• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.377-381
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• 2002

Recently, interests to remove nitrogen in the nitritation process have increased because of its economical advantages, since it could be a short-cut process to save both oxygen for nitrification and carbon for denitrification compared to a typical nitrification. However, the kinetics related with the nitritation process has not yet been fully understood. Furthermore, many useful models which have been successfully used for wastewater treatment processes cannot be used to estimate effluent nitrite concentration for evaluating performance of the nitritation process, since the process rate equations and population of microorganisms for nitrogen removal in these models have been set up only for the condition of full nitrification. Therefore, the present study was conducted to estimate an effluent nitrite concentration in the nitritation process with a concept of enzymatic inhibition kinetics based on long-term laboratory experiments. Using a nonlinear least squares regression method, kinetic parameters were accurately determined. By setting up a process rate equation along with a mass balance equation of the nitrite-oxidizing step, an effluent nitrite concentration in the nitritation process was then successfully estimated.

• The Korea Journal of Herbology
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• v.27 no.2
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• pp.43-46
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• 2012

Objectives : Sanguisorbae Radix(SO) is a plant in the family Rosaceae, which grows widely in open fields Korea. It has been used as traditional medicine for thousands of years, as a treatment for anti-inflammatory and it is widely used for throat infection, tonsilitis, conjuctivitis and lymphadentis. In this study, investigated skin antiaging and anti-bacterial by using SO fractions water, acetone and butanol, chloroform. Methods : The effects of anti-microbial on SO fractions and elastase inhibition activity, collagenase inhibition activity were experimented. Results : 1. The ethyl acetate fraction showed the strongest antimicrobial activity against Staphylococcus epidermidis. 2. The elastase inhibition rate and collagenase inhibition rate of the water fraction of SO was the highest other factions. Conclusions : From the above results, it was confirmed the SO has sufficient potentiality applying itself to industry and also SO can be utilized as antimicrobial natural materials and antiaging cosmetics.

• Journal of Applied Reliability
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• v.17 no.2
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• pp.122-128
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• 2017

Purpose: To investigate the corrosion inhibition effect of the natural spearmint oil extracted from Mentha Spicata plants on 304 stainless steel in different concentrations of hydrochloric acid. Method: The anti-corrosive effect has been investigated in 0.5m, 1m and 2m HCl using weight loss test and electrochemical polarization method as a function of inhibitor concentration and immersion time in strong chloride environment. The surface morphology was analysed by scanning electron microscopy (SEM). Results: The corrosion rate of steel decreased and inhibition efficiency increased with the increase in inhibitor concentration. Microscopic evaluation revealed significant corrosion in the specimens immersed in uninhibited conditions. Potentiodynamic polarization test results showed an increase in corrosion potential (Ecorr) and decrease in corrosion current (icorr) value with increasing concentration of inhibitor. Conclusions: Immersion of steel in higher concentration of inhibitor resulted in greater surface coverage value and hence lesser number of surface corrosion sites/pores were formed; thus lowering the corrosion rate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.903-907
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• 1998

Mass transfer characteristics during osmotic dehydration of mushrooms(Agaricus bisporus) in sugar solution were studied as a function of sugar concentration, immersion time and temperature, and the effect of osmotic dehydration on browning inhibition of air-dried mushrooms was also evaluated. Increasing the sugar concentration, immersion time and temperature increased moisture loss, sugar gain, molality and rate parameter. The changes of sugar gain and rate parameter were more significantly affected by concentration than by temperature of sugar solutions, while 1$0^{\circ}C$ increase in temperature or 10 Brix increase in concentration had the same effect on water loss. Water loss, sugar gain, molality were rapid in the first period of osmotic dehydration especially in the case of higher concentration and temperature of sugar solutions. Effects of osmotic dehydration in sugar solution(60 Brix, 8$0^{\circ}C$) with 18 min of immersion time(O.D.=0.099) rior to air dehydration on browning inhibition of dried mushrooms were more significant than blanching in water(8$0^{\circ}C$) with the same immersion time(O.D.=0.330) and the control (O.D.=0.559).

• The Korean Journal of Food And Nutrition
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• v.20 no.2
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• pp.114-119
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• 2007

Our research objective was to examine the in vitro biological activity of deer antler(Nogyong in Korean) extract, including the antioxidative, nitrite scavenging, and tyrosinase inhibitory effects, as well as the antithrombotic, and angiotensin I converting enzyme(ACE) inhibitory activities. The carbohydrate, protein, fat, and mineral contents of the deer antler were 7.6%, 65.3%, 3.2% and 23.9%, respectively. The electron donating ability(EDA) by the reduction of 2,2'-diphenyl-1-picrylhydrazyl(DPPH) was 67.1%, and the inhibition rate of lipid peroxidation by the thiocyanate method using linoleic acid was 92.1% in 100 mg/ml of extract. The nitrite scavenging effects were pH dependent, and were highest at pH 1.2 and lowest at pH 6.0. The sample inhibition rate against tyrosinase was above 64.0%. The platelet aggregation induced by ADP(adenosine-5'diphosphate) was inhibited up to 51.7%, and the inhibitory effect was dependent on the sample concentration. Lastly, the inhibition rate of ACE was 47.5% in 100 mg/ml of deer antler extract.

• The Korean Journal of Food And Nutrition
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• v.25 no.1
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• pp.90-98
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• 2012

With the addition of ethanol to wax gourd extract and by acetic fermentation, 5.0% acidity vinegar was produced. After putting 10% extract(10% concentration) of Chrysanthemum zawadskii in this, and by dissolving shell, Chrysanthemum zawadskii-pearl vinegar was produced. When a 1% of ark shell, oyster shell, or ear shell was added to wax gourd vinegar, 95.6~98.4% of the shell dissolved, and when a 2% content of shell was added, 97.2~98.4% was dissolved. The acidity of vinegar which dissolved 1% shell was pH 3.0~3.17, and the acidity of vinegar which dissolved 2% shell was pH 1.11~ 1.20. The pH values of vinegar which dissolved 1%, and 2% shell contents were 4.54~4.55, and 4.86~4.95, respectively. When 1% shell was dissolved, the acidity was higher than that of commercial vinegar, with a high pH value and low level of free acid. This shows that when Chrysanthemum zawadskii 1% is added during acetic acid fermentation, the inhibition was 44.4%, and 22.2% respectively. In this regard, Chrysanthemum zawadskii should be added after the fermentation of acetic acid. The calcium content of 1% shell vinegar is 0.4%, and that of 2% vinegar is 0.78%. Non-heated native wax gourd shows an angiotensin converting enzyme inhibition rate of 21.7%, an antioxidant activity of 5.23%, and a tyrosinase inhibition rate of 5.5%. In the case of heated-extracted wax gourd, the angiotensin converting enzyme inhibition rate was 16.1%, superoxide dismutase activity was 20.5%, antioxidant activity was 23.2%, and the tyrosinase inhibition rate was 7.1%. Also, in the case of Chrysanthemum zawadskii, the angiotensin converting enzyme inhibition rate was 28.8%, the xanthine oxidase inhibition rate was 28.2%, the superoxide dismutase activity was 14.5%, the antioxidant activity was 3.2%, and the tyrosinase inhibition rate was 9.2% Data also revealed that when a 10% sample of the heated-wax gourd extract was added to A549 human lung cancer epithelial cells of, the number of cancer cells declined by 80% in 72 hours, When a 10% native extract was added, the number of cells declined by, 74% in 48 hours, and when a heated-extract of Chrysanthemum zawadskii was added, 100% of the cells died after 72 hours.

• Environmental Engineering Research
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• v.13 no.3
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• pp.125-130
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• 2008

Free ammonia ($NH_3$-N) inhibition of nitrite-oxidizing bacteria (NOB) has been widely studied for partial nitrification (or nitrite accumulation) and denitrification via nitrite ($NO_2^-$-N) as a low-cost treatment of ammonium containing wastewater. The literature on $NH_3$-N inhibition of NOB, however, shows disagreement about the threshold $NH_3$-N concentration and its degree of inhibition. In order to clarify the confusion, a simple and cheap respirometric method was devised to investigate the effect of free ammonia inhibition of NOB. Sludge samples from an autotrophic nitrifying reactor were exposed to various $NH_3$-N concentrations to measure the maximum specific nitrite oxidation rate ($\hat{K}_{NO}$) using a respirometer. NOB biomass was estimated from the yield values in the literature. Free ammonia inhibition of nitrite oxidizing bacteria was reversible and the specific nitrite oxidation rate ($K_{NO}$) decreased from 0.141 to 0.116, 0.100, 0.097 and 0.081 mg $NO_2^-$-N/mg NOB h, respectively, as the $NH_3$-N concentration increased from 0.0 to 1.0, 4.1, 9.7 and 22.9 mg/L. A nonlinear regression based on the noncompetitive inhibition mode gave an estimate of the Inhibition concentration ($K_I$) of free ammonia to be 21.3 mg $NH_3$-N/L. Previous studies gave $\hat{K}_{NO}$ of Nitrobacter and Nitrospira as 0.120 and 0.032 mg/mg VSS h. The free ammonia concentration which inhibits Nitrobacter was $30{\sim}50\;mg$ $NH_3$-N/L and Nitrospira was inhibited at $0.04{\sim}0.08\;mg$ $NH_3$-N/L. The results support the fact that Nitrobacter is the dominant NOB in the reactor. The variations in the reported values of free ammonia inhibition may be due to the different species of nitrite oxidizers present in the reactors. The respirometric method provides rapid and reliable analysis of the behavior and community of the nitrite oxidizing bacteria.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.305-308
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• 2000

This study was observed to the effect of the feeding Platycodon grandiflorum A. DC (3 years) extract on the bronchus diseases bacteria ( C. diphtheriae, S. aureus, Mycobacterium sp., F. nucleatum, S. pygogenes, K. pneumoniae and N. gonorrhoeae) and fungi(A. fumicatus). Platycodon grandiflorum A. DC was extracted ethanon, water, ethyl ether and petroleum ether. The extraction rate of Platycodon grandiflorum A. DC to the extract solution was identified 71.8%, 100%, 15.4% and 14.1%. Each extract solution was injected culture media into several concentrations and then investigated the bacteria cell growth during 32 hours. As a result antimicrobial activity was excellent an extract by ethyl ether and petroleum ether. Among several concentrations, bacteria cell growth inhibition was observed from 0.06% to 0.14%. The rate of antimicrobial activity was over 70%. The cell growth inhibition rate of each bacteria was appeared in order of ethyl ether > petroleum ether > water > ethanol.

• YAKHAK HOEJI
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• v.25 no.3
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• pp.109-114
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• 1981

The authors investigated drug interaction of ibuprofen and prednisolone in antiinflammatory and antipyretic activities. We have found significant differences of the antiinflammatory and antipyretic activities between single and concurrent administration of ibuprofen and prednisolone, using Sprague-Dawley Strain rats, carrageenin as a phlogistic agent and brewer's yeast as a fever inducing agent. 1) Ibuprofen(20mg/kg) was administered to the rats orally and resulted in significant reduction of (31.70 %) the swelling of rat paw induced by carrageenin, 2) prednisolone (9mg/kg) showed significant reduction of (45.76%) the swelling, 3) concurrent administration of ibuprofen (20mg/kg) and prednisolone (9mg/kg) also reduced (57.40%) the swelling. In ibuprofen (125mg/kg) administration, the inhibition rate of edema was 39.32% and in prednisolone (1mg/kg) administration, the rate was 39.04%. In concurrent administration of ibuprofen (125mg/kg) and prednisolone (1mg/kg), the inhibition rate of edema was 63.09%. Concurrent administration of ibuprofen and prednisolone showed more anti-inflammatory effects than single administration of ibuprofen and prednisolone respectively. Prednisolone itself did not show antipyretic effect, but concurrent administration of ibuprofen and prednisolone showed more antipyretic effects than ibuprofen single administratron.

• Journal of dental hygiene science
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• v.23 no.1
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• pp.51-59
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• 2023

Background: Tea tree oil has antiviral, antimicrobial and antifungal effects and Mastic oil has antifungal and anticancer effects. For synergistic effects of oils, blending oil containing a mixture of two to three oils is recommended. This study aimed to determine the antibacterial effects of Tea tree oil, Mastic oil, and Blending oil containing the two oils in a mixture, to verify and suggest the potential use of these oils as a substance to prevent dental caries. Methods: Tea tree oil, Mastic oil, and Blending oil with a 1:1 blend of the two oils were diluted in liquid medium to 0% (negative control), 0.5%, 1.0%, and 2.0%. Streptococcus mutans was applied to each experimental group of the three diluted oils and after 8 h culture, the optical density (OD) was measured and the growth inhibition rate for S. mutans was estimated. Results: Tea tree oil had significantly low OD values across all concentrations (p<0.05) without significant variation among different concentrations (p>0.05). Mastic oil did not significantly vary in OD compared to the negative control across all concentrations (p>0.05) without significant variation among different concentrations (p>0.05). Blending oil, compared to the negative control, did not significantly vary in OD at 0.5% (p>0.05) but significant variation was found as the concentration increased (p<0.05). Additionally, for Tea tree oil and Mastic oil, the growth inhibition rate showed no significant variation according to concentration (p>0.05), whereas for Blending oil, the growth inhibition rate for S. mutans showed a significant difference at 1.0% (p<0.05) and at higher concentrations. Conclusion: Blending oil containing a Tea tree oil and Mastic oil demonstrated a significant growth inhibition effect on S. mutans from the concentration of 1.0%, which suggested its potential use as an effective antibacterial agent for dental caries.