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        검색결과 98

        81.
        2013.07 서비스 종료(열람 제한)
        We investigated whether sound could alter gene expression in plants. Using a sound-treated subtractive library, a set of sound-responsive genes in plants was demonstrated through mRNA expression analyses. Of them, the rbcS and ald genes, which are light responsive, up-regulated their expression with sound treatment in both light and in dark conditions. This suggested that sound could be used as a gene regulator instead of light. When we analyzed ald gene expression using various single wavelengths, a significant increase in mRNA levels was found at 125 or 250 Hz but decreased at 50 Hz, indicating that the gene responded to sound in a wavelength-specific manner. To determine whether the ald promoter respond to sound, we generated transgenic rice plants harboring the chimeric gene consisting of a 1,506-bp promoter fragment of the ald gene fused to Escherichia coli GUS reporter gene. Analyses of mRNA expressison level of three independent transgenic lines sound-treated with 50 or 250 Hz for 4 h showed that the Gus gene expression in all three transgenic lines was up regulated by 250 Hz, but down regulated by 50 Hz. These results correlated with sound responsive mRNA expression pattern observed for the ald gene in rice plants, indicating that the 1,506-bp ald promoter confers sound-responsiveness on a reporter gene in transgenic rice plants. We also investigated whether sound waves could improve salt tolerance in rice seedling. The rice seedlings were sound treated with 800 Hz for 1hr, and then treated with 0, 75, 150, and 225mM NaCl for 3 days to observe changes in physiological and morphological aspects. Sound treatment seedlings resulted in enhanced salt stress tolerance, mainly demonstrated by the sound treated seedlings exhibiting of increased root relative water contents (RWC), root length and weight, photochemical efficiency (ratio of variable to maximum fluorescence, Fv/Fm), and germination rate under salt stress condition. This demonstrates that a specific sound wave might be used, not only to alter gene expression in plant, but also to improve salt stress tolerance.
        82.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        Environment friendly agricultural material products (EFAMs) in current market were evaluated for their insecticidal or acaricidal activities. EFAMs were evaluated against Tetranychus urticae, Plutella xylostella, Myzus persicae and Nilaparvata lugens in spray method. Several EFAMs indicated high control value in spray method. Hatchability of T. urticae was relatively high after EFAM treatment. some materials show high insecticidal activities against P. xylostella larvae but not against eggs. Few meterials showed more than 80% insecticidal activities against M. persicae and N. lugen. The control value of more than half the materials for pest control was lower than 60%. EFAMs containing S. flavescens, neem oil and Rape showed higher control value
        87.
        2003.09 서비스 종료(열람 제한)
        This study was conducted to investigate the effect of vitrification solution(VS) on in vitro developmental competence of immature porcine oocytes. The immature porcine oocytes were exposed to the following vitrification solution, at RT. 1) EFS sol. : 20% ethylene glycol (EG) 3 min, 40% EG + 18%(w/v) Ficoll(MV70, 000) + 0.3 M sucrose 30 sec, 2) GE sol. : 10% glycerol 5 min, 10% G + 20% EG 5 min, 25% G +25% EG 30 sec, 3) EG sol : 1.5M EG 2.5 min, 5.5 M EG + 1.0 M sucrose 30 sec. Oocytes were immediately transferred into 1.0 M, 0.5 M, 0.25 M, 0125 M, 0 M sucrose solution for 2.5 min each at RT. After removal of VS, immature oocytes were matured in vitro and subsequently all oocytes were subjected to IVF followed in vitro culture for 7 days. Maturation rates of oocytes were 38.8%, 44.5%, 22.4% and 57.6%, in EFS, EG, GE and Control, respectively, maturation rates of oocytes in EG and Control was significantly higher than EFS and GE(P<0.01). Fertilization rates of oocytes in Control was significantly higher than other treated groups(P<0.05), but no difference were observed among treated groups. Polyspermic rates were no significant difference among four groups. Cleavage rates of oocytes were 21.9%, 47.1%, 19.0% and 65.9%, in EFS, EG, GE and Control, respectively, cleavage rates of oocytes in EG and Control was significantly higher than EFS and GE(P<0.05), but blastocyst formation rates were no significant difference among four groups. These results suggested that the use of EG solution could be a great challenge for reaching a successful vitrification of immature porcine oocytes.
        88.
        2003.09 서비스 종료(열람 제한)
        The high incidence of polyspermic fertilization is one of the major causes lowering the overall efficiency of porcine IVF. The common procedure for IVF involves the co-culture of both gametes in the medium drop, which increases sperm concentration and incidence of polyspermy. Therefore, the present study was carried out to increase the efficiency of porcine IVF by reducing polyspermy using a modified swim-up method. This method modifies conventional swim-up washing by placing oocytes directly at the time of washing. Sperm pellet was prepared in the tube and mature oocytes were placed on cell strainer with pore size (Falcon 2350) at the top of the tube. After insemination, the oocytes were stained for examination. Also, the developmental potential of fertilized embryos was measured to evaluate for the feasibility of this method. While having similar penetration rates in both methods (), there was a significant reduction of polyspermy in modified swim-up method () compare to the control ( (p<0.05). Subsequent culture showed higher rate of blastocyst formation in modified swim-up method (20.440.99%) than the control () (P<0.05), even though there was no significant difference. These results suggest that, by controlling the number of spermatozoa reaching the oocytes, porcine oocytes might be protected from polyspermy in vitro. Also, the developmental potential of the fertilized embryos using this method could be improved by increasing the pool of spermatozoa with better quality. Further optimization of the procedure required to implicate this method in routine porcine IVF.
        89.
        2003.09 서비스 종료(열람 제한)
        The lutropin/choriogonadotropin receptor (LHR) is a member of the rhodopsin-like subfamily of G protein coupled receptor (GPCRs), that has been shown to mediate the internalization of its two naturally occurring agonist, lutropin and choriogonadotropin (CG). The clustered agonist-receptor complex is internalized by a dynamin-dependent pathway and traverses the endosomal compartment without agonist dissociation Dissociation of the agonist-receptor complex occurs in the lysosomes, where both the agonist and receptor are degrade. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty (FMPP). A FMPP is a form of sexual precocious puberty in boys in which testosterone levels are elevated independent of changes in luteinizing hormone-releasing hormone and serum luteinizing hormone levels, We have now analyzed two naturally occurring, constitutively active mutants of the human LHR. These mutations were introduced into the rat LHR (rLHR) and are designated L435R and D556Y. Cells expressing rLHR-D556Y bind human choriogonadotropin (hCG) with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. Cells expressing rLHR-L435R also bind hCG with normal affinity, exhibit a 47-fold increase in basal cAMP, and do not respond to hCG with a further increase in cAMP accumulation. This mutation enhances the internalization of the free and agonist-occupied receptors ~2- and ~17- fold, respectively We conclude that the state of activation of the rLHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing rLHR-L435R is due to the fast rate of internalization of the bound hCG. The finding that membranes expressing rLHR-L435R respond to hCG with an increase in adenylyl cyclase activity supports this suggestion. Autonomous Leydig cell activity in FMPP is caused by a constitutively activating LH/CGR.
        95.
        1997.08 KCI 등재 서비스 종료(열람 제한)
        콩[Glycine max (L. ) Merrill] 종자내 저장양분의 전류에 대한 기초자료를 얻기 위하여, 콩 품종 '힐콩', '팔달콩', 및 '장엽콩' 의 발아와 초기 유묘발달단계 동안 유묘의 각 기관별 건물중의 변화를 고려대학교 자연자원대학 부속농장에서 5월 26일, 6월 5일, 및 6월 14일에 각각 조사하였다. 콩 세품종의 평균 생체중, 평균 건물중 및 평균 수분함량은 자엽부위를 제외한 유묘의 모든 기관에서 V2단계까지 증가하였다. 자엽의 평균 건물중은 V2단계까지 계속 감소하였으며, 발아단계시 자엽 건물중의 약80%가 감소되었다. 발아단계에서 자엽의 구조성분은 자엽 건물중의 약22.2%였다. 자엽의 대사성분은 V2단계까지 급격히 감소하였으며, 발아단계시 자엽 대사성분의 약 91%가 이용되었다. 그러나 전체 유묘의 대사성분은 V1단계 이후에 증가하였음을 보였다. 따라서 종자의 발아와 유묘발달을 위하여 종자내 저장양분의 이동 및 탄소동화작용에 의한 양분 공급자로서 자엽의 역할은 특히, V1단계까지 중요한 것으로 나타났다.
        97.
        1984.04 KCI 등재 서비스 종료(열람 제한)
        1981년부터 최 등이 재래종 옥수수의 수집종 가운데서 병발한 한계통(MET)을 분얼이 많이되고 또한 개체당 이삭(수)수도 많아서 사료용 옥수수의 육종재료로 가치가 있다고 생각되었으나 이 옥수수에 대한 유전적 분석이 확실히 되어 있지를 않았다. 따라서 본연구에서는 MET와 비분얼성이며 이삭도 하나 밖에 달리지 않는 수원 19호 (Mo17 B68) 교잡종을 이용하여 F1 , F2 , BC1 , 세대를 양성하고 Mather의 세대평균분석법에 의하여 분석한 결과 MET 계통의 다수.다얼성은 염색체상의 유전인자에 의한 다기 보다 세포질적 유전인자에 의한다는 것을 확인하였다. 이같은 결론은 MET계통을 모계로 하여 교잡한 려잡종 세대에서 확실히 얻을 수가 있었다. 즉 MET 계통을 모계로 이용했을 때의 평균분얼과 이삭수는 MET를 부계로 이용했을 때의 분얼수와 이삭수 보다 많았는데 이는 이같은 특성들이 모계유전을 하기 때문이다. 그러나 이같은 특성들이 F1 이나 F2 에서 나타나지 않은 것은 F1 에서 특히 보여주는 잡종강세현상 때문에 옥수수의 정부우세성이 매우커서 상반적으로 분얼이나 이삭의 발달이 억제되었기 때문이라고 생각된다. 그리고 분얼이나 이삭의 절대수가 모계로 이용했던 MET에서 보다 잡종세대가 진전될수록 적어지는 것은 잡종강세외에도 MET계통의 세포질약 내지 유전인자적 축적량(Dose)이 적어지기 때문이라고 생각되어진다. 이같은 MET계통의 특성은 려교잡에 의한 MET계통의 세포질을 유지하거나 축적하므로써 사료용 옥수수의 육종에 이용될 수 있을 것으로 보여졌다.에서 조생종이 높은 발아력을 나타냈으나 16℃ 에서는 조, 중, 만생종 간에 발아력 차이가 없었다. 5. 참깨 종자중과 발아율과의 관계는 단일품종 내에서는 종자중이 무거울수록 발아율이 높았으며 평균 발아일수도 단축되는 경향을 보였으나 공시품종들의 천립중의 경중 특성에 따른 발아력 차이는 없었다.e more the silica filler was added, and the lower the gel temperature was in the epoxy system. In this study it is concluded that the curing of the silica filled epoxy system was found to be accelerated, as silica was added to the epoxy compound.ed by adults who are middle-aged or elderly. If altered colors are applied to the digital products as much as popular culture changes, it can assist the elderly with their weakened physical abilities.동위효소 사이의 특성을 나타냈고, 골격근과 눈 조직에서 피루브산에 대한 LDH의 친화력이 상당히 크므로 LDH가 혐기적 조건에서 효율적으로 기능을 하는 것으로 사료된다.5) and "Cleanliness of clothes & features" (p <0.05) of VIP ward were significantly higher than those of a general ward.tive to apply.아울러 고려(考慮)해야 한다. 이것
        98.
        1981.06 KCI 등재 서비스 종료(열람 제한)
        출수 후 수확할 때까지 이삭이 전혀 추출하지 않고 엽초에 싸여 등숙되는 특성을 가진 Nepal의 수도품종 GAMADI를 포장 및 벽실 양조건의 8시간, 자연일장 및 24시간 일장하에서 생육시켜 일장조건이 GAMADI 품종의 이삭 추출에 미치는 영향을 검토하었다. 그 결과를 요약하면 다음과 같다. 1. 8시간과 자연일장 조건에서는 이삭이 전혀 추출되지 않았으며 24시간 일장조건에서 생육된 경우에만 전체 이삭 길이의 71% 정도가 추출되었다. 2. 24시간 일장조건에서는 상위 제일절간신장 정도가 8시간과 자연일장에 비하여 현저하여 이삭추출과 유의한 관계에 있는 것으로 나타났다. 3. 제3 및 제4절간신장 정도는 자연일장에 비하여 8시간 및 24시간 일장조건에서 유의하게 낮게 나타났다. 4. GAMADI 품종의 수장, 수당입수는 일장에 영향하지 않았다. 5. 수원의 자연상태에서의 GAMADI 품종의 임실율은 Nepal에서 보다 현저하게 낮았다.
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