Grant Glover T.,SAIC |
Peterson G.W.,Edgewood Chemical and Biological Center |
Schindler B.J.,SAIC |
Britt D.,University of California at Los Angeles |
Yaghi O.,University of California at Los Angeles
Chemical Engineering Science | Year: 2011
Metal organic framework (MOF-74) analogs have been synthesized using cobalt, magnesium, nickel, and zinc metal centers. The capability of these materials to remove ammonia, cyanogen chloride, and sulfur dioxide from air has been evaluated via fixed-bed breakthrough testing in both dry and humid conditions. Octane breakthrough tests were performed to determine the physisorption capacities of the materials. All materials were stored in air prior to use. Dynamic breakthrough capacities of the analogs were compared to 13X zeolite and BPL activated carbon. The impact of the metal center on the adsorption behavior is illustrated with each analog providing different ammonia and cyanogen chloride adsorption capacities. The results provide an important step in the assessment of the potential of MOFs to function as porous adsorbent materials. © 2010 Elsevier Ltd.
Roy E.,Rigaku Raman Technologies Inc. |
Wilcox P.G.,Edgewood Chemical and Biological Center |
Hoffland S.,Edgewood Chemical and Biological Center |
Pardoe I.,Excet Inc.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015
Raman spectroscopy is a powerful tool for obtaining molecular structure information of a sample. While Raman spectroscopy is a common laboratory based analytical tool, miniaturization of opto-electronic components has allowed handheld Raman analyzers to become commercially available. These handheld systems are utilized by Military and First Responder operators tasked with rapidly identifying potentially hazardous chemicals in the field. However, one limitation of many handheld Raman detection systems is strong interference caused by fluorescence of the sample or underlying surface which obscures the characteristic Raman signature of the target analyte. Munitions grade chemical warfare agents (CWAs) are produced and stored in large batches and typically have more impurities from the storage container, degradation, or unreacted precursors. In this work, Raman spectra of munitions grade CWAs were collected using a handheld Raman spectrometer with a 1064 nm excitation laser. While Raman scattering generated by a 1064 nm laser is inherently less efficient than excitation at shorter wavelengths, high quality spectra were easily obtained due to significantly reduced fluorescence of the munitions grade CWAs. The spectra of these less pure, but more operationally relevant, munitions grade CWAs were then compared to spectra of CASARM grade CWAs, as well as Raman spectra collected using the more common 785 nm excitation laser. © 2015 SPIE.
Pan Y.-L.,U.S. Army |
Hill S.C.,U.S. Army |
Santarpia J.L.,Johns Hopkins University |
Santarpia J.L.,Sandia National Laboratories |
And 14 more authors.
Optics Express | Year: 2014
A system for measuring spectrally-resolved fluorescence cross sections of single bioaerosol particles has been developed and employed in a biological safety level 3 (BSL-3) facility at Edgewood Chemical and Biological Center (ECBC). It is used to aerosolize the slurry or solution of live agents and surrogates into dried micron-size particles, and to measure the fluorescence spectra and sizes of the particles one at a time. Spectrallyresolved fluorescence cross sections were measured for (1) bacterial spores: Bacillus anthracis Ames (BaA), B. atrophaeus var. globigii (BG) (formerly known as Bacillus globigii), B. thuringiensis israelensis (Bti), B. thuringiensis kurstaki (Btk), B. anthracis Sterne (BaS); (2) vegetative bacteria: Escherichia coli (E. coli), Pantoea agglomerans (Eh) (formerly known as Erwinia herbicola), Yersinia rohdei (Yr), Yersinia pestis CO92 (Yp); and (3) virus preparations: Venezuelan equine encephalitis TC83 (VEE) and the bacteriophage MS2. The excitation wavelengths were 266 nm, 273 nm, 280 nm, 365 nm and 405 nm. © 2014 Optical Society of America.
Clewes R.J.,UK Defence Science and Technology Laboratory |
Howle C.R.,UK Defence Science and Technology Laboratory |
Guicheteau J.,Edgewood Chemical and Biological Center |
Emge D.,Edgewood Chemical and Biological Center |
And 5 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013
The ability of a stand-off chemical detector to distinguish two different chemical warfare agents is demonstrated in this paper. Using Negative Contrast Imaging, based upon IR absorption spectroscopy, we were able to detect 1 μl of VX, sulfur mustard and water on a subset of representative surfaces. These experiments were performed at a range of 1.3 metres and an angle of 45° to the surface. The technique employed utilises a Q-switched intracavity MgO:PPLN crystal that generated 1.4 - 1.8 μm (shortwave) and 2.6 - 3.6 μm (midwave) infrared radiation (SWIR and MWIR, respectively). The MgO:PPLN crystal has a fanned grating design which, via translation through a 1064 nm pump beam, enables tuning through the SWIR and MWIR wavelength ranges. The SWIR and MWIR beams are guided across a scene via a pair of raster scanned mirrors allowing detection of absorption features within these spectral regions. This investigation exploited MWIR signatures, as they provided sufficient molecular information to distinguish between toxic and benign chemicals in these proof-of-concept experiments. ©2013 SPIE.
PubMed | United States Medical Research Institute of Infectious Diseases, TMG Biosciences LLC, OptiMetrics, Inc., Edgewood Chemical and Biological Center and 2 more.
Type: | Journal: BMC bioinformatics | Year: 2015
The detection of pathogens in complex sample backgrounds has been revolutionized by wide access to next-generation sequencing (NGS) platforms. However, analytical methods to support NGS platforms are not as uniformly available. Pathosphere (found at Pathosphere.org) is a cloud - based open - sourced community tool that allowsfor communication, collaboration and sharing of NGS analytical tools and data amongst scientists working in academia, industry and government. The architecture allows for users to upload data and run available bioinformatics pipelines without the need for onsite processing hardware or technical support.The pathogen detection capabilities hosted on Pathosphere were tested by analyzing pathogen-containing samples sequenced by NGS with both spiked human samples as well as human and zoonotic host backgrounds. Pathosphere analytical pipelines developed by Edgewood Chemical Biological Center (ECBC) identified spiked pathogens within a common sample analyzed by 454, Ion Torrent, and Illumina sequencing platforms. ECBC pipelines also correctly identified pathogens in human samples containing arenavirus in addition to animal samples containing flavivirus and coronavirus. These analytical methods were limited in the detection of sequences with limited homology to previous annotations within NCBI databases, such as parvovirus. Utilizing the pipeline-hosting adaptability of Pathosphere, the analytical suite was supplemented by analytical pipelines designed by the United States Army Medical Research Insititute of Infectious Diseases and Walter Reed Army Institute of Research (USAMRIID-WRAIR). These pipelines were implemented and detected parvovirus sequence in the sample that the ECBC iterative analysis previously failed to identify.By accurately detecting pathogens in a variety of samples, this work demonstrates the utility of Pathosphere and provides a platform for utilizing, modifying and creating pipelines for a variety of NGS technologies developed to detect pathogens in complex sample backgrounds. These results serve as an exhibition for the existing pipelines and web-based interface of Pathosphere as well as the plug-in adaptability that allows for integration of newer NGS analytical software as it becomes available.
Swietnicki W.,Bethesda University |
Carmany D.,Batelle Memorial Institute |
Retford M.,Edgewood Chemical and Biological Center |
Guelta M.,Edgewood Chemical and Biological Center |
And 4 more authors.
PLoS ONE | Year: 2011
Yersinia pestis is a Gram negative zoonotic pathogen responsible for causing bubonic and pneumonic plague in humans. The pathogen uses a type III secretion system (T3SS) to deliver virulence factors directly from bacterium into host mammalian cells. The system contains a single ATPase, YscN, necessary for delivery of virulence factors. In this work, we show that deletion of the catalytic domain of the yscN gene in Y. pestis CO92 attenuated the strain over three million-fold in the Swiss-Webster mouse model of bubonic plague. The result validates the YscN protein as a therapeutic target for plague. The catalytic domain of the YscN protein was made using recombinant methods and its ATPase activity was characterized in vitro. To identify candidate therapeutics, we tested computationally selected small molecules for inhibition of YscN ATPase activity. The best inhibitors had measured IC50 values below 20 μM in an in vitro ATPase assay and were also found to inhibit the homologous BsaS protein from Burkholderia mallei animal-like T3SS at similar concentrations. Moreover, the compounds fully inhibited YopE secretion by attenuated Y. pestis in a bacterial cell culture and mammalian cells at μM concentrations. The data demonstrate the feasibility of targeting and inhibiting a critical protein transport ATPase of a bacterial virulence system. It is likely the same strategy could be applied to many other common human pathogens using type III secretion system, including enteropathogenic E. coli, Shigella flexneri, Salmonella typhimurium, and Burkholderia mallei/pseudomallei species.
Sullenberger R.M.,Lincoln Laboratory |
Clark M.L.,Lincoln Laboratory |
Kunz R.R.,Lincoln Laboratory |
Samuels A.C.,Edgewood Chemical and Biological Center |
And 3 more authors.
Optics Express | Year: 2014
Dynamic photoacoustic spectroscopy (DPAS) is a high sensitivity technique for standoff detection of trace vapors. A field-portable DPAS system has potential as an early warning provider for gaseous-based chemical threats. For the first time, we utilize DPAS to successfully detect the presence of trace aerosols. Aerosol identification via long-wavelength infrared (LWIR) spectra is demonstrated. We estimate the sensitivity of our DPAS system to aerosols comprised of silica particles is comparable to that of SF6 gas based on a signal level per absorbance unit metric for the two materials. The implications of these measurements are discussed. © 2014 Optical Society of America.
Robertson J.,Curtin University Australia |
Levy A.,Hospital Avenue |
Sagripanti J.-L.,Edgewood Chemical and Biological Center |
Inglis T.J.J.,Hospital Avenue
American Journal of Tropical Medicine and Hygiene | Year: 2010
We studied the effect of environmental parameters on the survival of Burkholderia pseudomallei. There was a small increase in bacterial count for up to 28 days in sterilized distilled water or rain water, in water at 20°C or 40°C, and in buffered solutions of pH 4 or higher. Counts of culturable B. pseudomallei declined at pH 3, in the presence of seawater or water with concentrations of 4% salt or higher, and under refrigeration. The morphological appearances of B. pseudomallei changed under conditions that maintained culturable numbers from bacilli to coccoid cells and spiral forms under pH or salt stress. These observations indicate that B. pseudomallei can endure nutrient-depleted environments as well as a wide range of pH, salt concentrations, and temperatures for periods of up to 28 days. The relative stability of B. pseudomallei under these conditions underlines the tenacity of this species and its potential for natural dispersal in water: in surface water collections, in managed water distribution systems, and through rainfall. These survival properties help explain the recent expansion of the known melioidosis endemic zone in Australia and may have played a part in recent melioidosis outbreaks. Copyright © 2010 by The American Society of Tropical Medicine and Hygiene.
Blatny J.,FFI Fotsvarets |
Fountain III A.W.,Edgewood Chemical and Biological Center
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011
To provide useful information during military operations, or as part of other security situations, a biological aerosol detector has to respond within seconds or minutes to an attack by virulent biological agents, and with low false alarms. Within this time frame, measuring virulence of a known microorganism is extremely difficult, especially if the microorganism is of unknown antigenic or nucleic acid properties. Measuring "live" characteristics of an organism directly is not generally an option, yet only viable organisms are potentially infectious. Fluorescence based instruments have been designed to optically determine if aerosol particles have viability characteristics. Still, such commercially available biological aerosol detection equipment needs to be improved for their use in military and civil applications. Air has an endogenous population of microorganisms that may interfere with alarm software technologies. To design robust algorithms, a comprehensive knowledge of the airborne biological background content is essential. For this reason, there is a need to study ambient live bacterial populations in as many locations as possible. Doing so will permit collection of data to define diverse biological characteristics that in turn can be used to fine tune alarm algorithms. To avoid false alarms, improving software technologies for biological detectors is a crucial feature requiring considerations of various parameters that can be applied to suppress alarm triggers. This NATO Task Group will aim for developing reference methods for monitoring biological aerosol characteristics to improve alarm algorithms for biological detection. Additionally, they will focus on developing reference standard methodology for monitoring biological aerosol characteristics to reduce false alarm rates. © 2011 SPIE.
Staymates M.,U.S. National Institute of Standards and Technology |
Bottiger J.,Edgewood Chemical and Biological Center |
Schepers D.,Edgewood Chemical and Biological Center |
Staymates J.,U.S. National Institute of Standards and Technology
Aerosol Science and Technology | Year: 2013
The design and characterization of a streamlined, high-volume particle impactor intended for use with trace chemical analysis is presented. The impactor has a single round jet and is designed to operate at a flow rate of 1000 L/min. Computational fluid dynamics (CFD) was used as a tool to optimize the aerodynamic performance of the impactor by iteratively redesigning the geometry and curvature of the internal walls. By eliminating recirculation zones within the flowfield of the impactor and using flowfield streamlines as new walls, successive designs revealed a significant reduction in the pressure drop across the impactor. Particle trajectories were simulated in the impactor and the 50% cutpoint was determined to be 1.05 μm. The impaction surface itself is easily removed fromthe body of the impactor assembly, potentially facilitating rapid trace chemical analysis using a variety of chemical detection techniques. A prototype impactor was fabricated with a 3D rapid prototyping printer and characterized in terms of particle cut-off diameter using test aerosols generated by an Ink Jet Aerosol Generator (IJAG) and fluorescence intensity measurements. The experimental particle cut-off diameter was not able to be measured because the smallest aerosol particles that could be tested were 1.86 μm which were collected at 100% efficiency. Particulate contamination from the high-explosive compound C4 was also collected with the impactor to demonstrate operational utility for trace explosives detection. Copyright © American Association for Aerosol Research.