• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.270-274
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• 2012

The nucleophilic substitution reactions of 1,2-phenylene phosphorochloridate (1c) with X-pyridines are investigated kinetically in acetonitrile at $-25.0^{\circ}C$. The free energy correlations for substituent X variations in the nucleophiles exhibit biphasic concave upwards with a break point at X = 3-Ph. The pyridinolysis rate of 1c with a cyclic five-membered ring is $2.70{\times}10^5$ times faster than its acyclic counterpart (1a: phenyl ethyl chlorophosphate) because of great positive value of the entropy of activation of 1c (${\Delta}S^{\neq}$ = +26 eu) compared to negative value of 1a (${\Delta}S^{\neq}$= -24 eu) over considerably unfavorable enthalpy of activation of 1c (${\Delta}H^{\neq}=20.5kcal\;mol^{-1}$) compared to 1a (${\Delta}H^{\neq}=12.7kcal\;mol^{-1}$). Great enthalpy and positive entropy of activation are ascribed to sterically congested transition state (TS) and solvent structure breaking in the TS. A concerted mechanism involving a change of nucleophilic attacking direction from a frontside attack with the strongly basic pyridines to a backside attack with the weakly basic pyridines is proposed on the basis of greater selectivity parameters (${\rho}_X$ = -1.99 and ${\beta}_X$ = 0.41) with the strongly basic pyridines compared to those (${\rho}_X$ = -0.42 and ${\beta}_X$ = 0.07) with the weakly basic pyridines.

• BMB Reports
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• 제47권12호
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• pp.685-690
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• 2014

The Ras/Raf/MEK/Erk signaling pathway is important for regulation of cell growth, proliferation, differentiation, survival, and apoptosis in response to a variety of extracellular stimuli. Lack of Erk MAPK activation is observed in several cancer cells despite active activation of Ras. However, little is known about the modulation of Erk1/2 activity by active Ras. Here, we show that overexpression of active H-Ras (H-RasG12R) in NIH3T3 fibroblasts impaired FGF2-induced Erk1/2 phosphorylation, as compared to wild-type cells. Northern blot analysis revealed that prolonged expression of active Ras increased MAP kinase phosphatase 3 (MKP3) mRNA expression, a negative regulator of Erk MAPK. Inhibition of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway abrogated active Ras-induced up-regulation of MKP3 expression, leading to the rescue of Erk1/2 phosphorylation. Our results demonstrated that the Ras/Raf/MEK/Erk signaling cascade is negatively regulated by the PI3K/Aktdependent transcriptional activation of the MKP3 gene.

• Bulletin of the Korean Chemical Society
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• 제9권1호
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• pp.32-36
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• 1988

The isotherms of oxygen chemisorption on polycrystaline nickel surface are obtained at various temperatures between 298K and 523K from intensity measurernent of O 1s xps peaks, and the activation energy of the chemisorption is estimated as a function of the coverage. The activation energy extrapolated to zero coverage is found to be -5.9 kJ/mol. The negative activation energy can be taken as a strong implication of the propriety of a currently accepted chemisorption model, in which molecularly adsorbed precursor state is assumed to exist. The residence time of this precursor state is estimated by assuming a molecularly physisorbed state for the precursor state and assuming a pairwise interaction energy of Lennard-Jones 12-6 potential between an admolecule and each substrate nickel atom. The sticking coefficients are also calculated from the isotherms. The calculated results agree well with those obtained by others with different methods.

• The Korean Journal of Physiology and Pharmacology
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• 제23권5호
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• pp.411-417
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• 2019

Humanin (HN) is a mitochondrial peptide that exhibits cytoprotective actions against various stresses and diseases. HN has been shown to induce the phosphorylation of AMP-activated protein kinase (AMPK), which is a negative regulator of receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL). However, the role of HN in osteoclastogenesis or other skeletal disorders remains unknown. Here, we examined whether HN regulates osteoclastogenesis via AMPK activation using bone marrow-derived macrophage (BMM) cultures. Our results show that HN inhibited RANKL-induced osteoclast formation and reduced the expression of genes involved in osteoclastogenesis, including nuclear factor of activated T-cells cytoplasmic 1, osteoclastassociated receptor, cathepsin K, and tartrate-resistant acid phosphatase. Moreover, HN increased the levels of phosphorylated AMPK protein; compound C, an AMPK inhibitor, recovered HN-induced osteoclast differentiation. In addition, we found that HN significantly decreased the levels of RANKL-induced reactive oxygen species in BMMs. Therefore, these results indicate that HN plays an important role in osteoclastogenesis and may function as an inhibitor of bone disorders via AMPK activation.

• 한국식품저장유통학회지
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• 제30권1호
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• pp.65-77
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• 2023

In this study, we investigated the immunological properties of six strains of Acetobacter pasteurianus through nuclear factor-kappa B/activator protein-1 (NF-κB/AP-1) transcription factor activation and nitric oxide (NO) and cytokine production in macrophages. We found that the six A. pasteurianus strains had no significant inhibitory effect on the cell viability of RAW-Blue^TM cells at the concentration of (25, 50, 100 CFU/macrophage). The production of NO and cytokines (TNF-α, IL-1β, and IL-6) showed different abilities of immune activation for each strain, and it was 0.7 to 0.9 times higher than that of the LPS (100 ng/mL, v/v) positive control and 7 to 8 times superior to that of the negative control group. To explore the underlying mechanism, we evaluated the mRNA expression of pro-inflammatory genes. Consequently, we found that inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 expression including genes expression of cytokines were elevated by the six A. pasteurianus treatment. These results suggested that the six strains of A. pasteurianus have an excellent industrial application value as a functional material for the purpose of enhancing immune function.

• 복식
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• 제30권
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• pp.41-58
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• 1996

To purpose of this study is to understand the present situation of the present situation of the fashion careers in apparel industry and to present a activation information for development of a specialty de-partment. This study has been proceeded with the library survey method, and 20 apparel enterprises have been researched with the questionaire and inter-view method. These were large and medium sized enterprises. The results were as follows: 1. Subdivision of fashion careers have been found insufficient on apparel enterprises in Korea. 2. Textile specialists have been needed on apparel enterprises in Korea. 3. Domestic enterprises have dropt out man-agement 4. These enterprises are negative for the consumer research and fashion information col-lection. 5. Fashion sepecialists have been found insuf-ficient on retail division, The propositions for activation of fashion careers are as follows: 1. Fashion careers should subdivide and specialize. 2. The apparel enterprises should employ textile designer. 3. The apparel enterprises should activate practical department. 4. The apparel enterprises should research consumer and collect fashion information. 5. The apparel enterprises should develop fashion specialists on retail division.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2001년도 춘계학술대회 논문집
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• pp.219-224
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• 2001

본 연구에서는 개인의 성격이 소리자극에 의하여 유도되는 감성에 미치는 영향을 조사하기 위하여 대학생 450명(남자: 210명)을 대상으로 행동활성화체계(BAS)와 행동억제체계(BIS) 민감성의 고저에 따라 두 집단을 추출하여 안정상태에서 전전두엽(PFC)의 비대칭적 활성화를 측정한 뒤, 긍정감성과 부정감성을 각각 유발하는 소리들을 제시하여 느끼는 감성에 대한 심리반응 변화를 평가하고 이에 따른 전전두엽의 비대칭적 활성화의 변화를 관찰하였다. 긍정감성과 부정감성을 유도하는 소리는 명상음악과 소음을 각각 사용하였으며 안정상태와 음향청취상태에서의 전전두엽 영역 활성화를 관찰하기 위하여 F7와 F8 부위에서 EEG의 알파밴드(8-13 Hz) 활성도를 분석하였다.

• Environmental Analysis Health and Toxicology
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• 제15권4호
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• pp.157-163
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• 2000

2- [(4- Cyanophenyl)amino] -3-chloro-1, 4- naphthalenedione (NQ-Y15) was asssayed for its genotoxic potential by using Salmonella typhimurium reversion assay and in vitro chromosome aberration test on Chinese hamster lung cells. In the Ames test, NQ-Y15 induced his + revertants of Salmonella typhimurium TA 98 and TA1537, reaching levels twice the negative control values. But, NQ-Y15 induced only his+ revertants of Salmonella typhimurium TA1537 more than twice the control values under the condition with metabolic activation system. In the cytogenetic test on chinese hamster lung cells. NQ -Y15 showed significant chromosomal aberrations, but the incidence was significantly reduced in the presence of metabolic activation.

• International Journal of Oral Biology
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• 제42권3호
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• pp.85-90
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• 2017

Mitochondria participate in various intracellular metabolic pathways such as generating intracellular ATP, synthesizing several essential molecules, regulating calcium homeostasis, and producing the cell's reactive oxygen species (ROS). Emerging studies have demonstrated newly discovered roles of mitochondria, which participate in the regulation of innate immune responses by modulating NLRP3 inflammasomes. Here, we review the recently proposed pathways to be involved in mitochondria-mediated regulation of inflammasome activation and inflammation: 1) mitochondrial ROS, 2) calcium mobilization, 3) nicotinamide adenine dinucleotide ($NAD^+$) reduction, 4) cardiolipin, 5) mitofusin, 6) mitochondrial DNA, 7) mitochondrial antiviral signaling protein. Furthermore, we highlight the significance of mitophagy as a negative regulator of mitochondrial damage and NLRP3 inflammasome activation, as potentially helpful therapeutic approaches which could potentially address uncontrolled inflammation.

• Molecules and Cells
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• 제38권7호
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• pp.651-656
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• 2015

Plant growth and development are coordinately orchestrated by environmental cues and phytohormones. Light acts as a key environmental factor for fundamental plant growth and physiology through photosensory phytochromes and underlying molecular mechanisms. Although phytochromes are known to possess serine/threonine protein kinase activities, whether they trigger a signal transduction pathway via an intracellular protein kinase network remains unknown. In analyses of mitogen-activated protein kinase kinase (MAPKK, also called MKK) mutants, the mkk3 mutant has shown both a hypersensitive response in plant hormone gibberellin (GA) and a less sensitive response in red light signaling. Surprisingly, light-induced MAPK activation in wild-type (WT) seedlings and constitutive MAPK phosphorylation in dark-grown mkk3 mutant seedlings have also been found, respectively. Therefore, this study suggests that MKK3 acts in negative regulation in darkness and in light-induced MAPK activation during dark-light transition.