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        검색결과 1,242

        1008.
        2011.09 KCI 등재 서비스 종료(열람 제한)
        The objective of this study was to elucidate the dynamics of microtubules in post-ovulatory aging in vivo and in vitro of mouse oocytes. The fresh ovulated oocytes were obtained from oviducts of superovulated female ICR mice at 16 hours after hCG injection. The post-ovulatory aged oocytes were collected at 24 and 48 hours after hCG injection from in vivo and in vitro, respectively. Immunocytochemistry was performed on -tubulin and acetylated -tubulin. The microtubules were localized in the spindle assembly, which was barrel-shaped or slightly pointed at its poles and located peripherally in the fresh ovulated oocytes. The frequency of misaligned metaphase chromosomes were significantly increased in post-ovulatory aged oocytes after 48 hours of hCG injection. The spindle length and width of post-ovulatory aged oocytes were significantly different from those of fresh ovulated oocytes, respectively. The staining intensity of acetylated -tubulin showed stronger in post-ovulatory aged oocytes than that in the fresh ovulated oocytes. In the aged oocytes, the spindles had moved towards the center of the oocytes from their original peripheral position and elongated, compared with the fresh ovulated oocytes. Microtubule organizing centers were formed and observed in the cytoplasm of the aged oocytes. On the contrary, it was not observed in the fresh ovulated oocytes. The alteration of spindle formation and chromosomes alignment substantiates the poor development and the increase of disorders from the post-ovulatory aged oocytes. It might be important to fertilize on time in ovulated oocytes for the developmental competence of embryos with normal karyotypes.
        1009.
        2011.05 KCI 등재 서비스 종료(열람 제한)
        This study examines the potential restoration of abandoned channels of the Mangyeong River in South Korea. To analyze the morphological changes and equilibrium conditions, a flow duration analysis was performed to obtain the discharge of 255 m3/s with a recurrence interval of 1.5 year. It is a gravel-bed stream with a median bed diameter of 36 mm. The reach-averaged results using HEC-RAS showed that the top width is 244 m, the mean flow depth is 1.11 m, the width/depth ratio is very high at 277, the channel velocity is 1.18 m/s, and the Froude number is also high at 0.42. The hydraulic parameters vary in the vicinity of the three sills which control the bed elevation. The total sediment load is 6,500 tons per day and the equivalent sediment concentration is 240 mg/l. The Engelund-Hansen method was closer to the field measurements than any other method. The bed material coarser than 33 mm will not move. The methods of Julien-Wargadalam and Lacey gave an equilibrium channel width of 83 m and 77 m respectively, which demonstrates that the Mangyeong River is currently very wide and shallow. The planform geometry for the Mangyeong River is definitely straight with a sinuosity as low as 1.03. The thalweg and mean bed elevation profiles were analyzed using field measurements in 1976, 1993 and 2009. The measured profiles indicated that the channel has degraded about 2 m since 1976. The coarse gravel material and large width-depth ratio increase the stability of the bed material in this reach.
        1010.
        2011.04 KCI 등재 서비스 종료(열람 제한)
        Fifty-five sweet pepper (Capsicum annuum L.) germplasm from the Rural Development Administration (RDA) were analyzed for their fruit yield and fruit quality characters, including fruit weight, fruit size, pericarp thickness, total soluble content, fruit lobe, fruit shape, fruit surface and fruit color. Fruit yield per plot ranged from 200 g to 8150 g (average, 1884 g). Fruit fresh-weight per fruit ranged from 27.3 g to 200.0 g with an average of 97.2 g. Fruit length varied from 4.0 cm to 16.2 cm (average, 9.6 cm). Fruit length-to-width ratio ranged from 0.6 to 3.0 with an average 1.7. The fruit pericarp thickness ranged from 1.8 mm to 10.7 mm (average, 4.8 mm). Total soluble content was the highest (8.5˚ Brix) in K156286 and the lowest (5.3˚ Brix) in K156208 with the average value 6.7˚ Brix. Fruit lobes numbers varied from 2 to 4. Blocky, triangular, elongated, rectangular and round fruit shape identified among the sweet pepper accessions. Fruit surface varied from smooth to wrinkle and fruit color also varied. The presence of variability in fruit yield and quality traits within the sweet pepper genotypes can be utilized to develop high yielding sweet pepper variety with better fruit quality characters.
        1011.
        2011.04 KCI 등재 서비스 종료(열람 제한)
        The groundnut or cultivated peanut (Arachis hypogaea L.) in Korea consists of 36 domestic varieties which have been developed and registered as cultivars for the public during last 25 years. To screen and identify of Korean peanut varieties and genetic resources, we present a simple and reliable method. A methodology based on simple sequence repeat (SSR) markers developed and widely used for prominent gene identification and variety discrimination. For identification of those 36 Korean peanut varieties, 238 unique peanut SSR markers were selected from some previously reported results, synthesized and used for polymerase chain reaction (PCR). Data were taken through acryl amide gel electrophoresis and changed into proper formats for application of data mining analysis using Biomine (all-in-one functional genomics data mining program). Consequently, twelve SSR primers were investigated and revealed the differences between those 36 varieties. These primer pairs amplified 27 alleles with an average of 2.3 allele per primer pair. In addition, those results showed genetic relationship by classification method within 36 varieties. The approach described here could be applied to monitoring of our varieties and adapting to peanut breeding program.
        1012.
        2011.04 KCI 등재 서비스 종료(열람 제한)
        A field experiment was conducted to examine the fruit quality characters in second generation (F2) hybrid cultivar and to compare the fruit characters with original F1 hybrid cultivar of minipaprika (yellow and orange type) at the Research Farm, Hwacheon in July, 2010. Fruit characters varied within F2 population of each minipaprika type. In minipaprika yellow, fruit weight varied from 12.2 g to 50.8 g (average 28.5 g) and fruit length/width varied from 1.4 to 2.8 (average, 2.0). Pericarp thickness ranged from 1.8 mm to 4.1 mm (average, 2.9 mm). Total soluble solid (TSS) varied from 6.2˚Brix to 13.5˚Brix with an average of 8.7˚Brix. Fruit volume varied from 10.3 cc to 46.7 cc with an average of 24.4 cc. In minipaprika orange type, fruit weight ranged from 19.7 g to 42.4 g (average, 29.0 g) and fruit length/width varied from 1.5 to 2.6 (average, 2.0). Pericarp thickness varied from 2.1 mm to 4.1 mm with an average of 3.0 mm. TSS varied from 5.0˚Brix to 12.2˚Brix (average, 7.9˚Brix) and average fruit volume was 24.6 cc ranging from 10.7 cc to 35.0 cc. The average fruit quality characters in F2 population in both yellow and orange minipaprika did not differ from their F1 hybrid parent and F2 seed can be an additional way to supply high yielding hybrid cultivars at lower cost to the minipaprika growers.
        1013.
        2010.12 KCI 등재 서비스 종료(열람 제한)
        Anther derived double haploids (DHs) from sweet pepper genotypes ('Special', 'Derby', 'Bossanova', 'Fiesta', 'Debora' and 'Minipaprika') were used to study the agronomic variation in 2006. Ninety-nine successful DHs regenerants (32 from 'Special', 25 from 'Derby', 23 from 'Bossanova', 10 from 'Fiesta', 6 from 'Debora' and 3 from 'Minipaprika') were transplanted at plastic house and studied on their agronomic characters. Variation in agronomic characters was observed within the DHs of each genotype. DHs obtained from 'Derby' and 'Fiesta' exhibited wide variation in fruit yield plant-1 whereas averaged fruit yield plant-1 was highest in 'Derby' (1608 g) and less variation was observed in DHs of 'Bossanova'. Based on the agronomic characters expressed in DHs population at this environment, SP55, SP56, SP60, and SP116 from 'Special', SP8, SP10, SP14, SP16, and SP34 from 'Derby', SP115, SP119, SP142, SP143, SP196, and SP199 from 'Bossanova', SP41, SP45, and SP114 from 'Fiesta', SP21 from 'Debora' and SP91 from 'Minipaprika' identified as elite inbred lines and these DH lines could be used for commercial hybrids production in sweet pepper. Genetic relationship among the selected inbred lines using molecular markers and their response to diseases are further recommended to study.
        1014.
        2010.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        공학적 안전설비 공기정화계통과 관련된 실험 수행을 위해 원자력등급 ESF 공기정화계통 시뮬레이터 를 설계, 제작, 검증하였다. 영광 5,6호기 주제어실 공기정화계통의 공급자 정보, 도면 등을 기준으로 실 사를 통해 치수를 확인하여 3D CAD 모델을 작성하였다. 모델과 현장 계통의 실측 유량을 기준으로 CFD 분석을 수행하였다. 공기정화계통으로 유입되는 공기는 30 ℃, 유동형태는 균일한 것으로 가정하고, 검사 기록지에 의한 주제어실 ESF 공기정화계통의 유량이 12,986 CFM이고, 610×610 ㎟의 HEPA 필터가 9개 설치되어 있으므로 HEPA 필터 단면를 지나는 유속은 1.83 m/s이다. 주제어실 공기정화계통 모델링시 공 기 유동이 흐르지 않는 필터 테두리 지지대를 고려하여 현장과 유사한 유동현상을 모사하였다. 약 8 m/s 로 기록된 활성탄 흡착기 하단의 공기유동은 별도의 분석을 통해 7 m/s 이상의 유속이 모사되도록 CFD 분석하였다. 연료건물 비상배기계통 및 비상노심냉각계통 기기실 배기정화계통의 공기정화계통에 대해 서도 CFD 분석한 결과, 시뮬레이터의 유속을 조절하면 세가지 ESF 공기정화계통을 모두 모사할 수 있음 을 확인하였다. CFD 분석 후 시뮬레이터를 원자력등급으로 제작하였고, 본 실험에 착수하기 전에 공기유 동 분포도실험을 통해 시뮬레이터의 신뢰도를 검증하였다. 검증결과 중급 필터를 장착한 상태에서 시뮬 레이터의 필터 지지대 부분을 제외한 내부에서 공기유동이 고르게 분포함을 확인하였고, 제작된 시뮬레 이터는 Reg. Guide 1.52(Rev.3) 개정 내용 확인을 위한 실험에 사용되었다.
        1015.
        2010.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        공학적 안전설비 공기정화계통의 규제지침인 Reg. Guide 1.52(Rev.3)의 변경사항중 성능시험과 관련 한 운전가능성 시험시간 단축, HEPA 필터 현장누설시험용 시험물질 변경 및 활성탄 성능시험 Methyl Iodidie 투과허용율 상향 변경을 영광 5,6호기에 적용하고자, 모사실험장치와 현장 설비를 활용하여 기술 적 타당성을 확인하는 실험을 수행하였다. 10시간 이상의 장시간 운전가능성 시험을 통해 계통내 습분을 제거하여도 시험후 1∼4일만에 회복됨을 확인하여 운전가능성 시험은 기기적 운전가능성 점검에 적합한 매월 15분 이상의 시험을 수행하는 것이 타당함을 확인하였다. HEPA 필터 현장누설시험용 시험물질 변 경을 위해 DOP와 PAO의 에어로졸 입자크기, 발생량, 누설인지도를 비교한 결과 PAO는 원전에서도 DOP 대체시험물질로 사용 가능함을 확인하였다. 베드깊이 4 인치 이상의 활성탄여과기에 대한 Methyl Iodide의 투과율 허용치가 0.175 %에서 0.5 %로 상향 변경된 것은, ASTM D3803(1989)으로의 활성탄 성 능시험 방법 변경에 따른 것으로서, 30 ℃ 상대습도 95 %에서의 Methyl Iodide 투과허용율 0.5 %가 사용 중 활성탄의 성능을 시험하기에 충분히 보수적인 시험방법임을 확인하였다. 본 실험 결과를 바탕으로 영 광 5,6호기는 인허가변경을 완료하였다.
        1016.
        2010.10 KCI 등재 서비스 종료(열람 제한)
        Rice is a staple food for more than 50% of the world's population. Embryo comprises only 2 to 3% of the weight distribution of the entire pericarp but has higher concentration of vitamins, proteins, and essential fatty acids than the other parts of grains. Moreover, α-tocoperol, γ-oryzanol, phytic acid and γ-aminobutric acid that have nutraceutical value are abundant. Increasing the volume of embryo assures the fortification of nutritional value of rice grain. We developed new black waxy giant embryo rice, Milyang 263 by crossing Josaengheugchal, a black waxy rice variety, and get, a giant embryo mutant generated by tissue culture. The nutrient contents and physical properties of Milyang 263 were compared with several giant embryo mutants and normal embryo rice varieties. Changes in the nutrient properties after germination were also observed. Results indicated that this new black waxy giant embryo rice, Milyang 263, offers a promising source for improving nutritional quality of rice especially anthocyanin, essential minerals, and GABA.
        1017.
        2010.10 KCI 등재 서비스 종료(열람 제한)
        Anthers of sweet pepper F1 cultivar ‘Special’ were cultured on Dumas De Vaulx (C medium), supplemented with 0.1mgL-1 2, 4-D and 0.1 mg · L-1 kinetin with 3% sucrose, and 0.32% phytagel. The calluses obtained were further sub-cultured on Murashige and Skoog (MS) medium without growth regulators for regeneration. Regenerated plantlets were grown in plastic pots under plastic house and characterized their cytological and morphological characters in spring, 2008. Twenty percent plantlets were identified as haploid plants after chromosome and ploidy analysis. Haploid plants contained 12 chromosomes, high stomatal density with small stomatal length as compared to diploid plants. Stomatal length in haploids was 23.3% smaller than diploids. Haploid plants were characterized as small leaf and petiole size, poor vigor, thin stem and short plant height, short internodes and small flower buds, fruit size and fruit weight as compared to diploid plants and most of the haploid fruits were seedless. SP55, SP62, SP68, SP72 and SP77 are found high yielding double haploids with high total soluble content (8.6, 8.7, 9.2, 9.1 and 9.8 ºBrix, respectively) and desirable fruit shape, and recommended them to exploit as inbred lines for heterosis breeding.
        1018.
        2010.09 KCI 등재 서비스 종료(열람 제한)
        Mobile Harbor (MH) is a new transportation platform that can load and unload containers onto and from very large container ships at sea. It could navigate near harbors where several vessels run, or it could navigate through very narrow channels. In the conceptual design phase when the candidate design changes frequently according to the various performance requirements, it is very expensive and time-consuming to carry out model tests using a large model in a large towing tank and a free-running model test in a large maneuvering basin. In this paper, a new Planar Motion Mechanism(PMM) test in a Circulating Water Channel (CWC) was conducted in order to determine the hydrodynamic coefficients of the MH. To do this, PMM devices including three-component load cells and inertia tare device were designed and manufactured, and various tests of the MH such as static drift test, pure sway test, pure yaw test, and drift-and-yaw combined test were carried out. Using those coefficients, course-keeping stability was analyzed. In addition, the PMM tests results carried out for the same KCS (KRISO container ship) were compared with our results in order to confirm the test validity.
        1019.
        2010.09 서비스 종료(열람 제한)
        A stroke is the major cause of death and can cause neurological damage. The striatum serves as an input gate of the basal ganglia in assisting motor behavior. The activity-dependent synaptic plasticity in the dorsal striatum (DS) is known to play a key role for recovery of motor control after brain injury. Exercise supports functional recovery from ischemic brain injury through brain-derived neurotrophic factor (BDNF) -induced synaptic plasticity. Exercise upregulate the levels of BDNF within both the hippocampus and cerebral cortes and might act as a gate that primes the brain to respond to environmental stimulation, while simultaneously increasing the ability of neurons to resist insult. However, little is known about the effects of exercise on neuroprotection in the DS. Therefore, in this study we attempted to investigate the effects of exercise on the neuronal cell population in the DS. Transient focal brain ischemia was induced by middle cerebral artery occlusion (MCAO) on male Sprague-Dawley rats (300±30). Animals were subjected to forced treadmill exercise group and sedentary group after MCAO. Exercise improved neurologic functions measured by modified neurological severity score. Exercise group showed reduced infarct volume measured by vital staining with 2,3,5-triphenyltetrazolium chloride. Immunohistochemical analysis was performed in the DS with antibodies of neuronal nuclei (NeuN) protein, glial fibrillary acidic protein (GFAP), a matured neuronal marker and an astrocyte marker respectively and BDNF. Ischemic injury decreased NeuN+ cell population but exercise attenuated this decrease while increase in GFAP+ cell population induced by MCAO was inhibited by exercise. These findings suggest that the neurological function recovery by exercise after ischemic brain injury may be mediated by alteration of neuronal cell population in the DS.
        1020.
        2010.09 서비스 종료(열람 제한)
        Mesenchymal stem cells (MSCs) has been reported as multipotent progenitor cells that can be expanded rapidly in vitro and differentiated into multiple mesodermal cell type. Human MSCs have been reported to be associated with neural differentiation especially in the cholinergic phenotype in several neural system. In this study, We investigated the ability of MSCs derived human aipose tissue to differentiation into neural cells expressing Islet-1 and further differentiates into cholinergic neurons in cholinergic differentiation media. Immunocytochemistry was performed to detect the expression of Islet-1 and demonstrate characteristic of neurons and cholinergic neurons. Islet-1 was massively detected in the induction stage. Following cholinergic differentiation from Islet-1-expressing MSCs, Cholinergic neuron marker ChAT was higly expressed. Also we examined the neuroprotective effects and neural differentiation of transplanted human adipose tissue-derived mesenchymal stem cells (AT-MSCs) in ischemic stroke. For transplantation, after 3days after MCAO. animal were divided into 2 group: Group A : injected phosphate buffered saline (PBS;5 ㎕ n=10), Group B: transplanted AT-MSCs (5×105 cells, n=10). Each animal received an injection into the right penumbra region (from bregma : AP;-1.3 ㎜, ML;-4.0 ㎜, DV;-5.9 ㎜). In all animals, behavior test were performed at 1, 3, 6, 9, 12, 15 days after MCAO, that was conducted by investigators who were blined to the experimental groups. mNSS test demonstrated that motor, sensory, and balance behavior were impaired after MCAO ischemic insult. Ischemic rats that received AT-MSCs exhibited significantly improved functional performance compared with PBS injected animals and histological analysis revealed that transplanted AT-MSCs expressed marker for neuron. These results suggest that AT-MSCs can be differentiated into neuron especially in cholinergic neuron and may be a potential source of treatment for neurodegenerative disease such as stroke.