• Tuberculosis and Respiratory Diseases
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• 제42권6호
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• pp.801-812
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• 1995

CR asthma is associated with disease chronicity, a positive family history of asthma and in vitro and in vivo defects in mononuclear cell function. The HPA axis in CR asthmatics is suppressed normally by dexamethasone and the pharmacokinetic profile of an oral dose of prednisolone is similar to that found in CS subjects. In addition, competitive binding studies have shown that the ligand binding and nuclear translocation functions of the GR are similar in the two groups. Studies using gel retardation assay have indicated a defect in DNA binding in CR subjects. Chemical mutational analysis of the GR has shown that is not due to a defect in its structure at the cDNA level. Scatchard analysis of the GR/DNA and GR/ligand interactions suggests that there may be transcriptional interference of the GR with other transcriptionally active molecules leading to defective gene transcription.

• The Journal of Asian Finance, Economics and Business
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• 제9권3호
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• pp.181-193
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• 2022

This paper seeks to investigate major macroeconomic factors and bond yield interactions in Thai bond markets, with the goal of forecasting future bond yields. This study examines the best predictive yields for future bond yields at different maturities of 1-, 3-, 5-, 7-, and 10-years using time series data of economic indicators covering the period from 1998 to 2020. The empirical findings support the hypothesis that macroeconomic factors influence bond yield fluctuations. In terms of forecasting future bond yields, static predictions reveal that in most cases, the BVAR model offers the best predictivity of bond rates at various maturities. Furthermore, the BVAR model has the best performance in dynamic rolling-window, forecasting bond yields with various maturities for 2-, 4-, and 8-quarters. The findings of this study imply that the BVAR model forecasts future yields more accurately and consistently than other competitive models. Our research could help policymakers and investors predict bond yield changes, which could be important in macroeconomic policy development.

• Applied Biological Chemistry
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• 제39권4호
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• pp.287-292
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• 1996

니켈 독성의 생물검정에 있어서 지표식물로서 무를 이용하였고 토양중 니켈의 농도, 토양 pH, 공존 이온의 첨가, 복토, 유기물, 석회처리의 요인을 변수로 하여 무의 생육 상태 및 니켈의 흡수축적량 차이를 비교하였다. 무종자의 발아율은 대조구에 비하여 니켈 처리농도 150 mg/kg에서 40%의 낮은 발아율을 나타내었다. 토양 중에 처리된 니켈 농도가 증가할수록 무의 초장, 근장, 건물량이 감소하는 경향이었으며, 니켈 처리농도 100 mg/kg에서 약 65%의 생육저해를 보였으며 150 mg/kg부터는 무의 정상적인 생육이 불가능하였다. 토양 pH가 증가함에 따라 무로 흡수 이행되는 니켈의 함량이 감소하는 역의 상관을 나타내었다. 토양에 니켈을 50 mg/kg으로 처리한 후 Fe의 농도를 10, 50, 100 mg/kg으로 증가시켰을 때 무로 이행되는 니켈의 흡수축적량간에 유의성이 인정되지 않았다(p>0.1). 토양에 니켈을 50mg/kg으로 처리한 후 Zn의 농도를 10, 50, 100mg/kg으로 증가시켰을 때 무로 흡수 이행되는 니켈의 흡수축적량간에 유의성이 인정되었다(줄기, 뿌리 p<0.05). 복토, 유기물과 석회처리시 모두 대조구에 비하여 니켈 흡수축적량이 감소하는 경향이었다(p<0.01). 각 처리구간의 니켈 흡수축적량 차이는 인정할 수 없었으나(줄기, 뿌리 p>0.5), 유기물>복토>석회처리의 순서대로 니켈 흡수량 감소의 효과가 나타났다.

• 상하수도학회지
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• 제28권4호
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• pp.419-429
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• 2014

Recent studies have been reported the presence of Endocrine Disrupting Compounds, Pharmaceuticals and Personal Care Products (EDC/PPCPs) in surface and wastewater, which could potentially affect to the complicate behavior in coupled presence of nano-colloid particles and surfactants (adsorption, dispersion, and partitioning). In this study, the adsorption of EDC/PPCPs by Single Walled Carbon Nanotubes (SWNTs) as a representative of nano-particles in cationic surfactant solutions were investigated. Hydrophobic interactions (${\pi}-{\pi}$ Electron Donor-Acceptor) have been reported as a potential adsorption mechanisms for EDC/PPCPs onto SWNTs. Generally, the adsorptive capacity of the relatively hydrophobic EDC/PPCPs onto SWNTs decreased in the presence of cationic surfactant (Cetyltrimethyl Ammonium Bromide, CTAB). This study revealed that the competitive adsorption occurred between CTAB cations and EDC/PPCPs by occupying the available SWNT surface (CTAB adsorption onto SWNTs shows five-regime and maximum adsorption capacity of 370.4 mg/g by applying the BET isotherm). The adsorption capacity of $17{\alpha}$-ethinyl estradiol (EE2) on SWNT showed the decrease of 48% in the presence of CTAB. However, the adsorbed naproxen (NAP) surely increased by forming hemimicelles and resulted in a favorable media formation for NAP partition to increase SWNTs adsorption capacity. The adsorbed NAP increased from 24 to 82.9 mg/g after the interaction of CTAB with NAP. The competitive adsorption for EDC/PPCPs onto SWNTs is likely to be a key factor in the presence of cationic surfactant, however, NAP adsorption showed a slight competition through $CH_3-CH_3$ interaction by forming hemimicelles on SWNT surface.

• 정보화정책
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• 제30권3호
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• pp.92-121
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• 2023

음악 스트리밍 서비스는 음악 소비 과정에서 사용자와의 다양한 상호작용이 발생한다는 점에서 사용자 경험(User Experience: UX)에 대한 이해가 중요하다. 본 연구는 사용자 경험의 '구조'(Structure)를 분석한 선행연구, 음악 서비스 사용자가 중요하게 생각하는 '품질 특성'(Quality Characteristics)에 관한 선행연구를 토대로 음악 스트리밍 서비스의 사용자 경험 모델을 개발하고 그 타당성을 검증하였다. 음악 스트리밍 서비스 사용자를 대상으로 한 설문 데이터를 분석한 결과, 기능성(검색, 브라우징, 개인화된 추천), 유저 인터페이스 사용성, 콘텐츠 품질(현재성, 충분성, 관련성), 금전적 비용이 해당 서비스에 관한 사용자 경험 결과(사용자 만족)를 결정하는 주요 요인인 것으로 밝혀졌다. 또한, 국내 서비스들과 글로벌 서비스를 비교한 결과, 기능성과 콘텐츠 품질에 대해서 사용자 경험의 차이가 있는 것으로 나타났다. 본 연구에서 제안한 음악 스트리밍 서비스 사용자 경험 모델은 관련 이론 기반 연구에 새로운 토대가 될 수 있으며, 실제 플랫폼들 간의 경쟁 구도 및 그들의 경쟁 전략에 대한 의미 있는 시사점을 제공한다.

• Journal of Ecology and Environment
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• 제31권3호
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• pp.167-176
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• 2008

Atmospheric N deposition has far-reaching impacts on forest ecosystems, including on-site impacts such as soil acidification, fertilization, and nutrient imbalances, and off-site environmental impacts such as nitrate leaching and nitrous oxide emission. Although chronic N deposition has been believed to lead to forest N saturation, recent evidence suggests that N retention capacity, particularly in the forest floor, can be surprisingly high even under high N deposition. This review aims to provide an overview of N retention processes in the forest floor and the implications of changing C-N interactions for C sequestration. The fate of available N in forest soils has been explained by the competitive balance between tree roots, soil heterotrophs, and nitrifiers. However, high rates of N retention have been observed in numerous N addition experiments without noticeable increases in tree growth and soil respiration. Alternative hypotheses have been proposed to explain the gap between the input and loss of N in N-enriched, C-limited systems, including abiotic immobilization and mycorrhizal assimilation, both of which do not require additional C sources to incorporate N in soil N pools. Different fates of N in the forest floor have different implications for C sequestration. N-induced tree growth can enhance C accumulation in tree biomass as observed across temperate regions. C loss from forests can amount to or outweigh C gain in N-saturated, declining forests, while another type of 'C-N decoupling' can have positive or neutral effects on soil C sequestration through hampered organic matter decomposition or abiotic N immobilization, respectively.

• BMB Reports
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• 제34권6호
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• pp.537-543
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• 2001

In the present study, an in vitro ELISA system to assess the interaction between Src homology (SH)2 domains and phosphotyrosine that contain peptides was established using purified GST-conjugated SH2 proteins and synthetic biotinylated phosphotyrosine that contain oligopeptides. The SH2 domains bound the relevant phosphopeptides that were immobilized in the streptavidin-coated microtiter plate in a highly specific and dose-dependent manner. The epidermal growth factor receptor (EGFR)-, T antigen (T Ag)-, and platelet-derived growth factor receptor (PDGFR)-derived phosphopeptides interacted with the growth factor receptor binding protein (Grb)2/SH2, Lck/SH2, and phosphatidyl inositol 3-kinase (PI3K) p85/SH2, respectively. No cross-reactions were observed. Competitive inhibition experiments showed that a short phosphopeptide of only four amino acids was long enough to determine the binding specificity. Optimal concentrations of the GST-SH2 fusion protein and phosphopeptide in this new ELISA system for screening the binding blockers were chosen at 2nM and 500nM, respectively. When two candidate compounds were tested in our ELISA system, they specifically inhibited the Lck/SH2 and/or p85/SH2 binding to the relevant phosphopeptides. Our results indicate that this ELISA system could be used as an easy screening method for the discovery of specific binding blockers of protein-protein interactions via SH2 domains.

• Molecules and Cells
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• 제42권6호
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• pp.460-469
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• 2019

Bacterial ${\alpha}-type$ carbonic anhydrase (${\alpha}-CA$) is a zinc metalloenzyme that catalyzes the reversible and extremely rapid interconversion of carbon dioxide to bicarbonate. In this study, we report the first crystal structure of a hyperthermostable ${\alpha}-CA$ from Persephonella marina EX-H1 (pmCA) in the absence and presence of competitive inhibitor, acetazolamide. The structure reveals a compactly folded pmCA homodimer in which each monomer consists of a 10-stranded ${\beta}-sheet$ in the center. The catalytic zinc ion is coordinated by three highly conserved histidine residues with an exchangeable fourth ligand (a water molecule, a bicarbonate anion, or the sulfonamide group of acetazolamide). Together with an intramolecular disulfide bond, extensive interfacial networks of hydrogen bonds, ionic and hydrophobic interactions stabilize the dimeric structure and are likely responsible for the high thermal stability. We also identified novel binding sites for calcium ions at the crystallographic interface, which serve as molecular glue linking negatively charged and otherwise repulsive surfaces. Furthermore, this large negatively charged patch appears to further increase the thermostability at alkaline pH range via favorable charge-charge interactions between pmCA and solvent molecules. These findings may assist development of novel ${\alpha}-CAs$ with improved thermal and/or alkaline stability for applications such as $CO_2$ capture and sequestration.

• 생명과학회지
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• 제20권2호
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• pp.298-303
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• 2010

본 연구에서는 발아 후 2일된 옥수수 유식물의 뿌리 생장에 미치는 영향을 조사하였다. 5 mM에서 30 mM에 이르는 CsCl을 처리하였을 때 옥수수 뿌리와 자엽초 마디 위쪽 shoot의 생중량이 감소하였다. 뿌리의 길이 생장도 역시 동일한 농도 범위의 CsCl에 의하여 감소하였는데 CsCl을 처리할 때 60 mM의 KCl을 함께 처리하면 CsCl에 의하여 감소되었던 신장 생장이 일부 회복되었다. CsCl과 KCl의 관계를 Lineweaver-Burk plot으로 분석한 결과 10 mM - 30 mM CsCl은 KCl과 경쟁 관계에 있는 것으로 나타났지만 5 mM CsCl은 경쟁관계에서 벗어나는 것으로 나타나 주변의 CsCl 농도에 따라 KCl의 작용 모드가 다른 또 하나의 메커니즘이 존재하는 것으로 사료되었다. CsCl의 농도에 따라서 KCl과의 상호작용 모드가 달라지는 현상은 CsCl에 의하여 유도되는 옥수수뿌리 정단 하부의 횡축 팽창에서도 관찰되었다. 또한, CsCl은 10 mM 이상에서 농도 증가에 비례하여 $K^+$ transporter인 ZmKUP1의 발현을 유도하였지만 5 mM CsCl의 ZmKUP1 발현 효과는 뚜렷하게 관찰되지 않았다. 한편, CsCl 존재 하에서도 근단 분열 조직의 수축은 관찰되지 않았다. 종합하면, 외부에서 처리된 CsCl은 2일된 옥수수 유식물의 뿌리의 생중량과 신장을 감소시켰으며 정단 하부의 횡축 팽창을 유도하고 ZmKUP1의 발현을 촉진하였다. 그러나 근단 분열조직의 수축은 없었으므로 CsCl의 효과는 주로 세포 팽창과 관련되는 것으로 판단되며 $Cs^+$와 $K^+$의 경쟁 및 비경쟁적 상호작용을 모두 포함하는 복합적인 메커니즘이 존재하는 것으로 사료된다.

• 한국초등과학교육학회지:초등과학교육
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• 제37권4호
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• pp.402-415
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• 2018

This study aims to inquire into the U. S. elementary school teachers' storylines for science teaching methods, scientific knowledge and interactions with students. As research subjects, two American elementary school teachers, named Christina and Melissa, were selected. As test tools, this study adopted Storyline Test and semi-structured interviews. Firstly, in regard to the science teaching method, Christina evaluated that she gradually improved her science teaching skills up to positive 6 points, starting from 2 points in the first year of teaching career, while Melissa sustained a stable state with 5 points in the 9th year of teaching career, starting from 1 point in the first year of teaching career. It was found that both the teachers had more confidence in their science teaching methods by participating in various training programs. Secondly, Christina evaluated her scientific knowledge in the first year of teaching career as 4 points, but evaluated her present scientific knowledge as stable as 6 points since she started studying teaching materials actively, discussing with other teachers and having more ability of application through science class integrated with other school subjects, in the 7th year of her teaching career. On the other hand, Melissa evaluated her scientific knowledge in the first year of teaching career as 1 point since she did not exactly know what to teach elementary school students, but in the 6th year of teaching career, she sustained a stable state with points through joint-activities with other teachers. It was found that chances to research with other teachers had important effect on both the teachers' confidence in scientific knowledge. Thirdly, in regard to interactions with students in science class, Christina said that she did not have any interaction with students when instructing inquiry activities in the first year of teaching career, but since the 10th year of her teaching career, she had sustained a stable state with 6 points through active interaction with students, by leading learning projects and science competitive exhibitions, etc. On the other hand, Melissa evaluated her interaction with students in the first year of teaching career as 1 point because her class was reading-oriented, but since the 9th year of teaching career, she had sustained a stable state with 6 points so far, by developing inquiry activity strategies to improve interaction with students. Overall, it was found that inquiry activities played a central role in improving both the teachers' interaction with students.