• The Korea Journal of Herbology
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• v.28 no.3
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• pp.25-31
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• 2013

Objectives : To develop a natural antioxidant and anti-hemolytic agents, we investigated the effects of ethanol extracts of Carpesii Fructus and Farfarae Flos. Methods : Aerial parts of Carpesii Fructus and Farfarae Flos were extracted with 80% ethanol. Antioxidant activity of Carpesii Fructus or Farfarae Flos extract was evaluated by employing three different assays, i.e., 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline-6-suphonic acid) diammonium (ABTS) scavenging and reducing power activities. Also, anti-hemolytic activity of Carpesii Fructus or Farfarae Flos extract was determined using [2,2'-azobis (2-methylpropionamidine) dihydrochloride (AAPH)]-induced hemolysis, glutathione (GSH) depletion and malondialdehyde (MDA) formation in normal rat red blood cells (RBC) or plasma. Results : The extracts obtained from Carpesii Fructus and Farfarae Flos dose-dependently increased the scavenging activity on DPPH- or ABTS-induced radicals and the reducing power activities. Carpesii Fructus and Farfarae Flos were similar to the scavenging activity and the reducing power of butylated hydroxy anisole effect at high concentration ($1,000{\mu}g/mL$). RBC oxidative hemolysis and plasma MDA formation induced by AAPH were significantly suppressed by the extracts of Carpesii Fructus and Farfarae Flos in a dose-dependent manner. Also, Carpesii Fructus and Farfarae Flos extracts prevented the depletion of cystosolic antioxidant GSH in RBCs. Carpesii Fructus generally had better than the free radical scavenging activity, the reducing power and anti-hemolytic effects of Farfarae Flos. Conclusions : These results suggest that Carpesii Fructus and Farfarae Flos may have value as the potential antioxidant and anti-hemolytic medicinal plant.

• Carbon letters
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• v.12 no.1
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• pp.31-38
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• 2011

This study experimentally investigated dicyclohexylammonium 2-cyanoacrylate (CA) as a potential comonomer for polyacrylonitrile (PAN) based carbon fiber precursors. The P(AN-CA) copolymers with different CA contents (0.19-0.78 mol% in the feed) were polymerized using solution polymerization with 2,2-azobis(isobutyronitrile) as an initiator. The chemical structure and composition of P(AN-CA) copolymers were determined by proton nuclear magnetic resonance and elemental analysis, and the copolymer composition was similar to the feeding ratio of the monomers. The effects of CA comonomer on the thermal properties of its copolymers were characterized differential scanning calorimetry (DSC) in nitrogen and air atmospheres. The DSC curves of P(AN-CA) under nitrogen atmosphere indicated that the initiation temperature for cyclization of nitrile groups was reduced to around $235^{\circ}C$. The heat release and the activation energy for cyclization reactions were decreased in comparison with those of PAN homopolymers. On the other hand, under air atmosphere, the P(AN-CA) with 0.78 mol% CA content showed that the initiation temperature of cyclization was significantly lowered to $160.1^{\circ}C$. The activation energy value showed 116 kJ/mol, that was smaller than that of the copolymers with 0.82 mol% of itaconic acids. The thermal stability of P(AN-CA), evidenced by thermogravimetric analyses in air atmosphere, was found higher than PAN homopolymer and similar to P(AN-IA) copolymers. Therefore, this study successfully demonstrated the great potential of P(AN-CA) copolymers as carbon fiber precursors, taking advantages of the temperature-lowering effects of CA comonomers and higher thermal stability of the CA copolymers for the stabilizing processes.

• ALGAE
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• v.35 no.2
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• pp.189-200
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• 2020

Pyropia yezoensis has been used as functional food in East Asia, especially in Korea and Japan, for more than five hundred years. This study aims to evaluate the antioxidant effect of polyphenols and proteins-rich extracts from P. yezoensis (PPPs) against 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced oxidative cell damage. Among six Korean local strains obtained from Jinhae (JiH), Haenam (HN), Jangheung (JaH), Jindo (JD), Wando (WD), and Sinan (SA) areas, the extracts of P. yezoensis from SA and JD are relatively higher in polyphenols and proteins contents. SA showed the lowest IC₅₀ scavenging activities against 1,1-diphenyl-2-picryl-hydrazyl and alkyl radicals and displayed protective effects against reactive oxygen species (ROS) in AAPH-induced Vero cells. Especially, the PPPs extracts from SA and JD showed protective activities against AAPH-induced apoptosis, as observed by nuclear staining with Hoechst 33342. Furthermore, in vivo studies of the SA extract in zebrafish showed significantly reduced ROS generation, lipid peroxidation, and cell damage. This is the first study, to our knowledge, to evaluate the antioxidant bioactivity of PPP in the Korean Peninsula using a zebrafish model. Due to SA and JD both located in the west coast of Korea, we deduced that the chemical content of the different PPP extracts was mildly influenced by their geographic location, and this alga has potential of protective activity against AAPH-induced ROS both in vitro and in vivo.

• Preventive Nutrition and Food Science
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• v.12 no.4
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• pp.191-196
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• 2007

We investigated radical scavenging effects and protective activities of fucoidan and alginic acid, active polysaccharide components from brown seaweeds, against peroxyl radical-induced oxidative stress under in vitro and cellular system. Fucoidan exerted strong radical scavenging effects against nitric oxide (NO) and superoxide anion $(O_2)$. On the other hand, alginic acid did not show inhibitory activity against NO and relatively weak $O_2{^-}$ scavenging effect. Additionally, alginic acid exhibited higher hydroxyl scavenging activity than fucoidan. Both fucoidan and alginic acid significantly enhanced cell viability against oxidative stress induced by 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH). At $1000{\mu}g/mL$ concentration of fucoidan and alginic acid, the viability was increased from 16.4% to 85.9% and 67.7%, respectively. In addition, fucoidan and alginic acid ameliorated the lipid peroxidation in LLC-PK1 cell induced by AAPH in a dose-dependent manner. In particular, fucoidan showed stronger inhibitory effect than alginic acid in the cellular system. The present study suggests that fucoidan and alginic acid may be promising antioxidants against oxidative stress induced by free radicals.

• Membrane Journal
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• v.18 no.2
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• pp.138-145
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• 2008

A series of anion exchange composite membranes were prepared and characterized for electro-dialysis process used in the removal of toxic anion and cation polutants in groundwater or wastewater. The membranes were prepared as follows; first, porous poly(ethylene) (PE) substrates were fully impregnated with monomer mixtures with various ratio of vinylbenzylchloride (VBC), divinylbenzene (DVB) and ${\alpha},\;{\alpha}$-azobis(isobutyronitrile) (AIBN). Second, they were thermally polymerized to yield crosslinked poly(VBC-DVB)/PE composite membranes. Finally, the membranes were treated in trimethylamine (TMA)/acetone to give $-N^+(CH_3)_3$-containing poly(VBC-DVB)/PE membranes. The basic membrane properties such as ion exchange capacity (IEC), electric resistance and water content of the resulting membranes were measured as a function of VBC/DVB and TMA/Acetone content. As a result, the composite membranes showed lower electric resistance, lower water content and higher IEC than commercial anion exchange membranes (AMX, Astom) due to thin PE substrates, indicating that the composite membranes could be successfully applied to the electrodialysis for water treatment.

• Membrane Journal
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• v.20 no.2
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• pp.142-150
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• 2010

A series of anion exchange composite membranes were prepared and characterized for electrodialysis processes used in the removal of nitrate nitrogen and ions in groundwater. The membranes were prepared as follows; first, fabric substrates were fully impregnated with monomer mixtures of vinylbenzylchloride (VBC), divinylbenzene (DVB), Styrene (ST) and $\alpha,\alpha$-Azobis(isobutyronitrile) (AIBN). Second, they were thermally polymerized to yield crosslinked poly (VBCST- DVB)/fabric composite membranes. Finally, the membranes were treated with trimethylamine (TMA) / acetone to give $-N^+(CH_3)_3^-$-containing poly(VBC-ST-DVB)/fabric membranes. The basic membrane properties such as ion exchange capacity (IEC), electric resistance and water content of the resulting membranes were measured as a function of VBC/DVB and TMA/Acetone content. As a result, the composite membranes showed lower electric resistance and higher IEC than commercial anion exchange membranes (AMX, Astom). Electrodialysis tests using the prepared membranes were carried out for the removal of various ions such as $NaNO_3$, $MgSO_4$ and NaF for 60 minutes. The results showed that the ions were removed below 1 mg/L within about 15 minutes which indicates that the anion exchange membranes prepared here could be applied to the electrodialysis process. as can be seen in the following that the ion conductivity values were almost no change after 15 minutes electrodialysis.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.3
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• pp.96-102
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• 2015

Traditional propellants emit toxic gases such as carbon dioxide and hydrogen chloride during combustion which are harmful to the environment. This study established a synthetic process of a high nitrogen containing derivative of tetrazine, 3,3-Azobis(6-Amino-1,2,4,5-Tetrazine) (DAAT), which can be applied as solid fuels for a solution to environmental concerns. Also, this paper described the detailed process and the analytic results of properties, which were not mentioned in previous reports. The compound was characterized by NMR, IR spectroscopy, and thermal, impact, and friction stability were measured. In addition, the heats of formation (${\Delta}H_f$) and detonation properties (pressure and velocity) of DAAT were calculated using Gaussian 09 and EXPLO5 programs.

• The Journal of Korean Medicine
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• v.27 no.4
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• pp.96-104
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• 2006

Insamsansa-eum (Renshenshanzha-yin, ISE) is a new medicine developed to prevent and treat atherosclerotic diseases. To explore antiatherosclerotic effects of ISE, we evaluated the effects of ISE on serum lipids of hypercholesterolemic rats in vivo, as well as its antioxidant activities in vitro. In vitro, ISE showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide radical scavenging activities, and inhibited hemolysis induced by 2,2' -azobis-2-amidinopropane dihydrochloride (AAPH) in a dose-dependent manner. In vivo, ISE significantly inhibited increase of total cholesterol (TC), low-density lipoprotein cholesterol (LDL) and triglyceride (TG) values in both high cholesterol diet and Triton WR-1339 models. It also significantly inhibited decrease of high-density lipoprotein cholesterol (HDL) value in the high cholesterol diet model. Collectively, our data suggest that ISE has the potential to control the risk of atherosclerosis development.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.1
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• pp.35-42
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• 2019

We investigated the protective effects of antioxidant fractions from a 70% ethanolic extract of Hizikia fusiformis in human dermal fibroblasts (HDFs). Powdered H. fusiformis was extracted with 70% ethanol and then partitioned into three fractions according to polarity using n-hexane (HFH), chloroform (HFC), and ethyl acetate (HFEA). Antioxidant activity was observed in HFEA at 0.66 mg/mL based on the half maximal inhibitory concentration ($IC_{50}$) of 1,1-diphenyl-2-picrylhydrazyl (DPPH), and at 0.24 mg/mL based on alkyl radical scavenging. The protective effects of the HFEA antioxidant fraction against 2,2-azobis-(2-amidinopropane) dihydrochloride (AAPH)-damaged HDFs and the expression of Type I procollagen in HDFs were examined. HFEA caused the proliferation of HDFs with and without AAPH treatment and protected against AAPH damage to HDFs in a dose-dependent manner ($50-200{\mu}g/mL$). This implies that the antioxidant properties of the fractions depended on their proliferative and protective effects. The HFEA antioxidant fraction had significant effects and caused the dose-dependent expression of Type I procollagen, an important anti-wrinkle protein, in HDFs. In conclusion, antioxidant substances in H. fusiformis were found in the ethyl acetate fraction, and the resulting HFEA may have cosmetic applications.

• The Korea Journal of Herbology
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• v.24 no.3
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• pp.129-138
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• 2009

Objectives : The Objective of this study is to compare the anti-oxidative effect of the Hoveniae Semen cum Fructus (HScF) to that of Hoveniae Ramulus (HR) in vivo. Methods : The extracts of HScF and HR were tested in vivo for their anti-oxidative effects. SD Rats were injected with the AAPH (2.2'-azobis (2-aminodinopropane) hydrochloride) to induce the acute oxidization stress, and the oxidized rats were administered with the HScF and HR decoction orally. The RBC, WBC and PLT populations in plasma, and the blood chemistry levels of the rats were measured to observe the overall changes in the blood. The anti-oxidative effects of the HScF and HR decoctions were investigated on the liver tissues of the oxidated rats. Results : 1. Thrombocyte decreased significantly in the group medicated with HScF. 2. Blood glucose increased significantly in the group medicated with HR. 3. SOD activity increased significantly in both the group medicated with HScF and that with HR. 4. NO concentration decreased significantly in both the group medicated with HScF and that with HR. 5. The catalase content increased significantly in both the group medicated with HScF and that with HR. Conclusions : The HScF and HR extracts have an anti-oxidative effect.