Tailored layer-by-layer deposition of silica reinforced polyelectrolyte layers on polymer microcapsules for enhanced antioxidant cargo retention

Lee, Jin Yong,Shin, Kyounghee,Seo, Hyemin,Jun, Hwiseok,Hirai, Alex Naoto Shishido,Lee, Jin Won,Nam, Yoon Sung,Kim, Jin Woong Elsevier 2018 Journal of industrial and engineering chemistry Vol.58 No.-

<P><B>Abstract</B></P> <P>This study reports a robust and straightforward approach to fabricate polymer microcapsules with a silica reinforced polyelectrolyte thin shell layer. We showed that the layer-by-layer deposition of silica nanoparticles with polyelectrolytes remarkably reinforced the shell layer, which was experimentally demonstrated by focused ion beam analysis. Moreover, we demonstrated that the molecular degradation of a model antioxidant encapsulated in our capsule system was effectively hindered during long-term storage. This indicates that the presence of the silica nanoparticles-reinforced polyelectrolyte shell layer displayed enhanced cargo retention against leakage of the antioxidant as well as oxygen attack from the surroundings.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Polymer microcapsules with a silica reinforced polyelectrolyte shell were produced. </LI> <LI> The LbL deposition of silica nanoparticles remarkably reinforced the shell layer. </LI> <LI> A model antioxidant was effectively stabilized during long-term storage. </LI> <LI> Our capsules enhanced cargo retention against antioxidant leakage and oxygen attack. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

The Arabidopsis MYB96 Transcription Factor Is a Positive Regulator of ABSCISIC ACID-INSENSITIVE4 in the Control of Seed Germination.

Lee, Kyounghee,Lee, Hong Gil,Yoon, Seongmun,Kim, Hyun Uk,Seo, Pil Joon American Society of Plant Physiologists 2015 PLANT PHYSIOLOGY - Vol.168 No.2

<P>Seed germination is a key developmental transition that initiates the plant life cycle. The timing of germination is determined by the coordinated action of two phytohormones, gibberellin and abscisic acid (ABA). In particular, ABA plays a key role in integrating environmental information and inhibiting the germination process. The utilization of embryonic lipid reserves contributes to seed germination by acting as an energy source, and ABA suppresses lipid degradation to modulate the germination process. Here, we report that the ABA-responsive R2R3-type MYB transcription factor MYB96, which is highly expressed in embryo, regulates seed germination by controlling the expression of abscisic acid-insensitive4 (ABI4) in Arabidopsis (Arabidopsis thaliana). In the presence of ABA, germination was accelerated in MYB96-deficient myb96-1 seeds, whereas the process was significantly delayed in MYB96-overexpressing activation-tagging myb96-ox seeds. Consistently, myb96-1 seeds degraded a larger extent of lipid reserves even in the presence of ABA, while reduced lipid mobilization was observed in myb96-ox seeds. MYB96 directly regulates ABI4, which acts as a repressor of lipid breakdown, to define its spatial and temporal expression. Genetic analysis further demonstrated that ABI4 is epistatic to MYB96 in the control of seed germination. Taken together, the MYB96-ABI4 module regulates lipid mobilization specifically in the embryo to ensure proper seed germination under suboptimal conditions.</P>

<i>Arabidopsis</i> ATXR2 deposits H3K36me3 at the promoters of <i>LBD</i> genes to facilitate cellular dedifferentiation

Lee, Kyounghee,Park, Ok-Sun,Seo, Pil Joon AAAS 2017 Science signaling Vol.10 No.507

<P><B>Epigenetic control of dedifferentiation</B></P><P>Some plant cells can dedifferentiate to form a mass of pluripotent cells called callus. This not only occurs at wound sites but can also be induced by specific laboratory culture conditions. Lee <I>et al</I>. found that the histone lysine methyltransferase ATXR2 promoted cellular dedifferentiation during callus formation in <I>Arabidopsis thaliana</I> by stimulating the expression of <I>LBD</I> genes, which encode transcription factors that promote cell cycle progression. ATXR2 localized to <I>LBD</I> promoters, stimulated the accumulation of lysine-methylated histones at these promoters, and was recruited to the promoters by the transcription factors ARF7 and ARF19. Epigenetic regulation is a key mechanism controlling cell potency and differentiation in both plants and animals, and these findings contribute to understanding the remarkable developmental plasticity of plant cells.</P><P>Cellular dedifferentiation, the transition of differentiated somatic cells to pluripotent stem cells, ensures developmental plasticity and contributes to wound healing in plants. Wounding induces cells to form a mass of unorganized pluripotent cells called callus at the wound site. Explanted cells can also form callus tissues in vitro. Reversible cellular differentiation-dedifferentiation processes in higher eukaryotes are controlled mainly by chromatin modifications. We demonstrate that ARABIDOPSIS TRITHORAX-RELATED 2 (ATXR2), a histone lysine methyltransferase that promotes the accumulation of histone H3 proteins that are trimethylated on lysine 36 (H3K36me3) during callus formation, promotes early stages of cellular dedifferentiation through activation of <I>LATERAL ORGAN BOUNDARIES DOMAIN</I> (<I>LBD</I>) genes. The <I>LBD</I> genes of <I>Arabidopsis thaliana</I> are activated during cellular dedifferentiation to enhance the formation of callus. Leaf explants from <I>Arabidopsis atxr2</I> mutants exhibited a reduced ability to form callus and a substantial reduction in <I>LBD</I> gene expression. ATXR2 bound to the promoters of <I>LBD</I> genes and was required for the deposition of H3K36me3 at these promoters. ATXR2 was recruited to <I>LBD</I> promoters by the transcription factors AUXIN RESPONSE FACTOR 7 (ARF7) and ARF19. Leaf explants from <I>arf7-1arf19-2</I> double mutants were defective in callus formation and showed reduced H3K36me3 accumulation at <I>LBD</I> promoters. Genetic analysis provided further support that ARF7 and ARF19 were required for the ability of ATXR2 to promote the expression of <I>LBD</I> genes. These observations indicate that the ATXR2-ARF-LBD axis is key for the epigenetic regulation of callus formation in <I>Arabidopsis</I>.</P>

Airborne signals from salt-stressed Arabidopsis plants trigger salinity tolerance in neighboring plants.

Lee, Kyounghee,Seo, Pil Joon Landes Bioscience 2014 Plant signaling & behavior Vol.9 No.1

<P>Plants have evolved sophisticated defense mechanisms to overcome their sessile nature. One remarkable strategy is the inter-plant communication mediated by volatile organic compounds (VOCs). Quantity and quality of plant VOCs are intricately regulated by biotic and abiotic stresses, and the alterations facilitate plant community to optimize their growth, development, and endogenous physiology to environmental fluctuations. Here, we report that Arabidopsis thaliana plants that experience high salinity emit VOCs and trigger induction of high salt resistance in neighboring plants. VOC emission of emitter plants is likely correlative to the plant damages to high salt, and VOC-fumigated receiver plants acquire high salt tolerance. The VOC-induced stress tolerance is independent of conventional abscisic acid (ABA) and salt stress signaling pathways. Together, this study demonstrates that salt-induced Arabidopsis VOCs are relevant in priming stress tolerance in neighboring plants. In addition, it also provides insight into how VOCs elicit stress responses in plant community.</P>

ATXR2 as a core regulator of <i>de novo</i> root organogenesis

Lee, Kyounghee,Park, Ok-Sun,Seo, Pil Joon Informa UK (TaylorFrancis) 2018 Plant signaling & behavior Vol.13 No.3

Arabidopsis tor signaling is essential for sugar‐regulated callus formation

Lee, Kyounghee,Seo, Pil Joon Wiley-Blackwell 2017 Journal of integrative plant biology Vol.59 No.10

The Arabidopsis MYB96 Transcription Factor Is a Positive Regulator of ABI4 in the Control of Seed Germination

Kyounghee Lee,Hong Gil Lee,Seongmun Yoon,Hyun Uk Kim,Pil Joon Seo 한국육종학회 2015 한국육종학회 심포지엄 Vol.2015 No.07

Seed germination is a key developmental transition that initiates the plant life cycle. The timing of germination is determined by coordinated action of two phytohormones, gibberellin (GA) and abscisic acid (ABA). In particular, ABA plays a key role in integrating environmental information and inhibiting the germination process. Utilization of embryonic lipid reserves contributes to seed germination by acting as an energy source, and ABA suppresses lipid degradation to modulate the germination process. Here, we report that the ABA-responsive R2R3-type MYB transcription factor MYB96, which is highly expressed in embryo, regulates seed germination by controlling the expression of ABA-INSENSITIVE 4 (ABI4). In the presence of ABA, germination was accelerated in MYB96-deficient myb96-1 seeds, whereas the process was significantly delayed in MYB96-overexpressing activation-tagging myb96-ox seeds. Consistently, myb96-1 seeds degraded a larger extent of lipid reserves even in the presence of ABA, while reduced lipid mobilization was observed in myb96-ox seeds. MYB96 directly regulates ABI4, which acts as a repressor of lipid breakdown, to define its spatial and temporal expression. Genetic analysis further demonstrated that ABI4 is epistatic to MYB96 in the control of seed germination. Taken together, the MYB96-ABI4 module regulates lipid mobilization specifically in the embryo to ensure proper seed germination under suboptimal conditions.

A Distributed Mobility Management Framework for 5G Converged Networks

Kyounghee Lee,No-Ik Park 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.11

A mobility management issue is surfacing again as it is expected that mobility requirements will be very essential and vary with application scenarios in the future 5G networks. An important research direction on this area is to design a flat and distributed control architecture to achieve scalability enough to be applied into the wide-scale real networks. In this paper, we propose a distributed mobility management framework for evolving networks toward 5G. The main idea is to separate location management from data traffic control during handling a node's handover. By being divided from location update to be propagated throughout whole network, handover control process can be localized and accelerated in a distributed manner. To apply different control operations according to handover types is another important feature of our approach. Experimental results from our simulation study show that the proposed framework considerably outperforms a well-known MM protocol, Proxy Mobile IPv6, in the aspects of handover latency, packet loss and dispersion of control overhead.

Democracy and Trade Policy:

Kyounghee Lee 대외경제정책연구원 2010 Working Papers Vol.2010 No.1

민주화가 진전됨에 따라 다양한 이익집단들이 정부의 무역자유화 정책에 대해 목소리를 높이고 있다. 본 연구는 민주화 이후 다양한 이익집단의 증가와 무역 정책에 대한 그들의 참여가 궁극적으로 정부의 무역정책에 어떤 영향을 미치는지를 실증분석한다. Grossman and Helpman (1994) 모델을 이용하여 수행한 분석결과에 따르면, 이익집단의 증가가 보호무역을 초래할 것이라는 일반적인 통념과 달리, 무역정책에 대한 다양한이익집단의 참여는 오히려 무역자유화에 긍정적인 영향을 미친다. 즉, 소수의 특정 이익집단이 정부로부터 보호를 요구할 때는 이 이익집단의 영향력이 강하게 반영되지만 다수의 이익집단이 동시에 무역정책에 영향을 미칠 때는 이익집단의 요구가 서로 상쇄되는 경향을 보인다. 본 연구결과는 민주주의 체제하에서 이익집단에 대한 ‘개방주의(openness)’와 ‘다원주의(pluralism)’ 정책이 궁극적으로 무역자유화 정책에 도움이 된다는점을 시사한다. As a democracy develops and matures, the number of interest groups attempting to voice their interests with respect to trade policies tends to increase, and sometimes governments collide with them in the process of enacting restraints. This paper aims to investigate empirically the role of interest groups in Korea’s trade policy, utilizing the Grossman and Helpman model (1994). Contrary to prevailing wisdom, the results of our empirical investigation suggest that a greater level of participation by diverse interest groups actually promotes trade liberalization, as different groups offset each other’s demands in the act of obtaining government protection. The findings imply that “openness and pluralism” with respect to interest groups is necessary if better strategies for trade liberalization are to be developed.

A STUDY ON THE EFFECT OF VERBAL BRAND PERSONIFICATION ON CONSUMER EVALUATION IN ADVERTISING: FOCUSED ON THE INTERNAL AND EXTERNAL PERSONIFICATION

Kyounghee Chu,Doo-Hee Lee,Ji Yoon Kim 글로벌지식마케팅경영학회 2016 Global Marketing Conference Vol.2016 No.7

Given the pervasive use of brand personification by marketers, it is surprising that there has been extremely limited research directly examining the effects of brand personification. In this article, we attempt to fill this gap in part by exploring how personified brand, in contrast to an objectified brand, might affect consumers’ response. Also, previous research have studied mainly on the visual or combined (visual-verbal) brand personification without differentiating the two types of brand personification. Therefore, this study tries to focus on the verbal brand personification which has not been studied extensively. And there are two types of verbal brand personification: external and internal image. So this study validates the effect of internal (kind) or external (looking good) verbal brand personification separately in the series of two experiments. Study 1 tests the effect of internal verbal brand personification on the consumer evaluation using product brand. Specifically, we test the moderating effect of brand knowledge between verbal brand personification and consumer evaluation and explore the underlying mechanisms (brand intimacy, psychological discomfort) about how the interaction effect of personification level and brand knowledge occurs. Study 2 tests the effect of external verbal brand personification on the consumer evaluation using service brand. Specifically, we test the effect of need-for-cognition on attitude towards personified brand ad and additionally explore the underlying mechanisms (perceived novelty, cognitive resistance) about how need-for-cognition influences. This research could provide useful guidelines for the marketers to utilize personification method when planning the head copy or slogan for advertisement. Therefore, marketers are better able to make an effective brand personification strategy through understanding the boundary conditions and mechanisms about the impact of brand personification based on the findings of this study.