摘要:
A magnetic recording medium consisting of a nonmagnetic substrate and at least two magnetizable layers which are applied thereon and contain metal oxides as magnetic pigment is described, the pigment of the upper layer having a higher BET value than that in the lower layer. According to the invention, the upper layer has a thickness in the range of 3-5 .mu.m when dry and the lower layer a thickness in the range of 1.1-3 .mu.m when dry. Particularly advantageous results are obtained when the magnetic pigment of the upper layer is cobalt-doped .gamma.--Fe.sub.2 O.sub.3 and that of the lower layer is acicular CrO.sub.2. With the double-layer recording medium obtained according to the invention, in particular the output level at low frequencies is improved without the frequency curve showing the usual depression in the middle.
摘要:
Described are tape-type magnetic recording media (I) including a non-magnetic substrate (III), at least one film applied to the substrate and, in at least one of these films, an inorganic acicular pigment (II) suitable for use as a supporting pigment, the ratio of the mean length to the mean diameter of the pigment (II) being at least 3 and the mean modulus of elasticity of the films being not less than 15 GPa in the longitudinal direction of the tape-type recording medium (I).
摘要:
The immunogenicity of the influenza virus hemagglutinin (HA) molecule may be increased by substitutions of amino acids in the HA sequence. The substitution of specific HA residues, such as asparagine at position 223 of H5 HA, increase the sensitivity of the hemagglutinin inhibition (HI) assay by altering receptor specificity and/or antibody-antigen binding. HA molecules containing such substitutions will be useful in the development of diagnostic reference viruses and improved influenza vaccines.
摘要:
Vectors and methods for the production of influenza viruses suitable as recombinant influenza vaccines in cell culture are provided. Bi-directional expression vectors for use in a multi-plasmid influenza virus expression system are provided. Additionally, the invention provides methods of producing influenza viruses with enhanced ability to replicate in embryonated chicken eggs and/or cells (e.g., Vero and/or MDCK) and further provides influenza viruses with enhanced replication characteristics. A method of producing a cold adapted (ca) influenza virus that replicates efficiently at, e.g., 25° C. (and immunogenic compositions comprising the same) is also provided.
摘要:
Vectors and methods for the production of influenza viruses suitable as recombinant influenza vaccines in cell culture are provided. Bi-directional expression vectors for use in a multi-plasmid influenza virus expression system are provided. Additionally, the invention provides methods of producing influenza viruses with enhanced ability to replicate in embryonated chicken eggs and/or cells (e.g., Vero and/or MDCK) and further provides influenza viruses with enhanced replication characteristics. A method of producing a cold adapted (ca) influenza virus that replicates efficiently at, e.g., 25° C. (and immunogenic compositions comprising the same) is also provided.
摘要:
The present invention is based on the development of a dual promoter system (preferably a RNA pol I-pol II system) for the efficient intracellular synthesis of viral RNA. The resultant minimal plasmid-based system may be used to synthesize any RNA virus, preferably viruses with a negative single stranded RNA genome. The viral product of the system is produced when the plasmids of the system are introduced into a suitable host cell. One application of the system is production of attenuated, reassortant influenza viruses for use as antigens in vaccines. The reassortant viruses generated by cotransfection of plasmids may comprise genes encoding the surface glycoproteins hemagglutinin and neuraminidase from an influenza virus currently infecting the population and the internal genes from an attenuated influenza virus. An advantageous property of the present invention is its versatility; the system may be quickly and easily adapted to synthesize an attenuated version of any RNA virus. Attenuated or inactivated RNA viruses produced by the present invention may be administered to a patient in need of vaccination by any of several routes including intranasally or intramuscularly.
摘要:
The present invention is based on the development of a dual promoter system (preferably a RNA pol I-pol II system) for the efficient intracellular synthesis of viral RNA. The resultant minimal plasmid-based system may be used to synthesize any RNA virus, preferably viruses with a negative single stranded RNA genome. The viral product of the system is produced when the plasmids of the system are introduced into a suitable host cell. One application of the system is production of attenuated, reassortant influenza viruses for use as antigens in vaccines. The reassortant viruses generated by cotransfection of plasmids may comprise genes encoding the surface glycoproteins hemagglutinin and neuraminidase from an influenza virus currently infecting the population and the internal genes from an attenuated influenza virus. An advantageous property of the present invention is its versatility; the system may be quickly and easily adapted to synthesize an attenuated version of any RNA virus. Attenuated or inactivated RNA viruses produced by the present invention may be administered to a patient in need of vaccination by any of several routes including intranasally or intramuscularly.
摘要:
The present invention concerns a water filter designed to be inserted into a drinking water circuit. The water filter has a support designed to house removably one or more different filters each having a different filtering property and adapted to be mounted either independently of each other or associated in a particular combination so as to effect a filtration of the drinking water according to its composition.
摘要:
Compounds of the general formulaX--Y--O--(A--O--Y--O).sub.m --A--O--Y--X (1)wherein X is a radical of the general formula[R.sup.1 --G.sub.p --(O--CHR.sup.2 --CHR.sup.3 --).sub.n ].sub.2 N--(1a)in which R.sup.1 is a saturated aliphatic radical of from 6 to 30 carbon atoms or an unsaturated aliphatic radical having one or several ethylenic bonds and being of from 6 to 30 carbon atoms, G is phenylene or naphthylene, p is zero or 1, R.sup.2 and R.sup.3 are hydrogen or methyl, but are not both methyl, and n is a number from 0 to 25, Y is a radical of the formula ##STR1## in which R.sup.2 and R.sup.3 have the indicated meanings and q represents identical or different numbers from 0 to about 200, A is a radical of the general formula ##STR2## in which R.sup.4 and R.sup.5 are hydrogen or alkyl of from 1 to 3 carbon atoms, and m is a number from zero to 5, n and q not being both zero; and their use, in particular as dispersing agents, are disclosed.
摘要:
Quaternary ammonium compounds of the formula 1 ##STR1## in which R is C.sub.8 -C.sub.30 -alkyl or alkenyl; R.sub.1 is alkyl, 2-hydroxyalkyl or alkenyl each having from 8 to 30 carbon atoms; R.sub.2 is C.sub.1 -C.sub.4 -alkyl or benzyl; A is a group of the formulae ##STR2## B is A or C.sub.1 -C.sub.4 -alkylene, X and Y are hydrogen or methyl with the proviso that X and Y are not simultaneously methyl; m is 1 or 2; n is a number of from 1 to 20; and A.sup.(-) is an anion; a process for the preparation thereof, and their use as fabric softeners.