Sensor based navigation for car-like mobile robots using generalized Voronoi graph

Our research objective is to realize sensor based navigation by car-like mobile robots. The generalized Voronoi graph (GVG) can describe a mobile robot's path for sensor based navigation from the point of view of completeness and safety. However, it is impossible to apply the path to a car-like mobile robot directly, because limitation of the minimum turning radius prevents following the non-smooth GVG. To solve the problem, we propose a local smooth path planning algorithm for car-like mobile robots. Basically, an initial path is generated by a conventional path planning algorithm using GVG theory, and it is deformed smoothly to enable car-like robots' following by maximizing an evaluation function proposed in the paper. The key topics are: definition of our evaluation function; and how to modify the GVG. We introduce a local smooth path planning algorithm based on the GVG, and explain a detail of the evaluation function. Simulation results support validity of the algorithm </p

Selective production of valuable chemicals from biomass by two-step conversion combining pre-oxidation and hydrothermal degradation

Biomass is getting notable as a new energy resource to replace fossil resources and to restrain CO₂ emission recently. However, it is obvious that the energy use of biomass is unsuitable for its limit of available amounts. Consequently, we investigated the possibility of new refinery scheme of biomass to utilize biomass as an alternative raw material to fossil resources with suggested two-step treatment method. We oxidized cellulose and biomass with H₂O₂ first and put the residue into hydrothermal condition to obtain some specific chemicals. Through the first oxidation of cellulose, 0.26 g/g-cellulose of organic acid was obtained, and 0.35 g/g-cellulose of oxalic acid was obtained under the catalytic condition. Both cedar and cellulose decreased their crystallinity through the first oxidation and increased their reactivity, we could obtain hydroxymethylfurfural(HMF) from cellulose and biomass through the hydrothermal degradation, 0.11 g/g-cellulose and 0.12 g/g-cedar respectively

Effects of photonic band gap of cholesteric liquid crystal on chemiluminescence

We have fabricated glass cells filled with cholesteric liquid crystalline materials (CLC reflectors), which are mixtures of a nematic liquid crystalline mixture, ZLI-2293 (Merck), and a chiral dopant, MLC-6248 (Merck). We reported the enhancement of the maximum emission intensity of luminol reaction by the photonic band gap (PBG) of the CLC reflectors. Here, we report the effect of the relative position of PBG of the CLC reflectors to the emission spectra of luminol reaction on the enhancement of the maximum emission intensity. © 2015This is an Accepted Manuscript of an article published by Taylor & Francis in Molecular Crystals and Liquid Crystals on 24 May 2015, available at https://doi.org/10.1080/15421406.2015.1032725

Temperature-dependent Color Change of Cholesteric Liquid Crystalline Core-shell Microspheres

We have fabricated water-in-oil-in-water (W/O/W) double emulsion droplets with a cholesteric liquid crystalline (CLC) material, which is a mixture of a nematic liquid crystalline compound, 4-cyano-4′-pentylbiphenyl (5CB), and a chiral dopant, cholesteryl oleyl carbonate (COC), as the middle phase and an aqueous poly(vinylalcohol) (PVA) solution as the inner and outer phases (CLC core-shell microspheres). Here we report the strongly temperature-dependent color change of CLC core-shell microsphere.This is an Accepted Manuscript of an article published by Taylor & Francis in Molecular Crystals and Liquid Crystals on 3 July 2015, available at https://doi.org/10.1080/15421406.2015.1066548

Real-Time Observation of Hydrogen Peroxide Transport through the Oil Phase in a W/O/W Double Emulsion with Chemiluminescence Emission

The evaluation of the transport rates of hydrophilic substances is important in agricultural and pharmaceutical chemistry and in the cosmetics and food-processing industries. Although there are some estimation methods focusing on the diffusion of the substances through the oil phase of the W/O/W core-shell double emulsions (oil microcapsules), all of them take several hours or days. This long-time measurement has a risk of rupture of the oil microcapsules, which causes significant errors. If it were possible to measure the transport rate of substances in the oil phase of the oil microcapsules in real time, the risk of rupture could be reduced. Here, we propose a new estimation method for the transport rates of hydrogen peroxide (H2O2) in the oil phase of an oil microcapsule for real-time estimation by means of chemiluminescence (CL) emission of the luminol reaction. We theoretically give the relationship among the CL emission intensity, diffusion coefficient, microcapsule size, and experimental time and successfully estimate the diffusion coefficient of H2O2 in the oil phase of the oil microcapsule from the experimental data. Moreover, we discuss the dependence of the permeation of H2O2 through the oil phase on the concentration of the oil-soluble surfactant; the difference in the permeation rate is likely to be attributed not to the diffusion coefficient but to the partition coefficient of H2O2 in the oil microcapsule.Hiroshi Kouno, Yosuke Iwai, Yoshiaki Uchida et al. Real-Time Observation of Hydrogen Peroxide Transport through the Oil Phase in a W/O/W Double Emulsion with Chemiluminescence Emission. Langmuir, 33 (15), 3802-3808, April 17, © 2017 American Chemical Society. https://doi.org/10.1021/acs.langmuir.7b0010

Size Control of Cholesteric Liquid Crystalline Microcapsules

We have succeeded the size-controlled fabrication of water-in-oil-in-water (W/O/W) double emulsion droplets with a cholesteric liquid crystalline (CLC) material, which is a mixture of a nematic liquid crystalline compound, 4-cyano-4′-pentylbiphenyl (5CB), and a chiral dopant, 1,4:3,6-dianhydro-2,5-bis[4-(n-hexyl-1-oxy)benzoic acid]sorbitol [ISO(6OBA)2], as the shell phase and an aqueous poly(vinylalcohol) (PVA) solution as the core and outer phases (CLC microcapsules). Here we report the size-controlled fabrication of the CLC microcapsules and the size-dependence of their transmission spectra.This is an Accepted Manuscript of an article published by Taylor & Francis in Molecular Crystals and Liquid Crystals on 06 July 2015, available at https://doi.org/10.1080/15421406.2015.1032066

Room-temperature fabrication of mono-dispersed liquid crystalline shells with high viscosity and high melting points

We propose a new method to fabricate mono-dispersed liquid crystalline (LC) microcapsules with shells consisting of LC materials showing high viscosity and/or high melting points at room temperature. In this method, it is important to control the state of the shell phase by the addition and removal of agents inducing LC-to-isotropic phase transitions and vice versa, respectively, at the right times.Reproduced from J. Mater. Chem. C , 2017, 5, 1303-1307 with permission from the Royal Society of Chemistry.https://doi.org/10.1039/c6tc05267

Reduction of lipid accumulation rescues Bietti’s crystalline dystrophy phenotypes

眼の難病クリスタリン網膜症の発症メカニズムを解明 --治療薬の有力候補発見により創薬研究の進展に期待--. 京都大学プレスリリース. 2018-03-27.Bietti’s crystalline dystrophy (BCD) is an intractable and progressive chorioretinal degenerative disease caused by mutations in the CYP4V2 gene, resulting in blindness in most patients. Although we and others have shown that retinal pigment epithelium (RPE) cells are primarily impaired in patients with BCD, the underlying mechanisms of RPE cell damage are still unclear because we lack access to appropriate disease models and to lesion-affected cells from patients with BCD. Here, we generated human RPE cells from induced pluripotent stem cells (iPSCs) derived from patients with BCD carrying a CYP4V2 mutation and successfully established an in vitro model of BCD, i.e., BCD patient-specific iPSC-RPE cells. In this model, RPE cells showed degenerative changes of vacuolated cytoplasm similar to those in postmortem specimens from patients with BCD. BCD iPSC-RPE cells exhibited lysosomal dysfunction and impairment of autophagy flux, followed by cell death. Lipidomic analyses revealed the accumulation of glucosylceramide and free cholesterol in BCD-affected cells. Notably, we found that reducing free cholesterol by cyclodextrins or δ-tocopherol in RPE cells rescued BCD phenotypes, whereas glucosylceramide reduction did not affect the BCD phenotype. Our data provide evidence that reducing intracellular free cholesterol may have therapeutic efficacy in patients with BCD

Effects of small interfering RNAs targeting fascin on human esophageal squamous cell carcinoma cell lines

<p>Abstract</p> <p>Background</p> <p>Fascin induces membrane protrusions and cell motility. Fascin overexpression was associated with poor prognosis, and its downregulation reduces cell motility and invasiveness in esophageal squamous cell carcinoma (ESCC). Using a stable knockdown cell line, we revealed the effect of fascin on cell growth, cell adhesion and tumor formation.</p> <p>Methods</p> <p>We examined whether fascin is a potential target in ESCC using <it>in vitro </it>and <it>in vivo </it>studies utilizing a specific siRNA. We established a stable transfectant with downregulated fascin from KYSE170 cell line.</p> <p>Results</p> <p>The fascin downregulated cell lines showed a slower growth pattern by 40.3% (p < 0.01) and detachment from collagen-coated plates by 53.6% (p < 0.01), compared to mock cells, suggesting that fascin plays a role in cell growth by maintaining cell adhesion to the extracellular matrix. <it>In vivo</it>, the tumor size was significantly smaller in the tumor with fascin knockdown cells than in mock cells by 95% at 30 days after inoculation.</p> <p>Conclusions</p> <p>These findings suggest that fascin overexpression plays a role in tumor growth and progression in ESCC and that cell death caused by its downregulation might be induced by cell adhesion loss. This indicates that targeting fascin pathway could be a novel therapeutic strategy for the human ESCC.</p