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A Study on the Water Quality of Indoor Swimming Pools and Waterscape Facilities
Daeun Hong(홍다은),Jiyoung Lee(이지영),Heesu Lee(이희수),Eunkyoung Park(박은경),Mihee Jeon(전미희),Hyeonseop Ha(하현섭),Munju Gwon(권문주) 환경독성보건학회 2021 한국독성학회 심포지움 및 학술발표회 Vol.2021 No.5
Waterscape facilities and swimming pools are popular spaces for leisure and exercise. In particular, in the case of waterscape facilities, the number of new apartment buildings and park sites has increased, and indoor swimming pools have become leisure facilities that many people enjoy due to the increase in the number of users because of the activation of sports-for-all. For these facilities, clean water quality control is most important because tap water and underground water come into direct contact with the human body. A survey of 200 samples of swimming pools showed that no P. aeruginosa and E. coli were detected, but the nonconformity rate due to free residual chlorine and combined residual chlorine was 6.5%. Since there is a high possibility of contamination by users, it is necessary to set the measurement cycle of free residual chlorine and combined residual chlorine for clean water quality management. A water quality analysis result of waterscape facilities showed that no P. aeruginosa were detected. But P. luteola was detected once in the early stages of operation in the stream type with slow water flow and low water depth, and was not detected again after disinfection treatment. B. cepacia was detected once in the waterfall fountain and twice in the stream. The nonconformity rate of E. coli was 5% for waterfall fountain, 19% for stream and 6% for general fountain. Due to the nature of the facility, the free residual chlorine was quickly consumed by the water's aeration and turbulent action. In this study, the concentration of free residual chlorine decreased to 0 mg/L in about two days, the disinfection effect is reduced, more than two times a week is needed.
PET식품 용기에서 발효 모사 식품으로 전이되는 아세트알데히드와 부틸알데히드 예측 모델
Daeun Lee,Hyunpyo Jeon,Sanghun Kim 한국환경보건학회 2016 한국환경보건학회지 Vol.42 No.3
Objectives: Materials coming into contact with food may result in the migration of chemical substances into the food. To protect consumers from exposure, Regulation (EU) No. 10/2011 specifies the use of standard migration tests. Polyethylene terephthalate (PET), widely used for food packaging materials, has drawn the attention of researchers because unwanted migration of PET into food might occur when consumers reuse packaging material. The aim of this study was to predict and develop a migration model for two components, acetaldehyde and butyraldehyde in PET, into food simulants under conditions of changing pH and solvents, such as those observed in fermented foods like kimchi or sauerkraut. Methods: Using a migration model based on Fick’s second law of diffusion in one dimension, the migration of acetaldehyde and butyraldehyde from PET into a simulant of fermented food at 20 °C over 10 days was evaluated. The simulant for fermented food was modelled as 10% ethanol for three days, followed by 3% acetic acid for seven days. Results: The migration of acetaldehyde into the 10% ethanol was 0.36 times that of a simulated fermented food system, while that of butyraldehyde was 1.34 times greater. These results may have been influenced by the chemical interactions among the migrants, polymers and simulants, as well as by the solubilities of the migrants in polymers and simulants. Conclusion: Because food simulants have a limited capacity to mimic real food systems under the current migration model, an appropriate simulant and migration test should be considered in the case of increasing acidity. Furthermore, since the accuracy of the worst-case estimation of migration predicted by the current model is severely limited under changing food conditions, food simulants and their interactions should be further investigated with respect to conservative migration modelling.
Lee, Jaeho,Kim, Shanghyeon,Sim, Ji-Yeong,Lee, Daeun,Kim, Ha Hyung,Hwang, Jae Sam,Lee, Dong Gun,Park, Zee-Yong,Kim, Jae Il Elsevier 2019 Biochimica et biophysica acta, Biomembranes Vol.1861 No.1
<P><B>Abstract</B></P> <P>The emergence of drug-resistant pathogenic bacteria threatens human health. Resistance to existing antibiotics is increasing, while the emergence of new antibiotics is slowing. Cationic antimicrobial peptides (CAMPs) are fascinating alternative antibiotics because they possess a broad spectrum of activity, being active against both Gram-positive and Gram-negative bacteria including those resistant to traditional antibiotics. However, low bioavailability resulting from enzymatic degradation and attenuation by divalent cations like Mg<SUP>2+</SUP> and Ca<SUP>2+</SUP> limits their use as antibiotic agents. Here, we report the design of new CAMPs showing both high antibacterial activity and serum stability under physiological ion concentrations. The peptides were designed by applying two approaches, the use of <SMALL>D</SMALL>-enantiomer and lipidation. Based on the sequence of the CopW (LLWIALRKK-NH<SUB>2</SUB>), a nonapeptide derived from coprisin, a series of novel <SMALL>D</SMALL>-form CopW lipopeptides with different acyl chain lengths (C6, C8, C10, C12, C14, and C16) were synthesized and evaluated with respect to their activity and salt sensitivity. Among the analogs, the <SMALL>D</SMALL>-form lipopeptide dCopW3 exhibited MIC values ranging from 1.25 to 5 μM against multidrug-resistant bacteria. Significantly, this compound did not induce bacterial resistance and was highly stable in human serum proteases. The results emphasize the potential of cationic <SMALL>D</SMALL>-form lipopeptide as therapeutically valuable antibiotics for treating drug-resistant bacterial infections.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CopW analogs were designed by introduction of <SMALL>D</SMALL>-amino acid and fatty acid to improve salt sensitivity and serum stability </LI> <LI> In physiological salt condition, dCopW3 most efficiently inhibited MDR-pathogen growth with a low hemolytic activity </LI> <LI> dCopW3 rapidly killed bacteria <I>via</I> bacterial membrane disruption </LI> <LI> dCopW3 reduced the possibility of the potential emergence of bacterial resistance </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Lee, Daeun,Yoo, Jung Hwa,Lee, Byung-Cheol Hindawi 2018 Evidence-based Complementary and Alternative Medic Vol.2018 No.-
<P>Obesity results in the progression of metabolic disorders, especially type 2 diabetes (T2DM). Obesity-induced insulin resistance (IR) is a causative factor of T2DM morbidity in obese people. It is generally held by clinicians that IR is caused by adiposity-related inflammation that is mediated by changes in composite ions in the gut microbiome. This experimental study was designed to investigate the effects of<I> Cucumis melo </I>L. (Cucumis) on obesity-induced IR in genetically leptin-deficient Lep<SUP>ob</SUP>/Lep<SUP>ob</SUP> mice. Specifically, we examined the anti-inflammatory effects of Cucumis and the effects of Cucumis on the gut microbiota. We evaluated glucose control by measuring FBS, performing the OGTT, quantifying serum IR, calculating the HOMA-IR, and determining the lipid profiles. To see whether inflammation was reduced, we analyzed adipose tissue macrophages as well as monocytes in the blood. We also profiled the gut microbiota to determine whether the ratios of microbial phyla changed. We found that Cucumis improved IR in obese mice and relieved inflammation in adipose tissue and blood. Simultaneously, the microbiota composition ratios changed. In conclusion, administration of Cucumis improved IR by reducing inflammation, thereby changing the gut microbiota composition. Cucumis is thus a promising treatment for obesity-induced insulin resistance and the inflammatory state. </P>
Lee, Daeun,Jeon, Hyunpyo,Kim, Sanghun Korean Society of Environmental Health 2016 한국환경보건학회지 Vol.42 No.3
Objectives: Materials coming into contact with food may result in the migration of chemical substances into the food. To protect consumers from exposure, Regulation (EU) No. 10/2011 specifies the use of standard migration tests. Polyethylene terephthalate (PET), widely used for food packaging materials, has drawn the attention of researchers because unwanted migration of PET into food might occur when consumers reuse packaging material. The aim of this study was to predict and develop a migration model for two components, acetaldehyde and butyraldehyde in PET, into food simulants under conditions of changing pH and solvents, such as those observed in fermented foods like kimchi or sauerkraut. Methods: Using a migration model based on Fick's second law of diffusion in one dimension, the migration of acetaldehyde and butyraldehyde from PET into a simulant of fermented food at $20^{\circ}C$ over 10 days was evaluated. The simulant for fermented food was modelled as 10% ethanol for three days, followed by 3% acetic acid for seven days. Results: The migration of acetaldehyde into the 10% ethanol was 0.36 times that of a simulated fermented food system, while that of butyraldehyde was 1.34 times greater. These results may have been influenced by the chemical interactions among the migrants, polymers and simulants, as well as by the solubilities of the migrants in polymers and simulants. Conclusion: Because food simulants have a limited capacity to mimic real food systems under the current migration model, an appropriate simulant and migration test should be considered in the case of increasing acidity. Furthermore, since the accuracy of the worst-case estimation of migration predicted by the current model is severely limited under changing food conditions, food simulants and their interactions should be further investigated with respect to conservative migration modelling.