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        검색결과 56

        41.
        1996.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have analyzed infrared (IR) images of Jupiter which was observed at the McDonald Observatory, Texas, U.S.A., during the P/SHoemaker-LEvy 9 (SL9) impact period and about one week after the last impact. The IR images were obtained on the 2.7m telescope using a NICMOS array with filters to isolate the 1.5 μm NH3 band, the 2.3 μm CH4 band, the 2.12 μm H2 S(0) pressure-induced absorption, and the continua at 1.58 μm and 2.0 μm (short K-band). All images except those with the 1.58 μm continuum filter show bright impact sites against the relatively dark Jovian disk near the impact latitude of about 45° S. This implies that dusts originated from the impacts reflect the solar radiation at high altitudes before absorbed by stratospheric CH4, NH3 or H2. The impact sites observed with the 2.3 μm filter are conspicuously bright against a very dark background. The morphology of impact sites, G, L, and H at 2.3 and 2.12 μm filters shows clearly an asymmetric structure toward the incident direction of the comet fragments, in agreement with the studies of visible impact images obtained with the Hubble Space Telescope. Comparisons of reflectances of G, L, and H sites with simple radiative transfer models suggest that optically thick dust layers were formed at high altitudes at which methane absorption attenuates incoming sunlight only by about 1%. The dust layers in these sites seem to form at about the same altitude regardless of the magnitude of the impacts, but they appear to descend gradually after the impacts. The dust layers have optical depths of 2-5, according to the models.
        4,000원
        42.
        2019.10 KCI 등재 서비스 종료(열람 제한)
        국내외 개발된 Hsota 품종의 잎의 생육과 개화 특성을 조사 한 결과, 식물의 크기는 H. ‘Abiqua Blue Crinkles’, H. ‘Abiqua Drinking Gourd’, H. ‘Dancing in the Rain’, H. ‘Elegance’, H. ‘Inniswood’, H. ‘Venus’등 6종류가 가장 컸으며(대형 계통, 50 ㎝ 이상), H. ‘Abby’, H. ‘Birchwood Parky’s Gold’, H. ‘Blue Cadet’, and H. ‘Blue Edge등을 포함한 27종은 소형 계통이다 (6 ㎝ 이상 20 ㎝ 미만). 79%가 무늬를 가지며 무늬 형태는 marginata (복륜), mediovarigata (중투), albomaculata (산반), striata (서반)이며, marginata 계통은 H. ‘Abby’, H. ‘Abiqua Moonbeam’, H. ‘Atlantis’등을 포함하여 31종류로 전체 비율 중 36%로 가장 많았다. 개화기는 H. ‘Abby’, H. ‘Abiqua Drinking Gourd’, H. ‘Abiqua Moonbeam’등 36종류가 5월 말 부터 개화였고, H. ‘Black Hills’, H. ‘Boeun’, H. ‘Fragrant Bouquet’등 9종은 8월 이후에 개화하였다. 꽃은 H. ‘Avocado’ 가 5.0 ㎝ 이상으로 대륜 계통이었으며, H. ‘Avocado’, H. ‘Fragrant Bouquet’, H. ‘Fried Bananas’ 등 H. plantaginea 계통이 대부분 크기가 컸다. 꽃의 색은 꽃의 색은 6가지로 분류되며, white 계열은 25.9%, lavender 계열은 45.9%, purple 계열은 28.2%가 개화하였다. H. ‘Blue Mouse Ears’, H. ‘Captain Kirk’, H. ‘Fragrant Bouquet’ 등 12종류는 개화시 향기가 있었다. H. ‘Cherry Berry’와 H. ‘Revolution’은 각각 빨간색과 노란색의 꽃대를 가지고 있다.
        43.
        2019.10 KCI 등재 서비스 종료(열람 제한)
        본 연구는 각시괴불나무 종자의 휴면유형과 발아특성을 구 명하기 위하여 수행되었다. 수분흡수 실험결과, 각시괴불나무 종자는 수분흡수가 원활히 이루어졌다. 따라서, 물리적 휴면은 가지지 않는 것으로 판단된다. 각시괴불나무 종자는 탈리 시점에 미숙배를 가지고 있으며, 발아직전까지 배/종자 비율이 약 46% 증가하였다. 온도실험결과, 5℃에서는 발아가 전혀 이루어지지 않았다. 20℃에서는 파종 후 1주부터 발아가 시작되었으며 최종 발아율은 2주차에 86.7%였다. 15℃에서는 파종 후 2주부터 발아를 시작하였으며, 최종 발아율은 4주차에 75.0%였다. 25℃에서 파종 후 1주부터 발아가 시작되었으며 최종 발아율은 19주차에 48.3%였다. 결론적으로, 각시괴불나무 종자의 발아를 위한 최적온도는 가장 높은 최종 발아율과 가장 짧은 평균 발아 일수를 나타낸 20℃이다. 각시괴불나무 종자는 5℃를 제외 한 모든 온도에서 4주 이내에 발아하였기 때문에 생리적 휴면은 관찰되지 않았다. 따라서, 각시괴불나무 종자는 오직 형태적 휴면만을 가지는 것으로 판단되었다.
        44.
        2019.08 KCI 등재 서비스 종료(열람 제한)
        본 연구는 기존에 절화용으로 개발되지 않았던 암대극을 새로운 관상식물로 개발하기 위해 수행되었다. 실험은 보존용액에 따른 절화 암대극의 영향을 구명하고자 수분흡수율, 절화수명, 상대생체중을 조사하였다. 수확 후 절화는 8-hydroxyquinoline sulfate (8-HQS) 10, 50, 100 ㎎·L-1, silver thiosulfate (STS) 0.1, 0.2 mM, Chrysal, Floralife의 보존용액에 처리 되었다. 실험은 온도 22.6℃, 상대습도 45%, 일장 9/15h, 광도 9.89 μmol·m-2·s-1 환경에서 수행되었다. 절화 암대극의 수분흡수율은 8-HQS 10 ㎎·L-1 보존용액에 처리 시 무처리된 절화보다 유의하게 높게 측정되었다. 그러나 절화 암대극의 수명은 무처리와 8-HQS 10 ㎎·L-1 보존용액 처리 시 차이가 관찰되지 않았다. 절화 수명은 STS 보존용액 처리 시 처리농도가 증가함에 따라 감소하였다. 절화 암대극의 상대 생체중은 상업용 절화수명연장제인 Chrysal 및 Floralife 보존용액 처리 시 무처리 보다 유의하게 감소하였다. 이러한 결과는 절화 암대극의 사용에 있어 유용한 자료가 될 것이다.
        45.
        2019.02 KCI 등재 서비스 종료(열람 제한)
        본 연구는 우리나라에 자생하고 있는 비비추속 식물 6종(일월비비추, 주걱비비추, 다도해비비추, 좀비비추, 한라비비추, 흑산도비비추)의 정단을 이용하여 대량증식과 품종개발 등을 위한 기내증식체계를 확립하고자 하였다. 정단은 0.5, 1.0, 2.0, 4.0 ㎎/L BA와 0.1, 0.5, 1.0, 2.0 ㎎/L TDZ를 0.1 ㎎/L NAA와 각각 혼용한 조건과 PGRs을 무첨가한 조건(control)의 MS배지에 배양하였다. 배양 8주 후에 embryogenic callus, somatic embryo, crown bud, 그리고 신초와 뿌리의 분화 및 생육, 생체중 등에 대하여 조사하였다. 6종의 비비추 식물 모두에서 control에 비하여 PGRs 처리구의 embryogenic callus와 somatic embryo 형성율, 다신초 분화율이 높았다. 분화된 신초의 개수는 일월비비추는 2.0 ㎎/L TDZ에서 5.4개, 주걱비비추와 다도해비비추는 1.0 ㎎/L TDZ에서 각각 3.3개, 5.8개, 좀비비추는 0.5㎎/L BA에서 11.1개, 흑산도비비추는 0.5 ㎎/L TDZ에서 9.8개, 한라비비추는 1.0 ㎎/L BA, 0.1 ㎎/L TDZ에서 8.1개로 가장 많았다. Somatic embryo 형성에서는 다도해비비추와 흑산도비비추가 처리한 PGRs에 대해 효과적이었고, 일월비비추, 주걱비비추, 좀비비추, 한라비비추에서는 상대적으로 효과가 적었다. 4종의 자생 비비추(일월비비추, 주걱비비추, 다도해비비추, 흑산도비비추)에서 조사된 crown bud도 control에 비하여 PGRs 처리구에서 더 많이 형성되었다. 주걱비비추는 cytokinin의 종류 및 농도와 상관없이 callus와 신초 분화에 큰 효과가 나타나지 않았지만, crown bud의 형성에는 TDZ에서 약간 증가하였다.
        46.
        2018.09 KCI 등재 서비스 종료(열람 제한)
        A Hosta cultivar ‘Neulpureum 1’ was bred at the Korea National Arboretum, which produces new cultivars using vegetative propagation techniques. The new cultivar ‘Neulpureum 1’ was derived by crossing Hosta minor with Hosta ‘Krossa Regal’. Among the induced leaf-color- and shape-modified hosta plants, the plants that exhibited deep-green color and small-bended leaves were selected. ‘Neulpureum 1’ maintained the deep-green leaves for longer than Hosta ‘Krossa Regal’. Additionally, the plant height of ‘Neulpureum 1’ was shorter than that of Hosta ‘Krossa Regal’ and several leaves were observed on the new cultivar; therefore, it is likely to be used as a pot plant. The botanical characteristics were investigated for three years beginning 2012. A Hosta ‘Neulpureum 1’ can prove to be useful as a material for a pot plant or as ground cover plant at half-shadow place.
        47.
        2018.09 KCI 등재 서비스 종료(열람 제한)
        Tiarella polyphylla D. Don is a native plant distributed only in Ulleung Island in Korea and has been traditionally used for medicinal purposes, although it is also used ornamentally. This study was conducted to determine the requirements for dormancy break and germination and to classify the type of seed dormancy. The experiments were performed with cold stratification (0 or 12 weeks at 5℃), warm stratification (0, 4, 8, or 12 weeks at 23℃, followed by 8 weeks at 5℃, and then incubation at 23℃), and GA3 treatments (0, 10, 100, or 1000 ㎎/L). The treated seeds were incubated on aseptic media at room chamber (23℃, a 16h photoperiod of fluorescent lamps with 40 μmol ․ m-2 ․ s-1). The seeds were dispersed in nature as underdeveloped embryos with no physical barrier to absorb water to prevent water absorption. However, the seeds did not germinate for 30 days after sowing without any pre-treatments. Thus, the seeds had morphological dormancy (MD) and physiological dormancy (PD). The final germination percentage following cold stratification (0 or 12 weeks) was 66.7% and 45.6%, respectively. The cold stratification delayed seed germination by about 3 weeks. In the warm stratification experiment (0, 4, 8, or 12 weeks), the final germination percentage was 21.1%, 27.8%, 41.1%, and 57.8%, respectively, 20 weeks after sowing. The embryos of the T. polyphylla seed grew in relatively warm temperatures (23℃). GA3 application overcame seed dormancy and promoted germination. Following GA3 treatment (0, 10, 100, or 1000 ㎎/L), the final germination percentage was 33.3%, 45.0%, 42.5%, and 72.5%, respectively. These results suggest that the T. polyphylla seeds had non-deep simple morphophysiological dormancy (MPD) and GA3 treatment could be used as a substitute for warm stratification for breaking seed dormancy. To our knowledge, this is the first report of seed dormancy characteristics of the genus Tiarella native to Korea.
        48.
        2017.09 서비스 종료(열람 제한)
        Surgery for thyroid disease is becoming much more common, but in some specialized institutions, ENT surgeons have difficulty obtaining experience of parathyroid surgery. Parathyroid disease can be divided into parathyroid adenoma with hyperparathyroidism and secondary hyperparathyroidism due to chronic kidney disease. Parathyroid adenoma with hyperparathyroidism is the most common cause of hypercalcemia and usually presents as nonspecific symptoms, such as, general weakness, osteoporosis, gastrointestinal disorder, kidney stones, and/or neurological symptoms, and thus, diagnosis is often delayed. Patients with secondary hyperparathyroidism due to chronic kidney disease require parathyroidectomy 10 years after the onset of dialysis in 6-10% of cases even when continuously treated in a nephrology department. Here, the authors share their experiences of parathyroid surgery.
        49.
        2017.03 서비스 종료(열람 제한)
        Benign thyroid nodule is a common disease. However, little is known about the natural course of it. The objective of the study was to evaluate the changes of ultrasonographic (US) findings and the fine needle aspiration (FNA) cytology. During 2 years, most of them have been in a benign natural course. However, we should note that malignant US findings is strongly associated with papillary thryoid carcinoma, though FNA revealed benign. Among them, our results would suggest that taller than wide feature in US finding is associated with malignancy
        50.
        2015.12 서비스 종료(열람 제한)
        The objective of this study is to access the prevalence of diffuse thyroid disorders by using ultrasonography in healthy adults. Among 1535 adults who underwent thyroid ultrasonography, thyroid disorders were detected in 191 subjects (12.4%). There was a rapid increase of thyroid functional abnormalities in addition to subclinical thyroid disease with more than 3 features of diffuse thyroid disorder. Therefore we suggest that the thyroid function test and thyroid auto-antibodies should be checked when there are more than 3 features of the diffuse thyroid disorder in ultrasonographic examination, even if the patient does not have any symptoms.
        51.
        2013.03 서비스 종료(열람 제한)
        Demacort® is mixture of betamethasone (high-potency corticosteroid) and clotrimazole (antifungal agent), an inhibitor of CYP3A4, which can inhibit the metabolism of betamethasone. Interaction of these drugs may result in decreased clearance of betamethasone and increased risk for adverse events such as iatrogenic Cushing’s syndrome. A 26-year-old female was admitted to the hospital due to rapid weight gain after application of Demacort®. During a period of one month, she showed weight gain of 30 kg and developed several Cushingoid appearances. The result of an overnight dexamethasone suppression test was negative, thus, endogenous Cushing’s syndrome was ruled out. A negative cortisol response was observed for the rapid ACTH stimulation test; therefore, we made a diagnosis of iatrogenic Cushing’s syndrome combined with additional secondary adrenal insufficiency.
        52.
        2012.12 KCI 등재 서비스 종료(열람 제한)
        Compared to wide ranges of genetic variation of natural populations, very limited Miscanthus cultivar has been released. This study was the first report on the development of Miscanthus cultivar by means of radiation breeding. Seeds of M. sinensis were initially exposed to gamma rays of 250 Gy for 24 h, generated from a 60Co gamma-irradiator. The irradiated seeds were sown and then the highly tiller-producing mutants were selected for this study. Biomass-related parameters including tiller number, plant height, stem diameter, and leaf number were measured. Ploidy level and internal transcribed spacer (ITS) were investigated to characterize the mutants compared to wild type (WT) Miscanthus. Plant height and tiller number were negatively related, where multi-tillering mutants were relatively short after 4 month growth. However stem diameter and leaf number were greater in mutants. All the materials used in this study were diploid, implying that the mutants with greater tiller numbers and stem diameter were not likely related to polyploidization. Based on the sequence of ITS regions, the mutants demonstrated base changes from the gamma irradiation where G+C content (%) was decreased in the ITS1, but increased in ITS2 when compared to WT sequence. ITS2 region was more variable than in ITS1 in the mutants, which collectively allows identification of the mutants from WT. Those mutants having enhanced tillers and allelic variations might be used as breeding materials for enhanced biomass-producing Miscanthus cultivars.
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