• International Journal of Precision Engineering and Manufacturing
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• 제6권4호
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• pp.55-59
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• 2005

This paper presents a feasibility study whether Shida's constitutive equation being widely used for plain carbon steel in steel manufacturing industry can be extended to alloy steels with a due carbon equivalent model. T,he constitutive relation of the alloy steels (SAE9254, AISI52100 and AISI4140) is measured using hot deformation simulator (GLEEBLE 3500C) at high temperatures ($800^{\circ}C{\~}1000^{\circ}C$) within strain rates of $0.05{\~}40\;s^{-1}$. It has been found the predicted flow stress behavior (constitutive relation) of AISI52100 steel is in agreement with the measured one. On the other hand, the measured flow stress behavior of SAE9254 and AISI4140 steel partly concords with the predicted one when material experiences relatively high strain rate ($10{\~}40\;s^{-1}$) deformation at low temperature ($800^{\circ}C$). It can be deduced that, for AISI52100 steel, Shida's equation with the carbon equivalent model can be applicable directly to the roughing and intermediate finishing stand in hot rolling process for calculating the roll force and torque.

• BMB Reports
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• 제40권6호
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• pp.1021-1027
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• 2007

We demonstrated the genetic polymorphism of aldehyde oxidase (AO) in Donryu strain rats: the ultrarapid metabolizer (UM) with nucleotide mutation of (377G, 2604C) coding for amino acid substitution of (110Gly, 852Val), extensive metabolizer (EM) with (377G/A, 2604C/T) coding for (110Gly/Ser, 852Val/Ala), and poor metabolizer (PM) with (377A, 2604T) coding for (110Ser, 852Ala), respectively. The results suggested that 377G > A and/or 2604C > T should be responsible for the genetic polymorphism. In this study, we constructed an E. coli expression system of four types of AO cDNA including Mut-1 with (377G, 2604T) and Mut-2 with (377A, 2604C) as well as naturally existing nucleotide sequences of UM and PM in order to clarify which one is responsible for the polymorphism. Mut-1 and Mut-2 showed almost the same high and low activity as that of the UM and PM groups, respectively. Thus, the expression study of mutant AO cDNA directly revealed that the nucleotide substitution of 377G > A, but not that of 2604C > T, will play a critical role in the genetic polymorphism of AO in Donryu strain rats. The reason amino acid substitution will cause genetic polymorphism in AO activity was discussed.

• 한국수정란이식학회지
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• 제30권3호
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• pp.137-142
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• 2015

Cryopreservation of boar semen is continually researched in reproductive technologies and genetic resource banking in breed conservation. For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Various researches have been trying to improve the quality of semen post-thawed in boar. Recently, polymorphism (g.158T>C) of phospholipase C zeta (PLCz) gene reported to be significant association with MOT. This study was conducted to evaluate the PLCz gene as a positional controlling for motility and kinematic characteristics of post-thawed boar semen. To results, The g.158 T>C SNP of PLCz was significantly associated with frozen semen motility and kinematic characteristics. g.158 T>C SNP was high significantly associated with MOT, VCL, VSL and VAP (p<0.0001, p=0.0002, p<0.0001 and p<0.0001, respectively). Therefore, we suggest that the intron region of the porcine PLCz, may be used as a molecular marker for Duroc boar post-thawed semen quality, although its functional effect was not defined yet. Whether the association is due to the candidate gene or not require further verification. Thus, it will be of interest to continue association studies in the regions surrounding those genes.

• 미생물학회지
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• 제51권2호
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• pp.141-147
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• 2015

소금생산을 위해 25% 이상의 함수를 저장해 놓는 염전의 해주로부터 호염성 세균 4균주를 분리하고 높은 염분농도에서도 ${\beta}$-glucosidase를 생성하는 HJS1과 HJS6 균주를 선발하였다. 이들 ${\beta}$-glucosidase 생성세균은 NaCl 1-10%에서 70-79U/mg의 최적 활성을 나타내었고, NaCl 3%에서 최대 활성을 나타내었으며 NaCl 0-20% 농도에서 최대 효소 활성대비 75%이상의 효소활성을 유지하는 내염성 ${\beta}$-glucosidase를 생성하는 것으로 확인되었다. 내염성 ${\beta}$-glucosidase 생성 HJS1과 HJS6 균주의 16S rRNA 유전자 염기서열을 검토한 결과, Roseivivax roseus $BH87090^T$ (FJ897782)와 99.8%의 상동성을 나타내었고 상기 균주들의 염기서열은 NCBI GenBank에 각각 AB971835와 AB971836로 등록하였다. 계통학적으로 근연종인 Roseivivax roseus $BH87090^T$와의 DNA-DNA 상동성을 비교 검토한 결과, 90.1-90.3%를 나타내었다. 이들 균주의 주요 균체지방산은 $C_{16:0}$, $C_{18:1}$ ${\omega}7c$, $C_{19:0}$ cyclo ${\omega}8c$ 그리고 11-methyl $C_{18:1}$ ${\omega}7c$를 함유하고 Quinone종은 Q-10로 근연종 Roseivivax roseus $BH87090^T$ 균주와 동일한 특징을 나타내어 Roseivivax roseus로 동정되었다. 반면, 비교 균주 Roseivivax roseus $BH87090^T$는 ${\beta}$-glucosidase 생성하지 않는 것으로 나타났다. 본 연구에서 분리된 Roseivivax roseus HJS1과 HJS6 균주는 내염성 ${\beta}$-glucosidase 효소 개발을 위한 유전자원으로 활용 가능하리라 사료된다.

• Elastomers and Composites
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• 제48권1호
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• pp.10-17
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• 2013

선형 poly(ethylene-ter-1-hexene-ter-divinylbenzene) 소프트 탄성체 블럭내의 styrene 관능기로부터 poly(t-butylstyrene)하드 블록을 graft-from 음이온 중합을 통해 고온에서 사용 가능한 기능성 폴레올레핀 열가소성 탄성체인 polyolefin-g-poly(t-butylstyrene)을 합성하였다. sec-BuLi/TMEDA와 styrene 단위로부터 반응에 의하여 100% 수율의 음이온 개시 자리를 만들고 4-tert-butylstyrene을 graft-from 중합시켜 10,000~30,000 g/mol 분자량을 가지는 블록을 합성함으로서, 고온 $T_g$를 가지는 폴리올레핀 그라프트 고분자를 얻을 수 있었다. 단량체 함량과 중합시간에 따라 그라프트 분자량이 비례하여 증가하는 효과적인 리빙 중합방법임을 확인하였다. 사슬 말단에 다수의 수산기가 도입된 폴리올레핀 TPE의 합성방법으로서, 리빙 그라프트 고분자 사슬에 계속하여 isoprene을 블록 중합하여 얻어진 polyolefin-g-[poly(t-butylstyrene)-b-high vinyl polyisoprene]의 비닐기와 2-mercaptoethanol간의 thiol-ene 클릭 반응을 이용하는 방법을 통해 진행하였다. 연구 결과, 높은 $T_g$(> $145^{\circ}C$)를 갖는 정밀 제어된 기능성 그라프트 형태의 폴리올레핀 기반 TPE를 합성하는 방법을 확립하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.473-474
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• 2009

본 연구에서는 기존 건축물에 석고보드류 정도로 마감되어 있는 기둥부재를 가정하여, 마감재 종류 및 두께에 따른 내화특성을 검토하였다. 내화시험 후 폭렬현상으로 모든 시험체에서 주근부까지 폭렬이 발생되는 것으로 나타났다. 온도이력 특성으로는 35 ${\sim}$ 60분에서 9.5 T, 3.5 T(2ruq), 12.5 T, 15 T, 내화 12.5 T의 순으로 100${\sim}$200 $^{\circ}C$ 부근에서 급격한 온도상승을 나타내므로서 보다 내화성능이 우수한 마감재의 시공이 필요한 것으로 분석되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권8호
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• pp.1145-1152
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• 2012

This experiment was conducted with male chicks to investigate the influence of hormones and nutrients on the development of fatty liver syndrome (FLS) as well as the effects of dietary lipotropic factors on hepatic fat accumulation and lipogenic enzyme gene expression. A total of two-hundred sixteen 4-wk-old Hy-Line male chicks were divided into six groups and fed an experimental diet (T1, low-energy diet with low levels of lipotropic factors; T2, high-energy diet with low levels of lipotropic factors; T3 and T5, low-energy diet with high levels of lipotropic factors; T4 and T6, high-energy diet with high levels of lipotropic factors) for six weeks. The chicks in T5 and T6 groups were treated with intramuscular injections of estradiol benzoate for three days prior to biopsy and clinical analysis of FLS. Chicks treated with estrogen had significantly greater liver weights than untreated chicks. The abdominal fat contents were increased in chicks consuming high-energy diets as compared to those consuming low-energy diets. Treatment with estrogen significantly increased the concentrations of serum cholesterol, triacylglycerol and phospholipid (p<0.05). The hepatic triacylglycerol levels were tenfold higher in the estrogen treated chicks than in the untreated chicks. There were no significant differences in malondialdehyde levels between the treatment groups. Estrogen treatment dramatically increased the levels of fatty acid synthetase, acetyl-CoA carboxylase and ApoB mRNA. The results indicated that treatment with exogenous estrogen in growing male chicks induced hepatic fat accumulation, which might be partially due to increased lipogenic enzyme gene expression.

• Journal of Korean Neurosurgical Society
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• 제47권2호
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• pp.151-154
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• 2010

The efficacy of spinal cord stimulation (SCS) for treatment of various chronic painful conditions is well established. Very few reports have documented the use of SCS for treatment of chronic pain after spinal cord injury. We present a case showing a good outcome after such treatment, and suggest that high cervical stimulation may be efficacious. A 53-year-old male underwent SCS on the C1-3 level for treatment of intractable neuropathic pain below the T3 level, and in the upper extremities, arising from spinal cord injury resulting from transverse myelitis caused by schistosomiasis. High cervical SCS significantly improved the pain in the upper extremities and at the T3-T10 dermatome level. The patient continues to report excellent pain relief 9 months later. The present case suggests that high cervical stimulation may improve chronic pain in the upper extremities and the T3-T10 dermatome level arising from spinal cord injury.

• 한국터널지하공간학회 논문집
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• 제6권4호
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• pp.345-356
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• 2004

지하구조물을 축조하는 공법으로 기존에 가장 많이 사용해 온 것이 개착식 공법이나, 지상교통 흐름을 방해하고 공사소음 및 주변 지반의 침하로 인한 민원 발생 등 많은 문제점을 야기해 왔다. 많은 경우에 있어 지중에 매설된 상수도관 하수도관 도시가스관 고압 전력구 통신 케이블 등 지중 매설물의 위치가 정확하게 파악되지 않아서 안전한 시공에 어려움이 크고, 개착공사 시 지하지장물의 이설로 인한 공지지연 및 추가공사비가 소요될 것으로 판단되다. 따라서 본 논문에서는 기존 지하구조물 축조공법을 개선하여 슬래브강관과 PC벽체 트렌치를 이용한 터널축조공법 (T.R.c.M.)을 서울지하철 현장에 적용한 시공사례를 소개하고자 한다. 연구결과, T.R.c.M.공법은 진동과 소음을 최소화하여 주변환경과 교통의 흐름에 전혀 지장을 주지 않고 안정적으로 터널을 축조할 수 있는 공법임을 알 수 있었다.

• 한국수정란이식학회지
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• 제30권3호
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• pp.143-147
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• 2015

Cryopreservation of boar semen is continually researched in reproductive technologies and genetic resource banking in breed conservation. For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Various researches have been trying to improve the quality of semen Post-thawed in boar. Recently, polymorphism (g. 35756 T>C) of Estrogen Receptor 1 (ESR1) gene reported to be significant association with MOT. This study was conducted to evaluate the ESR1 gene as a positional controlling for motility and kinematic characteristics of post-thawed boar semen. To results, The g.35756 T>C SNP of ESR1 was significantly associated with frozen semen motility and kinematic characteristics. The g.35756 T>C SNP was high significantly associated with MOT, VCL, VSL and VAP (p<0.001). The SNP was also significantly associated with ALH (P<0.05). Therefore, we suggest that the g. 35756 T>C polymorphism in the intron 1 region of the porcine ESR1 gene could potentially be applied in frozen semen programs to improve MOT trait, but only after validation in other populations.