• Carbon letters
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• 제7권1호
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• pp.1-8
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• 2006

The activated carbon "C" was obtained by carbonization followed by activation with steam at 40% of burn-off. Oxidized carbons C-N, C-P and C-H were obtained by oxidizing the activated carbon C with concentrated nitric acid, ammonium peroxysulfate and hydrogen peroxide, respectively. The textural properties of the carbons were determined from nitrogen adsorption at 77 K. The acidic surface functional groups were determined by pH titration, base neutralization capacity and electrophoretic mobility measurements. The cation exchange capacities of un-oxidized and oxidized carbons were determined by the removal of Cu(II) and Ni(II) from their aqueous solutions. The surface area and the total pore volume decreased but the pore radius increased by the treatment of activated carbon with oxidizing agents. These changes were more pronounced in case of oxidation with $HNO_3$. The surface pH of un-oxidized carbon was basic whereas those of the oxidized derivative were acidic. The removal of Cu(II) and Ni(II) was pH dependent and the maximum removal of the both ions was obtained at pH of 5-6. Cu(II) was more adsorbed, a phenomenon which was ascribed to its particular electronic configuration.

• Preventive Nutrition and Food Science
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• 제8권2호
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• pp.124-129
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• 2003

This study was designed to investigate whether a methanol extract of chlorella can suppress oxidative stress and nuclear factor kB (NFkB) activation in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophage cells. Treatment of RAW 264.7 cells with chlorella methanol extract (25, 50, and 100 $\mu$g/mL) significantly reduced LPS-stimulated nitric oxide production in a dose-dependent manner. Treatments with chlorella methanol extract at all concentrations also reduced thiobarbituric acid-reactive substances accumulation and enhanced glutathione level at 50 and 100 $\mu$g/mL levels. The specific DNA binding activities of NFkB on nuclear extracts in cells treated with 50 $\mu$g/mL and 100 $\mu$g/mL chlorella methanol extracts were significantly suppressed. These results suggest that chlorella methanol extract has mild antioxidative activity and the ability to suppress intracellular oxidative stress and NFkB activation.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.32.1-32.1
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• 2009

현재 ITO를 대체할 재료로 투명 전도성 탄소나노튜브(carbon nanotube, CNT) 필름에 대한 연구가 진행 되고 있다. 이러한 연구에서 특히 CNT 필름의 투과도에 따른 전기저항을 향상시키기 위한 연구가 활발히 진행되고 있다. 본 연구에서는 단일벽 CNT (single-walled CNT)를 여러 가지 계면활성제로 최적 분산시킨 수용액으로부터 제조한 CNT 필름의 투과도에 따른 면 저항 (sheet resistance) 변화를 관찰하였다. 우선 계면활성제로 분산시킨 CNT 수용액을 알루미나 재질의 필터에서 정량적으로 진공 필터링하여 CNT 필름을 제조하였다. 알루미나 필터를 sodium hydroxide (NaOH) 수용액으로 용해시켜 제거함으로써 얻은 CNT 필름을 유리기판 위에 부착시켰다. 필름의 전기저항을 낮추기 위해 유리기판 위에 부착된 CNT 필름을 질산 (HNO3) 용액으로 처리하였다. Scanning electron microscopy, UV-Vis spectroscopy를 이용하여 각각 필름의 형상과 광 투과도를 분석하였고, 4-point probe로 면 저항을 측정하였다. 계면활성제로 분산시킨 CNT 필름 대부분의 면 저항은 질산 처리에 의해 감소하였다. 이는 CNT 표면에 코팅되어 있던 계면활성제가 질산에 의해 제거되었기 때문인 것으로 예상된다. 여러 계면활성제 중 sodium dodecyl benzenesulfonate로 분산시킨 CNT 필름이 산 처리 후에 가장 낮은 면 저항을 보였다. 그리고 Polyvinyl pyrrolidone (PVP)과 cetyltrimethylammonium bromide (CTAB)를 사용하여 제조한 CNT 필름의 면 저항이 가장 뚜렷한 감소를 보였다.

• 한국환경보건학회지
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• 제26권4호
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• pp.88-96
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• 2000

The aim of the current study was to evaluate the transport system in EMT-6 cell for the uptake of the methylmercury(MeHg). Several inhibitors ere used to test used to test which potential transport system might be involoved in MeHg uptake. Probenecid was used to test the organic transport system, valinomycin for testing the effect of the membrane potential, cytochalasin B for testing the facilitated diffusive D-glucose transport system and colchicine for testing the microtubule system. Ouabain for evaluating active transport system, 4',4-diisothiocyano-2',2-stilbenedisulfonic acid(DIDS) the Cl- ion transport system and verapamil for the $Ca^{2+}$ transprot system. Significantly, MeHg decreased the synthesis of nitric oxcide(NO) and intracellular ATP in ENT-6 cells. In the condition of ouabain containing with MeHg decreased the production of NO and intracelluar ATP. In the treatment of inhibitors, ouabain showed protective effect against cytotoxicity of MeHg but ather inhibitors not showed protective effects. The protective effects of ouabain against the cytotoxicity of MeHg deoended on the concentration of added ouabain to the culture medium for MET-6 cells. These result showed that the uptake of MeHg might be involved in the active transport system. Active transports system seems to share similarities with the transport systems for the uptake of MeHg when using MeHg and MeHg-glutathione complex.x.

• 대한한방내과학회지
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• 제24권2호
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• pp.203-212
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• 2003

Objective : As a link in chain of research to confirm the oriental medical prescription which has the anti-atherosclerosis effects, this research evaluated the effects on the macrophage-related factors by using KanghwalSokdantang(KS). Methods : In order to perform this research, we have evaluated the effects on the oxLDL formation from the macrophages, the nitric oxide formation, and the oxidation of macrophages. Thus, with this evaluation, we have investigated the applicapability on the artherosclerosis. Results : KanghwalSokdantang has showed a noticeable reduction of protein oxidation in the process of oxLDL formation, has remarkably restrained phospholipid peroxidation, an index to estimated the phospholipid oxidation and reduction that are formed in the process of macrophage's oxLDL formation, and has increased the nitrite concentration noticeably in the LDL-dealing macrophages. By increasing the survival rate of macrophages, KanghwalSokdantang has restrained the cellular damages. KanghwalSokdantang is ineffective on the LDH outflow from damaged cells. $1{\mu}g/ml$ KanghwalSokdantang sample has increased acid phosphatase activity remarkably. Conclusion : KanghwalSokdantang has the possibility to be used in the prevention and treatment of atherosclerosis, which is formed by the oxLDL formation of macrophages.

• Journal of Microbiology and Biotechnology
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• 제33권6호
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• pp.823-830
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• 2023

Lactococcus lactis is a lactic acid bacterium and used in the dairy food industry. The ameliorating effects of Lactobacillus species on atopic dermatitis (AD) have been extensively studied, but the specific effect of L. lactis strains has not yet been investigated. In this study, the efficacy of L. lactis LB 1022, isolated from natural cheese, was evaluated using RAW 264.7, HMC-1 and HaCaT cell lines and an ovalbumin-sensitized AD mouse model. L. lactis LB 1022 exhibited nitric oxide suppression and anti-allergy and anti-inflammatory activity in vitro. Oral administration of L. lactis LB 1022 to AD mice significantly reduced the levels of IgE, mast cells, and eosinophils, and a range of T cell-mediated T helper Th1, Th2, and Th17-type cytokines under interleukin (IL)-10, transforming growth factor-β (TGF-β), thymus and activation-regulated chemokine (TARC), and thymic stromal lymphopoietin (TSLP). In addition, L. lactis LB 1022 treatment increased the concentration of short-chain fatty acids. Overall, L. lactis LB 1022 significantly modulated AD-like symptoms by altering metabolites and the immune response, illustrating its potential as candidate for use in functional food supplements to alleviate AD.

• 한국재료학회지
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• 제34권7호
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• pp.370-376
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• 2024

In this study, we report significant improvements in lithium-ion battery anodes cost and performance, by fabricating nano porous silicon (Si) particles from Si wafer sludge using the metal-assisted chemical etching (MACE) process. To solve the problem of volume expansion of Si during alloying/de-alloying with lithium ions, a layer was formed through nitric acid treatment, and Ag particles were removed at the same time. This layer acts as a core-shell structure that suppresses Si volume expansion. Additionally, the specific surface area of Si increased by controlling the etching time, which corresponds to the volume expansion of Si, showing a synergistic effect with the core-shell. This development not only contributes to the development of high-capacity anode materials, but also highlights the possibility of reducing manufacturing costs by utilizing waste Si wafer sludge. In addition, this method enhances the capacity retention rate of lithium-ion batteries by up to 38 %, marking a significant step forward in performance improvements.

• Journal of Dairy Science and Biotechnology
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• 제38권2호
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• pp.112-120
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• 2020

본 연구는 Enterococcus faecalis EF-2001 사균체를 발효유에 첨가하였을 시 나타나는 생리활성을 검증하고자 실시하였다. 발효유는 같은 양의 starter만 넣은 일반발효유 NFM, E. faecalis EF-2001 사균체를 100 ㎍/mL의 농도로 첨가한 EFM1, E. faecalis EF-2001 사균체를 500 ㎍/mL의 농도로 넣은 EFM2를 제조하였다. E. faecalis EF-2001 사균체를 발효유 첨가하였을 때 나타나는 항염증 효과를 검증하기 위해 mouse 유래 대식세포인 RAW 264.7 cell을 이용하였다. RAW 264.7 cell을 이용한 세포독성 실험의 결과, 사균의 농도가 높아질수록 세포 생존율이 유의적으로 감소하였으며(p<0.05), 80% 이상의 세포 생존율을 가지는 농도인 5, 10, 15 ㎍/mL에서 실험을 진행하였다. Nitric oxide의 생성 억제능 측정결과는 LPS 처리군에 비해 발효유에서 NO 생성을 저해하는 경향을 나타냈다. 또한, 일반발효유보다 사균을 첨가한 발효유에서 NO 생성을 더욱 저해하는 결과를 나타내었다. Prostaglandin E₂의 억제율 측정결과도 15 ㎍/mL의 농도에서 PGE₂ 분비량을 감소시킴을 확인하였으며, 일반 발효유보다 사균이 첨가된 발효유에서 더욱 억제됨을 확인하였다. 따라서, 본 연구를 통해 E. faecalis EF-2001 사균체가 발효유에 첨가되어도 염증 매개물질인 NO 및 PGE₂의 생성을 감소시킴으로써 추후 사균체가 첨가된 발효유 제조 및 연구에 대한 기초 연구 결과로 활용될 수 있을 것으로 사료된다.

• Biomolecules & Therapeutics
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• 제16권2호
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• pp.147-160
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• 2008

The present study was designed to examine effects of polyphenolic compounds isolated from red wine (PCRW) on the release of catecholamines (CA) from the isolated perfused model of the rat adrenal medulla, and to clarify its mechanism of action. PCRW (20${\sim}$180 ${\mu}$g/mL), given into an adrenal vein for 90 min, caused inhibition of the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (a direct membrane-depolarizer, 56 mM), DMPP (a selective neuronal nicotinic $N_N$ receptor agonist, 100 ${\mu}$M) and McN-A-343 (a selective muscarinic $M_1$ receptor agonist, 100 ${\mu}$M) in dose- and time-dependent fashion. PCRW itself did not affect basal CA secretion (data not shown). Following the perfusion of PCRW (60 ${\mu}$g/mL), the secretory responses of CA evoked by Bay-K-8644 (a L-type dihydropyridine $Ca^{2+}$ channel activator, 10 ${\mu}$M), cyclopiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, 10 ${\mu}$M) and veratridine (an activator of voltage-dependent $Na^+$ channels, 10 ${\mu}$M) were also markedly blocked, respectively. Interestingly, in the simultaneous presence of PCRW (60 ${\mu}$g/mL) and L-NAME (a selective inhibitor of NO synthase, 30 ${\mu}$M), the inhibitory responses of PCRW on the CA secretion evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclpiazonic acid were recovered to considerable level of the corresponding control release compared with those effects of PCRW-treatment alone. Practically, the amount of NO released from adrenal medulla after loading of PCRW (180 ${\mu}$g/mL) was significantly increased in comparison to the corresponding basal released level. Collectively, these results obtained here demonstrate that PCRW inhibits the CA secretory responses evoked by stimulation of cholinergic (both muscarinic and nicotinic) receptors as well as by direct membrane-depolarization from the isolated perfused adrenal gland of the normotensive rats. It seems that this inhibitory effect of PCRW is mediated by blocking the influx of both ions through $Na^+$ and $Ca^+{2$} channels into the rat adrenomedullary chromaffin cells as well as by inhibiting the release of $Ca^{2+}$ from the cytoplasmic calcium store, which are due at least partly to the increased NO production through the activation of nitric oxide synthase. Based on these data, it is also thought that PCRW may be beneficial to prevent or alleviate the cardiovascular diseases, such as hypertension and angina pectoris.

• 전기화학회지
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• 제2권4호
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• pp.183-189
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• 1999

원자력 시설의 가동 및 유지보수 중에 중$\cdot$저준위 방사성폐기물로 다량 생성되는 폐 유기이온교환수지를 상온의 수용 상 내에서 분해 처리하는 공정을 개발할 목적으로, 전기화학적으로 생성되는 Ag(II)를 매개산화제로 사용하여 양이온 및 음이온교환수지의 분해 연구를 수행하였다. Ag(II) 매개산화 공정에서 제어 가능한 인자인 전류, 온도 및 전해질 농도가 이온교환수지의 분해거동에 미치는 영향을 고찰하였다. 양이온교환수지는 거의 대부분 $CO_2$로 분해되었으며, 전류밀도가 감소할수록 전류효율이 증가됨을 보인 반면에 양극전해질로 사용된 질산의 농도 및 온도가 증가하더라도 분해거동에는 영향을 미치지 않았다. 양이온교환수지와는 달리 음이온교환수지의 분해시에는 온도와 무관하게 약 $10\%$ 정도가 CO로 분해되었고, $CO_2$로의 분해효율은 온도에 의존하는 경향을 보였으며, $60^{\circ}C$ 이상에서 효과적으로 분해가 가능하였다.