Controlled self-assembly of a trinitrofluorenone-appended gemini-shaped amphiphilic hexabenzocoronene selectively formed nanotubes or microfibers with different photochemical properties. In these nanotubes, which are 16 nanometers in diameter and several micrometers long, a molecular layer of electron-accepting trinitrofluorenone laminates an electron-donating graphitic layer of pi-stacked hexabenzocoronene. The coaxial nanotubular structure allows photochemical generation of spatially separated charge carriers and a quick photoconductive response with a large on/off ratio greater than 10(4). In sharp contrast, the microfibers consist of a charge-transfer complex between the hexabenzocoronene and trinitrofluorenone parts and exhibit almost no photocurrent generation.

Abstract Protein crystallization in human tissue rarely occurs. Charcot-Leyden crystals (CLCs) were described in various eosinophilic diseases >150 years ago, but our understanding of CLC formation still remains limited. In this study, we demonstrate that CLCs observed in varied inflamed human tissues are closely associated with eosinophil cell-free granules and nuclear envelope/plasma membrane disintegration with release of filamentous chromatin (extracellular traps), typical morphologies of a regulated pathway of extracellular trap cell death (ETosis). During the process of eosinophil ETosis, eccentrically localized cytoplasmic and perinuclear CLC protein (galectin-10) is homogeneously redistributed in the cytoplasm. Rapid (1-2 minutes) formation of intracytoplasmic CLCs was observed using time-lapse imaging. Plasma membrane rupture enabled the release of both intracellularly formed CLCs and soluble galectin-10 that further contributed to formation of CLCs extracellularly, in parallel with the expulsion of free intact granules and extracellular traps. CLC formation and galectin-10 release were dependent on nicotinamide adenine dinucleotide phosphate oxidase activation. To our knowledge, this is the first demonstration of natural formation of CLCs in association with an active physiological process (ie, ETosis). These results indicate that dynamic changes in intracellular localization and release of galectin-10 contribute to CLC formation in vivo and suggest that CLC/galectin-10 might serve as an indicator of ETosis.

Free-radical polymerization of an imidazolium ion-based ionic liquid bearing a methacrylate group, gelling with single-walled carbon nanotubes (SWNTs), allows fabrication of a mechanically reinforced, electroconductive soft material (bucky plastic). A film sample of this material displays an excellent conductivity of 1 S cm(-1) and a 120-fold enhancement of the Young's modulus at a 7 wt % content of SWNTs. The conductivity is temperature-dependent in the range 5-300 K, suggesting that the conductive process involves carrier hopping. Scanning electron and atomic force micrographs of a bucky plastic film display the presence of crosslinked networks consisting of finely dispersed SWNTs. Such nanotube networks, developed in the polymer matrix, likely suppress slipping of entrapped polymer molecules via a strong interfacial interaction and also facilitate intertubular carrier transport. Although a bucky plastic derived from a vinylimidazolium ion-based ionic liquid monomer shows a comparable conductivity to that of the methacrylate version, the film is brittle irrespective of the presence or absence of SWNTs.

Osteoclasts are multinucleated cells that resorb bone. Although osteoclasts originate from the monocyte/macrophage lineage, osteoclast precursors are not well characterized in vivo. The relationship between proliferation and differentiation of osteoclast precursors is examined in this study using murine macrophage cultures treated with macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-κB (RANK) ligand (RANKL). Cell cycle–arrested quiescent osteoclast precursors (QuOPs) were identified as the committed osteoclast precursors in vitro. In vivo experiments show that QuOPs survive for several weeks and differentiate into osteoclasts in response to M-CSF and RANKL. Administration of 5-fluorouracil to mice induces myelosuppression, but QuOPs survive and differentiate into osteoclasts in response to an active vitamin D3 analogue given to those mice. Mononuclear cells expressing c-Fms and RANK but not Ki67 are detected along bone surfaces in the vicinity of osteoblasts in RANKL-deficient mice. These results suggest that QuOPs preexist at the site of osteoclastogenesis and that osteoblasts are important for maintenance of QuOPs.

Despite a large steric bulk of C60, a molecular graphene with a covalently linked C 60 pendant [hexabenzocoronene (HBC)-C60; 1] self-assembles into a coaxial nanotube whose wall consists of a graphite-like -stacked HBC array, whereas the nanotube surface is fully covered by a molecular layer of clustering C 60. Because of this explicit coaxial configuration, the nanotube exhibits an ambipolar character in the field-effect transistor output [hole mobility ( h) ‫؍‬ 9.7 ؋ 10 ؊7 cm 2 V ؊1 s ؊1 ; electron mobility (e) ‫؍‬ 1 ambipolar transport ͉ field-effect transistor ͉ nanotube ͉ photovoltaic ͉ self-assembly

For tailoring solution-processable optoelectronic thin films, a rational strategy with amphiphilic molecular design is proposed. A donor-acceptor dyad consisting of an oligothiophene and C60, when modified with a hydrophilic wedge on one side and a paraffinic wedge on the other (1Amphi), forms over a wide temperature range a photoconducting smectic A liquid crystal having bicontinuous arrays of densely packed donor and acceptor units. In contrast, when modified with only paraffinic wedges (1Lipo), the dyad forms a smectic A liquid crystalline mesophase, which however is poorly conductive. As indicated by an absorption spectral feature along with a synchrotron radiation small-angle X-ray scattering profile, 1Lipo in the lamellar structure does not adopt a uniform head/tail orientation. Such defective donor and acceptor arrays likely contain a large number of trapping sites, leading to short-lived charge carriers, as observed by a flash photolysis time-resolved microwave conductivity study.

The IMP3 RNA-binding protein is associated with metastasis and poor outcome in human cancer. Using solid cancer transcriptome data, we found that IMP3 correlates with HMGA2 mRNA expression. Cytoplasmic IMP3 granules contain HMGA2, and IMP3 dose-dependently increases HMGA2 mRNA. HMGA2 is regulated by let-7, and let-7 antagomiRs make HMGA2 refractory to IMP3. Removal of let-7 target sites eliminates IMP3-dependent stabilization, and IMP3-containing bodies are depleted of Ago1-4 and miRNAs. The relationship between Hmga2 mRNA and IMPs also exists in the developing limb bud, where IMP1-deficient embryos show dose-dependent Hmga2 mRNA downregulation. Finally, IMP3 ribonucleoproteins (RNPs) contain other let-7 target mRNAs, including LIN28B, and a global gene set enrichment analysis demonstrates that miRNA-regulated transcripts in general are upregulated following IMP3 induction. We conclude that IMP3 RNPs may function as cytoplasmic safe houses and prevent miRNA-directed mRNA decay of oncogenes during tumor progression.

Upon slow admission of MeOH, the enantiomerically pure form of chiral amphiphilic porphyrin-fullerene dyad 1 in CH(2)Cl(2) self-assembles at 25 degrees C into nanofibers with a built-in donor/acceptor heterojunction, while its racemic form, under identical conditions, self-assembles into submicrometer-sized spheres with a donor/acceptor arrangement essentially different from that in the nanofiber assembly. Although a cast film of the latter hardly shows a photoconducting profile on micrometer-gap electrodes, the former sample clearly displays photoconduction with an ambipolar charge-transporting character. The electron and hole mobilities under zero electric field, as estimated from time-of-flight profiles, are 0.14 and 0.10 cm(2) V(-1) s(-1), respectively, which are comparable to or even better than those reported for top-class organic materials with a donor/acceptor heterojunction.