Abstract: Composite particles, each of which is obtained by forming, on the surface of a gadolinium oxide-containing particle, a cover film that contains a polymer obtained by polymerizing a monomer component containing a monomer having an ethylenically unsaturated bond; a macrophage imaging agent which contains the composite particles; and a method for producing composite particles, wherein a monomer component containing a monomer having an ethylenically unsaturated bond and gadolinium oxide-containing particles are mixed with each other, and after emulsifying the thus-obtained monomer component-containing mixture in water in the presence of a surfactant and a polymerization initiator in water, the monomer component is polymerized, thereby forming cover films on the surfaces of the gadolinium oxide-containing particles.

Abstract: To provide a polymer having a high ratio of the amount thereof present in a tumor to the amount thereof present in blood (hereinafter, sometimes abbreviated as a tumor/blood ratio). The polymer has phosphorylcholine (derivative) as a side chain and has a dye (near-infrared dye) having absorption in the near-infrared wavelength region bound to the polymer.

Abstract: As a substance used as a contrast agent for a method of nuclear magnetic resonance analysis or a method of magnetic resonance imaging, a substance with high selectivity and high sensitivity was demanded. According to the present invention, when a polymer having, in a side chain thereof, a sequence of a 1H—13C—15N, 1H—15N—13C or 1H—13C—13C bond, that is, a structure labeled with stable isotopes of 13C and 15N, is used, the abundance of such a sequence in one molecule can be increased, and hence, high selectivity and higher sensitivity can be attained when used as a contrast agent.

Abstract: To provide a polymer having a high ratio of the amount thereof present in a tumor to the amount thereof present in blood (hereinafter, sometimes abbreviated as a tumor/blood ratio). The polymer has phosphorylcholine (derivative) as a side chain and has a dye (near-infrared dye) having absorption in the near-infrared wavelength region bound to the polymer.

Abstract: A core of a cyclic structure represented by (—N—(CH2)n—)k is bonded to a dendrimer-type side chain with a specific branched structure at all nitrogen atoms in the core to produce a compound with a specific structure for producing a metal complex that exhibits a T1-reducing effect, and the resulting compound is coordinated to a metal ion that has a T1-reducing effect to obtain a metal complex that exhibits an excellent T1-reducing effect which is useful as an effective component of an MRI contrast agent and an MRI contrast agent using the same.

Abstract: As a substance used as a contrast agent for a method of nuclear magnetic resonance analysis or a method of magnetic resonance imaging, a substance with high selectivity and high sensitivity was demanded. According to the present invention, when a polymer having, in a side chain thereof, a sequence of a 1H—13C—15N, 1H—15N—13C or 1H—13C—13C bond, that is, a structure labeled with stable isotopes of 13C and 15N, is used, the abundance of such a sequence in one molecule can be increased, and hence, high selectivity and higher sensitivity can be attained when used as a contrast agent.

Abstract: A core of a cyclic structure represented by (—N—(CH2)n—)k is bonded to a dendrimer-type side chain with a specific branched structure at all nitrogen atoms in the core to produce a compound with a specific structure for producing a metal complex that exhibits a T1-reducing effect, and the resulting compound is coordinated to a metal ion that has a T1-reducing effect to obtain a metal complex that exhibits an excellent T1-reducing effect which is useful as an effective component of an MRI contrast agent and an MRI contrast agent using the same.

Abstract: A core of a cyclic structure represented by (—N—(CH2)n—)k is bonded to a dendrimer-type side chain with a specific branched structure at all nitrogen atoms in the core to produce a compound with a specific structure for producing a metal complex that exhibits a T1-reducing effect, and the resulting compound is coordinated to a metal ion that has a T1-reducing effect to obtain a metal complex that exhibits an excellent T1-reducing effect which is useful as an effective component of an MRI contrast agent and an MRI contrast agent using the same.

Abstract: A spark plug comprising: a cylindrical metal shell; a cylindrical insulator provided in an inner hole of said metal shell; a center electrode provided in a leading end side inner hole of said insulator; and a ground electrode having one end bonded to a leading end side of said metal shell and having another end face forming a spark discharge gap with said center electrode, wherein said ground electrode comprises an electrode material containing from 0.5 to 1.5 wt. % of Si, from 0.5 to 1.5 wt. % of Al, from 0.02 to 1.0 wt. % of at least one of Ti, V, Zr, Nb and Hf, from 0.03 to 0.09 wt. % of C and 95.5 wt. % or more of Ni, and having a specific resistance at 20° C. of 25 tincm or less.

Abstract: A core of a cyclic structure represented by (—N—(CH2)n—)k is bonded to a dendrimer-type side chain with a specific branched structure at all nitrogen atoms in the core to produce a compound with a specific structure for producing a metal complex that exhibits a T1-reducing effect, and the resulting compound is coordinated to a metal ion that has a T1-reducing effect to obtain a metal complex that exhibits an excellent T1-reducing effect which is useful as an effective component of an MRI contrast agent and an MRI contrast agent using the same.

Abstract: A spark plug comprising: a cylindrical metal shell; a cylindrical insulator provided in an inner hole of said metal shell; a center electrode provided in a leading end side inner hole of said insulator; and a ground electrode having one end bonded to a leading end side of said metal shell and having another end face forming a spark discharge gap with said center electrode, wherein said ground electrode comprises an electrode material containing from 0.5 to 1.5 wt. % of Si, from 0.5 to 1.5 wt. % of Al, from 0.02 to 1.0 wt. % of at least one of Ti, V, Zr, Nb and Hf, from 0.03 to 0.09 wt. % of C and 95.5 wt. % or more of Ni, and having a specific resistance at 20° C. of 25 tincm or less.

Abstract: A spark plug comprising: a cylindrical metal shell; a cylindrical insulator provided in an inner hole of said metal shell; a center electrode provided in a leading end side inner hole of said insulator; and a ground electrode having one end bonded to a leading end side of said metal shell and having another end face forming a spark discharge gap with said center electrode, wherein said ground electrode comprises an electrode material containing from 0.5 to 1.5 wt. % of Si, from 0.5 to 1.5 wt. % of Al, from 0.02 to 1.0 wt. % of at least one of Ti, V, Zr, Nb and Hf, from 0.03 to 0.09 wt. % of C and 95.5 wt. % or more of Ni, and having a specific resistance at 20° C. of 25 ??cm or less.

Abstract: A spark plug comprising: a cylindrical metal shell; a cylindrical insulator provided in an inner hole of said metal shell; a center electrode provided in a leading end side inner hole of said insulator; and a ground electrode having one end bonded to a leading end side of said metal shell and having another end face forming a spark discharge gap with said center electrode, wherein said ground electrode comprises an electrode material containing from 0.5 to 1.5 wt. % of Si, from 0.5 to 1.5 wt. % of Al, from 0.02 to 1.0 wt. % of at least one of Ti, V, Zr, Nb and Hf, from 0.03 to 0.09 wt. % of C and 95.5 wt. % or more of Ni, and having a specific resistance at 20° C. of 25 ??cm or less.