• Environmental Engineering Research
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• 제21권2호
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• pp.164-170
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• 2016

Since most of the existing wastewater treatment options lack the ability to treat micro-contaminants, the increased use of pharmaceuticals and personal care products (PPCPs) and release as human waste have become a serious concern in recent years. Constructed wetlands (CWs) are a low-cost technology for wastewater treatment, however, its performance in term of PPCPs removal has not yet been fully investigated. This study aimed to characterize the removal factors and efficiency of acetaminophen (ACT) removal by CWs. The results revealed the decreased concentrations of ACT with increasing hydraulic retention times (HRT) of 0, 3, 5 days. The contribution of removal factors was found to be varied with initial ACT concentration. At the low ACT concentration (i.e. 1 ppb), plant uptake was the dominant, followed by microbial and photolytic removal. In contrast, at the high ACT concentration (i.e. 100 ppb), microbial and photolytic removal were found as dominant factors. On the other hand, hydrogen peroxide ($H_2O_2$) concentration was found at higher level in the plant shoot than in the root probably due to occurrence of the Fenton reaction resulting in PPCPs removal.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1177-1181
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• 2010

The synthesis and characterization of gold nanoparticles coated by Gd-chelate (GdL@Au) is described, where L is a conjugate of DTPA (DTPA = diethylenetriamine-N,N,N',N",N"-pentaacetic acid) and 4-aminothiophenol. These particles are obtained by the replacement of citrate from the gold nanoparticle surfaces with gadolinium chelate (GdL). The average size of GdL@Au is 12 nm with a loading of GdL reaching up to $1.4{\times}10^3$ per particles, and they demonstrate very high r1 relaxivity (${\sim}10^4mM^{-1}s^{-1}$) and the r1 relaxivity per [Gd] is as high as $10mM^{-1}s{-1}$. Here, we also describe the use of bimodality of this contrast agent (CA) as a highly efficient CT contrast agent based on gold nanoparticles (GNPs) that overcome the limitations of iodine based contrast agent. The MTT assay performed on this CAs reveals the cytotoxicity as low as that for Omniscan$^{(R)}$ in the concentration range required to obtain intensity enhancement in the in vivo MRI study.

• 환경생물
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• 제22권3호
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• pp.405-410
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• 2004

The effect of treatment with Citrus junos fractions (citron 3W, citron 3H, citron 4W and citron 4H) upon rat hepatocytes exposed to alcohol was investigated. We compared the serum biochemistry of rats administered both alcohol and Citrus junos fractions to control rats treated with alcohol alone. The effects of Alanine amino transferase (ALT) were significantly lower in the citron 3H extract group compared with the negative control group (p<0.05) and other experimental groups were not significantly low but a little low compared to negative control group. The levels of triglyceride (TG) were significantly low in all experimental groups compared with negative control group. Especially triglyceride level of citron 3H was lowest near to normal control group. The concentration of total cholesterol was significantly high in negative groups compared with normal control group but in all experimental groups, the concentration of total cholesterol was similar to that of negative control group. Total cholesterol of the citron 4W group was somewhat low compared with negative control group. In contrast, activities of alcohol dehydrogenase (ADH) were significantly higher in all experimental groups compared with the negative control (p<0.05) group. These data suggest that Citrus junos fractions may represents an excellent candidate for protection of rat hepatocytes from alcohol-mediated damage.

• 한국산학기술학회논문지
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• 제12권8호
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• pp.3572-3578
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• 2011

양전자방출단층촬영에서 표준섭취계수는 종양의 진단에 사용이 되는 지표이다. 표준섭취계수는 여러 인자에 의해 변화한다. 본 연구에서는 Philips사의 GEMINI TF PET/CT를 이용하여 물질에 따른 영상의 왜곡 및 표준섭취계수의 변화에 대하여 실험하였다. 물질별 표준섭취계수의 변화는 스테인레스보정물은 1.8, 스텐트는 1.4, 요오드성조영제는 2.4, 황산바륨은 2.6, 석고는 1.6, 파라핀은 1.4 이였다. 황산바륨 일수록 농도가 높을수록 영상의 왜곡은 크게 나타났다. 실험의 결과 원자번호가 낮은 금속성 물질이나 농도가 낮은 조영제의 경우 큰 영향은 없었다. 그러나 검사전 반드시 금속성 물질을 제거하거나 조영제의 유무를 확인하여 영상의 왜곡 및 표준섭취계수의 변화를 최소화 해야할 것이다.

• 약학회지
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• 제23권3_4호
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• pp.173-179
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• 1979

A dose, 1g/kg of ethanol produced experimental hyperuricemia in mouse. Ginseng saponins were tested for their ability to alter the hepatic xanthine oxidase activity and the blood level of uric acid in the ethanol-treated mouse. Intraperitoneal injection of ginseng saponin 4mg/kg markedly decreased the xanthine oxidase activity in the ethanol-treated mouse liver. It was also observed that ginseng saponin reduced the blood concentration of uric acid in experimentally induced hyperuricemia by alcohol treatment. In vitro, it was found that a low concentration of ginseng saponin in the reaction mixture incresed the hepatic xanthine oxidase activity, while a high concentration inhibited both enzyme preparations of normal and ethanol treated mice. In contrast with the xanthine oxidase, uricase activity was not influenced by ginseng saponin as well as in vivo. These results suggest there is a possibility that ginseng saponin may have some therapeutic effect on gout and other hyperuricemia syndrome.

• 한국방사선학회논문지
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• 제9권1호
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• pp.47-53
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• 2015

본 연구에서 3.0 T에서 조영제 몰 농도에 따른 뇌 대사물질의 MR spectrum을 Phantom에서 PRESS 펄스 파형으로 분석하고자 하였다. 뇌 대사물질인 N-Acetyl Asparatate(NAA), Choline(Cho), Creatine(Cr)의 spectrum은 획득할 수 있었지만, Lactate(Lac)는 획득할 수 없었다. 조영제가 없는 대조군의 TR 2000 ms가 NAA, Cho에서 TR 1700 ms와 TR 1500 ms보다 높게 측정되었고, Cr에서는 TR 1500 ms에서 높게 측정되었다. 조영제가 희석된 TR 1700 ms에서 $0.1mmol/{\ell}$의 NAA 73%, Cho 249%, Cr 37%로 다른 TR 값보다 가장 높게 측정되었고, $0.3mmol/{\ell}$에서도 신호크기가 증가하였다. $0.5mmol/{\ell}$에서는 뇌 대사물질들의 신호크기가 감소하였으며, 특히 TR 1500 ms과 TR 2000 ms에서는 대조군보다도 감소하였다. NAA/Cr, Cho/Cr에서도 조영제 농도가 $0.1mmol/{\ell}$, $0.3mmol/{\ell}$, $0.5mmol/{\ell}$로 증가할수록 신호크기가 감소하였다. 조영제에 의한 MRS PRESS 펄스파형의 적정화를 위하여 3.0T에서 TR 2000 ms 보다 조영제 농도가 낮은 $0.1mmol/{\ell}$와 $0.3mmol/{\ell}$에서 신호크기가 가장 높고, 조영제 농도가 높은 $0.5mmol/{\ell}$에서는 신호크기가 가장 적게 감소한 TR 1700 ms로 반복시간을 단축시켜 사용하는 것이 유용할 것으로 사료된다.

• 한국환경과학회지
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• 제26권1호
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• pp.55-65
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• 2017

Average concentration of PM in Seoul metropolitan area satisfied the Korean air quality standard in 2010. Furthermore, concentration of PM in all boroughs across Seoul met the air environment standard in 2012. $PM_{10}$ concentration was relatively higher in center of Seoul in comparison to the rest, while $PM_{2.5}$ concentration showed exactly the contrary result. We analyzed the effect that PM emissions from vehicles would have on PM concentrations across Seoul. The results showed that average annual PM concentration recently decreased in Seoul although the number of vehicles registered annually continued its upward trend. By contrast, average fine dust concentrations in Seoul showed a decline which suggested that correlation between annual average PM concentrations and number of registered vehicles remained low. However, year-on-year vehicle registration rate recently showed a declining tendency in the same way as the trend of changes in average PM concentrations. Particularly, the upward trend in annual average PM concentrations in 2002 and 2007 was consistent with the increase in vehicle registration rate, suggesting that vehicle registration rate was closely associated with changes in PM concentrations.

• Environmental Analysis Health and Toxicology
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• 제9권1_2호
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• pp.9-17
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• 1994

The Ha-antagonist, cimetidine, has been shown to retard the hepatic elimination of low and high clearance drugs, and this has been attributed to inhibition of microsomal cytochrome P-450. This study was done to determine the effects of low (50$\mu\textrm{g}$) and high (1mg) dose of famotidine, another histamine H$_2$-receptor antagonist, on hepatic elimination of propranolol compared with cimetidine in the isolated perfused rat liver. Both low and high dose of cimetidine not only inhibited the elimination of propranolol but also increased the area under the perfusate propranolol concentration time curve (AUC). In contrast, low and high dose of famotidine did not affect hepatic elimination of propranolol. Our findings suggest that famotidine has not a propensity for hepatic microsomal inhibition.

• 한국안광학회지
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• 제20권3호
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• pp.355-362
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• 2015

목적: 확산적 흐림의 투과율이 시력과 대비감도에 미치는 영향에 대하여 알아보았다. 방법: 평균연령 $22.83{\pm}0.50$세의 대학생 30명(남 13명, 여 17명)을 대상으로 Optec$^{(R)}$ 6500으로 시력과 대비감도를 측정하였다. 확산적 흐림의 도구로 백내장 시뮬레이터용 확산필름을 사용하였고, 백내장의 진행 정도나 안개의 농도가 반영될 수 있도록 확산적 흐림의 투과율을 변화시키면서 측정하였다. 결과: 시력과 확산적 흐림의 투과율은 비례식 $VA(T)=1.84{\times}10^{-2}T-0.65$으로 맞춤되었다. 대비감도는 모든 공간주파수에서 감소하였는데, 고공간주파수 대역에서의 대비감도가 더 큰 영향을 받아 정상범위를 먼저 벗어났고 대비감도의 정점은 저공간주파수 방향으로 이동하였다. 대비감도함수들의 교차점으로부터 대비감도가 정상범위를 벗어나는 확산적 흐림의 투과율 및 정점공간주파수의 이동을 산출한 결과, 투과율이 약 78.70%이 되면 대비감도의 정점이 6 cpd에서 3 cpd로 이동하는 것으로, 그리고 약 69.71%이 되면 모든 공간주파수에서의 대비감도가 정상범위를 벗어나는 것으로 평가되었다. 결론: 확산적 흐림의 투과율의 감소는 시력의 저하와 더불어 대비감도의 감소, 정상범위의 이탈 및 정점대비감도 이동 등을 유발시켜 시각적 불편함을 일으킨다는 점에서 백내장이나 안개 운전 시에는 더 많은 주의가 요구된다.

• 한국환경과학회지
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• 제17권1호
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• pp.97-105
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• 2008

This study examined the contaminated soils with an indicator of TPH using SVE (Soil Vapor Extraction) and biological treatments. Their results are as follows. Water content in the polluted soils slowly decreased from 15% during the initial experimental condition to 10% during the final condition. Purification of polluted soils by Bioventing system is likely to hinder the microbial activity due to decrease of water content. Removal rate of TPH in the upper reaction chamber was a half of initial removal rate at the 25th day of the experiment. The removal rate in the lower reaction chamber was 45% with concentration of 995.4 mg/kg. When the Bioventing is used the removal rate at the 14th day of the experiment was 53%, showing 7 day shortenting. Since the Bioventing method control the microbial activity due to dewatering of the polluted soil, SVE method is likely to be preferable to remove in-situ TPH. The reactor that included microbes and nutrients showed somewhat higher removal rate of TPH than the reactor that included nurtients only during experimental period. In general, the concentration showed two times peaks and then decreased, followed by slight variation of the concentration in low concentration levels. Hence, in contrast to SVE treatment, the biological treatment tend to show continuous repetitive peaks of concentration followed by concentration decrease.