• 한국재료학회지
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• 제21권9호
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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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• 제24권5호
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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.

• 한국식품과학회지
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• 제39권5호
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• pp.575-579
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• 2007

본 연구는 홍삼 및 농축액의 합리적인 농약잔류허용기준 개정을 위한 과학적인 자료를 얻고자 수행하였다. 인삼 재배 시에 사용 등록된 농약 3종(azoxystrobia, fenhexamid, cyprodinil)을 인삼포에 직접 살포하여 수확한 수삼을 홍삼과 농축액으로 직접 제조하였다. 수확한 수삼에 azoxystrobin 0.12 ppm, fenhexamid 0.19 ppm, cyprodinil 1.78 ppm이 잔류하였으며 농약이 잔류된 수삼을 원료로 홍삼 및 농축액으로 가공하여 각 제품의 농약 잔류량을 조사한 결과 fenhexamid의 경우 홍삼에 0.54 ppm, 홍삼농축액에서 1.93 ppm이 잔류하였다. Azoxysoobin은 홍삼에서 0.24 ppm, 홍삼농축액에서 0.81 ppm이 잔류하여 가공단계를 거치면서 증가하였다. 그러나 cyprodinil의 경우 1.78 ppm이 잔류된 수삼이 홍삼으로 가공되면서 1.49 ppm으로 감소하였으나 홍삼농축액에서는 3.66 ppm으로 증가하였다. 농약이 잔류된 수삼을 이용하여 홍삼과 농축액 제조시 azoxystrobin, fenhexamid, cyprodinil의 감소계수(dry base)는 홍삼에서 0.66, 0.94, 0.28, 홍삼농축액에서 3.25, 4.94, 1.01이였다.

• Applied Science and Convergence Technology
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• 제27권2호
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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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• 제29권4호
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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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• 제20권9호
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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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• 제28권5호
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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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• 제18권5호
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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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• 제41권4호
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• pp.293-301
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• 2013

본 연구에서는 수분 흡착효과가 있다고 알려진 커피박을 첨가하여 중밀도섬유판을 제조한 다음 물성과 강도특성을 조사하여 커피박의 중밀도섬유판 원료로써의 가능성을 확인하고자 하였다. 커피박은 주로 인스턴트커피 제조 시 많이 발생하는 찌꺼기인데 가수분해된 것을 전건무게 기준 3, 6, 9% 수준에서 목섬유와 혼합해 중밀도섬유판을 제조하였으며, 이 때 사용한 접착제는 요소수지접착제였다. 커피박과 목섬유를 섞은 중밀도섬유판에 대해 물성과 강도 특성 및 포름알데히드 방산량을 측정하였다. 커피박과 목섬유를 무작위로 섞어 제조한 중밀도섬유판의 휨강도와 박리강도는 모두 KS 기준보다 높게 나타났으며 커피박을 층으로 구성한 적층 성형구조 경우에는 모두 기준에 미달하였다. 제조된 중밀도섬유판의 흡수 두께팽창률은 시판용 중밀도섬유판보다 낮아 물리적 특성 면에서 현저히 개선됨을 보여주었다. 포름알데히드 방산량은 시판용 중밀도섬유판과 유사한 것으로 나타났으며 모두 KS 기준상의 $E_1$급에 부합하였다. 이런 결과는 커피박이 친환경 중밀도섬유판 제조 시 원재료로 활용될 수 있음을 보여주고 있으며 중밀도섬유판의 성능 향상을 위해서는 접착제와 커피박 간의 상호 접착성 및 커피박의 흡착성능 향상을 위한 전환방법에 대한 추가 연구가 요구된다.

• Journal of Microbiology and Biotechnology
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• 제34권5호
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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.