Volatile organic compounds (VOCs) in breath could be clinically useful for the early detection and diagnosis of diseases, physiological disorders and therapeutic monitoring. However, it is crucial to ...compare the reliability and precision of breath measurements with those from blood if endogenous VOCs on breath are to be used as biomarkers. Few studies have been undertaken to investigate this, none of which relate to endogenous VOCs in freely breathing subjects. Here we establish the reliability and precision of breath measurements to determine endogenous VOC concentrations in comparison to blood measurements in order to assess the viability of using breath measurements for potential diagnostic and screening purposes. Acetone and isoprene concentration levels in the breath, radial arterial blood and peripheral venous blood and
in vivo arterial blood/breath ratios for freely breathing subjects have been determined using mass spectrometric techniques. Mean (range) breath concentrations in parts per billion by volume are 1090 (515–2335) for acetone and 465 (308–702) for isoprene. The mean (range) blood concentrations are: for acetone in radial arterial blood 26 (10–73)
μmol/l and in peripheral venous blood 18 (9–39)
μmol/l; for isoprene in radial arterial blood 6.8 (3.7–11)
μmol/l and in peripheral venous blood 14 (5.5–30)
μmol/l. Arterial blood/breath ratios mean (range) are 580 (320–860) for acetone and 0.38 (0.19–0.58) for isoprene. An important finding is that the coefficients of repeatability as a percentage of mean are less than 30% in breath but greater than 70% in blood. This study suggests that breath VOC measurements could provide a more consistent measure for investigating underlying physiological function or pathology than single blood measurements.
Data Intensive Computing refers to capturing, managing, analyzing, and understanding data at volumes and rates that push the frontiers of current technologies. The challenge of data intensive ...computing is to provide the hardware architectures and related software systems and techniques which are capable of transforming ultra-large data into valuable knowledge. Handbook of Data Intensive Computing is written by leading international experts in the field. Experts from academia, research laboratories and private industry address both theory and application. Data intensive computing demands a fundamentally different set of principles than mainstream computing. Data-intensive applications typically are well suited for large-scale parallelism over the data and also require an extremely high degree of fault-tolerance, reliability, and availability. Real-world examples are provided throughout the book. Handbook of Data Intensive Computing is designed as a reference for practitioners and researchers, including programmers, computer and system infrastructure designers, and developers. This book can also be beneficial for business managers, entrepreneurs, and investors.
Carbonyls from gasoline powered light-duty vehicles (LDVs) and heavy-duty diesel powered vehicles (HDDVs) operated on chassis dynamometers were measured using an annular denuder-quartz ...filter-polyurethane foam sampler with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine derivatization and chromatography-mass spectrometry analyses. Two internal standards were utilized based on carbonyl recovery, 4-fluorobenzaldehyde for<C8 carbonyls and 6-fluoro-4-chromanone for>_C8 compounds. Gas- and particle-phase emissions for 39 aliphatic and 20 aromatic carbonyls ranged from 0.1 ? 2000 ?g/L fuel for LDVs and 1.8 - 27000 mu g/L fuel for HDDVs. Gas-phase species accounted for 81-95percent of the total carbonyls from LDVs and 86-88percent from HDDVs. Particulate carbonyls emitted from a HDDV under realistic driving conditions were similar to concentrations measured in a diesel particulate matter (PM) standard reference material. Carbonyls accounted for 19percent of particulate organic carbon (POC) emissions from low-emission LDVs and 37percent of POC emissions from three-way catalyst equipped LDVs. This identifies carbonyls as one of the largest classes of compounds in LDV PM emissions. The carbonyl fraction of HDDV POC was lower, 3.3-3.9percent depending upon operational conditions. Partitioning analysis indicates the carbonyls had not achieved equilibrium between the gas- and particle-phase under the dilution factors of 126-584 used in the current study.
While earlier work has emphasized Kant's philosophy of religion as thinly
disguised morality, this timely and original reappraisal of Kant's philosophy of
religion incorporates recent scholarship. In ...this volume, Chris L. Firestone,
Stephen R. Palmquist, and the other contributors make a strong case for more
specific focus on religious topics in the Kantian corpus. Main themes include the
relationship between Kant's philosophy of religion and his philosophy as a whole,
the contemporary relevance of specific issues arising out of Kant's philosophical
theology, and the relationship of Kant's philosophy to Christian theology. As a
whole, this book capitalizes on contemporary movements in Kant studies by looking at
Kant not as an anti-metaphysician, but as a genuine seeker of spirituality in the
human experience.
The presynaptic terminals of skate (Raja montagui) electric organ were tested for their sensitivity to calcium channel antagonists. Acetylcholine (ACh) release and the elevation of intraterminal Ca2+ ...concentrations triggered by K+ depolarisation were studied. ACh release was measured as 3H efflux from slices of organ prelabelled with 3Hcholine. Depolarisation caused a marked, Ca(2+)-dependent increase in 3H efflux that was completely blocked by 100 microM Cd2+ and by 300 nM omega-conotoxin-MVIIC (MVIIC). Inhibition by MVIIC was concentration dependent (IC50 of approximately 20 nM) and reversible. No inhibition was seen with nifedipine (5 microM) or the two other peptide antagonists studied: omega-conotoxin-GVIA (GVIA) at 5 microM and omega-agatoxin-IVA (Aga-IVA) at 1 microM. In a "nerve plate" preparation (a presynaptic plexus of nerve fibres, Schwann cells, and nerve terminals) changes in intraterminal Ca2+ concentrations were measured by microfluorimetry using fluo-3. An increase in fluorescence, indicating a rise in the free Ca2+, rapidly followed K+ depolarisation, and this change was restricted to the nerve terminals. This response was insensitive to nifedipine (5 microM), GVIA (5 microM), and Aga-IVA (300 nM) but almost completely abolished by MVIIC (1 microM). MVIIC inhibition was concentration dependent and partially reversible. These results show that the nerve terminals in skate electric organ have calcium channels with a pharmacological sensitivity that is markedly different from the established L, N, and P types in other systems but shares some, but not all, of the features of the recently described Q type.
Rapid localised heating (<100 ms) was achieved in rat hippocampal brain slices by millisecond exposures to radiofrequency (RF) fields, using a metal stimulating electrode to focus the energy into the ...tissue. This produced very high specific absorption rates (>5 MWmiddotkg -1 ) in the tissue near the tip of the electrode. Electrophysiological recordings of evoked responses were made to characterise the physiological effects of the heating pulses.
