• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.184-191
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• 2003

New pyranone derivative, 2-((3E)-4(2H, 3H, -benzo[3, 4-d] 1, 3-dioxolan-5-yl)-2-oxo-but-3-enyloxy)-5-hydroxy-4H-pyran-4-one (Seletinoid $G^{TM}$), was designed as a novel retinoid on the assumption that the pyranone ring may mimic the carboxylic acid moiety in retinoid structure. The enolic hydroxy of pyranone at five position was easily deprotonated to form an enolate. The role of enolate was similar to that of carboxylic acid. To evaluate the value of Seletinoid G as an anti-aging ingredient, various tests were performed for example inhibitory effect for MMP-l expression, anti-oxidative activity, procollagen synthesis in hairless mouse and primary skin irritation. The result of this study suggested that our new synthetic retinoid could be used as a safe material for anti-aging cosmetics.

• 임산에너지
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• 제20권2호
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• pp.69-80
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• 2001

중부지방 낙엽송 조림지에 대하여 식재후 적정한 1차 간벌 시기를 추정하기 위하여 충북대학교 부속 연습림(월악산)을 대상으로 연구한 결과를 요약하면 다음과 같다. (1) 충북대학교 부속 연습림내에 조림된 낙엽송의 수고곡선식은 H=4.25783+0.80024D(H=수고, D=흉고직경)이었다. (2) 본 연구대상지의 재적식을 구하기 위해 최소제곱법으로 회귀분석을 한 결과, 수고와 흉고 직경을 모두 독립변수로 하는 경우 재적식은 V=0.001474-0.002095D-0.000211H+0.000150D·H+0.000744D²+0.000008H²(V=재적(㎥), H=수고(m), D=흉고직경(cm)) 이었다. 한편, 재적에 대하여 흉고직경만을 독립변수로 한 경우는 V=0.000079-0.000512D+0.000826D²이었다. (3) 간벌시기 추정을 위한 기준으로는 수고 MAI의 극대점을 이루는 연령과 고사목에서 총 흉고직경 생장량의 평균치 이하로 떨어지는 시점의 연령이 적절한 것으로 판단된다. (4) 수고 MAI의 극대점에 도달하는 연령은 임분밀도와 유의성 있는 상관을 보이지 않아 정확한 간벌시기의 판단기준으로 삼을 수 없었다 (5) 간벌시기를 결정하는 추정식은 고사목의 흉고직경생장량의 경년변화를 토대로 계산하였으며, 그 결과식은 Y=0.2825+0.01752X 이었다. (6) 관행적인 1.8m×l.8m의 식재밀도가 적용된 낙엽송 조림지에서 간벌 개시 임령은 12∼14년이 적당한 것으로 나타났다.

• 미생물학회지
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• 제29권6호
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• pp.387-391
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• 1991

Methylobacterium extorquens AM1 growing on methanol as a sole source of carbon and energy was found to grow most rapidly (t$t_{d}$ =6h) at 30.deg.C in a mineral medium (pH 7.0) containing 0.5% (v/v) methanol which was agitated at 200 rpm (optimal cultivation condition). Cells grown under the optimal cultivation condition contained more spermidine, but less putrescine, than the cells grown on 2.5%(v/v) ( $t_{d}$ =8h ) or at 20.deg.C ( $t_{d}$ =8h ). Cells cultivated under the optimal condition was found to contain more spermidine than the cells grown at pH 6.0 (( $t_{d}$ =7h ) and pH 8.0 ($t_{d}$ =7.3h). the cells growing at the stationary phase under the optimal condition accumulated more spermine or putrescine than the cells growing at the same phase on 2.5%(v/v) methanol or at pH 6.0 and pH 8.0, respectively. M. extorquens AM1 grown in a medium agitated at 100 rpm ( $t_{d}$ =8.8h ) contained less spermidine and spermine than the cells grown under the optimal cultivation condition.

• Asian-Australasian Journal of Animal Sciences
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• 제23권9호
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• pp.1152-1158
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• 2010

In differentiating human embryonic stem (d-hES) cells there are a number of types of cells which may secrete various nutrients and helpful materials for pre-implantation embryonic development. This study examined whether the d-hES could function as a feeder cell in vitro to support mouse embryonic development. By RT-PCR analysis, the d-hES cells revealed high expression of three germ-layered differentiation markers while having markedly reduced expression of stem cell markers. Also, in d-hES cells, LIF expression in embryo implantation-related material was confirmed at a similar level to undifferentiated ES cells. When mouse 2PN embryos were cultured in control M16 medium, co-culture control CR1aa medium or co-cultured with d-hES cells, their blastocyst development rate at embryonic day 4 (83.9%) were significantly better in the d-hES cell group than in the CR1aa group (66.0%), while not better than in the M16 group (90.7%)(p<0.05). However, at embryonic days 5 and 6, embryo hatching and hatched-out rates of the dhES cell group (53.6 and 48.2%, respectively) were superior to those of the M16 group (40.7 and 40.7%, respectively). At embryonic day 4, blastocysts of the d-hES cell group were transferred into pseudo-pregnant recipients, and pregnancy rate (75.0%) was very high compared to the other groups (M16, 57.1%; CR1aa, 37.5%). In addition, embryo implantation (55.9%) and live fetus rate (38.2%) of the d-hES cell group were also better than those of the other groups (M16, 36.7 and 18.3%, respectively; CR1aa, 23.2 and 8.7%, respectively). These results demonstrated that d-hES cells can be used as a feeder cell for enhancing in vitro and in vivo developmental potential of mouse pre-implantation embryos.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3641-3648
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• 2013

Energy transfer and bond dissociation of $C-H_{methyl}$ and $C-H_{ring}$ in excited toluene in the collision with $H_2$ and $D_2$ have been studied by use of classical trajectory procedures at 300 K. Energy lost by the vibrationally excited toluene to the ground-state $H_2/D_2$ is not large, but the amount increases with increasing vibrational excitation from 5000 and $40,000cm^{-1}$. The principal energy transfer pathway is vibration to translation (V-T) in both systems. The vibration to vibration (V-V) step is important in toluene + $D_2$, but plays a minor role in toluene + $H_2$. When the incident molecule is also vibrationally excited, toluene loses energy to $D_2$, whereas it gains energy from $H_2$ instead. The overall extent of energy loss is greater in toluene + $D_2$ than that in toluene + $H_2$. The different efficiency of the energy transfer pathways in two collisions is mainly due to the near-resonant condition between $D_2$ and C-H vibrations. Collision-induced dissociation of $C-H_{methyl}$ and $C-H_{ring}$ bonds occurs when highly excited toluene ($55,000-70,400cm^{-1}$) interacts with the ground-state $H_2/D_2$. Dissociation probabilities are low ($10^{-5}{\sim}10^{-2}$) but increase exponentially with rising vibrational excitation. Intramolecular energy flow between the excited C-H bonds occurring on a subpicosecond timescale is responsible for the bond dissociation.

• Asian-Australasian Journal of Animal Sciences
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• 제29권11호
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• pp.1608-1615
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• 2016

This study was conducted to determine the solubility of copper (Cu) in two sources of copper(II) sulfate ($CuSO_4$) including monohydrate and pentahydrate and three sources of dicopper chloride trihydroxide (dCCTH) including ${\alpha}$-form (dCCTH-${\alpha}$), ${\beta}$-form (dCCTH-${\beta}$), and a mixture of ${\alpha}$- and ${\beta}$-form (dCCTH-${\alpha}{\beta}$) at different pH and a 3-step in vitro digestion assay for pigs. In Exp. 1, Cu sources were incubated in water-based buffers at pH 2.0, 3.0, 4.8, and 6.8 for 4 h using a shaking incubator at $39^{\circ}C$. The $CuSO_4$ sources were completely dissolved within 15 min except at pH 6.8. The solubility of Cu in dCCTH-${\alpha}$ was greater (p<0.05) than dCCTH-${\beta}$ but was not different from dCCTH-${\alpha}{\beta}$ during 3-h incubation at pH 2.0 and during 2-h incubation at pH 3.0. At pH 4.8, there were no significant differences in solubility of Cu in dCCTH sources. Copper in dCCTH sources were non-soluble at pH 6.8. In Exp. 2, the solubility of Cu was determined during the 3-step in vitro digestion assay for pigs. All sources of Cu were completely dissolved in step 1 which simulated digestion in the stomach. In Exp. 3, the solubility of Cu in experimental diets including a control diet and diets containing 250 mg/kg of additional Cu from five Cu sources was determined during the in vitro digestion assay. The solubility of Cu in diets containing additional Cu sources were greater (p<0.05) than the control diet in step 1. In conclusion, the solubility of Cu was influenced by pH of digesta but was not different among sources based on the in vitro digestion assay.

• 한국수산과학회지
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• 제8권4호
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• pp.202-207
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• 1975

1975년 6월 7일에서 동년 8월 11일까지 풍양호(4,500H. P), 척양호(3,800H. P.), 동방호(3,000 H. P.), 오대산호(2,600 H. P.), 백경호(850 H. P.), 관악산호(1,000 H..P.) 계 6척의 기관실 소음을 주기관의 회전수에 따라 소음압이 변하는 것과 기관실 체격과 총 마력수에 따른 상관관계등을 조사한 결과를 요약하면 다음과 같다. 1. 각 선박의 총 마력수에 따라 기관실 체적이 비례로 커져가고 있으나 소음관계는 같은 종류의 기관(6기통)을 사용하고 있으므로 소음압이 낮아져 가는 경향을 보이는데 관악산초, 척양호, 동방호는 표준 곡선에 비해 소음압이 3dB정도 높은 경향을 보였고 백경호, 풍양호는 4dB 정도 낮은 경향을 보였다. 2. 각 주기관의 최대 회전수(r.p.m.)가 되기 전의 회전수에서 이미 최대의 소음압을 나타내고 있는데 그 회전수의 백분율은 선박에 따라 약간의 차이는 있으나 $67{\~}75{\%}$인 범위에서 최대소음이 되고 있다. 3. 각 기관실의 최대소음압은 $93.5{\~}105dB$의 범위 였고, stern trawl 선박구조를 가진 어획물 처리장은 81 dB 였는데 풍양호만은 72 dB로서 선원 상호간의 대화는 가능하였다. 4. 관악산호를 제외하고는 각 선박식당의 소음압은 $68{\~}75dB$, 싸롱은 $67{\~}72dB$ 선원실은$67{\~}75dB$ 학생실은$67{\~}72dB$였고 갑판의 소음압은 동방호를 제외하고는 $67{\~}72dB$의 범위였다.

• 한국수소및신에너지학회논문집
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• 제9권2호
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• pp.77-84
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• 1998

$H_2O/O_2$, $D_2O/H_2O$, $D_2O/H_$2 등의 반응계의 수소동위원소 교환반응용 전기방전을 이용하여 용이하게 일으킬 수 있다. 예를 들어, DC 코로나 방전을 위의 반응혼합물을 통하여 일으키면 여기된 상태의 반응물이 존재하는 플라즈마를 형성하게 된다. 이러한 플라즈마 내에서 반응물들은 양자에너지 준위의 여기, 이온화 그리고 라디칼 형성등을 통하여 매우 큰 반응성을 갖게되므로 실온에서도 용이하게 수소동위원소 교환반응을 일으킨다. 본 연구에서는 $H_2/D_2O$계의 기상에서의 교환반응에 대한 연구를 실시하였다. 위 반응계는 전기방전하에서 수소(H)와 중수소(D)간의 교환반응에 의하여 HDO와 HD를 생성하게 된다. 이러한 반응생성물을 FTIR 분광법을 이용하여 시간의 함수로 측정을 하였다.

• Applied Microscopy
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• 제32권3호
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• pp.223-230
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• 2002

Sprague-Dawley rat에 complete Freund's adjuvant (CFA)를 투여하여 유발한 골다공증에 미치는 $1{\alpha}$, 25 dihydroxyvitamin $D_3\;(Vit\;D_3)$의 효과를 알아보기 위하여 실험동물을 정상 대조군, CFA 투여 대조군, CFA 투여후 $1{\alpha}$, 25 dihydroxyvitamin $D_3\;0.01{\mu}g/kg$ 투여군 (Vit $D_{3}L$) 및 $0.1{\mu}g/kg$ 투여군(Vit $D_{3}H$)으로 분류하여 경구로 3주간 투여하였다. 골다공증의 억제 효과를 알아보기 위하여 골밀도와 골함유량의 변화 및 주사전자현미경적 소견을 관찰한 결과 다음과 같은 결론을 얻었다. 골밀도와 골함유량은 $1{\alpha}$, 25 dihydroxyvitamin $D_3$ 투여용량과 부위에 따라 차이가 있었는데 Vit $D_3$ 투여군이 CFA 투여 대조군과 비교하여 골밀도와 골함유량이 증가하였으며 Vit $D_{3}H$군이 Vit $D_{3}L$군보다 좀 더 효과적이었다. 대퇴골의 주사전자현미경적 소견은 Vit $D_3$ 투여군의 골피질과 골소주의 손상이 CFA 투여 대조군보다 억제되었음을 볼 수 있었으며 Vit $D_{3}H$ 투여군이 Vit $D_{3}L$ 투여군보다 좀 더 효과적이었다. 이상의 결과를 종합해 보면 $1{\alpha}$, 25 dihydroxyvitamin $D_3$의 투여는 CFA에 의해 유발된 rat의 골다공증 모델에서 골다공증의 진행을 억제하였고 Vit $D_{3}H$ 투여군이 Vit $D_{3}L$ 투여군보다 좀 더 효과적이었다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제3권2호
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• pp.69-75
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• 2003

Cell transistor and data retention time characteristics were studied in 90 nm design rule 512M-bit DRAM, for the first time. And, the characteristics of cell transistor are investigated for different STI gap-fill materials. HDP oxide with high compressive stress increases the threshold voltage of cell transistor, whereas the P-SOG oxide with small stress decreases the threshold voltage of cell transistor. Stress between silicon and gap-fill oxide material is found to be the major cause of the shift of the cell transistor threshold voltage. If high stress material is used for STI gap fill, channel-doping concentration can be reduced, so that cell junction leakage current is decreased and data retention time is increased.