• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.4
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• pp.287-292
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• 2009

Human skin is constantly exposed to environmental irritants such as smoke, chemicals and ultraviolet (UV). Free radicals and reactive oxygen species (ROS) caused by these environmental irritants play critical roles in cellular damage. In this study, to investigate the skin cell protective effect of Ophioglossum vulgatum extract, we investigated its effects on intercellular antioxidative activity and UVA-induced MMP expression in human dermal fibroblasts (HDFs). The dried O. vulgatum was extracted in a mixture of ethanol and water (1 : 1) for 24 h at room temperature. The extract was filtered and concentrated in vacuo and lyophilized. For testing intracellular ROS scavenging activity the cultured HDFs were analyzed by increase in DCF fluorescence upon exposure to UVB $20\;mJ/cm^2$. After treatment of O. vulgatum extracts, intracellular ROS levels were measured by luminescence spectrophotometer. Enzyme linked immuno sorbent assay (ELISA), and RT-PCR techniques were used for evaluating the effects of O. vulgatumon on MMP protein and mRNA expression in UVA irradiated HDFs. O. vulgatum extract was found to have ROS scavenging activity with the $IC_{50}$ values of $18.2\;{\mu}g/mL$ against superoxide radicals in the xanthine/xanthine oxidase system. After treatment of O. vulgatum extracts, the oxidation of CM-DCFDA was inhibited effectively and O. vulgatum extracts showed a potent free radical scavenging activity by 30.4 % at $100\;{\mu}g/mL$ in UVB-irradiated HDFs. UVA induced MMP protein expression was reduced 37.7 % by treatment with O. vulgatum extract, and MMP-1 mRNA expression was reduced in a dose-dependent manner. Taken together, these results suggest that O. vulgatum extract prevents the skin cell damage induced by UV irradiation, and implies that O. vulgatum extract may be useful as a new ingredient for anti-aging cosmetics.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.696-704
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• 2017

In this study, we investigated antioxidative and matrix metalloproteinases (MMPs) inhibitory effects of Sorbus commixta twig extracts and fermented extracts with Lactobacillus pentosus and analyzed active ingredients. The free radical scavenging activity ($FSC_{50}$) of non-fermented and fermented extracts of S. commixta twig' were 41.04 and $58.2{\mu}g/mL$, respectively. In the $Fe^{3+}-EDTA/H_2O_2$ system, the active oxygen scavenging activity ($OSC_{50}$) was 2.6 and $3.0{\mu}g/mL$, respectively. In the dermal fibroblasts, the intracellular reactive oxygen species (ROS) scavenging activity was 35.3% for non-fermented extract and 40.2% for fermented extracts at the concentration of $10{\mu}g/mL$. Also at the same concentration, the expression of MMPs (MMP-1, -2, -3) by western blot was 68.3, 35.0 and 24.2%, respectively for non-fermented extracts and 84.3, 70.5 and 69.2% for fermented extracts. TLC, HPLC, and LC/ESI-MS/MS were used for measuring the changes in the components of the extract before and after fermentation. As a result, caffeic acid, (-)-epicatechin, isoquercitrin, and quercetin were identified. From the results, S. commixta twig fermented extracts by L. pentosus showed greater ROS scavenging activity and inhibitory effects on MMPs expression than those of using non-fermented extracts. Therefore, it is suggested that S. commixta twig fermented extracts can be used as an anti-aging cosmetic material.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.936-942
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• 2012

In the present study, the effects of green tea catechin on microsomal phospholipase $A_2$ ($PLA_2$) activity and the arachidonic acid (AA) cascade in the lungs of microwave exposed rats were investigated. One Sprague-Dawley male rats weighting $100{\pm}10$ g was randomly assigned to the normal group and three were assigned to the microwave exposed groups. The microwave exposed groups were subdivided into three groups according to the levels of dietary catechin supplementation: catechin free diet (MW) group, 0.25% catechin (MW-0.25C) group and 0.5% catechin (MW-0.5C) group. Rats were sacrificed on the 6th day after microwave irradiation (2.45 GHz, 15 min). The lung microsomal $PLA_2$ activity in the MW and MW-0.25C groups was 30% and 15% greater than that of the normal group, respectively, whereas no significant difference between the normal group and MW-0.5C group was observed. The percentage of phosphatidylethanolamine (PE) hydrolyzed in the lung microsome in the MW, MW-0.25C and MW-0.5C group increased by 47%, 18% and 20%, respectively, due to microwave irradiation. The formation of thromboxane $A_2$ ($TXA_2$) in the lung microsome was 50% greater in the MW group than in the normal group. However, the levels of $TXA_2$ in the MW-0.25C and MW-0.5C group were normal. The formation of prostacyclin ($PGI_2$) in the lung microsome was 31% lower in the MW group than in the normal group, while the levels of $PGI_2$ in the MW-0.25C and MW-0.5C group were similar to the normal group. The lung microsomal thiobarbituric acid reactive substances (TBARS) concentration, which can be used as an index of lipid peroxide was 34% greater in the MW group, when compared with the normal group. However, there was no difference between the MW-0.25C, MW-0.5C and normal groups. In conclusion, lung function appeared to be improved by green tea catechin supplementation due to its antithrombus action, which in turn controls the AA cascade system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.10
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• pp.1458-1469
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• 2015

This study was carried out to investigate the nitrite scavenging activities (NSA) of nine kinds of wild vegetables in a $NaNO_2$ model system and nitrite of Chinese cabbage as well as the inhibitory effect of kimchi containing a mixture of wild vegetables (MWV) with nitrite scavenging activity on brain neuronal cell death. NSA was higher at pH 1.2 than pH 4.2 in all samples. NSA of extracts from sprouts of Oenothera laciniata and Aster scaber (AS) was above 90% at pH 1.2. AS, Codonopsis lanceolate (CL), Adenophora triphylla (AT), Platycodon grandiflorum (PG), and Taraxacum officinale (TO) extracts showed significantly higher levels of NSA than those from other extracts at pH 4.2. CL, AT, PG, and TO extracts showed high NSA on nitrite of Chinese cabbage. In addition, the effects of MWV on antioxidant and brain neuronal cell death induced by oxidative stress were investigated in human brain neuroblastoma SK-N-SH cells. MWV extract attenuated $H_2O_2$-induced cell death and reactive oxygen species (ROS) generation in SK-N-SH cells. MWV extract showed significantly higher DPPH radical scavenger activity when compared to normal kimchi extract. MWV extract showed an inhibitory effect on brain neuronal cell death against oxidative stress by antioxidant activities.

• Analytical Science and Technology
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• v.15 no.5
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• pp.417-426
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• 2002

Inductively Coupled Plasma Dynamic Reaction Cell Quadrupole Mass Spectrometry (ICP-DRC-QMS) was characterized for the detection of the six naturally occurring calcium isotopes. The effect of the operating conditions of the DRC system was studied to get the best signal-to-noise ratio. This experiment shows that the potentially interfering ions such as $Ar^+$, ${CO_2}^+$, ${NO_2}^+$, $CNO^+$ at the calcium masses m/z 40, 42, 43, 44 and 48 were removed by flowing $NH_3$ gas at the rate of 0.7 mL/min $NH_3$ as reactive cell gas in the DRC with a RPq value (rejection parameter) of 0.6. The limits of detection for $^{40}Ca$, $^{42}Ca$, $^{43}Ca$, $^{44}Ca$, and $^{48}Ca$ were 1, 29, 169, 34, and 15 pg/mL, respectively. This method was applied to the determination of calcium in synthetic food digest samples (CCQM-P13) provided by LGC for international comparison. The isotope dilution method was used for the determination of calcium in the samples. The uncertainty evaluation was performed according to the ISO/GUM and EURACHEM guidelines. The determined mean concentration and its expanded uncertainty of calcium was ($66.4{\pm}1.2$) mg/kg. In order to assess our method, two reference samples, Riverine Water reference sample (NRCC SLRS-3) and Trace Elements in Water reference sample (NIST SRM 1643d), were analyzed.

• Clinical and Experimental Pediatrics
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• v.50 no.2
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• pp.205-208
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• 2007

Purpose : Vascular endothelial cell damage and alteration of a fibrinolytic system was suggested to play a role in the development of coronary artery abnormalities in Kawasaki disease (KD). D-dimer is one of the markers of endothelial damage and fibrinolysis. We evaluated the clinical usefulness of D-dimer to differentiate KD from other febrile diseases and predict coronary artery abnormalities in KD. Methods : Sixty eight patients diagnosed as KD and twenty eight patients presented with acute febrile illnesses other than KD from September 2005 to July 2006 were included. Blood levels of D-dimer and various inflammatory markers were measured before treatment and the clinical course of KD was followed. Serial echocardiography was performed at the onset of disease and thereafter at a monthly interval for at least 2 months. Results : KD patients showed a higher D-dimer level than febrile controls, but the difference was not significant ($1.21{\pm}0.77{\mu}g/mL$ vs $0.92{\pm}0.71{\mu}g/mL$, P=0.083). Neither was the difference between KD patients who had coronary artery abnormalities and those who had not ($1.49{\pm}0.98{\mu}g/mL$ vs $1.15{\pm}0.71{\mu}g/mL$, P=0.169). D-dimer was significantly correlated with other inflammatory markers, such as C-reactive protein and erythrocyte sedimentation rate in both KD patients and febrile controls. Conclusion : D-dimer was not specific for KD. But it may be useful as an inflammatory marker to assess the severity of KD.

• Pediatric Infection and Vaccine
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• v.7 no.2
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• pp.193-200
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• 2000

Purpose : This study was designed and performed for evaluations of clinical manifestation and course of the children under 2 year of age with respiratory tract infection and positive respiratory syncytial virus(RSV) antigen. Methods : The selection criteria of the patients were children under 24 month-of-age, Clinical manifestation of respiratory tract infection, and positive RSV antigen that was detected by Vitek ImmunoDiagnostic Assay System(VIDAS) from nasal cavity. The additional laboratory and simple chest X-ray findings were reviewed from the chart of children who were admitted Wonkwang university hospital from October 1999 to March 2000. Results : Total number of patients enrolled on this study was 102. The 48(47%) children were RSV antigen positive by VIDAS method. Abnormal chest X-ray findings were noticed in 38 cases. The male to female sex ratio of 48 RSV antigen positive cases was 1.2 : 1. The mean and range of age was $10.2{\pm}5.9$ and 1.0~24 months. The peak outbreak of cases was noticed on November, 1999. All of the cases shows coughing but rale was audible in 30 cases(60%). Dyspnea, wheezing, and intercostal retraction were noticed 11(23%), 15(31%), and 10(21%) cases respectively. The most common chest X-ray finding was scattered patch infiltration that was noticed in 30 cases(63%). The mean total white blood cell counts in peripheral blood was $12,608{\pm}4,686/mm^3$. The mean blood level of IgA and IgE were $50.8{\pm}20.9$ and $72.1{\pm}98.3mg/dL$ respectively. The C-reactive protein was $16.0{\pm}18.5mg/L$. Total 5 cases need a mechanical respiraton. The duration of admission was under 7 days in 36 cases(75%). Conclusion : The RSV antigen was detected commonly in late fall and winter season. The severity of children under 2 years old with RSV respiratory tract infection take in some degree a gave courses.

• Food Science of Animal Resources
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• v.28 no.2
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• pp.171-180
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• 2008

This study was conducted to investigate the meat quality characteristics of pork loin in 3 crossbred groups (30 pigs/group). The crossbreeds were LY female${\times}$D male, Y female${\times}$B male and L female${\times}$B male (L: Landrace, Y: Yorkshire, B: Berkshire, D: Duroc). Pork loins were collected from animals ($110{\times}120kg$ body weight) slaughtered in a commercial slaughter house and stored at $-3^{\circ}C$. Samples were analyzed for general composition, physico-chemical properties, meat and fat color, texture characteristics, sensory evaluation and fatty acid composition at 24 hrs postmortem, and TBARS (Thiobarbituric Acid Reactive Substances) values were determined at various storage times. The LYD pigs showed a higher back fat thickness than the YB and LB pigs. There were no significant differences in intramuscular fat, intermuscular fat, subcutaneous fat and springiness among the 3 crossbreeds. In addition, there were no significant differences in general composition, pH, drip loss, cooking loss and cooked sensory evaluation among the 3 crossbreeds (p>0.05). The shear force value of LB pork was significantly lower than other crossbreeds (p<0.05). Total heme pigment was significantly higher in YB pork compared to LYD and LB pork (p<0.05). The TBARS value of YB pork was significantly lower than that of LYD pork, except after the I day of storage (p>0.05). TBARS values increased significantly during storage for all three crossbreeds. The lightness (CIE L) of YB pork was significantly lower, while the redness (CIE a) was significantly higher in YB pork relative to the other crossbreeds. With regard to textural properties, the hardness and adhesiveness values were significantly lower in YB pork compared to LB pork. In fresh meat, the color of YB pork was significantly higher than the other breeds (p<0.05). The content of myristic acid (C14:0) was significantly lower, while the content of arachidonic acid (C20:4) was significantly higher in LB pork (p<0.05). These results show that the YB breed has the highest quality meat of the three crossbreeds.

• Economic and Environmental Geology
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• v.43 no.1
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• pp.13-20
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• 2010

Acid mine drainage (AMD) from abandoned mine sites typically has low pH and contains high level of various heavy metals, aggravating ground- and surface water qualities and neighboring environments. This study investigated removal of heavy metals in a biological treatment system, mainly focusing on the removal by adsorption on a substrate material. Bench-scale batch experiments were performed with a mushroom compost to evaluate the adsorption characteristics of heavy metals leached out from a mine tailing sample and the role of SRB in the overall removal process. In addition, adsorption experiments were perform using an artificial AMD sample containing $Cd^{2+}$, $Cu^{2+}$, $Pb^{2+}$ and $Zn^{2+}$ to assess adsorption capacity of the mushroom compost. The results indicated Mn leached out from mine tailing was not subject to microbial stabilization or adsorption onto mushroom compost while microbially mediated stabilization played an important role in the removal of Zn. Fe leaching significantly increased in the presence of microbes as compared to autoclaved samples, and this was attributed to dissolution of Fe minerals in the mine tailing in a response to the depletion of $Fe^{3+}$ by iron reduction bacteria. Measurement of oxidation reduction potential (ORP) and pH indicated the reactive mixture maintained reducing condition and moderate pH during the reaction. The results of the adsorption experiments involving artificial AMD sample indicated adsorption removal efficiency was greater than 90% at pH 6 condition, but it decreased at pH 3 condition.

• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.45-47
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• 2002

반도체 소자의 고집적화 및 고속화가 요구됨에 따라 MOSFET 구조의 게이트 절연막으로 사용되고 있는 SiO₂ 박막의 두께를 감소시키려는 노력이 이루어지고 있다. 0.1㎛ 이하의 소자를 위해서는 15Å 이하의 두께를 갖는 SiO₂가 요구된다. 하지만 두께감소는 절연체의 두께와 지수적인 관계가 있는 누설전류를 증가시킨다[1-3]. 따라서 같은 게이트 개패시턴스를 유지하면서 누설전류를 감소시키기 위해서는 높은 유전상수를 갖는 두꺼운 박막이 요구되는 것이다. 그러므로 약 25정도의 높은 유전상수를 갖고 5.2～7.8 eV 정도의 비교적 높은 bandgap을 갖으며, 실리콘과 열역학적으로 안정한 물질로 알려진 HfO2[4-5]가 최근 큰 관심을 끌고 있다. 본 연구에서는 HfO₂ 박막을 실제 소자에 적용하기 위하여 전극 및 열처리에 따른 HfO₂ 박막의 미세구조 및 전기적 특성에 관한 연구를 수행하였다. 이를 위해, HfO₂ 박막을 reactive DC magnetron sputtering 방법으로 증착하고, XRD, TEM, XPS를 사용하여 ZrO₂ 박막의 미세구조를 관찰하였으며, MOS 캐패시터 구조의 C-V 및 I-V 특성을 측정하여 HfO₂ 박막의 전기적 특성을 관찰하였다. HfO₂ 타겟을 스퍼터링하면 Ar 스퍼터링에 의해 에너지를 가진 산소가 기판에 스퍼터링되어 Si 기판과 반응하기 때문에 HfO₂ 박막 형성과 더불어 Si 기판이 산화된다[6]. 그래서 HfO₂같은 금속 산화물 타겟 대신에 순수 금속인 Hf 타겟을 사용하고 반응성 기체로 O₂를 유입시켜 타겟이나 시편위에서 high-k 산화물을 만들면 SiO/sub X/ 계면층을 제어할 수 있다. 이때 저유전율을 갖는 계면층은 증착과 열처리 과정에서 형성되고 특히 500℃ 이상에서 high-k/Si를 열처리하면 계면 SiO₂층은 증가하는 데, 이것은 산소가 HfO₂의 high-k 박막층을 뚫고 확산하여 Si 기판을 급속히 산화시키기 때문이다. 본 방법은 증착에 앞서 Si 표면을 희석된 HF를 이용해 자연 산화막과 오염원을 제거한 후 Hf 금속층과 HfO₂ 박막을 직류 스퍼터링으로 증착하였다. 우선 Hf 긍속층이 Ar 가스 만의 분위기에서 증착되고 난 후 공기중에 노출되지 않고 연속으로 Ar/O₂ 가스 혼합 분위기에서 반응 스퍼터링 방법으로 HfO₂를 형성하였다. 일반적으로 Si 기판의 표면 위에 자연적으로 생기는 비정질 자연 산화막의 두께는 10～15Å이다. 그러나 Hf을 증착한 후 단면 TEM으로 HfO₂/Si 계면을 관찰하면 자연 산화막이 Hf 환원으로 제거되기 때문에 비정질 SiO₂ 층은 관찰되지 않았다. 본 실험에서는 HfO2의 두께를 고정하고 Hf층의 두께를 변수로 한 게이트 stack의 물리적 특성을 살펴보았다. 선증착되는 Hf 금속층을 0, 10, 25Å의 두께 (TEM 기준으로 한 실제 물리적 두께) 로 증착시키고 미세구조를 관찰하였다. Fig. 1(a)에서 볼 수 있듯이 Hf 금속층의 두께가 0Å일때 13Å의 HfO₂를 반응성 스퍼터링 방법으로 증착하면 HfO₂와 Si 기판 사이에는 25Å의 계면층이 생기며, 이것은 Ar/O₂의 혼합 분위기에서의 스퍼터링으로 인한 Si-rich 산화막 또는 SiO₂ 박막일 것이다. Hf 금속층의 두께를 증가시키면 계면층의 성장은 억제되는데 25Å의 Hf 금속을 증착시키면 HfO₂ 계면층은 10Å미만으로 관찰된다. 그러므로 Hf 금속층이 충분히 얇으면 플라즈마내 산소 라디칼, 이온, 그리고 분자가 HfO₂ 층을 뚫고 Si 기판으로 확산되어 SiO₂의 계면층을 성장시키고 Hf 금속층이 두꺼우면 SiO/sub X/ 계면층을 환원시키면서 Si 기판으로의 산소의 확산은 막기 때문에 계면층의 성장은 억제된다. 따라서 HfO₂/Hf(Variable)/Si 계에서 HfO₂ 박막이 Si 기판위에 직접 증착되면, 순수 HfO₂ 박막의 두께보다 높은 CET값을 보이고 Hf 금속층의 두께를 증가시키면 CET는 급격하게 감소한다. 그러므로 HfO₂/Hf 박막의 유효 유전율은 단순 반응성 스퍼터링에 의해 형성된 HfO₂ 박막의 유전율보다 크다. Fig. 2에서 볼 수 있듯이 Hf 금속층이 너무 얇으면 계면층의 두께가 두꺼워 지고 Hf 금속층이 두꺼우면 HfO₂층의 물리적 두께가 두꺼워지므로 CET나 EOT 곡선은 U자 형태를 그린다. Fig. 3에서 Hf 10초 (THf=25Å) 에서 정전 용량이 최대가 되고 CET가 20Å 이상일 때는 high-k 두께를 제어해야 하지만 20Å 미만의 두께를 유지하려면 계면층의 두께를 제어해야 한다.