• Preventive Nutrition and Food Science
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• 제19권1호
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• pp.19-26
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• 2014

Increased consumption of fresh vegetables that are high in polyphenols has been associated with a reduced risk of oxidative stress-induced disease. The present study aimed to evaluate the antioxidant effects of spinach in vitro and in vivo in hyperlipidemic rats. For measurement of in vitro antioxidant activity, spinach was subjected to hot water extraction (WE) or ethanol extraction (EE) and examined for total polyphenol content (TPC), oxygen radical absorbance capacity (ORAC), cellular antioxidant activity (CAA), and antigenotoxic activity. The in vivo antioxidant activity of spinach was assessed using blood and liver lipid profiles and antioxidant status in rats fed a high fat-cholesterol diet (HFCD) for 6 weeks. The TPC of WE and EE were shown as $1.5{\pm}0.0$ and $0.5{\pm}0.0mg$ GAE/g, respectively. Increasing the concentration of the extracts resulted in increased ORAC value, CAA, and antigenotoxic activity for all extracts tested. HFCD-fed rats displayed hyperlipidemia and increased oxidative stress, as indicated by a significant rise in blood and liver lipid profiles, an increase in plasma conjugated diene concentration, an increase in liver thiobarbituric acid reactive substances (TBARS) level, and a significant decrease in manganese superoxide dismutase (Mn-SOD) activity compared with rats fed normal diet. However, administration of 5% spinach showed a beneficial effect in HFCD rats, as indicated by decreased liver TBARS level and DNA damage in leukocyte and increased plasma conjugated dienes and Mn-SOD activity. Thus, the antioxidant activity of spinach may be an effective way to ameliorate high fat and cholesterol diet-induced oxidative stress.

• 자원리싸이클링
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• 제10권4호
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• pp.42-47
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• 2001

알루미늄 드로스와 장석을 이용하여 무기발포재의 제조 가능성을 검토하여 폐기물인 알루미늄 드로스의 재활용 및 자원화의 다양성을 제시하기 위한 실험을 행하였다. 소성한 발포재의 경우 장석은 소성온도에서 용해되어 비정질상으로 전이하고 드로스 중의 성분들이 Spinel($MgA1_2$$O_4$)을 형성한다. 장석 55 wt%, 드로스 40 wt%, 벤토나이트 5 wt% 시료의 경우 소성온도 $1220^{\circ}C$에서 소성시간이 증가할수록 밀도는 0.91에서 0.65까지 감소하고, 흡수율은 약 2.5에서 1.7%의 범위의 값을 나타냈다. $1220^{\circ}C$에서 30분 소성할 경우 굽힘강도는 10.8 MPa이며, 열전도도는 0.34 W/m.K로서 최대치를 나타냈다.

• 한국식품과학회지
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• 제32권5호
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• pp.1149-1157
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• 2000

고추장 변색 요인을 확인하기 위하여 전통적인 방법으로 떡고추장과 식혜고추장을 만들고 가열처리, 포장중 질소치환 및 U.V 조사여부에 따른 변화를 관찰하였다. 각 고추장의 색도 변화는 일반적으로 숙성기간이 경과됨에 따라 L, a, b값은 감소하고 ${\delta}E$ 값은 증가하는 경향을 보였다. 그 중 떡고추장의 ${\delta}E$ 값은 자외선 조사구에서 다른 처리구에 비하여 높았고 식혜고추장의 ${\delta}E$ 값은 비열처리구에서 전반적으로 높게 나타났다. 갈변 요인 분석에서는 떡고추장의 주요 갈변 요인으로는 빛이, 식혜고추장에서는 열처리와 빛이 작용하였으며 각각의 갈변 요인들이 상호 작용함으로 서 고추장의 갈변에 관여함을 확인하였다. 고추장 추출물의 흡광도 변화에서는 고추장을 아세톤으로 추출하여 흡광도를 측정한 결과 $450{\sim}470$ nm에서, 물 추출물의 흡광도는 $200{\sim}205$ nm에서 가장 최고치를 나타내었다.

• 산업식품공학
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• 제13권3호
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• pp.216-220
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• 2009

Aloe gel의 동결건조에 농축도가 서로 다른 액상 시료를 사용하였을 때 건조분말의 기능성 변화를 비교분석하였다. Aloe의 많은 기능성 중에서 유효 다당류의 농도, 기능성 작용기에 대한 FT-IR 특성, Jack bean urease 저해 효과, FAC(fat adsorption capacity)를 대상으로 하였다. 농축도가 높은 경우에 유효 다당류의 농도, urease 저해 효과, FAC 모두 상대적으로 크게 나타났다. FT-IR의 분석에서는 농축도가 높은 경우에 glucomannan의 acetyl 기에 대한 spectrum 영역인 1600-1550 $cm^{-1}$와 1450-1400 $cm^{-1}$에서 흡광도가 크게 관찰되었다. 결과적으로 Aloe gel의 동결건조시 전처리과정인 농축 공정에서는 농축도가 높을수록 유효다당류의 양과 acetyl기 함량의 수준이 크며, 간접적으로 urease 저해 효과에 따른 Helicobacter pylori의 억제 및 FAC의 증가 효과를 보였다.

• Journal of Korean Academy of Oral Health
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• 제42권4호
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• pp.210-215
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• 2018

Objectives: The main objectives of this study were to verify the antibacterial activity of two essential oils, lavender and peppermint, against dental caries and to review their synergistic effect when used in combination. Our results provide basic data for the evaluation of the use of these two substances towards the prevention and cure of dental caries. Methods: The sample solutions of lavender and peppermint oils were prepared in three different concentrations (30%, 50%, and 70% (v/v)) by diluting them with third-distilled water and Tween 20. Streptococcus mutans was selected as the bacterial species for testing. The disk diffusion method was used to measure the antibacterial activity of the sample solutions. For generating growth curves and measuring the number of clusters of the bacterial, the liquid medium-dilution method was used; the absorbance of the medium was measured at 600 nm after 3, 6, 12 and 24 hours. Results: When the antibacterial activity of the oils was tested via the disk diffusion method, the activity improved with increasing concentrations of all the sample solutions of peppermint, lavender, and the blend, but there was no significant difference between them with respect to the type of oil. In the growth curves of S. mutans, growth inhibition was observed after 12 hours. The inhibitory effect of 30% lavender oil on growth was 64.9% and 80.1% after 12 and 24 hours of treatment, respectively whereas that of peppermint oil was 71.3% and 80.1% after 12 and 24 hours of treatment, respectively. The inhibitory effect of the blended oil was 71.9% and 81.0% after 12 and 24 hours of treatment, respectively. Conclusions: Further research is still required in order to determine the efficacy of lavender and peppermint oils, as well as other essential oils, for wider use in preventing dental caries.

• Advances in environmental research
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• 제7권3호
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• pp.213-223
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• 2018

Continuous input into the aquatic ecosystem and persistent structures have created concern of antibiotics, primarily due to the potential for the development of antimicrobial resistance. Degradation kinetics and mineralization of vancomycin B (VAN-B) by photocatalysis using $TiO_2$ and ZnO nanoparticles was monitored at natural pH conditions. Photocatalysis (PC) efficiency was followed by means of UV absorbance, total organic carbon (TOC), and HPLC results to better monitor degradation of VAN-B itself. Experiments were run for two initial VAN-B concentrations ($20-50mgL^{-1}$) and using two catalysts $TiO_2$ and ZnO at different concentrations (0.1 and $0.5gL^{-1}$) in a multi-lamp batch reactor system (200 mL water volume). Furthermore, a set of toxicity tests with Daphnia magna was performed to evaluate the potential toxicity of oxidation by-products of VAN-B. Formation of intermediates such as chlorides and nitrates were monitored. A rapid VAN-B degradation was observed in ZnO-PC system (85% to 70% at 10 min), while total mineralization was observed to be relatively slower than $TiO_2-PC$ system (59% to 73% at 90 min). Treatment efficiency and mechanism of degradation directly affected the rate of transformation and by-products formation that gave rise to toxicity in the treated samples.

• 유기물자원화
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• 제29권2호
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• pp.25-30
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• 2021

본 연구는 인산염 인 농도 측정과 관련하여 숙련도에 의해서 정도관리의 지표가 어떻게 개선되는지를 조사하였다. 아울러 분석기기의 종류에 따른 측정값의 차이가 있는지 함께 비교하였다. 분석자의 숙련도가 분석결과에 미치는 영향을 알아보기 위해 3인의 실험자가 2종의 분석기기를 사용하여 수질오염공정시험기준에 따라 인산염 인을 7회에 걸쳐서 방법검출한계와 정량한계를 측정하였으며, 실험결과 5회 이상 반복실험하면 정도관리지표를 만족하였다. 인산염 인의 정량한계는 0.02 mg/L로 계산되었으며, 분석기기가 다른 경우 정량한계 부근의 시료에 대한 흡광도와 농도가 통계적으로 유의미하게 차이가 있음을 확인하였다.

• 대한의용생체공학회:의공학회지
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• 제41권6호
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• pp.228-234
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• 2020

Superparamagnetic iron oxide nanoparticles (SPIONs) are approved by the Food and Drug Administration (FDA) in the United States. SPIONs are used in magnetic resonance imaging (MRI) as contrast agents and targeted delivery in nanomedicine using external magnet sources. SPIONs act as an artificial peroxidase (i.e., nanozyme), and these reactions were highly stable in various pH conditions and temperatures. In this study, we report a nanozyme ability of the clustered SPIONs (CSPIONs) synthesized by the oil-in-water (O/W) method and coated with biocompatible poly(lactic-co-glycolic acid) (PLGA). We hypothesize that the CSPIONs can have high sensitivity toward H2O2 derived from the reaction between a fixed amount of glucose and glucose oxidase (GOX). As a result, CSPIONs oxidized a 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) commonly used as a substrate for hydrogen peroxidase in the presence of H2O2, leading to a change in the color of the substrate. We also utilized a colorimetric assay at 417 nm using various glucose concentrations from 5 mM to 1.25 μM to validate β-D-glucose detection. This study demonstrated that the absorbance value increases along with increasing the glucose level. The results were highly repeated at concentrations below 5 mM (all standard deviations < 0.03). Moreover, the sensitivity and limit of detection were 1.50 and 5.44 μM, respectively, in which CSPIONs are more responsive to glucose than SPIONs. In conclusion, this study suggests that CSPIONs have the potential to be used for glucose detection in diabetic patients using a physiological fluid such as ocular, saliva, and urine.

• International Journal of Oral Biology
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• 제45권4호
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• pp.143-151
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• 2020

Streptococcus mutans and Streptococcus sobrinus play important roles in dental caries. Coptis chinensis is a natural product with antimicrobial activity against enterobacteria; however, its effects on oral streptococci are still unknown. Therefore, the effects of C. chinensis on the growth and biofilm formation of the representative cariogenic bacteria S. mutans and S. sobrinus were investigated for the possible use of C. chinensis as an anticaries agent. The C. chinensis extract was diluted with sterile distilled water, and 0.1-2.5% of the extract was used in the experiment. The effects of the C. chinensis extract on the growth and glucan formation of S. mutans and S. sobrinus were measured by viable cell counting and spectrophotometry at 650 nm absorbance, respectively. Crystal violet staining was also carried out to confirm the C. chinensis extract's inhibitory effect on biofilm formation. The C. chinensis extract significantly inhibited the growth of S. mutans and S. sobrinus at concentrations of ≥ 0.3% as compared with the control group. The viable cell count of colonies decreased by 1.7-fold and 1.2-fold at 2.5% and 1.25%, respectively, compared with the control group. The biofilm formation of S. mutans and S. sobrinus was inhibited by > 20-fold at C. chinensis extract concentrations of ≥ 1.25% as compared with the control group. In summary, the C. chinensis extract inhibited the growth and biofilm and glucan formation of S. mutans and S. sobrinus. Therefore, C. chinensis might be a potential candidate for controlling dental caries.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1031-1031
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• 2001

The mammary gland is made up of remarkably sensitive tissue, which has the capability of producing a large volume of secretion, milk, under normal or healthy conditions. When bacteria enter the gland and establish an infection (mastitis), inflammation is initiated accompanied by an influx of white cells from the blood stream, by altered secretory function, and changes in the volume and composition of secretion. Cell numbers in milk are closely associated with inflammation and udder health. These somatic cell counts (SCC) are accepted as the international standard measurement of milk quality in dairy and for mastitis diagnosis. NIR Spectra of unhomogenized composite milk samples from 14 cows (healthy and mastitic), 7days after parturition and during the next 30 days of lactation were measured. Different multivariate analysis techniques were used to diagnose the disease at very early stage and determine how the spectral properties of milk vary with its composition and animal health. PLS model for prediction of somatic cell count (SCC) based on NIR milk spectra was made. The best accuracy of determination for the 1100-2500nm range was found using smoothed absorbance data and 10 PLS factors. The standard error of prediction for independent validation set of samples was 0.382, correlation coefficient 0.854 and the variation coefficient 7.63%. It has been found that SCC determination by NIR milk spectra was indirect and based on the related changes in milk composition. From the spectral changes, we learned that when mastitis occurred, the most significant factors that simultaneously influenced milk spectra were alteration of milk proteins and changes in ionic concentration of milk. It was consistent with the results we obtained further when applied 2DCOS. Two-dimensional correlation analysis of NIR milk spectra was done to assess the changes in milk composition, which occur when somatic cell count (SCC) levels vary. The synchronous correlation map revealed that when SCC increases, protein levels increase while water and lactose levels decrease. Results from the analysis of the asynchronous plot indicated that changes in water and fat absorptions occur before other milk components. In addition, the technique was used to assess the changes in milk during a period when SCC levels do not vary appreciably. Results indicated that milk components are in equilibrium and no appreciable change in a given component was seen with respect to another. This was found in both healthy and mastitic animals. However, milk components were found to vary with SCC content regardless of the range considered. This important finding demonstrates that 2-D correlation analysis may be used to track even subtle changes in milk composition in individual cows. To find out the right threshold for SCC when used for mastitis diagnosis at cow level, classification of milk samples was performed using soft independent modeling of class analogy (SIMCA) and different spectral data pretreatment. Two levels of SCC - 200 000 cells/$m\ell$ and 300 000 cells/$m\ell$, respectively, were set up and compared as thresholds to discriminate between healthy and mastitic cows. The best detection accuracy was found with 200 000 cells/$m\ell$ as threshold for mastitis and smoothed absorbance data: - 98% of the milk samples in the calibration set and 87% of the samples in the independent test set were correctly classified. When the spectral information was studied it was found that the successful mastitis diagnosis was based on reviling the spectral changes related to the corresponding changes in milk composition. NIRS combined with different ways of spectral data ruining can provide faster and nondestructive alternative to current methods for mastitis diagnosis and a new inside into disease understanding at molecular level.