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        검색결과 6

        1.
        2012.09 KCI 등재 구독 인증기관·개인회원 무료
        With AKARI, we carried out near-infrared spectroscopy of the nearby barred spiral galaxy, NGC 1097, categorized as Seyfert 1 with a circumnuclear starburst ring. Our observations mapped the galactic center region. As a result, we obtain the spatial distributions of the polycyclic aromatic hydrocarbon 3.3μm and the aliphatic hydrocarbon 3.4−3.6 μm emission. The former is detected from all the observed regions and the latter is enhanced near the bar connecting the ring with the nucleus. In addition, we detect absorption features due to H2O ice and CO/SiO at the ring and the galactic center, while we detect the hydrogen recombination line Brα only from the ring. Hence the observed spectra change dramatically within the central 1 kpc region.
        2.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The absorption features due to interstellar ices, especially H2O and CO2 ices, provide us with crucial information on present and past interstellar environments, and thus the evolutionary histories of galaxies. Before AKARI, however, few detections of ices were reported for nearby galaxies. The AKARI's unique capability of near-infrared spectroscopy with high sensitivity enables us to systematically study ices in nearby galaxies. Thus we have explored many near-infrared spectra ( 2.5−5μm ) of the 211 pointed observations, searching for the absorption features of ices. As a result, out of 122 nearby galaxies, we have significantly detected H2O ice from 36 galaxies and CO2 ice from 9 galaxies. It is notable that the ices are detected not only in late-type galaxies but also in early-type galaxies. We find that CO2 ice is more compactly distributed near the galactic center than H2O ice. Finally, we suggest that the gas density of a molecular cloud and UV radiation may be important factors to determine the abundance of ices.
        3,000원
        3.
        1997.05 구독 인증기관 무료, 개인회원 유료
        Bovine oocytes surrounded with compact cumulus cells were cultured for 20 to 22 hours(, 5% ) in modified TCM-199 medium supplemented with 5% superovulated cow serum(SCS) and inseminated by in vitro capacitated spermatozoa. Day 7 to 8 embryos were equilibrated for 10 minutes in 1.3M methyl cellosolve(MC) <1.1M diethylene glycol(DEG), 1.8M ethylene glycol(EG), 1.6M propylene glycol(PG) and 1.1 M 1,3-butylene glycol(BG) solutions. They were then loaded into 0.25ml straws, placed into an alcohol bath freezer at , cooled from to at /minute, seeded, held for 10 minutes, and stored in liquid nitrogen. After thawing in water, the embryos wee rehydrated in TCM-199 medium and then cultured for 48 hours in TCM-199 plus 5% SCS. Embryos were considered viable if they progressed to later developmental stages with a good morphology. Some of the embryos frozen in each cryoprotectant were thawed and transferred non-surgically without removing the cryoprotectant. Hatched embryos survived freezing and one-step dilution as follows : EG(50.0%), MC(53.6%), DEG(56.9%), PG(58.0%) and BG(11.5%). The survival rate of embryos cooled at vs. /minute was not significantly different(P<0.05), however, blastocysts hatched most often (P<0.01) in vitro when cooled at a rate of /minute(64.6%), 31/48) than at /minute(22.6%, 12/53). Pregnancy rates resulting from embryos frozen in the different cryoprotectants were as follows : MC(48%, 10/21); DEG(30%, 3/10); EG(74%, 20/27); and PG(40%, 4/10). These results indicate that MC, DEG, EG and PG have utility as cryoprotectants for the freezing and thawing of IVF Bovine embryos.
        4,000원
        4.
        1997.05 구독 인증기관 무료, 개인회원 유료
        치밀 난구세포로 둘러싸인 소 난자를 . 5% 배양기에시 5% superovulated cow serum(SCS)이 첨가된 m-TCM 199 medium 으로 시간 배양하였으며, 수정능이 획득된 정자와 체외수정하였다. 7일8일경의 수정란을 1.3M methyl cellosolve(MC), 1.1M diethylene glycol(DEG), 1.8M ethylene glycol(EG), 1.6M propylene glycol(PG) 및 1.1M 1,3-butylene glycol(BG) 용액에서 10분간 평형시킨 후 0.25 ml 스트로내에 장전하였다. 스트로를 의 alcohol bath freezer에 넣고 까지 /분 속도로 냉각, 식빙 후 10분간 정체시켰으며, /분 또는 /분으로 까지 냉각 후 스트로를 액체질소에 침지하여 보관하였다. 수정란이 들어있는 스트로를 온수에서 융해하였으며, 수정란을 TCM 199 medium 으로 옮긴 후 5% SCS가 첨가된 TCM 199 medium 에서 48시간 배양하였다. 수정란이 양호한 형태를 유지하며 나중의 발육단계로 진행된 것을 생존한 것으로 간주하였다. 각 종류의 동해방지제에서 동결된 수정란의 일부는 융해 후 동해방지제를 제거하지 않고 직접 비외과적으로 이식하였다. 동결-융해 후 동해방지제의 종류에 따른 탈출배반포 발달율은 EG 50.0%, MC 53.6%, DEG 56.9%, PG 58.0% 그리고 BG 11.5%였다. /분 또는 /분 으로 냉각한 수정란의 생존율은 두 그룹간에 유의적인 차이가 없었으나 (P<0.05), 탈출배반포 발달율은 -0.5분 /분(22.6%, 12/53)보다 /분(64.6%, 31/48) 냉각시에 유의적으로 높았다(P<0.01). 동해방지제의 종류에 따른 수정란의 수태율은 MC 48%(10/21). DEG 30%(3/10), EG 74%(20/27) 및 PG 40%(4/10) 였다. 이러한 결과로 보아 MC, DEG, EG 그리고 PG는 소의 체외수정란의 동결을 위한 동해방지제로서 이용될 수 있음을 보여주었다.
        4,000원