Abstract: Provided are a system and a method for determining the temperature of a body by imaging a hydrogen proton-rich material positioned within the body using nuclear magnetic resonance imaging. A method to increase changes in the MRI signal strength as a function of temperature, thus improving temperature sensitivity, is also provided. The system and method employ polymers having mechanical stability and magnetic image brightness at low temperatures of between 0° C. and ?65° C. or high temperatures of between +37° C. and +80° C.

Abstract: This disclosure describes systems, methods, and apparatus for beam steering of a circuit-board based phase array of antennas. An RF signal can be distributed via coplanar waveguide conductors to a plurality of microstrip line conductors arranged in a dual-frequency liquid crystal medium. A low frequency control signal can be injected into each of the microstrip line conductors, preferably while each line is still in a coplanar waveguide form. This low frequency control signal modified a local permittivity of the dual-frequency liquid crystal in the vicinity of a corresponding one of the microstrip lines, thereby imparting a controlled phase delay to the RF signal on each microstrip line. This in turn allows a phase-controlled RF signal to be received at each antenna in the array.

Abstract: In one example embodiment, a magnetic shutter antenna is provided including at least one dipole magnet comprising a first end and a second end and at least one shutter of magnetically soft material comprising at least one opening and disposed proximate the first end of the at least one dipole magnet. The antenna further includes a motor coupled to the shutter and configured to move the shutter between a first closed position comprising the magnetic material being positioned adjacent the first end of the dipole magnet and a second open configuration comprising the opening being positioned adjacent the first end of the dipole magnet. Alternation between the first closed position and the second open position modulates a magnetic flux emitting from the first end of the at least one dipole magnet.

Abstract: In one example embodiment, a magnetic shutter antenna is provided including at least one dipole magnet comprising a first end and a second end and at least one shutter of magnetically soft material comprising at least one opening and disposed proximate the first end of the at least one dipole magnet. The antenna further includes a motor coupled to the shutter and configured to move the shutter between a first closed position comprising the magnetic material being positioned adjacent the first end of the dipole magnet and a second open configuration comprising the opening being positioned adjacent the first end of the dipole magnet. Alternation between the first closed position and the second open position modulates a magnetic flux emitting from the first end of the at least one dipole magnet.

Abstract: The present invention provides doped ferrite particles or metallic compounds or alloys, which can be used as temperature-dependent sensors in magnetic resonance imaging. In certain embodiments, these particles have a Curie temperature near that of living animals, allowing one to obtain spatial maps of temperature useful for thermal medical procedures or diagnostics. In other embodiments, one can use the methods and materials of the present invention to obtain spatial temperature maps of materials and non-living objects, such as tires or polymers. This method allows for a non-invasive determination of internal body temperature with a resolution of about 1° C.

Abstract: Systems and methods are described for producing liquid crystal devices microwave that use metal alignment layers. The liquid crystal microwave devices include a liquid crystal layer sandwiched between metal layers, which are further sandwiched between substrate layers. At least one of the metal layers is rubbed to form micro-grooves that tend to align the liquid crystal molecules adjacent to those layers without using additional rubbed polymeric layers for the alignment. The thickness of the metal layers can be selected to yield a desired electromagnetic effect, such as constraint of propagation of microwave radiation.

Abstract: A layered microstrip device is described, in which at least two layers of different high internal field/high resonance frequency materials serve as the active elements of the device. The device is designed to filter ranges of high frequency electromagnetic waves, and is on a small scale to enable integration with high frequency electronics. The ranges of frequencies to be filtered depend on the active elements and device geometry selected for the device. The tradeoffs regarding active material and device geometry choices are explored in detail. The ranges of frequencies to be filtered can be modified in real time with the application of an external magnetic field. A variety of the devices were fabricated, and a number of experimental and theoretical studies were carried out.

Abstract: The invention is based in part on the discovery that the expression of co-stimulatory molecules such as B7.1, B7.2 or CD40 can be regulated using reactive oxygen species (ROS). Thus, the invention relates to methods of regulating co-stimulatory molecules by modulating reactive oxygen. The methods and products are useful, for example, for modulating antigen specific immune responses, treating disease, and for modulating cell growth.