• 한국의류학회지
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• 제10권3호
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• pp.71-81
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• 1986

In order to control the formaldehyde release from D.P. finished fabric, cotton fabric was padded in DMDHEU resin bath containing either $Zn(NO_3)_2$ or $MgCl_2$ catalyst and a form-aldehyde scavenger like Glycerol, Sorbitol, Formamide, Polyvinyl alcohol (PVA, n= 2000) or diols, then dried and cured. The results are as follows : 1. When Lewis acid catalyst like $Zn(NO_3)_2$ or $MgCl_2$ was added in pad bath, the fabric finished with $Zn(NO_3)_2$ catalyst released the lower formaldehyde than with $MgCl_2$. 2. When the effect of pad bath pH was examined with varying the kinds of catalyst and the scavenger, it was found that the pad bath pH influenced on the amount of formaldehyde release and the optimum pad bath pH is at 4.3. Especially, in case of finishing at pad bath pH 4.3 with adding Formamide, the amount of formaldehyde release was decreased by about $45\~$35\%$ with $Zn(NO_3)_2$, while by about $20\~$45\%$ with $MgCl_2$ catalyst. In case of varying the concentration of a scavenger (Formamide), $1\%$ concentration of a scavenger was found to be the optimum level ana the higher the curing temperature up to $180^{\circ}C$, the lesser the amount of formaldehyde release were observed. 3. When the diol was used as scavenger, the amount of formaldehyde release was decreased by about $40\~$50\%$, but the longer the intramolecular length between OH groups, the lessor the amount of decrease of formaldehyde release were observed. 4. When the mixture of scavengers (Formamide and Glycerol) was added in the pad bath, .synergistic effect on formaldehyde release between the two scavengers wasn't observed. 5. The tensile strength of the resin finished fabric was reduced with increasing the pad lath pH and was influenced by the kind of scavengers, and the tensile strength was severely reduced when scavengers, especially Formamide, was added. The wrinkle recovery property is generally improved by resin finish on cotton fabric. When Formamide was added, the wrinkle recovery property is slightly decreased compared with that of the fabrics resin finished without a scavenger, and when polyol was added, the wrinkle recovery property showed almost no change.

• 한국산학기술학회논문지
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• 제20권8호
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• pp.477-484
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• 2019

포유류에 존재하는 Collectin-Placenta 1 (CL-P1)을 포함한 여러 종류의 scavenger 수용체는 주로 내피 세포, 대식 세포 및 평활근 세포 표면에 발현되는 분자이다. 이들 분자는 산화 된 저밀도 지질 단백질 (oxLDL)에 결합하여 처리 할 수 있는 세포 표면 당 단백질이다. 이들 분자 중 케르세틴이 CL-P1 활성화에 어떤 영향을 미치는가를 확인하였다. 케르세틴은 산화 반응을 담당하는 자유 라디칼의 제거제 역할을 하여 산화를 중지시키는 항산화제로 알려져 있다. 본 논문에서는 마우스 CL-P1 유전자 promoter 부분의 전사 시작 점부터 -500 번째 염기까지의 단편을 DNA 중합효소를 이용하여 클로닝 하였다. 그 후에 대식세포 계열인 RAW264.7 및 섬유아세포계열의 NIH3T3 세포에 도입하여 케르세틴이 CL-P1 유전자 발현에 어떠한 영향을 미치는지에 대한 연구를 하였다. 이 부위에는 세포주기 조절 인자인 E2F 결합부위를 비롯해서 여러 종류의 전사 인자가 결합하는 염기서열이 다수 위치하고 있다. 이러한 500염기 단편을 pGL4.10 기본 벡터 및 프로모터에 연결시킨 후 세포에 도입시켰다. 그리고 배양 중에 케르세틴을 처리하여 유전자 발현양을 형광 색소 발현기법으로 측정하였다. 그 결과 유전자 발현이 시작되는 앞쪽 부분의 -250에서 -350사이의 염기들이 CL-P1 단백질을 만드는데 중요하다는 것을 확인하였다. 그 중에서도 E2F결합 부위가 결정적인 것 이라는 것을 DNA 돌연변이 실험을 통해 확인 하였다. 또한 부착 세포인 RAW264.7 배양액에 케르세틴을 첨가 한 결과, 배양용기 표면에서 탈락하는 현상을 확인하였다. 즉 발현된 CL-P1단백질이 케르세틴에 의해 세표 표면의 부착 분자에도 영향을 주는 것을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제1권2호
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• pp.45-49
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• 1980

During the homolytic reactions of $CCl_4$ or $Cl_3CBr with ${\beta}-halo^1$-styrenes,$\beta$-haloradicals are key intermediates. They are to be stabilized via three pathways; $\beta$-cleavage, halogen transfer and telomerization. The three reaction paths are delicately controlled by the energetics of their formation and stabilization. When the formation of a $\beta$-haloradical is accompanied by considerable excess of energy from an exothermic reaction, $\beta$ -cleavage is often dominant over the halogen transfer. On the other hand, if the radical forms via a reversible reaction, two processes become competitive. $\beta$-Eliminated bromine atoms from ${\beta}$ -bromoradicals generate $Br_2$ via $Cl_3CBr + {\cdot}Br {\leftrightarrow} Br_2 + {CCl_3}{\cdot}{Br_2}$ may act as a better scavenger than Cl3CBr for the ${\beta}$-bromoradicals. Different reactivities of chlorine, bromine and trichloromethyl radicals towards olefinic pi-bond are clarified in terms of the beat content of the addition reactions.

• Transactions on Electrical and Electronic Materials
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• 제1권2호
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• pp.1-6
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• 2000

This article presents the experiments and considerations possible about gate etching in polysilicon when oxygen gas is added in chamber, We propose the novel study with optical emission spectroscopy in polysilicon etching. It is shown that added oxygen gases play an important role in enhencement of density in chlorine gases as a scavenger of silicon from SiCl$\_$x/. And a small amount of Si-O bonds are deposited and then the deposited thin film protect silicon dioxyde against reaction chlorine with silicon in SiO$_2$. Consequently, we can improve the selectivity of polysilicon the silicon dioxide, which is clearly explained in this model.

• 한국작물학회지
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• 제46권5호
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• pp.411-415
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• 2001

Fifty-four Korean native and 28 foreign rice varieties harvested in 1998 and 1999 were examined for antioxidative activity that is measured to a chemiluminescence and superoxide radical intensity, by the flow injection chemiluminescence (FI-CL) system and an electron spin resonance (ESR) spectrophotometer, respectively. In the chemiluminescence measurement by FI-CL, radical scavenger activity did not differ significantly among rice varieties between origin types of rice varieties, and between storage periods. GinSun and Hongchoengdo, colored rice exhibited high electron scavenging effect by ESR. Therefore, these results indicate that the pigments of rice varieties may play important antioxidative roles and that it may be possible to breed rice varieties with higher antioxidative potentials.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.424.2-424.2
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• 2014

Ag-modified BiOX (X=Cl, Br and I) nanoplates were synthesized by an ion-exchange reaction. We examined the fundamental properties by scanning electron microscopy (SEM), electron transmission microscopy (TEM), X-ray diffraction, UV-visible absorption, Fourier-transform infrared and photoluminescence spectroscopy. The adsorption and photocatalytic performances of the catalysts were tested with dyes under UV and visible light. A chemical scavenger method was employed to test the roles of active species (${\cdot}OH$, ${\cdot}O2-$ and h+) and understand photodegradation mechanism. Photoluminescence spectroscopy was used to examine ${\cdot}OH$ radical formation using terephthalic acid during photoirradiation.

• 생명과학회지
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• 제14권2호
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• pp.286-290
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• 2004

동결건조한 청갓과 담금당일 청갓김치, 15$^{\circ}C$에서 5일간 발효시킨 청갓 김치로부터 극성이 다른 용매들을 사용하여 각각의 용매별 추출물을 얻고 methanol(MeOH), hexane(C$_{6}$ $H_{14}$), dichlorometane(C $H_2$Cl$_2$), ethyl acetate(EtOAc), butanol(BuOH), water($H_2O$)의 각각의 용매분획별(DPPH) 1,1-diphenyl-2-picrylhydrazyl assay에 의한 항산화성을 측정하였고 항산화효과를 상호 비교하였다. 청갓과 담금당일 청갓 김치에서 EtOAc와 n-BuOH에서 얻은 분획층이 다른 분획층보다 항상화효과가 높게 나타났으며 15$^{\circ}C$ 5일간 발효시킨 청갓 김치에서는 C $H_2$Cl$_2$와 EtOAc분획층이 다른 분획층에 비하여 radical scavenger효과가 있음을 확인할 수 있었다. 결과의 차이는 다양한 재료에 의한 발효공정에 기인된다고 판단된다.

• 생명과학회지
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• 제23권11호
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• pp.1342-1350
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• 2013

본 연구는 화학적 허혈에 의해 손상된 마우스 간세포에서 hydrogen sulfide ($H_2S$)의 효과를 규명하기 위해 수행되었다. 본 연구에서 허혈 모방 화합물로 알려져 있는 cobalt chloride ($CoCl_2$)는 간세포 손상을 시간 및 농도 의존적으로 유의성 있게 증가 시켰다. $CoCl_2$에 의한 간세포 손상은 Sodium sulfide (NaHS, $H_2S$ 공여제)의 전처리에 의해 유의적으로 감소 되었다. $CoCl_2$는 세포 내 활성산소(reactive oxygen species, ROS)의 농도를 증가시켰으며, 이는 NaHS 및 N-acetyl-cysteine (NAC, a ROS 제거제)에 의해 감소하였다. 또한, $CoCl_2$에 의해 증가된 p38 MAPK 인산화가 NaHS 및 NAC에 의해 억제되었다. $CoCl_2$에 의해 증가된 Bax/Bcl-2 비율은 NaHS, NAC 및 SB 203580 (p38 MAPK 저해제)에 의해 차단되었으며, $CoCl_2$에 의해 유발된 간세포의 손상 또한 NaHS, NAC 및 SB 203580의 전처리에 의해 억제되었다. NaHS는 $CoCl_2$에 의해 증가된 COX-2의 발현을 억제하였다. 또한, NaHS의 효과와 유사하게 $CoCl_2$에 의해 증가된 COX-2의 발현이 NAC에 의해 억제되었다. 더욱이, NS-398 (COX-2 선택적 억제제)는 $CoCl_2$에 의한 Bax/Bcl-2 비율의 증가를 억제하였을 뿐 아니라, 간세포의 세포 손상 또한 억제하였다. 결론적으로, $H_2S$는 초대배양 된 마우스 간세포에서 $CoCl_2$에 의해 유발된 간세포의 손상을 ROS에 의해 유발된 p38 MAPK 및 COX-2 경로의 활성화를 억제함으로써 세포보호효과를 수행하는 것을 알 수 있었다.

• 한국환경성돌연변이발암원학회지
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• 제19권1호
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• pp.34-38
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• 1999

Fumonisin B1 is a secondary metabolite of Fusarium moniliforme, a contaminant of corn and corn product. Fumonisin B1 has been shown to be responsible for major toxicological effects of the fungus in rats, horses, and pigs. Fumonisin B1 induced λ DNA fragmentation, which was increased with incubation time, reducing agent NADPH and metal ion (Cu2+). The DNA damage was inhibited by dimethyl sulfoxide (DMSO) or mannitol as radical scavenger for free radicals. DNA fragmentation, induced by fumonisin B1 in the presence of 1 mM NADPH and 0.1 mM CuCl2, was inhibited by 100 mM DMSO. By the in vitro reaction of fumonisin B1 with supercoiled plasmid pBR322 DNA, plasmid DNA was relaxed, eventually linearized in the agarose gel electrphoresis. From rifampicin sensitive E. coli CSH138 in bacterial mutagenesis system, the rifampicin resistant E. coli mutants were obtained by fumonisin B1. These results suggest that fumonisin B1 may be a possible environmental mutagen in bacterial mutagen assay system.

• Bulletin of the Korean Chemical Society
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• 제15권9호
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• pp.782-785
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• 1994

The dissociation kinetics of linear polyaminopolycarboxylate complexes of lanthanide ions (L$n^{3+}: Ce^{3+},\;Eu^{3+}\;and\;Yb^{3+}$) has been studied in an aqueous solution of 0.10 M (NaCl$O_4$) at 25.0${\pm}0.1^{\circ}C$ using Cu(II) ions as a scavenger. The dissociation rates of acid-catalyzed pathway decrease in the order Ln(EPDTA$)^- > Ln(DPOT)^- > In(TMDTA)^- > Ln(MPDTA)^- > Ln(EDTA)^- > Ln(PDTA)^- > Ln(DCTA)^-$ according to the present and literature data. An increase in the N-Ln-N chelate ring from 5 to 6 and substitution of two methyl groups, one ethyl and hydroxyl group on a chelate ring carbon of these ligands leads to a decrease in kinetic stabilities of the complexes. The substitution of one methyl group and cyclohexyl ring on a ring carbon, however, results in a significant increase in the kinetic stability of the resulting $Ln^{3+}$ complexes. Individual reaction steps taking place for each system, with different copper, acetate buffer concentration and pH dependence, are also discussed.