Patents by Inventor Johannes Roelofs

Johannes Roelofs 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: 11619638
    Abstract: A method for the in situ derivatization of at least one biogenic amine, precursor, or metabolite thereof in an isolated aqueous sample includes the steps of: (i) contacting the sample with a propionic anhydride/acetonitrile solution in the presence of a phosphate buffer having a pH in the range of 7.0 to 9.0 and allowing the conversion of amine and/or hydroxyl moieties of the biogenic amine, precursor, or metabolite thereof to form a propionyl derivative of the biogenic amine; followed by (ii) adding to the reaction mixture obtained in step (i) a carbodiimide compound and an electrophilic amine-containing compound, and allowing the carbodiimide-mediated derivatization of carboxylic acid moieties of the biogenic amine, precursor, or metabolite thereof.
    Type: Grant
    Filed: February 9, 2022
    Date of Patent: April 4, 2023
    Assignees: Rijksuniversiteit Groningen, Academisch Ziekenhuis Groningen
    Inventors: Ido Peter Kema, Claude Pascal Van Der Ley, Hermannus Johannes Roelof Van Faassen
  • Publication number: 20220341952
    Abstract: A method for the in situ derivatization of at least one biogenic amine, precursor, or metabolite thereof in an isolated aqueous sample includes the steps of: (i) contacting the sample with a propionic anhydride/acetonitrile solution in the presence of a phosphate buffer having a pH in the range of 7.0 to 9.0 and allowing the conversion of amine and/or hydroxyl moieties of the biogenic amine, precursor, or metabolite thereof to form a propionyl derivative of the biogenic amine; followed by (ii) adding to the reaction mixture obtained in step (i) a carbodiimide compound and an electrophilic amine-containing compound, and allowing the carbodiimide-mediated derivatization of carboxylic acid moieties of the biogenic amine, precursor, or metabolite thereof.
    Type: Application
    Filed: February 9, 2022
    Publication date: October 27, 2022
    Inventors: Ido Peter KEMA, Claude Pascal VAN DER LEY, Hermannus Johannes Roelof VAN FAASSEN
  • Patent number: 11280802
    Abstract: A method for the in situ derivatization of at least one biogenic amine, precursor, or metabolite thereof in an isolated aqueous sample includes the steps of: (i) contacting the sample with a propionic anhydride/acetonitrile solution in the presence of a phosphate buffer having a pH in the range of 7.0 to 9.0 and allowing the conversion of amine and/or hydroxyl moieties of the biogenic amine, precursor, or metabolite thereof to form a propionyl derivative of the biogenic amine; followed by (ii) adding to the reaction mixture obtained in step (i) a carbodiimide compound and an electrophilic amine-containing compound, and allowing the carbodiimide-mediated derivatization of carboxylic acid moieties of the biogenic amine, precursor, or metabolite thereof.
    Type: Grant
    Filed: May 24, 2017
    Date of Patent: March 22, 2022
    Assignees: Academisch Ziekenhuis Groningen, Rijksuniversiteit Groningen
    Inventors: Ido Peter Kema, Claude Pascal Van Der Ley, Hermannus Johannes Roelof Van Faassen
  • Publication number: 20190170776
    Abstract: The invention relates to analytical chemistry, in particular to means and methods for the quantitative determination of derivatized biogenic amines, precursors or metabolites thereof. Provided is a method for the in situ derivatization of at least one biogenic amine, precursor or metabolite thereof in an isolated aqueous sample, the derivatization comprising the steps of: (i) contacting said sample with a propionic anhydride/acetonitril solution in the presence of a phosphate buffer having a pH in the range of 7.0 to 9.0 and allowing the conversion of amine and/or hydroxyl moieties of said biogenic amine or metabolite thereof to form a propionyl derivative of said biogenic amine; followed by (ii) adding to the reaction mixture obtained in step (i) a carbodiimide compound and an electrophilic amine-containing compound, and allowing the carbodiimide-mediated derivatization of carboxylic acid moieties of a biogenic amine, precursor or metabolite thereof.
    Type: Application
    Filed: May 24, 2017
    Publication date: June 6, 2019
    Inventors: Ido Peter KEMA, Claude Pascal VAN DER LEY, Hermannus Johannes Roelof VAN FAASSEN
  • Publication number: 20150031581
    Abstract: The invention relates to the field of diagnostic methods, in particular to detection of biological molecules using mass spectroscopy (MS). Provided is an automated high-throughput method for quantitating a low molecular weight protein-bound biomarker directly in an isolated biological sample, comprising the steps of: (a) automated prepurification of the sample using an effective amount of an acid protease under conditions that allow for digestion of one or more binding proteins; (b) applying said protease-digested sample onto an on-line SPE column to capture at least part of said biomarker, followed by sequential washing of the solid phase; (c) eluting a fraction comprising said biomarker directly onto a liquid chromatography (LC) column comprising an apolar stationary phase and subjecting it to LC-MS or LC-MS-MS measurements to determine the amount of at least one biomarker; and (d) quantitating the biomarker(s).
    Type: Application
    Filed: November 29, 2012
    Publication date: January 29, 2015
    Inventors: Ido Peter Kema, Hermannus Johannes Roelof van Faassen, Bernhard Manz
  • Publication number: 20110152452
    Abstract: The present invention relates to a method to prepare a polymer dispersion using an aqueous substantially surfactant-free emulsion polymerization process comprising a seed and a feed stage, in which seed stage at least one ethylenically unsaturated monomer, having a water-solubility of at least 0.3 g/l at polymerization conditions, is polymerized in the presence of an addition fragmentation chain transfer agent and a hydrophilic free radical initiator to form a seed polymer that is substantially insoluble in water and in which feed stage at least one ethylenically unsaturated feed monomer is added to the seed polymer to form polymer particles. With this method a polymer dispersion can be obtained having at least 25 wt. % solid contents in combination with an average polymer particle size smaller than or equal to 300 nm.
    Type: Application
    Filed: October 11, 2010
    Publication date: June 23, 2011
    Applicant: Nuplex Resins BV
    Inventors: Dirk Emiel Paula Mestach, Richard Hendrikus Gerrit Brinkhuis, Andrea Henricus Johannes Roelofs, Hendrik Hermanus Rikus Van Der Horst
  • Patent number: 7128045
    Abstract: The invention relates to a combustion engine (1) having a housing (2) with a chamber (3). A rotor (4) is arranged herein which is provided with a number of vanes (5A, 5B, 6A, 6B) which divide the chamber into a number of compartments (3A, 3B, 3C, 3D). Each of the compartments is intended for performing at least one of the following functions: a) drawing in and/or compressing gas required for the combustion; b) bringing the fuel to combustion; c) producing work; and d) discharging combustion gases. A first pair of vanes (5A, 5B) is mounted rotatably on a first rotation axis (5). A second pair of vanes (6A, 6B) is mounted rotatably on a second rotation axis (6). The rotation axes are arranged eccentrically in the chamber (3). The rotary engine has the characteristic that the vanes in each pair (5A, 5B; 6A, 6B) are rotatable independently of each other.
    Type: Grant
    Filed: February 3, 2003
    Date of Patent: October 31, 2006
    Inventor: Johannes Roelofs
  • Publication number: 20050115536
    Abstract: The invention relates to a combustin engine (1) having a housing (2) with a chamber (3). A rotor (4) is arranged herein which is provided with a number of vanes (5A, 5B, 6A, 6B) which divide the chamber into a number of compartments (3A, 3B, 3C, 3D). Each of the compartments is intended for performing at least one of the following functions: a) drawing in and/or compressing gas required for the combustion; b) bringing the fuel to combustion; c) producing work; and d) discharging combustion gases. A first pair of vanes (5A, 5B) is mounted rotatably on a first rotation axis (5). A second pair of vanes (6A, 6B) is mounted rotatably on a second rotation axis (6). The rotation axes are arranged eccentrically in the chamber (3). The rotary engine has the characteristic that the vanes in each pair (5A, 5B; 6A, 6B) are rotatable independently of each other.
    Type: Application
    Filed: February 3, 2003
    Publication date: June 2, 2005
    Inventor: Johannes Roelofs
  • Patent number: 6872789
    Abstract: The invention pertains to a polymer obtainable from the steps: polymerizing a mixture, that is substantially free or organic solvents, of ethylenically unsaturated monomers which consist for at least 70% of methacrylates, and which comprises specific chain transfer agents, ?-methylstyrene dimer being preferred, to form a first polymer, aqueous emulsion polymerizing a mixture comprising ethylenically unsaturated monomers in the presence of the first polymer to form a dispersion of a water-insoluble second polymer, wherein these steps are preferably performed in the absence or the substantial absence of a surfactant.
    Type: Grant
    Filed: November 7, 2002
    Date of Patent: March 29, 2005
    Assignee: Akzo Nobel N.V.
    Inventors: Richard Hendrikus Gerrit Brinkhuis, Andreas Henricus Johannes Roelofs, Dirk Emiel Paula Mestach, Petrus Johannes Maria David Elfrink, Wincently Lambertus Stanislaw Pilaszek, Hendrik Hermanus Rikus van der Horst
  • Publication number: 20030153676
    Abstract: The invention pertains to a polymer obtainable from the steps:
    Type: Application
    Filed: November 7, 2002
    Publication date: August 14, 2003
    Inventors: Richard Hendrikus Gerrit Brinkhuis, Andreas Henricus Johannes Roelofs, Dirk Emiel Paula Mestach, Petrus Johannes Maria David Elfrink, Wincently Lambertus Stanislaw Pilaszek, Hendrik Hermanus Rikus Van Der Horst
  • Patent number: 6605668
    Abstract: The invention pertains to water-dissipatable polymers comprising lipophilic polymers having pendant sulfonic acid salt groups and, optionally, pendant nonionic groups, methods of making such water-dissipatable polymers and the use of such polymers in aqueous systems, including aqueous coating compositions. The invention also pertains to addition polymer polyols having such pendant sulfonic acid salt groups and, optionally, pendant nonionic groups, their methods of manufacture and their use in aqueous systems, including aqueous coating compositions. The polymers of the invention may be used as, for example, binders, emulsifying agents and dispersing agents in aqueous systems, especially aqueous coating compositions.
    Type: Grant
    Filed: May 10, 2000
    Date of Patent: August 12, 2003
    Assignee: Akzo Nobel N.V.
    Inventors: Roelof Buter, Andreas Henricus Johannes Roelofs
  • Publication number: 20020193512
    Abstract: The invention pertains to water-dissipatable polymers comprising lipophilic polymers having pendant sulfonic acid salt groups and, optionally, pendant nonionic groups, methods of making such water-dissipatable polymers and the use of such polymers in aqueous systems, including aqueous coating compositions. The invention also pertains to addition polymer polyols having such pendant sulfonic acid salt groups and, optionally, pendant nonionic groups, their methods of manufacture and their use in aqueous systems, including aqueous coating compositions. The polymers of the invention may be used as, for example, binders, emulsifying agents and dispersing agents in aqueous systems, especially aqueous coating compositions.
    Type: Application
    Filed: May 10, 2000
    Publication date: December 19, 2002
    Inventors: Roelof Buter, Andreas Henricus Johannes Roelofs