• Title/Summary/Keyword: fithess

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Comparative Studies on Polymorphism and Fithess between Two ADH Alleles in Drosophila melanogaster (Deosophila melanogadter의 ADH Polymorphism 과 두 유전자 사이의 적응성에 관한 비교 연구)

  • 최영헌;유미애;이원호
    • Korean journal of applied entomology
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    • v.33 no.3
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    • pp.141-147
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    • 1994
  • Tne present studies were camied out to ~nvestigate the allele frequency variations of alcohol dehydrogenase (ADH) in natural populat~ons of Drosophiio melonogoster and the correlations of iwo ADH alleles between fitness and ethanol. ADH alleles were found to be polymorphic in natural populations of D. rnelanogaster. The frequencies of FF, FS and SS genotypes were 47.66, 42 18, and 10.16%. respectively, therefore the F gene frequency (68.75) was shown to be hlgher than the S gene (31.25 %). The FF genotype was slightly superior to the SS genotype in both fecundiiy and eclaslon. The frequency of AdhF allele in the small alt>fic~apl opulaliow originated from natural populations was increased for 20 generations on normal media at 25$^{\circ}$C In resistance to ethanol, the FF genotype was supenor to the SS genotype, too. It meant that ethanol as environmental factor might be the selective factor on ADH locus in natural populat~ons of D meionogoster.

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A new manufacturing method of all ceramic restoration using alumina tape and presentation of clinical cases

  • Oh, Nam-Sik;Kim, Eui-Seong;Lee, Keun-Woo;Han, Jung-Suk;Kim, Dae-Joon;Lee, Myung-Hyun
    • The Journal of Korean Academy of Prosthodontics
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    • v.38 no.6
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    • pp.800-805
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    • 2000
  • In an effort to facilitate fabrication procedure of all ceramic crowns, a novel preparation method for all ceramic crown using alumina tape was developed. The alumina tape having a uniform thickness was cast by using Doctor blade method. The physical properties of newly introduced alumina tape has biaxial flexure strength of $500\sim600MPa$. The value of toughness is $3.18\sim3,28MPa.m^{1/2}$ which corelates with fracture and the linear shrinkage rate of the alumina tape is 0.44% during core production. The marginal fitness of the alumina tape all-ceramic restoration with $90{!`}$shoulder margin had average marginal discrepancy at $78.3{\S}$ > and average marginal gap at $44.4{\S}$ >. At the marginal preparation of $135{!`}$deep chamfer, the average marginal discrepancy at $82.1{\S}$ > and the average marginal gap at $40.2{\S}$ > had been reported. This fabrication procedure of all ceramic crowns with alumina tapes is easier and less technical sensitive for dental technicians. After restoration with new all ceramic crowns we followed the patients 2 years later, there were no complications as porcelain fractures or periodontal disease. We had good esthetic clinical results with new all ceramic crowns.

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