Hokkaido University Research Profiles

Japanese

"H" Researcher: 28

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  • Life Sciences
  • Information and Communication
  • Nanotechnology / Materials
  • Manufacturing Technology
  • Human and Social Sciences
  • Energy
  • Environment
  • Tourism / Community development
  • Arctic Research
  • Social Infrastructure
  • Open Facilities
  • A Single Microscopic Image Can Tell the Whole Story

    A Single Microscopic Image Can Tell the Whole Story

    The Nikon Imaging Center was established as a facility where researchers throughout Japan can use the latest biological microscopes, and is now operated by the Research Institute for Electronic Science. Our dedicated staff will explain how to operate the equipment and software to beginners who may never have touched a microscope before.

    Research

    Recent years have seen an increasing demand for bioimaging and significant performance improvement in gene transfer technology, molecular and cellular marking technology using fluorescent proteins and observation equipment such as microscopes. However, high performance microscope systems are very expensive, and it is difficult to obtain all the necessary equipment, especially at the start. Another factor that makes imaging technology difficult is the fact that not everyone can easily obtain excellent data
    The center’s equipment is made available for researchers outside the university and we not only provide instructions on the operation of the equipment and software, but also technical know-how on imaging. We have also joined the Advanced Bioimaging Support (ABiS) platform from this year, and are involved in supporting the use of cutting-edge microscopes in collaboration with other microscope facilities in Japan. We’d like companies that are exploring the application of imaging to consider the use of our services.

  • Health Benefit of Red Algae Phycobiliprotein

    Clarifying the health functions and mechanisms of phycoerythrin, which is abundantly contained in red algae dulse

    We have discovered that Dulse, an unused red alga distributed along the coast of Hokkaido, is rich in the red protein phycoerythrin (PE), which may have a variety of health functions. Currently, we are analyzing the structure of PE to elucidate the mechanism of its health functions.

    Research

    Dulse (Palmaria palmata) is a red alga mainly distributed in Hokkaido. It is an unused seaweed that thrives on kelp cultivation ropes during the winter. Dulse prevents the kelp from growing and is thus removed from the ropes. Recently, we have found that Dulse contains approximately 40% protein per dry weight (comparable to soybeans), and its major component is red phycoerythrin (PE), a photosynthetic auxiliary pigment. We have also found that this PE and peptides prepared from PE have health functions, such as ACE inhibition, antioxidation and brain function improvement (Marine Drugs 14:1-10 (2016), Journal of Food Biochemistry, 41: e12301 (2017)).

  • Event Information Recommendation System

    A system that collects data from a few weeks before an event to the day of the event and recommends appropriate event information.

    Although event information was only valid for a short time and it was hard to handle it with conventional information recommendation technology, we have developed a flexible recommendation method by combining multiple factors such as user interest and geographic characteristics.

    Research

    The system estimates the genres and information sources that a user prefers based on the user’s past information browsing history, and assesses the event information that the target user is interested in by referring to the browsing trends of users with similar interests. It also takes into account the geographic characteristics of the user and finally presents the information to him/her. The timing of information distribution is adjusted throughout the system so that the overall system performance can be improved.

  • Analysis of Economic Behavior and Software Development by the Stated Preference Method

    Using the data analysis environment R

    To statistically analyze people's economic behavior, we generally use the results of actual behavior. However, the necessary data may not always be available. In such cases, the stated preference method of questionnaire-based research is useful. We conduct research using the stated preference method and develop the software to implement it.

    Research

    People engage in economic activities every day, such as purchasing products and deciding what to do for recreation. Elucidating and predicting the factors that influence economic behavior is information that is needed both in academia and practice. The analysis of economic behavior is generally based on statistical data and other data that record actual past behavior, but the necessary data is not always available. In such cases, the stated preference method is useful for collecting and analyzing data by asking questions designed based on economic theory to target people. In addition to conducting empirical research using the stated preference method mainly in agricultural and rural areas (although the scope of application of this method is not limited to agricultural and rural areas), we have developed and released a software package for the data analysis environment R that can be freely used by anyone who is interested in practicing the stated preference method.

  • Iodine Reduction in Edible Dried Kelp

    Technology to reduce iodine in dried kelp by the competitive adsorption method

    We have developed technology that can remove approximately 90% of iodine from kelp by simply circulating and distributing an extraction solvent containing monosaccharides and calcium through a column filled with dried kelp and adsorbents.

    Research

    Iodine is an essential element for humans, but excessive intake of iodine can cause thyroid function problems. The Ministry of Health, Labour and Welfare (MHLW) has set the maximum tolerable dose of iodine at 2.2 mg/day, but only 1 g of kelp (Fig. 1) is enough to reach the maximum tolerable dose, due to its high iodine content. Technology for recovering iodine from seaweed has been available for many years, but there has been no research on developing technology for removing iodine from seaweed for consumption. Figure 2 shows the iodine removal rate (○) and mass loss rate (●) of kelp after circulating and distributing an extraction solvent (100 L) containing monosaccharide and calcium for 20 minutes in a column filled with dried kelp (5 kg) and adsorbent (1.5 kg). Although the extraction solvent was used four times to reduce the cost, an iodine removal rate of 90% or more was maintained.

    Hideshi Seki Specially Appointed Professor
  • Recognition and Modeling Technology for Laser Scanned Point Clouds

    Toward more sophisticated analysis, maintenance and management, and planning of environments and structures where human activity takes place

    We are developing theories and algorithms for point cloud processing to automatically recognize and create 3D models of objects and structures that exist in environments where human activity takes place, such as rooms, roads, pole-like objects (utility poles and street lights), street trees, and buildings, from 3D laser scanned point clouds.

    Research

    We are researching technologies for the automatic recognition and modeling of objects and structures in indoor and outdoor environments from point clouds obtained by ground-based and vehicle-mounted 3D laser scanning systems, as well as basic point cloud data processing methods. The objects to be recognized and modeled include a wide range of arbitrarily shaped objects, rooms, pole-like objects such as utility poles and street lights, trees, road surfaces, and buildings. In addition to the technology of generating mesh models, polygon models, and CAD models from point clouds, we also conduct research on point cloud registration, segmentation, shape feature extraction, machine learning, and procedural object recognition that serves as the foundation for the technology. This technology enables detailed recognition and analysis of the environment and structures, maintenance and management, various simulations and improvement plans using 3D models that faithfully reflect the current state.

  • Artificial Photosynthesis System Using Localized Plasmons

    Ammonia photosynthesis system involving hydrogen produced from water by visible and near-infrared light using an optical nano-antenna

    To realize highly efficient artificial photosynthesis, we have used an optical nano-antenna made of metal nanostructures to convert solar energy to a wide range of wavelengths from visible to near-infrared, succeeding in hydrogen generation based on the photolysis of water and the photosynthesis of ammonia, which has recently attracted attention as an energy carrier.

    Research

    To realize highly efficient artificial photosynthesis, it is essential to convert the energy into chemical substances by constructing a system that utilizes solar energy of visible and near-infrared wavelengths, which are not used in conventional artificial photosynthesis. We have succeeded in designing and fabricating an optical nano-antenna that can effectively collect light of various wavelengths by changing the shape and arrangement of the metal nanostructures. We have also successfully photodisintegrated water to produce hydrogen and oxygen stoichiometrically using sunlight in a wide range of wavelengths from visible to near-infrared. This system has also enabled us to photosynthesize ammonia through photoreduction of nitrogen in the air. Ammonia is attracting attention as a next-generation energy carrier, but its synthesis requires high-temperature and -pressure conditions, which may cause a huge environmental burden. This system is expected to be used as a method for ammonia synthesis at normal temperature and pressure using sunlight.

  • Nanotechnology Platform

    Microfabrication and microstructure analysis

    To support research and development of microfabrication and microstructure analysis, we make Hokkaido University’s state-of-the-art equipment and technical know-how available. In close cooperation with implementing institutions throughout Japan, we also support approaches to solving problems in the industrial field and at research sites under a nationwide system of equipment sharing.

    Research

    For microfabrication, we support the fabrication of devices on a micrometer to nanometer scale using a broad array of equipment for thin film formation, metal nanostructures, etc. Examples include pattern formation using a state-of-the-art electron beam lithography system installed in a clean room, film deposition using a multidimensional sputtering and atomic layer deposition system, etching using a reactive ion etching system, and device evaluation using FE-SEM.
    For microstructure analysis, we offer support for material analysis through internal structure observation using aberration-corrected transmission electron microscopy (S/TEM) and compound beam microscopy (FIB-SEM). We also support surface and state analysis using a scanning electron microscope (FE-SEM), Auger electron spectrometer (AES) and electron probe microanalyzer (EPMA), and assist with measurements under special beams and environments using ultra-high voltage electron microscopy, time-resolved photoelectron microscopy and spin SEM.

  • Geothermal Resource Monitoring and Risk Assessment of Induced Earthquakes

    Monitoring and risk assessment of geothermal resources through geophysical observations

    Evaluation of the subsurface structure necessary for geothermal resource development by gravity survey and precise determination of the seismic source. Monitoring of geothermal reservoir resources by precise gravity measurements and crustal deformation observations. Risk assessment of induced earthquakes associated with geothermal well development and research on seismic activity prediction.

    Research

    ○ For geothermal resource development, which has been actively promoted in recent years, geothermal reservoirs are examined through base structure surveys. We have been investigating the basement structure through gravity surveys, precise seismic source distribution, and seismic velocity structure analysis.
    ○ For geothermal power generation, steam is produced and hot water is returned to the underground, but it is necessary to monitor the level of the geothermal reservoir to ensure the sustainable use of resources. We will examine the appropriate resource utilization volume through physical assessment of the subsurface fluid conditions using precise gravity measurements and crustal deformation observations.
    ○ The injection of high-pressure fluids into geothermal wells may induce noticeable tremors and cause problems. We will provide guidelines for appropriate and sustainable resource development by developing a method to evaluate the risk of induced earthquakes based on such parameters as the crustal stress state in the geothermal development area, surrounding faults, the characteristics of the seismic activity, and fluid injection volume.

  • Liposomal Bioluminescence Immunoassay

    Preparation of liposomes encapsulating luciferase and application as an ultra-sensitive label in immunoassays

    We have encapsulated the enzyme luciferase (Luc), which catalyzes bioluminescence reactions, in liposome, a lipid bilayer vesicle, and applied it as an ultrasensitive label for immunoassays. As a model substance, we performed immunoassay of C-reactive protein, a marker of inflammation, and found that it could be quantified.

    Research

    Since immunoassay is an essential technology in clinical laboratories and for environmental analysis, technological advances (simplification, high sensitivity, high throughput, etc.) has come essential as the analytes are becoming more diverse and smaller. We aim to construct an ultra-sensitive immunoassay system in which the bioluminescent enzyme Luc is encapsulated in lipid bilayer membrane vesicles, called liposomes, and use it as a label in immunoassays. By encapsulating a large number of Luc in liposomes, it becomes possible to label antibodies in a stable state. However, although the method of encapsulating enzymes inside liposomes is already known, no studies have been done on Luc. In our study, we have encapsulated heat-stabilized recombinant Luc into liposomes and evaluated the amount and stability of the encapsulation. We have also constructed an immunoassay system for C-reactive protein using Luc-encapsulated liposomes as a label.

  • From Landscape to Hometown Revitalization

    Creating community value through resident participation

    From the perspective of landscape planning, we are researching ways to preserve and utilize the local environment by linking it to people's awareness and social understanding. In recent years, we have been practically researching how values and spatial needs that change with society, such as “health” and “funerals” can be reflected in the landscape.

    Research

    To conserve and manage local resources through resident participation, the “landscape” approach, which views the region from people's perspective, is very effective. We are developing research on people's and society's landscape perception, and conducting empirical research on how to utilize people’s place attachment in local resource management.
    Environmental planning using health resorts (Kurort)
    In Germany, medical insurance covers services at government-recognized recuperation and health resorts that make use of the natural environment such as hot springs, the sea, and the climate. In Japan, too, efforts are underway to create health resorts (Kurort) that combine health tourism with local health promotion.
    Forest utilization as burial sites:
    To utilize forest resources, we are conducting practical research on the development of forest burial sites in Japan, modeled after Germany’s examples. As a new method of managing forests, which account for 70% of Japan’s land area, we are promoting the creation of forest burial sites in various regions as a means of regional management in aging society.

  • Superomniphobic Aluminum

    Simple production of antifouling surfaces through a wet process

    We have successfully fabricated a micro/nano-hierarchical surface morphology through chemical etching/anodization of aluminum sheets and meshes. By coating the surface with a fluoroalkyl monolayer, we have also succeeded in obtaining a surface that is not wetted by almost any liquids, including oil.

    Research

    It is expected that superomniphobic surfaces, which do not get wet with water or oil, will possess antifouling and self-cleaning properties. In this study, we have realized a superomniphobic surface that does not only repel water but also octane and other liquids with a surface tension as low as 20 mN m-1, by using a simple wet process for aluminum, which is a practical metal material. This process can also be applied to aluminum foil, which can be used as an antifouling surface in various places. It can also be used as a filter to separate oil and water by controlling its wettability using aluminum mesh.

  • Ultra-rapid Deposition of Photocatalytic Crystalline Titanium Dioxide Thin Films

    Ultra-rapid electrochemical deposition technology that does not require high temperature heat treatment

    Crystalline titanium dioxide is a practically important oxide as a photocatalyst. We have developed a technology to form crystalline titanium dioxide thin films, which generally require heat treatment at high temperatures, on various metal substrates within only a few seconds using an electrochemical deposition method in aqueous solution.

    Research

    We have succeeded in obtaining titanium dioxide thin film on a practical metal substrate such as Cu, Al, Zn and Fe by electrolysis from an aqueous solution containing TiF62- within only a few seconds. The obtained titanium dioxide thin film is anatase crystalline and shows photocatalytic activity without heat treatment. The obtained titanium dioxide thin film is anatase crystalline and shows photocatalytic activity without heat treatment. We have confirmed that it has excellent properties such as decomposition of organic contaminants on the surface by UV irradiation and superhydrophilicity. Since the titanium dioxide film is doped with substrate elements, the development of new functions such as visible light responsiveness can be expected. It can also be deposited on a transparent conductive substrate.

  • Functional Modification of Food Proteins

    Sugar modification for processing and improved health functions

    Using the Maillard reaction to bind sugars to fish meat proteins, we can prepare water-soluble muscle proteins and peptides with modified processing properties and health functions (anti-inflammatory and antioxidant function, suppression of blood pressure increase and suppression of lipid absorption, etc.). It can also be applied to livestock and poultry meat and various proteins.

    Research

    Summary
    The Maillard reaction can be used to bind reducing sugars to proteins and peptides to create new fish food products with modified properties.
    Comparison with conventional technology and uniqueness
    High-molecular complex proteins such as muscle proteins are prone to thermal aggregation, and progression of the Maillard reaction leads to deterioration of various properties. We have developed a new method to create functional materials from unstable proteins such as fish food proteins by controlling both protein denaturation and the Maillard reaction.
    Characteristics of the materials and manufacturing technologies that can be created.
    1. Introduction of sugar chains without using chemical reagents
    2. Making muscle soluble in water and adding highly emulsifiable properties
    3. Improving the stability of unstable proteins
    4. Modification of in vivo active health functions
    5. Can be applied to the development of functional peptides.
    6. No limitations on the form of the raw materials

  • Semiconductor Devices That Display and Store Information Through Changes in Color and Conductivity

    Can windowpanes and mirrors serve as memory devices?

    We have developed new information display and storage devices by incorporating electrochromic materials, which are attracting attention as “electronic curtains,” into thin-film transistors and using the color change of colorless transparent ? black and the conductivity changes of insulator ? metal. Information can be displayed and stored on window glass and mirrors.

    Research

    With the spread of IoT, the amount of information that needs to be collected and stored continues to increase as not only personal computers but also various devices are connected to the internet. Current information storage devices use only electrical resistance changes in semiconductors, but with this research, we have developed a device that can use color changes in addition to electrical resistance changes for information display and storage. A three-terminal all-solid-state thin-film transistor structure was produced on a glass or plastic substrate with source, drain, and gate electrodes consisting of a laminate of an amorphous WO3 thin film (100 nm thick)/nanoporous glass thin film (300 nm)/polycrystalline NiO thin film (50 nm) and a transparent ITO thin film (20 nm). When a positive voltage of a few volts is applied between the gate and the source, the WO3 thin film changes to a dark blue color and simultaneously becomes metal, and when a negative voltage is applied, it returns to a colorless transparent insulator.

  • Stable and Practical Oxide Thermoelectric Conversion Materials

    As a result of replacing the sodium ions in the layered cobalt oxide with barium ions of heavier atomic mass, only the thermal conductivity decreased while the electrical properties remained unchanged. We have found that the thermoelectric figure of merit ZT reaches 0.11 at room temperature.

    Research

    Thermoelectric conversion has been attracting attention as a technology to recycle waste heat. Metal chalcogenides are known as thermoelectric materials, but they have thermal and chemical stability and toxicity issues. Layered cobalt oxides are stable at high temperatures and in air, but have the problems that thermal conductivity is high and conversion performance is low. The research group considered the strategy shown in Fig. 1 to reduce the thermal conductivity of layered cobalt oxide AxCoO2. Figure 2 summarizes the thermoelectric properties in the direction parallel to the layers of Ax-substituted AxCoO2 thin films measured at room temperature. The thermal conductivity shows a monotonically decreasing trend with increasing Ax atomic weight. The room temperature thermoelectric figure of merit of Ba1/3CoO2 is 0.11. The figure of merit ZT increases with increasing temperature. By further enhancing the thermoelectric conversion performance, it is expected to realize stable and practical thermoelectric conversion materials.

  • MALDI Matrix for Sensitive and High-Resolution Structural Analysis of Unmodified Sialylated Glycans and Glycoconjugates

    We have developed a matrix that can ionize sialylated glycans and glycoconjugates without modifying the carboxylic acid moiety of the sialic acids, and can analyze them with high sensitivity and resolution (reflector mode) without desorption of the sialic acid residue.

    Research

    Sialylation (addition of sialic acid) of glycans and glycoconjugates is an important biomarker involved in various biological phenomena such as development, differentiation, disease, infection, and immunity. MALDI (matrix-assisted laser desorption/ionization) is a simple and sensitive soft ionization method. However, the ionization efficiency of unmodified sialic acid-containing glycans is low, and there is a problem that the spectrum becomes complicated due to cleavage of sialic acids or other reasons. With this technique, we succeeded in measuring sialylated glycans and glycoconjugates with high sensitivity and high resolution without undergoing any modification process by improving the addition system to the conventional matrix while suppressing sialic acid desorption. With the change in the cleavage pattern and the increased sensitivity, TOF/TOF analysis and pseudo-MS3 analysis can now be performed using ultra-trace samples. This method does not require chemical modification and separation steps, and enables reaction tracking and rapid sample analysis.

  • Peptide and Glycopeptide Cyclization Technology

    Significant improvement of peptide cyclization efficiency by controlling hydrogen bonds

    By focusing on forming a hydrogen-bond network in the solvent, we have succeeded in both efficient peptide cyclization and improved solubility of poorly soluble peptides. This system can apply to drug discovery and molecular tool design.

    Research

    Cyclic peptides are an ideal molecular form for exploring biologically active compounds (drug discovery) and the design of molecular tools in life science. Cyclization of the peptide backbone can control their conformational stability, orientation, and symmetry. However, peptide cyclization requires specific dilution conditions and complex basic protection strategies. We found that combining a hydrogen-bond-controlled solvent system and a base-free condensation agent system enables the efficient cyclization of poorly soluble peptides under highly concentrated conditions. The simplicity of this technology gives a wide range of applications for drug discovery and life sciences by facilitating the free design and mass production of cyclic peptides.

  • Technology to Analyze Glycan Patterns Directly from Glycoproteins

    The world's first selective ionization technology for glycans that does not require pretreatment
    (This is a technology for which Hokkaido University is the sole applicant and sole inventor.)

    We have discovered the world's first mass spectrometry technique for selective ionization of glycans in complex macromolecules and mixtures such as glycoproteins and body fluids by the MALDI method. We have also demonstrated that this technique can be used for the direct analysis of glycans in complex mixtures such as egg white and body fluids.

    Research

    Glycan patterns on glycoproteins are important biomarkers because they are factors that determine the disposition of protein in the body. Until now, glycan pattern analysis has required complicated operations such as cutting, chemical modification, and purification of glycans. Mass spectrometry is an ultra-sensitive and high-resolution analytical technique that can directly ionize trace amounts of biomolecules. However, there has not been a method to selectively ionize glycoconjugates such as glycoproteins and glycans in complex macromolecules and mixtures such as body fluids, which requires the complicated pretreatment described above. We have achieved the world's first simultaneous selective cleavage and selective ionization of glycoconjugate glycans, and succeeded in the direct analysis of glycan patterns on glycoproteins. We have also demonstrated that this technique can be used to directly analyze glycan patterns in complex mixtures such as egg white.

  • Technology to Create Unique Glycan Derivative Libraries × Microarray Analysis System That Can Be Used Anywhere

    Original library using automated glycan synthesis technology × Microarray technology supporting on-site medical care and research

    Glycan-related interactions are important targets of infectious diseases and cancer diagnosis. We have developed a microarray system that can be used anywhere to utilize the libraries of glycans, glycoconjugates, glycan-related inhibitors, and their derivatives that have been constructed and accumulated in the process of developing automated glycan synthesis technology.

    Research

    Microarray technology is a technology that enables simultaneous comparative analysis of the interaction between a large number of compound libraries with well-defined structures and sequences and sample components. We also have the most advanced technology to design and produce our own carbohydrate compound libraries as molecules for microarray analysis based on our automated carbohydrate synthesis technology. The interaction information possessed by carbohydrates is widely used as biomarkers for in vitro diagnostics, such as blood types, serotypes such as O157, and cancer diagnostic markers (CAxx). In addition, we have succeeded in developing an independently powered mobile analyzer that can be used for online diagnosis, such as analysis of infection patterns associated with mutations in infectious diseases and detailed analysis of vaccine effects, by performing specimen collection and microarray analysis on the spot using a smartphone as a terminal.