• Journal of Microbiology and Biotechnology
• /
• v.10 no.1
• /
• pp.56-62
• /
• 2000

The hpa gene genetically linked to the ctxa2b gene was cloned into the pTED expression vector, and the constructed pTEDhpa/ctxa2b was transformed into Excherichia coli. The fusion protein, the adhesin fused to the cholera toxin subunit A2B (CTXA2B) subunit, was expressed to high levels as inclusion bodies in E. coli. The expressed protein was partially purified by washing the inclusion bodies with working solution containing 8M Urea and 0.1M DTT. Refolding of denatured fusion protein was carried out in the presence of glutathione redox buffer. The refolded fusion protein was purified by size exclusion chromatography. The expressed fusion protein was verified by SDS-PAGE, western blotting with antibodies to both antigenic components of adhesin and cholera toxin subunit B (CTXB), and its N-terminal amino acid sequence was analyzed. The orderly assembled fusion protein was confirmed by modified Gm1-ganglioside ELISA with Abs to adhesin. The results indicate that the purified fusion protein is an Adhesin/CTXA2B protein containing the H. pylori adhesin and $G_{m1}4-ganglioside binding activity of CTXB and the expressed fusion protein in E. coli could be easily purified by the refolding process, Its molecular weight was 168kDa as estimated by size exclusion chromatography. The Adhesin/CTXA2B protein may be used as a candidate antigen for oral immunization against H. pylori.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.16 no.11 s.102
• /
• pp.1147-1154
• /
• 2005

In this paper, we propose some PAPR(Peak to Average Power Ratio) reduction methods using WHT(Walsh Hadamard Transform) to reduce high PAPR generated in OFDM system because of multi carrier modulation. These proposed methods are the methods which has additional PAPR reduction performance without a loss of bandwidth efficiency and a large increment of calculation complexity than common PAPR reduction methods by combining the WHT with some common methods. In this paper, we propose two PAPR reduction methods made by combining a SLM(Selective Mapping) and DSI(Dummy Sequence Insertion) with a WHT. From simulation result, we can find that the PAPR reduction methods using a WHT can get about 1 dB additional PAPR reduction performance than common PAPR reduction methods; they are SLM and DSI. And, because our proposed methods have not only PAPR reduction effect, but also frequency diversity effect, more stabile data transmission is possible in nonlinear HPA and multipath fading channel.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.36D no.6
• /
• pp.1-12
• /
• 1999

This paper illustrates and analyzes system structure, link budget and cell coverage to accommodate Korea environment about LMDS systems that are expected to play an important role as the future wireless infrastructure of the information superhighway. In the mean time, many parameters used for the analysis apply to the allocated frequency bandwidth (Up-stream : 24.25GHz-24.75GHz, Down-stream : 25.5GHz-27.5GHz) of Ministry of Information and Communication. The modem and channel coding must be developed to accommodate specifications of DAVIC protocol. The materials about atmospheric phenomena refer to apply specifications of ITU-R. This paper will be need to disign the network structure and system configuration of LMDS system.

• The Korean Journal of Physiology and Pharmacology
• /
• v.16 no.1
• /
• pp.17-24
• /
• 2012

The hypothalamus-pituitary-adrenocortex (HPA) axis is the central mediator of the stress response. The supramammillary (SuM) region is relatively unique among the hypothalamic structures in that it sends a large, direct projection to the hippocampal formation. It has been shown that mild stress could activate the SuM cells that project to the hippocampus. However, the role of these cell populations in modulating the stress response is not known. The present study examined the effect of stress on different populations of SuM cells that project to the hippocampus by injecting the fluorescent retrograde tracer, fluorogold (FG), into the hippocampus and utilizing the immunohistochemistry of choline acetyltransferase (ChAT), corticotrophin releasing factor (CRF), serotonin (5-HT), glutamate decarboxylase (GAD), tyrosine hydroxylase (TH) and NADPH-d reactivity. Immobilization (IMO) stress (2 hr) produced an increase in the expression of ChAT- immunoreactivity, and tended to increase in CRF, 5-HT, GAD, TH-immunoreactivity and nitric oxide (NO)-reactivity in the SuM cells. Fifty-three percent of 5-HT, 31% of ChAT and 56% of CRF cells were double stained with retrograde cells from the hippocampus. By contrast, a few retrogradely labeled cells projecting to the hippocampus were immunoreactive for dopamine, ${\gamma}$-aminobutyric acid (GABA) and NO. These results suggest that the SuM region contains distinct cell populations that differentially respond to stress. In addition, the findings suggest that serotonergic, cholinergic and corticotropin releasing cells projecting to the hippocampus within the SuM nucleus may play an important role in modulating stress-related behaviors.

• Pediatric Infection and Vaccine
• /
• v.12 no.2
• /
• pp.166-177
• /
• 2005

Purpose : The purpose of this study was to examine the molecular epidemiology and genetic variability of adenovirus(Ad) serotypes Ad1, Ad2, and Ad5 over 14 years in Korea. Methods : A total of 382 adenoviral strains isolated from the nasopharyngeal aspirates of children with lower respiratory tract infections in Seoul, Korea from November 1990 to February 2003 were serotyped by neutralization assay with type-specific antisera. Viral DNAs were extracted from infected cell lysates by the modified Hirt procedure. Genome type(GT) was determined by DNA restriction analysis with 12 restriction enzymess(BamHI, BclI, BglI, BglII, BstEII, EcoRI, HindIII, HpaI, SalI, SmaI, XbaI, and XhoI). To evaluate the genetic relatedness, pairwise comigrating restriction fragments(PCRF) analysis was performed. Results : Of 382 strains, 33 strains(9%) were Ad1, 45 strains(12%) were Ad2, and 24 strains(6%) were Ad5. Eighteen GTs(Ad1p1-Ad1p7, Ad1a, Ad1b, Ad1b1-Ad1b3, Ad1c, Ad1d, Ad1e, Ad1e1, Ad1e2, Ad1f) among Ad1, 24(Ad2p1-Ad2p11, Ad2a, Ad2a1-Ad2a6, Ad2b, Ad2c, Ad2d, Ad2e, Ad2e1-Ad2e3) among Ad2, and 10(Ad5p1, Ad5p2, Ad5a, Ad5a1-Ad5a7) among Ad5 strains were identified. One or two strains of the vast majority of GTs were isolated during the study period while a few GTs were identified sporadically with more than 2 strains. It is notable that some GTs such as Ad1p5 and Ad5a1 appeared in cluster during a short period. In analysis of genetic relatedness, the degree of PCRFs(pairwise comigrating restriction fragments) for Ad1 varied from 79 to 99%, for Ad2, 82 to 99%, and for Ad5, 85 to 99%. Conclusion : This study established the comprehensive nomenclature systems of Ad1, Ad2, and Ad5. Diverse GTs identified in this study have crucial implications in the genomic diversity and epidemiological characteristics of Ad1, Ad2, and Ad5.