• Journal of Ginseng Research
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• 제34권2호
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• pp.132-137
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• 2010

Lead (Pb) is a metal that is generally considered to be toxic to the cardiovascular system. Pb-exposed animals display the evidence of increased oxidative stress and hypertension. The current study was designed to examine whether Korean red ginseng (KRG) has protective effects against Pb-induced hypertension and oxidative stress in Pb-exposed rats. Male Sprague-Dawley rats were randomly assigned to Pb exposure or control groups. KRG was administered in drinking water at a concentration of 100 mg/kg/day; the control group received plain drinking water. Animals in the Pb-exposed groups were provided with drinking water containing 100 ppm Pb acetate for 12 weeks. Blood pressure, plasma glutathione, blood Pb concentration, and hematologic data, such as red blood cell quantity, were determined. Pb poisoning was assessed by measuring the blood Pb concentration. Pb exposure (100 ppm) for 12 weeks resulted in a marked rise in systolic blood pressure and blood Pb concentration, as well as a significant reduction in plasma glutathione levels and red blood cell quantity. Other measurements, such as heart rate, body weight, and white blood cell quantity, were unchanged. Treatment with KRG significantly lowered blood pressure, raised plasma glutathione and increased red blood cell numbers in Pb-exposed animals; it also had no effect on heart rate, body weight, or white blood cell quantity. However, the elevated blood Pb concentration was not reduced by treatment with KRG (100 mg/kg). Taken together, these data indicate that treatment with KRG in Pb-exposed animals can reduce oxidative stress and lower blood pressure, suggesting that KRG might be protective against Pb-exposed hypertension and oxidative stress.

• 환경위생공학
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• 제7권1호
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• pp.57-66
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• 1992

To investigate on the element content of twelve edible mushrooms and Aloe arborescent, i.e., Lentinus edodes, Ganoderma lucidum (culturing in wood and soil), Tricholoma matsutake, Agaricus auricula-Jude (produced in Korea and China), sarcodon asparatus, Pleurotus ostreatus, Coriolus bisporus, Cyrophora esculenta, Auricularia auricula-Jude (produced in Korea and China), Sarcodon asparatus, Pleurotus ostreatus, Coriolus rersicolor, Smilax rotundifolia and Aloe arborescenstyl were analyzed by Atomic absorption spectrometer. The obtained results were summarized as follows : 1. Potassium, sodium, magnesium and iron content for the most part samples were in large quantities, especi phosphorus content of those was highest ammount for the all samples. 2. Sodium content f·as much ammount in the Lentinus edodes(39 mg, and Ganoderma lucidum(20 mg) , Culturing in wood and soil, while potassium was very high ammount in the Aloe arborescens and other samples. Mush ammount of magnesium as compared with others was Lentinus edodes(144 mg) , Ganoderma lucidum(128 mg), Aloe arborescens(50 mg) and Pleurotus ostreatus (60 mg) . 3, Phosphorus content of Lentinus edodes, Gyrophora esculenta, Auricularia polytricha and Agaricus bisporus was much ammount while iron content of all samples equality higher ammount. Sodium content of Aloe arborescens was not analyzed out for almost all, its potassium(82 mg), magnesium(50 mg) and iron(18 mg) content comparatively higher quentity than others nllnerals and phosphorus volume (4.9 mg) as compared with others, was conspicuously lower detect. 4. Cadimium and lead content of harmful metal element were detected on trace quantity for the most part samples. 5. Organic acids of samples i.e., Lentinus edodes, Agaricus bisporus, Pleuritus ostreatus and Ganoderma lucidum were Citrate, Malate, Fumalate, Succinate, Oxalate, Acetate, Lactate, and Tartarate and Citrate, Malate and Fumarate contents were higher amount remarkbly than other organic acids. Tartarate content was trace amount.

• ALGAE
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• 제24권1호
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• pp.47-55
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• 2009

Recently, interest in plant-derived food additives has developed natural antioxidants, in order to alternate syn-thetic antioxidants with several disadvantages. In the present study, different organic fractions from solvent parti-tions of 80% methanol extract from Jeju benthic diatoms, Achnanthes longipes, Navicula sp. and Amphora coffeaeformis was assessed for their potential antioxidant effects. Among the solvent fractions tested, n-hexane (80.4%) and 80% methanol extract (76.6%) from A. longipes, chloroform (63.2%) from Navicula sp. and n-hexane (67.4%) from A. cof-feaeformis were effective in DPPH free radical scavenging. Fractions of chloroform (53.4%) and n-hexane (53.1%) from A. longipes exhibited higher activities on $H_2O_2$ scavengin. Fraction of n-Hexane from A. longipes exhibited the highest hydroxyl radical scavenging activity and NO. scavenging activity (56.5% and 75.6%, respectively). Aqueous residue from A. coffeaeformis (75.6%) showed the highest metal chelating effect. chloroform and ethyl acetate frac-tion of all the diatoms exhibited significant antioxidant activities in lipid peroxidation inhibitory activity. In particu-lar, both chloroform and the ethyl ecetate fraction from A. longipes and A. coffeaeformis exhibited lipid peroxidation inhibitory activity significantly higher than that of $\alpha$- tocopherol. These data suggest that the Jeju benthic diatoms tested are rich in hydrophilic and hydrophobic antioxidative compounds with different antioxidative properties that can be applied in food industry.

• Applied Microscopy
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• 제25권1호
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• pp.1-14
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• 1995

The purpose of this study was to investigate the main sensory trigeminal nucleus in the aging rat brain by means of electron microscope. Male Sprague-Dawley rats, two (control group) and thirty six (aging group) months of age, were used. These animals were sacrificed by perfusion fixation with 2.5% glutaraldehyde-2.0% paraformaldehyde (0.1M phosphate buffer, pH 7.4) under sodium pentobarbital. The objective area was punched out with a sharp-edged metal cylinder of 0.8 mm in diameter. These blocks of tissue were then washed in 0.1M phosphate buffer, postfixed in 2% osmium tetroxide, dehydrated in a graded series of ethyl alcohol, and embedded in Epon 812. Thin sections were cut with Super Nova ultramicrotome, pick up on grids and double stained with lead citrate and uranyl acetate, and observed in JEOL 100B electron microscope. The results were as follows: 1. In the control group, the neuronal cell body of the main sensory trigeminal nucleus was filled with nucleus, Golgi complex, Nissl substance, mitochondria, microfilaments and microtubules. However, few Nissl substances are seen in neuronal cell body. Axoaxonic synapse, axodendritic synapse, axosomatic synapse, axospinous synapse, myelinated and unmyelinated nerve fibers were well organized around cell bodies. Neurons with abnormal changes were not seen. 2. In the aging group, the neuronal cell body of the main sensory trigeminal nucleus contained large number of lipofuscin granules, dense body and swollen mitochondria. Terminal boutons contained glycogen, crystal-like vesicle and membranous indicating first signs of degeneration. The dendrites were found to be in synaptic contact with altered axon terminals. Frequently axons filled with dark axoplasn and splitted myelin sheath were noticed.

• 한국화재소방학회논문지
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• 제19권3호
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• pp.13-19
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• 2005

본 논문에서는 금속염 첨가제를 함유한 미분무수의 소화성능을 연구하고자 아세트산 나트륨을 함유한 단일 액적의 증발속도를 측정하였으며, small-scale 챔버내에서의 헵탄 pool fire에 대한 소화실험을 실시하여, 화염의 온도를 분석함으로써 첨가제에 의한 미분무수 소화특성을 분석하였다. 순수물과 수용액의 증발특성을 비교한 결과 핵비등 영역에서 온도가 높을수록 용해된 첨가제의 석출 및 표면장력의 변화 등 물리적 영향으로 순수물에 비해 수용액의 증발속도가 현저히 느리게 나타났다. 소화실험 결과, 저압에서는 물 액적이 화염의 플림을 뚫지 못하기 때문에 소화는 이루어지지 않았고 단순히 화염의 크기를 작아지게 하였다. 중압에서는 첨가제를 넣었을 경우 액적의 운동량 증가에 따른 물리적 소화효과와 첨가제의 화학적 소화효과가 상승작용을 하여 화염을 억제하였고, 고압에서는 미분무수 시스템의 주요 소화 메커니즘 이외에도 blowing효과에 의해서 화염이 소화되는 것을 관찰할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.652-655
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• 2005

This paper describes the development of an enzymatic assay system for the identification of inhibitors of isocitrate lyase (ICL), one of the key enzymes of the glyoxylate cycle that is considered as a new target for antifungal drugs. A 1.6 kb DNA fragment encoding the isocitrate lyase from Candida albicans ATCC10231 was amplified by PCR, cloned into a vector providing His-Patch-thioredoxin-tag at the N-terminus, expressed in Escherichia coli, and purified by metal chelate affinity chromatography. The molecular mass of the purified ICL was approximately 62 kDa, as determined by SDS-PAGE, and the enzyme activity was directly proportional to incubation time and enzyme concentration. The effects of itaconate-related compounds on ICL activity were also investigated. Among them, itaconic acid, 3-nitropropionate, and oxalate had strong inhibitory activities with $IC_{50}$ values of 5.8, 5.4 and $8.6\;{mu}g/ml$, respectively. These inhibitors also exhibited antifungal activity on YPD agar media containing acetate as a sole carbon source, albeit at high concentration. The results indicate that the C. albicans ICL may be a regulatory enzyme playing a crucial role in fungal growth and is a prime target for antifungal agents.

• Journal of Microbiology and Biotechnology
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• 제24권7호
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• pp.969-978
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• 2014

The aprE2 gene with its prosequence from Bacillus subtilis CH3-5 was overexpressed in Escherichia coli BL21(DE3) by using plasmid pET26b(+). After IPTG induction, active and mature AprE2 was produced when cells were grown at $20^{\circ}C$, whereas inactive and insoluble enzyme was produced in a large amount when cells were grown at $37^{\circ}C$. The insoluble fraction was resuspended with 6 M guanidine-HCl and dialyzed against 2 M Tris-HCl (pH 7.0) or 0.5 M sodium acetate (pH 7.0) buffer. Then active AprE2 was regenerated and purified by a Ni-NTA column. Purified AprE2 from the soluble fraction had a specific activity of $1,069.4{\pm}42.4U/mg$ protein, higher than that from the renatured insoluble fraction. However, more active AprE2 was obtained by renaturation of the insoluble fraction. AprE2 was most stable at pH 7 and $40^{\circ}C$, respectively. The fibrinolytic activity of AprE2 was inhibited by PMSF, but not by EDTA and metal ions. AprE2 degraded $A{\alpha}$ and $B{\beta}$ chains of fibrinogen quickly, but not the ${\gamma}$-chain. AprE2 exhibited the highest specificity for N-succinyl-Ala-Ala-Pro-Phe-pNA. The $K_m$ and $k_{cat}/K_m$ of AprE2 was 0.56 mM and $3.10{\times}10^4S^{-1}M^{-1}$, respectively.

• Environmental Engineering Research
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• 제18권4호
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• pp.229-234
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• 2013

This study aimed to develop a new dust collecting system equipped with an activated carbon (A.C.) coated electrode. Before fabrication, pre-treatment of A.C. was performed to remove metal ions within the A.C. to enlarge its specific surface area. Then, pre-treated A.C., black carbon, polyvinyl acetate (PVAc), and methanol were mixed to make a gel compound, which was coated onto aluminum plates to fabricate electrodes. The optimal mixing ratio of A.C., black carbon, PVAc, and methanol was found to be 10 g: 2 g: 3 g: 20 mL. After fabrication, the electrodes were used in the batch-type experiment for $NH_3$ and $H_2S$ removal. The reduction rates of the gases were high at the beginning and slowly reduced with time. Dust collection experiments were conducted in continuous flow, with various voltages applied. Compared to 5 kV, dust removal efficiency was 1.5 times higher when 10 kV was applied. Increasing the number of electrodes applied also increased the collecting efficiency. The correlation coefficient between actual collecting efficiency and trend line was higher than 99%. Consequently, the novel dust collection system equipped with A.C. coated electrode appears to be a promising substitute for existing dust-control devices.

• 생명과학회지
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• 제16권4호
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• pp.653-658
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• 2006

사과 겹무늬썩음병균이(Botryosphaeria dothidea) 생성하는 세포벽 분해효소인 endopolygalaturonase를 억제하는 polygalacturonase-inhibiting protein (PGIP)를 사과 과실로부터 분리하였다. 분리되어진 사과 PGIP는 사과 겹무늬썩음병균이 생성하는 PG에 대하여 혼합형의 저해를 나타내었다. PGIP의 반응 최적온도는 $40^{\circ}C$이며 최적 pH는 5.0이었다. 이 효소는 $60^{\circ}C$까지는 비교적 안정하였으나 $70^{\circ}C$에서는 효소의 활성이 완전히 억제되었으며 pH 4.0에서 8.0까지는 안정하였다. PGIP는 $K^+$, $Cu^{2+}$, $Mg^{2+}$, $Ca^{2+}$ 과 $Zn^{2+}$ 등의 금속이온과 SDS 그리고 CDTA에 의해 효소의 활성이 저해되었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.192-193
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• 2007

An evaporated Ti/Pd/Ag contact system is most widely used to make high-efficiency silicon solar cells, however, the system is not cost effective due to expensive materials and vacuum techniques. Commercial solar cells with screen-printed contacts formed by using Ag paste suffer from a low fill factor and a high shading loss because of high contact resistance and low aspect ratio. Low-cost Ni and Cu metal contacts have been formed by using electro less plating and electroplating techniques to replace the Ti/Pd/Ag and screen-printed Ag contacts. Ni/Cu alloy is plated on a silicon substrate by electro-deposition of the alloy from an acetate electrolyte solution, and nickel-silicide formation at the interface between the silicon and the nickel enhances stability and reduces the contact resistance. It was, therefore, found that nickel-silicide was suitable for high-efficiency solar cell applications. Cu was electroplated on the Ni layer by using a light induced plating method. The Cu electroplating solution was made up of a commercially available acid sulfate bath and additives to reduce the stress of the copper layer. In this paper, we investigated low-cost Ni/Cu contact formation by electro less and electroplating for crystalline silicon solar cells.