Abstract: A wireless communication system and a wireless communication device capable of performing communication by each transmission signal without mutual interference, when a plurality of transmission signals of different communication systems or the same communication systems exist within the same frequency band. The system includes a first wireless communication device, a second wireless communication device, a third wireless communication device, and a fixed band-pass filter and a variable band-pass filter in the third wireless communication device. The first wireless communication signal includes control information indicating a variable pass band in the variable band-pass filter, and the control information is given to the variable band-pass filter, thereby allowing the first wireless communication signal to be selectively passed through the variable band-pass filter, while removing the second wireless communication signal.

Abstract: A wireless communication system and a wireless communication device capable of performing communication by each transmission signal without mutual interference, when a plurality of transmission signals of different communication systems or the same communication systems exist within the same frequency band. The system includes a first wireless communication device, a second wireless communication device, a third wireless communication device, and a fixed band-pass filter and a variable band-pass filter in the third wireless communication device. The first wireless communication signal includes control information indicating a variable pass band in the variable band-pass filter, and the control information is given to the variable band-pass filter, thereby allowing the first wireless communication signal to be selectively passed through the variable band-pass filter, while removing the second wireless communication signal.

Abstract: Thiazolo[5,4-f]quinoline-8-carboxylic acid derivatives having either the general formula (I): ##STR1## wherein R.sub.1 is a lower alkyl group, a lower alkenyl group or a benzyl group; or the general formula (III-a): ##STR2## WHEREIN R.sub.3 is a lower alkyl group and X is a halogen atom; and methods for the preparation thereof. The compounds of the general formula (I) are useful as antibacterial agents against gram-negative and gram-positive bacteria. The compounds of the general formula (III-a) are useful as antifungal agents against eumycetes and also as an intermediate in a peparation of the compounds of the general formula (I).

Abstract: Novel antibacterial agents consisting of a 2,3,5,8-tetrahydro-5-alkoxy-8-oxofuro(2,3-g)quinoline-7-carboxylic acid of the formula: ##STR1## wherein R is C.sub.1 -C.sub.4 alkyl, a process for producing the derivatives and pharmaceutical compositions containing the same. The above-identified derivatives possess antibacterial activity against gram-negative bacteria at test concentration levels of about 0.0001 to 1.0 mg/cc.

Abstract: A process for producing a compound of the formula: ##SPC1##Wherein Z is CH or N; R is a lower alkyl group, a lower alkenyl group, a cycloalkyl group or a hydroxyalkyl group; R.sub.1 is a hydrogen atom or lower alkyl group; when Z is N, R.sub.2, R.sub.3 and R.sub.4 are a hydrogen atom, a halogen atom a lower alkyl group, a lower alkoxyl group, a lower hydroxyalkyl group, a lower acyloxyalkyl group, trihalogenoalkyl group, a carboxyl group, a cyano group, or an aralkyl group; when Z is CH, R.sub.2, R.sub.3 and R.sub.4 are a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxyl group, a trihalogenoalkyl group, a cyano group, a nitro group, an alkylmercapto group, a lower alkylenedioxy group, or a lower alkylene bridge attached to the quinoline nucleus, which comprises heating a compound of the formula ##SPC2##Wherein R, R.sub.1, R.sub.2, R.sub.3, R.sub.4 and Z are as defined above, followed, if desired, by hydrolyzing the product obtained, is disclosed.

Abstract: Thiazolo[5,4-f]quinoline-8-carboxylic acid derivatives having either the general formula (I): ##SPC1##wherein R.sub.1 is a lower alkyl group, a lower alkenyl group or a benzyl group; or the general formula (III-a): ##SPC2##Wherein R.sub.3 is a lower alkyl group and X is a halogen atom; and methods for the preparation thereof. The compounds of the general formula (I) are useful as antibacterial agents against gram-negative and gram-positive bacteria. The compounds of the general formula (III-a) are useful as antifungal agents against eumycetes and also as an intermediate in a preparation of the compounds of the general formula (I).