We synthesized a series of new intrinsically stretchable block copolymers (BCPs) in linear AB-type, ABA-type, and star-shaped architectures composed of oligosaccharide (MH) and flexible poly(n-butyl ...acrylate) (PBA) blocks for the application in field-effect transistor memory. The BCP thin films are used as the charge trapping layers in the memory devices where the BCPs phase separate into ordered MH microdomains in soft PBA matrices. The MH microdomain works as the charge-trapping sites while the soft PBA matrix provides a stretchability. In particular, the BCPs of the ABA-type and star-shaped architectures with the end MH blocks not only show superior memory performances but also form physical networks that impart mechanical resilience to the thin films such that they can endure 100% strain without formation of cracks. The mobilities and the memory windows of the devices are nearly constant even when the charge trapping layers are stretched and released at 50% strain for 1000 cycles. This work highlights the importance of the molecular architectures on the BCPs intended for stretchable electronic materials.
Lysosomal integral membrane protein-2 (LIMP-2) is a type III transmembrane protein that is highly glycosylated and mainly localized to the lysosomal membrane. The diverse functions of LIMP-2 are ...currently being uncovered; however, its participation in macroautophagy, usually described as autophagy, has not yet been well-investigated. To determine the possible involvement of LIMP-2 in autophagic activity, we examined the intracellular amount of microtubule-associated protein 1 light chain 3 (LC3)-II, which is well-correlated with autophagosome levels, in exogenous rat LIMP-2-expressing COS7 and HEK293 cells. Transient or stable expression of LIMP-2-myc significantly increased the levels of LC3-II. Conversely, knockdown of LIMP-2 decreased the LC3-II levels in NIH3T3 cells. Furthermore, approaches using lysosomal protease inhibitors and mCherry-GFP-LC3 fluorescence suggested that exogenous expression of LIMP-2 increased the biogenesis of autophagosomes rather than decreased the lysosomal turnover of LC3-II. Considering the results of the biochemical assay and the quantitative fluorescence assay together, it is suggested that LIMP-2 has a possible involvement in autophagic activity, especially autophagosome biogenesis.
•Exogenous expression of LIMP-2 increases LC3-II protein level.•Knockdown of LIMP-2 decreases LC3-II protein level.•Approaches using protease inhibitors and mCherry-GFP-LC3 indicate the involvement of LIMP-2 in biogenesis of autophagosomes.
A series of fully bio-based block copolymers (BCPs) consisting of maltooligosaccharides (maltose, maltotriose, maltotetraose, and maltohexaose; A block) and poly(δ-decanolactone) (PDL; B block), ...with ABA-, A2BA2-, A3BA3-, A(BA)2-, and A2(BA)2-type architectures, were synthesized to demonstrate the potential of oligosaccharides as novel hard segments for bio-based elastomers. To understand the correlation between the BCP molecular structure and material properties, the BCPs were designed to have comparable molecular weights (ca. 12K) and total numbers of glucose units (12). Morphological analysis revealed the formation of body-centered-cubic sphere and hexagonally close-packed cylinder (HEX) morphologies depending on the branched architecture (interdomain distance 9.7–14.4 nm). While the PDL homopolymer is a viscous liquid due to its low T g and amorphous nature, all BCPs exhibited elastomeric properties, confirming that the oligosaccharide blocks segregated to form the hard domains to cross-link the rubbery PDL chains. Tensile testing revealed that the mechanical properties of the BCPs were mainly determined by the microphase-separated structure and less affected by the length of each oligosaccharide chain. The HEX-forming A2BA2- and A3BA3-type BCPs exhibited Young’s moduli of ∼6 MPa, which is comparable to well-known styrene-based thermoplastic elastomers. Furthermore, a readily available polydisperse maltooligosaccharide was employed to synthesize an A2BA2-type BCP with a higher molecular weight PDL block (20K), which exhibited a Young’s modulus of ∼6 MPa and an elongation at break of ∼700%. These results demonstrate that oligosaccharides are a sustainable alternative to the petroleum-derived synthetic hard segments (e.g., polystyrene), thereby opening up a new avenue for fully bio-based soft material design.
症例は50代男性．202X年3月に大動脈弁輪拡張症に対して自己弁温存大動脈基部置換術を施行した．手術から2か月後に一過性の右麻痺・嘔吐で当院受診し，胸部単純CTにて大動脈基部から上行大動脈周囲に液体貯留が疑われ入院となった．経胸壁心エコーで大動脈基部周囲にエコーフリースペースを認め，右冠尖と無冠尖の交連付近からto and ...froパターンの血流シグナルを認めた．また，大動脈周囲に著明な充実エコーを認めた．その一部は収縮期に可動性を認め，動脈血が流入していると考え，左室流出路破裂による仮性動脈瘤を疑った．造影CTでは大動脈基部から上行大動脈にかけて巨大動脈瘤を認め，大動脈基部付近から造影剤が漏出していた．各検査から左室流出路吻合部破裂による仮性動脈瘤と診断され緊急手術となった．術中所見では右冠尖と無冠尖交連部弁直下の左室流出路吻合部に亀裂が認められたが穿破は無く，亀裂部のフェルト閉鎖と大動脈弁置換術が行われた．大動脈周囲にエコーフリースペースを認め，血流情報を詳細に観察し解析することで重篤な合併症を迅速に診断することができた1例を報告した．自己弁温存基部置換術後の検査には術式をよく理解することが重要と考えられた．
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