• Environmental Engineering Research
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• 제15권1호
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• pp.23-27
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• 2010

Genotoxic- and ecotoxic assessments of silver nanoparticles (AgNPs) were conducted on the freshwater crustacean Daphnia magna. AgNPs may have genotoxic effects on D. magna, given that the DNA strand breaks increased when exposed to this nanoparticle. Increased mortality was concomitantly observed with DNA damage in the AgNPs-exposed D. magna, which suggests AgNPs-induced DNA damage might provoke higher-level consequences. The results of the comparative toxicities of AgNPs and Ag ions suggest that AgNPs are slightly more toxic than Ag ions. Overall, these results suggest that AgNPs may be genotoxic toward D. magna, which may contribute to the knowledge relating to the aquatic toxicity of AgNPs on aquatic ecosystems, for which little data are available.

• Restorative Dentistry and Endodontics
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• 제38권3호
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• pp.119-127
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• 2013

The purpose of a root-end filling is to establish a seal between the root canal space and the periradicular tissues. As root-end filling materials come into contact with periradicular tissues, knowledge of the tissue response is crucial. Almost every available dental restorative material has been suggested as the root-end material of choice at a certain point in the past. This literature review on root-end filling materials will evaluate and comparatively analyse the biocompatibility and tissue response to these products, with primary focus on newly introduced materials.

• 농약과학회지
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• 제4권4호
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• pp.40-47
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• 2000

점박이응애와 포식성 천적인 긴털이리응애와 긴꼬리이리응애에 대한 살비제 10종, 살충제 7종과 살균제 5종의 상대독성을 leaf spray 방법으로 시험하였다. Bifenazate, etoxazole, acequinocyl, flufenoxuron과 chlorfenapyr 등 5 종 살비제는 점박이응애 암컷성충보다 긴털이리응애와 긴꼬리이리응애 암컷성충에 매우 낮은 독성을 나타내었다. 또한 이들 5종 살비제를 처리한 긴털이리응애 암컷성충들은 무처리 암킷성충에 비해 $52{\sim}93%$의 산란수를 보였으며, 긴꼬리 이리응애 암컷성충들은 무처리 암컷성충에 비해 $54{\sim}73%$의 산란수를 보였다. 나머지 살비제들은 긴털이리응애와 긴꼬리이리응애 암컷성충에 대해 아주 강한 독성을 나타내었다. 시험 살충제는 모두 긴털이리응애와 긴꼬리이리응애의 암컷성충보다는 점박이응애의 암컷성충에 대해 더 낮은 독성을 나타내었다. 그러나 tebufenozide 와 diflubenzuron은 긴털 이리응애와 긴꼬리이리응애 암컷성충의 생존율과 산란수에 큰 영향을 미치지 않았다. 시험살균제는 모두 긴털이리응애와 긴꼬리이리응애 암컷성충에 대해 24% 이내의 낮은 치사율을 보였다. 그러나 benomyl은 두 종 천적의 산란수에 큰 영향을 나타내었다. 4종 살비제(bifenazate, acequinocyl, flufenoxuron과 chlorfenapyr)는 점박이응애 알보다 긴털이리응애와 긴꼬리이리응애 알에 매우 낮은 독성을 나타내었다. 그러나 etoxazole의 경우는 두 종 천적에서 상대적으로 낮은 부화율($58{\sim}62%$)을 보였다. 또한 시험 살충제와 살균제는 긴털이리응애와 긴꼬리이리응애 알의 부화율에 별 영향이 없었다. 이상의 결과에서 긴털이리응애와 긴꼬리이리응애의 암컷성충과 알에 적은 영향을 나타낸 4종 살비제, 2종 살충제와 4종 살균제는 배과원의 점박이응애 종합관리체계에서 긴털이리응애, 긴꼬리이리응애와 함께 이용할 수 있을 것으로 생각된다.

• Journal of Pharmaceutical Investigation
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• 제1권1호
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• pp.101-108
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• 1971

The stability and toxicity test for p.p'-DDT, DDVP and dipterex that put to used sample in this study effects is follows A. about p.p'-DDT (1) In elevating the stability of p.p'-DDT, best stabilizing solvent was benzene. (2) The stability-agent has no difficulty as long as it not contain metal ion for instance $Z_n^{2+}$,$C_r^{3+}$,$Al^{3+}$,and $Fe^{2+or3+}$ but in case of contain $F_e^{3+}$, the combination of salicylaminoguanidine is best effective. (3) Using this product for water-suspension, We must use span 40 for stability agent and adding it at the same time. (4) We must use container which does not week alkali and metal ion but it is to preserved in tight light-resistant container. (5) The stopper of container is adapted with above-mentioned condition of container, but it is better not to use metal material. (6) This product needs opening ventilation more than 30 minutes after diffusion or spray and in the room we remove cause of remained poison by cleaning the bottom. B. about DDVP and Dipterex (1) Benzene or toluene in best solvent to preserve stability of DDVP and Dipterex. (2) Span 40 is superior for stability agent of this product and second is span 80. (3) The pH of solution is very stable in pH 5-6 and comparative stable in alkali more than p,p'-DDT. (4) Container is to preserved in tight, lightresistant container and especially be careful of outflow and inflow of water. (5) Because this product is centeral stimulant poison, we must pay attention to prevent cause of contact diadermic toxicity after use.

• Environmental Analysis Health and Toxicology
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• 제14권3호
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• pp.113-120
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• 1999

Fluorination of drinking water has been used world widely to reduce the incidence of caries. Recently, contradictory results on the cytotoxicity of fluoride compounds are reported. In addition, there are attempts to use fluorosilicate for fluorination of drinking water in Korea, therefore, we tried to analyze the cytotoxicity of fluoride compounds on oral epidermoid carcinoma (KB and A253) and osteosarcoma (HOS and MG-63) cells in this study. We treated cells with 0, 10, 50 and 250 ppm of fluorosilicic acid (domestic or from Fluka, F$\_$6/H$_2$Si), sodium fluorosilicate (F$\_$6/Na$_2$Si), sodium fluoroacetate (FCH$_2$CO$_2$Na), sodium fluoride (NaF) or potassium fluoride(KF) and measured the relative cell survival by MTT assay. At the concentration of < 10ppm, no significant cytotoxicity was observed. At 50 ppm, each cells revealed different response to fluoride treatment. Among cells used in this study, MG-63 was the most resistant to fluoride treatment. Comparable toxicity data from domestic and imported fluorosilicic acids were obtained. When we compared the relative cytotoxicity of fluoride compounds against their fluoride contents, the differences in relative cell survival were smaller. Most of cells showed < 20% of survival at 250 ppm. In order to analyze the pH dependence of the cytotoxicity of fluorosilicates, the pH of cell culture media containing fluorosilicate was adjusted to 7.4 or 6.5 and the relative cytotoxicity was measured. At lower pH, about 10% higher cytotoxicity was obtained. Thus, our data suggested that the toxicity of domestic fluorosilicic acid was similar to that of fluorosilicic acid from Fluka, and the cytotoxicity of fluoride compounds was dependent on the relative content of fluoride and pH.

• 한국가스학회지
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• 제19권1호
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• pp.38-44
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• 2015

FDS (Fire Dynamics Simulator)는 화재안전공학 분야에서 가장 널리 사용되는 전산유체역학 소프트웨어로서 화재의 성장과 영향에 대한 다양한 평가에 응용될 수 있다. 본 연구에서는 화재시 발생하는 연소가스의 독성을 평가할 수 있는 유효복용분량 (Fractional Effective Dose, FED)와 유효부분농도 (Fractional Effective Concentration, FEC) 수준을 예측하기 위하여 FDS 시뮬레이션에서 얻어진 다양한 결과를 활용하였다. 그러나 FDS에서 기본적으로 제공하는 출력값으로는 이러한 값을 직접적으로 구할 수 없으므로, 피난 시뮬레이션에서 얻어진 결과를 결부시켜 별도의 계산과정을 통하여 FED와 FEC 수준을 계산하였다. 특히, 2013년 11월에 FDS의 버전이 업데이트된 바 있어 본 연구에서는 동일한 조건에 대하여 FDS의 구버전과 신버전을 비교하여 시뮬레이션 하였으며, 그 결과 FED, FEC값에 있어서 두 버전사이에 평균 약 10%의 차이가 발생함을 확인 할 수 있었다.

• Restorative Dentistry and Endodontics
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• 제38권4호
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• pp.204-209
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• 2013

Objectives: The objective of this in vitro study was to evaluate and compare the cytotoxicity of four different root canal sealers i.e. Apexit Plus (Ivoclar Vivadent), Endomethasone N (Septodont), AH-26 (Dentsply) and Pulpdent Root Canal Sealer (Pulpdent), on a mouse fibroblast cell line (L929). Materials and Methods: Thirty two discs for each sealer (5 mm in diameter and 2 mm in height) were fabricated in Teflon mould. The sealer extraction was made in cell culture medium (Dulbecco's Modified Eagle's Medium, DMEM) using the ratio 1.25 $cm^2/mL$ between the surface of the sealer samples and the volume of medium in a shaker incubator. Extraction of each sealer was obtained at 24 hr, 7th day, 14th day, and one month of interval. These extracts were incubated with L929 cell line and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay was done. Two-way ANOVA for interaction effects between sealer and time and Post-hoc multiple comparison using Tukey's test across all the 16 different groups were used for statistical analysis. Results: Apexit Plus root canal sealer was significantly less toxic than other sealers (p < 0.05) and showed higher cellular growth than control. Endomethasone N showed mild cytotoxicity. AH-26 showed severe toxicity which became mild after one month while Pulpdent Root Canal Sealer showed severe to moderate toxicity. Conclusions: Apexit Plus was relatively biocompatible sealer as compared to other three sealers which were cytotoxic at their initial stages, however, they became biocompatible with time.

• 대한본초학회지
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• 제34권4호
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• pp.9-18
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• 2019

Objectives : It has been known to be correlated between phlegm and dementia from the perspective of oriental medicine, but it is unexplored whether herbal medicines to treat phlegm have pharmacological actions on Alzheimer's disease (AD). The aim of this study was to evaluate and to compare effects of herbal medicines to treat phlegm against AD in vitro. Methods : We selected 11 herbal medicines which treat phlegm and obtained each extract by boiling in 10-fold distilled water for 2 h. And we performed the assay of acetylcholinesterase (AChE) inhibitory effects of 11 herbal extracts. Next, we evaluated neuroprotective effects of them against amyloid $beta_{25-35}$ ($A{\beta}_{25-35}$) plaque-induced toxicity in HT22 mouse hippocampal neuronal cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. To investigate whether they show the anti-inflammatory effects against lipopolysaccharide (LPS), we also measured the levels of nitric oxide (NO) in BV2 microglia cells using griess reagent assay. Results : We found that Gamiyeongsin-hwan (GYH) and Cheonghunhwadam-tang (CHT) exhibited remarkable AChE inhibitory effects. In HT22 cells, Arisaematis Rhizoma, Trichosanthis Semen and Fritillariae Thunbergii Bulbus suppressed $A{\beta}_{25-35}$ plaque-induced neuronal cell death. In BV2 cells, Cheongung-hwan significantly inhibited the increase of NO contents induced by LPS and GYH and CHT showed a tendency to inhibit LPS-induced NO generation. Conclusions : These results suggest that several herbal medicines to treat phlegm showed the significant effects on AChE inhibition, neuroprotection against $A{\beta}_{25-35}$ plaque-induced toxicity, and inhibition of NO generation. Therefore, we demonstrate the possibility that herbal medicines with treating phlegm has effects against AD.

• 한국응용곤충학회지
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• 제32권2호
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• pp.123-128
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• 1993

점박이응애에 대한 몇가지 살비제들의 각 발육단계에 다른 살란.성충효과를 조사하였다. fenpyroximate는 발육 전단계에 걸쳐 높은 효과를 보였다. Fenpyroximate 의 산란억제효과는 cyhexatin보다 훨씬 좋았다. 100ppm 농도 수준에서 약제잔효로 인한 산란억제효과는 fenpyroximate경우 85% 수준으로 25일동안 지속한 반면 cyhexatin의 효과는 점차 감소하여 처리 25일 후 40% 정도 감소했다. 또한 100ppm 농도 수준에서 fenpyroximate의 속효성은 3시간만에 100%의 살성충력을 보였지만 cyhexatin은 24시간이 지난 후에도 91%정도의 살성충력을 보여주었다. 공시된 대부분의 살비제가 침투이행성을 보여주지 않았지만 metasystox는 800ppm 농도 수준에서 처리 후 24시간에 100% 살성충효과를 나타냈다. 각기 다른 온도에 대하여 fenpyroximate는 다른 살비제와 비교했을 때 안정된 약효를 보였다.

• 대한환경공학회지
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• 제38권7호
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• pp.395-401
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• 2016

최근 나노물질의 산업 및 생활분야의 광범위한 사용으로 인한 나노안전성이 대두되고 있다. 특히 다양한 목적에 의해 가공된 나노물질의 잠재적 독성이 문제가 되고 있기 때문에, 지속가능한 나노물질 산업의 발전을 위해서는 적극적인 나노 안전성에 대한 연구가 진행되어야 한다. 현재까지 나노물질의 일반적 급성, 만성독성에 대한 연구는 비교적 활발하게 진행되고 있지만, 나노물질의 다세대 영향에 대한 연구는 시간적 및 실험적 제약으로 인해 미흡한 실정이다. 생태계 내 나노물질의 다세대 연구는 일반적 독성 종말점을 이용한 후세대 영향 연구와 나노물질의 세대 간 거동을 확인한 세대전이 연구로 나뉘어 진행되고 있다. 본 연구는 나노물질의 다세대 영향 및 전이연구 추세를 확인하고 제한점을 제시하여 앞으로의 연구방향을 제시하는데 그 목적이 있다. 나노물질에 대한 학술연구를 대상으로 문헌조사를 실시하였으며, 각 분야별 자료를 수집하고 비교분석하였다. 조사결과 후세대 영향을 확인한 연구는 총 13건 이었으며, 생존률, 생식률 그리고 운동성과 같은 지표를 이용하여 다음세대에 전달되는 영향을 확인하였다. 그리고, 7건의 세대전이 연구에서는 후세대로 전달된 나노물질을 다양한 이미징 기법을 통하여 확인하였다. 현재까지 나노물질이 후세대에 미치는 독성영향의 메커니즘은 밝혀진 바가 거의 없다. 본 연구에서는 나노물질의 다세대 연구추세를 분석하고, 후세대영향과 세대전이의 상호보완적 연구방향을 제시하였다.