• Korean Journal of Materials Research
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• v.21 no.9
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• pp.502-508
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• 2011

The goal of the present work was to investigate the development of a geopolymeric ceramic material from a mixture of mine residue, coal fly ash, blast furnace slag, and alkali activator solution by the geopolymer technique. The results showed that the higher compressive strength of geopolymeric ceramic material increased with an increase in active filler (blast furnace slag + coal fly ash) contents and with a reduction of mine residue contents. The geopolymeric ceramic had very high early age strength. The compressive strength of the geopolymeric ceramic depended on the added active filler content. The maximum compressive strength of the geopolymeric ceramic containing 20 wt.% mine residue was 141.2 MPa. The compressive strength of geopolymeric ceramic manufactured by adding mine residue was higher than that of portland cement mortar, which is 60 MPa, when cured for 28 days. SEM observation showed the possibility of having amorphous aluminosilicate gel within geopolymeric ceramic. XRD patterns indicate that the geopolymeric ceramic was composed of amorphous aluminosilicate, calcite, quartz, and muscovite. The Korea Standard Leaching Test (KSLT) was used to determine the leaching potential of the geopolymeric ceramic. The amounts of heavy metals were noticeably reduced after the solidification of mine residue with active filler.

• Archives of Pharmacal Research
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• v.24 no.5
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• pp.446-454
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• 2001

Peptide fragments, isolated from proteolytic cleavage of thyroglobulin at specific sites, were examined for the iodination of tyrosine residues. The 50 kDa polypeptide, which was prepared from digestion of bovine thyroglobulin and continuous preparative SDS-PAGE, was subjected to reduction with DTT and alkylation with iodoacetic acid to generate S-car-boxymethylated peptide derivative, which was further hydrohysed by endoproteinase-Asp-N. Peptide products were separated by RP-HPLC, and each fraction was analyzed by LC/ESI-MS and MALDI-MS analyses. Based on the specificity of endoproteinase-Asp-N andthe mass spectra data, a peptide fragment turned out to correspond to a peptide, DALCCVKCPEGSYFQ (1438-1452), characterized by the presence of a thioredoxin box (CVKC) and a tyrosine residue. In addition, another peptide fragment (1453-1465) containing a thioredoxin box (CIPC) and a tyrosine residue was also observed. However, any evidence of iodination of the tyrosine residue present in these peptides was not provided. Meanwhile, tyrosine residues in the peptides, DVEEALAGKYLAGRFA (1366-1381) and DYSGLLLAFQVFLL (1290-1303) were found to be iodinated; mono- or diiodinated tyrosine residues, characteristic of a hormogenic site, existed in both peptides. In addition, the tyrosine residue in the peptide (1218-1252), corresponding to a hormonogenic site was also iodinated. Thus, there was a sharp difference of the susceptibility to oxidative iodination between the tyrosine residue in a hormonogenic site and that in a thioredoxin region. From these results, it is suggested that polypeptide region adjacent to tyrosine residues may govern the susceptibility of tyrosine to oxidative iodination.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.575-579
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• 2007

This study was performed to acquire scientific data for establishing the maximum residue limits (MRLs) of pesticides in Korean red ginseng and its extract. Pesticides (azoxystrobin, fenhexamid, cyprodinil) were applied to a cultivated field of ginseng, and the fresh ginseng was harvested and processed to make Korean red ginseng and its extract. The reduction rates of the residue pesticides were calculated by determining the pesticide contents in each stage of ginseng processing. The residue levels in fresh ginseng were 0.12 ppm for azoxystrobin, 0.19 ppm for fenhexamid, and 1.78 ppm for cyprodinil. The residue levels in Korean red ginseng were 0.24, 0.54, and 1.49 ppm, and in the extract 0.81, 1.93, and 3.66 ppm for azoxystrobin, fenhexamid, and cyprodinil, respectively. The steaming and processing of fresh ginseng increased azoxystrobin and fenhexamid residues, but cyprodinil was reduced. The reduction rates (dry basis) of azoxystrobin, fenhexamid, and cyprodinil were 0.66, 0.94, and 0.28 for Korean red ginseng, and 3.25, 4.94, and 1.01 for the extract, respectively.

• Applied Science and Convergence Technology
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• v.27 no.2
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• pp.35-37
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• 2018

The redox reaction on graphene nanoribbon (GNR) field effect transistors(FET) has been studied. In detail, upon employing an electrolyte gating, we verified electron transport performance modulation of GNR FET by monitoring conductance variation under oxidation and reduction processes. The conductance enhancement of GNR via removal of PMMA residue on graphene surface during redox cycles was also observed.

• BMB Reports
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• v.29 no.4
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• pp.321-326
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• 1996

Spinach glycolate oxidase was subjected to a series of chemical modifications aimed at identifying amino acid residues essential for catalytic activity. The oxidase was reversibly inactivated by treatment with pyridoxal 5'-phosphate (PLP). The inactivation by PLP was accompanied by the appearance of an absorption peak of around 430 nm, which was shifted to 325 nm upon reduction with $NaBH_4$. After reduction, the PLP-treated oxidase showed a fluorescence spectrum with a maximum of around 395 nm by exciting at 325 nm. The substrate-competitive inhibitors oxalate and oxaloacetate provided protection against inactivation of the oxidase by PLP. These results suggest that PLP inactivates the enzyme by fonning a Schiff base with lysyl residue(s) at an active site of the oxidase. The enzyme was also inactivated by tryptophan-specific reagent N-bromosuccinimide (NBS). However, competitive inhibitors oxalate and oxaloacetate could not protect the oxidase significantly against inactivation of the enzyme by NBS. The results implicate that the inactivation of the oxidase by NBS is not directly related to modification of the tryptophanyl residue at an active site of the enzyme. Treatments of the oxidase with cysteine-specific reagents iodoacetate, silver nitrate, and 5,5'-dithiobis-2-nitrobenzoic acid did not affect significantly the activity of the enzyme.

• Fisheries and Aquatic Sciences
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• v.20 no.9
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• pp.22.1-22.6
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• 2017

The antihyperlipidemic and antioxidant activities of dietary supplementation of sea tangle from Goseong and the alginate-free residue of sea tangle were investigated in Sprague Dawley rats treated with a high-fat diet, streptozotocin, poloxamer 407, and bromobenzene. The alginate-free residue of Goseong sea tangle induced a significant reduction in triglycerides and total cholesterol levels, as well as a significant increase in high-density lipoprotein cholesterol levels. Alginate-free Goseong sea tangle residue reduced the activities of the phase I enzymes aminopyrine N-demethylase and aniline hydroxylase, which had been increased by intraperitoneal injection of bromobenzene. Pretreatment with Goseong sea tangle residue prevented a bromobenzene-induced decrease in epoxide hydrolase activity. Bromobenzene reduced hepatic glutathione content and increased hepatic lipid peroxide levels. Pretreatment with alginate-free Goseong sea tangle residue prevented lipid peroxidation induced by bromobenzene, but pretreatment with Goseong sea tangle did not. These results suggest that Goseong sea tangle residue exerted antihyperlipidemic and antioxidant activities that were higher than those induced by alginate-containing sea tangle. Therefore, the alginate-free residue may contain physiologically unknown active components, other than alginic acid, which may potentially be used to prevent hyperlipidemic atherosclerosis.

• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.772-776
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• 2007

In order to study the role of residue in the active site of glutathione S-transferase (GST), Arg13 residue in human GST P1-1 was replaced with alanine, lysine and leucine by site-directed mutagenesis to obtain mutants R13A, R13K and R13L. These three mutant enzymes were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized GSH. Mutation of Arg13 into Ala caused a substantial reduction of the specific activity by 10-fold. Km GSH, Km DCNB and Km EPNP values of R13A were approximately 2-3 fold larger than those of the wild type. Mutation of Arg13 into Ala also significantly affected I50 values of S-methyl-GSH that compete with GSH and ethacrynic acid, an electrophilic substrate-like compound. These results appeared that the substitution of Arg13 with Ala resulted in significant structural change of the active site. Mutation of Arg13 into Leu reduced the catalytic activity by approximately 2-fold, whereas substitution by Lys scarcely affected the activity, indicating the significance of a positively charged residue at position 13. Therefore, arginine 13 participates in catalytic activity as mainly involved in the construction of the proper electrostatic field and conformation of the active site in human GST P1-1.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1076-1082
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• 2009

Six pesticides were determined in hot pepper leaves after successive processing steps of washing, blanching, and drying. The tested pesticides included dichlofluanid, flusilazole, folpet, iprodione, ${\lambda}$-cyhalothrin, and lufenuron. Each pesticide was singly applied to the leaves of the pepper plants, which were being cultivated in a greenhouse. The processing factors were dependent on the type of pesticide, and were in the following ranges: 0.09-0.73 by washing, <0.00-0.48 after blanching, and <0.00-3.30 after drying. Only lufenuron showed a processing factor of more than 1, at 3.30 in dried leaves, while the processing factors of the other pesticides were less than 1. The removal ratios of the tested pesticides by washing ranged from 27 to 90%. The blanching step increased their removals by 10-25%. However, drying did not have an effect on residue reduction. Finally, after proceeding to the drying step, removal ratios ranged from 85 to 100%, with the exception of lufenuron at 47%.

• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.293-301
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• 2013

This study discusses the feasibility of coffee bean residue as a raw material of medium-density fiberboard (MDF). In this relation, the effect of coffee bean residue known as an absorbent material on the physical and mechanical properties of MDF manufactured at its different addition level. Coffee bean residue which is a by-product of coffee mill and large amount of waste left over after processing for instant coffee was added at the level of 3, 6, and 9% on dry basis and urea formaldehyde resin was used as the adhesive. The MDF made with mixture of wood fiber and coffee bean residue was tested for physical and mechanical properties as well as formaldehyde emission. The bending strength and internal bonding strength of the MDF made with mixture of wood fiber-coffee bean residue were higher than that of the KS standard in randomized mat structure type, but not in layered mat structure type. Also, the physical properties of MDF made with mixture of wood fiber-coffee bean residue showed a considerable improvement in thickness swelling over the commercial MDF. More importantly, the formaldehyde emission rate of MDF made with mixture of wood fiber-coffee bean residue met the KS standard and was close to that of commercial MDF. These results showed the feasibility of coffee bean residue as a raw material for the production of environmentally-friendly MDF. Additional works on adhesive-coffee bean compatibility, improvement of moisture absorption effect and reduction the formaldehyde emission rate by carbonization of coffee bean residue may be required.

• Journal of Microbiology and Biotechnology
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• v.34 no.5
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• pp.1040-1050
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• 2024

To isolate and analyze bacteria with Verticillium wilt-resistant properties from the fermentation residue of kitchen wastes, as well as explore their potential for new applications of the residue. A total of six bacterial strains exhibiting Verticillium wilt-resistant capabilities were isolated from the biogas residue of kitchen waste fermentation. Using a polyphasic approach, strain ZL6, which displayed the highest antagonistic activity against cotton Verticillium wilt, was identified as belonging to the Pseudomonas aeruginosa. Bioassay results demonstrated that this strain possessed robust antagonistic abilities, effectively inhibiting V. dahliae spore germination and mycelial growth. Furthermore, P. aeruginosa ZL6 exhibited high temperature resistance (42℃), nitrogen fixation, and phosphorus removal activities. Pot experiments revealed that P. aeruginosa ZL6 fermentation broth treatment achieved a 47.72% biological control effect compared to the control group. Through activity tracking and protein mass spectrometry identification, a neutral metalloproteinase (Nml) was hypothesized as the main virulence factor. The mutant strain ZL6ߡNml exhibited a significant reduction in its ability to inhibit cotton Verticillium wilt compared to the strain P. aeruginosa ZL6. While the inhibitory activities could be partially restored by a complementation of nml gene in the mutant strain ZL6CMߡNml. This research provides a theoretical foundation for the future development and application of biogas residue as biocontrol agents against Verticillium wilt and as biological preservatives for agricultural products. Additionally, this study presents a novel approach for mitigating the substantial amount of biogas residue generated from kitchen waste fermentation.