Regioregular-<i>block</i>-Regiorandom Poly(3-hexylthiophene) Copolymers for Mechanically Robust and High-Performance Thin-Film Transistors

Park, Hyeonjung,Ma, Boo Soo,Kim, Jin-Seong,Kim, Youngkwon,Kim, Hyeong Jun,Kim, Donguk,Yun, Hongseok,Han, Junghun,Kim, Felix Sunjoo,Kim, Taek-Soo,Kim, Bumjoon J. American Chemical Society 2019 Macromolecules Vol.52 No.20

<P>In this work, we develop mechanically robust and high-performance organic thin-film transistors (OTFTs) based on poly(3-hexylthiophene) (P3HT) regioblock copolymers (<I>block</I>-P3HTs). These <I>block</I>-P3HTs consist of regioregular (<I>rre</I>) and regiorandom (<I>rra</I>) P3HTs, where the highly crystalline <I>rre</I> block allows efficient charge transport while the amorphous <I>rra</I> block provides mechanical robustness and interdomain connection. To examine the effects of the molecular architecture on the OTFT performance and stretchability, we prepare a series of <I>block</I>-P3HTs having different number-average molecular weight (<I>M</I><SUB>n</SUB>) values of <I>rra</I> blocks (from 0 to 32 kg mol<SUP>-1</SUP>) and a fixed <I>M</I><SUB>n</SUB> of <I>rre</I> blocks (11 kg mol<SUP>-1</SUP>). Thin films of all of the <I>block</I>-P3HTs exhibit a high charge-carrier mobility due to the formation of well-developed edge-on crystallites from the <I>rre</I> blocks confined within the <I>rra</I> domains, leading to a hole mobility of 1.5 × 10<SUP>-1</SUP> cm<SUP>2</SUP> V<SUP>-1</SUP> s<SUP>-1</SUP>, which is superior to that of the <I>rre</I> P3HT homopolymer. In addition, the mechanical toughness of <I>block</I>-P3HT thin films is remarkably enhanced by the <I>rra</I> block. While the <I>rre</I> P3HT homopolymer thin film shows a brittle behavior with an elongation at break of only 0.3%, the elongation at break of the <I>block</I>-P3HT thin films increases by a factor of 100, yielding 30.2% with increasing <I>M</I><SUB>n</SUB> of the <I>rra</I> block, without sacrificing the electrical properties. In particular, a noticeable enhancement of both elongation at break and toughness is observed between <I>M</I><SUB>n</SUB> values of the <I>rra</I> block of 8 and 20 kg mol<SUP>-1</SUP>, indicating that the critical molecular weight of <I>rra</I> P3HT plays an important role in determining the mechanical response of the <I>block</I>-P3HT thin films. This study provides guidelines and strategies to improve the mechanical properties of organic electroactive materials without the disruption of optoelectrical properties, which is critical to fabricate high-performance soft electronics.</P> [FIG OMISSION]</BR>

Modulating Regioregularity of Poly(3-hexylthiophene)-based Amphiphilic Block Copolymers To Control Solution Assembly from Nanowires to Micelles

Kim, Youngkwon,Kim, Hyeong Jun,Kim, Jin-Seong,Yun, Hongseok,Park, Hyeonjung,Han, Junghun,Kim, Bumjoon J. American Chemical Society 2018 Chemistry of materials Vol.30 No.21

<P>In selective solvents, poly(3-hexylthiophene) (P3HT)-based block copolymers (BCPs) assemble into one-dimensional nanowires (NWs) due to strong π-π stacking interactions of the P3HT block. Herein, we report the effect of P3HT regioregularity (RR) on the assembly of P3HT-based amphiphilic BCPs in solution. We synthesized a series of P3HT-<I>block</I>-poly(2-vinylpyridine) (P3HT-<I>b</I>-P2VP) copolymers with similar molecular weights and P3HT volume fractions but with different RRs, ranging from 55% to 95%, and studied their assembly in tetrahydrofuran/<I>n</I>-butanol mixtures. P3HT-<I>b</I>-P2VP copolymers with high RR (>80%) crystallized into well-ordered NWs with core widths consistent with fully extended P3HT chains. In BCP nanostructures with decreasing RR, more flexible P3HT chains produced gradual increases in the width of the NWs, from 12 to 24 nm. Eventually, a morphological transition to spherical micelle structures was observed at 55% RR. The structural differences were visualized by incorporating Au nanoparticles, which locate at the interface of P3HT and P2VP blocks, onto the NWs and imaging the resulting hybrid nanostructures by transmission electron microscopy. In addition, the crystalline behaviors of the assembled nanostructures were determined using differential scanning calorimetry and grazing incidence X-ray scattering. We elucidated important relationships between the solution assembly behaviors and the crystalline interactions of conjugated semicrystalline-coil BCPs, which will guide design of future versatile BCP nanostructures.</P> [FIG OMISSION]</BR>

Transmembrane 4 L six family member 5 (TM4SF5) enhances migration and invasion of hepatocytes for effective metastasis

Lee, Sin‐,Ae,Kim, Tae You,Kwak, Tae Kyoung,Kim, Hyeonjung,Kim, Semi,Lee, Hyo Jeong,Kim, Sung‐,Hoon,Park, Ki Hun,Kim, Hyun Jeong,Cho, Moonjae,Lee, Jung Weon Wiley Subscription Services, Inc., A Wiley Company 2010 Journal of cellular biochemistry Vol.111 No.1

<P><B>Abstract</B></P><P>Overexpression of transmembrane 4 L six family member 5 (TM4SF5), a four‐transmembrane L6 family member, causes aberrant cell proliferation and angiogenesis, but the roles of TM4SF5 in migration, invasion, and tumor metastasis remain unknown. Using in vitro hepatocarcinoma cells that ectopically or endogenously express TM4SF5 and in vivo mouse systems, roles of TM4SF5 in metastatic potentials were examined. We found that TM4SF5 expression facilitated migration, invadopodia formation, MMP activation, invasion, and eventually lung metastasis in nude mice, but suppression of TM4SF5 with its shRNA blocked the effects. Altogether, TM4SF5‐mediated migration and invasion suggest that TM4SF5 may be therapeutically targeted to deal with TM4SF5‐mediated hepatocellular cancers. J. Cell. Biochem. 111: 59–66, 2010. © 2010 Wiley‐Liss, Inc.</P>

Synthesis of homogeneous and bright deep blue CsPbBr 3 perovskite nanoplatelets with solidified surface for optoelectronic material

Kim Taeyun,Suh Yo‐Han,Kim Kangyong,Kim Hyeonjung,Park Jongnam 대한화학회 2022 Bulletin of the Korean Chemical Society Vol.43 No.8

Halide perovskite nanocrystals have easily tunable emissions throughout the visible spectrum, making them an extremely promising material for lightemitting applications. Whereas high quantum yield and long-term colloidal stability have already been achieved for nanocrystals emitting in the red and green spectral range, the blue region currently lags behind with low quantum yields and insufficient colloidal stability. In this study, we present a facile synthetic and postsynthetic approach for obtaining two-dimensional CsPbBr3 nanoplatelets (NPLs) with homogeneous-thickness control of their solidified surface, resulting in sharp photoluminescence and electroluminescence peaks with a deep-blue emission at 465-nm wavelength owing to quantum confinement. The subsequent addition of a solidifying ligand solution seals the surface defects likely stemming from vacancies within a subensemble of weakly emissive NPLs. The overall photoluminescence quantum yield of the blue-emissive colloidal dispersions is consequently enhanced by 65% 2%.

Predicting Affective Responses based on Physiological Data using Regression-based Decoding

( Hyeonjung Kim ),( Jongwan Kim ) 서울대학교 인지과학연구소 2024 Journal of Cognitive Science Vol.25 No.2

Physiological responses have been regarded as better measures of arousal than valence of core affect dimensions. Recently, valence was explained by two valence hypotheses (bipolarity and bivalent), represented as signed and unsigned valence. In this paper, with reference to two valence models and an arousal dimension, we explored whether affective representations can be identified based on physiological responses across participants. By re-analyzing a shared dataset that includes physiological responses and behavioral ratings of affect, we performed a regression-based decoding to predict affective representations of participants based on their physiological responses. Additionally, a one-way repeated measures ANOVA with a trend analysis was conducted to compare the accuracies of two valence models and the arousal dimension. The results revealed that all predictions were significant, indicating that physiological responses can identify valence and arousal. A trend analysis showed that arousal was predicted more accurately than two valence models, suggesting that physiological responses capture arousal better than valence.

Consistency of affective responses to ASMR across individuals

( Hyeonjung Kim ),( Jongwan Kim ) 한국감성과학회 2023 한국감성과학회 국제학술대회(ICES) Vol.2023 No.-

In this study, we aimed to determine whether there are differences in the consistency of affective responses across individuals depending on the valence and identification difficulty of the ASMR sounds. Thirty participants were asked to rate items involving the emotional adjectives after watching each ASMRs divided into 6 conditions of identification difficulty (easy and hard) and valence (positive, neutral, and negative). We conducted an intersubject correlation analysis to check the consistency of affective responses across individuals. To compare between consistency in conditions, we extracted the intersubject correlation coefficients corresponding to the identification difficulty and valence conditions, and then we conducted a two-way repeated measures analysis of variance. Results revealed that consistency of affective responses is higher for easy identification difficulty condition than hard identification difficulty condition. Also, consistency was high in order of positive, negative, and neutral for easy identification difficulty, and in order of positive and negative for hard identification difficulty. In this study, we confirmed that the degree of identification difficulty of stimulus can influence the consistency of affective responses across participant.

Domain Structures of Poly(3-dodecylthiophene)-Based Block Copolymers Depend on Regioregularity

Kim, Jin-Seong,Han, Junghun,Kim, Youngkwon,Park, Hyeonjung,Coote, Jonathan P.,Stein, Gila E.,Kim, Bumjoon J. American Chemical Society 2018 Macromolecules Vol.51 No.11

<P>Microphase-separation behavior of conjugated-amorphous block copolymers (BCPs) is driven by a complex interplay between Flory-Huggins interaction (χ), liquid crystalline (LC) interaction, and crystallization. Herein, in order to elucidate the influence of LC interaction on the morphology of the BCPs, we report the effects of regioregularity (RR) on the microphase separation and molecular packing structures of poly(3-dodecylthiophene)-<I>block</I>-poly(2-vinylpyridine) (P3DDT-<I>b</I>-P2VP). To decouple the effect of LC interactions from crystallization kinetics, we investigate the morphological behavior of the P3DDT-<I>b</I>-P2VP at above the melting temperature of P3DDT (∼160 °C). Both electron microscopy and X-ray scattering show an abrupt reduction in the domain spacing of both lamellar and cylindrical phases as the RR of P3DDT block increases. Specifically, lower RR (i.e., 85, 79, and 70%) BCPs have larger domain spacings than high RR (94%) by 50% (lamellar) or 80% (cylindrical), even though the overall molecular weights and P2VP volume fractions were similar for each RR. We propose that the RR-driven transition in domain spacing is caused by a change in P3DDT conformations and interchain interactions. When RR is low, the system assembles into a typical bilayer structure like other semiflexible and flexible block copolymer systems. When RR is high, the less flexible P3DDT chains are extended, driving their assembly into an LC monolayer. Significantly, this study demonstrates that tunable RR provides a simple route to manipulate melt state self-assembly of conjugated-amorphous materials.</P> [FIG OMISSION]</BR>

Histone Deacetylase-3/CAGE Axis Targets EGFR Signaling and Regulates the Response to Anti-Cancer Drugs

Kim, Hyuna,Kim, Youngmi,Goh, Hyeonjung,Jeoung, Dooil Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.3

We have previously reported the role of miR-326-HDAC3 loop in anti-cancer drug-resistance. CAGE, a cancer/testis antigen, regulates the response to anti-cancer drug-resistance by forming a negative feedback loop with miR-200b. Studies investigating the relationship between CAGE and HDAC3 revealed that HDAC3 negatively regulated the expression of CAGE. ChIP assays demonstrated the binding of HDAC3 to the promoter sequences of CAGE. However, CAGE did not affect the expression of HDAC3. We also found that EGFR signaling regulated the expressions of HDAC3 and CAGE. Anti-cancer drug-resistant cancer cell lines show an increased expression of $pEGFR^{Y845}$. HDAC3 was found to negatively regulate the expression of $pEGFR^{Y845}$. CAGE showed an interaction and co-localization with EGFR. It was seen that miR-326, a negative regulator of HDAC3, regulated the expression of CAGE, $pEGFR^{Y845}$, and the interaction between CAGE and EGFR. miR-326 inhibitor induced the binding of HDAC3 to the promoter sequences in anti-cancer drug-resistant $Malme3M^R$ cells, decreasing the tumorigenic potential of $Malme3M^R$ cells in a manner associated with its effect on the expression of HDAC3, CAGE and $pEGFR^{Y845}$. The down-regulation of HDAC3 enhanced the tumorigenic, angiogenic and invasion potential of the anti-cancer drug-sensitive Malme3M cells in CAGE-dependent manner. Studies revealed that $PKC{\delta}$ was responsible for the increased expression of $pEGFR^{Y845}$ and CAGE in $Malme3M^R$ cells. CAGE showed an interaction with $PKC{\delta}$ in $Malme3M^R$ cells. Our results show that HDAC3-CAGE axis can be employed as a target for overcoming resistance to EGFR inhibitors.

Transgenic Arabidopsis Expressing acdS Gene of Pseudomonas veronii- KJ Alleviate the Adverse Effects of Salt and Water-Logging Stress

( Hyeonjung Jung ),( Sajid Ali ),( Joo Yeol Kim ),( Won-chan Kim ) 한국육종학회 2018 Plant Breeding and Biotechnology Vol.6 No.3

Several bacterial genes have been identified for the successful transformation of model and crop plants to cope with a variety of stressful conditions. Here, we isolated acdS gene from Pseudomonas veronii- KJ and cloned into Escherichia coli (DE3) for the successful expression of recombinant 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Then, Arabidopsis thaliana was transformed to express the bacterial acdS for the production of ACC deaminase and were compared to control plants in their response to water-logging and salt stress conditions. We used strong and constitutive 35S promoter from cauliflower mosaic virus to over-express the acdS gene. The plasmid (PCB302-3) including the acdS gene was transferred into Agrobacterium tumefaciens (GV3101) and the floral dip method was carried out for successful transformation of A. thaliana. We subsequently, measured the growth and development of transformed and control plants. The transgenic A. thaliana expressing acdS gene revealed increased tolerance to water-logging and salt stress conditions and were less prone to the adverse effects compare to wild type plants.

Variables Influencing the Depth of Conscious Sedation in Plastic Surgery: A Prospective Study

Yeo, Hyeonjung,Kim, Wonwoo,Park, Hyochun,Kim, Hoonnam Korean Society of Plastic and Reconstructive Surge 2017 Archives of Plastic Surgery Vol.44 No.1

Background Conscious sedation has been widely utilized in plastic surgery. However, inadequate research has been published evaluating adequate drug dosage and depth of sedation. In clinical practice, sedation is often inadequate or accompanied by complications when sedatives are administered according to body weight alone. The purpose of this study was to identify variables influencing the depth of sedation during conscious sedation for plastic surgery. Methods This prospective study evaluated 97 patients who underwent plastic surgical procedures under conscious sedation. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and glucose levels were measured. Midazolam and ketamine were administered intravenously according to a preset protocol. Bispectral index (BIS) recordings were obtained to evaluate the depth of sedation 4, 10, 15, and 20 minutes after midazolam administration. Associations between variables and the BIS were assessed using multiple regression analysis. Results Alcohol intake and female sex were positively associated with the mean BIS (P<0.01). Age was negatively associated with the mean BIS (P<0.01). Body mass index (P=0.263), creatinine clearance (P=0.832), smoking history (P=0.398), glucose (P=0.718), AST (P=0.729), and ALT (P=0.423) were not associated with the BIS. Conclusions Older patients tended to have a greater depth of sedation, whereas females and patients with greater alcohol intake had a shallower depth of sedation. Thus, precise dose adjustments of sedatives, accounting for not only weight but also age, sex, and alcohol consumption, are required to achieve safe, effective, and predictable conscious sedation.