• 대한화학회지
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• 제42권6호
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• pp.696-702
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• 1998

황피독에 저항성을 가지는 수성가스 전환반응용 CoMo 계열 촉매에 알칼리금속염 첨가가 반응활성에 미치는 영향에 대하여 연구하였다. 알칼리금속염의 음이온과 양이온의 각각에 대한 영향을 알아보기 위하여 크게 두 경우로 나누어 촉매를 제조하였다. 그 하나는, 양이온을 K로 고정시키고 음이온을 변형시킨 경우로서, 반응활성의 변화는 BET 표면적의 변화로 설명되었다. 다른 한 경우는, 음이온을 $NO_3^-$로 고정시키고 알칼리금속 이온을 변형시킨 경우로서, Li가 첨가된 촉매의 활성이 가장 뛰어났으며 다른 양이온의 경우에는 서로 비슷한 낮은 활성을 보였다. 알칼리금속의 첨가량의 변화에 따른 BET 표면적의 변화와 반응활성의 변화가 같은 경향을 보였다. 알칼리금속염의 양이온을 변화시킨 경우에는 BET 표면적과 정8면체 배위구조 속의 $Mo^{6+}$에 대한 정4면체 배위구조 속의 $Mo^{6+}$의 비, 즉 $Mo^6+[T]/Mo^{6+}[O]$ 값의 복합적인 관계를 통해 반응활성의 변화를 설명할 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권11호
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• pp.1612-1619
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• 2017

Objective: The objective of this study was to optimize ultrasonic-assisted enzymatic hydrolysis conditions, including enzyme-to-substrate (E/S) ratio, pH, and temperature, for producing porcine liver hydrolysates (PLHs) with the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity by using response surface methodology (RSM). Methods: The study used RSM to determine the combination of hydrolysis parameters that maximized the antioxidant activity of our PLHs. Temperature ($40^{\circ}C$, $54^{\circ}C$, and $68^{\circ}C$), pH (8.5, 9.5, and 10.5), and E/S ratio (0.1%, 2.1%, and 4.1%) were selected as the independent variables and analyzed according to the preliminary experiment results, whereas DPPH free radical scavenging activity was selected as the dependent variable. Results: Analysis of variance showed that E/S ratio, pH, and temperature significantly affected the hydrolysis process (p<0.01). The optimal conditions for producing PLHs with the highest scavenging activity were as follows: E/S ratio, 1.4% (v/w); temperature, $55.5^{\circ}C$; and initial pH, 10.15. Under these conditions, the degree of hydrolysis, DPPH free radical scavenging activity, ferrous ion chelating ability, and reducing power of PLHs were 24.12%, 79%, 98.18%, and 0.601 absorbance unit, respectively. The molecular weight of most PLHs produced under these optimal conditions was less than 5,400 Da and contained 45.7% hydrophobic amino acids. Conclusion: Ultrasonic-assisted enzymatic hydrolysis can be applied to obtain favorable antioxidant hydrolysates from porcine liver with potential applications in food products for preventing lipid oxidation.

• Food Science and Biotechnology
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• 제16권4호
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• pp.565-571
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• 2007

This study was carried out to investigate an optimum condition for the high angiotensin-l converting enzyme (ACE) inhibitory activity and the yield on enzyme concentration, casein concentration, and hydrolysis time. The optimum condition was performed by response surface methodology for acquirement of casein hydrolysate of milk which shows high ACE inhibitory activity, Among 8 tested enzymes, Protamex showed the highest activation degree with 77.03 unit/g from casein. Their hydrolysis degrees of flovourzyme 500MG, protamex, mixture from 1% casein were 85.5, 88.5, and 93.5%, respectively. The ranges of enzyme concentration (0.25-1.25%), casein concentration (2.5-12.5%), and hydrolysis time (20-100 min) as 3 independent variables through preliminary experiments of the yield of casein hydrolysate and ACE inhibitory activity, and it shows optimum response surface at a saddle point. It shows enzyme concentration (0.64%), casein concentration (8.38%), and hydrolysis time (55.81 min) in the yield aspect and showed the highest activity at enzyme concentration (0.86%), casein concentration (5.97%), and hydrolysis time (63.86 min) in ACE inhibitory aspect. The $R^2$ value of a fitted optimum formula on the hydrolysis yield was 0.9751 as the significant level of 1%. The $R^2$ value of a fitted optimum formula on ACE inhibitory activity is 0.8398, and the significance is recognized in the range of 5%.

• The Journal of Advanced Prosthodontics
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• 제8권3호
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• pp.235-240
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• 2016

PURPOSE. In this study, the aim of this study was to evaluate the effect of implant surface treatment on cell differentiation of osteoblast cells. For this purpose, three surfaces were compared: (1) a modified SLA (MSLA: sand-blasted with large grit, acid-etched, and immersed in 0.9% NaCl), (2) a laser treatment (LT: laser treatment) titanium surface and (3) a laser and acid-treated (LAT: laser treatment, acid-etched) titanium surface. MATERIALS AND METHODS. The MSLA surfaces were considered as the control group, and LT and LAT surfaces as test groups. Alkaline phosphatase expression (ALP) was used to quantify osteoblastic differentiation of MC3T3-E1 cell. Surface roughness was evaluated by a contact profilometer (URFPAK-SV; Mitutoyo, Kawasaki, Japan) and characterized by two parameters: mean roughness (Ra) and maximum peak-to-valley height (Rt). RESULTS. Scanning electron microscope revealed that MSLA (control group) surface was not as rough as LT, LAT surface (test groups). Alkaline phosphatase expression, the measure of osteoblastic differentiation, and total ALP expression by surface-adherent cells were found to be highest at 21 days for all three surfaces tested (P<.05). Furthermore, ALP expression levels of MSLA and LAT surfaces were significantly higher than expression levels of LT surface-adherent cells at 7, 14, and 21 days, respectively (P<.05). However, ALP expression levels between MSLA and LAT surface were equal at 7, 14, and 21 days (P>.05). CONCLUSION. This study suggested that MSLA and LAT surfaces exhibited more favorable environment for osteoblast differentiation when compared with LT surface, the results that are important for implant surface modification studies.

• The Korean Journal of Physiology
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• 제4권2호
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• pp.53-60
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• 1970

In an attempt to clarity the effect of X-irradiation on the activity of surfactant in rabbits, and also to observe the possible difference when the irradiation was made in single or fractionated dose, X-ray in dose of 900 r was irradiated to rabbits either in single or fractionated dose of 300 r each day for three day, Tension-area diagram of lung extract was recorded automatically by a modified Langmuir-Wilhelmy balance with a synchronized recording system designed in this department. The surface tension of lung extract was measured at 1,3,5,24, and 48 hours post-irradiation, and the results were compared with the non-irradiated normal group. The result obtained are summerized as follows: 1) The maximal surface tension, minimal surface tension, width of the tension-area diagram at the surface area of 40% in lung extract, and stability index of the normal rabbit lung extracts were 40.73 dynes/cm, 8.96 dynes/cm. 20.71 dynes/cm, and 1.28 respectively. 2) Activity of surfactant was significantly depressed by X-irradiation, and the pattern of depression was more prominent in the single irradiation group than in the fractionated group. 3) It was found that the changes of the width of the tension-area diagram at the surface area of 40% in lung extract and stability indices corresponded well with that of the maximal or minimal surface tension.

• Korean Chemical Engineering Research
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• 제58권2호
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• pp.280-285
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• 2020

We have developed a constitutive display system of the Pseudomonas fluorescens SIK W1 TliA lipase on the cell surface of Escherichia coli using E. coli outer membrane protein C (OmpC) as an anchoring motif, which is an economical compared to induced system. For the constitutive expression of truncated OmpC-TliA fusion proteins, gntT104 promoter was employed. Cell growth was not affected by over expression of fusion protein during entire culture time, suggesting cell lysis was not a problem. The localization of truncated OmpC-TliA fusion protein on the cell surface was confirmed by immunofluorescence microscopy and measuring whole cell lipase activity. Constitutively displayed lipase was very stable, retaining activity enantioselectivity throughout the five repeated reactions. These results suggest that OmpC from E. coli be a useful anchoring motif for displaying enzymes on the cell surface without any inducers, and this stable surface display system can be employed for a broad range of biotechnological applications.

• 한국수소및신에너지학회논문집
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• 제8권2호
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• pp.79-90
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• 1997

Extensive work has been done on investigating the inner cell pressure characteristics of sealed type Ni-MH battery in which Zr-Ti-Mn-V-Ni alloy is used as anode. The inner cell pressure of this type Ni-MH battery much more increases with the charge/discharge cycling than that of the other type Ni-MH battery where commercialized $AB_5$ type alloy is used as anode. The increase of inner cell pressure in the sealed type Ni/MH battery using Zr-Ti-Mn-V-Ni alloy system is mainly due to the accumulation of oxygen gas during charge/discharge cycling. The accumulation of oxygen gas arises mainly due to the low rate of oxygen recombination on the MH electrode surface during charge/discharge cycling. The difference of oxygen recombination rate between $AB_5$ type electrode and Zr-Ti-Mn-V-Ni electrode is caused by the difference of electrode reaction surface area resulting from different particle size after their activation and the difference of surface catalytic activity for oxygen recombination reaction, respectively. After EIS analysis, it is identified that the surface catalytic activity affects much more dominantly on the oxygen recombination reaction than the reaction surface area does. In order to suppress the inner cell pressure of Ni-MH battery where Zr-Ti-Mn-V-Ni is used as anode, it is suggested that the surface catalytic activity for oxygen recombination should be improved.

• Journal of Forest and Environmental Science
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• 제33권2호
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• pp.136-146
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• 2017

We selected 6 plots ($100m^2$) located 2.2-3.8 km from Minamidake Crater on the north flank of Sakurajima Volcano. We conducted a field study to investigate the effects of volcanic activity on vegetation succession and surface erosion rate. The results showed that trees growing in plots further from the crater had a greater diameter at breast height (DBH), total height, and age. In addition, these plots had a greater number of woody plants and species, as well as a greater total cross-sectional area at breast height. The Fisher-Williams index of diversity (${\alpha}$) and the proportion of evergreen broad-leaved trees were higher in plots located further from the crater. Vegetation succession in these plots was not at the level of a climax forest. From 1972 to 2015, the timing for active volcano, the depth of volcanic ash layer, the dry density, and the pH of ground surface were lower for plots located further from the crater. Furthermore, the average annual sheet erosion from 1972 to 2015 was also lower for plots located further away from the crater. Overall, plots further away from the crater have a better environment for vegetation growth and a lower dry density of the volcanic ash surface layer. It is thought that lower dry density results in increased soil permeability, which impedes surface flow. In order to prevent debris-flow disasters, caused by mud and rock flow resulting from impaired soil penetrability, it is essential to promote soil development and restore penetrability by artificial vegetation restoration.

• The Journal of Korean Physical Therapy
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• 제25권1호
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• pp.16-22
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• 2013

Purpose: This study evaluated the validity of measuring paravertebral muscle function with 3D-NEWTON (Hanmed, Korea) by assessing the correlation between Biodex (Biodex, USA) and surface electromyography (EMG). Methods: Nineteen healthy adults participated. The function of their paravertebral muscle was measured in three ways. Maximum endurance time was measured in seconds when 3D-NEWTON was inclined forward for assessing extensor function, and inclined backward for assessing flexor function. Using surface EMG, maximum muscle activity was obtained from the eractor spinae and rectus abdominis during the 3D-NEWTON measurement. Maximum muscle activity was the mean activity from 10 seconds when the root mean squared firing data was highest. Through Biodex the peak torques of the extensor and flexor were measured during isometric exercises. The Spearman correlation coefficiencts from 3D-NEWTON, surface EMG, and Biodex were calculated. Results: The data from surface EMG and Biodex were statistically correlated when measured for flexor function, but less so for extensor function. In the case of 3D-NEWTON, the correlation coefficient with Biodex was 0.50 (p=0.05), while the coefficient with surface EMG was 0.53 (p=0.02) when measured for extensor function. Similarly, the correlation coefficienct with Biodex was 0.60 (p=0.01), while the surface EMG was 0.51 (p=0.03) for flexor function. Conclusion: 3D-NEWTON was a useful method for measuring paravertebral muscle function and can give helpful information for treating people with diseases associated with the lumbar spine.

• Journal of Dairy Science and Biotechnology
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• 제40권3호
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• pp.93-102
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• 2022

본 연구는 L. plantarum K79를 이용하여 ACE 억제활성 향상을 위한 최적의 발효조건을 RSM을 이용하여 예측하고자 하였다. 4개의 독립변수[탈지유(포도당 1% 첨가) 농도(6%-14%), 배양 온도(32℃-42℃), 배양 시간(8-24시간), 스타터 첨가량(0.02%-0.2%)] 5단계 중심 합성 설계 및 반응 표면 분석법을 사용하여 최적의 발효 조건을 결정하는 데 사용하였다. 종속변수는 ACE 억제 활성과 pH였다(이때 ACE 억제율은 조건별 발효원액에서 100배 희석하여 나타낸 값이다). 결정 계수(R²)는 ACE 억제 활성, pH에 대해 각각 0.791, 0.905이었다. 최대 ACE 억제 활성은 10% 탈지유(포도당 1% 첨가) 농도, 37℃ 배양 온도, 17.8 h 배양 시간 및 0.2% 스타터 첨가량 조건에서 90%이었다. RSM에 기초하여 예측된 최적 발효 ACE 조건은 탈지유(포도당 1% 첨가) 농도 13.49%, 스타터 0.0578%, 배양온도 33.4℃에서 21.5시간 동안 배양할 때 ACE 억제 활성 및 pH의 예측 값은 86.69% 및 pH 4.6이었으며 실제 값은 각각 85.5%와 pH 4.58이었다.