Abstract: A self-biased, closed loop, low current free running oscillator clock generator method and apparatus are provided with a current mode comparator connected to a trimming resistor and configured to compare an internally generated voltage reference VREF signal to a voltage feedback signal VFB, where the current mode comparator comprises a common gate amplifier connected to a current mirror circuit in a negative self-biased closed loop to generate a control current signal for controlling a current controlled oscillator to produce an output clock signal having a clock frequency based on the control current signal, where a frequency-to-voltage converter is connected in a feedback path to receive the output clock signal and is configured to produce the voltage feedback signal VFB for input to the current mode comparator, wherein the clock frequency of the output clock signal is tuned to a nominal locked output frequency fOUT by the trimming resistor.

Abstract: Tissue and cellular samples can be electrically dissociated into single cells and/or smaller groups of cells. The tissue samples can be housed in a device (which may also include a fluid) with one or more electrodes residing within the device. The device can be used to process one or more tissue samples. An electric field can be established through the device and the tissue samples can be dissociated into single cells and/or smaller groups of cells under the electric field.

Abstract: The invention provides a lipid bilayer mimicking the lipid composition of the placenta. The lipid composition provides an in vitro placenta model using the lipid composition of the placental cell membrane.

Abstract: A device for assembling aggregations of adherent cells includes a gripper moveable within an assembly vessel that fixes aggregations of adherent cells at a membrane of the gripper and, by movement of the gripper, assembles aggregations of cells on a separate membrane within the vessel, thereby creating a three-dimensional assembly of aggregations of cells that fuse and can be employed in surgical procedures as a unitary tissue of adherent cells. The aggregations of cells, as assembled, can assume three-dimensional configurations distinct from any one of the component aggregations of cells assembled.

Abstract: A method is disclosed of dispersing conductive particles within a polymer. The method includes the steps of providing dry polymer particles, adding conductive material to the dry polymer particles to coat the dry polymer particles, and hot melt pressing the coated polymer particles.

Abstract: Drugs are screened for affects on inhibiting efflux pumps and blocking gap junction communication in tumors by culturing cells to thereby form self-assembled spheroids and incubating the spheroids. Uptake of a substrate of the efflux pump and distribution of a substrate for the efflux pump within the spheroids is imaged to thereby select drugs that inhibit the efflux pump or do not block gap junction communication. Selected drugs can then be employed to treat a tumor.

Abstract: A method and system is provided for automatically preparing transmission electron microscopy (TEM) samples for examination by depositing extremely small samples onto a grid without need for a blotting step. A sample liquid droplet is formed at the end of a capillary, wherein a portion of the liquid is transferred to the TEM sample grid by contact. The excess volume in the liquid droplet is then retracted by an adjacent capillary. After a predetermined time interval, the retraction capillary is moved toward the drop of the sample to remove the excess volume. As compared to a conventional machine, where the blotting procedure can deform the structure of the molecule of interest, the present invention utilizes a very low shear rate for removal of the excess sample fluid.

Abstract: A method and system is provided for automatically preparing transmission electron microscopy (TEM) samples for examination by depositing extremely small samples onto a grid without need for a blotting step. A sample liquid droplet is formed at the end of a capillary, wherein a portion of the liquid is transferred to the TEM sample grid by contact. The excess volume in the liquid droplet is then retracted by an adjacent capillary. After a predetermined time interval, the retraction capillary is moved toward the drop of the sample to remove the excess volume. As compared to a conventional machine, where the blotting procedure can deform the structure of the molecule of interest, the present invention utilizes a very low shear rate for removal of the excess sample fluid.

Abstract: This invention comprises a multiplex-capable oligonucleotide which is capable of hybridizing to at least one of the C. difficile tcdB, tcdC, or cdtB genes, wherein, wherein said primer consists of a sequence selected from the group consisting of SEQ ID NOS: 1 through 9, or a sequence that exhibits no more than one substitution of a base to a sequence selected from the group consisting of SEQ ID NOS: 1 through 9 and method for polymerase chain reaction (PCR) determining of the presence of a toxigenic strain of C. difficile in a biological sample utilizing said probes.

Abstract: A device for assembling aggregations of adherent cells includes a gripper moveable within an assembly vessel that fixes aggregations of adherent cells at a membrane of the gripper and, by movement of the gripper, assembles aggregations of cells on a separate membrane within the vessel, thereby creating a three-dimensional assembly of aggregations of cells that fuse and can be employed in surgical procedures as a unitary tissue of adherent cells. The aggregations of cells, as assembled, can assume three-dimensional configurations distinct from any one of the component aggregations of cells assembled.

Abstract: Disclosed herein is a diffusion-limiting reactor having a first element and a closure element, said reactor having at least two interconnected reservoirs said interconnection being by non-impinging microchannel, and at least one said reservoir and said microchannel being magnetic accessible. Further disclosed is a method of sample separation.

Abstract: An assay for detection of short sequences of RNA in a synthetic or clinically isolated sample is presented herein. Particular reference is made to detecting RNA based pathogens, such as H5 influenza.

Abstract: This invention comprises a multiplex-capable oligonucleotide which is capable of hybridizing to at least one of the C. difficile tcdB, tcdC, or cdtB genes, wherein, wherein said primer consists of a sequence selected from the group consisting of SEQ ID NOS: 1 through 9, or a sequence that exhibits no more than one substitution of a base to a sequence selected from the group consisting of SEQ ID NOS: 1 through 9 and method for polymerase chain reaction (PCR) determining of the presence of a toxigenic strain of C. difficile in a biological sample utilizing said probes.

Abstract: A method and system is provided for automatically preparing transmission electron microscopy (TEM) samples for examination by depositing extremely small samples onto a grid without need for a blotting step. A sample liquid droplet is formed at the end of a capillary, wherein a portion of the liquid is transferred to the TEM sample grid by contact. The excess volume in the liquid droplet is then retracted by an adjacent capillary. After a predetermined time interval, the retraction capillary is moved toward the drop of the sample to remove the excess volume. As compared to a conventional machine, where the blotting procedure can deform the structure of the molecule of interest, the present invention utilizes a very low shear rate for removal of the excess sample fluid.

Abstract: A method and system is provided for automatically preparing transmission electron microscopy (TEM) samples for examination by depositing extremely small samples onto a grid without need for a blotting step. A sample liquid droplet is formed at the end of a capillary, wherein a portion of the liquid is transferred to the TEM sample grid by contact. The excess volume in the liquid droplet is then retracted by an adjacent capillary. After a predetermined time interval, the retraction capillary is moved toward the drop of the sample to remove the excess volume. As compared to a conventional machine, where the blotting procedure can deform the structure of the molecule of interest, the present invention utilizes a very low shear rate for removal of the excess sample fluid.

Abstract: An apparatus includes a pump; a gas pressure sensor; a microfluidic chip defining a microfluidic conduit; and a gas conduit providing fluid communication between the pump, the gas sensor and the microfluidic conduit; and a controller coupled to the pump and the gas pressure sensor, whereby the controller controls the pump, thereby controlling the gas pressure at the microfluidic conduit. An apparatus includes a microfluidic chip defining a microfluidic conduit extending from a microfluidic source electrode to a microfluidic ground electrode; a first resistor coupled to the microfluidic source electrode; a first and a second voltage divider, the first divider coupling a first power ground to a side of the first resistor opposite the microfluidic chip, the second divider coupling a second power ground to the lead between the first resistor and the microfluidic source electrode, and a first voltage sensor; and a second voltage sensor. Also included are methods of operating the apparatus.

Abstract: An apparatus includes a pump; a gas pressure sensor; a microfluidic chip defining a microfluidic conduit; and a gas conduit providing fluid communication between the pump, the gas sensor and the microfluidic conduit; and a controller coupled to the pump and the gas pressure sensor, whereby the controller controls the pump, thereby controlling the gas pressure at the microfluidic conduit. An apparatus includes a microfluidic chip defining a microfluidic conduit extending from a microfluidic source electrode to a microfluidic ground electrode; a first resistor coupled to the microfluidic source electrode; a first and a second voltage divider, the first divider coupling a first power ground to a side of the first resistor opposite the microfluidic chip, the second divider coupling a second power ground to the lead between the first resistor and the microfluidic source electrode, and a first voltage sensor; and a second voltage sensor. Also included are methods of operating the apparatus.

Abstract: Microfluidic devices, systems, and methods measure viscosity, flow times, and/or pressures, other flow characteristics within the channels, and the measured flow characteristics can be used to generate a desired flow. Multi-reservoir pressure modulator and pressure controller systems, electrokinetic systems and/or other fluid transport mechanisms can generate the flow, controllably mix fluids, and the like.

Abstract: A method for determining the molecular diffusivity of a solute in a microchannel where a solute is introduced into a first end of a microchannel and a first concentration profile is measured at first and second locations along the microchannel. A theoretical concentration profile can be calculated at the second location based on the measured first concentration profile at the first location. The molecular diffusivity can be found by minimizing the error when comparing the theoretical concentration profile to the measured second concentration profile. Further, this technique allows for average velocity to be measured simultaneously with molecular diffusivity.

Abstract: A method for determining the molecular diffusivity of a solute in a microchannel where a solute is introduced into a first end of a microchannel and a first concentration profile is measured at first and second locations along the microchannel. A theoretical concentration profile can be calculated at the second location based on the measured first concentration profile at the first location. The molecular diffusivity can be found by minimizing the error when comparing the theoretical concentration profile to the measured second concentration profile. Further, this technique allows for average velocity to be measured simultaneously with molecular diffusivity.