bluuebunny/crossref_metadata_2025 huggingface dataset:
Malonyl-CoA decarboxylase inhibition suppresses fatty acid oxidation and reduces lactate production during demand-induced ischemia
Authors: Stanley William C. , Morgan Eric E. , Huang Hazel , McElfresh Tracy A. , Sterk Joseph P. , Okere Isidore C. , Chandler Margaret P. , Cheng Jiefei , Dyck Jason R. B. , Lopaschuk Gary D.
Published: August 2005

The rate of cardiac fatty acid oxidation is regulated by the activity of carnitine palmitoyltransferase-I (CPT-I), which is inhibited by malonyl-CoA. We tested the hypothesis that the activity of the enzyme responsible for malonyl-CoA degradation, malonyl-CoA decarboxlyase (MCD), regulates myocardial malonyl-CoA content and the rate of fatty acid oxidation during demand-induced ischemia in vivo. The myocardial content of malonyl-CoA was increased in anesthetized pigs using a specific inhibitor of MCD (CBM-301106), which we hypothesized would result in inhibition of CPT-I, reduction in fatty acid oxidation, a reciprocal activation of glucose oxidation, and diminished lactate production during demand-induced ischemia. Under normal-flow conditions, treatment with the MCD inhibitor significantly reduced oxidation of exogenous fatty acids by 82%, shifted the relationship between arterial fatty acids and fatty acid oxidation downward, and increased glucose oxidation by 50%. Ischemia was induced by a 20% flow reduction and β-adrenergic stimulation, which resulted in myocardial lactate production. During ischemia MCD inhibition elevated malonyl-CoA content fourfold, reduced free fatty acid oxidation rate by 87%, and resulted in a 50% decrease in lactate production. Moreover, fatty acid oxidation during ischemia was inversely related to the tissue malonyl-CoA content ( r = −0.63). There were no differences between groups in myocardial ATP content, the activity of pyruvate dehydrogenase, or myocardial contractile function during ischemia. Thus modulation of MCD activity is an effective means of regulating myocardial fatty acid oxidation under normal and ischemic conditions and reducing lactate production during demand-induced ischemia.
Stimulation of NTS A1 adenosine receptors evokes counteracting effects on hindlimb vasculature
Authors: McClure Joseph M. , O'Leary Donal S. , Scislo Tadeusz J.
Published: August 2005

Our previous studies concluded that stimulation of the nucleus of the solitary tract (NTS) A2a receptors evokes preferential hindlimb vasodilation mainly via inducing increases in preganglionic sympathetic nerve activity (pre-ASNA) directed to the adrenal medulla. This increase in pre-ASNA causes the release of epinephrine and subsequent activation of β-adrenergic receptors that are preferentially located in the skeletal muscle vasculature. Selective activation of NTS A1 adenosine receptors evokes variable, mostly pressor effects and increases pre-ASNA, as well as lumbar sympathetic activity, which is directed to the hindlimb. These counteracting factors may have opposite effects on the hindlimb vasculature resulting in mixed vascular responses. Therefore, in chloralose-urethane-anesthetized rats, we evaluated the contribution of vasodilator versus vasoconstrictor effects of stimulation of NTS A1 receptors on the hindlimb vasculature. We compared the changes in iliac vascular conductance evoked by microinjctions into the NTS of the selective A1 receptor agonist N6-cyclopentyladenosine (330 pmol in 50 nl volume) in intact animals with the responses evoked after β-adrenergic blockade, bilateral adrenalectomy, bilateral lumbar sympathectomy, and combined adrenalectomy + lumbar sympathectomy. In intact animals, stimulation of NTS A1 receptors evoked variable effects: increases and decreases in mean arterial pressure and iliac conductance with prevailing pressor and vasoconstrictor effects. Peripheral β-adrenergic receptor blockade and bilateral adrenalectomy eliminated the depressor component of the responses, markedly potentiated iliac vasoconstriction, and tended to increase the pressor responses. Lumbar sympathectomy tended to decrease the pressor and vasoconstrictor responses. After bilateral adrenalectomy plus lumbar sympathectomy, a marked vasoconstriction in iliac vascular bed still persisted, suggesting that the vasoconstrictor component of the response to stimulation of NTS A1 receptors is mediated mostly via circulating factors (e.g., vasopressin, angiotensin II, or circulating catecholamines released from other sympathetic terminals). These data strongly suggest that stimulation of NTS A1 receptors exerts counteracting effects on the iliac vascular bed: activation of the adrenal medulla and β-adrenergic vasodilation versus vasoconstriction mediated by neural and humoral factors.
Transgenic extracellular superoxide dismutase protects postnatal alveolar epithelial proliferation and development during hyperoxia
Authors: Auten Richard L. , O'Reilly Michael A. , Oury Tim D. , Nozik-Grayck Eva , Whorton Mary H.
Published: August 2005

Transgenic (TG) human (h) extracellular superoxide dismutase (EC-SOD) targeted to type II cells protects postnatal newborn mouse lung development against hyperoxia by unknown mechanisms. Because alveolar development depends on timely proliferation of type II epithelium and differentiation to type I epithelium, we measured proliferation in bronchiolar and alveolar (surfactant protein C-positive) epithelium in air and 95% O2-exposed wild-type (WT) and TG hEC-SOD newborn mice at postnatal days 3, 5, and 7 (P3-P7), traversing the transition from saccular to alveolar stages. We found that TG hEC-SOD ameliorated the 95% O2-impaired bromodeoxyuridine uptake in alveolar and bronchiolar epithelium at P3, but not at P5 and P7, when overall epithelial proliferation rates were lower in air-exposed WT mice. Mouse EC-, CuZn-, and Mn-SOD expression were unaffected by hyperoxia or genotype. TG mice had less DNA damage than 95% O2-exposed WT mice at P3, measured by TdT-mediated dUTP nick end labeling ( P < 0.05). Hyperoxia induced cell-cycle inhibitory protein p21cip/wafmRNA at P3, WT > TG, P = 0.06. 95% O2impaired apical expression of type I cell α protein (T1α) in WT but not in TG mice at P3 and increased T1α in WT and TG mice at P7. Reducing the 95% O2-induced impairment of epithelial proliferation at a critical window of lung development was associated with protection against DNA damage and preservation of apical T1α expression at P3.
Inflammatory response of tracheobronchial epithelial cells to endotoxin
Authors: Neff Simona B. , Z'graggen Birgit Roth , Neff Thomas A. , Jamnicki-Abegg Marina , Suter Dominik , Schimmer Ralph C. , Booy Christa , Joch Hana , Pasch Thomas , Ward Peter A. , Beck-Schimmer Beatrice
Published: August 2005

Respiratory epithelial cells play a crucial role in the inflammatory response in endotoxin-induced lung injury, an experimental model for acute lung injury. To determine the role of epithelial cells in the upper respiratory compartment in the inflammatory response to endotoxin, we exposed tracheobronchial epithelial cells (TBEC) to lipopolysaccharide (LPS). Expression of inflammatory mediators was analyzed, and the biological implications were assessed using chemotaxis and adherence assays. Epithelial cell necrosis and apoptosis were determined to identify LPS-induced cell damage. Treatment of TBEC with LPS induced enhanced protein expression of cytokines and chemokines (increases of 235–654%, P < 0.05), with increased chemotactic activity regarding neutrophil recruitment. Expression of the intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) was enhanced by 52–101% ( P < 0.0001). This upregulation led to increased adhesion of neutrophils, with >95% adherence to TBEC after LPS stimulation, which could be blocked by either ICAM-1 (69%) or VCAM-1 antibodies (55%) ( P < 0.05). Enhanced neutrophil-induced necrosis of TBEC was observed when TBEC were exposed to LPS. Reduced neutrophil adherence by ICAM-1 or VCAM-1 antibodies resulted in significantly lower TBEC death (52 and 34%, respectively, P < 0.05). Therefore, tight adherence of neutrophils to TBEC appears to promote epithelial cell killing. In addition to indirect effector cell-induced TBEC death, direct LPS-induced cell damage was seen with increased apoptosis rate in LPS-stimulated TBEC (36% increase of caspase-3, P < 0.01). These data provide evidence that LPS induces TBEC killing in a necrosis- and apoptosis-dependent manner.
Emerging Varieties of Capitalism in Former State Socialist Societies
Authors: Lane David
Published: August 2005

The transformation of the former state socialist societies involved the introduction of capitalism from above. The current ‘varieties of capitalism’ debate focuses on developed high income capitalist countries, whereas the former state socialist countries come from a low economic base and are in the process of capitalist formation. It is contended that, while levels of capital accumulation are very low, a modern capitalist system of the continental type characterises one group of central European societies. This group approaches the levels of OECD countries with respect to marketisation and has a positive participation in the global economy. A second, relatively poor and weakly coordinated, cluster has the characteristics of low income, primary sector exporting countries, with a very low integration into the global economy. This group is characterised as a hybrid state/market uncoordinated type of market capitalism. A third, relatively coherent, cluster has high levels of state control, relatively little privatisation and an undeveloped market.
Toward a theory for step pools in stream channels
Authors: Chin Anne , Wohl Ellen
Published: August 2005

Over the past 10 to 15 years there has been a surge in interest in step-pool streams in fluvial geomorphological research. This reflects recognition of the geomorphic significance of step pools in high-gradient channels, and a growing interest in rivers in mountainous regions in general. This paper synthesizes the recent literature on step pools, with particular reference to theory construction and progress made over the past decade and a half. Four groups of contributions are identified. The first focuses on understanding morphological relations in order to seek causal mechanisms. The second emphasizes processes that result from the step-pool configuration. The third is a group of integrative studies that seek broader explanations for step-pool sequences. The fourth and growing body of literature applies what has been learned about step pools toward managing and restoring steep channels. We conclude by highlighting some future possible research directions toward gaining a complete explanation for step pools in stream channels.
Flood frequency analysis: assumptions and alternatives
Authors: Kidson R. , Richards K. S.
Published: August 2005

Flood frequency analysis (FFA) is a form of risk analysis, yet a risk analysis of the activity of FFA itself is rarely undertaken. The recent literature of FFA has been characterized by: (1) a proliferation of mathematical models, lacking theoretical hydrologic justification, but used to extrapolate the return periods of floods beyond the gauged record; (2) official mandating of particular models, which has resulted in (3) research focused on increasingly reductionist and statistically sophisticated procedures for parameter fitting to these models from the limited gauged data. These trends have evolved to such a refined state that FFA may be approaching the ‘limits of splitting’; at the very least, the emphasis was shifted early in the history of FFA from predicting and explaining extreme flood events to the more soluble issue of fitting distributions to the bulk of the data. However, recent evidence indicates that the very modelling basis itself may be ripe for revision. Self-similar (power law) models are not only analytically simpler than conventional models, but they also offer a plausible theoretical basis in complexity theory. Of most significance, however, is the empirical evidence for self-similarity in flood behaviour. Self-similarity is difficult to detect in gauged records of limited length; however, one positive aspect of the application of statistics to FFA has been the refinement of techniques for the incorporation of historical and palaeoflood data. It is these data types, even over modest timescales such as 100 years, which offer the best promise for testing alternative models of extreme flood behaviour across a wider range of basins. At stake is the accurate estimation of flood magnitude, used widely for design purposes: the power law model produces far more conservative estimates of return period of large floods compared to conventional models, and deserves closer study.
Laser Raman Spectra and Normal Coordinate Analysis of Some Uranyl Tetrachloride Complexes
Authors: Ohwada Ken
Published: August 2005

Laser Raman spectra of uranyl tetrachloride complexes [K2UO2Cl4, Rb2UO2Cl4, Cs2UO2Cl4, (NH4)2UO2Cl4] have been measured in the region from 3500 to 10 cm−1. Vibrational assignments as well as normal coordinate analyses have been carried out with the assumption that all the complexes contain discrete (UO2Cl4)2− ions belonging to a point group D4h. To understand the nature of the uranyl bonds in the complexes, approximate π-bonding energies of such bonds have been estimated from the U—O stretching force constants. The reliability of the values obtained are discussed in detail on the basis of Mulliken's magic formula.
Application of Laser-Excited Atomic Fluorescence Spectrometry to the Determination of Nickel and Tin
Authors: Epstein M. S. , Bradshaw J. , Bayer S. , Bower J. , Voigtman E. , Winefordner J. D.
Published: August 2005

The analytical determination of nickel and tin by laser-excited atomic fluorescence spectrometry (LEAFS) is studied. Non-resonance nickel fluorescence near 340 nm is excited at several nickel lines near 300 nm and direct-line tin fluorescence at 317.5 and 380.1 nm is excited at the 300.9 nm line in a nitrogen-separated air-acetylene flame. Factors which affect detection limits and methods which can be used to improve them are discussed. The application of LEAFS to the determination of nickel and tin in several standard reference materials (river water, unalloyed copper, and fly ash) is investigated, including problems related to iron spectral interference encountered for analysis in these matrices.
A New Nonlinear Least Square Algorithm for Voigt Spectral Lines
Authors: Noll R. J. , Pires A.
Published: August 2005

In this paper a new fitting algorithm which works with Voigt functions is discussed. The fitting algorithm used is an extension of the rapidly convergent gradient method of Fletcher and Powell, who claim faster convergence than the Newton-Raphson method which has been used by Chang and Shaw for fitting Lorentz line widths. The Fletcher and Powell algorithm involves the effects of second derivatives although second derivatives are not explicitly calculated. In our algorithm, first and second derivatives are computed not numerically, but analytically via a modification to Drayson's Voigt function subroutine. This algorithm provides rapid convergence even when there are few data points. Profiles have been fitted with as few as five data points. Our typical line fits involve 40 points. The run time of the algorithm has been compared with the shrinking cube algorithm of Hillman and found to be at least 10 times faster under identical starting conditions. Sample single line and single line plus background are shown illustrating the speed and efficiency of the new algorithm, as well as the importance of good zero-order estimates to start the iterations.
Photoacoustic Fourier Transform Infrared Spectroscopy of Solid Samples
Authors: Vidrine D. Warren
Published: August 2005

Fourier transform infrared spectroscopy of solids and liquids using photoacoustic detection is reported here. The advantages and disadvantages of photoacoustic detection are discussed, and comparisons of sample spectra obtained by different techniques, including photoacoustic detection, are presented and compared. Photoacoustic Fourier transform infrared spectroscopy is a promising spectroscopic method for IR analysis in cases where sample preparation is difficult.
The Scope and Limitations of Curve Fitting
Authors: Maddams W. F.
Published: August 2005

There is an increasing awareness that the separation of overlapping bands by the mathematical technique of curve fitting offers many pitfalls and should not be undertaken lightly. This review discusses critically the various factors involved, with particular reference to vibrational band systems; other types of overlapping band systems encountered in analytical work are considered in less detail. Five parameters are involved: the number of component bands, their positions, shapes and widths, and the form of the baseline. Curve fitting, by a least squares optimization method to a suitable goodness of fit criterion, is considerably facilitated if approximate values for some of the parameters are known at the outset. The methods available for peak finding are discussed and, although not free from problems, are reasonably effective. Similarly, band shapes can usually be defined semiquantitatively. However, it is seldom possible to obtain prior information on band widths; these should be determined during the curve fitting calculations. Although statistical goodness of fit criteria are available they should be used in conjunction with a visual plot, to locate any regions of poor fit. Furthermore, the overriding consideration must always be that the computer fit is plausible in terms of acceptable chemical species for the system being examined.
Infrared and Raman Spectra of a Sulfur-Resistant Methanation Catalyst
Authors: Stencel J. M. , Bradley E. B. , Brown Fred R.
Published: August 2005

The infrared and Raman spectra of a sulfur-resistant NiO/Cr2O3/MgSiO3 methanation catalyst are presented and compared to the spectra of the catalyst after being reduced, sulfided, and tested for methanation activity. The molecular structure of the catalyst is shown to be represented by NiO and MgO dispersed in a quasi-tridimensional Cr-O-Si network. Reduction and sulfiding reorders this network and alters the SiOn coordination while reducing Cr6+ to Cr3+ or Cr2+. The data indicate that the SO4−2 which is present after sulfiding and methanation testing may have been formed during the methanation reaction.
Electron Paramagnetic Resonance as a Probe of Conformational Flexibility in Cyclic Alkanes
Authors: Heinig Marsha J. , Eaton G. R. , Eaton S. S.
Published: August 2005

Electron paramagnetic resonance (EPR) spectra of a homologous series of nitroxyl radicals derived from cyclic alkanones with 6 to 15 carbons in the ring have been obtained as a function of temperature. Long-range hyperfine coupling (0.7 to 2.2 G) was observed in the low-temperature spectra for rings with 6, 7, and 9 to 15 carbons. Deuteration of the 11- to 14-membered rings indicated that the long-range coupling was to one of the protons on the carbons adjacent to the point of attachment of the nitroxyl radical. For the 9- to 15-membered rings, there was a temperature region in which the hyperfine coupling decreased rapidly. This decrease is attributed to rapid conformational averaging on the EPR time scale. For the 12-, 13-, and 15-membered rings, the high temperature spectra exhibited resolved hyperfine coupling which can be computer-simulated, assuming four equivalent protons. The activation energies estimated from the coalescence temperatures in the EPR spectra fall in the range estimated by nuclear magnetic resonance and show similar influences of ring size on rigidity.
Solid State Circular Dichroism Spectra Obtained by Phase Modulation Spectroscopy Exemplified by the Tris(Ethylenediamine)chromium(III) Chromophore
Authors: Jensen Hans Peter
Published: August 2005

This paper shows what a marvelous thing it is to be able to get a complete dichroic tensor for an absorption band, how useful this information is, and what elegant tools there are available to help one out; namely, polarization, modulation spectroscopy, and group theory.
Observations on the Effects of Impact Beads, Mixer Paddles, and Auxiliary Oxidant on Droplet Distributions in Analytical Flame Spectroscopy
Authors: Cresser Malcolm S. , Browner Richard F.
Published: August 2005

The influences of impact beads, mixer paddles, and auxiliary oxidant upon the droplet size distributions reaching a burner head have been studied at three nebulization rates for a widely used Perkin Elmer nebulizer/spray chamber assembly. The trends observed are explained wherever possible and the practical significance of the results is briefly discussed.
Radiometric Correction of Raman Spectra
Authors: Purcell F. J. , Kaminski R. , Russavage E.
Published: August 2005

A method for the radiometric correction of Raman spectra over a wide frequency range utilizing a standard lamp and a microprocessor data system is described. The spectral irradiance factors of the standard lamp are entered into the data system, and the lamp spectrum is run and divided by the irradiances to generate correction factors. These factors are then applied to the data. The effects of different excitation frequencies, slit widths, sample size and state, and collection optics are discussed. The estimated error in the corrected data is ±5% over the frequency range of 21 839 to 17 000 cm−1.
Two-Way Electron Paramagnetic Resonance (EPR) Cavity and Stark Effect on Nitrogen Oxide
Authors: Suzuki Isao , Kaneko Yoshihisa
Published: August 2005

A two-way electron paramagnetic resonance cavity for magnetic dipole transition (MDT) and electric dipole transition (EDT) was manufactured. There are two openings to fit the sample cell for MDT and for EDT in the cylindrical TE011 mode. One opening is located on the axis of the cavity and the other is located away from the axis. EPR spectra obtained from the mixture of oxygen and nitrogen oxide when the sample cell was inserted in each opening showed the selective transition of the MDT or of the EDT of the species. When dc electric field parallel to the steady magnetic field was applied to the nitrogen oxide located away from the axis, each of the EDT peaks was divided into two peaks, one of which was higher than the other. The magnitude of the splitting was proportional to the electric field strength, in agreement with the theory. The permanent electric dipole moment 0.159 × 10−18 cgs esu obtained agreed with the value reported in the literature.
Electron Spin Resonance and Electron Nuclear Double Resonance Spectroscopy: Application to the Study of Trapped Electrons
Authors: Box Harold C. , Freund Harold G.
Published: August 2005

V band electron spin resonance-ENDOR spectroscopy has been applied to the study of “trapped” electrons in single crystals of polyhydroxy and carbohydrate compounds X-irradiated at low temperature. Evidence is presented from ENDOR measurements of hydroxy proton couplings that electrons are stabilized at intermolecular sites. The electron can be stabilized in the dipole fields of two or three hydroxy groups.
A New, More Efficient Conduction Cooling Device for Low Temperature Phosphorimetry
Authors: Ward J. L. , Walden G. L. , Bateh R. P. , Winefordner J. D.
Published: August 2005

Conduction cooling has been shown to be a viable means of improving precision and convenience in low temperature phosphorimetry. A new conduction cooling device is presented and evaluated. With this new device, phosphorimetry can now more practically be applied to routine analysis situations. Analytical figures of merit are given for several compounds as a means of comparison of conduction-cooled phosphorescence with immersion-cooled phosphorescence.
Laser Power Density Dependence in Absorption Measurements
Authors: Castle Peter M.
Published: August 2005

The absorption cross section of CF2Cl2 has been measured as a function of presure and CO2 laser input power at 10.764 μm. The laser was operated in the continuous wave mode providing a continuous energy deposition in the sample. It is shown that the absorption cross section measured has a strong dependence on input power density in the range from 5 to 15 W/cm2 and pressure in the 3 to 50 Torr regime. It is demonstrated that most of these effects can be attributed to the temperature rise in the beam interaction volume.
Atomic Nitrogen Spectra in the Argon Inductively Coupled Plasma (ICP)
Authors: Northway S. J. , Brown R. M. , Fry R. C.
Published: August 2005

Nonresonant, low-energy (visible-near infrared) atomic nitrogen transitions from high-energy (11 to 14.4 eV) doublet and quartet excited N(I) states are observed in the 1.5 to 2.2 kW argon inductively coupled plasma (ICP) when gaseous compounds containing this element (N) are introduced as samples. A Table of ICP excited nitrogen (I) lines and relative emission intensities from 2225 to 10 950 Å is presented. A number of new nitrogen lines are observed for which transitions have not been assigned. The ICP nonresonance emission spectrum of atomic nitrogen [N(I)] is found to be especially good in the near infrared region. The use of near infrared nonresonant N(I) lines for the analytical detection of nitrogen is reported. The relative intensity of N(I) emission (derived from N2 samples) is at a maximum between the turns of the rf load coil. An “equal intensity” contour “map” of N(I) emission in the ICP is presented using N2 as the sample. The present limit of nitrogen detection in argon for nonoptimized conditions is 1.0 ppm (v/v) using continuous sample introduction (limited by photomultiplier noise). For gas sampling loop injections, the present detection limit is 0.3 μg (limited by atmospheric leakage or permeation contamination into the sampling loop system). Considerable improvement is expected in the future. The relative contributions to the baseline signal of: (1) atmospheric nitrogen entrainment in the argon plasma, (2) atmospheric permeation into the present Teflon gas sampling loop system, and (3) argon tank contaminants are evaluated. Suggestions for further improvement are given. The response is linear, and the short-term precision for repetitive introduction of samples containing 20 μg of N2 is 0.4% RSD using a 157 μl Teflon gas sampling loop.
Electron Nuclear Double Resonance (ENDOR) Investigations of Organic Doublet Radicals in the Nematic and Smectic Phase of Liquid Crystals
Authors: Kirste B. , Kurreck H.
Published: August 2005

Different types of organic doublet radicals have been investigated in isotropic, nematic, and smectic phases of liquid crystals by performing electron nuclear double resonance (ENDOR), general TRIPLE and special TRIPLE experiments. For this purpose phenalenyls (perinaphthenyls), galvinoxyl, tetra- tert.-butylcarbazolyl, and bis(biphenylenyl)propenyl radicals have been chosen including some partially deuterated and 13C-labeled compounds. Anisotropic hyperfine interactions and deuterium quadrupole couplings could be determined. Smectic A phases have proved to be advantageous as compared to nematic phases in these studies. Detailed information about the orientation of the radicals within the liquid-crystalline solvent and about the conformations of the radicals could be obtained.
Atomic Oxygen Spectra in the Argon Inductively Coupled Plasma (ICP)
Authors: Northway S. J. , Fry R. C.
Published: August 2005

Nonresonant, low-energy atomic oxygen transitions from high-energy (11 to 16 eV) singlet, triplet, and quintet states are observed in the 2 kW argon inductively coupled plasma (ICP). A table of ICP oxygen lines and relative emission intensities from 2500 to 10 000 Å is presented. The degree of molecular dissociation in the ICP is evaluated for several small, highly stable molecules as a function of rf power level over the range of 0.2 to 2.25 kW. Quantitative dissociation is achieved at power levels ≥1.95 kW. The use of these nonresonance O(I) lines for the analytical detection of oxygen is reported. The present detection limit for nonoptimized conditions is 0.5 μg. Considerable improvement is expected in the future. The response is linear, and the precision using a gas sampling loop is 0.5% RSD.
Electron Paramagnetic Resonance Spectrum of Human Serum Copper
Authors: Kakuda T. , Tanaka H. , Kimoto E. , Morishige F.
Published: August 2005

The electron paramagnetic resonance signal of the cupric ion (its perpendicular component) at – 196°C was found to be different in shape in human blood plasma and serum. On the addition of acid, substrate of ceruloplasmin, reducing agent, or denaturing agent, serum exhibited a complex electron paramagnetic resonance spectrum similar to that of a copper-diethyldithiocarbamate complex in an organic solvent, with a simultaneous disappearance of the cupric ion signal. Such an electron paramagnetic resonance spectrum occurred only from human serum but not from animal (guinea pig, mouse, rat, cattle, or monkey) serum.
Surface Studies of Ancient Gold Coins and Modern Copies by X-ray Fluorescence, Scanning Electron Microscopy and Scanning Auger Spectroscopy
Authors: Love L. J. Cline , Soto Luis , Reagor B. T.
Published: August 2005

Several gold coins and modern copies were examined by three surface analysis techniques and the results were evaluated for possible use in authenticity testing of the coins. The coins supposedly ranged in age from 241 B.C. to 1894 A.D. The scanning electron microscope with an energy-dispersive x-ray analyzer was used to analyze for elemental composition, surface irregularities, contamination introduced during production, and accumulated debris. Conventional x-ray fluorescence provided elemental composition more representative of the bulk of the coins. Auger microprobe data provided corroborative qualitative analysis and information on the presence of low atomic number species. The significance of these results for authentication of ancient artifacts and art objects is discussed.
Evaluation of a Silicon-Intensified Target Image Detector for Inductively Coupled Plasma Emission Spectrometer
Authors: Furuta Naoki , McLeod C. W. , Haraguchi Hiroki , Fuwa Keiichiro
Published: August 2005

A silicon-intensified vidicon target tube coupled to an optical multichannel analyzer has been evaluated as a detector system for inductively coupled plasma emission spectrometer. The silicon-intensified target detector was combined with a relatively high resolution monochromator to provide a simultaneous spectral monitoring capability over a 5 nm range. The detection limits obtained for 27 elements were at the nanograms per milliliter level in many cases. The detection limit data are compared to those of flame emission spectrometry using the same instrumental system, and also to those obtained by a commercial direct reading inductively coupled plasma system which utilizes photomultiplier detection.
Detection Limits of AC-Coupled Inverse Raman Spectroscopy
Authors: Haushalter Jeanne P. , Ritz G. Patrick , Wallan David J. , Dien Kathy , Morris Michael D.
Published: August 2005

ac-coupled inverse Raman spectroscopy is shown to yield detection limits comparable to those obtained by spontaneous Raman spectroscopy. For an aqueous nitrate ion, inverse Raman limits are about 2.5 times higher than those reported for conventional measurements with similar laser powers and measurement times. Proposed improvements in instrumentation may lower detection limits another 10 times with no change in laser powers or measurement times.
Characterization of Pyrolysis and Combustion of Complex Systems Using Fourier Transform Infrared Spectroscopy
Authors: Lephardt John O. , Fenner Robert A.
Published: August 2005

Thermal analysis plays an important role in the evaluation and development of many complex chemical systems. Often combustion data as well as pyrolytic data on these systems may be important. Analytical techniques are required which maximize the amount of useful information which can be obtained per thermal experiment. Fourier transform infrared spectral analysis of gases evolving from materials vs temperature can provide information on both pyrolysis and combustion processes, and an apparatus for performing such analysis routinely is described. While the Fourier transform infrared evolved gas analysis (FT-IR-EGA) system has numerous applications, three applications using tobacco as a sample are presented for illustration. These include comparison of different materials, comparison of materials before and after modification and examination of oxygen-induced effects relative to pyrolysis effects. The FT-IR-EGA technique should prove to be a useful tool in elucidating thermal processes in complex systems.
A Schlieren System for Time and Space Resolved Photography of Self-Luminous Electrical Discharges
Authors: Mathews S. E. , Niemczyk Thomas M. , Walters John P.
Published: August 2005

A schlieren apparatus capable of recording index of refraction gradients in self-luminous discharges such as arcs, sparks, and inductively coupled plasmas is described. Resolution of better than 50 μm is obtained over a clear, bright, uniform field. The geometric design of the system cancels coma, and small off-axis angles are used to keep astigmatism low.
Double Resonance Excitation of Fluorescence in the Condensed Phase—An Alternative to Infrared, Raman, and Fluorescence Spectroscopy
Authors: Wright John C.
Published: August 2005

The feasibility of performing a double resonance excitation of fluorescence from molecules in a condensed phase is discussed. A vibrational excitation can be created by either stimulated Raman scattering or infrared absorption while a second excitation can excite the molecule to an excited electronic state from which fluorescence can occur. By providing high rates of excitation, one can overcome the rapid vibrational relaxation rates to produce fluorescence. By scanning the second excitation frequency in synchronization with either the infrared frequency or the difference frequency producing the stimulated Raman scattering, one can obtain spectra that are analogous to Raman or infrared spectra. This approach would have the sharp lines characteristic of Raman or infrared spectroscopy but would have an increased sensitivity characteristic of fluorescence spectroscopy.
Raman Microprobe Spectra and Vibrational Mode Assignments of Talc
Authors: Rosasco G. J. , Blaha J. J.
Published: August 2005

The Raman spectra of talc microparticles have been obtained with the Raman microprobe over the frequency range 100 to 3800 cm−1. The vibrational modes are discussed in terms of an idealized unit cell (1-M polymorph) of C2h symmetry. An electrostatic dipole-dipole interaction is used to compare the Raman and infrared active branches. Assignments of the Raman active stretching modes of the silicate sheet are found to support previous infrared assignments. Estimates of intrasheet dipole-dipole interactions are obtained.
Degradation Studies on Erbium Dideuteride Thin Films
Authors: Antepenko R. J. , Holloway D. M.
Published: August 2005

Rare earth metals are used as hydrogen isotope occluders and function as electrodes in neutron generator tubes. In this study, erbium dideuteride thin films have been quantitatively measured for purity in order to establish the deleterious effects resulting from film processing. These processes include deposition, hydriding, and neutron tube vacuum anneal. The data taken reveal that ∼0.02 mg/cm2 erbium metal is unavailable as the hydride due to surface oxidation and interfacial interactions between occluder metal and substrate.
Controlled-Atmosphere Rotating Cell for in Situ Studies of Catalysts Using Laser Raman Spectroscopy
Authors: Cheng C. P. , Ludowise J. D. , Schrader G. L.
Published: August 2005

Laser Raman spectroscopy was used to characterize molybdenum on alumina catalysts using a controlled-atmosphere rotating cell. In situ spectra could be recorded at temperatures up to 600°C and pressures as low as 1.333 × 10−4 Pa. Catalysts were examined during the drying and calcining operations; adsorption of pyridine was also studied. Spectra of the dried and calcined catalysts indicated the presence of aggregated molybdenum species. Close resemblance to the aggregation of molybdenum species in aqueous solution was apparent. At higher loadings of molybdenum, a molybdenum trioxide phase developed. Adsorbed pyridine spectra indicated that a considerable portion of the alumina surface was not covered by molybdenum even after molybdenum trioxide was formed. A new form of pyridine adsorption associated with the aggregated phase was observed.
Low Temperature Evaluation of Carbon and Oxygen Contaminants in Silicon
Authors: Mead D. G.
Published: August 2005

Low temperature Fourier transform infrared measurements at 20 K on some wafers containing substitutional atomic carbon and oxygen are presented. Spectral subtraction techniques at 20 K indicate an increase of approximately 5 times in sensitivity compared to the room temperature evaluation of the carbon and oxygen concentrations.
Second Derivative Tunable Diode Laser Spectrometry for Line Profile Determination. II. Experimental Results
Authors: Grieble David L. , Olson Mark L. , Sun Jeffrey N-P. , Griffiths Peter R.
Published: August 2005

The effect of the amplitude of the current modulation on experimental second derivative spectra measured using a tunable diode laser spectrometer is discussed. Spectra with adequate signal/noise ratios can only be measured when the amplitude of the modulation is about equal to the half width at half height. Two parameters, the distance between the zero crossings and the ratio of the minimal and maximal excursions, may be fit to an empirical hypersurface to obtain values for the peak absorbance, the actual half width and the collision-broadened half width. Although the peak absorbance is not accurately calculated, the line widths appear to be calculated to at least the same accuracy that can be obtained from the single-beam absorption spectrum.
Synthesis of High-Purity Copper(II) Fluoride Dihydrate for Carrier-Distillation Emission Spectroscopy
Authors: Dabeka R. W. , Tymchuk P. , Russell D. S.
Published: August 2005

The preparation and analysis of high-purity copper fluoride dihydrate for use as a carrier in emission spectroscopy is described. Copper metal was oxidized with hydrogen peroxide or nitric acid in the presence of an excess of different grades of hydrofluoric acid. The resulting copper fluoride was analyzed to determine the effect of different factors on the levels of impurities. The quality of the hydrofluoric acid was the main factor affecting the purity of the product. The order of appearance of contaminants during crystallization of copper fluoride is described. Iron, nickel, and manganese gradually appear as the mother liquor is concentrated, while silicon, tin, aluminum, and lead usually contaminate only the lots immediately preceding evaporation of the solution to dryness. Magnesium, regardless of its concentration in the mother liquor, coprecipitates with all lots of copper fluoride.
Infrared Photoacoustic Spectroscopy of Solids and Surface Species
Authors: Low M. J. D. , Parodi G. A.
Published: August 2005

Infrared photoacoustic spectra were recorded over the 3900 to 1400 cm−1 range with a single-beam, computer-controlled spectrometer fitted with a broad-band source and LiF and CaF2 prisms. The exploratory results indicate that structured IR spectra of organic solids can be obtained. Various surface treatments were used to alter the chemical composition of the surfaces of samples composed of thick catalyst pellets and of thick beds of powdered silica and alumina, under controlled conditions in a reactor attached to the acoustic cell. The IR bands of resulting surface species were observable at sub-monolayer coverages. With some improvements, IR-photoacoustic spectroscopy will be a useful ancillary technique especially suited for studying surface species on thick adsorbents, catalysts, and corrosion layers.
Burst Radio-Frequency Excited Pulsed Hollow-Cathode Lamp
Authors: Araki Tsutomu , Walters John P. , Minami Shigeo
Published: August 2005

Transient emission characteristics of a hollow-cathode lamp driven by a pulsed current in combination with a radio-frequency burst signal are described. The radio-frequency field excites electrode vapor that is transiently produced by the initial pulsed current discharge. To evaluate the performance of this radio-frequency injected lamp; peak line intensity, line width and line stability of Cu atomic and ionic emissions are compared to those from dc and pulsed current lamps. Results indicate that the radio-frequency lamp is superior to the conventional pulsed lamp in these three factors. However, due to experimental limitations of commercial lamps under applied radio-frequency voltage, the maximum possible intensity enhancement was not achieved. Atomic absorption working curves are also compared to anticipate practical situations. The steep and linear curve obtained using the radio-frequency lamp suggests its important role in practical analysis.
High-Temperature Absorption of the 3.39 μm He-Ne Laser Line by Acetylene, Ethylene, and Propylene
Authors: Koike T. , Gardiner W. C.
Published: August 2005

Absorptivity measurements for the 3.39 μm He-Ne laser line are reported for acetylene, ethylene, and propylene over the temperature ranges 1500 to 3000 K (acetylene), 1000 to 2000 K (ethylene), and 700 to 2300 K (propylene). In contrast to the behavior of other hydrocarbons, the absorptivities of acetylene and ethylene increase with increasing temperature. The conventional spectroscopic analysis of line positions based upon high-resolution infrared spectroscopy at room temperature and approximate line-broadening theory indicate that no absorption at all would be expected for acetylene or ethylene. The time-resolved absorption profiles and computer models of the chemical behavior expected for shock-heated test gas confirm that the absorption is really due to these molecules, but must be attributed to some heretofore unidentified absorption process.
Spectra and Structure of Silicon-Containing Compounds. XII. Infrared and Raman Spectra of Trimethylvinylsilane and Trimethyl-D9-vinylsilane
Authors: Durig J. R. , Natter W. J. , Johnson-Streusand M.
Published: August 2005

The Raman spectra (0 to 3300 cm−1) of (CH3)3Si(CHCH2) and (CD3)3Si(CHCH2) in the gaseous, liquid and solid states have been recorded. The infrared spectra (20 to 3300 cm−1) of the same two compounds in the gaseous and solid states have also been recorded. A vibrational assignment based upon depolarization ratios, frequency shifts with isotopic substitution, infrared band contours, and group frequencies is proposed. The SiC3 torsion was observed at 55 and 50 cm−1 for the “light” and “heavy” molecules, respectively, and the barriers to internal rotation were calculated to be 0.73 kcal/mol and 0.64 kcal/mol for the light and heavy compounds, respectively. These results are compared to the corresponding data for similar molecules.
Vibrational Spectra and Structure of Organophosphorous Compounds. XIX. Infrared and Raman Spectra and Structure of Methoxydifluorophosphine-D0 and -d3
Authors: Durig J. R. , Streusand B. J.
Published: August 2005

The infrared spectra of CH3OPF2 and CD3OPF2 in the gaseous and solid states and the Raman spectra of the gaseous, liquid, and solid states have been recorded from 3200 to 40 cm−1. Seventeen of the 18 normal modes have been assigned through the use of group frequencies, depolarization values, band contours, and frequency shifts with isotopic substitution. The V3 term of the asymmetric potential function was calculated to have a value of 3.41 kcal/mol from the fundamental and first overtone of the methoxy torsion. The vibrational spectra support a trans conformation for this molecule.
Evaluation of an Effective Conduction Cooling Device for Low-Temperature Phosphorimetry
Authors: Ward J. L. , Bateh R. P. , Winefordner J. D.
Published: August 2005

A conduction cooling system is presented as a possible means of improving the precision of sample introduction in low-temperature phosphorimetry. Analytical figures of merit are shown for several compounds as a means of evaluating the system and comparing it to immersion cooling systems. The results show that the two methods of cooling are comparable, but the new system does have advantages for routine analysis applications.
A Reflection Spectrophotometer for the Measurement of the Optical Constants of Liquids in the Infrared
Authors: Cameron D. G. , Escolar D. , Goplen T. G. , Nadeau A. , Young R. P. , Jones R. N.
Published: August 2005

The design and construction of an infrared spectrophotometer for the quantitative measurement of attenuated total reflection spectra are described. The instrument is used to determine the optical constants of liquids as part of a study of infrared band shapes and intensities.
Electronic Raman Spectroscopy of Rare Earth Doped Yttrium Aluminum Garnet Layers Grown by Liquid Phase Epitaxy
Authors: van den Boom H. , Breemer R. E. , Robertson J. M.
Published: August 2005

Thin films of garnet grown by liquid phase epitaxy have been studied by means of the electronic Raman effect. It is shown that films of moderate thickness (about 10 to 20 μm) can be measured directly, without using difficult lightguiding techniques. The method has been applied successfully to the study of electronic Raman transitions of the Tb3+ ion in yttrium aluminium garnet. In this way two transitions were measured in the ground state 7F6 and seven transitions between the ground state 7F6 and the first excited state 7F5. From these results, it is concluded that in crystalline films of yttrium aluminium garnet, terbium substitutes for yttrium in the same way as it does in single crystals.
Interferences in Sputter-Atomization Atomic Absorption Spectroscopy
Authors: McCamey D. A. , Niemczyk T. M.
Published: August 2005

A sputtering cell has been studied as a means for atomizing samples by a method other than a thermal mechanism. The effects of various matrices on the absorption signals for Cu, Sr, and Li were noted, and the results are compared to the same systems when atomized in a graphite furnace. Mechanisms for the observed interferences are discussed.
Photodiode Array Measurement System for Implementing Abel Inversions on Emission from an Inductively Coupled Plasma
Authors: Blades M. W. , Horlick Gary
Published: August 2005

The acquisition of detailed spatial emission data from a spectrochemical source such as an inductively coupled plasma requires a very large number of measurements if complete information is to be obtained. A photodiode array-based measurement system has been developed for the measurement of complete spatial emission profiles of analyte lines in an inductively coupled plasma. A complete map of analyte emission throughout the plasma is acquired via the measurement of a series of horizontal emission profiles. Such horizontal emission profiles provide only lateral intensity information. These lateral intensities are converted to radial intensities by Abel inversion. The photodiode array provides an almost ideal sensor for acquisition of lateral intensity data exactly in a format for input to an Abel inversion program. The complete hardward-software system is described, and results are presented for the inductively coupled plasma.
Absolute Absorption Intensity and Dispersion Measurements on Some Organic Liquids in the Infrared
Authors: Goplen T. G. , Cameron D. G. , Jones R. N.
Published: August 2005

The infrared absorption spectra and corresponding dispersion spectra of the following liquids have been measured over the range 4200 to 250 cm−1: cyclo-C5H10, CH3·NO2, CH3·CN, CH2Br2, CH2Cl2, CBrCl3, CCl4, C6H6, C6H5·CH3, C6H5Cl, C6H5Br, C6H5I, and C6F6. The spectra were measured in the absence of solvent and the results are reported as the real and imaginary components of the complex refractive index ( n, k). The experimental technique combines transmission measurements through thin films and attenuated total reflection measurements by a method which has been described previously. The complete spectral and dispersion curves are displayed graphically; the absorption maxima are tabulated as absorption indices ( kmax) and as molar absorption coefficients (εmax). The dispersion extrema ( nmin, nmax) are also listed and the experimental uncertainties in these quantities are evaluated. Provision is made to supply the complete optical constant data on magnetic tape at encoded intervals of 0.5 cm−1.