• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.342-344
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• 1999

인터넷 ED 시스템은 TCP/IP 프로토콜을 사용하여 문서를 전송하게 되는데 전송 도중 패킷 스니핑에 의하여 문서정보가 노출될 수 있다. 이러한 정보노출을 방지 할 수 있는 대표적인 보안 기법에는 인터넷 EDI 보안 프로토콜로 권고되고 있는 S/MIME과 전자우편 암호화 프로그램인 PGP가 있다. S/MIME은 내부에서 사용되는 암호알고리즘의 사용제약으로 인하여 완벽한 구현이 어려우며 PGP의 경우 보안측면에 있어서 수신부인 방지 기능을 제공하지 못하고 있다. 본 논문에서는 S/MIME과 PGP에서 사용되고 있는 보안 기법을 분석하여 기밀성, 인증, 무결성, 송수신 부인방지 기능을 가지는 시스템을 제시한다. 본 시스템은 기존 암호화 알고리즘들의 문제점을 보완할 수 있는 혼합모델을 사용하여 기밀성과 무결성, 송신부인방지 기능을 구현하였고, 인증서버인 삼성 PKI 서버와의 인터페이스를 개발하여 인증을 획득하였다. 수신부인방지의 경우 암호화 메카니즘만으로 획득될 수 없기 때문에 수신자가 문서를 읽는 순간 송신자 측으로 수신자의 전자서명을 자동으로 전송해 주는 프로토콜을 통하여 구현하였다.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.492-494
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• 1999

클라이언트용 메일 프로그램에 비해 웹 메일 시스템은 일반 사용자에게 인터페이스와 기능적인 면에서 편리함을 제공한다. 그러나 메일 메시지를 전송하고 관리하는 측면에서는 보안상의 취약점을 갖고 있다. 본 논문에서는 메일 메시지를 안전하게 전송하고 편리하게 관리하기 위한 웹 기반의 메일 시스템을 구현하였다. 이 시스템에서는 일반적인 메일 기능과 PGP(Pretty Good Privacy)를 이용한 메시지 암호화 기능, SSL(Secure Socket Layer) protocol을 이용하여 웹 메일 시스템과 웹 브라우저 사이의 메시지 보호 기능 등을 이용하여 클라이언트용 메일 프로그램을 이용하기 위한 설정이 필요 없이 웹 브라우저만을 가지고 안전한 메시지 전송과 관리를 할 수 있도록 하였다.

• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.34-43
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• 2005

Purpose: $^{99m}Tc$-sestamibi(MIBI) and $^{99m}Tc$-tetrofosmin have been used as substrates for P-glycoprotein (Pgp) and multidrug resistance associated protein (MRP), which are closely associated with multidrug resistance of the tumors. To understand different handling of radiotracers in cancer cell lines expressing Pgp and MRP, we compared cellular uptakes of $^{99m}Tc$-MIBI and $^{99m}Tc$-tetrofosmin. The effects of cyclosporin A (CsA), well-known multidrug resistant reversing agent, on the uptake of both tracers were also compared. Materials and Methods: HCT15/CL02 human colorectal cancer cells for Pgp expressing cells, and human non-small cell lung cancer A549 cells for MRP expressing cells, were used for in vitro and in vivo studies. RT-PCR, western blot analysis and immunohistochemistry were used for detection of Pgp and MRP. MDR-reversal effect with CsA was evaluated at different drug concentrations after incubation with MIBI or tetrofosmin. Radioactivities of supernatant and pellet were measured with gamma well counter. Tumoral uptake of the tracers were measured from tumor bearing nude mice treated with or without CsA. Results: RT-PCR, western blot analysis of the cells and irnrnunochemical staining revealed selective expression of Pgp and MRP for HCY15/CL02 and A549 cells, respectively. There were no significant difference in cellular uptakes of both tracers in HCT15/CL02 cells, but MIBI uptake was slightly higher than that of tetrofosmin in A549 cells. Co-incubation with CsA resulted in a increase in cellular uptakes of MIBI and tetrofosmin. Uptake of MIBI or tetrofosmin in HCT15/CL02 cells was increased by 10- and 2.4-fold, and by 7.5 and 6.3-fold in A549 cells, respectively. Percentage increase of MIBI was higher than that of tetrofosmin with CsA for both cells (p<0.05). In vivo biodistribution study showed that MIBI (114% at 10 min, 257% at 60 min, 396% at 240 min) and tetrofosmin uptake (110% at 10 min, 205% at 60 min, 410% at 240 min) were progressively increased by the time, up to 240 min with CsA. But increases in tumoral uptake were not significantly different between MIBI and tetrofosmin for both tumors. Conclusion: MIBI seems to be a better tracer than tetrofosmin for evaluating MDR reversal effect of the modulators in vitro, but these differences were not evident in vivo tumoral uptake. Both MIBI and tetrofosmin seem to be suitable tracers for imaging Pgp- and MRP-mediated drug resistance in tumors.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.70-72
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• 2002

전자우편(E-Mail)은 아주 편리한 통신수단이지만, 무분별한 광고성 스팸메일(Spam-Mail)의 침입과 무단으로 타인의 메일을 가로채거나 변조할 수 있기 때문에 메일의 신뢰성이 문제가 되고 있다. 본 연구에서는 이와 같은 문제를 해결하기 위하여 메일의 제목과 내용의 문자열을 분석하여 자동으로 스팸메일을 구분할 뿐만 아니라 보안도구인PGP(Pretty Good Privacy)를 이용하여 메일을 암호화하고 인증하여 근본적으로 스팸메일을차단하는 시스템을 개발한다.

• Korean Journal of Poultry Science
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• v.24 no.3
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• pp.107-116
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• 1997

In order to achieve optimal reproductive performance, reliable morphological and physiological basic data on the reproductive organs are desirable. Adult male Korean ring-necked pheasant in inactive(mid of January) and active state (end of April) were used in this study. In addition, five active state pheasants were received a single dose of 60Co-ray 500 rads each to damage the testes. The objective of this study was to investigate the distribution pattern of protein gene product (PGP) 9.5 and ${\alpha}$-tubulin in the pheasant testes of the active, inactive and ${\gamma}$-ray irradiated active states. The results obtained were summarized as follows 1. The seminiferous tubules collected in inactive states( mid of Jan) showed narrow lumen, and the spermatogonia and the Sertoli cell were well preserved. The PGP 9.5 immunoreactivity of these tubules showed a positive reaction in paranucleus area of the spermatogonia, and a positive reaction in a small number of the Leydig cells in the interstitium of the seminiferous tubules. 2. The seminiferous tubules were dilated in active state(end of April) as compared with the inactive state. The PGP 9.5 reactivity in these tubules showed a positive reaction in many Leydig cells in the interstitium of the seminiferous tubules, and the testes of ${\gamma}$-ray irradiated group showed partially weak reaction in the interstitium of the seminiferous tubules. 3. The ${\alpha}$-tubulin reactivity in the seminiferous tubules of the inactive testes was strongly positive in the cytoplasmic process of the Sertoli cell from the basal stem region to the apical ex-tension. From the broad part of the stem region to the luminal space, the active testes showed a strong positive reaction. The ${\gamma}$-ray irradiated groups showed diminished reaction in the basal region.

• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.20-29
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• 2007

Although E-mail system is considered as a most important communication media, 'Spam' is flooding the Internet with many copies of the same message, in an attempt to force the message on people who would not otherwise choose to receive it. Most spam is commercial advertising, often for dubious products, get-rich-quick schemes, or quasi-legal services. Therefore advanced anti-spam techniques are required to basically reduce its transmission volume on sender mail server or MTA, etc. In this study, we propose a new sender authentication model with encryption function based on modified DomainKey with SMS for Spam mail protection. From the SMS message, we can get secret information used for verification of its real sender on e-mail message. And by distributing this secret information with SMS like out-of-band channel, we can also combine proposed modules with existing PGP scheme for secure e-mail generation and authentication steps. Proposed scheme provide enhanced authentication function and security on Spam mail protection function because it is a 'dual mode' authentication mechanism.

• Journal of Korea Society of Industrial Information Systems
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• v.8 no.1
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• pp.43-54
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• 2003

E-Commerce, characterized by the exchange of message, occurs between individuals, organizations, or both. A critical promotion factor of e-Commerce is message authentication, the procedure that allows communicating parties to verify the received messages are authentic. It consists of message unforgery, message non-repudiation, message unalteration, and origin authentication. It is possible to perform message authentication by the use of public key encryption. PGP(Pretty Good Privacy) based on X.400 MHS(Message Handling System) and PKC(Public Key Cryptosystem) makes extensive use of message exchange. In this paper we propose, design and implement NMAP(New Message Authentication Protocol), an applied public information based encryption system to solve the message authentication problem inherent in public key encryption such as X.400 protocol and PGP protocol and were to cope with the verification of NMAP using fuzzy integral. This system is expected to be use in the promotion of the e-Commerce and can perform a non-interactive authentication service.

• Journal of Ginseng Research
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• v.47 no.1
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• pp.89-96
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• 2023

Background and aim: Panax ginseng, a key herbal medicine of replenishing Qi and tonifying Spleen, is widely used in the treatment of gastrointestinal diseases in East Asia. In this study, we aim to investigate the potential effects and mechanisms of polysaccharides from P. ginseng (PGP) on intestinal mucosal restitution which is one of the crucial repair modalities during the recovery of mucosal injury controlled by the Ca²⁺ signaling. Methods: Rat model of intestinal mucosal injury was induced by indomethacin. The fractional cell migration was carried out by immunohistochemistry staining with BrdU. The morphological observations on intestinal mucosal injury were also performed. Intestinal epithelial cell (IEC-6) migration in vitro was conducted by scratch method. Western-blot was adopted to determine the expressions of PLC-𝛾1, Rac1, TRPC1, RhoA and Cav-1. Immunoprecipitation was used to evaluate the levels of Rac1/PLC-𝛾1, RhoA/TRPC1 and Cav-1/TRPC1. Results: The results showed that PGP effectively reduced the assessment of intestinal mucosal injury, reversed the inhibition of epithelial cell migration induced by Indomethacin, and increased the level of Ca²⁺ in intestinal mucosa in vivo. Moreover, PGP dramatically promoted IEC-6 cell migration, the expression of Ca²⁺ regulators (PLC-𝛾1, Rac1, TRPC1, Cav-1 and RhoA) as well as protein complexes (Rac1/PLC-𝛾1, Cav-1/TRPC1 and RhoA/TRPC1) in vitro. Conclusion: PGP increases the Ca²⁺ content in intestinal mucosa partly through controlling the regulators of Ca²⁺ mobilization, subsequently promotes intestinal epithelial cell migration, and then prevents intestinal mucosal injury induced by indomethacin.

• The Plant Pathology Journal
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• v.39 no.5
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• pp.430-448
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• 2023

Recently, strategies for controlling Fusarium oxysporum f. sp. lycopersici (Fol), the causal agent of Fusarium wilt of tomato, focus on using effective biocontrol agents. In this study, an analysis of the biocontrol and plant growth promoting (PGP) attributes of 11 isolates of loamy soil Bacillus spp. has been conducted. Among them, the isolates B.PNR1 and B.PNR2 inhibited the mycelial growth of Fol by inducing abnormal fungal cell wall structures and cell wall collapse. Moreover, broad-spectrum activity against four other plant pathogenic fungi, F. oxysporum f. sp. cubense race 1 (Foc), Sclerotium rolfsii, Colletotrichum musae, and C. gloeosporioides were noted for these isolates. These two Bacillus isolates produced indole acetic acid, phosphate solubilization enzymes, and amylolytic and cellulolytic enzymes. In the pot experiment, the culture filtrate from B.PNR1 showed greater inhibition of the fungal pathogens and significantly promoted the growth of tomato plants more than those of the other treatments. Isolate B.PNR1, the best biocontrol and PGP, was identified as Bacillus stercoris by its 16S rRNA gene sequence and whole genome sequencing analysis (WGS). The WGS, through genome mining, confirmed that the B.PNR1 genome contained genes/gene cluster of a nonribosomal peptide synthetase/polyketide synthase, such as fengycin, surfactin, bacillaene, subtilosin A, bacilysin, and bacillibactin, which are involved in antagonistic and PGP activities. Therefore, our finding demonstrates the effectiveness of B. stercoris strain B.PNR1 as an antagonist and for plant growth promotion, highlighting the use of this microorganism as a biocontrol agent against the Fusarium wilt pathogen and PGP abilities in tomatoes.

• Journal of Microbiology and Biotechnology
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• v.34 no.2
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• pp.289-295
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• 2024

We have developed an aptamer that specifically binds to Porphyromonas gingivalis to reduce the cellular damage caused by P. gingivalis infection and applied it as a biosensor. P. gingivalis is one of the major pathogens causing destructive periodontal disease among the periodontal microorganisms constituting complex biofilms. Porphyromonas gingivalis G-protein (PGP) known to play an important role in the transmission of germs was used as a target protein for the screening of aptamer. The aptamer that has binds to the G-protein of P. gingivalis, was screened and developed through the Systemic Evolution of Ligands by Exponential Energy (SELEX) method. Modified-Western blot analysis was performed with the aptamer which consisted of 38 single-stranded DNA to confirm the selectivity. ELONA (enzyme linked oligonucleotide assay) used to confirm that the aptamer was sensitive to PGP even at low concentration of 1 ㎍/ml. For the rapid detection of P. gingivalis, we constructed a surface plasmon resonance biosensor with SPREETA using the PGP aptamer. It was confirmed that PGP could be detected as low concentration as at 0.1 pM, which is the minimum concentration of aptamer sensor within 5 min. Based on these results, we have constructed a SPREETA biosensor based on aptamer that can bind to P. gingivalis G-protein. It can be used as an infection diagnosis system to rapidly diagnose and analyze oral diseases caused by P. gingivalis.