11 research outputs found
Kernel Flow:a high channel count scalable time-domain functional near-infrared spectroscopy system
Significance: Time-domain functional near-infrared spectroscopy (TD-fNIRS) has been considered as the gold standard of noninvasive optical brain imaging devices. However, due to the high cost, complexity, and large form factor, it has not been as widely adopted as continuous wave NIRS systems. Aim: Kernel Flow is a TD-fNIRS system that has been designed to break through these limitations by maintaining the performance of a research grade TD-fNIRS system while integrating all of the components into a small modular device. Approach: The Kernel Flow modules are built around miniaturized laser drivers, custom integrated circuits, and specialized detectors. The modules can be assembled into a system with dense channel coverage over the entire head. Results: We show performance similar to benchtop systems with our miniaturized device as characterized by standardized tissue and optical phantom protocols for TD-fNIRS and human neuroscience results. Conclusions: The miniaturized design of the Kernel Flow system allows for broader applications of TD-fNIRS.</p
The soft x-ray instrument for materials studies at the linac coherent light source x-ray free-electron laser
This content may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This material originally appeared in Review of Scientific Instruments 83, 043107 (2012) and may be found at https://doi.org/10.1063/1.3698294.The soft x-ray materials science instrument is the second operational beamline at the linac coherent light source x-ray free electron laser. The instrument operates with a photon energy range of 480–2000 eV and features a grating monochromator as well as bendable refocusing mirrors. A broad range of experimental stations may be installed to study diverse scientific topics such as: ultrafast chemistry, surface science, highly correlated electron systems, matter under extreme conditions, and laboratory astrophysics. Preliminary commissioning results are presented including the first soft x-ray single-shot energy spectrum from a free electron laser
Biomolecules capturing live bacteria from clinical samples.
Rapid phenotypic antimicrobial susceptibility testing (AST) requires the enrichment of live bacteria from patient samples, which is particularly challenging in the context of life-threatening bloodstream infections (BSIs) due to low bacterial titers. Over two decades, an extensive array of pathogen-specific biomolecules has been identified to capture live bacteria. The prevailing biomolecules are immune proteins of the complement system, antibodies, aptamers, phage proteins, and antimicrobial peptides. These biomolecules differ by their binder generation technologies and exhibit highly variable specificities, ranging from bacterial strains to most pathogenic bacteria. Here, we summarize how these diverse biomolecules were identified, list examples of successfully reported capture assays, and provide an outlook on the use of nanobodies raised against conserved surface-accessible proteins as promising biomolecules for pathogen capture
Varying photo-dissociation mechanisms in Fe(CO)5 and Cr(CO)6 from femtosecond valence photoemission and excited-state moleculardynamics simulations
We present measured and calculated time-resolved photoelectron spectra of photoexcited gas-phase Fe(CO)5 and Cr(CO)6. Upon electronic excitation with 266 nm pump pulses and by probing with 23 eV photons from a femtosecond high-order har-monic generation source, we observe differences between Fe(CO)5 and Cr(CO)6 that indicate that the excited-state and dissociation dynamics are slower in Fe(CO)5 than in Cr(CO)6. Changing photoelectron intensities and binding energies combined with excited-state molecular dynamics simulations indicate repopulations of excited states from bound excited to dissociative excited states and to the dissociated species. We find that the more open and flexible structure of Fe(CO)5 with larger metal-carbonyl angles enables the photoexcited states of Fe(CO)5 to dissipate energy by angular distortions as observed in longer populations of bound excited states. The more compactand closed structure of Cr(CO)6 does not enable this relaxation resulting in fasterdissociation
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Geophysics Field Camp 1999
A geophysical study of the Patagonia-Sonoita Nature Conservancy property was carried out to determine the depth to bedrock and the geometry of the underlying basin in the area. The survey was part of the ongoing U.S. Geological Survey studies of the region. CSAMT, TEM, DC Resistivity, Seismic, Gravity, and Magnetic surveys were performed. Many of the surveys were not able to map depth to bedrock because the depth of penetration of these surveys was less than the large depth to bedrock, which we encountered in this area. The best estimate of depth to bedrock in the center of the valley is of the order of one kilometer, as identified by the CSAMT surveys. The CSAMT survey found a significant low-resistivity anomaly in the vicinity of the Nature Conservancy Visitor Center. This low-resistivity anomaly could be due to clay-rich rocks or possibly mineralized rocks. Magnetic and TEM anomalies also occurred in the same area as the CSAMT low-resistivity anomaly. Seismic surveys showed a loosely consolidated surface layer above more consolidated alluvium. The model from the · Gravity survey shows an extensive alluvial basin overlying rhyolite with high and low-angle faults.The Geophysics Field Camp Reports are made available by the Laboratory for Advanced Subsurface Imaging (LASI) and the University of Arizona Libraries. Visit the LASI website for more information http://www.lasi.arizona.edu
Kernel Flow:A high channel count scalable TD-fNIRS system
Time-Domain Near-Infrared Spectroscopy (TD-NIRS) has been considered as the gold standard of non-invasive optical brain imaging devices. However, due to the high cost, complexity, and large form-factor, it has not been as widely adopted as Continuous Wave (CW) NIRS systems. Kernel Flow is a TD-NIRS system that has been designed to break through these limitations by maintaining the performance of a research grade TD-NIRS system while integrating all of the components into a small modular device. The Kernel Flow modules are built around miniaturized laser drivers, custom integrated circuits, and specialized detectors. The modules can be assembled into a system with dense channel coverage over the entire head. We show performance similar to benchtop systems with our miniaturized device.</p
Bounds of Resemblance Measures for Binary (Presence/Absence) Variables
Association coefficients, Similarity coefficients, 2 × 2 table, Minimum value, Harmonic mean, Geometric mean, Arithmetic mean, Maximum value,