摘要:
An ultrasonic imaging apparatus and method of forming an image of an acoustic image of an object employing the aperture synthesis technique, in which at least one partial aperture for accommodating a predetermined number of successive transducers is established and applied to a transducer array to select the predetermined number of successive transducers accommodated in the partial aperture so that the selected transducers serve to transmit ultrasonic acoustic signals to an object and receive signals reflected from the object, and the at least one partial aperture is specifically moved along the arrayed transducers for similar signal transmission to and/or signal reception from the object, whereby the apparatus and the method do not suffer substantial noise caused during changeover between transmitting and receiving operation modes and/or enjoy and enlarged aperture for signal transmission or enlarged aperture for signal reception with a suppressed decrease of the frame rate.
摘要:
Cephalosporin compounds represented by the following formula (I) and pharmaceutically acceptable salts thereof have a broad bactericidal spectrum against various pathogenic bacteria including Psuedomonas aeruginosa and are useful as bactericidal remedies for pathogenic diseases of human and animals: ##STR1## wherein A represents an unsubstituted or substituted pyridylthio group of a formula (I-1); ##STR2## or an unsubstituted or substituted pyridiniumthio group of a formula (I-2): ##STR3## or an unsubstituted or substituted pyridinium group of a formula (I-3); ##STR4## or a 5- or 6-membered heterocyclicthio or bicycloheterocyclicthio group of a formula (I-4):--S--Het (I-4).
摘要:
New compounds, 6"-deoxydibekacin, 4", 6"-dideoxydibekacin, 1-N-(L-4-amino-2-hydroxybutyryl)-6"-deoxydibekacin and 1-N-(L-4-amino-2-hydroxybutyryl)-4",6"-dideoxydibekacin are now produced semi-synthetically from dibekacin, i.e. 3',4'-dideoxykanamycin B. These four new compounds are each useful as an antibacterial agent. Production of 6"-deoxydibekacin or 4",6"-dideoxydibekacin is made by removal of the 6"-hydroxyl group or by removal of the 4"- and 6"-hydroxyl groups from an amino-protected and hydroxyl-protected derivative of dibekacin. Production of 1-N-(L-4-amino-2-hydroxybutyryl)-6"-deoxydibekacin or -4",6"-dideoxydibekacin is made by acylating the 1-amino group of 6"-deoxydibekacin or 4",6"-dideoxydibekacin with the L-4-amino-2-hydroxybutyryl group, or alternatively by removal of the 6"-hydroxyl group or the 4"- and 6"-hydroxyl groups from a known compound, 1-N-(L-4-amino-2-hydroxybutyryl)-dibekacin.
摘要:
Four new antibiotics which are denominated istamycin A, istamycin B, istamycin A.sub.o and istamycin B.sub.o, and which are useful as antibacterial agents, are produced by fermentation of a new microorganism, Streptomyces tenjimariensis.
摘要:
1-N-(L-4-amino-2-hydroxybutyryl) derivatives of kanamycin C, 3'-deoxykanamycin C and 3',4'-dideoxykanamycin C have been prepared which possess high antibacterial activity against a wide variety of drug-resistant bacteria. These new derivatives are prepared by reacting L-4-amino-2-hydroxybutyric acid or a functional equivalent thereof with the 1-amino group of kanamycin C, 3'-deoxykanamycin C or 3',4'-dideoxykanamycin C.
摘要:
Kanamycin C, 3'-deoxykanamycin C and 3'4'-dideoxykanamycin C are obtained by a new process comprising treating the primary 6'-amino group of a tetra-N-protected derivative of kanamycin B, 3'-deoxykanamycin B and 3', 4'-dideoxykanamycin B with a nitrite to convert said amino group into hydroxyl group and then removing the protective groups. 3'-Deoxykanamycin C and 3', 4'-dideoxykanamycin C are new semi-synthetic aminoglycosidic antibiotics.
摘要:
An 1-N-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin of the formula ##STR1## wherein R is a hydrogen atom or .beta.-D-ribofuranosyl group of the formula ##STR2## and R.sub.3 is hydroxyl, amino-NH.sub.2 or acylamino group --NHR.sub.4 in which R.sub.4 is an acyl group, and n is a whole number of 1 to 4, may be produced by subjecting the corresponding O-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin of the formula ##STR3## or its hydroxyl-masked and maino-masked form, to the action of a basic medium to produce an acyl-migration product of the formula: ##STR4## and, optionally converting the amino-masking groups into hydrogen atoms and also the hydroxyl-masking group into hydroge atom in a known manner if said amino-masking groups and said hydroxyl-masking groups are present in the acyl-migration product. The 1-N-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin produced is characterized by its useful activity inhibitory to the growth of bacteria resistant to the parent substance neamine or ribostamycin.
摘要:
An 1-N-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin of the formula: ##STR1## wherein R is a hydrogen atom or .beta.-D-ribofuranosyl group of the formula ##STR2## and R.sub.3 is hydroxyl, amino-NH.sub.2 or acylamino group --NHR.sub.4 in which R.sub.4 is an acyl group, and n is a whole number of 1 to 4, may be produced by subjecting the corresponding O-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin of the formula ##STR3## or its hydroxyl-masked and amino-masked form, to the action of a basic medium to produce an acyl-migration product of the formula: ##STR4## and, optionally converting the amino-masking groups into hydrogen atoms and also the hydroxyl-masking group into hydrogen atom in a known manner if said amino-masking groups and said hydroxyl-masking groups are present in the acyl-migration product. The 1-N-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin produced is characterized by its useful activity inhibitory to the growth of bacteria resistant to the parent substance neamine or ribostamycin.
摘要:
This invention relates to a process for the preparation of coformycin, 3-(.beta.-D-ribofuranosyl)-6,7,8-trihydroimidazo[4,5-d][1,3]diazepin-8(R)-ol, through a synthetic route from a new derivative of 9-.beta.-D-ribofuranosyl-purine and other synthetic intermediates involved in the process and their preparation.
摘要:
An object is to provide a process for providing hydrogen or heavy hydrogens conveniently without the necessity of large-scale equipment and a process capable of performing hydrogenation (protiation, deuteration or tritiation) reaction conveniently without the use of an expensive reagent and a special catalyst. The production process includes a process for producing hydrogen or heavy hydrogens, containing subjecting water or heavy water to mechanochemical reaction in the presence of a catalyst metal, and a process for producing a hydrogenated (protiated, deuterated or tritiated) organic compound, containing subjecting an organic compound and water or heavy water to mechanochemical reaction in the presence of a catalyst metal.