Abstract: Provided methods for producing an afucosylated antibody, the afucosylated antibodies and composition thereof, and cells for producing antibodies. The method comprises introducing a nucleic acid encoding at least one modified enzyme of the fucosylation pathway to a host cell to produce the afucosylated antibody in the host cell. The afucosylated antibodies produced by the disclosed methods have increased ADCC activity and would not suppress their CDC and safety.

Abstract: Provided are methods for producing afucosylated antibodies, the afucosylated antibodies and composition thereof and cells for producing antibodies. The method comprises introducing a nucleic acid encoding at least one modified enzyme of the fucosylation pathway to a host cell to produce the afucosylated antibody in the host cell. The afucosylated antibodies produced by the disclosed methods have increased ADCC activity and would not suppress their CDC and safety.

Abstract: According to one aspect, embodiments herein provide a DC-AC inverter comprising a DC-DC converter portion, an inverter portion, a clamp circuit, a controller configured to operate, in a first mode, the DC-DC converter portion to convert input DC power into DC power having a desired voltage level at a first polarity and the inverter portion to provide output power having the desired voltage level at the first polarity to the output, operate, in a second mode, the DC-DC converter portion to convert the input DC power into DC power having a desired voltage level at a second polarity and the inverter portion to provide output power having the desired voltage level at the second polarity to the output; and operate, in a third mode, the clamp circuit to drive voltage at the output to zero and to store energy discharged by a load capacitance in an energy storage device.

Abstract: According to one aspect, embodiments of the invention provide an AC-DC rectifier comprising an input configured to receive input AC power from an AC power source having an input AC voltage waveform, an output configured to provide output DC power to a load, an active power filter coupled to the input, an inverter coupled to the input and configured to convert the input AC voltage waveform into an output AC voltage waveform at a desired magnitude, a rectifier portion coupled between the inverter and the output and configured to convert the output AC voltage waveform into the output DC power, and a controller coupled to the active power filter and the inverter and configured to operate the active power filter to provide Power Factor Correction (PFC) at the input and to operate the inverter to provide the output AC voltage waveform at the desired magnitude to the rectifier portion.

Abstract: According to one aspect, embodiments herein provide a DC-DC converter system comprising a plurality of switches configured to receive input DC power having a DC voltage level from a DC voltage source, a first capacitor coupled to the plurality of switches, a second capacitor coupled to the plurality of switches, and a controller configured to operate the plurality of switches such that in a first mode, voltage across the first capacitor is at a level equal to substantially half of the DC voltage level of the input DC power, in a second mode, voltage across the second capacitor is at a level equal to substantially half of the DC voltage level of the input DC power, and an output voltage level of DC power at an output is stepped down, by a voltage step down ratio, in relation to the DC voltage level of the input DC power.

Abstract: According to one aspect, embodiments herein provide an AC-DC converter comprising a rectifier, a capacitor, a DC bus coupled to the capacitor, a plurality of first switches coupled to the DC bus, a plurality of second switches coupled between the rectifier and the first switches, a transformer having a primary winding and a secondary winding, the primary winding coupled to the plurality of first switches, the plurality of second switches, and the rectifier, and the secondary winding coupled to an output, and a controller configured, in response to a determination that the input AC power is acceptable, to operate the plurality of second switches and the plurality of first switches such that output DC voltage is maintained at a desired output DC voltage level, and operate the plurality of first switches such that a DC bus voltage on the DC bus is maintained at a desired DC bus voltage level.

Abstract: According to one aspect, embodiments herein provide a DC-AC inverter comprising a DC-DC converter portion, an inverter portion, a clamp circuit, a controller configured to operate, in a first mode, the DC-DC converter portion to convert input DC power into DC power having a desired voltage level at a first polarity and the inverter portion to provide output power having the desired voltage level at the first polarity to the output, operate, in a second mode, the DC-DC converter portion to convert the input DC power into DC power having a desired voltage level at a second polarity and the inverter portion to provide output power having the desired voltage level at the second polarity to the output; and operate, in a third mode, the clamp circuit to drive voltage at the output to zero and to store energy discharged by a load capacitance in an energy storage device.

Abstract: According to one aspect, embodiments of the invention provide an AC-DC rectifier comprising an input configured to receive input AC power from an AC power source having an input AC voltage waveform, an output configured to provide output DC power to a load, an active power filter coupled to the input, an inverter coupled to the input and configured to convert the input AC voltage waveform into an output AC voltage waveform at a desired magnitude, a rectifier portion coupled between the inverter and the output and configured to convert the output AC voltage waveform into the output DC power, and a controller coupled to the active power filter and the inverter and configured to operate the active power filter to provide Power Factor Correction (PFC) at the input and to operate the inverter to provide the output AC voltage waveform at the desired magnitude to the rectifier portion.

Abstract: An active backup power supply with PFC and power output regulation comprises a power factor correction (PFC) circuit, a backup battery, an inverter and a control circuit. The said PFC circuit outputs current drawn as low THD (total harmonic distortion) and non-pulsating current from municipal power source. The said inverter connects to the PFC circuit and the backup battery at one end and outputs a precisely regulated power source at the other end. The said controller is to control the voltage relation between the PFC circuit and the inverter, so the PFC circuit is controlled in voltage boost mode to draw non-pulsating current from municipal power. With the above-mentioned components, the present invention enables an output power with PFC and voltage regulation to the load device (FIG. 3).

Abstract: An active backup power supply with PFC and power output regulation comprises a power factor correction (PFC) circuit, a backup battery, an inverter and a control circuit. The said PFC circuit outputs current drawn as low THD (total harmonic distortion) and non-pulsating current from municipal power source. The said inverter connects to the PFC circuit and the backup battery at one end and outputs a precisely regulated power source at the other end. The said controller is to control the voltage relation between the PFC circuit and the inverter, so the PFC circuit is controlled in voltage boost mode to draw non-pulsating current from municipal power. With the above-mentioned components, the present invention enables an output power with PFC and voltage regulation to the load device (FIG. 3).