• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.2041-2044
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• 2007

The reactions of mercury(II) chloride with O3S2-donor macrocyclic ligands with (L1) and without (L2) dibenzosubunit afforded respective exo- (1) and endo-coordinated (2) complexes depending on the ring rigidity of the ligands. From the X-ray crystal structures and comparative NMR studies for the complexes 1 and 2, it is confirmed that the resulting species with different coordination modes exist not only in solid state but also in solution state.

• Korean Journal of Environmental Biology
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• v.29 no.3
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• pp.236-240
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• 2011

Mercury known as quicksilver, is the most common cause of heavy metal toxicity. Toxicity caused by excessive mercury exposure is now being recognized as a widespread environmental problem and is continuing to attract a great deal of public concerns. The mercury genotoxicity could be its effect on DNA repair mechanisms, which constitute the defense system designated to protect genome integrity. The objective of this study is to confirm that mercuric chloride inhibits the repair of gamma ray-induced DNA damage. The earthworm of Eisenia fetida was chosen for this study because it is an internationally accepted model species for toxicity testing with a cosmopolitan distribution. Experiments were done to identify the levels of DNA damage and the repair kinetics in the coelomocytes of E. fetida irradiated with 20 Gy gamma rays alone or with gamma rays after 40 mg $kg^{-1}$ $HgCl_2$ treatment by means of the single cell gel electrophoresis assay. The Olive tail moments were measured during 0~96 hours after irradiation. The repair time in the animals treated with the combination of $HgCl_2$ and ionizing radiation was nearly five times longer than that in the animals treated with ionizing radiation alone. Also, E. fetida exposed to mercury showed a statistically lower repair efficiency of gamma ray-induced DNA damage. The results suggest that the mercury could even have deleterious effects on the DNA repair system. Influence of mercury on the DNA repair mechanisms has been confirmed by this study.

• Advances in concrete construction
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• v.9 no.5
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• pp.449-457
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• 2020

The influence of subsequent curing on the performance of fly ash contained mortar under steam curing was studied. Mortar samples incorporated with different content (0%, 20%, 50% and 70%) of Class F fly ash under five typical subsequent curing conditions, including standard curing (ZS), water curing(ZW) under 25℃, oven-dry curing (ZD) under 60℃, frozen curing (ZF) under -10℃, and nature curing (ZN) exposed to outdoor environment were implemented. The unsteady chloride diffusion coefficient was measured by rapid chloride migration test (RCM) to analyze the influence of subsequent curing condition on the resistance to chloride penetration of fly ash contained mortar under steam curing. The compressive strength was measured to analyze the mechanical properties. Furthermore, the open porosity, mercury intrusion porosimetry (MIP), x-ray diffraction (XRD) and thermogravimetric analysis (TGA) were examined to investigate the pore characteristics and phase composition of mortar. The results indicate that the resistance to chloride ingress and compressive strength of steam-cured mortar decline with the increase of fly ash incorporated, regardless of the subsequent curing condition. Compared to ZS, ZD and ZF lead to poor resistance to chloride penetration, while ZW and ZN show better performance. Interestingly, under different fly ash contents, the declining order of compressive strength remains ZS>ZW>ZN>ZD>ZF. When the fly ash content is blow 50%, the open porosity grows with increase of fly ash, regardless of the curing conditions are diverse. However, if the replacement amount of fly ash exceeds a certain high proportion (70%), the value of open porosity tends to decrease. Moreover, the main phase composition of the mortar hydration products is similar under different curing conditions, but the declining order of the C-S-H gels and ettringite content is ZS>ZD>ZF. The addition of fly ash could increase the amount of harmless pores at early age.

• Journal of the Korea Concrete Institute
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• v.19 no.4
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• pp.499-506
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• 2007

According to the high demand of concrete structures with high performance, various studies have examined on the high performance concrete, especially high strength concrete. Various admixtures are required to produce high strength concrete and silica fume has been the most popular admixture. Recently, however, metakaolin, which is similar to silica fume in properties but cheaper, has been introduced to high strength concrete. In this study, high-strength concrete using metakaolin were studied of capillary pore structure by mercury intrusion porosimetry technique and the accelerated chloride diffusivity by electrical difference. In result, it was found that the pore structure improved and compressive strength increased and chloride diffusivity reduced as more metakaolin content was added. In addition, a regression analysis of $5{\sim}2,000nm$ pore volume and both compression strength and chloride diffusivity revealed that each these had a high correlation of about 0.76 and 0.68.

• Journal of Plant Biotechnology
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• v.35 no.4
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• pp.291-298
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• 2008

Methylmercury, an organic derivative, is the principal form of mercury that biomagnifies and causes neurodegenerative symptoms in animals. In recent years, living modified organism (LMO) resulting from biotechnology has played a highly visible and controversial role. Despite the potential benefits of this technology, public concerns have been raised about the environmental risk of LMO. The concern on the risk from LMO release has urged efforts to evaluate and manage the risks of the LMO. To build up the capacity building of risk assessment method for LMO used environmental remediation, we engineered Solanum nigrum L, expressing the modified bacterial gene, merB, encoding organomercurial lyase. Two independently isolated transgenic lines produced merB RNA. Transgenic Solanum nigrum leaf discs expressing merB gene showed organic mercury resistance, forming shoots well on growth medium containing $0.5{\mu}M$ methylmercury (II) chloride and $1{\mu}M$ phenylmercuric acetate while control plants breached. Transgenic merB seeds germinated and grew on growth medium containing $2{\mu}M$ methylmercury (II) chloride and phenylmercuric acetate. The merB transgenic plants will be used for risk assessment of natural environment.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.443-448
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• 1999

Tests have been carried out on four concrete containing different levels of silica fume to measure their permeability coefficient using water and oxygen, chloride ion. The total cementitious content was 351kg/㎥, and the water/cementitious materials ratio was 0.55. The results show that a dramatic reduction in permeability of concrete containing silica fume occurs due to formation of a discontinuous macro-pore system which inhibits flow. Porosity estimates from mercury-intrusion porosimetry are used to develop an explanations for the water and air permeability reduction. And, results of the rapid permeability test showed that the resistance of concrete to the penetration of chloride ions increases significantly as a contents of silica-fume is increased. The current intensity passing through the concrete containing silica fume is presented from 664C to 2166C.

• Toxicological Research
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• v.9 no.2
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• pp.159-166
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• 1993

The treatmene of V79 cells with diethyl maleate (DEM) led to decrease in glutathione (GSH) level as increasing DEM concentration. Mercuric chloride, treated for 6 hrs with 2ng/ml, affected the GSH metabolizing enzymes glutathione S-transferase (GST) and glutathione peroxidase (GSP), dropping their activities to 60% and 75%, respectively, though not so much in GSH level(80%). However, the toxic effects of mercuric chloride on those enzymes and GSH level were both amplified when the Hg2+ treatment was combined with the preceding DEM treatment.

• Journal of the Korea Concrete Institute
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• v.21 no.5
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• pp.639-647
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• 2009

In order to evaluate the durability of reinforced concrete structures under chloride attack from sea water and frost damage, it is important to analyze both the microstructural characteristics of concrete and its diffusion resistance of concrete against chloride ingress. In this study, a relation between micro-pore structures of concrete obtained by the Mercury Intrusion Porosimetry and accelerated chloride diffusivity as well as long term chloride diffusivity were studied for ground granulated blast furnace slag(GGBS) concrete. Different water-cement ratio of 40, 45, 50% and different unit cement concrete of 300, 350, 400 or 450 kg/$m^3$ of the GGBS concrete along with OPC concrete were used and freeze and thawing, and the change in diffusivity and microstructure were observed for both GGBS concrete and damaged GGBS concrete due to rapid freezing and thawing.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1134-1137
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• 2002

To investigate the neurotoxic effect of organic chloride on cultured mouse cerebral neurons, cytotoxic effect was measured by MTT assay after cultured cerebral neurons were incubated with various concentrations of methyl mercuric chloride(MMC) for 24 hours. The protective effect of Radix Polygoni Multiflori(RPM) on MMC-induced neurotoxicity was also examined in these cultures. MMC decreased cell viability of cultured mouse cerebral neurons remarkably in a dose- and time-dependent manners. In protective effect of RPM it was remarkably effective in blocking the neuroxicity induced by MMC. From aboved the results, it is suggested that MMC induce neurotoxicity, and the herba extract, RPM is very effective in preventing MMC-induced cytotoxicity on cultured mouse cerebral neurons.

• Journal of the Korea Concrete Institute
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• v.11 no.4
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• pp.31-41
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• 1999

Blended Low Heat type cement is ground granulated blast furnace slag and fly ash mixed ternary with ordinary portland cement. From the viewpoint of X-ray patterns of domestic LHC, the main components of cement such as $C_2$S, $C_3$A, $C_3$S are considerably reduced. Therefore the heat evolution of LHC paste is 42cal/g lower than of OPC paste. At early age, the compressive strength development of LHC concrete is delayed, but the slump loss ratio of fresh concrete is reduced more than 20% with elapsed time. The penetrability of LHC is lower than that of OPC by 1/7.8 with the penetrability of chloride ion into the concrete until the age of 120 days. And the PD Index value of LHC is 0.44$\times$10-6 $\textrm{cm}^2$/s, which indicates only 39.3% of OPC. From the Mercury Intrusion Porosimetry test of cement past, we know that the pore size of LHC is more dense than that of OPC by production of C-S-H.