• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1195-1198
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• 2013

Nickel hexacyanoferrate supported palladium nanoparticles (Pd-NiHCF NPs) were synthesized and studied for oxygen reduction reactions in direct methanol fuel cell. The NiHCF support was readily synthesized by a comixing of $Ni(OCOCH_3)_2$ and equimolar $K_3[Fe(CN)_6]$ solution into DI water under rigorous stirring. After the preparation of NiHCF support, Pd NPs were loaded on NiHCF via L-ascorbic acid reduction method at $80^{\circ}C$. Pd-NiHCF NPs were electrochemically active for oxygen reduction reaction in 0.1 M $HClO_4$ solution. X-ray absorption near edge structure analysis was conducted to measure the white line intensity of Pd-NiHCF to verify the OH adsorption. As a comparison, carbon supported Pd NPs exhibited same white line intensity. This study provides a general synthetic approach to easily load Pd NPs on porous coordination polymers such as NiHCF and can provide further light to load Pd based alloy NPs on NiHCF framework.

• 한국산업융합학회 논문집
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• 제21권6호
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• pp.395-408
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• 2018

Even after the Fukushima nuclear accident in 2011, the rate of production of electric energy using nuclear energy is increasing, but there is a great danger such as the radioactive waste produced when using nuclear power, the catastrophic accident of nuclear power plant, and connection with nuclear weapons. In particular, Cs present in the ionic form of alkaline elements has a long half-life (30.17 years) because it is readily absorbed by the organism and emits intense gamma rays, thus presenting a serious radiation hazard. Therefore, it must be completely removed before it can be released into the natural ecosystem, because it can adversely affect not only humans but also natural ecosystems. Many adsorbents and ion exchangers which have high Cs removal efficiency have been used in recent years to completely separate and remove by self separation in water. Many adsorbents and ion exchangers which have high Cs removal efficiency have been used in recent years to completely separate and remove by self separation in water. In addition, researches have been doing to synthesize magnetic materials with adsorbents such as HCF and PB, and it shows a great effect in the removal rate of Cs present in wastewater or the maximum Cs adsorption amount. In particular, when a magnetic material was applied, excellent results were obtained in which only Cs was selectively removed from other cations. However, new problems such as applicability in the sea where Cs is directly released, applicability in various pH ranges, and failure to preserve the magnetizing force possessed by the magnetic body have been found. However, researches using ferromagnetic field with stronger magnetic properties than those of magnetic bodies is considered to be insufficient. Therefore, it is considered that if the researches combining the ferromagnetic field with the magnetization ability and functional adsorbents more actively, the radioactive material Cs which adversely affects the natural ecosystem can be effectively removed.

• 대한의생명과학회지
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• 제29권4호
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• pp.211-219
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• 2023

Caffeic acid phenethyl ester (CAPE) is an active component of propolis obtained from honeybee hives. CAPE possesses anti-mitogenic, anti-carcinogenic, anti-inflammatory, and immunomodulatory activities in diverse systems, which know as displays antioxidant activity and inhibits lipoxygenase activities, protein tyrosine kinase, and nuclear factor kappa B (NF-κB) activation. This study aimed to investigate the effect of CAPE on lipopolysaccharide (LPS)-induced human neutrophil phagocytosis. Human neutrophils were cultured with various concentrations of CAPE (1, 10, and 100 µM) with or without LPS. The pro-inflammatory proteins (tumor necrosis factor-alpha [TNF-α], interleukin [IL]-6 and IL-8) levels were measured after 4 h incubation. To investigate the intracellular signaling pathway, we measured the levels of mitogen-activated protein kinases (MAPK), including phosphorylation of p38, extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) and c-Jun N-terminal kinase (JNK). Next, to evaluate the potential phagocytosis, neutrophils were labeled with iron particles of superparamagnetic iron oxide nanoparticles (SPIONs, 40 nm) for 1 h in culture medium containing 5 mg/mL of iron. The labeling efficiency was determined by Prussian blue staining for intracellular iron and 3T-wighted magnetic resonance imaging. CAPE decreased the activation of intracellular signaling pathways, including ERK1/2 and c-Jun, and expression of pro-inflammatory cytokines, including TNF-α and IL-6, but had no effect on the signaling pathways of p38 and cytokine IL-8. Furthermore, images obtained after mannan-coated SPION treatment suggested that CAPE induced significantly higher signal intensities than the control or LPS group. Together, these results suggest that CAPE regulates LPS-mediated activation of human neutrophils to reduce phagocytosis.

• Investigative Magnetic Resonance Imaging
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• 제16권1호
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• pp.47-54
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• 2012

목적: 백서 중간엽 줄기세포에 페리틴 유전자를 형질 도입시켜 생물학적 특성의 변화 유무를 평가하고, 자기공명영상에서 신호강도의 차이를 확인해보고자 하였다. 대상과 방법: 백서 중간엽 줄기세포에 렌티바이러스를 이용하여 사람유래 재조합 페리틴과 녹색형광단백질 유전자의 과발현을 유도하였다. 페리틴 유전자가 발현된 백서 중간엽 줄기세포의 증식성과 생존능을 분석하기 위해 MTT 어세이를 수행하였으며, 유세포 분석을 수행하여 중간엽 줄기세포의 표면 마커 발현을 평가하고, 세포 내 철 함량을 측정하고 프러시안 블루 염색을 시행하여 철 축적능력을 분석하였다. 세포 팬텀을 이용하여 9.4 T 자기공영영상 기기를 이용하여 검출가능성을 평가하였다. 결과: 페리틴과 녹색형광 유전자는 백서 중간엽 줄기세포에서 안정적으로 발현되었다. 페리틴 유전자의 과발현으로 인해 백서 중간엽 줄기세포의 생물학적 특성 (증식능력, 생존능, 표면마커)은 영향을 받지 않았다. 페리틴을 발현하는 중간엽 줄기세포에서 철의 축적능력이 증가된 것이 확인되었고, T2 이완 시간은 유의하게 감소하였다. 결론: 줄기세포 치료 연구에서 자기공명 리포터 유전자 페리틴은 자기공명영상법을 이용하여 중간엽 줄기세포를 비침습적으로 가시화 할 수 있고 이를 이용하여 생체추적이 가능할 것으로 기대된다.

• 대한임상검사과학회지
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• 제43권4호
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• pp.194-204
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• 2011

This study was carried out to compare the histopathological differences of liver lesions in carbon tetrachloride ($CCI_4$), dimethylnitrosamine (DMN), thioacetamide (TAA) and bile duct ligation (BDL)-induced rats. $CCl_4$, DMN and TAA were administered intraperitoneally and conducted bile duct ligation for 4 weeks to induce hepatic fibrosis. Indices of liver cell injury (steatosis, hydropic degeneration, bile duct hyperplasia, hemorrhage & hemosiderin deposition), the extent of liver fibrosis (fibrotic area) and the rate of regeneration (number of PCNA-positive cells) were investigated in each group. Liver tissues were stained with hematoxylin-eosin (HE), sirius red, prussian blue and immunostained with ${\alpha}$-smooth muscle actin (${\alpha}$-SMA), transforming growth factor-${\beta}1$ (TGF-${\beta}1$), proliferative cell nuclear antigen (PCNA), and quantified using a computerized image analysis system. Liver cell steatosis was significantly increased in $CCl_4$ and TAA groups, and hydropic degeneration and bile duct hyperplasia were significantly increased in TAA and BDL groups when compared with that in normal control, respectively. Fibrosis area was significantly increased in all four groups, especially in $CCl_4$ group. Correlation between ${\alpha}$-SMA and TGF-${\beta}1$ expressions in four groups was good. Hemorrhage area in liver parenchyma was significantly increased in DMN group only when compared with that in normal control, while hemosiderin deposition area was significantly increased in TAA and BDL groups as well as DMN group. The Number of PCNA-positive cells was significantly increased in all four groups, especially in TAA group. These results indicate that the duration and methods of hepatotoxic drug treatment are very important factors to make plans for animal experimentation on the induction of hepatic fibrogenesis in rats.

• Composites Research
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• 제32권6호
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• pp.355-359
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• 2019

고효율의 물 분해 시스템은 수소 발생 반응(HER)과 산소 발생 반응(OER) 각각에서의 촉매로 인한 전기화학적 반응에서의 효율로 인해 향상되는 높은 과전압의 감소가 수반되어야 한다. 그 중에서도 전이 금속 기반의 화합물(산화물, 황화물, 인화물, 그리고 질화물)은 현재 상용되고 있는 귀금속을 대체할 촉매 재료로써 주목받고 있다. 본 연구에서, 우리는 FESEM 분석을 통해 최적의 단분산된 Co₃[Co(CN)₆]₂ PBAs를 합성하고 XRD, FT-IR 분석을 통하여 결정성을 확인하고 TG-DTA를 통해 PBAs의 열적 거동을 확인하였다. 그리고 합성된 최적의 Co₃[Co(CN)₆]₂ PBAs를 열처리해서 단분산된 Co₃O₄나노 큐브를 합성하였고 XRD를 통해 이의 결정성을 확인하고 OER 측정을 진행하였다. 최종적으로 합성된 Co₃O₄ 나노 큐브는 10 mA·cm^-2의 전류 밀도에서 312 mV의 낮은 과전압과 96.6 mV·dec^-1의 낮은 Tafel slope을 보인다.

• Toxicological Research
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• 제28권1호
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• pp.39-49
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• 2012

We investigated the effect of zinc on the formation of colonic aberrant crypt foci induced by azoxymethane (AOM) followed by dextran sodium sulfate (DSS) in mice with high iron diet (HFe; 450 ppm iron). Sixweek old ICR mice were fed on high iron diets with combination of three different levels of zinc in diets, low-zinc (LZn; 0.01 ppm), medium-zinc (MZn; 0.1 ppm), and high-zinc (HZn; 1 ppm) for 12 weeks. Animals were received weekly intraperitoneal injections of AOM (10 mg/kg B.W. in saline) for 3 weeks followed by 2% DSS (molecular weight 36,000~50,000) in the drinking water for a week. To confirm the iron storage in the body, the hepatic iron concentration has been determine chemically and compared with histological assessment visualized by Prussian blue reaction. Aberrant crypt (AC) and aberrant crypt foci (ACF) were analyzed in the colonic mucosa of mouse fed high dietary iron. Superoxide dismutase (SOD) activity and thiobarbituric acid-reactive substances (TBARS) level were also investigated. Apoptosis in the preneoplastic lesion was determined by terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling (TUNEL). In addition, immunohistochemistry of ${\beta}$-catenin was also performed on the mucous membrane of colon. The number of large ACF (${\geq}4$ AC/ACF), which possess greater tumorigenic potential, was significantly lower in MZn and HZn groups compared with LZn group. Cytosolic SOD activity in the liver was significantly higher in HZn group compared with LZn group. Hepatic MDA level was decreased significantly in HZn group compared with MZn and LZn groups. Apoptotic index was significantly higher in HZn group. Taken together, these findings indicate that dietary zinc might exert a protective effect against colonic preneoplastic lesion induced by AOM/DSS in ICR mice with high iron status, and suggest that dietary supplement of zinc might play a role in suppressing colon carcinogenesis in mice.

• KSBB Journal
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• 제17권2호
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• pp.162-168
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• 2002

본 연구에서는 유도성 promoter인 GAL1과 상시성 promoter인 GPD와 ADH1 promoter 하류에 사람 ferritin H-chain 유전자(hfL) 및 사람 ferritin L-chain 유전자(hfL)를 연결하여 재조합 plasmid를 구축하고 이들을 S. cerevisiae 2805에 형질 전환시켜 외래 유전자를 성공적으로 발현시켰다. Ferritin 발현에 미치는 promoter의 영향을 비교한 바, 이 두 단백질 생간에 있어서 GAL1 promoter가 GPD나 ABH1 promoter 보다 더 효율적이었다. GAL1 promoter를 사용한 형질 전환체 (YG-H와 YG-L)에서 H-chain의 발현율은 전체 수용성 단백질 중 4.5%에 해당하였고, L-chain의 발현율은 9.8%에 이르렀다. 각 균주에서 발현된 H 및 L subunit은 비변성 젤은 사용한 전기 영동의 결과 대장균에서 생산된 재조합 단백질과 마찬가지로 자발적으로 holoprotein으로 조합되어졌다. 재조합 H-와 L-ferritin들은 단백질 내공에 철을 축적할 수 있음이 Prussian blue 염색으로 확인되었다. 그리고 효모 세포를 10 mM ferric citrate를 함유한 배지에서 배양했을 때, H-ferritin과 L-ferritin을 생산하는 재조합 효모 균주에 있어서의 펄의 농도는 각각 174.9 $\mu\textrm{g}$ Per gram(dry cell weight)과 148.8 $\mu\textrm{g}$ Per gram(dry cell weight)이었고 야생형 효모 균주에 있어서의 털의 농도는 49.4 $\mu\textrm{g}$ Per gram(dry cell weight)이었다. 이것은 사람 ferritin 유전자를 효모 균주에 발현시킴으로써 효모의 철 함량이 증진되었음을 유추하는 결과이다.

• 한국결정성장학회지
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• 제27권3호
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• pp.110-114
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• 2017

$Ni_3[Co(CN)_6]_2$ PBAs의 하소과정을 통해 단분산된 $NiO/NiCo_2O_4$ 나노큐브를 성공적으로 합성했다. 단분산된 $Ni_3[Co(CN)_6]_2$ PBAs 나노큐브는 수열합성 반응 시 생성된 핵 들의 '자기조립'에 의해 형성된다. 이때 입자의 자기조립 속도는 온도와 계면활성제인 SDBS(Sodiumdodecylbenzenesulfonate)의 양에 의해 영향을 받으며, FESEM 분석을 통하여 SDBS: 0.25 g, 온도: $60^{\circ}C$에서 단분산된 200 nm의 PBA 나노큐브들을 얻을 수 있었다. 최적의 하소 조건을 결정하기 위해 Thermogravimetric-Differential Thermal Analysis(TG-DTA)를 통해 열적 거동을 확인하였다. 그리고 PBA 전구체 및 $NiO/NiCo_2O_4$ 입자의 형상과 결정성을 확인하기 위해 Field emission scanning electron microscopy(FESEM)과 X-ray diffraction(XRD) 분석을 진행하였다.

• 동아시아식생활학회지
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• 제20권5호
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• pp.735-742
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• 2010

식품 중 잠재적 위험 물질로 작용할 수 있는 BAs의 신속 검출을 위하여 전기전도성이 우수하다고 알려진 MWCNTs의 개질, 작업 전극의 제작, 효소반응기 제작을 통해 바이오센서 시스템을 구성하고 hydrogen peroxide와 주요 BAs 물질에 대한 감응도를 측정하였다. MWCTS의 성질을 향상시키기 위해 아민기를 도입하였고, 이를 FT-IR 스펙트럼을 통해 확인하였다. 아민기를 도입한 MWCNTs를 GCE에 고착시키고 PB 막을 입힌 후 cyclic voltammetry 반응을 비교한 결과, PB/MWCNT-$NH_2$/GCE 전극이 GCE에 비해 산화 전류는 8배 이상, 전체 전류는 25배 이상의 높은 전류 흐름을 보였으며, 미세한 전류 흐름의 측정도 용이해진 것으로 나타났다. 또한, carrier buffer의 pH를 달리하여 제작된 전극의 감응 전류를 비교한 결과, pH 7.0에서 전류의 감응도가 가장 높게 측정되었다. 과산화수소를 주입하여 전극의 성능의 검증한 결과, $0.5 {\mu}M{\sim}100 {\mu}M$ 범위에서 선형관계를 보였으며, 검출 한계는 $0.5{\mu}M$로 측정되었다. Histamine 표준 용액 주입 시 $1{\mu}M{\sim}100{\mu}M$ 범위에서 선형 관계를 나타내었고, tyramine은 histamine에 비해 약 95%, 2-phenylethylamine과 tryptamine은 histamine에 비해 각각 75%, 70% 수준의 감응도를 이용하여 구성된 바이오센서 시스템이 낮은 검출 한계와 높은 수준의 반응 감도를 나타내어 BAs를 측정하는데 좋은 장치임이 확인되었다.