Last data update: Sep 16, 2024. (Total: 47680 publications since 2009)
Records 1-6 (of 6 Records) |
Query Trace: Snyder JL [original query] |
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Direct diagnostic tests for Lyme disease
Schutzer SE , Body BA , Boyle J , Branson BM , Dattwyler RJ , Fikrig E , Gerald NJ , Gomes-Solecki M , Kintrup M , Ledizet M , Levin AE , Lewinski M , Liotta LA , Marques A , Mead PS , Mongodin EF , Pillai S , Rao P , Robinson WH , Roth KM , Schriefer ME , Slezak T , Snyder JL , Steere AC , Witkowski J , Wong SJ , Branda JA . Clin Infect Dis 2018 68 (6) 1052-1057 Borrelia burgdorferi was discovered to be the cause of Lyme disease in 1983, leading to seroassays. The 1994 serodiagnostic testing guidelines predated a full understanding of key B. burgdorferi antigens and have a number of shortcomings. These serologic tests cannot distinguish active infection, past infection, or reinfection. Reliable direct-detection methods for active B. burgdorferi infection have been lacking in the past but are needed and appear achievable. New approaches have effectively been applied to other emerging infections and show promise in direct detection of B. burgdorferi infections. |
Development of an inexpensive RGB color sensor for the detection of hydrogen cyanide gas
Greenawald LA , Boss GR , Snyder JL , Reeder A , Bell S . ACS Sens 2017 2 (10) 1458-1466 An inexpensive red, green, blue (RGB) color sensor was developed for detecting low ppm concentrations of hydrogen cyanide gas. A piece of glass fiber filter paper containing monocyanocobinamide [CN(H2O)Cbi] was placed directly above the RGB color sensor and an on chip LED. Light reflected from the paper was monitored for RGB color change upon exposure to hydrogen cyanide at concentrations of 1.0-10.0 ppm as a function of 25%, 50%, and 85% relative humidity. A rapid color change occurred within 10 s of exposure to 5.0 ppm hydrogen cyanide gas (near the NIOSH recommended exposure limit). A more rapid color change occurred at higher humidity, suggesting a more effective reaction between hydrogen cyanide and CN(H2O)Cbi. The sensor could provide the first real time respirator end-of-service-life alert for hydrogen cyanide gas. |
Development of a cobinamide-based end-of-service-life indicator for detection of hydrogen cyanide gas
Greenawald LA , Snyder JL , Fry NL , Sailor MJ , Boss GR , Finklea HO , Bell S . Sens Actuators B Chem 2015 221 379-385 We describe an inexpensive paper-based sensor for rapid detection of low concentrations (ppm) of hydrogen cyanide gas. A piece of filter paper pre-spotted with a dilute monocyanocobinamide [CN(H2O)Cbi] solution was placed on the end of a bifurcated optical fiber and the reflectance spectrum of the CN(H2O)Cbi was monitored during exposure to 1.0-10.0 ppm hydrogen cyanide gas. Formation of dicyanocobinamide yielded a peak at 583 nm with a simultaneous decrease in reflectance from 450-500 nm. Spectral changes were monitored as a function of time at several relative humidity values: 25, 50, and 85% relative humidity. With either cellulose or glass fiber papers, spectral changes occurred within 10 s of exposure to 5.0 ppm hydrogen cyanide gas (NIOSH recommended short-term exposure limit). We conclude that this sensor could provide a real-time end-of-service-life alert to a respirator user. |
Estimating reusability of organic air-purifying respirator cartridges
Wood GO , Snyder JL . J Occup Environ Hyg 2011 8 (10) 609-17 Reuse of organic vapor air-purifying respirator cartridges after a job or shift can provide economy and energy savings. However, standards and manufacturers' guidance discourage reuse, presumably due to a lack of quantitative objective exposure and use information. Storage and simulated reuse laboratory studies and modeling have been done to provide such information. Two important parameters of breakthrough curves, midpoint time (related to adsorption capacity) and midpoint slope (related to adsorption rate), have been shown to be unchanged during storage for reuse. Extrapolations to smaller breakthrough concentrations and times can be made from this reference breakthrough and time. Significant step increases in breakthrough concentration upon cartridge reuse have been observed in some cases. Values of immediate breakthrough concentrations upon reuse (IBURs) have been measured and correlated. The Dubinin/Radushkevich adsorption isotherm equation has been used to estimate maximum IBURs, which depend on many factors, including conditions and duration of first use. An empirical equation describing rate of approach to maximum IBUR as a function of storage time has been developed to provide intermediate IBUR estimates, which are also very dependent on the vapor identity and extent of first-use loading. Using these equations, IBUR estimates with appropriate safety factors can be compared with the allowable breakthrough concentration to help the Industrial Hygienist make reusability decisions. |
Robust gold nanoparticles stabilized by trithiol for application in chemiresistive sensors
Garg N , Mohanty A , Lazarus N , Schultz L , Rozzi TR , Santhanam S , Weiss L , Snyder JL , Fedder GK , Jin R . Nanotechnology 2010 21 (40) 405501 The use of gold nanoparticles coated with an organic monolayer of thiol for application in chemiresistive sensors was initiated in the late 1990s; since then, such types of sensors have been widely pursued due to their high sensitivities and reversible responses to volatile organic compounds (VOCs). However, a major issue for chemical sensors based on thiol-capped gold nanoparticles is their poor long-term stability as a result of slow degradation of the monothiol-to-gold bonds. We have devised a strategy to overcome this limitation by synthesizing a more robust system using Au nanoparticles capped by trithiol ligands. Compared to its monothiol counterpart, the new system is significantly more stable and also shows improved sensitivity towards different types of polar or non-polar VOCs. Thus, the trithiol-Au nanosensor shows great promise for use in real world applications. 2010 IOP Publishing Ltd. |
Porous silicon-based optical microsensors for volatile organic analytes: effect of surface chemistry on stability and specificity
Ruminski AM , King BH , Salonen J , Snyder JL , Sailor MJ . Adv Funct Mater 2010 20 (17) 2874-2883 Sensing of the volatile organic compounds (VOCs) isopropyl alcohol (IPA) and heptane in air using sub-millimeter porous silicon-based sensor elements is demonstrated in the concentration range 50-800 ppm. The sensor elements are prepared as one-dimensional photonic crystals (rugate filters) by programmed electrochemical etch of p++ silicon, and analyte sensing is achieved by measurement of the wavelength shift of the photonic resonance. The sensors are studied as a function of surface chemistry: ozone oxidation, thermal oxidation, hydrosilylation (1-dodecene), electrochemical methylation, reaction with dicholorodimethylsilane and thermal carbonization with acetylene. The thermally oxidized and the dichlorodimethylsilane-modified materials show the greatest stability under atmospheric conditions. Optical microsensors are prepared by attachment of the porous Si layer to the distal end of optical fibers. The acetylated porous Si microsensor displays a greater response to heptane than to IPA, whereas the other chemical modifications display a greater response to IPA than to heptane. The thermal oxide sensor displays a strong response to water vapor, while the acetylated material shows a relatively weak response. The results suggest that a combination of optical fiber sensors with different surface chemistries can be used to classify VOC analytes. Application of the miniature sensors to the detection of VOC breakthrough in a full-scale activated carbon respirator cartridge simulator is demonstrated. |
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