Abstract: The present disclosure provides a pH and oxygen dual-sensitive magnetic resonance imaging contrast agent and a preparation method thereof, which is a dual-modal nanoparticle contrast agent with 19F signal and CEST dual signal (19F-CEST), a CEST contrast agent that is dual-sensitive to pH and oxygen. The preparation method comprises: mixing a variety of phospholipid surfactants and cholesterol well to obtain a blend of phospholipid surfactants, which is dissolved in chloroform or a mixed solvent of chloroform and methanol, evaporated to dryness with a rotary evaporator and dried overnight in a vacuum oven at 40° C. after adding rhodamine, finally, it is dispersed in water containing glycerin by mechanical dispersion or ultrasonic vibration to obtain a lipid modifier; mixing perfluorocarbon, the lipid modifier obtained in step (1), glycerin, and water and ultrasonically mixing well with a probe, and extruding with an extruder to prepare a perfluorocarbon nanoemulsion.

Abstract: A wireless communication method using wireless signals including a preamble, the method comprising: acquiring a first symbol of the preamble by searching a common waveform; progressively acquiring subsequent symbols of the preamble using information from previous symbols including the first symbol; and acquiring critical system configuration information embedded in the preamble using the first symbol and the subsequent symbols.

Abstract: An integrated call processing system, comprising: a wireless telephone including a keypad, a speaker, and a microphone to enable entry of call information and to enable phone transaction through one of a plurality of telephone networks; and a software telephone processor configured to receive and process the call information, wherein the processed call information is used to open phone transaction through a telephone network that incurs lowest price.