Abstract: The present invention is directed to a much safer and less expensive way of providing portable oxygen from a gas concentrator for patients who do not want to be tied to a stationary machine or restricted by present oxygen technology. In one preferred embodiment, the present invention splits off some of the excess capacity gas flow from a gas concentrator which is then stored via liquefaction. The stored gas can then be used as a portable supply. A portion of the oxygen gas flow generated by the oxygen concentrator is channeled to a condenser which receives and liquefies the oxygen gas using cryocooler. A storage dewar is used for storing the oxygen liquefied by the condenser. Liquid is then selectively transferred to a smaller portable dewar. A controller can be used for monitoring the parameters of liquefaction, including oxygen concentration, the amount of liquid oxygen in the dewar, and for controlling the parameters of liquid oxygen generation and transfer.

Abstract: Compounds of formula (I): ##STR1## wherein ##STR2## is a 5-membered heterocyclic group having a 6-.pi.electron system, the five ring atoms being either(a) one carbon atom and four atoms selected from carbon and nitrogen,(b) two carbon atoms, two nitrogen atoms and one atom selected from oxygen and sulphur, or(c) four carbon atoms and one atom selected from oxygen and sulphurand R.sup.1 is a substituent on a carbon or nitrogen of ##STR3## selected from C.sub.1-20 alkyl, C.sub.2-8 alkenyl aryl, aralkyl and heterocyclyl, each of which may optionally be substituted; hydrogen and C.sub.3-7 cycloalkyl,and, where appropriate, R.sup.2 is a substituent on a carbon or nitrogen of ##STR4## and when present is the same or different to R.sup.1 and is selected from C.sub.1-20 alkyl, C.sub.2-8 alkenyl, aryl, aralkyl and heterocyclyl each of which may optionally be substituted; hydrogen and C.sub.3-7 cycloalkyl, have antibacterial and antimycoplasmal activity.

Abstract: A compound of the formula (I) ##STR1## wherein R is a group ##STR2## R.sup.1 is hydrogen, phenyl, C.sub.1-20 alkyl, C.sub.2-8 alkenyl or C.sub.2-8 alkynyl each of which may optionally be substituted; or C.sub.3-7 cycloalkyl,X is a divalent group --Y--C.dbd.C--, andY is oxygen or sulphur,have antibacterial and/or antimycoplasmal activity.

Abstract: A refrigerant expansion device such as a Joule-Thomson expander has a surface with grooves or recesses which capture contaminants that condense from the refrigerant flow in the device, thereby avoiding blockage of the device by the condensed contaminants.

Abstract: A self-regulated Joule-Thomson expansion valve and cryostat useful in miniaturized cryogenic gas liquefaction systems include a substantially frustroconical valve member having a base portion supported at the end of first means such as an elongate shaft and a tapered valve seat generally complementary to the valve member and supported circumferentially adjacent a lengthwise portion of the valve member by second means such as a sheath slidably received upon the shaft. The valve member and valve seat taper down toward a free extremity of the valve member, whereby opposing peripheral surfaces of the valve member and valve seat define a converging annular passageway terminating at an annular expansion opening.

Abstract: Compounds of formula (II): ##STR1## wherein Y is --CH.dbd.CH--CH.sub.2 --CH-- or ##STR2## R.sup.1 is hydrogen or C.sub.1-4 alkyl, R.sup.2 is hydrogen or C.sub.1-6 alkyl,R.sup.3 is hydrogen, nitro or C.sub.1-6 alkyl and, when Y represents ##STR3## and R.sup.2 and R.sup.3 are hydrogen, the nitro radical is in the meta- or para- position on the benzene ring.are novel and have antimycoplasmal activity. They may be produced by esterification of the corresponding carboxylic acid salt.

Abstract: Compounds of formula (II): ##STR1## in which Y represents ##STR2## and R.sub.0 represents a C.sub.2-20 alkyl, C.sub.3-8 cycloalkyl, C.sub.4-20 alkenyl, arakyl, cycloalkylalkyl, heterocyclyl or heterocyclylalkyl group, which is substituted by a hydroxyiminohydrazono- or semicarbazono group, have activity against human and veterinary bacteria and mycoplasma. They may be produced by conventional methods and are used in conventional formulations.