摘要:
A sample cell assembly employs optics for focusing light though a sample cell, such as one used in electrophoresis. The optical array includes a first cylindrical lens having a central longitudinal axis in a common plane with the longitudinal axis of the sample cell. A second cylindrical lens has its central longitudinal axis oriented transversely to this common plane on another side of the sample cell from the first cylindrical lens. Preferably, a fiber optic beam splitter has a plurality of strands terminating in parallel second ends in the common plane so as to pass light at different longitudinally spaced locations through the sample cell cavity. Here, a plurality of second lenses receive the different light components to focus them respectively on different photodetectors each to create a sample data signal. Where a plurality of sample data signals are generated, processing electronics superimpose them to obtain an augmented signal of aggregate data. The invention further includes a method of measuring optical absorbance utilizing this technique and apparatus.
摘要:
The present invention relates to methods and apparatus useful for detecting and measuring flow of a fluid along a flow path. In a method according to the invention, the temperature of a flowing fluid is altered at a selected location for a selected duration so as to generate a pulse in the fluid moving in a downstream direction along a flow path, and the fluid is monitored at a sensing region to detect the pulse passing therethrough. An apparatus according to the present invention may comprise a conduit, a sensor element disposed therein, an energy source proximate to the conduit, and a controller operative to generate an on signal and an off signal respectively operative to activate and deactivate the energy source. The present invention also relates to a liquid chromatography device having a fluid flow detecting and measuring apparatus according to the present invention.
摘要:
A spectrophotometer employs an array of optical elements to focus light from at least one, but preferably two light sources onto a fiber optic beam splitter that provides a pickup for a selected bandwidth of wavelengths of light in the spectral pattern. The spectral pattern can include wavelengths in the visible, near infrared and ultraviolet spectrum. To create the spectral pattern, two reflecting prisms having spherical surfaces are used, and the optical elements are arranged so that the two spectral bands from each prism are longitudinally aligned to create the spectral pattern. The prisms are on a motor driven pivot mount so that the spectral pattern may be swept across the pickup. The optical elements and the pickup are sized so that the selected bandwidth is less than twenty nanometers over the spectral pattern. The pickup is formed by a single row of the ends of fiber optic strands which are then collimated into two bundles to transmit a test component and a reference component of light. The sample cell is somewhat elongated, and a lens is interposed in the test component path before the sample cell, and this lens is sized to focus light axially through the sample cell without impinging on the sidewalls. Photodiode detectors, comparator circuitry and a controller are included.
摘要:
A process for the preparation of a compound of formula (I) ##STR1## comprising contacting a mixture containing at least one taxane compound having an ester linkage at the C-13 position with at least one borohydride reducing salt in a reaction solvent in the presence of a Lewis acid.
摘要:
Non-invasive drug delivery systems useful for the absorption of therapeutically active agents through the epithelial membrane are described. The non-invasive drug delivery system delivers a therapeutic active agent with an ionizable, or ionized, metal, transition metal or metal-containing vehicle. The non-invasive drug delivery system may also have a pH adjustable vehicle which facilitates the absorption of the therapeutic agents by altering the pH of the non-invasive drug delivery system at the site of administration. Also disclosed is a method for the pH “sweeping” of the administered therapeutic active agent to provide a consistent and reproducible absorption of the active agent. Certain formulations utilize low doses of active agents without altering the active agents from their current or previous form.
摘要:
A method is provided for making a high permittivity dielectric material for use in capacitors. Several high permittivity materials in an organic nonconductive media with enhanced properties and methods for making the same are disclosed. A general method for the formation of thin films of some particular dielectric material is disclosed, wherein the use of organic polymers, shellac, silicone oil, and/or zein formulations are utilized to produce low conductivity dielectric coatings. Additionally, a method whereby the formation of certain transition metal salts as salt or oxide matrices is demonstrated at low temperatures utilizing mild reducing agents. Further, a circuit structure and associated method of operation for the recovery and regeneration of the leakage current from the long-term storage capacitors is provided in order to enhance the manufacturing yield and utility performance of such devices.
摘要:
The present invention is a method that uses an absorption column for the cleavage and recovery of taxanes, which are not normally detected as free taxanes. The method processes a first solution that contains standard detectable taxanes and other undetectable taxane compounds to generate a second solution that contains a higher percentage of detectable standard taxane then the first solution. The first step of this method is loading a column having a first opening and a second opening with an ion exchange media. The next step is placing the first solution in the first opening of the column so that the first solution passes through the ion exchange media in the column and flows to the second opening. Thus, the taxane compounds are converted to standard taxanes by an ion exchange reaction and the second solution is formed. Then the next step is collecting, from the second opening of the column, the second solution and recovering from the second solution a larger percentage of standard taxanes then was detectable in the first solution. The ion exchange media of the present solution is an ion exchange resin. The ion exchange resin can be a mixture of an anion exchange resin and a cation exchange resin. The anion exchange resin is in the OH-form. The cation exchange resin is in the H.sup.+ form. Preferably, the ion exchange resin is alumina.
摘要:
An improved process and method for the formation of stable intermediate cyclophanes. Embodiments describe a general method for the production of substituted and unsubstituted cyclophanes. The components include a pyrolysis reaction tube that may be electrically heated into which a flowing stream of nitrous oxide with xylene vapor in an optional inert carrier gas at atmospheric pressure. The exit gas is condensed resulting in the deposition of [2,2′]paracyclophane. Additionally a process and method whereby the reactive intermediates of the reaction described above can be directly deposited and polymerized at atmospheric pressures or thereabout is disclosed.
摘要:
A spectrophotometer measures optical absorption of light by a sample received in a sample cell. An array of optical elements disperses the light over a spectral pattern, and a fiber optic beam splitter splits light at a selected spectral band into a reference component and a test component. Detectors measure the intensity of the reference component and the test component after the test component passes through the sample. The fiber optic beam splitter includes a plurality of strands arranged with first ends terminating in a common circular area. Opposite ends of peripheral strands are collected into a first set that transmits the test component while the remaining strands for a second set that transmits the reference component. Preferably, there is a single, central, large strand surrounded by smaller strands. Two emitters are provided for light of two different types, such as visible and UV. The optical array forms a collimated beam having an inner core of one type of light and an outer shell of the other. Specially constructed optical elements then reflect and refract the collimated beam. A motor drives a mirror to scan the beam across an optical slit positioned in front of the beam splitter to select a desired spectral band.
摘要:
A method of processing a feed liquid in the form of an extraction solution containing taxane solutes that is an extraction product of a biomass utilizes at least one semipermeable membrane to remove at least one taxane solute from the solvent by reverse osmosis. The feed liquid is placed in a first region on one side of the membrane and pressure is supplied to transport constitutes of the feed liquid across the membrane to a second region as a first permeate while retaining a first retentate in the first region. The taxane solute may be either retained or transported. Where the taxane solute is transported, the method can further include the use of a second semipermeable membrane of a pore size different from the first membrane and supplying a pressure to transport some of the first permeate across the second membrane as a second permeate while retaining a majority of the desired taxane solute as a second retentate. Here, the first membrane has a pore size which allows transport of the taxane solute while the second membrane has a pore size that retains the taxane solute. A variety of solvents and useable membranes is disclosed.