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147 Calpastatin Isoforms Related to Meat Tenderness in Beef Cattle. J Anim Sci 2018. [DOI: 10.1093/jas/sky027.147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Effects of Hermetic Storage on Adult Sitophilus oryzae L. (Coleoptera: Curculionidae) Acoustic Activity Patterns and Mortality. JOURNAL OF ECONOMIC ENTOMOLOGY 2017; 110:2707-2715. [PMID: 29045682 PMCID: PMC5946933 DOI: 10.1093/jee/tox260] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Indexed: 05/12/2023]
Abstract
Hermetic storage is of interest to farmers and warehouse managers as a method to control insect pests in small storage facilities. To develop improved understanding of effects of hermetic storage on insect pest activity and mortality over time, oxygen levels, acoustic signals, and observations of visual movement were recorded from replicates of 25, 50, and 100 adult Sitophilus oryzae (L.) (Coleoptera: Curculionidae) hermetically sealed in 500- and 1,000-ml glass jars. Recordings were done for 28 d; twice daily for the first 6 d and twice weekly thereafter. Insect sounds were analyzed as short bursts (trains) of impulses with spectra that matched average spectra (profiles) of previously verified insect sound impulses. Oxygen consumption was highest in treatments of 100 insects/500-ml jar and lowest in 25/1000-ml jars. The rates of bursts per insect, number of impulses per burst, and rates of burst impulses per insect decreased as the residual oxygen levels decreased in each treatment. Activity rates <0.02 bursts s-1, the acoustic detection threshold, typically occurred as oxygen fell below 5%. Mortality was observed at 2% levels. The time to obtain these levels of insect activity and oxygen depletion ranged from 3-14 d depending on initial infestation levels. Acoustic detection made it possible to estimate the duration required for reduction of insect activity to levels resulting in negligible damage to the stored product under hermetic conditions. Such information is of value to farmers and warehouse managers attempting to reduce pest damage in stored crops.
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Raman spectroscopy in bioanalysis. Talanta 2012; 51:131-44. [PMID: 18967845 DOI: 10.1016/s0039-9140(99)00254-4] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/1999] [Revised: 08/16/1999] [Accepted: 08/16/1999] [Indexed: 10/18/2022]
Abstract
Recent advances in instrument design have allowed researchers to use smaller, more efficient components in designing Raman spectrometers. Advances in instrumentation have increased the performance of Raman instruments and increased their usage in bioanalysis. This paper reviews recent improvements in instrument design and discusses several applications of Raman spectroscopy to diagnosis in biology, chemistry and medicine.
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Combined effects of Hurricane Katrina and Hurricane Gustav on the mental health of mothers of small children. J Psychiatr Ment Health Nurs 2011; 18:288-96. [PMID: 21418428 PMCID: PMC3472438 DOI: 10.1111/j.1365-2850.2010.01658.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Few studies have assessed the results of multiple exposures to disaster. Our objective was to examine the effect of experiencing Hurricane Gustav on mental health of women previously exposed to Hurricane Katrina. A total of 102 women from Southern Louisiana were interviewed by telephone. Experience of the hurricanes was assessed with questions about injury, danger and damage, while depression was assessed with the Edinburgh Depression Scale and post-traumatic stress disorder using the Post-Traumatic Checklist. Minor stressors, social support, trait resilience and perceived benefit had been measured previously. Mental health was examined with linear and log-linear models. Women who had a severe experience of both Gustav and Katrina scored higher on the mental health scales, but finding new ways to cope after Katrina or feeling more prepared was not protective. About half the population had better mental health scores after Gustav than at previous measures. Improvement was more likely among those who reported high social support or low levels of minor stressors, or were younger. Trait resilience mitigated the effect of hurricane exposure. Multiple disaster experiences are associated with worse mental health overall, although many women are resilient. Perceiving benefit after the first disaster was not protective.
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A study of ablation, spatial, and temporal characteristics of laser-induced plasmas generated by multiple collinear pulses. APPLIED SPECTROSCOPY 2010; 64:161-172. [PMID: 20149277 DOI: 10.1366/000370210790619609] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Multi-pulse laser-induced breakdown spectroscopy (LIBS) in the collinear pulse configuration with time-integrating detection was performed on metallic samples in ambient air in an effort to clarify the contributing processes responsible for the signal enhancement observed in comparison with single-pulse excitation. Complementary experiments were also carried out on another LIBS setup using detection by an imaging spectrograph with high time resolution. The effects of laser bursts consisting of up to seven ns-range pulses from Nd-doped solid-state lasers operating at their fundamental wavelength and separated by 8.5-50 micros time gaps was studied. The ablation and emission characteristics of the generated plasmas were investigated using light profilometry, microscopy, plasma imaging, emission distribution mapping, time-resolved line emission monitoring, and plasma temperature calculations. The experimental data suggest that the two contributing processes mainly responsible for the signal enhancement effect are the plume reheating caused by the sequential laser pulses and, more dominantly, the increased material ablation attributed to the lower breakdown threshold for the preheated (molten) sample surface and/or the reduced background gas pressure behind the shockwave of preceding pulses.
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The Subjective Experience of Cold Pain: a Comparison of Stimulus-related vs. Percept-related fMRI. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)70282-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Prediction of hemodynamic changes towards PEEP titrations at different volemic levels using a minimal cardiovascular model. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2008; 91:128-134. [PMID: 18472180 DOI: 10.1016/j.cmpb.2008.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 03/18/2008] [Accepted: 03/19/2008] [Indexed: 05/26/2023]
Abstract
A cardiovascular system model and parameter identification method have previously been validated for porcine experiments of induced pulmonary embolism and positive end-expiratory pressure (PEEP) titrations, accurately tracking all the main hemodynamic trends. In this research, the model and parameter identification process are further validated by predicting the effect of intervention. An overall population-specific rule linking specific model parameters to increases in PEEP is formulated to predict the hemodynamic effects on arterial pressure, pulmonary artery pressure and stroke volume. Hemodynamic changes are predicted for an increase from 0 to 10 cm H(2)O with median absolute percentage errors less than 7% (systolic pressures) and 13% (stroke volume). For an increase from 10 to 20 cm H(2)O median absolute percentage errors are less than 11% (systolic pressures) and 17% (stroke volume). These results validate the general applicability of such a rule, which is not pig-specific, but holds over for all analyzed pigs. This rule enables physiological simulation and prediction of patient response. Overall, the prediction accuracy achieved represents a further clinical validation of these models, methods and overall approach to cardiovascular diagnosis and therapy guidance.
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Model-based identification of PEEP titrations during different volemic levels. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2008; 91:135-144. [PMID: 18466998 DOI: 10.1016/j.cmpb.2008.03.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 03/18/2008] [Accepted: 03/19/2008] [Indexed: 05/26/2023]
Abstract
A cardiovascular system (CVS) model has previously been validated in simulated cardiac and circulatory disease states. It has also been shown to accurately capture all main hemodynamic trends in a porcine model of pulmonary embolism. In this research, a slightly extended CVS model and parameter identification process are presented and validated in a porcine experiment of positive end-expiratory pressure (PEEP) titrations at different volemic levels. The model is extended to more physiologically represent the separation of venous and arterial circulation. Errors for the identified model are within 5% when re-simulated and compared to clinical data. All identified parameter trends match clinically expected changes. This work represents another clinical validation of the underlying fundamental CVS model, and the methods and approach of using them for cardiovascular diagnosis in critical care.
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Laser induced breakdown spectroscopy as a tool for discrimination of glass for forensic applications. Anal Bioanal Chem 2008; 391:1961-8. [PMID: 18437364 DOI: 10.1007/s00216-008-2104-y] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 03/24/2008] [Accepted: 03/27/2008] [Indexed: 10/22/2022]
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Lifetime measurements of several S, P, and D states of thallium in a glow discharge by single-step and two-step laser-excited fluorescence. APPLIED SPECTROSCOPY 2008; 62:78-85. [PMID: 18230212 DOI: 10.1366/000370208783412582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The lifetimes of several states in a thallium see-through hollow cathode discharge, or galvatron, are obtained to characterize its potential as an atomic line filter. The lifetimes of the thallium 6(2)D(3/2), 6(2)D(5/2), and 7(2)S(1/2) states are measured by time-resolved single-step laser-excited fluorescence by use of a 276.787 nm laser pulse or a 535.046 nm laser pulse and measuring the resulting fluorescence waveform at the appropriate wavelength. Values of 6.4 +/- 0.1, 7.5 +/- 1.1, and 7.7 +/- 0.2 ns were obtained for the 6(2)D(3/2), 6(2)D(5/2), and 7(2)S(1/2) states, respectively, which agree with values obtained by previous authors, as well as calculated values. No current dependence was observed for each of these states. The lifetime of the long-lived thallium 6(2)P(3/2) degrees metastable state was measured by two-step laser-excited fluorescence at various applied currents. The metastable level was pumped by a 276.787 nm laser pulse, and a temporally delayed 535.046 nm laser pulse interrogated the population of the metastable state. Relating the fluorescence intensity to the population of the metastable state as a function of delay time yielded a decay curve for the 6(2)P(3/2) degrees metastable state. Values of 2.1 +/- 0.2, 2.8 +/- 0.1, 3.1 +/- 0.3, 3.8 +/- 0.4, and 4.8 +/- 0.6 micros were found for applied currents of 14.0, 12.0, 10.0, 8.0, and 6.0 mA, respectively. The resulting lifetimes for the 6(2)P(3/2) degrees metastable state clearly show a dependence on the applied current and are expected to be due to collisions with the wall of the cathode, as well as a contribution due to collisions with electrons.
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The application of microbore UPLC/oa-TOF-MS and 1H NMR spectroscopy to the metabonomic analysis of rat urine following the intravenous administration of pravastatin. J Pharm Biomed Anal 2007; 44:845-52. [PMID: 17561363 DOI: 10.1016/j.jpba.2007.04.035] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 04/26/2007] [Accepted: 04/27/2007] [Indexed: 11/17/2022]
Abstract
The metabonomic effects of hepatotoxic doses of pravastatin on the urinary metabolic profiles of female rats have been investigated using ultra performance liquid chromatography (UPLC)-oa-TOF-MS and, independently, by (1)H NMR spectroscopy. UPLC was performed using a 1 mm microbore column packed with 1.7 microm particles. Examination of the data obtained from the individual animals, aided by statistical interpretation of the data, made it possible to identify potential markers for toxicological effects, with both NMR and UPLC-MS analysis highlighting distinct changes in the urinary metabolite profiles. These markers, which included elevated taurine and creatine, as well as bile acids, were consistent with hepatotoxicity in some animals, and this hypothesis was supported by histopathological and clinical chemistry findings. The analytical data from both techniques could be used to define a metabolic "trajectory" as toxicity developed and to provide an explanation for the lack of hepatotoxicity for one of the animals. The two analytical approaches (UPLC-MS and NMR) were found to be complementary whilst the use of a 1mm i.d. x 100 mm column reduced the amount of sample required for analysis to 2 microL, compared with 10 microL for a 2.1mm i.d. x 100 mm column. The 1mm i.d. column also provided increased signal-to-noise without loss of chromatographic efficiency.
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Identification of patient specific parameters for a minimal cardiac model. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2004:813-6. [PMID: 17271801 DOI: 10.1109/iembs.2004.1403282] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A minimal cardiac model has been developed which accurately captures the essential dynamics of the cardiovascular system (CVS). This paper develops an integral based parameter identification method for fast and accurate identification of patient specific parameters for this minimal model. The integral method is implemented using a single chamber model to prove the concept, and turns a previously nonlinear and nonconvex optimization problem into a linear and convex problem. The method can be readily extended to the full minimal cardiac model and enables rapid identification of model parameters to match a particular patient condition in clinical real time (3-5 minutes). This information can then be used to assist medical staff in understanding, diagnosis and treatment selection.
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Computationally efficient velocity profile solutions for cardiac haemodynamics. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2004:944-7. [PMID: 17271835 DOI: 10.1109/iembs.2004.1403316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
This work reformulates the nonlinear differential equations associated with time varying resistance in minimal cardio-vascular system models into a system of linear equations with an analytical solution. The importance of including time varying resistance is shown for a single chamber model where there is a 17.5% difference in cardiac output when compared with a constant resistance model. However, the increased complexity has significant extra computational cost. This new formulation provides a significant computational saving of 15x over the previous method. This improvement enables more physiological accuracy with minimal cost in computational time. As a result, the model can be used in clinical situations to aid diagnosis and therapy selection without compromising on physiological accuracy.
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An automated method for measuring static pressure–volume curves of the respiratory system and its application in healthy lungs and after lung damage by oleic acid infusion. Physiol Meas 2007; 28:235-47. [PMID: 17322589 DOI: 10.1088/0967-3334/28/3/001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Elastic pressure/volume (PV) curves of the respiratory system have attracted increasing interest, because they may be helpful to optimize ventilator settings in patients undergoing mechanical ventilation. Clinically applicable methods need to be fast, use routinely available equipment, draw the inspiratory and expiratory PV curve limbs, separate the resistive and viscoelastic properties of the respiratory system from the elastic properties, and provide reproducible measurements. This paper presents a computer-controlled method for rapid measurements of static PV curves using a long inflation-deflation with pauses, and its evaluation in six pigs before and after lung damage caused by oleic acid. The method is fast, i.e. 20.5 +/- 1.9 s (mean +/- SD) in healthy lungs and 17.7 +/- 4.1 s in diseased lungs, this including inspiratory and expiratory pauses of 1.1 s duration. In addition the only equipment used was a clinical ventilator and a PC. For healthy and damaged lungs expiratory PV curve limbs were very reproducible and were at higher volume than the inspiratory limbs, indicating hysteresis. For damaged lungs inspiratory PV limbs were reproducible. For healthy lungs the inspiratory limbs were reproducible but only after the first inflation-deflation. It is possible that during the first inflation alveoli are recruited which are not derecruited on deflation, shifting the inspiratory limb of the PV curve. The paused long inflation-deflation technique provides a quick, automated measurement of static PV curves on both inspiratory and expiratory limbs using routinely available equipment in the intensive care unit.
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Using physiological models and decision theory for selecting appropriate ventilator settings. J Clin Monit Comput 2006; 20:421-9. [PMID: 16977430 DOI: 10.1007/s10877-006-9049-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Accepted: 08/16/2006] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To present a decision support system for optimising mechanical ventilation in patients residing in the intensive care unit. METHODS Mathematical models of oxygen transport, carbon dioxide transport and lung mechanics are combined with penalty functions describing clinical preference toward the goals and side-effects of mechanical ventilation in a decision theoretic approach. Penalties are quantified for risk of lung barotrauma, acidosis or alkalosis, oxygen toxicity or absorption atelectasis, and hypoxaemia. RESULTS The system is presented with an example of its use in a post-surgical patient. The mathematical models describe the patient's data, and the system suggests an optimal ventilator strategy in line with clinical practice. CONCLUSIONS The system illustrates how mathematical models combined with decision theory can aid in the difficult compromises necessary when deciding on ventilator settings.
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Radiative model of post-breakdown laser-induced plasma expanding into ambient gas. APPLIED OPTICS 2006; 45:2810-20. [PMID: 16633435 DOI: 10.1364/ao.45.002810] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The dynamics of the radiative plasma expansion into an ambient gas is considered. The model describes the evolution of the plasma emission spectrum and the dynamics of the resulting shock wave. The time frame for the applicability of the model is in the tens of nanoseconds after the laser pulse is terminated, until a few microseconds later when the plasma ceases to emit. It is assumed that local thermodynamic equilibrium is established and that the plume expands with spherical symmetry. The model outputs are spatial and temporal distributions of atoms, ions, and electron number densities, evolution of atom and ion line profiles, and the shock wave. The model should be applicable to spectroscopic analysis of the initial plasma state and plasma dynamics.
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High-resolution two-grating spectrometer for dual wavelength spectral imaging. APPLIED SPECTROSCOPY 2004; 58:1341-1346. [PMID: 18070408 DOI: 10.1366/0003702042475501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A two-grating high-resolution spectrometer for dual wavelength imaging is demonstrated based on the standard Czerny-Turner mounting with an auxiliary grating and a mirror. A two-dimensional charge-coupled device (CCD) detector in the spectrometer focal plane allows simultaneous detection of two spectral intervals. Each spectrometer grating is driven by a high-precision stepper motor interfaced to a computer via home-made software. The software allows fast tuning of the gratings to a desirable spectral interval anywhere between 200 nm and 800 nm. The spectral interval widths are 2-3 nm for a ''high-resolution'' (2400 grooves/mm) grating and 4-5 nm for a ''low-resolution'' (1200 grooves/mm) grating. The resolution varies between 0.01 nm and 0.02 nm depending on the grating used. The performance of the spectrometer is demonstrated by detecting spectrally resolved images from a back-illuminated template and from a laser-induced plasma. The spectrometer can be useful for two-line spectroscopic diagnostics or can be expanded for multi-element spectral analysis.
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Determination of the maximum temperature at the center of an optically thick laser-induced plasma using self-reversed spectral lines. APPLIED SPECTROSCOPY 2004; 58:1023-1031. [PMID: 15479517 DOI: 10.1366/0003702041959398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A method of temperature measurement based on the model developed by Bartels of an optically thick inhomogeneous plasma was applied to a laser plasma induced on a target containing barium. The method involves the intensity ratio measurement of two self-reversed Ba(II) lines. The temperature thus determined corresponds to the maximum temperature in the plasma center. The plasma temperature was measured for delay times between 0.5 micros and 10 micros in two spectrometer operating modes: the scanning mode and the dual-wavelength mode, the latter resulting in better precision. A detailed analysis of experimental errors was performed. The error strongly depended on the wavelength separation of the lines used. The most accurate results were obtained for the largest line separation. Using one line in the UV and the other in the visible region, the relative error was 2-6% for temperatures between 8000 K and 20 000 K. The distribution of the plasma temperature along the plasma height was measured in the same delay time range. The temperature was found to be uniform along the plasma vertical axis, thus confirming the plasma cylindrical symmetry.
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Dual-wavelength time-resolved resonance ionization imaging with cesium and mercury vapors. APPLIED SPECTROSCOPY 2004; 58:1020-1022. [PMID: 18070394 DOI: 10.1366/0003702041655485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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Microchip laser-induced breakdown spectroscopy: a preliminary feasibility investigation. APPLIED SPECTROSCOPY 2004; 58:762-769. [PMID: 15282039 DOI: 10.1366/0003702041389427] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A commercial, 7 microJ/pulse, 550 ps microchip laser is used to induce plasma on Pb, Si, Cu, Fe, Ni, Ti, Zn, Ta, and Mo foils and a Si wafer. The measured plasma lifetime is comparable with the duration of the laser pulse (a few ns). The plasma continuum radiation is low, while some of the strong resonance lines (e.g., Zn 213.86 nm) show self-reversal. Quantitative analysis is possible using non-gated detectors but analytical lines should be chosen with care to avoid reduction in the linear dynamic range. The mass removed (0.5-20 ng/pulse) is sufficient to yield spectra that are detectable with portable grating spectrometers equipped with non-gated, non-intensified detector arrays. The spectrum of Cd is detected with a broadband portable spectrometer (200-950 nm). The combination of the broadband spectrometer and the microchip laser is very promising for material identification, especially in field applications.
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Laser-enhanced ionization with avalanche amplification: detection of cesium at fg/mL levels. APPLIED SPECTROSCOPY 2003; 57:729-732. [PMID: 14658648 DOI: 10.1366/000370203322102780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The avalanche amplification of the laser-enhanced ionization signal of Cs atoms in a flame has been studied. Ionization of Cs atoms, enhanced by two-step excitation, was detected in hydrogen and propane flames. By employing the effect of avalanche amplification of electrons, high signal-to-noise ratio (approximately 10(4)) was obtained for a 100 ppt Cs solution. The extrapolated limit of detection was 30 fg/mL (ppq).
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Automatic correction of continuum background in laser-induced breakdown and Raman spectrometry. APPLIED SPECTROSCOPY 2003; 57:197-207. [PMID: 14610958 DOI: 10.1366/000370203321535123] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The goal of this work was the development and evaluation of an algorithm for the approximation and automatic subtraction of continuum backgrounds in laser-induced breakdown and Raman spectra. The background correction algorithm was applied to simple and complex spectra and its effect on identification accuracy was studied. Linear correlation was used for the identification of plastic samples using both laser-induced breakdown and Raman spectra. For both techniques, the algorithm successfully eliminated continuum background without compromising spectral integrity. A significant improvement in the percentage of correct plastic identifications was observed for Raman spectra. The approach should be applicable to a wide range of background correction problems in atomic and molecular spectroscopy.
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Speciation of inorganic and organometallic compounds in solid biological samples by thermal vaporization and plasma emission spectrometry. Anal Chem 2002. [DOI: 10.1021/ac00263a005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Estimation of absolute analyte number densities in atomic emission, absorption, and fluorescence using line and continuum sources. Anal Chem 2002. [DOI: 10.1021/ac00141a012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Arrays of C60 molecules nested inside single-walled nanotubes represent a class of nanoscale materials having tunable properties. We report electronic measurements of this system made with a scanning tunneling microscope and demonstrate that the encapsulated C60 molecules modify the local electronic structure of the nanotube. Our measurements and calculations also show that a periodic array of C60 molecules gives rise to a hybrid electronic band, which derives its character from both the nanotube states and the C60 molecular orbitals.
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Tunable resonance fluorescence monochromator with sub-Doppler spectral resolution. OPTICS LETTERS 2001; 26:1946-1948. [PMID: 18059740 DOI: 10.1364/ol.26.001946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A cesium-based resonance fluorescence monochromator with a spectral resolution of 200 MHz and a tunable response over the D(2) absorption line of cesium (380 MHz) is described. The narrow spectral response is achieved through excitation of a monokinetic population of the 6(2)P(3/2)( degrees ) state by arrangement of the excitation lasers in either a copropagating or a counterpropagating orientation. The narrow spectral response of the detector allows for excitation of specific hyperfine components involved in the 6(2)P(3/2)( degrees ) (F=3-5) to 6(2)D(5/2) (F=2-6) transition (917.23 nm). The selectivity gained through resolving specific hyperfine transitions allows for a photon detector that is both spectrally tunable and narrow. We report the sub-Doppler linewidths achieved through various laser beam orientations. We also describe how these beam geometries can be applied to spectrally narrow and tunable image detection.
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Abstract
OBJECTIVE The purpose of this study was to examine the role of depressive symptoms in reactivity to stress and pain in older women with rheumatoid arthritis (RA) and osteoarthritis (OA). METHODS Participants were 188 older women with RA (N = 87) and OA (N = 101). They were initially assessed for depressive symptoms and interviewed weekly for 12 to 20 weeks regarding interpersonal stress, arthritis pain, and negative affect. RESULTS Hierarchical linear modeling (HLM) revealed that depressive symptoms were related to weekly elevations in arthritis pain, negative events, perceived stress, and negative affect for RA respondents and elevations in arthritis pain and negative affect for OA respondents. HLM analyses also indicated that depressive symptoms were related to increased reactivity to perceived stress and arthritis pain in people with RA, but not those with OA. CONCLUSIONS Depression may be related to elevations in pain for people with RA and OA and to elevations in stress and increased reactivity to stress and pain for those with RA.
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A comparison of leg-to-leg bioelectrical impedance and skinfolds in assessing body fat in collegiate wrestlers. J Strength Cond Res 2001; 15:157-60. [PMID: 11710398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
A comparison of the leg-to-leg bioelectrical impedance (BIA) system and skinfold analysis in estimating % body fat in a large number of National Collegiate Athletic Association (NCAA) collegiate wrestlers was conducted. A series of 5 cross-sectional assessments, including the NCAA Division I and III Championships, were completed throughout the 1998-1999 wrestling season with samples ranging from (N = 90-274). Body density was determined from the 3 skinfold measures using the Lohman prediction equation. BIA measurements were determined using the Tanita body fat analyzer, model 305. Significant correlations between methods ranging from (r = 0.67-0.83, p < 0.001) and low standard error of estimates (SEE) for % body fat ranging from 2.1-3.5% were found throughout the 5 assessment periods. This preliminary study demonstrated that the leg-to-leg bioelectrical impedance system accurately estimated % body fat when compared to skinfolds in a diverse collegiate wrestling population.
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Abstract
A sealed, compact mercury atomic-absorption resonance ionization imaging detector has been developed and evaluated. The sensitivity of the detector as well as its ability to form two-dimensional images has been demonstrated. Images of faint light (1000 photons) have been recorded by image summation. It is shown that one can obtain high-quality images with a spatial resolution of at least 130 mum by detecting the ionic component of the imaging signal. Distortion, more noise, and poorer spatial resolution were observed when the electron component of the signal was detected. We studied the influence of voltage on the cell electrodes to find the conditions for optimum signal-to-noise ratio.
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Increased discrimination of "false memories" in autism spectrum disorder. Proc Natl Acad Sci U S A 2000; 97:8734-7. [PMID: 10900024 PMCID: PMC27017 DOI: 10.1073/pnas.97.15.8734] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/1999] [Accepted: 09/03/1999] [Indexed: 11/18/2022] Open
Abstract
Individuals with autism spectrum disorder (ASD) have impaired ability to use context, which may manifest as alterations of relatedness within the semantic network. However, impairment in context use may be more difficult to detect in high-functioning adults with ASD. To test context use in this population, we examined the influence of context on memory by using the "false memory" test. In the false memory task, lists of words were presented to high-functioning subjects with ASD and matched controls. Each list consists of words highly related to an index word not on the list. Subjects are then given a recognition test. Positive responses to the index words represent false memories. We found that individuals with ASD are able to discriminate false memory items from true items significantly better than are control subjects. Memory in patients with ASD may be more accurate than in normal individuals under certain conditions. These results also suggest that semantic representations comprise a less distributed network in high-functioning adults with ASD. Furthermore, these results may be related to the unusually high memory capacities found in some individuals with ASD. Research directed at defining the range of tasks performed superiorly by high-functioning individuals with ASD will be important for optimal vocational rehabilitation.
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Psychosocial resource loss as a mediator of the effects of flood exposure on psychological distress and physical symptoms. J Trauma Stress 2000; 13:349-57. [PMID: 10838680 DOI: 10.1023/a:1007745920466] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This study used the Conservation of Resources stress model to examine the role of psychosocial resource loss in the aftermath of Midwest flooding. Questionnaires were distributed through churches and completed by 131 adults in flood-affected communities 6 weeks and 6 months after the flood's crest. Frequent psychosocial losses included losses of routine, sense of control, sense of optimism, accomplishing goals, and time with loved ones. Path analysis revealed that psychosocial resource loss mediated the effects of flood exposure on both psychological distress and physical symptoms at 6 months post-flood. The findings suggest that interventions designed to prevent psychosocial resource loss may reduce the long-term effects of disasters.
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Analysis of interlaboratory performance in the determination of total selenium in water. J AOAC Int 1999; 82:1466-73. [PMID: 10589498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
This study explored the performance of experienced laboratories in the analysis for total selenium in water by a variety of analytical methods. The goal of the study was to examine intra- and interlaboratory variability. Replicates (n = 7) of 7 sample types that included a reference material of known Se concentration, natural waters, and treated wastewaters were submitted to 7 laboratories with prequalified Se analytical experience. Results of the study indicated wide ranges in minimum and maximum results, distinct differences in laboratory precision, and routine reporting of numerical results below statistical limits of quantitation. Hydride generation as a sample introduction technique demonstrated superior performance. In general, the study supports a caution advisory about using low-level Se data, especially results lower than about 10 micrograms Se/L, without quantitating the statistical uncertainty of the data. Because this study used data from samples that were submitted in bulk to participating laboratories prequalified for Se analytical expertise and experience, it can be considered a best-case demonstration of performance.
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Some Considerations on the Correlation between Signal and Background in Laser-Induced Breakdown Spectroscopy Using Single-Shot Analysis. Anal Chem 1999; 71:5447-9. [DOI: 10.1021/ac990766l] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Identification of Solid Materials by Correlation Analysis Using a Microscopic Laser-Induced Plasma Spectrometer. Anal Chem 1999. [DOI: 10.1021/ac9905524] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
OBJECTIVE To determine the prevalence and pattern of creatine use among varsity athletes at a National Collegiate Athletic Association (NCAA) Division I athletic program. DESIGN Anonymous descriptive survey. SETTING Institutional. PARTICIPANTS Collegiate varsity and junior varsity athletes. MAIN OUTCOME MEASURES Self-reports of creatine use, including pattern of use and dose, source of information on creatine, and expected and perceived effects from creatine use. RESULTS Surveys were obtained from 93% of 806 eligible athletes. Overall, 68% of athletes had heard of creatine and 28% reported using it. Forty-eight percent of men reported having used creatine as compared with 4% of women. With two exceptions, all men's teams had at least 30% of athletes who reported a history of creatine use. Of athletes that had used creatine, about one-third had first used it in high school. Friends and teammates were the most common sources of creatine information. Increased strength and muscle size were the most common effects the athletes expected and perceived from creatine use. CONCLUSION In this population of collegiate athletes, creatine use was widespread among men but was minimal among women. Athletes learned about creatine supplementation primarily from their peers, and substantial numbers began to take creatine while still in high school. Most athletes could not report their dosing of creatine. This study reported findings at one location for one academic year. Studies are needed at multiple locations and over time to further delineate creatine use patterns.
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Abstract
Exercise-induced asthma (EIA) is a complex disorder affecting a sizeable minority of athletes. Proper pharmacologic management allows most every athlete at any level to participate with EIA. This article briefly addresses the pathophysiology, diagnosis, and basic treatment principles, including nonpharmacologic management for EIA. Most of the article details the current treatment strategies and provides information on experimental treatments being investigated. In addition, ergogenic concerns and problems in treating elite athletes are discussed.
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Narrow-band resonance-ionization and fluorescence imaging in a mercury-vapor cell. OPTICS LETTERS 1998; 23:304-306. [PMID: 18084493 DOI: 10.1364/ol.23.000304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Characteristics of a novel type of ultranarrow-band image detector have been experimentally studied. The principle of this new imaging approach is to detect a resonance-ionization and (or) fluorescence-imaging signal formed on a thin planar cell filled with atomic vapor. A planar vapor cell with a thickness of 1.6 mm was used for imaging 253.7-nm radiation by Hg atoms. One- and two-dimensional images were produced and detected with ionization and fluorescence-signal acquisition. The feasibility of atomic-vapor image detectors with a spectral resolution of several megahertz is discussed.
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Resonance ionization image detectors: basic characteristics and potential applications. APPLIED OPTICS 1997; 36:8833-8843. [PMID: 18264433 DOI: 10.1364/ao.36.008833] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A type of spectrally selective imaging optical detector that is based on resonance ionization in an atomic vapor is proposed. It has the potential for improved spatial, spectral, and temporal resolutions compared with those of available techniques. Figures of merit are calculated and compared with those of existing techniques. Several potential applications such as the imaging of moving objects, ultrasonic fields, high-energy particle detection, and optical communications are discussed.
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A Review of Microwave Plasma Sources in Atomic Emission Spectrometry: Literature from 1985 to the Present. Crit Rev Anal Chem 1997. [DOI: 10.1080/10408349708052201] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Delayed sequelae after acute overdoses or poisonings: cranial neuropathy related to ethylene glycol ingestion. Clin Pharmacol Ther 1997; 61:692-9. [PMID: 9209253 DOI: 10.1016/s0009-9236(97)90105-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A 31-year-old woman came to the hospital with breathlessness, confusion, and a refractory anion gap metabolic acidosis; acute renal failure subsequently developed. Her blood ethylene glycol concentration was 390 mg/L, and she was treated with an intravenous ethanol infusion and hemodialysis. During the tenth and eleventh day after admission bilateral seventh cranial nerve paralysis developed, as well as bilateral dysfunction of cranial nerves II, V, VIII, IX, X and XII. Magnetic resonance imaging of her head showed gadolinium enhancement of the fifth cranial nerve bilaterally and a communicating hydrocephalus. Over the subsequent 11 months she recovered full function of her cranial nerves V, VII, IX, X, and XII, and she had subjective clinical improvement to baseline function in cranial nerves II and VIII. This case serves to introduce a discussion of agents that cause delayed complications after their acute toxic ingestion.
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Abstract
Two networks of medical care have grown up in Japan: 1 network based in hospitals and 1 based in private clinics. Most physicians in clinics practice general medicine, although only a small proportion of them are trained in primary care. Postgraduate medical education is oriented toward the training of specialists. Owing to the impending retirement of the cohort of clinic-based physicians who have dominated medical politics in Japan, the system is expected to change substantially in the next decade. Among the reformers is a small group of physicians who are attempting to introduce family practice.
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