• Carbon letters
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• 제6권4호
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• pp.234-242
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• 2005

Bending and tensile properties of 2D cross-ply C/C composites with processing heat treatment temperature (HTT) are evaluated. C/C composites used are made from two types of PAN based T700 and M40 carbon fibers with phenolic resin as carbon matrix precursor. Both the types of composites are heat treated at different temperatures (ranging from 750 to $2800^{\circ}C$) and characterized for bending and tensile properties. It is observed that, real density and open porosity increases with HTT, however, bulk density does show remarkable change. The real density and open porosity are higher in case T-700 carbon fiber composites at $2800^{\circ}C$, even though the density of M40 carbon fiber is higher. Bending strength is considerably greater than tensile strength through out the processing HTT due to the different mode of fracture. The bending and tensile strength decreases in both composites on $1000^{\circ}C$ which attributed to decrease in bulk density, thereafter with increase in HTT, bending and tensile strength increases. The maximum strength is in T700 fiber based composites at HTT $1500^{\circ}C$ and in M40 fiber based composites at HTT $2500^{\circ}C$. After attending the maximum value of strength in both types of composite at deflection HTT, after that strength decreases continuously. Decrease in strength is due to the degradation of fiber properties and in-situ fiber damages in the composite. The maximum carbon fiber strength realization in C/C composites is possible at a temperature that is same of fiber HTT. It has been found first time that the bending strength more or less 1.55 times higher in T700 fiber composites and in M40 fiber composites bending strength is 1.2 times higher than that of tensile strength of C/C composites.

• 생명과학회지
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• 제13권4호
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• pp.457-462
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• 2003

TCDD를 투여한지 일주일 후부터 어성초를 200mg/kg 복강 내로 4주간 격일로 투여하였다. TTA군과 NTT군은 saline을 투여하였다. 혈청에서 GOT, GPT의 활성도를 측정하였고, 간조직중에서 MDA, GSH, GSSG, GPx, SOD, Catalase의 level을 측정하였다. GOT 활성도는 HTT군이 TTA군과 비교해서 49.00%의 억제 효과를 보였다. 반면 GPT활성도는 TTA(29.70)군에 비해 68.36%의 억제효과를 보였다. MDA는 TTA군이 NTT군 보다 높게 나왔으며, HTT군은 NTT군에 비교하여 30.47%의 억제율을 보였다. HTT군의 GSH는 TTA군에 비해 1.91배 증가하였고, GSSG는 TTA군에 비해 46.72% 감소하였다. SOD는 TTA군이 NTT군보다 낮게 나타났고, HTT는 TTA군에 비해 46%의 증가를 보였다. Catalase는 TTA군(1.12mU/mg protein)의 활성은 NTT(3.44mU/mg protein)군 보다 32.56% 감소하였다. HTT군의 간의 Catalase 활성도는 TTA 군과 비교하여 50.00% 증가 하였다. 이러한 결과에서 보듯이 TCDD로 인해 생성된 free radical은 항산화 효소에 의해서 감소되었으며, 그리고 어성초가 항산화 효소 대신에 노화를 저해하는 작용을 하는 것으로 사료 된다.

• Journal of Ginseng Research
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• 제46권4호
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• pp.572-584
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• 2022

Background: Huntington's disease (HD) is a neurodegenerative disorder caused by the expansion of trinucleotide CAG repeat in the Huntingtin (Htt) gene. The major pathogenic pathways underlying HD involve the impairment of cellular energy homeostasis and DNA damage in the brain. The protein kinase ataxia-telangiectasia mutated (ATM) is an important regulator of the DNA damage response. ATM is involved in the phosphorylation of AMP-activated protein kinase (AMPK), suggesting that AMPK plays a critical role in response to DNA damage. Herein, we demonstrated that expression of polyQ-expanded mutant Htt (mHtt) enhanced the phosphorylation of ATM. Ginsenoside is the main and most effective component of Panax ginseng. However, the protective effect of a ginsenoside (compound K, CK) in HD remains unclear and warrants further investigation. Methods: This study used the R6/2 transgenic mouse model of HD and performed behavioral tests, survival rate, histological analyses, and immunoblot assays. Results: The systematic administration of CK into R6/2 mice suppressed the activation of ATM/AMPK and reduced neuronal toxicity and mHTT aggregation. Most importantly, CK increased neuronal density and lifespan and improved motor dysfunction in R6/2 mice. Conversely, CK enhanced the expression of Bcl2 protected striatal cells from the toxicity induced by the overactivation of mHtt and AMPK. Conclusions: Thus, the oral administration of CK reduced the disease progression and markedly enhanced lifespan in the transgenic mouse model (R6/2) of HD.

• Carbon letters
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• 제1권1호
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• pp.22-26
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• 2000

Raman spectroscopy has been used to investigate the structure of coal tar pitch heat-treated up to $3000^{\circ}C$ by using 514.5 run Ar ion laser line. Four critical temperature ranges were found on pyrolyzing coal tar pitch, which correspond to four distinct processes from disordered carbons to the well-ordered graphite structure. The range of heat treat temperature (HTT) below $1000^{\circ}C$ corresponds to gas evolution during the pyrolysis of coal tar pitch. Above the HTT are correlated to rearrangements of enlarged molecules, growth of the molecules along the direction of plane, finally stacking in the normal direction of the plane, in the respective HTT ranges of 1000-2000, above 2000 and $2500-3000^{\circ}C$.

• 동의생리병리학회지
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• 제27권4호
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• pp.422-430
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• 2013

This experiment was designed to investigate the effects of So-Oochim-tang-Gagam-bang (SOCT-G) on oxidative stress and serotonin metabolism in P815 Mast Cells The effects of SOCT-G on activity of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging and Super Oxide Dismutase (SOD) in P815 mast cells were investigated. The effect of SOCT-G on content of serotonin in P815 mast cells was investigated. The effects of SOCT-G on expression of 5-hydroxytryptamine transporter (5-HTT), Tryptophan hydroxylase 1 (TPH-1) mRNA in P815 mast cells were investigated. The SOCT-G increased DPPH radical-scavenging activity in P815 mast cells. The SOCT-G increased SOD activity in P815 mast cells. The SOCT-G decreased the intracellular content of serotonin in P815 mast cells. The SOCT-G decreased 5-HTT and TPH-1 mRNA expression in P815 mast cells. This experiment shows that So-Ochm-Tang-Gagam-bang has a significant effect of oxidative stress that help prevent free radical damage. And So-Ochim-Tang-Gagam-bang decreased the intracellular content of serotonin and mRNA expression of 5-HTT and TPH-1. Therefore, further researches are suggested to reveal the anti-depressive effectiveness of So-Ochim-Tang-Gagam-bang.

• 동의신경정신과학회지
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• 제24권2호
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• pp.189-200
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• 2013

Objectives : The purpose of this study is to examine the effects of antioxidant activities and serotonin activities of OnDam-tang-Kami-bang (ODK) on P815 Mast Cell. Methods : The effects of ODK on the activation of DPPH radical-scavenging and SOD in P815 mast cell were investigated. The effect of ODK on the content of serotonin in P815 mast cell was investigated. The effects of ODK on the activation of 5-HTT, TPH-1 mRNA in P815 mast cell were investigated. Results : It was found that the ODK increased SOD activities and DPPH radical-scavenging activities in the P815 mast cell. Also, the ODK decreased the intracellular concentration of serotonin in the P815 mast cell. Further, the ODK decreased 5-HTT and TPH-1 mRNA expression in the P815 mast cell. Conclusions : The results of this experiment reveal that ODK has significant antioxidative effects. However, ODK decreased the intracellular concentration of serotonin and mRNA expression of 5-HTT and TPH-1, which implies that ODK might not be effective for treating depression. Further research exploring the positive aspects of ODK is suggested such that ODK could adequately target symptoms that are to be treated.

• BMB Reports
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• 제56권3호
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• pp.178-183
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• 2023

Huntington's disease (HD) is a neurodegenerative disorder, of which pathogenesis is caused by a polyglutamine expansion in the amino-terminus of huntingtin gene that resulted in the aggregation of mutant HTT proteins. HD is characterized by progressive motor dysfunction, cognitive impairment and neuropsychiatric disturbances. Histone deacetylase 6 (HDAC6), a microtubule-associated deacetylase, has been shown to induce transport- and release-defect phenotypes in HD models, whilst treatment with HDAC6 inhibitors ameliorates the phenotypic effects of HD by increasing the levels of α-tubulin acetylation, as well as decreasing the accumulation of mutant huntingtin (mHTT) aggregates, suggesting HDAC6 inhibitor as a HD therapeutics. In this study, we employed in vitro neural stem cell (NSC) model and in vivo YAC128 transgenic (TG) mouse model of HD to test the effect of a novel HDAC6 selective inhibitor, CKD-504, developed by Chong Kun Dang (CKD Pharmaceutical Corp., Korea). We found that treatment of CKD-504 increased tubulin acetylation, microtubule stabilization, axonal transport, and the decrease of mutant huntingtin protein in vitro. From in vivo study, we observed CKD-504 improved the pathology of Huntington's disease: alleviated behavioral deficits, increased axonal transport and number of neurons, restored synaptic function in corticostriatal (CS) circuit, reduced mHTT accumulation, inflammation and tau hyperphosphorylation in YAC128 TG mouse model. These novel results highlight CKD-504 as a potential therapeutic strategy in HD.

• Carbon letters
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• 제14권1호
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• pp.22-26
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• 2013

The effects of heat treatment temperature (HTT) of polyacrylonitrile-based carbon fiber (CF) on the mechanical, thermal, and tribological properties of C/C composites were investigated. It was found that HTT (graphitization) of CF affects the thermal conductivity and mechanical and tribological characteristics of C/C composites. Thermal treatment of fibers at temperatures up to $2800^{\circ}C$ led to a decrease of the wear rate and the friction coefficient of C/C composite-based discs from 7.0 to 1.1 ${\mu}m$/stop and from 0.356 to 0.269, respectively. The friction surface morphology and friction mechanism strongly depended on the mechanical properties of the CFs. The relief of the friction surface of composites based on CFs with final graphitization was also modified, compared to that of composites based on initial fibers. This phenomenon could be explained by modification of the abrasive wear resistance of reinforcement fibers and consequently modification of the friction and wearing properties of composites. Correlation of the graphitization temperature with the increased flexural and compressive strength, apparent density, and thermal conductivity of the composites was also demonstrated.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.51-51
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• 2001

Cocaine and amphetamine-regulated transcript (CART) is a satiety factor that is regulated by leptin. It was reported that the mice intracerebroventricularly injected with CART showed behavioral changes resembled with the typical behavioral alterations found in the mice carrying disorders in the brain serotonergic (5-HT) system. Hence, this study was conducted to find out the relationships between CART and 5-HT. We first examined the mRNA levels of CART after the injections of para-chlorophenylalanine (pCPA, 300 mg/kg i.p., single injection or daily for three consecutive days) in the rat brains by in situ hybridization using the mouse CART cDNA probe cloned in our laboratory. Systemic administrations of pCPA, a potent inhibitor of tryptophan hydroxylase, the rate limiting enzyme of 5-HT biosynthesis, acutely depletes the brain 5-HT transporter (5-HTT) in the dorsal raphe nucleus (DRN), which reuptakes terminal 5-HT. Results indicated that the mRNA level of CART significantly decreased in the arcuate nucleus, paraventricular nucleus, and lateral hypothalamic nucleus by three days of daily injection with pCPA with no noticeable change detected 24 hrs after the single injection. The message levels of 5-HTT in DRN decreased in both single and three days of injections. Secondly, to investigate whether CART affect to 5-HT, mouse genomic CART gene, which is consist of 3 exons and 2 introns and mouse neurofilament light (NF-L) chain promoter were cloned. Then, we constructed neuron specific expression vector, which was transfected into HeLa cell using lipid-mediated transfection system. Expression of GFP and CART linked to NF-L-chain promoter in the transfected HeLa cell were detected by using fluorescent microscope and RT-PCR. These results confirmed normal expression of DNA constructs in vitro. Then, to increase brain specific expression of CART in vivo transgenic mice carrying CART gene controlled the deleted NF-L-chain promoter were generated by the DNA microinjection into pronuclei of fertilized embryos. Transgenic mice were detected by Southern blot. Further study is necessary to examine CART expression and 5-HTT in these transgenic mice. Therefore, these results suggest that there maybe a positive molecular correlation between CART and 5-HT in responding to the stimuli.

• Carbon letters
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• 제4권3호
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• pp.126-132
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• 2003

Granular Activated Carbon (GAC) has been proven to be an excellent material for many industrial applications. A systematic study has been carried out of the kinetics of physical as well as chemical activation of phenolic resin chars. Physical activation was carried out using $CO_2$ and chemical activation using KOH as activating agent. There are number of factors which influence the rate of activation. The activation temperature and residence time at HTT varied in the range $550{\sim}1000^{\circ}C$ and $\frac{1}{2}{\sim}8$ hrs respectively. Kinetic studies show that the rate of chemical activation is 10 times faster than physical activation even at much lower temperature. Above study show that the chemical activation process is suitable to prepare granular activated carbon with very high surface area i.e.$ 2895\;m^2/g$ in short duration of time i.e. 1 to 2 hrs at lower temperature i.e. $750^{\circ}C$ from phenolic resins.