• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.92-97
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• 2012

Antimicrobial peptides (AMPs) are important components of living organisms acting against Gram-negative and Gram-positive bacterial and fungal pathogens. Cathelicidin human peptides have a variety of biological activities that can be used in clinical applications. AMPs are not produced naturally in large quantities, and chemical synthesis is also economically impractical, especially for long peptides. Therefore, as an alternative, heterologous expression of AMPs by recombinant techniques has been studied as a means to reduce production costs. E. coli is an excellent host for the expression of AMPs, as well as other recombinant proteins, because of the low cost involved and its easy manipulation. However, overexpression of AMPs in E. coli has been shown to cause difficulties resulting from the toxicity of the subsequently produced AMPs. Therefore, fusion expression was theorized to be a solution to this problem. In this study, AMPs were expressed as fused proteins with the glutathione S-transferase (GST) binding protein to protect against the toxicity of AMPs when expressed in E. coli. The LL37, and hybrid gaegurin and LL37 (GGN4(1-16)-LL37(17-32), which we designated as GL32, peptides were expressed as GST-fusion proteins in E. coli and the fusion proteins were then purified by affinity columns. The purified peptides were obtained by removal of GST and were confirmed by western blot analysis. The purified antimicrobial peptides then demonstrated antimicrobial activities against Gram-negative and Gram-positive bacterial strains.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.4
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• pp.327-334
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• 2004

In this paper, a triplexer for Advanced Mobile Phone Service(AMPS), United States-Personal Communication Services(US-PCS), and Global Positioning System(CPS) is designed using L and C lumped elements. The triplexer shows the insertion loss of 0.6 ㏈, 1.1 ㏈, and 1.6 ㏈ for AMPS, US-PCS, and GPS bands, respectively. Also, it shows the attenuation characteristic of less than 18 ㏈, and the VSWR of less than 2.0 through the all pass-band.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.12
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• pp.3196-3204
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• 1996

We analyze the capacity of the imperfect power controlled DS/CDMA system with the Nakagami faded AMPS interferers by means of the analytical approach. Unlike the theoretical aassumption, the power control of the DS/CDMA system is not perfect. Therefore in this analysis we consider various parameters which cause the capacityreduction of the DS/CDMA system, the imperfect power control, the Nakagami fading index, he processing gain, and the number of AMPS interferers. The analytical results are compared with the Prasad's results which are considered only the imperfect power control of the DS/CDMA system. It is shown that the DS/CDMA capacity is decreased according to the increase of the deviation of the imperfect power control, to icrease the number pf the analog interfering users, and to decrease the processing gain.

• Journal of information and communication convergence engineering
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• v.3 no.1
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• pp.28-32
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• 2005

In this paper, we propose a novel test method to effectively detect hard and soft faults in CMOS 2-stage op-amps. The proposed method uses a very high frequency sinusoidal signal that exceeds unit gain bandwidth to maximize the fault effects. Since the proposed test method doesn't require any complex algorithms to generate the test pattern and uses only a single test pattern to detect all target faults, therefore test costs can be much reduced. The area overhead is also very small because the CUT is converted to a unit gain amplifier. Using HSPICE simulation, the results indicated a high degree of fault coverage for hard and soft faults in CMOS 2-stage op-amps. To verify this proposed method, we fabricated a CMOS op-amp that contained various short and open faults through the Hyundai 0.65-um 2-poly 2-metal CMOS process. Experimental results for the fabricated chip have shown that the proposed test method can effectively detect hard and soft faults in CMOS op-amps.

• 한국전기화학회:학술대회논문집
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• 2004.10a
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• pp.41-41
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• 2004

• Journal of Life Science
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• v.26 no.6
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• pp.737-748
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• 2016

By this time, insect antimicrobial peptides (AMPs) have been characterized more than 150 peptides since purification of cecropin in the hemolymph of pupae from Hyalophora cecropia in 1980. Therefore, it is considered that insects are good sources of AMP selection. Insect AMPs are small (low molecular weight) and cationic, and amphipathic with variable length, sequence, and structure. They perform a pivotal role on humoral immunity in the insect innate immune system against invading pathogens such as bacteria, fungi, parasites, and viruses. Most of the insect AMPs are induced rapidly in the fat bodies and other specific tissues of insects after septic injury or immune challenge. Then the AMPs subsequently released into the hemolymph to act against microorganisms. These peptides have a broad antimicrobial spectrum against various microbes including anticancer activities. Insect AMPs could be divided into four families based on their structures and sequences. That is the α-helical peptides, cysteine-rich peptides, proline-rich peptides, and glycine-rich peptides/proteins. For instance, cecropins, insect defensins, proline-rich peptides, and attacins are common insect AMPs, but gloverins and moricins have been identified only in lepidopteran species. This review focuses on AMPs from insects and discusses current knowledge and recent progress with potential applications of insect AMPs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.3
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• pp.247-259
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• 1992

In this paper, the types of the data exchange between a cell site and a cobile phonefor the call processing on the AMPS(Advanced Mobile Phone Service) are investigated, and the circuit for processing the wideband data stream according to the data types is designed and implemented. The circuit for detecting the Busy / Idle bit which is needed for determining the channel access, the circuit for detecting the word sync and the circuit for transmitting and receiving the wideband data is designed. The 3-out-of-5 majority vote of the 5received data is performed to reduce error and an algorithm requiring a small buffer size for real time processing of voting process is proposed. The method to overcome the computational complexity and the real time constraint of the conventional BCH decoding is proposed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.873-876
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• 2005

This paper presents a new current transient test technique for wideband CMOS Op Amps. This technique monitors the transient power supply current and output responses of the CMOS Op Amp to automatically differentiate faulty and fault-free op amps. The wideband op amp is designed using 0.25${\mu}$m CMOS technology. We present detailed simulation results for a wideband op amp. We show that catastrophic faults in op amps can be detected and analyzed by monitoring power supply currents and output responses. This technique is inexpensive and simple.

• Journal of the Korean Electrochemical Society
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• v.17 no.1
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• pp.65-70
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• 2014

In this study, crosslinked poly(POEM-co-AMPSLi-co-GMA)s were prepared by epoxy coupling of GMA after radical copolymerization of AMPS, POEM and GMA followed by acid-base titration reaction between sulfonic acid of AMPS and $Li_2CO_3$. It was observed that the crystalline melting temperature of POEM was effected by mol% of components and shifted to lower value by lithiation of AMPS group. The ionic conductivity of crosslinked polymer electrolyte was decreased by addition of GMA but maintained over $1.0{\times}10^{-6}S\;cm^{-1}$ until 16 mol%. Particularly, the self-doped polymer electrolyte with 2 mol% of GMA showed its ionic conductivity as high as $4.08{\times}10^{-6}S\;cm^{-1}$ at room temperature and electrochemical stability up to 6 V. In addition, 0.11 MPa of modulus and 270% of elongation were obtained from the free standing film of crosslinked polymer electrolyte.

• Journal of Periodontal and Implant Science
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• v.43 no.1
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• pp.3-11
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• 2013

Periodontitis is a chronic inflammation of periodontal tissue caused by subgingival plaque-associated bacteria. Periodontitis has long been understood to be the result of an excessive host response to plaque bacteria. In addition, periodontal pathogens have been regarded as the causative agents that induce a hyperinflammatory response from the host. In this brief review, host-microbe interaction of nonperiodontopathic versus periodontopathic bacteria with innate immune components encountered in the gingival sulcus will be described. In particular, we will describe the susceptibility of these microbes to antimicrobial peptides (AMPs) and phagocytosis by neutrophils, the induction of tissue-destructive mediators from neutrophils, the induction of AMPs and interleukin (IL)-8 from gingival epithelial cells, and the pattern recognition receptors that mediate the regulation of AMPs and IL-8 in gingival epithelial cells. This review indicates that true periodontal pathogens are poor activators/suppressors of a host immune response, and they evade host defense mechanisms.