• 생명과학회지
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• 제13권6호
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• pp.805-813
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• 2003

돌돔 (Oplegnathus fasciatus) SL을 암호화하는 cDNA clone을 뇌하수체로부터 RT-PCR 방법에 의해 획득하였다. 돌돔 SL cDNA의 길이는 1636 bp로서 24개의 아미노산인 signal peptide와 207개 의 aa으로 구성된 mature protein을 암호화하는 696 bp의 open reading frame을 갖고 있다. 또한, 돌돔 SL 아미노산에는 이황화 결합에 관여하는 7개의 시스테인 잔기 $(Cys^{5},\; Cys^{15},\; Cys^{42},\; Cys^{65},\; Cys^{181},\; Cys^{198}\$ 과 $Cys^{206})$와 두 개의 potential N-glycosylation site인 $Asn^{121}$ 과 $Asn^{153}$을 확인하였다. 돌돔 SL은 goldfish와 channel catfish를 제외한 다른 경골어류 SL에 아미노산 서열은 61.1∼92.6%, 뉴클레오타이드 서열은 63∼92.6%의 일치를 나타낸다. 아미노산 서열 alingment에서 돌돔 SL은 다른 어류 SL에 공통적인 4개의 conserved domain $(A_{SL},\; B_{SL},\; C_{SL}$과 $D_{SL})$을 갖고 있음을 확인하였다. 이들중 $A_{SL},\; B_{SL}$,과 $D_{SL}$,은 경골어류 growth hormone과 prolactin에도 잘 보존되어 있었다 재조합 돌돔 SL 단백질을 E. coli에서 생산하기 위해 돌돔 SL cDNA를 발현벡터에 클로닝하여 단백질의 발현을 유도하였다 발현된 단백질은 SDS-PAGE에 의해 분자량 약 27 kDa의 재조합 단백질의 발현을 확인하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.659-662
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• 2002

SL(Stereolithography) part is made by piling up thin layers which causes the stair stepping effect at the surface of SL parts. This effect brings about excessive surface roughness and requires additional post-process finishing such as abrasive techniques that are detrimental to part geometry and time consuming. Hence a wax coating and grinding post-process is proposed to improve the surface quality of SL part. The wax that has suitable properties for the proposed post-process is coated all over the part surface. By grinding the thin layer of coated on the SL part only, the surface roughness can be improved without any damage on the part. From the experimental results, This approach is considered to be very practical fur die casting with RT(Rapid Tooling) techniques.

• International Journal of Precision Engineering and Manufacturing
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• 제8권3호
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• pp.14-19
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• 2007

Rapid prototyping (RP) technology can fabricate any 3D physical model regardless of geometric complexity using the layered manufacturing (LM) process. Stereolithography (SL) is the best-known example of RP technology. In general, the surface quality of a raw SL-generated part is unsatisfactory for industrial purposes due to the step artefact created by the LM process. Despite of the increased number of applications for SL parts, this side effect limits their uses. In order to improve their surface quality, additional post-machining finishing, such as traditional grinding, is required, but post-machining is time consuming and can reduce the geometric accuracy of a part. Therefore, this study proposes a post-machining technology combining coating and grinding processes to improve the surface quality of SL parts. Paraffin wax and pulp are used as the coating and grinding materials. By grinding the coating wax only up to the boundary of the part, the surface smoothness can be improved without damaging the surface. Finally, moulding and casting experiments were performed to confirm the suitability of the SL parts finished using the proposed process with rapid tooling (RT) techniques.

• BMB Reports
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• 제31권6호
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• pp.536-541
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• 1998

The cDNA clone encoding the antibacterial peptide (SL-1) was isolated from the fat body of the common cutworm, Spodoptera litura, immunized with E. coli K12. The primary structure analysis revealed that its deduced amino acid sequence showed the characteristics of the cecropin family antibacterial peptides and that the amino acid residues highly conserved in the antibacterial peptides from moths and flies were also conserved, implying that SL-1 was a cecropin-like, and especially cecropin B-like, peptide. The predicted secondary structure of the mature SL-1 consists of three domains: (i) an amphiphilic ${\alpha}$-helical domain (Ile-4 to Gly-18); (ii) the hinge region (Gly-23 and Pro-24); and (iii) a hydrophobic domain (Ala-25 to IIe-38).

• 한국정보과학회논문지:데이타베이스
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• 제29권6호
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• pp.464-476
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• 2002

모든 데이타를 주기억장치에 상주시키는 주기억장치 데이타베이스 시스템은 고성능 실시간 트랜잭션 처리에 적합하다. 주기억장치 데이타베이스 시스템에서 트랜잭션이 데이타베이스에 접근하는 시간이 매우 짧기 때문에 동시성 제어를 위해 이단계 로킹 기법을 사용할 경우, 로크 충돌이 일어날 확률이 적은 반면에, 데이타 객체를 접근할 때마다 수행해야 하는 로킹 연산의 부하는 트랜잭션 수행시간에 비해 상대적으로 큰 비중을 차지하게 된다. 본 논문에서는 로킹 연산의 부하를 최소화하면서 트랜잭션의 우선 순위를 반영한 실시간 정적 로킹 기법을 설계하고, 이를 주기억장치 실시간 데이타베이스 시스템인 Mr.RT에서 구현하였다. 또한 이단계 로킹 기법을 기반으로 하는 기존의 실시간 동시성 제어 기법들(2PL-PI, 2PL-HP)과의 성능 비교를 통하여 실시간 정적 로킹 기법이 보다 좋은 성능을 보임을 확인하였다.

• 식물조직배양학회지
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• 제27권5호
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• pp.379-385
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• 2000

tRNA and 7SL RNA based antisense vehicles were prepared by inserting conserved anti-viral and anti-viroid domains. Anti-PVS coat protein leader sequence (ACPL) and antistructural antihairpin domain of PSTVd (AHII) were inserted in tRNA cassette; anti- zing finger domain of PVS, AHII and anti hop latent viroid ribozyme were inserted in 7SL RNA gene isolated from A. thaliana. These constructs were shown to be transcribed both, in in vitro and in in vivo conditions. However, it followed from our work that closely linked position of PoIII reference genes and PoIIII antisense genes within T-DNA lead to the impairment of RNA expression in transgenic plants. To assay in vivo transcription of antisense genes, hairy root potato cultures were established using h. tumefaciens A4-24 bearing both, Ri plasmid and PoIII-promoterless plant expression vectors with antisense RNA genes. Expression of antisense RNA in transgenic potato tissues was proven by specific RT-PCR reactions.

• 대한의생명과학회지
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• 제27권4호
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• pp.255-263
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• 2021

Human Astrovirus (HuAstV) is an important gastrointestinal pathogen that is frequently reported worldwide. Monitoring of contaminated groundwater has been suggested since HuAstV is transmitted through the fecal-oral route. This study developed a test method based on conventional reverse transcription (RT)-nested polymerase chain reaction (PCR) that involves SL^® non-specific reaction inhibitor for unknown non-specific amplification taking place in the groundwater environment. An optimal method for detecting HuAstV in groundwater sample through analysis and comparison against conventionally reported method was also suggested. The developed method enabled the production of nested PCR amplicon of 630 nt, which is a sufficient length for similarity analysis based on sequencing and genotyping. Amplicons suspected to be HuAstV were amplified in two out of the twenty groundwater samples collected in Korea, presenting 99.77% and 99.73% similarity against HuAstV 1 strain lhar/2011/kor (JN887820.1) in sequencing, respectively. These amplicons were identified as HuAstV 1.

• 열처리공학회지
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• 제13권6호
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• pp.383-390
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• 2000

The static creep behaviour of AlSl 420F stainless steel was investigated over the temperature range of $540{\sim}585^{\circ}C$ and the stress range of $13{\sim}19kg/mm^2$ (127.4~186.2MPa). Constant stress creep tests were carried out in the experiment. Measured stress exponent, n, for the creep deformation of the alloy under the given conditions was found to vary at the range of 9.59, 9.15, 8.78, and 8.53 for the temperature of 540, 555, 570, and $585^{\circ}C$ respectively. The activation energy, Qc, for the creep deformation was 106.42, 102.58,97.81, and 94.58 kcal/mole for the stress of 13, 15, 17, and $19kg/mm^2$, respectively. Lason-Miller parameter, P, for the crept specimens for AlSl 420F stainless steel was measured as $P=T(log\;t_T+21)$. The empirical static creep rate obtained by the regression analysis was as follows. $${\varepsilon}={\exp}[(3.79{\times}10^{-2}{\sigma}+2.722)T-3.0747{\sigma}+28.109]{\times}{\sigma}^{(-2.367{\times}10^{-2}T+22.33)}{\exp}\left[-\frac{(-2.015{\sigma}+132.580){\times}10^3}{RT}\right]$$ The failure plane were observed, intergranular fracture was dominated by r (round) type crack over the experimental range.

• 대한의생명과학회지
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• 제27권1호
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• pp.35-43
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• 2021

Human Sapovirus (HuSaV) is one of the major causes of acute gastroenteritis in humans, and it is used as a molecular diagnostic technique based on polymerase chain reaction (PCR) from humans, food, shellfish, and aquatic environments. In this study, the HuSaV diagnosis technique was used in an aquatic environment where a number of PCR inhibitors are included and pathogens, such as viruses, are estimated to exist at low concentration levels. HuSaV-specific primers are improved to detect 38 strains registered in the National Center for Biotechnology Information (NCBI). The established optimal condition and the composition, including the RT-nested PCR primers and SL® Non-specific reaction inhibitor, were found to have 100 times higher sensitivity based on HuSaV plasmid than the previously reported methods (100 ag based on HuSaV plasmid 1 ng/μL). Through an artificial infection test, the developed method was able to detect at least 1 fg/μL of HuSaV plasmid contaminated with total nucleic acid extracted from groundwater. In addition, RT-nested PCR primer sets for HuSaV detection can react, and a positive control is developed to verify false positives. This study is expected to be used as a HuSaV monitoring method in the future and applied to the safety response to HuSaV from water environments.

• 원예과학기술지
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• 제32권1호
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• pp.91-99
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• 2014

본 연구는 배추에서의 저온 저항성 유전자를 개발하는데 목적이 있으며 이를 위해 먼저 저온($4^{\circ}C$) 스트레스가 처리된 내혼계배추를 대상으로 한 KBGP-24K oligo chip의 결과 [BrEMD(Brassica rapa EST and Microarray Database)]를 분석하였다. 그 결과 23,929개의 배추 unigene 중 저온 처리시 대조군 대비 5배 이상 발현이 증가하는 417개(1.7%)의 저온 반응 유전자를 1차 선발하고, 이들 중 기능이 정확히 알려지지 않았으나 완전장을 갖추고 있는 BrCSR로 명명한 유전자를 선발하였다. 이 유전자의 저온 저항성을 분석하기 위하여 형질전환용 과발현 vector인 pSL101 binary vector를 제작하여 담배에 형질전환시켰다. BrCSR이 과발현된 $T_1$ 세대 담배 형질전환체들은 PCR과 Southern hybridization 분석에 의해 선발하였고, BrCSR의 기능은 저온 처리 시 유전자의 발현 수준 분석과 표현형 검정을 통해 확인하였다. Quantitative real-time RT-PCR과 Northern blot hybridization 분석 결과, 형질전환 담배에서 BrCSR의 발현이 대조군보다 약 2배 정도 높게 발현되었으며 실제로 $4^{\circ}C$ 처리 후 표현형 분석에서 BrCSR이 과발현된 형질전환체들이 대조군보다 우수한 저온 저항성을 보여 주었다. 위 결과들에 근거하여 BrCSR 유전자가 저온 환경 하에서 식물의 생장과 저항성 향상에 중요한 역할을 담당하고 있음을 확인할 수 있었다.