Measurement and analysis of the 241Am neutron capture cross section at the n_TOF facility at CERN

NASA Astrophysics Data System (ADS)

Mendoza, E.; Cano-Ott, D.; Altstadt, S.; Andriamonje, S.; Andrzejewski, J.; Audouin, L.; Balibrea, J.; Bécares, V.; Barbagallo, M.; Bečvář, F.; Belloni, F.; Berthier, B.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brugger, M.; Calviño, F.; Calviani, M.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Colonna, N.; Cortés, G.; Cortés-Giraldo, M. A.; Diakaki, M.; Dillmann, I.; Domingo-Pardo, C.; Durán, I.; Dzysiuk, N.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Furman, V.; Gómez-Hornillos, M. B.; Ganesan, S.; García, A. R.; Giubrone, G.; Gonçalves, I. F.; González, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gurusamy, P.; Heftrich, T.; Heinitz, S.; Hernández-Prieto, A.; Heyse, J.; Jenkins, D. G.; Jericha, E.; Käppeler, F.; Kadi, Y.; Karadimos, D.; Katabuchi, T.; Ketlerov, V.; Khryachkov, V.; Koehler, P.; Kokkoris, M.; Kroll, J.; Krtička, M.; Lampoudis, C.; Langer, C.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Leong, L. S.; Lerendegui-Marco, J.; Licata, M.; López, D.; Losito, R.; Manousos, A.; Marganiec, J.; Martínez, T.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Mondelaers, W.; Paradela, C.; Pavlik, A.; Perkowski, J.; Plompen, A. J. M.; Praena, J.; Quesada, J. M.; Rauscher, T.; Reifarth, R.; Riego-Perez, A.; Robles, M.; Roman, F.; Rubbia, C.; Ryan, J. A.; Sabaté-Gilarte, M.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Sedyshev, P.; Tagliente, G.; Tain, J. L.; Tarifeño-Saldivia, A.; Tarrío, D.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Vermeulen, M. J.; Versaci, R.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Ware, T.; Weigand, M.; Weiss, C.; Wright, T.; Žugec, P.; n TOF Collaboration

2018-05-01

The 241Am(n ,γ ) cross section has been measured at the n_TOF facility at CERN with the n_TOF BaF2 Total Absorption Calorimeter in the energy range between 0.2 eV and 10 keV. Our results are analyzed as resolved resonances up to 700 eV, allowing a more detailed description of the cross section than in the current evaluations, which contain resolved resonances only up to 150-160 eV. The cross section in the unresolved resonance region is perfectly consistent with the predictions based on the average resonance parameters deduced from the resolved resonances, thus obtaining a consistent description of the cross section in the full neutron energy range under study. Below 20 eV, our results are in reasonable agreement with JEFF-3.2 as well as with the most recent direct measurements of the resonance integral, and differ up to 20-30% with other experimental data. Between 20 eV and 1 keV, the disagreement with other experimental data and evaluations gradually decreases, in general, with the neutron energy. Above 1 keV, we find compatible results with previously existing values.

Development and Validation of a New Blade Element Momentum Skewed-Wake Model within AeroDyn: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ning, S. A.; Hayman, G.; Damiani, R.

Blade element momentum methods, though conceptually simple, are highly useful for analyzing wind turbines aerodynamics and are widely used in many design and analysis applications. A new version of AeroDyn is being developed to take advantage of new robust solution methodologies, conform to a new modularization framework for National Renewable Energy Laboratory's FAST, utilize advanced skewed-wake analysis methods, fix limitations with previous implementations, and to enable modeling of highly flexible and nonstraight blades. This paper reviews blade element momentum theory and several of the options available for analyzing skewed inflow. AeroDyn implementation details are described for the benefit of usersmore » and developers. These new options are compared to solutions from the previous version of AeroDyn and to experimental data. Finally, recommendations are given on how one might select from the various available solution approaches.« less

Influences of upwind emission sources and atmospheric processing on aerosol chemistry and properties at a rural location in the Northeastern U.S.: URBAN INFLUENCE ON RURAL AEROSOL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Shan; Collier, Sonya; Xu, Jianzhong

2016-05-19

Continuous real-time measurements of atmospheric aerosol with an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-AMS) coupled with a fast temperature-stepping thermodenuder were carried out in summer 2011 at Brookhaven National Laboratory (BNL, 40.871°N, 72.89°W) during the DOE Aerosol Life Cycle Intensive Operational Period (ALC-IOP) campaign.

Gas- and Particle-phase Chemical Composition Measurements Onboard the G1 Research Aircraft during the CARES Campaign

NASA Astrophysics Data System (ADS)

Shilling, J. E.; Alexander, L.; Jayne, J.; Fortner, E.

2010-12-01

An Aerodyne High Resolution Aerosol Mass Spectrometer (AMS) and an Ionicon Proton Transfer Reaction Mass Spectrometer (PTRMS) were deployed on the G1 research aircraft during the CARES campaign in Sacramento, CA to investigate aerosol gas- and particle-phase chemical composition. Preliminary analysis of PTRMS data suggests that biogenic volatile organic compounds (VOCs), particularly isoprene, dominate the region with anthropogenic VOCs, such as benzene and toluene, providing much smaller contributions to the VOC pool. Data from the AMS shows that the particle phase is dominated by organic material with smaller concentrations of ammonium sulfate and ammonium nitrate observed. Organic particle mass concentration strongly correlated with isoprene and gas-phase isoprene oxidation products, suggesting isoprene chemistry is largely controlling the organic aerosol loading in the area. The chemical evolution of the plume as it traveled downwind from Sacramento and into the foothills will also be discussed.

PTR-QMS versus PTR-TOF comparison in a region with oil and natural gas extraction industry in the Uintah Basin in 2013

NASA Astrophysics Data System (ADS)

Warneke, C.; Veres, P.; Murphy, S. M.; Soltis, J.; Field, R. A.; Graus, M. G.; Koss, A.; Li, S.-M.; Li, R.; Yuan, B.; Roberts, J. M.; de Gouw, J. A.

2015-01-01

Here we compare volatile organic compound (VOC) measurements using a standard proton-transfer-reaction quadrupole mass spectrometer (PTR-QMS) with a new proton-transfer-reaction time of flight mass spectrometer (PTR-TOF) during the Uintah Basin Winter Ozone Study 2013 (UBWOS2013) field experiment in an oil and gas field in the Uintah Basin, Utah. The PTR-QMS uses a quadrupole, which is a mass filter that lets one mass to charge ratio pass at a time, whereas the PTR-TOF uses a time of flight mass spectrometer, which takes full mass spectra with typical 0.1 s-1 min integrated acquisition times. The sensitivity of the PTR-QMS in units of counts per ppbv (parts per billion by volume) is about a factor of 10-35 times larger than the PTR-TOF, when only one VOC is measured. The sensitivity of the PTR-TOF is mass dependent because of the mass discrimination caused by the sampling duty cycle in the orthogonal-acceleration region of the TOF. For example, the PTR-QMS on mass 33 (methanol) is 35 times more sensitive than the PTR-TOF and for masses above 120 amu less than 10 times more. If more than 10-35 compounds are measured with PTR-QMS, the sampling time per ion decreases and the PTR-TOF has higher signals per unit measuring time for most masses. For UBWOS2013 the PTR-QMS measured 34 masses in 37 s and on that timescale the PTR-TOF is more sensitive for all masses. The high mass resolution of the TOF allows for the measurements of compounds that cannot be separately detected with the PTR-QMS, such as oxidation products from alkanes and cycloalkanes emitted by oil and gas extraction. PTR-TOF masses do not have to be preselected, allowing for identification of unanticipated compounds. The measured mixing ratios of the two instruments agreed very well (R2 ≥ 0.92 and within 20%) for all compounds and masses monitored with the PTR-QMS.

PTR-QMS vs. PTR-TOF comparison in a region with oil and natural gas extraction industry in the Uintah Basin in 2013

NASA Astrophysics Data System (ADS)

Warneke, C.; Veres, P. R.; Murphy, S. M.; Soltis, J.; Field, R. A.; Graus, M. G.; Koss, A.; Li, S.-M.; Li, R.; Yuan, B.; Roberts, J. M.; de Gouw, J. A.

2014-07-01

Here we compare volatile organic compound (VOC) measurements using a standard Proton-Transfer-Reaction Quadrupole Mass Spectrometer (PTR-QMS) with a new Proton-Transfer-Reaction Time Of Flight Mass Spectrometer (PTR-TOF) during the Uintah Basin Winter Ozone Study 2013 (UBWOS2013) field experiment in an oil and gas field in the Uintah Basin, Utah. The PTR-QMS uses a quadrupole, which is a mass filter that lets one mass pass at a time, whereas the PTR-TOF uses a Time Of Flight mass spectrometer, which takes full mass spectra with typical 0.1 s to 1 min integrated acquisition times. The sensitivity of the PTR-QMS in units of counts per ppbv is about a factor of 10-35 times larger than the PTR-TOF, when only one VOC is measured. The sensitivity of the PTR-TOF is mass dependent because of the mass discrimination caused by the sampling duty cycle in the orthogonal-acceleration region of the TOF. For example, the PTR-QMS on mass 33 (methanol) is 35 times more sensitive than the PTR-TOF and for masses above 120 amu less than 10 times more. If more than 10-35 compounds are measured with PTR-QMS, the sampling time per ion decreases and the PTR-TOF has higher signals per unit measuring time for most masses. For UBWOS2013 the PTR-QMS measured 34 masses in 37 s and on that time-scale the PTR-TOF is more sensitive for all masses. The high mass resolution of the TOF allows for the measurements of compounds that cannot be separately detected with the PTR-QMS, such as oxidation products from alkanes and cycloalkanes emitted by oil and gas extraction. PTR-TOF masses do not have to be pre-selected allowing for identification of unanticipated compounds. The measured mixing ratios of the two instruments agreed very well (R2 ≥ 0.92 and within 20%) for all compounds and masses monitored with the PTR-QMS.

Improved mass resolution and mass accuracy in TOF-SIMS spectra and images using argon gas cluster ion beams.

PubMed

Shon, Hyun Kyong; Yoon, Sohee; Moon, Jeong Hee; Lee, Tae Geol

2016-06-09

The popularity of argon gas cluster ion beams (Ar-GCIB) as primary ion beams in time-of-flight secondary ion mass spectrometry (TOF-SIMS) has increased because the molecular ions of large organic- and biomolecules can be detected with less damage to the sample surfaces. However, Ar-GCIB is limited by poor mass resolution as well as poor mass accuracy. The inferior quality of the mass resolution in a TOF-SIMS spectrum obtained by using Ar-GCIB compared to the one obtained by a bismuth liquid metal cluster ion beam and others makes it difficult to identify unknown peaks because of the mass interference from the neighboring peaks. However, in this study, the authors demonstrate improved mass resolution in TOF-SIMS using Ar-GCIB through the delayed extraction of secondary ions, a method typically used in TOF mass spectrometry to increase mass resolution. As for poor mass accuracy, although mass calibration using internal peaks with low mass such as hydrogen and carbon is a common approach in TOF-SIMS, it is unsuited to the present study because of the disappearance of the low-mass peaks in the delayed extraction mode. To resolve this issue, external mass calibration, another regularly used method in TOF-MS, was adapted to enhance mass accuracy in the spectrum and image generated by TOF-SIMS using Ar-GCIB in the delayed extraction mode. By producing spectra analyses of a peptide mixture and bovine serum albumin protein digested with trypsin, along with image analyses of rat brain samples, the authors demonstrate for the first time the enhancement of mass resolution and mass accuracy for the purpose of analyzing large biomolecules in TOF-SIMS using Ar-GCIB through the use of delayed extraction and external mass calibration.

Simultaneous factor analysis of organic particle and gas mass spectra: AMS and PTR-MS measurements at an urban site

NASA Astrophysics Data System (ADS)

Slowik, J. G.; Vlasenko, A.; McGuire, M.; Evans, G. J.; Abbatt, J. P. D.

2009-03-01

During the winter component of the SPORT (Seasonal Particle Observations in the Region of Toronto) field campaign, particulate non-refractory chemical composition and concentration of selected volatile organic compounds (VOCs) were measured by an Aerodyne time-of-flight aerosol mass spectrometer (AMS) and a proton transfer reaction-mass spectrometer (PTR-MS), respectively. Sampling was performed in downtown Toronto ~15 m from a major road. The mass spectra from the AMS and PTR-MS were combined into a unified dataset, which was analyzed using positive matrix factorization (PMF). The two instruments were given equal weight in the PMF analysis by application of a scaling factor to the uncertainties of each instrument. A residual based metric, Δesc, was used to evaluate the relative weight. The PMF analysis yielded a 5-factor solution that included factors characteristic of regional transport, local traffic emissions, charbroiling, and oxidative processing. The unified dataset provides information on particle and VOC sources and atmospheric processing that cannot be obtained from the datasets of the individual instruments, such as apportionment of oxygenated VOCs to direct emission sources vs. secondary reaction products, improved correlation of oxygenated aerosol factors with photochemical age, and increased detail regarding the composition of oxygenated organic aerosol factors. This analysis represents the first application of PMF to a unified AMS/PTR-MS dataset.

Advantages of TOF-SIMS analysis of hydroxyapatite and fluorapatite in comparison with XRD, HR-TEM and FT-IR.

PubMed

Okazaki, Masayuki; Hirata, Isao; Matsumoto, Takuya; Takahashi, Junzo

2005-12-01

The chemical analysis of hydroxyapatite and fluorapatite was carried out using time-of-flight secondary ion mass spectrometry (TOF-SIMS). Hydroxyapatite and fluorapatite were synthesized at 80 +/- 1 degrees C and pH 7.4 +/- 0.2. Fluorapatite was better crystallized, with its (300) reflection shifted to a slightly higher angle. High-resolution transmission electron microscopy clearly revealed a typical, regular hexagonal cross section perpendicular to the c-axis for fluorapatite and a flattened hexagonal cross section for hydroxyapatite. FT-IR spectra of fluorapatite confirmed the absence of OH absorption peak--which was seen in hydroxyapatite at about 3570 cm(-1). TOF-SIMS mass spectra showed a peak at 40 amu due to calcium. In addition, a peak at 19 amu due to fluorine could be clearly seen, although the intensities of PO, PO2, and PO3 were very low. It was confirmed that TOF-SIMS clearly showed the differences between positive and negative mass spectra of hydroxyapatite and fluorapatite, especially for F-. We concluded that TOF-SIMS exhibited distinct advantages compared with other methods of analysis.

Simultaneous factor analysis of organic particle and gas mass spectra: AMS and PTR-MS measurements at an urban site

NASA Astrophysics Data System (ADS)

Slowik, J. G.; Vlasenko, A.; McGuire, M.; Evans, G. J.; Abbatt, J. P. D.

2010-02-01

During the winter component of the SPORT (Seasonal Particle Observations in the Region of Toronto) field campaign, particulate non-refractory chemical composition and concentration of selected volatile organic compounds (VOCs) were measured by an Aerodyne time-of-flight aerosol mass spectrometer (AMS) and a proton transfer reaction-mass spectrometer (PTR-MS), respectively. Sampling was performed in downtown Toronto ~15 m from a major road. The mass spectra from the AMS and PTR-MS were combined into a unified dataset, which was analysed using positive matrix factorization (PMF). The two instruments were given balanced weight in the PMF analysis by the application of a scaling factor to the uncertainties of each instrument. A residual based metric, Δesc, was used to evaluate the instrument relative weight within each solution. The PMF analysis yielded a 6-factor solution that included factors characteristic of regional transport, local traffic emissions, charbroiling and oxidative processing. The unified dataset provides information on emission sources (particle and VOC) and atmospheric processing that cannot be obtained from the datasets of the individual instruments: (1) apportionment of oxygenated VOCs to either direct emission sources or secondary reaction products; (2) improved correlation of oxygenated aerosol factors with photochemical age; and (3) increased detail regarding the composition of oxygenated organic aerosol factors. This analysis represents the first application of PMF to a unified AMS/PTR-MS dataset.

Airborne testing and demonstration of a new flight system based on an Aerodyne N2O-CO2-CO-H2O mini-spectrometer

NASA Astrophysics Data System (ADS)

Gvakharia, A.; Kort, E. A.; Smith, M. L.; Conley, S.

2017-12-01

Nitrous oxide (N2O) is a powerful greenhouse gas and ozone depleting substance. With high atmospheric backgrounds and small relative signals, N2O emissions have been challenging to observe and understand on regional scales with traditional instrumentation. Fast-response airborne measurements with high precision and accuracy can potentially bridge this observational gap. Here we present flight assessments of a new flight system based on an Aerodyne mini-spectrometer as well as a Los Gatos N2O/CO analyzer during the Fertilizer Emissions Airborne Study (FEAST). With the Scientific Aviation Mooney aircraft, we conducted test flights for both analyzers where a known calibration gas was sampled throughout the flight (`null' tests). Clear altitude/cabin-pressure dependencies were observed for both analyzers if operated in an "off-the-shelf' manner. For the remainder of test flights and the FEAST campaign we used a new flight system based on an Aerodyne mini-spectrometer with the addition of a custom pressure control/calibration system. Instead of using traditional approaches with spectral-zeros and infrequent in-flight calibrations, we employ a high-flow system with stable flow control to enable high frequency (2 minutes), short duration (15 seconds) sampling of a known calibration gas. This approach, supported by the null test, enables correction for spectral drift caused by a variety of factors while maintaining a 90% duty cycle for 1Hz sampling from an aircraft. Preliminary in-flight precisions are estimated at 0.05 ppb, 0.1 ppm, 1 ppb, and 10 ppm for N2O, CO2, CO, and H2O respectively. We also present a further 40 hours of inter-comparison in flight with a Picarro 2301-f ring-down spectrometer demonstrating consistency between CO2 and H2O measurements and no altitude dependent error.

Measurement of fine particulate and gas-phase species during the New Year's fireworks 2005 in Mainz, Germany

NASA Astrophysics Data System (ADS)

Drewnick, Frank; Hings, Silke S.; Curtius, Joachim; Eerdekens, Gunter; Williams, Jonathan

The chemical composition and chemically resolved size distributions of fine aerosol particles were measured at high time resolution (5 min) with a time-of-flight aerosol mass spectrometer (TOF-AMS) during the New Year's 2005 fireworks in Mainz, central Germany. In addition, particle number concentrations and trace gas concentrations were measured using a condensation particle counter (CPC) and a proton transfer reaction mass spectrometer (PTR-MS). The main non-refractory components of the firework aerosol were potassium, sulfate, total organics and chloride. Increased trace gas mixing ratios of methanol, acetonitrile, acetone and acetaldehyde were observed. Aerosol nitrate and ammonium concentrations were not significantly affected by the fireworks as well as the measured aromatic trace gases. The sub-micron aerosol concentrations peaked about 20 min after midnight with total mass concentrations larger than 600 μg m -3. The trace gas concentrations peaked about 30 min later. Using the sulfur-to-potassium concentration ratio measured in another fireworks aerosol, it was for the first time possible to estimate the relative ionization efficiency of aerosol potassium, measured with the TOF-AMS. Here we found a value of RIE K=2.9.

Ambient VOC-Measurements by GC-PTR-TOF

NASA Astrophysics Data System (ADS)

Langebner, S.; Schnitzhofer, R.; Hasler, C.; Jocher, M.; Hansel, A.; Brilli, F.

2011-12-01

Authors: Stephan LANGEBNER, Federico BRILLI, Ralf SCHNITZHOFER, Christoph HASLER, Markus JOCHER, Armin HANSEL; During the past 16 years PTR MS (Proton Transfer Reaction Mass Spectrometry) became a well established technique for real time measurements of environmentally important volatile organic compounds (VOCs) [HANSEL 1995]. The recent development of PTR ToF [GRAUS 2010] increased the VOC separation capability by strongly improving the mass separation capability and the duty cycle. Now isobaric compounds can be separated and whole mass spectra are recorded within a fraction of a second. Isomeric VOCs, however, remain undistinguishable with this technique. Therefore a Thermo-Desorption-System-Gas-Chromatograph (TDS GC) with isomeric separation capabilities was coupled with a PTR ToF. The performance of this new GC PTR TOF instrument was evaluated analysing ambient air for several days. The measurement cycle started with simultaneous GC-sampling and direct PTR ToF measurements of ambient air. After the fifteen minute TDS cycle, the output of the GC column was directed to the PTR ToF and the timely separated VOC peaks were recorded for 40 minutes. We will present first results which look very promising e.g. different monoterpene isomers can be clearly distinguished at ambient levels.

A dedicated AMS setup for medium mass isotopes at the Cologne FN tandem accelerator

NASA Astrophysics Data System (ADS)

Schiffer, M.; Altenkirch, R.; Feuerstein, C.; Müller-Gatermann, C.; Hackenberg, G.; Herb, S.; Bhandari, P.; Heinze, S.; Stolz, A.; Dewald, A.

2017-09-01

AMS measurements of medium mass isotopes, e.g. of 53Mn and 60Fe, are gaining interest in various fields of operation, especially geoscience. Therefore a dedicated AMS setup has been built at the Cologne 10 MV FN tandem accelerator. This setup is designed to obtain a sufficient suppression of the stable isobars at energies around 100 MeV. In this contribution we report on the actual status of the new setup and the first in-beam tests of its individual components. The isobar suppression is done with (dE/dx) techniques using combinations of energy degrader foils with an electrostatic analyzer (ESA) and a time of flight (ToF) system, as well as a (dE/dx),E gas ionization detector. Furthermore, the upgraded ion source and its negative ion yield measurement for MnO- are presented.

A field-deployable GC-EI-HRTOF-MS for in situ characterization of volatile organic compounds

NASA Astrophysics Data System (ADS)

Lerner, B. M.; Herndon, S. C.; Yacovitch, T. I.; Roscioli, J. R.; Fortner, E.; Knighton, W. B.; Sueper, D.; Isaacman-VanWertz, G. A.; Jayne, J. T.; Worsnop, D. R.

2017-12-01

Previous authors have demonstrated the value of coupling conventional gas chromatograph (GC) separation techniques with the new generation of electron-impact high-resolution time-of-flight mass spectrometry (EI-HR-ToF-MS) detectors for the measurement of halocarbons and semi-volatile organic species. Here, we present new instrumentation, analytical techniques and field data from the deployment of a GC-EI-HR-ToF-MS system in the mini Aerodyne mobile laboratory to sites upwind and downwind of San Antonio, Texas in May 2017. The instrument employed a multi-component adsorbent trap pre-concertation system followed by single-column separation. We will show results from the field work, including inter-comparison with other VOC measurements and characterization of C5-C10 hydrocarbon mixing ratios to distinguish urban and oil/gas emission sources in characterized air. We will discuss practical aspects of deployment of the GC-EI-HRTOF-MS in a mobile laboratory and system performance in the field. Will we also present further development of Aerodyne's TERN software package for chromatographic data analysis to processing of HRTOF-MS datasets.

Pharmaceutical identifier confirmation via DART-TOF.

PubMed

Easter, Jacob L; Steiner, Robert R

2014-07-01

Pharmaceutical analysis comprises a large amount of the casework in forensic controlled substances laboratories. In order to reduce the time of analysis for pharmaceuticals, a Direct Analysis in Real Time ion source coupled with an accurate mass time-of-flight (DART-TOF) mass spectrometer was used to confirm identity. DART-TOF spectral data for pharmaceutical samples were analyzed and evaluated by comparison to standard spectra. Identical mass pharmaceuticals were differentiated using collision induced dissociation fragmentation, present/absent ions, and abundance comparison box plots; principal component analysis (PCA) and linear discriminant analysis (LDA) were used for differentiation of identical mass mixed drug spectra. Mass assignment reproducibility and robustness tests were performed on the DART-TOF spectra. Impacts on the forensic science community include a decrease in analysis time over the traditional gas chromatograph/mass spectrometry (GC/MS) confirmations, better laboratory efficiency, and simpler sample preparation. Using physical identifiers and the DART-TOF to confirm pharmaceutical identity will eliminate the use of GC/MS and effectively reduce analysis time while still complying with accepted analysis protocols. This will prove helpful in laboratories with large backlogs and will simplify the confirmation process. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Accelerated time-of-flight (TOF) PET image reconstruction using TOF bin subsetization and TOF weighting matrix pre-computation.

PubMed

Mehranian, Abolfazl; Kotasidis, Fotis; Zaidi, Habib

2016-02-07

Time-of-flight (TOF) positron emission tomography (PET) technology has recently regained popularity in clinical PET studies for improving image quality and lesion detectability. Using TOF information, the spatial location of annihilation events is confined to a number of image voxels along each line of response, thereby the cross-dependencies of image voxels are reduced, which in turns results in improved signal-to-noise ratio and convergence rate. In this work, we propose a novel approach to further improve the convergence of the expectation maximization (EM)-based TOF PET image reconstruction algorithm through subsetization of emission data over TOF bins as well as azimuthal bins. Given the prevalence of TOF PET, we elaborated the practical and efficient implementation of TOF PET image reconstruction through the pre-computation of TOF weighting coefficients while exploiting the same in-plane and axial symmetries used in pre-computation of geometric system matrix. In the proposed subsetization approach, TOF PET data were partitioned into a number of interleaved TOF subsets, with the aim of reducing the spatial coupling of TOF bins and therefore to improve the convergence of the standard maximum likelihood expectation maximization (MLEM) and ordered subsets EM (OSEM) algorithms. The comparison of on-the-fly and pre-computed TOF projections showed that the pre-computation of the TOF weighting coefficients can considerably reduce the computation time of TOF PET image reconstruction. The convergence rate and bias-variance performance of the proposed TOF subsetization scheme were evaluated using simulated, experimental phantom and clinical studies. Simulations demonstrated that as the number of TOF subsets is increased, the convergence rate of MLEM and OSEM algorithms is improved. It was also found that for the same computation time, the proposed subsetization gives rise to further convergence. The bias-variance analysis of the experimental NEMA phantom and a clinical

Accelerated time-of-flight (TOF) PET image reconstruction using TOF bin subsetization and TOF weighting matrix pre-computation

NASA Astrophysics Data System (ADS)

Mehranian, Abolfazl; Kotasidis, Fotis; Zaidi, Habib

2016-02-01

Time-of-flight (TOF) positron emission tomography (PET) technology has recently regained popularity in clinical PET studies for improving image quality and lesion detectability. Using TOF information, the spatial location of annihilation events is confined to a number of image voxels along each line of response, thereby the cross-dependencies of image voxels are reduced, which in turns results in improved signal-to-noise ratio and convergence rate. In this work, we propose a novel approach to further improve the convergence of the expectation maximization (EM)-based TOF PET image reconstruction algorithm through subsetization of emission data over TOF bins as well as azimuthal bins. Given the prevalence of TOF PET, we elaborated the practical and efficient implementation of TOF PET image reconstruction through the pre-computation of TOF weighting coefficients while exploiting the same in-plane and axial symmetries used in pre-computation of geometric system matrix. In the proposed subsetization approach, TOF PET data were partitioned into a number of interleaved TOF subsets, with the aim of reducing the spatial coupling of TOF bins and therefore to improve the convergence of the standard maximum likelihood expectation maximization (MLEM) and ordered subsets EM (OSEM) algorithms. The comparison of on-the-fly and pre-computed TOF projections showed that the pre-computation of the TOF weighting coefficients can considerably reduce the computation time of TOF PET image reconstruction. The convergence rate and bias-variance performance of the proposed TOF subsetization scheme were evaluated using simulated, experimental phantom and clinical studies. Simulations demonstrated that as the number of TOF subsets is increased, the convergence rate of MLEM and OSEM algorithms is improved. It was also found that for the same computation time, the proposed subsetization gives rise to further convergence. The bias-variance analysis of the experimental NEMA phantom and a clinical

A new application of hierarchical cluster analysis to investigate organic peaks in bulk mass spectra obtained with an Aerodyne Aerosol Mass Spectrometer

NASA Astrophysics Data System (ADS)

Middlebrook, A. M.; Marcolli, C.; Canagaratna, M. R.; Worsnop, D. R.; Bahreini, R.; de Gouw, J. A.; Warneke, C.; Goldan, P. D.; Kuster, W. C.; Williams, E. J.; Lerner, B. M.; Roberts, J. M.; Meagher, J. F.; Fehsenfeld, F. C.; Marchewka, M. L.; Bertman, S. B.

2006-12-01

We applied hierarchical cluster analysis to an Aerodyne aerosol mass spectrometer (AMS) bulk mass spectral dataset collected aboard the NOAA research vessel Ronald H. Brown during the 2002 New England Air Quality Study off the east coast of the United States. Emphasizing the organic peaks, the cluster analysis yielded a series of categories that are distinguishable with respect to their mass spectra and their occurrence as a function of time. The differences between the categories mainly arise from relative intensity changes rather than from the presence or absence of specific peaks. The most frequent category exhibits a strong signal at m/z 44 and represents oxidized organic matter probably originating from both anthropogenic as well as biogenic sources. On the basis of spectral and trace gas correlations, the second most common category with strong signals at m/z 29, 43, and 44 contains contributions from isoprene oxidation products. The third through the fifth most common categories have peak patterns characteristic of monoterpene oxidation products and were most frequently observed when air masses from monoterpene rich regions were sampled. Taken together, the second through the fifth most common categories represent on average 17% of the total organic mass that stems likely from biogenic sources during the ship's cruise. These numbers have to be viewed as lower limits since the most common category was attributed to anthropogenic sources for this calculation. The cluster analysis was also very effective in identifying a few contaminated mass spectra that were not removed during pre-processing. This study demonstrates that hierarchical clustering is a useful tool to analyze the complex patterns of the organic peaks in bulk aerosol mass spectra from a field study.

Mobile Measurements of Gas and Particle Emissions from Marcellus Shale Gas Development

NASA Astrophysics Data System (ADS)

DeCarlo, P. F.; Goetz, J. D.; Floerchinger, C. R.; Fortner, E.; Wormhoudt, J.; Knighton, W. B.; Herndon, S.; Kolb, C. E.; Shaw, S. L.; Knipping, E. M.

2013-12-01

Production of natural gas in the Marcellus shale is increasing rapidly due to the vast quantities of natural gas stored in the formation. Transient and long-term activities have associated emissions to the atmosphere of methane, volatile organic compounds, NOx, particulates and other species from gas production and transport infrastructure. In the summer of 2012, a team of researchers from Drexel University and Aerodyne Research deployed the Aerodyne mobile laboratory (AML) and measured in-situ concentrations of gas-phase and aerosol chemical components in the main gas producing regions of Pennsylvania, with the overall goal of understanding the impacts to regional ozone and particulate matter (PM) concentrations. State-of-the-art instruments including quantum cascade laser systems, proton transfer mass spectrometry, tunable diode lasers and a soot particle aerosol mass spectrometer, were used quantify concentrations of pollutants of interest. Chemical species measured include methane, ethane, NO, NO2, CO, CO2, SO2, and many volatile organic compounds, and aerosol size and chemical composition. Tracer-release techniques were employed to link sources with emissions and to quantify emission rates from gas facilities, in order to understand the regional burden of these chemical species from oil and gas development in the Marcellus. Measurements were conducted in two regions of Pennsylvania: the NE region that is predominantly dry gas (95% + methane), and the SW region where wet gas (containing greater than 5% higher hydrocarbons) is found. Regional scale measurements of current levels of air pollutants will be shown and will put into context how further development of the gas resource in one of the largest natural gas fields in the world impacts air quality in a region upwind of the highly urbanized east coast corridor.

Generalized interpretation scheme for arbitrary HR InSAR image pairs

NASA Astrophysics Data System (ADS)

Boldt, Markus; Thiele, Antje; Schulz, Karsten

2013-10-01

Land cover classification of remote sensing imagery is an important topic of research. For example, different applications require precise and fast information about the land cover of the imaged scenery (e.g., disaster management and change detection). Focusing on high resolution (HR) spaceborne remote sensing imagery, the user has the choice between passive and active sensor systems. Passive systems, such as multispectral sensors, have the disadvantage of being dependent from weather influences (fog, dust, clouds, etc.) and time of day, since they work in the visible part of the electromagnetic spectrum. Here, active systems like Synthetic Aperture Radar (SAR) provide improved capabilities. As an interactive method analyzing HR InSAR image pairs, the CovAmCohTM method was introduced in former studies. CovAmCoh represents the joint analysis of locality (coefficient of variation - Cov), backscatter (amplitude - Am) and temporal stability (coherence - Coh). It delivers information on physical backscatter characteristics of imaged scene objects or structures and provides the opportunity to detect different classes of land cover (e.g., urban, rural, infrastructure and activity areas). As example, railway tracks are easily distinguishable from other infrastructure due to their characteristic bluish coloring caused by the gravel between the sleepers. In consequence, imaged objects or structures have a characteristic appearance in CovAmCoh images which allows the development of classification rules. In this paper, a generalized interpretation scheme for arbitrary InSAR image pairs using the CovAmCoh method is proposed. This scheme bases on analyzing the information content of typical CovAmCoh imagery using the semisupervised k-means clustering. It is shown that eight classes model the main local information content of CovAmCoh images sufficiently and can be used as basis for a classification scheme.

The physico-chemical evolution of atmospheric aerosols and the gas-particle partitioning of inorganic aerosol during KORUS-AQ

NASA Astrophysics Data System (ADS)

Lee, T.; Park, T.; Lee, J. B.; Lim, Y. J.; Ahn, J.; Park, J. S.; Soo, C. J.; Desyaterik, Y.; Collett, J. L., Jr.

2017-12-01

Aerosols influence climate change directly by scattering and absorption and indirectly by acting as cloud condensation nuclei and some of the effects of aerosols are reduction in visibility, deterioration of human health, and deposition of pollutants to ecosystems. Urban area is large source of aerosols and aerosol precursors. Aerosol sources are both local and from long-range transport. Long-range transport processed aerosol are often dominant sources of aerosol pollution in Korea. To improve our knowledge of aerosol chemistry, Korea and U.S-Air Quality (KORUS-AQ) of Aircraft-based aerosol measurement took place in and around Seoul, Korea during May and June 2016. KORUS-AQ campaigns were conducted to study the chemical characterization and processes of pollutants in the Seoul Metropolitan area to regional scales of Korean peninsula. Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed on aircraft platforms on-board DC-8 (NASA) aircraft. We characterized aerosol chemical properties and mass concentrations of sulfate, nitrate, ammonium and organics in polluted air plumes and investigate the spatial and vertical distribution of the species. The results of studies show that organics is predominant in Aerosol and a significant fraction of the organics is oxygenated organic aerosol (OOA) at the high altitude. Both Nitrate and sulfate can partition between the gas and particle phases. The ratios for HNO3/(N(V) (=gaseous HNO3 + particulate Nitrate) and SO2/(SO2+Sulfate) were found to exhibit quite different distributions between the particles and gas phase for the locations during KORUS-AQ campaign, representing potential for formation of additional particulate nitrate and sulfate. The results of those studies can provide highly resolved temporal and spatial air pollutant, which are valuable for air quality model input parameters for aerosol behaviour.

Cluster Analysis of the Organic Peaks in Bulk Mass Spectra Obtained During the 2002 New England Air Quality Study with an Aerodyne Aerosol Mass Spectrometer

NASA Astrophysics Data System (ADS)

Marcolli, C.; Canagaratna, M. R.; Worsnop, D. R.; Bahreini, R.; de Gouw, J. A.; Warneke, C.; Goldan, P. D.; Kuster, W. C.; Williams, E. J.; Lerner, B. M.; Roberts, J. M.; Meagher, J. F.; Fehsenfeld, F. C.; Marchewka, M.; Bertman, S. B.; Middlebrook, A. M.

2006-12-01

We applied hierarchical cluster analysis to an Aerodyne aerosol mass spectrometer (AMS) bulk mass spectral dataset collected aboard the NOAA research vessel R. H. Brown during the 2002 New England Air Quality Study off the east coast of the United States. Emphasizing the organic peaks, the cluster analysis yielded a series of categories that are distinguishable with respect to their mass spectra and their occurrence as a function of time. The differences between the categories mainly arise from relative intensity changes rather than from the presence or absence of specific peaks. The most frequent category exhibits a strong signal at m/z 44 and represents oxidized organic matter probably originating from both anthropogenic as well as biogenic sources. On the basis of spectral and trace gas correlations, the second most common category with strong signals at m/z 29, 43, and 44 contains contributions from isoprene oxidation products. The third through the fifth most common categories have peak patterns characteristic of monoterpene oxidation products and were most frequently observed when air masses from monoterpene rich regions were sampled. Taken together, the second through the fifth most common categories represent on average 17% of the total organic mass that stems likely from biogenic sources during the ship's cruise. These numbers have to be viewed as lower limits since the most common category was attributed to anthropogenic sources for this calculation. The cluster analysis was also very effective in identifying a few contaminated mass spectra that were not removed during pre-processing. This study demonstrates that hierarchical clustering is a useful tool to analyze the complex patterns of the organic peaks in bulk aerosol mass spectra from a field study.

Highly time-resolved chemical characterization of atmospheric submicron particles during 2008 Beijing Olympic Games using an Aerodyne High-Resolution Aerosol Mass Spectrometer

NASA Astrophysics Data System (ADS)

Huang, X.-F.; He, L.-Y.; Hu, M.; Canagaratna, M. R.; Sun, Y.; Zhang, Q.; Zhu, T.; Xue, L.; Zeng, L.-W.; Liu, X.-G.; Zhang, Y.-H.; Jayne, J. T.; Ng, N. L.; Worsnop, D. R.

2010-09-01

As part of Campaigns of Air Quality Research in Beijing and Surrounding Region-2008 (CAREBeijing-2008), an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed in urban Beijing to characterize submicron aerosol particles during the time of 2008 Beijing Olympic Games and Paralympic Games (24 July to 20 September 2008). The campaign mean PM1 mass concentration was 63.1 ± 39.8 μg m-3; the mean composition consisted of organics (37.9%), sulfate (26.7%), ammonium (15.9%), nitrate (15.8%), black carbon (3.1%), and chloride (0.87%). The average size distributions of the species (except BC) were all dominated by an accumulation mode peaking at about 600 nm in vacuum aerodynamic diameter, and organics was characterized by an additional smaller mode extending below 100 nm. Positive Matrix Factorization (PMF) analysis of the high resolution organic mass spectral dataset differentiated the organic aerosol into four components, i.e., hydrocarbon-like (HOA), cooking-related (COA), and two oxygenated organic aerosols (OOA-1 and OOA-2), which on average accounted for 18.1, 24.4, 33.7 and 23.7% of the total organic mass, respectively. The HOA was identified to be closely associated with primary combustion sources, while the COA mass spectrum and diurnal pattern showed similar characteristics to that measured for cooking emissions. The OOA components correspond to aged secondary organic aerosol. Although the two OOA components have similar elemental (O/C, H/C) compositions, they display differences in mass spectra and time series which appear to correlate with the different source regions sampled during the campaign. Back trajectory clustering analysis indicated that the southerly air flows were associated with the highest PM1 pollution during the campaign. Aerosol particles in southern airmasses were especially rich in inorganic and oxidized organic species. Aerosol particles in northern airmasses contained a large fraction of primary HOA

High-resolution abundance analysis of the metallic-line star HR 7250

NASA Astrophysics Data System (ADS)

Elmaslı, Aslı; Ünal, Kübraözge; Çalışkan, Şeyma

2018-07-01

We estimated the stellar parameters and chemical abundances of the highly neglected A-type star HR 7250. The star's high resolution spectrum, spanning a wavelength range from 3900 to 7900 Å, was obtained at the TÜBİTAK National Observatory. We derived the abundances of 14 elements (O, Na, Mg, Si, S, Ca, Sc, Ti, Cr, Fe, Ni, Sr, Y, and Ba) for HR 7250 from the unblended lines of the star's spectrum. Our analysis shows that HR 7250 is a chemically peculiar Am star. We also estimated its age and mass as 400 ± 70 Myr and 3.25 ± 0.17 M⊙ from evolutionary tracks and isochrones.

Secondary organic aerosol formation from isoprene photo-oxidation during cloud condensation-evaporation cycles (CUMULUS project)

NASA Astrophysics Data System (ADS)

Brégonzio-Rozier, Lola; Siekmann, Frank; Giorio, Chiara; Temime-Roussel, Brice; Pangui, Edouard; Morales, Sébastien; Gratien, Aline; Ravier, Sylvain; Monod, Anne; Doussin, Jean-Francois

2014-05-01

It is acknowledged that atmospheric photo-oxidation of Volatile Organic Compounds (VOC) leads to the formation of less volatile oxidized species. These compounds can undergo gas-to-particle conversion, leading to the formation of Secondary Organic Aerosols (SOA) in the atmosphere. Nevertheless, some of these oxidized species are water soluble and could also partition into cloud droplets. Higher molecular weight and less volatile compounds could be produced in the aqueous phase and remain in the particle phase after water evaporation (Ervens et al., 2011). The aim of the present work is to study SOA formation in the presence of cloud droplets during isoprene photo-oxidation. To this end, an original multiphase approach in a simulation chamber was set up in order to investigate the chemistry occurring in the gaseous, particulate and aqueous phases, and the exchange between these phases. Experiments were performed, within the CUMULUS project (CloUd MULtiphase chemistry of organic compoUndS in the troposphere), in the CESAM chamber (Wang et al., 2011). This chamber was designed to investigate multiphase processes under realistic actinic flux, and accurate control of both temperature and relative humidity. A specific protocol was set up to produce cloud events in the simulation chamber exhibiting a significant lifetime in the presence of light (10-12 minutes). By using this protocol, many clouds could be generated in a single experiment. In each experiment, around 800 ppb of isoprene was injected in the chamber together with HONO under dry conditions before irradiation. A Fourier Transform Infrared Spectrometer (FTIR), a Proton Transfer Reaction Mass Spectrometer (PTR-TOF-MS) and NOx and O3 analyzers were used to analyze gas-phase composition. Dried SOA size distributions and total concentrations were measured by a Scanning Mobility Particle Sizer (SMPS). An Aerodyne High Resolution Time-Of-Flight Aerosol Mass Spectrometer (HR-TOF-AMS) was also used to investigate

Aircraft-based Aerosol Size and Composition Measurements during ACE-Asia and CRYSTAL-FACE using an Aerodyne Aerosol Mass Spectrometer

NASA Astrophysics Data System (ADS)

Bahreini, R.; Jimenez, J.; Delia, A.; Flagan, R. C.; Seinfeld, J. H.; Jayne, J. T.; Worsnop, D. R.

2002-12-01

An Aerodyne Aerosol Mass Spectrometer (AMS) was deployed in an aircraft for the first time during the ACE-Asia field campaign. The AMS was operated on board the CIRPAS Twin Otter aircraft to measure the size-resolved chemical composition of the submicron aerosols in the outflow from Eastern Asia. Research flights were carried out from March 31 to May 1, 2001 in an area that covered 127 E-135 E and 32 N-38 N on longitude and latitude, respectively. The submicron aerosol was typically distributed in distinct layers (from the boundary layer to ~ 3700 m). This is consistent with other on-board measurements. The aerosol in the pollution layers was mainly composed of sulfate, ammonium, and organics separated by cleaner layers. Sub-micron nitrate aerosols were also detected in some layers. Since the molar ratio of positive to negative ions did not exceed one on most of the constant altitude legs of the flights, the particles were not completely neutralized. Sulfate and organics concentrations of up to 10 and 5 ug m-3 (STP), respectively, were measured on some pollution layers. AMS measurements of sulfate concentration and NH4/SO4 mass ratio (~0.16 on average) are consistent with previously reported measurements at Cheju Island, South Korea [Charmichael et al., 1997; Chen et al., 1997] and Sapporo, Japan [Kaneyasu et al., 1995]. The mass-weighed size distribution of the sub-micron sulfate was relatively constant from day to day and layer to layer, with an aerodynamic mode at 350-500 nm (vacuum aerodynamic diameter) and FWHM ~ 400 nm on most of the layers. Furthermore, the ratios between SO4/ NH4/ NO3/ Organics were approximately independent of size in the sub-micron size range. Comparisons of AMS data to other on-board aerosol measurements will be presented. In particular, the AMS mass concentration correlates well with the aerosol volume determined by the on-board Differential Automated Classifying Aerosol Detector (DCAD). In addition, preliminary results of airborne size

HR Public meeting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heuer, Rolf; Catherin, Anne-Sylvie; Vuillemin, Vin

2010-06-25

Cher(e)s collègues, En collaboration avec le Département HR, le Directeur général a le plaisir de vous convier à une réunion publique qui se tiendra le vendredi 25 juin 2010 à 9h30 dans l’Amphithéâtre principal (Bâtiment 500)*. Un café d’accueil y sera servi à partir de 9h. Cette réunion abordera les thèmes suivants : • Valeurs de l’Organisation (Directeur général) • Code de Conduite (Directeur général / Anne-Sylvie Catherin) • Création du nouveau rôle d’Ombudsperson (Vincent Vuillemin); Ces présentations seront suivies d’une séance de questions-réponses. Nous espérons vous retrouver nombreux le 25 juin ! Meilleures salutations, Anne-Sylvie Catherin Chef du Départementmore » des Ressources humaines *Cette réunion sera retransmise simultanément dans l’Amphithéâtre BE de Prévessin (Bâtiment 864) et également disponible à l’adresse suivante : http://webcast.cern.ch. Dear colleagues, In collaboration with HR Department, the Director-General would like to invite you to an information meeting which will be held on Friday 25 June 2010 at 9:30 am in the Main Auditorium (Building 500)*. A welcome coffee will be available from 9:00 am. During this meeting, information will be given about: • Organization’s values (Director-General) • Code of Conduct (Director-General / Anne-Sylvie Catherin) • New Ombudsperson role (Vincent Vuillemin) These presentations will be followed by a questions & answers session. We look forward to seeing you all on 25 June! Best regards, Anne-Sylvie Catherin Head, Human Resources Department. This meeting will be simultaneously retransmitted in BE Auditorium (Building 864) and available at the following address: http://webcast.cern.ch.« less

HR Public meeting

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-10-12

Cher(e)s collègues, En collaboration avec le Département HR, le Directeur général a le plaisir de vous convier à une réunion publique qui se tiendra le vendredi 25 juin 2010 à 9h30 dans l’Amphithéâtre principal (Bâtiment 500)*. Un café d’accueil y sera servi à partir de 9h. Cette réunion abordera les thèmes suivants : Valeurs de l’Organisation (Directeur général); Code de Conduite (Directeur général / Anne-Sylvie Catherin); Création du nouveau rôle d’Ombudsperson (Vincent Vuillemin) Ces présentations seront suivies d’une séance de questions-réponses. Nous espérons vous retrouver nombreux le 25 juin ! Meilleures salutations, Anne-Sylvie Catherin Chef du Département des Ressources humainesmore » *Cette réunion sera retransmise simultanément dans l’Amphithéâtre BE de Prévessin (Bâtiment 864) et également disponible à l’adresse suivante : http://webcast.cern.ch [Dear colleagues, In collaboration with HR Department, the Director-General would like to invite you to an information meeting which will be held on Friday 25 June 2010 at 9:30 am in the Main Auditorium (Building 500)*. A welcome coffee will be available from 9:00 am. During this meeting, information will be given about: Organization’s values (Director-General); Code of Conduct (Director-General / Anne-Sylvie Catherin); New Ombudsperson role (Vincent Vuillemin); These presentations will be followed by a questions & answers session. We look forward to seeing you all on 25 June! Best regards, Anne-Sylvie Catherin Head, Human Resources Department *This meeting will be simultaneously retransmitted in BE Auditorium (Building 864) and available at the following address: http://webcast.cern.ch.« less

Secondary metabolite profiling of Curcuma species grown at different locations using GC/TOF and UPLC/Q-TOF MS.

PubMed

Lee, Jueun; Jung, Youngae; Shin, Jeoung-Hwa; Kim, Ho Kyoung; Moon, Byeong Cheol; Ryu, Do Hyun; Hwang, Geum-Sook

2014-07-04

Curcuma, a genus of rhizomatous herbaceous species, has been used as a spice, traditional medicine, and natural dye. In this study, the metabolite profile of Curcuma extracts was determined using gas chromatography-time of flight mass spectrometry (GC/TOF MS) and ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) to characterize differences between Curcuma aromatica and Curcuma longa grown on the Jeju-do or Jin-do islands, South Korea. Previous studies have performed primary metabolite profiling of Curcuma species grown in different regions using NMR-based metabolomics. This study focused on profiling of secondary metabolites from the hexane extract of Curcuma species. Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) plots showed significant differences between the C. aromatica and C. longa metabolite profiles, whereas geographical location had little effect. A t-test was performed to identify statistically significant metabolites, such as terpenoids. Additionally, targeted profiling using UPLC/Q-TOF MS showed that the concentration of curcuminoids differed depending on the plant origin. Based on these results, a combination of GC- and LC-MS allowed us to analyze curcuminoids and terpenoids, the typical bioactive compounds of Curcuma, which can be used to discriminate Curcuma samples according to species or geographical origin.

Dose Optimization in TOF-PET/MR Compared to TOF-PET/CT

PubMed Central

Queiroz, Marcelo A.; Delso, Gaspar; Wollenweber, Scott; Deller, Timothy; Zeimpekis, Konstantinos; Huellner, Martin; de Galiza Barbosa, Felipe; von Schulthess, Gustav; Veit-Haibach, Patrick

2015-01-01

Purpose To evaluate the possible activity reduction in FDG-imaging in a Time-of-Flight (TOF) PET/MR, based on cross-evaluation of patient-based NECR (noise equivalent count rate) measurements in PET/CT, cross referencing with phantom-based NECR curves as well as initial evaluation of TOF-PET/MR with reduced activity. Materials and Methods A total of 75 consecutive patients were evaluated in this study. PET/CT imaging was performed on a PET/CT (time-of-flight (TOF) Discovery D 690 PET/CT). Initial PET/MR imaging was performed on a newly available simultaneous TOF-PET/MR (Signa PET/MR). An optimal NECR for diagnostic purposes was defined in clinical patients (NECRP) in PET/CT. Subsequent optimal activity concentration at the acquisition time ([A]0) and target NECR (NECRT) were obtained. These data were used to predict the theoretical FDG activity requirement of the new TOF-PET/MR system. Twenty-five initial patients were acquired with (retrospectively reconstructed) different imaging times equivalent for different activities on the simultaneous PET/MR for the evaluation of clinically realistic FDG-activities. Results The obtained values for NECRP, [A]0 and NECRT were 114.6 (± 14.2) kcps (Kilocounts per second), 4.0 (± 0.7) kBq/mL and 45 kcps, respectively. Evaluating the NECRT together with the phantom curve of the TOF-PET/MR device, the theoretical optimal activity concentration was found to be approximately 1.3 kBq/mL, which represents 35% of the activity concentration required by the TOF-PET/CT. Initial evaluation on patients in the simultaneous TOF-PET/MR shows clinically realistic activities of 1.8 kBq/mL, which represent 44% of the required activity. Conclusion The new TOF-PET/MR device requires significantly less activity to generate PET-images with good-to-excellent image quality, due to improvements in detector geometry and detector technologies. The theoretically achievable dose reduction accounts for up to 65% but cannot be fully translated into clinical

Preliminary Analysis of High-Flux RSG-GAS to Transmute Am-241 of PWR’s Spent Fuel in Asian Region

NASA Astrophysics Data System (ADS)

Budi Setiawan, M.; Kuntjoro, S.

2018-02-01

A preliminary study of minor actinides (MA) transmutation in the high flux profile RSG-GAS research reactor was performed, aiming at an optimal transmutation loading for present nuclear energy development. The MA selected in the analysis includes Am-241 discharged from pressurized water reactors (PWRs) in Asian region. Until recently, studies have been undertaken in various methods to reduce radiotoxicity from actinides in high-level waste. From the cell calculation using computer code SRAC2006, it is obtained that the target Am-241 which has a cross section of the thermal energy absorption in the region (group 8) is relatively large; it will be easily burned in the RSG-GAS reactor. Minor actinides of Am-241 which can be inserted in the fuel (B/T fuel) is 2.5 kg which is equivalent to Am-241 resulted from the partition of spent fuel from 2 units power reactors PWR with power 1000MW(th) operated for one year.

Cluster analysis of the organic peaks in bulk mass spectra obtained during the 2002 New England Air Quality Study with an Aerodyne aerosol mass spectrometer

NASA Astrophysics Data System (ADS)

Marcolli, C.; Canagaratna, M. R.; Worsnop, D. R.; Bahreini, R.; de Gouw, J. A.; Warneke, C.; Goldan, P. D.; Kuster, W. C.; Williams, E. J.; Lerner, B. M.; Roberts, J. M.; Meagher, J. F.; Fehsenfeld, F. C.; Marchewka, M. L.; Bertman, S. B.; Middlebrook, A. M.

2006-06-01

We applied hierarchical cluster analysis to an Aerodyne aerosol mass spectrometer (AMS) bulk mass spectral dataset collected aboard the NOAA research vessel Ronald H. Brown during the 2002 New England Air Quality Study off the east coast of the United States. Emphasizing the organic peaks, the cluster analysis yielded a series of categories that are distinguishable with respect to their mass spectra and their occurrence as a function of time. The differences between the categories mainly arise from relative intensity changes rather than from the presence or absence of specific peaks. The most frequent category exhibits a strong signal at m/z 44 and represents oxidized organic matter most probably originating from both, anthropogenic as well as biogenic sources. On the basis of spectral and trace gas correlations, the second most common category with strong signals at m/z 29, 43, and 44 contains contributions from isoprene oxidation products. The third through the fifth most common categories have peak patterns characteristic of monoterpene oxidation products and were most frequently observed when air masses from monoterpene rich regions were sampled. Taken together, the second through the fifth most common categories represent as much as 5 µg/m3 organic aerosol mass - 17% of the total organic mass - that can be attributed to biogenic sources. These numbers have to be viewed as lower limits since the most common category was attributed to anthropogenic sources for this calculation. The cluster analysis was also very effective in identifying a few contaminated mass spectra that were not removed during pre-processing. This study demonstrates that hierarchical clustering is a useful tool to analyze the complex patterns of the organic peaks in bulk aerosol mass spectra from a field study.

DEVELOPMENT AND APPLICATION OF A MASS SPECTRA-VOLATILITY DATABASE OF COMBUSTION AND SECONDARY ORGANIC AEROSOL SOURCES FOR THE AERODYNE AEROSOL MASS SPECTROMETER

EPA Science Inventory

1. Thermodenuder Development:

Two TD systems were designed, constructed, and tested at Aerodyne. In this design, the vaporizer consists of a 50 cm long, 1 inch OD stainless steel tube wrapped with three heating tapes and fiberglass insulation and then mounted in a sta...

Structural analysis of aerosol particles by microscopic observation using a time-of-flight secondary ion mass spectrometer

NASA Astrophysics Data System (ADS)

Takami, Akinori; Mayama, Norihito; Sakamoto, Tetsuo; Ohishi, Kenji; Irei, Satoshi; Yoshino, Ayako; Hatakeyama, Shiro; Murano, Kentaro; Sadanaga, Yasuhiro; Bandow, Hiroshi; Misawa, Kentaro; Fujii, Masaaki

2013-06-01

The chemical composition and structure of fine aerosol particles with diameters of less than 1 µm were analyzed in the spring of 2011 at Fukue Island, Japan, using an aerosol quadrupole mass spectrometer (Q-AMS, Aerodyne Research, Inc.) and a time-of-flight secondary ion mass spectrometer (TOF-SIMS). The Q-AMS results were similar to those of previous studies conducted at the same location, suggesting that the composition we observed is typical of this site. Based on the TOF-SIMS results, we classified the fine aerosol particles into three types: Type A, in which sulfate was covered with organic matter (OM); Type B, in which soil-containing particles with a diameter of 0.5 µm were associated with sulfate and OM; and Type C, in which black carbon (BC) and sulfate aggregates were associated with OM. During the observation period, the relative abundances of Type A, B, and C particles were 55%, 20%, and 25%, respectively. The structure, chemical composition, and the proportion of each type of particles provide information for a more representative particle model in radiative models. The relative abundance of Type C, i.e., BC-containing particles, is quite different to that in Tokyo, suggesting that Type C could be an indicator of transboundary air pollution, in this case from mainland China.

Phase partitioning and volatility of secondary organic aerosol components formed from α-pinene ozonolysis and OH oxidation: the importance of accretion products and other low volatility compounds

DOE PAGES

Lopez-Hilfiker, F. D.; Mohr, C.; Ehn, M.; ...

2015-07-16

We measured a large suite of gas- and particle-phase multi-functional organic compounds with a Filter Inlet for Gases and AEROsols (FIGAERO) coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) developed at the University of Washington. The instrument was deployed on environmental simulation chambers to study monoterpene oxidation as a secondary organic aerosol (SOA) source. We focus here on results from experiments utilizing an ionization method most selective towards acids (acetate negative ion proton transfer), but our conclusions are based on more general physical and chemical properties of the SOA. Hundreds of compounds were observed in both gas andmore » particle phases, the latter being detected by temperature-programmed thermal desorption of collected particles. Particulate organic compounds detected by the FIGAERO–HR-ToF-CIMS are highly correlated with, and explain at least 25–50 % of, the organic aerosol mass measured by an Aerodyne aerosol mass spectrometer (AMS). Reproducible multi-modal structures in the thermograms for individual compounds of a given elemental composition reveal a significant SOA mass contribution from high molecular weight organics and/or oligomers (i.e., multi-phase accretion reaction products). Approximately 50 % of the HR-ToF-CIMS particle-phase mass is associated with compounds having effective vapor pressures 4 or more orders of magnitude lower than commonly measured monoterpene oxidation products. The relative importance of these accretion-type and other extremely low volatility products appears to vary with photochemical conditions. We present a desorption-temperature-based framework for apportionment of thermogram signals into volatility bins. The volatility-based apportionment greatly improves agreement between measured and modeled gas-particle partitioning for select major and minor components of the SOA, consistent with thermal decomposition during desorption causing the

MALDI-TOF mass spectrometry-based identification of group A Streptococcus isolated from areas of the 2011 scarlet fever outbreak in china.

PubMed

Xiao, Di; You, Yuanhai; Bi, Zhenwang; Wang, Haibin; Zhang, Yongchan; Hu, Bin; Song, Yanyan; Zhang, Huifang; Kou, Zengqiang; Yan, Xiaomei; Zhang, Menghan; Jin, Lianmei; Jiang, Xihong; Su, Peng; Bi, Zhenqiang; Luo, Fengji; Zhang, Jianzhong

2013-03-01

There was a dramatic increase in scarlet fever cases in China from March to July 2011. Group A Streptococcus (GAS) is the only pathogen known to cause scarlet fever. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) coupled to Biotyper system was used for GAS identification in 2011. A local reference database (LRD) was constructed, evaluated and used to identify GAS isolates. The 75 GAS strains used to evaluate the LRD were all identified correctly. Of the 157 suspected β-hemolytic strains isolated from 298 throat swab samples, 127 (100%) and 120 (94.5%) of the isolates were identified as GAS by the MALDI-TOF MS system and the conventional bacitracin sensitivity test method, respectively. All 202 (100%) isolates were identified at the species level by searching the LRD, while 182 (90.1%) were identified by searching the original reference database (ORD). There were statistically significant differences with a high degree of credibility at species level (χ(2)=6.052, P<0.05 between the LRD and ORD). The test turnaround time was shortened 36-48h, and the cost of each sample is one-tenth of the cost of conventional methods. Establishing a domestic database is the most effective way to improve the identification efficiency using a MALDI-TOF MS system. MALDI-TOF MS is a viable alternative to conventional methods and may aid in the diagnosis and surveillance of GAS. Copyright © 2013 Elsevier B.V. All rights reserved.

Measurements of the aerosol chemical composition and mixing state in the Po Valley using multiple spectroscopic techniques

NASA Astrophysics Data System (ADS)

Decesari, S.; Allan, J.; Plass-Duelmer, C.; Williams, B. J.; Paglione, M.; Facchini, M. C.; O'Dowd, C.; Harrison, R. M.; Gietl, J. K.; Coe, H.; Giulianelli, L.; Gobbi, G. P.; Lanconelli, C.; Carbone, C.; Worsnop, D.; Lambe, A. T.; Ahern, A. T.; Moretti, F.; Tagliavini, E.; Elste, T.; Gilde, S.; Zhang, Y.; Dall'Osto, M.

2014-04-01

The use of co-located multiple spectroscopic techniques can provide detailed information on the atmospheric processes regulating aerosol chemical composition and mixing state. So far, field campaigns heavily equipped with aerosol mass spectrometers have been carried out mainly in large conurbations and in areas directly affected by their outflow, whereas lesser efforts have been dedicated to continental areas characterized by a less dense urbanization. We present here the results obtained in San Pietro Capofiume, which is located in a sparsely inhabited sector of the Po Valley, Italy. The experiment was carried out in summer 2009 in the framework of the EUCAARI project ("European Integrated Project on Aerosol, Cloud Climate Aerosol Interaction"). For the first time in Europe, six state-of-the-art techniques were used in parallel: (1) on-line TSI aerosol time-of-flight mass spectrometer (ATOFMS), (2) on-line Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS), (3) soot particle aerosol mass spectrometer (SP-AMS), (4) on-line high resolution time-of-flight mass spectrometer-thermal desorption aerosol gas chromatograph (HR-ToFMS-TAG), (5) off-line twelve-hour resolution proton nuclear magnetic resonance (H-NMR) spectroscopy, and (6) chemical ionization mass spectrometry (CIMS) for the analysis of gas-phase precursors of secondary aerosol. Data from each aerosol spectroscopic method were analysed individually following ad-hoc tools (i.e. PMF for AMS, Art-2a for ATOFMS). The results obtained from each techniques are herein presented and compared. This allows us to clearly link the modifications in aerosol chemical composition to transitions in air mass origin and meteorological regimes. Under stagnant conditions, atmospheric stratification at night and early morning hours led to the accumulation of aerosols produced by anthropogenic sources distributed over the Po Valley plain. Such aerosols include primary components such as black carbon (BC

Screening of 439 Pesticide Residues in Fruits and Vegetables by Gas Chromatography-Quadrupole-Time-of-Flight Mass Spectrometry Based on TOF Accurate Mass Database and Q-TOF Spectrum Library.

PubMed

Li, Jian-Xun; Li, Xiao-Ying; Chang, Qiao-Ying; Li, Yan; Jin, Ling-He; Pang, Guo-Fang; Fan, Chun-Lin

2018-05-03

Because of its unique characteristics of accurate mass full-spectrum acquisition, high resolution, and fast acquisition rates, GC-quadrupole-time-of-flight MS (GC-Q-TOF/MS) has become a powerful tool for pesticide residue analysis. In this study, a TOF accurate mass database and Q-TOF spectrum library of 439 pesticides were established, and the parameters of the TOF database were optimized. Through solid-phase extraction (SPE), whereby pesticides are extracted from fruit and vegetable substrates by using 40 mL 1% acetic acid in acetonitrile (v/v), purified by the Carbon/NH₂ SPE cartridge, and finally detected by GC-Q-TOF/MS, the rapid analysis of 439 pesticides in fruits and vegetables can be achieved. The methodology verification results show that more than 70 and 91% of pesticides, spiked in fruits and vegetables with concentrations of 10 and 100 μg/kg, respectively, saw recoveries that conform to the European Commission's criterion of between 70 and 120% with RSD ≤20%. Eighty-one percent of pesticides have screening detection limits lower than 10 μg/kg, which makes this a reliable analysis technology for the monitoring of pesticide residues in fruits and vegetables. This technology was further validated for its characteristics of high precision, high speed, and high throughput through successful detection of 9817 samples during 2013-2015.

Mobile Gas and Particulate Emission Studies of the New York City Transit Bus Fleet

NASA Astrophysics Data System (ADS)

Jayne, J. T.; Canagaratna, M.; Herndon, S.; Shorter, J.; Zahniser, M.; Shi, Q.; Kolb, C.; Worsnop, D.; Jimenez, J.; Drewnick, F.; Demerjian, K.; Lanni, T.

2001-12-01

Emissions from both diesel and gasoline powered motor vehicles are a significant source of particulate (PM2.5) and trace gas pollution, especially in urban environments. Emission characterizations of motor vehicles can be performed using a dynamometer but these studies make fleet characterization impractical. Few studies have been performed which characterize emissions from in-use vehicles using a mobile sampling platform. This work describes application of new technology instrumentation for rapid (1-5 second) and real-time characterization of both gas and particulate emissions from in-use vehicles and is part of the PM2.5 Technology Assessment and Characterization Study in New York (PMTACS-NY). An aerosol mass spectrometer (AMS) and a tunable infrared laser differential absorption spectrometer (TILDAS) system were deployed on the Aerodyne Research mobile laboratory designed to "chase" target vehicles in and around the New York City area and measure their emissions under actual driving conditions. The AMS provides particle size and composition information for volatile and semi-volatile matter while the TILDAS system was configured to measure NO, NO2, CO, CH4, SO2 and formaldehyde. In addition to a GPS, an ELPI and a condensation particle counter, the mobile laboratory was also equipped with a CO2 monitor to allow emission ratios to be computed for the targeted vehicles. Emission ratios for both particulate and trace gases are reported for a representative fraction of the NYC Metropolitan Transit Authority (MTA) bus fleet in an effort to characterize new emission control technologies currently implemented by the NYC MTA.

HR Public meeting

ScienceCinema

None

2018-05-24

Cher(e)s collègues, En collaboration avec le Département HR, le Directeur général a le plaisir de vous convier à une réunion publique qui se tiendra le vendredi 25 juin 2010 à 9h30 dans l’Amphithéâtre principal (Bâtiment 500)*. Un café d’accueil y sera servi à partir de 9h. Cette réunion abordera les thèmes suivants : Valeurs de l’Organisation (Directeur général); Code de Conduite (Directeur général / Anne-Sylvie Catherin); Création du nouveau rôle d’Ombudsperson (Vincent Vuillemin) Ces présentations seront suivies d’une séance de questions-réponses. Nous espérons vous retrouver nombreux le 25 juin ! Meilleures salutations, Anne-Sylvie Catherin Chef du Département des Ressources humaines *Cette réunion sera retransmise simultanément dans l’Amphithéâtre BE de Prévessin (Bâtiment 864) et également disponible à l’adresse suivante : http://webcast.cern.ch [Dear colleagues, In collaboration with HR Department, the Director-General would like to invite you to an information meeting which will be held on Friday 25 June 2010 at 9:30 am in the Main Auditorium (Building 500)*. A welcome coffee will be available from 9:00 am. During this meeting, information will be given about: Organization’s values (Director-General); Code of Conduct (Director-General / Anne-Sylvie Catherin); New Ombudsperson role (Vincent Vuillemin); These presentations will be followed by a questions & answers session. We look forward to seeing you all on 25 June! Best regards, Anne-Sylvie Catherin Head, Human Resources Department *This meeting will be simultaneously retransmitted in BE Auditorium (Building 864) and available at the following address: http://webcast.cern.ch.

Measurements of Gas and Particle Phase Emissions From Munitions Detonation in a Field Environment

NASA Astrophysics Data System (ADS)

Fortner, E. C.; Knighton, W. B.; Timko, M.; Wood, E.; Onasch, T. B.; Kolb, C. E.; Beardsley, H. M.

2007-12-01

During the Point of Fire (POF) field campaign conducted at Fort Sill Oklahoma U.S.A. in March 2007 a suite of real- time trace gas and fine (submicron) particulate matter (PM) instrumentation characterized the point of fire emission plumes from large, medium and small caliber weapons systems. Muzzle emission plumes were measured and where appropriate, breach plumes and gun crew breathing zone measurements were also conducted. Aerosol measurements were conducted with an aerosol mass spectrometer (Aerodyne CTOF-AMS) for particle composition, condensation particle counter (CPC) for particle number density and DUSTRAK aerosol monitor for particle mass. Gas phase measurements included CO, CO2, NOx and a variety of trace gas species measured by proton transfer reaction mass spectrometry (PTR-MS) including hydrogen cyanide (HCN), acetonitrile, acrylonitrile, benzene, toluene, benzonitrile and styrene. In the majority of the plume measurements, HCN was the most prominent compound measured by PTR-MS. Quantification of HCN by PTR-MS is difficult due to its proton affinity being close enough to that of water to allow a significant backward reaction of protonated HCN with water, reducing the detection sensitivity and making the response dependent on humidity. We have developed a quantification procedure for HCN based on laboratory measurements of a calibration gas standard of HCN, which allows the humidity dependence to be extracted directly from the proton hydrate ion intensities. The correction factors for HCN are quite significant varying between 10 and 30 depending on sample humidity.

The MR-TOF-MS isobar separator for the TITAN facility at TRIUMF

NASA Astrophysics Data System (ADS)

Jesch, Christian; Dickel, Timo; Plaß, Wolfgang R.; Short, Devin; Ayet San Andres, Samuel; Dilling, Jens; Geissel, Hans; Greiner, Florian; Lang, Johannes; Leach, Kyle G.; Lippert, Wayne; Scheidenberger, Christoph; Yavor, Mikhail I.

2015-11-01

At TRIUMF's Ion Trap for Atomic and Nuclear Science (TITAN) a multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) will extend TITAN's capabilities and facilitate mass measurements and in-trap decay spectroscopy of exotic nuclei that so far have not been possible due to strong isobaric contamination. This MR-TOF-MS will also enable mass measurements of very short-lived nuclides (half-life > 1 ms) that are produced in very low quantities (a few detected ions overall). In order to allow the installation of an MR-TOF-MS in the restricted space on the platform, on which the TITAN facility is located, novel mass spectrometric methods have been developed. Transport, cooling and distribution of the ions inside the device is done using a buffer gas-filled RFQ-based ion beam switchyard. Mass selection is achieved using a dynamic retrapping technique after time-of-flight analysis in an electrostatic isochronous reflector system. Only due to the combination of these novel methods the realization of an MR-TOF-MS based isobar separator at TITAN has become possible. The device has been built, commissioned off-line and is currently under installation at TITAN.

Detailed Gas Chimney Structures in Joetsu Area at Southeastern Margin of Japan Sea, Revealed by High-Resolution 3D Seismic Survey (HR3D)

NASA Astrophysics Data System (ADS)

Ohkawa, S.; Hiruta, A.; Yanagimoto, Y.; Matsumoto, R.; Asakawa, E.

2016-12-01

To delineate the detailed structure of the gas chimneys, a high-resolution three-dimensional seismic survey (HR3D) was carried out in Joetsu area, at the southeastern margin of Japan Sea where hydrate-related mound and pockmark systems with gas chimneys are widely developed. HR3D data have successfully revealed the fine structure of gas chimneys which were not clearly imaged by the existing seismic data, such as sub-bottom profilers and conventional large-scale 3D surveys for petroleum exploration. HR3D data are also useful to interpolate and extrapolate spatially the geological/geophysical information obtained at wells most of which were drilled into the gas hydrate concentrated zones (GHCZs.) In the areas of low hydrate concentration, the reflections show a parallel-stratified pattern and the bottom simulating reflector (BSR) is parallel to the sea floor reflections. On the other hand, GHCZs are seismologically characterized by (1) strong sea floor reflections on the chimney mounds, (2) chaotic reflection patterns in the chimneys, and (3) pull-up of bottom simulating reflector (BSR) as shown in the attached figure. Strong sea floor reflections suggest that solid hydrates deposit in the very shallow part beneath the sea floor and the chaotic reflections indicate the hydrates are not continuously layered but interspersedly distributed. The BSR pull-up phenomena as much as 70 80msec are caused by high-velocity materials existing between the sea floor and the BSR. The sonic logs acquired by LWD at wells drilled into GHCZs show high velocity up to 3,800 m/s in the massive hydrates. The pull-up times estimated from the sonic data are consistent in general with the observed pull-up times on HR3D sections, suggesting the pull-up times could be useful for a preliminary evaluation of hydrate zones before drilling and/or in the areas without well data. This study was conducted under the commission from AIST as a part of the methane hydrate research project funded by METI

Influence of aqueous chemistry on the chemical composition of fog water and interstitial aerosol in Fresno

NASA Astrophysics Data System (ADS)

Kim, Hwajin; Ge, Xinlei; Collier, Sonya; Xu, Jianzhong; Sun, Yele; Wang, Youliang; Herckes, Pierre; Zhang, Qi

2015-04-01

A measurement study was conducted in the Central Valley (Fresno) of California in January 2010, during which radiation fog events were frequently observed. Fog plays important roles in atmospheric chemistry by scavenging aerosol particles and trace gases and serving as a medium for various aqueous-phase reactions. Understanding the effects of fog on the microphysical and chemical processing of aerosol particles requires detailed information on their chemical composition. In this study, we characterized the chemical composition of fog water and interstitial aerosol particles to study the effects of fog processing on aerosol properties. Fog water samples were collected during the 2010 Fresno campaigns with a Caltech Active Strand Cloud water Collector (CASCC) while interstitial submicron aerosols were characterized in real time with an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and a scanning Mobility Particle Sizer (SMPS). The fog water samples were later analyzed using the HR-ToF-AMS, ion chromatography, and a total carbon analyzer. The chemical composition and characteristics of interstitial particles during the fog events were compared to those of dissolved inorganic and organic matter in fog waters. Compared to interstitial aerosols, fog water is composed of a higher fraction of ammonium nitrate and oxygenated organics, due to aqueous formation of secondary aerosol species as well as enhanced gas-to-particle partitioning of water soluble species under water rich conditions. Sulfate is formed most efficiently in fog water although its contribution to total dissolved mass is relatively low. The HR-ToF-AMS mass spectra of organic matter in fog water (FOM) are very similar to that of oxygenated organic aerosols (OOA) derived from positive matrix factorization (PMF) of the HR-ToF-AMS spectra of ambient aerosol (r2 = 0.96), but FOM appears to contain a large fraction of acidic functional groups than OOA. FOM is also enriched of

Determination of the glycation sites of Bacillus anthracis neoglycoconjugate vaccine by MALDI-TOF/TOF-CID-MS/MS and LC-ESI-QqTOF-tandem mass spectrometry

PubMed Central

Jahouh, Farid; Hou, Shu-jie; Kováč, Pavol; Banoub, Joseph H.

2012-01-01

We present herein an efficient mass spectrometric method for the localization of the glycation sites of a model neoglycoconjugate vaccine formed by a construct of the tetrasaccharide side chain of the Bacillus anthracis exosporium and the protein carrier bovine serum albumin. The glycoconjugate was digested with both trypsin and GluC V8 endoproteinases, and the digests were then analyzed by MALDI-TOF/TOF-CID-MS/MS and nano-LC-ESI-QqTOF-CID-MS/MS. The sequences of the unknown peptides analyzed by MALDI-TOF/TOF-CID-MS/MS, following digestion with the GluC V8 endoproteinase, allowed us to recognize three glycopeptides whose glycation occupancies were, respectively, on Lys 235, Lys 420, and Lys 498. Similarly, the same analysis was performed on the tryptic digests, which permitted us to recognize two glycation sites on Lys 100 and Lys 374. In addition, we have also used LC-ESI-QqTOF-CID-MS/MS analysis for the identification of the tryptic digests. However, this analysis identified a higher number of glycopeptides than would be expected from a glycoconjugate composed of a carbohydrate–protein ratio of 5.4:1, which would have resulted in glycation occupancies of 18 specific sites. This discrepancy was due to the large number of glycoforms formed during the synthetic carbohydrate–spacer–carrier protein conjugation. Likewise, the LC-ESI-QqTOF-MS/MS analysis of the GluC V8 digest also identified 17 different glycation sites on the synthetic glycoconjugate. PMID:22012665

HR Public meeting

ScienceCinema

Heuer, Rolf; Catherin, Anne-Sylvie; Vuillemin, Vin

2018-05-25

Cher(e)s collègues, En collaboration avec le Département HR, le Directeur général a le plaisir de vous convier à une réunion publique qui se tiendra le vendredi 25 juin 2010 à 9h30 dans l’Amphithéâtre principal (Bâtiment 500)*. Un café d’accueil y sera servi à partir de 9h. Cette réunion abordera les thèmes suivants : • Valeurs de l’Organisation (Directeur général) • Code de Conduite (Directeur général / Anne-Sylvie Catherin) • Création du nouveau rôle d’Ombudsperson (Vincent Vuillemin); Ces présentations seront suivies d’une séance de questions-réponses. Nous espérons vous retrouver nombreux le 25 juin ! Meilleures salutations, Anne-Sylvie Catherin Chef du Département des Ressources humaines *Cette réunion sera retransmise simultanément dans l’Amphithéâtre BE de Prévessin (Bâtiment 864) et également disponible à l’adresse suivante : http://webcast.cern.ch. Dear colleagues, In collaboration with HR Department, the Director-General would like to invite you to an information meeting which will be held on Friday 25 June 2010 at 9:30 am in the Main Auditorium (Building 500)*. A welcome coffee will be available from 9:00 am. During this meeting, information will be given about: • Organization’s values (Director-General) • Code of Conduct (Director-General / Anne-Sylvie Catherin) • New Ombudsperson role (Vincent Vuillemin) These presentations will be followed by a questions & answers session. We look forward to seeing you all on 25 June! Best regards, Anne-Sylvie Catherin Head, Human Resources Department. This meeting will be simultaneously retransmitted in BE Auditorium (Building 864) and available at the following address: http://webcast.cern.ch.

Quantitative detection of RO2 radicals and other products from cyclohexene ozonolysis with ammonium-CI3-TOF and acetate-CI-API-TOF

NASA Astrophysics Data System (ADS)

Hansel, A.; Scholz, W.; Mentler, B.; Fischer, L.; Berndt, T.

2017-12-01

The performance of the novel ammonium-CI3-TOF utilizing NH4+ adduct ion chemistry to measure quantitatively first generation oxidized product molecules (OMs) as well as highly oxidized organic molecules (HOMs) was investigated for the first time. The gas-phase ozonolysis of cyclohexene served as a test system in order to evaluate the capability of the detection systems. Experiments have been carried out in the TROPOS free-jet flow system at close to atmospheric conditions. Product ion signals were simultaneously observed by the ammonium-CI3-TOF and the acetate-CI-API-TOF. Both instruments are in remarkable good agreement within a factor of two for HOMs. For OMs not containing an OOH group the acetate technique can considerably underestimate OM concentrations by 2-3 orders of magnitude. First steps of cyclohexene ozonolysis generate ten different (m/z product peaks) main products comprising 92% of observed OMs. The remaining 8% are distributed over several (m/z peaks) minor products that can be attributed to HOMs, predominately to highly oxidized RO2 radicals. Summing up, observed ammonium-CI3-TOF products yield 4.9 x 109 molecules cm-³ in excellent agreement with the amount of reacted cyclohexene of 5.0 x 109 molecules cm-³ for reactant concentrations of [O3] = 2.25 x 1012 molecules cm-³ and [cyclohexene] = 2.0 x 1012 molecules cm-³ and a reaction time of 7.9 s. NH4+ adduct ion chemistry based CIMS techniques offer a unique opportunity for complete detection of the whole product distribution, and consequently, for a much better understanding of atmospheric oxidation processes.

Top-down proteomic identification of bacterial protein biomarkers and toxins using MALDI-TOF-TOF-MS/MS and post-source decay

USDA-ARS?s Scientific Manuscript database

Matrix-assisted laser desorption/ionization time-of-flight-time-of-flight mass spectrometry(MALDI-TOF-TOF-MS)has provided new capabilities for the rapid identification of digested and non-digested proteins. The tandem (MS/MS) capability of TOF-TOF instruments allows precursor ion selection/isolation...

Réunion publique HR

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-04-30

Chers Collègues,Je me permets de vous rappeler qu'une réunion publique organisée par le Département HR se tiendra aujourd'hui:Vendredi 30 avril 2010 à 9h30 dans l'Amphithéâtre principal (café offert dès 9h00).Durant cette réunion, des informations générales seront données sur:le CERN Admin e-guide, qui est un nouveau guide des procédures administratives du CERN ayant pour but de faciliter la recherche d'informations pratiques et d'offrir un format de lecture convivial;le régime d'Assurance Maladie de l'Organisation (présentation effectuée par Philippe Charpentier, Président du CHIS Board) et;la Caisse de Pensions (présentation effectuée par Théodore Economou, Administrateur de la Caisse de Pensions du CERN).Une transmission simultanéemore » de cette réunion sera assurée dans l'Amphithéâtre BE de Prévessin et également disponible à l'adresse suivante: http://webcast.cern.chJe me réjouis de votre participation!Meilleures salutations,Anne-Sylvie CatherinChef du Département des Ressources humaines__________________________________________________________________________________Dear Colleagues,I should like to remind you that a plublic meeting organised by HR Department will be held today:Friday 30 April 2010 at 9:30 am in the Main Auditorium (coffee from 9:00 am).During this meeting, general information will be given about:the CERN Admin e-guide which is a new guide to the Organization's administrative procedures, drawn up to facilitate the retrieval of practical information and to offer a user-friendly format;the CERN Health Insurance System (presentation by Philippe Charpentier, President of the CHIS Board) and;the Pension Fund (presentation by Theodore Economou, Administrator of the CERN Pension Fund).A simultaneous transmission of this meeting will be broadcast in the BE Auditorium at Prévessin and will also be available at the following address. http://webcast.cern.chI look forward to your participation!Best regards

High-energy Collision-induced Dissociation by MALDI TOF/TOF Causes Charge-Remote Fragmentation of Steroid Sulfates

PubMed Central

Yan, Yuetian; Ubukata, Masaaki; Cody, Robert B.; Holy, Timothy E.; Gross, Michael L.

2014-01-01

A method for structural elucidation of biomolecules dating to the 1980s utilized high-energy collisions (~10 keV, laboratory frame) that induced charge-remote fragmentations (CRF), a class of fragmentations particularly informative for lipids, steroids, surfactants, and peptides. Unfortunately, the capability for high-energy activation has largely disappeared with the demise of magnetic sector instruments. With the latest designs of tandem time-of-flight mass spectrometers (TOF/TOF), however, this capability is now being restored to coincide with the renewed interest in metabolites and lipids including steroid-sulfates and other steroid metabolites. For these metabolites, structure determinations are required at concentration levels below that appropriate for NMR. To meet this need, we explored CRF with TOF/TOF mass spectrometry for two groups of steroid sulfates, 3-sulfates and 21-sulfates. We demonstrated that the current generation of MALDI TOF/TOF instruments can generate charge-remote-fragmentations for these materials. The resulting collision-induced dissociation (CID) spectra are useful for positional isomer differentiation and very often allow the complete structure determination of the steroid. We also propose a new nomenclature that directly indicates the cleavage sites on the steroid ring with carbon numbers. PMID:24781458

High-energy collision-induced dissociation by MALDI TOF/TOF causes charge-remote fragmentation of steroid sulfates.

PubMed

Yan, Yuetian; Ubukata, Masaaki; Cody, Robert B; Holy, Timothy E; Gross, Michael L

2014-08-01

A method for structural elucidation of biomolecules dating to the 1980s utilized high-energy collisions (~10 keV, laboratory frame) that induced charge-remote fragmentations (CRF), a class of fragmentations particularly informative for lipids, steroids, surfactants, and peptides. Unfortunately, the capability for high-energy activation has largely disappeared with the demise of magnetic sector instruments. With the latest designs of tandem time-of-flight mass spectrometers (TOF/TOF), however, this capability is now being restored to coincide with the renewed interest in metabolites and lipids, including steroid-sulfates and other steroid metabolites. For these metabolites, structure determinations are required at concentration levels below that appropriate for NMR. To meet this need, we explored CRF with TOF/TOF mass spectrometry for two groups of steroid sulfates, 3-sulfates and 21-sulfates. We demonstrated that the current generation of MALDI TOF/TOF instruments can generate charge-remote fragmentations for these materials. The resulting collision-induced dissociation (CID) spectra are useful for positional isomer differentiation and very often allow the complete structure determination of the steroid. We also propose a new nomenclature that directly indicates the cleavage sites on the steroid ring with carbon numbers.

MAP Reconstruction for Fourier Rebinned TOF-PET Data

PubMed Central

Bai, Bing; Lin, Yanguang; Zhu, Wentao; Ren, Ran; Li, Quanzheng; Dahlbom, Magnus; DiFilippo, Frank; Leahy, Richard M.

2014-01-01

Time-of-flight (TOF) information improves signal to noise ratio in Positron Emission Tomography (PET). Computation cost in processing TOF-PET sinograms is substantially higher than for nonTOF data because the data in each line of response is divided among multiple time of flight bins. This additional cost has motivated research into methods for rebinning TOF data into lower dimensional representations that exploit redundancies inherent in TOF data. We have previously developed approximate Fourier methods that rebin TOF data into either 3D nonTOF or 2D nonTOF formats. We refer to these methods respectively as FORET-3D and FORET-2D. Here we describe maximum a posteriori (MAP) estimators for use with FORET rebinned data. We first derive approximate expressions for the variance of the rebinned data. We then use these results to rescale the data so that the variance and mean are approximately equal allowing us to use the Poisson likelihood model for MAP reconstruction. MAP reconstruction from these rebinned data uses a system matrix in which the detector response model accounts for the effects of rebinning. Using these methods we compare performance of FORET-2D and 3D with TOF and nonTOF reconstructions using phantom and clinical data. Our phantom results show a small loss in contrast recovery at matched noise levels using FORET compared to reconstruction from the original TOF data. Clinical examples show FORET images that are qualitatively similar to those obtained from the original TOF-PET data but a small increase in variance at matched resolution. Reconstruction time is reduced by a factor of 5 and 30 using FORET3D+MAP and FORET2D+MAP respectively compared to 3D TOF MAP, which makes these methods attractive for clinical applications. PMID:24504374

High sensitive and throughput screening of Aflatoxin using MALDI-TOF-TOF-PSD-MS/MS

USDA-ARS?s Scientific Manuscript database

We have achieved sensitive and efficient detection of aflatoxin B1(AFB1) through matrix-assisted laser desorption/ionization time-of-flight-time-of-flight mass spectrometry (MALDI-TOF-TOF) and post-source decay (PSD) tandem mass spectrometry (MS/MS) using an acetic acid – a-cyano-4-hydroxycinnamic a...

Characterization of Long-Chain Fatty Acid as N-(4-Aminomethylphenyl) Pyridinium Derivative by MALDI LIFT-TOF/TOF Mass Spectrometry

NASA Astrophysics Data System (ADS)

Frankfater, Cheryl; Jiang, Xuntian; Hsu, Fong-Fu

2018-05-01

Charge remote fragmentation (CRF) elimination of CnH2n+2 residues along the aliphatic tail of long chain fatty acid is hall mark of keV high-energy CID fragmentation process. It is an important fragmentation pathway leading to structural characterization of biomolecules by CID tandem mass spectrometry. In this report, we describe MALDI LIFT TOF-TOF mass spectrometric approach to study a wide variety of fatty acids (FAs), which were derivatized to N-(4-aminomethylphenyl) pyridinium (AMPP) derivative, and desorbed as M+ ions by laser with or without matrix. The high-energy MALDI LIFT TOF-TOF mass spectra of FA-AMPP contain fragment ions mainly deriving from CRF cleavages of CnH2n+2 residues, as expected. These ions together with ions from specific cleavages of the bond(s) involving the functional group within the molecule provide more complete structural identification than those produced by low-energy CID/HCD using a linear ion-trap instrument. However, this LIFT TOF-TOF mass spectrometric approach inherits low sensitivity, a typical feature of high-energy CID tandem mass spectrometry. Because of the lack of unit mass precursor ion selection with sufficient sensitivity of the current LIFT TOF-TOF technology, product ion spectra from same chain length fatty acids with difference in one or two double bonds in a mixture are not distinguishable.

High sensitive analysis of steroids in doping control using gas chromatography/time-of-flight mass-spectrometry.

PubMed

Revelsky, A I; Samokhin, A S; Virus, E D; Rodchenkov, G M; Revelsky, I A

2011-04-01

The method of high sensitive gas chromatographic/time-of-flight mass-spectrometric (GC/TOF-MS) analysis of steroids was developed. Low-resolution TOF-MS instrument (with fast spectral acquisition rate) was used. This method is based on the formation of the silyl derivatives of steroids; exchange of the reagent mixture (pyridine and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA)) for tert-butylmethylether; offline large sample volume injection of this solution based on sorption concentration of the respective derivatives from the vapour-gas mixture flow formed from the solution and inert gas flows; and entire analytes solvent-free concentrate transfer into the injector of the gas chromatograph. Detection limits for 100 µl sample solution volume were 0.5-2 pg/µl (depending on the component). Application of TOF-MS model 'TruTOF' (Leco, St Joseph, MO, USA) coupled with gas chromatograph and ChromaTOF software (Leco, St Joseph, MO, USA) allowed extraction of the full mass spectra and resolving coeluted peaks. Due to use of the proposed method (10 µl sample aliquot) and GC/TOF-MS, two times more steroid-like compounds were registered in the urine extract in comparison with the injection of 1 µl of the same sample solution. Copyright © 2010 John Wiley & Sons, Ltd.

The Gas-rich Circumbinary Disk of HR 4049. II. A Detailed Study of the Near-infrared Spectrum

NASA Astrophysics Data System (ADS)

Malek, S. E.; Cami, J.

2014-10-01

HR 4049 is a peculiar evolved binary surrounded by a circumbinary disk. Mid-infrared observations show that the disk is rich in molecular gas and radially extended. To study the properties of this disk, we re-analyzed a set of near-infrared observations at high spectral resolution obtained with Gemini-Phoenix. These data cover absorption lines originating from the first overtone of CO and from H2O in the 2.3 μm region as well as more complex emission-absorption profiles from H2O and the fundamental mode of CO near 4.6 μm. By using an excitation diagram and from modeling the spectrum, we find that most of the CO overtone and H2O absorption originates from hot gas (T ex ≈ 1000 K) with high column densities, consistent with the mid-infrared data. The strong emission in the wavelength range of the CO fundamental furthermore suggests that there is a significant quantity of gas in the inner cavity of the disk. In addition, there is a much colder component in the line of sight to the disk. A detailed analysis of the overtone line profiles reveals variations in the line widths that are consistent with a radially extended disk in Keplerian rotation with hotter gas closer to the central star. We estimate the mass of the primary to be ~0.34 M ⊙ and discuss the implications for its evolutionary status.

Réunion publique HR

ScienceCinema

None

2017-12-09

Chers Collègues,Je me permets de vous rappeler qu'une réunion publique organisée par le Département HR se tiendra aujourd'hui:Vendredi 30 avril 2010 à 9h30 dans l'Amphithéâtre principal (café offert dès 9h00).Durant cette réunion, des informations générales seront données sur:le CERN Admin e-guide, qui est un nouveau guide des procédures administratives du CERN ayant pour but de faciliter la recherche d'informations pratiques et d'offrir un format de lecture convivial;le régime d'Assurance Maladie de l'Organisation (présentation effectuée par Philippe Charpentier, Président du CHIS Board) et;la Caisse de Pensions (présentation effectuée par Théodore Economou, Administrateur de la Caisse de Pensions du CERN).Une transmission simultanée de cette réunion sera assurée dans l'Amphithéâtre BE de Prévessin et également disponible à l'adresse suivante: http://webcast.cern.chJe me réjouis de votre participation!Meilleures salutations,Anne-Sylvie CatherinChef du Département des Ressources humaines__________________________________________________________________________________Dear Colleagues,I should like to remind you that a plublic meeting organised by HR Department will be held today:Friday 30 April 2010 at 9:30 am in the Main Auditorium (coffee from 9:00 am).During this meeting, general information will be given about:the CERN Admin e-guide which is a new guide to the Organization's administrative procedures, drawn up to facilitate the retrieval of practical information and to offer a user-friendly format;the CERN Health Insurance System (presentation by Philippe Charpentier, President of the CHIS Board) and;the Pension Fund (presentation by Theodore Economou, Administrator of the CERN Pension Fund).A simultaneous transmission of this meeting will be broadcast in the BE Auditorium at Prévessin and will also be available at the following address. http://webcast.cern.chI look forward to your participation!Best regards,Anne-Sylvie Catherin

MALDI-TOF MS for the Identification of Cultivable Organic-Degrading Bacteria in Contaminated Groundwater near Unconventional Natural Gas Extraction Sites.

PubMed

Santos, Inês C; Martin, Misty S; Carlton, Doug D; Amorim, Catarina L; Castro, Paula M L; Hildenbrand, Zacariah L; Schug, Kevin A

2017-08-10

Groundwater quality and quantity is of extreme importance as it is a source of drinking water in the United States. One major concern has emerged due to the possible contamination of groundwater from unconventional oil and natural gas extraction activities. Recent studies have been performed to understand if these activities are causing groundwater contamination, particularly with respect to exogenous hydrocarbons and volatile organic compounds. The impact of contaminants on microbial ecology is an area to be explored as alternatives for water treatment are necessary. In this work, we identified cultivable organic-degrading bacteria in groundwater in close proximity to unconventional natural gas extraction. Pseudomonas stutzeri and Acinetobacter haemolyticus were identified using matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-TOF MS), which proved to be a simple, fast, and reliable method. Additionally, the potential use of the identified bacteria in water and/or wastewater bioremediation was studied by determining the ability of these microorganisms to degrade toluene and chloroform. In fact, these bacteria can be potentially applied for in situ bioremediation of contaminated water and wastewater treatment, as they were able to degrade both compounds.

MALDI-TOF MS for the Identification of Cultivable Organic-Degrading Bacteria in Contaminated Groundwater near Unconventional Natural Gas Extraction Sites

PubMed Central

Martin, Misty S.; Carlton, Doug D.; Castro, Paula M. L.; Hildenbrand, Zacariah L.; Schug, Kevin A.

2017-01-01

Groundwater quality and quantity is of extreme importance as it is a source of drinking water in the United States. One major concern has emerged due to the possible contamination of groundwater from unconventional oil and natural gas extraction activities. Recent studies have been performed to understand if these activities are causing groundwater contamination, particularly with respect to exogenous hydrocarbons and volatile organic compounds. The impact of contaminants on microbial ecology is an area to be explored as alternatives for water treatment are necessary. In this work, we identified cultivable organic-degrading bacteria in groundwater in close proximity to unconventional natural gas extraction. Pseudomonas stutzeri and Acinetobacter haemolyticus were identified using matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-TOF MS), which proved to be a simple, fast, and reliable method. Additionally, the potential use of the identified bacteria in water and/or wastewater bioremediation was studied by determining the ability of these microorganisms to degrade toluene and chloroform. In fact, these bacteria can be potentially applied for in situ bioremediation of contaminated water and wastewater treatment, as they were able to degrade both compounds. PMID:28796186

[MALDI-TOF and SELDI-TOF analysis: "tandem" techniques to identify potential biomarker in fibromyalgia].

PubMed

Giacomelli, C; Bazzichi, L; Giusti, L; Ciregia, F; Baldini, C; Da Valle, Y; De Feo, F; Sernissi, F; Rossi, A; Bombardieri, S; Lucacchini, A

2011-11-09

Fibromyalgia (FM) is characterized by the presence of chronic widespread pain throughout the musculoskeletal system and diffuse tenderness. Unfortunately, no laboratory tests have been appropriately validated for FM and correlated with the subsets and activity. The aim of this study was to apply a proteomic technique in saliva of FM patients: the Surface Enhance Laser Desorption/Ionization Time-of-Flight (SELDI-TOF). For this study, 57 FM patients and 35 HC patients were enrolled. The proteomic analysis of saliva was carried out using SELDI-TOF. The analysis was performed using different chip arrays with different characteristics of binding. The statistical analysis was performed using cluster analysis and the difference between two groups was underlined using Student’s t-test. Spectra analysis highlighted the presence of several peaks differently expressed in FM patients compared with controls. The preliminary results obtained by SELDI-TOF analysis were compared with those obtained in our previous study performed on whole saliva of FM patients by using electrophoresis. The m/z of two peaks, increased in FM patients, seem to overlap well with the molecular weight of calgranulin A and C and Rho GDP-dissociation inhibitor 2, which we had found up-regulated in our previous study. These preliminary results showed the possibility of identifying potential salivary biomarker through salivary proteomic analysis with MALDI-TOF and SELDI-TOF in FM patients. The peaks observed allow us to focus on some of the particular pathogenic aspects of FM, the oxidative stress which contradistinguishes this condition, the involvement of proteins related to the cytoskeletal arrangements, and central sensibilization.

Application of modern online instrumentation for chemical analysis of gas and particulate phases of exhaust at the European Commission heavy-duty vehicle emission laboratory.

PubMed

Adam, T W; Chirico, R; Clairotte, M; Elsasser, M; Manfredi, U; Martini, G; Sklorz, M; Streibel, T; Heringa, M F; Decarlo, P F; Baltensperger, U; De Santi, G; Krasenbrink, A; Zimmermann, R; Prevot, A S H; Astorga, C

2011-01-01

The European Commission recently established a novel test facility for heavy-duty vehicles to enhance more sustainable transport. The facility enables the study of energy efficiency of various fuels/scenarios as well as the chemical composition of evolved exhaust emissions. Sophisticated instrumentation for real-time analysis of the gas and particulate phases of exhaust has been implemented. Thereby, gas-phase characterization was carried out by a Fourier transform infrared spectrometer (FT-IR; carbonyls, nitrogen-containing species, small hydrocarbons) and a resonance-enhanced multiphoton ionization time-of-flight mass spectrometer (REMPI-TOFMS; monocyclic and polycyclic aromatic hydrocarbons). For analysis of the particulate phase, a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS; organic matter, chloride, nitrate), a condensation particle counter (CPC; particle number), and a multiangle absorption photometer (MAAP; black carbon) were applied. In this paper, the first application of the new facility in combination with the described instruments is presented, whereby a medium-size truck was investigated by applying different driving cycles. The goal was simultaneous chemical characterization of a great variety of gaseous compounds and particulate matter in exhaust on a real-time basis. The time-resolved data allowed new approaches to view the results; for example, emission factors were normalized to time-resolved consumption of fuel and were related to emission factors evolved during high speeds. Compounds could be identified that followed the fuel consumption, others showed very different behavior. In particular, engine cold start, engine ignition (unburned fuel), and high-speed events resulted in unique emission patterns.

An advanced LC-MS (Q-TOF) technique for the detection of amino acids in atmospheric aerosols

EPA Science Inventory

Methodology for detection of native (underivitized) amino acids in atmospheric aerosols has been developed. This article describes the use of LC-MS (Q-TOF) and microwave-assisted gas phase hydrolysis for detection of free and combined amino acids in aerosols collected in a Southe...

Formation of secondary organic aerosols from gas-phase emissions of heated cooking oils

NASA Astrophysics Data System (ADS)

Liu, Tengyu; Li, Zijun; Chan, ManNin; Chan, Chak K.

2017-06-01

Cooking emissions can potentially contribute to secondary organic aerosol (SOA) but remain poorly understood. In this study, formation of SOA from gas-phase emissions of five heated vegetable oils (i.e., corn, canola, sunflower, peanut and olive oils) was investigated in a potential aerosol mass (PAM) chamber. Experiments were conducted at 19-20 °C and 65-70 % relative humidity (RH). The characterization instruments included a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS). The efficiency of SOA production, in ascending order, was peanut oil, olive oil, canola oil, corn oil and sunflower oil. The major SOA precursors from heated cooking oils were related to the content of monounsaturated fat and omega-6 fatty acids in cooking oils. The average production rate of SOA, after aging at an OH exposure of 1. 7 × 1011 molecules cm-3 s, was 1. 35 ± 0. 30 µg min-1, 3 orders of magnitude lower compared with emission rates of fine particulate matter (PM2. 5) from heated cooking oils in previous studies. The mass spectra of cooking SOA highly resemble field-derived COA (cooking-related organic aerosol) in ambient air, with R2 ranging from 0.74 to 0.88. The average carbon oxidation state (OSc) of SOA was -1.51 to -0.81, falling in the range between ambient hydrocarbon-like organic aerosol (HOA) and semi-volatile oxygenated organic aerosol (SV-OOA), indicating that SOA in these experiments was lightly oxidized.

Investigating the microstructure of keratin extracted from wool: peptide sequence (MALDI-TOF/TOF) and protein conformation (FTIR)

USDA-ARS?s Scientific Manuscript database

Keratin was extracted from wool by reduction with 2-mercaptoethanol. It was isolated as intact keratin and characterized by its similar molecular weight, protein composition, and secondary structure to native keratin. Gel electrophoresis patterns and MALDI-TOF/TOF peptide sequences provided the ide...

[THE FIRST EPIDEMIOLOGICAL DATA ABOUT THE HR-HUMAN PAPILLOMA VIRUS TYPES IN SOUTH AND NORTHERN BULGARIA].

PubMed

Kovachev, S; Slavov, V; Slavova, K; Ganovska, A

2015-01-01

The aim of our study were to evaluate the prevalence of HR-HPV infection in women between 15 and 55 years of age in the South and Northern Bulgaria. We have analyzed the HPV status (using DNA-sorb-AM nucleic acid extraction kit) in cervical samples collected during a 3 year period (2010-2012) from 1020 women, aged 15-55 and divided in four age groups, who attended their gynecologists for HPV-DNA cervical test. The rate of the HR-HPV infection was established to be 39.9%. HR-HPV negative were 60.1% of the evaluated subjects. The most commonly isolated genotype in all 407 (100%) infected women was HPV 16 - 190 women (46.7%), followed by HPV 56 - 78 (19.1%), HPV 31- 48 (11.8%) and HPV 33 - 45 (11.1%). To our knowledge, this is the first survey evaluating the prevalence of HR-HPV infection in the South and Northern regions of Bulgarian towns and drawing attention to the unusually high proportion of different HR-HPV.

Topochemical Analysis of Cell Wall Components by TOF-SIMS.

PubMed

Aoki, Dan; Fukushima, Kazuhiko

2017-01-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a recently developing analytical tool and a type of imaging mass spectrometry. TOF-SIMS provides mass spectral information with a lateral resolution on the order of submicrons, with widespread applicability. Sometimes, it is described as a surface analysis method without the requirement for sample pretreatment; however, several points need to be taken into account for the complete utilization of the capabilities of TOF-SIMS. In this chapter, we introduce methods for TOF-SIMS sample treatments, as well as basic knowledge of wood samples TOF-SIMS spectral and image data analysis.

Quantitation of 47 human tear proteins using high resolution multiple reaction monitoring (HR-MRM) based-mass spectrometry.

PubMed

Tong, Louis; Zhou, Xi Yuan; Jylha, Antti; Aapola, Ulla; Liu, Dan Ning; Koh, Siew Kwan; Tian, Dechao; Quah, Joanne; Uusitalo, Hannu; Beuerman, Roger W; Zhou, Lei

2015-02-06

Tear proteins are intimately related to the pathophysiology of the ocular surface. Many recent studies have demonstrated that the tear is an accessible fluid for studying eye diseases and biomarker discovery. This study describes a high resolution multiple reaction monitoring (HR-MRM) approach for developing assays for quantification of biologically important tear proteins. Human tear samples were collected from 1000 subjects with no eye complaints (411 male, 589 female, average age: 55.5±14.5years) after obtaining informed consent. Tear samples were collected using Schirmer's strips and pooled into a single global control sample. Quantification of proteins was carried out by selecting "signature" peptides derived by trypsin digestion. A 1-h nanoLC-MS/MS run was used to quantify the tear proteins in HR-MRM mode. Good reproducibility of signal intensity (using peak areas) was demonstrated for all 47 HR-MRM assays with an average coefficient of variation (CV%) of 4.82% (range: 1.52-10.30%). All assays showed consistent retention time with a CV of less than 0.80% (average: 0.57%). HR-MRM absolute quantitation of eight tear proteins was demonstrated using stable isotope-labeled peptides. In this study, we demonstrated for the first time the technique to quantify 47 human tear proteins in HR-MRM mode using approximately 1μl of human tear sample. These multiplexed HR-MRM-based assays show great promise of further development for biomarker validation in human tear samples. Both discovery-based and targeted quantitative proteomics can be achieved in a single quadrupole time-of-flight mass spectrometer platform (TripleTOF 5600 system). Copyright © 2015 Elsevier B.V. All rights reserved.

AMS of 93Zr: Passive absorber versus gas-filled magnet

NASA Astrophysics Data System (ADS)

Hain, Karin; Deneva, Boyana; Faestermann, Thomas; Fimiani, Leticia; Gómez-Guzmán, José Manuel; Koll, Dominik; Korschinek, Gunther; Ludwig, Peter; Sergeyeva, Victoria; Thiollay, Nicolas

2018-05-01

Two different isobar separation techniques were tested for the detection of the long-lived fission product 93Zr (T1/2 = 1.64 · 106 a) using Accelerator Mass Spectrometry (AMS), i.e. a passive absorber and a gas-filled magnet, respectively. Both techniques were used in combination with a Time-of-Flight path for the identification of the stable neighboring isotopes 92Zr and 94Zr. The passive absorber was represented by a stack of silicon nitride foils for high flexibility regarding the thickness for optimal isobar separation. Ion beams with a large variety of energies, between 80 and 180 MeV, were provided for this experiment by the tandem accelerator at the Maier-Leibnitz Laboratory in Garching, Germany. With these beams, the stopping powers of 93Zr and 93Nb as a function of energy were determined experimentally and compared to the results obtained with the simulation program SRIM. Considerable discrepancies regarding the energy dependence of the two stopping power curves relative to each other were found. The lowest detection limit for 93Zr achieved with the passive absorber setup was 93Zr/Zr = 1 · 10-10. In comparison, by optimizing the gas-filled magnet set-up, 93Nb was suppressed by around six orders of magnitude and a detection limit of 93Zr/Zr = 5 · 10-11 was obtained. To our knowledge, these results represent the lowest detection limit achieved for 93Zr until now.

HR Shared Services and the Realignment of HR.

ERIC Educational Resources Information Center

Reilly, P.

This report examines how adopting the shared services model of human resources (HR) services delivery can help businesses achieve better alignment between their HR service and specific business needs. Chapter 1 provides background information on the research project underlying this report, which included the following data collection activities:…

Status of the measurement of the nuclear components in cosmic rays with the AMS-02 experiment

NASA Astrophysics Data System (ADS)

Donnini, F.

2017-01-01

The Alpha Magnetic Spectrometer (AMS-02) is a large-acceptance (0.45 m 2 sr) magnetic spectrometer operating on board the International Space Station since May 2011. One of the main scientific objectives of the mission is the measurement of the nuclei fluxes in cosmic rays (CR). The identification of nuclei is achieved by the combination of independent measurements of the absolute charge, provided by different sub-detectors: the Silicon Tracker, the Time-of-Flight system (TOF), the Ring Imaging Cherenkov Counter (RICH), the Transition Radiation Detector (TRD) and the Electromagnetic Calorimeter (ECAL). In this contribution the results of nuclei fluxes already shown by the AMS collaboration are presented.

Intact cell MALDI-TOF mass spectrometry on single bovine oocyte and follicular cells combined with top-down proteomics: A novel approach to characterise markers of oocyte maturation.

PubMed

Labas, Valérie; Teixeira-Gomes, Ana-Paula; Bouguereau, Laura; Gargaros, Audrey; Spina, Lucie; Marestaing, Aurélie; Uzbekova, Svetlana

2018-03-20

Intact cell MALDI-TOF mass spectrometry (ICM-MS) was adapted to bovine follicular cells from individual ovarian follicles to obtain the protein/peptide signatures (<17kDa) of single oocytes, cumulus cells (CC) and granulosa cells (GC), which shared a total of 439 peaks. By comparing the ICM-MS profiles of single oocytes and CC before and after in vitro maturation (IVM), 71 different peaks were characterised, and their relative abundance was found to vary depending on the stage of oocyte meiotic maturation. To identify these endogenous biomolecules, top-down workflow using high resolution MS/MS (TD HR-MS) was performed on the protein extracts from oocytes, CC and GC. The TD HR-MS proteomic approach allowed for: (1) identification of 386 peptide/proteoforms encoded by 194 genes; and (2) characterisation of proteolysis products likely resulting from the action of kallikreins and caspases. In total, 136 peaks observed by ICM-MS were annotated by TD HR-MS (ProteomeXchange PXD004892). Among these, 16 markers of maturation were identified, including IGF2 binding protein 3 and hemoglobin B in the oocyte, thymosins beta-4 and beta-10, histone H2B and ubiquitin in CC. The combination of ICM-MS and TD HR-MS proved to be a suitable strategy to identify non-invasive markers of oocyte quality using limited biological samples. Intact cell MALDI-TOF mass spectrometry on single oocytes and their surrounding cumulus cells, coupled to an optimised top-down HR-MS proteomic approach on ovarian follicular cells, was used to identify specific markers of oocyte meiotic maturation represented by whole low molecular weight proteins or products of degradation by specific proteases. Copyright © 2017 Elsevier B.V. All rights reserved.

The thymus of the hairless rhino-j (hr/hr-j) mice

PubMed Central

SAN JOSE, I.; GARCÍA-SUÁREZ, O.; HANNESTAD, J.; CABO, R.; GAUNA, L.; REPRESA, J.; VEGA, J. A.

2001-01-01

The hairless (hr) gene is expressed in a large number of tissues, primarily the skin, and a mutation in the hr gene is responsible for the typical cutaneous phenotype of hairless mice. Mutant hr mouse strains show immune defects involving especially T cells and macrophages, as well as an age-related immunodeficiency and an accelerated atrophy of the thymus. These data suggest that the hr mutation causes a defect of this organ, although hr transcripts have not been detected in fetal or adult mice thymus. The present study analyses the thymus of young (3 mo) and adult (9 mo) homozygous hr-rh-j mice (a strain of hairless mice) by means of structural techniques and immunohistochemistry to selectively identify thymic epithelial cells, dendritic cells, and macrophages. There were structural alterations in the thymus of both young and adult rh-rh-j mice, which were more severe in older animals. These alterations consisted of relative cortical atrophy, enlargement of blood vessels, proliferation of perivascular connective tissue, and the appearance of cysts. hr-rh-j mice also showed a decrease in the number of epithelial and dendritic cells, and macrophages. Taken together, present results strongly suggest degeneration and accelerated age-dependent regression of the thymus in hr-rh-j mice, which could explain at least in part the immune defects reported in hairless mouse strains. PMID:11327202

Differentiation of isomeric N-glycan structures by normal-phase liquid chromatography-MALDI-TOF/TOF tandem mass spectrometry.

PubMed

Maslen, Sarah; Sadowski, Pawel; Adam, Alex; Lilley, Kathryn; Stephens, Elaine

2006-12-15

The detailed characterization of protein N-glycosylation is very demanding given the many different glycoforms and structural isomers that can exist on glycoproteins. Here we report a fast and sensitive method for the extensive structure elucidation of reducing-end labeled N-glycan mixtures using a combination of capillary normal-phase HPLC coupled off-line to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and TOF/TOF-MS/MS. Using this method, isobaric N-glycans released from honey bee phospholipase A2 and Arabidopsis thaliana glycoproteins were separated by normal-phase chromatography and subsequently identified by key fragment ions in the MALDI-TOF/TOF tandem mass spectra. In addition, linkage and branching information were provided by abundant cross-ring and "elimination" fragment ions in the MALDI-CID spectra that gave extensive structural information. Furthermore, the fragmentation characteristics of N-glycans reductively aminated with 2-aminobenzoic acid and 2-aminobenzamide were compared. The identification of N-glycans containing 3-linked core fucose was facilitated by distinctive ions present only in the MALDI-CID spectra of 2-aminobenzoic acid-labeled oligosaccharides. To our knowledge, this is the first MS/MS-based technique that allows confident identification of N-glycans containing 3-linked core fucose, which is a major allergenic determinant on insect and plant glycoproteins.

Derivatization of organophosphorus nerve agent degradation products for gas chromatography with ICPMS and TOF-MS detection.

PubMed

Richardson, Douglas D; Caruso, Joseph A

2007-06-01

Separation and detection of seven V-type (venomous) and G-type (German) organophosphorus nerve agent degradation products by gas chromatography with inductively coupled plasma mass spectrometry (GC-ICPMS) is described. The nonvolatile alkyl phosphonic acid degradation products of interest included ethyl methylphosphonic acid (EMPA, VX acid), isopropyl methylphosphonic acid (IMPA, GB acid), ethyl hydrogen dimethylamidophosphate sodium salt (EDPA, GA acid), isobutyl hydrogen methylphosphonate (IBMPA, RVX acid), as well as pinacolyl methylphosphonic acid (PMPA), methylphosphonic acid (MPA), and cyclohexyl methylphosphonic acid (CMPA, GF acid). N-(tert-Butyldimethylsilyl)-N-methyltrifluroacetamide with 1% TBDMSCl was utilized to form the volatile TBDMS derivatives of the nerve agent degradation products for separation by GC. Exact mass confirmation of the formation of six of the TBDMS derivatives was obtained by GC-time of flight mass spectrometry (TOF-MS). The method developed here allowed for the separation and detection of all seven TBDMS derivatives as well as phosphate in less than ten minutes. Detection limits for the developed method were less than 5 pg with retention times and peak area precisions of less than 0.01 and 6%, respectively. This method was successfully applied to river water and soil matrices. To date this is the first work describing the analysis of chemical warfare agent (CWA) degradation products by GC-ICPMS.

Classification of organic aerosol in the atmosphere over Seoul based on chemical group separation using two dimensional gas chromatography-time of flight mass spectrometry (GC×GC TOFMS) data

NASA Astrophysics Data System (ADS)

Jeon, S.; Lim, H. B.; Choi, N.; Lee, J.; Ahn, Y. K.; Kim, Y. P.

2016-12-01

Organic aerosols contain thousands of organic compounds and contribute to 20-90% of the total fine aerosol mass. For analyzing organic aerosols, a wide range of analytical techniques have been used such as gas chromatography mass spectrometer (GC/MS), liquid chromatography mass spectrometer (LC/MS), aerosol mass spectrometer (AMS), etc. Among them, comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometer (GCxGC/TOF-MS) can provide higher chemical resolution than AMS and analyze more mass fractions of organic aerosols than GC/MS. In this study, we suggest a new data processing method using GCxGC/TOF-MS data for analyzing organic compounds in the ambient aerosols. TSP samples were collected on the roof of the Asan engineering building, Ewha Womans University, Seoul, South Korea (37.56 °N, 126.94 °E, 20 m above ground level). A total of 67 samples were obtained during summer (August 2013) and winter (January and February 2014) with a PUF sampler (Tisch, TE-1000) on quartz fiber filter. Filters were extracted using accelerated solvent extractor with a mixture of dichloromethane and methanol (3:1, v/v). Total extracts were blown down to 0.5 mL using a nitrogen evaporator (Turbo Vap Ⅱ, caliper Life Sciences). Organic compounds in the TSP samples were separated into 6 chemical groups, depending on their retention time in two dimensions for their volatility and polarity. All area of peaks in each group was summed and variance of total area in each group was compared depending on season and diurnal cycle.

Survey of Emissions Associated with Enclosed Combustor Emission Control Devices in the Denver-Julesburg Basin

NASA Astrophysics Data System (ADS)

Knighton, W. B.; Floerchinger, C. R.; Wormhoult, J.; Massoli, P.; Fortner, E.; Brooks, B.; Roscioli, J. R.; Bon, D.; Herndon, S. C.

2014-12-01

Volatile organic compounds (VOCs) play an important role in local and regional air quality. A large source of VOCs comes from the oil and gas industry and the Denver-Julesburg Basin (D-J Basin) has seen a sharp increase in production in recent years primarily due to advances in horizontal drilling techniques. To help curb emissions with extraction and production of natural gas and its associated oil, emission control devices are required for facilities emitting over 6 tons of hydrocarbons per year. Within the ozone non-attainment area, which encompasses Denver and much of the front range, enclosed combustion devices (enclosed flares) are required to reduce hydrocarbon emissions by at least 95%. While certification tests indicate that these enclosed combustor devices provide high destruction removal efficiencies, there is considerable interest in knowing how well they perform in the field. As part of Front Range Air Pollution and Photochemistry Experiment (FRAPPE) project conducted during the Summer of 2014, the Aerodyne Mobile Laboratory (AML) surveyed oil and gas operations within the Wattenberg gas field and the surrounding D-J Basin. The AML deployed a full suite of gas and particle phase instrumentation providing a comprehensive set of on-line, real-time measurements for the major natural gas components (methane and ethane) and their combustion products (CO2, CO, NOx) using a variety of spectroscopic techniques. Additional gas phase organic gas emissions were made using a proton transfer reaction mass spectrometer (PTR-MS). Particle number and composition were determined using a condensation particle counter and an Aerodyne Aerosol Mass Spectrometer (AMS). A summary of the number of enclosed combustor devices measured and their observed combustion efficiencies will be presented.

Photometric behavior and general characteristics of the nova HR Delphini

NASA Astrophysics Data System (ADS)

Raikova, D.

The light curve and the B-V color-index curve of HR Del were constructed on the basis of published UBV observations. From the normal color indices, the effective photosphere temperature and radius were determined using calibrations for normal stars. As the brightness reached its peak, the effective photosphere was expanding with a velocity of approximately 23 km/s, which is more than 10 times less than the gas velocity. This phenomenon is explained by decreasing continuous opacity as the ejected gas expands.

HR, Streamlined

ERIC Educational Resources Information Center

Ramaswami, Rama

2008-01-01

Human Resources (HR) administrators are finding that as software modules are installed to automate various processes, they have more time to focus on strategic objectives. And as compliance with affirmative action and other employment regulations comes under increasing scrutiny, HR staffers are finding that software can deliver and track data with…

MALDI-TOF and cluster-TOF-SIMS imaging of Fabry disease biomarkers

NASA Astrophysics Data System (ADS)

Touboul, David; Roy, Sandrine; Germain, Dominique P.; Chaminade, Pierre; Brunelle, Alain; Laprevote, Olivier

2007-02-01

Fabry disease is an X-linked disorder of glycosphingolipid metabolism, in which a partial or total deficiency of [alpha]-galactosidase A, a lysosomal enzyme, results in the progressive accumulation of neutral glycosphingolipids (globotriaosylceramide and digalactosylceramide) in most fluids and tissues of the body. Few information is available about the composition and distribution in tissues of the accumulated glycosphingolipids species. Mass spectrometry imaging is an innovative technique, which can provide pieces of information about the distribution of numerous biological compounds, such as lipids, directly on the tissue sections. MALDI-TOF and cluster-TOF-SIMS imaging approaches were used to study the localization of lipids (cholesterol, cholesterol sulfate, vitamin E, glycosphingolipids ...) on skin and kidney sections of patients affected by the Fabry disease. Numerous information on pathophysiology were enlightened by both techniques.

Fireside Corrosion Behaviors of Super304H and HR3C in Coal Ash/Gas Environment with Different SO2 Contents at 650 °C

NASA Astrophysics Data System (ADS)

Lu, Jintao; Yang, Zhen; Li, Yan; Huang, Jinyang; Zhou, Yongli; Zhao, Xinbao; Yuan, Yong

2018-05-01

The corrosion behaviors of Super304H and HR3C used for USC boiler applications were investigated in simulated coal ash/gas environments with 0.1 and 1.5% of SO2 at 650 °C for 500 h. The results indicated that the increase in SO2 accelerated the corrosion rate and the spalling tendency of the corrosion layer in both tested alloys. Fe2O3, Cr2O3 and FeCr2O4 main peaks were revealed by XRD on Super304H, but on HR3C only the Cr2O3 peak showed a high intensity. The SO2 content did not affect the corrosion product composition of any of the alloys, but accelerated the inner sulfidation and the spallation on Super304H. No obvious internal sulfidation was observed on HR3C in either SO2 content. Based on the experimental results, the alloy corrosion mechanism and the influence of sulfur content on the corrosion process were discussed.

Gas and particulate phase products from the ozonolysis of acenaphthylene

NASA Astrophysics Data System (ADS)

Riva, Matthieu; Healy, Robert M.; Tomaz, Sophie; Flaud, Pierre-Marie; Perraudin, Emilie; Wenger, John C.; Villenave, Eric

2016-10-01

Polycyclic aromatic hydrocarbons (PAHs) are recognized as important secondary organic aerosol (SOA) precursors in the urban atmosphere. In this work, the gas-phase ozonolysis of acenaphthylene was investigated in an atmospheric simulation chamber using a proton transfer reaction time-of-flight-mass spectrometer (PTR-TOF-MS) and an aerosol time-of-flight-mass spectrometer (ATOFMS) for on-line characterization of the oxidation products in the gas and particle phases, respectively. SOA samples were also collected on filters and analyzed by ultra performance liquid chromatography/electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-QTOFMS) and gas chromatography/electron impact ionization-mass spectrometry (GC/EI-MS). The major gas-phase products included a range of oxygenated naphthalene derivatives such as 1,8-naphthalic anhydride, naphthalene 1,8-dicarbaldehyde and naphthaldehyde, as well as a secondary ozonide. Possible reaction mechanisms are proposed for the formation of these products and favoured pathways have been suggested. Many of these products were also found in the particle phase along with a range of oligomeric compounds. The same range of gas and particle phase products was observed in the presence and absence of excess cyclohexane, an OH scavenger, indicating that OH radical production from the ozonolysis of acenaphthylene is negligible. SOA yields in the range 23-37% were determined and indicate that acenaphthylene ozonolysis may contribute to part of the SOA observed in urban areas.

Reducing time to identification of positive blood cultures with MALDI-TOF MS analysis after a 5-h subculture.

PubMed

Verroken, A; Defourny, L; Lechgar, L; Magnette, A; Delmée, M; Glupczynski, Y

2015-02-01

Speeding up the turn-around time of positive blood culture identifications is essential in order to optimize the treatment of septic patients. Several sample preparation techniques have been developed allowing direct matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) identification of positive blood cultures. Yet, the hands-on time restrains their routine workflow. In this study, we evaluated an approach whereby MALDI-TOF MS identification without any additional steps was carried out on short subcultured colonies from positive blood bottles with the objective of allowing results reporting on the day of positivity detection. Over a 7-month period in 2012, positive blood cultures detected by 9 am with an automated system were inoculated onto a Columbia blood agar and processed after a 5-h incubation on a MALDI-TOF MicroFlex platform (Bruker Daltonik GmbH). Single-spotted colonies were covered with 1 μl formic acid and 1 μl matrix solution. The results were compared to the validated identification techniques. A total of 925 positive blood culture bottles (representing 470 bacteremic episodes) were included. Concordant identification was obtained in 727 (81.1 %) of the 896 monomicrobial blood cultures, with failure being mostly observed with anaerobes and yeasts. In 17 episodes of polymicrobic bacteremia, the identification of one of the two isolates was achieved in 24/29 (82.7 %) positive cultures. Routine implementation of MALDI-TOF MS identification on young positive blood subcultures provides correct results to the clinician in more than 80 % of the bacteremic episodes and allows access to identification results on the day of blood culture positivity detection, potentially accelerating the implementation of targeted clinical treatments.

A new calibrant for MALDI-TOF-TOF-PSD-MS/MS of non-digested proteins for top-down proteomic analysis

USDA-ARS?s Scientific Manuscript database

RATIONALE: Matrix-assisted laser desorption/ionization (MALDI) time-of-flight-time-of-flight (TOF-TOF) tandem mass spectrometry (MS/MS) has seen increasing use for post-source decay (PSD)-MS/MS analysis of non-digested protein ions for top-down proteomic identification. However, there is no commonl...

Sodiation as a tool for enhancing the diagnostic value of MALDI-TOF/TOF-MS spectra of complex astaxanthin ester mixtures from Haematococcus pluvialis.

PubMed

Weesepoel, Yannick; Vincken, Jean-Paul; Pop, Raluca Maria; Liu, Kun; Gruppen, Harry

2013-07-01

The microalga Haematococcus pluvialis produces the pigment astaxanthin mainly in esterified form with a multitude of fatty acids, which results in a complex mixture of carotenol mono- and diesters. For rapid fingerprinting of these esters, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF/TOF-MS) might be an alternative to traditional chromatographic separation combined with MS. Investigation of ionization and fragmentation of astaxanthin mono- and diester palmitate standards in MALDI-TOF/TOF-MS showed that sodium adduct parent masses [M + Na](+) gave much simpler MS(2) spectra than radical / protonated [M](+●) / [M + H](+) parents. [M + Na](+) fragments yielded diagnostic polyene-specific eliminations and fatty acid neutral losses, whereas [M](+●) / [M + H](+) fragmentation resulted in a multitude of non-diagnostic daughters. For diesters, a benzonium fragment, formed by polyene elimination, was required for identification of the second fatty acid attached to the astaxanthin backbone. Parents were forced into [M + Na](+) ionization by addition of sodium acetate, and best signal-to-noise ratios were obtained in the 0.1 to 1.0 mM range. This method was applied to fingerprinting astaxanthin esters in a crude H. pluvialis extract. Prior to MALDI-TOF/TOF-MS, the extract was fractionated by normal phase Flash chromatography to obtain fractions enriched in mono- and diesters and to remove pheophytin a, which compromised monoester signals. All 12 types of all-trans esterified esters found in LC were identified with MALDI-TOF/TOF-MS, with the exception of two minor monoesters. Copyright © 2013 John Wiley & Sons, Ltd.

Wind tunnel validation of AeroDyn within LIFES50+ project: imposed Surge and Pitch tests

NASA Astrophysics Data System (ADS)

Bayati, I.; Belloli, M.; Bernini, L.; Zasso, A.

2016-09-01

This paper presents the first set of results of the steady and unsteady wind tunnel tests, performed at Politecnico di Milano wind tunnel, on a 1/75 rigid scale model of the DTU 10 MW wind turbine, within the LIFES50+ project. The aim of these tests is the validation of the open source code AeroDyn developed at NREL. Numerical and experimental steady results are compared in terms of thrust and torque coefficients, showing good agreement, as well as for unsteady measurements gathered with a 2 degree-of-freedom test rig, capable of imposing the displacements at the base of the model, and providing the surge and pitch motion of the floating offshore wind turbine (FOWT) scale model. The measurements of the unsteady test configuration are compared with AeroDyn/Dynin module results, implementing the generalized dynamic wake (GDW) model. Numerical and experimental comparison showed similar behaviours in terms of non linear hysteresis, however some discrepancies are herein reported and need further data analysis and interpretations about the aerodynamic integral quantities, with a special attention to the physics of the unsteady phenomenon.

Study of 236U/238U ratio at CIRCE using a 16-strip silicon detector with a TOF system

NASA Astrophysics Data System (ADS)

De Cesare, M.; De Cesare, N.; D'Onofrio, A.; Gialanella, L.; Terrasi, F.

2015-04-01

Accelerator Mass Spectrometry (AMS) is presently the most sensitive technique for the measurement of long-lived actinides, e.g. 236U and xPu isotopes. A new actinide AMS system, based on a 3-MV pelletron tandem accelerator, is operated at the Center for Isotopic Research on Cultural and Environmental Heritage (CIRCE) in Caserta, Italy. In this paper we report on the procedure adopted to increase the 236U abundance sensitivity as low as possible. The energy and position determinations of the 236U ions, using a 16-strip silicon detector have been obtained. A 236U/238U isotopic ratio background level of about 2.9×10-11 was obtained, summing over all the strips, using a Time of Flight-Energy (TOF-E) system with a 16-strip silicon detector (4.9×10-12 just with one strip).

A study of photochemical againg of ambient air using Potential Aerosol Mass (PAM) chamber under the different sources and types of emissions

NASA Astrophysics Data System (ADS)

Lee, T.; Son, J.; Kim, J.; Kim, S.; Sung, K.; Park, G.; Link, M.; Park, T.; Kim, K.; Kang, S.; Ban, J.; Kim, D. S.

2016-12-01

Recent research proposed that Secondary Aerosol (SA) is important class of predicting future climate change scenarios, health effect, and a general air quality. However, there has been lack of studies to investigate SA formation all over the world. This study tried to focus on understanding potential secondary aerosol formation and its local impact by the photochemical aging of inorganic and organic aerosols in the ambient air using the Potential Aerosol Mass (PAM) chamber under the different sources and types of emissions. PAM chamber manufactured by Aerodyne make an oxidizing environment that simulates oxidation processes on timescales of 12-15 hrs in the atmosphere. Chemical compositions of ambient aerosol and aerosol that was aged in the PAM chamber were alternately measured every 2-minutes using the High Resolution-Time of Flight-Aerosol Mass Spectrometer (HR-ToF-AMS). HR-ToF-AMS provides non-refractory aerosol mass concentrations including nitrate, sulfate, hydrocarbon-like and oxygenated organic aerosol in real time. This study includes a residence area of mixture of sources, a forest site of dominant source of biogenic VOCs, an underground parking lot of dominant vehicle emission, and laboratory experiment of vehicle emissions under different fuels and speeds using the chassis dynamometer. As a result, it was revealed that gasoline and LPG vehicle relatively made more potential SA than diesel vehicle.

Analytic TOF PET reconstruction algorithm within DIRECT data partitioning framework

PubMed Central

Matej, Samuel; Daube-Witherspoon, Margaret E.; Karp, Joel S.

2016-01-01

Iterative reconstruction algorithms are routinely used for clinical practice; however, analytic algorithms are relevant candidates for quantitative research studies due to their linear behavior. While iterative algorithms also benefit from the inclusion of accurate data and noise models the widespread use of TOF scanners with less sensitivity to noise and data imperfections make analytic algorithms even more promising. In our previous work we have developed a novel iterative reconstruction approach (Direct Image Reconstruction for TOF) providing convenient TOF data partitioning framework and leading to very efficient reconstructions. In this work we have expanded DIRECT to include an analytic TOF algorithm with confidence weighting incorporating models of both TOF and spatial resolution kernels. Feasibility studies using simulated and measured data demonstrate that analytic-DIRECT with appropriate resolution and regularization filters is able to provide matched bias vs. variance performance to iterative TOF reconstruction with a matched resolution model. PMID:27032968

Analytic TOF PET reconstruction algorithm within DIRECT data partitioning framework

NASA Astrophysics Data System (ADS)

Matej, Samuel; Daube-Witherspoon, Margaret E.; Karp, Joel S.

2016-05-01

Iterative reconstruction algorithms are routinely used for clinical practice; however, analytic algorithms are relevant candidates for quantitative research studies due to their linear behavior. While iterative algorithms also benefit from the inclusion of accurate data and noise models the widespread use of time-of-flight (TOF) scanners with less sensitivity to noise and data imperfections make analytic algorithms even more promising. In our previous work we have developed a novel iterative reconstruction approach (DIRECT: direct image reconstruction for TOF) providing convenient TOF data partitioning framework and leading to very efficient reconstructions. In this work we have expanded DIRECT to include an analytic TOF algorithm with confidence weighting incorporating models of both TOF and spatial resolution kernels. Feasibility studies using simulated and measured data demonstrate that analytic-DIRECT with appropriate resolution and regularization filters is able to provide matched bias versus variance performance to iterative TOF reconstruction with a matched resolution model.

A dedicated AMS setup for 53Mn/60Fe at the Cologne FN tandem accelerator

NASA Astrophysics Data System (ADS)

Schiffer, M.; Dewald, A.; Feuerstein, C.; Altenkirch, R.; Stolz, A.; Heinze, S.

2015-10-01

Following demands for AMS measurements of medium mass isotopes, especially for 53Mn and 60Fe, we started to build a dedicated AMS setup at the Cologne FN tandem accelerator. This accelerator with a maximum terminal voltage of 10 MV can be reliably operated at a terminal voltage of 9.5 MV which corresponds to energies of 93-102 MeV for 60Fe or 53Mn beams using the 9+ or 10+ charge state. These charge states can be obtained by foil stripping with efficiencies of 30% and 20%, respectively. Energies around 100 MeV are sufficient to effectively suppress the stable isobars 60Ni and 53Cr by (dE/dx) techniques using combinations of energy degrader foils and dispersive elements like electrostatic analyzers and time of flight (TOF) systems as well as (dE/dx)E ion detectors. In this contribution we report on the actual status of the AMS setup and discuss details and expected features.

Proteome analysis of excretory-secretory proteins of Entamoeba histolytica HM1:IMSS via LC-ESI-MS/MS and LC-MALDI-TOF/TOF.

PubMed

Ujang, Jorim Anak; Kwan, Soon Hong; Ismail, Mohd Nazri; Lim, Boon Huat; Noordin, Rahmah; Othman, Nurulhasanah

2016-01-01

Excretory-secretory (ES) proteins of E. histolytica are thought to play important roles in the host invasion, metabolism, and defence. Elucidation of the types and functions of E. histolytica ES proteins can further our understanding of the disease pathogenesis. Thus, the aim of this study is to use proteomics approach to better understand the complex ES proteins of the protozoa. E. histolytica ES proteins were prepared by culturing the trophozoites in protein-free medium. The ES proteins were identified using two mass spectrometry tools, namely, LC-ESI-MS/MS and LC-MALDI-TOF/TOF. The identified proteins were then classified according to their biological processes, molecular functions, and cellular components using the Panther classification system (PantherDB). A complementary list of 219 proteins was identified; this comprised 201 proteins detected by LC-ESI-MS/MS and 107 proteins by LC-MALDI-TOF/TOF. Of the 219 proteins, 89 were identified by both mass-spectrometry systems, while 112 and 18 proteins were detected exclusively by LC-ESI-MS/MS and LC-MALDI-TOF/TOF respectively. Biological protein functional analysis using PantherDB showed that 27% of the proteins were involved in metabolic processes. Using molecular functional and cellular component analyses, 35% of the proteins were found to be involved in catalytic activity, and 21% were associated with the cell parts. This study showed that complementary use of LC-ESI-MS/MS and LC-MALDI-TOF/TOF has improved the identification of ES proteins. The results have increased our understanding of the types of proteins excreted/secreted by the amoeba and provided further evidence of the involvement of ES proteins in intestinal colonisation and evasion of the host immune system, as well as in encystation and excystation of the parasite.

Gas phase emissions from cooking processes and their secondary aerosol production potential

NASA Astrophysics Data System (ADS)

Klein, Felix; Platt, Stephen; Bruns, Emily; Termime-roussel, Brice; Detournay, Anais; Mohr, Claudia; Crippa, Monica; Slowik, Jay; Marchand, Nicolas; Baltensperger, Urs; Prevot, Andre; El Haddad, Imad

2014-05-01

Long before the industrial evolution and the era of fossil fuels, high concentrations of aerosol particles were alluded to in heavily populated areas, including ancient Rome and medieval London. Recent radiocarbon measurements (14C) conducted in modern megacities came as a surprise: carbonaceous aerosol (mainly organic aerosol, OA), a predominant fraction of particulate matter (PM), remains overwhelmingly non-fossil despite extensive fossil fuel combustion. Such particles are directly emitted (primary OA, POA) or formed in-situ in the atmosphere (secondary OA, SOA) via photochemical reactions of volatile organic compounds (VOCs). Urban levels of non-fossil OA greatly exceed the levels measured in pristine environments strongly impacted by biogenic emissions, suggesting a contribution from unidentified anthropogenic non-fossil sources to urban OA. Positive matrix factorization (PMF) techniques applied to ambient aerosol mass spectrometer (AMS, Aerodyne) data identify primary cooking emissions (COA) as one of the main sources of primary non-fossil OA in major cities like London (Allan et al., 2010), New York (Sun et al., 2011) and Beijing (Huang et al., 2010). Cooking processes can also emit VOCs that can act as SOA precursors, potentially explaining in part the high levels of oxygenated OA (OOA) identified by the AMS in urban areas. However, at present, the chemical nature of these VOCs and their secondary aerosol production potential (SAPP) remain virtually unknown. The approach adopted here involves laboratory quantification of PM and VOC emission factors from the main primary COA emitting processes and their SAPP. Primary emissions from deep-fat frying, vegetable boiling, vegetable frying and meat cooking for different oils, meats and vegetables were analysed under controlled conditions after ~100 times dilution. A high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a high resolution proton transfer time-of-flight mass spectrometer (PTR

Direct screening of herbal blends for new synthetic cannabinoids by MALDI-TOF MS.

PubMed

Gottardo, Rossella; Chiarini, Anna; Dal Prà, Ilaria; Seri, Catia; Rimondo, Claudia; Serpelloni, Giovanni; Armato, Ubaldo; Tagliaro, Franco

2012-01-01

Since 2004, a number of herbal blends containing different synthetic compounds mimicking the pharmacological activity of cannabinoids and displaying a high toxicological potential have appeared in the market. Their availability is mainly based on the so-called "e-commerce", being sold as legal alternatives to cannabis and cannabis derivatives. Although highly selective, sensitive, accurate, and quantitative methods based on GC-MS and LC-MS are available, they lack simplicity, rapidity, versatility and throughput, which are required for product monitoring. In this context, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) offers a simple and rapid operation with high throughput. Thus, the aim of the present work was to develop a MALDI-TOF MS method for the rapid qualitative direct analysis of herbal blend preparations for synthetic cannabinoids to be used as front screening of confiscated clandestine preparations. The sample preparation was limited to herbal blend leaves finely grinding in a mortar and loading onto the MALDI plate followed by addition of 2 µl of the matrix/surfactant mixture [α-cyano-4-hydroxy-cinnamic acid/cetyltrimethylammonium bromide (CTAB)]. After drying, the sample plate was introduced into the ion source for analysis. MALDI-TOF conditions were as follows: mass spectra were analyzed in the range m/z 150-550 by averaging the data from 50 laser shots and using an accelerating voltage of 20 kV. The described method was successfully applied to the screening of 31 commercial herbal blends, previously analyzed by GC-MS. Among the samples analyzed, 21 contained synthetic cannabinoids (namely JWH-018, JWH-073, JWH-081, JWH-250, JWH-210, JWH-019, and AM-694). All the results were in agreement with GC-MS, which was used as the reference technique. Copyright © 2012 John Wiley & Sons, Ltd.

SP2 Deployment at Boston College—Aerodyne-Led Coated Black Carbon Study (BC4) Final Campaign Summary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onasch, T. B.; Sedlacek, A. J.

The main objective of the Boston College-Aerodyne led laboratory study (BC4) was to measure the optical properties of black carbon (BC) particles from a diffusion flame directly and after being coated with secondary organic and inorganic material and to achieve optical closure with model predictions. The measurements of single particle BC mass and population mixing states provided by a single particle soot photometer (SP2) was central to achieving the laboratory-based study’s objective. Specifically, the DOE ARM SP2 instrument participated in the BC4 project to address the following scientific questions: 1. What is the mass-specific absorption coefficient as a function ofmore » secondary organic and inorganic material coatings? 2. What is the spread in the population mixing states within our carefully generated laboratory particles? 3. How does the SP2 instrument respond to well-characterized, internally mixed BC-containing particles?« less

Highly accurate adaptive TOF determination method for ultrasonic thickness measurement

NASA Astrophysics Data System (ADS)

Zhou, Lianjie; Liu, Haibo; Lian, Meng; Ying, Yangwei; Li, Te; Wang, Yongqing

2018-04-01

Determining the time of flight (TOF) is very critical for precise ultrasonic thickness measurement. However, the relatively low signal-to-noise ratio (SNR) of the received signals would induce significant TOF determination errors. In this paper, an adaptive time delay estimation method has been developed to improve the TOF determination’s accuracy. An improved variable step size adaptive algorithm with comprehensive step size control function is proposed. Meanwhile, a cubic spline fitting approach is also employed to alleviate the restriction of finite sampling interval. Simulation experiments under different SNR conditions were conducted for performance analysis. Simulation results manifested the performance advantage of proposed TOF determination method over existing TOF determination methods. When comparing with the conventional fixed step size, and Kwong and Aboulnasr algorithms, the steady state mean square deviation of the proposed algorithm was generally lower, which makes the proposed algorithm more suitable for TOF determination. Further, ultrasonic thickness measurement experiments were performed on aluminum alloy plates with various thicknesses. They indicated that the proposed TOF determination method was more robust even under low SNR conditions, and the ultrasonic thickness measurement accuracy could be significantly improved.

Phase partitioning and volatility of secondary organic aerosol components formed from α-pinene ozonolysis and OH oxidation: the importance of accretion products and other low volatility compounds

DOE PAGES

Lopez-Hilfiker, F. D.; Mohr, C.; Ehn, M.; ...

2015-02-18

We measured a large suite of gas and particle phase multi-functional organic compounds with a Filter Inlet for Gases and AEROsols (FIGAERO) coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) developed at the University of Washington. The instrument was deployed on environmental simulation chambers to study monoterpene oxidation as a secondary organic aerosol (SOA) source. We focus here on results from experiments utilizing an ionization method most selective towards acids (acetate negative ion proton transfer), but our conclusions are based on more general physical and chemical properties of the SOA. Hundreds of compounds were observed in both gasmore » and particle phases, the latter being detected upon temperature programmed thermal desorption of collected particles. Particulate organic compounds detected by the FIGAERO HR-ToF-CIMS are highly correlated with, and explain at least 25–50% of, the organic aerosol mass measured by an Aerodyne Aerosol Mass Spectrometer (AMS). Reproducible multi-modal structures in the thermograms for individual compounds of a given elemental composition reveal a significant SOA mass contribution from large molecular weight organics and/or oligomers (i.e. multi-phase accretion reaction products). Approximately 50% of the HR-ToF-CIMS particle phase mass is associated with compounds having effective vapor pressures 4 or more orders of magnitude lower than commonly measured monoterpene oxidation products. The relative importance of these accretion-type and other extremely low volatility products appears to vary with photochemical conditions. We present a desorption temperature based framework for apportionment of thermogram signals into volatility bins. The volatility-based apportionment greatly improves agreement between measured and modeled gas–particle partitioning for select major and minor components of the SOA, consistent with thermal decomposition during desorption causing the

Non-Halal biomarkers identification based on Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography-Time of Flight Mass Spectroscopy (GC-TOF MS) techniques

NASA Astrophysics Data System (ADS)

Witjaksono, Gunawan; Saputra, Irwan; Latief, Marsad; Jaswir, Irwandi; Akmeliawati, Rini; Abdelkreem Saeed Rabih, Almur

2017-11-01

Consumption of meat from halal (lawful) sources is essential for Muslims. The identification of non-halal meat is one of the main issues that face consumers in meat markets, especially in non-Islamic countries. Pig is one of the non-halal sources of meat, and hence pig meat and its derivatives are forbidden for Muslims to consume. Although several studies have been conducted to identify the biomarkers for nonhalal meats like pig meat, these studies are still in their infancy stages, and as a result there is no universal biomarker which could be used for clear cut identification. The purpose of this paper is to use Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography-Time of Flight Mass Spectroscopy (GC-TOF MS) techniques to study fat of pig, cow, lamb and chicken to find possible biomarkers for pig fat (lard) identification. FTIR results showed that lard and chicken fat have unique peaks at wavenumbers 1159.6 cm-1, 1743.4 cm-1, 2853.1 cm-1 and 2922.5 cm-1 compared to lamb and beef fats which did not show peaks at these wavenumbers. On the other hand, GC/MS-TOF results showed that the concentration of 1,2,3-trimethyl-Benzene, Indane, and Undecane in lard are 250, 14.5 and 1.28 times higher than their concentrations in chicken fat, respectively, and 91.4, 2.3 and 1.24 times higher than their concentrations in cow fat, respectively. These initial results clearly indicate that there is a possibility to find biomarkers for non-halal identification.

A new strategy for faster urinary biomarkers identification by Nano-LC-MALDI-TOF/TOF mass spectrometry

PubMed Central

Benkali, K; Marquet, P; Rérolle, JP; Le Meur, Y; Gastinel, LN

2008-01-01

Background LC-MALDI-TOF/TOF analysis is a potent tool in biomarkers discovery characterized by its high sensitivity and high throughput capacity. However, methods based on MALDI-TOF/TOF for biomarkers discovery still need optimization, in particular to reduce analysis time and to evaluate their reproducibility for peak intensities measurement. The aims of this methodological study were: (i) to optimize and critically evaluate each step of urine biomarker discovery method based on Nano-LC coupled off-line to MALDI-TOF/TOF, taking full advantage of the dual decoupling between Nano-LC, MS and MS/MS to reduce the overall analysis time; (ii) to evaluate the quantitative performance and reproducibility of nano-LC-MALDI analysis in biomarker discovery; and (iii) to evaluate the robustness of biomarkers selection. Results A pool of urine sample spiked at increasing concentrations with a mixture of standard peptides was used as a specimen for biological samples with or without biomarkers. Extraction and nano-LC-MS variabilities were estimated by analyzing in triplicates and hexaplicates, respectively. The stability of chromatographic fractions immobilised with MALDI matrix on MALDI plates was evaluated by successive MS acquisitions after different storage times at different temperatures. Low coefficient of variation (CV%: 10–22%) and high correlation (R2 > 0.96) values were obtained for the quantification of the spiked peptides, allowing quantification of these peptides in the low fentomole range, correct group discrimination and selection of "specific" markers using principal component analysis. Excellent peptide integrity and stable signal intensity were found when MALDI plates were stored for periods of up to 2 months at +4°C. This allowed storage of MALDI plates between LC separation and MS acquisition (first decoupling), and between MS and MSMS acquisitions while the selection of inter-group discriminative ions is done (second decoupling). Finally the recording of

Dissemination of data measured at the CERN n_TOF facility

NASA Astrophysics Data System (ADS)

Dupont, E.; Otuka, N.; Cabellos, O.; Aberle, O.; Aerts, G.; Altstadt, S.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Audouin, L.; Bacak, M.; Badurek, G.; Balibrea, J.; Barbagallo, M.; Barros, S.; Baumann, P.; Bécares, V.; Bečvář, F.; Beinrucker, C.; Belloni, F.; Berthier, B.; Berthoumieux, E.; Billowes, J.; Boccone, V.; Bosnar, D.; Brown, A.; Brugger, M.; Caamaño, M.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Capote, R.; Cardella, R.; Carrapiço, C.; Casanovas, A.; Castelluccio, D. M.; Cennini, P.; Cerutti, F.; Chen, Y. H.; Chiaveri, E.; Chin, M.; Colonna, N.; Cortés, G.; Cortés-Giraldo, M. A.; Cosentino, L.; Couture, A.; Cox, J.; Damone, L. A.; David, S.; Deo, K.; Diakaki, M.; Dillmann, I.; Domingo-Pardo, C.; Dressler, R.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Fernández-Domínguez, B.; Ferrant, L.; Ferrari, A.; Ferreira, P.; Finocchiaro, P.; Fraval, K.; Frost, R. J. W.; Fujii, K.; Furman, W.; Ganesan, S.; Garcia, A. R.; Gawlik, A.; Gheorghe, I.; Gilardoni, S.; Giubrone, G.; Glodariu, T.; Göbel, K.; Gomez-Hornillos, M. B.; Goncalves, I. F.; Gonzalez-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gurusamy, P.; Haight, R.; Harada, H.; Heftrich, T.; Heil, M.; Heinitz, S.; Hernández-Prieto, A.; Heyse, J.; Igashira, M.; Isaev, S.; Jenkins, D. G.; Jericha, E.; Kadi, Y.; Kaeppeler, F.; Kalamara, A.; Karadimos, D.; Karamanis, D.; Katabuchi, T.; Kavrigin, P.; Kerveno, M.; Ketlerov, V.; Khryachkov, V.; Kimura, A.; Kivel, N.; Kokkoris, M.; Konovalov, V.; Krtička, M.; Kroll, J.; Kurtulgil, D.; Lampoudis, C.; Langer, C.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Naour, C. Le; Lerendegui-Marco, J.; Leong, L. S.; Licata, M.; Meo, S. Lo; Lonsdale, S. J.; Losito, R.; Lozano, M.; Macina, D.; Manousos, A.; Marganiec, J.; Martinez, T.; Marrone, S.; Masi, A.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Matteucci, F.; Maugeri, E. A.; Mazzone, A.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Mondelaers, W.; Montesano, S.; Moreau, C.; Mosconi, M.; Musumarra, A.; Negret, A.; Nolte, R.; O'Brien, S.; Oprea, A.; Palomo-Pinto, F. R.; Pancin, J.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perkowski, J.; Perrot, L.; Pigni, M. T.; Plag, R.; Plompen, A.; Plukis, L.; Poch, A.; Porras, I.; Praena, J.; Pretel, C.; Quesada, J. M.; Radeck, D.; Rajeev, K.; Rauscher, T.; Reifarth, R.; Riego, A.; Robles, M.; Roman, F.; Rout, P. C.; Rudolf, G.; Rubbia, C.; Rullhusen, P.; Ryan, J. A.; Sabaté-Gilarte, M.; Salgado, J.; Santos, C.; Sarchiapone, L.; Sarmento, R.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Sedyshev, P.; Smith, A. G.; Sosnin, N. V.; Stamatopoulos, A.; Stephan, C.; Suryanarayana, S. V.; Tagliente, G.; Tain, J. L.; Tarifeño-Saldivia, A.; Tarrío, D.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Versaci, R.; Vermeulen, M. J.; Villamarin, D.; Vicente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Wallner, A.; Walter, S.; Ware, T.; Warren, S.; Weigand, M.; Weiß, C.; Wolf, C.; Wiesher, M.; Wisshak, K.; Woods, P. J.; Wright, T.; Žugec, P.

2017-09-01

The n_TOF neutron time-of-flight facility at CERN is used for high quality nuclear data measurements from thermal energy up to hundreds of MeV. In line with the CERN open data policy, the n_TOF Collaboration takes actions to preserve its unique data, facilitate access to them in standardised format, and allow their re-use by a wide community in the fields of nuclear physics, nuclear astrophysics and various nuclear technologies. The present contribution briefly describes the n_TOF outcomes, as well as the status of dissemination and preservation of n_TOF final data in the international EXFOR library.

TOF-SIMS imaging technique with information entropy

NASA Astrophysics Data System (ADS)

Aoyagi, Satoka; Kawashima, Y.; Kudo, Masahiro

2005-05-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is capable of chemical imaging of proteins on insulated samples in principal. However, selection of specific peaks related to a particular protein, which are necessary for chemical imaging, out of numerous candidates had been difficult without an appropriate spectrum analysis technique. Therefore multivariate analysis techniques, such as principal component analysis (PCA), and analysis with mutual information defined by information theory, have been applied to interpret SIMS spectra of protein samples. In this study mutual information was applied to select specific peaks related to proteins in order to obtain chemical images. Proteins on insulated materials were measured with TOF-SIMS and then SIMS spectra were analyzed by means of the analysis method based on the comparison using mutual information. Chemical mapping of each protein was obtained using specific peaks related to each protein selected based on values of mutual information. The results of TOF-SIMS images of proteins on the materials provide some useful information on properties of protein adsorption, optimality of immobilization processes and reaction between proteins. Thus chemical images of proteins by TOF-SIMS contribute to understand interactions between material surfaces and proteins and to develop sophisticated biomaterials.

Gas chromatography time-of-flight mass spectrometry (GC-TOF-MS)-based metabolomics for comparison of caffeinated and decaffeinated coffee and its implications for Alzheimer's disease.

PubMed

Chang, Kai Lun; Ho, Paul C

2014-01-01

Findings from epidemiology, preclinical and clinical studies indicate that consumption of coffee could have beneficial effects against dementia and Alzheimer's disease (AD). The benefits appear to come from caffeinated coffee, but not decaffeinated coffee or pure caffeine itself. Therefore, the objective of this study was to use metabolomics approach to delineate the discriminant metabolites between caffeinated and decaffeinated coffee, which could have contributed to the observed therapeutic benefits. Gas chromatography time-of-flight mass spectrometry (GC-TOF-MS)-based metabolomics approach was employed to characterize the metabolic differences between caffeinated and decaffeinated coffee. Orthogonal partial least squares discriminant analysis (OPLS-DA) showed distinct separation between the two types of coffee (cumulative Q(2) = 0.998). A total of 69 discriminant metabolites were identified based on the OPLS-DA model, with 37 and 32 metabolites detected to be higher in caffeinated and decaffeinated coffee, respectively. These metabolites include several benzoate and cinnamate-derived phenolic compounds, organic acids, sugar, fatty acids, and amino acids. Our study successfully established GC-TOF-MS based metabolomics approach as a highly robust tool in discriminant analysis between caffeinated and decaffeinated coffee samples. Discriminant metabolites identified in this study are biologically relevant and provide valuable insights into therapeutic research of coffee against AD. Our data also hint at possible involvement of gut microbial metabolism to enhance therapeutic potential of coffee components, which represents an interesting area for future research.

Towards Spectral Library-free MALDI-TOF MS Bacterial Identification.

PubMed

Cheng, Ding; Qiao, Liang; Horvatovich, Péter

2018-05-11

Bacterial identification is of great importance in clinical diagnosis, environmental monitoring and food safety control. Among various strategies, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has drawn significant interests, and has been clinically used. Nevertheless, current bioinformatics solutions use spectral libraries for the identification of bacterial strains. Spectral library generation requires acquisition of MALDI-TOF spectra from monoculture bacterial colonies, which is time-consuming and not possible for many species and strains. We propose a strategy for bacterial typing by MALDI-TOF using protein sequences from public database, i.e. UniProt. Ten genes were identified to encode proteins most often observed by MALD-TOF from bacteria through 500 times repeated a 10-fold double cross-validation procedure, using 403 MALDI-TOF spectra corresponding to 14 genera, 81 species and 403 strains, and the protein sequences of 1276 species in UniProt. The 10 genes were then used to annotate peaks on MALDI-TOF spectra of bacteria for bacterial identification. With the approach, bacteria can be identified at the genus level by searching against a database containing the protein sequences of 42 genera of bacteria from UniProt. Our approach identified 84.1% of the 403 spectra correctly at the genus level. Source code of the algorithm is available at https://github.com/dipcarbon/BacteriaMSLF.

A new method to discriminate secondary organic aerosols from different sources using high-resolution aerosol mass spectra

NASA Astrophysics Data System (ADS)

Heringa, M. F.; Decarlo, P. F.; Chirico, R.; Tritscher, T.; Clairotte, M.; Mohr, C.; Crippa, M.; Slowik, J. G.; Pfaffenberger, L.; Dommen, J.; Weingartner, E.; Prévôt, A. S. H.; Baltensperger, U.

2012-02-01

Organic aerosol (OA) represents a significant and often major fraction of the non-refractory PM1 (particulate matter with an aerodynamic diameter da < 1 μm) mass. Secondary organic aerosol (SOA) is an important contributor to the OA and can be formed from biogenic and anthropogenic precursors. Here we present results from the characterization of SOA produced from the emissions of three different anthropogenic sources. SOA from a log wood burner, a Euro 2 diesel car and a two-stroke Euro 2 scooter were characterized with an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) and compared to SOA from α-pinene. The emissions were sampled from the chimney/tailpipe by a heated inlet system and filtered before injection into a smog chamber. The gas phase emissions were irradiated by xenon arc lamps to initiate photo-chemistry which led to nucleation and subsequent particle growth by SOA production. Duplicate experiments were performed for each SOA type, with the averaged organic mass spectra showing Pearson's r values >0.94 for the correlations between the four different SOA types after five hours of aging. High-resolution mass spectra (HR-MS) showed that the dominant peaks in the MS, m/z 43 and 44, are dominated by the oxygenated ions C2H3O+ and CO2+, respectively, similarly to the relatively fresh semi-volatile oxygenated OA (SV-OOA) observed in the ambient aerosol. The atomic O:C ratios were found to be in the range of 0.25-0.55 with no major increase during the first five hours of aging. On average, the diesel SOA showed the lowest O:C ratio followed by SOA from wood burning, α-pinene and the scooter emissions. Grouping the fragment ions revealed that the SOA source with the highest O:C ratio had the largest fraction of small ions. The HR data of the four sources could be clustered and separated using principal component analysis (PCA). The model showed a significant separation of the four SOA types and clustering of the duplicate

GC-TOF/MS-based metabolomic profiling of estrogen deficiency-induced obesity in ovariectomized rats

PubMed Central

Ma, Bo; Zhang, Qi; Wang, Guang-ji; A, Ji-ye; Wu, Di; Liu, Ying; Cao, Bei; Liu, Lin-sheng; Hu, Ying-ying; Wang, Yong-lu; Zheng, Ya-ya

2011-01-01

Aim: To explore the alteration of endogenous metabolites and identify potential biomarkers using metabolomic profiling with gas chromatography coupled a time-of-flight mass analyzer (GC/TOF-MS) in a rat model of estrogen-deficiency-induced obesity. Methods: Twelve female Sprague-Dawley rats six month of age were either sham-operated or ovariectomized (OVX). Rat blood was collected, and serum was analyzed for biomarkers using standard colorimetric methods with commercial assay kits and a metabolomic approach with GC/TOF-MS. The data were analyzed using multivariate statistical techniques. Results: A high body weight and body mass index inversely correlated with serum estradiol (E2) in the OVX rats compared to the sham rats. Estrogen deficiency also significantly increased serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol. Utilizing GC/TOF-MS-based metabolomic analysis and the partial least-squares discriminant analysis, the OVX samples were discriminated from the shams. Elevated levels of cholesterol, glycerol, glucose, arachidonic acid, glutamic acid, glycine, and cystine and reduced alanine levels were observed. Serum glucose metabolism, energy metabolism, lipid metabolism, and amino acid metabolism were involved in estrogen-deficiency-induced obesity in OVX rats. Conclusion: The series of potential biomarkers identified in the present study provided fingerprints of rat metabolomic changes during obesity and an overview of multiple metabolic pathways during the progression of obesity involving glucose metabolism, lipid metabolism, and amino acid metabolism. PMID:21293480

Companions to peculiar red giants: HR 363 and HR 1105

NASA Technical Reports Server (NTRS)

Ake, Thomas B., III; Johnson, Hollis R.; Perry, Benjamin F., Jr.

1988-01-01

Recent IUE observations of two Tc-deficient S-type peculiar red giants that are also spectroscopic binaries, HR 363 and HR 1105 are reported. A 675 min SWP exposure of HR 363 shows emission lines of O I 1304 and Si II 1812 and a trace of continuum. Compared to the M giants, the far UV flux may be relatively larger, indicating a possible contribution from a white dwarf companion, but no high temperature emission lines are seen to indicate that this is an interacting system where mass-transfer recently occurred. However, HR 1105 appears to have a highly variable UV companion. In 1982, no UV flux was discerned for this system, but by 1986 C IV was strong, increasing by a factor of 3 in 1987 with prominent lines of Si III, C III, O III, Si IV, and N V. Using orbital parameters, these observations are consistent with high activity occuring when the side of the S-star primary illuminated by the companion faces the Earth, but since the IUE data were taken over 3 orbits, a secular change in the UV component cannot be excluded.

Evaluation of ice-tea quality by DART-TOF/MS.

PubMed

Rajchl, Aleš; Prchalová, Jana; Kružík, Vojtěch; Ševčík, Rudolf; Čížková, Helena

2015-11-01

DART (Direct Analysis in Real Time) coupled with Time-of-Flight Mass Spectrometry (TOF/MS) has been used for analyses of ice-teas. The article focuses on quality and authenticity of ice-teas as one of the most important tea-based products on the market. Twenty-one samples of ice-teas (black and green) were analysed. Selected compounds of ice-teas were determined: theobromine, caffeine, total phenolic compounds, total soluble solids, total amino acid concentration, preservatives and saccharides were determined. Fingerprints of DART-TOF/MS spectra were used for comprehensive assessment of the ice-tea samples. The DART-TOF/MS method was used for monitoring the following compounds: citric acid, caffeine, saccharides, artificial sweeteners (saccharin, acesulphame K), and preservatives (sorbic and benzoic acid), phosphoric acid and phenolic compounds. The measured data were subjected to a principal components analysis. The HPLC and DART-TOF/MS methods were compared in terms of determination of selected compounds (caffeine, benzoic acid, sorbic acid and saccharides) in the ice-teas. The DART-TOF/MS technique seems to be a suitable method for fast screening, testing quality and authenticity of tea-based products. Copyright © 2015 John Wiley & Sons, Ltd.

Prediction of Susceptibility to Acute Mountain Sickness Using Hypoxia-Induced Intrapulmonary Arteriovenous Shunt and Intracardiac Shunt Fractions

DTIC Science & Technology

2012-10-31

intrapulmonary and intracardiac shunt using saline contrast echocardiography to determine bubble/shunt scores. We will also use nuclear medicine imaging to...subjects have completed saline contrast echocardiography while breathing hypoxic gas mixtures. For Task #2 “10 hr hypoxic exposure and AMS... echocardiography while breathing an FIO2=0.14, will be susceptible or resistant to developing AMS after 10 hr hypoxic exposure. For Task #3 “Hypoxia

Complementation of UPLC-Q-TOF-MS and CESI-Q-TOF-MS on identification and determination of peptides from bovine lactoferrin.

PubMed

Chen, Hui; Shi, Pujie; Fan, Fengjiao; Tu, Maolin; Xu, Zhe; Xu, Xianbing; Du, Ming

2018-05-01

Digested peptides of bovine lactoferrin as the functional hydrolysates were identified by the Q-TOF tandem mass spectrometry (Q-TOF-MS) coupled with ultra performance liquid chromatograph (UPLC) and capillary electrophoresis (CE). The former (UPLC-Q-TOF-MS) identified 106 peptides while the latter (CE-Q-TOF-MS) characterized 102 peptides after comparison of peptides in terms of their molecular weight (MW), mass-to-charge ratio (m/z), and isoelectric point (pI). In addition, the hydrophilic value, net charge (q), and molecular radius (r) of the peptides were calculated, and a correlation analysis of the two methods was conducted between the retention time (RT) and r/q ratio of the peptides in order to elucidate the different separation principles of the unique peptides. It was shown that the peptides with larger hydrophilic value were beneficial to be separated by UPLC, while the peptides with larger r/q ratio were beneficial to be separated by CE. Combination of the above mentioned two complementary techniques have confidently improved the sequence coverage of lactoferrin and enhanced the identification of peptides, which makes it up to 65.8% in this study. Copyright © 2018. Published by Elsevier B.V.

Gas Chromatography Time-Of-Flight Mass Spectrometry (GC-TOF-MS)-Based Metabolomics for Comparison of Caffeinated and Decaffeinated Coffee and Its Implications for Alzheimer’s Disease

PubMed Central

Chang, Kai Lun; Ho, Paul C.

2014-01-01

Findings from epidemiology, preclinical and clinical studies indicate that consumption of coffee could have beneficial effects against dementia and Alzheimer’s disease (AD). The benefits appear to come from caffeinated coffee, but not decaffeinated coffee or pure caffeine itself. Therefore, the objective of this study was to use metabolomics approach to delineate the discriminant metabolites between caffeinated and decaffeinated coffee, which could have contributed to the observed therapeutic benefits. Gas chromatography time-of-flight mass spectrometry (GC-TOF-MS)-based metabolomics approach was employed to characterize the metabolic differences between caffeinated and decaffeinated coffee. Orthogonal partial least squares discriminant analysis (OPLS-DA) showed distinct separation between the two types of coffee (cumulative Q2 = 0.998). A total of 69 discriminant metabolites were identified based on the OPLS-DA model, with 37 and 32 metabolites detected to be higher in caffeinated and decaffeinated coffee, respectively. These metabolites include several benzoate and cinnamate-derived phenolic compounds, organic acids, sugar, fatty acids, and amino acids. Our study successfully established GC-TOF-MS based metabolomics approach as a highly robust tool in discriminant analysis between caffeinated and decaffeinated coffee samples. Discriminant metabolites identified in this study are biologically relevant and provide valuable insights into therapeutic research of coffee against AD. Our data also hint at possible involvement of gut microbial metabolism to enhance therapeutic potential of coffee components, which represents an interesting area for future research. PMID:25098597

MALDI-TOF-mass spectrometry applications in clinical microbiology.

PubMed

Seng, Piseth; Rolain, Jean-Marc; Fournier, Pierre Edouard; La Scola, Bernard; Drancourt, Michel; Raoult, Didier

2010-11-01

MALDI-TOF-mass spectrometry (MS) has been successfully adapted for the routine identification of microorganisms in clinical microbiology laboratories in the past 10 years. This revolutionary technique allows for easier and faster diagnosis of human pathogens than conventional phenotypic and molecular identification methods, with unquestionable reliability and cost-effectiveness. This article will review the application of MALDI-TOF-MS tools in routine clinical diagnosis, including the identification of bacteria at the species, subspecies, strain and lineage levels, and the identification of bacterial toxins and antibiotic-resistance type. We will also discuss the application of MALDI-TOF-MS tools in the identification of Archaea, eukaryotes and viruses. Pathogenic identification from colony-cultured, blood-cultured, urine and environmental samples is also reviewed.

Global Survey of Submicron Aerosol Acidity (pH)

NASA Astrophysics Data System (ADS)

Nault, B.; Day, D. A.; Campuzano Jost, P.; Hu, W.; Schroder, J. C.; Bian, H.; Chin, M.; Clegg, S. L.; Colarco, P. R.; Dibb, J. E.; Kim, M. J.; Kodros, J.; Marais, E. A.; Pierce, J. R.; Scheuer, E. M.; Wennberg, P. O.; Jimenez, J. L.

2017-12-01

Aerosol acidity (H+, often expressed as "pH" defined in various ways) is an important property that influences uptake and partitioning of gases, and homogeneous and surface aqueous reactions of key inorganic and organic compounds. As there is currently no rapid method to measure ambient aerosol acidity, a thermodynamic model, constrained by both inorganic aerosol species (e.g., NH4, NO3, SO4, Cl) and at least one inorganic gas (HNO3, NH3, or HCl), are currently understood to lead to the most reliable estimates of aerosol acidity. In this study, we calculated submicron (less than PM1) aerosol pH from the NASA ATom, "pole-to-pole," flights that covers both the Pacific and Atlantic ocean basins. The E-AIM thermodynamic model was used with measurements by an Aerodyne high-resolution time-of-flight aerosol-mass-spectrometer (HR-ToF-AMS) of inorganic aerosol species, along with inorganic gas measurements from other mass spectrometers and ion chromatography. We compare the results with those for the NASA KORUS-AQ, SEAC4RS, DC3, and ARCTAS campaigns, as well as several ground-based campaigns and recently-published studies. This provides an opportunity to compare the aerosol acidity in urban, rural, and remote regions, by season, and between the boundary layer and free troposphere. In addition, we compare the submicron aerosol acidity from these various localities with results from global models, such as GEOS-Chem, in order to investigate the ability of the global models to simulate aerosol acidity, and the processes it affects, such as nitrate, ammonium, and MSA partitioning.

Status report: Implementation of gas measurements at the MAMS 14C AMS facility in Mannheim, Germany

NASA Astrophysics Data System (ADS)

Hoffmann, Helene; Friedrich, Ronny; Kromer, Bernd; Fahrni, Simon

2017-11-01

By implementing a Gas Interface System (GIS), CO2 gas measurements for radiocarbon dating of small environmental samples (<100 μgC) have been established at the MICADAS (Mini Carbon Dating System) AMS instrument in Mannheim, Germany. The system performance has been optimized and tested with respect to stability and ion yield by repeated blank and standard measurements for sample sizes down to 3 μgC. The highest 12C- low-energy (LE) ion currents, typically reaching 8-15 μA, could be achieved for a mixing ratio of 4% CO2 in Helium, resulting in relative counting errors of 1-2% for samples larger than 10 μgC and 3-7% for sample sizes below 10 μgC. The average count rate was ca. 500 counts per microgram C for OxII standard material. The blank is on the order of 35,000-40,000 radiocarbon years, which is comparable to similar systems. The complete setup thus enables reliable dating for most environmental samples (>3 μgC).

241Am (n,gamma) isomer ratio measurement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bond, Evelyn M; Vieira, David J; Moody, Walter A

The objective of this project is to improve the accuracy of the {sup 242}Cm/{sup 241}Am radiochemistry ratio. We have performed an activation experiment to measure the {sup 241}Am(n,{gamma}) cross section leading to either the ground state of {sup 242g}Am (t{sub 1/2} = 16 hr) which decays to {sup 242}Cm (t{sub 1/2} = 163 d) or the long-lived isomer {sup 242m}Am (t{sub 1/2} = 141 yr). This experiment will develop a new set of americium cross section evaluations that can be used with a measured {sup 242}Cm/{sup 241}Am radiochemical measurement for nuclear forensic purposes. This measurement is necessary to interpret themore » {sup 242}Cm/{sup 241}Am ratio because a good measurement of this neutron capture isomer ratio for {sup 241}Am does not exist. The targets were prepared in 2007 from {sup 241}Am purified from LANL stocks. Gold was added to the purified {sup 241}Am as an internal neutron fluence monitor. These targets were placed into a holder, packaged, and shipped to Forschungszentrum Karlsruhe, where they were irradiated at their Van de Graff facility in February 2008. One target was irradiated with {approx}25 keV quasimonoenergetic neutrons produced by the {sup 7}Li(p,n) reaction for 3 days and a second target was also irradiated for 3 days with {approx}500 keV neutrons. Because it will be necessary to separate the {sup 242}Cm from the {sup 241}Am in order to measure the amount of {sup 242}Cm by alpha spectrometry, research into methods for americium/curium separations were conducted concurrently. We found that anion exchange chromatography in methanol/nitric acid solutions produced good separations that could be completed in one day resulting in a sample with no residue. The samples were returned from Germany in July 2009 and were counted by gamma spectrometry. Chemical separations have commenced on the blank sample. Each sample will be spiked with {sup 244}Cm, dissolved and digested in nitric acid solutions. One third of each sample will be processed at a

[Rapid analysis of compounds in leaves of Chinese seabuckthorn and Tibetan seabuckthorn by UPLC/Q-TOF-MS].

PubMed

Qin, Zhen-Xian; Zhang, Yu; Qi, Meng-Die; Zhang, Quan; Liu, Shuang; Li, Ming-Hui; Liu, Yong-Gang; Liu, Yong

2016-04-01

The study is aimed to analyze the chemical components in leaves of Chinese seabuckthorn and Tibetan seabuckthorn qualitatively and compare the differences between them by using ultra performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS).The chromatographic separation of the components was achieved ona Waters ACQUITY UPLC-T3 column (2.1 mm×100 mm, 1.7 μm）using gradient mobile phase consisting of acetonitrile (A) and aqueous solution (B). The identification of the separated compounds was performed on atandem mass spectrometry (MS/MS)by fragmentation patterns under the negative electrospray ionization. The parameters of ion source were as follows：capillary voltage, 2 000 V; Cone voltage, 40 V. The ion source temperature, 100 ℃; collision gas argon; sheath gas flow rate, 900 L•h⁻¹; sheath gas temperature, 450 ℃. Through the analysis of mass spectrometry data and with the help of literature data, a total of 35 compounds were detected and most of them were flavonoids. Among these compounds, 29 were common components for the two species, two components were unique to Chinese seabuckthorn and 4 were characteristic components of Tibetan seabuckthorn. The results indicated that the compositions of the two kinds of seabuckthorn leaves were quite similar. It is also demonstrated that UPLC/Q-TOF-MS method could be applied to rapidly and effectively analyze and speculate the compounds in leaves of Chinese seabuckthorn and Tibetan seabuckthorn. Copyright© by the Chinese Pharmaceutical Association.

Detection of Protein Modifications and Counterfeit Protein Pharmaceuticals Using iTRAQ and MALDI TOF/TOF Mass Spectrometry: Studies with Insulins

PubMed Central

Ye, Hongping; Hill, John; Kauffman, John; Gryniewicz, Connie; Han, Xianlin

2013-01-01

iTRAQ (isotope tags for relative and absolute quantification) reagent coupled with MALDI TOF/TOF mass spectrometric analysis has been evaluated as both a qualitative and quantitative method for the detection of modifications to active pharmaceutical ingredients derived from recombinant DNA technologies, and as a method to detect counterfeit drug products. Five types of insulin (human, bovine, porcine, Lispro, Lantus®) were used as model products in the study because of their minor variations in amino acid sequence. Several experiments were conducted in which each insulin variant was separately digested with Glu-C, and the digestate was labeled with one of four different iTRAQ reagents. All digestates were then combined for desalting and MALDI TOF/TOF mass spectrometric analysis. When the digestion procedure was optimized, the insulin sequence coverage was 100%. Five different types of insulin were readily differentiated, including Human insulin (P28K29) and Lispro (K28P29), which only differ by the interchange of two contiguous residues. Moreover, quantitative analyses show that the results obtained from the iTRAQ method agree well with those determined by other conventional methods. Collectively, the iTRAQ method can be used as a qualitative and quantitative technique for the detection of protein modification and counterfeiting. PMID:18489896

Effect of Vaporizer Temperature on Ambient Non-Refractory Submicron Aerosol Composition and Mass Spectra Measured by the Aerosol Mass Spectrometer

EPA Science Inventory

Aerodyne Aerosol Mass Spectrometers (AMS) are routinely operated with a constant vaporizer temperature (Tvap) of 600^oC in order to facilitate quantitative detection of non-refractory submicron (NR-PM1) species. By analogy with other thermal desorption instrument...

Complementary b/y fragment ion pairs from post-source decay of metastable YahO for calibration of MALDI-TOF-TOF-MS/MS

USDA-ARS?s Scientific Manuscript database

Complementary b/y fragment ion pairs from post-source decay (PSD) of metastable YahO protein ion were evaluated for use in the calibration of MALDI-TOF-TOF for tandem mass spectrometry (MS/MS). The yahO gene from pathogenic Escherichia coli O157:H7 strain EDL933 was cloned into a pBAD18 plasmid vect...

Quantified, Interactive Simulation of AMCW ToF Camera Including Multipath Effects

PubMed Central

Lambers, Martin; Kolb, Andreas

2017-01-01

In the last decade, Time-of-Flight (ToF) range cameras have gained increasing popularity in robotics, automotive industry, and home entertainment. Despite technological developments, ToF cameras still suffer from error sources such as multipath interference or motion artifacts. Thus, simulation of ToF cameras, including these artifacts, is important to improve camera and algorithm development. This paper presents a physically-based, interactive simulation technique for amplitude modulated continuous wave (AMCW) ToF cameras, which, among other error sources, includes single bounce indirect multipath interference based on an enhanced image-space approach. The simulation accounts for physical units down to the charge level accumulated in sensor pixels. Furthermore, we present the first quantified comparison for ToF camera simulators. We present bidirectional reference distribution function (BRDF) measurements for selected, purchasable materials in the near-infrared (NIR) range, craft real and synthetic scenes out of these materials and quantitatively compare the range sensor data. PMID:29271888

Quantified, Interactive Simulation of AMCW ToF Camera Including Multipath Effects.

PubMed

Bulczak, David; Lambers, Martin; Kolb, Andreas

2017-12-22

In the last decade, Time-of-Flight (ToF) range cameras have gained increasing popularity in robotics, automotive industry, and home entertainment. Despite technological developments, ToF cameras still suffer from error sources such as multipath interference or motion artifacts. Thus, simulation of ToF cameras, including these artifacts, is important to improve camera and algorithm development. This paper presents a physically-based, interactive simulation technique for amplitude modulated continuous wave (AMCW) ToF cameras, which, among other error sources, includes single bounce indirect multipath interference based on an enhanced image-space approach. The simulation accounts for physical units down to the charge level accumulated in sensor pixels. Furthermore, we present the first quantified comparison for ToF camera simulators. We present bidirectional reference distribution function (BRDF) measurements for selected, purchasable materials in the near-infrared (NIR) range, craft real and synthetic scenes out of these materials and quantitatively compare the range sensor data.

Development of a Direct Headspace Collection Method from Arabidopsis Seedlings Using HS-SPME-GC-TOF-MS Analysis

PubMed Central

Kusano, Miyako; Iizuka, Yumiko; Kobayashi, Makoto; Fukushima, Atsushi; Saito, Kazuki

2013-01-01

Plants produce various volatile organic compounds (VOCs), which are thought to be a crucial factor in their interactions with harmful insects, plants and animals. Composition of VOCs may differ when plants are grown under different nutrient conditions, i.e., macronutrient-deficient conditions. However, in plants, relationships between macronutrient assimilation and VOC composition remain unclear. In order to identify the kinds of VOCs that can be emitted when plants are grown under various environmental conditions, we established a conventional method for VOC profiling in Arabidopsis thaliana (Arabidopsis) involving headspace-solid-phase microextraction-gas chromatography-time-of-flight-mass spectrometry (HS-SPME-GC-TOF-MS). We grew Arabidopsis seedlings in an HS vial to directly perform HS analysis. To maximize the analytical performance of VOCs, we optimized the extraction method and the analytical conditions of HP-SPME-GC-TOF-MS. Using the optimized method, we conducted VOC profiling of Arabidopsis seedlings, which were grown under two different nutrition conditions, nutrition-rich and nutrition-deficient conditions. The VOC profiles clearly showed a distinct pattern with respect to each condition. This study suggests that HS-SPME-GC-TOF-MS analysis has immense potential to detect changes in the levels of VOCs in not only Arabidopsis, but other plants grown under various environmental conditions. PMID:24957989

YahO protein as a calibrant for top-down proteomic identification of Shiga toxin using MALDI-TOF-TOF-MS/MS and post-source decay

USDA-ARS?s Scientific Manuscript database

Matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF-TOF) mass spectrometry is increasingly utilized for rapid top-down proteomic identification of proteins. This identification may involve analysis of either a pure protein or a protein mixture. For analysis of a pure protein...

CE-TOF/MS: fundamental concepts, instrumental considerations and applications.

PubMed

Staub, Aline; Schappler, Julie; Rudaz, Serge; Veuthey, Jean-Luc

2009-05-01

This review discusses the fundamental principles of TOF analyzers and covers the great progress that has been made in this area in recent years (i.e. orthogonal acceleration, reflectron). This paper also gives an overview of applications performed by CE coupled to TOF/MS detection. The main domains of interest include the analysis of biomolecules and natural compounds.

40 CFR 60.5365 - Am I subject to this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Natural Gas Production, Transmission and Distribution § 60.5365 Am I subject to this subpart? You are... custody transfer to the natural gas transmission and storage segment. A centrifugal compressor located at... transmission and storage segment. A reciprocating compressor located at a well site, or an adjacent well site...

APD Response Time Measurements for Future TOF-E Systems

NASA Astrophysics Data System (ADS)

Starkey, M. J.; Ogasawara, K.; Dayeh, M. A.; Desai, M. I.

2017-12-01

In space physics, the ability to detect ions is crucial to understanding plasma distributions in the solar wind. This usually typically requires the determination of the particle's mass, charge, and total energy. Current ion detection schemes are implemented in three sequential parts; an electrostatic analyzer for energy per charge (E/Q) measurements, a time-of-flight (TOF) for mass per charge (M/Q) measurements, and a solid-state detector (SSD) for total energy (E) measurements. Recent work has suggested the use of avalanche photodiode detectors (APD) for a simultaneous TOF and total energy (TOF-E) measurement system, which would replace traditional SSDs, simplify design, and reduce costs. Although TOF based ion spectrometry typically requires timing resolution of <1ns, the timing profile for ion detection by APDs is not well understood. In this study we examine the timing profile of 3 different APDs for ion measurements over a suprathermal energy range of 50-300 keV. The three APDs differ by their doping type (N or P) and their detector thickness (30 μm or 150 μm). We find that APD P30, which is P doped and 30μm thick, provides the fastest rise times of the three APDs. Furthermore, these rise times are species independent and less than 1 ns. Our study shows that APDs are capable of sub-nanosecond response times for low energy ions and thus supports the future use of APDs in replacing SSDs in some TOF-E systems.

Secondary Organic Aerosol Formation and Aging in a Flow Reactor in the Forested Southeast US during SOAS

NASA Astrophysics Data System (ADS)

Hu, W.; Palm, B. B.; Hacker, L.; Campuzano Jost, P.; Day, D. A.; de Sá, S. S.; Ayres, B. R.; Draper, D.; Fry, J.; Ortega, A. M.; Kiendler-Scharr, A.; Pajunoja, A.; Virtanen, A.; Krechmer, J.; Canagaratna, M. R.; Thompson, S.; Yatavelli, R. L. N.; Stark, H.; Worsnop, D. R.; Martin, S. T.; Farmer, D.; Brown, S. S.; Jimenez, J. L.

2015-12-01

A major field campaign (Southern Oxidant and Aerosol Study, SOAS) was conducted in summer 2013 in a forested area in Centreville Supersite, AL (SEARCH network) in the southeast U.S. To investigate secondary organic aerosol (SOA) formation from biogenic volatile organic compounds (BVOCs), 3 oxidation flow reactors (OFR) were used to expose ambient air to oxidants and their output was analyzed by state-of-the-art gas and aerosol instruments including a High-Resolution Aerosol Mass Spectrometer (HR-AMS), a HR Proton-Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-TOFMS), and Two HR-TOF Chemical Ionization Mass Spectrometers (HRToF-CIMS). Ambient air was exposed 24/7 to variable concentrations of each of the 3 main atmospheric oxidants (OH, NO3 radicals and O3) to investigate the oxidation of BVOCs (including isoprene derived epoxydiols, IEPOX) and SOA formation and aging. Effective OH exposures up to 1×1013 molec cm-3 s were achieved, equivalent to over a month of aging in the atmosphere. Multiple oxidation products from isoprene and monoterpenes including small gas-phase acids were observed in OH OFR. High SOA formation of up to 12 μg m-3 above ambient concentrations of 5 μg m-3 was observed under intermediate OH exposures, while very high OH exposures led to destruction of ~30% of ambient OA, indicating shifting contributions of functionalization vs. fragmentation, consistent with results from urban and terpene-dominated environments. The highest SOA enhancements were 3-4 times higher than ambient OA. More SOA is typically formed during nighttime when terpenes are higher and photochemistry is absent, and less during daytime when isoprene is higher, although the IEPOX pathway is suppressed in the OFR. SOA is also observed after exposure of ambient air to O3 or NO3, although the amounts and oxidation levels were lower than for OH. Formation of organic nitrates in the NO3 reaction will also be discussed.A major field campaign (Southern Oxidant and Aerosol

Alloy NASA-HR-1

NASA Technical Reports Server (NTRS)

Chen, Po-Shou; Mitchell, Michael

2005-01-01

NASA-HR-1 is a high-strength Fe-Ni-base superalloy that resists high-pressure hydrogen environment embrittlement (HEE), oxidation, and corrosion. Originally derived from JBK-75, NASA-HR-1 has exceptional HEE resistance that can be attributed to its gamma-matrix and eta-free (Ni3Ti) grain boundaries. The chemistry was formulated using a design approach capable of accounting for the simultaneous effects of several alloy additions. This approach included: (1) Systematically modifying gamma-matrix compositions based on JBK-75; (2) Increasing gamma (Ni3(Al,Ti)) volume fraction and adding gamma-matrix strengthening elements to obtain higher strength; and (3) Obtaining precipitate-free grain boundaries. The most outstanding attribute of NASA-HR-1 is its ability to resist HEE while showing much improved strength. NASA-HR-1 has approximately 25% higher yield strength than JXK-75 and exhibits tensile elongation of more than 20% with no ductility loss in a hydrogen environment at 5 ksi, an achievement unparalleled by any other commercially available alloy. Its Cr and Ni contents provide exceptional resistance to environments that promote oxidation and corrosion. Microstructural stability was maintained by improved solid solubility of the gamma-matrix, along with the addition of alloying elements to retard eta (Ni3Ti) precipitation. NASA-HR-1 represents a new system that greatly extends the compositional ranges of existing HEE-resistant Fe-Ni-base superalloys.

Identification of lubrication oil in the particulate matter emissions from engine exhaust of in-service commercial aircraft.

PubMed

Yu, Zhenhong; Herndon, Scott C; Ziemba, Luke D; Timko, Michael T; Liscinsky, David S; Anderson, Bruce E; Miake-Lye, Richard C

2012-09-04

Lubrication oil was identified in the organic particulate matter (PM) emissions of engine exhaust plumes from in-service commercial aircraft at Chicago Midway Airport (MDW) and O'Hare International Airport (ORD). This is the first field study focused on aircraft lubrication oil emissions, and all of the observed plumes described in this work were due to near-idle engine operations. The identification was carried out with an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF AMS) via a collaborative laboratory and field investigation. A characteristic mass marker of lubrication oil, I(85)/I(71), the ratio of ion fragment intensity between m/z = 85 and 71, was used to distinguish lubrication oil from jet engine combustion products. This AMS marker was based on ion fragmentation patterns measured using electron impact ionization for two brands of widely used lubrication oil in a laboratory study. The AMS measurements of exhaust plumes from commercial aircraft in this airport field study reveal that lubrication oil is commonly present in organic PM emissions that are associated with emitted soot particles, unlike the purely oil droplets observed at the lubrication system vent. The characteristic oil marker, I(85)/I(71), was applied to quantitatively determine the contribution from lubrication oil in measured aircraft plumes, which ranges from 5% to 100%.

MALDI-TOF typing highlights geographical and fluconazole resistance clusters in Candida glabrata.

PubMed

Dhieb, C; Normand, A C; Al-Yasiri, M; Chaker, E; El Euch, D; Vranckx, K; Hendrickx, M; Sadfi, N; Piarroux, R; Ranque, S

2015-06-01

Utilizing matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectra for Candida glabrata typing would be a cost-effective and easy-to-use alternative to classical DNA-based typing methods. This study aimed to use MALDI-TOF for the typing of C. glabrata clinical isolates from various geographical origins and test its capacity to differentiate between fluconazole-sensitive and -resistant strains.Both microsatellite length polymorphism (MLP) and MALDI-TOF mass spectra of 58 C. glabrata isolates originating from Marseilles (France) and Tunis (Tunisia) as well as collection strains from diverse geographic origins were analyzed. The same analysis was conducted on a subset of C. glabrata isolates that were either susceptible (MIC ≤ 8 mg/l) or resistant (MIC ≥ 64 mg/l) to fluconazole.According to the seminal results, both MALDI-TOF and MLP classifications could highlight C. glabrata population structures associated with either geographical dispersal barriers (p < 10(-5)) or the selection of antifungal drug resistance traits (<10(-5)).In conclusion, MALDI-TOF geographical clustering was congruent with MPL genotyping and highlighted a significant population genetic structure according to fluconazole susceptibility in C. glabrata. Furthermore, although MALDI-TOF and MLP resulted in distinct classifications, MALDI-TOF also classified the isolates with respect to their fluconazole susceptibility profile. Further prospective studies are required to evaluate the capacity of MALDI-TOF typing to investigate C. glabrata infection outbreaks and predict the antifungal susceptibility profile of clinical laboratory isolates. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

[Applications of MALDI-TOF technology in clinical microbiology].

PubMed

Suarez, S; Nassif, X; Ferroni, A

2015-02-01

Until now, the identification of micro-organisms has been based on the cultural and biochemical characteristics of bacterial and fungal species. Recently, Mass Spectrometry type Matrix-Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF MS) was developed in clinical microbiology laboratories. This new technology allows identification of micro-organisms directly from colonies of bacteria and fungi within few minutes. In addition, it can be used to identify germs directly from positive blood culture bottles or directly from urine samples. Other ways are being explored to expand the use of MALDI-TOF in clinical microbiology laboratories. Indeed, some studies propose to detect bacterial antibiotic resistance while others compare strains within species for faster strain typing. The main objective of this review is to update data from the recent literature for different applications of MALDI-TOF technique in microbiological diagnostic routine. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Graphene Oxide as a Novel Evenly Continuous Phase Matrix for TOF-SIMS

NASA Astrophysics Data System (ADS)

Cai, Lesi; Sheng, Linfeng; Xia, Mengchan; Li, Zhanping; Zhang, Sichun; Zhang, Xinrong; Chen, Hongyuan

2017-03-01

Using matrix to enhance the molecular ion signals for biomolecule identification without loss of spatial resolution caused by matrix crystallization is a great challenge for the application of TOF-SIMS in real-world biological research. In this report, graphene oxide (GO) was used as a matrix for TOF-SIMS to improve the secondary ion yields of intact molecular ions ([M + H]+). Identifying and distinguishing the molecular ions of lipids ( m/z >700) therefore became straightforward. The spatial resolution of TOF-SIMS imaging could also be improved as GO can form a homogeneous layer of matrix instead of crystalline domain, which prevents high spatial resolution in TOF-SIMS imaging. Lipid mapping in presence of GO revealed the delicate morphology and distribution of single vesicles with a diameter of 800 nm. On GO matrix, the vesicles with similar shape but different chemical composition could be distinguished using molecular ions. This novel matrix holds potentials in such applications as the analysis and imaging of complex biological samples by TOF-SIMS.

MALDI-TOF MS in the Microbiology Laboratory: Current Trends.

PubMed

Schubert, Sören; Kostrzewa, Markus

2017-01-01

Within less than a decade matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has become a gold standard for microbial identification in clinical microbiology laboratories. Besides identification of microorganisms the typing of single strains as well as the antibiotic and antimycotic resistance testing has come into focus in order to speed up the microbiological diagnostic. However, the full potential of MALDI-TOF MS has not been tapped yet and future technological advancements will certainly expedite this method towards novel applications and enhancement of current practice. So, the following chapter shall be rather a brainstorming and forecast of how MALDI-TOF MS will develop to influence clinical diagnostics and microbial research in the future. It shall open up the stage for further discussions and does not claim for overall validity.

Field performance and identification capability of the Innsbruck PTR-TOF

NASA Astrophysics Data System (ADS)

Graus, M.; Müller, M.; Hansel, A.

2009-04-01

Over the last one and a half decades Proton Transfer Reaction Mass Spectrometry (PTR-MS) [1, 2] has gained recognition as fast on-line sensor for monitoring volatile organic compounds (VOC) in the atmosphere. Sample collection is very straight forward and the fact that no pre-concentration is needed is of particular advantage for compounds that are notoriously difficult to pre-concentrate and/or analyze by gas chromatographic (GC) methods. Its ionization method is very versatile, i.e. all compounds that perform exothermic proton transfer with hydronium ions - and most VOCs do so - are readily ionized, producing quasi-molecular ions VOC.H+. In the quasi-molecular ion the elemental composition of the analyte compound is conserved and allows, in combination with some background knowledge of the sample, conclusions about the identity of that compound. De Gouw and Warneke (2007) [3] summarized the applicability of PTR-MS in atmospheric chemistry but they also pointed out shortcomings in the identification capabilities. Goldstein and Galbally (2007) [4] addressed the multitude of VOCs potentially present in the atmosphere and they emphasized the gasphase-to-aerosol partitioning of organic compounds (volatile and semi-volatile) in dependence of carbon-chain length and oxygen containing functional groups. In collaboration with Ionicon and assisted by TOFWERK we developed a PTR time-of-flight (PTR-TOF) instrument that allows for the identification of the atomic composition of oxygenated hydrocarbons by exact-mass determination. A detection limit in the low pptv range was achieved at a time resolution of one minute, one-second detection limit is in the sub-ppbv range. In 2008 the Innsbruck PTR-TOF was field deployed in the icebreaker- and helicopter based Arctic Summer Cloud Ocean Study (ASCOS) to characterize the organic trace gas composition of the High Arctic atmosphere. During the six-week field campaign the PTR-TOF was run without problems even under harsh conditions in

Mini 3D for shallow gas reconnaissance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vallieres, T. des; Enns, D.; Kuehn, H.

1996-12-31

The Mini 3D project was undertaken by TOTAL and ELF with the support of CEPM (Comite d`Etudes Petrolieres et Marines) to define an economical method of obtaining 3D seismic HR data for shallow gas assessment. An experimental 3D survey was carried out with classical site survey techniques in the North Sea. From these data 19 simulations, were produced to compare different acquisition geometries ranging from dual, 600 m long cables to a single receiver. Results show that short offset, low fold and very simple streamer positioning are sufficient to give a reliable 3D image of gas charged bodies. The 3Dmore » data allow a much more accurate risk delineation than 2D HR data. Moreover on financial grounds Mini-3D is comparable in cost to a classical HR 2D survey. In view of these results, such HR 3D should now be the standard for shallow gas surveying.« less

Spontaneous-Desorption Ionizer for a TOF-MS

NASA Technical Reports Server (NTRS)

Schultz, J. Albert

2006-01-01

A time-of-flight mass spectrometer (TOF-MS) like the one mentioned in the immediately preceding article has been retrofitted with an ionizer based on a surface spontaneous-desorption process. This ionizer includes an electron multiplier in the form of a microchannel plate (MCP). Relative to an ionizer based on a hot-filament electron source, this ionizer offers advantages of less power consumption and greater mechanical ruggedness. The current density and stability characteristics of the electron emission of this ionizer are similar to those of a filament-based ionizer. In tests of various versions of this ionizer in the TOF-MS, electron currents up to 100 nA were registered. Currents of microamperes or more - great enough to satisfy requirements in most TOFMS applications - could be obtained by use of MCPs different from those used in the tests, albeit at the cost of greater bulk. One drawback of this ionizer is that the gain of the MCP decreases as a function of the charge extracted thus far; the total charge that can be extracted over the operational lifetime is about 1 coulomb. An MCP in the ion-detector portion of the TOF-MS is subject to the same limitation.

Organic aerosol components derived from 25 AMS datasets across Europe using a newly developed ME-2 based source apportionment strategy

NASA Astrophysics Data System (ADS)

Crippa, M.; Canonaco, F.; Lanz, V. A.; Äijälä, M.; Allan, J. D.; Carbone, S.; Capes, G.; Dall'Osto, M.; Day, D. A.; DeCarlo, P. F.; Di Marco, C. F.; Ehn, M.; Eriksson, A.; Freney, E.; Hildebrandt Ruiz, L.; Hillamo, R.; Jimenez, J.-L.; Junninen, H.; Kiendler-Scharr, A.; Kortelainen, A.-M.; Kulmala, M.; Mensah, A. A.; Mohr, C.; Nemitz, E.; O'Dowd, C.; Ovadnevaite, J.; Pandis, S. N.; Petäjä, T.; Poulain, L.; Saarikoski, S.; Sellegri, K.; Swietlicki, E.; Tiitta, P.; Worsnop, D. R.; Baltensperger, U.; Prévôt, A. S. H.

2013-09-01

Organic aerosols (OA) represent one of the major constituents of submicron particulate matter (PM1) and comprise a huge variety of compounds emitted by different sources. Three intensive measurement field campaigns to investigate the aerosol chemical composition all over Europe were carried out within the framework of EUCAARI and the intensive campaigns of EMEP during 2008 (May-June and September-October) and 2009 (February-March). In this paper we focus on the identification of the main organic aerosol sources and we propose a standardized methodology to perform source apportionment using positive matrix factorization (PMF) with the multilinear engine (ME-2) on Aerodyne aerosol mass spectrometer (AMS) data. Our source apportionment procedure is tested and applied on 25 datasets accounting for urban, rural, remote and high altitude sites and therefore it is likely suitable for the treatment of AMS-related ambient datasets. For most of the sites, four organic components are retrieved, improving significantly previous source apportionment results where only a separation in primary and secondary OA sources was possible. Our solutions include two primary OA sources, i.e. hydrocarbon-like OA (HOA) and biomass burning OA (BBOA) and two secondary OA components, i.e. semi-volatile oxygenated OA (SV-OOA) and low-volatility oxygenated OA (LV-OOA). For specific sites cooking-related (COA) and marine-related sources (MSA) are also separated. Finally, our work provides a large overview of organic aerosol sources in Europe and an interesting set of highly time resolved data for modeling evaluation purposes.

eHR: An Introduction. IES Report.

ERIC Educational Resources Information Center

Kettley, P.; Reilly, P.

This document introduces the concept of electronic human resources (eHR) and its application. Chapter 1 presents a brief overview of the guide's development, purpose, and structure. Chapter 2 defines the concept of eHR as "the application of conventional, Web, and voice technologies to improve HR administration, transactions, and process…

Graphene Oxide as a Novel Evenly Continuous Phase Matrix for TOF-SIMS.

PubMed

Cai, Lesi; Sheng, Linfeng; Xia, Mengchan; Li, Zhanping; Zhang, Sichun; Zhang, Xinrong; Chen, Hongyuan

2017-03-01

Using matrix to enhance the molecular ion signals for biomolecule identification without loss of spatial resolution caused by matrix crystallization is a great challenge for the application of TOF-SIMS in real-world biological research. In this report, graphene oxide (GO) was used as a matrix for TOF-SIMS to improve the secondary ion yields of intact molecular ions ([M + H] + ). Identifying and distinguishing the molecular ions of lipids (m/z >700) therefore became straightforward. The spatial resolution of TOF-SIMS imaging could also be improved as GO can form a homogeneous layer of matrix instead of crystalline domain, which prevents high spatial resolution in TOF-SIMS imaging. Lipid mapping in presence of GO revealed the delicate morphology and distribution of single vesicles with a diameter of 800 nm. On GO matrix, the vesicles with similar shape but different chemical composition could be distinguished using molecular ions. This novel matrix holds potentials in such applications as the analysis and imaging of complex biological samples by TOF-SIMS. Graphical Abstract ᅟ.

[Utility of MALDI-TOF MS for the identification of anaerobic bacteria].

PubMed

Zárate, Mariela S; Romano, Vanesa; Nievas, Jimena; Smayevsky, Jorgelina

2014-01-01

The analysis by MALDI-TOF MS (Matrix-assited laser desorption/ionization time-of-flight mass spectrometry) has become a reference method for the identification of microorganisms in Clinical Microbiology. However, data on some groups of microorganisms are still controversial. The aim of this study is to determine the utility of MALDI-TOF MS for the identification of clinical isolates of anaerobic bacteria. One-hundred and six anaerobic bacteria isolates were analyzed by MALDI-TOF MS and by conventional biochemical tests. In those cases where identification by conventional methodology was not applicable or in the face of discordance between sequencing methodologies, 16 S rRNA gene sequence analysis was performed. The conventional method and MALDI-TOF MS agreed at genus and species level by 95.3 %. Concordance in gram-negative bacilli was 91.4% and 100% among gram-positive bacilli; there was also concordance both in the 8 isolates studied in gram-positive cocci and in the single gram-negative cocci included. The data obtained in this study demonstrate that MALDI-TOF MS offers the possibility of adequate identification of anaerobic bacteria. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

FR/HR Sewing Thread

DTIC Science & Technology

2015-09-01

position unless so designated by other authorized documents. Citation of trade names in this report does not constitute an official endorsement or...project to design and develop a Fire Resistant (FR) and Heat Resistant (HR) sewing thread. The main goal of the project is to produce sewing threads made...addresses the design , development and testing of various Fire Resistant (FR)/Heat Resistant (HR) sewing threads for US Army applications. Such a sewing

Elemental abundances of the B and A stars Gamma Geminorum, 7 Sextantis, HR 4817, and HR 5780

NASA Technical Reports Server (NTRS)

Adelman, Saul J.; Philip, A. G. D.

1992-01-01

Fine analyses of the B and A stars, Gamma Geminorum, 7 Sextantis, HR 4817, and HR 5780 are performed. Although the data cover rather limited spectral regions, still useful results were obtained. The data were mostly obtained at the KPNO coude feed telescope with CCD TI No. 3, camera 5, and grating A. The He/H ratio of HR 4817 confirms the similarity of many abundance values with those of the peculiar Mn star 53 Tauri. For the most part Gamma Gem, 7 Sex, and HR 5780 have derived abundances similar to those of other normal sharp-lined stars of similar effective temperature.

Flavonoids as matrices for MALDI-TOF mass spectrometric analysis of transition metal complexes

NASA Astrophysics Data System (ADS)

Petkovic, Marijana; Petrovic, Biljana; Savic, Jasmina; Bugarcic, Zivadin D.; Dimitric-Markovic, Jasmina; Momic, Tatjana; Vasic, Vesna

2010-02-01

Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a suitable method for the analysis of inorganic and organic compounds and biomolecules. This makes MALDI-TOF MS convenient for monitoring the interaction of metallo-drugs with biomolecules. Results presented in this manuscript demonstrate that flavonoids such as apigenin, kaempferol and luteolin are suitable for MALDI-TOF MS analysis of Pt(II), Pd(II), Pt(IV) and Ru(III) complexes, giving different signal-to-noise ratios of the analyte peak. The MALDI-TOF mass spectra of inorganic complexes acquired with these flavonoid matrices are easy to interpret and have some advantages over the application of other commonly used matrices: a low number of matrix peaks are detectable and the coordinative metal-ligand bond is, in most cases, preserved. On the other hand, flavonoids do not act as typical matrices, as their excess is not required for the acquisition of MALDI-TOF mass spectra of inorganic complexes.

Effect of Local TOF Kernel Miscalibrations on Contrast-Noise in TOF PET

NASA Astrophysics Data System (ADS)

Clementel, Enrico; Mollet, Pieter; Vandenberghe, Stefaan

2013-06-01

TOF PET imaging requires specific calibrations: accurate characterization of the system timing resolution and timing offset is required to achieve the full potential image quality. Current system models used in image reconstruction assume a spatially uniform timing resolution kernel. Furthermore, although the timing offset errors are often pre-corrected, this correction becomes less accurate with the time since, especially in older scanners, the timing offsets are often calibrated only during the installation, as the procedure is time-consuming. In this study, we investigate and compare the effects of local mismatch of timing resolution when a uniform kernel is applied to systems with local variations in timing resolution and the effects of uncorrected time offset errors on image quality. A ring-like phantom was acquired on a Philips Gemini TF scanner and timing histograms were obtained from coincidence events to measure timing resolution along all sets of LORs crossing the scanner center. In addition, multiple acquisitions of a cylindrical phantom, 20 cm in diameter with spherical inserts, and a point source were simulated. A location-dependent timing resolution was simulated, with a median value of 500 ps and increasingly large local variations, and timing offset errors ranging from 0 to 350 ps were also simulated. Images were reconstructed with TOF MLEM with a uniform kernel corresponding to the effective timing resolution of the data, as well as with purposefully mismatched kernels. To CRC vs noise curves were measured over the simulated cylinder realizations, while the simulated point source was processed to generate timing histograms of the data. Results show that timing resolution is not uniform over the FOV of the considered scanner. The simulated phantom data indicate that CRC is moderately reduced in data sets with locally varying timing resolution reconstructed with a uniform kernel, while still performing better than non-TOF reconstruction. On the other

Putting HR outsourcing into practice.

PubMed

Berger, Michael

2007-01-01

Faced with the time-consuming responsibility of human resources (HR) management, a growing number of medical practices are outsourcing their HR to professional employer organizations (PEOs) so they can concentrate on their core business. A PEO functions as an HR department-minus the high overhead-managing daily administrative tasks such as payroll processing and related tax filings, employee benefits, and workers' compensation coverage and claims resolution. PEOs help physicians' offices keep up with the piles of paperwork that never seem to shrink, freeing doctors to focus on patient care and building their practice. Because of their volume buying power, PEOs are able to offer employees of small medical practices big-company benefits-everything from health, dental, and vision coverage to long-term disability insurance and tuition assistance. A fledgling industry only a decade ago, HR outsourcing has morphed into a blossoming industry. Enlisting the services of a PEO is now considered de rigueur in many small business circles.

On-line I-/Te- separation for the AMS analysis of 125I

NASA Astrophysics Data System (ADS)

Charles, C. R. J.; Cornett, R. J.; Zhao, X.-L.; Litherland, A. E.; Kieser, W. E.

2015-10-01

The isobar separator for anions (ISA) was used together with a 3 MV tandem accelerator mass spectrometer (AMS) to demonstrate the real time (on-line) separation of Te- from I-. Following the ion source mass spectrometry and major retardation to tens of eV, the ISA uses a radiofrequency quadrupole (RFQ) ion guide to confine and direct I- and associated Te- isobar anions through a gas-reaction cell, where chemical reactions occur at eV energies with the electronegative gas NO2. Anions are subsequently reaccelerated out of the ISA to near original ion source extraction energies for AMS analysis. At 5 mTorr NO2 in the ISA gas-reaction cell, 125Te- was observed to be attenuated by a factor of ∼107 as compared to 127I- that did not experience significant (<50%) losses. A comparative test using 37Cl- and 32S- (having similar chemical properties to iodine and tellurium) showed a 32S- attenuation of >107 relative to 37Cl- under the same ISA-AMS conditions. The preferential destruction of Te- (and S-) at eV energies in the ISA is likely due to a larger favorable destruction cross-section with NO2. This study is the first demonstration of I-Te anion separation for AMS, and makes possible the use of 125I, free of the contaminant 125Te isobar after suitable sample purification, for future 129I/125I carrier-free analyses of natural samples at ultra-low trace levels.

Identification of Eight Synthetic Cannabinoids, Including 5F-AKB48 in Seized Herbal Products Using DART-TOF-MS and LC-QTOF-MS as Nontargeted Screening Methods.

PubMed

Moore, Katherine N; Garvin, Demetra; Thomas, Brian F; Grabenauer, Megan

2017-09-01

Synthetic cannabinoids are sprayed onto plant material and smoked for their marijuana-like effects. Clandestine manufacturers modify synthetic cannabinoid structures by creating closely related analogs. Forensic laboratories are tasked with detection of these analog compounds, but targeted analytical methods are often thwarted by the structural modifications. Here, direct analysis in real time coupled to accurate mass time-of-flight mass spectrometry (DART-TOF-MS) in combination with liquid chromatography quadruple time-of-flight mass spectrometry (LC-QTOF-MS) are presented as a screening and nontargeted confirmation method, respectively. Methanol extracts of herbal material were run using both methods. Spectral data from four different herbal products were evaluated by comparing fragmentation pattern, accurate mass and retention time to available reference standards. JWH-018, JWH-019, AM2201, JWH-122, 5F-AKB48, AKB48-N-(4-pentenyl) analog, UR144, and XLR11 were identified in the products. Results demonstrate that DART-TOF-MS affords a useful approach for rapid screening of herbal products for the presence and identification of synthetic cannabinoids. © 2017 American Academy of Forensic Sciences.

Shiga toxin 2 subtypes of enterohemorrhagic E. coli O157:H- E32511 analyzed by RT-qPCR and top-down proteomics using MALDI-TOF-TOF-MS

USDA-ARS?s Scientific Manuscript database

We have measured the relative abundance of the B-subunits and mRNA transcripts of two Stx2 subtypes present in Shiga toxin-producing Escherichia coli (STEC) O157:H- strain E32511 using matrix-assisted laser desorption/ionization time-of-flight-time-of-flight tandem mass spectrometry (MALDI-TOF-TOF-M...

Compton scatter tomography in TOF-PET

NASA Astrophysics Data System (ADS)

Hemmati, Hamidreza; Kamali-Asl, Alireza; Ay, Mohammadreza; Ghafarian, Pardis

2017-10-01

Scatter coincidences contain hidden information about the activity distribution on the positron emission tomography (PET) imaging system. However, in conventional reconstruction, the scattered data cause the blurring of images and thus are estimated and subtracted from detected coincidences. List mode format provides a new aspect to use time of flight (TOF) and energy information of each coincidence in the reconstruction process. In this study, a novel approach is proposed to reconstruct activity distribution using the scattered data in the PET system. For each single scattering coincidence, a scattering angle can be determined by the recorded energy of the detected photons, and then possible locations of scattering can be calculated based on the scattering angle. Geometry equations show that these sites lie on two arcs in 2D mode or the surface of a prolate spheroid in 3D mode, passing through the pair of detector elements. The proposed method uses a novel and flexible technique to estimate source origin locations from the possible scattering locations, using the TOF information. Evaluations were based on a Monte-Carlo simulation of uniform and non-uniform phantoms at different resolutions of time and detector energy. The results show that although the energy uncertainties deteriorate the image spatial resolution in the proposed method, the time resolution has more impact on image quality than the energy resolution. With progress of the TOF system, the reconstruction using the scattered data can be used in a complementary manner, or to improve image quality in the next generation of PET systems.

TOF-SIMS Analysis of Red Color Inks of Writing and Printing Tools on Questioned Documents.

PubMed

Lee, Jihye; Nam, Yun Sik; Min, Jisook; Lee, Kang-Bong; Lee, Yeonhee

2016-05-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a well-established surface technique that provides both elemental and molecular information from several monolayers of a sample surface while also allowing depth profiling or image mapping to be performed. Static TOF-SIMS with improved performances has expanded the application of TOF-SIMS to the study of a variety of organic, polymeric, biological, archaeological, and forensic materials. In forensic investigation, the use of a minimal sample for the analysis is preferable. Although the TOF-SIMS technique is destructive, the probing beams have microsized diameters so that only small portion of the questioned sample is necessary for the analysis, leaving the rest available for other analyses. In this study, TOF-SIMS and attenuated total reflectance Fourier transform infrared (ATR-FTIR) were applied to the analysis of several different pen inks, red sealing inks, and printed patterns on paper. The overlapping areas of ballpoint pen writing, red seal stamping, and laser printing in a document were investigated to identify the sequence of recording. The sequence relations for various cases were determined from the TOF-SIMS mapping image and the depth profile. TOF-SIMS images were also used to investigate numbers or characters altered with two different red pens. TOF-SIMS was successfully used to determine the sequence of intersecting lines and the forged numbers on the paper. © 2016 American Academy of Forensic Sciences.

Analysis of human serum lipoprotein lipid composition using MALDI-TOF mass spectrometry.

PubMed

Hidaka, Hiroya; Hanyu, Noboru; Sugano, Mitsutoshi; Kawasaki, Kenji; Yamauchi, Kazuyoshi; Katsuyama, Tsutomu

2007-01-01

This study used matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify all lipid classes in human serum lipoproteins. After the major lipoproteins classes were isolated from serum by ultracentrifugation, the lipids were extracted and mixed with 2,5-dihydroxybenzoic acid (2,5-DHB) dissolved in Folch's solution (chloroform/methanol 2:1, v/v). MALDI-TOF MS analysis of the samples identified phospholipids (PLs), lysophospholipids (lysoPLs), sphingolipids (SLs), triglycerides (TGs), cholesteryl esters (CEs), and free cholesterol; it also showed the characteristics of individual fatty acid chains in serum lipids. MALDI-TOF MS allowed analysis of strongly hydrophobic and non-polar molecules such as CEs and TGs as well as hydrophilic molecules such as phospholipids. Direct analysis of fatty acids was not possible. The concentrations of lipids were not consistent with the ion peak intensities, since the extent of polarity affected the ionization characteristics of the molecules. However, lipid molecules with similar molecular structures but various fatty acid chains, such as phosphatidylcholine (PCs), were analyzed quantitatively by MALDI-TOF MS. Quantitative measurement of cholesterol was possible with the use of an internal standard. This study shows that MALDI-TOF MS can be used for direct investigation and quantitative analysis of the phospholipid composition of serum lipoproteins.

Identification of bacteria isolated from veterinary clinical specimens using MALDI-TOF MS.

PubMed

Pavlovic, Melanie; Wudy, Corinna; Zeller-Peronnet, Veronique; Maggipinto, Marzena; Zimmermann, Pia; Straubinger, Alix; Iwobi, Azuka; Märtlbauer, Erwin; Busch, Ulrich; Huber, Ingrid

2015-01-01

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has recently emerged as a rapid and accurate identification method for bacterial species. Although it has been successfully applied for the identification of human pathogens, it has so far not been well evaluated for routine identification of veterinary bacterial isolates. This study was performed to compare and evaluate the performance of MALDI-TOF MS based identification of veterinary bacterial isolates with commercially available conventional test systems. Discrepancies of both methods were resolved by sequencing 16S rDNA and, if necessary, the infB gene for Actinobacillus isolates. A total of 375 consecutively isolated veterinary samples were collected. Among the 357 isolates (95.2%) correctly identified at the genus level by MALDI-TOF MS, 338 of them (90.1% of the total isolates) were also correctly identified at the species level. Conventional methods offered correct species identification for 319 isolates (85.1%). MALDI-TOF identification therefore offered more accurate identification of veterinary bacterial isolates. An update of the in-house mass spectra database with additional reference spectra clearly improved the identification results. In conclusion, the presented data suggest that MALDI-TOF MS is an appropriate platform for classification and identification of veterinary bacterial isolates.

Gas-phase conformation-specific photofragmentation of proline-containing peptide ions.

PubMed

Kim, Tae-Young; Valentine, Stephen J; Clemmer, David E; Reilly, James P

2010-08-01

Singly-protonated proline-containing peptides with N-terminal arginine are photodissociated with vacuum ultraviolet (VUV) light in an ESI linear ion trap/orthogonal-TOF (LIT/o-TOF). When proline is the nth residue from the N-terminus, unusual b(n) + 2 and a(n) + 2 ions are observed. Their formation is explained by homolytic cleavage of the C(alpha)-C bond in conjunction with a rearrangement of electrons and an amide hydrogen. The latter is facilitated by a proline-stabilized gas-phase peptide conformation. Copyright 2010 American Society for Mass Spectrometry. Published by Elsevier Inc. All rights reserved.

30 CFR 250.468 - What well records am I required to submit?

Code of Federal Regulations, 2013 CFR

2013-07-01

... THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Applying for A Permit to Modify and Well Records § 250.468 What well records am I... surveys. (b) For drilling operations in the GOM OCS Region, you must submit form BSEE-0133, Well Activity...

30 CFR 250.468 - What well records am I required to submit?

Code of Federal Regulations, 2014 CFR

2014-07-01

... THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Applying for A Permit to Modify and Well Records § 250.468 What well records am I... surveys. (b) For drilling operations in the GOM OCS Region, you must submit form BSEE-0133, Well Activity...

30 CFR 250.468 - What well records am I required to submit?

Code of Federal Regulations, 2012 CFR

2012-07-01

... THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Applying for A Permit to Modify and Well Records § 250.468 What well records am I... surveys. (b) For drilling operations in the GOM OCS Region, you must submit form BSEE-0133, Well Activity...

Rapid detection of AAC(6')-Ib-cr production using a MALDI-TOF MS strategy.

PubMed

Pardo, C-A; Tan, R N; Hennequin, C; Beyrouthy, R; Bonnet, R; Robin, F

2016-12-01

Plasmid-mediated quinolone resistance mechanisms have become increasingly prevalent among Enterobacteriaceae strains since the 1990s. Among these mechanisms, AAC(6')-Ib-cr is the most difficult to detect. Different detection methods have been developed, but they require expensive procedures such as Sanger sequencing, pyrosequencing, polymerase chain reaction (PCR) restriction, or the time-consuming phenotypic method of Wachino. In this study, we describe a simple matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) method which can be easily implemented in clinical laboratories that use the MALDI-TOF technique for bacterial identification. We tested 113 strains of Enterobacteriaceae, of which 64 harbored the aac(6')-Ib-cr gene. We compared two MALDI-TOF strategies, which differed by their norfloxacin concentration (0.03 vs. 0.5 g/L), and the method of Wachino with the PCR and sequencing strategy used as the reference. The MALDI-TOF strategy, performed with 0.03 g/L norfloxacin, and the method of Wachino yielded the same high performances (Se = 98 %, Sp = 100 %), but the turnaround time of the MALDI-TOF strategy was faster (<5 h), simpler, and inexpensive (<1 Euro). Our study shows that the MALDI-TOF strategy has the potential to become a major method for the detection of many different enzymatic resistance mechanisms.

Dissymmetry effects on the laser spectroscopy of supersonically expanded rare gas/chiral arene heteroclusters.

PubMed

Filippi, Antonello; Giardini, Anna; Marcantoni, Enrico; Paladini, Alessandra; Piccirillo, Susanna; Renzi, Gabriele; Rondino, Flaminia; Roselli, Graziella; Satta, Mauro; Speranza, Maurizio

2007-04-14

The R2PI-TOF spectra of supersonically expanded rare gas/chiral arene heteroclusters have been rationalized in terms of the distortion of the pi-electron density reflecting the different dipole and quadrupole momenta induced in the rare gas atoms by interaction with the opposite pi-faces of the chiral arene itself.

Measurements of Short Lived Gas Phase Pollutants during AN Anthropogenic Biomass Burning Event during Winter in Manchester, UK Using a Tof-Cims

NASA Astrophysics Data System (ADS)

Priestley, M.; Bannan, T.; le Breton, M.; Leather, K.; Bacak, A.; Villegas, E.; Khan, A.; Allan, J. D.; Shallcross, D. E.; Coe, H.; Percival, C.

2017-12-01

Anthropogenic biomass burning represents a significant source of short lived harmful gases that reduces air quality and is one of the least well constrained processes in air quality and climate modelling (Andreae & Merlet 2001). Guy Fawkes Night (bonfire night) is a regular event in the UK where open fires are lit. Previous gas phase studies of bonfire night have typically used offline techniques focusing on persistent organic pollutants. Here, the first simultaneous online gas phase measurements of short lived pollutants from mixed biomass and anthropogenic fuel types were made using a chemical ionisation mass spectrometer (TOF-CIMS) with the iodide reagent ion in November 2014 in Manchester, UK. We detected a suite of compounds including isocyanates, nitrates and amides. Ambient concentrations of hydrogen cyanide (HCN), isocyanic acid and methyl isocyanate increased from maximums of 132 ppt, 144 ppt and 327 ppt to peak plume concentrations of 1.2 ppb, 1.6 ppb and 4.3 ppb respectively. We used the 6 sigma approach to define the biomass plume using HCN as a tracer and find the [HNCO]/[CO] ratio definition of burning phase is applicable (Roberts et al. 2010). Flaming emission increased the normalised excess mixing ratio (NEMR) by a factor of 2-4 relative to smouldering emission and treating burning phases separately improved the average accuracy of the NEMR by 29%. References Andreae, M.O. & Merlet, P., 2001. Emission of trace gases and aerosols from biomass burning. Global Biogeochemical Cycles, 15(4), pp.955-966. Available at: http://dx.doi.org/10.1029/2000GB001382. Roberts, J.M. et al., 2010. Measurement of HONO, HNCO, and other inorganic acids by negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS): Application to biomass burning emissions. Atmospheric Measurement Techniques, 3, pp.981-990.

TOF-SIMS investigation of metallic material surface after culturing cells

NASA Astrophysics Data System (ADS)

Aoyagi, Satoka; Hiromoto, Sachiko; Hanawa, Takao; Kudo, Masahiro

2004-06-01

Biomolecules such as extracellular matrix and adhesive proteins generated by adhered cells on metallic specimens were characterized by means of time-of-flight secondary ion mass spectrometry (TOF-SIMS) in order to clarify the interaction between cells and metal surfaces. Since composition and structure of the extracellular matrix depends on conditions of cells, characterization of the interaction between cells and metallic specimens is important in order to evaluate the biocompatibility and the degradation behavior of metallic biomaterials and artificial organs. Moreover, the obtained data can contribute to the development of new metallic biomaterials. TOF-SIMS spectra were analyzed by means of mutual information described by information theory and principal components analysis (PCA). The results show that cells have great influence on adsorption of biomolecules on metallic materials because they change surface conditions of the materials. Thus TOF-SIMS is a useful technique to investigate the interaction between metallic biomaterials and cells.

TOF-SIMS imaging of protein adsorption on dialysis membrane

NASA Astrophysics Data System (ADS)

Aoyagi, Satoka; Hayama, Msayo; Hasegawa, Urara; Sakai, Kiyotaka; Hoshi, Takahiro; Kudo, Masahiro

2004-06-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is capable of chemical imaging of proteins on insulated samples such as hollow-fiber dialysis membranes. Albumin loss and a lowering of diffusive permeability caused by protein adsorption on dialysis membranes should be reduced in order to enhance dialysis adequacy of the patients. Bovine serum albumin (BSA)-adsorbed hollow-fiber dialysis membranes were tested in the present study. TOF-SIMS images and spectra of both native membranes and BSA-adsorbed membranes were compared in order to identify secondary ions related to BSA and membranes. Peaks of secondary ions related to BSA and each membrane were selected by means of information theory, and they are characterized by principal component analysis (PCA). Chemical images of BSA adsorption on both native and treated membranes were obtained to find that BSA permeability and interaction between the membranes and BSA definitely depend on the properties of a membrane. TOF-SIMS imaging obtained with information theory is a powerful tool to estimate protein adsorption on the dialysis membranes.

Exploratory analysis of TOF-SIMS data from biological surfaces

NASA Astrophysics Data System (ADS)

Vaidyanathan, Seetharaman; Fletcher, John S.; Henderson, Alex; Lockyer, Nicholas P.; Vickerman, John C.

2008-12-01

The application of multivariate analytical tools enables simplification of TOF-SIMS datasets so that useful information can be extracted from complex spectra and images, especially those that do not give readily interpretable results. There is however a challenge in understanding the outputs from such analyses. The problem is complicated when analysing images, given the additional dimensions in the dataset. Here we demonstrate how the application of simple pre-processing routines can enable the interpretation of TOF-SIMS spectra and images. For the spectral data, TOF-SIMS spectra used to discriminate bacterial isolates associated with urinary tract infection were studied. Using different criteria for picking peaks before carrying out PC-DFA enabled identification of the discriminatory information with greater certainty. For the image data, an air-dried salt stressed bacterial sample, discussed in another paper by us in this issue, was studied. Exploration of the image datasets with and without normalisation prior to multivariate analysis by PCA or MAF resulted in different regions of the image being highlighted by the techniques.

Towards Discovery and Targeted Peptide Biomarker Detection Using nanoESI-TIMS-TOF MS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garabedian, Alyssa; Benigni, Paolo; Ramirez, Cesar E.

Abstract. In the present work, the potential of trapped ion mobility spectrometry coupled to TOF mass spectrometry (TIMS-TOF MS) for discovery and targeted monitoring of peptide biomarkers from human-in-mouse xenograft tumor tissue was evaluated. In particular, a TIMS-MS workflow was developed for the detection and quantification of peptide biomarkers using internal heavy analogs, taking advantage of the high mobility resolution (R = 150–250) prior to mass analysis. Five peptide biomarkers were separated, identified, and quantified using offline nanoESI-TIMSCID- TOF MS; the results were in good agreement with measurements using a traditional LC-ESI-MS/MS proteomics workflow. The TIMS-TOF MS analysis permitted peptidemore » biomarker detection based on accurate mobility, mass measurements, and high sequence coverage for concentrations in the 10–200 nM range, while simultaneously achieving discovery measurements« less

How to: identify non-tuberculous Mycobacterium species using MALDI-TOF mass spectrometry.

PubMed

Alcaide, F; Amlerová, J; Bou, G; Ceyssens, P J; Coll, P; Corcoran, D; Fangous, M-S; González-Álvarez, I; Gorton, R; Greub, G; Hery-Arnaud, G; Hrábak, J; Ingebretsen, A; Lucey, B; Marekoviċ, I; Mediavilla-Gradolph, C; Monté, M R; O'Connor, J; O'Mahony, J; Opota, O; O'Reilly, B; Orth-Höller, D; Oviaño, M; Palacios, J J; Palop, B; Pranada, A B; Quiroga, L; Rodríguez-Temporal, D; Ruiz-Serrano, M J; Tudó, G; Van den Bossche, A; van Ingen, J; Rodriguez-Sanchez, B

2018-06-01

The implementation of MALDI-TOF MS for microorganism identification has changed the routine of the microbiology laboratories as we knew it. Most microorganisms can now be reliably identified within minutes using this inexpensive, user-friendly methodology. However, its application in the identification of mycobacteria isolates has been hampered by the structure of their cell wall. Improvements in the sample processing method and in the available database have proved key factors for the rapid and reliable identification of non-tuberculous mycobacteria isolates using MALDI-TOF MS. The main objective is to provide information about the proceedings for the identification of non-tuberculous isolates using MALDI-TOF MS and to review different sample processing methods, available databases, and the interpretation of the results. Results from relevant studies on the use of the available MALDI-TOF MS instruments, the implementation of innovative sample processing methods, or the implementation of improved databases are discussed. Insight about the methodology required for reliable identification of non-tuberculous mycobacteria and its implementation in the microbiology laboratory routine is provided. Microbiology laboratories where MALDI-TOF MS is available can benefit from its capacity to identify most clinically interesting non-tuberculous mycobacteria in a rapid, reliable, and inexpensive manner. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Rocuronium: automatic infusion versus manual administration with TOF monitorisation.

PubMed

Ozturk Arikan, Fatma Gulcin; Turan, Guldem; Ozgultekin, Asu; Sivrikaya, Zubeyir; Cosar, Bekir Cem; Onder, Dondu Nisa

2016-10-01

TOF (train-of-four) monitoring provides objective data in application of neuromuscular blocking agent. Thus, applicator-based differences are eliminated and optimum muscle relaxation is maintained during operation. In the present study, we aimed to compare the effects of target-controlled infusion system and standard TOF monitoring, on use of rocuronium. ASA I-II patients, who were aged between 18 and 75 years and scheduled for elective abdominal surgery at Haydarpaşa Numune Training and Research Hospital, were enrolled in the study. In order to evaluate neuromuscular blockade, the patients in Group 1 were connected to the acceleromyography device of the target-controlled infusion pump (Veryark-CLMRIS-I-China) while the ones in Group 2 were connected to the routinely used acceleromyography device (TOF Watch SX). There was no significant difference between groups regarding patient characteristics, the durations of anaesthesia and surgery, quality of intubation, time to extubation and time to recovery (TOF ratio of 0.9). Intubation time was significantly longer in Group 1 (Automated group) as compared to Group 2 (Control group) (p < 0.05). The total rocuronium amount used in Group 1 was found to be significantly higher than the amount used in Group 2 (p < 0.05). There was no clinical evidence of residual neuromuscular blockage or reoccurrence of neuromuscular blockage in any patient in either group. Both methods can be used for administration of neuromuscular blocker agent during moderate time anesthesia. No advantage was noted when rocuronium was administered via automatical infusion pump during anaesthesia.

Characterization of urban aerosol in Cork City (Ireland) using aerosol mass spectrometry

NASA Astrophysics Data System (ADS)

Dall'Osto, M.; Ovadnevaite, J.; Ceburnis, D.; Martin, D.; Healy, R. M.; O'Connor, I. P.; Sodeau, J. R.; Wenger, J. C.; O'Dowd, C.

2012-11-01

Ambient wintertime background urban aerosol in Cork City, Ireland, was characterized using aerosol mass spectrometry. During the three-week measurement study in 2009, 93% of the 1 200 000 single particles characterized by an Aerosol Time-Of-Flight Mass Spectrometer (TSI ATOFMS) were classified into five organic-rich particle types, internally-mixed to different proportions with Elemental Carbon (EC), sulphate and nitrate while the remaining 7% was predominantly inorganic in nature. Non-refractory PM1 aerosol was also characterized using a High Resolution Time-Of-Flight Aerodyne Aerosol Mass Spectrometer (HR-ToF-AMS) and was also found to comprise organic matter as the most abundant species (62%), followed by nitrate (15%), sulphate (9%) and ammonium (9%), and then chloride (5%). Positive matrix factorization (PMF) was applied to the HR-ToF-AMS organic matrix and a five-factor solution was found to describe the variance in the data well. Specifically, "Hydrocarbon-like" Organic Aerosol (HOA) comprised 19% of the mass, "Oxygenated low volatility" Organic Aerosols (LV-OOA) comprised 19%, "Biomass wood Burning" Organic Aerosol (BBOA) comprised 23%, non-wood solid-fuel combustion "Peat and Coal" Organic Aerosol (PCOA) comprised 21%, and finally, a species type characterized by primary m/z peaks at 41 and 55, similar to previously-reported "Cooking" Organic Aerosol (COA) but possessing different diurnal variations to what would be expected for cooking activities, contributed 18%. Despite wood, cool and peat being minor fuel types used for domestic space heating in urban areas, their relatively low combustion efficiencies result in a significant contribution to PM1 aerosol mass (44% and 28% of the total organic aerosols mass and non refractory PM1, respectively).

Aircraft-Based measurement of the physico-chemical evolution of atmospheric aerosols in the air pollution plume over a megacity and a remote area

NASA Astrophysics Data System (ADS)

Park, J. S.; Lee, T.; Park, T.; Lee, J. B.; Lim, Y. J.; Ahn, J.; Kim, J.; Park, S.; Collett, J. L., Jr.

2017-12-01

Aerosols influence climate change directly (scattering and absorption) and indirectly (cloud condensation nuclei), also adverse health effects. The Korean peninsula is a great place to study different sources of the aerosols: urban, rural and marine. In addition, Seoul is one of the large metropolitan areas in the world and has a variety of sources because half of the Korean population lives in Seoul, which comprises only 12% of the country's area. To understand the physico-chemical evolution of atmospheric aerosols in the air pollution plume over a megacity and a remote area, an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed on an airborne platform (NASA DC-8 and Beechcraft King Air) in June, 2015 and May-June, 2016 during MAPS-Seoul and KORUS-AQ campaigns, respectively, in Korea. The HR-ToF-AMS is capable of measuring non-refractory size resolved chemical composition of submicron particle (NR-PM1). NR-PM1 includes mass concentration of organics, nitrate, sulfate, and ammonium with 10 seconds time resolution. Organics was dominated species in aerosol during all of flights. Organics and nitrate were dominant around energy industrial complex near by Taean, South Korea. The presentation will provide an overview of the composition of NR-PM1 measured in air pollution plumes, and deliver detail information about width, depth and spatial distribution of the pollutant in the air pollution plumes. The results of this study will provide high temporal and spatial resolved details on the air pollution plumes, which are valuable input parameters of aerosol properties for the current air quality models.

Texas A&M vortex type phase separator

NASA Astrophysics Data System (ADS)

Best, Frederick

2000-01-01

Phase separation is required for regenerative biological and chemical process systems as well as thermal transport and rejection systems. Liquid and gas management requirements for future spacecraft will demand small, passive systems able to operate over wide ranges of inlet qualities. Conservation and recycling of air and water is a necessary part of the construction and operation of the International Space Station as well as future long duration space missions. Space systems are sensitive to volume, mass, and power. Therefore, it is necessary to develop a method to recycle wastewater with minimal power consumption. Regenerative life support systems currently being investigated require phase separation to separate the liquid from the gas produced. The microgravity phase separator designed and fabricated at Texas A&M University relies on centripetal driven buoyancy forces to form a gas-liquid vortex within a fixed, right-circular cylinder. Two-phase flow is injected tangentially along the inner wall of this cylinder producing a radial acceleration gradient. The gradient produced from the intrinsic momentum of the injected mixture results in a rotating flow that drives the buoyancy process by the production of a hydrostatic pressure gradient. Texas A&M has flown several KC-135 flights with separator. These flights have included scaling studies, stability and transient investigations, and tests for inventory instrumentation. Among the hardware tested have been passive devices for separating mixed vapor/liquid streams into single-phase streams of vapor only and liquid only. .

Partially oxidised organic components in urban aerosol using GCXGC-TOF/MS

NASA Astrophysics Data System (ADS)

Hamilton, J. F.; Webb, P. J.; Lewis, A. C.; Hopkins, J. R.; Smith, S.; Davy, P.

2004-08-01

Partially oxidised organic compounds associated with PM2.5 aerosol collected in London, England, have been analysed using direct thermal desorption coupled to comprehensive gas chromatography-time of flight mass spectrometry (GCXGC-TOF/MS). Over 10000 individual organic components were isolated from around 10µg of aerosol material in a single procedure and with no sample pre-treatment. Chemical functionalities observed using this analytical technique ranged from alkanes to poly-oxygenated species. The chemical band structures commonly used in GCXGC for group type identifications overlap for this sample type, and have required mass spectrometry as an additional level of instrument dimensionality. An investigation of oxygenated volatile organic compounds (o-VOC) contained within urban aerosol has been performed and in a typical sample around 130 o-VOCs were identified based on retention behaviour and spectral match. In excess of 100 other oxygenated species were also observed but lack of mass spectral library or pure components prevents positive identification. Many of the carbonyl species observed could be mechanistically linked to gas phase aromatic hydrocarbon oxidation and there is good agreement in terms of speciation between the urban samples analysed here and those degradation products observed in smog chamber experiments of aromatic oxidation. The presence of partially oxidised species such as linear chain aldehydes and ketones and cyclic products such as furanones suggests that species generated early in the oxidative process may undergo gas to particle partitioning despite their relatively high volatility.

Unlocking the proteomic information encoded in MALDI-TOF-MS data used for microbial identification and characterization.

PubMed

Fagerquist, Clifton K

2017-01-01

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is increasingly utilized as a rapid technique to identify microorganisms including pathogenic bacteria. However, little attention has been paid to the significant proteomic information encoded in the MS peaks that collectively constitute the MS 'fingerprint'. This review/perspective is intended to explore this topic in greater detail in the hopes that it may spur interest and further research in this area. Areas covered: This paper examines the recent literature on utilizing MALDI-TOF for bacterial identification. Critical works highlighting protein biomarker identification of bacteria, arguments for and against protein biomarker identification, proteomic approaches to biomarker identification, emergence of MALDI-TOF-TOF platforms and their use for top-down proteomic identification of bacterial proteins, protein denaturation and its effect on protein ion fragmentation, collision cross-sections and energy deposition during desorption/ionization are also explored. Expert commentary: MALDI-TOF and TOF-TOF mass spectrometry platforms will continue to provide chemical analyses that are rapid, cost-effective and high throughput. These instruments have proven their utility in the taxonomic identification of pathogenic bacteria at the genus and species level and are poised to more fully characterize these microorganisms to the benefit of clinical microbiology, food safety and other fields.

Application of MALDI-TOF MS for the Identification of Food Borne Bacteria

PubMed Central

Pavlovic, Melanie; Huber, Ingrid; Konrad, Regina; Busch, Ulrich

2013-01-01

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently emerged as a powerful tool for the routine identification of clinical isolates. MALDI-TOF MS based identification of bacteria has been shown to be more rapid, accurate and cost-efficient than conventional phenotypic techniques or molecular methods. Rapid and reliable identification of food-associated bacteria is also of crucial importance for food processing and product quality. This review is concerned with the applicability of MALDI-TOF MS for routine identification of foodborne bacteria taking the specific requirements of food microbiological laboratories and the food industry into account. The current state of knowledge including recent findings and new approaches are discussed. PMID:24358065

Comparison between Slow Components of HR and V[Combining Dot Above]O2 Kinetics: Functional Significance.

PubMed

Zuccarelli, Lucrezia; Porcelli, Simone; Rasica, Letizia; Marzorati, Mauro; Grassi, Bruno

2018-03-22

Aerobic exercise prescription is often based on a linear relationship between pulmonary oxygen consumption (V[Combining Dot Above]O2) and heart rate (HR). The aim of the present study was to test the hypothesis that during constant work rate (CWR) exercises at different intensities the slow component of HR kinetics occurs at lower work rate and is more pronounced that the slow component of V[Combining Dot Above]O2 kinetics. Seventeen male (age, 27±4yr) subjects performed on a cycle ergometer an incremental exercise to voluntary exhaustion and several CWR exercises: 1) moderate CWR exercises (MODERATE), below gas exchange threshold (GET); 2) heavy CWR exercise (HEAVY), at 45% of the difference between GET and V[Combining Dot Above]O2 peak (□); 3) severe CWR exercise (SEVERE), at 95% of Δ; 4) "HRCLAMPED" exercise in which work rate was continuously adjusted to maintain a constant HR, slightly higher than that determined at GET. Breath-by-breath V[Combining Dot Above]O2, HR and other variables were determined. In MODERATE, no slow component of V[Combining Dot Above]O2 kinetics was observed, whereas a slow component with a relative amplitude (with respect to the total response) of 24.8±11.0% was observed for HR kinetics. During HEAVY, the relative amplitude of the HR slow component was more pronounced than that for V[Combining Dot Above]O2 (31.6±11.2 and 23.3±9.0%, respectively). During HRCLAMPED the decrease in work rate (~14%) needed in order to maintain a constant HR was associated with a decreased V[Combining Dot Above]O2 (~10%). The HR slow component occurred at a lower work rate and was more pronounced than the V[Combining Dot Above]O2 slow component. Exercise prescriptions at specific HR values, when carried out for periods longer than a few minutes, could lead to premature fatigue.

Atmospheric emission characterization of Marcellus shale natural gas development sites.

PubMed

Goetz, J Douglas; Floerchinger, Cody; Fortner, Edward C; Wormhoudt, Joda; Massoli, Paola; Knighton, W Berk; Herndon, Scott C; Kolb, Charles E; Knipping, Eladio; Shaw, Stephanie L; DeCarlo, Peter F

2015-06-02

Limited direct measurements of criteria pollutants emissions and precursors, as well as natural gas constituents, from Marcellus shale gas development activities contribute to uncertainty about their atmospheric impact. Real-time measurements were made with the Aerodyne Research Inc. Mobile Laboratory to characterize emission rates of atmospheric pollutants. Sites investigated include production well pads, a well pad with a drill rig, a well completion, and compressor stations. Tracer release ratio methods were used to estimate emission rates. A first-order correction factor was developed to account for errors introduced by fenceline tracer release. In contrast to observations from other shale plays, elevated volatile organic compounds, other than CH4 and C2H6, were generally not observed at the investigated sites. Elevated submicrometer particle mass concentrations were also generally not observed. Emission rates from compressor stations ranged from 0.006 to 0.162 tons per day (tpd) for NOx, 0.029 to 0.426 tpd for CO, and 67.9 to 371 tpd for CO2. CH4 and C2H6 emission rates from compressor stations ranged from 0.411 to 4.936 tpd and 0.023 to 0.062 tpd, respectively. Although limited in sample size, this study provides emission rate estimates for some processes in a newly developed natural gas resource and contributes valuable comparisons to other shale gas studies.

Identification of clinically relevant Corynebacterium strains by Api Coryne, MALDI-TOF-mass spectrometry and molecular approaches.

PubMed

Alibi, S; Ferjani, A; Gaillot, O; Marzouk, M; Courcol, R; Boukadida, J

2015-09-01

We evaluated the Bruker Biotyper matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) for the identification of 97 Corynebacterium clinical in comparison to identification strains by Api Coryne and MALDI-TOF-MS using 16S rRNA gene and hypervariable region of rpoB genes sequencing as a reference method. C. striatum was the predominant species isolated followed by C. amycolatum. There was an agreement between Api Coryne strips and MALDI-TOF-MS identification in 88.65% of cases. MALDI-TOF-MS was unable to differentiate C. aurimucosum from C. minutissimum and C. minutissimum from C. singulare but reliably identify 92 of 97 (94.84%) strains. Two strains remained incompletely identified to the species level by MALDI-TOF-MS and molecular approaches. They belonged to Cellulomonas and Pseudoclavibacter genus. In conclusion, MALDI-TOF-MS is a rapid and reliable method for the identification of Corynebacterium species. However, some limits have been noted and have to be resolved by the application of molecular methods. Copyright © 2015. Published by Elsevier SAS.

MALDI-TOF MS of Trichoderma: A model system for the identification of microfungi

USDA-ARS?s Scientific Manuscript database

This investigation aimed to assess whether MALDI-TOF MS analysis of proteomics could be applied to the study of Trichoderma, a fungal genus selected because it includes many species and is phylogenetically well defined. We also investigated whether MALDI-TOF MS analysis of proteomics would reveal ap...

What Is New in Clinical Microbiology—Microbial Identification by MALDI-TOF Mass Spectrometry

PubMed Central

Murray, Patrick R.

2012-01-01

Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) offers the possibility of accurate, rapid, inexpensive identification of bacteria, fungi, and mycobacteria isolated in clinical microbiology laboratories. The procedures for preanalytic processing of organisms and analysis by MALDI-TOF MS are technically simple and reproducible, and commercial databases and interpretive algorithms are available for the identification of a wide spectrum of clinically significant organisms. Although only limited work has been reported on the use of this technique to identify molds, perform strain typing, or determine antibiotic susceptibility results, these are fruitful areas of promising research. As experience is gained with MALDI-TOF MS, it is expected that the databases will be expanded to resolve many of the current inadequate identifications (eg, no identification, genus-level identification) and algorithms for potential misidentification will be developed. The current lack of Food and Drug Administration approval of any MALDI-TOF MS system for organism identification limits widespread use in the United States. PMID:22795961

Towards Discovery and Targeted Peptide Biomarker Detection Using nanoESI-TIMS-TOF MS

NASA Astrophysics Data System (ADS)

Garabedian, Alyssa; Benigni, Paolo; Ramirez, Cesar E.; Baker, Erin S.; Liu, Tao; Smith, Richard D.; Fernandez-Lima, Francisco

2018-05-01

In the present work, the potential of trapped ion mobility spectrometry coupled to TOF mass spectrometry (TIMS-TOF MS) for discovery and targeted monitoring of peptide biomarkers from human-in-mouse xenograft tumor tissue was evaluated. In particular, a TIMS-MS workflow was developed for the detection and quantification of peptide biomarkers using internal heavy analogs, taking advantage of the high mobility resolution (R = 150-250) prior to mass analysis. Five peptide biomarkers were separated, identified, and quantified using offline nanoESI-TIMS-CID-TOF MS; the results were in good agreement with measurements using a traditional LC-ESI-MS/MS proteomics workflow. The TIMS-TOF MS analysis permitted peptide biomarker detection based on accurate mobility, mass measurements, and high sequence coverage for concentrations in the 10-200 nM range, while simultaneously achieving discovery measurements of not initially targeted peptides as markers from the same proteins and, eventually, other proteins. [Figure not available: see fulltext.

Identification of fungal microorganisms by MALDI-TOF mass spectrometry.

PubMed

Chalupová, Jana; Raus, Martin; Sedlářová, Michaela; Sebela, Marek

2014-01-01

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as a reliable tool for fast identification and classification of microorganisms. In this regard, it represents a strong challenge to microscopic and molecular biology methods. Nowadays, commercial MALDI systems are accessible for biological research work as well as for diagnostic applications in clinical medicine, biotechnology and industry. They are employed namely in bacterial biotyping but numerous experimental strategies have also been developed for the analysis of fungi, which is the topic of the present review. Members of many fungal genera such as Aspergillus, Fusarium, Penicillium or Trichoderma and also various yeasts from clinical samples (e.g. Candida albicans) have been successfully identified by MALDI-TOF MS. However, there is no versatile method for fungi currently available even though the use of only a limited number of matrix compounds has been reported. Either intact cell/spore MALDI-TOF MS is chosen or an extraction of surface proteins is performed and then the resulting extract is measured. Biotrophic fungal phytopathogens can be identified via a direct acquisition of MALDI-TOF mass spectra e.g. from infected plant organs contaminated by fungal spores. Mass spectrometric peptide/protein profiles of fungi display peaks in the m/z region of 1000-20000, where a unique set of biomarker ions may appear facilitating a differentiation of samples at the level of genus, species or strain. This is done with the help of a processing software and spectral database of reference strains, which should preferably be constructed under the same standardized experimental conditions. Copyright © 2013 Elsevier Inc. All rights reserved.

Analysis of protein glycation products by MALDI-TOF/MS.

PubMed

Kislinger, Thomas; Humeny, Andreas; Peich, Carlo C; Becker, Cord-Michael; Pischetsrieder, Monika

2005-06-01

Matrix-assisted laser desorption ionization-mass spectrometry with time-of-flight detection (MALDI-TOF/MS) is a promising tool to analyze advanced glycation end product (AGE)-modified proteins. The combination of soft ionization (MALDI) with time-of-flight mass detection allows analysis of peptides and proteins of a molecular mass up to 300 kDa with minimal sample workup. Because the direct structural analysis of intact AGE proteins is not possible due to the formation of broad and poorly resolved peaks, peptide mapping was introduced into the analysis of AGE proteins by MALDI-TOF/MS, allowing site-specific analysis of defined AGEs. When methylglyoxal-modified lysozyme was subjected to MALDI-TOF/MS peptide mapping, methylimidazolone and argpyrimidine attached to the arginine residue and carboxyethyl (CEL) bound to the lysine were detected on peptide(aa1-7) (KVFGRCE). In contrast, only one methylimidazolone was found on peptide(aa8-35) (LAAAMKRHGLDNYRGYSLGNWVCAAKFE) and peptide(aa120-129) (VQAWIRGCRL), respectively. The analysis of AGE protein, which had been incubated with glucose, revealed the presence of an Amadori product and a carboxymethyl residue (CML) on peptide(aa1-7) and peptide(aa8-35), as well as an imidazolone A on peptide(aa120-129). Furthermore, the early Maillard reaction of lysozyme, which had been glycated by seven different sugars, was monitored by MALDI-TOF/MS peptide mapping. Finally, this approach was successfully applied for site- and product-specific relative quantification of AGEs. For example, kinetics of CML and Amadori product formation on peptide(aa1-7), as well as imidazolone A formation on peptide(aa120-129), were determined.

Detection of Rickettsia spp in Ticks by MALDI-TOF MS

PubMed Central

Yssouf, Amina; Almeras, Lionel; Terras, Jérôme; Socolovschi, Cristina; Raoult, Didier; Parola, Philippe

2015-01-01

Background Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has been shown to be an effective tool for the rapid identification of arthropods, including tick vectors of human diseases. Methodology/Principal Findings The objective of the present study was to evaluate the use of MALDI-TOF MS to identify tick species, and to determine the presence of rickettsia pathogens in the infected Ticks. Rhipicephalus sanguineus and Dermacentor marginatus Ticks infected or not by R. conorii conorii or R. slovaca, respectively, were used as experimental models. The MS profiles generated from protein extracts prepared from tick legs exhibited mass peaks that distinguished the infected and uninfected Ticks, and successfully discriminated the Rickettsia spp. A blind test was performed using Ticks that were laboratory-reared, collected in the field or removed from patients and infected or not by Rickettsia spp. A query against our in-lab arthropod MS reference database revealed that the species and infection status of all Ticks were correctly identified at the species and infection status levels. Conclusions/Significance Taken together, the present work demonstrates the utility of MALDI-TOF MS for a dual identification of tick species and intracellular bacteria. Therefore, MALDI-TOF MS is a relevant tool for the accurate detection of Rickettsia spp in Ticks for both field monitoring and entomological diagnosis. The present work offers new perspectives for the monitoring of other vector borne diseases that present public health concerns. PMID:25659152

A molten Salt Am242M Production Reactor for Space Applications

NASA Technical Reports Server (NTRS)

Emrich, William

2005-01-01

The use of Am242m holds great promise for increasing the efficiency nuclear thermal rocket engines. Because Am242m has the highest fission cross section of any known isotope (1000's of barns), its extremely high reactivity may be used to directly heat a propellant gas with fission fragments. Since this isotope does not occur naturally, it must be bred in special production reactors designed for that purpose. The primary advantage to using molten salt reactors for breeding Am242m is that the reactors can be reprocessed continually yielding a constant rate of production of the isotope. Once built and initially fueled, the reactor will continually breed the additional fuel it needs to remain critical. The only feedstock required is a salt of U238. No enriched fuel is required during normal operation and all fissile material, except the Am242m, is maintained in a closed loop. For a reactor operating at 200 MW several kilograms of Am242m may be bred each year.

Argon offline-AMS source apportionment of organic aerosol over yearly cycles for an urban, rural, and marine site in northern Europe

NASA Astrophysics Data System (ADS)

Bozzetti, Carlo; Sosedova, Yuliya; Xiao, Mao; Daellenbach, Kaspar R.; Ulevicius, Vidmantas; Dudoitis, Vadimas; Mordas, Genrik; Byčenkienė, Steigvilė; Plauškaitė, Kristina; Vlachou, Athanasia; Golly, Benjamin; Chazeau, Benjamin; Besombes, Jean-Luc; Baltensperger, Urs; Jaffrezo, Jean-Luc; Slowik, Jay G.; El Haddad, Imad; Prévôt, André S. H.

2017-01-01

The widespread use of Aerodyne aerosol mass spectrometers (AMS) has greatly improved real-time organic aerosol (OA) monitoring, providing mass spectra that contain sufficient information for source apportionment. However, AMS field deployments remain expensive and demanding, limiting the acquisition of long-term datasets at many sampling sites. The offline application of aerosol mass spectrometry entailing the analysis of nebulized water extracted filter samples (offline-AMS) increases the spatial coverage accessible to AMS measurements, being filters routinely collected at many stations worldwide. PM1 (particulate matter with an aerodynamic diameter < 1 µm) filter samples were collected during an entire year in Lithuania at three different locations representative of three typical environments of the southeast Baltic region: Vilnius (urban background), Rūgšteli\\vskis (rural terrestrial), and Preila (rural coastal). Aqueous filter extracts were nebulized in Ar, yielding the first AMS measurements of water-soluble atmospheric organic aerosol (WSOA) without interference from air fragments. This enables direct measurement of the CO+ fragment contribution, whose intensity is typically assumed to be equal to that of CO2+. Offline-AMS spectra reveal that the water-soluble CO2+ : CO+ ratio not only shows values systematically > 1 but is also dependent on season, with lower values in winter than in summer. AMS WSOA spectra were analyzed using positive matrix factorization (PMF), which yielded four factors. These factors included biomass burning OA (BBOA), local OA (LOA) contributing significantly only in Vilnius, and two oxygenated OA (OOA) factors, summer OOA (S-OOA) and background OOA (B-OOA), distinguished by their seasonal variability. The contribution of traffic exhaust OA (TEOA) was not resolved by PMF due to both low concentrations and low water solubility. Therefore, the TEOA concentration was estimated using a chemical mass balance approach, based on the

Characterization of aerosol particles from grass mowing by joint deployment of ToF-AMS and ATOFMS instruments

NASA Astrophysics Data System (ADS)

Drewnick, Frank; Dall'Osto, Manuel; Harrison, Roy

During a measurement campaign at a semi-urban/industrial site a grass-cutting event was observed, when the lawn in the immediate surrounding of the measurement site was mowed. Using a wide variety of state-of-the-art aerosol measurement technology allowed a broad characterization of the aerosol generated by the lawn mowing. The instrumentation included two on-line aerosol mass spectrometers: an Aerodyne Time-of-Flight Aerosol Mass Spectrometer (ToF-AMS) and a TSI Aerosol Time-of-Flight Mass Spectrometer (ATOFMS); in addition, a selection of on-line aerosol concentration and size distribution instruments (OPC, APS, SMPS, CPC, FDMS-TEOM, MAAP) was deployed. From comparison of background aerosol measurements during most of the day with the aerosol measured during the lawn mowing, the grass cutting was found to generate mainly two different types of aerosol particles: an intense ultrafine particle mode (1 h average: 4 μg m -3) of almost pure hydrocarbon-like organics and a distinct particle mode in the upper sub-micrometer size range containing particles with potassium and nitrogen-organic compounds. The ultrafine particles are probably lubricating oil particles from the lawn mower exhaust; the larger particles are swirled-up plant debris particles from the mowing process. While these particle types were identified in the data from the two mass spectrometers, the on-line aerosol concentration and size distribution data support these findings. The results presented here show that the combination of quantitative aerosol particle ensemble mass spectrometry (ToF-AMS) and single particle mass spectrometry (ATOFMS) provides much deeper insights into the nature of the aerosol properties than each of the instruments could do alone. Therefore a combined deployment of both types of instruments is strongly recommended.

TOFSIMS-P: a web-based platform for analysis of large-scale TOF-SIMS data.

PubMed

Yun, So Jeong; Park, Ji-Won; Choi, Il Ju; Kang, Byeongsoo; Kim, Hark Kyun; Moon, Dae Won; Lee, Tae Geol; Hwang, Daehee

2011-12-15

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has been a useful tool to profile secondary ions from the near surface region of specimens with its high molecular specificity and submicrometer spatial resolution. However, the TOF-SIMS analysis of even a moderately large size of samples has been hampered due to the lack of tools for automatically analyzing the huge amount of TOF-SIMS data. Here, we present a computational platform to automatically identify and align peaks, find discriminatory ions, build a classifier, and construct networks describing differential metabolic pathways. To demonstrate the utility of the platform, we analyzed 43 data sets generated from seven gastric cancer and eight normal tissues using TOF-SIMS. A total of 87 138 ions were detected from the 43 data sets by TOF-SIMS. We selected and then aligned 1286 ions. Among them, we found the 66 ions discriminating gastric cancer tissues from normal ones. Using these 66 ions, we then built a partial least square-discriminant analysis (PLS-DA) model resulting in a misclassification error rate of 0.024. Finally, network analysis of the 66 ions showed disregulation of amino acid metabolism in the gastric cancer tissues. The results show that the proposed framework was effective in analyzing TOF-SIMS data from a moderately large size of samples, resulting in discrimination of gastric cancer tissues from normal tissues and identification of biomarker candidates associated with the amino acid metabolism.

LC-IM-TOF Instrument Control & Data Visualization Software

DOE Office of Scientific and Technical Information (OSTI.GOV)

2011-05-12

Liquid Chromatography-Ion Mobility-time of Flight Instrument Control and Data Visualization software is designed to control instrument voltages for the Ion Mobility drift tube. It collects and stores information collected from the Agilent TOF instrument and analyses/displays the ion intensity information acquired. The software interface can be split into 3 categories -- Instrument Settings/Controls, Data Acquisition, and Viewer. The Instrument Settings/Controls prepares the instrument for Data Acquisition. The Viewer contains common objects that are used by Instrument Settings/Controls and Data Acquisition. Intensity information is collected in 1 nanosec bins and separated by TOF pulses called scans. A collection of scans aremore » stored side by side making up an accumulation. In order for the computer to keep up with the stream of data, 30-50 accumulations are commonly summed into a single frame. A collection of frames makes up an experiment. The Viewer software then takes the experiment and presents the data in several possible ways, each frame can be viewed in TOF bins or m/z (mass to charge ratio). The experiment can be viewed frame by frame, merging several frames, or by viewing the peak chromatogram. The user can zoom into the data, export data, and/or animate frames. Additional features include calibration of the data and even post-processing multiplexed data.« less

Formation of Oxidized Organic Aerosol (OOA) through Fog Processing in the Po Valley

NASA Astrophysics Data System (ADS)

Gilardoni, S.; Paglione, M.; Rinaldi, M.; Giulianelli, L.; Massoli, P.; Hillamo, R. E.; Carbone, S.; Lanconelli, C.; Laaksonen, A. J.; Russell, L. M.; Poluzzi, V.; Fuzzi, S.; Facchini, C.

2014-12-01

Aqueous phase chemistry might be responsible for the formation of a significant fraction of the organic aerosol (OA) observed in the atmosphere, and could explain some of the discrepancies between OA concentration and properties predicted by models and observed in the environment. Aerosol - fog interaction and its effect on submicron aerosol properties were investigated in the Po Valley (northern Italy) during fall 2011, in the framework of the Supersite project (ARPA Emilia Romagna). Composition and physical properties of submicron aerosol were measured online by a High Resolution- Time of Flight - Aerosol Mass Spectrometer (HR-TOF-AMS), a Soot Photometer - Aerosol Mass Spectrometer (SP-AMS), and a Tandem Differential Mobility Particle Sizer (TDMPS). Organic functional group analysis was performed off-line by Hydrogen - Nuclear Magnetic Resonance (H-NMR) spectrometry and by Fourier Transform Infrared (FTIR) spectrometry. Aerosol absorption, scattering, and total extinction were measured simultaneously with a Particle Soot Absorption Photometer (PSAP), a Nephelometer, and a Cavity Attenuated Phase Shift Spectrometer particle extinction monitor (CAPS PMex), respectively. Water-soluble organic carbon in fog-water was characterized off-line by HR-TOF-AMS. Fourteen distinct fog events were observed. Fog dissipation left behind an aerosol enriched in particles larger than 400 nm, typical of fog and cloud processing, and dominated by secondary species, including ammonium nitrate, ammonium sulfate and oxidized OA (OOA). Source apportionment of OA allowed us to identify OOA as the difference between total OA and primary OA (hydrocarbon like OA and biomass burning OA). The formation of OOA through fog processing is proved by the correlation of OOA concentration with hydroxyl methyl sulfonate signal and by the similarity of OOA spectra with organic mass spectra obtained by re-aerosolization of fog water samples. The oxygen to carbon ratio and the hydrogen to carbon ratio of

Cocoa content influences chocolate molecular profile investigated by MALDI-TOF mass spectrometry.

PubMed

Bonatto, Cínthia C; Silva, Luciano P

2015-06-01

Chocolate authentication is a key aspect of quality control and safety. Matrix-assisted laser desorption ionization time-of flight (MALDI-TOF) mass spectrometry (MS) has been demonstrated to be useful for molecular profiling of cells, tissues, and even food. The present study evaluated if MALDI-TOF MS analysis on low molecular mass profile may classify chocolate samples according to the cocoa content. The molecular profiles of seven processed commercial chocolate samples were compared by using MALDI-TOF MS. Some ions detected exclusively in chocolate samples corresponded to the metabolites of cocoa or other constituents. This method showed the presence of three distinct clusters according to confectionery and sensorial features of the chocolates and was used to establish a mass spectra database. Also, novel chocolate samples were evaluated in order to check the validity of the method and to challenge the database created with the mass spectra of the primary samples. Thus, the method was shown to be reliable for clustering unknown samples into the main chocolate categories. Simple sample preparation of the MALDI-TOF MS approach described will allow the surveillance and monitoring of constituents during the molecular profiling of chocolates. © 2014 Society of Chemical Industry.

Accurate differentiation of Mycobacterium chimaera from Mycobacterium intracellulare by MALDI-TOF MS analysis.

PubMed

Pranada, Arthur B; Witt, Ellen; Bienia, Michael; Kostrzewa, Markus; Timke, Markus

2017-05-01

The increasing number of infections caused by nontuberculous mycobacteria (NTM) has prompted the need for rapid and precise identification methods of these pathogens. Several studies report the applicability of MALDI-TOF mass spectrometry (MS) for identification of NTM. However, some closely related species have very similar spectral mass fingerprints, and until recently, Mycobacterium chimaera and M. intracellulare could not be separated from each other by MALDI-TOF MS. The conventional identification methods used in routine diagnostics have similar limitations. Recently, the differentiation of these two species within the Mycobacterium avium complex has become increasingly important due to reports of M. chimaera infections related to open heart surgery in Europe and in the USA. In this report, a method for the distinct differentiation of M. chimaera and M. intracellulare using a more detailed analysis of MALDI-TOF mass spectra is presented. Species-specific peaks could be identified and it was possible to assign all isolates (100 %) from reference strain collections as well as clinical isolates to the correct species. We have developed a model for the accurate identification of M. chimaera and M. intracellulare by MALDI-TOF MS. This approach has the potential for routine use in microbiology laboratories, as the model itself can be easily implemented into the software of the currently available systems by MALDI-TOF MS manufacturers.

The n_TOF facility: Neutron beams for challenging future measurements at CERN

NASA Astrophysics Data System (ADS)

Chiaveri, E.; Aberle, O.; Andrzejewski, J.; Audouin, L.; Bacak, M.; Balibrea, J.; Barbagallo, M.; Bečvář, F.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brown, A.; Caamaño, M.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Cardella, R.; Casanovas, A.; Cerutti, F.; Chen, Y. H.; Colonna, N.; Cortés, G.; Cortés-Giraldo, M. A.; Cosentino, L.; Damone, L. A.; Diakaki, M.; Domingo-Pardo, C.; Dressler, R.; Dupont, E.; Durán, I.; Fernández-Domínguez, B.; Ferrari, A.; Ferreira, P.; Finocchiaro, P.; Göbel, K.; García, A. R.; Gawlik, A.; Gilardoni, S.; Glodariu, T.; Gonçalves, I. F.; González, E.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Harada, H.; Heinitz, S.; Heyse, J.; Jenkins, D. G.; Jericha, E.; Käppeler, F.; Kadi, Y.; Kalamara, A.; Kavrigin, P.; Kimura, A.; Kivel, N.; Kokkoris, M.; Krtička, M.; Kurtulgil, D.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Lerendegui-Marco, J.; Meo, S. Lo; Lonsdale, S. J.; Macina, D.; Marganiec, J.; Martínez, T.; Masi, A.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Maugeri, E. A.; Mazzone, A.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Musumarra, A.; Negret, A.; Nolte, R.; Oprea, A.; Patronis, N.; Pavlik, A.; Perkowski, J.; Porras, I.; Praena, J.; Quesada, J. M.; Radeck, D.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Ryan, J. A.; Sabaté-Gilarte, M.; Saxena, A.; Schillebeeckx, P.; Schumann, D.; Smith, A. G.; Sosnin, N. V.; Stamatopoulos, A.; Tagliente, G.; Tain, J. L.; Tarifeño-Saldivia, A.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Warren, S.; Woods, P. J.; Wright, T.; Žugec, P.

2017-09-01

The CERN n_TOF neutron beam facility is characterized by a very high instantaneous neutron flux, excellent TOF resolution at the 185 m long flight path (EAR-1), low intrinsic background and coverage of a wide range of neutron energies, from thermal to a few GeV. These characteristics provide a unique possibility to perform high-accuracy measurements of neutron-induced reaction cross-sections and angular distributions of interest for fundamental and applied Nuclear Physics. Since 2001, the n_TOF Collaboration has collected a wealth of high quality nuclear data relevant for nuclear astrophysics, nuclear reactor technology, nuclear medicine, etc. The overall efficiency of the experimental program and the range of possible measurements has been expanded with the construction of a second experimental area (EAR-2), located 20 m on the vertical of the n_TOF spallation target. This upgrade, which benefits from a neutron flux 30 times higher than in EAR-1, provides a substantial extension in measurement capabilities, opening the possibility to collect data on neutron cross-section of isotopes with short half-lives or available in very small amounts. This contribution will outline the main characteristics of the n_TOF facility, with special emphasis on the new experimental area. In particular, we will discuss the innovative features of the EAR-2 neutron beam that make possible to perform very challenging measurements on short-lived radioisotopes or sub-mg samples, out of reach up to now at other neutron facilities around the world. Finally, the future perspectives of the facility will be presented.

Model Atmospheres for Massive Gas Giants with Thick Clouds: Application to the HR 8799 Planets and Predictions for Future Detections

NASA Astrophysics Data System (ADS)

Madhusudhan, Nikku; Burrows, Adam; Currie, Thayne

2011-08-01

We have generated an extensive new suite of massive giant planet atmosphere models and used it to obtain fits to photometric data for the planets HR 8799b, c, and d. We consider a wide range of cloudy and cloud-free models. The cloudy models incorporate different geometrical and optical thicknesses, modal particle sizes, and metallicities. For each planet and set of cloud parameters, we explore grids in gravity and effective temperature, with which we determine constraints on the planet's mass and age. Our new models yield statistically significant fits to the data, and conclusively confirm that the HR 8799 planets have much thicker clouds than those required to explain data for typical L and T dwarfs. Both models with (1) physically thick forsterite clouds and a 60 μm modal particle size and (2) clouds made of 1 μm sized pure iron droplets and 1% supersaturation fit the data. Current data are insufficient to accurately constrain the microscopic cloud properties, such as composition and particle size. The range of best-estimated masses for HR 8799b, HR 8799c, and HR 8799d conservatively span 2-12 MJ , 6-13 MJ , and 3-11 MJ , respectively, and imply coeval ages between ~10 and ~150 Myr, consistent with previously reported stellar ages. The best-fit temperatures and gravities are slightly lower than values obtained by Currie et al. using even thicker cloud models. Finally, we use these models to predict the near-to-mid-IR colors of soon-to-be imaged planets. Our models predict that planet-mass objects follow a locus in some near-to-mid-IR color-magnitude diagrams that is clearly separable from the standard L/T dwarf locus for field brown dwarfs.

Computed Temperature Distribution and Cooling of Solid Gas-Turbine Blades

NASA Technical Reports Server (NTRS)

Reuter, J. George; Gazley, Carl, Jr.

1947-01-01

Computations were made to determine the temperature distribution and cooling of solid gas-turbine blades.A range of temperatures was used from 1500 degrees to 2500 degrees F, blade-root temperatures from 100 degrees to 1000 degrees F, blade thermal conductivity from 8 to 220 BTU/(hr)(sq ft)(degrees F/ft), and net gas to metal heat transfer coefficients from 75 to 250 BTU/(hr)(sq ft)(degrees F).

Technological developments for strontium-90 determination using AMS

NASA Astrophysics Data System (ADS)

Satou, Yukihiko; Sueki, Keisuke; Sasa, Kimikazu; Matsunaka, Tetsuya; Takahashi, Tsutomu; Shibayama, Nao; Izumi, Daiki; Kinoshita, Norikazu; Matsuzaki, Hiroyuki

2015-10-01

Accelerator mass spectrometry (AMS) is one of method used for 90Sr determination. It would enable rapid 90Sr measurements from environmental samples such as water, soil, and milk. However, routine analysis of 90Sr using AMS has not yet been achieved because of difficulties associated with isobaric separation and production of intense negative ion beams characterized by currents from hundreds of nanoamperes to several microamperes. We have developed a rapid procedure for preparing samples with optimum compositions for use with AMS, which enables production of intense Sr beam currents from an ion source. Samples of SrF2 were prepared from a standard Sr solution and agricultural soil. The time required to prepare a SrF2 sample from a soil sample was 10 h. Negative 88SrF3- ions were successfully extracted at 500 nA from mixed samples of SrF2 and PbF2. In the present work, negative ions of 90Zr, included as an impurity, were accelerated with a tandem accelerator operated at a terminal voltage of 5 MV. Ions characterized by a charge state of 6+ were channeled into a gas counter. An atomic ratio of 90Zr/88Sr of 3 × 10-8 was estimated for the soil sample. No signal was detected from the assay of PbF2, which was pressed in an aluminum cathode, for a mass number of 90. PbF2 revealed good performance in the production of negative SrF3- molecular ion beams and detection of 90Sr with a gas counter.

Organic aerosol components derived from 25 AMS data sets across Europe using a consistent ME-2 based source apportionment approach

NASA Astrophysics Data System (ADS)

Crippa, M.; Canonaco, F.; Lanz, V. A.; Äijälä, M.; Allan, J. D.; Carbone, S.; Capes, G.; Ceburnis, D.; Dall'Osto, M.; Day, D. A.; DeCarlo, P. F.; Ehn, M.; Eriksson, A.; Freney, E.; Hildebrandt Ruiz, L.; Hillamo, R.; Jimenez, J. L.; Junninen, H.; Kiendler-Scharr, A.; Kortelainen, A.-M.; Kulmala, M.; Laaksonen, A.; Mensah, A. A.; Mohr, C.; Nemitz, E.; O'Dowd, C.; Ovadnevaite, J.; Pandis, S. N.; Petäjä, T.; Poulain, L.; Saarikoski, S.; Sellegri, K.; Swietlicki, E.; Tiitta, P.; Worsnop, D. R.; Baltensperger, U.; Prévôt, A. S. H.

2014-06-01

Organic aerosols (OA) represent one of the major constituents of submicron particulate matter (PM1) and comprise a huge variety of compounds emitted by different sources. Three intensive measurement field campaigns to investigate the aerosol chemical composition all over Europe were carried out within the framework of the European Integrated Project on Aerosol Cloud Climate and Air Quality Interactions (EUCAARI) and the intensive campaigns of European Monitoring and Evaluation Programme (EMEP) during 2008 (May-June and September-October) and 2009 (February-March). In this paper we focus on the identification of the main organic aerosol sources and we define a standardized methodology to perform source apportionment using positive matrix factorization (PMF) with the multilinear engine (ME-2) on Aerodyne aerosol mass spectrometer (AMS) data. Our source apportionment procedure is tested and applied on 25 data sets accounting for two urban, several rural and remote and two high altitude sites; therefore it is likely suitable for the treatment of AMS-related ambient data sets. For most of the sites, four organic components are retrieved, improving significantly previous source apportionment results where only a separation in primary and secondary OA sources was possible. Generally, our solutions include two primary OA sources, i.e. hydrocarbon-like OA (HOA) and biomass burning OA (BBOA) and two secondary OA components, i.e. semi-volatile oxygenated OA (SV-OOA) and low-volatility oxygenated OA (LV-OOA). For specific sites cooking-related (COA) and marine-related sources (MSA) are also separated. Finally, our work provides a large overview of organic aerosol sources in Europe and an interesting set of highly time resolved data for modeling purposes.

Volatility-resolved Measurements of the Chemical Composition of Arctic Aerosol Particles

NASA Astrophysics Data System (ADS)

Ehn, M.; Kroll, J.; Coffman, D.; Quinn, P.; Bates, T.; Williams, E.; Kulmala, M.; Worsnop, D.

2008-12-01

Here we describe measurements of the chemical composition of submicron particles in the Arctic marine boundary layer, taken on board the R/V Knorr during the IPY-ICEALOT mission (March-April 2008). Measurements were made with an Aerodyne high-resolution aerosol mass spectrometer (HR-AMS) for the measurement of the non-refractory fraction of the aerosol, in particular allowing for the determination of the oxygen/carbon (O/C) ratio of the particulate organics and the unambiguous identification of trace inorganic species. Sampling alternated between ambient air and air sent through a thermodenuder (TD), continually scanned between 50 and 250C in order to remove aerosol components by volatility. The mass spectra of particulate matter in the Arctic (including Arctic haze) were dominated by sulfur-containing peaks and the CO2+ ion (at m/z 44), indicating the main non-refractory components of the aerosol are acidic sulfate and highly oxygenated organics. Thermodenuder measurements allow for the clear speciation of sulfate compounds by volatility, as well as the comparison of the degree of atmospheric aging of the organics to measurements taken elsewhere (including at terrestrial sites). AMS measurements will be compared to results from a hygroscopicity tandem differential mobility analyzer (HTDMA), also downstream of the thermodenuder, as well as from semicontinuous (PILS) and offline (filter) measurements of particle composition.

Improved source apportionment of organic aerosols in complex urban air pollution using the multilinear engine (ME-2)

NASA Astrophysics Data System (ADS)

Zhu, Qiao; Huang, Xiao-Feng; Cao, Li-Ming; Wei, Lin-Tong; Zhang, Bin; He, Ling-Yan; Elser, Miriam; Canonaco, Francesco; Slowik, Jay G.; Bozzetti, Carlo; El-Haddad, Imad; Prévôt, André S. H.

2018-02-01

Organic aerosols (OAs), which consist of thousands of complex compounds emitted from various sources, constitute one of the major components of fine particulate matter. The traditional positive matrix factorization (PMF) method often apportions aerosol mass spectrometer (AMS) organic datasets into less meaningful or mixed factors, especially in complex urban cases. In this study, an improved source apportionment method using a bilinear model of the multilinear engine (ME-2) was applied to OAs collected during the heavily polluted season from two Chinese megacities located in the north and south with an Aerodyne high-resolution aerosol mass spectrometer (HR-ToF-AMS). We applied a rather novel procedure for utilization of prior information and selecting optimal solutions, which does not necessarily depend on other studies. Ultimately, six reasonable factors were clearly resolved and quantified for both sites by constraining one or more factors: hydrocarbon-like OA (HOA), cooking-related OA (COA), biomass burning OA (BBOA), coal combustion (CCOA), less-oxidized oxygenated OA (LO-OOA) and more-oxidized oxygenated OA (MO-OOA). In comparison, the traditional PMF method could not effectively resolve the appropriate factors, e.g., BBOA and CCOA, in the solutions. Moreover, coal combustion and traffic emissions were determined to be primarily responsible for the concentrations of PAHs and BC, respectively, through the regression analyses of the ME-2 results.

MALDI-TOF mass spectrometry in the clinical mycology laboratory: identification of fungi and beyond.

PubMed

Posteraro, Brunella; De Carolis, Elena; Vella, Antonietta; Sanguinetti, Maurizio

2013-04-01

MALDI-TOF mass spectrometry (MS) is becoming essential in most clinical microbiology laboratories throughout the world. Its successful use is mainly attributable to the low operational costs, the universality and flexibility of detection, as well as the specificity and speed of analysis. Based on characteristic protein spectra obtained from intact cells - by means of simple, rapid and reproducible preanalytical and analytical protocols - MALDI-TOF MS allows a highly discriminatory identification of yeasts and filamentous fungi starting from colonies. Whenever used early, direct identification of yeasts from positive blood cultures has the potential to greatly shorten turnaround times and to improve laboratory diagnosis of fungemia. More recently, but still at an infancy stage, MALDI-TOF MS is used to perform strain typing and to determine antifungal drug susceptibility. In this article, the authors discuss how the MALDI-TOF MS technology is destined to become a powerful tool for routine mycological diagnostics.

Copernicus observations of Ly-alpha and Mg II emission from HR 1099 /V711 Tauri/ and UX Ari

NASA Technical Reports Server (NTRS)

Weiler, E. J.

1978-01-01

Ultraviolet observations of two RS CVn binaries obtained with Copernicus are described. High-resolution (0.05 A) U1 observations indicate that both HR 1099 and UX Ari display broad Ly-alpha emission. The Ly-alpha emission strength from HR 1099 is variable and seems to be correlated with orbital phase, while the UX Ari results indicate no significant variation. Moderate resolution (0.51 A) V2 scans of both systems show variable Mg II h and k emission-line profiles which usually matched the velocity of the more active star in each binary. Additionally, displaced emission components were seen at velocities of up to + or - 250 km/s, indicative of high-velocity gas motions. The radial velocities of these emission features from HR 1099 are marginally correlated with orbital phase. Highly active and variable chromospheric phenomena are found to be the most consistent explanation of these results.

Phosphorylation of CMG helicase and Tof1 is required for programmed fork arrest

PubMed Central

Bastia, Deepak; Srivastava, Pankaj; Zaman, Shamsu; Choudhury, Malay; Mohanty, Bidyut K.; Bacal, Julien; Langston, Lance D.; Pasero, Philippe; O’Donnell, Michael E.

2016-01-01

Several important physiological transactions, including control of replicative life span (RLS), prevention of collision between replication and transcription, and cellular differentiation, require programmed replication fork arrest (PFA). However, a general mechanism of PFA has remained elusive. We previously showed that the Tof1–Csm3 fork protection complex is essential for PFA by antagonizing the Rrm3 helicase that displaces nonhistone protein barriers that impede fork progression. Here we show that mutations of Dbf4-dependent kinase (DDK) of Saccharomyces cerevisiae, but not other DNA replication factors, greatly reduced PFA at replication fork barriers in the spacer regions of the ribosomal DNA array. A key target of DDK is the mini chromosome maintenance (Mcm) 2–7 complex, which is known to require phosphorylation by DDK to form an active CMG [Cdc45 (cell division cycle gene 45), Mcm2–7, GINS (Go, Ichi, Ni, and San)] helicase. In vivo experiments showed that mutational inactivation of DDK caused release of Tof1 from the chromatin fractions. In vitro binding experiments confirmed that CMG and/or Mcm2–7 had to be phosphorylated for binding to phospho-Tof1–Csm3 but not to its dephosphorylated form. Suppressor mutations that bypass the requirement for Mcm2–7 phosphorylation by DDK restored PFA in the absence of the kinase. Retention of Tof1 in the chromatin fraction and PFA in vivo was promoted by the suppressor mcm5-bob1, which bypassed DDK requirement, indicating that under this condition a kinase other than DDK catalyzed the phosphorylation of Tof1. We propose that phosphorylation regulates the recruitment and retention of Tof1–Csm3 by the replisome and that this complex antagonizes the Rrm3 helicase, thereby promoting PFA, by preserving the integrity of the Fob1–Ter complex. PMID:27298353

Biogenic volatile organic compound analyses by PTR-TOF-MS: Calibration, humidity effect and reduced electric field dependency.

PubMed

Pang, Xiaobing

2015-06-01

Green leaf volatiles (GLVs) emitted by plants after stress or damage induction are a major part of biogenic volatile organic compounds (BVOCs). Proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) is a high-resolution and sensitive technique for in situ GLV analyses, while its performance is dramatically influenced by humidity, electric field, etc. In this study the influence of gas humidity and the effect of reduced field (E/N) were examined in addition to measuring calibration curves for the GLVs. Calibration curves measured for seven of the GLVs in dry air were linear, with sensitivities ranging from 5 to 10 ncps/ppbv (normalized counts per second/parts per billion by volume). The sensitivities for most GLV analyses were found to increase by between 20% and 35% when the humidity of the sample gas was raised from 0% to 70% relative humidity (RH) at 21°C, with the exception of (E)-2-hexenol. Product ion branching ratios were also affected by humidity, with the relative abundance of the protonated molecular ions and higher mass fragment ions increasing with humidity. The effect of reduced field (E/N) on the fragmentation of GLVs was examined in the drift tube of the PTR-TOF-MS. The structurally similar GLVs are acutely susceptible to fragmentation following ionization and the fragmentation patterns are highly dependent on E/N. Overall the measured fragmentation patterns contain sufficient information to permit at least partial separation and identification of the isomeric GLVs by looking at differences in their fragmentation patterns at high and low E/N. Copyright © 2015. Published by Elsevier B.V.

The Ongoing Revolution of MALDI-TOF Mass Spectrometry for Microbiology Reaches Tropical Africa

PubMed Central

Fall, Bécaye; Lo, Cheikh Ibrahima; Samb-Ba, Bissoume; Perrot, Nadine; Diawara, Silman; Gueye, Mamadou Wague; Sow, Kowry; Aubadie-Ladrix, Maxence; Mediannikov, Oleg; Sokhna, Cheikh; Diemé, Yaya; Chatellier, Sonia; Wade, Boubacar; Raoult, Didier; Fenollar, Florence

2015-01-01

Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) represents a revolution in routine pathogen identification in clinical microbiology laboratories. A MALDI-TOF MS was introduced to tropical Africa in the clinical microbiology laboratory of the Hôpital Principal de Dakar (Senegal) and used for routine pathogen identification. Using MS, 2,429 bacteria and fungi isolated from patients were directly assayed, leading to the identification of 2,082 bacteria (85.7%) and 206 fungi (8.5%) at the species level, 109 bacteria (4.5%) at the genus level, and 16 bacteria (0.75%) at the family level. Sixteen isolates remained unidentified (0.75%). Escherichia coli was the most prevalent species (25.8%) followed by Klebsiella pneumoniae (14.8%), Streptococcus agalactiae (6.2%), Acinetobacter baumannii (6.1%), Pseudomonas aeruginosa (5.9%), and Staphylococcus aureus (5.9%). MALDI-TOF MS has also enabled the detection of rare bacteria and fungi. MALDI-TOF MS is a powerful tool for the identification of bacterial and fungal species involved in infectious diseases in tropical Africa. PMID:25601995

Enhanced MALDI-TOF MS Analysis of Phosphopeptides Using an Optimized DHAP/DAHC Matrix

PubMed Central

Hou, Junjie; Xie, Zhensheng; Xue, Peng; Cui, Ziyou; Chen, Xiulan; Li, Jing; Cai, Tanxi; Wu, Peng; Yang, Fuquan

2010-01-01

Selecting an appropriate matrix solution is one of the most effective means of increasing the ionization efficiency of phosphopeptides in matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). In this study, we systematically assessed matrix combinations of 2, 6-dihydroxyacetophenone (DHAP) and diammonium hydrogen citrate (DAHC), and demonstrated that the low ratio DHAP/DAHC matrix was more effective in enhancing the ionization of phosphopeptides. Low femtomole level of phosphopeptides from the tryptic digests of α-casein and β-casein was readily detected by MALDI-TOF-MS in both positive and negative ion mode without desalination or phosphopeptide enrichment. Compared with the DHB/PA matrix, the optimized DHAP/DAHC matrix yielded superior sample homogeneity and higher phosphopeptide measurement sensitivity, particularly when multiple phosphorylated peptides were assessed. Finally, the DHAP/DAHC matrix was applied to identify phosphorylation sites from α-casein and β-casein and to characterize two phosphorylation sites from the human histone H1 treated with Cyclin-Dependent Kinase-1 (CDK1) by MALDI-TOF/TOF MS. PMID:20339515

Progress on multi-nuclide AMS of JAEA-AMS-TONO

NASA Astrophysics Data System (ADS)

Saito-Kokubu, Yoko; Matsubara, Akihiro; Miyake, Masayasu; Nishizawa, Akimitsu; Ohwaki, Yoshio; Nishio, Tomohiro; Sanada, Katsuki; Hanaki, Tatsumi

2015-10-01

The JAEA-AMS-TONO (Japan Atomic Energy Agency's Accelerator Mass Spectrometer established at the Tono Geoscience Center) facility has been used for the dating of geological samples. The AMS system is versatile, based on a 5 MV tandem Pelletron-type accelerator. Since its establishment in 1997, the AMS system has been used for measurement of carbon-14 (14C) mainly for 14C dating studies in neotectonics and hydrogeology, in support of JAEA's research on geosphere stability applicable to the long-term isolation of high-level radioactive waste. Results of the measurement of 14C in soils and plants has been applied to the dating of fault activity and volcanism. Development of beryllium-10 (10Be) and aluminum-26 (26Al) AMS systems are now underway to enhance the capability of the multi-nuclide AMS in studies of dating by cosmogenic nuclides. The 10Be-AMS system has already been used for routine measurements in applied studies and improvements of the measurement technique have been made. Now we plan to fine tune the system and perform test measurements to develop the 26Al-AMS system.

Technical developments in the Chalk River AMS program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrews, H.R.; Chant, L.; Cornett, R.J.J.

1995-12-01

The Chalk River AMS Program is centered on measurements of {sup 36}Cl and {sup 129}I with particular emphasis on samples related to nuclear activities including environmental monitoring, high level waste management, and nuclear safeguards. We are presently pursuing improvements in the areas of the gas-filled magnet, the ion source and data handling. Progress to date in these areas will be reported.

Atmospheric Retrieval Analysis of the Directly Imaged Exoplanet HR 8799b

NASA Astrophysics Data System (ADS)

Lee, Jae-Min; Heng, Kevin; Irwin, Patrick G. J.

2013-12-01

Directly imaged exoplanets are unexplored laboratories for the application of the spectral and temperature retrieval method, where the chemistry and composition of their atmospheres are inferred from inverse modeling of the available data. As a pilot study, we focus on the extrasolar gas giant HR 8799b, for which more than 50 data points are available. We upgrade our non-linear optimal estimation retrieval method to include a phenomenological model of clouds that requires the cloud optical depth and monodisperse particle size to be specified. Previous studies have focused on forward models with assumed values of the exoplanetary properties; there is no consensus on the best-fit values of the radius, mass, surface gravity, and effective temperature of HR 8799b. We show that cloud-free models produce reasonable fits to the data if the atmosphere is of super-solar metallicity and non-solar elemental abundances. Intermediate cloudy models with moderate values of the cloud optical depth and micron-sized particles provide an equally reasonable fit to the data and require a lower mean molecular weight. We report our best-fit values for the radius, mass, surface gravity, and effective temperature of HR 8799b. The mean molecular weight is about 3.8, while the carbon-to-oxygen ratio is about unity due to the prevalence of carbon monoxide. Our study emphasizes the need for robust claims about the nature of an exoplanetary atmosphere to be based on analyses involving both photometry and spectroscopy and inferred from beyond a few photometric data points, such as are typically reported for hot Jupiters.

A new method to discriminate secondary organic aerosols from different sources using high-resolution aerosol mass spectra

NASA Astrophysics Data System (ADS)

Heringa, M. F.; Decarlo, P. F.; Chirico, R.; Tritscher, T.; Clairotte, M.; Mohr, C.; Crippa, M.; Slowik, J. G.; Pfaffenberger, L.; Dommen, J.; Weingartner, E.; Prévôt, A. S. H.; Baltensperger, U.

2011-10-01

Organic aerosol (OA) represents a significant and often major fraction of the non-refractory PM1 (particulate matter with an aerodynamic diameter da < 1 μm) mass. Secondary organic aerosol (SOA) is an important contributor to the OA and can be formed from biogenic and anthropogenic precursors. Here we present results from the characterization of SOA produced from the emissions of three different anthropogenic sources. SOA from a log wood burner, a Euro 2 diesel car and a two-stroke Euro 2 scooter were characterized with an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) and compared to SOA from α-pinene. The emissions were sampled from the chimney/tailpipe by a heated inlet system and filtered before injection into a smog chamber. The gas phase emissions were irradiated by xenon arc lamps to initiate photo-chemistry which led to nucleation and subsequent particle growth by SOA production. Duplicate experiments were performed for each SOA type, with the averaged organic mass spectra in the m/z range 12-250 showing Pearson's r values >0.94 for the correlations between the different SOA types after 5 h of aging. High-resolution mass spectra (HR-MS) showed that the dominant peaks in the MS, m/z 43 and 44, are dominated by the oxygenated ions C2H3O+ and CO2+, respectively, similarly to the relatively fresh semi-volatile oxidized OA (SV-OOA) observed in the ambient aerosol. The atomic O : C ratios were found to be in the range of 0.25-0.55 with no major increase during the first 5 h of aging. On average, the diesel SOA showed the lowest O : C ratio followed by SOA from wood burning, α-pinene and the scooter emissions. Grouping the fragment ions based on their carbon number revealed that the SOA source with the highest O : C ratio had the largest fraction of small ions. Fragment ions containing up to 3 carbon atoms accounted for 66%, 68%, 72% and 76% of the organic spectrum of the SOA produced by the diesel car, wood burner, α-pinene and

Analysis of organic sulfur compounds in atmospheric aerosols at the HKUST supersite in Hong Kong using HR-ToF-AMS.

PubMed

Huang, Dan Dan; Li, Yong Jie; Lee, Berto P; Chan, Chak K

2015-03-17

Organic sulfur compounds have been identified in ambient secondary organic aerosols, but their contribution to organic mass is not well quantified. In this study, using a high-resolution time-of-flight aerosol mass spectrometer (AMS), concentrations of organic sulfur compounds were estimated based on the high-resolution fragmentation patterns of methanesulfonic acid (MSA), and organosulfates (OS), including alkyl, phenyl, and cycloalkyl sulfates, obtained in laboratory experiments. Mass concentrations of MSA and minimum mass concentrations of OS were determined in a field campaign conducted at a coastal site of Hong Kong in September 2011. MSA and OS together accounted for at least 5% of AMS detected organics. MSA is of marine origin with its formation dominated by local photochemical activities and enhanced by aqueous phase processing. OS concentrations are better correlated with particle liquid water content (LWC) than with particle acidity. High-molecular-weight OS were detected in the continental influenced period probably because they had grown into larger molecules during long-range transport or they were formed from large anthropogenic precursors. This study highlights the importance of both aqueous-phase processing and regional influence, i.e., different air mass origins, on organic sulfur compound formation in coastal cities like Hong Kong.

HR 7098: a new cool HgMN star ?

NASA Astrophysics Data System (ADS)

Monier, R.; Gebran, M.; Royer, F.; Kılıcoǧlu, T.

2017-12-01

Using one archival high dispersion high quality spectrum of HR 7098 (A0V) obtained with the échelle spectrograph SOPHIE at Observatoire de Haute Provence, we show that this star is not a superficially normal A0V star as hitherto thought. The model atmosphere and spectrum synthesis modeling of the spectrum of HR 7098 reveals real departures of its abundances from the solar composition. We report here on our first determinations of the elemental abundances of 35 elements in the atmosphere of HR 7098. Helium and Carbon are underabundant whereas the very heavy elements are overabundant in HR 7098.

Evaluation of the new capture vapourizer for aerosol mass spectrometers (AMS) through laboratory studies of inorganic species

NASA Astrophysics Data System (ADS)

Hu, Weiwei; Campuzano-Jost, Pedro; Day, Douglas A.; Croteau, Philip; Canagaratna, Manjula R.; Jayne, John T.; Worsnop, Douglas R.; Jimenez, Jose L.

2017-08-01

Aerosol mass spectrometers (AMSs) and Aerosol Chemical Speciation Monitors (ACSMs) commercialized by Aerodyne are widely used to measure the non-refractory species in submicron particles. With the standard vapourizer (SV) that is installed in all commercial instruments to date, the quantification of ambient aerosol mass concentration requires the use of the collection efficiency (CE) to correct for the loss of particles due to bounce. A new capture vapourizer (CV) has been designed to reduce the need for a bounce-related CE correction. Two high-resolution AMS instruments, one with a SV and one with a CV, were operated side by side in the laboratory. Four standard species, NH4NO3, NaNO3, (NH4)2SO4 and NH4Cl, which typically constitute the majority of the mass of ambient submicron inorganic species, are studied. The effect of vapourizer temperature (Tv ˜ 200-800 °C) on the detected fragments, CE and size distributions are investigated. A Tv of 500-550 °C for the CV is recommended. In the CV, CE was identical (around unity) for more volatile species (e.g. NH4NO3) and comparable to or higher than the SV for less-volatile species (e.g. (NH4)2SO4), demonstrating an improvement in CE for laboratory inorganic species in the CV. The detected relative intensities of fragments of NO3 and SO4 species observed with the CV are different from those observed with the SV, and are consistent with additional thermal decomposition arising from the increased residence time and multiple collisions. Increased residence times with the CV also lead to broader particle size distribution measurements than with the SV. A method for estimating whether pure species will be detected in AMS sizing mode is proposed. Production of CO2(g) from sampled nitrate on the vapourizer surface, which has been reported for the SV, is negligible for the CV for NH4NO3 and comparable to the SV for NaNO3. . We observe an extremely consistent fragmentation for ammonium compared to very large changes for the

Receptor modeling of near-roadway aerosol mass spectrometer data in Las Vegas, Nevada, with EPA PMF

NASA Astrophysics Data System (ADS)

Brown, S. G.; Lee, T.; Norris, G. A.; Roberts, P. T.; Collett, J. L., Jr.; Paatero, P.; Worsnop, D. R.

2012-01-01

Ambient non-refractory PM1 aerosol particles were measured with an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-AMS) at an elementary school 18 m from the US 95 freeway soundwall in Las Vegas, Nevada, during January 2008. Additional collocated continuous measurements of black carbon (BC), carbon monoxide (CO), nitrogen oxides (NOx), and meteorological data were collected. The US~Environmental Protection Agency's~(EPA) positive matrix factorization (PMF) data analysis tool was used to apportion organic matter (OM) as measured by HR-AMS, and rotational tools in EPA PMF were used to better characterize the solution space and pull resolved factors toward known source profiles. Three- to six-factor solutions were resolved. The four-factor solution was the most interpretable, with the typical AMS PMF factors of hydrocarbon-like organic aerosol (HOA), low-volatility oxygenated organic aerosol (LV-OOA), biomass burning organic aerosol (BBOA), and semi-volatile oxygenated organic aerosol (SV-OOA). When the measurement site was downwind of the freeway, HOA composed about half the OM, with SV-OOA and LV-OOA accounting for the rest. Attempts to pull the PMF factor profiles toward source profiles were successful but did not qualitatively change the results, indicating that these factors are very stable. Oblique edges were present in G-space plots, suggesting that the obtained rotation may not be the most plausible one. Since solutions found by pulling the profiles or using Fpeak retained these oblique edges, there appears to be little rotational freedom in the base solution. On average, HOA made up 26% of the OM, while LV-OOA was highest in the afternoon and accounted for 26% of the OM. BBOA occurred in the evening hours, was predominantly from the residential area to the north, and on average constituted 12% of the OM; SV-OOA accounted for the remaining third of the OM. Use of the pulling techniques available in EPA PMF and ME-2 suggested that the four

Bacterial flora analysis of coliforms in sewage, river water, and ground water using MALDI-TOF mass spectrometry.

PubMed

Suzuki, Yoshihiro; Niina, Kouki; Matsuwaki, Tomonori; Nukazawa, Kei; Iguchi, Atsushi

2018-01-28

The aim of this study was to rapidly and effectively analyze coliforms, which are the most fundamental indicators of water quality for fecal pollution, using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Coliform bacteria were isolated from municipal sewage, river water, and groundwater. For each sample, 100 isolates were determined by MALDI-TOF MS. In addition, these same 100 isolates were also identified via 16S rRNA gene sequence analysis. Obtained MALDI-TOF MS data were compared with the 16S rRNA sequencing analysis, and the validity of MALDI-TOF MS for classification of coliform bacteria was examined. The concordance rate of bacterial identification for the 100 isolates obtained by MALDI-TOF MS analysis and 16S rRNA gene sequence analysis for sewage, river water, and ground water were 96%, 74%, and 62% at the genus level, respectively. Among the sewage, river water, and ground water samples, the coliform bacterial flora were distinct. The dominant genus of coliforms in sewage, river water, and groundwater were Klebsiella spp., Enterobacter spp., and Serratia spp., respectively. We determined that MALDI-TOF MS is a rapid and accurate tool that can be used to identify coliforms. Therefore, without using conventional 16S rRNA sequencing, it is possible to rapidly and effectively classify coliforms in water using MALDI-TOF MS.

Integrated quantitative and qualitative workflow for in vivo bioanalytical support in drug discovery using hybrid Q-TOF-MS.

PubMed

Ranasinghe, Asoka; Ramanathan, Ragu; Jemal, Mohammed; D'Arienzo, Celia J; Humphreys, W Griffith; Olah, Timothy V

2012-03-01

UHPLC coupled with orthogonal acceleration hybrid quadrupole-TOF (Q-TOF)-MS is an emerging technique offering new strategies for the efficient screening of new chemical entities and related molecules at the early discovery stage within the pharmaceutical industry. In the first part of this article, we examine the main instrumental parameters that are critical for the integration of UHPLC-Q-TOF technology to existing bioanalytical workflows, in order to provide simultaneous quantitative and qualitative bioanalysis of samples generated following in vivo studies. Three modern Q-TOF mass spectrometers, including Bruker maXis™, Agilent 6540 and Sciex TripleTOF™ 5600, all interfaced with UHPLC systems, are evaluated in the second part of the article. The scope of this work is to demonstrate the potential of Q-TOF for the analysis of typical small molecules, therapeutic peptides (molecular weight <6000 Da), and enzymatically (i.e., trypsin, chymotrypsin and pepsin) cleaved peptides from larger proteins. This work focuses mainly on full-scan TOF data obtained under ESI conditions, the major mode of TOF operation in discovery bioanalytical research, where the compounds are selected based on their pharmacokinetic/pharmacodynamic behaviors using animal models prior to selecting a few desirable candidates for further development. Finally, important emerging TOF technologies that could potentially benefit bioanalytical research in the semi-quantification of metabolites without synthesized standards are discussed. Particularly, the utility of captive spray ionization coupled with TripleTOF 5600 was evaluated for improving sensitivity and providing normalized MS response for drugs and their metabolites. The workflow proposed compromises neither the efficiency, nor the quality of pharmacokinetic data in support of early drug discovery programs.

MALDI-TOF for the rapid detection of carbapenemase-producing Enterobacteriaceae: comparison of the commercialized MBT STAR®-Carba IVD Kit with two in-house MALDI-TOF techniques and the RAPIDEC® CARBA NP.

PubMed

Dortet, Laurent; Tandé, Didier; de Briel, Dominique; Bernabeu, Sandrine; Lasserre, Camille; Gregorowicz, Guillaume; Jousset, Agnès B; Naas, Thierry

2018-06-11

There is an urgent need for accurate and fast diagnostic tests to identify carbapenemase-producing bacteria. Here, we have evaluated three MALDI-TOF-based techniques to detect carbapenemase-producing Enterobacteriaceae (CPE) from cultured colonies. The performance of three MALDI-TOF-based techniques, including the commercialized MBT STAR®-Carba IVD Kit (Bruker Daltonics) and two in-house protocols performed on the Microflex LT Biotyper (Bruker Daltonics) and the VITEK® MS Plus (bioMérieux), were compared with those of the RAPIDEC® CARBA NP (bioMérieux). A collection of 175 isolates including 120 carbapenemase producers and 55 non-carbapenemase producers was tested. Samples were tested blind in the three participating centres. The repeatability of the MBT STAR®-Carba IVD Kit was also evaluated. The three MALDI-TOF techniques possess sensitivities ranging from 95% to 100% and specificities from 98.2% to 100% compared with 99.2% and 100%, respectively, for the RAPIDEC® CARBA NP. The MBT STAR®-Carba IVD Kit gave highly reproducible results and is the only technique able to provide a concomitant identification of the bacterial isolate. The three MALDI-TOF techniques possess a fast turnaround time (less than 1.5 h). Overall, MALDI-TOF is a reliable technique for the rapid detection of CPE from cultured colonies. MBT STAR®-Carba IVD Kit, the only commercially available assay, could easily be implemented in a clinical microbiology laboratory if it is already equipped with a Microflex LT Biotyper mass spectrometer.

Identification of urinary tract pathogens after 3-hours urine culture by MALDI-TOF mass spectrometry.

PubMed

Haiko, Johanna; Savolainen, Laura E; Hilla, Risto; Pätäri-Sampo, Anu

2016-10-01

Complicated urinary tract infections, such as pyelonephritis, may lead to sepsis. Rapid diagnosis is needed to identify the causative urinary pathogen and to verify the appropriate empirical antimicrobial therapy. We describe here a rapid identification method for urinary pathogens: urine is incubated on chocolate agar for 3h at 35°C with 5% CO2 and subjected to MALDI-TOF MS analysis by VITEK MS. Overall 207 screened clinical urine samples were tested in parallel with conventional urine culture. The method, called U-si-MALDI-TOF (urine short incubation MALDI-TOF), showed correct identification for 86% of Gram-negative urinary tract pathogens (Escherichia coli, Klebsiella pneumoniae, and other Enterobacteriaceae), when present at >10(5)cfu/ml in culture (n=107), compared with conventional culture method. However, Gram-positive bacteria (n=28) were not successfully identified by U-si-MALDI-TOF. This method is especially suitable for rapid identification of E. coli, the most common cause of urinary tract infections and urosepsis. Turnaround time for identification using U-si-MALDI-TOF compared with conventional urine culture was improved from 24h to 4-6h. Copyright © 2016 Elsevier B.V. All rights reserved.

The Effect of Susceptibility Artifacts Related to Metallic Implants on Adjacent-Lesion Assessment in Simultaneous TOF PET/MR.

PubMed

Svirydenka, Hanna; Delso, Gaspar; De Galiza Barbosa, Felipe; Huellner, Martin; Davison, Helen; Fanti, Stefano; Veit-Haibach, Patrick; Ter Voert, Edwin E G W

2017-07-01

Metalic implants may affect attenuation correction (AC) in PET/MR imaging. The purpose of this study was to evaluate the effect of susceptibility artifacts related to metallic implants on adjacent metabolically active lesions in clinical simultaneous PET/MR scanning for both time-of-flight (TOF) and non-TOF reconstructed PET images. Methods: We included 27 patients without implants but with confirmed 18 F-FDG-avid lesions adjacent to common implant locations. In all patients, a clinically indicated whole-body 18 F-FDG PET/MR scan was acquired. Baseline non-TOF and TOF PET images were reconstructed. Reconstruction was repeated after the introduction of artificial signal voids in the AC map to simulate metallic implants in standard anatomic areas. All reconstructed images were qualitatively and quantitatively assessed and compared with the baseline images. Results: In total, 51 lesions were assessed. In 40 and 50 of these cases (non-TOF and TOF, respectively), the detectability of the lesions did not change; in 9 and 1 cases, the detectability changed; and in 2 non-TOF cases, the lesions were no longer visible after the introduction of metallic artifacts. The inclusion of TOF information significantly reduced artifacts due to simulated implants in the femoral head, sternum, and spine ( P = 0.01, 0.01, and 0.03, respectively). It also improved image quality in these locations ( P = 0.02, 0.01, and 0.01, respectively). The mean percentage error was -3.5% for TOF and -4.8% for non-TOF reconstructions, meaning that the inclusion of TOF information reduced the percentage error in SUV max by 28.5% ( P < 0.01). Conclusion: Qualitatively, there was a significant reduction of artifacts in the femoral head, sternum, and spine. There was also a significant qualitative improvement in image quality in these locations. Furthermore, our study indicated that simulated susceptibility artifacts related to metallic implants have a significant effect on small, moderately 18 F

MALDI-TOF MS Distinctly Differentiates Nontypable Haemophilus influenzae from Haemophilus haemolyticus

PubMed Central

Zhang, Huifang; Zhang, Yongchan; Gao, Yuan; Xu, Li; Lv, Jing; Wang, Yingtong; Zhang, Jianzhong; Shao, Zhujun

2013-01-01

Nontypable Haemophilus influenzae (NTHi) and Haemophilus haemolyticus exhibit different pathogenicities, but to date, there remains no definitive and reliable strategy for differentiating these strains. In this study, we evaluated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a potential method for differentiating NTHi and H. haemolyticus. The phylogenetic analysis of concatenated 16S rRNA and recombinase A (recA) gene sequences, outer membrane protein P6 gene sequencing and single-gene PCR were used as reference methods. The original reference database (ORD, provided with the Biotyper software) and new reference database (NRD, extended with Chinese strains) were compared for the evaluation of MALDI-TOF MS. Through a search of the ORD, 76.9% of the NTHi (40/52) and none of the H. haemolyticus (0/20) strains were identified at the species level. However, all NTHi and H. haemolyticus strains used for identification were accurately recognized at the species level when searching the NRD. From the dendrogram clustering of the main spectra projections, the Chinese and foreign H. influenzae reference strains were categorized into two distinct groups, and H. influenzae and H. haemolyticus were also separated into two categories. Compared to the existing methods, MALDI-TOF MS has the advantage of integrating high throughput, accuracy and speed. In conclusion, MALDI-TOF MS is an excellent method for differentiating NTHi and H. haemolyticus. This method can be recommended for use in appropriately equipped laboratories. PMID:23457514

Principal component analysis of TOF-SIMS spectra, images and depth profiles: an industrial perspective

NASA Astrophysics Data System (ADS)

Pacholski, Michaeleen L.

2004-06-01

Principal component analysis (PCA) has been successfully applied to time-of-flight secondary ion mass spectrometry (TOF-SIMS) spectra, images and depth profiles. Although SIMS spectral data sets can be small (in comparison to datasets typically discussed in literature from other analytical techniques such as gas or liquid chromatography), each spectrum has thousands of ions resulting in what can be a difficult comparison of samples. Analysis of industrially-derived samples means the identity of most surface species are unknown a priori and samples must be analyzed rapidly to satisfy customer demands. PCA enables rapid assessment of spectral differences (or lack there of) between samples and identification of chemically different areas on sample surfaces for images. Depth profile analysis helps define interfaces and identify low-level components in the system.

Multi-dimensional TOF-SIMS analysis for effective profiling of disease-related ions from the tissue surface.

PubMed

Park, Ji-Won; Jeong, Hyobin; Kang, Byeongsoo; Kim, Su Jin; Park, Sang Yoon; Kang, Sokbom; Kim, Hark Kyun; Choi, Joon Sig; Hwang, Daehee; Lee, Tae Geol

2015-06-05

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) emerges as a promising tool to identify the ions (small molecules) indicative of disease states from the surface of patient tissues. In TOF-SIMS analysis, an enhanced ionization of surface molecules is critical to increase the number of detected ions. Several methods have been developed to enhance ionization capability. However, how these methods improve identification of disease-related ions has not been systematically explored. Here, we present a multi-dimensional SIMS (MD-SIMS) that combines conventional TOF-SIMS and metal-assisted SIMS (MetA-SIMS). Using this approach, we analyzed cancer and adjacent normal tissues first by TOF-SIMS and subsequently by MetA-SIMS. In total, TOF- and MetA-SIMS detected 632 and 959 ions, respectively. Among them, 426 were commonly detected by both methods, while 206 and 533 were detected uniquely by TOF- and MetA-SIMS, respectively. Of the 426 commonly detected ions, 250 increased in their intensities by MetA-SIMS, whereas 176 decreased. The integrated analysis of the ions detected by the two methods resulted in an increased number of discriminatory ions leading to an enhanced separation between cancer and normal tissues. Therefore, the results show that MD-SIMS can be a useful approach to provide a comprehensive list of discriminatory ions indicative of disease states.

Multi-dimensional TOF-SIMS analysis for effective profiling of disease-related ions from the tissue surface

PubMed Central

Park, Ji-Won; Jeong, Hyobin; Kang, Byeongsoo; Kim, Su Jin; Park, Sang Yoon; Kang, Sokbom; Kim, Hark Kyun; Choi, Joon Sig; Hwang, Daehee; Lee, Tae Geol

2015-01-01

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) emerges as a promising tool to identify the ions (small molecules) indicative of disease states from the surface of patient tissues. In TOF-SIMS analysis, an enhanced ionization of surface molecules is critical to increase the number of detected ions. Several methods have been developed to enhance ionization capability. However, how these methods improve identification of disease-related ions has not been systematically explored. Here, we present a multi-dimensional SIMS (MD-SIMS) that combines conventional TOF-SIMS and metal-assisted SIMS (MetA-SIMS). Using this approach, we analyzed cancer and adjacent normal tissues first by TOF-SIMS and subsequently by MetA-SIMS. In total, TOF- and MetA-SIMS detected 632 and 959 ions, respectively. Among them, 426 were commonly detected by both methods, while 206 and 533 were detected uniquely by TOF- and MetA-SIMS, respectively. Of the 426 commonly detected ions, 250 increased in their intensities by MetA-SIMS, whereas 176 decreased. The integrated analysis of the ions detected by the two methods resulted in an increased number of discriminatory ions leading to an enhanced separation between cancer and normal tissues. Therefore, the results show that MD-SIMS can be a useful approach to provide a comprehensive list of discriminatory ions indicative of disease states. PMID:26046669

Chemical characterization and source apportionment of fine particulate matter in Yangzhou, China, using offline aerosol mass spectrometry

NASA Astrophysics Data System (ADS)

Li, L.; Ge, X.; Xu, J.; Ye, Z.

2016-12-01

In recent years, Aerodyne Aerosol Mass Spectrometer (AMS) has been widely used for online and real-time monitoring of fine aerosol particles all over the world. However, due to the high cost and complex maintenance, the AMS was typically deployed for short-term intense field measurements, limiting its ability in elucidating the long-term behaviors and dominant sources of regional fine particles (PM2.5). In this study, we collected daily PM2.5 filter samples across a relatively long period (November 2015 to April 2016, in total >100 samples) using a high-volume sampler, in urban Yangzhou - a city in the Yangtze River Delta region, China. These samples were analyzed by using a suite of analytical techniques, for the water-soluble inorganic ions (WSIs), organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC) and total nitrogen (TN), trace metal elements, etc. More importantly, an Aerodyne soot particle aerosol mass spectrometer (SP-AMS) was for the first time introduced for the offline characterization of the PM2.5 samples collected in this region. In particular, Positive matrix factorization was conducted on the SP-AMS determined water-soluble fraction of organic aerosols (WSOA), and three distinct sources were separated, including a primary OA (POA), a less oxygenated OA (LOOA), and a more oxygenated OA (MOOA). Chemical characteristics and evolution processes of these OA subcomponents were further discussed. Our results are useful for the air pollution management in the YRD region, and the technique developed can be applied elsewhere as well.

No scanning depth imaging system based on TOF

NASA Astrophysics Data System (ADS)

Sun, Rongchun; Piao, Yan; Wang, Yu; Liu, Shuo

2016-03-01

To quickly obtain a 3D model of real world objects, multi-point ranging is very important. However, the traditional measuring method usually adopts the principle of point by point or line by line measurement, which is too slow and of poor efficiency. In the paper, a no scanning depth imaging system based on TOF (time of flight) was proposed. The system is composed of light source circuit, special infrared image sensor module, processor and controller of image data, data cache circuit, communication circuit, and so on. According to the working principle of the TOF measurement, image sequence was collected by the high-speed CMOS sensor, and the distance information was obtained by identifying phase difference, and the amplitude image was also calculated. Experiments were conducted and the experimental results show that the depth imaging system can achieve no scanning depth imaging function with good performance.

A multi-center ring trial for the identification of anaerobic bacteria using MALDI-TOF MS.

PubMed

Veloo, A C M; Jean-Pierre, H; Justesen, U S; Morris, T; Urban, E; Wybo, I; Shah, H N; Friedrich, A W; Morris, T; Shah, H N; Jean-Pierre, H; Justesen, U S; Nagy, E; Urban, E; Kostrzewa, M; Veloo, A; Friedrich, A W

2017-12-01

Inter-laboratory reproducibility of Matrix Assisted Laser Desorption Time-of-Flight Mass Spectrometry (MALDI-TOF MS) of anaerobic bacteria has not been shown before. Therefore, ten anonymized anaerobic strains were sent to seven participating laboratories, an initiative of the European Network for the Rapid Identification of Anaerobes (ENRIA). On arrival the strains were cultured and identified using MALDI-TOF MS. The spectra derived were compared with two different Biotyper MALDI-TOF MS databases, the db5627 and the db6903. The results obtained using the db5627 shows a reasonable variation between the different laboratories. However, when a more optimized database is used, the variation is less pronounced. In this study we show that an optimized database not only results in a higher number of strains which can be identified using MALDI-TOF MS, but also corrects for differences in performance between laboratories. Copyright © 2017 Elsevier Ltd. All rights reserved.

Elemental abundances of the B and A stars. 2: Gamma Geminorum, HD 60825, 7 Sextantis, HR 4817, and HR 5780

NASA Technical Reports Server (NTRS)

Adelman, Saul J.; Philip, A. G. Davis

1994-01-01

We extend fine analyses of the B and A stars, gamma Geminorum, 7 Sextantis, HR 4817, and HR 5780 using additional spectroscopic data from the Kitt Peak National Observatory (KPNO) coude feed telescope with a TI CCD, camera 5, and grating A, and ATLAS9 model atmospheres. In addition we study HD 60825, which had colors similar to the FHB A stars, but was found to be a Population I star. HD 60825, as is gamma Gem, is a sharp-lined early-A star with nearly solar derived abundances. HR 5780 and 7 Sex are also examples of stars which for the most part have solar abundances. The newly derived abundances for HR 4817 reveal important differences with respect to 53 Tau, a somewhat similar HgMn star.

Characterization of urban aerosol in Cork city (Ireland) using aerosol mass spectrometry

NASA Astrophysics Data System (ADS)

Dall'Osto, M.; Ovadnevaite, J.; Ceburnis, D.; Martin, D.; Healy, R. M.; O'Connor, I. P.; Kourtchev, I.; Sodeau, J. R.; Wenger, J. C.; O'Dowd, C.

2013-05-01

Ambient wintertime background urban aerosol in Cork city, Ireland, was characterized using aerosol mass spectrometry. During the three-week measurement study in 2009, 93% of the ca. 1 350 000 single particles characterized by an Aerosol Time-of-Flight Mass Spectrometer (TSI ATOFMS) were classified into five organic-rich particle types, internally mixed to different proportions with elemental carbon (EC), sulphate and nitrate, while the remaining 7% was predominantly inorganic in nature. Non-refractory PM1 aerosol was characterized using a High Resolution Time-of-Flight Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS) and was also found to comprise organic aerosol as the most abundant species (62%), followed by nitrate (15%), sulphate (9%) and ammonium (9%), and chloride (5%). Positive matrix factorization (PMF) was applied to the HR-ToF-AMS organic matrix, and a five-factor solution was found to describe the variance in the data well. Specifically, "hydrocarbon-like" organic aerosol (HOA) comprised 20% of the mass, "low-volatility" oxygenated organic aerosol (LV-OOA) comprised 18%, "biomass burning" organic aerosol (BBOA) comprised 23%, non-wood solid-fuel combustion "peat and coal" organic aerosol (PCOA) comprised 21%, and finally a species type characterized by primary {m/z} peaks at 41 and 55, similar to previously reported "cooking" organic aerosol (COA), but possessing different diurnal variations to what would be expected for cooking activities, contributed 18%. Correlations between the different particle types obtained by the two aerosol mass spectrometers are also discussed. Despite wood, coal and peat being minor fuel types used for domestic space heating in urban areas, their relatively low combustion efficiencies result in a significant contribution to PM1 aerosol mass (44% and 28% of the total organic aerosol mass and non-refractory total PM1, respectively).

Chemical composition of aerosol measurements in the air pollution plume during KORUS-AQ

NASA Astrophysics Data System (ADS)

Park, T.; Lee, J. B.; Lim, Y. J.; Ahn, J.; Park, J. S.; Soo, C. J.; Kim, J.; Park, S.; Lee, Y.; Desyaterik, Y.; Collett, J. L., Jr.; Lee, T.

2017-12-01

The Korean peninsula is a great place to study different sources of the aerosols: urban, rural and marine. In addition, Seoul is one of the large metropolitan areas in the world and has a variety of sources because half of the Korean population lives in Seoul, which comprises only 12% of the country's area. To understand the chemical composition of aerosol form long-range transport and local sources better, an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed on an airborne platform (NASA DC-8 aircraft). The HR-ToF-AMS is capable of measuring non-refractory size resolved chemical composition of submicron particle(NR-PM1) in the air pollution plume, including mass concentration of organic carbon, nitrate, sulfate, and ammonium with 10 seconds time resolution. The measurements were performed twenty times research flight for understanding characteristic of the air pollution from May to June, 2016 on the South Korean peninsula during KORUS-AQ 2016 campaign. The scientific goal of this study is to characterize aerosol chemical properties and mass concentration in order to understand the role of the long-range transport from northeast Asia to South Korea, and influence of the local sources. To brief, organics dominated during all of flights. Also, organics and nitrate were dominant around energy industrial complex near by Taean, South Korea. The presentation will provide an overview of the composition of NR-PM1 measured in air pollution plumes, and deliver detail information about width, depth and spatial distribution of the pollutant in the air pollution plumes. The results of this study will provide high temporal and spatial resolved details on the air pollution plumes, which are valuable input parameters of aerosol properties for the current air quality models.

Rapid identification and source-tracking of Listeria monocytogenes using MALDI-TOF mass spectrometry.

PubMed

Jadhav, Snehal; Gulati, Vandana; Fox, Edward M; Karpe, Avinash; Beale, David J; Sevior, Danielle; Bhave, Mrinal; Palombo, Enzo A

2015-06-02

Listeria monocytogenes is an important foodborne pathogen responsible for the sometimes fatal disease listeriosis. Public health concerns and stringent regulations associated with the presence of this pathogen in food and food processing environments underline the need for rapid and reliable detection and subtyping techniques. In the current study, the application of matrix assisted laser desorption/ionisation-time-of-flight mass spectrometry (MALDI-TOF MS) as a single identification and source-tracking tool for a collection of L. monocytogenes isolates, obtained predominantly from dairy sources within Australia, was explored. The isolates were cultured on different growth media and analysed using MALDI-TOF MS at two incubation times (24 and 48 h). Whilst reliable genus-level identification was achieved from most media, identification at the species level was found to be dependent on culture conditions. Successful speciation was highest for isolates cultured on the chromogenic Agar Listeria Ottaviani Agosti agar (ALOA, 91% of isolates) and non-selective horse blood agar (HBA, 89%) for 24h. Chemometric statistical analysis of the MALDI-TOF MS data enabled source-tracking of L. monocytogenes isolates obtained from four different dairy sources. Strain-level discrimination was also observed to be influenced by culture conditions. In addition, t-test/analysis of variance (ANOVA) was used to identify potential biomarker peaks that differentiated the isolates according to their source of isolation. Source-tracking using MALDI-TOF MS was compared and correlated with the gold standard pulsed-field gel electrophoresis (PFGE) technique. The discriminatory index and the congruence between both techniques were compared using the Simpsons Diversity Index and adjusted Rand and Wallace coefficients. Overall, MALDI-TOF MS based source-tracking (using data obtained by culturing the isolates on HBA) and PFGE demonstrated good congruence with a Wallace coefficient of 0.71 and

Identification of Algerian Field-Caught Phlebotomine Sand Fly Vectors by MALDI-TOF MS

PubMed Central

Lafri, Ismail; Almeras, Lionel; Bitam, Idir; Caputo, Aurelia; Yssouf, Amina; Forestier, Claire-Lise; Izri, Arezki; Raoult, Didier; Parola, Philippe

2016-01-01

Background Phlebotomine sand flies are known to transmit Leishmania parasites, bacteria and viruses that affect humans and animals in many countries worldwide. Precise sand fly identification is essential to prevent phlebotomine-borne diseases. Over the past two decades, progress in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as an accurate tool for arthropod identification. The objective of the present study was to investigate the usefulness of MALDI-TOF MS as a tool for identifying field-caught phlebotomine. Methodology/Principal Findings Sand flies were captured in four sites in north Algeria. A subset was morphologically and genetically identified. Six species were found in these areas and a total of 28 stored frozen specimens were used for the creation of the reference spectrum database. The relevance of this original method for sand fly identification was validated by two successive blind tests including the morphological identification of 80 new specimens which were stored at -80°C, and 292 unknown specimens, including engorged specimens, which were preserved under different conditions. Intra-species reproducibility and inter-species specificity of the protein profiles were obtained, allowing us to distinguish specimens at the gender level. Querying of the sand fly database using the MS spectra from the blind test groups revealed concordant results between morphological and MALDI-TOF MS identification. However, MS identification results were less efficient for specimens which were engorged or stored in alcohol. Identification of 362 phlebotomine sand flies, captured at four Algerian sites, by MALDI-TOF MS, revealed that the subgenus Larroussius was predominant at all the study sites, except for in M’sila where P. (Phlebotomus) papatasi was the only sand fly species detected. Conclusion The present study highlights the application of MALDI-TOF MS for monitoring sand fly fauna captured in the field

[Application of MALDI-TOF-MS in gene testing for non-syndromic hearing loss].

PubMed

Zeng, Yun; Jiang, Dan; Feng, Da-fei; Jin, Dong-dong; Wu, Xiao-hui; Ding, Yan-li; Zou, Jing

2013-12-01

To investigate the feasibility of Matrix-Assisted Laser Desorption-Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS) , according to the genetic test of non-syndromic hearing loss (NSHL), and check using the direct sequencing. Peripheral blood was collected from 454 NSHL patients. DNA samples were extracted and 20 loci of the four common disease-causing genes were analysed by MALDI-TOF-MS, including GJB2 (35delG, 167delT, 176_191del16, 235delC, 299_300delAT ), GJB3 (538C→T, 547G→A), SLC26A4 (281C→T, 589G→A, IVS7-2A→G, 1174A→T, 1226G→A, 1229C→T, IVS15+5G→A, 1975G→C, 2027T→A, 2162C→T, 2168A→G), and mitochondrial 12S rRNA (1494C→T, 1555A→G). Direct sequencing was also used to analyse the aforementioned 20 loci in order to validate the accuracy of MALDI-TOF-MS. Among the 454 patients, 166 cases (36.56%) of disease-causing mutations were detected, which included 69 cases (21.15%) of GJB2 gene mutation, four cases (0.88%) of GJB3 gene mutation, 64 cases (14.10%) of SLC26A4 gene mutation, and three cases (0.66%) of mitochondrial 12S rRNA gene mutation. Moreover, the results obtained from direct sequencing and MALDI-TOF-MS were consistent, and the results showed that the two methods were consistent. The MALDI-TOF-MS detection method was designed based on the hearing loss-related mutation hotspots seen in the Chinese population, and it has a high detection rate for NSHL related mutations. In comparison to the conventional detection methods, MALDI-TOF-MS has the following advantages: more detection sites, greater coverage, accurate, high throughput and low cost. Therefore, this method is capable of satisfying the needs of clinical detection for hearing impairment and it is suitable for large-scale implementation.

Identification of Algerian Field-Caught Phlebotomine Sand Fly Vectors by MALDI-TOF MS.

PubMed

Lafri, Ismail; Almeras, Lionel; Bitam, Idir; Caputo, Aurelia; Yssouf, Amina; Forestier, Claire-Lise; Izri, Arezki; Raoult, Didier; Parola, Philippe

2016-01-01

Phlebotomine sand flies are known to transmit Leishmania parasites, bacteria and viruses that affect humans and animals in many countries worldwide. Precise sand fly identification is essential to prevent phlebotomine-borne diseases. Over the past two decades, progress in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as an accurate tool for arthropod identification. The objective of the present study was to investigate the usefulness of MALDI-TOF MS as a tool for identifying field-caught phlebotomine. Sand flies were captured in four sites in north Algeria. A subset was morphologically and genetically identified. Six species were found in these areas and a total of 28 stored frozen specimens were used for the creation of the reference spectrum database. The relevance of this original method for sand fly identification was validated by two successive blind tests including the morphological identification of 80 new specimens which were stored at -80°C, and 292 unknown specimens, including engorged specimens, which were preserved under different conditions. Intra-species reproducibility and inter-species specificity of the protein profiles were obtained, allowing us to distinguish specimens at the gender level. Querying of the sand fly database using the MS spectra from the blind test groups revealed concordant results between morphological and MALDI-TOF MS identification. However, MS identification results were less efficient for specimens which were engorged or stored in alcohol. Identification of 362 phlebotomine sand flies, captured at four Algerian sites, by MALDI-TOF MS, revealed that the subgenus Larroussius was predominant at all the study sites, except for in M'sila where P. (Phlebotomus) papatasi was the only sand fly species detected. The present study highlights the application of MALDI-TOF MS for monitoring sand fly fauna captured in the field. The low cost, reliability and rapidity of MALDI-TOF

Inhalation Toxicology. 4. Times to Incapacitation and Death for Rats Exposed Continuously to Atmospheric Hydrogen Chloride Gas

DTIC Science & Technology

1985-05-01

Governrent Accession No. 3. Recipient’s Cutalog No. "FAA-AM-85-P i 4. Title and Subtitle 5. Report Date Inhalation Toxicology : IV. Times To...reported for humans is discuss dA.erin7o r I F. I 17. Key Words Di Ostribution Statement ."Combustion toxicology ; Smoke, Irritant ’Diocument is available to...F 1700.7 (8-72) Reproduction of completed page authorized INHALATION TOXICOLOGY : IV. TIMES TO INCAPACITATION AND DEATH FOR RATS EXPOSED CONTINUOUSLY

Building HR capability in health care organizations.

PubMed

Khatri, Naresh

2006-01-01

The current human resource (HR) management practices in health care are consistent with the industrial model of management. However, health care organizations are not factories. They are highly knowledge-intensive and service-oriented entities and thus require a different set of HR practices and systems to support them. Drawing from the resource-based theory, I argue that HRs are a potent weapon of competitive advantage for health care organizations and propose a five-dimensional conception of HR capability for harnessing HRs in health care organizations. The significant complementarities that exist between HRs and information technologies for delivering safer and better quality of patient care are also discussed.

Characterizing Neutron Diagnostics on the nTOF Line at SUNY Geneseo

NASA Astrophysics Data System (ADS)

Harrison, Hannah; Seppala, Hannah; Visca, Hannah; Wakwella, Praveen; Fletcher, Kurt; Padalino, Stephen; Forrest, Chad; Regan, Sean; Sangster, Craig

2016-10-01

Charged particle beams from SUNY Geneseo's 1.7 MV Tandem Pelletron Accelerator induce nuclear reactions that emit neutrons ranging from 0.5 to 17.9 MeV via 2H(d,n)3He and 11B(d,n)12C. This adjustable neutron source can be used to calibrate ICF and HEDP neutron scintillators for ICF diagnostics. However, gamma rays and muons, which are often present during an accelerator-based calibration, are difficult to differentiate from neutron signals in scintillators. To mitigate this problem, a new neutron time-of-flight (nTOF) line has been constructed. The nTOF timing is measured using the associated particle technique. A charged particle produced by the nuclear reaction serves as a start signal, while its associated neutron is the stop signal. Each reaction is analyzed event-by-event to determine whether the scintillator signal was generated by a neutron, gamma or muon. Using this nTOF technique, the neutron response for different scintillation detectors can be determined. Funded in part by a LLE contract through the DOE.

Assessment of heat treatment of dairy products by MALDI-TOF-MS.

PubMed

Meltretter, Jasmin; Birlouez-Aragon, Inès; Becker, Cord-Michael; Pischetsrieder, Monika

2009-12-01

The formation of the Amadori product from lactose (protein lactosylation) is a major parameter to evaluate the quality of processed milk. Here, MALDI-TOF-MS was used for the relative quantification of lactose-adducts in heated milk. Milk was heated at a temperature of 70, 80, and 100 degrees C between 0 and 300 min, diluted, and subjected directly to MALDI-TOF-MS. The lactosylation rate of alpha-lactalbumin increased with increasing reaction temperature and time. The results correlated well with established markers for heat treatment of milk (concentration of total soluble protein, soluble alpha-lactalbumin and beta-lactoglobulin at pH 4.6, and fluorescence of advanced Maillard products and soluble tryptophan index; r=0.969-0.997). The method was also applied to examine commercially available dairy products. In severely heated products, protein pre-purification by immobilized metal affinity chromatography improved spectra quality. Relative quantification of protein lactosylation by MALDI-TOF-MS proved to be a very fast and reliable method to monitor early Maillard reaction during milk processing.

Rapid typing of Mannheimia haemolytica major genotypes 1 and 2 using MALDI-TOF mass spectrometry

USDA-ARS?s Scientific Manuscript database

Genotype 2 M. haemolytica predominantly associate over genotype 1 with the lungs of cattle with respiratory disease and ICEs containing antimicrobial resistance genes. Distinct protein masses were detected by MALDI-TOF MS between genotype 1 and 2 strains. MALDI-TOF MS could rapidly differentiate ge...

New Insights for Diagnosis of Pineapple Fusariosis by MALDI-TOF MS Technique.

PubMed

Santos, Cledir; Ventura, José Aires; Lima, Nelson

2016-08-01

Fusarium is one of the most economically important fungal genus, since it includes many pathogenic species which cause a wide range of plant diseases. Morphological or molecular biology identification of Fusarium species is a limiting step in the fast diagnosis and treatment of plant disease caused by these fungi. Mass spectrometry by matrix-assisted laser/desorption ionisation-time-of-flight (MALDI-TOF)-based fingerprinting approach was applied to the fungal growth monitoring and direct detection of strain Fusarium guttiforme E-480 inoculated in both pineapple cultivars Pérola and Imperial side shoots, that are susceptible and resistant, respectively, to this fungal strain. MALDI-TOF MS technique was capable to detect fungal molecular mass peaks in the susceptible pineapple stem side shoot tissue. It is assumed that these molecular masses are mainly constituted by ribosomal proteins. MALDI-TOF-based fingerprinting approach has herein been demonstrated to be sensitive and accurate for the direct detection of F. guttiforme E-480 molecular masses on both susceptible and resistant pineapple side stem free of any pre-treatment. According to the results obtained, the changing on molecular mass peaks of infected susceptible pineapple tissue together with the possibility of fungal molecular masses analysis into this pineapple tissue can be a good indication for an early diagnosis by MALDI-TOF MS of pineapple fusariosis.

HO2 measurements at atmospheric concentrations using a chemical ionization mass spectrometry

NASA Astrophysics Data System (ADS)

Albrecht, S.; Novelli, A.; Hofzumahaus, A.; Kang, S.; Baker, Y.; Mentel, T. F.; Fuchs, H.

2017-12-01

Correct and precise measurements of atmospheric radical species are necessary for a better understanding of the oxidative capacity of the atmosphere. Due to the reactivity of radicals, and their consequent low concentrations, direct measurements of these species are particularly challenging and have been proven in the past to be affected by interfering species. Here we present a chemical ionization source coupled to an APi-HR-TOF-MS (Aerodyne Research Inc.), which has a limit of detection for HO2 radicals well below its atmospheric concentrations ( 1 x 108 molecules cm-3). The instrument was calibrated with a well-established and characterized HO2 calibration source in use for the laser induced fluorescence instrument in the Forschungszentrum Jülich. Within the source, a well characterized amount of HO2 radicals is produced after photolysis of water by a mercury lamp. In addition, several experiments were performed in the atmosphere simulation chamber SAPHIR at the Forschungszentrum Jülich to test for potential interferences. Measurements of HO2 radicals were concurrently detected by a laser induced fluorescence instrument allowing for the comparison of measurements within the two different and independent techniques for various atmospheric conditions regarding concentrations of O3, NOx and VOCs. Results from the intercomparison together with the calibration procedure of the instrument and laboratory characterization will be presented.

High-throughput identification of the microbial biodiversity of cocoa bean fermentation by MALDI-TOF MS.

PubMed

Miescher Schwenninger, S; Freimüller Leischtfeld, S; Gantenbein-Demarchi, C

2016-11-01

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a powerful biotyping tool increasingly used for high-throughput identification of clinical microbial isolates, however, in food fermentation research this approach is still not well established. This study examines the microbial biodiversity of cocoa bean fermentation based on the isolation of micro-organisms in cocoa-producing regions, followed by MALDI-TOF MS in Switzerland. A preceding 6-week storage test to mimic lengthy transport of microbial samples from cocoa-producing regions to Switzerland was performed with strains of Lactobacillus plantarum, Acetobacter pasteurianus and Saccharomyces cerevisiae. Weekly MALDI-TOF MS analysis was able to successfully identify microbiota to the species level after storing live cultures on slant agar at mild temperatures (7°C) and/or in 75% aqueous ethanol at differing temperatures (-20, 7 and 30°C). The efficacy of this method was confirmed by on-site recording of the microbial biodiversity in cocoa bean fermentation in Bolivia and Brazil, with a total of 1126 randomly selected isolates. MALDI-TOF MS analyses revealed known dominant cocoa bean fermentation species with Lact. plantarum and Lactobacillus fermentum in the lactic acid bacteria taxon, Hanseniaspora opuntiae and S. cerevisiae in the yeast taxon, and Acet. pasteurianus, Acetobacter fabarum, Acetobacter ghanensis and Acetobacter senegalensis in the acetic acid bacteria taxon. Microbial identification with MALDI-TOF MS has increased the number of samples that can be analysed in a given time, a prerequisite for high-throughput methods. This method is already widely used for the identification of clinical microbial isolates, whereas in food fermentation research, including cocoa bean fermentation, microbiota is mostly identified by time-consuming, biochemical-based phenotyping and molecular approaches. This study presents the use of MALDI-TOF MS for characterizing the

MALDI-TOF MS identification of Anopheles gambiae Giles blood meal crushed on Whatman filter papers.

PubMed

Niare, Sirama; Almeras, Lionel; Tandina, Fatalmoudou; Yssouf, Amina; Bacar, Affane; Toilibou, Ali; Doumbo, Ogobara; Raoult, Didier; Parola, Philippe

2017-01-01

Identification of the source of mosquito blood meals is an important component for disease control and surveillance. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) profiling has emerged as an effective tool for mosquito blood meal identification, using the abdomens of freshly engorged mosquitoes. In the field, mosquito abdomens are crushed on Whatman filter papers to determine the host feeding patterns by identifying the origin of their blood meals. The aim of this study was to test whether crushing engorged mosquito abdomens on Whatman filter papers was compatible with MALDI-TOF MS for mosquito blood meal identification. Both laboratory reared and field collected mosquitoes were tested. Sixty Anopheles gambiae Giles were experimentally engorged on the blood of six distinct vertebrate hosts (human, sheep, rabbit, dog, chicken and rat). The engorged mosquito abdomens were crushed on Whatman filter papers for MALDI-TOF MS analysis. 150 Whatman filter papers, with mosquitoes engorged on cow and goat blood, were preserved. A total of 77 engorged mosquito abdomens collected in the Comoros Islands and crushed on Whatman filter papers were tested with MALDI-TOF MS. The MS profiles generated from mosquito engorged abdomens crushed on Whatman filter papers exhibited high reproducibility according to the original host blood. The blood meal host was correctly identified from mosquito abdomens crushed on Whatman filter papers by MALDI-TOF MS. The MS spectra obtained after storage were stable regardless of the room temperature and whether or not they were frozen. The MS profiles were reproducible for up to three months. For the Comoros samples, 70/77 quality MS spectra were obtained and matched with human blood spectra. This was confirmed by molecular tools. The results demonstrated that MALDI-TOF MS could identify mosquito blood meals from Whatman filter papers collected in the field during entomological surveys. The

Rapid identification of acetic acid bacteria using MALDI-TOF mass spectrometry fingerprinting.

PubMed

Andrés-Barrao, Cristina; Benagli, Cinzia; Chappuis, Malou; Ortega Pérez, Ruben; Tonolla, Mauro; Barja, François

2013-03-01

Acetic acid bacteria (AAB) are widespread microorganisms characterized by their ability to transform alcohols and sugar-alcohols into their corresponding organic acids. The suitability of matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF MS) for the identification of cultured AAB involved in the industrial production of vinegar was evaluated on 64 reference strains from the genera Acetobacter, Gluconacetobacter and Gluconobacter. Analysis of MS spectra obtained from single colonies of these strains confirmed their basic classification based on comparative 16S rRNA gene sequence analysis. MALDI-TOF analyses of isolates from vinegar cross-checked by comparative sequence analysis of 16S rRNA gene fragments allowed AAB to be identified, and it was possible to differentiate them from mixed cultures and non-AAB. The results showed that MALDI-TOF MS analysis was a rapid and reliable method for the clustering and identification of AAB species. Copyright © 2012 Elsevier GmbH. All rights reserved.

Development of an AMS method to study oceanic circulation characteristics using cosmogenic 39Ar

USGS Publications Warehouse

Collon, P.H.; Bichler, M.; Caggiano, J.; Cecil, L.D.; El, Masri Y.; Golser, R.; Jiang, C.L.; Heinz, A.; Henderson, D.; Kutschera, W.; Lehmann, B.E.; Leleux, P.; Loosli, H.H.; Pardo, R.C.; Paul, M.; Rehm, K.E.; Schlosser, P.; Scott, R.H.; Smethie, W.M.; Vondrasek, R.

2004-01-01

Initial experiments at the ATLAS facility [Nucl. Instr. and Meth. B 92 (1994) 241] resulted in a clear detection of cosmogenic 39Ar signal at the natural level. The present paper summarizes the recent developments of 39Ar AMS measurements at ATLAS: the use of an electron cyclotron resonance (ECR) positive ion source equipped with a special quartz liner to reduce 39K background, the development of a gas handling system for small volume argon samples, the acceleration of 39Ar8+ ions to 232 MeV, and the final separation of 39Ar from 39K in a gas-filled spectrograph. The first successful AMS measurements of 39Ar in ocean water samples from the Southern Atlantic ventilation experiment (SAVE) are reported. Published by Elsevier B.V.

Heat capacities and thermal conductivities of AmO 2 and AmO 1.5

NASA Astrophysics Data System (ADS)

Nishi, Tsuyoshi; Itoh, Akinori; Ichise, Kenichi; Arai, Yasuo

2011-07-01

The thermal diffusivity of AmO 2 was measured from 473 to 773 K and that of AmO 1.5 between 473 and 1373 K using a laser flash method. The enthalpy increment of AmO 2 was measured from 335 to 1081 K and that of AmO 1.5 between 335 and 1086 K using drop calorimetry. The heat capacities of AmO 2 and AmO 1.5 were derived from the enthalpy increment measurements. The thermal conductivity was determined from the measured thermal diffusivity, heat capacity and bulk density. The heat capacities of AmO 2 was found larger than that of AmO 1.5. The thermal conductivities of AmO 2 and AmO 1.5 were found to decrease with increasing temperature in the investigated temperature range. The thermal conductivity of AmO 1.5 with A -type hexagonal structure was smaller than that of AmO 2 with C-type fluorite structure but larger than that of sub-stoichiometric AmO 1.73.

Modelling the inner debris disc of HR 8799

NASA Astrophysics Data System (ADS)

Contro, B.; Horner, J.; Wittenmyer, R. A.; Marshall, J. P.; Hinse, T. C.

2016-11-01

In many ways, the HR 8799 planetary system strongly resembles our own. It features four giant planets and two debris belts, analogues to the Asteroid and Edgeworth-Kuiper belts. Here, we present the results of dynamical simulations of HR8799's inner debris belt, to study its structure and collisional environment. Our results suggest that HR 8799's inner belt is highly structured, with gaps between regions of dynamical stability. The belt is likely constrained between sharp inner and outer edges, located at ˜6 and ˜8 au, respectively. Its inner edge coincides with a broad gap cleared by the 4:1 mean-motion resonance with HR 8799e. Within the belt, planetesimals are undergoing a process of collisional attrition like that observed in the Asteroid belt. However, whilst the mean collision velocity in the Asteroid belt exceeds 5 km s-1, the majority of collisions within HR 8799's inner belt occur with velocities of order 1.2 km s-1, or less. Despite this, they remain sufficiently energetic to be destructive - giving a source for the warm dust detected in the system. Interior to the inner belt, test particles remain dynamically unstirred, aside from narrow bands excited by distant high-order resonances with HR 8799e. This lack of stirring is consistent with earlier thermal modelling of HR 8799's infrared excess, which predicted little dust inside 6 au. The inner system is sufficiently stable and unstirred that the formation of telluric planets is feasible, although such planets would doubtless be subject to a punitive impact regime, given the intense collisional grinding required in the inner belt to generate the observed infrared excess.

Molecular and MALDI-TOF identification of ticks and tick-associated bacteria in Mali

PubMed Central

Diarra, Adama Zan; Almeras, Lionel; Berenger, Jean-Michel; Koné, Abdoulaye K.; Bocoum, Zakaria; Dabo, Abdoulaye; Doumbo, Ogobara; Raoult, Didier; Parola, Philippe

2017-01-01

Ticks are considered the second vector of human and animal diseases after mosquitoes. Therefore, identification of ticks and associated pathogens is an important step in the management of these vectors. In recent years, Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been reported as a promising method for the identification of arthropods including ticks. The objective of this study was to improve the conditions for the preparation of tick samples for their identification by MALDI-TOF MS from field-collected ethanol-stored Malian samples and to evaluate the capacity of this technology to distinguish infected and uninfected ticks. A total of 1,333 ticks were collected from mammals in three distinct sites from Mali. Morphological identification allowed classification of ticks into 6 species including Amblyomma variegatum, Hyalomma truncatum, Hyalomma marginatum rufipes, Rhipicephalus (Boophilus) microplus, Rhipicephalus evertsi evertsi and Rhipicephalus sanguineus sl. Among those, 471 ticks were randomly selected for molecular and proteomic analyses. Tick legs submitted to MALDI-TOF MS revealed a concordant morpho/molecular identification of 99.6%. The inclusion in our MALDI-TOF MS arthropod database of MS reference spectra from ethanol-preserved tick leg specimens was required to obtain reliable identification. When tested by molecular tools, 76.6%, 37.6%, 20.8% and 1.1% of the specimens tested were positive for Rickettsia spp., Coxiella burnetii, Anaplasmataceae and Borrelia spp., respectively. These results support the fact that MALDI-TOF is a reliable tool for the identification of ticks conserved in alcohol and enhances knowledge about the diversity of tick species and pathogens transmitted by ticks circulating in Mali. PMID:28742123

Molecular and MALDI-TOF identification of ticks and tick-associated bacteria in Mali.

PubMed

Diarra, Adama Zan; Almeras, Lionel; Laroche, Maureen; Berenger, Jean-Michel; Koné, Abdoulaye K; Bocoum, Zakaria; Dabo, Abdoulaye; Doumbo, Ogobara; Raoult, Didier; Parola, Philippe

2017-07-01

Ticks are considered the second vector of human and animal diseases after mosquitoes. Therefore, identification of ticks and associated pathogens is an important step in the management of these vectors. In recent years, Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been reported as a promising method for the identification of arthropods including ticks. The objective of this study was to improve the conditions for the preparation of tick samples for their identification by MALDI-TOF MS from field-collected ethanol-stored Malian samples and to evaluate the capacity of this technology to distinguish infected and uninfected ticks. A total of 1,333 ticks were collected from mammals in three distinct sites from Mali. Morphological identification allowed classification of ticks into 6 species including Amblyomma variegatum, Hyalomma truncatum, Hyalomma marginatum rufipes, Rhipicephalus (Boophilus) microplus, Rhipicephalus evertsi evertsi and Rhipicephalus sanguineus sl. Among those, 471 ticks were randomly selected for molecular and proteomic analyses. Tick legs submitted to MALDI-TOF MS revealed a concordant morpho/molecular identification of 99.6%. The inclusion in our MALDI-TOF MS arthropod database of MS reference spectra from ethanol-preserved tick leg specimens was required to obtain reliable identification. When tested by molecular tools, 76.6%, 37.6%, 20.8% and 1.1% of the specimens tested were positive for Rickettsia spp., Coxiella burnetii, Anaplasmataceae and Borrelia spp., respectively. These results support the fact that MALDI-TOF is a reliable tool for the identification of ticks conserved in alcohol and enhances knowledge about the diversity of tick species and pathogens transmitted by ticks circulating in Mali.

Technologies in the Whole-Genome Age: MALDI-TOF-Based Genotyping.

PubMed

Vogel, Nicolas; Schiebel, Katrin; Humeny, Andreas

2009-01-01

With the decipherment of the human genome, new questions have moved into the focus of today's research. One key aspect represents the discovery of DNA variations capable to influence gene transcription, RNA splicing, or regulating processes, and their link to pathology. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) is a powerful tool for the qualitative investigation and relative quantification of variations like single nucleotide polymorphisms, DNA methylation, microsatellite instability, or loss of heterozygosity. After its introduction into proteomics, efforts were made to adopt this technique to DNA analysis. Initially intended for peptide/protein analysis, it held several difficulties for application to nucleic acids. Today, MALDI-TOF-MS has reached worldwide acceptance and application in nucleic acid research, with a wide spectrum of methods being available. One of the most versatile approaches relies on primer extension to genotype single alleles, microsatellite repeat lengths or the methylation status of a given cytosine. Optimized methods comprising intelligent primer design and proper nucleotide selection for primer extension enabled multiplexing of reactions, rendering the analysis more economic due to parallel genotyping of several alleles in a single experiment. Laboratories equipped with MALDI-TOF-MS possess a universal technical platform for the analysis of a large variety of different molecules.

Plasma-laser ion discrimination by TOF technique applied to coupled SiC detectors.

NASA Astrophysics Data System (ADS)

Cavallaro, Salvatore

2018-01-01

The rate estimation of nuclear reactions induced in high intensity laser-target interaction (≥1016 W/cm2), is strongly depending on the neutron detection efficiency and ion charge discrimination, according to particles involved in exit open-channels. Ion discrimination is basically performed by means of analysis of pits observed on track detector, which is critically dependent on calibration and/or fast TOF devices based on SiC and diamond detectors. Last setup is used to determine the ion energy and to obtain a rough estimation of yields. However, for each TOF interval, the dependence of yield from the energy deposited in the detector sensitive region, introduces a distortion in the ion spectra. Moreover, if two ion species are present in the same spectrum, the discrimination of their contribution is not attainable. In this paper a new method is described which allows to discriminate the contribution of two ion species in the wide energy range of nuclear reactions induced in laser-target interactions. The method is based on charge response of two TOF-SiC detectors, of suitable thicknesses, placed in adjacent positions. In presence of two ion species, the response of the detectors, associated with different energy losses, can determine the ion specific contribution to each TOF interval.

Pushing the Limits of MALDI-TOF Mass Spectrometry: Beyond Fungal Species Identification

PubMed Central

Rizzato, Cosmeri; Lombardi, Lisa; Zoppo, Marina; Lupetti, Antonella; Tavanti, Arianna

2015-01-01

Matrix assisted laser desorption ionization time of flight (MALDI-TOF) is a powerful analytical tool that has revolutionized microbial identification. Routinely used for bacterial identification, MALDI-TOF has recently been applied to both yeast and filamentous fungi, confirming its pivotal role in the rapid and reliable diagnosis of infections. Subspecies-level identification holds an important role in epidemiological investigations aimed at tracing virulent or drug resistant clones. This review focuses on present and future applications of this versatile tool in the clinical mycology laboratory. PMID:29376916

Characterizing Atmospheric Processing of Aerosols from Forest Fires at the Mt. Bachelor Observatory during BBOP

NASA Astrophysics Data System (ADS)

Zhou, S.; Collier, S.; Hee, J.; Wigder, N. L.; Jaffe, D. A.; Zhang, Q.

2014-12-01

This study investigates the physical and chemical characteristics and atmospheric processing of aerosols from uncontrolled forest fires across the Pacific Northwest. The measurements were made at the Mt. Bachelor Observatory (MBO) located at the summit of Mt. Bachelor in central Oregon (43.9794° N, 121.6885° W, 2,763 m asl) in summer 2013 during the DOE sponsored Biomass Burning Observation Project (BBOP) field campaign. We utilized an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) coupled with a thermodenuder. Observations during periods affected by biomass burning (BB) pollution showed elevated non-refractory submicron aerosol (NR-PM1) concentration up to 140 μg/m3. NR-PM1 correlated well with PM light scattering (up to ~ 600 Mm-1 at 550 nm) and gas phase CO (up to ~0.4 ppmv). The AMS BB tracer, f60, i.e., fraction of organic signals at m/z = 60, was also enhanced with a maximum of ~ 2%. Organic aerosol (OA) dominated the PM composition in BB plumes (94.1% of the NR-PM1 mass) with an average concentration of 13.9 μg/m3. Three distinctive BBOA factors were identified by Positive Matrix Factorization (PMF): a fresh BBOA-I factor (O/C=0.27, H/C=1.52, f60 = 2.26%) that correlates well with ammonium nitrate; an intermediately oxidized BBOA-II (O/C=0.52, H/C=1.47, f60 = 1.05%), and a highly oxidized BBOA-III (O/C=0.95, H/C=1.02) with a low f60 (< 0.01%) and enhanced tracer ions for carboxylic acids (e.g., CHO2+). During persistent BB plume events from fixed fire sources, fresh BBOA-I initially dominated the OA composition, but decreased as the more oxidized BBOA-II increased while BBOA-III remained unchanged. These events shed light on the chemical transformation of BB aerosol during atmospheric aging. We will examine the enhancement of different BBOA factors relative to CO to investigate secondary organic aerosol (SOA) formation processes in BB plumes.

Apportionment of urban aerosol sources in Cork (Ireland) by synergistic measurement techniques.

PubMed

Dall'Osto, Manuel; Hellebust, Stig; Healy, Robert M; O'Connor, Ian P; Kourtchev, Ivan; Sodeau, John R; Ovadnevaite, Jurgita; Ceburnis, Darius; O'Dowd, Colin D; Wenger, John C

2014-09-15

The sources of ambient fine particulate matter (PM2.5) during wintertime at a background urban location in Cork city (Ireland) have been determined. Aerosol chemical analyses were performed by multiple techniques including on-line high resolution aerosol time-of-flight mass spectrometry (Aerodyne HR-ToF-AMS), on-line single particle aerosol time-of-flight mass spectrometry (TSI ATOFMS), on-line elemental carbon-organic carbon analysis (Sunset_EC-OC), and off-line gas chromatography/mass spectrometry and ion chromatography analysis of filter samples collected at 6-h resolution. Positive matrix factorization (PMF) has been carried out to better elucidate aerosol sources not clearly identified when analyzing results from individual aerosol techniques on their own. Two datasets have been considered: on-line measurements averaged over 2-h periods, and both on-line and off-line measurements averaged over 6-h periods. Five aerosol sources were identified by PMF in both datasets, with excellent agreement between the two solutions: (1) regional domestic solid fuel burning--"DSF_Regional," 24-27%; (2) local urban domestic solid fuel burning--"DSF_Urban," 22-23%; (3) road vehicle emissions--"Traffic," 15-20%; (4) secondary aerosols from regional anthropogenic sources--"SA_Regional" 9-13%; and (5) secondary aged/processed aerosols related to urban anthropogenic sources--"SA_Urban," 21-26%. The results indicate that, despite regulations for restricting the use of smoky fuels, solid fuel burning is the major source (46-50%) of PM2.5 in wintertime in Cork, and also likely other areas of Ireland. Whilst wood combustion is strongly associated with OC and EC, it was found that peat and coal combustion is linked mainly with OC and the aerosol from these latter sources appears to be more volatile than that produced by wood combustion. Ship emissions from the nearby port were found to be mixed with the SA_Regional factor. The PMF analysis allowed us to link the AMS cooking organic

Tests of positive ion beams from a microwave ion source for AMS

NASA Astrophysics Data System (ADS)

Schneider, R. J.; von Reden, K. F.; Hayes, J. M.; Wills, J. S. C.; Kern, W. G. E.; Kim, S.-W.

2000-10-01

A test facility has been constructed to evaluate high-current positive ion beams from small gaseous samples for AMS applications. The major components include a compact permanent magnet microwave ion source built at the AECL Chalk River Laboratory and now on loan from the University of Toronto, and a double-focusing spectrometer magnet on loan from Argonne National Laboratory. Samples are introduced by means of a silica capillary injection system. Loop injection into a carrier gas provides a stable feed for the microwave driven plasma. The magnetic analysis system is utilized to isolate carbon ions derived from CO 2 samples from other products of the plasma discharge, including argon ions of the carrier gas. With a smaller discharge chamber, we hope to exceed a conversion efficiency of 14% for carbon ions produced per atom, which we reported at AMS-7. The next step will be to construct an efficient charge-exchange cell, to produce negative ions for injection into the WHOI recombinator injector.

HR Presentation - New Contract Policy

ScienceCinema

None

2018-06-21

Presentation on CERN's contract policy as of 2009. Topics covered include: staff member survey, work environment, career development, financial and social benefits, HR department activities and policy analysis.

Real-time motion artifacts compensation of ToF sensors data on GPU

NASA Astrophysics Data System (ADS)

Lefloch, Damien; Hoegg, Thomas; Kolb, Andreas

2013-05-01

Over the last decade, ToF sensors attracted many computer vision and graphics researchers. Nevertheless, ToF devices suffer from severe motion artifacts for dynamic scenes as well as low-resolution depth data which strongly justifies the importance of a valid correction. To counterbalance this effect, a pre-processing approach is introduced to greatly improve range image data on dynamic scenes. We first demonstrate the robustness of our approach using simulated data to finally validate our method using sensor range data. Our GPU-based processing pipeline enhances range data reliability in real-time.

Application of MALDI-TOF mass spectrometry in clinical diagnostic microbiology.

PubMed

De Carolis, Elena; Vella, Antonietta; Vaccaro, Luisa; Torelli, Riccardo; Spanu, Teresa; Fiori, Barbara; Posteraro, Brunella; Sanguinetti, Maurizio

2014-09-12

Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently emerged as a powerful technique for identification of microorganisms, changing the workflow of well-established laboratories so that its impact on microbiological diagnostics has been unparalleled. In comparison with conventional identification methods that rely on biochemical tests and require long incubation procedures, MALDI-TOF MS has the advantage of identifying bacteria and fungi directly from colonies grown on culture plates in a few minutes and with simple procedures. Numerous studies on different systems available demonstrate the reliability and accuracy of the method, and new frontiers have been explored besides microbial species level identification, such as direct identification of pathogens from positive blood cultures, subtyping, and drug susceptibility detection.

Immunological activation following transcutaneous delivery of HR-gp100 protein

PubMed Central

Frankenburg, Shoshana; Grinberg, Igor; Bazak, Ziva; Fingerut, Lena; Pitcovski, Jacob; Gorodetsky, Raphael; Peretz, Tamar; Spira, Ram M.; Skornik, Yehuda; Goldstein, Ronald S.

2009-01-01

Transcutaneous immunization aims at taking advantage of the skin’s immune system for the purpose of immunoprotection. In the present study we evaluated the potential of topical delivery of a recombinant melanoma protein, HR-gp100, derived from a shorter sequence of the native gp100 gene. The protein was applied on the skin, with and without the addition of two forms of heat labile enterotoxin (nLT and LTB). HR-gp100 fused to Haptide, a cell penetrating 20mer peptide (HR-gp100H) was also tested. Topical HR-gp100 and HR-gp100H application on the ears of mice elicited the production of specific antibodies, and transcutaneous delivery to intact human skin induced dose-dependent LC activation. nLT and LTB also activated LC, but did not further increase the activation induced by HR-gp100. These results show that HR-gp100, an antigenic tumor-derived protein, activates the immune system following transcutaneous delivery, as shown by both Langerhans cell activation and induction of antibody production. PMID:17493711

TOF-SIMS imaging of chlorhexidine-digluconate transport in frozen hydrated biofilms of the fungus Candida albicans

NASA Astrophysics Data System (ADS)

Tyler, Bonnie J.; Rangaranjan, Srinath; Möller, Jörg; Beumer, Andre'; Arlinghaus, Heinrich F.

2006-07-01

The diffusion of the anti-microbial chlorhexidine digluconate (CHG) has been studied in C. albicans biofilms by time-of-flight secondary-ion mass spectrometry (TOF-SIMS). C. albicans has been shown to become resistant to common anti-microbial agents, including CHG, when growing as a biofilm. Mass transport resistance within biofilms has commonly been suggested as a resistance mechanism, but measurement of transport for most anti-microbial agents in biofilms has proven extremely difficult because of the heterogeneity of the biofilms and the difficulty in detecting these agents within an intact biofilm. In this study, TOF-SIMS has been used to study the transport of CHG and glucose in a frozen hydrated biofilm. The TOF-SIMS images reveal a progression of CHG from the top of the biofilm to its base with time. Images suggest that there are channels within the biofilm and show preferential binding of CHG to cellular components of the biofilm. Additionally, both living and dead cells can be identified in the TOF-SIMS images by the sequestration of K + and the presence of cell markers. This study demonstrates that TOF-SIMS has the unique potential to simultaneously observe the presence of an antimicrobial agent, concentration of nutrients, and the viability of the cell population.

Fabrication of (U,Am)O2 pellet with controlled porosity from oxide microspheres

NASA Astrophysics Data System (ADS)

Ramond, Laure; Coste, Philippe; Picart, Sébastien; Gauthé, Aurélie; Bataillea, Marc

2017-08-01

U1-xAmxO2±δ mixed-oxides are considered as promising compounds for americium heterogeneous transmutation in Sodium Fast Neutron Reactor. Porous microstructure is envisaged in order to facilitate helium and fission gas release and to reduce pellet swelling during irradiation and under self-irradiation. In this study, the porosity is created by reducing (U,Am)3O8 microspheres into (U,Am)O2 during the sintering. This reduction is accompanied by a decrease of the lattice volume that leads to the creation of open porosity. Finally, an (U0.90Am0.10)O2 porous ceramic pellet (D∼89% of the theoretical density TD) with controlled porosity (≥8% open porosity) was obtained from mixed-oxide microspheres obtained by the Weak Acid Resin (WAR) process.

Daphnia HR96 is a Promiscuous Xenobiotic and Endobiotic Nuclear Receptor

PubMed Central

Karimullina, Elina; Li, Yangchun; Ginjupalli, Gautam; Baldwin, William S.

2012-01-01

Daphnia pulex is the first crustacean to have its genome sequenced. The genome project provides new insight and data into how an aquatic crustacean may respond to environmental stressors, including toxicants. We cloned Daphnia pulex HR96 (DappuHR96), a nuclear receptor orthologous to the CAR/PXR/VDR group of nuclear receptors. In Drosophila melanogaster, (hormone receptor 96) HR96 responds to phenobarbital exposure and has been hypothesized as a toxicant receptor. Therefore, we set up a transactivation assay to test whether DappuHR96 is a promiscuous receptor activated by xenobiotics and endobiotics similar to the constitutive androstane receptor (CAR) and the pregnane X-receptor (PXR). Transactivation assays performed with a GAL4-HR96 chimera demonstrate that HR96 is a promiscuous toxicant receptor activated by a diverse set of chemicals such as pesticides, hormones, and fatty acids. Several environmental toxicants activate HR96 including estradiol, pyriproxyfen, chlorpyrifos, atrazine, and methane arsonate. We also observed repression of HR96 activity by chemicals such as triclosan, androstanol, and fluoxetine. Nearly 50% of the chemicals tested activated or inhibited HR96. Interestingly, unsaturated fatty acids were common activators or inhibitors of HR96 activity, indicating a link between diet and toxicant response. The omega-6 and omega-9 unsaturated fatty acids linoleic and oleic acid activated HR96, but the omega-3 unsaturated fatty acids alpha-linolenic acid and docosahexaenoic acid inhibited HR96, suggesting that these two distinct sets of lipids perform opposing roles in Daphnia physiology. This also provides a putative mechanism by which the ratio of dietary unsaturated fats may affect the ability of an organism to respond to a toxic insult. In summary, HR96 is a promiscuous nuclear receptor activated by numerous endo- and xenobiotics. PMID:22466357

Chemical Visualization of Sweat Pores in Fingerprints Using GO-Enhanced TOF-SIMS.

PubMed

Cai, Lesi; Xia, Meng-Chan; Wang, Zhaoying; Zhao, Ya-Bin; Li, Zhanping; Zhang, Sichun; Zhang, Xinrong

2017-08-15

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has been used in imaging of small molecules (<500 Da) in fingerprints, such as gunshot residues and illicit drugs. However, identifying and mapping relatively high mass molecules are quite difficult owing to insufficient ion yield of their molecular ions. In this report, graphene oxide (GO)-enhanced TOF-SIMS was used to detect and image relatively high mass molecules such as poison, alkaloids (>600 Da) and controlled drugs, and antibiotics (>700 Da) in fingerprints. Detail features of fingerprints such as the number and distribution of sweat pores in a ridge and even the delicate morphology of one pore were clearly revealed in SIMS images of relatively high mass molecules. The detail features combining with identified chemical composition were sufficient to establish a human identity and link the suspect to a crime scene. The wide detectable mass range and high spatial resolution make GO-enhanced TOF-SIMS a promising tool in accurate and fast analysis of fingerprints, especially in fragmental fingerprint analysis.

Welding of AM350 and AM355 steel

NASA Technical Reports Server (NTRS)

Davis, R. J.; Wroth, R. S.

1967-01-01

A series of tests was conducted to establish optimum procedures for TIG welding and heat treating of AM350 and AM355 steel sheet in thicknesses ranging from 0.010 inch to 0.125 inch. Statistical analysis of the test data was performed to determine the anticipated minimum strength of the welded joints.

In-beam test of the RPC architecture foreseen to be used for the CBM-TOF inner wall

NASA Astrophysics Data System (ADS)

Petriş, M.; Bartoş, D.; Petrovici, M.; Rădulescu, L.; Simion, V.; Deppner, I.; Herrmann, N.; Simon, C.; Frühauf, J.; Kiš, M.; Loizeau, P.-A.

2018-05-01

The Time Of Flight (TOF) subsystem is one of the main detectors of the CBM experiment. The TOF wall in conjunction with Silicon Tracking System (STS) is foreseen to identify charged hadrons, i.e. pions, kaons and protons, with a full azimuthal coverage at 2.50 - 250 polar angles. A system time resolution of at least 80 ps, including all contributions, such as electronics jitter and the resolution of the time reference system, is required. Such a performance should be maintained up to a counting rate larger than 30 kHz/cm2 at the most inner region of TOF wall. Our R&D activity has been focused on the development of two-dimensional position sensitive Multi-gap Resistive Plate Counter (MRPC) prototypes for the forward region of the CBM-TOF subdetector, the most demanding zone in terms of granularity and counting rate. The in-beam tests using secondary particles produced in 30 GeV/u Pb ion collisions on a Pb target at SPS - CERN aimed to test the performance of these prototypes in conditions similar to the ones expected at SIS100 at FAIR. The performance of the prototypes is studied in conditions of exposure of the whole active area of the chamber to high multiplicity of reaction products. The results show that this type of MRPC fulfill the challenging requirements of the CBM-TOF wall. Therefore, such an architecture is recommended as basic solution for CBM-TOF inner zone.

[3D-TOF MR-angiography with high spatial resolution for surgical planning in insular lobe gliomas].

PubMed

Bykanov, A E; Pitskhelauri, D I; Pronin, I N; Tonoyan, A S; Kornienko, V N; Zakharova, N E; Turkin, A M; Sanikidze, A Z; Shkarubo, M A; Shkatova, A M; Shults, E I

2015-01-01

Despite the obvious progress in modern neurosurgery, surgery for glial tumors of the insular lobe is often associated with a high risk of postoperative neurological deficit, which is primarily caused by damage to perforating arteries of the M1 segment of the middle cerebral artery. The work is aimed at evaluating the effectiveness of high resolution time-of-flight (3D-TOF) MR angiography in imaging of medial and lateral lenticulostriate arteries and determining their relationship to tumor edge in patients with gliomas of the insula. 3D-TOF MR angiography data were analyzed in 20 patients with primarily diagnosed cerebral gliomas involving the insula. All patients underwent non-contrast enhanced 3D-TOF MR angiography. In 6 cases, 3D-TOF MRA was performed before and after contrast enhancement. 3D-TOF angiography before intravenous contrast injection was capable of visualizing the medial lenticulostriate arteries in 19 patients (95% of all cases) and lateral lenticulostriate arteries in 18 patients (90% of all cases). Contrast-enhanced 3D-TOF angiography allows for better visualization of both the proximal and distal segments of lenticulostriate arteries. Three variants of relationship between the tumor and lenticulostriate arteries were identified. Variant I: the tumor grew over the arteries without their displacement in 2 cases (10% of the total number of observations); variant II: the tumor caused medial displacement of arteries without growing over them in 11 cases (55% of the total number of observations); variant III: the tumor partially grew over and displaced arteries in 2 cases (10%). In 25% of cases (5 patients), tumor was poorly visualized on 3D-TOF MR angiograms because their signal characteristics did not differ from those of the medulla (tumor tissue was T1 isointense). As a result, it was impossible to determine the relationship between the tumor and lenticulostriate arteries. High spatial resolution time-of-flight MR angiography can be recommended for

High-resolution EEG (HR-EEG) and magnetoencephalography (MEG).

PubMed

Gavaret, M; Maillard, L; Jung, J

2015-03-01

High-resolution EEG (HR-EEG) and magnetoencephalography (MEG) allow the recording of spontaneous or evoked electromagnetic brain activity with excellent temporal resolution. Data must be recorded with high temporal resolution (sampling rate) and high spatial resolution (number of channels). Data analyses are based on several steps with selection of electromagnetic signals, elaboration of a head model and use of algorithms in order to solve the inverse problem. Due to considerable technical advances in spatial resolution, these tools now represent real methods of ElectroMagnetic Source Imaging. HR-EEG and MEG constitute non-invasive and complementary examinations, characterized by distinct sensitivities according to the location and orientation of intracerebral generators. In the presurgical assessment of drug-resistant partial epilepsies, HR-EEG and MEG can characterize and localize interictal activities and thus the irritative zone. HR-EEG and MEG often yield significant additional data that are complementary to other presurgical investigations and particularly relevant in MRI-negative cases. Currently, the determination of the epileptogenic zone and functional brain mapping remain rather less well-validated indications. In France, in 2014, HR-EEG is now part of standard clinical investigation of epilepsy, while MEG remains a research technique. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

The use of MOX caramel fuel mixed with 241Am, 242mAm and 243Am as burnable absorber actinides for the MTR research reactors.

PubMed

Shaaban, Ismail; Albarhoum, Mohamad

2017-07-01

The MOX (UO 2 &PuO 2 ) caramel fuel mixed with 241 Am, 242m Am and 243 Am as burnable absorber actinides was proposed as a fuel of the MTR-22MW reactor. The MCNP4C code was used to simulate the MTR-22MW reactor and estimate the criticality and the neutronic parameters, and the power peaking factors before and after replacing its original fuel (U 3 O 8 -Al) by the MOX caramel fuel mixed with 241 Am, 242m Am and 243 Am actinides. The obtained results of the criticality, the neutronic parameters, and the power peaking factors for the MOX caramel fuel mixed with 241 Am, 242m Am and 243 Am actinides were compared with the same parameters of the U 3 O 8 -Al original fuel and a maximum difference is -6.18% was found. Additionally, by recycling 2.65% and 2.71% plutonium and 241 Am, 242m Am and 243 Am actinides in the MTR-22MW reactor, the level of 235 U enrichment is reduced from 4.48% to 3% and 2.8%, respectively. This also results in the reduction of the 235 U loading by 32.75% and 37.22% for the 2.65%, the 2.71% plutonium and 241 Am, 242m Am and 243 Am actinides, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Time-of-flight scattering and recoiling spectrometer (TOF-SARS) for surface analysis

NASA Astrophysics Data System (ADS)

Grizzi, O.; Shi, M.; Bu, H.; Rabalais, J. W.

1990-02-01

A UHV spectrometer system has been designed and constructed for time-of-flight scattering and recoiling spectrometry (TOF-SARS). The technique uses a pulsed primary ion beam and TOF methods for analysis of both scattered and recoiled neutrals (N) and ions (I) simultaneously with continuous scattering angle variation over a flight path of ≊1 m. The pulsed ion beam line uses an electron impact ionization source with acceleration up to 5 keV; pulse widths down to 20 ns with average current densities of 0.05-5.0 nA/mm2 have been obtained. Typical current densities used herein are ≊0.1 nA/mm2 and TOF spectra can be collected with a total ion dose of <10-3 ions/surface atom. A channel electron multiplier detector, which is sensitive to both ions and fast neutrals, is mounted on a long tube connected to a precision rotary motion feedthru, allowing continuous rotation over a scattering angular range 0°<θ<165°. The sample is mounted on a precision manipulator, allowing azimuthal δ and incident α angle rotation, as well as translation along three orthogonal axes. The system also accommodates standard surface analysis instrumentation for LEED, AES, XPS, and UPS. The capabilities of the system are demonstrated by the following examples: (A) TOF spectra versus scattering angle θ; (B) comparison to LEED and AES; (C) surface and adsorbate structure determinations; (D) monitoring surface roughness; (E) surface semichanneling measurements; (F) measurements of scattered ion fractions; and (G) ion induced Auger electron emission.

Measurement of the temperature dependent partitioning of semi-volatile organics onto aerosol near roadways

NASA Astrophysics Data System (ADS)

Wentzell, J. J.; Liggio, J.; Li, S.; Brook, J.; Staebler, R. M.; Evans, G. J.; Jeong, C.; Sheppard, A.; Lu, G.; Gordon, M.; Mihele, C.

2010-12-01

The volatility of the organic aerosol fraction has received a great deal of attention recently in light of new volatility-based modelling approaches and due to the inability of current models to fully account for secondary organic aerosol (SOA). In this regard, evaporation of primary organic aerosol species and their subsequent oxidation may contribute significantly to SOA downwind of sources. This implies that moderate ambient temperature fluctuations can significantly increase or decrease the aerosol bound fraction of semi-volatile and intermediate volatility (SVOC + IVOC) compounds. In order to examine the importance of these more volatile organic components, a temperature controlled inlet was developed with the ability to heat and cool the aerosol in 2 C increments to 15 C above or below ambient temperature. The inlet was coupled to an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and deployed on a mobile platform upwind and downwind of a major Southern Ontario highway as part of the Fast Evolution of Vehicle Emissions near Roadways (FEVER 2010) campaign. Preliminary results suggest that changes in temperature of 5-10 C can alter the partitioning of volatile organic aerosol components by up to 30%. Although the largest affect was observed 10-13 meters downwind of the vehicle emissions, a measurable affect was observed beyond 500 m and in aerosol upwind of the highway. These results suggest that a significant pool of semi-volatile organics exist, which can condense onto particles at slightly lower temperatures or evaporate to the gas phase and be further oxidized. The nature of these organic species at locations upwind and downwind of vehicle emissions will be discussed.

MALDI-TOF MS as a tool to identify foodborne yeasts and yeast-like fungi.

PubMed

Quintilla, Raquel; Kolecka, Anna; Casaregola, Serge; Daniel, Heide M; Houbraken, Jos; Kostrzewa, Markus; Boekhout, Teun; Groenewald, Marizeth

2018-02-02

Since food spoilage by yeasts causes high economic losses, fast and accurate identifications of yeasts associated with food and food-related products are important for the food industry. In this study the efficiency of the matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify food related yeasts was evaluated. A CBS in-house MALDI-TOF MS database was created and later challenged with a blinded test set of 146 yeast strains obtained from food and food related products. Ninety eight percent of the strains were correctly identified with log score values>1.7. One strain, Mrakia frigida, gained a correct identification with a score value<1.7. Two strains could not be identified at first as they represented a mix of two different species. These mixes were Rhodotorula babjevae with Meyerozyma caribbica and Clavispora lusitaniae with Debaryomyces hansenii. After separation, all four species could be correctly identified with scores>1.7. Ambiguous identifications were observed due to two incorrect reference mass spectra's found in the commercial database BDAL v.4.0, namely Candida sake DSM 70763 which was re-identified as Candida oleophila, and Candida inconspicua DSM 70631 which was re-identified as Pichia membranifaciens. MALDI-TOF MS can distinguish between most of the species, but for some species complexes, such as the Kazachstania telluris and Mrakia frigida complexes, MALDI-TOF MS showed limited resolution and identification of sibling species was sometimes problematic. Despite this, we showed that the MALDI-TOF MS is applicable for routine identification and validation of foodborne yeasts, but a further update of the commercial reference databases is needed. Copyright © 2017 Elsevier B.V. All rights reserved.

Bayesian Peptide Peak Detection for High Resolution TOF Mass Spectrometry.

PubMed

Zhang, Jianqiu; Zhou, Xiaobo; Wang, Honghui; Suffredini, Anthony; Zhang, Lin; Huang, Yufei; Wong, Stephen

2010-11-01

In this paper, we address the issue of peptide ion peak detection for high resolution time-of-flight (TOF) mass spectrometry (MS) data. A novel Bayesian peptide ion peak detection method is proposed for TOF data with resolution of 10 000-15 000 full width at half-maximum (FWHW). MS spectra exhibit distinct characteristics at this resolution, which are captured in a novel parametric model. Based on the proposed parametric model, a Bayesian peak detection algorithm based on Markov chain Monte Carlo (MCMC) sampling is developed. The proposed algorithm is tested on both simulated and real datasets. The results show a significant improvement in detection performance over a commonly employed method. The results also agree with expert's visual inspection. Moreover, better detection consistency is achieved across MS datasets from patients with identical pathological condition.

Quantification issues of trace metal contaminants on silicon wafers by means of TOF-SIMS, ICP-MS, and TXRF

NASA Astrophysics Data System (ADS)

Rostam-Khani, P.; Hopstaken, M. J. P.; Vullings, P.; Noij, G.; O'Halloran, O.; Claassen, W.

2004-06-01

Measurement of surface metal contamination on silicon wafers is essential for yield enhancement in IC manufacturing. Vapor phase decomposition coupled with either inductively coupled plasma mass spectrometry (VPD-ICP-MS), or total reflection X-ray fluorescence (VPD-TXRF), TXRF and more recently time of flight secondary ion mass spectrometry (TOF-SIMS) are used to monitor surface metal contamination. These techniques complement each other in their respective strengths and weaknesses. For reliable and accurate quantification, so-called relative sensitivity factors (RSF) are required for TOF-SIMS analysis. For quantification purposes in VPD, the collection efficiency (CE) is important to ensure complete collection of contamination. A standard procedure has been developed that combines the determination of these RSFs as well as the collection efficiency using all the analytical techniques mentioned above. Therefore, sample wafers were intentionally contaminated and analyzed (by TOF-SIMS) directly after preparation. After VPD-ICP-MS, several scanned surfaces were analyzed again by TOF-SIMS. Comparing the intensities of the specific metals before and after the VPD-DC procedure on the scanned surface allows the determination of so-called removing efficiency (RE). In general, very good agreement was obtained comparing the four analytical techniques after updating the RSFs for TOF-SIMS. Progress has been achieved concerning the CE evaluation as well as determining the RSFs more precisely for TOF-SIMS.

Evaluation of the new capture vapourizer for aerosol mass spectrometers (AMS) through laboratory studies of inorganic species

DOE PAGES

Hu, Weiwei; Campuzano-Jost, Pedro; Day, Douglas A.; ...

2017-08-15

Aerosol mass spectrometers (AMSs) and Aerosol Chemical Speciation Monitors (ACSMs) commercialized by Aerodyne are widely used to measure the non-refractory species in submicron particles. With the standard vapourizer (SV) that is installed in all commercial instruments to date, the quantification of ambient aerosol mass concentration requires the use of the collection efficiency (CE) to correct for the loss of particles due to bounce. A new capture vapourizer (CV) has been designed to reduce the need for a bounce-related CE correction. Two high-resolution AMS instruments, one with a SV and one with a CV, were operated side by side in themore » laboratory. Four standard species, NH 4NO 3, NaNO 3, (NH 4) 2SO 4 and NH 4Cl, which typically constitute the majority of the mass of ambient submicron inorganic species, are studied. The effect of vapourizer temperature ( T v ∼ 200–800 °C) on the detected fragments, CE and size distributions are investigated. A T v of 500–550 °C for the CV is recommended. In the CV, CE was identical (around unity) for more volatile species (e.g. NH 4NO 3) and comparable to or higher than the SV for less-volatile species (e.g. (NH 4) 2SO 4), demonstrating an improvement in CE for laboratory inorganic species in the CV. The detected relative intensities of fragments of NO 3 and SO 4 species observed with the CV are different from those observed with the SV, and are consistent with additional thermal decomposition arising from the increased residence time and multiple collisions. Increased residence times with the CV also lead to broader particle size distribution measurements than with the SV. A method for estimating whether pure species will be detected in AMS sizing mode is proposed. Production of CO 2(g) from sampled nitrate on the vapourizer surface, which has been reported for the SV, is negligible for the CV for NH 4NO 3 and comparable to the SV for NaNO 3. . We observe an extremely consistent fragmentation for

Evaluation of the new capture vapourizer for aerosol mass spectrometers (AMS) through laboratory studies of inorganic species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Weiwei; Campuzano-Jost, Pedro; Day, Douglas A.

Aerosol mass spectrometers (AMSs) and Aerosol Chemical Speciation Monitors (ACSMs) commercialized by Aerodyne are widely used to measure the non-refractory species in submicron particles. With the standard vapourizer (SV) that is installed in all commercial instruments to date, the quantification of ambient aerosol mass concentration requires the use of the collection efficiency (CE) to correct for the loss of particles due to bounce. A new capture vapourizer (CV) has been designed to reduce the need for a bounce-related CE correction. Two high-resolution AMS instruments, one with a SV and one with a CV, were operated side by side in themore » laboratory. Four standard species, NH 4NO 3, NaNO 3, (NH 4) 2SO 4 and NH 4Cl, which typically constitute the majority of the mass of ambient submicron inorganic species, are studied. The effect of vapourizer temperature ( T v ∼ 200–800 °C) on the detected fragments, CE and size distributions are investigated. A T v of 500–550 °C for the CV is recommended. In the CV, CE was identical (around unity) for more volatile species (e.g. NH 4NO 3) and comparable to or higher than the SV for less-volatile species (e.g. (NH 4) 2SO 4), demonstrating an improvement in CE for laboratory inorganic species in the CV. The detected relative intensities of fragments of NO 3 and SO 4 species observed with the CV are different from those observed with the SV, and are consistent with additional thermal decomposition arising from the increased residence time and multiple collisions. Increased residence times with the CV also lead to broader particle size distribution measurements than with the SV. A method for estimating whether pure species will be detected in AMS sizing mode is proposed. Production of CO 2(g) from sampled nitrate on the vapourizer surface, which has been reported for the SV, is negligible for the CV for NH 4NO 3 and comparable to the SV for NaNO 3. . We observe an extremely consistent fragmentation for

Real-time analysis of aromatics in combustion engine exhaust by resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOF-MS): a robust tool for chassis dynamometer testing.

PubMed

Adam, T W; Clairotte, M; Streibel, T; Elsasser, M; Pommeres, A; Manfredi, U; Carriero, M; Martini, G; Sklorz, M; Krasenbrink, A; Astorga, C; Zimmermann, R

2012-07-01

Resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOF-MS) is a robust method for real-time analysis of monocyclic and polycyclic aromatic hydrocarbons in complex emissions. A mobile system has been developed which enables direct analysis on site. In this paper, we utilize a multicomponent calibration scheme based on the analytes' photo-ionisation cross-sections relative to a calibrated species. This allows semi-quantification of a great number of components by only calibrating one compound of choice, here toluene. The cross-sections were determined by injecting nebulised solutions of aromatic compounds into the TOF-MS ion source with the help of a HPLC pump. Then, REMPI-TOF-MS was implemented at various chassis dynamometers and test cells and the exhaust of the following vehicles and engines investigated: a compression ignition light-duty (LD) passenger car, a compression ignition LD van, two spark ignition LD passenger cars, 2 two-stroke mopeds, and a two-stroke engine of a string gas trimmer. The quantitative time profiles of benzene are shown. The results indicate that two-stroke engines are a significant source for toxic and cancerogenic compounds. Air pollution and health effects caused by gardening equipment might still be underestimated.

Establishing MALDI-TOF as Versatile Drug Discovery Readout to Dissect the PTP1B Enzymatic Reaction.

PubMed

Winter, Martin; Bretschneider, Tom; Kleiner, Carola; Ries, Robert; Hehn, Jörg P; Redemann, Norbert; Luippold, Andreas H; Bischoff, Daniel; Büttner, Frank H

2018-07-01

Label-free, mass spectrometric (MS) detection is an emerging technology in the field of drug discovery. Unbiased deciphering of enzymatic reactions is a proficient advantage over conventional label-based readouts suffering from compound interference and intricate generation of tailored signal mediators. Significant evolvements of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS, as well as associated liquid handling instrumentation, triggered extensive efforts in the drug discovery community to integrate the comprehensive MS readout into the high-throughput screening (HTS) portfolio. Providing speed, sensitivity, and accuracy comparable to those of conventional, label-based readouts, combined with merits of MS-based technologies, such as label-free parallelized measurement of multiple physiological components, emphasizes the advantages of MALDI-TOF for HTS approaches. Here we describe the assay development for the identification of protein tyrosine phosphatase 1B (PTP1B) inhibitors. In the context of this precious drug target, MALDI-TOF was integrated into the HTS environment and cross-compared with the well-established AlphaScreen technology. We demonstrate robust and accurate IC 50 determination with high accordance to data generated by AlphaScreen. Additionally, a tailored MALDI-TOF assay was developed to monitor compound-dependent, irreversible modification of the active cysteine of PTP1B. Overall, the presented data proves the promising perspective for the integration of MALDI-TOF into drug discovery campaigns.

Variations in AmLi source spectra and their estimation utilizing the 5 Ring Multiplicity Counter

NASA Astrophysics Data System (ADS)

Weinmann-Smith, R.; Beddingfield, D. H.; Enqvist, A.; Swinhoe, M. T.

2017-06-01

Active-mode assay systems are widely used for the safeguards of uranium items to verify compliance with the Non-Proliferation Treaty. Systems such as the Active-Well Coincidence Counter (AWCC) and the Uranium Neutron Coincidence Collar (UNCL) use americium-lithium (AmLi) neutron sources to induce fissions which are measured to determine the sample mass. These systems have historically relied on calibrations derived from well-defined standards. Recently, restricted access to standards or more difficult measurements have resulted in a reliance on modeling and simulation for the calibration of systems, which introduces potential simulation biases. The AmLi source energy spectra commonly used in the safeguards community do not accurately represent measurement results and the spectrum uncertainty can represent a large contribution to the total modeling uncertainty in active-mode systems. The 5-Ring Multiplicity Counter (5RMC) has been used to measure 17 AmLi sources. The measurements showed a significant spectral variation between different sources. Utilization of a spectrum that is specific to an individual source or a series of sources will give improved results over historical general spectra when modeling AmLi sources. Candidate AmLi neutron spectra were calculated in MCNP and SOURCES4C for a range of physical AmLi characteristics. The measurement and simulation data were used to fit reliable and accurate AmLi spectra for use in the simulation of active-mode systems. Spectra were created for average Gammatron C, Gammatron N, and MRC series sources, and for individual sources. The systematic uncertainty introduced by physical aspects of the AmLi source were characterized through simulations. The accuracy of spectra from the literature was compared.

Prototype of the gas chromatograph - mass spectrometer to investigate volatile species in the lunar soil for the Luna-Glob and Luna-Resurs missions.

NASA Astrophysics Data System (ADS)

Hofer, L.; Lasi, D.; Tulej, M.; Wurz, P.; Cabane, M.; Cosica, D.; Gerasimov, M.; Rodinov, D.

2013-09-01

In preparation for the Russian Luna-Glob and Luna-Resurs missions we combined our compact time-offlight mass spectrometer (TOF-MS) with a chemical pre-separation of the species by gas chromatography (GC). Combined measurements with both instruments were successfully performed with the laboratory prototype of the mass spectrometer and a flight-like gas chromatograph. Due to its capability to record mass spectra over the full mass range at once with high sensitivity and a dynamic range of up to 106 within 1s, the TOF-MS system is a valuable extension of the GC analysis. The combined GC-MS complex is able to detect concentrations of volatile species in the sample of about 2·10^-9 by mass.

Cycle analysis of MCFC/gas turbine system

NASA Astrophysics Data System (ADS)

Musa, Abdullatif; Alaktiwi, Abdulsalam; Talbi, Mosbah

2017-11-01

High temperature fuel cells such as the solid oxide fuel cell (SOFC) and the molten carbonate fuel cell (MCFC) are considered extremely suitable for electrical power plant application. The molten carbonate fuel cell (MCFC) performances is evaluated using validated model for the internally reformed (IR) fuel cell. This model is integrated in Aspen Plus™. Therefore, several MCFC/Gas Turbine systems are introduced and investigated. One of this a new cycle is called a heat recovery (HR) cycle. In the HR cycle, a regenerator is used to preheat water by outlet air compressor. So the waste heat of the outlet air compressor and the exhaust gases of turbine are recovered and used to produce steam. This steam is injected in the gas turbine, resulting in a high specific power and a high thermal efficiency. The cycles are simulated in order to evaluate and compare their performances. Moreover, the effects of an important parameters such as the ambient air temperature on the cycle performance are evaluated. The simulation results show that the HR cycle has high efficiency.

HR4EU--A Web-Portal for E-Learning of Croatian

ERIC Educational Resources Information Center

Filko, Matea; Farkaš, Daša; Hriberski, Diana

2016-01-01

In this paper, we present the HR4EU--a web portal for e-learning of Croatian. HR4EU is the first portal that offers Croatian language courses which are free-of-charge and developed by language professionals. Moreover, HR4EU also integrates bidirectional interaction with some of the previously developed language resources for Croatian. The HR4EU…

A computational platform for MALDI-TOF mass spectrometry data: application to serum and plasma samples.

PubMed

Mantini, Dante; Petrucci, Francesca; Pieragostino, Damiana; Del Boccio, Piero; Sacchetta, Paolo; Candiano, Giovanni; Ghiggeri, Gian Marco; Lugaresi, Alessandra; Federici, Giorgio; Di Ilio, Carmine; Urbani, Andrea

2010-01-03

Mass spectrometry (MS) is becoming the gold standard for biomarker discovery. Several MS-based bioinformatics methods have been proposed for this application, but the divergence of the findings by different research groups on the same MS data suggests that the definition of a reliable method has not been achieved yet. In this work, we propose an integrated software platform, MASCAP, intended for comparative biomarker detection from MALDI-TOF MS data. MASCAP integrates denoising and feature extraction algorithms, which have already shown to provide consistent peaks across mass spectra; furthermore, it relies on statistical analysis and graphical tools to compare the results between groups. The effectiveness in mass spectrum processing is demonstrated using MALDI-TOF data, as well as SELDI-TOF data. The usefulness in detecting potential protein biomarkers is shown comparing MALDI-TOF mass spectra collected from serum and plasma samples belonging to the same clinical population. The analysis approach implemented in MASCAP may simplify biomarker detection, by assisting the recognition of proteomic expression signatures of the disease. A MATLAB implementation of the software and the data used for its validation are available at http://www.unich.it/proteomica/bioinf. (c) 2009 Elsevier B.V. All rights reserved.

Professional Development of HR Practitioners--A Phenomenographic Study

ERIC Educational Resources Information Center

Bailey, Moira

2015-01-01

Purpose: The purpose of this paper is an investigation into the experiences of professional development of human resource (HR) practitioners in the North of Scotland, and the use of non-formal learning in that development. Design/methodology/approach: In-depth semi-structured interviews from a purposively selected sample of HR practitioners were…

[Applications of MALDI-TOF-MS in clinical microbiology laboratory].

PubMed

Carbonnelle, Etienne; Nassif, Xavier

2011-10-01

For twenty years, mass spectrometry (MS) has emerged as a particularly powerful tool for analysis and characterization of proteins in research. It is only recently that this technology, especially MALDI-TOF-MS (Matrix Assisted Laser Desorption Ionization Time-Of-Flight) has entered the field of routine microbiology. This method has proven to be reliable and safe for the identification of bacteria, yeasts, filamentous fungi and dermatophytes. MALDI-TOF-MS is a rapid, precise and cost-effective method for identification, compared to conventional phenotypic techniques or molecular biology. Its ability to analyse whole microorganisms with few sample preparation has greatly reduced the time to identification (1-2 min). Furthermore, this technology can be used to identify bacteria directly from clinical samples as blood culture bottles or urines. Future applications will be developed in order to provide direct information concerning virulence or resistance protein markers. © 2011 médecine/sciences – Inserm / SRMS.

Low inlet gas velocity high throughput biomass gasifier

DOEpatents

Feldmann, Herman F.; Paisley, Mark A.

1989-01-01

The present invention discloses a novel method of operating a gasifier for production of fuel gas from carbonaceous fuels. The process disclosed enables operating in an entrained mode using inlet gas velocities of less than 7 feet per second, feedstock throughputs exceeding 4000 lbs/ft.sup.2 -hr, and pressures below 100 psia.

Rapid and reliable MALDI-TOF mass spectrometry identification of Candida non-albicans isolates from bloodstream infections.

PubMed

Pulcrano, Giovanna; Iula, Dora Vita; Vollaro, Antonio; Tucci, Alessandra; Cerullo, Monica; Esposito, Matilde; Rossano, Fabio; Catania, Maria Rosaria

2013-09-01

Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) fingerprinting has recently become an effective instrument for rapid microbiological diagnostics and in particular for identification of micro-organisms directly in a positive blood culture. The aim of the study was to evaluate a collection of 82 stored yeast isolates from bloodstream infection, by MALDI-TOF MS; 21 isolates were identified also directly from positive blood cultures and in the presence of other co-infecting micro-organisms. Of the 82 isolates grown on plates, 64 (76%) were correctly identified by the Vitek II system and 82 (100%) by MALDI-TOF MS; when the two methods gave different results, the isolate was identified by PCR. MALDI-TOF MS was unreliable in identifying two isolates (Candida glabrata and Candida parapsilosis) directly from blood culture; however, direct analysis from positive blood culture samples was fast and effective for the identification of yeast, which is of great importance for early and adequate treatment. © 2013. Published by Elsevier B.V. All rights reserved.

Development of capacitive multiplexing circuit for SiPM-based time-of-flight (TOF) PET detector

NASA Astrophysics Data System (ADS)

Choe, Hyeok-Jun; Choi, Yong; Hu, Wei; Yan, Jianhua; Jung, Jin Ho

2017-04-01

There has been great interest in developing a time-of-flight (TOF) PET to improve the signal-to-noise ratio of PET image relative to that of non-TOF PET. Silicon photomultiplier (SiPM) arrays have attracted attention for use as a fast TOF PET photosensor. Since numerous SiPM arrays are needed to construct a modern human PET, a multiplexing method providing both good timing performance and high channel reduction capability is required to develop a SiPM-based TOF PET. The purpose of this study was to develop a capacitive multiplexing circuit for the SiPM-based TOF PET. The proposed multiplexing circuit was evaluated by measuring the coincidence resolving time (CRT) and the energy resolution as a function of the overvoltage using three different capacitor values of 15, 30, and 51 pF. A flood histogram was also obtained and quantitatively assessed. Experiments were performed using a 4× 4 array of 3× 3 mm2 SiPMs. Regarding the capacitor values, the multiplexing circuit using a smaller capacitor value showed the best timing performance. On the other hand, the energy resolution and flood histogram quality of the multiplexing circuit deteriorated as the capacitor value became smaller. The proposed circuit was able to achieve a CRT of 260+/- 4 ps FWHM and an energy resolution of 17.1 % with a pair of 2× 2× 20 mm3 LYSO crystals using a capacitor value of 30 pF at an overvoltage of 3.0 V. It was also possible to clearly resolve a 6× 6 array of LYSO crystals in the flood histogram using the multiplexing circuit. The experiment results indicate that the proposed capacitive multiplexing circuit is useful to obtain an excellent timing performance and a crystal-resolving capability in the flood histogram with a minimal degradation of the energy resolution, as well as to reduce the number of the readout channels of the SiPM-based TOF PET detector.

[EXPRESS IDENTIFICATION OF POSITIVE BLOOD CULTURES USING DIRECT MALDI-TOF MASS SPECTROMETRY].

PubMed

Popov, D A; Ovseenko, S T; Vostrikova, T Yu

2015-01-01

To evaluate the effectiveness of direct identification of pathogens of bacteremia by direct matrix assisted laser desorption ionization time-flight mass spectrometry (mALDI-TOF) compared to routine method. A prospective study included 211 positive blood cultures obtained from 116 patients (106 adults and 10 children, aged from 2 weeks to 77 years old in the ICU after open heart surgery. Incubation was carried out under aerobic vials with a sorbent for antibiotics Analyzer BacT/ALERT 3D 120 (bioMerieux, France) in parallel with the primary sieving blood cultures on solid nutrient media with subsequent identification of pure cultures using MALDI-TOF mass spectrometry analyzer Vitek MS, bioMerieux, France routine method), after appropriate sample preparation we carried out a direct (without screening) MALDI-TOF mass spectrometric study of monocomponental blood cultures (n = 201). using a routine method in 211 positive blood cultures we identified 23 types of microorganisms (Staphylococcus (n = 87), Enterobacteria- ceae (n = 71), Enterococci (n = 20), non-fermentative Gram-negative bacteria (n = 18), others (n = 5). The average time of incubation of samples to obtain a signal of a blood culture growth was 16.2 ± 7.4 h (from 3.75 to 51 hours.) During the first 12 hours of incubation, growth was obtained in 32.4% of the samples, and on the first day in 92.2%. In the direct mass spectrometric analysis mnonocomponental blood cultures (n = 201) is well defined up to 153 species of the sample (76.1%), while the share of successful identification of Gram-negative bacteria was higher than that of Gram-positive (85.4 and 69, 1%, respectively p = 0.01). The high degree of consistency in the results of standard and direct method of identifying blood cultures using MALDI-TOF mass spectrometry (κ = 0.96, p < 0.001; the samples included in the calculation for which both option given result). Duration of the direct mass spectrometric analysis, including sample preparation, was no

MALDI-TOF mass spectrometry as a potential tool for Trichomonas vaginalis identification.

PubMed

Calderaro, Adriana; Piergianni, Maddalena; Montecchini, Sara; Buttrini, Mirko; Piccolo, Giovanna; Rossi, Sabina; Arcangeletti, Maria Cristina; Medici, Maria Cristina; Chezzi, Carlo; De Conto, Flora

2016-06-10

Trichomonas vaginalis is a flagellated protozoan causing trichomoniasis, a sexually transmitted human infection, with around 276.4 million new cases estimated by World Health Organization. Culture is the gold standard method for the diagnosis of T. vaginalis infection. Recently, immunochromatographic assays as well as PCR assays for the detection of T. vaginalis antigen or DNA, respectively, have been also available. Although the well-known genome sequence of T. vaginalis has made possible the application of proteomic studies, few data are available about the overall proteomic expression profiling of T. vaginalis. The aim of this study was to investigate the potential application of MALDI-TOF MS as a new tool for the identification of T. vaginalis. Twenty-one isolates were analysed by MALDI-TOF MS after the creation of a Main Spectrum Profile (MSP) from a T. vaginalis reference strain (G3) and its subsequent supplementation in the Bruker Daltonics database, not including any profile of protozoa. This was achieved after the development of a new identification method created by modifying the range setting (6-10 kDa) for the MALDI-TOF MS analysis in order to exclude the overlapping of peaks derived from the culture media used in this study. Two MSP reference spectra were created in 2 different range: 3-15 kDa (standard range setting) and 6-10 kDa (new range setting). Both MSP spectra were deposited in the MALDI BioTyper database for further identification of additional T. vaginalis strains. All the 21 strains analysed in this study were correctly identified by using the new identification method. In this study it was demonstrated that changes in the MALDI-TOF MS standard parameters usually used to identify bacteria and fungi allowed the identification of the protozoan T. vaginalis. This study shows the usefulness of MALDI-TOF MS in the reliable identification of microorganism grown on complex liquid media such as the protozoan T. vaginalis, on the basis of the

Sequencing RNA by a combination of exonuclease digestion and uridine specific chemical cleavage using MALDI-TOF.

PubMed Central

Tolson, D A; Nicholson, N H

1998-01-01

The determination of DNA sequences by partial exonuclease digestion followed by Matrix-Assisted Laser Desorption Time of Flight Mass Spectrometry (MALDI-TOF) is a well established method. When the same procedure is applied to RNA, difficulties arise due to the small (1 Da) mass difference between the nucleotides U and C, which makes unambiguous assignment difficult using a MALDI-TOF instrument. Here we report our experiences with sequence specific endonucleases and chemical methods followed by MALDI-TOF to resolve these sequence ambiguities. We have found chemical methods superior to endonucleases both in terms of correct specificity and extent of sequence coverage. This methodology can be used in combination with exonuclease digestion to rapidly assign RNA sequences. PMID:9421498

Rapid and accurate bacterial identification in probiotics and yoghurts by MALDI-TOF mass spectrometry.

PubMed

Angelakis, Emmanouil; Million, Matthieu; Henry, Mireille; Raoult, Didier

2011-10-01

Probiotic food is manufactured by adding probiotic strains simultaneously with starter cultures in fermentation tanks. Here, we investigate the accuracy and feasibility of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) for bacterial identification at the species level in probiotic food and yoghurts. Probiotic food and yoghurts were cultured in Columbia and Lactobacillus specific agar and tested by quantitative real-time PCR (qPCR) for the detection and quantification of Lactobacillus sp. Bacterial identification was performed by MALDI-TOF analysis and by amplification and sequencing of tuf and 16S rDNA genes. We tested 13 probiotic food and yoghurts and we identified by qPCR that they presented 10(6) to 10(7) copies of Lactobacillus spp. DNA/g. All products contained very large numbers of living bacteria varying from 10(6) to 10(9) colony forming units/g. These bacteria were identified as Lactobacillus casei, Lactococcus lactis, Bifidobacterium animalis, Lactobacillus delbrueckii, and Streptococcus thermophilus. MALDI-TOF MS presented 92% specificity compared to the molecular assays. In one product we found L. lactis, instead of Bifidus spp. which was mentioned on the label and for another L. delbrueckii and S. thermophilus instead of Bifidus spp. MALDI-TOF MS allows a rapid and accurate bacterial identification at the species level in probiotic food and yoghurts. Although the safety and functionality of probiotics are species and strain dependent, we found a discrepancy between the bacterial strain announced on the label and the strain identified. Practical Application:  MALDI-TOF MS is rapid and specific for the identification of bacteria in probiotic food and yoghurts. Although the safety and functionality of probiotics are species and strain dependent, we found a discrepancy between the bacterial strain announced on the label and the strain identified. © 2011 Institute of Food Technologists®

Drug screening in medical examiner casework by high-resolution mass spectrometry (UPLC-MSE-TOF).

PubMed

Rosano, Thomas G; Wood, Michelle; Ihenetu, Kenneth; Swift, Thomas A

2013-10-01

Postmortem drug findings yield important analytical evidence in medical examiner casework, and chromatography coupled with nominal mass spectrometry (MS) serves as the predominant general unknown screening approach. We report screening by ultra performance liquid chromatography (UPLC) coupled with hybrid quadrupole time-of-flight mass spectrometer (MS(E)-TOF), with comparison to previously validated nominal mass UPLC-MS and UPLC-MS-MS methods. UPLC-MS(E)-TOF screening for over 950 toxicologically relevant drugs and metabolites was performed in a full-spectrum (m/z 50-1,000) mode using an MS(E) acquisition of both molecular and fragment ion data at low (6 eV) and ramped (10-40 eV) collision energies. Mass error averaged 1.27 ppm for a large panel of reference drugs and metabolites. The limit of detection by UPLC-MS(E)-TOF ranges from 0.5 to 100 ng/mL and compares closely with UPLC-MS-MS. The influence of column recovery and matrix effect on the limit of detection was demonstrated with ion suppression by matrix components correlating closely with early and late eluting reference analytes. Drug and metabolite findings by UPLC-MS(E)-TOF were compared with UPLC-MS and UPLC-MS-MS analyses of postmortem blood in 300 medical examiner cases. Positive findings by all methods totaled 1,528, with a detection rate of 57% by UPLC-MS, 72% by UPLC-MS-MS and 80% by combined UPLC-MS and UPLC-MS-MS screening. Compared with nominal mass screening methods, UPLC-MS(E)-TOF screening resulted in a 99% detection rate and, in addition, offered the potential for the detection of nontargeted analytes via high-resolution acquisition of molecular and fragment ion data.

Visualization of water transport into soybean nodules by Tof-SIMS cryo system.

PubMed

Iijima, Morio; Watanabe, Toshimasa; Yoshida, Tomoharu; Kawasaki, Michio; Kato, Toshiyuki; Yamane, Koji

2015-04-15

This paper examined the route of water supply into soybean nodules through the new visualization technique of time of flight secondary ion mass spectrometry (Tof-SIMS) cryo system, and obtained circumstantial evidence for the water inflow route. The maximum resolution of the Tof-SIMS imaging used by this study was 1.8 μm (defined as the three pixel step length), which allowed us to detect water movement at the cellular level. Deuterium-labeled water was supplied to soybean plants for 4h and the presence of deuterium in soybean nodules was analyzed by the Tof-SIMS cryo system. Deuterium ions were found only in the endodermis tissue surrounding the central cylinder in soybean nodules. Neither xylem vessels nor phloem complex itself did not indicate any deuterium accumulation. Deuterium-ion counts in the endodermis tissue were not changed by girdling treatment, which restricted water movement through the phloem complex. The results strongly indicated that nodule tissues did not receive water directly from the phloem complex, but received water through root cortex apoplastic pathway from the root axis. Copyright © 2015 Elsevier GmbH. All rights reserved.

MALDI-TOF mass spectrometry: an emerging technology for microbial identification and diagnosis.

PubMed

Singhal, Neelja; Kumar, Manish; Kanaujia, Pawan K; Virdi, Jugsharan S

2015-01-01

Currently microorganisms are best identified using 16S rRNA and 18S rRNA gene sequencing. However, in recent years matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a potential tool for microbial identification and diagnosis. During the MALDI-TOF MS process, microbes are identified using either intact cells or cell extracts. The process is rapid, sensitive, and economical in terms of both labor and costs involved. The technology has been readily imbibed by microbiologists who have reported usage of MALDI-TOF MS for a number of purposes like, microbial identification and strain typing, epidemiological studies, detection of biological warfare agents, detection of water- and food-borne pathogens, detection of antibiotic resistance and detection of blood and urinary tract pathogens etc. The limitation of the technology is that identification of new isolates is possible only if the spectral database contains peptide mass fingerprints of the type strains of specific genera/species/subspecies/strains. This review provides an overview of the status and recent applications of mass spectrometry for microbial identification. It also explores the usefulness of this exciting new technology for diagnosis of diseases caused by bacteria, viruses, and fungi.

Bayesian Peptide Peak Detection for High Resolution TOF Mass Spectrometry

PubMed Central

Zhang, Jianqiu; Zhou, Xiaobo; Wang, Honghui; Suffredini, Anthony; Zhang, Lin; Huang, Yufei; Wong, Stephen

2011-01-01

In this paper, we address the issue of peptide ion peak detection for high resolution time-of-flight (TOF) mass spectrometry (MS) data. A novel Bayesian peptide ion peak detection method is proposed for TOF data with resolution of 10 000–15 000 full width at half-maximum (FWHW). MS spectra exhibit distinct characteristics at this resolution, which are captured in a novel parametric model. Based on the proposed parametric model, a Bayesian peak detection algorithm based on Markov chain Monte Carlo (MCMC) sampling is developed. The proposed algorithm is tested on both simulated and real datasets. The results show a significant improvement in detection performance over a commonly employed method. The results also agree with expert’s visual inspection. Moreover, better detection consistency is achieved across MS datasets from patients with identical pathological condition. PMID:21544266

Application of targeted quantitative proteomics analysis in human cerebrospinal fluid using a liquid chromatography matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometer (LC MALDI TOF/TOF) platform.

PubMed

Pan, Sheng; Rush, John; Peskind, Elaine R; Galasko, Douglas; Chung, Kathryn; Quinn, Joseph; Jankovic, Joseph; Leverenz, James B; Zabetian, Cyrus; Pan, Catherine; Wang, Yan; Oh, Jung Hun; Gao, Jean; Zhang, Jianpeng; Montine, Thomas; Zhang, Jing

2008-02-01

Targeted quantitative proteomics by mass spectrometry aims to selectively detect one or a panel of peptides/proteins in a complex sample and is particularly appealing for novel biomarker verification/validation because it does not require specific antibodies. Here, we demonstrated the application of targeted quantitative proteomics in searching, identifying, and quantifying selected peptides in human cerebrospinal spinal fluid (CSF) using a matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometer (MALDI TOF/TOF)-based platform. The approach involved two major components: the use of isotopic-labeled synthetic peptides as references for targeted identification and quantification and a highly selective mass spectrometric analysis based on the unique characteristics of the MALDI instrument. The platform provides high confidence for targeted peptide detection in a complex system and can potentially be developed into a high-throughput system. Using the liquid chromatography (LC) MALDI TOF/TOF platform and the complementary identification strategy, we were able to selectively identify and quantify a panel of targeted peptides in the whole proteome of CSF without prior depletion of abundant proteins. The effectiveness and robustness of the approach associated with different sample complexity, sample preparation strategies, as well as mass spectrometric quantification were evaluated. Other issues related to chromatography separation and the feasibility for high-throughput analysis were also discussed. Finally, we applied targeted quantitative proteomics to analyze a subset of previously identified candidate markers in CSF samples of patients with Parkinson's disease (PD) at different stages and Alzheimer's disease (AD) along with normal controls.

Hearing on Computer Education. Hearing before the Subcommittee on Elementary, Secondary, and Vocational Education of the Committee on Education and Labor, House of Representatives, Ninety-Eighth Congress, Second Session, on H.R. 3750, H.R. 1134, and H.R. 4628.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. House Committee on Education and Labor.

This hearing report covers three bills: (1) H.R. 3750, which would authorize grants to local educational agencies to purchase computer equipment; (2) H.R. 1134, which would provide funds to establish and operate model centers for computers in education; and (3) H.R. 4628, which would establish a government corporation to promote the development…

The eclipsing AM Herculis variable H1907 + 690

NASA Technical Reports Server (NTRS)

Remillard, R. A.; Silber, A.; Stroozas, B. A.; Tapia, S.

1991-01-01

The discovery is reported of an eclipsing cataclysmic variable that exhibits up to 10 percent circular polarization at optical wavelengths, securing its classification as an AM Herculis type binary. The object, H1907 + 609, was located with the guidance of X-ray positions from the HEAO 1 survey. Optical CCD photometry exhibits deep eclipses, from which is derived a precise orbital period of 1.743750 hr. The eclipse duration suggests an inclination angle about 80 deg for a main-sequence secondary star. The optical flux has been persistently faint during observations spanning 1987-1990, while the X-ray measurements suggest long-term X-ray variability. The polarization and photometric light curves can be interpreted with a geometric model in which most of the accretion is directed toward a single magnetic pole, with an accretion spot displaced about 17 deg in longitude from the projection of the secondary star on the white dwarf surface.

MALDI-TOF mass spectrometry for differentiation between Streptococcus pneumoniae and Streptococcus pseudopneumoniae.

PubMed

van Prehn, Joffrey; van Veen, Suzanne Q; Schelfaut, Jacqueline J G; Wessels, Els

2016-05-01

We compared the Vitek MS and Microflex MALDI-TOF mass spectrometry platform for species differentiation within the Streptococcus mitis group with PCR assays targeted at lytA, Spn9802, and recA as reference standard. The Vitek MS correctly identified 10/11 Streptococcus pneumoniae, 13/13 Streptococcus pseudopneumoniae, and 12/13 S. mitis/oralis. The Microflex correctly identified 9/11 S. pneumoniae, 0/13 S. pseudopneumoniae, and 13/13 S. mitis/oralis. MALDI-TOF is a powerful tool for species determination within the mitis group. Diagnostic accuracy varies depending on platform and database used. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Combined use of ESI-QqTOF-MS and ESI-QqTOF-MS/MS with mass-spectral library search for qualitative analysis of drugs.

PubMed

Pavlic, Marion; Libiseller, Kathrin; Oberacher, Herbert

2006-09-01

The potential of the combined use of ESI-QqTOF-MS and ESI-QqTOF-MS/MS with mass-spectral library search for the identification of therapeutic and illicit drugs has been evaluated. Reserpine was used for standardizing experimental conditions and for characterization of the performance of the applied mass spectrometric system. Experiments revealed that because of the mass accuracy, the stability of calibration, and the reproducibility of fragmentation, the QqTOF mass spectrometer is an appropriate platform for establishment of a tandem-mass-spectral library. Three-hundred and nineteen substances were used as reference samples to build the spectral library. For each reference compound, product-ion spectra were acquired at ten different collision-energy values between 5 eV and 50 eV. For identification of unknown compounds, a library search algorithm was developed. The closeness of matching between a measured product-ion spectrum and a spectrum stored in the library was characterized by a value called "match probability", which took into account the number of matched fragment ions, the number of fragment ions observed in the two spectra, and the sum of the intensity differences calculated for matching fragments. A large value for the match probability indicated a close match between the measured and the reference spectrum. A unique feature of the library search algorithm-an implemented spectral purification option-enables characterization of multi-contributor fragment-ion spectra. With the aid of this software feature, substances comprising only 1.0% of the total amount of binary mixtures were unequivocally assigned, in addition to the isobaric main contributors. The spectral library was successfully applied to the characterization of 39 forensic casework samples.

Identification and differentiation of food-related bacteria: A comparison of FTIR spectroscopy and MALDI-TOF mass spectrometry.

PubMed

Wenning, Mareike; Breitenwieser, Franziska; Konrad, Regina; Huber, Ingrid; Busch, Ulrich; Scherer, Siegfried

2014-08-01

The food industry requires easy, accurate, and cost-effective techniques for microbial identification to ensure safe products and identify microbial contaminations. In this work, FTIR spectroscopy and MALDI-TOF mass spectrometry were assessed for their suitability and applicability for routine microbial diagnostics of food-related microorganisms by analyzing their robustness according to changes in incubation time and medium, identification accuracy and their ability to differentiate isolates down to the strain level. Changes in the protocol lead to a significantly impaired performance of FTIR spectroscopy, whereas they had only little effects on MALDI-TOF MS. Identification accuracy was tested using 174 food-related bacteria (93 species) from an in-house strain collection and 40 fresh isolates from routine food analyses. For MALDI-TOF MS, weaknesses in the identification of bacilli and pseudomonads were observed; FTIR spectroscopy had most difficulties in identifying pseudomonads and enterobacteria. In general, MALDI-TOF MS obtained better results (52-85% correct at species level), since the analysis of mainly ribosomal proteins is more robust and seems to be more reliable. FTIR spectroscopy suffers from the fact that it generates a whole-cell fingerprint and intraspecies diversity may lead to overlapping species borders which complicates identification. In the present study values between 56% and 67% correct species identification were obtained. On the opposite, this high sensitivity offers the opportunity of typing below the species level which was not possible using MALDI-TOF MS. Using fresh isolates from routine diagnostics, both techniques performed well with 88% (MALDI-TOF) and 75% (FTIR) correct identifications at species level, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

Screening natural antioxidants in peanut shell using DPPH-HPLC-DAD-TOF/MS methods.

PubMed

Qiu, Jiying; Chen, Leilei; Zhu, Qingjun; Wang, Daijie; Wang, Wenliang; Sun, Xin; Liu, Xiaoyong; Du, Fangling

2012-12-15

Peanut shell, a byproduct in oil production, is rich in natural antioxidants. Here, a rapid and efficient method using DPPH-HPLC-DAD-TOF/MS was used for the first time to screen antioxidants in peanut shell. The method is based on the hypothesis that upon reaction with 1, 1-diphenyl-2-picrylhydrazyl (DPPH), the peak areas of compounds with potential antioxidant activities in the HPLC chromatogram will be significantly reduced or disappeared, and the identity confirmation could be achieved by HPLC-DAD-TOF/MS technique. With this method, three compounds possessing potential antioxidant activities were found abundantly in the methanolic extract of peanut shell. They were identified as 5,7-dihydroxychromone, eriodictyol, and luteolin. The contents of these compounds were 0.59, 0.92, and 2.36 mg/g, respectively, and luteolin possessed the strongest radical scavenging capacity. DPPH-HPLC-DAD-TOF/MS assay facilitated rapid identification and determination of natural antioxidants in peanut shell, which may be helpful for value-added utilization of peanut processing byproducts. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Evaluation of mass spectrometry: MALDI-TOF MS for fast and reliable yeast identification].

PubMed

Relloso, María S; Nievas, Jimena; Fares Taie, Santiago; Farquharson, Victoria; Mujica, María T; Romano, Vanesa; Zarate, Mariela S; Smayevsky, Jorgelina

2015-01-01

The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry technique known as MALDI-TOF MS is a tool used for the identification of clinical pathogens by generating a protein spectrum that is unique for a given species. In this study we assessed the identification of clinical yeast isolates by MALDI-TOF MS in a university hospital from Argentina and compared two procedures for protein extraction: a rapid method and a procedure based on the manufacturer's recommendations. A short protein extraction procedure was applied in 100 isolates and the rate of correct identification at genus and species level was 98.0%. In addition, we analyzed 201 isolates, previously identified by conventional methods, using the methodology recommended by the manufacturer and there was 95.38% coincidence in the identification at species level. MALDI TOF MS showed to be a fast, simple and reliable tool for yeast identification. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Analysis of high mass resolution PTR-TOF mass spectra from 1,3,5-trimethylbenzene (TMB) environmental chamber experiments

NASA Astrophysics Data System (ADS)

Müller, M.; Graus, M.; Wisthaler, A.; Hansel, A.; Metzger, A.; Dommen, J.; Baltensperger, U.

2011-09-01

A series of 1,3,5-trimethylbenzene (TMB) photo-oxidation experiments was performed in the 27-m3 Paul Scherrer Institute environmental chamber under various NOx conditions. A University of Innsbruck prototype high resolution Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-TOF) was used for measurements of gas and particulate phase organics. The gas phase mass spectrum displayed ~200 ion signals during the TMB photo-oxidation experiments. Molecular formulas CNmHnNoOp were determined and ion signals were separated and grouped according to their C, O and N numbers. This allowed to determine the time evolution of the O:C ratio and of the average carbon oxidation state OSC of the reaction mixture. Both quantities were compared with master chemical mechanism (MCMv3.1) simulations. The O:C ratio in the particle phase was about twice the O:C ratio in the gas phase. Average carbon oxidation states of secondary organic aerosol (SOA) samples OSCSOA were in the range of -0.34 to -0.31, in agreement with expected average carbon oxidation states of fresh SOA (OSC = -0.5 - 0).

Analysis of high mass resolution PTR-TOF mass spectra from 1,3,5-trimethylbenzene (TMB) environmental chamber experiments

NASA Astrophysics Data System (ADS)

Müller, M.; Graus, M.; Wisthaler, A.; Hansel, A.; Metzger, A.; Dommen, J.; Baltensperger, U.

2012-01-01

A series of 1,3,5-trimethylbenzene (TMB) photo-oxidation experiments was performed in the 27-m3 Paul Scherrer Institute environmental chamber under various NOx conditions. A University of Innsbruck prototype high resolution Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-TOF) was used for measurements of gas and particulate phase organics. The gas phase mass spectrum displayed ~200 ion signals during the TMB photo-oxidation experiments. Molecular formulas CmHnNoOp were determined and ion signals were separated and grouped according to their C, O and N numbers. This allowed to determine the time evolution of the O:C ratio and of the average carbon oxidation state OSC of the reaction mixture. Both quantities were compared with master chemical mechanism (MCMv3.1) simulations. The O:C ratio in the particle phase was about twice the O:C ratio in the gas phase. Average carbon oxidation states of secondary organic aerosol (SOA) samples OSCSOA were in the range of -0.34 to -0.31, in agreement with expected average carbon oxidation states of fresh SOA (OSC = -0.5-0).

MALDI-TOF Mass Spectrometry: A Powerful Tool for Clinical Microbiology at Hôpital Principal de Dakar, Senegal (West Africa)

PubMed Central

Lo, Cheikh I.; Fall, Bécaye; Sambe-Ba, Bissoume; Diawara, Silman; Gueye, Mamadou W.; Mediannikov, Oleg; Sokhna, Cheikh; Faye, Ngor; Diemé, Yaya; Wade, Boubacar; Raoult, Didier; Fenollar, Florence

2015-01-01

Our team in Europe has developed the routine clinical laboratory identification of microorganisms by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). To evaluate the utility of MALDI-TOF MS in tropical Africa in collaboration with local teams, we installed an apparatus in the Hôpital Principal de Dakar (Senegal), performed routine identification of isolates, and confirmed or completed their identification in France. In the case of discordance or a lack of identification, molecular biology was performed. Overall, 153/191 (80.1%) and 174/191 (91.1%) isolates yielded an accurate and concordant identification for the species and genus, respectively, with the 2 different MALDI-TOF MSs in Dakar and Marseille. The 10 most common bacteria, representing 94.2% of all bacteria routinely identified in the laboratory in Dakar (Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus haemolyticus, Enterobacter cloacae, Enterococcus faecalis, and Staphylococcus epidermidis) were accurately identified with the MALDI-TOF MS in Dakar. The most frequent misidentification in Dakar was at the species level for Achromobacter xylosoxidans, which was inaccurately identified as Achromobacter denitrificans, and the bacteria absent from the database, such as Exiguobacterium aurientacum or Kytococcus schroeteri, could not be identified. A few difficulties were observed with MALDI-TOF MS for Bacillus sp. or oral streptococci. 16S rRNA sequencing identified a novel bacterium, “Necropsobacter massiliensis.” The robust identification of microorganisms by MALDI-TOF MS in Dakar and Marseille demonstrates that MALDI-TOF MS can be used as a first-line tool in clinical microbiology laboratories in tropical countries. PMID:26716681

A&M. Plot plan of administration and A&M areas. Shows relationships ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. Plot plan of administration and A&M areas. Shows relationships among administration buildings and to A&M building (TAN-607), railroad turntable. Ralph M. Parsons 902-2&3-ANP-U 3. Date: December 1952. INEEL index code no. 032-0100-00-693-106690 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

The origin and reduction of spurious extrahepatic counts observed in 90Y non-TOF PET imaging post radioembolization

NASA Astrophysics Data System (ADS)

Walrand, Stephan; Hesse, Michel; Jamar, François; Lhommel, Renaud

2018-04-01

Our literature survey revealed a physical effect unknown to the nuclear medicine community, i.e. internal bremsstrahlung emission, and also the existence of long energy resolution tails in crystal scintillation. None of these effects has ever been modelled in PET Monte Carlo (MC) simulations. This study investigates whether these two effects could be at the origin of two unexplained observations in 90Y imaging by PET: the increasing tails in the radial profile of true coincidences, and the presence of spurious extrahepatic counts post radioembolization in non-TOF PET and their absence in TOF PET. These spurious extrahepatic counts hamper the microsphere delivery check in liver radioembolization. An acquisition of a 32P vial was performed on a GSO PET system. This is the ideal setup to study the impact of bremsstrahlung x-rays on the true coincidence rate when no positron emission and no crystal radioactivity are present. A MC simulation of the acquisition was performed using Gate-Geant4. MC simulations of non-TOF PET and TOF-PET imaging of a synthetic 90Y human liver radioembolization phantom were also performed. Internal bremsstrahlung and long energy resolution tails inclusion in MC simulations quantitatively predict the increasing tails in the radial profile. In addition, internal bremsstrahlung explains the discrepancy previously observed in bremsstrahlung SPECT between the measure of the 90Y bremsstrahlung spectrum and its simulation with Gate-Geant4. However the spurious extrahepatic counts in non-TOF PET mainly result from the failure of conventional random correction methods in such low count rate studies and poor robustness versus emission-transmission inconsistency. A novel proposed random correction method succeeds in cleaning the spurious extrahepatic counts in non-TOF PET. Two physical effects not considered up to now in nuclear medicine were identified to be at the origin of the unusual 90Y true coincidences radial profile. TOF reconstruction removing

Characterization of Novel Fusaricidins Produced by Paenibacillus polymyxa-M1 Using MALDI-TOF Mass Spectrometry

NASA Astrophysics Data System (ADS)

Vater, Joachim; Niu, Ben; Dietel, Kristin; Borriss, Rainer

2015-09-01

Paenibacillus polymyxa-M1 is a potent producer of bioactive compounds, such as lipopeptides, polyketides, and lantibiotics of biotechnological and medical interest. Genome sequencing revealed nine gene clusters for nonribosomal biosynthesis of such agents. Here we report on the investigation of the fusaricidins, a complex of cyclic lipopeptides containing 15-guanidino-3-hydroxypentadecanoic acid (GHPD) as fatty acid component by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). More than 20 variants of these compounds were detected and characterized in detail. Mass spectrometric sequence analysis was performed by MALDI-LIFT-TOF/TOF fragment analysis. The obtained product ion spectra show a specific processing in the fatty acid part. GHPD is cleaved between the α- and ß-position yielding two fragments a and b, one bearing the end-standing guanidine group and another one comprising the residual two C-atoms of GHPD with the attached peptide moiety. The complete sequence of all fusaricidins was derived from sets of bn- and yn-ions. The fusaricidin complex can be divided into four lipopeptide families, three of them showing variations of the amino acid in position 3, Val or Ile for the first and Tyr or Phe for families 2 and 3, respectively. A collection of novel fusaricidins was detected differing from those of families 1-3 by an additional residue of 71 Da (family 4). LIFT-TOF/TOF fragment spectra of these species imply that in their peptide moiety, an Ala-residue is attached by an ester bond to the free hydroxyl group of Thr4. More than 10 novel fusaricidins were characterized mass spectrometrically.

Web Server for Peak Detection, Baseline Correction, and Alignment in Two-Dimensional Gas Chromatography Mass Spectrometry-Based Metabolomics Data.

PubMed

Tian, Tze-Feng; Wang, San-Yuan; Kuo, Tien-Chueh; Tan, Cheng-En; Chen, Guan-Yuan; Kuo, Ching-Hua; Chen, Chi-Hsin Sally; Chan, Chang-Chuan; Lin, Olivia A; Tseng, Y Jane

2016-11-01

Two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC/TOF-MS) is superior for chromatographic separation and provides great sensitivity for complex biological fluid analysis in metabolomics. However, GC×GC/TOF-MS data processing is currently limited to vendor software and typically requires several preprocessing steps. In this work, we implement a web-based platform, which we call GC 2 MS, to facilitate the application of recent advances in GC×GC/TOF-MS, especially for metabolomics studies. The core processing workflow of GC 2 MS consists of blob/peak detection, baseline correction, and blob alignment. GC 2 MS treats GC×GC/TOF-MS data as pictures and clusters the pixels as blobs according to the brightness of each pixel to generate a blob table. GC 2 MS then aligns the blobs of two GC×GC/TOF-MS data sets according to their distance and similarity. The blob distance and similarity are the Euclidean distance of the first and second retention times of two blobs and the Pearson's correlation coefficient of the two mass spectra, respectively. GC 2 MS also directly corrects the raw data baseline. The analytical performance of GC 2 MS was evaluated using GC×GC/TOF-MS data sets of Angelica sinensis compounds acquired under different experimental conditions and of human plasma samples. The results show that GC 2 MS is an easy-to-use tool for detecting peaks and correcting baselines, and GC 2 MS is able to align GC×GC/TOF-MS data sets acquired under different experimental conditions. GC 2 MS is freely accessible at http://gc2ms.web.cmdm.tw .

Laboratory Studies Of Titan Haze: Simultaneous In Situ Detection Of Gas And Particle Species

NASA Astrophysics Data System (ADS)

Horst, Sarah; Li, R.; Yoon, H.; Hicks, R.; de Gouw, J.; Tolbert, M.

2012-10-01

Analyses of data obtained by multiple instruments carried by Cassini and Huygens have increased our knowledge of the composition of Titan’s atmosphere. While a wealth of new information about the aerosols in Titan’s atmosphere was obtained, their composition is still not well constrained. Laboratory experiments will therefore play a key role in furthering our understanding of the chemical processes resulting in the formation of haze in Titan’s atmosphere and its possible composition. We have obtained simultaneous in situ measurements of the gas- and particle-phase compositions produced by our Titan atmosphere simulation experiments (see e.g. [1]). The gas phase composition was measured using a Proton-Transfer Ion-Trap Mass Spectrometer (PIT-MS) and the aerosol composition was measured using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS). This complementary set of measurements will allow us to address the partitioning of gas- and aerosol-phase species. Knowledge of the gas phase composition in which the particles in our experiments form allows both for better comparison to the chemistry that is occurring in Titan’s atmosphere and for enabling more accurate determination of the possible pathways involved in the transition from gas phase to aerosol. We will compare the results from experiments that used two different initial gas mixtures (98% N2/2% CH4 and 98%N2/2%CH4/50 ppm CO) and two different energy sources to initiate the chemical reactions that result in particle formation (spark discharge using a Tesla coil or FUV irradiation from a deuterium lamp (115-400 nm)). [1] Trainer, M.G., et al. (2012) Astrobiology, 12, 315-326. SMH is supported by NSF Astronomy and Astrophysics Postdoctoral Fellowship AST-1102827.

Whole-cell MALDI-TOF MS: a new tool to assess the multifaceted activation of macrophages.

PubMed

Ouedraogo, Richard; Daumas, Aurélie; Ghigo, Eric; Capo, Christian; Mege, Jean-Louis; Textoris, Julien

2012-10-22

Whole-cell MALDI-TOF MS is routinely used to identify bacterial species in clinical samples. This technique has also proven to allow identification of intact mammalian cells, including macrophages. Here, we wondered whether this approach enabled the assessment human macrophages plasticity. The whole-cell MALDI-TOF spectra of macrophages stimulated with IFN-γ and IL-4, two inducers of M1 and M2 macrophage polarisation, consisted of peaks ranging from 2 to 12 kDa. The spectra of unstimulated and stimulated macrophages were clearly different. The fingerprints induced by the M1 agonists, IFN-γ, TNF, LPS and LPS+IFN-γ, and the M2 agonists, IL-4, TGF-β1 and IL-10, were specific and readily identifiable. Thus, whole-cell MALDI-TOF MS was able to characterise M1 and M2 macrophage subtypes. In addition, the fingerprints induced by extracellular (group B Streptococcus, Staphylococcus aureus) or intracellular (BCG, Orientia tsutsugamushi, Coxiella burnetii) bacteria were bacterium-specific. The whole-cell MALDI-TOF MS fingerprints therefore revealed the multifaceted activation of human macrophages. This approach opened a new avenue of studies to assess the immune response in the clinical setting, by monitoring the various activation patterns of immune cells in pathological conditions. Copyright © 2012 Elsevier B.V. All rights reserved.

In vitro and in vivo metabolic investigation of the Palbociclib by UHPLC-Q-TOF/MS/MS and in silico toxicity studies of its metabolites.

PubMed

Chavan, Balasaheb B; Tiwari, Shristy; G, Shankar; Nimbalkar, Rakesh D; Garg, Prabha; R, Srinivas; Talluri, M V N Kumar

2018-05-14

Palbociclib (PAB) is a CDK4/6 inhibitor and U. S Food and Drug Administration (FDA) granted regular approval for the treatment of hormone receptor (HR) positive, metastatic breast cancer in combination with an aromatase inhibitor in postmenopausal women. Metabolite identification is a crucial aspect during drug discovery and development as the drug metabolites may be pharmacologically active or possess toxicological activity. As there are no reports on the metabolism studies of the PAB, the present study focused on investigation of the in vitro and in vivo metabolic fate of the drug. The in vitro metabolism studies were carried out by using microsomes (HLM and RLM) and S9 fractions (Human and rat). The in vivo metabolism of the drug was studied by administration of the PAB orally to the Sprague-Dawley rats followed by analysis of urine, faeces and plasma samples. The sample preparation includes simple protein precipitation (PP) followed by solid phase extraction (SPE). The extracted samples were analyzed by ultrahigh-performance liquid chromatography-quadruple time-of-flight tandem mass spectrometry (UHPLC/Q-TOF/MS/MS). A total of 14 metabolites were detected in in vivo matrices. The PAB was metabolized via hydroxylation, oxidation, sulphation, N-dealkylation, acetylation and carbonylation pathways. A few of the metabolites were also detected in in vitro samples. Metabolite identification and characterization were performed by using UHPLC/Q-TOF/MS/MS in combination with HRMS data. To identify the toxicity potential of these metabolites, in silico toxicity assessment was carried out using TOPKAT and DEREK softwares. Copyright © 2018. Published by Elsevier B.V.

Cerebral TOF Angiography at 7T: Impact of B1+ Shimming with a 16-Channel Transceiver Array

PubMed Central

Schmitter, Sebastian; Wu, Xiaoping; Adriany, Gregor; Auerbach, Edward J.; Uğurbil, Kâmil; Van de Moortele, Pierre-François

2014-01-01

Purpose Time-of-flight (TOF) MR imaging is clinically among the most common cerebral non-contrast enhanced MR angiography techniques allowing for high spatial resolution. As shown by several groups TOF contrast significantly improves at ultra-high field (UHF) of B0=7T, however, spatially varying transmit B1 (B1+) fields at 7T reduce TOF contrast uniformity, typically resulting in sub-optimal contrast and reduced vessel conspicuity in the brain periphery. Methods Using a 16-channel B1+ shimming system we compare different dynamically applied B1+ phase shimming approaches on the RF excitation to improve contrast homogeneity for a (0.5 mm)3 resolution multi-slab TOF acquisition. In addition, B1+ shimming applied on the venous saturation pulse was investigated to improve venous suppression, subcutaneous fat signal reduction and enhanced background suppression originating from MT effect. Results B1+ excitation homogeneity was improved by a factor 2.2 to 2.6 on average depending on the shimming approach, compared to a standard CP-like phase setting, leading to improved vessel conspicuity particularly in the periphery. Stronger saturation, higher fat suppression and improved background suppression were observed when dynamically applying B1+ shimming on the venous saturation pulse. Conclusion B1+ shimming can significantly improve high resolution TOF vascular investigations at UHF, holding strong promise for non contrast-enhanced clinical applications. PMID:23640915

Transient Fission Gas Behavior in Uranium Nitride Fuel Under Proposed Space Applications

DTIC Science & Technology

1991-12-01

Press, Oxford UK, 1959). [7] M.H. Wood, J. Nucl. Mater. 82 (1979) 264 . [8] H. Blank and Hj. Matzke, Rad. Effects. 17 (1973) 57. [9] C. Ronchi and P.T...Benson, P.I. Freeman and E. Dempsey, J. Am. Ceramic Soc. 46 (1963) 43. [77] H.R. Warner and F.A. Nichols, Report WAPD -T-2161 (Bettis Atomic Power

Simple gas chromatographic method for furfural analysis.

PubMed

Gaspar, Elvira M S M; Lopes, João F

2009-04-03

A new, simple, gas chromatographic method was developed for the direct analysis of 5-hydroxymethylfurfural (5-HMF), 2-furfural (2-F) and 5-methylfurfural (5-MF) in liquid and water soluble foods, using direct immersion SPME coupled to GC-FID and/or GC-TOF-MS. The fiber (DVB/CAR/PDMS) conditions were optimized: pH effect, temperature, adsorption and desorption times. The method is simple and accurate (RSD<8%), showed good recoveries (77-107%) and good limits of detection (GC-FID: 1.37 microgL(-1) for 2-F, 8.96 microgL(-1) for 5-MF, 6.52 microgL(-1) for 5-HMF; GC-TOF-MS: 0.3, 1.2 and 0.9 ngmL(-1) for 2-F, 5-MF and 5-HMF, respectively). It was applied to different commercial food matrices: honey, white, demerara, brown and yellow table sugars, and white and red balsamic vinegars. This one-step, sensitive and direct method for the analysis of furfurals will contribute to characterise and quantify their presence in the human diet.

Validation of MALDI-TOF MS for rapid classification and identification of lactic acid bacteria, with a focus on isolates from traditional fermented foods in Northern Vietnam.

PubMed

Doan, N T L; Van Hoorde, K; Cnockaert, M; De Brandt, E; Aerts, M; Le Thanh, B; Vandamme, P

2012-10-01

To evaluate the potential use of MALDI-TOF MS for fast and reliable classification and identification of lactic acid bacteria (LAB) from traditional fermented foods. A total of 119 strains of LAB from fermented meat (nem chua) were analysed with both (GTG)(5)-PCR fingerprinting and MALDI-TOF MS. Cluster analysis of the profiles revealed five species represented by a single isolate both in (GTG)(5)-PCR and in MALDI-TOF MS; five species grouped alike for (GTG)(5)-PCR and for MALDI-TOF MS; however, differences in minimal similarity between the delineated (GTG)(5)-PCR and MALDI-TOF MS clusters could be observed; three species showed more heterogeneity in their MALDI-TOF MS profiles compared to their (GTG)(5)-PCR profiles; two species, each represented by a single MALDI-TOF cluster, were subdivided in the corresponding (GTG)(5)-PCR dendrogram. As proof of the identification potential of MALDI-TOF MS, LAB diversity from one fermented mustard sample was analysed using MALDI-TOF MS. PheS gene sequencing was used for validation. MALDI-TOF MS is a powerful, fast, reliable and cost-effective technique for the identification of LAB associated with the production of fermented foods. Food LAB can be identified using MALDI-TOF MS, and its application could possibly be extended to other food matrices and/or other food-derived micro-organisms. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

A simple and effective method for detecting precipitated proteins in MALDI-TOF MS.

PubMed

Oshikane, Hiroyuki; Watabe, Masahiko; Nakaki, Toshio

2018-04-01

MALDI-TOF MS has developed rapidly into an essential analytical tool for the life sciences. Cinnamic acid derivatives are generally employed in routine molecular weight determinations of intact proteins using MALDI-TOF MS. However, a protein of interest may precipitate when mixed with matrix solution, perhaps preventing MS detection. We herein provide a simple approach to enable the MS detection of such precipitated protein species by means of a "direct deposition method" -- loading the precipitant directly onto the sample plate. It is thus expected to improve routine MS analysis of intact proteins. Copyright © 2018. Published by Elsevier Inc.

Optimization of a two stage light gas gun. M.S. Thesis

NASA Technical Reports Server (NTRS)

Rynearson, R. J.; Rand, J. L.

1972-01-01

Performance characteristics of the Texas A&M University light gas gun are presented along with a review of basic gun theory and popular prediction methods. A computer routine based on the simple isentropic compression method is discussed. Results from over 60 test shots are given which demonstrate an increase in gun muzzle velocity from 9.100 ft/sec. to 19,000 ft/sec. The data gathered indicated the Texas A&M light gas gun more closely resembles an isentropic compression gun rather than a shock compression gun.

Urban traffic pollution reduction for sedan cars using petrol engines by hydro-oxide gas inclusion.

PubMed

Al-Rousan, Ammar A; Alkheder, Sharaf; Musmar, Sa'ed A

2015-12-01

Petrol cars, in particular nonhybrid cars, contribute significantly to the pollution problem as compared with other types of cars. The originality of this article falls in the direction of using hydro-oxy gas to reduce pollution from petrol car engines. Experiments were performed in city areas at low real speeds, with constant engine speeds in the average of 2500 rpm and at variable velocity ratios (first speed was 10-20 km/hr, second speed was 20-35 km/hr, and third speed was 35-50 km/hr). Results indicated that through using hydro-oxy gas, a noticeable reduction in pollution was recorded. Oxygen (O2) percentage has increased by about 2.5%, and nitric oxide (NO) level has been reduced by about 500 ppm. Carbon monoxide (CO) has decreased by about 2.2%, and also CO2 has decreased by 2.1%. It's worth mentioning that for hybrid system in cars at speeds between 10 and 50 km/hr, the emission percentage change is zero. However, hybrid cars are less abundant than petrol cars. The originality of this paper falls in the direction of using hydro-oxy gas to reduce pollution from petrol car engines. Experiments were performed in city areas at low real speeds, with constant engine speeds in the average of 2500 rpm and at variable velocity ratios (first speed was 10-20 km/hr, second speed was 20-35 km/hr, and third speed was 35-50 km/h).

The use of MALDI-TOF ICMS as an alternative tool for Trichophyton rubrum identification and typing.

PubMed

Pereira, Leonel; Dias, Nicolina; Santos, Cledir; Lima, Nelson

2014-01-01

In this study, the potential of matrix-assisted laser desorption/ionization time-of-flight intact cell mass spectrometry (MALDI-TOF ICMS) was investigated for the identification of clinical isolates. The isolates were analyzed at the species and strain level. Spectral identification by MALDI-TOF ICMS was performed for all strains, and compared with the results of sequencing of the internal transcribed spacers (ITS1 and ITS2), and the 5.8S rDNA region. PCR fingerprinting analysis using primers M13, (GACA)4, and (AC)10 was performed in order to assess the intra-specific variability of Trichophyton rubrum strains. The identification of strains at species level by MALDI-TOF ICMS was in agreement with the previously performed morphological and biochemical analysis. Sequence data confirmed spectral mass identification at species level. Intra-specific variability was assessed. Within the T. rubrum cluster, strains were distributed into smaller highly related sub-groups with a similarity values above 85%. MALDI-TOF ICMS was shown to be a rapid, low-cost and accurate alternative tool for the identification and strain typing of T. rubrum. Copyright © 2012 Elsevier España, S.L. All rights reserved.

MALDI-TOF MS identification of anaerobic bacteria: assessment of pre-analytical variables and specimen preparation techniques.

PubMed

Hsu, Yen-Michael S; Burnham, Carey-Ann D

2014-06-01

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a tool for identifying clinically relevant anaerobes. We evaluated the analytical performance characteristics of the Bruker Microflex with Biotyper 3.0 software system for identification of anaerobes and examined the impact of direct formic acid (FA) treatment and other pre-analytical factors on MALDI-TOF MS performance. A collection of 101 anaerobic bacteria were evaluated, including Clostridium spp., Propionibacterium spp., Fusobacterium spp., Bacteroides spp., and other anaerobic bacterial of clinical relevance. The results of our study indicate that an on-target extraction with 100% FA improves the rate of accurate identification without introducing misidentification (P<0.05). In addition, we modify the reporting cutoffs for the Biotyper "score" yielding acceptable identification. We found that a score of ≥1.700 can maximize the rate of identification. Of interest, MALDI-TOF MS can correctly identify anaerobes grown in suboptimal conditions, such as on selective culture media and following oxygen exposure. In conclusion, we report on a number of simple and cost-effective pre- and post-analytical modifications could enhance MALDI-TOF MS identification for anaerobic bacteria. Copyright © 2014 Elsevier Inc. All rights reserved.

Neutron cross-sections for next generation reactors: new data from n_TOF.

PubMed

Colonna, N; Abbondanno, U; Aerts, G; Alvarez, H; Alvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Berthoumieux, E; Calviani, M; Calviño, F; Cano-Ott, D; Capote, R; de Albornoz, A Carrillo; Cennini, P; Chepel, V; Chiaveri, E; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Duran, I; Eleftheriadis, C; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Frais-Koelbl, H; Fujii, K; Furman, W; Goncalves, I; González-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Isaev, S; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Ketlerov, V; Koehler, P; Konovalov, V; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Martínez, T; Massimi, C; Mastinu, P; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stephan, C; Tagliente, G; Tain, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vicente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

2010-01-01

In 2002, an innovative neutron time-of-flight facility started operation at CERN: n_TOF. The main characteristics that make the new facility unique are the high instantaneous neutron flux, high resolution and wide energy range. Combined with state-of-the-art detectors and data acquisition system, these features have allowed to collect high accuracy neutron cross-section data on a variety of isotopes, many of which radioactive, of interest for Nuclear Astrophysics and for applications to advanced reactor technologies. A review of the most important results on capture and fission reactions obtained so far at n_TOF is presented, together with plans for new measurements related to nuclear industry. Copyright 2010 Elsevier Ltd. All rights reserved.

Micrometeorological flux measurements of aerosol and gases above Beijing

NASA Astrophysics Data System (ADS)

Nemitz, Eiko; Langford, Ben; Mullinger, Neil; Cowan, Nicholas; Coyle, Mhairi; Acton, William Joe; Lee, James; Fu, Pingqing

2017-04-01

Air pollution is estimated to cause 1.6 million premature deaths in China every year and in the winter 2016/17 Beijing had to issue health alerts and put in place ad hoc limitations on industrial and vehicular activity. Much of this pollution is attributed to emissions from industrial processes and in particular coal combustion. By contrast, the diffuse pollutant sources within the city are less well understood. This includes, e.g., emissions from the Beijing traffic fleet, the sewage system, food preparation, solid fuel combustion in the streets and small industrial processes. Within the framework of a major UK-Chinese collaboration to study air pollution and its impact on human health in Beijing, we therefore measured fluxes of a large range of pollutants from a height of 102 m on the 325 m meteorological tower at the Institute of Atmospheric Physics. Several instruments were mounted at 102 m: fluxes of CO2 and H2O were measured with an infrared gas analyser (LiCOR 7500) and fluxes of ozone with a combination of a relative fast-response ozone analyser (ROFI) and a 2B absolute O3 instrument. Total particle number fluxes were measured with a condensation particle counter (TSI CPC 3785), and size-segregated fluxes over the size range 0.06 to 20 μm with a combination of an optical Ultrafine High Sensitivity Aerosol Spectrometer (UHSAS) and an Aerodynamic Particle Sizer Spectrometer (TSI APS3321). Ammonia (NH3) fluxes were measured for the first time above the urban environment using an Aerodyne compact quantum cascade laser (QCL). In addition, composition resolved aerosol fluxes were measured with an Aerodyne Aerosol Mass Spectrometer (HR-ToF-AMS), operated in a measurement container at the bottom of the tower, which subsampled from a 120 m long copper tube (15 mm OD). The analysis so far suggests that, due to often low wind speeds, fluxes were at times de-coupled from the surface. Fluxes normalised by CO2, a tracer for the amount of fossil fuel consumed, should be

Receptor modeling of near-roadway aerosol mass spectrometer data in Las Vegas, Nevada, with EPA PMF

NASA Astrophysics Data System (ADS)

Brown, S. G.; Lee, T.; Norris, G. A.; Roberts, P. T.; Collett, J. L., Jr.; Paatero, P.; Worsnop, D. R.

2011-08-01

Ambient non-refractory PM1 aerosol particles were measured with an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-AMS) at an elementary school 20 m from the US 95 freeway in Las Vegas, Nevada, during January 2008. Additional collocated continuous measurements of black carbon (BC), carbon monoxide (CO), nitrogen oxides (NOx), and meteorological data were collected. The US Environmental Protection Agency's (EPA) positive matrix factorization (PMF) data analysis tool was used to apportion organic matter (OM) as measured by HR-AMS, and rotational tools in EPA PMF were used to better characterize the solution space and pull resolved factors toward known source profiles. Three- to six-factor solutions were resolved. The four-factor solution was the most interpretable, with the typical AMS PMF factors of hydrocarbon-like organic aerosol (HOA), low-volatility oxygenated organic aerosol (LV-OOA), biomass burning organic aerosol (BBOA), and semi-volatile oxygenated organic aerosol (SV-OOA). When the measurement site was downwind of the freeway, HOA composed about half the OM, with SV-OOA and LV-OOA accounting for the rest. Attempts to pull the PMF factor profiles toward source profiles were successful but did not qualitatively change the results, indicating that these factors are very stable. Oblique edges were present in G-space plots, suggesting that the obtained rotation may not be the most plausible one. Since solutions found by pulling the profiles or using Fpeak retained these oblique edges, there appears to be little rotational freedom in the base solution. On average, HOA made up 26 % of the OM, and it made up nearly half of the OM when the monitoring site was downwind of US 95 during morning rush hour. LV-OOA was highest in the afternoon and accounted for 26 % of the OM. BBOA occurred in the evening hours, was predominantly from the residential area to the north, and on average constituted 12 % of the OM; SV-OOA accounted for the remaining

Bactec™ blood culture bottles allied to MALDI-TOF mass spectrometry: rapid etiologic diagnosis of bacterial endophthalmitis.

PubMed

Tanaka, Tatiana; Oliveira, Luiza Manhezi de Freitas; Ferreira, Bruno Fortaleza de Aquino; Kato, Juliana Mika; Rossi, Flavia; Correa, Karoline de Lemes Giuntini; Pimentel, Sergio Luis Gianotti; Yamamoto, Joyce Hisae; Almeida Junior, João Nóbrega

2017-07-01

Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) has been used for direct identification of pathogens from blood-inoculated blood culture bottles (BCBs). We showed that MALDI-TOF MS is an useful technique for rapid identification of the causative agents of endophthalmitis from vitreous humor-inoculated BCBs with a simple protocol. Copyright © 2017 Elsevier Inc. All rights reserved.

SCIPUFF Tangent-Linear/Adjoint Model for Release Source Location from Observational Data

DTIC Science & Technology

2011-01-18

magnitudes, times? Inverse model based on SCIPUFF (AIMS) 1/17/2011 Aerodyne Research, Inc. W911NF-06-C-0161 5 (1981), Daescu and Carmichael (2003...Defined Choice- Situations” The Journal of the Operational Research Society, Vol. 32, No. 2 (1981) Daescu, D. N., and Carmichael , G. R., “An Adjoint...Intelligence Applications to Environmental Sciences at AMS Annual Meeting, Atlanta, GA, Jan 17-21 (2010 ) N. Platt, S. Warner and S. M. Nunes, ’Plan for

Comparative analysis of Campylobacter isolates from wild birds and chickens using MALDI-TOF MS, biochemical testing, and DNA sequencing.

PubMed

Lawton, Samantha J; Weis, Allison M; Byrne, Barbara A; Fritz, Heather; Taff, Conor C; Townsend, Andrea K; Weimer, Bart C; Mete, Aslı; Wheeler, Sarah; Boyce, Walter M

2018-05-01

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was compared to conventional biochemical testing methods and nucleic acid analyses (16S rDNA sequencing, hippurate hydrolysis gene testing, whole genome sequencing [WGS]) for species identification of Campylobacter isolates obtained from chickens ( Gallus gallus domesticus, n = 8), American crows ( Corvus brachyrhynchos, n = 17), a mallard duck ( Anas platyrhynchos, n = 1), and a western scrub-jay ( Aphelocoma californica, n = 1). The test results for all 27 isolates were in 100% agreement between MALDI-TOF MS, the combined results of 16S rDNA sequencing, and the hippurate hydrolysis gene PCR ( p = 0.0027, kappa = 1). Likewise, the identifications derived from WGS from a subset of 14 isolates were in 100% agreement with the MALDI-TOF MS identification. In contrast, biochemical testing misclassified 5 isolates of C. jejuni as C. coli, and 16S rDNA sequencing alone was not able to differentiate between C. coli and C. jejuni for 11 sequences ( p = 0.1573, kappa = 0.0857) when compared to MALDI-TOF MS and WGS. No agreement was observed between MALDI-TOF MS dendrograms and the phylogenetic relationships revealed by rDNA sequencing or WGS. Our results confirm that MALDI-TOF MS is a fast and reliable method for identifying Campylobacter isolates to the species level from wild birds and chickens, but not for elucidating phylogenetic relationships among Campylobacter isolates.

Clinical Imaging of Bone Microarchitecture with HR-pQCT

PubMed Central

Nishiyama, Kyle K.; Shane, Elizabeth

2014-01-01

Osteoporosis, a disease characterized by loss of bone mass and structural deterioration, is currently diagnosed by dual-energy x-ray absorptiometry (DXA). However, DXA does not provide information about bone microstructure, which is a key determinant of bone strength. Recent advances in imaging permit the assessment of bone microstructure in vivo using high-resolution peripheral quantitative computed tomography (HR-pQCT). From these data, novel image processing techniques can be applied to characterize bone quality and strength. To date, most HR-pQCT studies are cross-sectional comparing subjects with and without fracture. These studies have shown that HR-pQCT is capable of discriminating fracture status independent of DXA. Recent longitudinal studies present new challenges in terms of analyzing the same region of interest and multisite calibrations. Careful application of analysis techniques and educated clinical interpretation of HR-pQCT results have improved our understanding of various bone-related diseases and will no doubt continue to do so in the future. PMID:23504496

A multiplexed TOF and DOI capable PET detector using a binary position sensitive network.

PubMed

Bieniosek, M F; Cates, J W; Levin, C S

2016-11-07

Time of flight (TOF) and depth of interaction (DOI) capabilities can significantly enhance the quality and uniformity of positron emission tomography (PET) images. Many proposed TOF/DOI PET detectors require complex readout systems using additional photosensors, active cooling, or waveform sampling. This work describes a high performance, low complexity, room temperature TOF/DOI PET module. The module uses multiplexed timing channels to significantly reduce the electronic readout complexity of the PET detector while maintaining excellent timing, energy, and position resolution. DOI was determined using a two layer light sharing scintillation crystal array with a novel binary position sensitive network. A 20 mm effective thickness LYSO crystal array with four 3 mm  ×  3 mm silicon photomultipliers (SiPM) read out by a single timing channel, one energy channel and two position channels achieved a full width half maximum (FWHM) coincidence time resolution of 180  ±  2 ps with 10 mm of DOI resolution and 11% energy resolution. With sixteen 3 mm  ×  3 mm SiPMs read out by a single timing channel, one energy channel and four position channels a coincidence time resolution 204  ±  1 ps was achieved with 10 mm of DOI resolution and 15% energy resolution. The methods presented here could significantly simplify the construction of high performance TOF/DOI PET detectors.

MALDI-TOF mass spectrometry: an emerging technology for microbial identification and diagnosis

PubMed Central

Singhal, Neelja; Kumar, Manish; Kanaujia, Pawan K.; Virdi, Jugsharan S.

2015-01-01

Currently microorganisms are best identified using 16S rRNA and 18S rRNA gene sequencing. However, in recent years matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a potential tool for microbial identification and diagnosis. During the MALDI-TOF MS process, microbes are identified using either intact cells or cell extracts. The process is rapid, sensitive, and economical in terms of both labor and costs involved. The technology has been readily imbibed by microbiologists who have reported usage of MALDI-TOF MS for a number of purposes like, microbial identification and strain typing, epidemiological studies, detection of biological warfare agents, detection of water- and food-borne pathogens, detection of antibiotic resistance and detection of blood and urinary tract pathogens etc. The limitation of the technology is that identification of new isolates is possible only if the spectral database contains peptide mass fingerprints of the type strains of specific genera/species/subspecies/strains. This review provides an overview of the status and recent applications of mass spectrometry for microbial identification. It also explores the usefulness of this exciting new technology for diagnosis of diseases caused by bacteria, viruses, and fungi. PMID:26300860

A CD45-based barcoding approach to multiplex mass-cytometry (CyTOF).

PubMed

Lai, Liyun; Ong, Raymond; Li, Juntao; Albani, Salvatore

2015-04-01

CyTOF enables the study of the immune system with a complexity, depth, and multidimensionality never achieved before. However, the full potential of using CyTOF can be limited by scarce cell samples. Barcoding strategies developed based on direct labeling of cells using maleimido-monoamide-DOTA (m-DOTA) provide a very useful tool. However, using m-DOTA has some inherent problems, mainly associated with signal intensity. This may be a source of uncertainty when samples are multiplexed. As an alternative or complementary approach to m-DOTA, conjugating an antibody, specific for a membrane protein present on most immune cells, with different isotopes could address the issues of stability and signal intensity needed for effective barcoding. We chose for this purpose CD45, and designed experiments to address different types of cultures and the ability to detect extra- and intra-cellular targets. We show here that our approach provides an useful alternative to m-DOTA in terms of sensitivity, specificity, flexibility, and user-friendliness. Our manuscript provides details to effectively barcode immune cells, overcoming limitations in current technology and enabling the use of CyTOF with scarce samples (for instance precious clinical samples). © 2015 The Authors. Published by Wiley Periodicals, Inc.

Optimization of a ΔE - E detector for 41Ca AMS

NASA Astrophysics Data System (ADS)

Hosoya, Seiji; Sasa, Kimikazu; Matsunaka, Tetsuya; Takahashi, Tsutomu; Matsumura, Masumi; Matsumura, Hiroshi; Sundquist, Mark; Stodola, Mark; Sueki, Keisuke

2017-09-01

A series of nuclides (14C, 26Al, and 36Cl) was measured using the 12UD Pelletron tandem accelerator before replacement by the horizontal 6 MV tandem accelerator at the University of Tsukuba Tandem Accelerator Complex (UTTAC). This paper considers the modification of the accelerator mass spectrometry (AMS) measurement parameters to suit the current 6 MV tandem accelerator setup (e.g., terminal voltage, detected ion charge state, gas pressure, and entrance window material in detector). The Particle and Heavy Ion Transport code System (PHITS) was also used to simulate AMS measurement to determine the best conditions to suppress isobaric interference. The spectra of 41Ca and 41K were then successfully separated and their nuclear spectra were identified; the system achieved a background level of 41Ca/40Ca ∼ 6 ×10-14 .

Implant-specific follow-up imaging of treated intracranial aneurysms: TOF-MRA vs. metal artifact reduced intravenous flat panel computed tomography angiography (FPCTA).

PubMed

Hänsel, N H; Schubert, G A; Scholz, B; Nikoubashman, O; Othman, A E; Wiesmann, M; Pjontek, R; Brockmann, M A

2018-02-01

To compare the diagnostic quality of time-of-flight magnetic resonance angiography (TOF-MRA) and metal-artefact-reduction (MAR) flat-panel-detector computed tomography angiography (FPCTA) and to determine the imaging technique best suited for evaluation endovascular and surgically treated aneurysms. The image quality of TOF-MRA and MAR-FPCTA of 44 intracranial implants (coiling: n=20; clipping: n=15; coiling + stenting: n=9) in a patient cohort of 25 was evaluated by two independent readers. Images obtained using MAR-FPCTA (20 second scan time, 496 projections, intravenous contrast medium administration; Artis Zee, Siemens Healthcare, Forchheim) were compared with TOF-MRA-images (1.5 or 3 T). Nominal data were analysed using McNemar's chi-square test and ordinal variables using the Wilcoxon rank test. Compared to TOF-MRA, MAR-FPCTA was significantly better suited to detect aneurysm remnants and to evaluate parent vessels after clipping (p<0.01). For coil packages >160 mm 3 , TOF-MRA provided significantly better assessment than MAR-FPCTA (p<0.01). For small coil packages (<160 mm 3 ), no significant difference between TOF-MRA and MAR-FPCTA (p=0.232) was observed. For different clip sizes (cut-off 492 mm 3 ) likewise no significant differences were found. The interobserver comparison showed high interrater agreement. MAR-FPCTA is significantly better suited for follow-up examinations of clipped aneurysms, whereas for larger coil packages TOF-MRA is preferable. Smaller coil packages can be analysed using MAR-FPCTA or TOF-MRA. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Composition and structure of surfaces by time-of-flight scattering and recoiling spectrometry (TOF-SARS)

NASA Astrophysics Data System (ADS)

Ahn, Jeongheon

1997-10-01

Time-of-flight scattering and recoiling spectrometry (TOF-SARS) was applied to characterize surface structures in order to understand the chemical and physical phenomena on various surfaces. The combination of TOF-SARS, LEED, and classical ion trajectory simulations has allowed characterization of the elemental composition in the outermost atomic layers, surface symmetry, and possible reconstruction or relaxation. The composition and structure of the CdS\\{0001\\}-(1 x 1) and CdS\\{000bar1\\}-(1 x 1) surfaces were investigated. The termination layer of each surface was determined by grazing incidence TOF-SARS. Both (1 x 1) surfaces are bulk-terminated without any reconstruction or relaxation detected by TOF-SARS. Each surface has two domains which are rotated by 60sp° from each other and there exist steps on both surfaces. The CdS\\{0001\\}-(1 x 1) surface is stabilized by O and H covering half a monolayer which are structurally ordered on the surface, while the O and H on the CdS\\{000bar1\\}-(1 x 1) stabilize the surface without ordering. The study of GaN\\{000bar1\\}-(1 x 1) shows the bulk-termination of the surface with no detectable reconstruction or relaxation. The surface is terminated in a N layer with Ga in the 2sp{nd}-layer. H atoms are bound to the outermost N atoms with a coverage of ˜3/4 monolayer and protrude outward from the surface. The surface termination, composition and structure of the Alsb2Osb3 (sapphire) were examined. The surface relaxation was studied quantitatively using classical ion trajectory simulations along with TOF-SARS. The surface undergoes 1sp{st}{-}2sp{nd}-layer relaxation as large as 0.5 A from the bulk value resulting in near coplanarity of Al and O atoms. The reconstruction of the Ni\\{100\\}-(2 x 2)-C surface was studied by TOF-SARS. The surface contained 80% of the (2 x 2)p4g phase and 20% of the unreconstructed (2 x 2) phase. The displacement of Ni atoms was determined by comparing the experimental and simulated results.

16 CFR Appendix G1 to Part 305 - Furnaces-Gas

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Furnaces-Gas G1 Appendix G1 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE CONCERNING... Part 305—Furnaces—Gas Manufacturer's rated heating capacities (Btu's/hr.) Range of annual fuel...

MALDI-TOF mass spectrometry and high-consequence bacteria: safety and stability of biothreat bacterial sample testing in clinical diagnostic laboratories.

PubMed

Tracz, Dobryan M; Tober, Ashley D; Antonation, Kym S; Corbett, Cindi R

2018-03-01

We considered the application of MALDI-TOF mass spectrometry for BSL-3 bacterial diagnostics, with a focus on the biosafety of live-culture direct-colony testing and the stability of stored extracts. Biosafety level 2 (BSL-2) bacterial species were used as surrogates for BSL-3 high-consequence pathogens in all live-culture MALDI-TOF experiments. Viable BSL-2 bacteria were isolated from MALDI-TOF mass spectrometry target plates after 'direct-colony' and 'on-plate' extraction testing, suggesting that the matrix chemicals alone cannot be considered sufficient to inactivate bacterial culture and spores in all samples. Sampling of the instrument interior after direct-colony analysis did not recover viable organisms, suggesting that any potential risks to the laboratory technician are associated with preparation of the MALDI-TOF target plate before or after testing. Secondly, a long-term stability study (3 years) of stored MALDI-TOF extracts showed that match scores can decrease below the threshold for reliable species identification (<1.7), which has implications for proficiency test panel item storage and distribution.

Identification of prohibitin 1 as a potential prognostic biomarker in human pancreatic carcinoma using modified aqueous two-phase partition system combined with 2D-MALDI-TOF-TOF-MS/MS.

PubMed

Zhong, Ning; Cui, Yazhou; Zhou, Xiaoyan; Li, Tianliang; Han, Jinxiang

2015-02-01

Membrane proteins are an important source of potential targets for anticancer drugs or biomarkers for early diagnosis. In this study, we used a modified aqueous two-phase partition system combined with two-dimensional (2D) matrix-assisted laser desorption ionization (MALDI) time of flight (TOF) mass spectrometry (MS, 2D-MALDI-TOF-TOF-MS/MS) analysis to isolate and identify membrane proteins in PANC-1 pancreatic cancer cells. Using this method, we identified 55 proteins, of which 31 (56.4 %) were membrane proteins, which, according to gene ontology annotation, are associated with various cellular processes including cell signal transduction, differentiation, and apoptosis. Immunohistochemical analysis showed that the expression level of one of the identified mitochondria membrane proteins, prohibitin 1 (PHB1), is correlated with pancreatic carcinoma differentiation; PHB1 is expressed at a higher level in normal pancreatic tissue than in well-differentiated carcinoma tissue. Further studies showed that PHB1 plays a proapoptotic role in human pancreatic cancer cells, which suggests that PHB1 has antitumorigenic properties. In conclusion, we have provided a modified method for isolating and identifying membrane proteins and demonstrated that PHB1 may be a promising biomarker for early diagnosis and therapy of pancreatic (and potentially other) cancers.

A new IBA-AMS laboratory at the Comenius University in Bratislava (Slovakia)

NASA Astrophysics Data System (ADS)

Povinec, Pavel P.; Masarik, Jozef; Kúš, Peter; Holý, Karol; Ješkovský, Miroslav; Breier, Robert; Staníček, Jaroslav; Šivo, Alexander; Richtáriková, Marta; Kováčik, Andrej; Szarka, Ján; Steier, Peter; Priller, Alfred

2015-01-01

A Centre for Nuclear and Accelerator Technologies (CENTA) has been established at the Comenius University in Bratislava comprising of a tandem laboratory designed for Ion Beam Analysis (IBA), Ion Beam Modification (IBM) of materials and Accelerator Mass Spectrometry (AMS). The main equipment of the laboratory, i.e. Alphatross and MC-SNICS ion sources, 3 MV Pelletron tandem accelerator, and analyzers of accelerated ions are described. Optimization of ion beam characteristics for different ion sources with gas and solid targets, for transmission of accelerated ions with different energy and charge state, for different parameters of the high-energy ion analyzers, as well as first AMS results are presented. The scientific program of the CENTA will be devoted mainly to nuclear, environmental, life and material sciences.

Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass-Spectrometry (MALDI-TOF MS) Based Microbial Identifications: Challenges and Scopes for Microbial Ecologists

PubMed Central

Rahi, Praveen; Prakash, Om; Shouche, Yogesh S.

2016-01-01

Matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS) based biotyping is an emerging technique for high-throughput and rapid microbial identification. Due to its relatively higher accuracy, comprehensive database of clinically important microorganisms and low-cost compared to other microbial identification methods, MALDI-TOF MS has started replacing existing practices prevalent in clinical diagnosis. However, applicability of MALDI-TOF MS in the area of microbial ecology research is still limited mainly due to the lack of data on non-clinical microorganisms. Intense research activities on cultivation of microbial diversity by conventional as well as by innovative and high-throughput methods has substantially increased the number of microbial species known today. This important area of research is in urgent need of rapid and reliable method(s) for characterization and de-replication of microorganisms from various ecosystems. MALDI-TOF MS based characterization, in our opinion, appears to be the most suitable technique for such studies. Reliability of MALDI-TOF MS based identification method depends mainly on accuracy and width of reference databases, which need continuous expansion and improvement. In this review, we propose a common strategy to generate MALDI-TOF MS spectral database and advocated its sharing, and also discuss the role of MALDI-TOF MS based high-throughput microbial identification in microbial ecology studies. PMID:27625644

Rapid identification of oral Actinomyces species cultivated from subgingival biofilm by MALDI-TOF-MS

PubMed Central

Stingu, Catalina S.; Borgmann, Toralf; Rodloff, Arne C.; Vielkind, Paul; Jentsch, Holger; Schellenberger, Wolfgang; Eschrich, Klaus

2015-01-01

Background Actinomyces are a common part of the residential flora of the human intestinal tract, genitourinary system and skin. Isolation and identification of Actinomyces by conventional methods is often difficult and time consuming. In recent years, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has become a rapid and simple method to identify bacteria. Objective The present study evaluated a new in-house algorithm using MALDI-TOF-MS for rapid identification of different species of oral Actinomyces cultivated from subgingival biofilm. Design Eleven reference strains and 674 clinical strains were used in this study. All the strains were preliminarily identified using biochemical methods and then subjected to MALDI-TOF-MS analysis using both similarity-based analysis and classification methods (support vector machine [SVM]). The genotype of the reference strains and of 232 clinical strains was identified by sequence analysis of the 16S ribosomal RNA (rRNA). Results The sequence analysis of the 16S rRNA gene of all references strains confirmed their previous identification. The MALDI-TOF-MS spectra obtained from the reference strains and the other clinical strains undoubtedly identified as Actinomyces by 16S rRNA sequencing were used to create the mass spectra reference database. Already a visual inspection of the mass spectra of different species reveals both similarities and differences. However, the differences between them are not large enough to allow a reliable differentiation by similarity analysis. Therefore, classification methods were applied as an alternative approach for differentiation and identification of Actinomyces at the species level. A cross-validation of the reference database representing 14 Actinomyces species yielded correct results for all species which were represented by more than two strains in the database. Conclusions Our results suggest that a combination of MALDI-TOF-MS with powerful

MALDI-TOF MS typing of a nosocomial methicillin-resistant Staphylococcus aureus outbreak in a neonatal intensive care unit.

PubMed

Steensels, Deborah; Deplano, Ariane; Denis, Olivier; Simon, Anne; Verroken, Alexia

2017-08-01

The early detection of a methicillin-resistant Staphylococcus aureus (MRSA) outbreak is decisive to control its spread and rapidly initiate adequate infection control measures. Therefore, prompt determination of epidemiologic relatedness of clinical MRSA isolates is essential. Genetic typing methods have a high discriminatory power but their availability remains restricted. In this study, we aimed to challenge matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a typing tool of a nosocomial MRSA outbreak in a neonatal intensive care unit. Over a 2-year period, 15 MRSA isolates were recovered from patients (n = 14) and health care workers (n = 1) at the neonatal intensive care unit. Five reference strains were included for comparison. Identification was performed by MALDI-TOF MS and susceptibility profiles determined by automated broth microdilution. Typing analysis by MALDI-TOF MS included mean spectrum profiles and subsequent dendrogram creation using BioNumerics software. Results were compared with spa typing and pulsed-field gel electrophoresis (PFGE). Our study showed good concordance (93%) between PFGE, spa typing, and MALDI-TOF MS for the outbreak-related MRSA strains. MALDI-TOF MS typing showed excellent typeability and discriminatory power but showed poor reproducibility. This study is one of the first to document the potential usefulness of MALDI-TOF MS with standardized data analysis as a typing tool for investigating a nosocomial MRSA outbreak. A concordance of 93% compared to reference typing techniques was observed. However, because of poor reproducibility, long-term follow-up of prospective isolated strains is not practical for routine use. Further studies are needed to confirm our observations.

Chemometric classification of morphologically similar Umbelliferae medicinal herbs by DART-TOF-MS fingerprint.

PubMed

Lee, Sang Min; Kim, Hye-Jin; Jang, Young Pyo

2012-01-01

It needs many years of special training to gain expertise on the organoleptic classification of botanical raw materials and, even for those experts, discrimination among Umbelliferae medicinal herbs remains an intricate challenge due to their morphological similarity. To develop a new chemometric classification method using a direct analysis in real time-time of flight-mass spectrometry (DART-TOF-MS) fingerprinting for Umbelliferae medicinal herbs and to provide a platform for its application to the discrimination of other herbal medicines. Angelica tenuissima, Angelica gigas, Angelica dahurica and Cnidium officinale were chosen for this study and ten samples of each species were purchased from various Korean markets. DART-TOF-MS was employed on powdered raw materials to obtain a chemical fingerprint of each sample and the orthogonal partial-least squares method in discriminant analysis (OPLS-DA) was used for multivariate analysis. All samples of collected species were successfully discriminated from each other according to their characteristic DART-TOF-MS fingerprint. Decursin (or decursinol angelate) and byakangelicol were identified as marker molecules for Angelica gigas and A. dahurica, respectively. Using the OPLS method for discriminant analysis, Angelica tenuissima and Cnidium officinale were clearly separated into two groups. Angelica tenuissima was characterised by the presence of ligustilide and unidentified molecular ions of m/z 239 and 283, while senkyunolide A together with signals with m/z 387 and 389 were the marker compounds for Cnidium officinale. Elaborating with chemoinformatics, DART-TOF-MS fingerprinting with chemoinformatic tools results in a powerful method for the classification of morphologically similar Umbelliferae medicinal herbs and quality control of medicinal herbal products, including the extracts of these crude drugs. Copyright © 2012 John Wiley & Sons, Ltd.

H.R. 1992, the Internet Equity and Education Act of 2001. Hearing before the Subcommittee on 21st Century Competitiveness of the Committee on Education and the Workforce. House of Representatives, One Hundred Seventh Congress, First Session (June 20, 2001).

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. House Committee on Education and the Workforce.

The Subcommittee on 21st Century Competitiveness, Committee on Education and the Workforce, U.S. House of Representatives met at 10:33 a.m. on Wednesday, June 20, 2001, in Room 2175, Rayburn House Office Building to hear testimony on H.R. 1992, the Internet Equity and Education Act of 2001. Chairman of the Subcommittee, Hon. Howard P.…

The Elevation of LC-ESI-Q-TOF-MS Response in the Analysis of Isoquinoline Alkaloids from Some Papaveraceae and Berberidaceae Representatives.

PubMed

Kukula-Koch, Wirginia

2017-01-01

Twenty-five methanol extracts obtained from various representatives of Papaveraceae and Berberidaceae botanical families (genera: Papaver , Argemone , Eschscholzia , Chelidonium , Glaucium , and Berberis ) were screened for their alkaloid content in an optimized method suitable for the LC-ESI-Q-TOF-MS analysis. Twelve pharmacologically important isoquinoline alkaloids from four groups, aporphines, benzylisoquinolines, protoberberines, and benzophenanthridines, present in these traditionally used plant species were quantitatively determined in each studied sample, providing their alkaloid profile. A Zorbax Stable Bond RP-18 column and a mobile phase composed of 0.1% formic acid and 0.1% formic acid in acetonitrile (v/v) were used at the flow rate of 0.2 mL/min. A profound study on the optimization of MS response to four groups of isoquinoline alkaloids (validation of capillary voltage, gas flows, nebulizer pressure, skimmer, and fragmentor voltages), repeatability of results, and stability and linearity of measurements were described, showing, among others, 3000 V of capillary voltage, 350°C of gas temperature, 12 L/min of gas flows, nebulizer pressure of 35 psig, 65 V for skimmer voltage, and 30 V for collision energy as the most advantageous operation parameters.

The Elevation of LC-ESI-Q-TOF-MS Response in the Analysis of Isoquinoline Alkaloids from Some Papaveraceae and Berberidaceae Representatives

PubMed Central

2017-01-01

Twenty-five methanol extracts obtained from various representatives of Papaveraceae and Berberidaceae botanical families (genera: Papaver, Argemone, Eschscholzia, Chelidonium, Glaucium, and Berberis) were screened for their alkaloid content in an optimized method suitable for the LC-ESI-Q-TOF-MS analysis. Twelve pharmacologically important isoquinoline alkaloids from four groups, aporphines, benzylisoquinolines, protoberberines, and benzophenanthridines, present in these traditionally used plant species were quantitatively determined in each studied sample, providing their alkaloid profile. A Zorbax Stable Bond RP-18 column and a mobile phase composed of 0.1% formic acid and 0.1% formic acid in acetonitrile (v/v) were used at the flow rate of 0.2 mL/min. A profound study on the optimization of MS response to four groups of isoquinoline alkaloids (validation of capillary voltage, gas flows, nebulizer pressure, skimmer, and fragmentor voltages), repeatability of results, and stability and linearity of measurements were described, showing, among others, 3000 V of capillary voltage, 350°C of gas temperature, 12 L/min of gas flows, nebulizer pressure of 35 psig, 65 V for skimmer voltage, and 30 V for collision energy as the most advantageous operation parameters. PMID:29435385

African American Accounting Majors and the 150-hr Requirement

ERIC Educational Resources Information Center

Booker, Quinton; Hill, Cecil L.; Wright, Carl

2010-01-01

The study provides information on African American accounting majors' views regarding 150-hr issues. The authors collected data from 152 students at two schools. Students at one school supported the requirement while those at the other school did not. However, students believed that the 150-hr requirement enhances the quality of certified public…

Outsourcing HR Services: The Role of Human Resource Intermediaries

ERIC Educational Resources Information Center

Kock, Henrik; Wallo, Andreas; Nilsson, Barbro; Hoglund, Cecilia

2012-01-01

Purpose: In this article, the area of interest is an emerging type of organisation called human resource intermediaries (HRIs), which focus on delivering human resource (HR) services to public sector organisations and private companies. The purpose of this article is, thus, to explore HRIs as deliverers of HR services. More specifically, the…

Evaluation of capacity to detect ability to form biofilm in Candida parapsilosis sensu stricto strains by MALDI-TOF MS.

PubMed

Mlynáriková, Katarína; Šedo, Ondrej; Růžička, Filip; Zdráhal, Zbyněk; Holá, Veronika; Mahelová, Martina

2016-11-01

Matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is, currently, used as a rapid and reliable tool in microbial diagnostics. The discriminatory power of the method extends its applicability also beyond species level. This study examined the possibility to use MALDI-TOF MS to differentiate between Candida parapsilosis sensu stricto biofilm-positive (n = 12) and biofilm-negative (n = 9) strains. The results indicated a grouping trend within MALDI-TOF mass spectra belonging to each of the tested groups. However, these trends were eclipsed by mass spectral variations resulting from limited repeatability of the method, making its application for the selected purpose impossible. Improvement in the discriminatory power of the method was not obtained neither by using different matrices (α-cyano-4-hydroxycinnamic acid, ferulic acid, 5-chloro-2-mercaptobenzothionazole) for MALDI-TOF MS analysis nor by testing different culture conditions (cultivation length, culture media).

Neutron cross section measurements at n-TOF for ADS related studies

NASA Astrophysics Data System (ADS)

Mastinu, P. F.; Abbondanno, U.; Aerts, G.; Álvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Bustreo, N.; aumann, P.; vá, F. Be; Berthoumieux, E.; Calviño, F.; Cano-Ott, D.; Capote, R.; Carrillo de Albornoz, A.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Dolfini, R.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; itzpatrick, L.; Frais-Kölbl, H.; Fujii, K.; Furman, W.; Guerrero, C.; Goncalves, I.; Gallino, R.; Gonzalez-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Isaev, S.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karamanis, D.; Karadimos, D.; Kerveno, M.; Ketlerov, V.; Koehler, P.; Konovalov, V.; Kossionides, E.; Krti ka, M.; Lamboudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marques, L.; Marrone, S.; Massimi, C.; Mengoni, A.; Milazzo, P. M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Oshima, M.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rosetti, M.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wendler, H.; Wiescherand, M.; Wisshak, K.

2006-05-01

A neutron Time-of-Flight facility (n_TOF) is available at CERN since 2001. The innovative features of the neutron beam, in particular the high instantaneous flux, the wide energy range, the high resolution and the low background, make this facility unique for measurements of neutron induced reactions relevant to the field of Emerging Nuclear Technologies, as well as to Nuclear Astrophysics and Fundamental Nuclear Physics. The scientific motivations that have led to the construction of this new facility are here presented. The main characteristics of the n_TOF neutron beam are described, together with the features of the experimental apparata used for cross-section measurements. The main results of the first measurement campaigns are presented. Preliminary results of capture cross-section measurements of minor actinides, important to ADS project for nuclear waste transmutation, are finally discussed.

AMS Prototyping Activities

NASA Technical Reports Server (NTRS)

Burleigh, Scott

2008-01-01

This slide presentation reviews the activity around the Asynchronous Message Service (AMS) prototype. An AMS reference implementation has been available since late 2005. It is aimed at supporting message exchange both in on-board environments and over space links. The implementation incoroporates all mandatory elements of the draft recommendation from July 2007: (1) MAMS, AMS, and RAMS protocols. (2) Failover, heartbeats, resync. (3) "Hooks" for security, but no cipher suites included in the distribution. The performance is reviewed, and a Benchmark latency test over VxWorks Message Queues is shown as histograms of a count vs microseconds per 1000-byte message

Obstacle Classification and 3D Measurement in Unstructured Environments Based on ToF Cameras

PubMed Central

Yu, Hongshan; Zhu, Jiang; Wang, Yaonan; Jia, Wenyan; Sun, Mingui; Tang, Yandong

2014-01-01

Inspired by the human 3D visual perception system, we present an obstacle detection and classification method based on the use of Time-of-Flight (ToF) cameras for robotic navigation in unstructured environments. The ToF camera provides 3D sensing by capturing an image along with per-pixel 3D space information. Based on this valuable feature and human knowledge of navigation, the proposed method first removes irrelevant regions which do not affect robot's movement from the scene. In the second step, regions of interest are detected and clustered as possible obstacles using both 3D information and intensity image obtained by the ToF camera. Consequently, a multiple relevance vector machine (RVM) classifier is designed to classify obstacles into four possible classes based on the terrain traversability and geometrical features of the obstacles. Finally, experimental results in various unstructured environments are presented to verify the robustness and performance of the proposed approach. We have found that, compared with the existing obstacle recognition methods, the new approach is more accurate and efficient. PMID:24945679

Exploring MALDI-TOF MS approach for a rapid identification of Mycobacterium avium ssp. paratuberculosis field isolates.

PubMed

Ricchi, M; Mazzarelli, A; Piscini, A; Di Caro, A; Cannas, A; Leo, S; Russo, S; Arrigoni, N

2017-03-01

The aim of the study was to explore the suitability of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) for a rapid and correct identification of Mycobacterium avium ssp. paratuberculosis (MAP) field isolates. MALDI-TOF MS approach is becoming one of the most popular tests for the identification of intact bacterial cells which has been shown to be fast and reliable. For this purpose, 36 MAP field isolates were analysed through MALDI-TOF MS and the spectra compared with two different databases: one provided by the vendor of the system employed (Biotyper ver. 3·0; Bruker Daltonics) and a homemade database containing spectra from both tuberculous and nontuberculous Mycobacteria. Moreover, principal component analysis procedure was employed to confirm the ability of MALDI-TOF MS to discriminate between very closely related subspecies. Our results suggest MAP can be differentiated from other Mycobacterium species, both when the species are very close (M. intracellulare) and when belonging to different subspecies (M. avium ssp. avium and M. avium ssp. silvaticum). The procedure applied is fast, easy to perform, and achieves an earlier accurate species identification of MAP and nontuberculous Mycobacteria in comparison to other procedures. The gold standard test for the diagnosis of paratuberculosis is still isolation of MAP by cultural methods, but additional assays, such as qPCR and subculturing for determination of mycobactin dependency are required to confirm its identification. We have provided here evidence pertaining to the usefulness of MALDI-TOF MS approach for a rapid identification of this mycobacterium among other members of M. avium complex. © 2016 The Society for Applied Microbiology.

DISCOVERY OF A LOW-MASS COMPANION AROUND HR 3549

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mawet, D.; David, T.; Bottom, M.

2015-10-01

We report the discovery of a low-mass companion to HR 3549, an A0V star surrounded by a debris disk with a warm excess detected by WISE at 22 μm (10σ significance). We imaged HR 3549 B in the L band with NAOS-CONICA, the adaptive optics infrared camera of the Very Large Telescope, in January 2013 and confirmed its common proper motion in 2015 January. The companion is at a projected separation of ≃80 AU and position angle of ≃157°, so it is orbiting well beyond the warm disk inner edge of r > 10 AU. Our age estimate for thismore » system corresponds to a companion mass in the range 15–80 M{sub J}, spanning the brown dwarf regime, and so HR 3549 B is another recent addition to the growing list of brown dwarf desert objects with extreme mass ratios. The simultaneous presence of a warm disk and a brown dwarf around HR 3549 provides interesting empirical constraints on models of the formation of substellar companions.« less

T wave alternans threshold late after repair of tetralogy of Fallot

NASA Technical Reports Server (NTRS)

Cheung, Michael M H.; Weintraub, Robert G.; Cohen, Richard J.; Karl, Tom R.; Wilkinson, James L.; Davis, Andrew M.

2002-01-01

INTRODUCTION: Sustained microvolt-level T wave alternans (TWA) is a marker of increased risk for malignant ventricular arrhythmia. There is a significant risk of arrhythmia and sudden death after repair of congenital heart disease. The aim of this study was to determine the prevalence and characteristics of TWA after repair of tetralogy of Fallot (TOF). METHODS AND RESULTS: TWA was evaluated during bicycle exercise in 49 subjects who had consecutively undergone transatrial-transpulmonary repair. Median values for age, age at repair, and follow-up duration were 14.9 years (11.5-20.8), 1.6 years (0.2-4.9), and 11.6 years (9.4-17.2), respectively. All patients were in New York Heart Association functional class I and were asymptomatic. Median QRS duration was 120 msec (80-150). Sustained TWA was detected in 7 (23%) of 31 subjects with adequate tests. In these 7 subjects, median onset heart rate (HR) was 120 (98-155). Median HR threshold as a percentage of predicted maximum HR (220 - age) was 58% (48-77). Sustained TWA prevalence was not significantly different compared with normal subjects (7/31 vs 9/83; P = 0.1). Onset HR in the TOF group was significantly lower [mean (SD) of 122 (20) vs 139 (12), P < 0.05]. In the TOF group with sustained TWA, the TWA occurred in 4 of 7 at <60% predicted maximum HR versus 1 of 9 normal subjects (P < 0.05); 3 of 7 had onset HR <120 versus 0 of 9 normal subjects (P < 0.03). There was no significant difference in age, gender, transannular patch use, restrictive right ventricular physiology, QRS duration, QTc, QT/QRS dispersion, or nonsustained ventricular tachycardia in subjects with or those without sustained TWA. CONCLUSION: The onset HR for sustained TWA is significantly lower after repair of TOF. Further study is required to determine whether this represents an increased risk for arrhythmia in this patient group.

[Rapid identification of two new isomers in bear bile powder by LC-Q-TOF-MS combined with PCC oxidation].

PubMed

Jian, Long-Hai; Hu, Chun; Yu, Hong; Wang, Ke; Ji, Shen

2013-07-01

A rapid method of Liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) combined with pyridinium chlorochromate (PCC) oxidation has been developed to determine chemical structures of two novel isomers in bear bile powder. Derivatives of ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) were semi-synthesized by PCC oxidation, then were analyzed by LC-Q-TOF-MS. Separation was carried out on a reverse column with the mobile phase of acetonitrile-0.1% formic acid (45:55). The data of Q-TOF-MS was acquired by MS, MS/MS, positive and negative modes. Since UDCA and CDCA were stereochemical isomeric at an alcohol position, two oxidation products were same and have been confirmed by LC-Q-TOF-MS. Other two products were also determined based on the PCC oxidation theory. Samples of bear bile powder were dissolved by methanol and measured by LC-Q-TOF-MS. Two unknown peaks were found and identified by matching their retention times and accurate mass spectra ions with PCC oxidation productS. Finally, the structures of two new bile acids in bear bile powder were confirmed as 3alpha-hydroxy-7-oxo-5beta-cholanic acid, 7alpha-hydroxy-3-oxo-5beta-cholanic acid, respectively.

Enabling quaternion derivatives: the generalized HR calculus

PubMed Central

Xu, Dongpo; Jahanchahi, Cyrus; Took, Clive C.; Mandic, Danilo P.

2015-01-01

Quaternion derivatives exist only for a very restricted class of analytic (regular) functions; however, in many applications, functions of interest are real-valued and hence not analytic, a typical case being the standard real mean square error objective function. The recent HR calculus is a step forward and provides a way to calculate derivatives and gradients of both analytic and non-analytic functions of quaternion variables; however, the HR calculus can become cumbersome in complex optimization problems due to the lack of rigorous product and chain rules, a consequence of the non-commutativity of quaternion algebra. To address this issue, we introduce the generalized HR (GHR) derivatives which employ quaternion rotations in a general orthogonal system and provide the left- and right-hand versions of the quaternion derivative of general functions. The GHR calculus also solves the long-standing problems of product and chain rules, mean-value theorem and Taylor's theorem in the quaternion field. At the core of the proposed GHR calculus is quaternion rotation, which makes it possible to extend the principle to other functional calculi in non-commutative settings. Examples in statistical learning theory and adaptive signal processing support the analysis. PMID:26361555

Enabling quaternion derivatives: the generalized HR calculus.

PubMed

Xu, Dongpo; Jahanchahi, Cyrus; Took, Clive C; Mandic, Danilo P

2015-08-01

Quaternion derivatives exist only for a very restricted class of analytic (regular) functions; however, in many applications, functions of interest are real-valued and hence not analytic, a typical case being the standard real mean square error objective function. The recent HR calculus is a step forward and provides a way to calculate derivatives and gradients of both analytic and non-analytic functions of quaternion variables; however, the HR calculus can become cumbersome in complex optimization problems due to the lack of rigorous product and chain rules, a consequence of the non-commutativity of quaternion algebra. To address this issue, we introduce the generalized HR (GHR) derivatives which employ quaternion rotations in a general orthogonal system and provide the left- and right-hand versions of the quaternion derivative of general functions. The GHR calculus also solves the long-standing problems of product and chain rules, mean-value theorem and Taylor's theorem in the quaternion field. At the core of the proposed GHR calculus is quaternion rotation, which makes it possible to extend the principle to other functional calculi in non-commutative settings. Examples in statistical learning theory and adaptive signal processing support the analysis.

Secondary Organic Aerosol Formation in the Captive Aerosol Growth and Evolution (CAGE) Chambers during the Southern Oxidant and Aerosol Study (SOAS) in Centreville, AL

NASA Astrophysics Data System (ADS)

Leong, Y.; Karakurt Cevik, B.; Hernandez, C.; Griffin, R. J.; Taylor, N.; Matus, J.; Collins, D. R.

2013-12-01

Secondary organic aerosol (SOA) represents a large portion of sub-micron particulate matter on a global scale. The composition of SOA and its formation processes are heavily influenced by anthropogenic and biogenic activity. Volatile organic compounds (VOCs) that are emitted naturally from forests or from human activity serve as precursors to SOA formation. Biogenic SOA (BSOA) is formed from biogenic VOCs and is prevalent in forested regions like the Southeastern United States. The formation and enhancement of BSOA under anthropogenic influences such as nitrogen oxides (NOx), sulfur dioxide (SO2), and oxygen radicals are still not well understood. The lack of information on anthropogenic BSOA enhancement and the reversibility of SOA formation could explain the underprediction of SOA in current models. To address some of these gaps in knowledge, this study was conducted as part of the Southern Oxidant and Aerosol Study (SOAS) in Centreville, AL during the summer of 2013. SOA growth experiments were conducted in two Captive Aerosol Growth and Evolution (CAGE) outdoor chambers located at the SEARCH site. Ambient trace gas concentrations were maintained in these chambers using semi-permeable gas-exchange membranes, while studying the growth of injected monodisperse seed aerosol. The control chamber was operated under ambient conditions; the relative humidity and oxidant and NOx levels were perturbed in the second chamber. This design allows experiments to capture the natural BSOA formation processes in the southeastern atmosphere and to study the influence of anthropogenic activity on aerosol chemistry. Chamber experiments were periodically monitored with physical and chemical instrumentation including a scanning mobility particle sizer (SMPS), a cloud condensation nuclei counter (CCNC), a humidified tandem differential mobility analyzer (H-TDMA), and an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The CAGE experiments focused on SOA

Evaluation of MALDI-TOF MS (Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry) for routine identification of anaerobic bacteria.

PubMed

Rodríguez-Sánchez, Belén; Alcalá, Luis; Marín, Mercedes; Ruiz, Adrián; Alonso, Elena; Bouza, Emilio

2016-12-01

Information regarding the use of MALDI-TOF MS as an alternative to conventional laboratory methods for the rapid and reliable identification of bacterial isolates is still limited. In this study, MALDI-TOF MS was evaluated on 295 anaerobic isolates previously identified by 16S rRNA gene sequencing and with biochemical tests (Rapid ID 32A system, BioMérieux). In total, 85.8% of the isolates were identified by MALDI-TOF MS at the species level vs 49.8% using the Rapid ID 32A system (p < 0.0001). None of the isolates was discordantly identified at the genus level using MALDI-TOF MS and only 9 of them could not be identified using the method. Thus, our results show that MALDI-TOF MS is a robust and reliable tool for the identification of anaerobic isolates in the microbiology laboratory. Its implementation will reduce the turnaround time for a final identification and the number of isolates that require 16S rRNA sequencing. Copyright © 2016 Elsevier Ltd. All rights reserved.

HR Positions on the Internet.

ERIC Educational Resources Information Center

Coghill, Carey Cox; Kirk, James J.

The question of whether the online job market reflects the trends predicted for the job market was examined in a study of a random sample of 690 Internet job postings over a 6-month period. Each listing was categorized by type of position, desired qualifications, salary, and job specifications. Of the human resources (HR) jobs posted, 7.2% were…

The subunits of the S-phase checkpoint complex Mrc1/Tof1/Csm3: dynamics and interdependence

PubMed Central

2014-01-01

Background The S-phase checkpoint aims to prevent cells from generation of extensive single-stranded DNA that predisposes to genome instability. The S. cerevisiae complex Tof1/Csm3/Mrc1 acts to restrain the replicative MCM helicase when DNA synthesis is prohibited. Keeping the replication machinery intact allows restart of the replication fork when the block is relieved. Although the subunits of the Tof1/Csm3/Mrc1 complex are well studied, the impact of every single subunit on the triple complex formation and function needs to be established. Findings This work studies the cellular localization and the chromatin binding of GFP-tagged subunits when the complex is intact and when a subunit is missing. We demonstrate that the complex is formed in cell nucleus, not the cytoplasm, as Tof1, Csm3 and Mrc1 enter the nucleus independently from one another. Via in situ chromatin binding assay we show that a Tof1-Csm3 dimer formation and chromatin binding is required to ensure the attachment of Mrc1 to chromatin. Our study indicates that the translocation into the nucleus is not the process to regulate the timing of chromatin association of Mrc1. We also studied the nuclear behavior of Mrc1 subunit in the process of adaptation to the presence hydroxyurea. Our results indicate that after prolonged HU incubation, cells bypass the S-phase checkpoint and proceed throughout the cell cycle. This process is accompanied by Mrc1 chromatin detachment and Rad53 dephosphorylation. Conclusions In S. cerevisiae the subunits of the S-phase checkpoint complex Mrc1/Tof1/Csm3 independently enter the cell nucleus, where a Tof1-Csm3 dimer is formed to ensure the chromatin binding of Mrc1 and favor DNA replication and S-phase checkpoint fork arrest. In the process of adaptation to the presence of hydroxyurea Mrc1 is detached from chromatin and Rad53 checkpoint activity is diminished in order to allow S-phase checkpoint escape and completion of the cell cycle. PMID:25379053

The subunits of the S-phase checkpoint complex Mrc1/Tof1/Csm3: dynamics and interdependence.

PubMed

Uzunova, Sonya Dimitrova; Zarkov, Alexander Stefanov; Ivanova, Anna Marianova; Stoynov, Stoyno Stefanov; Nedelcheva-Veleva, Marina Nedelcheva

2014-01-01

The S-phase checkpoint aims to prevent cells from generation of extensive single-stranded DNA that predisposes to genome instability. The S. cerevisiae complex Tof1/Csm3/Mrc1 acts to restrain the replicative MCM helicase when DNA synthesis is prohibited. Keeping the replication machinery intact allows restart of the replication fork when the block is relieved. Although the subunits of the Tof1/Csm3/Mrc1 complex are well studied, the impact of every single subunit on the triple complex formation and function needs to be established. This work studies the cellular localization and the chromatin binding of GFP-tagged subunits when the complex is intact and when a subunit is missing. We demonstrate that the complex is formed in cell nucleus, not the cytoplasm, as Tof1, Csm3 and Mrc1 enter the nucleus independently from one another. Via in situ chromatin binding assay we show that a Tof1-Csm3 dimer formation and chromatin binding is required to ensure the attachment of Mrc1 to chromatin. Our study indicates that the translocation into the nucleus is not the process to regulate the timing of chromatin association of Mrc1. We also studied the nuclear behavior of Mrc1 subunit in the process of adaptation to the presence hydroxyurea. Our results indicate that after prolonged HU incubation, cells bypass the S-phase checkpoint and proceed throughout the cell cycle. This process is accompanied by Mrc1 chromatin detachment and Rad53 dephosphorylation. In S. cerevisiae the subunits of the S-phase checkpoint complex Mrc1/Tof1/Csm3 independently enter the cell nucleus, where a Tof1-Csm3 dimer is formed to ensure the chromatin binding of Mrc1 and favor DNA replication and S-phase checkpoint fork arrest. In the process of adaptation to the presence of hydroxyurea Mrc1 is detached from chromatin and Rad53 checkpoint activity is diminished in order to allow S-phase checkpoint escape and completion of the cell cycle.

Cosensitized Porphyrin System for High-Performance Solar Cells with TOF-SIMS Analysis.

PubMed

Wu, Wenjun; Xiang, Huaide; Fan, Wei; Wang, Jinglin; Wang, Haifeng; Hua, Xin; Wang, Zhaohui; Long, Yitao; Tian, He; Zhu, Wei-Hong

2017-05-17

To date, development of organic sensitizers has been predominately focused on light harvesting, highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels, and the electron transferring process. In contrast, their adsorption mode as well as the dynamic loading behavior onto nanoporous TiO 2 is rarely considered. Herein, we have employed the time-of-flight secondary ion mass spectrometry (TOF-SIMS) to gain insight into the competitive dye adsorption mode and kinetics in the cosensitized porphyrin system. Using novel porphyrin dye FW-1 and D-A-π-A featured dye WS-5, the different bond-breaking mode in TOF-SIMS and dynamic dye-loading amount during the coadsorption process are well-compared with two different anchoring groups, such as benzoic acid and cyanoacrylic acid. With the bombardment mode in TOF-SIMS spectra, we have speculated that the cyano group grafts onto nanoporous TiO 2 as tridentate binding for the common anchoring unit of cyanoacrylic acid and confirmed it through extensive first-principles density functional theory calculation by anchoring either the carboxyl or cyano group, which shows that the cyano group can efficiently participate in the adsorption of the WS-5 molecule onto the TiO 2 nanocrystal. The grafting reinforcement interaction between the cyano group and TiO 2 in WS-5 can well-explain the rapid adsorption characteristics. A strong coordinate bond between the lone pair of electrons on the nitrogen or oxygen atom and the Lewis acid sites of TiO 2 can increase electron injection efficiencies with respect to those from the bond between the benzoic acid group and the Brønsted acid sites of the TiO 2 surface. Upon optimization of the coadsorption process with dye WS-5, the photoelectric conversion efficiency based on porphyrin dye FW-1 is increased from 6.14 to 9.72%. The study on the adsorption dynamics of organic sensitizers with TOF-SIMS analysis might provide a new venue for improvement of cosensitized solar

Evolution of Asian aerosols during transpacific transport in INTEX-B

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunlea, E. J.; DeCarlo, Peter; Aiken, Allison

2009-10-01

Measurements of aerosol composition were made with an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) on board the NSF/NCAR C-130 aircraft as part of the Intercontinental Chemical Transport Experiment Phase B 5 (INTEX-B) field campaign over the Eastern Pacific Ocean. The HR-ToF-AMS measurements of non-refractory submicron aerosol mass are shown to compare well with other aerosol instrumentation in the INTEX-B field study. Two case studies are described for pollution layers transported across the Pacific from the Asian continent, intercepted 3–4 days and 7–10 days downwind of Asia, respectively. Aerosol chemistry is shown to 10 be a robust tracer formore » air masses originating in Asia, specifically the presence of sulfate dominated aerosol is a distinguishing feature of Asian pollution layers that have been transported to the Eastern Pacific. We examine the time scales of processing for sulfate and organic aerosol in the atmosphere and show that our observations confirm a conceptual model for transpacific transport from Asia proposed by Brock et al. (2004). 15 Our observations of both sulfate and organic aerosol in aged Asian pollution layers are consistent with fast formation near the Asian continent, followed by washout during lofting and subsequent transformation during transport across the Pacific. Our observations are the first atmospheric measurements to indicate that although secondary organic aerosol (SOA) formation from pollution happens on the timescale of one day, 20 the oxidation of organic aerosol continues at longer timescales in the atmosphere. Comparisons with chemical transport models of data from the entire campaign reveal an under-prediction of SOA mass in the MOZART model, but much smaller discrepancies with the GEOS-Chem model than found in previous studies over the Western Pacific. No evidence is found to support a previous hypothesis for significant secondary 25 organic aerosol formation in the free

Development of a TOF SIMS setup at the Zagreb heavy ion microbeam facility

NASA Astrophysics Data System (ADS)

Tadić, Tonči; Bogdanović Radović, Iva; Siketić, Zdravko; Cosic, Donny Domagoj; Skukan, Natko; Jakšić, Milko; Matsuo, Jiro

2014-08-01

We describe a new Time-of-flight Secondary Ion Mass Spectrometry (TOF SIMS) setup for MeV SIMS application, which is constructed and installed at the heavy ion microbeam facility at the Ruđer Bošković Institute in Zagreb. The TOF-SIMS setup is developed for high sensitivity molecular imaging using a heavy ion microbeam that focuses ion beams (from C to I) with sub-micron resolution. Dedicated pulse processing electronics for MeV SIMS application have been developed, enabling microbeam-scanning control, incoming ion microbeam pulsing and molecular mapping. The first results showing measured MeV SIMS spectra as well as molecular maps for samples of interest are presented and discussed.

[MALDI-TOF mass spectrometry in the investigation of large high-molecular biological compounds].

PubMed

Porubl'ova, L V; Rebriiev, A V; Hromovyĭ, T Iu; Minia, I I; Obolens'ka, M Iu

2009-01-01

MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight) mass spectrometry has become, in the recent years, a tool of choice for analyses of biological polymers. The wide mass range, high accuracy, informativity and sensitivity make it a superior method for analysis of all kinds of high-molecular biological compounds including proteins, nucleic acids and lipids. MALDI-TOF-MS is particularly suitable for the identification of proteins by mass fingerprint or microsequencing. Therefore it has become an important technique of proteomics. Furthermore, the method allows making a detailed analysis of post-translational protein modifications, protein-protein and protein-nucleic acid interactions. Recently, the method was also successfully applied to nucleic acid sequencing as well as screening for mutations.

Anesthetic gas exposure in veterinary clinics.

PubMed

Korczynski, R E

1999-06-01

Concerns were raised by several workers from veterinary clinics in Manitoba, Canada, regarding potential exposure to isoflurane and halothane during anesthetic administration. There has been no guideline established for isoflurane by the American Conference of Governmental Industrial Hygienist (ACGIH) or a Permissible Exposure Limit by the Occupational Safety and Health Administration (OSHA) or a recommended exposure limit (REL) by the National Institute for Occupational Safety and Health (NIOSH). The ACGIH TLV-TWA for halothane is 50 ppm and NIOSH has established 2 ppm as a recommended level based on an one-hour sampling. OSHA has established no guideline for halothane. The Miran IB Portable Ambient Air Analyzer was used to conduct real-time sampling and to identify leaks during administration. All veterinary clinics inspected had installed the passive waste gas scavenging system. Ten clinics were each monitored during anesthetic gas delivery for one surgical procedure performed. Induction was 4 to 5 percent and maintenance 1.5 to 2.5 percent. Nine clinics were small animal practices and the tenth was an equine clinic. Veterinarians' personal exposures were higher than the assistants'. Veterinarians' personal exposures for isoflurane ranged from 1.3 to 13 ppm (AM = 5.3; SD +/- 2.7; GM = 4.6; GSD +/- 1.6) and for their assistants, personal exposures ranged from 1.2 to 9 ppm (AM = 4.7; SD +/- 2.5; GM = 3.9; GSD +/- 1.6). Veterinarians' personal exposures for halothane ranged from 0.7 to 12 ppm (AM = 4.2; SD +/- 3.6; GM = 2.9; GSD +/- 1.4) and for their assistants, personal exposures ranged from 0.4 to 3.2 ppm (AM = 1.8; SD +/- 1.0; GM = 1.5; GSD +/- 1.7). One clinic had significant leaks in the anesthetic gas delivery lines. Personal halothane exposure for the veterinarian at this clinic was 7.2 to 65 ppm (AM = 18.0; SD +/- 11.5; GM = 15.9; GSD +/- 1.8). Based on this study, worker exposures were acceptable. Peak exposures were recorded when the cuffed endotracheal

Measurements of Methane Emissions and Volatile Organic Compounds from Shale Gas Operations in the Marcellus Shale

NASA Astrophysics Data System (ADS)

Omara, M.; Subramanian, R.; Sullivan, M.; Robinson, A. L.; Presto, A. A.

2014-12-01

The Marcellus Shale is the most expansive shale gas reserve in play in the United States, representing an estimated 17 to 29 % of the total domestic shale gas reserves. The rapid and extensive development of this shale gas reserve in the past decade has stimulated significant interest and debate over the climate and environmental impacts associated with fugitive releases of methane and other pollutants, including volatile organic compounds. However, the nature and magnitude of these pollutant emissions remain poorly characterized. This study utilizes the tracer release technique to characterize total fugitive methane release rates from natural gas facilities in southwestern Pennsylvania and West Virginia that are at different stages of development, including well completion flowbacks and active production. Real-time downwind concentrations of methane and two tracer gases (acetylene and nitrous oxide) released onsite at known flow rates were measured using a quantum cascade tunable infrared laser differential absorption spectrometer (QC-TILDAS, Aerodyne, Billerica, MA) and a cavity ring down spectrometer (Model G2203, Picarro, Santa Clara, CA). Evacuated Silonite canisters were used to sample ambient air during downwind transects of methane and tracer plumes to assess volatile organic compounds (VOCs). A gas chromatograph with a flame ionization detector was used to quantify VOCs following the EPA Method TO-14A. A preliminary assessment of fugitive emissions from actively producing sites indicated that methane leak rates ranged from approximately 1.8 to 6.2 SCFM, possibly reflecting differences in facility age and installed emissions control technology. A detailed comparison of methane leak rates and VOCs emissions with recent published literature for other US shale gas plays will also be discussed.

Simultaneous ground-based and airborne measurements of biogenic VOC oxidation products using iodide-adduct HR-ToF-CIMS in the Southeast U.S

NASA Astrophysics Data System (ADS)

Lee, B.; Mohr, C.; Lopez-Hilfiker, F.; Warneke, C.; Graus, M.; Gilman, J.; Lerner, B. M.; Pollack, I. B.; Ryerson, T. B.; Roberts, J. M.; Edwards, P. M.; Brown, S. S.; Holloway, J.; Aikin, K.; Dube, W. P.; Liao, J.; Welti, A.; Middlebrook, A. M.; Nowak, J. B.; Neuman, J. A.; Brioude, J. F.; McKeen, S. A.; Hanisco, T. F.; Kaiser, J.; Keutsch, F. N.; Wolfe, G. M.; Hallquist, M.; Trainer, M.; De Gouw, J. A.; Thornton, J. A.

2013-12-01

We present measurements by two high-resolution time-of-flight chemical-ionization mass spectrometers (HR-ToF-CIMS) during the Southeast Atmosphere Study in June and July of 2013. Both HR-ToF-CIMS used iodide as the reagent ion, which provides minimum fragmentation during ionization. Isoprene and monoterpene oxidation byproducts such as hydroxy hydroperoxides, carboxylic acids and organic nitrates, were ubiquitous in the mass spectra. In addition, we observed select inorganic gases such as N2O5 and ClNO2. The flight instrument was deployed aboard the NOAA WP-3D during SENEX, which explored the lower atmosphere over the Southeast U.S., logging a total of 125 flight hours. These measurements provide insight into the spatial and temporal variation of these types of compounds and the influence of natural gas fields, power plants, biomass burning, urban and biogenic emissions on their abundance under both day and nighttime conditions. The ground-based instrument was located near Brent, Alabama as part of the SOAS campaign and utilized the Filter Inlet for Gas and AEROsol (FIGAERO) - developed at the University of Washington - which allows measurement of both the gas and particle phases. Continuous observations spanning more than 4 weeks show the diurnal variability and the influence of meteorology and anthropogenic emissions on the gas-particle partitioning. Flights during SENEX over the ground site provide a unique opportunity to investigate the vertical distribution of a whole suite of these chemical species measured by these two cross-calibrated nearly identical instruments.

30 CFR 250.524 - When am I required to take action from my casing diagnostic test?

Code of Federal Regulations, 2010 CFR

2010-07-01

... casing diagnostic test; (c) Any well that has demonstrated tubing/casing, tubing/riser, casing/casing... casing diagnostic test? 250.524 Section 250.524 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT... Gas Well-Completion Operations Casing Pressure Management § 250.524 When am I required to take action...

Comparison of 3D TOF-MRA and 3D CE-MRA at 3T for imaging of intracranial aneurysms.

PubMed

Cirillo, Mario; Scomazzoni, Francesco; Cirillo, Luigi; Cadioli, Marcello; Simionato, Franco; Iadanza, Antonella; Kirchin, Miles; Righi, Claudio; Anzalone, Nicoletta

2013-12-01

To compare 3T elliptical-centric CE MRA with 3T TOF MRA for the detection and characterization of unruptured intracranial aneurysms (UIAs), by using digital subtracted angiography (DSA) as reference. Twenty-nine patients (12 male, 17 female; mean age: 62 years) with 41 aneurysms (34 saccular, 7 fusiform; mean diameter: 8.85 mm [range 2.0-26.4mm]) were evaluated with MRA at 3T each underwent 3D TOF-MRA examination without contrast and then a 3D contrast-enhanced (CE-MRA) examination with 0.1mmol/kg bodyweight gadobenate dimeglumine and k-space elliptic mapping (Contrast ENhanced Timing Robust Angiography [CENTRA]). Both TOF and CE-MRA images were used to evaluate morphologic features that impact the risk of rupture and the selection of a treatment. Almost half (20/41) of UIAs were located in the internal carotid artery, 7 in the anterior communicating artery, 9 in the middle cerebral artery and 4 in the vertebro-basilar arterial system. All patients also underwent DSA before or after the MR examination. The CE-MRA results were in all cases consistent with the DSA dataset. No differences were noted between 3D TOF-MRA and CE-MRA concerning the detection and location of the 41 aneurysms or visualization of the parental artery. Differences were apparent concerning the visualization of morphologic features, especially for large aneurysms (>13 mm). An irregular sac shape was demonstrated for 21 aneurysms on CE-MRA but only 13/21 aneurysms on 3D TOF-MRA. Likewise, CE-MRA permitted visualization of an aneurismal neck and calculation of the sac/neck ratio for all 34 aneurysms with a neck demonstrated at DSA. Conversely, a neck was visible for only 24/34 aneurysms at 3D TOF-MRA. 3D CE-MRA detected 15 aneurysms with branches originating from the sac and/or neck, whereas branches were recognized in only 12/15 aneurysms at 3D TOF-MRA. For evaluation of intracranial aneurysms at 3T, 3D CE-MRA is superior to 3D TOF-MRA for assessment of sac shape, detection of aneurysmal neck, and

Can-AMS: The New Accelerator Mass Spectrometry Facility At The University Of Ottawa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kieser, W. E.; Zhao, X.-L.; Clark, I. D.

2011-06-01

The Canadian Centre for Accelerator Mass Spectrometry (AMS) at the University of Ottawa will be equipped with a new, 3 MV tandem accelerator with peripheral equipment for the analysis of elements ranging from tritium to the actinides. This facility, along with a wide array of support instrumentation recently funded by the Canada Foundation for Innovation, will be located in a new science building on the downtown campus of the University of Ottawa. In addition to providing the standard AMS measurements on {sup 14}C, {sup 10}Be, {sup 26}Al, {sup 36}Cl and {sup 129}I for earth, environmental, cultural and biomedical sciences, thismore » facility will incorporate the new technologies of anion isobar separation at low energies using RFQ chemical reaction cells for {sup 36}Cl and new heavy element applications, integrated sample combustion and gas ion source for biomedical and environmental {sup 14}C analysis and the use of novel target matrices for expanding the range of applicable elements and simplifying sample preparation, all currently being developed at IsoTrace. This paper will outline the design goals for the new facility, present some details of the new AMS technologies, in particular the Isobar Separator for Anions and discuss the design of the AMS system resulting from these requirements.« less

2D-DIGE and MALDI TOF/TOF MS analysis reveal that small GTPase signaling pathways may play an important role in cadmium-induced colon cell malignant transformation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Jian, E-mail: lujian@ujs.edu.cn; Institute of Life Sciences, Jiangsu University, Zhenjiang 212013; Zhou, Zhongping

Cadmium is a toxic heavy metal present in the environment and in industrial materials. Cadmium has demonstrated carcinogenic activity that induces cell transformation, but how this occurs is unclear. We used 2D-DIGE and MALDI TOF/TOF MS combined with bioinformatics and immunoblotting to investigate the molecular mechanism of cadmium transformation. We found that small GTPases were critical for transformation. Additionally, proteins involved in mitochondrial transcription, DNA repair, and translation also had altered expression patterns in cadmium treated cells. Collectively, our results suggest that activation of small GTPases contributes to cadmium-induced transformation of colon cells. - Highlights: • Colon epithelial cell linemore » is firstly successfully transformed by cadmium. • 2D-DIGE is applied to visualize the differentially expressed proteins. • RhoA plays an important role in cadmium induced malignant transformation. • Bioinformatic and experimental methods are combined to explore new mechanisms.« less

Application of MALDI-TOF MS Systems in the Rapid Identification of Campylobacter spp. of Public Health Importance.

PubMed

Hsieh, Ying-Hsin; Wang, Yun F; Moura, Hercules; Miranda, Nancy; Simpson, Steven; Gowrishankar, Ramnath; Barr, John; Kerdahi, Khalil; Sulaiman, Irshad M

2018-05-01

Campylobacteriosis is an infectious gastrointestinal disease caused by Campylobacter spp. In most cases, it is either underdiagnosed or underreported due to poor diagnostics and limited databases. Several DNA-based molecular diagnostic techniques, including 16S ribosomal RNA (rRNA) sequence typing, have been widely used in the species identification of Campylobacter. Nevertheless, these assays are time-consuming and require a high quality of bacterial DNA. Matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) MS is an emerging diagnostic technology that can provide the rapid identification of microorganisms by using their intact cells without extraction or purification. In this study, we analyzed 24 American Type Culture Collection reference isolates of 16 Campylobacter spp. and five unknown clinical bacterial isolates for rapid identification utilizing two commercially available MADI-TOF MS platforms, namely the bioMérieux VITEK® MS and Bruker Biotyper systems. In addition, 16S rRNA sequencing was performed to confirm the species-level identification of the unknown clinical isolates. Both MALDI-TOF MS systems identified the isolates of C. jejuni, C. coli, C. lari, and C. fetus. The results of this study suggest that the MALDI-TOF MS technique can be used in the identification of Campylobacter spp. of public health importance.

Nickel remediation by AM-colonized sunflower.

PubMed

Ker, Keomany; Charest, Christiane

2010-08-01

This greenhouse study aimed to examine the contribution of arbuscular mycorrhizal (AM) colonization on the uptake of and tolerance to nickel (Ni) in sunflower (Helianthus annuus L.). We hypothesized that AM colonization increases Ni content and tolerance in sunflower grown under varying soil Ni concentrations. The combined effect of AM colonization and soil Ni input on the assimilation of nitrogen, in particular the activity of glutamine synthetase (GS), in sunflower plants was also investigated. A factorial experimental design was performed with sunflower cv. Lemon Queen, with or without the AM fungus, Glomus intraradices Schenck & Smith, and treated with 0, 100, 200, or 400 mg Ni kg(-1) dry soil (DS). The AM colonization significantly enhanced plant growth and Ni content, especially at the lower soil Ni treatments. Furthermore, the AM plants exposed to the highest soil Ni level of 400 mg Ni kg(-1) DS had a significantly higher shoot Ni extracted percentage than non-AM plants, suggesting that the AM symbiosis contributed to Ni uptake, then its translocation from roots to shoots. The AM colonization also significantly increased the GS activity in roots, this being likely an indicator of an enhanced Ni tolerance. These findings support the hypothesis that AM symbiosis contributes to an enhanced Ni plant uptake and tolerance and should be considered as part of phytoremediation strategies.

Validation of calcaneus trabecular microstructure measurements by HR-pQCT.

PubMed

Metcalf, Louis M; Dall'Ara, Enrico; Paggiosi, Margaret A; Rochester, John R; Vilayphiou, Nicolas; Kemp, Graham J; McCloskey, Eugene V

2018-01-01

Assessment of calcaneus microstructure using high-resolution peripheral quantitative computed tomography (HR-pQCT) might be used to improve fracture risk predictions or to assess responses to pharmacological and physical interventions. To develop a standard clinical protocol for the calcaneus, we validated calcaneus trabecular microstructure measured by HR-pQCT against 'gold-standard' micro-CT measurements. Ten human cadaveric feet were scanned in situ using HR-pQCT (isotropic 82μm voxel size) at 100, 150 and 200ms integration times, and at 100ms integration time following removal of the calcaneus from the foot (ex vivo). Dissected portions of these bones were scanned using micro-computed tomography (micro-CT) at an isotropic 17.4μm voxel size. HR-pQCT images were rigidly registered to those obtained with micro-CT and divided into multiple 5mm sided cubes to evaluate and compare morphometric parameters between the modalities. Standard HR-pQCT measurements (derived bone volume fraction (BV/TV d ); trabecular number, Tb.N; derived trabecular thickness, Tb.Th d ; derived trabecular spacing, Tb.Sp d ) and corresponding micro-CT voxel-based measurements (BV/TV, Tb.N, Tb.Th, Tb.Sp) were compared. A total of 108 regions of interest were analysed across the 10 specimens. At all integration times HR-pQCT BV/TV d was strongly correlated with micro-CT BV/TV (r 2 =0.95-0.98, RMSE=1%), but BV/TV d was systematically lower than that measured by micro-CT (mean bias=5%). In contrast, HR-pQCT systematically overestimated Tb.N at all integration times; of the in situ scans, 200ms yielded the lowest mean bias and the strongest correlation with micro-CT (r 2 =0.61, RMSE=0.15mm -1 ). Regional analysis revealed greater accuracy for Tb.N in the superior regions of the calcaneus at all integration times in situ (mean bias=0.44-0.85mm -1 ; r 2 =0.70-0.88, p<0.001 versus mean bias=0.63-1.46mm -1 ; r 2 ≤0.08, p≥0.21 for inferior regions). Tb.Sp d was underestimated by HR-pQCT compared

16 CFR Appendix G6 to Part 305 - Boilers-Gas (Steam)

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Boilers-Gas (Steam) G6 Appendix G6 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE... Appendix G6 to Part 305—Boilers—Gas (Steam) Manufacturer's rated heating capacities (Btu's/hr.) Range of...

Follow-up assessment of coiled intracranial aneurysms using zTE MRA as compared with TOF MRA: a preliminary image quality study.

PubMed

Shang, Song'an; Ye, Jing; Luo, Xianfu; Qu, Jianxun; Zhen, Yong; Wu, Jingtao

2017-10-01

To prospectively assess coiled intracranial aneurysms using a novel non-contrast enhanced zero echo time (zTE) MR angiography (MRA) method, and compare its image quality with time-of-flight (TOF) MRA, using digital subtraction angiography (DSA) as reference. Twenty-five patients (10 males and 15 females; age 53.96 ± 12.46 years) were enrolled in this monocentric study. MRA sequences were performed 24 h before DSA. Susceptibility artefact intensity and flow signal within the parent artery were carried out using a 4-point scale. Occlusion status was assessed using the 3-grade Montreal scale. Scores of zTE were higher than TOF for both susceptibility artefact intensity (3.42 ± 0.64, 2.92 ± 0.63, P = 0.01) and flow signal (3.66 ± 0.95, 3.24 ± 1.24, P = 0.01). DSA revealed 17 complete occlusions, five residual neck aneurysms and two residual aneurysms. Inter-observer agreement was excellent (weighted κ: 0.89) for zTE and good (weighted κ: 0.68) for TOF. Intermodality agreement was excellent for zTE (weighted κ: 0.95) and good for TOF (weighted κ: 0.80). Correlations of both MRA sequences with DSA were high (zTE, Spearman's ρ: 0.91; TOF, Spearman's ρ: 0.81). zTE MRA showed promising results for follow-up assessment of coiled intracranial aneurysms and was superior to TOF MRA for visualizing the parent artery and evaluating occlusion status. • Various MRA sequences were applied for follow-up assessment of coiled intracranial aneurysms. • zTE MRA was less sensitive to susceptibility artefacts and haemodynamics. • In this monocentric study, zTE MRA was equivalent to DSA. • zTE MRA maybe an alternative to TOF MRA for follow-up assessment.

Rapid Classification and Identification of Microcystis aeruginosa Strains Using MALDI-TOF MS and Polygenetic Analysis.

PubMed

Sun, Li-Wei; Jiang, Wen-Jing; Sato, Hiroaki; Kawachi, Masanobu; Lu, Xi-Wu

2016-01-01

Matrix-assisted laser desorption-ionization-time-of-flight mass spectrometry (MALDI-TOF MS) was used to establish a rapid, simple, and accurate method to differentiate among strains of Microcystis aeruginosa, one of the most prevalent types of bloom-forming cyanobacteria. M. aeruginosa NIES-843, for which a complete genome has been sequenced, was used to characterize ribosomal proteins as biomarkers and to optimize conditions for observing ribosomal proteins as major peaks in a given mass spectrum. Thirty-one of 52 ribosomal subunit proteins were detected and identified along the mass spectrum. Fifty-five strains of M. aeruginosa from different habitats were analyzed using MALDI-TOF MS; among these samples, different ribosomal protein types were observed. A polygenetic analysis was performed using an unweighted pair-group method with arithmetic means and different ribosomal protein types to classify the strains into five major clades. Two clades primarily contained toxic strains, and the other three clades contained exclusively non-toxic strains. This is the first study to differentiate cyanobacterial strains using MALDI-TOF MS.

AmO 2 Analysis for Analytical Method Testing and Assessment: Analysis Support for AmO 2 Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuhn, Kevin John; Bland, Galey Jean; Fulwyler, James Brent

Americium oxide samples will be measured for various analytes to support AmO 2 production. The key analytes that are currently requested by the Am production customer at LANL include total Am content, Am isotopics, Pu assay, Pu isotopics, and trace element content including 237Np content. Multiple analytical methods will be utilized depending on the sensitivity, accuracy and precision needs of the Am matrix. Traceability to the National Institute of Standards and Technology (NIST) will be achieved, where applicable, by running NIST traceable quality control materials. This given that there are no suitable AmO 2 reference materials currently available for requestedmore » analytes. The primary objective is to demonstrate the suitability of actinide analytical chemistry methods to support AmO 2 production operations.« less

Contaminant screening of wastewater with HPLC-IM-qTOF-MS and LC+LC-IM-qTOF-MS using a CCS database.

PubMed

Stephan, Susanne; Hippler, Joerg; Köhler, Timo; Deeb, Ahmad A; Schmidt, Torsten C; Schmitz, Oliver J

2016-09-01

Non-target analysis has become an important tool in the field of water analysis since a broad variety of pollutants from different sources are released to the water cycle. For identification of compounds in such complex samples, liquid chromatography coupled to high resolution mass spectrometry are often used. The introduction of ion mobility spectrometry provides an additional separation dimension and allows determining collision cross sections (CCS) of the analytes as a further physicochemical constant supporting the identification. A CCS database with more than 500 standard substances including drug-like compounds and pesticides was used for CCS data base search in this work. A non-target analysis of a wastewater sample was initially performed with high performance liquid chromatography (HPLC) coupled to an ion mobility-quadrupole-time of flight mass spectrometer (IM-qTOF-MS). A database search including exact mass (±5 ppm) and CCS (±1 %) delivered 22 different compounds. Furthermore, the same sample was analyzed with a two-dimensional LC method, called LC+LC, developed in our group for the coupling to IM-qTOF-MS. This four dimensional separation platform revealed 53 different compounds, identified over exact mass and CCS, in the examined wastewater sample. It is demonstrated that the CCS database can also help to distinguish between isobaric structures exemplified for cyclophosphamide and ifosfamide. Graphical Abstract Scheme of sample analysis and database screening.

Evaluation of three sample preparation methods for the direct identification of bacteria in positive blood cultures by MALDI-TOF.

PubMed

Tanner, Hannah; Evans, Jason T; Gossain, Savita; Hussain, Abid

2017-01-18

Patient mortality is significantly reduced by rapid identification of bacteria from sterile sites. MALDI-TOF can identify bacteria directly from positive blood cultures and multiple sample preparation methods are available. We evaluated three sample preparation methods and two MALDI-TOF score cut-off values. Positive blood culture bottles with organisms present in Gram stains were prospectively analysed by MALDI-TOF. Three lysis reagents (Saponin, SDS, and SepsiTyper lysis bufer) were applied to each positive culture followed by centrifugation, washing and protein extraction steps. Methods were compared using the McNemar test and 16S rDNA sequencing was used to assess discordant results. In 144 monomicrobial cultures, using ≥2.000 as the cut-off value, species level identifications were obtained from 69/144 (48%) samples using Saponin, 86/144 (60%) using SDS, and 91/144 (63%) using SepsiTyper. The difference between SDS and SepsiTyper was not statistically significant (P = 0.228). Differences between Saponin and the other two reagents were significant (P < 0.01). Using ≥1.700 plus top three results matching as the cut-off value, species level identifications were obtained from 100/144 (69%) samples using Saponin, 103/144 (72%) using SDS, and 106/144 (74%) using SepsiTyper and there was no statistical difference between the methods. No true discordances between culture and direct MALDI-TOF identification were observed in monomicrobial cultures. In 32 polymicrobial cultures, MALDI-TOF identified one organism in 34-75% of samples depending on the method. This study demonstrates two inexpensive in-house detergent lysis methods are non-inferior to a commercial kit for analysis of positive blood cultures by direct MALDI-TOF in a clinical diagnostic microbiology laboratory.

Characterization of Enterococcus species isolated from marine recreational waters by MALDI-TOF MS and Rapid ID API® 20 Strep system.

PubMed

Christ, Ana Paula Guarnieri; Ramos, Solange Rodrigues; Cayô, Rodrigo; Gales, Ana Cristina; Hachich, Elayse Maria; Sato, Maria Inês Zanoli

2017-05-15

MALDI-TOF Mass Spectrometry Biotyping has proven to be a reliable method for identifying bacteria at the species level based on the analysis of the ribosomal proteins mass fingerprint. We evaluate the usefulness of this method to identify Enterococcus species isolated from marine recreational water at Brazilian beaches. A total of 127 Enterococcus spp. isolates were identified to species level by bioMérieux's API® 20 Strep and MALDI-TOF systems. The biochemical test identified 117/127 isolates (92%), whereas MALDI identified 100% of the isolates, with an agreement of 63% between the methods. The 16S rRNA gene sequencing of isolates with discrepant results showed that MALDI-TOF and API® correctly identified 74% and 11% of these isolates, respectively. This discrepancy probably relies on the bias of the API® has to identify clinical isolates. MALDI-TOF proved to be a feasible approach for identifying Enterococcus from environmental matrices increasing the rapidness and accuracy of results. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ion-neutral potential models in atmospheric pressure ion mobility time-of-flight mass spectrometry IM(tof)MS.

PubMed

Steiner, Wes E; English, William A; Hill, Herbert H

2006-02-09

The ion mobilities and their respective masses of several classes of amines (primary, secondary, and tertiary) were measured by electrospray ionization atmospheric pressure ion mobility time-of-flight mass spectrometry IM(tof)MS. The experimental data obtained were comparatively analyzed by the one-temperature kinetic theory of Chapman-Enskog. Several theoretical models were used to estimate the collision cross-sections; they include the rigid-sphere, polarization-limit, 12-6-4, and 12-4 potential models. These models were investigated to represent the interaction potentials contained within the collision integral that occurs between the polyatomic ions and the neutral drift gas molecules. The effectiveness of these collision cross-section models on predicting the mobility of these amine ions was explored. Moreover, the effects of drift gas selectivity on the reduced-mass term and in the collision cross-section term was examined. Use of a series of drift gases, namely, helium, neon, argon, nitrogen, and carbon dioxide, made it possible to distinguish between mass effects and polarizability effects. It was found that the modified 12-4 potential that compensates for the center of charge not being at the same location as the centers of mass showed improved agreement over the other collision cross-section models with respect to experimental data.

High-cost gas wells need fast pipeline hook-up

DOE Office of Scientific and Technical Information (OSTI.GOV)

Webb, B.

1982-12-13

Construction of a gas pipeline in Oklahoma to consist of 2 miles of 6-in. trunkline and two 3-in. laterals to each of the wells is described. Designed and constructed according to USAS B31.8 and DOT 192 title 49, the pipeline was hydrostatically tested at 2,150 psig for 8 hr. Illustrations show dehydrators and meter station for delivery gas, and receiving separators.

Elemental ratio measurements of organic compounds using aerosol mass spectrometry: characterization, improved calibration, and implications

DOE PAGES

Canagaratna, M. R.; Jimenez, J. L.; Kroll, J. H.; ...

2014-07-31

Elemental compositions of organic aerosol (OA) particles provide useful constraints on OA sources, chemical evolution, and effects. The Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) is widely used to measure OA elemental composition. This study evaluates AMS measurements of atomic oxygen-to-carbon (O : C), hydrogen-to-carbon (H : C), organic mass-to-organic carbon (OM : OC), and carbon oxidation state (OS C) for a vastly expanded laboratory dataset of multifunctional oxidized OA standards. For the expanded standard dataset, the "Aiken-Explicit" method (Aiken et al., 2008), which uses experimentally measured ion intensities at all ions to determine elemental ratios, reproduces known molecular Omore » : C and H : C ratio values within 20% (average absolute value of relative errors) and 12% respectively. The more commonly used "Aiken-Ambient" method, which uses empirically estimated H 2O + and CO + ion intensities to avoid gas phase air interferences at these ions, reproduces O : C and H : C of multifunctional oxidized species within 28% and 14% of known values. These values are systematically biased low, however, with larger biases observed for alcohols and simple diacids. A detailed examination of the H 2O +, CO +, and CO 2 + fragments in the high-resolution mass spectra of the standard compounds indicates that the Aiken-Ambient method underestimates the CO + and H 2O + produced from many oxidized species. Combined AMS-vacuum ultraviolet (VUV) ionization measurements indicate that these ions are produced by dehydration and decarboxylation on the AMS vaporizer (usually operated at 600 °C). Thermal decomposition is observed to be efficient at vaporizer temperatures down to 200 °C. These results are used together to develop an "Improved-Ambient" elemental analysis method for AMS spectra measured in air. The Improved-Ambient method reduces the systematic biases and reproduces O : C (H : C) ratios of individual oxidized standards

16S-ARDRA and MALDI-TOF mass spectrometry as tools for identification of Lactobacillus bacteria isolated from poultry.

PubMed

Dec, Marta; Puchalski, Andrzej; Urban-Chmiel, Renata; Wernicki, Andrzej

2016-06-13

The objective of our study is to evaluate the potential use of Amplified 16S Ribosomal DNA Restriction Analysis (16S-ARDRA) and MALDI-TOF mass spectrometry (MS) as methods for species identification of Lactobacillus strains in poultry. A total of 80 Lactobacillus strains isolated from the cloaca of chicken, geese and turkeys were identified to the species level by MALDI-TOF MS (on-plate extraction method) and 16S-ARDRA. The two techniques produced comparable classification results, some of which were additionally confirmed by sequencing of 16S rDNA. MALDI-TOF MS enabled rapid species identification but produced more than one reliable identification result for 16.25 % of examined strains (mainly of the species L. johnsonii). For 30 % of isolates intermediate log(scores) of 1.70-1.99 were obtained, indicating correct genus identification but only presumptive species identification. The 16S-ARDRA protocol was based on digestion of 16S rDNA with the restriction enzymes MseI, HinfI, MboI and AluI. This technique was able to distinguish 17 of the 19 Lactobacillus reference species tested and enabled identification of all 80 wild isolates. L. salivarius dominated among the 15 recognized species, followed by L. johnsonii and L. ingluviei. The MALDI-TOF MS and 16S-ARDRA assays are valuable tools for the identification of avian lactobacilli to the species level. MALDI-TOF MS is a fast, simple and cost-effective technique, and despite generating a high percentage of results with a log(score) <2.00, the on-plate extraction method is characterized by high-performance. For samples for which Biotyper produces more than one reliable result, MALDI-TOF MS must be used in combination with genotypic techniques to achieve unambiguous results. 16S-ARDRA is simple, repetitive method with high power of discrimination, whose sole limitation is its inability to discriminate between species with very high 16S rDNA sequence homology, such as L. casei and L. zeae. The assays can be used for

Radiocarbon measurements of small gaseous samples at CologneAMS

NASA Astrophysics Data System (ADS)

Stolz, A.; Dewald, A.; Altenkirch, R.; Herb, S.; Heinze, S.; Schiffer, M.; Feuerstein, C.; Müller-Gatermann, C.; Wotte, A.; Rethemeyer, J.; Dunai, T.

2017-09-01

A second SO-110 B (Arnold et al., 2010) ion source was installed at the 6 MV CologneAMS for the measurement of gaseous samples. For the gas supply a dedicated device from Ionplus AG was connected to the ion source. Special effort was devoted to determine optimized operation parameters for the ion source, which give a high carbon current output and a high 14C- yield. The latter is essential in cases when only small samples are available. Additionally a modified immersion lens and modified target pieces were tested and the target position was optimized.

Dehydrogenation and dehalogenation of amines in MALDI-TOF MS investigated by isotopic labeling.

PubMed

Kang, Chuanqing; Zhou, Yihan; Du, Zhijun; Bian, Zheng; Wang, Jianwei; Qiu, Xuepeng; Gao, Lianxun; Sun, Yuequan

2013-12-01

Secondary and tertiary amines have been reported to form [M-H](+) that correspond to dehydrogenation in matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). In this investigation, we studied the dehydrogenation of amines in MALDI-TOF MS by isotopic labeling. Aliphatic amines were labeled with deuterium on the methylene of an N-benzyl group, which resulted in the formation of [M-D](+) and [M-H](+) ions by dedeuteration and dehydrogenation, respectively. This method revealed the proton that was removed. The spectra of most tertiary amines with an N-benzyl group showed high-intensity [M-D](+) and [M-H](+) ion peaks, whereas those of secondary amines showed low-intensity ion peaks. Ratios between the peak intensities of [M-D](+) and [M-H](+) greater than 1 suggested chemoselective dehydrogenation at the N-benzyl groups. The presence of an electron donor group on the N-benzyl groups enhanced the selectivity. The dehalogenation of amines with an N-(4-halobenzyl) group was also observed alongside dehydrogenation. The amino ions from dehalogenation can undergo second dehydrogenation. These results provide the first direct evidence about the position at which dehydrogenation of an amine occurs and the first example of dehalogenation of haloaromatic compounds in MALDI-TOF MS. These results should be helpful in the structural identification and elucidation of synthetic and natural molecules. Copyright © 2013 John Wiley & Sons, Ltd.

A pilot study to assess residential noise exposure near natural gas compressor stations.

PubMed

Boyle, Meleah D; Soneja, Sutyajeet; Quirós-Alcalá, Lesliam; Dalemarre, Laura; Sapkota, Amy R; Sangaramoorthy, Thurka; Wilson, Sacoby; Milton, Donald; Sapkota, Amir

2017-01-01

U.S. natural gas production increased 40% from 2000 to 2015. This growth is largely related to technological advances in horizontal drilling and high-volume hydraulic fracturing. Environmental exposures upon impacted communities are a significant public health concern. Noise associated with natural gas compressor stations has been identified as a major concern for nearby residents, though limited studies exist. We conducted a pilot study to characterize noise levels in 11 homes located in Doddridge County, West Virginia, and determined whether these levels differed based on time of day, indoors vs. outdoors, and proximity of homes to natural gas compressor stations. We also compared noise levels at increasing distances from compressor stations to available noise guidelines, and evaluated low frequency noise presence. We collected indoor and outdoor 24-hour measurements (Leq, 24hr) in eight homes located within 750 meters (m) of the nearest compressor station and three control homes located >1000m. We then evaluated how A-weighted decibel (dBA) exposure levels differed based on factors outlined above. The geometric mean (GM) for 24-hour outdoor noise levels at homes located <300m (Leq,24hr: 60.3 dBA; geometric standard deviation (GSD): 1.0) from the nearest compressor station was nearly 9 dBA higher than control homes (Leq,24hr: 51.6 dBA; GSD: 1.1). GM for 24 hour indoor noise for homes <300m (Leq,24hr: 53.4 dBA; GSD: 1.2) from the nearest compressor station was 11.2 dBA higher than control homes (Leq,24hr: 42.2 dBA; GSD: 1.1). Indoor average daytime noise for homes <300m of the nearest compressor stations were 13.1 dBA higher than control homes, while indoor nighttime readings were 9.4 dBA higher. Findings indicate that living near a natural gas compressor station could potentially result in high environmental noise exposures. Larger studies are needed to confirm these findings and evaluate potential health impacts and protection measures.

A pilot study to assess residential noise exposure near natural gas compressor stations

PubMed Central

Boyle, Meleah D.; Quirós-Alcalá, Lesliam; Dalemarre, Laura; Sapkota, Amy R.; Sangaramoorthy, Thurka; Wilson, Sacoby; Milton, Donald; Sapkota, Amir

2017-01-01

Background U.S. natural gas production increased 40% from 2000 to 2015. This growth is largely related to technological advances in horizontal drilling and high-volume hydraulic fracturing. Environmental exposures upon impacted communities are a significant public health concern. Noise associated with natural gas compressor stations has been identified as a major concern for nearby residents, though limited studies exist. Objectives We conducted a pilot study to characterize noise levels in 11 homes located in Doddridge County, West Virginia, and determined whether these levels differed based on time of day, indoors vs. outdoors, and proximity of homes to natural gas compressor stations. We also compared noise levels at increasing distances from compressor stations to available noise guidelines, and evaluated low frequency noise presence. Methods We collected indoor and outdoor 24-hour measurements (Leq, 24hr) in eight homes located within 750 meters (m) of the nearest compressor station and three control homes located >1000m. We then evaluated how A-weighted decibel (dBA) exposure levels differed based on factors outlined above. Results The geometric mean (GM) for 24-hour outdoor noise levels at homes located <300m (Leq,24hr: 60.3 dBA; geometric standard deviation (GSD): 1.0) from the nearest compressor station was nearly 9 dBA higher than control homes (Leq,24hr: 51.6 dBA; GSD: 1.1). GM for 24 hour indoor noise for homes <300m (Leq,24hr: 53.4 dBA; GSD: 1.2) from the nearest compressor station was 11.2 dBA higher than control homes (Leq,24hr: 42.2 dBA; GSD: 1.1). Indoor average daytime noise for homes <300m of the nearest compressor stations were 13.1 dBA higher than control homes, while indoor nighttime readings were 9.4 dBA higher. Conclusions Findings indicate that living near a natural gas compressor station could potentially result in high environmental noise exposures. Larger studies are needed to confirm these findings and evaluate potential health impacts

Intact Cell MALDI-TOF MS on Sperm: A Molecular Test For Male Fertility Diagnosis.

PubMed

Soler, Laura; Labas, Valérie; Thélie, Aurore; Grasseau, Isabelle; Teixeira-Gomes, Ana-Paula; Blesbois, Elisabeth

2016-06-01

Currently, evaluation of sperm quality is primarily based on in vitro measures of sperm function such as motility, viability and/or acrosome reaction. However, results are often poorly correlated with fertility, and alternative diagnostic tools are therefore needed both in veterinary and human medicine. In a recent pilot study, we demonstrated that MS profiles from intact chicken sperm using MALDI-TOF profiles could detect significant differences between fertile/subfertile spermatozoa showing that such profiles could be useful for in vitro male fertility testing. In the present study, we performed larger standardized experimental procedures designed for the development of fertility- predictive mathematical models based on sperm cell MALDI-TOF MS profiles acquired through a fast, automated method. This intact cell MALDI-TOF MS-based method showed high diagnostic accuracy in identifying fertile/subfertile males in a large male population of known fertility from two distinct genetic lineages (meat and egg laying lines). We additionally identified 40% of the m/z peaks observed in sperm MS profiles through a top-down high-resolution protein identification analysis. This revealed that the MALDI-TOF MS spectra obtained from intact sperm cells contained a large proportion of protein degradation products, many implicated in important functional pathways in sperm such as energy metabolism, structure and movement. Proteins identified by our predictive model included diverse and important functional classes providing new insights into sperm function as it relates to fertility differences in this experimental system. Thus, in addition to the chicken model system developed here, with the use of appropriate models these methods should effectively translate to other animal taxa where similar tests for fertility are warranted. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

A designed experiments approach to optimizing MALDI-TOF MS spectrum processing parameters enhances detection of antibiotic resistance in Campylobacter jejuni

USDA-ARS?s Scientific Manuscript database

MALDI-TOF MS has been utilized as a reliable and rapid tool for microbial fingerprinting at the genus and species levels. Recently, there has been keen interest in using MALDI-TOF MS beyond the genus and species levels to rapidly identify antibiotic resistant strains of bacteria. The purpose of this...

Am phases in the matrix of a U–Pu–Zr alloy with Np, Am, and rare-earth elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Janney, Dawn E.; Kennedy, J. Rory; Madden, James W.

2015-01-01

Phases and microstructures in the matrix of an as-cast U-Pu-Zr alloy with 3 wt% Am, 2% Np, and 8% rare-earth elements were characterized by scanning and transmission electron microscopy. The matrix consists primarily of two phases, both of which contain Am: ζ-(U, Np, Pu, Am) (~70 at% U, 5% Np, 14% Pu, 1% Am, and 10% Zr) and δ-(U, Np, Pu, Am)Zr 2 (~25% U, 2% Np, 10-15% Pu, 1-2% Am, and 55-60 at% Zr). These phases are similar to those in U-Pu-Zr alloys, although the Zr content in ζ-(U, Np, Pu, Am) is higher than that in ζ-(U, Pu)more » and the Zr content in δ-(U, Np, Pu, Am)Zr 2 is lower than that in δ-UZr 2. Nanocrystalline actinide oxides with structures similar to UO2 occurred in some areas, but may have formed by reactions with the atmosphere during sample handling. Planar features consisting of a central zone of ζ-(U, Np, Pu, Am) bracketed by zones of δ-(U, Np, Pu, Am)Zr 2 bound irregular polygons ranging in size from a few micrometers to a few tens of micrometers across. The rest of the matrix consists of elongated domains of ζ-(U, Np, Pu, Am) and δ-(U, Np, Pu, Am)Zr 2. Each of these domains is a few tens of nanometers across and a few hundred nanometers long. The domains display strong preferred orientations involving areas a few hundred nanometers to a few micrometers across.« less

MALDI-TOF mass spectrometry for rapid diagnosis of postoperative endophthalmitis.

PubMed

Mailhac, Adriane; Durand, Harmonie; Boisset, Sandrine; Maubon, Danièle; Berger, Francois; Maurin, Max; Chiquet, Christophe; Bidart, Marie

2017-01-30

This study describes an innovative strategy for rapid detection and identification of bacteria causing endophthalmitis, combining the use of an automated blood culture system with MALDI-TOF mass spectrometry methodology. Using this protocol, we could identify 96% of 45 bacterial strains isolated from vitreous samples collected in acute post-operative endophthalmitis patients. Copyright © 2016 Elsevier B.V. All rights reserved.

Assessment of various parameters to improve MALDI-TOF MS reference spectra libraries constructed for the routine identification of filamentous fungi.

PubMed

Normand, Anne-Cécile; Cassagne, Carole; Ranque, Stéphane; L'ollivier, Coralie; Fourquet, Patrick; Roesems, Sam; Hendrickx, Marijke; Piarroux, Renaud

2013-04-08

The poor reproducibility of matrix-assisted desorption/ionization time-of-flight (MALDI-TOF) spectra limits the effectiveness of the MALDI-TOF MS-based identification of filamentous fungi with highly heterogeneous phenotypes in routine clinical laboratories. This study aimed to enhance the MALDI-TOF MS-based identification of filamentous fungi by assessing several architectures of reference spectrum libraries. We established reference spectrum libraries that included 30 filamentous fungus species with various architectures characterized by distinct combinations of the following: i) technical replicates, i.e., the number of analyzed deposits for each culture used to build a reference meta-spectrum (RMS); ii) biological replicates, i.e., the number of RMS derived from the distinct subculture of each strain; and iii) the number of distinct strains of a given species. We then compared the effectiveness of each library in the identification of 200 prospectively collected clinical isolates, including 38 species in 28 genera.Identification effectiveness was improved by increasing the number of both RMS per strain (p<10-4) and strains for a given species (p<10-4) in a multivariate analysis. Addressing the heterogeneity of MALDI-TOF spectra derived from filamentous fungi by increasing the number of RMS obtained from distinct subcultures of strains included in the reference spectra library markedly improved the effectiveness of the MALDI-TOF MS-based identification of clinical filamentous fungi.

Assessment of various parameters to improve MALDI-TOF MS reference spectra libraries constructed for the routine identification of filamentous fungi

PubMed Central

2013-01-01

Background The poor reproducibility of matrix-assisted desorption/ionization time-of-flight (MALDI-TOF) spectra limits the effectiveness of the MALDI-TOF MS-based identification of filamentous fungi with highly heterogeneous phenotypes in routine clinical laboratories. This study aimed to enhance the MALDI-TOF MS-based identification of filamentous fungi by assessing several architectures of reference spectrum libraries. Results We established reference spectrum libraries that included 30 filamentous fungus species with various architectures characterized by distinct combinations of the following: i) technical replicates, i.e., the number of analyzed deposits for each culture used to build a reference meta-spectrum (RMS); ii) biological replicates, i.e., the number of RMS derived from the distinct subculture of each strain; and iii) the number of distinct strains of a given species. We then compared the effectiveness of each library in the identification of 200 prospectively collected clinical isolates, including 38 species in 28 genera. Identification effectiveness was improved by increasing the number of both RMS per strain (p<10-4) and strains for a given species (p<10-4) in a multivariate analysis. Conclusion Addressing the heterogeneity of MALDI-TOF spectra derived from filamentous fungi by increasing the number of RMS obtained from distinct subcultures of strains included in the reference spectra library markedly improved the effectiveness of the MALDI-TOF MS-based identification of clinical filamentous fungi. PMID:23565856

Visualization of lenticulostriate arteries at 3T: Optimization of slice-selective off-resonance sinc pulse-prepared TOF-MRA and its comparison with flow-sensitive black-blood MRA.

PubMed

Okuchi, Sachi; Okada, Tomohisa; Fujimoto, Koji; Fushimi, Yasutaka; Kido, Aki; Yamamoto, Akira; Kanagaki, Mitsunori; Dodo, Toshiki; Mehemed, Taha M; Miyazaki, Mitsue; Zhou, Xiangzhi; Togashi, Kaori

2014-06-01

To optimize visualization of lenticulostriate artery (LSA) by time-of-flight (TOF) magnetic resonance angiography (MRA) with slice-selective off-resonance sinc (SORS) saturation transfer contrast pulses and to compare capability of optimal TOF-MRA and flow-sensitive black-blood (FSBB) MRA to visualize the LSA at 3T. This study was approved by the local ethics committee, and written informed consent was obtained from all the subjects. TOF-MRA was optimized in 20 subjects by comparing SORS pulses of different flip angles: 0, 400°, and 750°. Numbers of LSAs were counted. The optimal TOF-MRA was compared to FSBB-MRA in 21 subjects. Images were evaluated by the numbers and length of visualized LSAs. LSAs were significantly more visualized in TOF-MRA with SORS pulses of 400° than others (P < .003). When the optimal TOF-MRA was compared to FSBB-MRA, the visualization of LSA using FSBB (mean branch numbers 11.1, 95% confidence interval (CI) 10.0-12.1; mean total length 236 mm, 95% CI 210-263 mm) was significantly better than using TOF (4.7, 95% CI 4.1-5.3; 78 mm, 95% CI 67-89 mm) for both numbers and length of the LSA (P < .0001). LSA visualization was best with 400° SORS pulses for TOF-MRA but FSBB-MRA was better than TOF-MRA, which indicates its clinical potential to investigate the LSA on a 3T magnetic resonance imaging. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

Analysis of illicit dietary supplements sold in the Italian market: identification of a sildenafil thioderivative as adulterant using UPLC-TOF/MS and GC/MS.

PubMed

Damiano, Fabio; Silva, Claudia; Gregori, Adolfo; Vacondio, Federica; Mor, Marco; Menozzi, Mattia; Di Giorgio, Domenico

2014-05-01

Identification of pharmaceutical active ingredients sildenafil and tadalafil and the characterization of a dimethylated thio-derivative of sildenafil, called thioaildenafil or thiodimethylsildenafil, in illicit dietary supplements were described. A multi-residual ultra-performance liquid chromatography-time of flight mass spectrometry (UPLC-TOF/MS) method was developed to screen for the presence of the phosphodiesterase-5 (PDE-5) inhibitors sildenafil, tadalafil, and vardenafil and their analogues thioaildenafil and thiohomosildenafil in powders and pharmaceutical dosage forms. The study was developed in connection with an operation supervised by the Italian Medicines Agency (A.I.F.A.), aimed to monitor dietary supplements in the Italian market. In two of the eleven specimens under investigation, high-resolution mass spectrometry (HR-MS) allowed the identification of the PDE-5 inhibitors sildenafil and tadalafil, while another specimen proved to contain a unapproved dimethylated thioderivative of sildenafil, thioaildenafil or thiodimethylsildenafil, identified for the first time in Italy as adulterant in food supplements. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

Chemical resolution of Pu+ from U+ and Am+ using a band-pass reaction cell inductively coupled plasma mass spectrometer.

PubMed

Tanner, Scott D; Li, Chunsheng; Vais, Vladimir; Baranov, Vladimir I; Bandura, Dmitry R

2004-06-01

Determination of the concentration and distribution of the Pu and Am isotopes is hindered by the isobaric overlaps between the elements themselves and U, generally requiring time-consuming chemical separation of the elements. A method is described in which chemical resolution of the elemental ions is obtained through ion-molecule reactions in a reaction cell of an ICPMS instrument. The reactions of "natural" U(+), (242)Pu(+), and (243)Am(+) with ethylene, carbon dioxide, and nitric oxide are reported. Since the net sensitivities to the isotopes of an element are similar, chemical resolution is inferred when one isobaric element reacts rapidly with a given gas and the isobar (or in this instance surrogate isotope) is unreactive or slowly reactive. Chemical resolution of the m/z 238 isotopes of U and Pu can be obtained using ethylene as a reaction gas, but little improvement in the resolution of the m/z 239 isobars is obtained. However, high efficiency of reaction of U(+) and UH(+) with CO(2), and nonreaction of Pu(+), allows the sub-ppt determination of (239)Pu, (240)Pu, and (242)Pu (single ppt for (238)Pu) in the presence of 7 orders of magnitude excess U matrix without prior chemical separation. Similarly, oxidation of Pu(+) by NO, and nonreaction of Am(+), permit chemical resolution of the isobars of Pu and Am over 2-3 orders of magnitude relative concentration. The method provides the potential for analysis of the actinides with reduced sample matrix separation.

16 CFR Appendix G5 to Part 305 - Boilers-Gas (Except Steam)

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Boilers-Gas (Except Steam) G5 Appendix G5 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE... Appendix G5 to Part 305—Boilers—Gas (Except Steam) Manufacturer's rated heating capacities (Btu's/hr...

Readout electronics for CBM-TOF super module quality evaluation based on 10 Gbps ethernet

NASA Astrophysics Data System (ADS)

Jiang, D.; Cao, P.; Huang, X.; Zheng, J.; Wang, Q.; Li, B.; Li, J.; Liu, S.; An, Q.

2017-07-01

The Compressed Baryonic Matter-Time of Flight (CBM-TOF) wall uses high performance of Multi-gap Resistive Plate Chambers (MRPC) assembled in super modules to identify charged particles with high channel density and high measurement precision at high event rate. Electronics meet the challenge for reading data out from a super module at high speed of about 6 Gbps in real time. In this paper, the readout electronics for CBM-TOF super module quality evaluation is proposed based on 10 Gigabit Ethernet. The digitized TOF data from one super module will be concentrated at the front-end electronics residing on the side of the super module and transmitted to an extreme speed readout module (XSRM) housed in the backend crate through the PCI Express (PCIe) protocol via optic channels. Eventually, the XSRM transmits data to the data acquisition (DAQ) system through four 10 Gbps Ethernet ports in real time. This readout structure has advantages of high performance and expansibility. Furthermore, it is easy to operate. Test results on the prototype show that the overall data readout performance for each XSRM can reach up to 28.8 Gbps, which means XSRM can meet the requirement of reading data out from 4 super modules with 1280 channels in real time.

MALDI-TOF MS is more accurate than VITEK II ANC card and API Rapid ID 32 A system for the identification of Clostridium species.

PubMed

Kim, Young Jin; Kim, Si Hyun; Park, Hyun-Jung; Park, Hae-Geun; Park, Dongchul; Song, Sae Am; Lee, Hee Joo; Yong, Dongeun; Choi, Jun Yong; Kook, Joong-Ki; Kim, Hye Ran; Shin, Jeong Hwan

2016-08-01

All 50 Clostridium difficile strains were definitely identified by Vitek2 system, Rapid ID 32A system, and MALDI-TOF. For 18 non-difficile Clostridium strains, the identification results were correct in 0, 2, and 17 strains by Vitek2, Rapid ID 32A, and MALDI-TOF, respectively. MALDI-TOF could be used as the primary tool for identification of Clostridium species. Copyright © 2016 Elsevier Ltd. All rights reserved.

AMS in drug development at GSK

NASA Astrophysics Data System (ADS)

Young, G. C.; Ellis, W. J.

2007-06-01

A history of the use of AMS in GSK studies spanning the last 8 years (1998-2005) is presented, including use in pilot studies through to clinical, animal and in vitro studies. A brief summary of the status of GSK's in-house AMS capability is outlined and views on the future of AMS in GSK are presented, including potential impact on drug development and potential advances in AMS technology.

MALDI-TOF Mass Spectrometry for the Detection and Differentiation of Entamoeba histolytica and Entamoeba dispar

PubMed Central

Calderaro, Adriana; Piergianni, Maddalena; Buttrini, Mirko; Montecchini, Sara; Piccolo, Giovanna; Gorrini, Chiara; Rossi, Sabina; Chezzi, Carlo; Arcangeletti, Maria Cristina; Medici, Maria Cristina; De Conto, Flora

2015-01-01

Detection of Entamoeba histolytica and its differentiation from Entamoeba dispar is an important goal of the clinical parasitology laboratory. The aim of this study was the identification and differentiation of E. histolytica and E. dispar by MALDI-TOF MS, in order to evaluate the application of this technique in routine diagnostic practice. MALDI-TOF MS was applied to 3 amebic reference strains and to 14 strains isolated from feces that had been differentiated by molecular methods in our laboratory. Protein extracts from cultures of these strains (axenic cultures for the 3 reference strains and monoxenic cultures for the 14 field isolates) were analyzed by MALDI-TOF MS and the spectra obtained were analyzed by statistical software. Five peaks discriminating between E. histolytica and E. dispar reference strains were found by protein profile analysis: 2 peaks (8,246 and 8,303 Da) specific for E. histolytica and 3 (4,714; 5,541; 8,207 Da) for E. dispar. All clinical isolates except one showed the discriminating peaks expected for the appropriate species. For 2 fecal samples from which 2 strains (1 E. histolytica and 1 E. dispar) out of the 14 included in this study were isolated, the same discriminating peaks found in the corresponding isolated amebic strains were detected after only 12h (E. histolytica) and 24h (E. dispar) of incubation of the fecal samples in Robinson’s medium without serum. Our study shows that MALDI-TOF MS can be used to discriminate between E. histolytica and E. dispar using in vitro xenic cultures and it also could have potential for the detection of these species in clinical samples. PMID:25874612

Rapid and reliable discrimination between Shigella species and Escherichia coli using MALDI-TOF mass spectrometry.

PubMed

Paauw, Armand; Jonker, Debby; Roeselers, Guus; Heng, Jonathan M E; Mars-Groenendijk, Roos H; Trip, Hein; Molhoek, E Margo; Jansen, Hugo-Jan; van der Plas, Jan; de Jong, Ad L; Majchrzykiewicz-Koehorst, Joanna A; Speksnijder, Arjen G C L

2015-01-01

E. coli-Shigella species are a cryptic group of bacteria in which the Shigella species are distributed within the phylogenetic tree of E. coli. The nomenclature is historically based and the discrimination of these genera developed as a result of the epidemiological need to identify the cause of shigellosis, a severe disease caused by Shigella species. For these reasons, this incorrect classification of shigellae persists to date, and the ability to rapidly characterize E. coli and Shigella species remains highly desirable. Until recently, existing matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) assays used to identify bacteria could not discriminate between E. coli and Shigella species. Here we present a rapid classification method for the E. coli-Shigella phylogroup based on MALDI-TOF MS which is supported by genetic analysis. E. coli and Shigella isolates were collected and genetically characterized by MLVA. A custom reference library for MALDI-TOF MS that represents the genetic diversity of E. coli and Shigella strains was developed. Characterization of E. coli and Shigella species is based on an approach with Biotyper software. Using this reference library it was possible to distinguish between Shigella species and E. coli. Of the 180 isolates tested, 94.4% were correctly classified as E. coli or shigellae. The results of four (2.2%) isolates could not be interpreted and six (3.3%) isolates were classified incorrectly. The custom library extends the existing MALDI-TOF MS method for species determination by enabling rapid and accurate discrimination between Shigella species and E. coli. Copyright © 2015 Elsevier GmbH. All rights reserved.

Hybrid Ion-Detector/Data-Acquisition System for a TOF-MS

NASA Technical Reports Server (NTRS)

Burton, William D., Jr.; Schultz, J. Albert; Vaughn, Valentine; McCully, Michael; Ulrich, Steven; Egan, Thomas F.

2006-01-01

A modified ion-detector/data-acquisition system has been devised to increase the dynamic range of a time-of-flight mass spectrometer (TOF-MS) that, previously, included a microchannel-plate detector and a data-acquisition system based on counting pulses and time-tagging them by use of a time-to-digital converter (TDC). The dynamic range of the TOF-MS was limited by saturation of the microchannel plate detector, which can handle no more than a few million counts per second. The modified system includes (1) a combined microchannel plate/discrete ion multiplier and (2) a hybrid data-acquisition system that simultaneously performs analog current or voltage measurements and multianode single-ion-pulse-counting time-of-flight measurements to extend the dynamic range of a TDC into the regime in which a mass peak comprises multiple ions arriving simultaneously at the detector. The multianode data are used to determine, in real time, whether the detector is saturated. When saturation is detected, the data-acquisition system selectively enables circuitry that simultaneously determines the ion-peak intensity by measuring the time profile of the analog current or voltage detector-output signal.

High- and low-Am RE inclusion phases in a U-Np-Pu-Am-Zr alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Janney, Dawn E.; Madden, James W.; O'Holleran, Thomas P.

2015-03-01

Structural, microstructural, and microchemical data were collected from rare-earth inclusions in an as-cast U-Pu-Zr alloy with ~3 at% Am, 2% Np, and 9% rare-earth elements (La, Ce, Pr, and Nd). Two RE phases with different concentrations of Am were identified. The composition of high-Am RE inclusions is ~2-5 at% La, 15-20 % Ce, 5-10% Pr, 25-45% Nd, 1% Np, 5-10% Pu, and 10-20% Am. Some areas also have O, although this does not appear to be an essential part of the high-Am RE phase. The inclusions have a face-centered cubic structure with a lattice parameter a ~ 0.54 nm. Themore » composition of the only low-Am RE inclusion studied in detail is ~~35-40 at% O, 40-45 % Nd, 1-2% Zr, 4-5% La, 9-10% Ce, and 6-7% Pr. This inclusion is an oxide with a crystal structure similar to the room-temperature structure of Nd 2O 3. Microstructural features suggest that oxidation occurred during casting, and that early crystallization of high-temperature oxides led to formation of two distinct RE phases.« less

Rapid Identification of Microorganisms from Positive Blood Culture by MALDI-TOF MS After Short-Term Incubation on Solid Medium.

PubMed

Curtoni, Antonio; Cipriani, Raffaella; Marra, Elisa Simona; Barbui, Anna Maria; Cavallo, Rossana; Costa, Cristina

2017-01-01

Matrix-assisted laser-desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) is a useful tool for rapid identification of microorganisms. Unfortunately, its direct application to positive blood culture is still lacking standardized procedures. In this study, we evaluated an easy- and rapid-to-perform protocol for MALDI-TOF MS direct identification of microorganisms from positive blood culture after a short-term incubation on solid medium. This protocol was used to evaluate direct identification of microorganisms from 162 positive monomicrobial blood cultures; at different incubation times (3, 5, 24 h), MALDI-TOF MS assay was performed from the growing microorganism patina. Overall, MALDI-TOF MS concordance with conventional methods at species level was 60.5, 80.2, and 93.8% at 3, 5, and 24 h, respectively. Considering only bacteria, the identification performances at species level were 64.1, 85.0, and 94.1% at 3, 5, and 24 h, respectively. This protocol applied to a commercially available MS typing system may represent, a fast and powerful diagnostic tool for pathogen direct identification and for a promptly and pathogen-driven antimicrobial therapy in selected cases.

Fullerene Soot in Eastern China Air: Results from Soot Particle-Aerosol Mass Spectrometer

NASA Astrophysics Data System (ADS)

Wang, J.; Ge, X.; Chen, M.; Zhang, Q.; Yu, H.; Sun, Y.; Worsnop, D. R.; Collier, S.

2015-12-01

In this work, we present for the first time, the observation and quantification of fullerenes in ambient airborne particulate using an Aerodyne Soot Particle - Aerosol Mass Spectrometer (SP-AMS) deployed during 2015 winter in suburban Nanjing, a megacity in eastern China. The laser desorption and electron impact ionization techniques employed by the SP-AMS allow us to differentiate various fullerenes from other aerosol components. Mass spectrum of the identified fullerene soot is consisted by a series of high molecular weight carbon clusters (up to m/z of 2000 in this study), almost identical to the spectral features of commercially available fullerene soot, both with C70 and C60 clusters as the first and second most abundant species. This type of soot was observed throughout the entire study period, with an average mass loading of 0.18 μg/m3, accounting for 6.4% of the black carbon mass, 1.2% of the total organic mass. Temporal variation and diurnal pattern of fullerene soot are overall similar to those of black carbon, but are clearly different in some periods. Combining the positive matrix factorization, back-trajectory and analyses of the meteorological parameters, we identified the petrochemical industrial plants situating upwind from the sampling site, as the major source of fullerene soot. In this regard, our findings imply the ubiquitous presence of fullerene soot in ambient air of industry-influenced area, especially the oil and gas production regions. This study also offers new insights into the characterization of fullerenes from other environmental samples via the advanced SP-AMS technique.

[Studies of bacterial typing with MALDI-TOF].

PubMed

Culebras, Esther; Alvarez-Buylla, Adela; Jose Artacho Reinoso, M; Antonio Lepe, Jose

2016-06-01

MALDI-TOF (matrix-assisted laser desorption ionization time-of-flight) mass spectrometry has emerged as a potential tool for microbial characterization and identification in many microbiology departments. The technology is rapid, sensitive, and relatively inexpensive in terms of both the labour and costs involved. This review provides an overview on its utility for strain typing and epidemiological studies and explains the methodological approaches that can be used both for the performance of the technique and for the analysis of results. Finally, the review summarizes studies on the characterization of distinct bacterial species. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Multi-wavelength observations of the peculiar red giant HR 3126

NASA Technical Reports Server (NTRS)

Pesce, Joseph E.; Stencel, Robert E.; Walter, Frederick M.; Doggett, Jesse; Dachs, Joachim; Whitelock, Patricia A.; Mundt, Reinhard

1988-01-01

Ultraviolet observations of the red giant HR 3126 are combined with multi-wavelength data in order to provide a firmer basis for explaining the arc-minute sized nebula surrounding the object. Possibilities as to the location of HR 3126 on the Hertzsprung-Russel diagram, and to the formation mechanisms of the reflection nebula IC 2220 associated with it, are summarized.

Profiling LC-DAD-ESI-TOF MS method for the determination of phenolic metabolites from avocado (Persea americana).

PubMed

Hurtado-Fernández, Elena; Carrasco-Pancorbo, Alegría; Fernández-Gutiérrez, Alberto

2011-03-23

A powerful HPLC-DAD-ESI-TOF MS method was established for the efficient identification of the chemical constituents in the methanolic extracts of avocado (Persea americana). Separation and detection conditions were optimized by using a standard mix containing 39 compounds belonging to phenolic acids and different categories of flavonoids, analytes that could be potentially present in the avocado extracts. Optimum LC separation was achieved on a Zorbax Eclipse Plus C18 analytical column (4.6×150 mm, 1.8 μm particle size) by gradient elution with water+acetic acid (0.5%) and acetonitrile as mobile phases, at a flow rate of 1.6 mL/min. The detection was carried out by ultraviolet-visible absorption and ESI-TOF MS. The developed method was applied to the study of 3 different varieties of avocado, and 17 compounds were unequivocally identified with standards. Moreover, around 25 analytes were tentatively identified by taking into account the accuracy and isotopic information provided by TOF MS.

Independent component analysis for the extraction of reliable protein signal profiles from MALDI-TOF mass spectra.

PubMed

Mantini, Dante; Petrucci, Francesca; Del Boccio, Piero; Pieragostino, Damiana; Di Nicola, Marta; Lugaresi, Alessandra; Federici, Giorgio; Sacchetta, Paolo; Di Ilio, Carmine; Urbani, Andrea

2008-01-01

Independent component analysis (ICA) is a signal processing technique that can be utilized to recover independent signals from a set of their linear mixtures. We propose ICA for the analysis of signals obtained from large proteomics investigations such as clinical multi-subject studies based on MALDI-TOF MS profiling. The method is validated on simulated and experimental data for demonstrating its capability of correctly extracting protein profiles from MALDI-TOF mass spectra. The comparison on peak detection with an open-source and two commercial methods shows its superior reliability in reducing the false discovery rate of protein peak masses. Moreover, the integration of ICA and statistical tests for detecting the differences in peak intensities between experimental groups allows to identify protein peaks that could be indicators of a diseased state. This data-driven approach demonstrates to be a promising tool for biomarker-discovery studies based on MALDI-TOF MS technology. The MATLAB implementation of the method described in the article and both simulated and experimental data are freely available at http://www.unich.it/proteomica/bioinf/.

Ga + TOF-SIMS lineshape analysis for resolution enhancement of MALDI MS spectra of a peptide mixture

NASA Astrophysics Data System (ADS)

Malyarenko, D. I.; Chen, H.; Wilkerson, A. L.; Tracy, E. R.; Cooke, W. E.; Manos, D. M.; Sasinowski, M.; Semmes, O. J.

2004-06-01

The use of mass spectrometry to obtain molecular profiles indicative of alteration of concentrations of peptides in body fluids is currently the subject of intense investigation. For surface-based time-of-flight mass spectrometry the reliability and specificity of such profiling methods depend both on the resolution of the measuring instrument and on the preparation of samples. The present work is a part of a program to use Ga + beam TOF-SIMS alone, and as an adjunct to MALDI, in the development of reliable protein and peptide markers for diseases. Here, we describe techniques to prepare samples of relatively high-mass peptides, which serve as calibration standards and proxies for biomarkers. These are: Arg8-vasopressin, human angiotensin II, and somatostatin. Their TOF-SIMS spectra show repeatable characteristic features, with mass resolution exceeding 2000, including parent peaks and chemical adducts. The lineshape analysis for high-resolution parent peaks is shown to be useful for filter construction and deconvolution of inferior resolution SELDI-TOF spectra of calibration peptide mixture.

Fission-gas-release rates from irradiated uranium nitride specimens

NASA Technical Reports Server (NTRS)

Weinstein, M. B.; Kirchgessner, T. A.; Tambling, T. N.

1973-01-01

Fission-gas-release rates from two 93 percent dense UN specimens were measured using a sweep gas facility. Specimen burnup rates averaged .0045 and .0032 percent/hr, and the specimen temperatures ranged from 425 to 1323 K and from 552 to 1502 K, respectively. Burnups up to 7.8 percent were achieved. Fission-gas-release rates first decreased then increased with burnup. Extensive interconnected intergranular porosity formed in the specimen operated at over 1500 K. Release rate variation with both burnup and temperature agreed with previous irradiation test results.

Am I Doing Anything Wrong?

NASA Astrophysics Data System (ADS)

Chang, Eun-Woo

1998-04-01

Absolutely not! Let me be more specific. Am I doing anything I do not want to do with my career? I don't think so. Am I satisfied? My initial career goal was to teach at a small four-year university and do research with undergraduate students. But I am more than satisfied with what I am doing now, and I am enjoying my job. It is true that many new and talented Ph.D.'s are currently looking for careers at two-year colleges instead of universities. Many people expect this trend will be even greater in the future. Surveys also show that younger people (20-30's) care a great deal about both family and career. Thus, a teaching job at a two-year college is ideal for them. It was quite a surprise to find that many of my friends, who are very talented in research, are now teaching at two-year colleges.

Multiplex detection of protein toxins using MALDI-TOF-TOF tandem mass spectrometry: application in unambiguous toxin detection from bioaerosol.

PubMed

Alam, Syed Imteyaz; Kumar, Bhoj; Kamboj, Dev Vrat

2012-12-04

Protein toxins, such as botulinum neurotoxins (BoNTs), Clostridium perfringens epsilon toxin (ETX), staphylococcal enterotoxin B (SEB), shiga toxin (STX), and plant toxin ricin, are involved in a number of diseases and are considered as potential agents for bioterrorism and warfare. From a bioterrorism and warfare perspective, these agents are likely to cause maximum damage to a civilian or military population through an inhalational route of exposure and aerosol is considered the envisaged mode of delivery. Unambiguous detection of toxin from aerosol is of paramount importance, both for bringing mitigation protocols into operation and for implementation of effective medical countermeasures, in case a "biological cloud" is seen over a population. A multiplex, unambiguous, and qualitative detection of protein toxins is reported here using tandem mass spectrometry with MALDI-TOF-TOF. The methodology involving simple sample processing steps was demonstrated to identify toxins (ETX, Clostridium perfringes phospholipase C, and SEB) from blind spiked samples. The novel directed search approach using a list of unique peptides was used to identify toxins from a complex protein mixture. The bioinformatic analysis of seven protein toxins for elucidation of unique peptides with conservation status across all known sequences provides a high confidence for detecting toxins originating from any geographical location and source organism. Use of tandem MS data with peptide sequence information increases the specificity of the method. A prototype for generation of aerosol using a nebulizer and collection using a cyclone collector was used to provide a proof of concept for unambiguous detection of toxin from aerosol using precursor directed tandem mass spectrometry combined with protein database searching. ETX prototoxin could be detected from aerosol at 0.2 ppb concentration in aerosol.

Absolute Quantification of Rifampicin by MALDI Imaging Mass Spectrometry Using Multiple TOF/TOF Events in a Single Laser Shot

NASA Astrophysics Data System (ADS)

Prentice, Boone M.; Chumbley, Chad W.; Caprioli, Richard M.

2017-01-01

Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) allows for the visualization of molecular distributions within tissue sections. While providing excellent molecular specificity and spatial information, absolute quantification by MALDI IMS remains challenging. Especially in the low molecular weight region of the spectrum, analysis is complicated by matrix interferences and ionization suppression. Though tandem mass spectrometry (MS/MS) can be used to ensure chemical specificity and improve sensitivity by eliminating chemical noise, typical MALDI MS/MS modalities only scan for a single MS/MS event per laser shot. Herein, we describe TOF/TOF instrumentation that enables multiple fragmentation events to be performed in a single laser shot, allowing the intensity of the analyte to be referenced to the intensity of the internal standard in each laser shot while maintaining the benefits of MS/MS. This approach is illustrated by the quantitative analyses of rifampicin (RIF), an antibiotic used to treat tuberculosis, in pooled human plasma using rifapentine (RPT) as an internal standard. The results show greater than 4-fold improvements in relative standard deviation as well as improved coefficients of determination (R2) and accuracy (>93% quality controls, <9% relative errors). This technology is used as an imaging modality to measure absolute RIF concentrations in liver tissue from an animal dosed in vivo. Each microspot in the quantitative image measures the local RIF concentration in the tissue section, providing absolute pixel-to-pixel quantification from different tissue microenvironments. The average concentration determined by IMS is in agreement with the concentration determined by HPLC-MS/MS, showing a percent difference of 10.6%.

Overview of AMS (CCSDS Asynchronous Message Service)

NASA Technical Reports Server (NTRS)

Burleigh, Scott

2006-01-01

This viewgraph presentation gives an overview of the Consultative Committee for Space Data Systems (CCSDS) Asynchronous Message Service (AMS). The topics include: 1) Key Features; 2) A single AMS continuum; 3) The AMS Protocol Suite; 4) A multi-continuum venture; 5) Constraining transmissions; 6) Security; 7) Fault Tolerance; 8) Performance of Reference Implementation; 9) AMS vs Multicast (1); 10) AMS vs Multicast (2); 11) RAMS testing exercise; and 12) Results.

Efficient identification of Malassezia yeasts by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).

PubMed

Kolecka, A; Khayhan, K; Arabatzis, M; Velegraki, A; Kostrzewa, M; Andersson, A; Scheynius, A; Cafarchia, C; Iatta, R; Montagna, M T; Youngchim, S; Cabañes, F J; Hoopman, P; Kraak, B; Groenewald, M; Boekhout, T

2014-02-01

Infections caused by Malassezia yeasts are most likely underdiagnosed, because fatty acid supplementation is needed for growth. Rapid identification of Malassezia species is essential for appropriate treatment of Malassezia-related skin infections, fungaemia and nosocomial outbreaks in neonates, children and adults and can be life-saving for those patients. Ma-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been reported to be a rapid and reliable diagnostic tool to identify clinically important yeasts, but so far no data have been reported on identification of Malassezia isolates with this technique. To create an extensive database of main mass spectra (MSPs) that will allow quick identification of Malassezia species by MALDI-TOF MS. An in-house library of 113 MSPs was created from 48 reference strains from the CBS-KNAW yeast collection. The in-house library was challenged with two test sets of Malassezia strains, namely 165 reference strains from the CBS collection and 338 isolates collected in Greece, Italy, Sweden and Thailand. MALDI-TOF MS allowed correct identification of all 14 Malassezia spp. MALDI-TOF MS results were concordant with those of sequence analyses of the internal transcribed spacers (ITS1/ITS2) and the D1/D2 domains of the large subunit of the ribosomal DNA. Implementation of the MALDI-TOF MS system as a routine identification tool will contribute to correct identification of Malassezia yeasts with minimal effort and in a short turnaround time, which is especially important for the rapid identification of Malassezia in skin diseases and nosocomial outbreaks. © 2013 British Association of Dermatologists.

PTR-3-TOF a novel in-situ instrument for studying the lifecycle of reactive organic carbon in the atmosphere

NASA Astrophysics Data System (ADS)

Hansel, Armin; Breitenlechner, Martin; Fischer, Lukas; Hainer, Markus

2017-04-01

Existing proton transfer reaction time of flight (PTR-TOF) instruments are known to detect volatile organic compounds (VOCs) and could in principle also detect highly oxidized organic compounds such as low volatility organic compounds (LVOC) but PTR-TOF inlets were not optimized to avoid wall losses of such low volatility compounds. In addition PTR-TOF is not sensitive enough to quantify second order and even higher order oxidation products at atmospherically relevant concentrations. To solve this problem, as well as to enable bridging the gap in understanding how atmospherically relevant BVOC form SVOC, LVOC and even ELVOC, we developed the PTR3, a compact and field deployable ultrasensitive instrument based on chemical ionization mass spectrometry. Here we report first results from PTR-3-TOF measurements at Hyytiälä where we measured concentrations and fluxes of precursor gases (BVOC) and their oxidation products: semi and low volatile organic compounds. The recently developed PTR-3-TOF instrument uses a discharge ion source coupled to a contact free inlet system running at high sample flow rates through the novel reaction chamber at 80 mbar. The PTR-3 front part is coupled to TOFWERK's newest Long-TOF mass analyzer. The first prototype has sensitivities of up to 20.000 cps per ppb and a mass resolution of 8.000 m/Δm. The instrument has been successfully tested at CERN for the CLOUD campaign in 2015. During pure α-pinene ozonolysis experiments at low NOx conditions we observed in total several hundred peaks in the mass spectrum, including α-Pinene present in the ppb range, first and higher order oxidation products present in the ppt range and highly oxydized α-pinene monomers and dimers (e.g., C20H30O18H+; m/z = 559.1506 Th) in the low ppq range and even sub-ppq range. The advantage of this new technology based on positive ion chemistry is the capability to measure precursor gases as well as condensing- and even nucleating vapors.

Elemental abundance analyses with DAO spectrograms: XXXII. HR 6455 (A3 III), δ Aqr (A3 V), η Lep (F2 V), and 1 Boo (A1 V)

NASA Astrophysics Data System (ADS)

Yüce, K.; Adelman, S. J.; Gulliver, A. F.; Hill, G.

2011-08-01

We examine the sharp-lined stars HR 6455 (A3 III, v sin i = 8.7 km s-1) and η Lep (F2 V, v sin i = 13.5 km s-1) as well as δ Aqr (A3 V, v sin i = 81 km s-1) and 1 Boo (A1 V, v sin i = 59 km s-1) to increase the number consistently analyzed A and F stars using high dispersion and high S/N (≥200) spectrograms obtained with CCD detectors at the long Coudé camera of the 1.22-m telescope of the Dominion Astrophysical Observatory. Such studies contribute to understanding systematic abundance differences between normal and non-magnetic main-sequence band chemically peculiar A and early F stars. LTE fine analyses of HR 6455, δ Aqr, and 1 Boo using Kurucz's ATLAS suite programs show the same general elemental abundance trends with differences in the metal richness. Light and iron-peak element abundances are generally solar or overabundant while heavy element and rare earth element abundances are overabundant. HR 6455 is an evolved Am star while δ Aqr and 1 Boo show the phenomenon to different extents. Most derived abundances of η Lep are solar. Table 3 is available at the CDS via http://cdsarc.u-strasbg.fr/cgi-bin/qcat?J/AN/332/681

Bringing human resources to the table: utilization of an HR balanced scorecard at Mayo Clinic.

PubMed

Fottler, Myron D; Erickson, Eric; Rivers, Patrick A

2006-01-01

Rather than viewing HR as a critical driver of organizational strategy and outcomes, most health care organizations see HR as a drain on the organization's bottom line. Only by aligning HR with the organizational strategy will HR leaders truly get a seat at the leadership table. HR professionals can overcome impediments and gain a seat at the table by learning the language of business and the ways in which organizational leaders use data to drive their decisions. This article shows how Mayo Clinic uses the popular Balanced Scorecard approach to align its measures of HR performance to the organization's strategic plan.

76 FR 78641 - Southwestern Gas Storage Technical Conference; Notice of Public Conference

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-19

... Storage Technical Conference; Notice of Public Conference Take notice that on February 16, 2012 at 9 a.m... technical conference with interested parties to discuss issues related to natural gas storage development in... Cold Weather Event of February 1-5, 2011: Causes and Recommendations, ``[a]dditional gas storage...

Evaluation of Three MALDI-TOF Mass Spectrometry Libraries for the Identification of Filamentous Fungi in Three Clinical Microbiology Laboratories in Manitoba, Canada.

PubMed

Stein, Markus; Tran, Vanessa; Nichol, Kimberly A; Lagacé-Wiens, Philippe; Pieroni, Peter; Adam, Heather J; Turenne, Christine; Walkty, Andrew J; Normand, Anne-Cécile; Hendrickx, Marijke; Piarroux, Renaud; Karlowsky, James A

2018-06-12

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is commonly used by clinical microbiology laboratories to identify bacterial pathogens and yeasts, but not for the identification of moulds. Recent progress in extraction protocols and the composition of comparative libraries support potential application of MALDI-TOF MS for mould identification in clinical microbiology laboratories. We evaluated the performance of the Bruker Microflex ™ MALDI-TOF MS instrument (Billerica, MA, USA) to identify clinical isolates and reference strains of moulds using three libraries, the Bruker mould library, the National Institutes of Health (NIH) library, and the Mass Spectrometry Identification (MSI) online library, and compared those results to conventional (morphological) and molecular (18S/ITS; gold standard) identification methods. All three libraries demonstrated greater accuracy in genus identification (≥94.9%) than conventional methods (86.4%). MALDI-TOF MS identified 73.3% of isolates to species-level compared to only 31.7% by conventional methods. The MSI library demonstrated the highest rate of species-level identification (72.0%) compared to NIH (19.5%) and Bruker (13.6%) libraries. Greater than 20% of moulds remained unidentified to species-level by all three MALDI-TOF MS libraries primarily because of library limitations or imperfect spectra. The overall identification rate of each MALDI-TOF MS library depended on the number of species and the number of spectra representing each species in the library. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Assessment of Residential Biomass Burning During Winter in Las Vegas, Nevada

NASA Astrophysics Data System (ADS)

Brown, S. G.; Lee, T.; Olson, D.; Norris, G.; Roberts, P. T.; Collett, J. L.

2011-12-01

Concentrations of organic matter (OM) and black carbon (BC) were measured at a site in a residential area of Las Vegas, Nevada, and multiple analytical methods were used to determine the amounts attributable to biomass burning. In January 2008, measurements of a wood burning tracer, levoglucosan, were made via gas chromatography-mass spectroscopy (n=17). In addition, an Aerodyne High Resolution Aerosol Mass Spectrometer (HR-AMS) measured OM and C2H4O2+, a levoglucosan-derived fragment. During 2007 and 2008, two-channel Aethalometer data were also collected; the difference between the 370 nm and 880 nm channels (UV-BC difference) was used to indicate the presence of wood smoke. Concentrations of OM, BC, C2H4O2+, and levoglucosan, as well as the UV-BC difference, were all highest during the evening hours (generally between 1800 and 0000 LST). Average OM concentrations were 3.3 μg/m3 during January but were 6.9 μg/m3 during the overnight hours (between 1700 and 0000 LST). Median levoglucosan concentrations were 0.14 μg/m3. The correlation of levoglucosan with C2H4O2+ was very high (r2=0.92). During the evening hours, correlation between BC and C2H4O2+ was good (r2=0.79); however, correlation was poor during other hours (r2<0.40), suggesting that other emissions such as mobile-source emissions were likely the dominant source of BC during those hours. C2H4O2+ showed modest correlation with UV-BC (e.g., r2=0.45). Using EPA's positive matrix factorization tool, EPA PMF, on the January HR-AMS data, we determined that biomass burning organic aerosol (BBOA) constituted 12% of the OM on average, but about 25% of the OM during evening hours. BBOA correlated well with levoglucosan (r2=0.82) and C2H4O2+ (r2=0.93). Levoglucosan measurements suggested that wood burning could constitute 38% of the OM during the overnight periods on average, although this number greatly depends on the assumed ratio of levoglucosan to OM in a source profile for residential biomass burning. The

SELDI-TOF MS of quadruplicate urine and serum samples to evaluate changes related to storage conditions.

PubMed

Traum, Avram Z; Wells, Meghan P; Aivado, Manuel; Libermann, Towia A; Ramoni, Marco F; Schachter, Asher D

2006-03-01

Proteomic profiling with SELDI-TOF MS has facilitated the discovery of disease-specific protein profiles. However, multicenter studies are often hindered by the logistics required for prompt deep-freezing of samples in liquid nitrogen or dry ice within the clinic setting prior to shipping. We report high concordance between MS profiles within sets of quadruplicate split urine and serum samples deep-frozen at 0, 2, 6, and 24 h after sample collection. Gage R&R results confirm that deep-freezing times are not a statistically significant source of SELDI-TOF MS variability for either blood or urine.

FORMALDEHYDE GAS INACTIVATION OF BACILLUS ANTHRACIS, BACILLUS SUBTILIS AND GEOBACILLUS STEAROTHERMOPHILUS SPORES ON INDOOR SURFACE MATERIALS.

EPA Science Inventory

Research evaluated the decontamination of Bacillus anthracis, Bacillus subtilis, and Geobacillus stearothermophilus spores on indoor surface material using formaldehyde gas. Spores were dried on seven types of indoor surfaces and exposed to 1100 ppm formaldehyde gas for 10 hr. Fo...

Gold patterned biochips for on-chip immuno-MALDI-TOF MS: SPR imaging coupled multi-protein MS analysis.

PubMed

Kim, Young Eun; Yi, So Yeon; Lee, Chang-Soo; Jung, Yongwon; Chung, Bong Hyun

2012-01-21

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis of immuno-captured target protein efficiently complements conventional immunoassays by offering rich molecular information such as protein isoforms or modifications. Direct immobilization of antibodies on MALDI solid support enables both target enrichment and MS analysis on the same plate, allowing simplified and potentially multiplexing protein MS analysis. Reliable on-chip immuno-MALDI-TOF MS for multiple biomarkers requires successful adaptation of antibody array biochips, which also must accommodate consistent reaction conditions on antibody arrays during immuno-capture and MS analysis. Here we developed a facile fabrication process of versatile antibody array biochips for reliable on-chip MALDI-TOF-MS analysis of multiple immuno-captured proteins. Hydrophilic gold arrays surrounded by super-hydrophobic surfaces were formed on a gold patterned biochip via spontaneous chemical or protein layer deposition. From antibody immobilization to MALDI matrix treatment, this hydrophilic/phobic pattern allowed highly consistent surface reactions on each gold spot. Various antibodies were immobilized on these gold spots both by covalent coupling or protein G binding. Four different protein markers were successfully analyzed on the present immuno-MALDI biochip from complex protein mixtures including serum samples. Tryptic digests of captured PSA protein were also effectively detected by on-chip MALDI-TOF-MS. Moreover, the present MALDI biochip can be directly applied to the SPR imaging system, by which antibody and subsequent antigen immobilization were successfully monitored.

Contrast Enhancement in TOF cerebral angiography at 7 T using Saturation and MT pulses under SAR constraints: impact of VERSE and sparse pulses

PubMed Central

Schmitter, Sebastian; Bock, Michael; Johst, Sören; Auerbach, Edward J.; Uğurbil, Kâmil; Van de Moortele, Pierre-François

2011-01-01

Cerebral 3D time of flight (TOF) angiography significantly benefits from ultra high fields, mainly due to higher SNR and to longer T1 relaxation time of static brain tissues, however, SAR significantly increases with B0. Thus, additional RF pulses commonly used at lower field strengths to improve TOF contrast such as saturation of venous signal and improved background suppression by magnetization transfer typically cannot be used at higher fields. In this work we aimed at reducing SAR for each RF pulse category in a TOF sequence. We use the VERSE principle for the slab selective TOF excitation as well as the venous saturation RF pulses. Additionally, MT pulses are implemented by sparsely applying the pulses only during acquisition of the central k-space lines to limit their SAR contribution. Image quality, angiographic contrast and SAR reduction were investigated as a function of VERSE parameters and of the total number of MT pulses applied. Based on these results, a TOF protocol was generated that increases the angiographic contrast by more than 50% and reduces subcutaneous fat signal while keeping the resulting SAR within regulatory limits. PMID:22139829

Understanding the Changes to Biomass Surface Characteristics after Ammonia and Organosolv Pretreatments by Using Time-of-Flight Secondary-Ion Mass Spectrometry (TOF-SIMS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tolbert, Allison K.; Yoo, Chang Geun; Ragauskas, Arthur J.

Surface characteristic changes to poplar after ammonia and organosolv pretreatments were investigated by means of time-of-flight secondary-ion mass spectrometry (TOF-SIMS) analysis. Whereas normalized total polysaccharides and lignin contents on the surface differed from bulk chemical compositions, the surface cellulose ions detected by TOF-SIMS showed the same value trend as the cellulose content in the biomass. In addition, the lignin syringyl/guaiacyl ratio according to TOF-SIMS results showed the same trend as the ratio measured by means of NMR spectroscopic analysis, even though the ratio scales for each method were different. A similar correlation was determined between the surface cellulose and glucosemore » release after enzymatic hydrolysis. Lastly, these results demonstrate that surface characterization using TOF-SIMS can provide important information about the effects of pretreatment on biomass properties and its hydrolysis.« less

Understanding the Changes to Biomass Surface Characteristics after Ammonia and Organosolv Pretreatments by Using Time-of-Flight Secondary-Ion Mass Spectrometry (TOF-SIMS)

DOE PAGES

Tolbert, Allison K.; Yoo, Chang Geun; Ragauskas, Arthur J.

2017-03-20

Surface characteristic changes to poplar after ammonia and organosolv pretreatments were investigated by means of time-of-flight secondary-ion mass spectrometry (TOF-SIMS) analysis. Whereas normalized total polysaccharides and lignin contents on the surface differed from bulk chemical compositions, the surface cellulose ions detected by TOF-SIMS showed the same value trend as the cellulose content in the biomass. In addition, the lignin syringyl/guaiacyl ratio according to TOF-SIMS results showed the same trend as the ratio measured by means of NMR spectroscopic analysis, even though the ratio scales for each method were different. A similar correlation was determined between the surface cellulose and glucosemore » release after enzymatic hydrolysis. Lastly, these results demonstrate that surface characterization using TOF-SIMS can provide important information about the effects of pretreatment on biomass properties and its hydrolysis.« less

LBT observations of the HR8799 planetary system

NASA Astrophysics Data System (ADS)

Mesa, D.; Arcidiacono, C.; Claudi, R. U.; Desidera, S.; Esposito, S.; Gratton, R.; Masciadri, E.

2013-09-01

We present here observations of the HR8799 planetary system performed in H and Ks band exploiting the AO system at the Large Binocular Telescope and the PISCES camera. Thanks to the excellent performence of the instrument we were able to detect for the first time the inner known planet of the system (HR8799) in the H band. Precise photometric and astrometric measures have been taken for all the four planets. Further, exploiting ours and previous astrometric results, we were able to put some limits on the planetary orbits of the four planets. The analysis of the dinamical stability of the system seems to show lower planetary masses than the ones adopted until now.

Identification and Characterization of Cell Wall Proteins of a Toxic Dinoflagellate Alexandrium catenella Using 2-D DIGE and MALDI TOF-TOF Mass Spectrometry

PubMed Central

Wang, Da-Zhi; Dong, Hong-Po; Li, Cheng; Xie, Zhang-Xian; Lin, Lin; Hong, Hua-Sheng

2011-01-01

The cell wall is an important subcellular component of dinoflagellate cells with regard to various aspects of cell surface-associated ecophysiology, but the full range of cell wall proteins (CWPs) and their functions remain to be elucidated. This study identified and characterized CWPs of a toxic dinoflagellate, Alexandrium catenella, using a combination of 2D fluorescence difference gel electrophoresis (DIGE) and MALDI TOF-TOF mass spectrometry approaches. Using sequential extraction and temperature shock methods, sequentially extracted CWPs and protoplast proteins, respectively, were separated from A. catenella. From the comparison between sequentially extracted CWPs labeled with Cy3 and protoplast proteins labeled with Cy5, 120 CWPs were confidently identified in the 2D DIGE gel. These proteins gave positive identification of protein orthologues in the protein database using de novo sequence analysis and homology-based search. The majority of the prominent CWPs identified were hypothetical or putative proteins with unknown function or no annotation, while cell wall modification enzymes, cell wall structural proteins, transporter/binding proteins, and signaling and defense proteins were tentatively identified in agreement with the expected role of the extracellular matrix in cell physiology. This work represents the first attempt to investigate dinoflagellate CWPs and provides a potential tool for future comprehensive characterization of dinoflagellate CWPs and elucidation of their physiological functions. PMID:21904561

Offline identification and characterization of biogenic primary emissions

NASA Astrophysics Data System (ADS)

Bozzetti, Carlo; El-Haddad, Imad; Dällenbach, Kaspar Rudolf; Sciare, Jean; Kasper-Giebl, Anne; Hueglin, Christoph; Canonaco, Francesco; Flasch, Mira; Wolf, Robert; Krepelova, Adela; Gates Slowik, Jay; Baltensperger, Urs; Prévôt, André Stéphan Henry

2014-05-01

Primary biological particles (e.g. pollen, spores) are known to have adverse influence on human health. Several studies illustrated also their ice-nuclei activity (Vali et al., 1976) showing their potential role in the climate changes. Nevertheless, the contribution and the chemical characterization of the biogenic emissions are poorly understood. The Aerodyne aerosol mass spectrometer (AMS, Aerodyne) has significantly advanced real-time PM1 monitoring. The AMS provides both quantitative measurements of the non-refractory (NR) components (organic aerosol (OA), Cl-, NO3-, NH4+, SO42-) and organic fraction mass spectra of the submicron fraction. Application of the positive matrix factorization (PMF) and other statistical tools such as ME-2 (Paatero, 1999; Canonaco et al., 2013) demonstrated that OA AMS mass spectra contain enough information to differentiate several factors subsequently associated with different aerosol sources (Jimenez et al., 2009). However, AMS measurements are restricted to the PM1 fraction and the AMS deployment remains complex and expensive, limiting long-term sampling and the spatial coverage. We explored a novel offline AMS application (Dällenbach et al., 2014) including a water extraction of the particulate matter from quartz filters by sonication. The resulting liquid extracts are nebulized generating an aerosol analyzed by High-Resolution-Time-of-Flight-AMS. The approach allows registering mass spectra and monitoring different particle size fractions not available by normal online AMS measurement (e.g. PM10). Moreover it broadens the sampling coverage since the filters are relatively easy and inexpensive to be collected and stored, furthermore filter samples are already routinely collected at many air quality stations worldwide. PM1, PM2.5, and PM10 filter samples from Payerne (a rural site on the Swiss Plateau)were collected both in summer and in winter. We clearly identified using PMF the contribution of biogenic primary emissions in

Surface and adsorbate structural analysis from time-of-flight scattering and recoiling spectrometry (TOF-SARS)

NASA Astrophysics Data System (ADS)

Rabalais, J. W.; Bu, H.; Roux, C.

1992-02-01

The methods of obtaining surface structural information from low energy ion scattering spectrometry are described. These methods include measurements of backscattering, forwardscattering, and recoiling intensities vs beam incident α, beam exit β, crystal azimuthal δ, and scattering Θ angles. References are provided which give examples of each different kind of measurement. The technique of time-of-flight scattering and recoiling spectrometry (TOF-SARS), which collects both scattered.and recoiled neutrals and ions simultaneously, is described. TOF-SARS data for the three surface phases, clean Ni{110}-(1 × 1), Ni{110}-(1 × 2)-H missing row, and Ni{110}-(2 × 1)-O missing row, are used to illustrate some of the structural measurements.

Polyphasic Approach Including MALDI-TOF MS/MS Analysis for Identification and Characterisation of Fusarium verticillioides in Brazilian Corn Kernels

PubMed Central

Chang, Susane; Porto Carneiro-Leão, Mariele; Ferreira de Oliveira, Benny; Souza-Motta, Cristina; Lima, Nelson; Santos, Cledir; Tinti de Oliveira, Neiva

2016-01-01

Fusarium verticillioides is considered one of the most important global sources of fumonisins contamination in food and feed. Corn is one of the main commodities produced in the Northeastern Region of Brazil. The present study investigated potential mycotoxigenic fungal strains belonging to the F. verticillioides species isolated from corn kernels in 3 different Regions of the Brazilian State of Pernambuco. A polyphasic approach including classical taxonomy, molecular biology, MALDI-TOF MS and MALDI-TOF MS/MS for the identification and characterisation of the F. verticillioides strains was used. Sixty F. verticillioides strains were isolated and successfully identified by classical morphology, proteomic profiles of MALDI-TOF MS, and by molecular biology using the species-specific primers VERT-1 and VERT-2. FUM1 gene was further detected for all the 60 F. verticillioides by using the primers VERTF-1 and VERTF-2 and through the amplification profiles of the ISSR regions using the primers (GTG)5 and (GACA)4. Results obtained from molecular analysis shown a low genetic variability among these isolates from the different geographical regions. All of the 60 F. verticillioides isolates assessed by MALDI-TOF MS/MS presented ion peaks with the molecular mass of the fumonisin B1 (721.83 g/mol) and B2 (705.83 g/mol). PMID:26927172

Content-Based Networking: DTN, AMS, Sharednet

NASA Technical Reports Server (NTRS)

Burleigh, Scott

2006-01-01

A detailed viewgraph presentation on DTN, AMS, and Sharednet content-based networking is shown. The contents include: 1) DARPA Content-Based Networking Summary of Requirements; 2) Concept; 3) Key Features of AMS; 4) Overview of Sharednet; 5) SharedNet Deployment History; 6) SharedNet AMS DTN; 7) Detailed Structure; and 8) Bottom line.

Advanced Gas Turbine (AGT) technology development project

NASA Technical Reports Server (NTRS)

1987-01-01

This report is the final in a series of Technical Summary Reports for the Advanced Gas Turbine (AGT) Technology Development Project, authorizrd under NASA Contract DEN3-167 and sponsored by the DOE. The project was administered by NASA-Lewis Research Center of Cleveland, Ohio. Plans and progress are summarized for the period October 1979 through June 1987. This program aims to provide the US automotive industry the high risk, long range technology necessary to produce gas turbine engines for automobiles that will reduce fuel consumption and reduce environmental impact. The intent is that this technology will reach the marketplace by the 1990s. The Garrett/Ford automotive AGT was designated AGT101. The AGT101 is a 74.5 kW (100 shp) engine, capable of speeds to 100,000 rpm, and operates at turbine inlet temperatures to 1370 C (2500 F) with a specific fuel consumption level of 0.18 kg/kW-hr (0.3 lbs/hp-hr) over most of the operating range. This final report summarizes the powertrain design, power section development and component/ceramic technology development.

Multidimensional gas chromatography in combination with accurate mass, tandem mass spectrometry, and element-specific detection for identification of sulfur compounds in tobacco smoke.

PubMed

Ochiai, Nobuo; Mitsui, Kazuhisa; Sasamoto, Kikuo; Yoshimura, Yuta; David, Frank; Sandra, Pat

2014-09-05

A method is developed for identification of sulfur compounds in tobacco smoke extract. The method is based on large volume injection (LVI) of 10μL of tobacco smoke extract followed by selectable one-dimensional ((1)D) or two-dimensional ((2)D) gas chromatography (GC) coupled to a hybrid quadrupole time-of-flight mass spectrometer (Q-TOF-MS) using electron ionization (EI) and positive chemical ionization (PCI), with parallel sulfur chemiluminescence detection (SCD). In order to identify each individual sulfur compound, sequential heart-cuts of 28 sulfur fractions from (1)D GC to (2)D GC were performed with the three MS detection modes (SCD/EI-TOF-MS, SCD/PCI-TOF-MS, and SCD/PCI-Q-TOF-MS). Thirty sulfur compounds were positively identified by MS library search, linear retention indices (LRI), molecular mass determination using PCI accurate mass spectra, formula calculation using EI and PCI accurate mass spectra, and structure elucidation using collision activated dissociation (CAD) of the protonated molecule. Additionally, 11 molecular formulas were obtained for unknown sulfur compounds. The determined values of the identified and unknown sulfur compounds were in the range of 10-740ngmg total particulate matter (TPM) (RSD: 1.2-12%, n=3). Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Characterisation of the aerobic bacterial flora of boid snakes: application of MALDI-TOF mass spectrometry.

PubMed

Plenz, Bastian; Schmidt, Volker; Grosse-Herrenthey, Anke; Krüger, Monika; Pees, Michael

2015-03-14

The aim of this study was to identify aerobic bacterial isolates from the respiratory tract of boids with matrix-assisted laser desorption ionisation-time-of-flight mass spectrometry (MALDI-TOF MS). From 47 boid snakes, swabs from the oral cavity, tracheal wash samples and, in cases in which postmortem examination was performed, pulmonary tissue samples were taken. Each snake was classified as having inflammation of the respiratory tract and/or oral cavity, or without evidence of inflammation based on combination of clinical, cytological and histopathological findings. Samples collected from the respiratory tract and oral cavity were inoculated onto routine media and bacteria were cultured aerobically. All morphologically distinct individual colonies obtained were analysed using MALDI-TOF MS. Unidentified isolates detected in more than three snakes were selected for further 16S rDNA PCR and sequencing. Among all examined isolates (n=243), 49 per cent (n=119) could be sufficiently speciated using MALDI-TOF MS. Molecular biology revealed several bacterial species that have not been previously described in reptiles. With an average of 6.3 different isolates from the respiratory tract and/or oral cavity, boids with inflammatory disease harboured significantly more bacterial species than boids without inflammatory disease (average 2.8 isolates). British Veterinary Association.

A flowsheet concept for an Am/Ln separation based on Am{sup VI} solvent extraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mincher, B.J.; Law, J.D.

2013-07-01

The separation of Am from the lanthanides and curium is a key step in proposed advanced fuel cycle scenarios. The partitioning and transmutation of Am is desirable to minimize the long-term radiotoxicity of material interred in a future high-level waste repository. However, a separation amenable to process scale-up remains elusive. Higher oxidation states of americium have recently been used to demonstrate solvent extraction-based separations using conventional fuel cycle ligands. Here, the successful partitioning of Am{sup VI} from the bulk of lanthanides and curium using diamyl-amyl-phosphonate (DAAP) extraction is reported. Due to the instability of Am{sup VI} in the organic phasemore » it was readily selectively stripped to a new acidic aqueous phase to provide separation from co-extracted Ce{sup IV}. The use of NaBiO{sub 3} as an oxidant to separate Am from the lanthanides and Cm by solvent extraction has been successfully demonstrated on the bench scale. Based on these results, flowsheet concepts can be designed that result in 96 % Am recovery in the presence of a few percent of the remaining Cm and the lanthanides in two extraction contacts. Preliminary results also indicate that the DAAP extractant is robust toward γ- irradiation under realistic conditions of acidity and dissolved oxygen concentration.« less

MALDI-TOF mass spectrometry following short incubation on a solid medium is a valuable tool for rapid pathogen identification from positive blood cultures.

PubMed

Kohlmann, Rebekka; Hoffmann, Alexander; Geis, Gabriele; Gatermann, Sören

2015-01-01

Rapid identification of the causative microorganism is a key element in appropriate antimicrobial therapy of bloodstream infections. Whereas traditional analysis of positive blood cultures requires subculture over at least 16-24h prior to pathogen identification by, e.g. matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), sample preparation procedures enabling direct MALDI-TOF MS, i.e. without preceding subculture, are associated with additional effort and costs. Hence, we integrated an alternative MALDI-TOF MS approach in diagnostic routine using a short incubation on a solid medium. Positive blood cultures were routinely plated on chocolate agar plates and incubated for 4h (37 °C, 5% CO2). Subsequently, MALDI-TOF MS using a Microflex LT instrument (Bruker Daltonics) and direct smear method was performed once per sample. For successful identification of bacteria at species level, score cut-off values were used as proposed by the manufacturer (≥ 2.0) and in a modified form (≥ 1.5 for MALDI-TOF MS results referring to Gram-positive cocci and ≥ 1.7 for MALDI-TOF MS results referring to bacteria other than Gram-positive cocci). Further data analysis also included an assessment of the clinical impact of the MALDI-TOF MS result. Applying the modified score cut-off values, our approach led to an overall correct species identification in 69.5% with misidentification in 3.4% (original cut-offs: 49.2% and 1.8%, respectively); for Gram-positive cocci, correct identification in 68.4% (100% for Staphylococcus aureus and enterococci, 80% for beta-hemolytic streptococci), for Gram-negative bacteria, correct identification in 97.6%. In polymicrobial blood cultures, in 72.7% one of the pathogens was correctly identified. Results were not reliable for Gram-positive rods and yeasts. The approach was easy to implement in diagnostic routine. In cases with available clinical data and successful pathogen identification, in 51.1% our

Innovative Instructional Tools from the AMS

NASA Astrophysics Data System (ADS)

Abshire, W. E.; Geer, I. W.; Mills, E. W.; Nugnes, K. A.; Stimach, A. E.

2016-12-01

Since 1996, the American Meteorological Society (AMS) has been developing online educational materials with dynamic features that engage students and encourage additional exploration of various concepts. Most recently, AMS transitioned its etextbooks to webBooks. Now accessible anywhere with internet access, webBooks can be read with any web browser. Prior versions of AMS etextbooks were difficult to use in a lab setting, however webBooks are much easier to use and no longer a hurdle to learning. Additionally, AMS eInvestigations Manuals, also in webBook format, include labs with innovative features and educational tools. One such example is the AMS Climate at a Glance (CAG) app that draws data from NOAA's Climate at a Glance website. The user selects historical data of a given parameter and the app calculates various statistics revealing whether or not the results are consistent with climate change. These results allow users to distinguish between climate variability and climate change. This can be done for hundreds of locations across the U.S. and on multiple time scales. Another innovative educational tool used in AMS eInvestigations Manuals is the AMS Conceptual Climate Energy Model (CCEM). The CCEM is a computer simulation designed to enable users to track the paths that units of energy might follow as they enter, move through and exit an imaginary system according to simple rules applied to different scenarios. The purpose is to provide insight into the impacts of physical processes that operate in the real world. Finally, AMS educational materials take advantage of Google Earth imagery to reproduce the physical aspects of globes, allowing users to investigate spatial relationships in three dimensions. Google Earth imagery is used to explore tides, ocean bottom bathymetry and El Nino and La Nina. AMS will continue to develop innovative educational materials and tools as technology advances, to attract more students to the Earth sciences.

2D and 3D characterization of pore defects in die cast AM60

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Zhuofei; CanmetMATERIALS, 183 Longwood Road South, Hamilton L8P 0A5, Ontario Canada; Maurey, Alexandre

2016-04-15

The widespread application of die castings can be hampered due to the potential of large scale porosity to act as nucleation sites for fracture and fatigue. It is therefore important to develop robust approaches to the characterization of porosity providing parameters that can be linked to the material's mechanical properties. We have tackled this problem in a study of the AM60 die cast Mg alloy, using samples extracted from a prototype shock tower. A quantitative characterization of porosity has been undertaken, analyzing porosity in both 2D (using classical metallographic methods) and in 3D (using X-ray computed tomography (XCT)). Metallographic characterizationmore » results show that shrinkage pores and small gas pores can be distinguished based on their distinct geometrical features. Shrinkage pores are irregular with multiple arms, resulting in a form factor less than 0.4. In contrast, gas pores are generally more circular in shape yielding form factors larger than 0.6. XCT provides deeper insight into the shape of pores, although this understanding is limited by the resolution obtainable by laboratory based XCT. It also shows how 2D sectioning can produce artefacts as single complex pores are sectioned into multiple small pores. - Highlights: • Mg (e.g. AM60) die castings may contain large scale porosity that act as nucleation sites for fracture and fatigue • Quantitative characterization of porosity metallography (2D) and X-ray tomography (3D) is used • Shrinkage pores and small gas pores can be distinguished based on their distinct geometrical features. • Shrinkage pores are irregular giving a form factor < 0.4; gas pores are rounder with form factors > 0.6 • XCT enables pore visualization, although limited by the resolution obtainable by laboratory based XCT.« less

Mobile Particulate Emission Measurements of New York City Transit Buses and Other in use Vehicles

NASA Astrophysics Data System (ADS)

Jayne, J. T.; Canagaratna, M.; Herndon, S.; Shorter, J.; Zahniser, M.; Kolb, C.; Williams, L.; Worsnop, D.; Drewnick, F.; Demerjian, K. L.; Lanni, T.

2002-12-01

Emissions from both diesel and gasoline powered motor vehicles are a significant source of particulate (PM2.5) and trace gas pollution, especially in urban environments. Emission characterizations of motor vehicles can be performed using a dynamometer but these studies make fleet characterization impractical. Few studies have been performed which characterize emissions from in-use vehicles using a mobile sampling platform. This work describes application of new technology instrumentation for rapid (1-5 second) and real-time characterization of both gas and particulate emissions from in-use vehicles and is part of the PM2.5 Technology Assessment and Characterization Study in New York (PMTACS-NY). An aerosol mass spectrometer (AMS) and a tunable infrared laser differential absorption spectrometer (TILDAS) system were deployed on the Aerodyne Research mobile laboratory designed to "chase" target vehicles in and around the New York City area and measure their emissions under actual driving conditions. The AMS provides particle size and composition information for volatile and semi-volatile matter (0.03 - 1 um) while the TILDAS system was configured to measure NO, NO2, CO, CH4, SO2 and formaldehyde. In addition to a global positioning system, an ELPI and a condensation particle counter, the mobile laboratory was also equipped with a Licor CO2 monitor to allow emission indices to be computed for the targeted vehicles. Emission indices for both particulate and trace gases correlated with engine type are reported for a representative fraction of the NYC Metropolitan Transit Authority (MTA) bus fleet in an effort to characterize new emission control technologies currently implemented by the NYC MTA.

Two More Candidate AM Canum Venaticorum (am CVn) Binaries from the Sloan Digital Sky Survey

NASA Astrophysics Data System (ADS)

Anderson, Scott F.; Becker, Andrew C.; Haggard, Daryl; Prieto, Jose Luis; Knapp, Gillian R.; Sako, Masao; Halford, Kelly E.; Jha, Saurabh; Martin, Blake; Holtzman, Jon; Frieman, Joshua A.; Garnavich, Peter M.; Hayward, Suzanne; Ivezić, Željko; Mukadam, Anjum S.; Sesar, Branimir; Szkody, Paula; Malanushenko, Viktor; Richmond, Michael W.; Schneider, Donald P.; York, Donald G.

2008-06-01

AM CVn systems are a select group of ultracompact binaries with the shortest orbital periods of any known binary subclass; mass transfer is likely from a low-mass (partially-)degenerate secondary onto a white dwarf primary, driven by gravitational radiation. In the past few years, the Sloan Digital Sky Survey (SDSS) has provided five new AM CVns. Here we report on two further candidates selected from more recent SDSS data. SDSS J1208+3550 is similar to the earlier SDSS discoveries, recognized as an AM CVn via its distinctive spectrum which is dominated by helium emission. From the expanded SDSS Data Release 6 (DR6) spectroscopic area, we provide an updated surface density estimate for such AM CVns of order 10-3.1-10-2.5 deg-2 for 15 < g < 20.5. In addition, we present another new candidate AM CVn, SDSS J2047+0008, which was discovered in the course of follow-up of SDSS-II supernova candidates. It shows nova-like outbursts in multi-epoch imaging data; in contrast to the other SDSS AM CVn discoveries, its (outburst) spectrum is dominated by helium absorption lines, reminiscent of KL Dra, and 2003aw. The variability selection of SDSS J2047+0008 from the 300 deg2 of SDSS Stripe 82 presages further AM CVn discoveries in future deep, multicolor, and time-domain surveys such as the Large Synoptic Survey Telescope (LSST). The new additions bring the total SDSS yield to seven AM CVns thus far, a substantial contribution to this rare subclass, versus the dozen previously known. Includes optical observations obtained with the Sloan Digital Sky Survey I and II and the Apache Point Observatory (APO) 3.5 m telescope which is owned and operated by the Astrophysical Research Consortium (ARC), and the WIYN Observatory which is a joint facility of the University of Wisconsin, Indiana University, Yale University, and NOAO.

The composite nature of the peculiar star HR 6560 (HD 159870)

NASA Technical Reports Server (NTRS)

Wegner, Gary; Cowley, Charles R.

1992-01-01

Ground-based high-dispersion photographic spectra and ultraviolet spectra obtained with the IUE satellite are described and employed to determine the nature of the peculiar star HR 6560 (HD 159870). Previously this object had been described as both a composite system and as a strong Fm star. The UBVRI, Stromgren, and ultraviolet colors of HR 6560 are compared with objects classified composite from the Bright Star Catalogue and normal dwarfs and giants. The colors of HR 6560 are not unusual for a composite and are consistent with a late-A dwarf, combined with a late-G or early-K giant. The ultraviolet satellite clearly shows the presence of an A component, but its precise spectral type is difficult to assign. The IUE and TD-1 data suggest that the ultraviolet is dominated by light from an A5 V secondary and the visual from a GO III primary. This does not agree well with the most plausible model that fits the visual photometry. The peculiar nature of HR 6560's spectrum is most likely due to its composite nature.

Real-Time Measurements of Gas/Particle Partitioning of Semivolatile Organic Compounds into Different Probe Particles in a Teflon Chamber

NASA Astrophysics Data System (ADS)

Liu, X.; Day, D. A.; Ziemann, P. J.; Krechmer, J. E.; Jimenez, J. L.

2017-12-01

The partitioning of semivolatile organic compounds (SVOCs) into and out of particles plays an essential role in secondary organic aerosol (SOA) formation and evolution. Most atmospheric models treat the gas/particle partitioning as an equilibrium between bulk gas and particle phases, despite potential kinetic limitations and differences in thermodynamics as a function of SOA and pre-existing OA composition. This study directly measures the partitioning of oxidized compounds in a Teflon chamber in the presence of single component seeds of different phases and polarities, including oleic acid, squalane, dioctyl sebacate, pentaethylene glycol, dry/wet ammonium sulfate, and dry/wet sucrose. The oxidized compounds are generated by a fast OH oxidation of a series of alkanols under high nitric oxide conditions. The observed SOA mass enhancements are highest with oleic acid, and lowest with wet ammonium sulfate and sucrose. A chemical ionization mass spectrometer (CIMS) was used to measure the decay of gas-phase organic nitrates, which reflects uptake by particles and chamber walls. We observed clear changes in equilibrium timescales with varying seed concentrations and in equilibrium gas-phase concentrations across different seeds. In general, the gas evolution can be reproduced by a kinetic box model that considers partitioning and evaporation with particles and chamber walls, except for the wet sucrose system. The accommodation coefficient and saturation mass concentration of each species in the presence of each seed are derived using the model. The changes in particle size distributions and composition monitored by a scanning mobility particle sizer (SMPS) and a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) are investigated to probe the SOA formation mechanism. Based on these results, the applicability of partitioning theory to these systems and the relevant quantitative parameters, including the dependencies on seed particle composition, will

Measurements of aerosol chemical composition in boreal forest summer conditions

NASA Astrophysics Data System (ADS)

ńijälä, M.; Junninen, H.; Ehn, M.; Petäjä, T.; Vogel, A.; Hoffmann, T.; Corrigan, A.; Russell, L.; Makkonen, U.; Virkkula, A.; Mäntykenttä, J.; Kulmala, M.; Worsnop, D.

2012-04-01

Boreal forests are an important biome, covering vast areas of the northern hemisphere and affecting the global climate change via various feedbacks [1]. Despite having relatively few anthropogenic primary aerosol sources, they always contain a non-negligible aerosol population [2]. This study describes aerosol chemical composition measurements using Aerodyne Aerosol Mass Spectrometer (C-ToF AMS, [3]), carried out at a boreal forest area in Hyytiälä, Southern Finland. The site, Helsinki University SMEAR II measurement station [4], is situated at a homogeneous Scots pine (Pinus sylvestris) forest stand. In addition to the station's permanent aerosol, gas phase and meteorological instruments, during the HUMPPA (Hyytiälä United Measurements of Photochemistry and Particles in Air) campaign in July 2010, a very comprehensive set of atmospheric chemistry measurement instrumentation was provided by the Max Planck Institute for chemistry, Johannes Gutenberg-University, University of California and the Finnish Meteorological institute. In this study aerosol chemical composition measurements from the campaign are presented. The dominant aerosol chemical species during the campaign were the organics, although periods with elevated amounts of particulate sulfates were also seen. The overall AMS measured particle mass concentrations varied from near zero to 27 μg/m observed during a forest fire smoke episode. The AMS measured aerosol mass loadings were found to agree well with DMPS derived mass concentrations (r2=0.998). The AMS data was also compared with three other aerosol instruments. The Marga instrument [5] was used to provide a quantitative semi-online measurement of inorganic chemical compounds in particle phase. Fourier Transform Infrared Spectroscopy (FTIR) analysis was performed on daily filter samples, enabling the identification and quantification of organic aerosol subspecies. Finally an Atmospheric Pressure Chemical Ionization Ion Trap Mass Spectrometer (APCI

Energy-Efficient Ammonia Recovery in an Up-Scaled Hydrogen Gas Recycling Electrochemical System

PubMed Central

2018-01-01

Nutrient and energy recovery is becoming more important for a sustainable future. Recently, we developed a hydrogen gas recycling electrochemical system (HRES) which combines a cation exchange membrane (CEM) and a gas-permeable hydrophobic membrane for ammonia recovery. This allowed for energy-efficient ammonia recovery, since hydrogen gas produced at the cathode was oxidized at the anode. Here, we successfully up-scaled and optimized this HRES for ammonia recovery. The electrode surface area was increased to 0.04 m2 to treat up to 11.5 L/day (∼46 gN/day) of synthetic urine. The system was operated stably for 108 days at current densities of 20, 50, and 100 A/m2. Compared to our previous prototype, this new cell design reduced the anode overpotential and ionic losses, while the use of an additional membrane reduced the ion transport losses. Overall, this reduced the required energy input from 56.3 kJ/gN (15.6 kW h/kgN) at 50 A/m2 (prototype) to 23.4 kJ/gN (6.5 kW h/kgN) at 100 A/m2 (this work). At 100 A/m2, an average recovery of 58% and a TAN (total ammonia nitrogen) removal rate of 598 gN/(m2 day) were obtained across the CEM. The TAN recovery was limited by TAN transport from the feed to concentrate compartment. PMID:29888142

MALDI-TOF mass spectrometry provides high accuracy in identification of Salmonella at species level but is limited to type or subtype Salmonella serovars.

PubMed

Kang, Lin; Li, Nan; Li, Ping; Zhou, Yang; Gao, Shan; Gao, Hongwei; Xin, Wenwen; Wang, Jinglin

2017-04-01

Salmonella can cause global foodborne illnesses in humans and many animals. The current diagnostic gold standard used for detecting Salmonella infection is microbiological culture followed by serological confirmation tests. However, these methods are complicated and time-consuming. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis offers some advantages in rapid identification, for example, simple and fast sample preparation, fast and automated measurement, and robust and reliable identification up to genus and species levels, possibly even to the strain level. In this study, we established a reference database for species identification using whole-cell MALDI-TOF MS; the database consisted of 12 obtained main spectra of the Salmonella culture collection strains belonged to seven serotypes. Eighty-two clinical isolates of Salmonella were identified using established database, and partial 16S rDNA gene sequencing and serological method were used as comparison. We found that MALDI-TOF mass spectrometry provided high accuracy in identification of Salmonella at species level but was limited to type or subtype Salmonella serovars. We also tried to find serovar-specific biomarkers and failed. Our study demonstrated that (a) MALDI-TOF MS was suitable for identification of Salmonella at species level with high accuracy and (b) that MALDI-TOF MS method presented in this study was not useful for serovar assignment of Salmonella currently, because of its low matching with serological method and (c) MALDI-TOF MS method presented in this study was not suitable to subtype S. typhimurium because of its low discriminatory ability.

Evaluation of two matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems for the identification of Candida species.

PubMed

Lacroix, C; Gicquel, A; Sendid, B; Meyer, J; Accoceberry, I; François, N; Morio, F; Desoubeaux, G; Chandenier, J; Kauffmann-Lacroix, C; Hennequin, C; Guitard, J; Nassif, X; Bougnoux, M-E

2014-02-01

Candida spp. are responsible for severe infections in immunocompromised patients and those undergoing invasive procedures. The accurate identification of Candida species is important because emerging species can be associated with various antifungal susceptibility spectra. Conventional methods have been developed to identify the most common pathogens, but have often failed to identify uncommon species. Several studies have reported the efficiency of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for the identification of clinically relevant Candida species. In this study, we evaluated two commercially available MALDI-TOF systems, Andromas™ and Bruker Biotyper™, for Candida identification in routine diagnosis. For this purpose, we investigated 1383 Candida isolates prospectively collected in eight hospital laboratories during routine practice. MALDI-TOF MS results were compared with those obtained using conventional phenotypic methods. Analysis of rDNA gene sequences with internal transcribed regions or D1-D2 regions is considered the reference standard for identification. Both MALDI-TOF MS systems could accurately identify 98.3% of the isolates at the species level (1359/1383 for Andromas™; 1360/1383 for Bruker Biotyper™) vs. 96.5% for conventional techniques. Furthermore, whereas conventional methods failed to identify rare or emerging species, these were correctly identified by MALDI-TOF MS. Both MALDI-TOF MS systems are accurate and cost-effective alternatives to conventional methods for mycological identification of clinically relevant Candida species and should improve the diagnosis of fungal infections as well as patient management. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

The potential of combining ion trap/MS/MS and TOF/MS for identification of emerging contaminants

USGS Publications Warehouse

Ferrer, I.; Furlong, E.T.; Heine, C.E.; Thurman, E.M.

2002-01-01

The use of a method combining ion trap tandem mass spectrometry (MS/MS) and time of flight mass spectrometry (TOF/MS) for identification of emerging contaminates was discussed. The two tools together complemented each other in sensitivity, fragmentation and accurate mass determination. Liquid chromatography/electrospray ionization/ion-trap tandem mass spectrometry (LC/ESI/MS/MS), in positive ion mode of operation, was used to separate and identify specific compounds. Diagnostic fragment ions were obtained for a polyethyleneglycol(PEG) homolog by ion trap MS/MS, and fragments were measured by TOF/MS. It was observed that the combined method gave an exact mass measurement that differed from the calculated mass.

(18)O(2) label mechanism of sulfur generation and characterization in properties over mesoporous Sm-based sorbents for hot coal gas desulfurization.

PubMed

Liu, B S; Wan, Z Y; Wang, F; Zhan, Y P; Tian, M; Cheung, A S C

2014-02-28

Using a sol-gel method, SmMeOx/MCM-41 or SBA-15 (Me=Fe, Co and Zn) and corresponding unsupported sorbents were prepared. The desulfurization performance of these sorbents was evaluated over a fixed-bed reactor and the effects of reaction temperature, feed and sorbent composition on desulfurization performance were studied. Samarium-based sorbents used to remove H2S from hot coal gas were reported for the first time. The results of successive sulfidation/regeneration cycles revealed that SmFeO3/SBA-15 sorbent was suitable for desulfurization of hot coal gas in the chemical industry. The formation of elemental sulfur during both sulfidation and regeneration processes depended strongly on the catalytic action of Sm2O2S species, which was confirmed for the first time via high sensitive time of flight mass spectrometer (TOF-MS) using 6%vol(18)O2/Ar regeneration gas and can reduce markedly procedural complexity. The sorbents were characterized using N2-adsorption, high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), temperature-programmed reduction of H2 (H2-TPR), thermogravimetry (TG) and time-of-flight mass spectrometry (TOF-MS) techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

ToF diagnostic of Tin resonant laser photoionization in SPES laser offline laboratory

NASA Astrophysics Data System (ADS)

Scarpa, D.; Fedorov, D.; Andrighetto, A.; Mariotti, E.; Nicolosi, P.; Sottili, L.; Tomaselli, A.; Cecchi, R.; Stiaccini, L.

2016-09-01

Tin is the principal element of interest in the SPES ISOL facility, which is under construction at Legnaro INFN Laboratories. Atomic nuclei have a shell structure in which nuclei with \\textquoteleft magic numbers\\textquoteright of protons and neutrons are analogous to the noble gasses in atomic physics. In particular, recent theoretical studies, reveal double-magic nature of radioactive 132Sn. For this reason the nuclear physics community demonstrated, in the last years, a huge interest to produce and study this radioactive neutron rich isotope. Experiments on Tin laser resonant ionization have been performed in the offline SPES laser laboratory to investigate the capability of the new home-made Time of Flight (ToF) mass spectrometer. Several three-step, two color ionization schemes have been tested by comparing fast and slow optogalvanic signals from a Tin Hollow Cathode Lamp (HCL) and Time of Flight signals from the spectrometer. By scanning the wavelength of one of the two dye lasers across the specific resonance, comparisons of ionization signals from both the ToF and the HCL have been made, finding perfect agreement. Furthermore, with the mass spectrometer, resolved peaks of all the natural Tin isotopes have been detected. The natural abundances extracted from these measurements are in agreement with the table values for Tin isotopes. This work, with comparison of OGE and ToF signals, confirm the fully functional SPES offline laser laboratory capability in order to develop scheme studies also for the other possible Radioactive Ion Beam (RIB) elements.

The heart of parenting: Parent HR dynamics and negative parenting while resolving conflict with child.

PubMed

Zhang, Xutong; Cui, Lixian; Han, Zhuo Rachel; Yan, Jia

2017-03-01

The current study examined parent heart rate (HR) dynamic changing patterns and their links to observed negative parenting (i.e., emotional unavailability and psychological control) during a parent-child conflict resolution task among 150 parent-child dyads (child age ranged from 6 to 12 years, Mage = 8.54 ± 1.67). Parent HR was obtained from electrocardiogram (ECG) data collected during the parent-child conflict resolution task. Negative parenting was coded offline based on the video recording of the same task. Results revealed that emotionally sensitive parents during the task showed greater HR increases while discussing a conflict and greater HR decreases while resolving the conflict, whereas emotionally unavailable parents showed no changes in HR. However, parent psychological control was not associated with HR dynamics during the task. These findings indicated the physiological underpinnings of parent emotional sensitivity and responsiveness during parent-child interactions. The potential association between HR baseline levels and parenting behaviors was also discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Social Simulation for AmI Systems Engineering

NASA Astrophysics Data System (ADS)

Garcia-Valverde, Teresa; Serrano, Emilio; Botia, Juan A.

This paper propose the use of multi-agent based simulation (MABS) to allow testing, validating and verifying Ambient Intelligence (AmI) environments in a flexible and robust way. The development of AmI is very complex because of this technology must often adapt to contextual information as well as unpredictable and changeable behaviours. The concrete simulation is called Ubik and is integrated into the AmISim architecture which is also presented in this paper. This architecture deals with AmI applications in order to discover defects, estimate quality of applications, help to make decisions about the design, etc. The paper shows that Ubik and AmISim provide a simulation framework which can test scenarios that would be impossible in real environments or even with previous AmI simulation approaches.

Novel, improved sample preparation for rapid, direct identification from positive blood cultures using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry.

PubMed

Schubert, Sören; Weinert, Kirsten; Wagner, Chris; Gunzl, Beatrix; Wieser, Andreas; Maier, Thomas; Kostrzewa, Markus

2011-11-01

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is widely used for rapid and reliable identification of bacteria and yeast grown on agar plates. Moreover, MALDI-TOF MS also holds promise for bacterial identification from blood culture (BC) broths in hospital laboratories. The most important technical step for the identification of bacteria from positive BCs by MALDI-TOF MS is sample preparation to remove blood cells and host proteins. We present a method for novel, rapid sample preparation using differential lysis of blood cells. We demonstrate the efficacy and ease of use of this sample preparation and subsequent MALDI-TOF MS identification, applying it to a total of 500 aerobic and anaerobic BCs reported to be positive by a Bactec 9240 system. In 86.5% of all BCs, the microorganism species were correctly identified. Moreover, in 18/27 mixed cultures at least one isolate was correctly identified. A novel method that adjusts the score value for MALDI-TOF MS results is proposed, further improving the proportion of correctly identified samples. The results of the present study show that the MALDI-TOF MS-based method allows rapid (<20 minutes) bacterial identification directly from positive BCs and with high accuracy. Copyright © 2011 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Operation of the “Small” BioAMS spectrometers at CAMS: Past and future prospects

DOE PAGES

Ognibene, T. J.; Haack, K. W.; Bench, G.; ...

2015-05-26

A summary of results from the solid samples run on our compact 1 MV AMS system over its 13.5 years of operation is presented. On average 7065 samples per year were measured with that average dropping to 3278 samples per year following the deployment of our liquid sample capability. Although the dynamic range of our spectrometer is 4.5 orders in magnitude, most of the measured graphitic samples had 14C/C concentrations between 0.1 and 1 modern. Furthermore, the measurements of our ANU sucrose standard followed a Gaussian distribution with an average of 1.5082 ± 0.0134 modern. The LLNL biomedical AMS programmore » supported many different types of experiments, however, the large majority of samples measured were derived from animal model systems. We have transitioned all of our biomedical AMS measurements to the recently installed 250 kV SSAMS instrument with good agreement compared in measured 14C/C isotopic ratios between sample splits. We then present results from replacement of argon stripping gas with helium in the SSAMS with a 22% improvement in ion transmission through the accelerator and high-energy analyzing magnet.« less

Operation of the “Small” BioAMS Spectrometers at CAMS: Past and Future Prospects

PubMed Central

Ognibene, T.J.; Haack, K.W.; Bench, G.; Brown, T.A.; Turteltaub, K.W.

2015-01-01

A summary of results from the solid samples run on our compact 1 MV AMS system over its 13.5 years of operation is presented. On average 7065 samples per year were measured with that average dropping to 3278 samples per year following the deployment of our liquid sample capability. Although the dynamic range of our spectrometer is 4.5 orders in magnitude, most of the measured graphitic samples had 14C/C concentrations between 0.1 and 1 modern. The measurements of our ANU sucrose standard followed a Gaussian distribution with an average of 1.5082 ± 0.0134 modern. The LLNL biomedical AMS program supported many different types of experiments, however, the large majority of samples measured were derived from animal model systems. We have transitioned all of our biomedical AMS measurements to the recently installed 250 kV SSAMS instrument with good agreement compared in measured 14C/C isotopic ratios between sample splits. Finally, we present results from replacement of argon stripping gas with helium in the SSAMS with a 22% improvement in ion transmission through the accelerator and high-energy analyzing magnet. PMID:26456990

A&M. A&M building (TAN607). Camera facing east. From left to ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

A&M. A&M building (TAN-607). Camera facing east. From left to right, pool section, hot shop, cold shop, and machine shop. Biparting doors to hot shop are in open position behind shroud. Four rail tracks lead to hot shop and cold shop. Date: August 20, 1954. INEEL negative no. 11706 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Semi-quantitative MALDI-TOF for antimicrobial susceptibility testing in Staphylococcus aureus.

PubMed

Maxson, Tucker; Taylor-Howell, Cheryl L; Minogue, Timothy D

2017-01-01

Antibiotic resistant bacterial infections are a significant problem in the healthcare setting, in many cases requiring the rapid administration of appropriate and effective antibiotic therapy. Diagnostic assays capable of quickly and accurately determining the pathogen resistance profile are therefore crucial to initiate or modify care. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) is a standard method for species identification in many clinical microbiology laboratories and is well positioned to be applied towards antimicrobial susceptibility testing. One recently reported approach utilizes semi-quantitative MALDI-TOF MS for growth rate analysis to provide a resistance profile independent of resistance mechanism. This method was previously successfully applied to Gram-negative pathogens and mycobacteria; here, we evaluated this method with the Gram-positive pathogen Staphylococcus aureus. Specifically, we used 35 strains of S. aureus and four antibiotics to optimize and test the assay, resulting in an overall accuracy rate of 95%. Application of the optimized assay also successfully determined susceptibility from mock blood cultures, allowing both species identification and resistance determination for all four antibiotics within 3 hours of blood culture positivity.

On the ancient field blue straggler HR 5455

NASA Astrophysics Data System (ADS)

Fuhrmann, Klaus; Chini, Rolf

2017-10-01

We report the discovery of HR 5455 as an ancient field blue straggler that upon Roche lobe overflow from its evolved companion, now a white dwarf, has been rejuvenated to a MBS = 1.32 ± 0.05 M⊙ bright F6V source with a purported age of τ ≃ 1.7 Gyr. The unequivocal evidence for HR 5455 being instead a τ ≃ 12 Gyr old Population II star arises from its low iron-to-magnesium abundance ratio, and is supported by its kinematics, the lack of lithium and a companion mass MWD = 0.49 ± 0.09 M⊙ from the P = 1086 ± 77 d Hipparcos astrometric orbit, which is in perfect agreement with the Rappaport et al. period-white dwarf mass relation. Like the F7V star 49 Lib that we recently disclosed as an ancient field blue straggler in a similar context, HR 5455 is also a very metal-rich source at [Mg/H] = +0.19 and [Fe/H] = -0.10. Unlike 49 Lib, however, only the white dwarf progenitor mass is directly constrained to MWD,progenitor = 1.06 ± 0.02 M⊙. In case of a conservative mass transfer, which in analogy to the 49 Lib system appears likely, a blue straggler progenitor mass MBS,progenitor = 0.75 M⊙ would follow.

Orientations of AM Her stars from their polarization properties - The case of the missing AM Her stars

NASA Technical Reports Server (NTRS)

Brainerd, J. J.; Lamb, D. Q.

1985-01-01

Observation of the polarization properties of the AM Her stars is used to determine their orientations. It is found that the AM Her stars are randomly distributed with respect to their inclination angle i but not with respect to their magnetic colatitude delta. The stars are concentrated along the semicircle cos-squared delta + cos-squared i = 1, where delta is the angle between the magnetic moment and the spin axis of the degenerate dwarf. This result implies that the discovery of AM Her stars is strongly affected by observational selection effects. It is suggested that these effects are a result of the way in which the AM Her stars have been identified observationally, and of the angular properties of high harmonic cyclotron emission. It is estimated that there are about three times as many AM Her stars as have been found so far.

MALDI-TOF MS Andromas strategy for the routine identification of bacteria, mycobacteria, yeasts, Aspergillus spp. and positive blood cultures.

PubMed

Bille, E; Dauphin, B; Leto, J; Bougnoux, M-E; Beretti, J-L; Lotz, A; Suarez, S; Meyer, J; Join-Lambert, O; Descamps, P; Grall, N; Mory, F; Dubreuil, L; Berche, P; Nassif, X; Ferroni, A

2012-11-01

All organisms usually isolated in our laboratory are now routinely identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) using the Andromas software. The aim of this study was to describe the use of this strategy in a routine clinical microbiology laboratory. The microorganisms identified included bacteria, mycobacteria, yeasts and Aspergillus spp. isolated on solid media or extracted directly from blood cultures. MALDI-TOF MS was performed on 2665 bacteria isolated on solid media, corresponding to all bacteria isolated during this period except Escherichia coli grown on chromogenic media. All acquisitions were performed without extraction. After a single acquisition, 93.1% of bacteria grown on solid media were correctly identified. When the first acquisition was not contributory, a second acquisition was performed either the same day or the next day. After two acquisitions, the rate of bacteria identified increased to 99.2%. The failures reported on 21 strains were due to an unknown profile attributed to new species (9) or an insufficient quality of the spectrum (12). MALDI-TOF MS has been applied to 162 positive blood cultures. The identification rate was 91.4%. All mycobacteria isolated during this period (22) were correctly identified by MALDI-TOF MS without any extraction. For 96.3% and 92.2% of yeasts and Aspergillus spp., respectively, the identification was obtained with a single acquisition. After a second acquisition, the overall identification rate was 98.8% for yeasts (160/162) and 98.4% (63/64) for Aspergillus spp. In conclusion, the MALDI-TOF MS strategy used in this work allows a rapid and efficient identification of all microorganisms isolated routinely. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

Variations in AmLi source spectra and their estimation utilizing the 5 Ring Multiplicity Counter

DOE PAGES

Weinmann-Smith, Robert; Beddingfield, David H.; Enqvist, Andreas; ...

2017-02-28

Active-mode assay systems are widely used for the safeguards of uranium items to verify compliance with the Non-Proliferation Treaty. Systems such as the Active-Well Coincidence Counter (AWCC) and the Uranium Neutron Coincidence Collar (UNCL) use americium-lithium (AmLi) neutron sources to induce fissions which are measured to determine the sample mass. These systems have historically relied on calibrations derived from well-defined standards. Recently, restricted access to standards or more difficult measurements have resulted in a reliance on modeling and simulation for the calibration of systems, which introduces potential simulation biases. Furthermore, the AmLi source energy spectra commonly used in the safeguardsmore » community do not accurately represent measurement results and the spectrum uncertainty can represent a large contribution to the total modeling uncertainty in active-mode systems.« less

Investigation of gaseous and particulate emissions from various marine vessel types measured on the banks of the Elbe in Northern Germany

NASA Astrophysics Data System (ADS)

Diesch, J.-M.; Drewnick, F.; Klimach, T.; Borrmann, S.

2013-04-01

Measurements of the ambient aerosol, various trace gases and meteorological quantities using a mobile laboratory (MoLa) were performed on the banks of the Lower Elbe in an emission control area (ECA) which is passed by numerous private and commercial marine vessels reaching and leaving the port of Hamburg, Germany. From 25-29 April 2011 a total of 178 vessels were probed at a distance of about 0.8-1.2 km with high temporal resolution. 139 ship emission plumes were of sufficient quality to be analyzed further and to determine emission factors (EFs). Concentrations of aerosol number and mass as well as polycyclic aromatic hydrocarbons (PAH) and black carbon were measured in PM1 and size distribution instruments covered the diameter range from 6 nm up to 32 μm. The chemical composition of the non-refractory submicron aerosol was measured by means of an Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS). Gas phase species analyzers monitored various trace gases (O3, SO2, NO, NO2, CO2) in the air and a weather station provided wind, precipitation, solar radiation data and other quantities. Together with ship information for each vessel obtained from Automatic Identification System (AIS) broadcasts a detailed characterization of the individual ship types and of features affecting gas and particulate emissions is provided. Particle number EFs (average 2.6e+16 # kg-1) and PM1 mass EFs (average 2.4 g kg-1) tend to increase with the fuel sulfur content. Observed PM1 composition of the vessel emissions was dominated by organic matter (72%), sulfate (22%) and black carbon (6%) while PAHs only account for 0.2% of the submicron aerosol mass. Measurements of gaseous components showed an increase of SO2 (average EF: 7.7 g kg-1) and NOx (average EF: 53 g kg-1) while O3 decreased when a ship plume reached the sampling site. The particle number size distributions of the vessels are generally characterized by a bimodal size distribution, with the nucleation mode in the 10-20 nm diameter

Investigation of gaseous and particulate emissions from various marine vessel types measured on the banks of the Elbe in Northern Germany

NASA Astrophysics Data System (ADS)

Diesch, J.-M.; Drewnick, F.; Klimach, T.; Borrmann, S.

2012-08-01

Measurements of the ambient aerosol, various trace gases and meteorological parameters using a mobile laboratory (MoLa) were performed on the banks of the Lower Elbe in an emission control area (ECA) which is passed by numerous private and commercial marine vessels reaching and leaving the port of Hamburg, Germany. From 25-30 April 2011 a total of 178 vessels were probed at a distance of about 0.8-2 km with high temporal resolution. 139 ship emission plumes were of sufficient quality to be analyzed further and to determine emission factors (EFs). Concentrations of aerosol number and mass as well as polycyclic aromatic hydrocarbons (PAH) and black carbon were measured in PM1 and size distribution instruments covered the size diameter range from 6 nm up to 32 μm. The chemical composition of the non-refractory submicron aerosol was measured by means of an Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS). Gas phase species analyzers monitored various trace gases (O3, SO2, NO, NO2, CO2) in the air and a weather station provided wind, precipitation, solar radiation and other parameters. Together with ship information for each vessel obtained from Automatic Identification System (AIS) broadcasts a detailed characterization of the individual ship types and of features affecting gas and particulate emissions is provided. Particle number EFs (average 2.6×1016 # kg -1) and PM1 mass EFs (average 2.4 g kg -1) positively correlate with the fuel sulfur content and depend on the engine type and performance. Observed PM1 composition of the vessel emissions was dominated by organic matter (72%), sulfate (22%) and black carbon (6%) while PAHs only account for 0.2% of the submicron aerosol mass. Measurements of gaseous components showed an increase of SO2 (average EF: 7.7 g kg-1) and NOx (average EF: 53 g kg-1) while O3 decreased when a ship plume reached the sampling site. The particle number size distributions of the vessels are generally characterized by a bimodal size