• Title/Summary/Keyword: $3{\alpha}$

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The Study of TSEE and TSL Phenomena on α-A12O3 Single Crystals Using the 2π Proportional Counter (2π 비례계수기에 의한 α-A12O3 단결정의 TSEE와 TSL 현상에 관한 연구)

  • Doo, Ha-Young;Sim, Sang-Hung
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.1
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    • pp.69-73
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    • 2004
  • TSEE and TSL phenomena have been measured for ${\alpha}-Al_2O_3$ single crystals by the use of the $2{\pi}$ proportional counter. The ${\alpha}-Al_2O_3$ crystals irradiated to X-ray and UV for the temperature range from room temperature to about 500k degree. Three peaks of TSEE and three peaks of TSL were observed after X-ray irradiation. Also, two peaks of TSEE and three TSL peaks were observed after UV irradiation. TSEE and TSL glow curves of ${\alpha}-Al_2O_3$ single crystals showed very similar to the peaks position regardless of excitation sorts. Form this work, we knew that the $2{\pi}$ proportional counter is useful to not only the energy spectrum analysis device of ${\alpha}$-particle, but also the measurement instrument of TSEE and TSL.

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Cloning and Expression of A Liquefying $\alpha$-Amylase Gene from Bacillus amyloliquefaciens in Bacillus subtilis (Bacillus amyloliquefaciens 액화형 $\alpha$-amylase 유전자의 클로닝 및 Bacillus subtilis에서의 발현)

  • 김사열;송방호;이인구;서정환;홍순덕
    • Microbiology and Biotechnology Letters
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    • v.14 no.6
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    • pp.479-485
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    • 1986
  • A 5200 basepair DNA fragment containing the Bacillus amyloliquefaciens amyE gene, encoding liquefying $\alpha$-amylase (1,4-$\alpha$-1)-glucan glucanohydrolase, EC 3.2.1.1), has been inserted into BamHI site of the pUB110 and the hybrid plasmid was designated as pSKS3. The pSKS3 was transformed into the Bacillus subtilis KM2l3 as a host which is a saccharifying $\alpha$-amylase deficient mutant of Bacillus subtilis NA64, and the plasmid in the transformed cell was expressed $\alpha$-amylase production and kanamycin resistance. The $\alpha$-amylase production of the transformed cell was reduced to one fifth of that of the donor strain. The Bacillus subtilis KM2l3 tarring pSKS3 indicated that the amyE gene product is a polypeptide which has the same electrophoretic mobility with that of the Bacillus amyloliquefaciens, but different from the saccharifying $\alpha$-amylase of Bacillus subtilis NA64. It means that the amyE gene of pSKS3 originales from the Bacillus amyloliquefaciens.

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Activity and application of 20α-hydroxysteroid dehydrogenase in rat 1. Changes in activities of 20α-hydroxysteroid dehydrogenase and serum progesterone concentration (Progesterone의 이화(異化)효소, 20α-hydroxysteroid dehydrogenase의 활성 및 활용에 관한 연구 1. 20α-hydroxysteroid dehydrogenase의 활성 및 혈청 progesterone 농도의 변화)

  • Kang, Chung-boo;Kwak, Soo-dong
    • Korean Journal of Veterinary Research
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    • v.34 no.4
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    • pp.867-872
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    • 1994
  • Progesterone catabolizing enzyme, the enzyme $20{\alpha}$-hydroxysteroid dehydrgenase($20{\alpha}$-HSD) is pivotal in the regulation of ovarian function in rodents, which catabolizes progesterone into biologically inactive $20{\alpha}$-hydroxypregn-4-en-3-one($20{\alpha}$-OHP). In this study was carried out the influence of $20{\alpha}$-HSD activity of ovarian function, we investigated changes in ovarian cytosol $20{\alpha}$-HSD activity and serume progesterone concentration during the estrous cycles and pregnancy in rat. During the estrous cycles, the $20{\alpha}$-HSD activities were highest on the progestrous, but serum progesterone concentration was lowest on this phase. During the pregnancy, the $20{\alpha}$-HSD activities were relatively higher early pregnancy(day-1-3 gestation) and late pregnancy(day 21 to parturition), serum progesterone concentration was maintained significantly high to day 19 of gestation. The $20{\alpha}$-HSD activities were lower during the middle pregnancy. From these results, ovarian $20{\alpha}$-HSD activities may possibly act as physiologically very important in the control and maintenance of estrous cycles in rat.

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한국산 초파리 집단의 유전 생화학적 연구: 노랑 초파리의 $\alpha$-Glycerophosphate dehydrogenase allele에 대하여

  • 정용재;한영수;정영란
    • The Korean Journal of Zoology
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    • v.25 no.3
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    • pp.123-129
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    • 1982
  • In order to establish a biochemical genetic system in Drosophila populations in Korea, the $\\alpha$-glycerophosphate dehydrogenase alleles of eleven natural populations of D. melanogaster in Korea were examined by means of agarose gel electrophoresis. The results obtained are presented below: 1. $\\alpha$-Glycerophosphate dehydrogenase ($\\alpha$-GPDH) allele is scored for eleven natural populations of D. melanogaster in Korea, resulting that $\\alpha$-GPDH is found to be widely polymorphic for two electrophoretic variants. 2. The heterozygosity of $\\alpha$-GPDH is calculated as $40\\sim50%$. 3. The frequency of the FF genotype of $\\alpha$-GPDH is found to be roughly same as the SS genotype, but less than the FS genotype. 4. The F gene of $\\alpha$-GPDH is distributed almost frequently as the S gene.

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Secretory Expression of Human $\alpha_{s1}$-Casein in Saccharomyces cerevisiae

  • Kim, Yoo-Kyeong;Yu, Dae-Yeul;Kang, Hyun-Ah;Yoon, Sun;Chung, Bong-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.9 no.2
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    • pp.196-200
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    • 1999
  • A recombinant human $\alpha_{s1}$-casein was expressed as a secretory product in the yeast Saccharomyces cerevisiae. Three different leader sequences derived from the mating factor $\alpha$l (MF$\alpha$l), inulinase, and human $\alpha_{s1}$-casein were used to direct the secretion of human $\alpha_{s1}$-casein into the extracellular medium. Among the three leader sequences tested, the native leader sequence of human $\alpha_{s1}$-casein was found to be the most efficient in the secretory expression of human $\alpha_{s1}$-casein, which implies that the native leader sequence of human $\alpha_{s1}$-casein might be used very efficiently for the secretory production of other heterologous proteins in yeast. The recombinant human $\alpha_{s1}$-casein was proteolytically cleaved as the culture proceeded. Therefore, an attempt was made to produce human $\alpha_{s1}$-casein using a S. cerevisiae mutant in which the YAP3 gene encoding yeast aspartic protease 3 (YAP3) was disrupted. After 72 h of culture, most of the human $\alpha_{s1}$-casein secreted by the wild type was cleaved, whereas more than 70% of the human $\alpha_{s1}$-casein secreted by yap3-disruptant remained intact. The results suggest that YAP3 might be involved in the internal cleavage of human $\alpha_{s1}$-casein expressed in yeast

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A Facile Synthesis of Disacharides Containing $\alpha$ -Altropyranosidic Linkage by 1, 2-trans Glycosidation of D-allal Derivatives (D-알알 유도체의 1, 2-trans 글리코시드 형성 반응을 이용한 $\alpha$ -알트로피라노시드 결합을 갖는 이당류의 효과적 합성법의 개발)

  • Choi, Jong Lak;Yoon, Shin Sook;Chun, Keun Ho;Nam Shin, Jeong E.
    • Journal of the Korean Chemical Society
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    • v.42 no.1
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    • pp.78-83
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    • 1998
  • It's necessary to develope a facile methodology forming ${\alpha}$-altropyranosidic linkage, for the synthesis of trisaccharide repeating unit of O-antigenic part of Campylobacter jejuni gram negative bacteria. In this paper, the effective synthesis of disaccharides containing ${\alpha}$-altropyranosidic linkage by 1,2-trans glycosidation of allal derivatives was discussed. 4, 6-O-Benzylidene-3-O-(t-butyldimethylsilyl)-D-allal was treated with DMDO (3,3-dimethy ldioxirane) to yield 1,2-anhydro-4, 6-O-benzylidene-3-O-(t-butyldimethylsilyl)-${\beta}$-D-altropyranose. The reaction of 1,2-anhydro-4, 6-O-benzylidene-3-O-(t-butyldimethylsilyl)-${\beta}$-D-altropyranose with allyl alcohol gave allyl 4, 6-O-benzylidene-3-(t-butyldimethylsilyl)-${\alpha}$-D-altropyranoside quantitatively, and reactions with glucals were also successful to prepare ${\alpha}$-altropyranosodic disaccharides. It is convinced that 1,2-trans glycosidation of allal derivatives should be an attractive choice for preparing oligosaccharides containing ${\alpha}$-altropyranosidic linkages.

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WEAK α-SKEW ARMENDARIZ RINGS

  • Zhang, Cuiping;Chen, Jianlong
    • Journal of the Korean Mathematical Society
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    • v.47 no.3
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    • pp.455-466
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    • 2010
  • For an endomorphism $\alpha$ of a ring R, we introduce the weak $\alpha$-skew Armendariz rings which are a generalization of the $\alpha$-skew Armendariz rings and the weak Armendariz rings, and investigate their properties. Moreover, we prove that a ring R is weak $\alpha$-skew Armendariz if and only if for any n, the $n\;{\times}\;n$ upper triangular matrix ring $T_n(R)$ is weak $\bar{\alpha}$-skew Armendariz, where $\bar{\alpha}\;:\;T_n(R)\;{\rightarrow}\;T_n(R)$ is an extension of $\alpha$ If R is reversible and $\alpha$ satisfies the condition that ab = 0 implies $a{\alpha}(b)=0$ for any a, b $\in$ R, then the ring R[x]/($x^n$) is weak $\bar{\alpha}$-skew Armendariz, where ($x^n$) is an ideal generated by $x^n$, n is a positive integer and $\bar{\alpha}\;:\;R[x]/(x^n)\;{\rightarrow}\;R[x]/(x^n)$ is an extension of $\alpha$. If $\alpha$ also satisfies the condition that ${\alpha}^t\;=\;1$ for some positive integer t, the ring R[x] (resp, R[x; $\alpha$) is weak $\bar{\alpha}$-skew (resp, weak) Armendariz, where $\bar{\alpha}\;:\;R[x]\;{\rightarrow}\;R[x]$ is an extension of $\alpha$.

Studies on $\alpha$-amylase of Bacillus circulans F-2 (Part 3) Hydrolysis of Various Substrates by Purified $\alpha$-amylase (Bacillus circulans F-2가 생산하는 $\alpha$-amylase에 관한 연구 (제3보) 정제 $\alpha$-amylase에 의한 각종 기질의 분해)

  • ;Hajime Taniguchi;Yoshiharu Maruyama
    • Microbiology and Biotechnology Letters
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    • v.10 no.4
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    • pp.259-265
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    • 1982
  • These experiments were conducted to investigate the hydrolysis products on the various oligosaccharides of Bacillus cirulans F-2 $\alpha$-amylase, and the hydrolysis rate on the various raw starches of Bacillus circulans F-2 $\alpha$-amylase, Bacillus amylotiquefaciens $\alpha$-amylase and Rhizopus niveus glucoamylase. The results obtained were as follows : 1. Maltotetraose, maltopentaose, maltohexaose, maltoheptaose and maltooctaose were hydrolyzed, but maltose and maltotriose were not hydrolyzed by Bacillus circulans F-2 $\alpha$-amylase. Among maltotetraose, maltopentaose, maltohexaose, maltoheptaose and maltooctaose, especially maltotetraose was hydrolyzed weakly by Bacillus circulans F-2 $\alpha$-amylase. 2. The Hydrolysis rate of oyster glycogen was slightly lower than soluble starch, amylose and amylopectin. 3. The hydrolysis rate of com starch was higher in shaking incubation than in stationary incubation, but the hydrolysis rate of potato starch was not definite according to kinds of enzyme. 4. On com, rice, arrowroot, high amylose corn, banana, sago, yam and potato starch, Bacillus circulans F-2 $\alpha$-amylase exhibited a remarkably higher hydrolysis rate than Bacillus amyloquefaciems $\alpha$-amylase and Rhizopus niveus glucoamylase.

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Fabrication and Properties of $\alpha$-$Fe_{2}O_{3}$Thin Films Prepared by RF-magnetron sputtering method (RF-magnetron sputtering 법을 이용한 개스 센서용 $\alpha$-$Fe_{2}O_{3}$박막의 제조 및 특성)

  • 최진영;장건익
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.499-502
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    • 2000
  • In this study, $\alpha$-Fe$_2$O$_3$thin films were deposited on $Al_2$O$_3$substrate by RF magnetron sputtering method from a $\alpha$-Fe$_2$O$_3$target(99.9%). The sputtering atmosphere was Ar and 80%Ar:20%O$_2$mixture in a total gas pressure of 1~3mTorr. As-deposited $\alpha$-Fe$_2$O$_3$thin films were heated to 300, 400, 500, $600^{\circ}C$ for 5hr in oxygen atmosphere. The structure and the morphology of $\alpha$-Fe$_2$O$_3$thin films were examined by scanning Electron microscopy(SEM) and the crystal structure was analyzed by X-Ray Diffractometer(XRD). The microstructure of the annealed $\alpha$-Fe$_2$O$_3$films exhibits rather gross particle and the grain size was less than 100nm. Since the grain size was very small, the gas sensitivity was expected to be improved.

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Fabrication and characterization of $\alpha$-Fe$_2$O$_3$ thin film gas sensor by CVD (CVD법을 이용한 $\alpha$-Fe$_2$O$_3$박막 가스센서의 제조 및 물성평가)

  • 최성민;이세훈;최성철
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.3
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    • pp.280-285
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    • 1999
  • $\alpha$-$Fe_2O_3$ thin film gas sensors were deposited at various temperature by CVD method. Polycrystalline $\alpha$-$Fe_2O_3$ thin films were deposited at $175^{\circ}C$ and $200^{\circ}C$. $\gamma$-$\alpha$-$Fe_2O_3$ phase was obtained when the deposition temperature was higher than $250^{\circ}C$. The crystallite size of $\alpha$-$Fe_2O_3$ was affected by the deposition and annealing temperature. The specimen deposited at $175^{\circ}C$ showed maximum sensitivity. In this condition, the sensitivity of $\alpha$-$Fe_2O_3$ thin film for NO gas (at 250 ppm) was 3.2 and response time (at 100ppm) was 12 second.

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