127 results match your criteria: "School of Integrated Design Engineering[Affiliation]"

Neural depolarization triggers Mg2+ influx in rat hippocampal neurons.

Neuroscience

December 2015

Center for Biosciences and Informatics, School of Fundamental Science and Technology, Graduate School of Science and Technology, Keio University, Yokohama, Kanagawa 223-8522, Japan. Electronic address:

Homeostasis of magnesium ion (Mg(2+)) plays key roles in healthy neuronal functions, and deficiency of Mg(2+) is involved in various neuronal diseases. In neurons, we have reported that excitotoxicity induced by excitatory neurotransmitter glutamate increases intracellular Mg(2+) concentration ([Mg(2+)]i). However, it has not been revealed whether neuronal activity under physiological condition modulates [Mg(2+)]i.

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Article Synopsis
  • - Globalization and competition in manufacturing have prompted companies to enhance their machine tools to meet market demands, leading to the need for effective decision-making in machine tool selection using uncertain information.
  • - This study proposes an integrated method combining fuzzy AHP (Analytic Hierarchy Process) and fuzzy COPRAS (COmplex PRoportional ASsessment) to aid in the multi-attribute decision-making process for selecting the best machine tool.
  • - The fuzzy AHP helps manage vague data through pair-wise comparison to determine attribute weights, and its outcomes feed into the fuzzy COPRAS for ranking options, validated through a numerical example demonstrating its effectiveness in uncertain scenarios.
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Optically transparent superhydrophobic surfaces with enhanced mechanical abrasion resistance enabled by mesh structure.

ACS Appl Mater Interfaces

March 2015

School of Integrated Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama-shi, Kanagawa-ken 223-8522, Japan.

Inspired by naturally occurring superhydrophobic surfaces such as "lotus leaves", a number of approaches have been attempted to create specific surfaces having nano/microscale rough structures and a low surface free energy. Most importantly, much attention has been paid in recent years to the improvement of the durability of highly transparent superhydrophobic surfaces. In this report, superhydrophobic surfaces are fabricated using three steps.

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Highly site-selective transvascular drug delivery by the use of nanosecond pulsed laser-induced photomechanical waves.

J Control Release

October 2014

School of Integrated Design Engineering, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan.

Photomechanical waves (PMWs), which were generated by irradiation of a light-absorbing material (laser target) with nanosecond laser pulses, were used for targeted transvascular drug delivery in rats. An Evans blue (EB) solution was injected into the tail vein, and laser targets were placed on the skin, muscle and brain. Each laser target was irradiated with a laser pulse(s) and 4h later, the rat was perfused and the distribution of EB fluorescence in the targeted tissues was examined.

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Pial arteries respond earlier than penetrating arterioles to neural activation in the somatosensory cortex in awake mice exposed to chronic hypoxia: an additional mechanism to proximal integration signaling?

J Cereb Blood Flow Metab

November 2014

1] Molecular Imaging Center, National Institute of Radiological Sciences, Inage, Chiba, Japan [2] Brain Science Inspired Life Support Research Center, University of Electro-Communications, Chofu, Tokyo, Japan.

The pial and penetrating arteries have a crucial role in regulating cerebral blood flow (CBF) to meet neural demand in the cortex. Here, we examined the longitudinal effects of chronic hypoxia on the arterial diameter responses to single whisker stimulation in the awake mouse cortex, where activity-induced responses of CBF were gradually attenuated. The vasodilation responses to whisker stimulation under prehypoxia normal conditions were 8.

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Here we describe our new high-precision instrument that simultaneously measures the surface tension, viscosity, and surface viscoelasticity of liquids. The instrument works on the ripplon surface-laser light scattering principle and operates with an automatically tunable selection of ripplon wavelength from 4 to 1500 μm, which corresponds to the frequency range of observing surface phenomena from approximately 400 Hz to 3 MHz in the case of water. The heterodyne technique instrument uses a reference laser beam which intersects at an arbitrarily adjustable angle with a vertically directed probing beam.

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High-transparency, self-standable gel-SLIPS fabricated by a facile nanoscale phase separation.

ACS Appl Mater Interfaces

February 2014

School of Integrated Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan.

Slippery liquid-infused porous surfaces (SLIPSs) that were both highly transparent and free-standing (self-standability) were fabricated by an extremely simple process using non-solvent-induced phase separation (NIPS) of a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/di-n-butyl phthalate solution. We call these "Gel-SLIPS" because the porous PVDF-HFP film fabricated using the NIPS process has been used as a gel electrolyte in a lithium-ion battery. In previous reports, SLIPS fabrication required complex processes, high annealing temperatures, and drying.

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Endothelial progenitor cell (EPC) transplantation induces the formation of new blood-vessel networks to supply nutrients and oxygen, and is feasible for the treatment of ischemia and cardiovascular diseases. However, the role of EPCs as a source of proangiogenic cytokines and consequent generators of an extracellular growth factor microenvironment in three-dimensional (3D) microvessel formation is not fully understood. We focused on the contribution of EPCs as a source of proangiogenic cytokines on 3D microvessel formation using an in vitro 3D network model.

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Porous surface structure fabricated by breath figures that suppresses Pseudomonas aeruginosa biofilm formation.

ACS Appl Mater Interfaces

November 2013

Graduate School of Science and Technology, School of Integrated Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan.

As colonizers of medical-device surfaces, Pseudomonas aeruginosa strains present a serious source of infection and are of major concern. In this study, we fabricated films with porous surfaces by breath figures that disturb mergence by bacterial attachment, thereby impeding biofilm development. Previous studies have shown that microtopography prevents the development of P.

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Viscous conductive glue layer in semitransparent polymer-based solar cells fabricated by a lamination process.

ACS Appl Mater Interfaces

November 2013

School of Integrated Design Engineering, Keio University, Minato, Tokyo 108-8345, Japan.

Semitransparent polymer-based solar cells were fabricated by using a low-cost, vacuum-free lamination process. This process is to deposit a conductive glue solution on the transparent Ag film, followed by lamination with the active layer. The glue solution and a mixture of poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) and d-sorbitol was used.

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Information on the state of edema is important for treating severe burn injuries, but a method for noninvasive real-time quantitative diagnosis of edema is not available. Thus, in vivo spatiotemporal characteristics of serum albumin, which would behave differently from water in burned tissue, are not fully understood. In this study, we used a photoacoustic (PA) imaging method to visualize depth distribution of albumin in a rat deep burn model, for which Evans blue was used as a nontoxic molecular probe.

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Rare-metal-free flexible counter electrodes for dye-sensitized solar-cells produced using wet processes only.

ACS Appl Mater Interfaces

May 2013

School of Integrated Design Engineering, Keio University, Kohoku-ku, Yokohama, Kanagawa, Japan.

Dye-sensitized solar-cells (DSCs) are cheap because they are produced using low-cost materials and simple manufacturing processes. However, the substrates of DSC counter electrodes are sputtered with a transparent conductive oxide and platinum. This involves vacuum manufacturing processes and high-cost (rare-metal) materials, and increases the costs of DSCs.

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Near-field fluorescence thermometry using highly efficient triple-tapered near-field optical fiber probe.

Rev Sci Instrum

December 2012

School of Integrated Design Engineering, Keio University, Kanagawa 223-8522, Japan.

A novel local temperature measurement method using fluorescence near-field optics thermal nanoscopy (Fluor-NOTN) has been developed. Fluor-NOTN enables nanoscale temperature measurement in situ by detecting the temperature-dependent fluorescence lifetime of CdSe quantum dots (QDs). In this paper, we report a novel triple-tapered near-field optical fiber probe that can increase the temperature measurement sensitivity of Fluor-NOTN.

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Reconstruction of hepatic stellate cell-incorporated liver capillary structures in small hepatocyte tri-culture using microporous membranes.

J Tissue Eng Regen Med

March 2015

Centre for System Integration Engineering, School of Integrated Design Engineering, Keio University, 3-1-14-1 Kohoku, Yokohama, 223-0061, Japan.

In liver sinusoids, hepatic stellate cells (HSCs) locate the outer surface of microvessels to form a functional unit with endothelia and hepatocytes. To reconstruct functional liver tissue in vitro, formation of the HSC-incorporated sinusoidal structure is essential. We previously demonstrated capillary formation of endothelial cells (ECs) in tri-culture, where a polyethylene terephthalate (PET) microporous membrane was intercalated between the ECs and hepatic organoids composed of small hepatocytes (SHs), i.

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The influence of the organic/inorganic interface on the organic-inorganic hybrid solar cells.

J Nanosci Nanotechnol

May 2012

Center for Science and Technology for Designing Functions, School of Integrated Design Engineering, Graduate School of Science and Technology, Keio University, 223-8522, Japan.

Organic-inorganic hybrid solar cells based on poly(3-hexylthiophene) (P3HT) and (6,6)-phenyl C61 butyric acid methyl ester (PCBM) hybridized with ZnO nanorods were fabricated by growing vertical ZnO nanorods on indium tin oxide (ITO) substrates and filling with bulk heterojunction polymers (P3HT:PCBM). The interface between the organic and inorganic nanostructures influences the performance of the organic-inorganic hybrid solar cells. In this paper, the influence of the state of the P3HT:PCBM/ZnO interface on the performance of organic-inorganic hybrid solar cells is examined.

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Reconstruction of 3D stacked hepatocyte tissues using degradable, microporous poly(d,l-lactide-co-glycolide) membranes.

Biomaterials

March 2012

Center for System Integration Engineering, School of Integrated Design Engineering, Keio University, 3-1-14-1, Kohoku, Yokohama 223 0061, Japan.

There is great demand for constructing well-organized three-dimensional (3D) tissues in vitro. Here, we developed a 3D stacked culture method using biodegradable poly(d,l-lactide-co- glycolide) (PLGA) membranes with defined topography. Pore size and porosity of the membranes can be controlled by changing the moisture content during fabrication.

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Spatio-temporal control of hepatic stellate cell-endothelial cell interactions for reconstruction of liver sinusoids in vitro.

Tissue Eng Part A

May 2012

Center for System Integration Engineering, School of Integrated Design Engineering, Keio University, Kohoku-ku, Yokohama, Japan.

Vascularization of engineered tissues in vitro remains a major challenge in liver tissue engineering. Liver microvessels, termed liver sinusoids, have highly specialized structures, and recapturing these sinusoidal structures is essential for reconstruction of functional liver tissue in vitro. Liver sinusoids are composed of hepatocytes, hepatic stellate cells (HSCs), and endothelial cells (ECs).

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We have developed a novel nanoscale temperature-measurement method using fluorescence in the near-field called fluorescence near-field optics thermal nanoscopy (Fluor-NOTN). Fluor-NOTN enables the temperature distributions of nanoscale materials to be measured in vivo/in situ. The proposed method measures temperature by detecting the temperature dependent fluorescence lifetimes of Cd/Se quantum dots (QDs).

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We present experimental and theoretical results on plasmonic control of far-field interference for regular ripple formation on semiconductor and metal. Experimental observation of interference ripple pattern on Si substrate originating from the gold nanosphere irradiated by femtosecond laser is presented. Gold nanosphere is found to be an origin for ripple formation.

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A thin film of poly(3,4-ethylenedioxythiophene)-poly(4-styrenesulfonic acid) (PEDOT-PSS), which is an alternative cathodic catalyst for Pt in dye-sensitized solar cells, was prepared using the layer-by-layer self-assembly method (LbL). The film is highly adhesive to the substrate and has a controllable thickness. Therefore, the PEDOT-PSS film prepared using LbL is expected have high performance and durability as a counter electrode.

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Correlation of antithrombogenicity and heat treatment for layer-by-layer self-assembled polyelectrolyte films.

Langmuir

April 2011

School of Integrated Design Engineering, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan.

Antithrombogenic films with high durability were fabricated in a wet process. Antithrombogenicity was achieved with polyelectrolyte multilayer thin film prepared from poly(vinyl alcohol)-poly(acrylic acid) (PVA-PAA) blends, deposited in alternate layers with poly(allylamine hydrochloride) (PAH). Film durability, assessed by abrasion resistance and water resistance, was enhanced by forming cross-links via amide bonds induced by heat treatment of the film.

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We describe theoretical and experimental results on near-field interaction of two-dimensionally (2D) arrayed, high-permittivity spherical particles on a substrate in the Mie resonance scattering domain for surface nano-patterning processing. When a touching particle pair of Mie resonance particles on the substrate is considered, an electromagnetic mode different from the single particle mode is excited inside the particles, resulting in an intensity enhancement in a gap between two hotspots at particle-substrate contact points. As for 2D hexagonal close-packed particle arrays on the substrate, the refractive index of particle exhibiting a maximal enhancement factor for the 2D particle arrays is found to be shifted from the Mie resonance conditions for the single particle system.

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Control of cellular activity of fibroblasts on size-tuned fibrous hydroxyapatite nanocrystals.

Acta Biomater

March 2011

School of Integrated Design Engineering, Graduate School of Science and Technology, Keio University, Hiyoshi, Kohoku, Yokohama 223-8522, Japan.

We controlled the performance of L929 mouse fibroblasts using various hydroxyapatite (HA) nanocrystals, such as nanofibers, nanoneedles, and nanosheets, to better understand the effects of size and shape of the HA nanocrystals on the cells. The cellular activity on nanofibers with a diameter of 50-100 nm was significantly enhanced relative to that on a flat HA surface because large amounts of the proteins needed for adhesion and proliferation could be stored in the substrate. On the other hand, initial adhesion and subsequent proliferation were inhibited on surfaces consisting of fine nanoneedles and nanosheets with a diameter/thickness of less than 30 nm due to the limited area available for the formation of focal adhesions.

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Hepatic stellate cell-mediated three-dimensional hepatocyte and endothelial cell triculture model.

Tissue Eng Part A

February 2011

Center for System Integration Engineering, School of Integrated Design Engineering, Keio University, Yokohama, Japan.

Hepatic stellate cells (HSCs) form a functional unit with endothelia and hepatocytes in the liver to play a pivotal role in heterotypic cellular communication. To investigate this role of HSCs, it is of great benefit to establish a triculture model that forms the functional unit from proximal layers of hepatocytes, HSCs, and endothelial cells (ECs). Here, we established a three-dimensional triculture model, using a microporous membrane to create the functional unit.

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Mechanical design of an intracranial stent for treating cerebral aneurysms.

Med Eng Phys

November 2010

School of Integrated Design Engineering, Graduate School of Keio University, Keio University, Hiyoshi, Kohoku, Yokohama, Japan.

Endovascular treatment of cerebral aneurysms using stents has advanced markedly in recent years. Mechanically, a cerebrovascular stent must be very flexible longitudinally and have low radial stiffness. However, no study has examined the stress distribution and deformation of cerebrovascular stents using the finite element method (FEM) and experiments.

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