Patents by Inventor Peter H. Yu

Peter H. Yu 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: 5508311
    Abstract: The invention relates to a series of propargylamines, their salts and pharmaceutical compositions containing a compound of formula (III) wherein R.sub.1, R.sub.3 and R.sub.4 are the same or different and represent hydrogen or a straight chain or branched lower alkyl; y is an integer ranging from 0 to 5; z is an integer ranging from 0 to 5; and R.sub.2 is a straight chain or branched alkyl, alkenyl, alkynyl, alkoxy, alkylthio or alkyl sulphinyl group having from 3 to 11 carbon atoms, said group being unsubstituted or substituted with at least one of the substituents selected from hydroxy, aldehyde, oxo, loweracyloxy, halogen, thio, sulfoxide, sulfone, phenyl, halogen-substituted phenyl, hydroxy-substituted phenyl, cycloalkyl having from 3 to 6 carbon atoms and heterocyclic substituents having between 3 and 6 atoms, of which form 1 to 3 are heteroatoms selected from O, S and/or N, and pharmaceutically acceptable salts thereof, in admixture with a pharmaceutically acceptable carrier, excipient or adjuvant.
    Type: Grant
    Filed: December 23, 1993
    Date of Patent: April 16, 1996
    Assignee: University of Saskatchewan
    Inventors: Peter H. Yu, Bruce A. Davis, Alan A. Boulton
  • Patent number: 5169868
    Abstract: A component having the following formula I: ##STR1## wherein X represents an integer ranging from 1 to 2 or 7 to 13;Y represents an integer ranging from 0 to 5;Z represents an integer ranging from 0 to 5;R.sub.1, R.sub.2 and R.sub.3 are the same or different and represent H or a straight chain or branched lower alkyl; andR' and R" are the same or different and represent H or halogen,and pharmaceutically acceptable salts thereof. Preferably, the lower alkyl has between 1 and 4 carbon atoms and the halogen is selected from the group consisting of fluorine, chlorine, bromine and iodine. The compound is useful as a MAO-B inhibitor. Also within the scope of the present invention is a composition for the inhibition of MAO-B activity and a method for alleviating Parkinsonism, Alzheimer's disease, depression, attention deficit hyperactive disorders, aging and other neuropsychiatric disorders and for improving the quality of life.
    Type: Grant
    Filed: March 1, 1991
    Date of Patent: December 8, 1992
    Assignee: University of Saskatchewan
    Inventors: Peter H. Yu, Bruce A. Davis, Alan A. Boulton
  • Patent number: 4738718
    Abstract: A gold recovery pretreatment process is disclosed in which the gold content is more completely extracted from refractory sulfidic ores which contain large quantities of metal carbonates such as dolomite than occurs in traditional gold extraction methods. The process includes treating the ore in an autoclave at elevated temperature and oxygen overpressure conditions in the presence of soda ash or other alkaline materials. The autoclaving of the slurried ore is performed for a sufficient amount of time to oxidize the sulfidic compounds in the ore. The oxidized ore is then more amenable to subsequent conventional gold extraction techniques.
    Type: Grant
    Filed: October 28, 1985
    Date of Patent: April 19, 1988
    Assignee: Freeport Minerals Company
    Inventors: Nandkumar Bakshani, Peter H. Yu
  • Patent number: 4497659
    Abstract: Selenium is precipitated from solutions containing at least one metal selected from the group consisting of nickel, cobalt, copper, iron, zinc, manganese, magnesium, chromium and cadmium by adding chromous sulfate to the solution to precipitate selenium therefrom.
    Type: Grant
    Filed: August 19, 1983
    Date of Patent: February 5, 1985
    Assignee: Amax Inc.
    Inventors: Ranko Crnojevich, Edward I. Wiewiorowski, Peter H. Yu
  • Patent number: 4214900
    Abstract: Selenium is precipitated from solutions or slurries containing nonferrous metals, particularly nickel by contacting the solution or slurries with a semimetallic chromous precipitant of the nonferrous metal, particularly nickel, which has a nonferrous metal to chromium ratio between about 10:1 and about 200:1 and which has a metallic content between about 50% and about 90%. The semimetallic chromous precipitant of the nonferrous metal is prepared by hydrogen reducing a solution of the nonferrous metal or slurries containing chromous salts in amount to provide the aforementioned nickel to chromium ratios.
    Type: Grant
    Filed: August 8, 1979
    Date of Patent: July 29, 1980
    Assignee: Amax Inc.
    Inventors: Ranko Crnojevich, Edward I. Wiewiorowski, Peter H. Yu
  • Patent number: 4175014
    Abstract: A method is provided for the recovery of cobalt from nickel solutions, wherein cobalt is separated from said solution as a precipitate containing cobaltic hydroxide precipitate and also containing nickel, the method comprising dissolving the precipitate for the subsequent recovery of cobalt therefrom by reducing trivalent metal in said precipitate to the divalent state. This is achieved by forming an aqueous slurry of said precipitate acidified with sulfuric acid to a pH ranging from about 0.1 to 2, subjecting the precipitate of said aqueous slurry to electrolytic reduction at the cathode of an electrolytic cell having an insoluble anode, said precipitate being isolated from said anode during said electrolytic reduction and continuing the electrolytic reduction of said precipitate from the trivalent to the divalent state and effect the dissolution thereof.
    Type: Grant
    Filed: March 6, 1978
    Date of Patent: November 20, 1979
    Assignee: AMAX Inc.
    Inventors: Ranko Crnojevich, Edward I. Wiewiorowski, Peter H. Yu