• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1944-1953
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• 2015

A novel alkaline protease from Streptomyces sp. M30, SapHM, was purified by ammonium sulfate precipitation, hydrophobic interaction chromatography, and DEAE-Sepharose chromatography, with a yield of 15.5% and a specific activity of 29,070 U/mg. Tryptic fragments of the purified SapHM were obtained by electrospray ionization quadrupole time-of-flight mass spectrometry. Nucleotide sequence analysis revealed that the gene sapHM contained 1,179 bp, corresponding to 392 amino acids with conserved Asp156, His187, and Ser339 residues of alkaline protease. The first 24 amino acid residues were predicted to be a signal peptide, and the molecular mass of the mature peptide was 37.1 kDa based on amino acid sequences and mass spectrometry. Pure SapHM was optimally active at 80℃ in 50 mM glycine-NaOH buffer (pH 9.0), and was broadly stable at 0-50℃ and pH 4.0-9.0. The protease relative activity was increased in the presence of Ni²⁺, Mn²⁺, and Cu²⁺ to 112%, 113%, and 147% of control, respectively. Pure SapHM was also activated by dimethylformamide, dimethyl sulfoxide, Tween 80, and urea. The activity of the purified enzyme was completely inhibited by phenylmethylsulfonyl fluoride, indicating that it is a serine-type protease. The K_m and V_max values were estimated to be 35.7 mg/ml, and 5 × 10⁴ U/mg for casein. Substrate specificity analysis showed that SapH was active on casein, bovine serum albumin, and bovine serum fibrin.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.9
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• pp.499-504
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• 2015

The composite anodes of expanded graphite (EG) and multiwall carbon nanotube (MWCNT) for microbial fuel cells were fabricated by using coal tar pitch (CTP) binder containing nickel (Ni), and the effect of the anodes with the binders on the performance of the MFCs were examined in a batch reactor. During the start-up of the MFCs, quick increase in voltage was observed after a short lag phase time, indicating that the CTP binder is biocompatible. The biomass attatched on the anode surface was more at higher Ni content in the binder, as well as at smaller amount of CTP binder for the fabrication of the anode. The internal resistance of the MFC was smaller for the anode with more biomass. Based on the results, the ideal combination of CTP and Ni for the CTP binder for anode was 2 g and 0.2 g, respectively. The maximum power density was $731.8mW/m^2$, which was higher 23.7% than the anode with Nafion binder as control. The CTP binder containing Ni for the fabrication of anode is a good alternative in terms of performance and economics of MFCs.

• Journal of Korea Technology Innovation Society
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• v.20 no.3
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• pp.576-606
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• 2017

It is more salient in the high-tech industry to cooperate even among competitors in order to promptly respond to the changes in product architecture. In this sense, 'co-opetition,' which is the combination word between 'cooperation' and 'competition,' is the new business term in the strategic management and represents the two concepts "simultaneously co-exist." From this view, this study set up the research purposes as follows: 1) investigating the corporate managerial and technological behavioral characteristics in the co-opetition of the global display industry. 2) verifying the emerging factors during the co-opetition behavior hereafter. 3) suggesting the strategic direction focusing on the co-opetition behavioral characteristics. To this end, this study used co-word network analysis to understand the structure in context level of the co-opetition. In order to understand topics on each network, we clustered the keywords by community detection algorithm based on modularity and labeled the cluster name. The results show that there were increasing patterns of competition rather than cooperation. Especially, the litigations for mutual control against Korean firms much more severely occurred and increased as time passed by. Investigating these network structure in technological evolution perspective, there were already active cooperation and competition among firms in the early 2000s surrounding the issues of OLED-related technology developments. From the middle of the 2000s, firm behaviors have focused on the acceleration of the existing technologies and the development of futuristic display. In other words, there has been competition to take leadership of the innovation in the level of final products such as the TV and smartphone by applying the display panel products. This study will provide not only better understanding on the context of the display industry, but also the analytical framework for the direction of the predictable innovation through analyzing the managerial and technological factors. Also, the methods can support CTOs and practitioners in the technology planning who should consider those factors in the process of decision making related to the strategic technology management and product development.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1123-1130
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• 2004

Two experiments were conducted to examine the effects of dietary inclusion of xylose on growth performance, nutrient digestibility and xylose absorption in the portal-drained viscera of broiler chicks. In Exp. 1, ninety male 14 day-old broilers were used to study the effects of different inclusion levels (0, 5, 10, 20 and 40%) of D-xylose in the semi-purified diets on the growth and nutrient digestibility of broilers. In Exp. 2, One hundred and eight male broilers, fed by precision feeding at 22 day-old, were used to investigate the absorption and transportation of dietary xylose in the portal-drained viscera of broiler. The results of Exp. 1 indicated that the growth of broilers was gradually decreased as the xylose level increased (p<0.01). With the xylose supplementation increased, the moisture in broiler excreta was gradually elevated (p<0.01), AME and the digestibilities of crude protein and ether extract were significantly reduced and the digestibilities of xylose and arabinose were also decreased (p<0.01). The results of Exp. 2 showed that the concentrations of ribose, xylose and galactose in serum were significantly influenced by different dietary levels of xylose (p<0.01), but there's no apparent difference among rhamnose, glucose and arabinose (p>0.05). The xylose concentration in serum was highest in Vena Cava, middle in Portal Vein and lowest in Ulnar Vein within 6 h after precision feeding. And then the xylose concentration in Portal Vein and Ulnar Vein were higher than that of Vena Cava. The concentration of ribose, xylose and galactose in serum were also significantly changed with time prolongation (p<0.01). The concentration of xylose in serum was highest in the 40% xylose treatment, middle in the 20% xylose group and lowest in the control group. The glycogen contents in liver and muscle were linearly decreased as the level of xylose increased (p<0.01). The higher the dietary level of xylose was, the lower digestibility of dietary xylose was (p<0.10). 40% xylose markedly decreased the digestibility of dietary glucose (p<0.01). In conclusion, high levels of xylose in the diets inhibited the growth and nutrient digestibility of broiler. The outputs of xylose from the hydrolyzation of wheat-based diet by xylanase should have no adverse effects on broiler performance.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.880-886
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• 2007

Ensiled or oven-dried green tea by-products (GTB) were evaluated in goats for their nutritive potential as protein feedstuffs based on in vitro and in vivo digestibility. To elucidate the effects of tea tannin on in vitro digestibility, polyethylene glycol (PEG) was used as a tannin binding agent. Both ensiled and dried GTB contained 31.9 to 32.6% of crude protein (CP) on a dry matter (DM) basis. Phenolics and tannins in soybean meal and alfalfa hay were low or not detected, but they were high in both ensiled and dried GTB (7.3-10.1% DM as total extractable tannins). In vitro protein digestibility in the rumen ranked: soybean meal>alfalfa hay cube>ensiled GTB = dried GTB. The protein digestibility post-ruminally of these feedstuffs showed a similar trend to that in the rumen, but the digestibility of ensiled GTB was significantly higher than that of dried GTB. Addition of PEG improved the in vitro protein digestibility of both kinds of GTB in the rumen and post-ruminally, indicating that tannins suppressed the potential protein digestibility of GTB. The increased protein digestibility by PEG addition was not significantly different between ensiled and dried GTB in the rumen, but the percentage increment of ensiled GTB was higher than dried GTB post-ruminally. In the in vivo digestibility trial, ensiled and dried GTB were offered to goats as partial substitutes for soybean meal and alfalfa hay cubes. Offering both GTB to goats as 5-10% on a DM basis did not affect nutrient digestibility, ruminal pH, volatile fatty acids, and ammonia concentration. However, the eating time of the GTB-incorporated diet was longer than that of the basal diet. It took 1.4 and 1.6 times longer than the control diet, to eat the diet completely when GTB silage was offered at 5 and 10% levels, respectively, of the total diet. These results show that ensiled and dried GTB are useful as partial substitutes for soybean meal and alfalfa hay cubes for goats with respect to nutritive value. Because of lessened palatability, it is recommended that GTB be incorporated into the diet at 5% on a DM basis.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7165-7169
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• 2013

Purpose: The aim of this study was to evaluate any association of GSTM1 and GSTT1 null genotypes with the risk of lung cancer in a South Korean population. Methods: We conducted a large-scale, population-based case-control study including 3,933 lung cancer cases and 1,699 controls. Genotypes of GSTM1 and GSTT1 were determined using real-time polymerase chain reaction. Results: In logistic regression analysis adjusted for age and smoking, we did not find any association between GSTM1 or GSTT1 and LC risk in women. However, in men, the GSTM1 and GSTTI null genotypes were borderline associated with risk (OR=1.18, 95% CI=0.99-1.41 for GSTM1, OR=1.18, 95% CI=0.99-1.41 for GSTT1), and combined GSTM1 and GSTT1 null genotypes conferred an increased risk for LC in men (OR=1.39, 95% CI=1.08-1.78). The OR for the GSTT1 null genotype was greater in subjects aged 55 years old or younger (OR=1.45, 95% CI=1.09-1.92 for men; OR=1.36, 95% CI=0.97-1.90 for women), than in those over age 55 (OR=1.03, 95% CI=0.83-1.27 for men; OR=0.86, 95% CI=0.66-1.12 for women) in both genders (p for interaction <0.05). Conclusions: In the Korean population, the GSTM1 and GSTT1 null genotypes are risk factors for LC in men; the GSTT1 null genotype has a more prominent effect on LC risk in younger people (age 55 years and under) than in older individuals.

• Journal of Applied Biological Chemistry
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• v.57 no.1
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• pp.83-87
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• 2014

The effects of combined treatment of aqueous chlorine dioxide ($ClO_2$) and fumaric acid on the microbial growth in fresh-cut paprika were investigated. After the combined treatment, the populations of total aerobic bacteria and inoculated Listeria monocytogenes in the paprika sample were reduced by 0.82 and 1.21 log CFU/g, respectively, compared to those of the control. In addition, after 10 d of storage at $10^{\circ}C$, the populations were decreased by 1.21 and 2.10 log CFU/g, respectively. The predictive model for the populations of total aerobic bacteria and L. monocytogenes in the paprika was applied during storage. The prediction equation using Gompertz model was appropriate, based on the statistical analysis such as accuracy factor and bias factor. These results suggest that the combined treatment of aqueous $ClO_2$ and fumaric acid can be an effective technology for microbial decontamination and it can improve microbial safety by decreasing maximum growth rate and increasing lag time of bacteria in the fresh-cut paprika.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.563-580
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• 2010

In 2009 the Korea Ministry of Environment announced 'A Comprehensive Plan for the Improvement of Sewer Service in Rural Area' aiming at reduction of the sewer service gap between urban and rural areas as well as improvement in the residential environment of the rural area. According to the plan, the sewer system supply rate for the rural area is expected to reach up to 75% until 2015 with the budget of 4.7 trillion won (Korean currency). It is not certain, however, that the increase in the sewer system supply rate will accompany improvement of water quality in receiving water because several veiled problems that can occur in small-scale sewer treatment plants are poorly addressed in the plan. In this study, those issues for the small-scale sewer treatment plants and their solutions were discussed based on a case study in which we investigated 19 treatment facilities at two rural regions in Gyeonggi province. This study also included strategies useful for the plan. From the results of investigation, some problems, e.g., high hourly variations but low in flowrates and low mass loading were commonly identified. Although operation parameters in sewer treatment plants require to be modified depending on the mass loading, most of the plants were operated with the initial design parameters which causes the decrease of removal efficiency. In the intensive diagnosis, we arranged and applied solutions (e.g., flow equalization, air on/off time control, etc) to the two selected plants and found out improvement of effluent water quality, especially organic matters (COD and SS) and T-N with better denitrification performance.

• Journal of Biomedical Engineering Research
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• v.38 no.6
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• pp.342-351
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• 2017

The neural decoding is a procedure that uses spike trains fired by neurons to estimate features of original stimulus. This is a fundamental step for understanding how neurons talk each other and, ultimately, how brains manage information. In this paper, the strategies of neural decoding are classified into three methodologies: rate decoding, temporal decoding, and population decoding, which are explained. Rate decoding is the firstly used and simplest decoding method in which the stimulus is reconstructed from the numbers of the spike at given time (e. g. spike rates). Since spike number is a discrete number, the spike rate itself is often not continuous and quantized, therefore if the stimulus is not static and simple, rate decoding may not provide good estimation for stimulus. Temporal decoding is the decoding method in which stimulus is reconstructed from the timing information when the spike fires. It can be useful even for rapidly changing stimulus, and our sensory system is believed to have temporal rather than rate decoding strategy. Since the use of large numbers of neurons is one of the operating principles of most nervous systems, population decoding has advantages such as reduction of uncertainty due to neuronal variability and the ability to represent a stimulus attributes simultaneously. Here, in this paper, three different decoding methods are introduced, how the information theory can be used in the neural decoding area is also given, and at the last machinelearning based algorithms for neural decoding are introduced.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.8
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• pp.3794-3803
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• 2013

The purpose of this study was to find out the relationships between emotional labour and depressive symptoms among nurses in university hospitals. Subjects were 514 nurses working at three university hospitals in Daejeon City, and the survey was a structured self- administered questionnaire based from April 1 until May 31 2012. As a results, the level of depressive symptoms by the subjects emotional labour level was significantly higher in the group with higher total average points of the emotional labour than the lower group, As for the correlation between the level of depressive symptoms and emotional labour factors, the depressive symptoms points showed significant positive correlation with the total points of the emotional labour. As a result of hierarchical multiple regression, age, leisure time, coffee consumption, subjective health status, physical burden of work, sense of satisfaction at work, fit to the job and emotional labour were selected as significant variables and related variables effecting the level of depressive symptoms. These variables' descriptive power was 39.4%, especially, it can be seen that 11.0% descriptive power increased by putting the emotional labor variables. The results above imply that there is significant relation between emotional labor and depressive symptoms and various variables such as socio-demographic characteristics, health-related behavior factors and job-related factors. Also, it can be seen that the emotional labour and depressive symptoms showed significant positive correlation. Therefore, the development and implementation of a program to control emotional labor appropriately should be required for lowering the level of depressive symptoms.