POSTERS / PM-097 : PRELIMINARY X-RAY CRYSTALLOGRAPHIC STUDIES OF GLUTARYL-7 AMINOCEPHALOSPORANIC ACID ( GL-7-ACA ) ACYLASE FROM Pseudomonas sp. STRAIN GK16

(Taek Hun Kwon),(Young Sik Lee),(Sung Soo Park),(Kyung Hyun Kim) 한국생화학분자생물학회 (구 한국생화학회) 1999 6th IUBMB SEOUL CONFERENCE Vol.- No.-

Crystallization and X-ray crystallographic analysis of ribose 5-phosphate isomerase B in complex with its ligand from Vibrio vulnificus

Taek Hun Kwon,Kyoungin Min,Matthias Wolf,Changill Ban,Tae Gyun Kim 한국구조생물학회 2022 Biodesign Vol.10 No.2

Ribose 5-phosphate isomerase is an enzyme that interconverts ribose 5-phosphate and ribulose 5-phosphate in the pentose phosphate pathway, which participates in NADPH generation, as well as an oxidative and non-oxidative synthesis of pentose sugars. Two distinct forms, ribose 5-phosphate isomerase A (RpiA) and ribose 5-phosphate isomerase B (RpiB), show no sequence identity even though they exist as ubiquitous, highly-conserved proteins in most kingdoms. RpiB from pathogenic, marine Vibrio vulnificus YJ016 (VvRpiB) was purified, crystallized, and analyzed to determine its structure in the apo form and in complex with a ligand. Crystals of the apo form of VvRpiB diffracted X-rays to 3.06 Å resolution, belonging to tetragonal space group I41 while co-crystals of VvRpiB with R5P belonged to the monoclinic space group C2 and diffracted X-rays to 2.07 Å resolution.

Studies on Printing Inks Containing Poly[2-methoxy-5-(2-ethylhexyl-oxyl)-1,4-phenylenevinylene] as an Emissive Material for the Fabrication of Polymer Light-Emitting Diodes by Inkjet Printing

Kwon, Jae-Taek,Eom, Seung-Hun,Moon, Byung-Seuk,Shin, Jin-Koog,Kim, Kyu-Sik,Lee, Soo-Hyoung,Lee, Youn-Sik Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.2

Three solvent systems, chlorobenzene (ink 1), chlorobenzene/o-dichlorobenzene (ink 2) and chlorobenzene/tetrahydronaphthalene (ink 3), were compared as printable inks for the fabrication of polymer light-emitting diodes (PLEDs) using poly[2-methoxy-5-(2-ethylhexyl-oxyl)-1,4-phenylenevinylene (MEH-PPV) as an emissive material and an inkjet printer (Fujifilm Dimatix DMP-2831). Ink 1 clogged the printer's nozzle and gave non-uniform film. Inks 2 and 3 were used to fabricate PLEDs with ITO/PEDOT:PSS/MEH-PPV/LiF/Al configurations. The best performance (turn-on voltage, 3.5 V; luminance efficiency, 0.17 cd/A; luminance, 1,800 cd/m) was obtained when ink 3 was used to form the emissive layer (thickness, 49 nm), attributable to the better morphology and suitable thickness of the MEH-PPV layer.

The Controlling Greenhouse Using ZigBee Wireless Network for Crop Production and Quality

Hun Kyo Seo,Jong Pill Han,Yoo Taek Seo,Yeo Jin Jung,Kwon Kyoo Kang,Yu Jin Jung 한국원예학회 2015 한국원예학회 학술발표요지 Vol.2015 No.5

이산화염소처리가 밀의 살균과 밀가루의 레올리지 특성에 미치는 영향

권천택,정헌철,정동효 中央大學校 食糧資源硏究所 1992 食糧資源硏究所 論文集 Vol.4 No.1

밀가루의 품질개량제와 상하수의 처리에 살균제로 사용되는 이산화염소에 의한 소맥의 살균효과를 CIO₂농도, 세균농도, 가수온도 등의 측면에서 연구하고 이산화염소를 첨가하지 않고 가수한 소맥과 이산화염소의 첨가농도(50, 100 및 200㎎/㎏)를 다르게 하여 가수한 소맥을 재분하였을 때 각각의 밀가루 성분과 리올리지 특성의 변화를 비교 연구한 결과를 요약하면 다음과 같다. (1) 이산화염소의 첨가농도가 증가함에 따라 E. agglomerans의 살균효과는 증가하여 12∼18시간 가수에서 최소의 생존율을 나타내었다. 그러나 이산화염소의 첨가농도가 증가함에 따라 가수초기의 세균농도가 살균효과에 미치는 영향은 적은 것으로 나타났다. (2) 이산화염소에 의한 살균에서 가수온도의 증가(15∼35℃범위)에 따라 생존율이 급격히 감소하였으나 가수시간이 경과함에 따라 다시 증가하기 시작하여 12시간 가수에서는 35℃에서의 생존율이 15℃, 25℃에서 보다 오히려 높은 생존율을 나타내었다. (3) DNS, SW glour의 수분, 조회분, 조단백질과 gluten함량은 이산화염소의 처리량을 달리 한 것과 처리하지 않은 것간에 거의 변화가 없었고 백색도와 pH에서도 유의성이 없었다. (4) Farinogram특성에서 이산화염소 처리량이 증가함에 따라 DNS flour 반죽형성시간과 안정도 그리고 valorimeter value는 증가하는 경향이었으나 약화도와 흡수율은 감소하였으며 탄력도는 변화가 거의 없었다. SW flour의 반죽형성시간, 안정도, valorimeter value와 약화도는 일정하지 않으나 변화가 거의 없었다. 흡수율은 처리량이 100㎎/㎏일 때 가장 낮으며 탄력도는 처리양이 100㎎/㎏일 때 가장 높았다. (5) Extensogram특성에서 DNS, SW flour모두 이산화염소 처리량의 증가에 따른 신장도의 변화는 일정하지 않으며 방치시간이 길어짐에 따라 신장도는 감소하였다. 이산화염소처리량이 증가함에 따라 신장저항도와 형상계수(R/E)는 증가하였으며 이산화염소를 처리하지 않은 것과 처리한 것 모두 반죽시간이 길수록 신장저항도와 형상계수는 증가하였다. (6) Amylogram특성에서 DNS,SW flour 모두 이산화염소 처리량이 증가함에 따라 호화 개시온도와 최고점도시 온도는 이산화염소를 처리하지 않은 것과 동일하거나 변화의 차이가 적었다. 이산화염소 처리량이 증가함에 따라 최고점도는 증가하였다. The objective of this study was to investigate the effect of chlorine dioxide on the bacterial disinfection of wheat and the rheological properties of wheat flour. Chlorine dioxide was applied to wheat at levels of 0, 50, 100 and 200㎎㎏, respectively. As chlorine dioxide concentration was increased, the survival rate of E. agglomerans was decreased. It was the lowest at tempering time of 12∼18hrs, and then increased as tempering time was extended. Bactericidal effect of chlorine dioxide was less affected by the initial bacterial population at high concentration of chlorine dioxide. The survival rea of E . agglomerans was rapidly decreased as the tempering temperature was raised in the range of 15∼35℃, but increased as the tempering time was extended. Chlorine dioxide treastment did not affect pH, whiteness and contents of moisture, crude ash, crude protein and gluten in patent flour. Farinograms showed that dough development time, stability and valorimeter value of Dark Northern Spring patent flour were increased, whereas weakneww and water absorption decreased by chlorine dioxide treatment. On the other hand, dough development time, stability, valorimeter value and weaknewss of Soft White patent flour were not changed by chlorine dioxide treatment. Extensograms of Dark Northern Spring and Soft white patent flour revealed that extensibility was not affected, but resistence was affected by chlorine dioxide treatment. Chlorine dioxide treatment did not affected gelatination temp. and temp. of maximum viscosity, but affected maximum viscosity of Dark Nothern Spring and Soft White patent flour.

Evaluation of Pumping Characteristics of High Strength Concrete using Continuous Pumping System

Kwon, Dae-Hun,Lee, Han-Seung,Jeon, Jun-Young,Jeong, Woong-Taek,Jo, Ho-Kyoo,Kim, Hyung-Rae The Korean Institute of Building Construction 2011 한국건축시공학회지 Vol.11 No.4

In the construction of tall-building, concrete pumping influences the success of the project. In order to establish pumping technology for high speed construction of tall building, study for quantitative evaluation of flow characteristics and pumpability should be conducted. So in this study, the characteristics including the inner pipe pressure, rheological properties of concrete and mortar through the continuous pumping test were evaluated. Then we analyzed the relations between rheological properties and pumpability. In the result of test, there are high correlations between the rheological characteristics which represented by yield stress and plastic viscosity and pressure loss with pipe length. Also, we estimated pressure loss according to conditions of concrete mix and pumping through the evaluation of inner pipe friction.

Genetic Transformation with Herbicide-resistant Gene Does not alter Cross Ability and Pollen Viability in Chile Pepper

Taek-Ryoun Kwon(권택륜),Tae-San Kim(김태산),Young-Hwan Park(박용환),Tae-Hun Ryu(류태훈),Hwa-Suk Song(송화숙),Jeong-Keun Choi(최정근) 한국원예학회 2003 한국원예학회 학술발표요지 Vol.2003 No.10

Comparative fracture strength analysis of Lava and Digident CAD/CAM zirconia ceramic crowns

Kwon, Taek-Ka,Pak, Hyun-Soon,Yang, Jae-Ho,Han, Jung-Suk,Lee, Jai-Bong,Kim, Sung-Hun,Yeo, In-Sung The Korean Academy of Prosthodonitics 2013 The Journal of Advanced Prosthodontics Vol.5 No.2

PURPOSE. All-ceramic crowns are subject to fracture during function. To minimize this common clinical complication, zirconium oxide has been used as the framework for all-ceramic crowns. The aim of this study was to compare the fracture strengths of two computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia crown systems: Lava and Digident. MATERIALS AND METHODS. Twenty Lava CAD/CAM zirconia crowns and twenty Digident CAD/CAM zirconia crowns were fabricated. A metal die was also duplicated from the original prepared tooth for fracture testing. A universal testing machine was used to determine the fracture strength of the crowns. RESULTS. The mean fracture strengths were as follows: $54.9{\pm}15.6$ N for the Lava CAD/CAM zirconia crowns and $87.0{\pm}16.0$ N for the Digident CAD/CAM zirconia crowns. The difference between the mean fracture strengths of the Lava and Digident crowns was statistically significant (P<.001). Lava CAD/CAM zirconia crowns showed a complete fracture of both the veneering porcelain and the core whereas the Digident CAD/CAM zirconia crowns showed fracture only of the veneering porcelain. CONCLUSION. The fracture strengths of CAD/CAM zirconia crowns differ depending on the compatibility of the core material and the veneering porcelain.

Effect of recombinant human bone morphogenetic protein-2 on bisphosphonate-treated osteoblasts

Taek-Kyun Kwon,Jae-Min Song,In-Ryoung Kim,Bong-Soo Park,Chul-Hoon Kim,In-Kyo Cheong,Sang-Hun Shin 대한구강악안면외과학회 2014 대한구강악안면외과학회지 Vol.40 No.6

Objectives: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a side effect of bisphophonate therapy that has been reported in recent years. Osteoclastic inactivity by bisphosphonate is the known cause of BRONJ. Bone morphogenetic protein-2 (BMP-2) plays an important role in the development of bone. Recombinant human BMP-2 (rhBMP-2) is potentially useful as an activation factor for bone repair. We hypothesized that rhBMP-2 would enhance the osteoclast-osteoblast interaction related to bone remodeling. Materials and Methods: Human fetal osteoblast cells (hFOB 1.19) were treated with 100 μM alendronate, and 100 ng/mL rhBMP-2 was added. Cells were incubated for a further 48 hours, and cell viability was measured using an MTT assay. Expression of the three cytokines from osteoblasts, receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), and macrophage colony-stimulating factor (M-CSF), were analyzed by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Results: Cell viability was decreased to 82.75%±1.00% by alendronate and then increased to 110.43%±1.35% after treatment with rhBMP-2 (P<0.05, respectively). OPG, RANKL, and M-CSF expression were all decreased by alendronate treatment. RANKL and M-CSF expression were increased, but OPG was not significantly affected by rhBMP-2. Conclusion: rhBMP2 does not affect OPG gene expression in hFOB, but it may increase RANKL and M-CSF gene expression.

A COMPARATIVE STUDY OF THE 1-PIECE AND 2-PIECE CONICAL ABUTMENT JOINT: THE STRENGTH AND THE FATIGUE RESISTANCE

Kwon, Taek-Ka,Yang, Jae-Ho,Kim, Sung-Hun,Han, Jung-Suk,Lee, Jai-Bong The Korean Academy of Prosthodonitics 2007 대한치과보철학회지 Vol.45 No.6

Statement of problem. The performance and maintenance of implant-supported prostheses are primarily dependent upon load transmission both at the bone-to-implant interface and within the implant-abutment-prosthesis complex. The design of the interface between components has been shown to have a profound influence on the stability of screw joints. Purpose. The Purpose of this study was to compare the strength and the fatigue resistance of 1-piece and 2-piece abutment connected to oral implant, utilizing an internal conical interface. Material and methods. Twenty $Implatium^{(R)}$ tapered implants were embedded to the top of the fixture in acrylic resin blocks. Ten $Combi^{(R)}$(1-piece) and $Dual^{(R)}$(2-piece) abutments of the same dimension were assembled to the implant, respectively. The assembled units were mounted in a testing machine. A load was applied perpendicular to the long axis of the assemblies and the loading points was at the distance of 7mm from the block surface. Half of 1-piece and 2-piece abutment-implant units were tested for the evaluation of the bending strength, and the others were cyclically loaded for the evaluation of the fatigue resistance until plastic deformation occurred. Nonparametric statistical analysis was performed for the results. Results. Mean plastic and maximum bending moment were $1,900{\pm}18Nmm,\;3,609{\pm}106Nmm$ for the 1-piece abutment, and $1,250{\pm}31Nmm,\;2,688{\pm}166Nmm$ for the 2-piece abutment, respectively. Mean cycles and standard deviation when implant-abutment joint showed a first plastic deformation were $238,610{\pm}44,891$. cycles for the 1-piece abutment and $9,476{\pm}3,541$ cycles for the 2-piece abutment. A 1-piece abutment showed significantly higher value than a 2-piece abutment in the first plastic bending moment (p<.05), maximum bending moment (p<.05) and fatigue strength (p<.05). Conclusion. Both 1-piece and 2-piece conical abutment had high strength and fatigue resistance and this suggests long-term durability without mechanical complication. However, the 1-piece conical abutment was more stable than the 2-piece conical abutment in the strength and the fatigue resistance.