Abstract: An upconversion nanoparticle (UCN) coated with a layer of semiconductor material is disclosed. The UCN core acts as a nanotransducer to convert near infrared (NIR) to visible and/or ultraviolet (UV) light while the semiconductor shell serves as a photocatalyst. Upon excitation by NIR light, the UCN upconverts NIR light to UV and/or visible light of different wavelengths. Spectral overlap between the emitted UV and absorption wavelength of the coated TiO2 activates the TiO2 layer to generate cytotoxic reactive oxygen species (ROS), which can be used in photodynamic therapy for the treatment of cancer cells. Stability and uptake of the nanoparticles can be increased by altering the coating of the nanoparticle, such as by a polymer and a dispersion stabilizer.

Abstract: Disclosed are a method and a system for controlling invoking of a hardware instruction. The method comprises: receiving a hardware instruction; determining whether the received hardware instruction is a legal instruction; and when it is determined that the received hardware instruction is a legal instruction, sending the hardware instruction to a corresponding hardware device. In this application, the legality of the hardware instruction is checked before the hardware instruction is sent to the hardware device, and only a legal hardware instruction can be sent to the hardware device for execution, thereby avoiding sending an illegal operation to the hardware device for execution, and improving the security of the hardware device.