• 한국미생물·생명공학회지
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• 제10권4호
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• pp.283-288
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• 1982

Streptomyces속 균이 생산하는 trypsin inhibitor의 trypsin에 대한 반응성을 조사해 본 결과 본 저해물질은 crystalline trypsin (20.000 unit, hog pancreas)에 대하여 1/8량에서 약 50%의 저해률을 나타내었으며 trypsin에 대한 저해양상은 mixed noncompetitive-competitive inhibition type이었으며 enzyme-inhibitor complex를 빨리 형성하는데 반응액중 isoleucine이 공존하면 활성이 증가되였으며 Ag$_{＋}$ Hg$_{＋＋}$등의 금속ion은 강하게 본 저해물질의 작용을 억제하였다. 저해률은 사용한 기질의 종류에 따라 차이가 나서 albumin을 사용하였을 때는 casein이나 hemoglobin을 사용하였을 때보다 저해률이 높았다. 그러고 혈액의 응고에 대해서도 저해작용을 나타내었다.

• 상하수도학회지
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• 제21권5호
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• pp.521-529
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• 2007

Nutrient removal from synthetic wastewater was investigated using a MLE (Modified-Ludzack Ettinger) type MBBR (Moving Bed Biofilm Reactor), with different phenol ($C_6H_5OH$) concentrations, in order to determine the inhibition effects of phenol on biological nutrient removal and the biodegradation of phenolic wastewater. The wastewater was prepared by mixing a solution of molasses with known amounts of phenol and nutrients. The experiments were conducted in a lab-scale MLE type MBBR, operated with four different phenol concentrations (0, 67, 100 and 168mg/L) in the synthetic feed. Throughout the experiments, the ratio of the phenolic COD concentration to the total COD was varied from 0 to 1. Throughout batch test, the SNR (Specific Nitrification Rate) and SDNR (Specific Denitrification Rate) were significantly influenced by changes of the phenol concentration. Phenol was inhibitory to the nitrification/denitrification process, and showed greater inhibition with higher initial phenol concentrations. The SNR observed with 0, 67, 100 and 168mg phenol/L were very different like 10.12, 6.95, 1.51 and $0.35mg\;NH_{3^-}N/gMLVSS$ hr, respectively. Similarly, the SDNR observed at 0, 67, 100 and 168mg phenol/L were different like 0.322, 0.143, 0.049and 0.006mgN/gMLVSS day, respectively.

• 생약학회지
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• 제42권1호
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• pp.61-67
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• 2011

In this study, we evaluated the bioactivities of methanol extract and its solvent fractions of Sonchus asper (L.) Hill. The EtOAc fraction of S. asper exhibited more strong antioxidant activity than other extracts as evidenced by the strongest 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity with a $EC_{50}$ value at $33.55\;{\mu}g/mL$ and reducing power, the total polyphenol (180.71 mg GAE/g) and flavonoid contents (145.86 mg QE/g) of S. asper extract were higher than other extracts. The EtOAc fraction of the S. asper also showed 47.38% mushroom tyrosinase inhibition activity, 56.22% ${\alpha}$-glucosidase inhibition and 46.58% ${\alpha}$-amylase inhibition ratio at 1 mg/mL. Both methylene chloride and EtOAc fractions of methanol extract of S. asper effectively reduced of the 86.34% and 62.03% angiotensin I converting enzyme (ACE) activity at 2 mg/mL, respectively. These findings suggest that the EtOAc fraction of the S. asper could be a potential antioxidant in food additive, medicinal, and industry product.

• 대한전자공학회논문지SP
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• 제45권2호
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• pp.95-102
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• 2008

본 논문에서는 다양한 배경잡음에 의해 열화된 음성을 강조하기 위하여 청각시스템을 기초로 한 적응적인 음성강조시스템을 제안한다. 제안한 시스템은 먼저 유성음과 무성음의 구간을 검출한 후, 각 입력 프레임에서 검출된 결과에 따라서 상호억제 계수와 진폭성분조정계수를 적응적으로 조정한다. 마지막으로 시간지연신경회로망을 사용하여 잡음신호를 제거한다. 실험결과 본 시스템은 신호대잡음비의 평가방법을 통하여 다양한 잡음에 의해서 열화된 음성신호를 백색잡음 및 유색잡음에 대해서 효과적인 것을 보여준다.

• 한국식물병리학회지
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• 제14권6호
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• pp.693-699
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• 1998

Three three hundred and ninety seven isolates of Botrytis cinerea were isolated from infected plants of strawberry, tomato and cucumber from several areas in Korea during 1994∼1996 and the resistance of these isolates against some fungicides were examined. The isolation frequency of phenotypes resistant to carbendazim, procymidone, and diethofencarb were found to be 69.9 43.7, and 31.8%, respectively. The isolates were divided into six phenotypic groups; SSR, SRR, RSS, RRS, RSR and RRR, representing sensitive (S) or resistant (R) to benzimidazole, dicarboximide, and N-phenylcarbamate fungicides in order. The percentage of six phenotypes were 28.2, 2.0, 27.2, 41.0, 0.9 and 0.8%, respectively. On the basis of the mycelial growth inhibition (%) B. cinerea isolates were divided into three classes (class 1; 0∼50%, class 2; 51-99%, class 3; 100% inhibition) on carbendazim and three classes (class 1; 0∼75%, class 2; 76∼99%, class 3; 100% inhibition) on procymidone and the mixture of carbendazim+diethofencarb, respectively. Changes in sensitivity levles to carbendazim and carbendazim+diethofencarb were affected by introduction and increasing ratio of the use of diethofencarb.

• Archives of Pharmacal Research
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• 제22권2호
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• pp.143-150
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• 1999

melatonin (MLT), N-acetyl-5-methoxytryptamine, is mainly secreted by the pineal gland. The ultraviolet (UV), infrared (IR) and 1H-NMR spectra of irradiated and non-irradiated MLT were measured, and phototoxicity tests of MLT, anthracence (positive control) and sodium lauryl sulfate (SLS, negative control) were performed. The methods employed include both in vitro test such as MTS assay using the human fibroblast cell and yeast growth inhibition assay using Candida albicans and in vivo method using the skin of guinea pig. UV absorption spectra and 1H-NMR spectra of MLT were changed by UVA (365 nm, 15 J/$\textrm{cm}^2$), but IR spectra of MLT were not changed. The fifty percent inhibitory concentration (IC50) ratio (UV-/UV+) of MLT was 10. The inhibition zone of irradiated-paper disks treated with MLT was not observed. According to the results of histophathological examination, no pathologic lesion was observed in the non-irradiated group, but slight degeneration of keratinocytes in the epidermis, homorrhage and vasodilation in dermis were observed in the irradiated group. These results indicated that the molecular structure of MLT is altered by UVA to unidentified photoproducts and a moderate phototoxicity of MLT is predicted.

• Korean Chemical Engineering Research
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• 제47권5호
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• pp.553-557
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• 2009

참당귀 뿌리 추출물에서 기능성 화장품소재를 개발하고자 하였다. 기기분석시험을 통하여 참당귀 뿌리 추출물에는 유효성분으로서 decursin과 decursinol angelate가 약 97%로 매우 고농도로 존재하였으며 그 비가 약 3:2로 나타났다. 화장품소재 시험으로는 항산화(DPPH free radical scavenging assay), 미백(Tyrosinase inhibition assay, Melanogenesis inhibition assay), 주름개선(Elastase inhibition assay), 자외선 흡수 및 안전성 시험(MTT assay)이 실시되었다. 참당귀 뿌리 추출물은 $15{\mu}g/ml$의 농도에서 tyrosine에 대한 tyrosinase 저해효과가 $45.2{\pm}3.9%$, melanin 생성억제 효과가 $24.2{\pm}12.0$로 미백효과가 우수하였다. 항산화효과는 $240{\mu}g/ml$의 추출물농도에서 DPPH free radical 소거율이 $40.9{\pm}9.1%$로 비교적 우수하였다. 주름개선 효과는 $100{\mu}g/ml$의 추출물농도에서 $12.7{\pm}6.8%$로 낮았으며, 자외선 흡수효과도 거의 없었다. 따라서 본 연구를 통하여 참당귀 뿌리 추출물은 화장품용 미백소재로서 가능성을 보여주었다.

• 한국식품과학회지
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• 제15권1호
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• pp.56-61
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• 1983

전분질로부터 효모균체를 직접 생산하기 위하여 분리 동정된 전분이용성 효모, Sp, holsaticus FRI Y-5에 대한 배지의 탄소원과 질소원, P원, S원간의 영양균형에 대하여 실험하였다. C/P비와 C/S비가 각각 33.33과 100으로 일정할 때 비성장속도는 전분농도 67.5g/l, 그때의 C/N비가 100일 때 $0.178hr^{-1}$로 가장 빨랐으며, 최대균체량은 전분농도 90g/l C/N비가 50일 때 14g/l로 최대였다. 또한 균체수율은 전분농도 67.5g/l, C/N비가 50일 때 0.344로 가장 좋았고 균체생산속도는 전분농도 45g/l C/N비가 50일 때 0.113g/l h로 가장 빨랐다. 한편 C/P 비의 영향은, 전분농도 67.5g/l, C/N비 50, C/S비 100으로 일정할 때 균체수율과는 무관하나 비성장속도와 최대균체량은 C/P가 50일 때 각각 $0.165hi^{-1}$, 11.88g/l로 최대였다. 또한 C/S의 영향은, 전분농도 67.5g/l, C/N비 50, C/P비 33.33으로 일정할 때, 균체수율과 최대균체량은 거의 무관하나 비성장속도는 C/S비가 77.57일때 $0.157hr^{-1}$로 최대였다.

• 대한치과교정학회지
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• 제24권3호
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• pp.555-567
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• 1994

The purpose of this study is to observe the effect of high pull headgear on the craniofacial structures of mixed dentition with Class II malocclusion. The cephalometric headplates of 16 children treated by high pull headgeaar during 6 months and 18 children during 12 months were traced, digitized and statistically analyzed. The results were as follows. 1. Inhibition of foreward growth of maxilla was observed in both group. 2. Clockwise rotation of maxilla was observed in both group. 3. There were distal movement of maxillary 1st molar and inhibition of alveolar bone growth of maxilla. 4. There was compensatory extrusion on mandibular 1st molar. 5. The ratio of anterior facial height to posterior facial height was almostly not changed. In the treatment plan of C II malocclusion by high pull headgear, ire must prevent the mandibulasr 1st molar from extruding and for orthopedic effect, at least 6 months is needed.

• Biomolecules & Therapeutics
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• 제13권1호
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• pp.32-34
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• 2005

Effect of isoliquiritigenin isolated from the heartwood of Dalbergia odorifera T. Chen (Leguminosae) on mushroom tyrosinase activity was investigated in vitro using L-tyrosine and L-3, 4-dihydroxyphenylalanine (L-DOPA) as the substrates. When L-tyrosine was used as a substrate, both isoliquiritigenin and kojic acid, a positive control, inhibited tyrosinase activity in a concentration-dependent manner. IC$_{50}$ values of isoliquiritigenin and kojic acid were 61.4 and 52.2 ${\muM}$, respectively. However, isoliquiritigenin showed week inhibitory effect on the oxidation of L-DOPA by tyrosinase with inhibition ratio of 9.1 ${\pm}$ 7.1% at 100 ${\muM}$. It is also suggested that 3-unsubstituted and 4-hydroxyl phenyl group in isoliquiritigenin plays an important role on the inhibition of tyrosinase activity when L-tyrosine was used as a substrate. Analysis of Lineweaver-Burk plot showed that isoliquiritigenin acts as a competitive inhibitor in case of L-tyrosine as a substrate.