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        검색결과 1,713

        401.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon materials with tailorable structures and superior properties have great potential applications in environmental protection, energy conversion, and catalysis. Plant biomass as abundant and green non-toxic raw materials has been considered as good precursors for synthesizing heteroatom-doped carbon materials. However, few studies have been reported on the different natures of carbon materials derived from different parts of the same plant biomass. In this study, we prepared carbon materials from the petioles and blades of apricot leaves by direct pyrolysis without additives. Detailed characterizations indicate that these two carbon materials are similar in element composition and graphitization degree, but differ greatly in surface area and pore volume. These differences can be attributed to the different contents of inorganic salts, vascular bundles, and proteins in petioles and blades. When used as catalysts for the oxidation of ethylbenzene, the petiole-derived carbon shows better catalytic performance than the blades derived carbon due to its high surface area, large average pore size, and doped nitrogen atoms. Furthermore, the carbon catalysts derived from the petioles and blades of poplar leaves and parasol tree leaves show the same difference in catalytic reaction, implying that the above-mentioned conclusion is rather universal, which can provide reference for the synthesis of carbon materials from leaves.
        4,000원
        402.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A highly functional, environmentally friendly carbonaceous adsorbent material using black liquor (a by-product from the pulp manufacturing) was produced and characterized. This study showed the effect of self-chemical activation driven by inherent alkali, originated from the unique composition of black liquor. A preparation of the micropore-dominant activated carbon was made in an easy and simple manner. The specific surface areas of samples were found to be 718–1591 m2/ g variated upon heat treatment conditions. The sample activated at 850 °C (50 min as retention time) showed the maximum specific surface area of 1591 m2/ g with 13.6% as a production yield. Considering the factors influencing pore structure of activated carbon materials in this study, it was confirmed that mesopore-related surface area increased gradually as the activation temperature and retention time increased. It is noteworthy to address that economically valuable micropore-dominant activated carbon can be produced by a simple heat treatment of the waste material, black liquor. The activated carbon sample derived from black liquor can be applied to various fields, such as environment and energy storage.
        4,000원
        403.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nitric oxide (NO)-induced protein S-nitrosylation triggers mitochondrial dysfunction and was related to cell senescence. However, the exact mechanism of these damages is not clear. In the present study, to investigate the relationship between in vitro aging and NO-induced protein S-nitrosylation, oocytes were treated with sodium nitroprusside dihydrate (SNP), and the resultant S-nitrosylated proteins were detected through biotin-switch assay. The results showed that levels of protein S-nitroso thiols (SNO)s and expression of S-nitrosoglutathione reductase (GSNOR) increased, while activity and function of mitochondria were impaired during oocyte aging. Addition of SNP, a NO donor, to the oocyte culture led to accelerated oocyte aging, increased mitochondrial dysfunction and damage, apoptosis, ATP deficiency, and enhanced ROS production. These results suggested that the increased NO signal during oocyte aging in vitro, accelerated oocyte degradation due to increased protein S-nitrosylation, and ROS-related redox signaling.
        4,000원
        404.
        2020.03 구독 인증기관 무료, 개인회원 유료
        Enamel knot (EK)—a signaling center—refers to a transient morphological structure comprising epithelial tissue. EK is believed to regulate tooth development in early organogenesis without its own cellular alterations, including proliferation and differentiation. EKs show a very simple but conserved structure and share functions with teeth of recently evolved vertebrates, suggesting conserved signaling in certain organs, such as functional teeth, through the course of evolution. In this study, we examined the expression patterns of key EK-specific genes including Dusp26 , Fat4, Meis2, Sln , and Zpld1 during mice embryogenesis. Expression patterns of these genes may reveal putative differentiation mechanisms underlying tooth morphogenesis.
        4,000원
        405.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 관상가치가 뛰어난 산꼬리풀의 분화 재배법을 확립하고자 차광, 기비, 추비, 왜화제 및 적심처리를 각각 달리하여 수행하였다. 연구의 결과 차광 시 산꼬리풀의 생육이 감소 하였으며, 차광률이 증가할수록 크게 억제되었다. 기비 처리는 초장, 절간장, 경직경 및 엽수를 유의적으로 증가하였으나, Hyponex를 이용한 추비 처리는 무처리와 비교했을 때 생육증가에 큰 영향을 미치지 않았다. 왜화제 처리시 diniconazole은 농도에 관계없이 왜화효과가 나타났으며, 농도가 증가할수록 크게 억제되었다. Daminozide는 저농도 처리시 무처리와 비교하여 큰 차이가 없었으나, 2000mg·L-1 농도로 처리하였을 때 왜화효과가 나타났으며, 개화율은 diniconazole 저농도에서 가장 낮은 결과를 보였다. 한편 적심 처리에 따른 유의적인 생육 차이는 확인되지 않았다.
        4,000원
        406.
        2020.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        At q = 1.81 ± 0.20 × 10-5, KMT-2018-BLG-0029Lb has the lowest planet-host mass ratio q of any microlensing planet to date by more than a factor of two. Hence, it is the first planet that probes below the apparent "pile-up" at q = 5-10 ×10-5. The event was observed by Spitzer, yielding a microlens-parallax πE measurement. Combined with a measurement of the Einstein radius θE from finite-source effects during the caustic crossings, these measurements imply masses of the host Mhost = 1.14+0.10-0.12 M⊙ and planet Mplanet = 7.59+0.75-0.69 M⊕, system distance DL = 3.38+0.22-0.26 kpc and projected separation a⊥ = 4.27+0.21-0.23 AU. The blended light, which is substantially brighter than the microlensed source, is plausibly due to the lens and could be observed at high resolution immediately.
        5,200원
        407.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We report potentiometric performances of ion-to-electron transducer based on reduced graphene oxide (RGO) for application of all-solid-state potassium ion sensors. A large surface area and pore structure of RGO are obtained by a hydrothermal self-assembly of graphene oxide. The extensive electrochemical characterization of RGO solid contact at the interface of ionselective membrane and gold electrode shows that the potassium ion-selective electrode based on RGO had a high sensitivity (53.34 mV/log[K+]), a low detection of limit (− 4.24 log[ K+], 0.06 mM) a good potential stability, and a high resistance to light and gas interferences. The potentiometric K+- sensor device was fabricated by combining of screen-printed electrodes and a printed circuit board. The K+- sensor device accurately measures the ion concentration of real samples of commercial sports drinks, coke and orange juice, and then transfers the collected data to a mobile application through a Bluetooth module. The screen-printed ion sensors based on RGO solid contact show a great potential for real-time monitoring and point-of-care devices in human health care, water-treatment process, and environmental and chemical industries.
        4,000원
        409.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 아이스플랜트의 기능성 소금 대체제로서의 가능성을 조사하고자 천연 및 정제소금과의 NaCl, Dpinitol, 총 페놀, 총 플라보노이드 및 DPPH 라디칼 소거능에 대한 기초자료를 비교 조사하였다. 아이스플랜트 동 결건조분말의 NaCl 함량을 분석한 결과 19%이었고 Dpinitol의 함량은 777 mg/100 g으로 천일염 및 정제염에 비해 NaCl 함량은 유의적으로 낮으나 D-pinitol을 함유하고 있어 건강기능성에는 도움이 될 것으로 사료된다. 또한, 아이스플랜트 동결건조분말의 총 페놀 및 플라보노이드 함량은 각각 115 mg/100 g 및 985 mg/100 g을 함유 하고 있어 DPPH라디칼 소거능의 항산화효과를 갖는 것으로 나타났다. 따라서 아이스플랜트 분말의 bioactive compound을 함유한 대체 소금 천연소재로서 가능성을 확인한 기초 연구를 제공하였다.
        4,000원
        410.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 Veronica속 20종의 생장 및 개화 특성을 평가하기 위해 2년 동안 국립수목원 식물자원연구과 육종온실에서 수행하였다. Veronica속 식물은 다양한 생장 및 개화 특성을 가지고 있었다. 꼬리풀 20종을 식물 형태 및 초장에 따라 분류하였다. 포복형의 10cm 미만 초장은 V. armena와 V. repens, 직립형 30cm 미만 초장은 V. gentianoides ‘Little blues’ 등 4종, 직립형 30~60cm 사이 초장은 V. gentianoides ‘Blue Streak’ 등 7종, 직립형 60cm 이상 초장은 V. incana 등 7종이었다. 대부분의 엽색은 초록색이었고 V. incana와 V. incana ‘Silbersee’는 잎에 흰 털이 있었다. 꽃대 수는 5.3개부터 80.7개, 화수는 4.5개부터 67.3개였고 개화일은 3월 초순부터 6월 중순이었다. 화서의 형태는 총상화서, 수상화서, 취산화서로 분류하였다. 화색은 보라색 13종, 분홍색 2종, 흰색 5종이었다. 2017년 모든 개체가 개화한 종은 3종으로 V. longifolia ‘Blue Shades’, V. spicata ‘Blue Bouquet’, V. subsessilis ‘Blue Pyramid’였고, 일부 개체만 개화한 종은 7종으로 V. armena, V. gentianoides ‘Little Blues’, V. longifolia ‘Alba’, V. prostrata ‘Nestor’, V. spicata, V. spicata ‘Alba’, V. spicata ‘Sightseeing’ 이었다. 모든 개체가 개화하지 않은 종은 10종으로 V. gentianoides ‘Blue Streak’, V. incana, V. incana ‘Silbersee’, V. longifolia ‘Pink Shades’, V. orchidea ‘Blue Fingers’, V. repens, V. schmidtiana, V. spicata ‘Blue Carpet’, V. spicata ‘Pink Goblin’, V. teucrium ‘Royal Blue’였다. 반면, 2018년에는 모든 종의 개체가 개화하였다.
        4,000원
        411.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Viral protein 2 (VP2) of porcine parvovirus (PPV) is responsible for inducing neutralizing antibodies in immunized animals. It is the major viral structural protein. In this study, novel subunit vaccines against PPV based on virus-like particles (VLPs) formed from VP2 proteins (PPV 13-7 Korean strain) were expressed in an insect baculovirus cell system and purified using Ni-NTA affinity column chromatography. These VP2 proteins assembled into virus-like particles (VLPs). They showed antigenic properties similar to those of natural PPV. In addition, they showed high hemagglutination (HA) titers (211 for PPV 13-7 Korean strain). This study provides a foundation for the application of the difference immunization of recombinant protein in the diversity of PPV VP2 genes and in vaccination against PPV in the future.
        3,000원
        412.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Objective: To evaluate item-factor structures of the 15 sensory items from the Survey of Pathways to Diagnosis and Services (Pathways) and examine the best fitting model. Methods: The study subjects were 1,968 children aged 6-17 years, who had ever been diagnosed with Autism Spectrum Disorder (ASD) and/or Intellectual Disability (ID). Factor analyses and item response theory models were used to determine the best fitting item-factor structure of the sensory items. The Strengths and Difficulties Questionnaires (SDQ) was used to test the concurrent validity of the sensory severity estimates. Results: A bifactor MIRT model (a general and four sensory factors) was selected as the best fitting model. All items statistically fitted to the bifactor model (p > .01) and showed moderate correlations with all five subscales of the SDQ (r s = .31 ~.51, p < .0001). The general sensory score differentiated the four different diagnostic groups (ASD, ID, ASD with ID, and no current symptoms) [F (3,1961) = 207.4, p < .0001]. Conclusion: The Pathways sensory items yielded reliable estimates of the general and each corresponding sensory factor by applying a bifactor MIRT model. The sensory score can be used as a valid sensory measure in the population survey.
        4,900원
        413.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Canine parvovirus type-2 (CPV-2) has been reported worldwide as the main agent associated with acute hemorrhagic enteritis, resulting in high morbidity, especially in young dogs. CPV-2 has three genetic variants, 2a, 2b, and 2c. Here, we report three cases of canine parvovirus enteritis associated with CPV-2a (2 samples) and -2c (1 sample) infections that occurred in three young dogs suffering from enteritis. Isolates from dog diarrheic fecal samples were sequenced by polymerase chain reaction (PCR) and identified as two types of CPV-2a and one type of CPV-2c. This work constitutes the first isolation and genetic characterization of CPV-2c in the Republic of Korea.
        4,000원
        414.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The advance of information technology with governmental support allows researchers to utilize big data to conduct rigorous rehabilitation-related studies in both the United States and Korea. While big data research has been actively conducted in the United States, few Korean rehabilitation scientists currently conduct big data research. In this paper, we discuss the existing rehabilitation-related big data in Korea and introduce the current big data research trends in the United States. In addition, we provide potential research areas by discussing the previous big data studies in the United States, including 1) functional outcomes, 2) geographical variation, 3) linkage of a population-based cohort to hospital data, 4) cross-national comparison, and 5) scale development. We also discuss various statistical methods required in big data research and compare how these methods differ compared to the traditional research methods in rehabilitation research. Lastly, we discuss the importance of workforce development in rehabilitation-related big data research. We hope this paper will provide occupational therapy scientists and clinicians with practical and useful information about big data research and accelerate big data rehabilitation research communities in Korea.
        4,200원
        415.
        2019.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: The wall squat exercise has been recommended for strengthening of the lower extremity muscles with maintaining lumbar lordosis. Although squat has been studied to be related to lower extremity extensor strength, the relationship between wall squat and lower extremity extensor strength unclear. Because squat and wall squat are biomechanically different, study on the relationship is needed. Objects: The purpose of this study was to determine the lower extremity extensor strength associated with wall squat performance. Methods: 74 healthy volunteers were recruited to participate in this study. The volunteers were measured hip and knee extensors strength and then performed wall squat exercise for maximum count. Results: We found significant relationships between wall squat performance and hip extensor strength normalized by body weight, knee extensor strength normalized by body weight and the composite value. In a regression analysis, hip extensor strength normalized by body weight explained 29% of the variation in wall squat performance in males and 35% in females. Conclusion: These results demonstrate that hip extensor strength normalized by body weight is critical to wall squat performance in both sexes.
        4,000원