Abstract: A method for the preparation of a compound of formula (VI): in which R2 is an optionally substituted C1–C6 alkyl; R4 is H, OH, an optionally substituted C1–C6 alkyl or an optionally substituted C1–C6 alkoxy; R5 is an optionally substituted aryl, an optionally substituted aralkyl, or an optionally substituted alkyl; and R6 is H or an optionally substituted C1–C6 alkyl; the method including the step of subjecting a ketone of formula (V) in which R2, R4 and R5 are as defined above, to reductive amination with an amine of formula R3NH2 in which R3 is an optionally substituted alkyl, and a reductant to form the compound of formula (VI), wherein the reaction is conducted in the presence of a supercritical fluid or a liquefied gas.

Abstract: The invention provides a method of synthesis of a substituted or unsubstituted carbinol compound, comprising the steps of subjecting the corresponding substituted or unsubstituted aromatic aldehyde to acyloin condensation mediated by yeast in the presence of either (a) a supereritical fluid or (b) a liquefied gas, and recovering the carbinol compound. Preferably the yeast is Saccharomyces cerevisiae. In a particularly preferred embodiment the aromatic aldehyde is benzaldehyde and the carbinol is phenylacetylcarbinol, according to the reaction (I): in which the benzaldehyde, the pyruvic acid, or both may optionally be substituted.

Abstract: Organic compounds, such as precursors for aryl ethylamines such as ephedrine, aryl propylamines such as fluoxetine and propionic acid derivatives such as ibuprofen, naproxen and fenoprofen, are subjected to a yeast mediated reduction conducted in the absence of a solvent. The yeast is moistened with water and contacted with the organic compound. The yeast may then be contacted with an organic solvent to dissolve the product of the reaction into the solvent, and a solid/liquid separation used to separate the product from the yeast.

Abstract: A method of erasable/rewritable optical data storage is provided in which a laser beam from a laser (10) operated in either a pulsed or continuous wave mode is focussed by an optical system (11-18) onto a photorefractive polymeric material (32) to cause two photon excitation of the material to record data which may subsequently be erased by illuminating the material with radiation having a wavelength in the ultraviolet or visible spectrum to erase the recorded data. New photorefractive polymeric materials having a relatively narrow absorption band for use in the method are also disclosed.

Abstract: This invention relates to yeast-mediated catalysis in organic solvents, and in particular the yeast-mediated condensation between pyruvate and a substituted aromatic aldehyde to yield the corresponding acyloin (hydroxy ketone) compound. The invention provides a method of synthesis of a substituted carbinol compound, comprising the step of subjecting the corresponding substituted aromatic aldehyde to acyloin condensation mediated by a yeast in an organic solvent under non-fermenting conditions. Preferably the yeast is Saccharomyces cerevisiae. In a preferred embodiment, the reaction is that between pyruvate and benzaldehyde to yield phenylacetylcarbinol, the precursor to ephedrine, to yield a product of high enantiomeric purity.

Abstract: An apparatus for producing dried and dehumidified cooling air for bulk stored grains and other produce from which moisture evaporates comprising a multiplicity of narrow elongate beds 2 of desiccant between which a multiplicity of heat exchange channels 3 providing heat exchange surfaces 4 in contact with each bed 2 of desiccant are provided. Air to be treated is passed through the beds 2 of desiccant while secondary air is forced through the heat exchange channels 3 to cool and remove the heat of sorption collected by the desiccant from the air being treated. desiccant can be regenerated by passing heated air through the beds.

Abstract: A linearized power amplifier is provided which comprises a non-linear radio frequency (RF) power amplifier, a linearization circuit such as a Cartesian Feedback circuit, an RF feedback circuit; an IF feedback circuit; or a feedforward circuit, and a dynamic bias modulation circuit for modulating an operating voltage of the amplifier. The dynamic bias modulation means includes an envelope determining circuit, signal processing circuits in which predetermined data or a simplified transfer function determined from measured characteristics of the amplifier is stored and used to produce power bias and/or base or gate bias signals, and driver circuits for modulating the power supply voltage and/or base or gate bias voltage of the RF amplifier in response to the bias signals. The dynamic bias modulation may be used with a BJT-based, and FET-based or any other type of RF power amplifier.