http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 윤성철(Sung Chul Yoon) (검색결과 71 건)
- 무료
- 기관 내 무료
- 유료
-
여러 가지 Perturbing media 에서의 알부민의 비가역적 열변성
윤성철,장광숙 ( Sung Chul Yoon,Kwang Sook Chang ) 생화학분자생물학회 1994 BMB Reports Vol.27 No.5
The thermal denaturation mechanisms of bovine serum albumin (BSA) and its reduced form of cysteinylBSA in PBS buffer (pH 7.0, ionic strength=0.1 or 0.2) were investigated on the basis of kinetic analysis in which in-eversible two-state transition (N→D) was assumed. Several perturbants such as urea, N-methylurea, N,N`-dimethylurea, tetrnmethylurea, acetamide, thiourea, guanidine-HCl, sorbitol and glycerol were employed to perturb the system and to see their effect on the thermal denaturation of BSA and disulfide-broken cysteinyl-BSA. The thermal transition parnmeters, T_m (denaturation peak temperature), ΔH_(cal) (endothermic heat) and C_p (heat capacity) of the two proteins were measured on a Setaram micro-DSC (differential scanning calorimeter) in the presence or absence of those perturbants. The activation energies (E_a) of thermal denaturation of BSA and cysteinyl-BSA were estimated from the analysis of DSC-scan profiles. The estimated activation energies (E_a) ranged from 216 to ∼380 KJ/mol depending on the type and the concentration of the perturbant employed. The activation energy of thermal denaturation of unreduced BSA is higher than that of cysteinyl-BSA, which means that the 17 disulfide bonds contribute to the stabilization of BSA. It was also found that urea, methyl substituted ureas and high-concentration guanidine-HCl destabilized BSA, but the polyhydroxyl perturbants of sorbitol and glycerol stabilized the protein, which was determined from both T_m and E_a data. However, increasing acetamide concentration caused a gradual decrease of T_m and a grndual increase of E_a of BSA Thus, this indicates that the two determinants (T_m and E_a) for thermal stability of proteins are independent of each other. Apparent deviation from the two-state mechanism of BSA thermal denaturation in acetamide-containing PBS buffer was estimated by calculating the van`t Hoff enthalpies (ΔH_(VH)) and comparing them with the calorimetric enthalpies (ΔH_(cal)). An increase of acetamide concentration generally decreased the deviation from the two-state mechanism.
-
여러 가지 Perturbing Media에서의 알부민의 비가역적 열변성
윤성철,장광숙,Yoon, Sung-Chul,Chang, Kwang-Sook 생화학분자생물학회 1994 한국생화학회지 Vol.27 No.5
Two-state model을 바탕으로 하여 혈장 알부민(bovine serum albumin)과 그 disulfide 결합이 끊어진 cysteinyl-알부민의 비가역적 열변성 기작을 조사하였다. 고감도 시차주사 열량계(differential scanning calorimeter, DSC)로부터 얻은 알부민의 DSC scan profiles을 속도론적으로 분석하므로써 열변성 활성화에너지($E{\alpha}$)를 구하였다. Urea, N-methylurea, N,N'-dimethylurea, tetramethylurea, acetamide, thiourea, guanidine-HCl, sorbitol, glycerol 등과 같은 perturbants가 알부민의 변성에 어떤 영향을 주는지를 조사하였다. Perturbant의 종류 및 농도에 따라 $E{\alpha}$가 216~380 kJ/mol의 범위값을 나타냈다. 비환원 알부민의 $E{\alpha}$가 cysteinyl-알부민보다 높게 나타났다. 이는 17개의 disulfide 결함이 알부민의 안정화에 기여함을 의미한다. 이용된 perturbants는 네가지 type으로 분류되었다. 첫째, sorbitol, glycerol, 등은 농도를 증가시킴에 따라 알부민의 $E{\alpha}$와 $T_m$(endothermic peak temperature) 모두를 증가시킴으로써 강력한 안정화제임을 나타냈다. 둘째, urea, 메틸치환 urea, thiourea 등은 농도가 증가함에 따라 알부민 변성 활성화에너지($E{\alpha}$)와 $T_m$의 감소를 보임으로써 강력한 변성제임을 나타냈다. 셋째, acetamide는 농도가 증가함에 따라 $E{\alpha}$의 증가, $T_m$의 감소의 양면성을 보여주었다. 특히, acetamide의 경우 농도가 7~8M일 때 알부민의 열변성은 정확한 two-state 전이과정을 거치는 것으로 확인되었다. 넷째, guanidine-HCl은 ~1M 이하 농도에서는 안정화 효과를 보이다가 그 이상 농도에서는 변성제로 작용하는 현상을 보였다. The thermal denaturation mechanisms of bovine serum albumin (BSA) and its reduced form of cysteinyl-BSA in PBS buffer (pH 7.0, ionic strength = 0.1 or 0.2) were investigated on the basis of kinetic analysis in which irreversible two-state transition ($N{\rightarrow}D$) was assumed. Several perturbants such as urea, N-methylurea, N,N'-dimethylurea, tetramethylurea, acetamide, thiourea, guanidine-HCl, sorbitol and glycerol were employed to perturb the system and to see their effect on the thermal denaturation of BSA and disulfide-broken cysteinyl-BSA. The thermal transition parameters, $T_m$ (denaturation peak temperature), ${\Delta}H_{cal}$ (endothermic heat) and $C_p$ (heat capacity) of the two proteins were measured on a Setaram micro-DSC (differential scanning calorimeter) in the presence or absence of those perturbants. The activation energies ($E{\alpha}$) of thermal denaturation of BSA and cysteinyl-BSA were estimated from the analysis of DSC-scan profiles. The estimated activation energies ($E{\alpha}$) ranged from 216 to ~380 KJ/mol depending on the type and the concentration of the perturb ant employed. The activation energy of thermal denaturation of unreduced BSA is higher than that of cysteinyl-BSA, which means that the 17 disulfide bonds contribute to the stabilization of BSA. It was also found that urea, methyl substituted ureas and high-concentration guanidine-HCl destabilized BSA, but the polyhydroxyl perturbants of sorbitol and glycerol stabilized the protein, which was determined from both $T_m$ and $E{\alpha}$ data. However, increasing acetamide concentration caused a gradual decrease of $T_m$ and a gradual increase of $E{\alpha}$ of BSA. Thus, this indicates that the two determinants ($T_m$ and $E{\alpha}$) for thermal stability of proteins are independent of each other. Apparent deviation from the two-state mechanism of BSA thermal denaturation in acetamide-containing PBS buffer was estimated by calculating the van't Hoff enthalpies (${\Delta}H_{VH}$) and comparing them with the calorimetric enthalpies (${\Delta}H_{cal}$). An increase of acetamide concentration generally decreased the deviation from the two-state mechanism.
-
윤성철,최해운,Yoon, Sung Chul,Choi, Hae-Woon 한국레이저가공학회 2015 한국레이저가공학회지 Vol.18 No.4
Specially designed and 3D printed samples were prepared and joined by a diode laser source. To increase the strength of joining and reliability of samples, the surface was patterned by using a 3D printer. The joining surface was prepared as hemispherical shape with no-patterns, 0.5mm pitch, 0.75mm pitch and 1mm pitch. The optical properties of samples were measured by using an integrated sphere where classical Kubelka-Munk theory and modified Richard-Mudgetts theory for the analysis applied. Scanning speed was set at 500mm/min and laser power was varied between 9 and 10watts for the preliminary joining characteristic analysis.
-
안경테제조를 위한 친환경 아세테이트 수지의 레이저 접합특성에 관한 연구
윤성철,박승규,박중언,최해운,Yoon, Sung Chul,Park, Sung Gyu,Park, Joong Un,Choi, Hae Woon 한국레이저가공학회 2014 한국레이저가공학회지 Vol.17 No.4
Laser beam was applied on the boundary of the polyurethane and biodegradable polyacetate polymers. The distributed laser passed through the polyurethane layer and heated the polyacetate layer, then the soften acetate was squeezed thorough the 1mm square slots of polyurethane for the mechanical joining. The surface roughness ranging between $0.28{\mu}m$ and $3.06{\mu}m$ had almost no effect on joining strength, but the optical properties of HD (High Definition) and UHD (Ultra High Definition) mode affected laser beam transmittance. The optimum laser power was found to be between 8watt and 10watt with 500mm/min of scanning speed. The joining boundary was characterized by optical and SEM analysis. Based on the experiment and characterization results, the laser energy was effective for the polymer joining and efficiency of joining.
-
열경화성 3D 프린트 몰드와 생분해성 소재 접합에 관한 연구
윤성철,마재권,방대욱,최해운,Yoon, Sung Chul,Ma, Jae Kwon,Bang, Dae Wook,Choi, Hae Woon 대한용접접합학회 2014 대한용접·접합학회지 Vol.32 No.4
Laser heat source was applied on 3D poly urethane model built by 3D printer and cellulous acetate for joining. A diode laser with 808nm wavelength was transmitted through the 3D model and applied on the boundary of ABS/Acetate and 3D poly urethane model. Based on the experimental result, the ABS and 3D built poly-urethane polymers was successfully joined, but the mechanical strength was not enough at the joining boundaries in the range of 6watt to 8watt of laser heat source. However, biodegradable acetate was successfully joined without damaging the 3D built model and mechanical strength was properly achieved. The optimum laser power was found between 5watt and 8watt with scanning speed of 500mm/min, 700mm/min and 1,000mm/min. Based on the SEM analysis the filling mechanism was that the applied pressure on 3D built model squeezed the fluidic thermoplastics, ABS and acetate, into the structure of 3D model. Therefore soundness of joining was strongly depending on the viscosity of thermoplastics in polymers. The developed laser process is expected to increase productivity and minimize the cost for the final products.
-
-
-
-
공공부문 IT 아웃소싱 의사결정 요인 도출:델파이 방법
윤성철(Sung Chul Yoon),이슬(Seul Lee) 한국IT서비스학회 2003 한국IT서비스학회지 Vol.2 No.2
To improve the quality of the services and to concentrate on the core capability, in public sector the IT outsourcing is recently being vitalized by the institutional support of the government for the entrusting non-government. Because the lots of general studies so far have simply focused on indicating fragmentary factors i.e. economical factors, risk factors, system factors, or induction objects, etc., they are insufficient in making the practical decisions, therefore we indicated systemized model extending over the whole range of the IT outsourcing to support substantial decision makings, and assorted 4 categories and drew considerable 55 factors from the literature study to materialize the previously considerable factors at each decision making stage. And the principal factors were drawn from each decision making category by a group of 11 experts. Besides, a henceforth plan for the application was also presented through an actual example of the IT outsourcing decision making process of ‘M’, a public enterprise.
-
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
