• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.1
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• pp.55-66
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• 1996

This study was conducted to evaluate breakthrough characteristics of respirator cartridge using multi-organic vapors, including carbon tetrachloride, trichloroethylene, and toluene. The organic vapors were used as single phase, binary system, and ternary system. The results are summarized as follows. 1. Organic vapors studied were 1,000 ppm, 750 ppm, 500 ppm and 250 ppm in single phase. Carbon tetrachloride having the highest molecular weight showed the breakthrough first, and breakthrough sequency by organic vapor was dependent on its molecular weight. The 10% breakthrough times at 1,000 ppm of organic vapor were 97 minutes for carbon tetrachloride, 129 minutes for trichloroethylene and 135 minutes for toluene. 2. When concentrations of organic vapors were at levels of the Threshold Limit Values, the lives of the respirator cartridges were 122 hours in carbon tetrachloride, 18 hours in trichloroethylene and 28 hours in toluene. 3. In the binary system at a total concentration of 1,000 ppm with carbon tetrachloride and trichloroethylene, breakthrough times ranged from 104 minutes to 125 minutes, which were longer than 97 minutes in a single phase (1,000 ppm) for carbon tetrachloride, but shorter than breakthrough times for TCE and Toluene. 4. Breakthrough times in the binary system with carbon tetrachloride and toluene were 131~132 minutes. 5. Breakthrough times in the ternary system with carbon tetrachloride, toluene, and trichloroethyl ene were $120{\pm}8$ minutes, which were longer than 97 minutes in the single phase (1,000 ppm) for carbon tetrachloride, equal to 129 minutes for trichloroethylene, and shorter than 135 minutes for toluene. Those were almost similar to $124{\pm}9$ minutes of breakthrough times in the binary systems.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.1
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• pp.1-8
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• 2018

The nerippe fritillary butterfly, Argynnis nerippe, is listed as an endangered species in Korea. Establishment of effective conservation strategies can be aided by the development and application of molecular markers that can be used to investigate the population genetics of the butterfly. Therefore, in this study, we identified ten microsatellite markers specific to A. nerippe using the Next-Seq 500 platform, and applied these markers to investigate the characteristics of five South Korean butterfly populations. Genotyping of 48 A. nerippe individuals from five localities showed that at each locus the number of alleles ranged from 4 to 14, and that the observed and expected heterozygosities were 0.324-0.863 and 0.138-0.985, respectively. Significant deviation from the Hardy-Weinberg equilibrium was not observed at any locus. Population structure analysis indicated that there are two genetic groups in Korea, but no population-based gene pool assignments were found. Analysis of $F_{ST}$, $R_{ST}$, and a principal coordinates analysis suggested that the Gureopdo and Yaecheon populations were isolated from other populations. Genetic isolation of the Gureopdo population may be a consequence of unequal population change between Gureopdo and inland populations and to the offshore habitat of Gureopdo. Genetic isolation of the Yaecheon population may be a consequence either of the southernmost location of the population or of the limited sample size available. Further studies with increased sample sizes will be necessary to draw robust conclusions on population isolation and to devise conservation strategies.

• Development and Reproduction
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• v.13 no.2
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• pp.63-77
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• 2009

The neuronal ceroid-lipofuscinoses (NCLs) are a kind of neurodegenerative storage disorders. The NCLs are charecterizated by accumulation of autofluorescent lipofuscin or lipopigment in the brain. All NCL group belongs to in lysosomal storage disorders (LSDs), except Northern epilepsy. NCLs are the most common group of progressive neurodegenerative disorders in childhood, with an incidence as high as I in 12,500 live births. Four main clinical types have been described based on the onset age : infantile, late infantile, juvenile and adult types. Clinical symptoms of NCLs include loss of vision, seizures, epilepsy, progressive mental retardation and a premature death. Although mutation causes neurodegeneration in NCLs, the molecular mechanism by which mutation leads to neurodegeneration remains unclear. In this paper, we review the characteristics of these NCLs.

• Microbiology and Biotechnology Letters
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• v.13 no.1
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• pp.41-49
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• 1985

Bacillus sphaericus was mutagenized with UV light irradiation and dimethyl sulfate. Thirty-five conditional lethal temperature-sensitive(ts) mutants were isolated at the nonpermissive temperature of $42^{\circ}C$ and classified into three groups by their growth characteristics on the nutrient broth, peptone glucose yeast extract agar and mineral salts agar. First was the lethal ts group, 24 mutants, which did not grow at the nonpermissive temperature, the second, 9 mutants, was the less growth is group whose growth was restricted to one-half, and the third, 2 mutants, was the cold lethal ts group whose growth was restricted at the permissive temperature($25^{\circ}C$and $30^{\circ}C$)

• Journal of Microbiology and Biotechnology
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• v.30 no.2
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• pp.271-278
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• 2020

Glycerol dehydrogenase (GlyDH) catalyzes the oxidation of glycerol to dihydroxyacetone (DHA), which is the first step in the glycerol metabolism pathway. GlyDH has attracted great interest for its potential industrial applications, since DHA is a precursor for the synthesis of many commercially valuable chemicals and various drugs. In this study, GlyDH from Klebsiella pneumoniae (KpGlyDH) was overexpressed in E. coli and purified to homogeneity for biochemical and molecular characterization. KpGlyDH exhibits an exclusive preference for NAD⁺ over NADP⁺. The enzymatic activity of KpGlyDH is maximal at pH 8.6 and pH 10.0. Of the three common polyol substrates, KpGlyDH showed the highest k_cat/K_m value for glycerol, which is three times higher than for racemic 2,3-butanediol and 32 times higher than for ethylene glycol. The k_cat value for glycerol oxidation is notably high at 87.1 ± 11.3 sec^-1. KpGlyDH was shown to exist in an equilibrium between two different oligomeric states, octamer and hexadecamer, by size-exclusion chromatography analysis. KpGlyDH is structurally thermostable, with a T_m of 83.4℃, in thermal denaturation experiment using circular dichroism spectroscopy. The biochemical and biophysical characteristics of KpGlyDH revealed in this study should provide the basis for future research on its glycerol metabolism and possible use in industrial applications.

• Journal of Animal Science and Technology
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• v.54 no.6
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• pp.383-394
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• 2012

Microarray analyses provide information that can be used to enhance the efficiency of livestock production. For example, microarray profiling can potentially identify the biological processes responsible for the phenotypic characteristics of porcine liver. We performed transcriptome profiling to identify differentially expressed genes (DEGs) in liver of pigs from two breeds, the Korean native pigs (KNP) and Yorkshire pigs. We correctly identified expected DEGs using factor analysis for robust microarray summarization (FARMS) and robust multi-array average (RMA) strategies. We identified 366 DEGs in liver (p<0.05, fold-change>2). We also performed functional analyses, including gene ontology and molecular network analyses. In addition, we identified the regulatory relationship between DEGs and their transcription factors using in silico and qRT-PCR analysis. Our findings suggest that DEGs and their transcription factors may have a potential role in adipogenesis and/or lipid deposition in liver tissues of two pig breeds.

• Journal of Microbiology and Biotechnology
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• v.21 no.12
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• pp.1312-1321
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• 2011

Enzyme extracts of cellulase [filter paper cellulase (FPase) and carboxymethyl cellulase (CMCase)], chitinase, and chitosanase produced by Aspergillus niger NRRL-567 were evaluated. The interactive effects of initial moisture and different inducers for FP cellulase and CMCase production were optimized using response surface methodology. Higher enzyme activities [FPase $79.24{\pm}4.22$ IU/gram fermented substrate (gfs) and CMCase $124.04{\pm}7.78$ IU/gfs] were achieved after 48 h fermentation in solid-state medium containing apple pomace supplemented with rice husk [1% (w/w)] under optimized conditions [pH 4.5, moisture 55% (v/w), and inducers veratryl alcohol (2 mM/kg), copper sulfate (1.5 mM/kg), and lactose 2% (w/w)] (p<0.05). Koji fermentation in trays was carried out and higher enzyme activities (FPase $96.67{\pm}4.18$ IU/gfs and CMCase $146.50{\pm}11.92$ IU/gfs) were achieved. The nonspecific chitinase and chitosanase activities of cellulase enzyme extract were analyzed using chitin and chitosan substrates with different physicochemical characteristics, such as degree of deacetylation, molecular weight, and viscosity. Higher chitinase and chitosanase activities of $70.28{\pm}3.34$ IU/gfs and $60.18{\pm}3.82$ to $64.20{\pm}4.12$ IU/gfs, respectively, were achieved. Moreover, the enzyme was stable and retained 92-94% activity even after one month. Cellulase enzyme extract obtained from A. niger with chitinolytic and chitosanolytic activities could be potentially used for making low-molecular-weight chitin and chitosan oligomers, having promising applications in biomedicine, pharmaceuticals, food, and agricultural industries, and in biocontrol formulations.

• Journal of Conservation Science
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• v.36 no.2
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• pp.103-111
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• 2020

To compare the cleaning effect of solvents such as water and ethanol used to clean lacquer relics, the components extracted with various solvents were analyzed. A freshly dried lacquer sample and a lacquer sample exposed to ultraviolet radiation for 24 days were treated with water, ethanol, acetone, and hexane, and the dissolved material was detected by pyrolysis-gas chromatography-mass spectrometry. The amount extracted was significantly higher in acetone and ethanol than in hexane, a nonpolar solvent. Water, a highly polar solvent, was relatively efficient for extracting low-molecular-weight materials. After experiencing 24 days of ultraviolet radiation, the lacquer exhibited a significant increase of extracted materials compared with the nonexposed one. This may be due to the degradation of the urushiol chain in the form of polymers, resulting in the formation of low-molecular-weight polar substances, including dicarboxylic acids. In addition to the deterioration status of lacquer relics, such solvent extraction properties will be a crucial consideration in selecting the appropriate cleaning solvent.

• Fisheries and Aquatic Sciences
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• v.14 no.1
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• pp.43-54
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• 2011

Gene structure of copper/zinc-superoxide dismutase (Cu/Zn-SOD; sod1) was characterized in Hemibarbus mylodon (Teleostei; Cypriniformes), an endangered freshwater fish species in Korean peninsula. Full-length cDNA of H. mylodon SOD1 consisted of a 796-bp open reading frame sequence encoding 154 amino acids, and the deduced polypeptide sequence shared high sequence homology with other orthologs, particularly with regard to metal-coordinating ligands. Genomic structure of the H. mylodon sod1 gene (hmsod1; 1,911 bp from the ATG start codon to the stop codon) was typical quinquepartite (i.e., five exons interrupted by four introns); the lengths of the exons were similar among species belonging to various taxonomic positions. The molecular phylogeny inferred from sod1 genes in the teleost lineage was in accordance with the conventional taxonomic assumptions. 5'-flanking upstream region of hmsod1, obtained using the genome walking method, contained typical TATA and CAAT boxes. It also showed various transcription factor binding motifs that may be potentially involved in stress/immune response (e.g., sites for activating proteins or nuclear factor kappa B) or metabolism of xenobiotic compounds (e.g., xenobiotic response element; XRE). The hmsod1 transcripts were ubiquitously detected among tissues, with the liver and spleen showing the highest and lowest expression, respectively. An experimental challenge with Edwardsiella tarda revealed significant upregulation of the hmsod1 in kidney (4.3-fold) and spleen (3.1-fold), based on a real-time RT-PCR assay. Information on the molecular characteristics of this key antioxidant enzyme gene could be a useful basis for a biomarker-based assay to understand cellular stresses in this endangered fish species.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.315-320
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• 2014

Purpose: The purpose of this study was to investigate the recurrence pattern and characteristics of patients based on the 2013 St. Gallen surrogate molecular subtypes after breast-conserving surgery (BCS) in Chinese women. Methods: This retrospective analysis included 709 consecutive breast cancer patients undergoing BCS from 1999-2010 at our institution. Five different surrogate subtypes were created using combined expression of the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2. Locoregional relapse-free survival (LRRFS), distant metastasis-free survival (DMFS), and disease-free survival (DFS) rates were calculated. Results: The 5-year LRRFS, DMFS, and DFS rates were 90.5%, 88.2%, and 81.5%, respectively. Multivariate analysis revealed that young age, node-positive disease, and HER2 enrichment were independent prognostic factors in LRRFS patients. There was also an independent prognostic role of lymph node-positive disease in DMFS and DFS patients. Patients with luminal A tumors had the most favorable prognosis, with LRRFS, DMFS, and DFS rates of 93.2%, 91.5%, and 87.4% at 5 years, respectively. Conversely, HER-2-enriched tumors exhibited the highest rate of locoregional recurrence (20.6%). Conclusion: Surrogate subtypes present with significant differences in RFS, DMFS, and LRRFS. Luminal A tumors have the best prognosis, whereas HER2-enriched tumors have the poorest.