Kyushu University

About: Kyushu University is a education organization based out in Fukuoka, Japan. It is known for research contribution in the topics: Population & Catalysis. The organization has 68284 authors who have published 135190 publications receiving 3055928 citations. The organization is also known as: Kyūshū Daigaku.

Circularly polarized light generated by photoexcitation of luminophores in glassy liquid-crystal films

Abstract: Optical information processing, display and storage can be accomplished with linearly or circularly polarized light. In passive (non-emitting) devices, linear polarization can be produced by anisotropic absorption of light1, whereas circular polarization has been attained by selective reflection of unpolarized light propagating through a chiral-nematic liquid-crystal film2. Active (light-emitting) devices capable of polarized emission are also needed. In principle, optical and electronic excitation of materials containing uniaxially and helically arranged luminophores should produce linearly and circularly polarized emission, respectively. In practice, the former is easier to achieve and is therefore more technologically advanced3,4,5,6,7,8. Here we report the generation of strongly circularly polarized photoluminescence from films of glass-forming chiral-nematic liquid crystals9 in which are embedded light-emitting dopants. This host material apparently induced alignment of the luminophores to a degree that produces almost pure circular polarization within the 400–420-nm wavelength band of the emitted light. We anticipate that composite films of this sort might find applications within photonic technology such as colour-image projection10 and stereoscopic displays11.

Interaction of reactive astrocytes with type I collagen induces astrocytic scar formation through the integrin–N-cadherin pathway after spinal cord injury

Abstract: Central nervous system (CNS) injury transforms naive astrocytes into reactive astrocytes, which eventually become scar-forming astrocytes that can impair axonal regeneration and functional recovery. This sequential phenotypic change, known as reactive astrogliosis, has long been considered unidirectional and irreversible. However, we report here that reactive astrocytes isolated from injured spinal cord reverted in retrograde to naive astrocytes when transplanted into a naive spinal cord, whereas they formed astrocytic scars when transplanted into injured spinal cord, indicating the environment-dependent plasticity of reactive astrogliosis. We also found that type I collagen was highly expressed in the spinal cord during the scar-forming phase and induced astrocytic scar formation via the integrin-N-cadherin pathway. In a mouse model of spinal cord injury, pharmacological blockade of reactive astrocyte-type I collagen interaction prevented astrocytic scar formation, thereby leading to improved axonal regrowth and better functional outcomes. Our findings reveal environmental cues regulating astrocytic fate decisions, thereby providing a potential therapeutic target for CNS injury.

Nanoparticles of adaptive supramolecular networks self-assembled from nucleotides and lanthanide ions.

Abstract: Amorphous nanoparticles of supramolecular coordination polymer networks are spontaneously self-assembled from nucleotides and lanthanide ions in water. They show intrinsic functions such as energy transfer from nucleobase to lanthanide ions and excellent performance as contrast enhancing agents for magnetic resonance imaging (MRI). Furthermore, adaptive inclusion properties are observed in the self-assembly process: functional materials such as fluorescent dyes, metal nanoparticles, and proteins are facilely encapsulated. Dyes in these nanoparticles fluoresce in high quantum yields with a single exponential decay, indicating that guest molecules are monomerically wrapped in the network. Gold nanoparticles and ferritin were also wrapped by the supramolecular shells. In addition, these nucleotide/lanthanide nanoparticles also serve as scaffolds for immobilizing enzymes. The adaptive nature of present supramolecular nanoparticles provides a versatile platform that can be utilized in a variety of applications...