a cross-linking agent with starch and LBG to improve the functional properties of a starch-based film.
- Published
- 2008
40. Effect of gamma irradiation on viscosity reduction of cereal porridges for improving energy density
- Author
-
Eui-Hong Byun, Ju-Woon Lee, Mee Ree Kim, Hong-Sun Yook, Kwan-Soo Kim, Jae-Hun Kim, Myung-Woo Byun, and Sang-Hee Oh
- Subjects
Radiation ,Chemistry ,Starch ,digestive, oral, and skin physiology ,food and beverages ,Nutrient density ,Viscosity ,chemistry.chemical_compound ,Low energy ,Energy density ,Food science ,Irradiation ,Solid content ,Gamma irradiation - Abstract
Cereal porridges have low energy and nutrient density because of its viscosity. The objective of the present study was to evaluate the effect of irradiation on the reduction of viscosity and on the increasing solid content of cereal porridge. Four cereals, wheat, rice, maize (the normal starchy type) and waxy rice, were used in this study. The porridge with 3000 cP was individually prepared from cereal flour, gamma-irradiated at 20 kGy and tested. Gamma irradiation of 20 kGy was allowed that the high viscous and rigid cereal porridges turned into semi-liquid consistencies. The solid contents of all porridges could increase by irradiation, compared with non-irradiated ones. No significant differences of starch digestibility were observed in all cereal porridge samples. The results indicated that gamma irradiation might be helpful for improving energy density of cereal porridge with acceptable consistency.
- Published
- 2008
41. Enhanced anti-tumor effect of combination therapy with gemcitabine and apigenin in pancreatic cancer
- Author
-
Sang Myung Woo, Ji Kon Ryu, Sang Hyub Lee, Kyeung Yeup Lee, Young Tae Kim, Ji Won Yoo, Joo Kyung Park, and Yong Bum Yoon
- Subjects
Antimetabolites, Antineoplastic ,Cancer Research ,Combination therapy ,Down-Regulation ,Apoptosis ,Pharmacology ,Deoxycytidine ,Mice ,chemistry.chemical_compound ,In vivo ,Cell Line, Tumor ,Pancreatic cancer ,Antineoplastic Combined Chemotherapy Protocols ,Animals ,Humans ,Medicine ,Apigenin ,Protein kinase B ,Cell Proliferation ,bcl-2-Associated X Protein ,Dose-Response Relationship, Drug ,business.industry ,NF-kappa B ,Drug Synergism ,medicine.disease ,Xenograft Model Antitumor Assays ,Gemcitabine ,Pancreatic Neoplasms ,Oncology ,chemistry ,Growth inhibition ,business ,Proto-Oncogene Proteins c-akt ,medicine.drug - Abstract
Apigenin is a dietary flavonoid possessing therapeutic potential against cancers. This study was designed to investigate whether combination therapy with gemcitabine and apigenin enhanced anti-tumor efficacy in pancreatic cancer. In vitro, the combination treatment resulted in more growth inhibition and apoptosis through the down-regulation of NF-kappa B activity with suppression of Akt activation in pancreatic cancer cell lines (MiaPaca-2, AsPC-1). In vivo, the combination therapy augmented tumor growth inhibition through the down-regulation of NF-kappa B activity with the suppression of Akt in tumor tissue. The combination of gemcitabine and apigenin enhanced anti-tumor efficacy through Akt and NF-kappa B activity suppression and apoptosis induction.
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- 2008
42. Controlling the radiation degradation of carboxymethylcellulose solution
- Author
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Hee Sub Lee, Ju-Woon Lee, Kwang Won Lee, Ke Won Kang, Jae-Hun Kim, Jong-il Choi, Seog-Jin Seo, and Myung-Woo Byun
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musculoskeletal diseases ,Polymers and Plastics ,Chemistry ,technology, industry, and agriculture ,Gamma ray ,macromolecular substances ,musculoskeletal system ,Condensed Matter Physics ,Scavenger ,body regions ,Viscosity ,Radiation degradation ,Mechanics of Materials ,Materials Chemistry ,Molar mass distribution ,Degradation (geology) ,Irradiation ,Electron beam radiation ,Nuclear chemistry - Abstract
In this study, the effects of an irradiation on the viscosity of the carboxymethylcellulose (CMC) solution were investigated, and the methods to control the degradation of the CMC caused by an irradiation were developed. The viscosity of the CMC solution was decreased with an increase in the irradiation dose, but the extent of the degradation by an irradiation was found to decrease with an increase in the CMC concentration in the solution. The dependency of the irradiation sources showed that an electron beam radiation had degraded the CMC less severely than a gamma ray radiation. An addition of vitamin C as a radical scavenger to the solution was shown to be effective in preventing the decrease of the viscosity of the solution. Also, in the case of an irradiation at −70 °C, the decrease of its viscosity was efficiently inhibited. The degradation of CMC in the solution was confirmed by the molecular weight distribution.
- Published
- 2008
43. The combined effects of N2-packaging, heating and gamma irradiation on the shelf-stability of Kimchi, Korean fermented vegetable
- Author
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Wang-Geun Kim, Myung-Woo Byun, Young-Jin Chung, Jae-Hun Kim, Jin-Gyu Park, and Ju-Woon Lee
- Subjects
chemistry.chemical_compound ,Combined treatment ,chemistry ,Organoleptic ,Fermentation ,Irradiation ,Food science ,Softening ,Food Science ,Biotechnology ,Gamma irradiation ,Lactic acid - Abstract
This study was conducted to evaluate the combined effects of N2-packaging (N2), mild heating at 60 °C (HT) and gamma irradiation of 20 kGy (IR) on the shelf-stability and quality of Kimchi during storage at 35 °C for 30 days. Total microbes including lactic acid bacteria were sterilized perfectly by the combination treatment of HT–IR or N2–HT–IR, and the acidity of Kimchi was not changed during storage. Irradiation softened textural property of Kimchi. However, combination of N2-packaging with heating and irradiation retarded this softening of Kimchi by high dose irradiation. Organoleptic qualities were improved by the combination treatment during the storage period.
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- 2008
44. Does endoscopic sphincterotomy reduce the recurrence rate of cholangitis in patients with cholangitis and suspected of a common bile duct stone not detected by ERCP?
- Author
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Young Soo Park, Kwang Hyuck Lee, Ji Kon Ryu, Sang Hyub Lee, Joo Kyung Park, Ji Won Yoo, Jin-Hyeok Hwang, Ki Young Yang, Yong Bum Yoon, Yong Tae Kim, and Sang Myung Woo
- Subjects
Adult ,Male ,medicine.medical_specialty ,Cholangitis ,Outcome measurements ,Gallstones ,Gastroenterology ,Sphincterotomy, Endoscopic ,Internal medicine ,Secondary Prevention ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Common bile duct stone ,In patient ,Aged ,Retrospective Studies ,Aged, 80 and over ,Cholangiopancreatography, Endoscopic Retrograde ,medicine.diagnostic_test ,Common bile duct ,business.industry ,Gallbladder ,Hazard ratio ,Retrospective cohort study ,Middle Aged ,Prognosis ,medicine.disease ,Endoscopy ,Surgery ,Treatment Outcome ,medicine.anatomical_structure ,Female ,business - Abstract
Background It has not been established whether endoscopic sphincterotomy (ES) prevents subsequent cholangitis in patients with cholangitis and with a common bile duct (CBD) stone not documented by ERCP. Objective The aim of this study was to investigate the role of ES on the recurrence of cholangitis in patients with a high probability of having a CBD stone, not demonstrated by ERCP. Design and Patients A total of 117 patients who were diagnosed as having cholangitis and a high probability of a CBD stone, not detected by ERCP, were retrospectively reviewed. Cumulative recurrence rates of cholangitis were compared for treatments with and without ES. Setting Multicenter, retrospective study. Interventions ES. Main Outcome Measurements Cumulative recurrence of cholangitis after ERCP. Results Eighty-three patients underwent ES (ES group) and 34 patients did not (non-ES group). No statistically significant differences between the 2 groups were evident in terms of demographic factors or laboratory findings. The mean (standard deviation) follow-up was 22.1 ± 17.2 months (range 3-66 months) in the ES group and 23.3 ± 14.9 months (range 6-84 months) in the non-ES group ( P = .72). The cumulative rates of cholangitis were 6.3% (4.8% vs 9.9%) at 1 year, 15.6% (9.2% vs 29.3%) at 3 years, and 19.5% (9.2% vs 52.9%) at 5 years for ES vs non-ES groups, respectively ( P = .04). By multivariate analysis, ES reduced cholangitis recurrence, with a hazard ratio of 0.305 (95% CI 0.095-0.975, P = .045). Limitations Retrospective study. Conclusions ES reduced further episodes of cholangitis in patients with an episode of cholangitis and a high probability of choledocholithiasis, despite the lack of a CBD stone seen on ERCP.
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- 2008
45. Effects of gamma irradiation on the yields of volatile extracts of Angelica gigas Nakai
- Author
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Jun-Hyoung Kim, Hyun-Pa Song, J.H. Kwon, Dong-Ho Kim, Kyong Su Kim, Myung-Woo Byun, and Hye-Young Seo
- Subjects
Limonene ,Pinene ,Radiation ,Chromatography ,biology ,biology.organism_classification ,law.invention ,Steam distillation ,Terpene ,chemistry.chemical_compound ,Angelica gigas ,chemistry ,law ,Camphene ,Gas chromatography ,Essential oil ,Nuclear chemistry - Abstract
The study was carried out to determine the effects of gamma irradiation on the volatile flavor components including essential oils, of Angelica gigas Nakai. The volatile organic compounds from non- and irradiated A. gigas Nakai at doses of 1, 3, 5, 10 and 20 kGy were extracted by a simultaneous steam distillation and extraction (SDE) method and identified by GC/MS analysis. A total of 116 compounds were identified and quantified from non- and irradiated A. gigas Nakai. The major volatile compounds were identified 2,4,6-trimethyl heptane, α -pinene, camphene, α -limonene, β -eudesmol, α -murrolene and sphatulenol. Among these compounds, the amount of essential oils in non-irradiated sample were 77.13%, and the irradiated samples at doses of 1, 3, 5, 10 and 20 kGy were 84.98%, 83.70%, 83.94%, 82.84% and 82.58%, respectively. Oxygenated terpenes such as β -eudesmol, α -eudesmol, and verbenone were increased after irradiation but did not correlate with the irradiation dose. The yields of active substances such as essential oil were increased after irradiation; however, the yields of essential oils and the irradiation dose were not correlated. Thus, the profile of composition volatiles of A. gigas Nakai did not change with irradiation.
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- 2007
46. Inactivation of Enterobacter sakazakii of dehydrated infant formula by gamma-irradiation
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Jae-Ho Woon, Eui-Baek Byun, Jae-Hun Kim, Sang-Hee Oh, Ju-Woon Lee, Jang-Ho Kim, and Myung-Woo Byun
- Subjects
education.field_of_study ,Radiation ,Population ,Enterobacter ,Biology ,medicine.disease ,biology.organism_classification ,Neonatal meningitis ,Age groups ,Infant formula ,medicine ,Potential source ,Food science ,Causal organism ,education ,Gamma irradiation - Abstract
Enterobacter sakazakii has been implicated as a causal organism in a severe form of neonatal meningitis, with reported mortality rates of 20%. The population at greatest risk is immunocompromised infants of any age. Dried infant formula has been identified as a potential source of the organism in both outbreaks and sporadic cases. The objective of this study was to investigate theirradiation effect of the inactivation on E. sakazakii (ATCC 29544) of a dehydrated infant formula. The D10-values were 0.22–0.27 and 0.76 kGy for broth and dehydrated infant formula, respectively. The irradiation at 5.0 kGy was able to completely eliminate the E. sakazakii inoculated at 8.0 to 9.0 log CFU g−1 onto a dehydrated infant formula. There was no regrowth for all samples during the time they were stored at 10 °C for 6 h after rehydration. The present results indicated that a gamma-irradiation could potentially be used to inactivate E. sakazakii in a dehydrated powdered infant formula.
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- 2007
47. Verification of biological activity of irradiated Sopoongsan, an oriental medicinal prescription, for industrial application of functional cosmetic material
- Author
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Cheorun Jo, Myung Woo Byun, Tae-Soon Park, Jun Ho Son, Bong-Jeun An, and Jin-Young Lee
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Radiation ,biology ,Chemistry ,Stereochemistry ,Arbutin ,Biological activity ,Human skin ,Superoxide dismutase ,Melanin ,chemistry.chemical_compound ,biology.protein ,Composition (visual arts) ,Irradiation ,Food science ,Xanthine oxidase - Abstract
Sopoongsan is an oriental medicinal prescription including 12 medicinal herbs. Sopoongsan is known to have anti-inflammatory, anti-microbial, anti-allergic, and anti-cancer effects on human skin. To use Sopoongsan extract for functional cosmetic composition, its dark color should be brighter for seeking consumer demand, clear products, without any adverse change in its function. Irradiation with doses 0, 5, 10, and 20 kGy was applied to improve color of ethanol- or water-extracted Sopoongsan and also superoxide dismutase (SOD), xanthine oxidase (XO), melanoma cell growth inhibition, and anti-microbial activity was investigated. Generally, ethanol extract was better than water extract in function and irradiation up to 20 kGy did not change any functional effect. Especially, the inhibition of melanin deposition on skin measured by inhibition of B16F10 (melanoma) cell growth was as high as arbutin, commercially available product, when the ethanol-extracted Sopoongsan was irradiated for 20 kGy. Results showed that when irradiation technology is used, the limitation of addition amount of natural materials for food or cosmetic composition caused by color problem can be decreased significantly with time saving and cost benefit compared to conventional color removal process. Therefore, irradiation would be one of the good methods to pose an additional value for related industry.
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- 2007
48. Reduction of the IgE-binding ability and maintenance of immunogenicity of gamma-irradiated Dermatophagoides farinae
- Author
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Soo Young Lee, Myung Woo Byun, Joong Won Park, Ji-Hyun Seo, Ju Woon Lee, and Jae-Hun Kim
- Subjects
Allergy ,Radiation ,Chromatography ,biology ,Immunogenicity ,Immunoglobulin E ,medicine.disease ,medicine.disease_cause ,Molecular biology ,Epitope ,respiratory tract diseases ,chemistry.chemical_compound ,Allergen ,chemistry ,Antigen ,biology.protein ,medicine ,Sodium dodecyl sulfate ,Polyacrylamide gel electrophoresis - Abstract
House dust mites, Dermatophagoides farinae (DF) and Dermatophagoides pteronyssinus , are major allergens in the most common indoor allergen and are important risk factor for asthma. The modified antigen has been studied to treat allergic disorder. This study was carried out to measure possibility of modified allergen using gamma irradiation to treat allergy such as asthma. DF solutions (2 mg/ml) as target allergen were irradiated with Co-60 at 50 and 100 kGy. Conformational alternation of irradiated DF was observed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Levels of anti-irradiated DF mouse IgGs (sub-isotypes) against intact DF were measured similar to that of anti-intact DF IgGs. The binding abilities of house dust mite-allergic patients’ IgE were reduced depending on radiation dose, and irradiation could inhibit the binding ability of patients’ IgE more than 40%. This study has shown that the binding ability of IgE was reduced by conformational alteration by irradiation and the irradiated DF had epitopes capable to induce immunogeniciy.
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- 2007
49. The identification of irradiated seasoned filefish (Thamnaconus modestus) by different analytical methods
- Author
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Myung-Woo Byun, Dong-Ho Kim, Kwan-Soo Kim, Jungeun Noh, Tusneem Kausar, Kyong Su Kim, and Joong-Ho Kwon
- Subjects
Radiation ,biology ,Chemistry ,High intensity ,Radiochemistry ,Cyclobutanone ,Thamnaconus modestus ,biology.organism_classification ,Thermoluminescence ,chemistry.chemical_compound ,Filefish ,Photon emission ,Glow curve ,Irradiation - Abstract
Dried seasoned filefish (Thamnaconus modestus) was irradiated at 0–10 kGy and the identification of irradiation treatment was investigated by analyzing the characteristics of thermoluminescence (TL), hydrocarbon (HC), and 2-alkylacyclobutanone (2-ACB). The TL (TL1), glow curve of the irradiated samples peaked at approximately 150 °C with high intensity, but that of the non-irradiated samples peaked at about 300 °C with little intensity, thus making it possible to discriminate between irradiated and non-irradiated samples. Moreover, TL ratio (TL1/TL2), through normalization steps, enhanced the reliability of the TL1 results. Six kinds of HCs and three kinds of 2-ACBs quantitatively determined for the samples linearly increased in proportion to irradiation doses. In particular, two HCs like 1-hexadecane and 1,7-hexadecadine, and three ACBs, such as 2-dodecylcyclobutanone, 2-(5′-tetradeceyl)cyclobutanone, and 2-tetradecylcyclobutanone, were identified only in the irradiated samples as radiation-induced markers.
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- 2007
50. Radiation sensitivity of selected pathogens in ice cream
- Author
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Jun-Sang Ham, Cheorun Jo, Wan-Kyu Lee, Dong-Ho Kim, Hyun-Joo Kim, and Myung-Woo Byun
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Salmonella ,Aerobic bacteria ,Inoculation ,digestive, oral, and skin physiology ,food and beverages ,Biology ,medicine.disease_cause ,biology.organism_classification ,Radiation sensitivity ,Ice cream ,medicine ,Food science ,Listeria ivanovii ,Escherichia coli ,Flavor ,Food Science ,Biotechnology - Abstract
Microbial contamination was investigated using ice creams with a vanilla, chocolate, and strawberry flavor commercially available in Korea. Radiation sensitivity of the food-borne pathogens was also determined by an inoculation test. Food-borne pathogens used were Listeria ivanovii, Escherichia coli, and Salmonella typhimurium. Total aerobic bacteria, moulds and yeasts, and coliforms in the ice creams ranged from 2 to 3 log CFU/g. Irradiation of 3 kGy was enough to inactivate the total aerobic bacteria for the vanilla ice cream but that of 5 kGy was needed for the chocolate or strawberry ice creams at a frozen condition (−20 °C). To inactivate (>log 6.5) the inoculated L. ivanovii, E. coli, and S. typhimurium into ice cream irradiation of 3, 1, and 0.1 kGy was needed, respectively. The D10 value of L. ivanovii and E. coli was calculated as 0.71–0.77 and 0.28–0.38 kGy range for the ice cream with different flavors at −72 °C, respectively. The D10 value of S. typhimurium could not be calculated in this study because even 0.1 kGy of irradiation reduced the number of S. typhimurium to undetected level. Results suggest that a low dose irradiation can improve the microbial quality and reduce the risk by the food-borne pathogens of ice cream, which has limited alternative sterilization methods due to the temperature characteristics of the products.
- Published
- 2007
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