• Journal of Life Science
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• v.11 no.3
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• pp.259-265
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• 2001

Mercury vapor inhalation-induced acute respiratory failure(ARF) has been reported to be fatal. This study was designed to observe the possible mechanism of inhaled mercury vapor poisoning in the respiratory system. Sixty percent of rats(12/20) exposed to mercury vapor were dead within 72 hours of exposure whereas all the rats(20/20) exposed to mercury vapor combined with dithiothreitol(DTT) vapor survived. The histological observation showed that ARF was a direct cause of the death induced by mercury vapor inhalation, which was significantly circumvented by DTT vapor. Cyclic AMP mediated chloride secretion was inhibited by luminal side but not serosal side sulfhydryl blocking agents (Hf$^{2+}$ $\rho$-chloromercuribenzoic acid or $\rho$-chloromercuriphenyl sulfonic acid) in a dose-dependent manner in a primary cultured rat airway monolayer. The inhibitory component of cAMP induced chloride secretion was completely restored by luminal side DTT(0.5mM). these results suggest that the oxidized form(Hg$^{2+}$) of mercury vapor(Hg0) contribute to ARF and subsequent death. The finding is important as it can provide important information regarding emergency manipulation of ARF patients suffering from by mercury vapor poisoning.ing.

• Korean Journal of Materials Research
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• v.30 no.8
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• pp.393-398
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• 2020

We propose a novel stripping solution containing acids (HCl and HNO₃), an oxidant [(NH₄)₂S₂O₈], and complexing agents (NaCl and citric acid) to remove surface passivation layers from 14K gold alloys fabricated using an investment casting process. The optimized solution employing only HCl acid is determined by varying molar fractions of HCl and HNO₃ on 14K yellow gold samples. Stripping properties are also identified for red and white gold alloy samples under the optimized stripping conditions. The removal of passivation layers, weight loss, and microstructure evolution are characterized using Raman spectroscopy, a precision scale, and optical microscopy. The proposed stripping solution effectively removes passivation layers more rapidly than conventional cyanide stripping. Weight loss increases linearly for up to 5 min for all 14K gold alloys. Red gold exhibits the greatest weight loss, followed by yellow gold and white gold. The results of microstructural analysis reveal that the conformal stripping occurs according to time. These results imply that the proposed oxidative chloride stripping might replace conventional cyanide stripping.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.233-239
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• 2005

Lipid-soluble fractions extracted with methylene chloride and ethyl acetate as well as 70% ethanolic extract were made from 5 cultivars of the pigmented rice brans (DZ 78, Elwee, LK1A-2-12-1-1, LK1-3-6-12-1-1 and Killimhukmi) to determine their antioxidative activities and to measure the contents of phenolic compounds, phytic acid, together with unsaponificated compounds such as retinol, tocopherol and stigmasterol. We also attempted to characterize candidate components in charge of antioxidation and measure their relative contents in each methylene chloride and ethyl acetate fraction by using GC-MS techniques. As the results, we found a 30% higher antioxidative activity with 26-fold greater phenolic compound content of the pigmented rices as compared to those of the normal rice. Especially, in Killimhukmi, the contents of the unsaponificated compounds such as retinol, tocopherol and stigmasterol were also found to be more than 2.3-fold greater than those of normal rice. However, we could not find the overall correlations between antioxidativity of rices and their color values, or unsaponificated compounds contents. Methylene chloride fraction from Killimhukmi and LK1A-2-12-1-1, both showing strong antioxidativity, contained relatively high contents of (Z)-9-hexadecenyl ester-9-octadecanoic acid and 2-Hydroxyl-1-1(hydroxymethyl) ethyl-9-octadecanoic acid, respectively. In ethyl acetate fractions, on the contrary, 1H indene, methyl ester-tetradecanoic acid and methyl ester-hexadecanoic acid were detected as the commonly-occurring substances in the 5 cultivars of pigmented rices, implying a possible role in antioxidative action.

• Resources Recycling
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• v.16 no.5
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• pp.8-12
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• 2007

Anhydrous magnesium chloride, dehydration product from magnesium chloride hydrate is a general raw material to prepare electrolytic magnesium. However, the dehydration is not trivial and can be accompanied by hydrolysis leading to the production of undesirable hydroxy chloride compounds of magnesium. Therefore, dehydration process is actually the most complicated and hardest in the electrolysis methods for the production of magnesium. In this work, the influence of dehydrating temperature has been studied at the temperature range from $200^{\circ}C$ to $600^{\circ}C$ in air and HCl gas atmosphere individually to compare the results. With increasing of dehydration temperature MgOHCl and MgO were obtained in air. On the other hand, when the temperature was increased above $300^{\circ}C$ anhydrous magnesium chlorides were prepared in HCl gas atmosphere. Anhydrous magnesium chloride was formed at near $300^{\circ}C$ and completely crystallized at about $500^{\circ}C$. All of the HCl used as atmosphere gas in the dehydration was recovered as hydrochloric acid solution at a water vessel up to 41% by weight at $20^{\circ}C$.

• Applied Biological Chemistry
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• v.31 no.4
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• pp.376-381
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• 1988

The optimal reaction conditions were investigated to produce L-phenylalanine from transcinnamic acid and ammonia by Rhodotorula glutinis IFO 0559. The highest amount of L-phenylalanine was produced when the reaction mixture containing 200mM of traps-cinnamic acid, 4M of $NH_4OH$, 250mM of $(NH_4)_2SO_4$, 0.005% of cetylpyridinium chloride (pH 10.5) and 50mg/ml of dry cell was used. Among the nonaqueous organic solvents, petroleum ether was the most effective on the production of L-phenylalanine. The optimal concentration of petroleum ether in the reaction mixture was 50%. Under the optimal conditions, 21.1g/l of L-phenylalanine was produced in 12hr, and the yield was 63.9% based on transcinnamic acid.

• Journal of the Korean Chemical Society
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• v.5 no.1
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• pp.38-41
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• 1961

By varying groups on biologically active molecules, it is possible to produce analogues which sometimes inhibit the action of the parent compound. Such is true of taurine(${\beta}$-amino-ethane sulfonic acid)as an analogue of ${\beta}$-alanine and of pantoyl taurine for pantothenic acid. It seemed possible that the sulfonic acid analogues of amino acids built into peptides might possibly produce inhibition of the parent peptide. Tauryl-L-histidine was selected to prepare as an analogue of carnosine(${\beta}$-alanyl-L-histidine). There were several reasons for this choice. Camosine causes a slight contraction of isolated uterine muscle and inhibition of this action can be easily tested. Also, taurine, being a ${\beta}$-amino sulfonic acid, is much more stable than the ${\beta}$-amino sulfonic acids. Phthalyl tauryl-L-histidine methyl ester was prepared by condensing phthalyl tauryl chloride with histidine methyl ester in chloroform. The yields were quite low possibly due to reaction between the acid chloride and the imidazole of histidine. Approximately 50 per cent yield of crude amorphous product was obtained, but upon purification by crystallization they yielded only 25 percent of a pure product. The methyl ester was removed by acid hydrolysis to prevent partial cleavage of the phthalyl group. Crystalline tauryl histidine was then obtained from this acid by removal of the phthalyl group by hydrazinolysis. Tests for inhibition were carried out by comparing the action of camosine on isolated uterine muscle before and after tauryl histidine had been added to the bath surrounding the muscle strip. Only in very high relative concentrations of tauryl histidine was there any demonstrable inhibition.

• Korean Journal of Hazardous Materials
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• v.2 no.1
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• pp.6-11
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• 2014

There have been frequent chemical leaks over the past 10 years. Particularly, inorganic acids like sulfuric acid, nitric acid, and hydrogen chloride take up 37 % of the total chemical accidents which took place for the past 10 years. When an acid chemical leak happens, fume is generated, diffusing into the air, which might cause serious damage to health of local residents and the environment. However, most of the acid-based chemicals, detecting and analysis methods have not been settled considering the frequency of accidents. In this study, we investigated detection and analysis methods to quickly analyze accident sites and evaluate the impacts on environments. Reviewing local and international test analysis methods of acids suggested that nitric acid, sulfuric acid, hydrogen chloride and hydrogen fluoride can be analyzed with IC. It was also found that UV is better for the analysis of hydrogen fluoride and GC/MS for acrylic acid. The analytical methods suggested in the official test methods basically have limitations of consuming much time at stages of preparation and analysis. Considering prompt responses to chemical accidents, further studies should be done to compare the applicability of rapid monitoring methods such as FT-IR, IMR-MS and SIFT-MS.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.578-581
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• 2006

This study was performed to develop acid-soluble extraction solution and water-soluble extraction solution for hardened concrete. By use of this potentiometric method one can determinate chloride ion concentration in hardened concrete without pre-treatment and it can be used on-site.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.385.1-385.1
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• 2002

Cordyceps has been used as a tonic for replenishing vital function in Chinese traditional medicines. As an attempt to obtain fundamental data for the kidney function, MeOH Ex. and its hexane. ethyl acetate, butanol and water fractions of cultivated Cordyceps pruinosa on mercuric chloride induced renal failure rats were investigated. Urin volume. blood parameters(urea nitrogen. uric acid. creatinine) and urinary electrolytes content (natrium. potassium. chloride) were determined. MeOH extract and butanol fraction showed diuretic effect. (omitted)

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.546-554
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• 2006

To understand antitumor activity of Zanthoxylum schinfolium, which has been used as an aromatic and medicinal plant in Korea, the cytotoxic effect of various organic solvent extracts of its leaves on human tumor cells were investigated. Among these extracts such as methanol extract (SL-13), methylene chloride extract (SL-14), ethyl acetate extract (SL-15), n-butanol extract (SL-16), and residual fraction (SL-17), SL-14 appeared to contain the most cytotoxic activity against leukemia and breast cancer cells tested. The methylene chloride extra.1 (SL-14) possessed an apoptogenic activity causing apoptotic DNA fragmentation of human acute leukemia Jurkat T cells via mitochondrial cytochrome c release into cytoplasm, subsequent activation of caspase-9 and caspase-3, and cleavage of PARP, which could be negatively regulated by antiapoptotic protein Bcl-xL. The GC-MS analysis of SL-14 revealed that the twenty-two ingredients of SL-14 were 9,19-cyclolanost-24-en-3-ol (15.1%), 2-a-methyl-17, b-hop-21-ene (15.1%), 15-methyl-2,3-dihydro-1H benzazepin (11.95%), phytol (10.38%), lupeol (9.92%), 12-methylbenzofuran (8.23%), hexadecanoic acid (5.96%), cis,cis,cis-9,12,15-octadecatrienoic acid-methyl-ester (5.49%), 9,12,15-octadecatrienoic acid-methylester (3.59%), 15-methyl-4-(1-methylethylidene)-2-(4-nitrophenyl) (3.36%), hexadecanoic acid methyl ester (1.93%), vitamine E (1.88%), beta-amyrin (0.96%), and auraptene (0.89%). These results demonstrate that the cytotoxicity of the methylene chloride extract of the leaves of Z. schinifolium toward Jurkat T cells is mainly attributable to apoptosis mediated by mitochondria-dependent caspase cascade regulated by Bcl-xL, and provide an insight into the mechanism underlying antitumor activity of the edible plant Z. schinifolium.