• 한국버섯학회지
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• 제12권2호
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• pp.96-106
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• 2014

느타리(Pleurotus ostreatus)의 이핵-단핵 계통간(di-mono) 교잡주의 DNA 유전에 관한 특성을 구명하기 위하여 느타리 6계통 및 사철느타리 1계통으로 이핵-단핵 계통간 12조합 48교잡주를 얻어 교잡율, 교잡주의 핵 DNA 패턴 양상과 유연관계도, 자실체의 형태, 갓 색깔을 분석하였다. 이핵-단핵 계통간 교잡에서 느타리와 느타리간, 느타리와 사철느타리간 교잡은 모두 교잡율 100%로 나타났다. 이핵-단핵 계통간 교잡주는 공여체(donor) 이핵체의 핵이수용체(recipient) 단핵체로 전이되었다. 이핵-단핵 계통간 교잡주의 DNA 패턴은 이핵체와 유사하거나 동일한 것이 87.5%, 양친의 중간 패턴이 12.5%였다. 즉, 느타리 이핵주와 느타리 단핵 계통간 교잡주는 이핵체와 유사한 DNA 패턴이 70.9%, 양친의 핵이 공존하는 중간 패턴이 12.5%였으며, 사철느타리와 느타리간 이핵-단핵 계통간 교잡주는 16.6%로 모두 사철느타리 핵 DNA 패턴과 유사하거나 동일하였다. 교잡주의 핵 DNA 패턴은 교잡조합에 따라 차이가 나타났는데 12교잡조합 중에서 4조합에서만 단핵주와 유사하거나 중간 형태를 나타내었고 나머지는 이핵주와 동일한 양상이었다. 교잡주의 자실체 형태는 이핵주 형태가 79.2%, 양친의 중간형태 또는 단핵체 모군주의 형태가 20.8%였다. 하지만 이핵체 형태라 하더라도 자실체 색깔은 다소 달랐다. 사철느타리 이핵-느타리 단핵주간 교잡주의 자실체 갓 색깔은 모두 이핵체 사철느타리와 유사하거나 동일하였다. 느타리 이핵-사철느타리 단핵 계통간 교잡주는 양친의 중간 갓 색깔로 모두 나타났으며 다소 이핵체와 유연관계가 가까운 색깔이었다. 따라서 사철느타리가 다소 우성으로 나타나는 경향이었다. 이러한 결과로 보아 교잡주는 3종류의 핵이 모두 공존하는 세포가 많을 것으로 생각되며, 이핵-단핵 계통간 교잡 방법은 우수한 계통을 육성하는 훌륭한 방법으로 이용될 수 있을 것으로 기대된다.

• 한국식품영양과학회지
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• 제43권7호
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• pp.1025-1035
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• 2014

본 연구는 polyethyleneimine(PEI)을 이용하여 음이온계 레진에 비 고정화 효소인 lipase AH(Burkholderia cepacia)를 고정화한 후 효소적 interesterification을 통해 고정화 효소의 반응 특성을 확인하고자 하였다. 효소적 interesterification에 canola oil, palmitic ethyl ester와 stearic ethyl ester를 기질로 사용하였으며 합성물의 TAG 조성 분석을 통해 특성 연구를 진행하였다. 또한 두 가지 고정화방법(multi layer, mono layer)으로 고정화를 진행하였으며 사용된 lipase solution의 농도와 pH를 달리하여 실시하였다. 먼저 효소와 support 간의 친화력을 확인하기 위하여 단백질 함량을 측정하였다. 그 결과 고정화에 사용된 lipase solution의 농도가 8 mg/mL일 때 친화력이 좋았으며 MUIM의 경우 pH 7.5에서, MOIM의 경우 pH 8.0에서 고정화 효율이 가장 좋았다. 또한 고정화 효소의 활성을 확인하기 위하여 interesterification을 진행하였고 TAG와 sn-2 position 분석을 통하여 활성을 비교하였다. 이러한 결과를 참고하여 가장 친화력이 좋았던 조건에서 고정화를 진행하였다. 그 결과 MUIM의 경우 total saturated fatty acid(${\Sigma}SFA$)의 함량이 16.79 area%였으며 MOIM의 경우는 ${\Sigma}SFA$의 함량이 26.17 area%로 나타났다. 반면에 sn-2 position 분석결과 MUIM과 MOIM 모두 palmitic acid와 stearic acid의 함량이 증가한 경향을 나타내었는데, 이는 기존의 sn-1, 3 특이성을 가지는 lipase AH가 고정화를 통해 무작위 특이성으로 변화한 것으로 생각되었다. 또한 RP-HPLC를 이용하여 TAG의 조성을 확인한 결과, 기질은 canola oil이 주로 OOO와 LOO로 조성되었으나 고정화 효소의 interesterification 반응 후 합성물은 주로 POO/SLO, LPO/LOP와 SOO, SOS 등으로 이루어진 것으로 확인되었다. 위와 같은 결과를 바탕으로 최종 생산된 MUIM과 MOIM을 이용하여 interesterification 반응을 온도, 시간을 달리하여 진행하였다. 전체적으로 MOIM의 활성이 가장 높았으며 lipase AH, MOIM과 MUIM 모두 반응시간이 증가할수록 ${\Sigma}SFA$의 함량은 증가하였으나 12시간 이후로는 시간대비 효율은 크게 증가하지 않았다. 또한 시간이 증가함에 따라 sn-2 position의 ${\Sigma}SFA$ 함량이 높아졌다. 한편 반응온도가 높을수록 ${\Sigma}SFA$의 함량도 증가하였는데, 이는 상온인 $25^{\circ}C$보다 높은 melting point를 가지는 stearic ethyl ester와 palmitic ethyl ester가 semi solid 형태로 존재하여 활성이 저해된 것으로 생각된다. 또한 lipase AH는 재사용이 불가능하였지만 고정화 효소인 MUIM과 MOIM은 5번을 재사용하여도 그 효소의 활성이 유지되는 것을 확인할 수 있었다. 이러한 결과를 토대로 음이온계 레진에 PEI를 이용하여 lipase AH를 고정화하였을 경우 비 고정화 효소인 lipase AH보다 MUIM과 MOIM의 활성이 더 높아 산업적으로 이용 가능할 것으로 생각된다.

• 한국미생물·생명공학회지
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• 제37권1호
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• pp.75-79
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• 2009

In this study, we polymerized new materials for soft contact lens using HEMA (2-hydroxyethyl methacrylate) which is the based-monomer of soft contact lens, EGDMA (ethylene glycol dimethacrylate) as cross linkage agent, and the new additives of monoester or di-ester derived from itaconic acid commercially produced by the fermentation of Asp. itaconicus. New polymer materials for soft contact lens were synthesized with the mixture of HEMA and mono- or diester at different ratios and presented to a good water content and oxygen transmissibility (Dk/L) values. In case of polymerization with HEMA and mono-ester (15%), the water content and oxygen transmissibility of contact lens were found to be good values at 57.6% and 28.5 Dk respectively. The mixture of HEMA and mono-ester is more excellent than HEMA/di-ester in the water content and oxygen transmissibility. The toxicity of new contact lens materials were confirmed in the fibroblast L-929 cell line using a agar overlay test and a growth inhibition test with the extract solution of contact lens.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.338-343
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• 2003

Various factors, such as the adsorption pH, adjuvant dose, and adjuvant age, which affect the adsorption degree and immunogenicity of an antigen, were investigated. In addition, the effect of pH, antigen content, and adjuvant content on immunogenicity was also studied through animal experiments. Within the ranges studied, a low pH for adsorption, freshly preformed gel, and low pH formulation for the combined DTwP-HepB vaccine were preferrable for the adsorption of the antigens. In addition, a higher DT content was found to have a positive effect on the HBsAg immunogenicity in the combined vaccine. Accordingly, considering the factors affecting the adsorption rate and immunogenicity of the antigens, a novel DTwP-HepB vaccine (40 Lf/ml of diphtheria toxoid, 15 Lf/ml of tetanus toxoid, 20 OU/ml of detoxified whole cell pertussis, $24\;\mu\textrm{g}$ of HBsAg, $24\;\mu\textrm{g}\;Al/ml\;of \;Al(OH)_3\;gel,\;776\;\mu\textrm{g}\; Al/ml\;of\;AIPO_4\;gel$, and pH 7.1) was developed, whose immunogenicity was comparable to the case of administrating, separately and simultaneously, a combined DTwP vaccine (40 Lf/ml of diphtheria toxoid, 15 Lf/ml of tetanus toxoid, 20 OU/ml of detoxified whole cell pertussis, $300\;\mu\textrm{g}\;Al/ml\;of\; AIPO_4\;gel$, and pH 7.1) and mono HepB vaccine [$Hepavax^{\circledR},\;24\;\mu\textrm{g}/ml$ of HBsAg and $500\;\mu\textrm{g}\;Al/ml\;of\;Al(OH)_3\;gel$], which satisfies the potency criteria of the K-FDA for a combined DTwP vaccine and mono HepB vaccine.

• Structural Engineering and Mechanics
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• 제52권4호
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• pp.787-813
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• 2014

Starting with Hamilton's variational principle, the governing field equations for the steady state response of thin-walled beams under harmonic forces are derived. The formulation captures shear deformation effects due to bending and warping, translational and rotary inertia effects and as well as torsional flexural coupling effects due to the cross section mono-symmetry. The equations of motion consist of four coupled differential equations in the unknown displacement field variables. A general closed form solution is then developed for the coupled system of equations. The solution is subsequently used to develop a family of shape functions which exactly satisfy the homogeneous form of the governing field equations. A super-convergent finite element is then formulated based on the exact shape functions. Key features of the element developed include its ability to (a) isolate the steady state response component of the response to make the solution amenable to fatigue design, (b) capture coupling effects arising as a result of section mono-symmetry, (c) eliminate spatial discretization arising in commonly used finite elements, (d) avoiding shear locking phenomena, and (e) eliminate the need for time discretization. The results based on the present solution are found to be in excellent agreement with those based on finite element solutions at a small fraction of the computational and modelling cost involved.

• Macromolecular Research
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• 제15권3호
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• pp.244-255
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• 2007

Nucleation is the most sensitive stage in the preparation of highly cross-linked, monodisperse microspheres by dispersion polymerization, since the addition of a small amount of cross-linker results in particle deformation and coagulation. To overcome these problems, $5\;{\mu}m$ poly(methyl methacrylate) seed particles prepared by dispersion polymerization were used in the preparation of mono disperse, cross-linked PMMA particles containing up to 7 wt% divinylbenzene by seeded batch dispersion polymerization. Spherical particles with a narrow size distribution containing up to 8 wt% of EGDMA were prepared by seeded multi-batch dispersion polymerization processes. These particles were identified by scanning electron microscopy and DSC.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.179-183
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• 2003

• Steel and Composite Structures
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• 제18권3호
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• pp.603-621
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• 2015

In this study, theoretical models and design procedures of the behavior of thin-walled simply supported steel beams with an open cross section under a large torsional effect are presented. I-sections were chosen as the cross section types. Firstly, the widely used differential equations for the lateral buckling for the pure bending moment effect in a beam element were adopted for the various moment distributions along the span of the beam. This solution was obtained for both mono-symmetric and bisymmetric sections. The buckling loads were then obtained by using the energy method. When using the energy method to solve the problem, it is possible to locate the load not only on the shear center but also at several points of the section depth. Buckling loads were obtained for six different load types. Results obtained for different load and cross section types were checked with ABAQUS software and compared with several standard rules.

• 한국생산제조학회지
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• 제9권3호
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• pp.169-177
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• 2000

In machining screws which are important members in mono pumps or progressive cavity pumps CNC turning center with 3 axes is usually used. This sort of screw machining requires large amount of CL data points and rotational tools are used in machining. When working out the CL data points consideration of possible tool interference is important in order to avoid undercut. This paper describes the checking methods of tool interference in the screw machining on the CNC turning center. First of all a specific shape of a screw cross-section that could commonly be applied to all screws was chosen and then possible tool interference associated with that shape was identified. Checking method was mathematically developed and verified. This checking method will be utilized in the CAM system developed by the authors for screw machining on the 3-axis CNC turning center.

• Structural Engineering and Mechanics
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• 제33권4호
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• pp.447-484
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• 2009

The spatially coupled buckling, in-plane, and lateral bucking analyses of thin-walled Timoshenko curved beam with non-symmetric, double-, and mono-symmetric cross-sections resting on elastic foundation are performed based on series solutions. The stiffness matrices are derived rigorously using the homogeneous form of the simultaneous ordinary differential equations. The present beam formulation includes the mechanical characteristics such as the non-symmetric cross-section, the thickness-curvature effect, the shear effects due to bending and restrained warping, the second-order terms of semitangential rotation, the Wagner effect, and the foundation effects. The equilibrium equations and force-deformation relationships are derived from the energy principle and expressions for displacement parameters are derived based on power series expansions of displacement components. Finally the element stiffness matrix is determined using force-deformation relationships. In order to verify the accuracy and validity of this study, the numerical solutions by the proposed method are presented and compared with the finite element solutions using the classical isoparametric curved beam elements and other researchers' analytical solutions.