• Asian-Australasian Journal of Animal Sciences
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• v.29 no.11
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• pp.1608-1615
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• 2016

This study was conducted to determine the solubility of copper (Cu) in two sources of copper(II) sulfate ($CuSO_4$) including monohydrate and pentahydrate and three sources of dicopper chloride trihydroxide (dCCTH) including ${\alpha}$-form (dCCTH-${\alpha}$), ${\beta}$-form (dCCTH-${\beta}$), and a mixture of ${\alpha}$- and ${\beta}$-form (dCCTH-${\alpha}{\beta}$) at different pH and a 3-step in vitro digestion assay for pigs. In Exp. 1, Cu sources were incubated in water-based buffers at pH 2.0, 3.0, 4.8, and 6.8 for 4 h using a shaking incubator at $39^{\circ}C$. The $CuSO_4$ sources were completely dissolved within 15 min except at pH 6.8. The solubility of Cu in dCCTH-${\alpha}$ was greater (p<0.05) than dCCTH-${\beta}$ but was not different from dCCTH-${\alpha}{\beta}$ during 3-h incubation at pH 2.0 and during 2-h incubation at pH 3.0. At pH 4.8, there were no significant differences in solubility of Cu in dCCTH sources. Copper in dCCTH sources were non-soluble at pH 6.8. In Exp. 2, the solubility of Cu was determined during the 3-step in vitro digestion assay for pigs. All sources of Cu were completely dissolved in step 1 which simulated digestion in the stomach. In Exp. 3, the solubility of Cu in experimental diets including a control diet and diets containing 250 mg/kg of additional Cu from five Cu sources was determined during the in vitro digestion assay. The solubility of Cu in diets containing additional Cu sources were greater (p<0.05) than the control diet in step 1. In conclusion, the solubility of Cu was influenced by pH of digesta but was not different among sources based on the in vitro digestion assay.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1605-1608
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• 2015

Purpose: To investigate the expression of Ki67 protein in papillary thyroid microcarcinoma(PTMC), and to analyze its clinical significance. Materials and Methods: Ki67 protein expression was evaluated in the tissues of 108 human PTMC and 50 other benign papillary hyperplasia of thyroid specimens using immunohistochemistry. Results: The expression intensity of Ki67 in PTMC and benign papillary hyperplasia of thyroid specimens were $1.45{\pm}1.83%$ and $0.46{\pm}0.46%$.The positive expression rates were 46.3% and 14%. There were significant differences between these two groups (p<0.01). There was no significant variation of the expression intensity and positive expression rates of Ki67 in PTMC with gender, age, position of the tumor and the level of TSH pre-operation (p>0.05), but these parameters varied with tumor size, invasion by membrane and cervical lymph node metastasis (p<0.05 or p<0.01). Conclusions: The expression of Ki67 in PTMC was related to tumor size, invasion by membrane and cervical lymph node metastasis, and could be the important indicator for judging clinical progress and estimating prognosis.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1598-1608
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• 1999

Performance testing for ATM network deals with evaluation of maximal throughput of network by measuring and analyzing of various performance parameters. However, because of the absence of the methodology and framework for performance testing, the results of performance measurements for same implementation under test were much relied on tester. In this paper, the concept of ATM performance testing is described in both cell and frame level and a framework of ATM performance testing is suggested by describing of testing environment for performance measurement and requirements of performance evaluation. For this, we define performance measuring method and parameters for each case.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1602-1608
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• 2013

PoC (Push-to-Talk over Cellular) provides one-to-one as well as one-to-many communications with VoIP technology based on SIP over cellular networks. According to above property, PoC is considered as perscrptive technology for public protection for disaster relief networks. For this networks, group communication is the essential function. However, since current standardization process takes into general scenarios account without any consideration for mentioned networks, it have some problems in the point of adaptability. To solve above problem, in this paper, we propose how to reduce the overhead on the PoC server to reduce the transmission delay. Simulation results are shown to evaluate the improved performance.

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2087-2097
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• 2016

Most cold-adapted enzymes possess higher $K_m$ and $k_{cat}$ values than those of their mesophilic counterparts to maximize the reaction rate. This characteristic is often ascribed to a high structural flexibility and improved dynamics in the active site. However, this may be less convincing to cold-adapted metabolic enzymes, which work at substrate concentrations near $K_m$. In this respect, cold adaptation of a shikimate kinase (SK) in the shikimate pathway from psychrophilic Colwellia psychrerythraea (CpSK) was characterized by comparing it with a mesophilic Escherichia coli homolog (EcSK). The optimum temperatures for CpSK and EcSK activity were approximately $30^{\circ}C$ and $40^{\circ}C$, respectively. The melting points were $33^{\circ}C$ and $45^{\circ}C$ for CpSK and EcSK, respectively. The ${\Delta}G_{H_2O}$ (denaturation in the absence of denaturing agent) values were 3.94 and 5.74 kcal/mol for CpSK and EcSK, respectively. These results indicated that CpSK was a cold-adapted enzyme. However, contrary to typical kinetic data, CpSK had a lower $K_m$ for its substrate shikimate than most mesophilic SKs, and the $k_{cat}$ was not increased. This observation suggested that CpSK may have evolved to exhibit increased substrate affinity at low intracellular concentrations of shikimate in the cold environment. Sequence analysis and homology modeling also showed that some important salt bridges were lost in CpSK, and higher Arg residues around critical Arg 140 seemed to increase flexibility for catalysis. Taken together, these data demonstrate that CpSK exhibits characteristics of cold adaptation with unusual kinetic parameters, which may provide important insights into the cold adaptation of metabolic enzymes.

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2098-2105
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• 2016

Massive reserves of methane ($CH_4$) remain unexplored as a feedstock for the production of liquid fuels and chemicals, mainly because of the lack of economically suitable and sustainable strategies for selective oxidation of $CH_4$ to methanol. The present study demonstrates the bioconversion of $CH_4$ to methanol mediated by Type I methanotrophs, such as Methylomicrobium album and Methylomicrobium alcaliphilum. Furthermore, immobilization of a Type II methanotroph, Methylosinus sporium, was carried out using different encapsulation methods, employing sodium-alginate (Na-alginate) and silica gel. The encapsulated cells demonstrated higher stability for methanol production. The optimal pH, temperature, and agitation rate were determined to be pH 7.0, $30^{\circ}C$, and 175 rpm, respectively, using inoculum (1.5 mg of dry cell mass/ml) and 20% of $CH_4$ as a feed. Under these conditions, maximum methanol production (3.43 and 3.73 mM) by the encapsulated cells was recorded. Even after six cycles of reuse, the Na-alginate and silica gel encapsulated cells retained 61.8% and 51.6% of their initial efficiency for methanol production, respectively, in comparison with the efficiency of 11.5% observed in the case of free cells. These results suggest that encapsulation of methanotrophs is a promising approach to improve the stability of methanol production.

• Journal of Conservation Science
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• v.32 no.1
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• pp.11-19
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• 2016

Seungja Chongtong is a small korean tubular arm that made by particular arm-making way imitating a chinese arm. This study organizes scientific analysis results with results of inscriptions reading of Seungja Chongtong in the Central museum of Kyunghee University. Three of Seungja Chongtongs are made with Cu-Sn-Pb ternary alloy which is not much differ in contents and the results of microstructure analysis of Seungja Chongtong 1 which could investigate a microstructure among the Chongtongs were found out that Seungja Chongtong is made by general casting, with no evidences of an additional heat-treatment and tempering. Furthermore, in results of lead isotope ratio analysis to find out a source of lead using during the production of Seungja Chongtong, It seems that Seungja Chongtong is made with a lead ore from northern Gyeongsangbuk-do Province and southern Gangwon-do Province called Korea southern zone 2 area.

• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.1863-1870
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• 2016

Antimicrobial peptides/proteins (AMPs) are present in all types of organisms, from microbes and plants to vertebrates and invertebrates such as insects. The grasshopper Oxya chinensis sinuosa is an insect species that is widely consumed around the world for its broad medicinal value. However, the lack of available genetic information for this species is an obstacle to understanding the full potential of its AMPs. Analysis of the O. chinensis sinuosa transcriptome and expression profile is essential for extending the available genetic information resources. In this study, we determined the whole-body transcriptome of O. chinensis sinuosa and analyzed the potential AMPs induced by bacterial immunization. A high-throughput RNA-Seq approach generated 94,348 contigs and 66,555 unigenes. Of these unigenes, 36,032 (54.14%) matched known proteins in the NCBI database in a BLAST search. Functional analysis demonstrated that 38,219 unigenes were clustered into 5,499 gene ontology terms. In addition, 26 cDNAs encoding novel AMPs were identified by an in silico approach using public databases. Our transcriptome dataset and AMP profile greatly improve our understanding of O. chinensis sinuosa genetics and provide a huge number of gene sequences for further study, including genes of known importance and genes of unknown function.

• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.1965-1971
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• 2016

Livestock wastewater containing high concentrations of ammonium and nitrate ions was pretreated with microbubbles and an Fe/MgO catalyst prior to its application in microbial fuel cells because high ion concentrations can interfere with current generation. Therefore, tests were designed to ascertain the effect of pretreatment on current generation. In initial tests, the optimal amount of catalyst was found to be 300 g/l. When 1,000 ml/min $O_2$ was used as the oxidant, the removal of ammonium- and nitrate-nitrogen was highest. After the operating parameters were optimized, the removal of ammonium and nitrate ions was quantified. The maximum ammonium removal was 32.8%, and nitrate was removed by up to 75.8% at a 500 g/l catalyst concentration over the course of the 2 h reaction time. The current was about 0.5 mA when livestock wastewater was used without pretreatment, whereas the current increased to $2.14{\pm}0.08mA$ when livestock wastewater was pretreated with the method described above. This finding demonstrates that a 4-fold increase in the current can be achieved when using pretreated livestock wastewater. The maximum power density and current density performance were $10.3W/m^3$ and $67.5W/m^3$, respectively, during the evaluation of the microbial fuel cells driven by pretreated livestock wastewater.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.277-288
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• 2017

Rhizomucor miehei NRRL 5282 and Rhizopus oryzae NRRL 1526 can produce lipases with high synthetic activities in wheat bran-based solid-state culture. In this study, the purification and biochemical characterization of the lipolytic activities of these lipases are presented. SDS-PAGE indicated a molecular mass of about 55 and 35 kDa for the purified R. miehei and Rh. oryzae enzymes, respectively. p-Nitrophenyl palmitate (pNPP) hydrolysis was maximal at $40^{\circ}C$ and pH 7.0 for the R. miehei lipase, and at $30^{\circ}C$ and pH 5.2 for the Rh. oryzae enzyme. The enzymes showed almost equal affinity to pNPP, but the $V_{max}$ of the Rh. oryzae lipase was about 1.13 times higher than that determined for R. miehei using the same substrate. For both enzymes, a dramatic loss of activity was observed in the presence of 5 mM $Hg^{2+}$, $Zn^{2+}$, or $Mn^{2+}$, 10 mM N-bromosuccinimide or sodium dodecyl sulfate, and 5-10% (v/v) of hexanol or butanol. At the same time, they proved to be extraordinarily stable in the presence of n-hexane, cyclohexane, n-heptane, and isooctane. Moreover, isopentanol up to 10% (v/v) and propionic acid in 1 mM concentrations increased the pNPP hydrolyzing activity of R. miehei lipase. Both enzymes had 1,3-regioselectivity, and efficiently hydrolyzed p-nitrophenyl (pNP) esters with C8-C16 acids, exhibiting maximum activity towards pNP-caprylate (R. miehei) and pNP-dodecanoate (Rh. oryzae). The purified lipases are promising candidates for various biotechnological applications.