• Journal of Microbiology
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• 제35권4호
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• pp.309-314
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• 1997

The manganese-containing superoxide dismutase (MnSOD) is a major component of the cellular defence mechanisms against the toxic effects of the superoxide radical. Within the framework of studies on oxidative stress=responsible enzymes in the Candida sp., the gene encoding the MnSOD was isolated and examined in this study. A specific primer was designed based on conserved regions of MnSOD sequences from other organisms, and was used to isolate the gene by PCR on reverse-transcribed Candida poly($A^{+}$) RNA. The PCR product was used to screen a Candida genomic lambda library and the nucleotide wequence of positive clone was determined. The deduced primary sequence encodes a 25kDa protein which has the conserved residues for enzyme activity and metal binding. The 28 N-terminal amino acids encoded by the Candida cDNA comprise a putatice mitochondrial transit peptide. Potential regulatory elements were identified in the 5' flanking sequences. Northern blot analysis showed that the transcription of the MnSOD gene is induced 5-to 10-fold in response to mercury, cadmium ions and hydrogen peroxide.

• Journal of Plant Biotechnology
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• 제4권3호
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• pp.123-127
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• 2002

Herbicide tolerant rice (Oryza sativa L. cv. Ilpumbyeo) cell lines were selected from $\gamma$-ray-irradiated anther-derived cell cultures. The anther-derived cell clusters were small (300 to 400 ${\mu}{\textrm}{m}$ in diameter) and uniform ones that were screened by miracloth filtering. The cell suspensions were very efficient to plate one layer onto agar medium and to screen target cell lines. Herbicide tolerant cell lines were selected by 5 mg/L cyhalofop butyl (CHB) treatment by using the small cell suspensions on agar N6 medium containing 1 mg/L 2,4-D and 0.2 mg/L kinetin. Of the cell lines, one line (CHB-1) showed stable tolerance at 10 mg/L concentration after 6-month culture without herbicide suspension. Growth stability of CHB-1 was similar to that of control cell line on 10 mg/L CHB containing medium. In this experiment we established herbicide tolerant cell line selection system by using anther-derived uniform-cell suspensions with $\gamma$-ray-irradiation.

• 한국재료학회지
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• 제14권3호
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• pp.224-228
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• 2004

Respectively the powder made of ZnO added $SnO_2$ was prepared by coprecipitation method and the thick film gas sensor was fabricated by screen-printing technique, The morphology and phase of the powder and film was investigated by SEM and XRD. The specific area of the particle was linearly increased with ZnO contents. Target gas was di(propylene glycol) methylether ($CH_3$($OC_3$$H_{6}$ )$_2$OH, DPGME), which is simulant gas of blister gas. The gas sensing characteristics for DPGME were examined with flow type measurement system and the concentrations of target gas were controlled from 500 ppb to 1500 ppb. ZnO (2 wt%) added $SnO_2$ showed maximum sensitivity to DPGME at $300^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• 제19권4호
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• pp.378-386
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• 2009

A sequential optimization strategy, based on statistical experimental designs, is employed to enhance the production of alkaline protease by a Bacillus pseudofirmus local isolate. To screen the bioprocess parameters significantly influencing the alkaline protease activity, a 2-level Plackett-Burman design was applied. Among 15 variables tested, the pH, peptone, and incubation time were selected based on their high positive significant effect on the protease activity. A near-optimum medium formulation was then obtained that increased the protease yield by more than 5-fold. Thereafter, the response surface methodology(RSM) was adopted to acquire the best process conditions among the selected variables, where a 3-level Box-Behnken design was utilized to create a polynomial quadratic model correlating the relationship between the three variables and the protease activity. The optimal combination of the major medium constituents for alkaline protease production, evaluated using the nonlinear optimization algorithm of EXCEL-Solver, was as follows: pH of 9.5, 2% peptone, and incubation time of 60 h. The predicted optimum alkaline protease activity was 3,213 U/ml/min, which was 6.4 times the activity with the basal medium.

• Transactions on Electrical and Electronic Materials
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• 제13권2호
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• pp.73-77
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• 2012

Operation of liquid crystal displays (LCDs) can be improved by monolithic integration of the pixel transistors with light emitting diodes (LEDs) on a single substrate. Conventional LCDs make use of filters to control the backlighting which reduces the overall efficiency. These LCDs also utilize LEDs in series which impose failure and they require high voltage for operation with a power factor correction. The screen of small hand-held devices can operate from moderate brightness. Therefore, III-V nanowires that are grown along with transistors over Silicon substrates can be utilized. Control of nanowire LEDs with nanowire transistors will significantly lower the cost, increase the efficiency, improve the manufacturing yield and simplify the structure of the small displays that are used in portable devices. The steps to grow nanowires on Silicon substrates are described. The vertical n-type and p-type nanowire transistors with surrounding gate structures are characterized. While biased at 0.5 V, nanowire transistors with minimum radius or channel width have an OFF current which is less than 1pA, an ON current more than 1 ${\mu}A$, a total delay less than 10 ps and a transconductance gain of more than 10 ${\mu}A/V$. The low power and fast switching characteristics of the nanowire transistor make them an ideal choice for the realization of future displays of portable devices with long battery lifetime.

• Current Photovoltaic Research
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• 제4권1호
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• pp.12-15
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• 2016

Screen printing technique followed by firing has commonly been used as metallization for both laboratory and industrial based solar cells. In the solar cell industry, the firing process is usually conducted in a belt furnace and needs to be optimized for fabricating high efficiency solar cells. The printed-Al layer on the silicon is rapidly heated at over $800^{\circ}C$ which forms a layer of back surface field (BSF) between Si-Al interfaces. The BSF layer forms $p-p^+$ structure on the rear side of cells and lower rear surface recombination velocity (SRV). To have low SRV, deep $p^+$ layer and uniform junction formation are required. In this experiment, firing process was carried out by using conventional tube furnace with $N_2$ gas atmosphere to optimize $V_{oc}$ of laboratory cells. To measure the thickness of BSF layer, selective etching was conducted by using a solution composed of hydrogen fluoride, nitric acid and acetic acid. The $V_{oc}$ and pseudo efficiency were measured by Suns-$V_{oc}$ to compare cell properties with varied firing condition.

• 한국태양에너지학회 논문집
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• 제37권1호
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• pp.39-45
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• 2017

This paper presents the effect of solar collectors on the performance of solar tracking daylighting systems. A series of measurements were made for two different types of solar collectors mounted on double axis solar trackers: Parabolic dish concentrator and Fresnel Lens. Indoor light levels were measured at different locations of an office space (longitude: 126.33 E, latitude 33.45 N) as photo sensors were placed on a task plane 80 cm above the floor. To accurately monitor the applicability of the systems, measurements were performed under clear and overcast sky conditions with the roll-screen (on the south window) in the down position. Comparing the illuminance data, the system with Fresnel lens outperformed that of parabolic dish concentrator. On clear days, the former delivered the light levels of 400~600 lux on the task plane whereas the latter recorded 100~200 lux. Depending on the amount of cloud cover, on overcast days, illuminance readings fluctuated to some extent.

• Journal of Communications and Networks
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• 제17권1호
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• pp.67-74
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• 2015

In this paper, we propose a web-based content syndication system in which users can easily choose Internet protocol television (IPTV) contents. This system generates personalized content guide to provide a list of IPTV contents with respect to users' interests and statistics information of their online social community. For this, IPTV contents and relevant metadata are collected from various sources and transformed. Then, the service and content metadata are processed by user metadata including audience measurement and community metadata. The metadata flows are separated from content flows of transport network. The implementation of IPTV content syndication system demonstrates how to arrange IPTV contents efficiently from content providers to the end user's screen. We also show that the user metadata including online community information are important for the system's performance and the user's satisfaction.

• Asian-Australasian Journal of Animal Sciences
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• 제30권2호
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• pp.262-266
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• 2017

Objective: This study was conducted to screen scrotal hernia in domesticated swine from selected breeders in the Philippines. This defect is associated with a cytosine to thymine mutation in the BCL-2 associated X protein (BAX) gene of swine. Methods: Genetic screening was done by DNA extraction followed by amplification and digestion using polymerase chain reaction-restriction fragment length polymorphism, amplifying the 416 bp region of the BAX gene that was subjected to digestion using the Ear I enzyme. Sequencing was also conducted to validate the results. Results: Results revealed that out of 538 samples tested, 411 (76.4%) of the samples were found to be normal whereas the remaining were carriers of the mutation in which 80 (14.9%) were heterozygous mutants and 47 (8.7%) were homozygous mutants. Pietrain breed was found to have the highest incidence. Conclusion: Having a scrotal hernia eliminates the chances of using the boar as a breeder stock because the following generations arising from it would most likely exhibit herniation. It is therefore advised to establish a genetic screening method for Scrotal Hernia in the Philippines to eliminate the negative gene from the herd.

• BMB Reports
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• 제42권12호
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• pp.812-816
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• 2009

To screen chaperone proteins from Schizosaccharomyce pombe (S. pombe), we prepared recombinant citrate synthase of the fission yeast as a substrate of anti-aggregation assay. Purified recombinant citrate synthase showed citrate synthase activity and was suitable for the substrate of chaperone assay. Several heat stable proteins including aspartyl aminopeptidase (AAP) for candidates of chaperone were screened from the supernatant fraction of heat-treated crude extract of S. pombe. The purified AAP migrated as a single band of 47 kDa on SDS-polyacrylamide gel electrophoresis. The native size of AAP was estimated as 200 kDa by a HPLC gel permeation chromatography. This enzyme can remove the aspartyl residue at N-terminus of angiotensin I. In addition, AAP showed the heat stability and protected the aggregation of citrate synthase caused by thermal denaturation. This study showed that S. pombe AAP is a moonlight protein that has aspartyl aminopeptidase and chaperone activities.