• Title/Summary/Keyword: experssion

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자료-도서관과 지적 자유에 관한 선언

  • Korean Library Association
    • KLA journal
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    • v.40 no.2 s.315
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    • pp.40-43
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    • 1999
  • 아래의 자료는 국제도서관협회연맹(IFLA, International Federation Library Associations and Institutions)의 '정보에의 자유로운 접근과 표현의 자유를 위한 위원회'(FAIFE. committee for Free Access to Infermation and Freedom of Experssion)가 이사회의 심사를 받아 그 문안을 확정하여 1999년 3월 25일 발표한 "Statement on Libraries and Intellectual Freedom"을 도서관문화 편집실에서 번역한 것으로, 번역문과 영문원문을 함께 게재하였음. <편집자주>

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Effects of Gene Expression of Photobacterium leiognathi CuZn Superoside Dismutase (PSOD) by lacZ Promotor Control under Oxidative Stress

  • Kim, Young-Gon
    • Korean Journal of Microbiology
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    • v.30 no.6
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    • pp.460-465
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    • 1992
  • The effect of PSOD expression on lacZ-sodP fusion (pYK4) was explored in Escherichia coli sodA sodB mutants (QC774) under oxidative stress. In this system, although .betha.-galactosidase activity was not fully induced by isopropyl-1-thio-.betha.-galactosidase (IPTG) and was inhibited by glucose, functional PSOD was under lacZ promotor control and was induced by IPTC, lactose, PQ and copper isons, finally, the results show that higher PSOD expression leel was consistently importnat in defending against superoxide radicals.

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Transiently Experessed Salt-Stress Protection of Rice by Transfer of a Bacterial Gene, mtlD

  • Lee, Eun-A;Kim, Jung-Dae;Cha, Yoo-Kyung;Woo, Dong-Ho;Han, In-Seob
    • Journal of Microbiology and Biotechnology
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    • v.10 no.3
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    • pp.415-418
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    • 2000
  • Productivity of a rice plant is greatly influenced by salt stress. One of the ways to achieve tolerance to salinity is to transfer genes encoding protective enzymes from other organisms, such as microorganisms. The bacterial gene, mtlD, which encodes mannitol-1-phosphate dehydrogenase (Mtl-DH), was introduced to the cytosol of a rice plant by an imbibition technique to overproduce mannitol. The germination and survival rate of the imbibed rice seeds were markedly increased by transferring the mtlD gene when it was delivered in either a pBIN19 or pBmin binary vector. When a polymerase chain reaction was performed with the genomic DNAs of the imbibed rice leaves as a template and with mtlD-specific primers, several lines were shown to contain an exogenous mtlD DNA. However, a reverse transcription (RT)-PCR analysis revealed that not all of them showed an expression of this foreign gene. This paper demonstrates that the growth and germination of rice plants transiently transformed with the bacterial gene, mtlD, are enhanced and these enhancements may have resulted from the experssion of the mtlD gene. The imbibition method empolyed in this study fulfills the requirements for testing the function of such a putative gene in vivo prior to the production of a stable transgenic plant.

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Expression of Hepatitis B Viral Core Antigen Gene in Excherichia coli (대장균에서 한국형 B형 간염바이러스 내면항원 유전자의 발현)

  • 최수근;이원상;김성기;노현모
    • Korean Journal of Microbiology
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    • v.29 no.2
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    • pp.80-84
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    • 1991
  • We cloned and expressed hepatitis B viral core antigen (HBcAg) gene in E. coli using $P_{L}$ promoter system. For optimal expression of the gene, we undertook the studies on the effects of the distance between Shine-Dalgarno (SD) sequence and start codon, copy number of repressor gene, induction temperature, and the stability of the core antigen. The results demonstrated that the induction at 37.deg.C was more efficient than at 42.deg.C, and the 11 base pairs (bp) distance between SD sequence and start codon of HBcAg gene was more efficient than the 15 bp distance in E. coli. The copy number of cI857 repressor gene did not influence on the expression of HBcAg, and the expression level of HBcAg in mutant type (low protease activity) and wild type strains was almost the same. The produced core antigen appeared to be HBcAg not HBeAg judged by two different radioimmunoassat (RIA) kits. This result suggested that the antigen was stable in E. coli.i.

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Electrical Breakdown Strength of Insulation under Combined DC-AC Voltages

  • Grzybowski, S.
    • Electrical & Electronic Materials
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    • v.11 no.10
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    • pp.32-39
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    • 1998
  • Electrical breakdown strength of paper-oil and polypropylene/film-oil insulation samples was measured under dc, ac and pulsating voltages. The latter was obtained by superimposing ac upon dc volate and provides an attractive method for a simultaneous testing and assessment of the state of insulation of the various parts of HV apparatus in service. The measurements were carried out over a wide range of the pulsation ratio defined as p=Eac/Edc. The results obtained under pulsating voltages follow colsely an experssion which relates the breakdown strength to the sum of arc tangent and arc cotangent function of the parameter p. The study was carried out using dry paper as well as paper containing various degrees of moisture. The presence of moisture showed a pronounced effect upon the breakdown strength which varied with the pulsation parameter p.

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Reproductive Cvcle-related Changes in GnRH Immunoreactivitv in the Brains of Three Congeneric Species of Frog. (3종의 개구리 뇌에서 생식주기에 따른 GnRH 면역반응성의 변화)

  • 임욱빈;김정우
    • The Korean Journal of Zoology
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    • v.37 no.3
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    • pp.311-317
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    • 1994
  • Seasonal variations of GnRH were investigated by immunohlstochemicsl technique in three species of frog, Rona niEromaculutu, R. dvbowskii 8nd R. mgosa with different ovulation period in order to examine the relationship between GnRH expression and reproductive function. In all three species of frog, the intensity of GnRH immunoreactivitv and the number of GnRH neurons in the brawn were relatively high in frogs at the pre-ovulation period and markedly increased at the ovulation period. Those were then decreased after ovulation and further lowered during early hibernation period. These results indicate that GnRH experssion is closely related to specific phases of annual reproductive cycle in frog.

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