• Title/Summary/Keyword: inhibition process

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Toxic action of N-dimethylphosphinothioyl carbofuran by oxidative activation process (산화적 활성화 과정을 통한 N-dimethoxyphosphinothioyl carbofuran의 독성발현)

  • Yang, Kyew-Wan;Lee, Seog-Jong;Kim, Song-Mun;Han, Dae-Sung;Hur, Jang-Hyun
    • The Korean Journal of Pesticide Science
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    • v.2 no.2
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    • pp.10-15
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    • 1998
  • The bimolecular inhibition rate constants of carbofuran and N-dimethylphosphinothioyl carbofuran(PSC) to acetylcholinesterase(AChE) were $7.7{\times}10^{5}\;M^{-1}{\cdot}min^{-1}$ and $1.2{\times}10^{3}\;M^{-1}{\cdot}min^{-1}$, respectively. These results showed that PSC required a bioactivation process for its toxic action because it didn't inhibit the target enzyme effectively. The potency of PSC as an inhibitor of AChE increased when PSC and AChE were incubated with microsomes fortified with NADPH compared with microsome alone. Piperonyl butoxide(PBO) addition to these coupled systems greatly reduced the inhibition of the target enzyme by blocking the bioactivation process. In vivo inhibition study of mouse brain AChE, $I_{50}$ value for AChE was 28 mg/kg for PSC and the value increased to 57 mg/kg when PBO was pretreated. This result showed that cytochrome $P_{450}$ would also play a role in the bioactivation process of PSC in vivo. And conversioin of carbofuran from PSC was 55 % in a chemical oxidation system using meta-chloroperoxybenzoic acid. The oxidative activation of PSC to carbofuran was shown to be essential for showing its toxicological action and cytochrome $P_{450}$ was identified as an important enzyme which participated in this process.

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Effects of Behavioral Inhibition in Young Children on Self-Determination: Sequential Mediating Effects of Mother's Parenting Anxiety and Autonomy Support (유아의 행동억제가 자기결정성에 미치는 영향: 어머니의 양육불안과 자율성 지지의 순차매개효과)

  • Ji-Hyo Kim;Nary Shin
    • Korean Journal of Childcare and Education
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    • v.19 no.6
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    • pp.97-113
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    • 2023
  • Objective: The purpose of this study is to investigate the effect of young children's behavioral inhibition on self-determination, examining the sequential mediating effects of mothers' parenting anxiety and autonomy support. Methods: Participants in this study were 225 mothers with children aged 6 years. An online survey was conducted, and SPSS Statistics 23.0 was used for basic analysis. The research model used the Process Macro 4.0 program. Results: The higher the level of behavioral inhibition, the lower the child's self-determination. Furthermore, a mediating effect was confirmed when parenting anxiety was added. However, in the single mediation model and the sequential mediation model in which autonomy support was added, the direct effects of behavioral inhibition temperament and parenting anxiety on self-determination disappeared. As a result, behavioral inhibition characteristics were found to have an indirect effect on self-determination through the sequential mediating effects of mother's parenting anxiety and autonomy support. Conclusion/Implications: If a mother with a child with a behaviorally inhibited temperament properly handles the negative emotions experienced during parenting based on her understanding of the child and supports the child to have a high degree of autonomy, she can enhance the child's right to self-determination.

Optimal Treatment of Molasses Wastewater Using UASB Process (UASB 공정에 의한 당밀폐수의 최적처리 방안)

  • Huh, Kwan-Yong;Jeong, Eui-Geun;Chung, Yoon-Jin;Yoo, Sang-Keun
    • Journal of Korean Society of Water and Wastewater
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    • v.11 no.2
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    • pp.112-127
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    • 1997
  • The purpose of this study is to get optimum operating factors of Upflow Anaerobic Sludge Blanket (UASB) reactor by introducing methods that make it to reduce inhibition possible in each process wastewater treatment. The used substrates, concentrated corn starch liquid (CSL) wastewater, modified starch, filtering and decoloring wastewater, ion refining wastewater, and mixed wastewater including modified starch and not including modified starch, are generated from molasses process. The seeding sludge is the digested sludge that had been applied to molasses wastewater. Batch test to reduce the inhibition factors that might be existed in each wastewater was examined. Based on the this test, the optimum operating factors according to alkalinity and pH variation was studied through the continuous test using three 5.5 L UASB reactor. The first reactor added $NaHCO_3$ to control alkalinity. The hydraulic retention time (HRT) reduced to 8 hours and the organic loading rate increased gradually. The second reactor changed the pH of influent from 7.0 to 6.0 using NaOH. The third reactor was operated without changes to compare the above two reactors. As the result, the inhibition in concentrated CSL wastewater was removed by adding iron (II). When trace metals were added to mixed wastewater not including modified starch, the digestability by gas production rate increased to more fifty percentage than mixed wastewater that was not adding the trace metals. The reason that the inhibition did not decreased in spite of adding trace metals and nutrients was influenced by high concentration generated during the acid fermentation. The UASB reactors using the mixed wastewater with the most effective performance were operated as 500 mg/L as $CaCO_3$ alkalinity and 6.0 pH at steady state, and at this time, the gas production rates were 283 and 311mL gas/g $COD_{added}$. The COD removal rates were 84.7 and 86.3%, respectively.

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Combinational Effect of Moist Heating and Gamma Irradiation on The Inactivation of Trypsin Inhibitory Activity in Soybean

  • Felipe, Penelope;Yang, Yun-Hyoung;Lee, Jeong-Hee;Sok, Dai-Eun;Kim, Hyoung-Chin;Yoon, Won-Kee;Kim, Hwan-Mook;Kim, Mee-Ree
    • Food Science and Biotechnology
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    • v.14 no.6
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    • pp.732-737
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    • 2005
  • The combinational effect of gamma irradiation and moist heating on the trypsin inhibitor activity (TIA) in soaked and dried soybeans was evaluated by measuring the inhibition using N-benzoyl-DL-arginine-p-nitroanilide (BAPNA) as substrate. Gamma irradiation significantly decreased the TIA level in soybean at doses above 5 kGy, and the $ID_{50}$ (the gamma irradiation dose required to reach 50% inhibition) value for TIA was 13.53 kGy. Soaking prior to gamma irradiation significantly lowered the $ID_{50}$ to 8.44 kGy, and the soaking process enhanced the efficiency to inactivate TIA by as much as 48%. When soaking prior to gamma irradiation was followed by subsequent mild heating ($60^{\circ}C$) process, the $IT_{50}$ (heating time required to reach the 50% inhibition of TIA) value at even 1 kGy (5.28 min) was greatly reduced by over 50% compared to the level for the no-soaking process. In addition, the activation energy of soaking prior to gamma irradiation at 1 kGy was 2.45 kcal/mole, which was also about 50% lower than the 5.10 kcal/mole of dried soybean gamma-irradiated. Based on these results, soaking prior to gamma irradiation is an effective method for TIA inhibition. Furthermore, a combination of two or more processing methods such as soaking, heating and gamma irradiation is much more effective than any single processing method.

The effect of Elastase inhibition and Tyrosinase by Rheum undulatum Stokes extracts (대황(大黃)의 Elastase 활성 억제와 Tyrosinase 억제연구)

  • Lee, Jong-Chul;Kim, Kyung-Jun
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.22 no.3
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    • pp.36-46
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    • 2009
  • Objective : Recently, the demands for the effective and safe depigmentating and anti-aging agents of the skin have increased due to the medical, pharmaceutical and cosmetic reasons. The aim of this study is to search new materials from the traditional herbal medicines which inhibit the aging process of skin in vitro. Methods : herbal medicines(80% ethanol or water extracts) were screened for their inhibitory activities against elastase. Results : Rheum undulatum (final concentrstion 1 mg/ml) appeared over 30% of inhibition of elastase activity. so we are investigated anti wrinkle effects of Rheum undulatum look through MMP-1 inhibition activity. also Extracts of Rheum undulatum showed higher anti tyrosinase activity than arbutin (final concentration 1 mg/ml). Conclusion : These results suggest that herbal medicines could be strong potential sources of inhibition of anti-aging and whitening effects for the skin.

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Lornoxicam & Tenoxicam Drugs as Green Corrosion Inhibitors for Carbon Steel in 1 M H2SO4 Solution

  • Fouda, A.S.;El-Defrawy, A.M.;El-Sherbeni, M.W.
    • Journal of Electrochemical Science and Technology
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    • v.4 no.2
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    • pp.47-56
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    • 2013
  • Inhibition performance of Lornoxicam & Tenoxicam against corrosion of carbon steel in 1M $H_2SO_4$ solutions was investigated by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. The inhibition efficiency increased with increasing inhibitor's concentration, but decreased with increase in temperature. Potentiodynamic polarization curves showed that, the inhibitors were of mixed type. The apparent activation energy ($E^*_a$) and other thermodynamic parameters for the corrosion process have also been calculated and discussed. The inhibition of carbon steel corrosion is due to the adsorption of the inhibitor molecules on the surface, which follows Temkin adsorption isotherm. The mechanism of inhibition was discussed in the light of the chemical structure of the undertaken inhibitors.

Inhibition Effects of Toxic Solvent Mixture in Catalytic Oxidation Process (유독성 유기용매의 촉매산화공정에서 혼합조성에 따른 간섭효과)

  • 이승범;김원일;홍인권;김형진
    • Journal of environmental and Sanitary engineering
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    • v.16 no.3
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    • pp.72-79
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    • 2001
  • The selective catalytic oxidation of toxic aromatic solvents (benzene, toluene, ethylbenzene, and styrene) and their mixtures were studied on a $Pt/{\;}{\gamma}-Al_2O_3$ catalyst at temperature ranging from $160~350^{\circ}C$. The deep conversion of aromatic solvents was increased as the inlet concentration was decreased and the reaction temperature was increased. The reactivity increases in order benzene > toluene > ethylbenzene > styrene. In mixture, remarkable effects on reaction rate and selectivity have been evidence ; the strongest inhibition effect is shown by styrene and increase in a reverse order with respect to that of reactivity. The inhibition effect was increased in order styrene > ethylbenzene > toluzene > benzene. This trend is due to the competition adsorption between the two or three reactants on the oxidized catalyst. Also, the deep conversion change of benzene was a small in tertiary mixtures(including of benzene and styrene) comparing with conversion characteristics of binary mixture with styrene. This result was due to small concentration of styrene. which had very strong inhibition effect.

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Inhibition Effect of a Few Amino Acids on the Corrosion of Copper in Aerated Artificial Sea Water (공기가 포화된 인공해수에서 몇 가지 아미노산의 구리 부식 억제 효과)

  • Kim, Youn-Kyoo
    • Journal of the Korean Chemical Society
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    • v.54 no.6
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    • pp.680-686
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    • 2010
  • Inhibition effects of alanine(Ala), asparagine(Asn), aspartic acid(Asp), glutamine(Gln) and methionine(Met) on the corrosion of copper were investigated in aerated artificial sea water. Amino acid adsorption process in copper surface can be explained by Temkin logarithmic isotherm due to the interaction between the adsorbed molecules. The inhibition efficiency for the copper corrosion depended on the concentration of amino acids.

A Study on the Inhibition of Propylene Chlorohydrins in HPMC Manufacturing Process ( I ) (HPMC 제조공정의 PCH 발생 억제에 관한 연구 ( I ))

  • Jang, Hyun-Duk;Yoo, Jae-Seong;Kim, Bong-Sun
    • Proceedings of the Safety Management and Science Conference
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    • 2011.11a
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    • pp.315-324
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    • 2011
  • The purpose of this study is to improve for the inhibition of the generating the PCH(Propylene Chlorohydrins) in HPMC(Hydroxypropylmethyl Cellulose) manufacturing process. HPMC is made of cellulose which is natural high polymer. And HPMC is applicable to several industrial areas. Especially it can be used in food industrial as an effective additive. PCH is the by-product which is generated in chemical reaction in HPMC manufacturing process. So it is essential to eliminate PCH for the improvement of product quality. Therefore we have studied to minimize the amount of PCH. It is expected that the application of HPMC could be enlarged as the result of this study.

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Fatty acid oxidation regulates cellular senescence by modulating the autophagy-SIRT1 axis

  • Seungyeon Yang;Subin Moon;Soojung Claire Hur;Seung Min Jeong
    • BMB Reports
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    • v.56 no.12
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    • pp.651-656
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    • 2023
  • Senescence, a cellular process through which damaged or dysfunctional cells suppress the cell cycle, contributes to aging or age-related functional decline. Cell metabolism has been closely correlated with aging processes, and it has been widely recognized that metabolic changes underlie the cellular alterations that occur with aging. Here, we report that fatty acid oxidation (FAO) serves as a critical regulator of cellular senescence and uncover the underlying mechanism by which FAO inhibition induces senescence. Pharmacological or genetic ablation of FAO results in a p53-dependent induction of cellular senescence in human fibroblasts, whereas enhancing FAO suppresses replicative senescence. We found that FAO inhibition promotes cellular senescence through acetyl-CoA, independent of energy depletion. Mechanistically, increased formation of autophagosomes following FAO inhibition leads to a reduction in SIRT1 protein levels, thereby contributing to senescence induction. Finally, we found that inhibition of autophagy or enforced expression of SIRT1 can rescue the induction of senescence as a result of FAO inhibition. Collectively, our study reveals a distinctive role for the FAO-autophagy-SIRT1 axis in the regulation of cellular senescence.