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        검색결과 13

        2.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigated the period variation for 79 eclipsing binary systems using 20 years (1990-2009) of EROS, Macho, and OGLE survey observations. We discovered 9 apsidal motions, 8 mass transfers, 5 period increasing and decreasing systems, 12 light-travel-time effects, 5 eccentric systems and 40 other systems showing no period variations. We select 3 representative eclipsing binary systems; EROS 1052 for apsidal motion, EROS 1056 for mass transfer, and EROS 1037 for the light-travel-time effect. We determine the period variation rate (dP/dt), orbital parameters of the 3rd body (e3, ω3, f(m3), P3, T3), apsidal motion parameters (dω/dt, U, Ps, Pa, e) and apsidal motion period by analyzing the light curves and O-C diagrams.
        3,000원
        7.
        2003.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 TCM-199, mSOF, NCSU-23 세 종류의 배지의 자연 단위 발생 유도로 형성된 돼지 배아의 초기 발육에 대한 효과를 조사하였다. 실험 1에서는 세 종류의 배지에서 체외 성숙된 도축장 유래 돼지 난자의 성숙율을 성숙 48 시간째 핵상 관찰로 조사하였다. 각 배지에서의 핵 성숙율은 mSOF군에서 83.12%, NCSU-23 군에서 78.03%, TCM-199군에서 83.52%로 세 배지의 난자 성숙율에 대한 유의적 차이는 없었다(P
        4,000원
        8.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Embryos derived from pig oocytes matured in mSOF are able to develop to blastocysts after IVF. Experiment 1 evaluated the effects of two maturation media (TCM-199 vs mSOF) on maturation rate, fertilization parameters, including penetration, polyspermy, male pronuclear formation, and the mean number of sperm penetrated per oocyte. Experiment 2 and Experiments 3 examined the effects of two maturation media on zona pellucida solubility and cortical granule distribution by transmissible electron microscopy, respectively. Experiment 4 assessed the effects of two maturation media on the in vitro embryo cleavage rate and development to blastocyst. Lastly, experiment 5 examined the cell number of blastocyst. An effect of media (P<0.05) was detected for mSOF on the mean number of sperm per oocyte. In TCM group, zona digestion time (196.515.5 vs 131.620.1 before IVF, 397.530.3s vs 185.316.4s after IVF, p<0.05) was higher in TCM-199 group. No significant effects of media was observed on cortical granule distribution between two groups by TEM. An effect (P<0.05) was observed on embryo development to blastocyst (16% vs 8%) but not on cleavage rates. No significant effects of media was observed on total cell number of blastocyst. We found that the high mean number of sperm penetrated per oocyte and the weaker zona pellucida on the basis of the digestion time was shown in pig oocytes matured in mSOF, however, porcine oocyte maturation with supplemented synthetic oviduct fluid medium (mSOF) resulted in blastocyst cell numbers comparable to those observed with Tissue Culture Medium 199.
        4,200원
        9.
        2002.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study was conducted for the production of transgenic cloned cows those secrete human lactoferricin into milk by somatic cell nuclear transfer (NT). To estimate detrimental effects of gene transfection on transgenic cloned embryo production, development rates of NT embryos were compared between transfected and non-transfected cumulus and ear fibroblast cells. An expression plasmid for human lactofericin (pbeta-LFC) was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and human lactoferricin target gene into a pcDNA3 plasmid. Two bovine somatic cell lines (cumulus cell and ear fibroblast) were established and transfected with the expression plasmid using a liposomal transfection reagent, Fugene6 as a carrier. Cumulus cell and ear fibroblast were transfected at the passage of 2 to 4, trypsinized and GFP-expressing cells were randomly selected and used for somatic cell NT. Developmental competences (rates of fusion, cleavage, and blastocyst formation) in bovine transgenic somatic cell NT embryos reconstructed with non-transfectecd cells were significantly higher than those from transfected cells in cumulus cell and ear fibroblast (P<0.05). This study indicated that transfection of done. cell has detrimental effect on embryo development in bovine transgenic NT.
        4,000원
        10.
        2002.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Human Prourokinase (proUK) offers potential as a novel agent with improved fibrin specificity and, as such, may offer advantages as an attractive alternative to urokinase that is associated with clinical benefits in patients with acute peripheral arterial occlusion. For production of transgenic cow as human proUK bioreacotor, we conducted this study to establish efficient production system for bovine transgenic embryos by somatic cell nuclear transfer (NT) using human prourokinase gene transfected donor cell. An expression plasmid for human prourokinase was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and human prourokinase target gene into a pcDNA3 plasmid. Cumulus cells were used as donor cell and transfected with the expression plasmid using the Fugene 6 as a carrier. To increase the efficiency for the production of transgenic NT, development rates were compared between non-transfected and transfected cell in experiment 1, and in experiment 2, development rates were compared according to level of GFP expression in donor cells. In experiment 1, development rates of non-transgenic NT embryos were significantly higher than transgenic NT embryos (43.3 vs. 28.4%). In experiment 2, there were no significant differences in fusion rates (85.4 vs. 78.9%) and cleavage rates (78.7 vs. 84.4%) between low and high expressed cells. However, development rates to blastocyst were higher in low expressed cells (17.0 vs. 33.3%), and GFP expression rates in blastocyst were higher in high expressed cells (75.0 vs. 43.3%), significantly.
        4,000원
        11.
        1973.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        1) 쇠파리의 누대 실내사육을 위한 온도는 약 가 좋으며, 이때 유충기간은 약 6.8일, 용기간은 5.3일, 산란전기간은 10.4일, 성충의 수명은 약 30일이었다. 2) 인공사육에 있어서 용화율은 우화율은 였으며 성비는 1 : 1이었다. 3) 용의 체중량은 약 14.5mg이었으며, Wheat bran medium 보다 Standard medium이 사육성적이 좋았다. 4) medium 125gr에 대한 난의 접종수는 약 310개가 가장 적합하였다. 5) rectangular cage를 사용할 경우, 성충의 resting place는 가 적합할 것으로 본다.
        4,000원
        12.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        The effects of seawater on growth of fettuce(Lactuca sativa L.), leaf perilla(perilIa frutescens var. japonica Hara), red pepper(Capsicum annuum L.) and cucumber(Cucumis sativus L.) seedlings were investigated in the glass greenhouse. These effects were studied on seedlings, and diluted seawater (1%, 5%, 10%, 20%, 50%, 100% v/v) was sprayed enough on feaves. The tested four vegetable crops have well grown up to 10% diluted seawater, but the tested vegetable crops were damaged from increasing salt levels. Of these, lettuce was provided salt-tolerant vegetable crop and red pepper was considered salt-sensitive vegetable crop. The salt tolerance of vegetable crops is different between crops and complicated because of additional detrimental effects caused by accumulated ions or specific ion toxicities in their leaves. These results show that agricultural use of seawater may be benefit crop cultivation in organic farming system as well as in conventional farming system.
        13.
        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.