Abstract: A first-dimension-guided differential scaling algorithm of the contour plot in comprehensive two-dimensional gas chromatography (2D GC) system is developed by incorporating both 1D and 2D chromatograms obtained by first and second detectors. This differential scaling method is shown to significantly improve 2D GC results in terms of retention time accuracy and consistency, peak width and hence peak capacity, and analyte quantification accuracy, which are inevitably affected by the modulation period and phase shift in modulation when the conventional contour plot reconstruction methods. Furthermore, the differential scaling method is shown to better handle the coelution and missing peak issues often encountered in the conventional methods. Finally, the differential scaling method exhibits high versatility in detector selection, which greatly broadens the 2D GC utility and can be easily adapted to other 2D chromatography systems.

Abstract: Systems and methods for aligning gas chromatography peaks are disclosed. An example method includes receiving chromatographic data of a user that includes data representing at least one volatile organic compound (VOC), and analyzing the chromatographic data using a trained peak alignment model to output a set of peak match probabilities. The trained peak alignment model may be trained using a plurality of chromatographic data to output a plurality of peak match probabilities. The example method may further include generating a set of identified VOCs between the chromatographic data and a set of reference VOCs by applying a post-processing algorithm to the set of peak match probabilities; and causing the set of identified VOCs to be displayed to the user.

Abstract: Nearly all existing direct current (DC) chemical vapor sensing methodologies are based on charge transfer between sensor and adsorbed molecules. However, the high binding energy at the charge-trapped sites, which is critical for high sensitivity, significantly slows sensors' response and makes the detection of non-polar molecules difficult. By exploiting the incomplete screening effect of graphene, this disclosure demonstrates a DC graphene electronic sensor for rapid (sub-second) and sensitive (ppb) detection of a broad range of vapor analytes, including polar, non-polar, organic and inorganic molecules. Molecular adsorption induced capacitance change in the graphene transistor is revealed to be the main sensing mechanism. This work provides an avenue for a broad spectrum real-time gas sensing technology and serves as an ideal testbed for probing molecular physisorption on graphene.

Abstract: An integrated microfluidic photoionization detector (PID) is provided including a microfluidic ionization chamber a microfluidic ultraviolet radiation chamber that is configured to generate ultraviolet photons. An ultrathin transmissive window is disposed between the microfluidic ionization chamber and the microfluidic ultraviolet radiation chamber that permits the ultraviolet photons to pass from the microfluidic ultraviolet radiation chamber into the microfluidic ionization chamber. Detection systems for one or more VOC analytes are also provided that include a gas chromatography (GC) unit including at least one gas chromatography column and an integrated microfluidic photoionization detector (PID) disposed downstream of the gas chromatography (GC) unit.

Abstract: Transepidermal water loss (TEWL) measurement approach is presented that achieves accurate and continuous monitoring completely independent of ambient environmental variations. This new measurement approach uses short dry air purges to dry the skin surface and the water vapor collection chamber, thus refreshing the measurement site each time during skin barrier analysis. These dry air purges help maintain a highly controlled localized measuring environment without disturbing any inherent skin properties, enabling one to produce reproducible TEWL results. A mathematical model developed based on Fick's laws of diffusion is presented, and shown to have excellent agreement with the mathematical model of a commercial TEWL device. The application of this mathematical model in deciphering the TEWL values from the transient microclimate behavior in the vapor measuring chamber of the new TEWL approach is also discussed.

Abstract: An integrated microfluidic photoionization detector (PID) is provided including a microfluidic ionization chamber a microfluidic ultraviolet radiation chamber that is configured to generate ultraviolet photons. An ultrathin transmissive window is disposed between the microfluidic ionization chamber and the microfluidic ultraviolet radiation chamber that permits the ultraviolet photons to pass from the microfluidic ultraviolet radiation chamber into the microfluidic ionization chamber. Detection systems for one or more VOC analytes are also provided that include a gas chromatography (GC) unit including at least one gas chromatography column and an integrated microfluidic photoionization detector (PID) disposed downstream of the gas chromatography (GC) unit.

Abstract: A laser whose emission is modulated by ultrasound is presented. The laser is usually micron-sized. In response to ultrasound modulation, the laser emission increases and decreases. Such a change in emission can be detected by external optical detectors. This type of laser can be used as a new type of imaging modality, in which laser emission in combination with sound waves or ultrasound waves, is used for imaging Laser emission has a much narrower spectral linewidth and stronger intensity than fluorescence and therefore is able to achieve higher sensitivity, whereas sound waves are used to provide a better spatial resolution of the laser emission from the laser. In ultrasound modulated laser based imaging, multiple lasers can be placed inside cells or tissues.

Abstract: Systems and methods are described for making repair decisions to improve resilience of a utility distribution network (UDN). A graph convolutional network (GCN) integrates reinforcement learning to provide an integrated model framework, in which the GCN encodes the information of the UDN, such as topology and operating characteristics. A neural network is connected to the GCN, and the framework trains the neural network to provide a recovery sequence based on the current state (e.g., a damaged state) of the UDN based one or more performance indicators.

Abstract: In a described example, a system for leak detection and localization is provided. The system includes a water distribution network (WDN) partition stage programmed to cluster a WDN model into partition zones based on applying a modified k-means clustering algorithm to leakage characteristic data and physical connectivity data. A leakage monitoring stage can be programmed to detect the occurrence of leakage in the WDN and provide leak detection data based on applying a trained unsupervised leakage detection machine-learning model to the partition zones and sensor data. The leakage monitoring stage can also provide localization data to identify a location of a leakage zone in the WDN based on feeding the leak detection data to a localization machine-learning model.

Abstract: An optofluidic diagnostic system and methods for rapid analyte detections. The system comprises an optofluidic sensor array, a test plate and an optical detection cartridge. The sensor array supports one or more distinct sensor units, each having a reactor section designed to temporarily enter a series of different kinds of wells in the test plate. One kind of well is a sample reservoir that holds reagent solution to be transferred into the reactor section. Another kind of well is a drainage chamber that removes reagent solution from the reactor section. A third kind of well is a colorant reservoir that holds a colorant reagent transferable into a reactor section. Finally, the sensor unit is transferred to the optical detection cartridge where it is placed into an isolation booth during the optical detection process so that its flat observation face is stationed in a viewing window opposite an optical detector lens.

Abstract: An optofluidic diagnostic system and methods for rapid analyte detections. The system comprises an optofluidic sensor array, a test plate and an optical detection cartridge. The sensor array supports one or more distinct sensor units, each having a reactor section designed to temporarily enter a series of different kinds of wells in the test plate. One kind of well is a sample reservoir that holds reagent solution to be transferred into the reactor section. Another kind of well is a drainage chamber that removes reagent solution from the reactor section. A third kind of well is a colorant reservoir that holds a colorant reagent transferable into a reactor section. Finally, the sensor unit is transferred to the optical detection cartridge where it is placed into an isolation booth during the optical detection process so that its flat observation face is stationed in a viewing window opposite an optical detector lens.

Abstract: The present disclosure provides an imaging system. The imaging system may include a laser cavity that is configured to receive a biological sample, where the biological sample is treated with a dye; an excitation light source that is configured to direct energy at the laser cavity so as to cause an emission from the biological sample, where the emission includes a laser emission at a first spectral band and a fluorescence emission at a second spectral band; a first detector that is configured to measure the laser emission generated by the biological sample; a second detector that is configured to measure the fluorescence emission generated by the biological sample; a splitter that is configured to direct the laser emission to the first detector and the fluorescence emission to the second detector; and a controller interfaced with the excitation light source, the first detector, and the second detector.

Abstract: An assay plate assembly comprising a plurality of microfluidic modules arranged in a rectilinear matrix of rows and columns microfluidic channels. Each microfluidic module has an inlet well leading to a serpentine microfluidic channel that is set at a cant angle. The well is laterally offset from the detection area to avoid optical interference. The geometric center of each detection area is positioned according to ANSI/SLAS standards for well-centers. A drain from each microfluidic channel is located so that it does not interfere with any detection areas. An array of micro-posts are disposed within each microfluidic channel. The micro-posts extend perpendicularly from the top surface of the top plate toward the underside and are equally distributed throughout the entire detection area. The plate assembly provides reduced assay time and sample volume, and increased sensitivity and specificity in biological and chemical assays.

Abstract: An imaging system for cell-based therapies is provided. The imagining system includes one or more optical tags configured for insertion into a cell or biological tissue, an excitation light source configured to illuminate the one or more optical tags; a detector configured to measure optical emission of the one or more optical tags; an imaging subsystem configured to determine a three-dimensional location of each of the one or more optical tags in the cell or biological tissue; and a controller in electrical communication with the excitation light source, the detector, and the imaging subsystem. Each of the one or more optical tags has a contrasting feature and includes a fluorescent material. The contrasting feature may be defined by at least one of a refractive index, shape, color, and laser emission of each optical tag of the one or more optical tags.

Abstract: An automated microfluidic bioreactor device and methods to rapidly detect drugs of abuse from human sweat are provided. The bioreactor can perform either single-plexed measurements (detecting only one target analyte at a time) or multiplexed measurement (detecting multiple analytes simultaneously). The bioreactor device has a cartridge comprising a capillary array that employs competitive enzyme-linked immunosorbent assay (ELISA) to detect the presence of various drugs or metabolite compounds. For example, four common drugs, methadone, methamphetamine, amphetamine, and tetrahydrocannabinol, were detected rapidly and quantitatively in about 16 minutes with a low sweat sample volume (about 4 ?L per analyte) and a large dynamic range (methadone: 0.0016 ng/mL-1 ng/mL; METH: 0.016 ng/mL-25 ng/mL; amphetamine: 0.005 ng/mL-10 ng/mL; THC: 0.02 ng/mL-1000 ng/mL).

Abstract: An optofluidic diagnostic system and methods for rapid analyte detections. The system comprises an optofluidic sensor array, a test plate and an optical detection cartridge. The sensor array supports one or more distinct sensor units, each having a reactor section designed to temporarily enter a series of different kinds of wells in the test plate. One kind of well is a sample reservoir that holds reagent solution to be transferred into the reactor section. Another kind of well is a drainage chamber that removes reagent solution from the reactor section. A third kind of well is a colorant reservoir that holds a colorant reagent transferable into a reactor section. Finally, the sensor unit is transferred to the optical detection cartridge where it is placed into an isolation booth during the optical detection process so that its flat observation face is stationed in a viewing window opposite an optical detector lens.

Abstract: A gas chromatography device for peak focusing of one or more target analytes is provided that include a chromatographic column with an inlet and an outlet. A stationary phase is deposited inside the chromatographic column and has a positive thickness gradient. The stationary phase extends from the inlet to the outlet and has a first thickness at the inlet of the chromatographic column and a second thickness at the outlet of the chromatographic column. The second thickness is at least about 10% greater than the first thickness. Methods of peak focusing in a gas chromatography device, method of verifying peak focusing in a gas chromatography device and creating a gas chromatography device having a chromatographic column with a positive thickness gradient are also provided.

Abstract: Laser emission based microscope devices and methods of using such devices for detecting laser emissions from a tissue sample are provided. The scanning microscope has first and second reflection surfaces and a scanning cavity holding a stationary tissue sample with at least one fluorophore/lasing energy responsive species. At least a portion of the scanning cavity corresponds to a high quality factor (Q) Fabry-Pérot resonator cavity. A lasing pump source directs energy at the scanning cavity while a detector receives and detects emissions generated by the fluorophore(s) or lasing energy responsive species. The second reflection surface and/or the lasing pump source are translatable with respect to the stationary tissue sample for generating a two-dimensional scan of the tissue sample. Methods for detecting multiplexed emissions or quantifying one or more biomarkers in a histological tissue sample, for example for detection and diagnosis of cancer, or other disorders/diseases are provided.

Abstract: A laser whose emission is modulated by ultrasound is presented. The laser is usually micron-sized. In response to ultra-sound modulation, the laser emission increases and decreases. Such a change in emission can be detected by external optical detectors. This type of laser can be used as a new type of imaging modality, in which laser emission in combination with sound waves or ultra-sound waves, is used for imaging Laser emission has a much narrower spectral linewidth and stronger intensity than fluorescence and therefore is able to achieve higher sensitivity, whereas sound waves are used to provide a better spatial resolution of the laser emission from the laser. In ultrasound modulated laser based imaging, multiple lasers can be placed inside cells or tissues.

Abstract: An optofluidic diagnostic system and methods for rapid analyte detections. The system comprises an optofluidic sensor array, a test plate and an optical detection cartridge. The sensor array supports one or more distinct sensor units, each having a reactor section designed to temporarily enter a series of different kinds of wells in the test plate. One kind of well is a sample reservoir that holds reagent solution to be transferred into the reactor section. Another kind of well is a drainage chamber that removes reagent solution from the reactor section. A third kind of well is a colorant reservoir that holds a colorant reagent transferable into a reactor section. Finally, the sensor unit is transferred to the optical detection cartridge where it is placed into an isolation booth during the optical detection process so that its flat observation face is stationed in a viewing window opposite an optical detector lens.