Patents by Inventor ChoKyun Rha

ChoKyun Rha 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).

  • Publication number: 20040097463
    Abstract: Products containing asiatic acid or asiaticoside, and uses thereof, for the treatment of cancer and other proliferative diseases are provided.
    Type: Application
    Filed: December 1, 2003
    Publication date: May 20, 2004
    Inventors: Se-Kyung Oh, ChoKyun Rha, Azizol Abdul Kadir, Teik Lean Ng
  • Publication number: 20040087493
    Abstract: The invention provides new uses and products for treatment of sexual dysfunction and male infertility. The products include bioactive components of extracts from roots of the plant Eurycoma longifolia mixed in preparations for topical application and administation.
    Type: Application
    Filed: December 12, 2003
    Publication date: May 6, 2004
    Inventors: T.G. Sambandan, ChoKyun Rha, Azizol Abdul Kadir, Norhaniza Aminudim, Joharl Mohammed Saad
  • Patent number: 5811272
    Abstract: A method has been developed for control of molecular weight and molecular weight dispersity during production of polyhydroxyalkanoates in genetically engineered organism by control of the level and time of expression of one or more PHA synthases in the organisms. The method was demonstrated by constructing a synthetic operon for PHA production in E. coli in which the level of PHA synthase activity could be tightly controlled by placement of the synthase behind an inducible promoter. Modulation of the total level of PHA synthase activity in the host cell by varying the concentration of the inducer, isopropyl .beta.-D-thiogalactoside (IPTG), was found to effect the molecular weight of the polymer produced in the cell. Specifically, high concentrations of synthase activity were found to yield polymers of low molecular weight while low concentrations of synthase activity yielded polymers of higher molecular weight.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: September 22, 1998
    Assignee: Massachusetts Institute of Technology
    Inventors: Kristi D. Snell, Scott A. Hogan, Sang Jun Sim, Anthony J. Sinskey, Chokyun Rha
  • Patent number: 5569483
    Abstract: A degradation product of a polysaccharide derivative comprising a mixture of oligomers of the polysaccharide derivative, the majority of said oligomers having a molecular weight such that the oligomer conforms to a rod-like configuration.
    Type: Grant
    Filed: June 7, 1994
    Date of Patent: October 29, 1996
    Assignee: Alko Group Ltd.
    Inventors: Maritta Timonen, ChoKyun Rha, Timo Vaara, Lindsey Bagley, Sarah Bosdet, Michael Lindley, Tarja Lahtinen, Marja Turunen, Martti Vaara
  • Patent number: 5543162
    Abstract: An insoluble polymeric capsule comprising at least two polymeric components, wherein one of said components is a hydrophilic colloid, and another of said components comprises a degradation product of a cellulose derivative, the degradation product comprising a mixture of oligomers, a majority of said oligomers having a degree of polymerization such that the oligomers conform to a rod-like configuration.
    Type: Grant
    Filed: November 23, 1994
    Date of Patent: August 6, 1996
    Assignee: Alko Group Ltd.
    Inventors: Maritta Timonen, Chokyun Rha
  • Patent number: 5525368
    Abstract: A degradation product of a polysaccharide derivative comprising a mixture of oligomers of the polysaccharide derivative, the majority of said oligomers having a molecular weight such that the oligomer conforms to a rod-like configuration.
    Type: Grant
    Filed: June 6, 1994
    Date of Patent: June 11, 1996
    Assignee: Alko Group Ltd.
    Inventors: ChoKyun Rha, Timo Vaara, Maritta Timonen, Tarja Lahtinen, Marja Turunen, Martti Vaara, Lindsey Bagley, Sarah Bosdet, Michael Lindley
  • Patent number: 5506124
    Abstract: Three dimensional glucan matrix compositions are prepared by separating growing yeast from its growth medium, subjecting the yeast with cell walls intact to an alkali material, thereby extracting whole glucan particles having an intact cell wall structure. The whole glucans can then, optionally, be treated with acetic acid to alter the .beta.(1-6) linkages, or with glucanase to alter the .beta.(1-3) linkages. The glucans have viscosity characteristics dependent upon the strain of yeast utilized and are useful as stabilizers or thickeners.
    Type: Grant
    Filed: August 17, 1993
    Date of Patent: April 9, 1996
    Assignee: Massachusetts Institute of Technology
    Inventors: Spiros Jamas, ChoKyun Rha, Anthony J. Sinskey
  • Patent number: 5366755
    Abstract: A degradation product of a polysaccharide derivative comprising a mixture of oligomers of the polysaccharide derivative, the majority of said oligomers having a molecular weight such that the oligomer conforms to a rod-like configuration.
    Type: Grant
    Filed: August 9, 1991
    Date of Patent: November 22, 1994
    Inventors: Maritta Timonen, ChoKyun Rha, Timo Vaara, Lindsey Bagley, Sarah Bosdet, Michael Lindley, Tarja Lahtinen, Marja Turunen, Martti Vaara
  • Patent number: 5354424
    Abstract: A paper product treated with a degradation product of a polysaccharide derivative comprising a mixture of oligomers of the polysaccharide derivative, a majority of said oligomers having a degree of polymerization such that the oligomer conforms to a rod-like configuration.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: October 11, 1994
    Inventors: Chokyun Rha, Maritta Timonen
  • Patent number: 5250436
    Abstract: Three dimensional glucan matrix compositions are prepared by separating growing yeast from its growth medium, subjecting the yeast with cell walls intact to an alkali material, thereby extracting whole glucan particles having an intact cell wall structure. The whole glucans can then, optionally, be treated with acetic acid to alter the .beta.(1-6) linkages, or with glucanase to alter the .beta.(1-3) linkages. The glucans have viscosity characteristics dependent upon the strain of yeast utilized and are useful as stabilizers or thickeners.
    Type: Grant
    Filed: June 2, 1992
    Date of Patent: October 5, 1993
    Assignee: Massachusetts Institute of Technology
    Inventors: Spiros Jamas, ChoKyun Rha, Anthony J. Sinskey
  • Patent number: 5110733
    Abstract: The extraction or purification of biomaterials and other products by liquid-liquid extraction in an aqueous system is enhanced by introducing a particulate polymeric adsorbent into the extraction system and agitating the system, whereupon the adsorbent reversibly binds the product or material to be separated from the product, to form a complex, and the complex preferentially partitions into one of the liquid phases. The complex is then separated, and the product recovered from the complex or the remaining liquid. Ion exchange resins comprising beads or ground particles, of 0.01-10 micrometer average diameter, are representative adsorbents.
    Type: Grant
    Filed: December 21, 1989
    Date of Patent: May 5, 1992
    Assignee: Rohm and Haas Company
    Inventors: Chan W. Kim, Elizabeth M. Robinson, Chokyun Rha
  • Patent number: 5082936
    Abstract: Three dimensional glucan matrix compositions are prepared by separating growing yeast from its growth medium, subjecting the yeast with cell walls intact to an alkali material, thereby extracting whole glucan particles having an intact cell wall structure. The whole glucans can then, optionally, be treated with acetic acid to alter the .beta.(1-6) linkages, or with glucanase to alter the .beta.(1-3) linkages. The glucans have viscosity characteristics dependent upon the strain of yeast utilized and are useful as stabilizers or thickeners.
    Type: Grant
    Filed: January 17, 1989
    Date of Patent: January 21, 1992
    Assignee: Massachusetts Institute of Technology
    Inventors: Spiros Jamas, ChoKyun Rha, Anthony J. Sinskey
  • Patent number: 5037972
    Abstract: Three dimensional glucan matrix compositions are prepared by separating growing yeast from its growth medium, subjecting the yeast with cell walls intact to an alkali material, thereby extracting whole glucan particles having an intact cell wall structure. The whole glucans can then, optionally, be treated with acetic acid to alter the .beta.(1-6) linkages, or with glucanase to alter the .beta.(1-3) linkages. The glucans have viscosity characteristics dependent upon the strain of yeast utilized and are useful as stabilizers or thickeners.
    Type: Grant
    Filed: April 3, 1990
    Date of Patent: August 6, 1991
    Assignee: Massachusetts Institute of Technology
    Inventors: Spiros Jamas, ChoKyun Rha, Anthony J. Sinskey
  • Patent number: 5028703
    Abstract: Three dimensional glucan matrix compositions are prepared by separating growing yeast from its growth medium, subjecting the yeast with cell walls intact to an alkali material, thereby extracting whole glucan particles having an intact cell wall structure. The whole glucans can then, optionally, be treated with acetic acid to alter the .beta.(1-6) linkages, or with glucanase to alter the .beta.(1-3) linkages. The glucans have viscosity characteristics dependent upon the strain of yeast utilized and are useful as stabilizers or thickeners.
    Type: Grant
    Filed: April 5, 1989
    Date of Patent: July 2, 1991
    Assignee: Massachusetts Institute of Technology
    Inventors: Spiros Jamas, ChoKyun Rha, Anthony J. Sinskey
  • Patent number: 5008108
    Abstract: A method for utilizing a purified exocellular polysaccharide, Zooglan, produced by Zoogloea ramigera, as a viscosity modifier, gellant, drag reducing agent, dispersant, flocculant, or emulsifying agent, wherein the properties of the polymer are dependent on, and can therefore be controlled by varying, the pH, the concentration of polymer, the ionic strength of the solution, and the processing parameters such as mechanical shear.The overall conformation of Zooglan, which is responsible for its functional properties, can be manipulated with pH and/or ionic strength of the solution. For example, the intrinsic viscosity of Zooglan (estimated m.w.=2.times.10.sup.7) can vary from 16 to 170 dl/g in aqueous solution as a function of pH between 2-9 and salt concentration between 0 and 1M KCl. Zooglan is a polyelectrolyte above pH 2. The Zooglan chain is relatively stiff, with a stiffness parameter of 0.02. Zooglan solutions at a concentration above 0.
    Type: Grant
    Filed: March 28, 1989
    Date of Patent: April 16, 1991
    Assignee: Massachusetts Institute of Technology
    Inventors: ChoKyun Rha, Pasawadee Pradipasena, TetsuHisa Nakamura, Donald D. Easson, Jr., Anthony J. Sinskey
  • Patent number: 4992540
    Abstract: Three dimensional glucan matrix compositions are prepared by separating growing yeast from its growth medium, subjecting the yeast with cell walls intact to an alkali material, thereby extracting whole glucan particles having an intact cell wall structure. The whole glucans can then, optionally, be treated with acetic acid to alter the .beta.(1-6) linkages, or with glucanase to alter the .beta.(1-3) linkages. The glucans have viscosity characteristics dependent upon the strain of yeast utilized and are useful as stabilizers or thickeners.
    Type: Grant
    Filed: January 17, 1989
    Date of Patent: February 12, 1991
    Assignee: Massachusetts Institute of Technology
    Inventors: Spiros Jamas, ChoKyun Rha, Anthony J. Sinskey
  • Patent number: 4851393
    Abstract: A method for utilizing a purified exocellular polysaccharide, Zooglan, produced by Zoogloea ramigera, as a viscosity modifier, gellant, drag reducing agent, dispersant, flocculant, or emulsifying agent, wherein the properties of the polymer are dependent on, and can therefore be controlled by varying, the pH, the concentration of polymer, the ionic strength of the solution, and the processing parameters such as mechanical shear.The overall conformation of Zooglan, which is responsible for its functional properties, can be manipulated with pH and/or ionic strength of the solution. For example, the intrinsic viscosity of Zooglan (estimated m.w.=2.times.10.sup.7) can vary from 16 to 170 dl/g in aqueous solution as a function of pH between 2-9 and salt concentration between 0 and 1M KCl. Zooglan is a polyelectrolyte above pH 2. The Zooglan chain is relatively stiff, with a stiffness parameter of 0.02. Zooglan solutions at a concentration above 0.
    Type: Grant
    Filed: July 28, 1986
    Date of Patent: July 25, 1989
    Assignee: Massachusetts Institute of Technology
    Inventors: ChoKyun Rha, Pasawadee Pradipasena, TetsuHisa Nakamura, Donald D. Easson Jr., Anthony J. Sinskey
  • Patent number: 4810646
    Abstract: Three dimensional glucan matrix compositions are prepared by separating growing Saccharomyces cerevisiae yeast from its growth medium, subjecting the yeast with cell walls intact to aqueous hydroxide and treating the insoluble glucan with acetic acid to alter the .beta.(1-6) linkages. The glucans have viscosity characteristics dependent upon the strain of Saccharomyces cerevisiae utilized and are useful as stabilizer or thickeners.
    Type: Grant
    Filed: November 28, 1984
    Date of Patent: March 7, 1989
    Assignee: Massachusetts Institute of Technology
    Inventors: Spiros Jamas, ChoKyun Rha, Anthony J. Sinskey
  • Patent number: 4749620
    Abstract: Capsules are formed herein a liquified core while avoiding capsule core gelation by adding drops of a solution of either an anionic polymer composition or a cationic polymer composition to a solution of an ionic polymer of opposite charge. The drops contain an active ingredient such as a cell or microorganism capable of producing a biologically active product or can contain a biological or chemical composition. The interface of the ionic polymers form a permeable membrane surrounding the liquid drops.
    Type: Grant
    Filed: September 18, 1985
    Date of Patent: June 7, 1988
    Assignee: Massachusetts Institute of Technology
    Inventors: ChoKyun Rha, Dolores Rodriguez-Sanchez
  • Patent number: 4744933
    Abstract: Capsules are formed herein a liquified core while avoiding capsule core gelation by adding drops of a solution of either an anionic polymer composition or a cationic polymer composition to a solution of an ionic polymer of opposite charge. The drops contain an active ingredient such as a cell or microorganism capable of producing a biologically active product or can contain a biological or chemical composition. The interface of the ionic polymers form a permeable membrane surrounding the liquid drops.
    Type: Grant
    Filed: August 16, 1985
    Date of Patent: May 17, 1988
    Assignee: Massachusetts Institute of Technology
    Inventors: ChoKyun Rha, Dolores Rodriguez-Sanchez