Abstract: A submicron structure having a silica body defining a plurality of pores is described. The submicron body may be spherical or non-spherical, and may include a cationic polymer or co-polymer on the surface of said silica body. The submicron structure may further include an oligonucleotide and be used to deliver the oligonucleotide to a cell. The submicron structure may further include a therapeutic agent and be used to deliver the therapeutic agent to a cell. An oligonucleotide and therapeutic agent may be used together. For example, when the oligonucleotide is an siRNA, the composition may be used to decrease cellular resistance to the therapeutic agent by decreasing translation of a resistance gene.

Abstract: A body coil assembly for a magnetic resonance apparatus has a first coil and a second coil for generating a radio-frequency field in space, and a power control apparatus connected to the first coil and the second coil for controlling the transmitting power of the first coil and the second coil. In a method for generating a radio-frequency field using such a body coil assembly, the transmitting powers of the first coil and the second coil are controlled, to provide unequal transmitting powers to the first coil and the second coil when needed to generate a required radio-frequency field distribution, so as to form a stronger field strength at a certain position, thus improving the signal to noise ratio at that position during the receiving process.