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217 results on '"Nonaka, Koji"'

3. Stereographical visualization of a polarization state using weak measurements with an optical-vortex beam

Author

Kobayashi, Hirokazu, Nonaka, Koji, and Shikano, Yutaka

Subjects
Quantum Physics, Physics - Optics
Abstract

We propose a stereographical-visualization scheme for a polarization state by two-dimensional imaging of a weak value with a single setup. The key idea is to employ Laguerre-Gaussian modes or an optical vortex beam for a probe state in weak measurement. Our scheme has the advantage that we can extract information on the polarization state from the single image in which the zero-intensity point of the optical vortex beam corresponds to a stereographic projection point of the Poincare sphere. We experimentally perform single-setup weak measurement to validate the stereographical relationship between the polarization state on the Poincare sphere and the location of the zero-intensity point., Comment: 6 pages, 4 figures

Published
2013
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8. Antiproliferative and anti‐inflammatory effects of fractionated crude lectins from boiled kidney beans (Phaseolus vulgaris).

Author

Une, Satsuki, Nakata, Rieko, Nonaka, Koji, and Akiyama, Junich

Subjects
COMMON bean, KIDNEY bean, LECTINS, ALPHA fetoproteins, ANTINEOPLASTIC agents, ANTI-inflammatory agents
Abstract

In this study, we investigated the biological profile of lectins isolated from raw and boiled Japanese red Kintoki beans (red kidney beans [RKB]; Phaseolus vulgaris). Lectins in beans showing agglutination activity were retained after heating. Raw and boiled RKB lectins were fractionated using carboxymethyl‐ and diethylaminoethyl‐Sepharose, respectively. Boiled RKB lectins were evaluated for carbohydrate specificity as well as cytokine‐inducing and antiproliferative activities against cancer cells and compared with raw RKB lectins. Raw RKB lectins showed specificity for thyroglobulin and fetuin, whereas boiled lectins showed specificity for N‐acetylneuraminic acid. Raw RKB lectins showed low resistance to proteases and tolerated temperatures greater than 80°C for 5 min. Notably, lectins from raw and boiled beans showed antiproliferative activity against five types of cancer cells B16, LM8, HeLa, HepG2, and Colo 679. In particular, lectins from raw beans exhibited a significantly stronger activity than those from boiled beans. Anti‐inflammatory effects were notably observed in crude extracts from raw and boiled beans. Specifically, lectins fractionated from boiled beans markedly inhibited the expression of tumor necrosis factor‐α and interleukin‐6. Overall, our results showed that RKB lectins from boiled beans exert anti‐inflammatory and anticancer effects and could be developed as potential chemopreventive agents. Practical Application: Japanese red kidney beans (RKB) are cultivated in numerous parts of the temperate zone and consumed in many countries. Lectins from boiled beans exhibited anticancer activity, similar to lectins from raw beans. Additionally, crude and fractionated lectins from boiled beans showed anti‐inflammatory activity. Thus, boiled RKB lectins have the potential to be used as a bioactive protein for medical research and could be developed as anticancer agents. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Age‑related changes in endoplasmic reticulum stress response‑associated protein expression in rat tibial nerves.

Author

Sakita, Masahiro, Isobe, Wataru, Nonaka, Koji, Murakami, Shinichiro, Miyachi, Ryo, Sakane, Kento, Sugimoto, Saki, Yamaguchi, Airi, and Yamamoto, Koki

Subjects
BRAIN-derived neurotrophic factor, GLUCOSE-regulated proteins, PROTEIN disulfide isomerase, TIBIAL nerve, HEAT shock proteins
Abstract

In age-related peripheral neurodegeneration, changes in the promotion or inhibition of endoplasmic reticulum (ER) stress response related to the ubiquitin-proteasome degradation system (UPS), autophagy and apoptosis signaling factors during aging remain unclear. In the present study, the expression of ER stress response signaling-related protein factors was examined in tibial nerves during aging in rats. Tibial nerves were extracted from continuously housed rats at 20, 50, 70, 90 and 105 weeks of age. Expression of factors associated with ER stress-related degradation, including X-box binding protein 1 (XBP1s), eukaryotic translation initiation factor 2 subunit 1 (eIF2α), Beclin-1 (Becn1), and Caspase-3 (Casp3); ER stress-related repair, including binding immunoglobulin protein [also known as 78 kDa glucose-regulated protein (BiP/GRP78)], protein disulfide isomerase (PDI), brain-derived neurotrophic factor (BDNF) and the inflammatory cytokine IL6, was assessed by western blotting of tibial nerves from rats in each age group. Expression of XBP1s and Becn1, which promote UPS and autophagy, decreased significantly after 50 weeks of age. However, expression of eIF2α and Casp3, which inhibit new protein biosynthesis and promote apoptosis, increased significantly after 50 weeks. Expression of BiP/GRP78 and PDI, which are refolding factors for denatured proteins, showed a significant decrease after 50 (or 70) weeks of age. The expression of BDNF, a ligand protein for the repair cascade, showed a significant increase after 70 weeks of age, while that of IL6 increased significantly after 50 weeks of age. These results indicate that ER stress-related degradation (UPS and autophagy) and refolding repair functions are reduced in rat tibial nerves after 50 weeks, followed by enhanced apoptosis and inflammation. These findings shed light on the progression of age-related peripheral neurodegeneration in rats. [ABSTRACT FROM AUTHOR]

Published
2025
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36. Optical Wireless Communications and Autonomous Beam Control Moving User Terminal

Author

TANGTRONGBENCHASIL, Charoen, HAMADA, Yoichi, KATO, Toshihiro, NONAKA, Koji, TANGTRONGBENCHASIL, Charoen, HAMADA, Yoichi, KATO, Toshihiro, and NONAKA, Koji

Abstract

Optical wireless communications is a research topic of extreme interest since it offers high data rate (Gbps data rate), security, and RF interference immunity. However, optical wireless communications places severe restrictions on the communications paths; they must be direct beam connections. To increase the number of users and link robustness, optical wireless communications must be able to operate even when obstacles are placed between transmitters and receivers, so optical micro-cell (OMC) with autonomous beam control can overcome link robustness. In addition, OMC based optical wireless communication yields compact systems. This paper presents the design, an implementation, and a demonstration of a 114 Mbps autonomous beam control optical wireless communication system based on an OMC technique. The robust posture control results optimum downlink alignment and good eye diagram of data transmission.

Published
2019

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