Patents by Inventor Takashi Ohshima

Takashi Ohshima has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6833442
    Abstract: There is provided a complex having a specified chemical structure and an asymmetric catalyst using such a complex. Further, an epoxidation of amine or ketone is enantioselectively conducted by using such an asymmetric catalyst.
    Type: Grant
    Filed: August 5, 2002
    Date of Patent: December 21, 2004
    Assignee: The University of Tokyo
    Inventors: Masakatsu Shibasaki, Takashi Ohshima, Tetsuhiro Nemoto
  • Publication number: 20030130488
    Abstract: There is provided a complex having a specified chemical structure and an asymmetric catalyst using such a complex. Further, an epoxidation of amine or ketone is enantioselectively conducted by using such an asymmetric catalyst.
    Type: Application
    Filed: August 5, 2002
    Publication date: July 10, 2003
    Applicant: THE UNIVERSITY OF TOKYO
    Inventors: Masakatsu Shibasaki, Takashi Ohshima, Tetsuhiro Nemoto
  • Patent number: 5965718
    Abstract: Sarcodictyin A and B, eleutherobin, and bioactive analogs thereof synthesized using solid phase and solution phase chemistries. The synthetic method employs an attachment of common precursors, e.g., compounds 1880 or 200, on a solid support for generating conjugates 230 and 240, followed by standard chemical manipulations. A combinatorial library of sarcodictyins and eletherobin analogs was constructed with modified C-8 ester, C-15 ester and C-4 ketal functionalities and was screened for activity with respect to tubulin polymerization and cytotoxic activity against tumor cells, including Taxol-resistant lines. Compounds 600, 610, 630, 660-700, 730, 760, 850, and 920 were identified to be of equal or superior biological activities as compared to their corresponding natural product.
    Type: Grant
    Filed: September 1, 1998
    Date of Patent: October 12, 1999
    Assignee: The Scripps Research Institute
    Inventors: Kyriacos C. Nicolaou, Floris VanDelft, Seijiro Hosokawa, Sanghee Kim, Tianhu Li, Takashi Ohshima, Jeff Pfefferkorn, Dionisios Vourloumis, Jin-You Xu, Nicolas Winssinger
  • Patent number: 5811819
    Abstract: An electron beam source is provided with an electron forming means such as a doped layer of Si for forming conduction band electrons near the surface of the pointed tip of a needle-shaped structure while suppressing emission of electrons from a valence band. The surface of the pointed tip of the needle-shaped structure is formed with a single-crystal semiconductor or insulator. Preferably a surface passivation layer and/or a highly doped layer is formed on the surface of the needle-shaped structure. Also, means for exciting electrons in a valence band may be provided. An electron beam source apparatus and electron beam apparatus incorporating the electron beam source as defined above are also disclosed.
    Type: Grant
    Filed: December 5, 1995
    Date of Patent: September 22, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Ohshima, Hiroyuki Shinada, Katsuhiro Kuroda
  • Patent number: 5616926
    Abstract: A Schottky emission cathode has a filament, a needle-shaped piece of single crystal refractory metal which is attached to the filament and has a flat crystal surface at a tip thereof, and an adsorbed layer including at least one kind of a metal other than the single crystal refractory metal on the flat crystal surface. The piece of single crystal refractory metal is heated by passing a current through the filament and electrons are extracted by an electric field applied on a tip of the needle-shaped piece of single crystal refractory metal. The tip of the needle-shaped piece of single crystal refractory metal as a radius of curvature of a value to produce an energy width among electrons extracted from the tip not exceeding a predetermined value when the electric field is sufficient to prevent the flat crystal surface from collapsing during operation of the cathode.
    Type: Grant
    Filed: July 31, 1995
    Date of Patent: April 1, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Shinada, Shingo Kimura, Katsuhiro Kuroda, Satoru Fukuhara, Takashi Ohshima
  • Patent number: 5241197
    Abstract: A transistor having a high carrier mobility and suited for a high-speed operation can be formed by utilizing a fact that the carrier mobility in a strained germanium layer is large. A strain control layer is provided beneath the germanium layer to impose a compressive strain on the germanium layer, and the composition of the strain control layer in a predetermined range is used to generate the compressive strain surely.
    Type: Grant
    Filed: September 13, 1991
    Date of Patent: August 31, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Eiichi Murakami, Kiyokazu Nakagawa, Takashi Ohshima, Hiroyuki Eto, Masanobu Miyao
  • Patent number: 5066355
    Abstract: A method of producing a hetero structure, including the steps of depositing hydrogen atoms or halogen atoms onto a surface of a first single crystal layer formed of semiconductor or metal silicide, and forming a second single crystal layer on the first single crystal layer by hetero epitaxial growth, the second single crystal layer being formed of semiconductor or metal silicide different from the material of the first single crystal layer, wherein both of the steps are continuously conducted without taking the hetero structure out of a producing device. Further, the number of the hydrogen atoms or the halogen atoms to be deposited is equal to or in the range of .+-.50% with reference to the number of dangling bonds existing in a hetero interface between the first single crystal layer and the second single crystal layer, so that the lattice defects in the hetero interface can be reduced.
    Type: Grant
    Filed: November 16, 1989
    Date of Patent: November 19, 1991
    Assignee: Agency of Industrial Science and Technology
    Inventors: Masanobu Miyao, Kiyokazu Nakagawa, Kiyonori Ohyu, Eiichi Murakami, Takashi Ohshima
  • Patent number: 5047111
    Abstract: Films of desired metal, e.g., Ni or Co, and of Si are laminated alternately n a single crystal silicon substrate to form a multi-layered structure, and thereafter the substrate is heated to grow an epitaxial NiSi.sub.2 or CoSi.sub.2 film in solid phase with less diffusion of Ni or Co atoms into the silicon substrate. Each layer in the multi-layered structure has a thickness selected in the range of 30-300 A with the overall composition ratio Si/Ni (or Si/Co) in the range of 1.8-2.0. The lamination process is done at a substrate temperature which does not cause the laminated films to react with the substrate and does not cause the multi-layered structure to become polycrystalline, e.g. below 350.degree. C. for the formation of an NiSi.sub.2 film or below 450.degree. C. for the formation of a CoSi.sub.2 film. The solid phase epitaxy is achieved at a substrate heating temperature in a range of 350.degree.-750.degree. C. for the formation of an epitaxial NiSi.sub.2 film or 450.degree.-1000.degree. C.
    Type: Grant
    Filed: October 16, 1987
    Date of Patent: September 10, 1991
    Assignee: Director-General of the Agency of Industrial Science and Technology
    Inventors: Akitoshi Ishizaka, Yasuhiro Shiraki, Takashi Ohshima
  • Patent number: 4621419
    Abstract: An automatic IC mounting process for mounting a plurality of ICs on an upper surface of a printed circuit board in accordance with a predetermined sequence program. Each of the ICs has a plurality of leads, each of which is to be inserted into a predetermined corresponding through-hole of the printed circuit board.
    Type: Grant
    Filed: December 28, 1984
    Date of Patent: November 11, 1986
    Assignee: Fujitsu Limited
    Inventors: Toshikatsu Hino, Fumio Arase, Takashi Ohshima