• Toxicological Research
• /
• 제17권2호
• /
• pp.143-149
• /
• 2001

In the present study, we examined eye irritation oj six anti-wrinkle agents (ascorbic acid, glycolic acid, all trans-retinoic acid, ginseng extract, retinol, EB). We also compared eye irritation with skin irritation and cytotoxicity in HaCaT cells by these agents. The highest eye irritation was found in glycolic acid, but all trans-retinoic acid showed the highest skin irritation. The rank of eye irritation was not correlated with the cytotoxicity of agents. This result shows that eye irritation potency by these agents were not correlated with skin irritation potency, and cytotoxicity in HaCaT cells.

• Animal Bioscience
• /
• 제34권4호
• /
• pp.533-538
• /
• 2021

Objective: Pluripotent stem cell-derived lymphatic endothelial cells (LECs) show great promise in their therapeutic application in the field of regenerative medicine related to lymphatic vessels. We tested the approach of forced differentiation of mouse embryonal stem cells into LECs using biodegradable poly lactic-co-glycolic acid (PLGA) nanospheres in conjugation with growth factors (vascular endothelial growth factors [VEGF-A and VEGF-C]). Methods: We evaluated the practical use of heparin-conjugated PLGA nanoparticles (molecular weight ~15,000) in conjugation with VEGF-A/C, embryoid body (EB) formation, and LEC differentiation using immunofluorescence staining followed by quantification and quantitative real-time polymerase chain reaction analysis. Results: We showed that formation and differentiation of EB with VEGF-A/C-conjugated PLGA nanospheres, compared to direct supplementation of VEGF-A/C to the EB differentiation media, greatly improved yield of LYVE1(+) LECs. Our analyses revealed that the enhanced potential of LEC differentiation using VEGF-A/C-conjugated PLGA nanospheres was mediated by elevation of expression of the genes that are important for lymphatic vessel formation. Conclusion: Together, we not only established an improved protocol for LEC differentiation using PLGA nanospheres but also provided a platform technology for the mechanistic study of LEC development in mammals.

• 청정기술
• /
• 제29권1호
• /
• pp.46-52
• /
• 2023

옥살산(oxalic acid)은 기존에 질산을 사용한 carbohydrates의 산화 공정에 의해 얻어질 수 있으며 여러 분야에서 사용되고 있다. 하지만 이 반응은 다양한 질소 산화물을 형성하고 많은 증간 생산물의 분리를 필요로 하기에 복잡하고 환경에 유해하다. 한편, 이산화탄소로부터 전기화학적 방법에 의해 옥살산을 높은 효율로 얻을 수 있는 방법이 제안되었다. 아연 전극 산화에 의해 생성된 Zn²⁺이온과 CO₂ 환원에 의한 oxalate이온의 반응으로 zinc oxalate(ZnC₂O₄)가 얻어진다. 이후 산처리에 의해 옥살산이 생성될 수 있으나 강산과 열을 필요로 한다. 본 연구에서는 CO₂의 전기화학적 전환으로 형성된 ZnC₂O₄을 강산을 사용하지 않고, 간단하고 분리가 쉬운 방법을 적용하여 옥살산으로 전환하고자 한다. 또한, 고부가 물질인 글리콜산으로 더 전환시킴으로써 이산화탄소에서 고부가 물질로의 전환 가치를 높이고자 하였다. ZnC₂O₄를 상온, 상압에서 화학적 방법 및 여과 과정을 통해 효과적으로 Zn(OH)₂ 입자와 oxalate 용액으로 분리하였으며 얻어진 Zn(OH)₂와 oxalate는 전기화학적 방법을 사용하여 각각 Zn, 글리콜산으로 전환되었다.

• 대한기관식도과학회:학술대회논문집
• /
• 대한기관식도과학회 2002년도 제2차 추계학술대회
• /
• pp.10-10
• /
• 2002

• Molecules and Cells
• /
• 제44권12호
• /
• pp.900-910
• /
• 2021

Sour is one of the fundamental taste modalities that enable taste perception in animals. Chemoreceptors embedded in taste organs are pivotal to discriminate between different chemicals to ensure survival. Animals generally prefer slightly acidic food and avoid highly acidic alternatives. We recently proposed that all acids are aversive at high concentrations, a response that is mediated by low pH as well as specific anions in Drosophila melanogaster. Particularly, some carboxylic acids such as glycolic acid, citric acid, and lactic acid are highly attractive to Drosophila compared with acetic acid. The present study determined that attractive carboxylic acids were mediated by broadly expressed Ir25a and Ir76b, as demonstrated by a candidate mutant library screen. The mutant deficits were completely recovered via wild-type cDNA expression in sweet-sensing gustatory receptor neurons. Furthermore, sweet gustatory receptors such as Gr5a, Gr61a, and Gr64a-f modulate attractive responses. These genetic defects were confirmed using binary food choice assays as well as electrophysiology in the labellum. Taken together, our findings demonstrate that at least two different kinds of receptors are required to discriminate attractive carboxylic acids from other acids.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1999년도 봄 학술발표회 논문집
• /
• pp.206-210
• /
• 1999

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1991년도 제2차 학술발표초록집
• /
• pp.58-60
• /
• 1991

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1992년도 제1차 학술발표초록집
• /
• pp.37-37
• /
• 1992

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1992년도 제1차 학술발표초록집
• /
• pp.38-38
• /
• 1992

• 한국연초학회지
• /
• 제24권2호
• /
• pp.113-120
• /
• 2002

This study was conducted to determine the smoke component changes by adding oriental, reconstituted, and expanded tobacco leaves. 7 different cigarette brands which were mixed with flue-cured, burley, oriental, reconstituted and expanded tobacco leaves were used for this study. 64 kinds of smoke components which were 6 of general components, 34 of semi-volatile and volatile components, 9 of acid components, and 15 of phenolic components were analyzed. All smoke components of mainstream smoke were changed by the different branding. As Tar, nicotine, ammonia, pH, all of acid compounds(except lacatic and glycolic acid) were decreased; HCN, levoglucosame, 4-vinyl phenol, 4-vinyl catechol, quinic acid-r-lactone, acetaldehyde, 2,3-butadiene, stylene were increased by adding oriental tobacco leaves. When the reconstituted tobaccos were added to 20%, the concentration of nicotine, all of acid compounds(except lactic. glycolic, palmitic acid) and all of phenol compounds were reduced; the concentration of ammonia, HNC, CO, aeconitrile, benzene, 2-butanone, moth-acrolene, butyronitrile, stylene, o-xylene were increased. As decreasing ammonia, pH, nicotine, all of acid compounds, all of phenol compounds, Isoprene, acetonitrile, 2-methyl-2-butene, 1,3-pentadiene, 2-nlethyl furane, ethylene cyclopentanone, ethyl bezene; increasing CO concentration were followed by adding expanded tobacco leaves.