• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.2
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• pp.154-159
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• 2006

Interleukin-18 (IL-18), otherwise known as interferon-gamma-inducing factor (IGIF), is one of several well characterized and important cytokines that contribute to host defenses. The complementary DNA (cDNA) of mature human interleukin-18 gene (hIL-18) was fused with the signal peptide of the rice amylase 1A gene (Ramy1A) and introduced into the plant expression vector under the control of a duplicated CaMV 35S promoter. The recombinant plasmid was transformed into tobacco (Nicotiana tabacum L. cv Havana) using the Agrobacterium-mediated transformation method. The integration of the hlL-18 gene into the genome of transgenic tobacco plants was confirmed by polymerase chain reaction (PCR) amplification and its expression was observed in the suspension cells that were derived from the transgenic plant callus by using Northern blot analysis. The hlL-18 protein was detected in the extracts of the transgenic callus and in the medium of the transgenic tobacco suspension culture by using immunoblot analysis. Based upon enzyme-linked immunosorbant assay (ELISA) results, the expression level of the hlL-18 protein approximated $166{\mu}g/L$ in the suspension culture medium. Bioassay results from the induction of $interferon-{\gamma}$ from a KG-1 cell line indicated that the hlL-18 secreted into the suspension culture medium was bioactive.

• Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.263-271
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• 2010

G protein-coupled receptors (GPCR) constitute the largest superfamily of cell membrane receptors, mediating diverse signal-transduction pathways. The melanocortin 4 receptor (MC4R) has been of interest for its physiological role and size, one of the smallest among the GPCRs, which makes it a good model system for the structural study of GPCRs. To study the molecular structure and tissue-specific expression of MC4R in olive flounder (Paralichthys olivaceus), the full-length MC4R gene was obtained using PCR amplification of genomic DNA as well as cDNA synthesis. Sequence analysis of the gene indicates that 978 bp of the MC4R gene encodes 325 amino acids without introns. Sequence alignment with the MC4Rs from other fish shows the highest degree of identity (96%) between Paralichthys olivaceous and Verasper moseri, followed by Takifugu rubripes and Tetraodon nigroviridis (89%). RNA was isolated from various tissues to examine the tissue distribution of MC4R by using RT-PCR. The results showed major expression of MC4R in the liver, brain, and eye, which is consistent with the expression pattern in other fish belonging to the order Pleuronectiformes.

• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.409-413
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• 2006

This paper deals with the design and testing of a simulator system for microgrids with distributed generations. This system is composed of a Real Time Digital Simulator (RTDS) and a power amplifier. The RTDS parts are operated for real time simulation for the microgrid model and the distributed generation source model. The power amplifiers are operated fur amplification of the RTDS's simulated output signal, which is a node voltage of the microgrid and distributed generation source. In this paper, we represent an RTDS system design, specification and test results of a power amplifier and simulation results of a PV (Photovoltaic) system and wind turbine system. The proposed system is applicable for development and performance testing of a PCS (Power Conversion System) for renewable energy sources.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6A
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• pp.547-555
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• 2006

We implemented DPU(Double-Pass Gain-Clamped) L-band EDFA for highly efficient amplification. A lasing signal generated within the linear cavity, can minimize the fluctuation of surviving channels when several WDM(Wavelength Division Multiplexing) channels are added or dropped. The new method measuring the characteristics of transient response of surviving channels quantitatively is suggested. It is to measure the ratio of lasing output before add or drop to that after add or drop. We investigated dynamic characteristics by using this method according to lasing wavelengths and propagation directions within the cavity. Experimental measurements show that the short lasing wavelength and backward propagation direction is the best condition for small fluctuation of surviving channels.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.4
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• pp.15-21
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• 2008

Secondary electron detectors used in scanning electron microscope accept secondary electrons emitted from the specimen and convert them to an electrical signal that, after amplification, is used to modulate the gray-level intensities on a cathode ray tube, producing an image of the specimen. In order to acquire images with good qualities, as many secondary electrons as possible should be reached to the detector. To realize this it is very important to select an appropriate mounting position and angle of the detector inside the chamber of scanning electron microscope. In this paper, a number of numerical simulations are performed to explore the relationships between detection rates of secondary electrons and the values of some parameters, such as distances between the detector and sample, relative mounting positions of scintillator positioned inside the detector with respect to detector cover, two types of mounting angles of the detector. The relationships between detection rates and applied voltages to corona ring and faraday cage, and energies of secondary electrons are investigated as well.

• The Journal of Engineering Research
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• v.7 no.1
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• pp.5-16
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• 2005

We implemented DPGC(Double-Pass Gain-Clamped) L-band EDFA for highly efficient amplification. A lasing signal generated within the linear cavity, can minimize the fluctuation of surviving channels when several WDM(Wavelength Division Multiplexing) channels are added or dropped. The new method describing the characteristics of transient response of surviving channels quantitatively is suggested. It is to measure the ratio of lasing output before add or drop to that after add or drop. We investigated dynamic characteristics by using this method according to lasing wavelengths and propagation directions within the cavity. The experimental measurements show that the short lasing wavelength and backward propagation direction is the best condition for small fluctuation of surviving channels.

• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1323-1329
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• 2021

Micro-scale magnetic beads are widely used for isolation of proteins, DNA, and cells, leading to the development of in vitro diagnostics. Efficient isolation of target biomolecules is one of the keys to developing a simple and rapid point-of-care diagnostic. A zinc finger protein (ZFP) is a double-stranded (ds) DNA-binding domain, providing a useful scaffold for direct reading of the sequence information. Here, we utilized two engineered ZFPs (Stx2-268 and SEB-435) to detect the Shiga toxin (stx2) gene and the staphylococcal enterotoxin B (seb) gene present in foodborne pathogens, Escherichia coli O157 and Staphylococcus aureus, respectively. Engineered ZFPs are immobilized on a paramagnetic bead as a detection platform to efficiently isolate the target dsDNA-ZFP bound complex. The small paramagnetic beads provide a high surface area to volume ratio, allowing more ZFPs to be immobilized on the beads, which leads to increased target DNA detection. The fluorescence signal was measured upon ZFP binding to fluorophore-labeled target dsDNA. In this study, our system provided a detection limit of ≤ 60 fmol and demonstrated high specificity with multiplexing capability, suggesting a potential for development into a simple and reliable diagnostic for detecting multiple pathogens without target amplification.

• ETRI Journal
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• v.46 no.2
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• pp.323-332
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• 2024

Receiver and transmitter monolithic microwave integrated circuit (MMIC) multifunction chips (MFCs) for active phased-array antennas for Ka-band satellite communication (SATCOM) terminals have been designed and fabricated using a 0.15-㎛ GaAs pseudomorphic high-electron mobility transistor (pHEMT) process. The MFCs consist of four-channel radio frequency (RF) paths and a 4:1 combiner. Each channel provides several functions such as signal amplification, 6-bit phase shifting, and 5-bit attenuation with a 44-bit serial-to-parallel converter (SPC). RF pads are implemented on the bottom side of the chip to remove the parasitic inductance induced by wire bonding. The area of the fabricated chips is 5.2 mm × 4.2 mm. The receiver chip exhibits a gain of 18 dB and a noise figure of 2.0 dB over a frequency range from 17 GHz to 21 GHz with a low direct current (DC) power of 0.36 W. The transmitter chip provides a gain of 20 dB and a 1-dB gain compression point (P1dB) of 18.4 dBm over a frequency range from 28 GHz to 31 GHz with a low DC power of 0.85 W. The P1dB can be increased to 20.6 dBm at a higher bias of +4.5 V.

• Microbiology and Biotechnology Letters
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• v.45 no.2
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• pp.155-161
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• 2017

A gene coding for the xylanase predicted from the partial genomic sequence of Paenibacillus woosongensis was cloned by PCR amplification and sequenced completely. This xylanase gene, designated xyn11B, consisted of 1,071 nucleotides encoding a polypeptide of 356 amino acid residues. Based on the deduced amino acid sequence, Xyn11B was identified to be a modular enzyme, including a single carbohydrate-binding module besides the catalytic domain, and was highly homologous to xylanases belonging to glycosyl hydrolase family 11. The SignalP4.1 server predicted a stretch of 26 residues in the N-terminus to be the signal peptide. Using DEAE-Sepharose and Phenyl-Sepharose column chromatography, Xyn11B was partially purified from the cell-free extract of recombinant Escherichia coli carrying a copy of the P. woosongensis xyn11B gene. The partially purified Xyn11B protein showed maximal activity at $50^{\circ}C$ and pH 6.5. The enzyme was more active on arabinoxylan than on oat spelt xylan and birchwood xylan, whereas it did not exhibit activity towards carboxymethylcellulose, mannan, and para-nitrophenyl-${\beta}$-xylopyranoside. The activity of Xyn11B was slightly increased by $Ca^{2+}$ and $Mg^{2+}$, but was significantly inhibited by $Cu^{2+}$, $Ni^{2+}$, $Fe^{3+}$, and $Mn^{2+}$, and completely inhibited by SDS.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.1
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• pp.1-9
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• 2009

In this paper, a 2.4 GHz doppler radar system consisting of a doppler radar sensor and a baseband module were designed to detect heart beat and respiration signal without direct skin contact. The doppler radar system emits RF signal of 2.4 GHz toward human chest, and then detects phase modulation of the reflected signal so as to investigate cardiopulmonary activities. The heartbeat and respiration signals acquired from I/Q channels of the doppler radar system are applied to the pre-processing circuit, the amplification circuit, and the offset circuit of the baseband module. The designed system was tested on mouse, rabbit and mankind, which have different range of heart rates and respiration signals, to evaluate detection accuracy of the system. ECG acquisition system and respiration transducer were used to generate the reference signal. In our experiments, a performance of detection were found to be high in the case that the subject stays still. In this paper, we confirmed that non-contact heart beat and respiration detection using the doppler radar has the possibility and limitation according to distance, cardiopulmonary activities, range of heart rates and respiration.