Japan Institute of Systems, Information Technologies and Nanotechnologies

Fukuoka, Japan

Japan Institute of Systems, Information Technologies and Nanotechnologies

Fukuoka, Japan

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Hirata S.,Kyushu University | Kubota K.,Kyushu University | Jung H.H.,Kyushu University | Hirata O.,Nissan Chemical Industries Ltd | And 3 more authors.
Advanced Materials | Year: 2011

Organic light-emitting diodes containing a liquid emitting layer that exhibit improved external electroluminescence quantum efficiency (Î∥EL) and maximum luminance are presented. Doping the liquid emitting layer with an electrolyte significantly decreases the turn-on voltage for electroluminescence. Insertion of a TiO2 hole-blocking layer between the liquid emitting layer and indium tin oxide cathode improves Î∥EL. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Numata M.,Kyoto Prefectural University | Shinkai S.,Japan Institute of Systems, Information Technologies and Nanotechnologies | Shinkai S.,Sojo University
Chemical Communications | Year: 2011

We have exploited novel supramolecular wrapping techniques by helix-forming polysaccharides, β-1,3-glucans, which have strong tendency to form regular helical structures on versatile nanomaterials in an induced-fit manner. This approach is totally different from that using the conventional interpolymer interactions seen in both natural and synthetic polymeric architectures, and therefore has potential to create novel polymeric architectures with diverse and unexpected functionalities. The wrapping by β-1,3-glucans enforces the entrapped guest polymer to adopt helical or twisted conformations through the convergent interpolymer interactions. On the contrary, the wrapping by chemically modified semi-artificial β-1,3-glucans can bestow the divergent self-assembling abilities on the entrapped guest polymer to create hierarchical polymeric architectures, where the polymer/β-1,3-glucan composite acts as a huge one-dimensional building block. Based on the established wrapping strategy, we have further extended the wrapping techniques toward the creation of three-dimensional polymeric architectures, in which the polymer/β-1,3- glucan composite behaves as a sort of amphiphilic block copolymers. The present wrapping system would open several paths to accelerate the development of the polymeric supramolecular assembly systems, giving the strong stimuli to the frontier of polysaccharide-based functional chemistry. © 2011 The Royal Society of Chemistry.


Yasunaga K.,Japan Institute of Systems, Information Technologies and Nanotechnologies
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

In a public-key encryption scheme, if a sender is not concerned about the security of a message and is unwilling to generate costly randomness, the security of the encrypted message can be compromised. This is caused by the laziness of the sender. In this work, we characterize lazy parties in cryptography. Lazy parties are regarded as honest parties in a protocol, but they are not concerned about the security of the protocol in a certain situation. In such a situation, they behave in an honest-looking way, and are unwilling to do a costly task. We study, in particular, public-key encryption with lazy parties. Specifically, as the first step toward understanding the behavior of lazy parties in public-key encryption, we consider a rather simple setting in which the costly task is to generate randomness used in algorithms, and parties can choose either costly good randomness or cheap bad randomness. We model lazy parties as rational players who behaves rationally to maximize their utilities, and define a security game between lazy parties and an adversary. A secure encryption scheme requires that the game is conducted by lazy parties in a secure way if they follow a prescribed strategy, and the prescribed strategy is a good equilibrium solution for the game. Since a standard secure encryption scheme does not work for lazy parties, we present some public-key encryption schemes that are secure for lazy parties. © 2012 Springer-Verlag.


Yamaguchi K.,Nihon University | Suzuki M.,Japan Institute of Systems, Information Technologies and Nanotechnologies
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

Although DAISY is an excellent solution for various print-disabled people, producing DAISY content is not necessarily accessible works. In particular, it is almost impossible for them to edit technical DAISY content such as mathematics. Here, a new accessible authoring tool to enable both of sighted people and the print disabled to produce/edit easily a DAISY book ranging from mathematics to others is shown. In it, since a new function to control speech output is implemented, all the content is read out in a correct manner with speech synthesis. This approach can be applied also to DAISY content in many languages other than English or Japanese. © 2012 Springer-Verlag.


Jung J.H.,Gyeongsang National University | Lee J.H.,Gyeongsang National University | Shinkai S.,Sojo University | Shinkai S.,Japan Institute of Systems, Information Technologies and Nanotechnologies
Chemical Society Reviews | Year: 2011

Functionalized magnetic nanoparticles, composed of both inorganic and organic components, have recently been examined as promising platforms for detection and separation applications. This unique class of nanomaterials can retain not only beneficial features of both the inorganic and organic components, but can also provide the ability to systematically tune the properties of the hybrid materials through the combination of appropriate functional components. This tutorial review focuses on the recent development of functionalized magnetic nanoparticles for use in biological and environmental applications, in which these chromogenic and fluorogenic chemosensors can selectively detect and separate specific toxic metal ions. © 2011 The Royal Society of Chemistry.


Dawn A.,Kyushu University | Shiraki T.,Japan Institute of Systems, Information Technologies and Nanotechnologies | Ichikawa H.,Kyushu University | Takada A.,Kyushu University | And 5 more authors.
Journal of the American Chemical Society | Year: 2012

Self-assembly behaviors of a series of systems (G1, G2, and G3) possessing same organic building blocks based on a substituted anthracene have been investigated in decalin. G2 and G3 are dominated by head-to-tail (ht) and head-to-head (hh) type dimers of G1, respectively. G1 gives a thermoresponsive gel that behaves ideally, showing frequency-independent elastic and viscous moduli. Interestingly, G2 produces a thixotropic gel that shows the signature of structural relaxation, signifying the dynamic nature of the system. In contrast, G3 remains fluidlike. As investigated by scanning electron microscopy (SEM), in the assembly process of G2, first disklike nanoaggregates are formed, and in the second step these aggregates interact to construct the densely packed secondary assembly. A transition from secondary assembly to primary assembly under shear initiates the mechanoresponsive destruction of the gel. In the self-assembly process, G1 propagates in a one-dimensional fashion, whereas G2 and G3 can propagate in a two-dimensionional fashion. The same side orientation of the substituents in G3 facilitates the formation of a compact closed-shell-type structure, which results in the generation of isolated nanocrystals. The long-range weak interaction together with the capability of propagating in two dimensions is found to be essential for the construction of such a mechanoresponsive assembly. C 60 and C 70 could be incorporated successfully in G2 assembly to develop mechanoresponsive fullerene assemblies. The presence of fullerenes not only enhances the elastic properties of G2 but also intensifies the thixotropy. C 70 appears to be a superior guest in terms of property enhancement due to its better size fitting with the concave-shaped host. © 2011 American Chemical Society.


Tamesue S.,Osaka University | Takashima Y.,Osaka University | Yamaguchi H.,Osaka University | Shinkai S.,Japan Institute of Systems, Information Technologies and Nanotechnologies | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2010

Shine a light: A supramolecular hydrogel is formed by the glucan curdlan equipped with α-cyclodextrins (CD-CUR) and azobenzene-modified poly(acrylic acid)(pAC12Azo). The sol-gel transition and the morphology of the supramolecular hydrogel can be switched by photoirradiation at the appropriate wavelength, which controls the formation of an inclusion complex between the α-cyclodextrins and the azobenzene moieties (see picture). © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.


Sobczuk A.A.,Sojo University | Tamaru S.-I.,Sojo University | Shinkai S.,Sojo University | Shinkai S.,Japan Institute of Systems, Information Technologies and Nanotechnologies
Chemical Communications | Year: 2011

A new functional low molecular-weight gelator (LMWG) based on crown-appended quaterthiophene was synthesized and investigated as a new alkali metal cation responsive material with enhanced fluorescence emission upon gel-to-sol phase transition. © 2011 The Royal Society of Chemistry.


Jung J.H.,Gyeongsang National University | Park M.,Gyeongsang National University | Shinkai S.,Sojo University | Shinkai S.,Japan Institute of Systems, Information Technologies and Nanotechnologies
Chemical Society Reviews | Year: 2010

This critical review focuses on the preparation methods of a variety of the silica nanotubes by self-assembled organogels and the recent development of silica-based organic-inorganic hybrid nanomaterials for use as chemosensors in environmental studies as well as adsorbents for inorganic guest molecules and in biological applications for delivery of organic guest molecules (127 references). © 2010 The Royal Society of Chemistry.


Sobczuk A.A.,Sojo University | Tsuchiya Y.,Japan Institute of Systems, Information Technologies and Nanotechnologies | Shiraki T.,Japan Institute of Systems, Information Technologies and Nanotechnologies | Tamaru S.-I.,Sojo University | And 2 more authors.
Chemistry - A European Journal | Year: 2012

A unique class of oligothiophene-based organogelator bearing two crown ethers at both ends was synthesized. This compound could gelatinize several organic solvents, forming one-dimensional fibrous aggregates. From the observation of circular dichroism, it was confirmed that the helical handedness of the fibrous assembly is controllable by the chirality of 1,2bisammonium guests, thus suggesting that one guest molecule bridges two gelator molecules through the crown-ammonium interaction. Interestingly, we have found that such chirality is created by thermal gelation, whereas it disappears by thixotropic gelation. The new finding implies that the present organogel system is applicable as a reversible switching memory device, featuring memory creation by a heat mode and memory erasing by a mechanical mode. Chiral memory switching: A unique class of functional organogelator based on crown ether appended oligothiophene was created, the chirality of which was influenced by the interaction with chiral ammonium guests. Stimuli-induced circular dichroism with controlled handedness of aggregates was observed. The reversibility of thixotropic/thermal behaviors can be applied to chirality switching memory devices (see scheme). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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