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Full-Text Articles in Physics
A Simple And Efficient Centrifugation Filtration Method For Bacterial Concentration And Isolation Prior To Testing Liquid Specimens With Laser-Induced Breakdown Spectroscopy, Dylan J. Malenfanta, Alexandra E. Paulick, Steven J. Rehse
A Simple And Efficient Centrifugation Filtration Method For Bacterial Concentration And Isolation Prior To Testing Liquid Specimens With Laser-Induced Breakdown Spectroscopy, Dylan J. Malenfanta, Alexandra E. Paulick, Steven J. Rehse
Physics Publications
An inexpensive filtration device was designed and constructed to rapidly concentrate bacteria in a liquid suspension on the surface of a disposable filter medium while at the same time separating the bacterial cells from larger contaminants in the suspension on the basis of their size. The device consists of a two-stage insert that is held rigidly in a standard tube during bacterial suspension centrifugation. The filters can be easily removed from the insert for subsequent testing with laser-induced breakdown spectroscopy in a process that takes only three minutes. Filter media of 0.45 micron pore size was found to capture approximately …
Concentration Of Bacterial Specimens During Centrifugation Prior To Laser-Induced Breakdown Spectroscopy Analysis, Alexandra E. Paulicka, Dylan J. Malenfanta, Steven J. Rehse
Concentration Of Bacterial Specimens During Centrifugation Prior To Laser-Induced Breakdown Spectroscopy Analysis, Alexandra E. Paulicka, Dylan J. Malenfanta, Steven J. Rehse
Physics Publications
A metal cone device has been designed and fabricated for use with a custom centrifuge tube insert to allow the simple and rapid concentration of bacterial cells in a circular area with a diameter of 1 mm. The device concentrates cells suspended in up to 1 mL of liquid at the center of a highly flat disposable filter medium which can be easily removed from the centrifuge tube insert for subsequent testing with laser-induced breakdown spectroscopy. Two-dimensional elemental mapping of the filter evidenced a high concentration of bacteria on the filter under the location of the cone hole, as well …
A Review Of The Use Of Laser-Induced Breakdown Spectroscopy For Bacterial Classification, Quantification, And Identification, Steven J. Rehse
A Review Of The Use Of Laser-Induced Breakdown Spectroscopy For Bacterial Classification, Quantification, And Identification, Steven J. Rehse
Physics Publications
The use of laser-induced breakdown spectroscopy to determine the elemental composition of bacterial cells has been described in the peer-reviewed literature since 2003. Fifteen years on, significant accomplishments have been reported that have served to clarify and underscore the areas of bacteriological investigation that LIBS is well-suited for as well as the challenges that yet remain to be faced. This review will attempt to summarize the state of the field by surveying the available body of knowledge. The early days of these experiments, roughly from 2003 to 2007, in which many of the most fundamental experiments were initially conducted will …
Determination Of The Zinc Concentration In Human Fingernails By Laser-Induced Breakdown Spectroscopy, Steven J. Rehse, Vlora A. Riberdy, Christopher J. Frederickson
Determination Of The Zinc Concentration In Human Fingernails By Laser-Induced Breakdown Spectroscopy, Steven J. Rehse, Vlora A. Riberdy, Christopher J. Frederickson
Physics Publications
The absolute concentration of zinc in human fingernail clippings tested ex vivo was determined by 1064 nm laser-induced breakdown spectroscopy and confirmed by speciated isotope dilution mass spectrometry. A nail testing protocol that sampled across the nail (perpendicular to the direction of growth) was developed and validated by scanning electron microscopy energy dispersive x-ray spectroscopy. Using this protocol, a partial least squares regression model predicted the zinc concentration in five subjects’ fingernails to within 7 ppm on average. The variation of the zinc concentration with depth into the nail as determined by laser-induced breakdown spectroscopy was studied and found to …
A Comparison Of Multivariate Analysis Techniques And Variable Selection Strategies In A Laser-Induced Breakdown Spectroscopy Bacterial Classification, Russell Putnam, Q.I. Mohaidat, Andrew Daabous, Steven Rehse
A Comparison Of Multivariate Analysis Techniques And Variable Selection Strategies In A Laser-Induced Breakdown Spectroscopy Bacterial Classification, Russell Putnam, Q.I. Mohaidat, Andrew Daabous, Steven Rehse
Physics Publications
Laser-induced breakdown spectroscopy has been used to obtain spectral fingerprints from live bacterial specimens from thirteen distinct taxonomic bacterial classes representative of five bacterial genera. By taking sums, ratios, and complex ratios of measured atomic emission line intensities three unique sets of independent variables (models) were constructed to determine which choice of independent variables provided optimal genuslevel classification of unknown specimens utilizing a discriminant function analysis. A model composed of 80 independent variables constructed from simple and complex ratios of the measured emission line intensities was found to provide the greatest sensitivity and specificity. This model was then used in …