Abstract: The present invention provides compositions and methods of use of nanoparticle-based probes for in vivo imaging and therapy. The probes can be used to track diseased target cells by non-invasive imaging in the near-infrared range. Additionally, the probes can induce cell death of the target cells via photodynamic treatment.

Abstract: The present invention provides compositions and methods of use of nanoparticle-based probes for in vivo imaging and therapy. The probes can be used to track diseased target cells by non-invasive imaging in the near-infrared range. Additionally, the probes can induce cell death of the target cells via photodynamic treatment.

Abstract: The present invention provides compositions and methods of use of nanoparticle-based probes for in vivo imaging and therapy. The probes can be used to track diseased target cells by non-invasive imaging in the near-infrared range. Additionally, the probes can induce cell death of the target cells via photodynamic treatment.

Abstract: An apparatus and method for providing proper bias current and load resistance for a telephone microphone regardless of the type of microphone used. Microphone bias voltage, if any exists at the microphone, is compared to a reference voltage selected to define a distinction between various types of microphones. If the bias voltage exceeds the reference voltage, an impedance matching the correlated type of microphone is interdicted on both sides of the microphone. If reference voltage exceeds bias voltage, a different impedance path is presented to match it with the type of correlated microphone. Therefore, the invention automatically provides proper bias current and load resistance for the microphone.

Abstract: An apparatus and method for determining the presence and polarity of DC bias voltage at a telephone microphone. A circuit can be added in parallel between any hand or headset and a telephone base unit. The circuit converts the DC bias voltage, if any, across the microphone into a pulsed signal. Each pulse charges a capacitor. The output of the capacitor is passed through a resistor transformer network, and sampled. In between each pulse, the capacitor is discharged and the resulting signal is passed through the transistor/resistor network and sampled. By determining the averages of the charging and discharging signals, and sampling them to convert it into digital information, a digital signal processor can derive whether any bias voltage is present across the microphone, and, if so, its polarity. The circuit can be electrically isolated from the microphone and telephone.

Abstract: A numerically controlled oscillator employing a 1/2 least significant bit (LSB) phase offset and a negative 1/2 LSB amplitude offset of data samples in memory devices for improved quadrant replication. Also, fine values are added or subtracted to the coarse values further reducing the amount of data needed in memory and further reducing the size of the phase-to-amplitude converter.

Abstract: A phase locked loop including a programmable frequency divider with a variable modulus divider (VMD) having two modes of operation, n and n+1, a programmable counter for counting the number of times the VMD divides the input signal and a comparator for comparing the count in the counter to a predetermined number and switching the VMD from the first mode to the second mode when the instant count and predetermined number are equal. The programmable counter provides an output pulse each time the total count equals a selected number. The VMD is a GaAs semiconductor device.