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This study demonstrated the use of a thermally crosslinked polyimide (PI) for the liquid crystal (LC) alignment layer of an LC display (LCD) cell. Polyamic acid was prepared using 4,4′-oxydianiline (ODA) and 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA). The 6FDA−ODA-based polyimide (PI) prepared by the thermal cyclic dehydration of the polyamic acid (PAA) was soluble in various polar solvents. After forming a thin film by mixing trifunctional epoxide [4-(oxiran-2-ylmethoxy)-N,N-bis(oxiran-2-ylmethyl)aniline] with the 6FDA−ODA-based PAA, it was confirmed that thermal curing at −110 °C caused an epoxy ring opening reaction, which could result in the formation of a networked polyimide not soluble in tetrahydrofuran. The crosslinked PI film showed a higher rigidity than the neat PI films, as measured by the elastic modulus. Furthermore, based on a dynamic mechanical analysis of the neat PI and crosslinked PI films, the glass transition temperatures (Tgs) were 217 and 339 °C, respectively, which provided further evidence of the formation of crosslinking by the addition of the epoxy reagent. After mechanical rubbing using these two PI films, an LC cell was fabricated using an anisotropic PI film as an LC alignment film. LC cells with crosslinked PI layers showed a high voltage holding ratio and low residual direct current voltage. This suggests that the crosslinked PI has good potential for use as an LC alignment layer material in advanced LCD technologies that require high performance and reliability.

We introduce an efficient cell tracking imaging protocol using positron emission tomography (PET). Since macrophages are known to home and accumulate in tumor tissues and atherosclerotic plaque, we design a PET imaging protocol for macrophage cell tracking using aza-dibenzocyclooctyne-tethered PEGylated mesoporous silica nanoparticles (DBCO-MSNs) with the short half-life F-18-labeled azide-radiotracer via an in vivo strain-promoted alkyne azide cycloaddition (SPAAC) covalent labeling reaction inside macrophage cells in vivo. This PET imaging protocol for in vivo cell tracking successfully visualizes the migration of macrophage cells into the tumor site by the bioorthogonal SPAAC reaction of DBCO-MSNs with [18F]fluoropentaethylene glycolic azide ([18F]2) to form 18F-labeled aza-dibenzocycloocta-triazolic MSNs (18F-DBCOT-MSNs) inside RAW 264.7 cells. The tissue radioactivity distribution results were consistent with PET imaging findings. In addition, PET images of atherosclerosis in ApoE−/- mice fed a western diet for 30 weeks were obtained using the devised macrophage cell-tracking protocol.

Prostate cancer (PC) progressed to castration resistance (CRPC) is a fatal disease. CRPC tumors develop resistance to new-generation antiandrogen enzalutamide through lineage plasticity, characterized by epithelial-mesenchymal transition (EMT) and a basal-like phenotype. FOXA1 is a transcription factor essential for epithelial lineage differentiation. Here, we demonstrate that FOXA1 loss leads to remarkable upregulation of transforming growth factor beta 3 (TGFB3), which encodes a ligand of the TGF-β pathway. Mechanistically, this is due to genomic occupancy of FOXA1 on an upstream enhancer of the TGFB3 gene to directly inhibit its transcription. Functionally, FOXA1 downregulation induces TGF-β signaling, EMT, and cell motility, which is effectively blocked by the TGF-β receptor I inhibitor galunisertib (LY2157299). Tissue microarray analysis confirmed reduced levels of FOXA1 protein and a concordant increase in TGF-β signaling, indicated by SMAD2 phosphorylation, in CRPC as compared with primary tumors. Importantly, combinatorial LY2157299 treatment sensitized PC cells to enzalutamide, leading to synergistic effects in inhibiting cell invasion in vitro and xenograft CRPC tumor growth and metastasis in vivo. Therefore, our study establishes FOXA1 as an important regulator of lineage plasticity mediated in part by TGF-β signaling, and supports a novel therapeutic strategy to control lineage switching and potentially extend clinical response to antiandrogen therapies.

The photophysical properties of donor (D)-acceptor (A) polymers were studied by designing two types of polymers, (D-σ-A)n and (D-π-A)n , with non-conjugated alkyl (sp3) and π-conjugated (sp2) linkers using π-extended donor and acceptor monomers that exhibit planar A-D-A structures. The non-conjugated alkyl linker provides structural flexibility to the (D-σ-A)n polymers, while the π-conjugated linker retains the rigid structure of the (D-π-A)n polymers. Photoinduced energy transfer occurs from the large donor to acceptor units in both polymers. However, the photoinduced energy transfer dynamics are found to be dependent on the conformation of the polymers, where the difference is dictated by the types of linkers between the donor and acceptor units. In solution, intramolecular energy transfer is relatively favorable for the (D-σ-A)n polymers with flexible linkers that allow the donor and acceptor units to be proximally located in the polymers. On the other hand, intermolecular (or interchain) energy transfer is dominant in the two polymer films because the π-extended donor and acceptor units in polymers are closely packed. The structural flexibility of the linkers between the donor and acceptor repeating units in the polymers affects the efficiency of energy transfer between the donor and acceptor units and the overall photophysical properties of the polymers.

A highly crystalline conjugated donor (D)–acceptor (A) block copolymer (PBDT2T‐b‐N2200) that has good solubility in nonhalogenated solvents is successfully synthesized. PBDT2T‐b‐N2200 shows a broad complementary absorption behavior owing to a wide‐band gap donor (PBDT2T) present as a D‐block and a narrow‐band gap acceptor (N2200) present as an A‐block. Polymer solar cells (PSCs) with conjugated block copolymer (CBCP) are fabricated using a toluene solution and PSC created with an annealed film showing the highest power conversion efficiency of 6.43%, which is 2.4 times higher than that made with an annealed blend film of PBDT2T and N2200. Compared to the blend film, the PBDT2T‐b‐N2200 film exhibits a highly improved surface and internal morphology, as well as a faster photoluminescence decay lifetime, indicating a more efficient photoinduced electron transfer. In addition, the PBDT2T‐b‐N2200 film shows high crystallinity through an effective self‐assembly of each block during thermal annealing and a predominant face‐on chain orientation favorable to a vertical‐type PSC. Moreover, the CBCP‐based PSCs exhibit an excellent shelf‐life time of over 1020 h owing to their morphological stability. From these results, a D–A block copolymer system is one of the efficient strategies to improve miscibility and morphological stability in all polymer blend systems., Polymer solar cells (PSCs) with conjugated block copolymer are fabricated using a PBDT2T‐b‐N2200 solution in a nonhalogenated solvent such as toluene. PSCs created with an annealed film show the highest power conversion efficiency of 6.43% and an excellent shelf‐life time of over 1020 h owing to their morphological stability.

To implement a highly flexible polymer solar cell (PSC), the mechanical properties of the material constituting the active layer are considered crucial, having a significant influence on the stability of the device. In this study, the mechanical properties of a main-chain conjugated copolymer (PBDT2T-b-PNDI2T) containing donor- and acceptor-based macromolecular species in the polymer backbone was measured and compared with that of donor and acceptor polymer blend film (P(BDT2T):P(NDI2T)). It was observed that the PBDT2T-b-PNDI2T active layer exhibited a higher crack-onset-strain and toughness compared to P(BDT2T):P(NDI2T) active layer. Correspondingly, the YTRON/polyethylene naphthalate (PEN) based flexible PSC with a PBDT2T-b-PNDI2T active layer was used, which exhibited superior mechanical stability under multiple bending conditions. The results of this study indicate that flexible PSCs with excellent durability can be developed by replacing the polymer blend used for all-PSCs with PBDT2T-b-PNDI2T as the active layer material for highly efficient future applications.

This study performed an appreciative inquiry into models of instruction for the community learning. For this purpose, this study examined the principle of learning, instruction models for community learning, and appreciative inquiry. Next, draft appreciative inquiry models were built based on the principle of instruction models for the community learning. The previously designed appreciative inquiry models were revised and complemented through expert investigation by a focus group interview. This paper proposes a process of seven steps core learning activities. The seven steps were selecting a theme, interviewing for finding success story, analyzing an organization`s success stories and deriving the core values, deriving future of the organization, sharing future of the organization, designing the ideal future of the organization consist of a practice, implement, and reflect. Because the proposed seven steps process is based on the literature and focus group interview, a follow-up study will be needed to verify the result.

Appreciative inquiry is applicable to schools to minimize the resistance of the members, and the subjectof the school community Forming is suitable for the introduction of an AI program. But to become a way for a sustainable school community we must reconstruct the 4D modes of appreciative inquiry that the members can beapplied as needed. In this paper, we propose the process of seven steps core learning activities based on systems theory. Seven steps are selecting a theme, interviewing for finding success story, analyzing an organization's successstories and deriving the core values, deriving future of the organization, sharing future of the organization, designing the ideal future of the organization consist of a practice. Since the proposed seven steps process is based on the literature it is necessary to apply follow-up study is to verify the result, and a variety of research methods for processimprovement in AI. Key Words : Appreciative inquiry, Systems theory, Process, Learning process reengineering, core learning activities

The purpose of this study was to extract an u-PBL support system core value and design strategy based upon field experience learning. To accomplish this the study, first of all, analyzed the core values, design strategy which was selected after needs analysis and literature review of theories and cases regarding the PBL, e-PBL, blended-PBL, Field experience learning based on ubiquitous environment, and learning model based on ubiquitous technology. This study identified the three core values as; systemic support for instructional activity, just in time support for instructional activity and support for interaction facilitation. As further research areas, it might be useful to develop u-PBL instructional support system based upon the model designed from this study. Also, research concerning the verification of the model based upon implementation of the program case might be necessary.