• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1502-1510
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• 2018

Organic solvent-tolerant (OST) enzymes are widely applied in various industries for their activity and stability in organic solvents, for their higher substrate solubility, and for their greater stero-selectivity. However, the criteria for identifying OST enzymes largely remain undefined. In this study, we compared the amino acid composition of 19 OST esterases with that of 19 non OST esterases. OST esterases have increased the ratio of Ala and Arg residues and decreased the ratio of Asn, Ile, Tyr, Lys, and Phe residues. Based on our amino acid composition analysis, we cloned a carboxylesterase (EstSP2) from a psychrophilic bacterium, Sphingomonas glacialis PAMC 26605, and characterized its recombinant protein. EstSP2 is a substrate specific to p-nitrophenyl acetate and hydrolyzed aspirin, with optimal activity at $40^{\circ}C$; at $4^{\circ}C$, the activity is approximately 50% of its maximum. As expected, EstSP2 showed tolerance in up to 40% concentration of polar organic solvents, including dimethyl sulfoxide, methanol, and ethanol. The results of this study suggest that selecting OST esterases based on their amino acid composition could be a novel approach to identifying OST esterases produced from bacterial genomes.

• Journal of Veterinary Clinics
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• v.18 no.4
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• pp.358-362
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• 2001

Brain dead (BD) patients remain the largest source of solid organs for transplantation. BD has shown to decrease graft function and survival in rodent models. The aim of this study was to evaluate how brain death affects graft viability in the donor and kidney tolerance to cold preservation as assessed by survival in a canine transplantation. 13 Beagle dogs were used for the study. Brain death was induced by the sudden inflation of a subdural balloon catheter with continuous monitoring of arterial blood pressure and eletroencephalographic activity (n=3). Sixteen hours after conformation of brain death, kidney graft were retrieved (n=6). Non-BD donors served as controls (n=4). All kidneys were flushed with University of Wisconsin (UW) solution and preserved for 24 hours at 4$^{\circ}C$ before transplantation. Recipient survival rates, serum creatinine level were analyzed. Brain death induced the well-known Cushing reaction with a severe increase in blood pressure and tachycardia. Thereafter, cardiac function returned progressively to baseline within 8 hours and remained stable until the end of the experiment. All of dogs in both group transplanted were survived until 7 days (100%), and the kidneys showed functional early rejection at 8.3$\pm$0.5 days and 8.5$\pm$0.5 days after transplantation, in BD and allograft group, respectively. BD kidneys were functionally similar to control kidneys for 7 days after transplantated. Brain death has no deleterious effect on preservation injury and survival of dog kidney transplantation, although it induces changes in hemodynamic parameters. This study reveals that kidneys from BD donors do not exhibit more ischemia reperfusion injury, and support good early function and survival.

• Weed & Turfgrass Science
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• v.2 no.3
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• pp.292-297
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• 2013

Winter turfgrass injury is one of the critical problems of many golf courses in Korea. Turfgrass loss from freezing injury due to low temperature leads to many types of damages including weed invasion, increased herbicide cost, increased soil erosion, and expensive re-establishment. Although Kentucky bluegrass (Poa pratensis L.) which is the most widely used among cool-season grasses in Korea is well known as cold tolerance species, freezing injuries to Kentucky bluegrass during winter are often found. Protecting the turfgrass crown is necessary to recover from low temperature stress in winter because shoots and roots can be recovered from the crown. Turf covers may protect the crowns from direct low temperatures and desiccation. Six different turf covers were installed to cover Kentucky bluegrass during a period of low temperatures. Turf covers had positive effects for spring green-up of Kentucky bluegrass based on the study. Applying any type of turf covers on Kentucky bluegrass resulted in an increase average and minimum temperature compared to the uncovered plot. Among turf covers, clear PVC film without holes produced the longest root length and the highest turfgrass quality.

• Journal of Plant Biotechnology
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• v.39 no.3
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• pp.175-181
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• 2012

Drought and high salinity stresses often imposes adverse effects on crop yield. MYB transcription factors have been shown to be an important regulator in defense responses to these environmental stresses. In this study, we have cloned and characterized a soybean gene GmMYB184 (Glycine max MYB transcription factor 184). Deduced amino acid sequences of GmMYB184 show highest homology with that from Vitis vinifera legume plant (75%). Different expression patterns of GmMYB184 mRNA were observed subjected to drought, cold, high salinity stress and abscisic acid treatment, suggesting its role in the signaling events in the osmotic stress-related defense response. Subcellular localization studies demonstrated that the GFP-GmMYB184 fusion protein was localized in the nucleus. Using the yeast assay system, the C-terminal region of GmMYB184 was found to be essential for the transactivation activity. These results indicate that the GmMYB184 may play a role in abiotic stress tolerance in plant.

• Journal of Powder Materials
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• v.14 no.3 s.62
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• pp.202-207
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• 2007

Novel polymer mold process for fabrication of microcomponents using metal nanopowders was developed and experimentally optimized. Polymer mold for forming green components was produced by using a hard master mold and polydimethylsiloxane (PDMS). In the preparation of metallic powder premix for the green components without any defect, 90 wt.% 17-4PH statinless steel nanopowders and 10 wt.% organic binder were mixed by a ball milling process. The green components with very clear gear shape were formed by filling the powder premix into the PDMS soft mold in surrounding at about $100^{\circ}C$. Cold isostatic pressing (CIP) was very potent process to decrease a porosity in the sintered microcomponent. The microgear fabricated by the improved process showed a good dimension tolerance of about 1.2%.

• Journal of Microbiology and Biotechnology
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• v.21 no.7
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• pp.697-702
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• 2011

A strain of the cyanobacterium Arthrospira was isolated from Lake Chahannaoer in northern China and was characterized according to microscopic morphology, photosynthetic oxygen-evolving activity, growth rate, and nutritional profile. Compared with thermophilic Arthrospira species occurring naturally in tropical and subtropical lakes, this isolate is mesophilic and grows optimally at ${\sim}20^{\circ}C$. The total protein, fatty acid, phycocyanin, carotenoid, and chlorophyll a contents were 67.6, 6.1, 4.32, 0.29, and 0.76 grams per 100 grams of dry weight, respectively. The strain is rich in polyunsaturated fatty acids (PUFAs). An essential omega-3 fatty acid, docosahexaenoic acid (DHA), was detected, and ${\gamma}$-linolenic acid (GLA) and DHA accounted for 28.3% of the total fatty acid content. These features of this newly isolated strain make it potentially useful in commercial mass culture in local areas or as a biofuel feedstock. It is also an alternative resource for studying the metabolic PUFA pathways and mechanisms of cold stress tolerance in cyanobacteria.

• Journal of Environmental Science International
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• v.31 no.2
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• pp.181-193
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• 2022

The study was conducted to provide basic data for stable forest management according to climate change by identifying the ecological characteristics of Mt. Dalma warm temperate forest. 30 survey plots were established for vegetation structure analysis, and communities which classified by applying TWINSPAN analysis and DCA analysis techniques. Four plant communities were subdivided into Quercus acuta-Eurya japonica community, Quercus acuta community, Quercus salicina-Camellia japonica community, and Quercus acuta-Camellia japonica community. The tree layers were dominated by Quercus acuta and Quercus salicina, and the subtree layers were dominated by Camellia japonica and Eurya japonica, and the Sasa borealis. The species diversity index were in the range of 0.849 to 0.969, and the degree of Evenness index were 0.514 to 0.569, and the similarity index were 59.57 to 75.47%. The species composition in the community indicated that the deciduous broad-leaved and coniferous trees have already been eliminated in competition with evergreen broad-leaved trees. Tree species with good cold resistance such as Quercus acuta and Quercus salicina were dominant species under current climatic conditions, but the dominant species might be changed to more shade-tolerance evergreen broad-leaved through the succession.

• Corrosion Science and Technology
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• v.23 no.3
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• pp.228-234
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• 2024

Zinc wiping is a phenomenon used to control zinc-coating thickness on steel substrate during hot dip galvanizing by equipment called air knife. Uniformity of zinc coating weight in length and width profile along with surface quality are most critical quality parameters of galvanized steel. Deviation from tolerance level of coating thickness causes issues like overcoating (excess consumption of costly zinc) or undercoating leading to rejections due to non-compliance of customer requirement. Main contributor of deviation from target coating weight is dynamic change in air knives equipment setup when thickness, width, and type of substrate changes. Additionally, cold coating measurement gauge measure coating weight after solidification but are installed down the line from air knife resulting in delayed feedback. This study presents a coating weight control model (Galvantage) predicting critical air knife parameters air pressure, knife distance from strip and line speed for coating control. A reverse engineering approach is adopted to design a predictive, prescriptive, and descriptive model recommending air knife setups that estimate air knife distance and expected coating weight in real time. Implementation of this model eliminates feedback lag experienced due to location of coating gauge and achieving setup without trial-error by operator.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1659-1669
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• 2020

1,3-α-3,6-anhydro-L-galactosidase (α-neoagarooligosaccharide hydrolase) catalyzes the last step of agar degradation by hydrolyzing neoagarobiose into monomers, D-galactose, and 3,6-anhydro-L-galactose, which is important for the bioindustrial application of algal biomass. Ahg943, from the agarolytic marine bacterium Gayadomonas joobiniege G7, is composed of 423 amino acids (47.96 kDa), including a 22-amino acid signal peptide. It was found to have 67% identity with the α-neoagarooligosaccharide hydrolase ZgAhgA, from Zobellia galactanivorans, but low identity (< 40%) with the other α-neoagarooligosaccharide hydrolases reported. The recombinant Ahg943 (rAhg943, 47.89 kDa), purified from Escherichia coli, was estimated to be a monomer upon gel filtration chromatography, making it quite distinct from other α-neoagarooligosaccharide hydrolases. The rAhg943 hydrolyzed neoagarobiose, neoagarotetraose, and neoagarohexaose into D-galactose, neoagarotriose, and neoagaropentaose, respectively, with a common product, 3,6-anhydro-L-galactose, indicating that it is an exo-acting α-neoagarooligosaccharide hydrolase that releases 3,6-anhydro-L-galactose by hydrolyzing α-1,3 glycosidic bonds from the nonreducing ends of neoagarooligosaccharides. The optimum pH and temperature of Ahg943 activity were 6.0 and 20℃, respectively. In particular, rAhg943 could maintain enzyme activity at 10℃ (71% of the maximum). Complete inhibition of rAhg943 activity by 0.5 mM EDTA was restored and even, remarkably, enhanced by Ca²⁺ ions. rAhg943 activity was at maximum at 0.5 M NaCl and maintained above 73% of the maximum at 3M NaCl. K_m and V_max of rAhg943 toward neoagarobiose were 9.7 mg/ml and 250 μM/min (3 U/mg), respectively. Therefore, Ahg943 is a unique α-neoagarooligosaccharide hydrolase that has cold- and high-salt-adapted features, and possibly exists as a monomer.

• The Korean Journal of Applied Statistics
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• v.33 no.6
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• pp.823-832
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• 2020

The analgesic effects of music in people with glasses on perceived pain through cold-pressor task (CPT) is assessed based on three-sequence, three-period, crossover trial with three treatment conditions(music-listening, news-listening, and no-sound) to each subject. Fifty subjects are divided into three sequence groups by randomization, and CPTs under the pre-assigned treatment conditions at each period are performed. Pain responses after each CPT, subjects' pain tolerance (PT) in time scale and pain intensity (PI) and pain unpleasantness (PU) in visual analog scale (VAS) are measured. After classifying the group by whether or not to wear glasses, which is the phenotype of the myopia gene, pain responses are compared by F-tests and Tukey's multiple comparisons. CPT pain responses in group with glasses during the music intervention are significantly different from responses during the news intervention and the control conditions, respectively. This study investigates the pain responses of music intervention in the group wearing glasses, which can be seen as a phenotype of the nearsighted gene, and this result would play a role in explaining the biopsychosocial model of the pain mechanism.