• 미생물학회지
• /
• 제28권2호
• /
• pp.114-119
• /
• 1990

효모 Saccharomyces cerevisiae의 염색체상에 존재하는 superkiller 유전자인 SKIB 유전자를 cloning 시켜 ski 변이 주내에서 발현시켰다. 이 유전자의 C-말단부위에 E. coli의 tacZ 구조 유전자를 융합시켜 효모와 E. coli의 shuttle vector인 pSR605를 제조하고 이를 효모에 형질전환 시킨 후 나타나는 $\beta$-galactosidase의 융합단백질을 확인할 수 있었다.

• 센서학회지
• /
• 제13권5호
• /
• pp.342-349
• /
• 2004

SK (SPR Kinds) index, which can categorize the complicated measurement methods of surface plasmon resonance by simple method, has been proposed and verified. SK index is composed of three digits, where each digit presents the type of immobilized ligand, the type of illumination and the kinds of varying parameter, sequentially. The measurement method of (33#) series among SK indices shows the possibility of the multi-sensing capability, by which the response of 2-dimensional array of immobilized ligands can be detected simultaneously. The proposed possibility of multi-sensing capability has been verified by the modeling that is based on Fresnel reflection model.

• 자연, 터널 그리고 지하공간
• /
• 제13권6호
• /
• pp.33-41
• /
• 2011

• 미생물학회지
• /
• 제50권1호
• /
• pp.8-14
• /
• 2014

본 연구는 home-made 요구르트에서 분리한 Lactobacillus casei SK-7과 시중에서 판매되고 있는 요구르트에서 분리한 Lactobacillus bulgaricus YK-11의 기능성을 비교 분석하기 위해 실시하였다. 먼저 분리세균인 SK-7과 YK-11의 생리화학적 특성조사를 진행하였다. 이들 균주는 16S rRNA 염기서열을 이용한 계통유전학적 분석방법으로 동정하여, 각각 L. casei SK-7와 L. bulgaricus YK-11로 명명하였다. 16S rRNA 염기서열을 바탕으로 SK-7과 YK-11의 유전적 계통수를 작성하였다. 72시간 동안 SK-7과 YK-11 배양에서 lactic acid와 acetic acid의 생산, 그리고 pH 변화를 조사하였다. 배양기간 동안 L. casei SK-7과 L. bulgaricus YK-11의 몇가지 기능성을 조사하였다. L. casei SK-7과 L. bulgaricus YK-11 배양상등액은 주어진 nitrite를 각각 93.9%와 88.2% 소거하였다. SK-7 and YK-11 배양상등액의 항산화능은 각각 62.6%와 54.9%였으며, ${\beta}$-galactosidase 활성은 14.9 units/mg과 13.1 units/mg로 측정되었다. 항미생물능력은 SK-7과 YK-11 배양의 20배 배양농축액으로 조사되었으며, SK-7은 이 조사에 사용된 모든 미생물에서 명백한 것으로 관찰되었으나, YK-11에서는 관찰되지 않았다. 부가적인 기능성 연구가 이루어져야 되겠지만, 본 연구에서는 home-made 요구르트에서 분리된 젖산균의 기능성은 시판요구르트에서의 기능성과 비교하여 우수한 것으로 조사되었다.

• 음성과학
• /
• 제13권1호
• /
• pp.55-66
• /
• 2006

A purpose of this study is to investigate the acoustic characteristics of English stress produced by the two groups of South Kyungsang (henceforth, SK) Korean speakers: high-proficiency and low-proficiency with reference to English native speakers. Another purpose is to compare results from the high- and low-proficiency SK Korean subjects with those of the native speakers, and to provide an analytical account of how approximate the high-proficiency SK Korean subjects' production is to the native speakers' and how different the low-proficiency SK Korean subjects' is from the native speakers'. Results indicated that the native speakers' main strategy used in producing stressed syllables was duration while the high-proficiency SK Korean subjects' was predominantly pitch-oriented. The low-proficiency SK Korean subjects' pitch patterns showed regularity, emphasizing the penultimate syllable with pitch. In comparing duration among the three groups, both groups of the SK Korean subjects became more even in their duration values for each syllable as the structure of the word or the sentence became more complex.

• 약학회지
• /
• 제39권6호
• /
• pp.661-665
• /
• 1995

Ginsenoside-Rg$_{1}$(G-Rg$_{1}$) has been shown to stimulate DNA synthetic activity in SK-HEP-1 cells. This study was therefore designed to determine in SK-HEP-1 cells whether the stimulatory effect of G-Rg$_{1}$ may be mediated by protein kinase C (PKC) which is known to play a key role in the signal transduction pathway leading to the cell proliferation. Using the tn situ PKC assay method, the PKC enzyme activity was determined in SK-HEP-1 cell cultures in response to G-Rg$_{1}$ at 3*10$^{-5}$ M or phorbol 12-myristate 13-acetate(PMA) at 10$^{-6}$ M which in the enzyme activity by 1.5- and 7-fold, respectively. Furthermore, G-Rg$_{1}$, was also able to synergistically increase the enzyme activity by 11-fold m the cell cultures in the presence of PMA. These stimulatory effects of G-Rg$_{1}$ or PMA on the DNA synthetic activity and the PKC activity were ablished by a specific PKC inhibitor, GF109203X. These results suggest that the stimulatory effect of G-Rg$_{1}$ on the DNA synthetic activity may be partly due to stimulation of PKC-mediated signal transduction pathway leading to the proliferation of SK-HEP-1 cells.

• 한국미생물·생명공학회지
• /
• 제13권4호
• /
• pp.417-422
• /
• 1985

Streptococcus faecalis var. liquefaciens에서 plasmid DNA를 분석한 결과, 4개의 plasmid를 가지고 있었으며, 각각의 대략적인 분자량은 6.8M-dal, 5.2Mdal, 2.6Mdal, 2.1Mdal로 측정되었다. 이 균주를 novobiocin으로 처리하여, 각각 다른 2개의 plasmid가 소실된 2개의 변이주를 얻었다. 이들 균주는 당발효성, 온도감수성, gelatin 용해성, 단백질응고성은 wild type과 동일하였으나 이중 한 균주가 lincomycin과 erythromycin에 대한 감수성을 나타내었다. 따라서 본 실험에서 검출한 4개의 plasmid는 당발효성 등의 특성과는 관련이 없는 것으로 추정할 수 있으며, pSK₂와 pSK₄의 두 plasmid 중 하나는 항생물질 저항성에 관련된 것으로 보인다.

• Journal of Welding and Joining
• /
• 제15권2호
• /
• pp.54-63
• /
• 1997

For the purpose of establishing laser welding condition (laser power, welding speed and beam focus) and of evaluating tailored blanks for two kinds of thin steel sheets SPCC and SK5M using in the thin plate structure such as automobile, train, and so on, investigated their $CO^2$ laser weldability under various initial welding conditions. SPCC thin sheet showed good weldability under some welding conditions. But, high carbon steel sheet SK5M needed heat treatment after welding to obtain ductility of the welded joint. And next, tailored blank was tested through deep drawing to evaluate reliability of their obtained laser welding conditions. The forming depths by tailored blank were SPCC+SPCC=22-25mm and SK5M+SK5M=13-25mm.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 1996년도 춘계학술대회 논문집
• /
• pp.159-164
• /
• 1996

For the purpose of establishing laser welding condition(laser power, welding speed and beam focus) and of evaluating tailor welded blank for three kinds of thin steel sheets of SPCC, SK5M and SUS304 using in the thin plate structure such as automobile, train and so on. Their $CO_2$ laser weldability were primarily tested under various welding condition. SPCC and SUS304 thin sheets showed good weldability under some welding condition. But, high carbon steel sheet SK5M needs heat treatment after welding to obtain higher tensile strength and ductility of the welded joint. And next, laser welding condition. Butt-welded specimens were not nearly broken at weld bead. However, base material were ruptured in the direction of circumference. The forming depths by tailor weld bead. However, base material were ruptured in the direction of circumference. The forming depths by tailor welded blank were SPCC+SPCC=22~25mm, SUS304+SUS304=25~43mm and SK5M+SK5M=13~17mm.

• The Korean Journal of Physiology and Pharmacology
• /
• 제13권3호
• /
• pp.139-145
• /
• 2009

The purpose of this study was to evaluate the effects of the water extract of Samultang (SMT), a Chinese herb, on apoptotic cell death by $H_2O_2$-induced oxidative stress in SK-N-M C cells. A nuclear fragmentation was observed via fluorescence imaging 12 h after exposure to 30 ${\mu}M$ $H_2O_2$ and DNA laddering was detected via agarose electrophoresis gel. In addition, increases in sub-G1 phase and cleavage of the PARP protein were observed. However, treatment with SMT for 2 h prior to $H_2O_2$ exposure significantly reduced apoptotic cell death induced by incubation with 30 ${\mu}M$ $H_2O_2$ in SK-N-MC cells. Pre-incubation with water extract of SMT for 2 h prevented the $H_2O_2$-induced decrease in mitochondrial transmembrane potential. SMT also attenuated the increase in caspase-3 activity and the breakdown of PARP protein caused by $H_2O_2$-induced oxidative stress. These results suggest that the water extract of SMT provides inhibition of apoptotic cell death against oxidative injury in SK-N-MC cells.