Abstract: Provided is a T1 contrast agent for magnetic resonance imaging. The T1 contrast agent includes fine iron oxide nanoparticle cores and micelles encapsulating the core particles. The micelles include a nonionic surfactant consisting of a hydrophilic moiety containing at least two chains and a hydrophobic moiety containing at least one C10-C30 hydrocarbon chain. The T1 contrast agent of the present invention is a novel one based on fine iron oxide nanoparticles that can replace conventional gadolinium-based T1 contrast agents. The T1 contrast agent based on fine iron oxide nanoparticles according to the present invention is harmless to humans, is rapidly distributed in the blood, and has a uniform size, ensuring its uniform contrast effect. In addition, the T1 contrast agent of the present invention enables image observation for at least 1 hour to up to 2 hours and is excreted through the kidneys and liver.

Abstract: Provided is a capacitive micromachined ultrasonic transducer (CMUT) including a substrate, a top electrode provided on the substrate to be spaced apart from the substrate, a supporter made of an insulating material and coupled between the substrate and an edge of the top electrode to support and fix the edge of the top electrode and to define a gap between the substrate and the edge of the top electrode, and a plurality of nanoposts having both ends coupled and fixed to the substrate and the top electrode in the gap, and being compressible and stretchable in a longitudinal direction to at least vertically move the top electrode when power is applied to the top electrode.