• 자연과학논문집
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• 제14권1호
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• pp.7-24
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• 2004

Thiol peroxidase인 E.coli AhpC의 아미노산 서열을 database를 이용해 분석하여, TPx와 상동성이 있는 새로운 형태의 Thiol peroxidase를 찾아내었다. 그 중 병원성을 갖는 박테리아인 Haemophilus Influenzae에서 존재하는 TPx와 유사하고, GRX와 함께 fusion 되어있는 새로운 형태의 단백질의 유전자를 클로닝하여 E.coli에서 과발현시켜 분리정제 하였다. 정제된 TPx-GRX는 환원제로 thiol 성분을 갖는 MCO system(Fe, DTT, Oxygen)에 의하여 Glutamine Synthetase(GS)의 불활성화를 방어하는 티올 특이적 향산화활성을 갖고, peroxides를 제거하는 peroxidase 활성을 갖는 것을 밝혔다. 이 결과들로부터 TPx-GRX는 새로운 형태의 Thiol perosidase임을 알 수 있었다. 더 나아가서 이 결과들은 TPx-GRX가 병원성 박테리아에서 oxidative stress를 막는 생리적으로 중요한 역할을 할 것이라는 것을 시사한다.

• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.23-29
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• 2020

Multilayer sub-contracting is a significant practice among the world, including Hong Kong. When a principal contractor secured a project from a developer, the specific jobs will usually be breaking down and sub-contractors with the lowest bid [1]. The adoption of multilayer sub-contracting has been a controversy issue which is considered as a two-side blade. While certain studies have been carried out to examine both the contributions, damages and improvements for multi-layer subcontracting, the construction industry and researchers are still waiting for a solid measure to enhance the system. Hence, this research attempts to study the advantages, disadvantages, conducts a comparison between single and multilayer sub-contracting and measures of current Hong Kong construction industry based on literature review, questionnaire and in-depth interviews. To achieve the objectives, Analytic Hierarchy Process (AHP) and total weighted score methods are adopted to examine and rank the criterion. The findings of this study provide a good basis for understanding the major reasons and problems caused by the adoption of multilayer sub-contracting. Besides, the identified safety perspective explores a new perspective regarding to issues of multi-layer subcontracting, which will serve as a solid foundation for further research to enhance safety performance. Finally, the findings of measurements towards improvement of multilayer sub-contracting will also provide a solidsolution for construction industry.

• 한국조경학회지
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• 제42권5호
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• pp.101-109
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• 2014

환경을 훼손하지 않는 경제 성장을 위하여 건설부문의 비용 절감 및 품질 향상의 요구가 커지면서 VE/LCC 분석기법의 활용이 증가되는 추세이다. 본 연구는 생애주기비용과 성능 분석을 고려한 비탈면 생태복원 공법의 가치 분석을 목적으로 수행되었으며 비탈면 생태복원 시공조건을 경사도와 기반조건으로 3가지 조건을 나누고 각 조건별로 비탈면 생태복원 공법 3가지를 선정하여 총 9가지 조건별로 생애주기비용 분석과 성능 분석을 통하여 가치 분석을 실시하였다. 비탈면의 경사도와 기반조건에 따라 조건 1은 경사도 1:1.2 이하, 일반토사이고, 조건 2는 경사도 1:1.0 이하, 리핑암이다. 조건 3은 경사도 1:0.7 이하, 연암 및 발파암이다. 생애주기비용과 성능 분석 결과를 바탕으로 가치 분석을 한 결과, 조건1에서 B공법 108.4점, A공법 90.3점, C공법 45.8점 순으로 나타났으며, 조건 2에서는 A공법 89.1점, B공법 47.5점, C공법 47.0점 순으로 나타났고, 조건 3에서는 A공법 89.1점, B공법 55.4점, C공법 40.2점 순으로 나타나, 조건 1에서는 B공법이 높았으나, 조건 2, 3에서는 A공법의 점수가 높았다. 본 연구결과를 토대로 생애주기비용과 성능 분석을 고려하여 비탈면 생태복원 사업의 원가절감 및 품질 향상을 도모할 수 있는 합리적인 의사결정에 사용될 수 있을 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권11호
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• pp.1610-1613
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• 2003

The aim of the experiment was to study the changes in the activities of various rumen fibre degrading enzymes due to the feeding of chemically treated mustard (Brassica campestris) straw in sheep. Mustard straw (MS) (<5 cm particle size) was treated either with urea (4% (w/w), or with 2% sodium hydroxide (NaOH), or with alkaline hydrogen peroxide (2% NaOH and 1.5% hydrogen peroxide ($H_2O_2$)) and/or supplemented with 2% (w/w) urea. Seven maintenance type rations were prepared using MS (70 parts) with molasses (5 parts) and concentrate (25 parts). They were untreated MS (CMS), urea treated MS (UMS), urea supplemented MS (MSUS), alkali treated MS (AMS), alkali treated and urea supplemented MS (AMS-US), alkali $H_2O_2$ treated MS (AHMS) and alkali $H_2O_2$ treated and urea supplemented MS (AHMS-US). They were then compressed into a complete feed block with the help of block making machine. Forty two male hoggets of Malpura breed sheep were equally distributed into each treatment group and (were) offered feed and water ad libitum. At the end of 21 days of feeding trial, rumen liquor was collected through stomach tube from three animals in each group at 0 h, 4 h, 8 h, 12 h of post feeding. Results showed that the level of enzyme varied from 8.52 to 11.12, 40.85 to 50.37, 3.22 to 3.78, 2.09 to 2.77 and 31.44 to 44.24 units/100 ml SRL respectively for carboxymethyl cellulase (CMCase), $\alpha$-amylase, microcrystalline cellulase (MCCase), filter paper (FP) degrading enzyme and $\alpha$-glucosidase. Processing of MS affected the enzyme activities, in a way, that NaOH and AHP treatment significantly reduced CMCase and FP degrading enzyme. The effect of urea treatment showed an increase in the activity of MCCase and $\alpha$-glucosidase. But the supplementation of urea increased the activity of CMCase, FP degrading enzyme and $\alpha$-glucosidase. The CMCase, $\alpha$-amylase, $\alpha$-glucosidase activities were highest at 4hr whereas MCCase and FP degrading enzyme had maximum activities at 12 h post feeding Results suggested that MS might need longer time in the rumen for its effective degradation.

• The Korean Journal of Physiology and Pharmacology
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• 제2권3호
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• pp.297-305
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• 1998

This study used in vivo intracellular recording in rat hippocampus to evaluate the effect of lidocaine and MK-801 on the membrane properties and the synaptic responses of individual neurons to electrical stimulation of the commissural pathway. Cells in control group typically fired in a tonic discharge mode with an average firing frequency of $2.4{\pm}0.9$ Hz. Neuron in MK-801 treated group (0.2 mg/kg, i.p.) had an average input resistance of $3.28{\pm}5.7\;M{\Omega}$ and a membrane time constant of $7.4{\pm}1.8$ ms. These neurons exhibited $2.4{\pm}0.2$ ms spike durations, which were similar to the average spike duration recorded in the neurons of the control group. Slightly less than half of these neurons were firing spontaneously with an average discharge rate of $2.4{\pm}1.1$ Hz. The average peak amplitude of the AHP following the spikes in these groups was $7.4{\pm}0.6$ mV with respect to the resting membrane potential. Cells in MK-801 and lidocaine treated group (5 mg/kg, i.c.v.) had an average input resistance of $3.45{\pm}6.0\;M{\Omega}$ and an average time constant of $8.0{\pm}1.4$ ms. The cells were firing spontaneously at an average discharge rate of $0.6{\pm}0.4$ Hz. Upon depolarization of the membrane by 0.8 nA for 400 ms, all of the tested cells exhibited accommodation of spike discharge. The most common synaptic response contained an EPSP followed by early-IPSP and late-IPSP. Analysis of the voltage dependence revealed that the early-IPSP and late-IPSP were putative $Cl^--and\;K^+-dependent$, respectively. Systemic injection of the NMDA receptor blocker, MK-801, did not block synaptic responses to the stimulation of the commissural pathway. No significant modifications of EPSP, early-IPSP, or late-IPSP components were detected in the MK-801 and/or lidocaine treated group. These results suggest that MK-801 and lidocaine manifest their CNS effects through firing pattern of hippocampal pyramidal cells and neural network pattern by changing the synaptic efficacy and cellular membrane properties.