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Light Scattering Detector
David W. Larsen and Zhi Xu
The invention concerns high sensitivity light scattering detection and its application to evaporative light scattering detection in liquid chromatography. The exemplary embodiment includes a detection cell to accept particles suspended in a gas stream and permit a polarized light beam to pass through a trajectory of the particles and gas stream. A sample light detector is disposed to detect light scattered in the detection cell. A light trap accepts the polarized beam after it passes through the detection cell. The light trap includes an elongated housing through which the polarized beam passes, and light absorptive material within the elongated housing. An absorptive filter is aligned such that the angle of incidence of the light beam upon the filter approximates Brewster's angle and the electric field vector of the beam is aligned with the plane of incidence between the beam and the filter. Other embodiments of the invention provide increased light collection. Embodiments of the invention include temperature-controlled entrance and exit ports that control particle trajectory. Embodiments of the invention include a reference cell disposed between a detection cell and a light trap, and the reference cell includes lensing and a spherical mirror to direct light toward a reference light detector. The reference light detector provides a reference signal that may be used with noise cancellation circuitry, operating in either voltage or current mode, to reduce light source noise in the sample signal.
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Apparatus and method for assessing visual suppression
Carl Bassi, Michael Howe, and Wayne Garver
A device is used to determine the presence of and the amount (depth) of visual suppression in a subject. The device includes a first light source emitting a first light and a second light source emitting a second light. Intensities of the light sources are independently controllable. A first filter disposed over one eye of the subject allows transmission of the first light and prevents transmission of the second light. A second filter disposed over the other eye of the subject allows transmission of the second light and prevents transmission of the first light. In a method of using the device, the intensity of at least one of the first and second lights is independently controlled, wherein the difference in intensities of the first and second lights at which the lights appear to be at equal brightness to the subject determines the amount of visual suppression in the subject.
For the most up-to-date information about these patents, including the availability of Certificates of Correction, be sure to check the United States Patent and Trademark Office's free, publicly accessible database: Patent Public Search https://ppubs.uspto.gov/pubwebapp/static/pages/landing.html
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Light scattering detector
David W. Larsen and Zhi Xu
The invention concerns high sensitivity light scattering detection and its application to evaporative light scattering detection in liquid chromatography. The exemplary embodiment includes a detection cell to accept particles suspended in a gas stream and permit a polarized light beam to pass through a trajectory of the particles and gas stream. A sample light detector is disposed to detect light scattered in the detection cell. A light trap accepts the polarized beam after it passes through the detection cell. The light trap includes an elongated housing through which the polarized beam passes, and light absorptive material within the elongated housing. An absorptive filter is aligned such that the angle of incidence of the light beam upon the filter approximates Brewster's angle and the electric field vector of the beam is aligned with the plane of incidence between the beam and the filter. Other embodiments of the invention provide increased light collection. Embodiments of the invention include temperature-controlled entrance and exit ports that control particle trajectory. Embodiments of the invention include a reference cell disposed between a detection cell and a light trap, and the reference cell includes lensing and a spherical mirror to direct light toward a reference light detector. The reference light detector provides a reference signal that may be used with noise cancellation circuitry, operating in either voltage or current mode, to reduce light source noise in the sample signal.
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Ultrasensitive Spectrophotometer
David W. Larsen and Zhi Xu
The invention concerns measurements in which light interacts with matter to generate light intensity changes, and spectrophotometer devices of the invention provide ultrasensitive measurements. Light source noise in these measurements can be reduced in accordance with the invention. Exemplary embodiments of the invention use sealed housings lacking an internal light source. In some embodiments a substantially solid thermally conductive housing is used. Other embodiments include particular reflection based sample and reference cells. One embodiment includes a prism including an interaction surface, a detector, a lens that focuses a prism beam output onto the detector, and a closed interaction volume for delivering gas or liquid to the interaction surface. Another embodiment replaces a prism with a reflective surface. Another embodiment replaces a prism with a scattering matte surface. Aspects of the invention identify noise-contributing components in spectrophotometry and realize noise levels very near the shot noise limit.
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Opiate analogs selective for the δ-opioid receptor
William J. Welsh, Seong Jae Yu, and Anil Nair
Novel compounds which selectively bind to the δ-opioid receptor have been designed. These compounds have greater selectivity, improved water (blood) solubility, and enhanced therapeutic value as analgesics. Because agonists with selectivity for the δ-opioid receptor have shown promise in providing enhanced analgesis without the addictive properties, the compounds of the present invention are better than morphine, naltrindole (NTI), spiroindanyloxymorphone (SIOM), and other known μ-opioid receptor selectors as analgesics.
For the most up-to-date information about these patents, including the availability of Certificates of Correction, be sure to check the United States Patent and Trademark Office's free, publicly accessible database: Patent Public Search https://ppubs.uspto.gov/pubwebapp/static/pages/landing.html
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Opioid receptor active compounds
William J. Welsh, Seong Jae Yu, and Anil Nair
The invention provides compounds of formula I: wherein R1 to R4 and n have any of the meanings defined in the specification and their pharmaceutically acceptable salts. The invention also provides pharmaceutical compositions comprising a compound of formula I, processes for preparing compounds of formula I, intermediates useful for preparing compounds of formula I, and therapeutic methods for treating pain and treating other conditions which involve, for example, binding opioid receptors using compounds of formula I.
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Opioid receptor active compounds
William J. Welsh, Seong Jae Yu, and Anil Nair
The invention provides compounds of formula I: wherein R1 to R4 and n have any of the meanings defined in the specification and their pharmaceutically acceptable salts. The invention also provides pharmaceutical compositions comprising a compound of formula I, processes for preparing compounds of formula I, intermediates useful for preparing compounds of formula I, and therapeutic methods for treating pain and treating other conditions which involve, for example, binding opioid receptors using compounds of formula I.
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Ultrasensitive spectrophotometer
David W. Larsen, Zhi Xu, and Wayne Garver
The invention concerns improvements in spectrophotometry. Aspects of the invention may be used independently or together to increase the sensitivity of spectrophotometry. One aspect of the invention is a spectrophotometer detection circuit. In this aspect of the invention, currents attributable to reference and sample beams are cancelled in the current mode. The detection circuit produces a first voltage proportional to the difference in currents and a second voltage proportional to one of the reference or sample beams. Both voltages are available to allow simultaneous measurement and analysis. Another aspect of the invention concerns thermal stability. According to the invention, thermal conductivity is established among the housing and optical system components to promote equilibrium. Another preferred embodiment has a unitary solid metal housing with a hollowed portion defined to mount and place optical system components. Recognition and identification of important noise sources in spectrophotometers forms an aspect of the invention contributing to the features and combinations of features in preferred embodiments. Many noise sources would not normally be considered in conventional spectrophotometry because the magnitude of particular noise sources dominates device performance.
For the most up-to-date information about these patents, including the availability of Certificates of Correction, be sure to check the United States Patent and Trademark Office's free, publicly accessible database: Patent Public Search https://ppubs.uspto.gov/pubwebapp/static/pages/landing.html
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Bleaching of lignocellulosic material with in-situ-generated dioxirane
Chung-Li Lee, Robert W. Murray, Kenneth Hunt, James T. Wearing, Robert M. Hogikyan, Colin W. Oloman, and Jianxin Chen
A chemical pulp which contains reactants capable of generating dioxirane within the pulp is produced in a process which comprises mixing a pulp with reactants comprising a carbonyl compound, preferably acetone, and an oxygen donor, preferably monoperoxysulfate, in proportions which produce a water-soluble dioxirane having a molecular diameter of less than 140 angstrom units. Such a pulp bleaching process which employs dioxirane as a bleaching agent is rendered environmentally and economically acceptable by recycling the reactants employed to produce the dioxirane.
For the most up-to-date information about these patents, including the availability of Certificates of Correction, be sure to check the United States Patent and Trademark Office's free, publicly accessible database: Patent Public Search https://ppubs.uspto.gov/pubwebapp/static/pages/landing.html
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Artificial redox enzymes
Valerian T. D'Souza and Ding Rong
Artificial redox enzymes are disclosed wherein one or more redox coenzymes or cofactors are linked to the 2-O, 3-O or 6-O positions of a D-glucopyranose ring of α-, β-, or γ-cyclodextrins. Also disclosed are facile synthetic methods for producing said artificial redox enzymes in good yield, and methods of use of such compositions.
For the most up-to-date information about these patents, including the availability of Certificates of Correction, be sure to check the United States Patent and Trademark Office's free, publicly accessible database: Patent Public Search https://ppubs.uspto.gov/pubwebapp/static/pages/landing.html
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Synthesis of nitroxides using dioxiranes
Robert W. Murray and Megh Singh
The subject invention relates to a method of synthesizing nitroxides from secondary amines. This method uses a suitable dioxirane compound such as dimethyldioxirane (DMD), which is relatively stable and simple to synthesize, as the oxidizing agent. A quantity of a secondary amine having no hydrogen atoms directly attached to the alpha carbon atoms is mixed with a 2x molar ratio of the dioxirane. In a first reaction, the secondary amine is oxidized to form a hydroxylamine; in a second reaction, the hydroxylamine is further oxidized to form a nitroxide. When the dioxirane loses an oxygen atom it converts into a ketone; for example, dimethyldioxirane is converted into acetone. This is very convenient, since the ketone byproduct is a solvent that can be easily removed after the reaction without causing interfering reactions. This method provides a simple, highly selective, rapid reaction with very high yields. It can be carried out in a single reaction vessel and can be used with a wide variety of secondary amines (including secondary amines having more than one amine group) to create a corresponding variety of nitroxides.
For the most up-to-date information about these patents, including the availability of Certificates of Correction, be sure to check the United States Patent and Trademark Office's free, publicly accessible database: Patent Public Search https://ppubs.uspto.gov/pubwebapp/static/pages/landing.html
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Synthesis of Hydroxylaminesusing Doxiranes
Robert W. Murray and Megh Singh
The subject invention relates to a method of synthesizing hydroxylamines from secondary amines. This method uses a dioxirane compound such as dimethyldioxirane (DMD, which is relatively stable and simple to synthesize), as the oxidizing agent. The reaction proceeds as follows: ##STR1## This method provides a simple, one-step reaction with high yields. It can be performed in acetone solution, and the transferral of an oxygen atom from dimethyldioxirane to the secondary amine converts the dioxirane into acetone, the solvent, permitting simple workup and purification. This method can be used with a wide variety of secondary amines, including aliphatic, aromatic, cyclic, and heterocyclic secondary amines, to create a corresponding variety of hydroxylamines.
For the most up-to-date information about these patents, including the availability of Certificates of Correction, be sure to check the United States Patent and Trademark Office's free, publicly accessible database: Patent Public Search https://ppubs.uspto.gov/pubwebapp/static/pages/landing.html
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