61 research outputs found
X-ray Parametric Down Conversion at the APS Synchrotron
We present measurements of X-ray Parametric Down Conversion at the Advanced
Photon Source synchrotron facility. We use an incoming pump beam at 22 keV to
observe the simultaneous, elastic emission of down-converted photon pairs
generated in a diamond crystal. The pairs are detected using high count rate
silicon drift detectors with low noise. Production by down-conversion is
confirmed by measuring time-energy correlations in the detector signal, where
photon pairs within an energy window ranging from 10 to 12 keV are only
observed at short time differences. By systematically varying the crystal
misalignment and detector positions, we obtain results that are consistent with
the constant total of the down-converted signal
CEPH family 1362 STR database: An online resource for characterization of PCR products using electrospray ionization mass spectrometry
Differentiation of Gram-Negative Bacterial Aerosol Exposure Using Detected Markers in Bronchial-Alveolar Lavage Fluid
The identification of biosignatures of aerosol exposure to pathogens has the potential to provide useful diagnostic information. In particular, markers of exposure to different types of respiratory pathogens may yield diverse sets of markers that can be used to differentiate exposure. We examine a mouse model of aerosol exposure to known Gram negative bacterial pathogens, Francisella tularensis novicida and Pseudomonas aeruginosa. Mice were subjected to either a pathogen or control exposure and bronchial alveolar lavage fluid (BALF) was collected at four and twenty four hours post exposure. Small protein and peptide markers within the BALF were detected by matrix assisted laser desorption/ionization (MALDI) mass spectrometry (MS) and analyzed using both exploratory and predictive data analysis methods; principle component analysis and degree of association. The markers detected were successfully used to accurately identify the four hour exposed samples from the control samples. This report demonstrates the potential for small protein and peptide marker profiles to identify aerosol exposure in a short post-exposure time frame
Evaluation of sample preparation techniques for mass measurements of PCR products using ESI-FT-ICR mass spectrometry
The influence of cultivation methods on Shewanella oneidensis physiology and proteome expression
High-throughput analyses that are central to microbial systems biology and ecophysiology research benefit from highly homogeneous and physiologically well-defined cell cultures. While attention has focused on the technical variation associated with high-throughput technologies, biological variation introduced as a function of cell cultivation methods has been largely overlooked. This study evaluated the impact of cultivation methods, controlled batch or continuous culture in bioreactors versus shake flasks, on the reproducibility of global proteome measurements in Shewanellaoneidensis MR-1. Variability in dissolved oxygen concentration and consumption rate, metabolite profiles, and proteome was greater in shake flask than controlled batch or chemostat cultures. Proteins indicative of suboxic and anaerobic growth (e.g., fumarate reductase and decaheme c-type cytochromes) were more abundant in cells from shake flasks compared to bioreactor cultures, a finding consistent with data demonstrating that βaerobicβ flask cultures were O2 deficient due to poor mass transfer kinetics. The work described herein establishes the necessity of controlled cultivation for ensuring highly reproducible and homogenous microbial cultures. By decreasing cell to cell variability, higher quality samples will allow for the interpretive accuracy necessary for drawing conclusions relevant to microbial systems biology research
The effects of a dynamic patellar realignment brace on disease determinants for patellofemoral instability in the upright weight-bearing condition
Flow-injection electrospray ionization mass spectrometry of crude cell extracts for high-throughput bacterial identification
Origin of supercharging in electrospray ionization of noncovalent complexes from aqueous solution
Covalent attachment and dissociative loss of sinapinic acid to/from cysteine-containing proteins from bacterial cell lysates analyzed by MALDI-TOF-TOF mass spectrometry
Retrieval of DNA Using Soft-Landing after Mass Analysis by ESI-FTICR for Enzymatic Manipulation
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