bluuebunny/crossref_metadata_2025 huggingface dataset:
XRCC1 and XPDgenetic polymorphisms, smoking and breast cancer risk in a Finnish case-control study
Authors: Metsola Katja , Kataja Vesa , Sillanpää Pia , Siivola Päivi , Heikinheimo Liisa , Eskelinen Matti , Kosma Veli-Matti , Uusitupa Matti , Hirvonen Ari
Published: October 2005

Introduction

It has been suggested that individuals with reduced DNA repair capacities might have increased susceptibility to environmentally induced cancer. In this study, we evaluated if polymorphisms in DNA repair genes XRCC1 (Arg280His, Arg399Gln) and XPD (Lys751Gln) modify individual breast cancer risk, with emphasis on tobacco smoking.

Methods

The study population consisted of 483 incident breast cancer cases and 482 population controls of Finnish Caucasian origin. The genotypes were determined by PCR-RFLP-based methods. Odds ratio (OR) and confidence intervals (CIs) were calculated by unconditional logistic regression analyses.

Results

No statistically significant overall effect in the breast cancer risk was seen for any of the studied polymorphisms. However, a significant increase in breast cancer risk was seen among ever smoking women if they carried at least one XRCC1-399 Gln allele (OR 2.33, 95% CI 1.30–4.19, pint 0.025) or XPD-751 Gln/Gln genotype (OR 2.52, 95% CI 1.27–5.03, pint 0.011) compared to smoking women not carrying these genotypes. The risks were found to be confined to women smoking at least five pack-years; the respective ORs were 4.14 (95% CI 1.66–10.3) and 4.41 (95% CI 1.62–12.0). Moreover, a significant trend of increasing risk with increasing number of the putative at-risk genotypes (p for trend 0.042) was seen. Women with at least two at-risk genotypes had an OR of 1.54 (95% CI 1.00–2.41) compared to women with no at-risk genotypes. Even higher estimates were seen for ever actively smoking women with at least two at-risk genotypes.

Conclusion

Our results do not indicate a major role for XRCC1 and XPD polymorphisms in breast cancer susceptibility, but suggest that they may modify the risk especially among smoking women.
Early hemoperfusion with an immobilized polymyxin B fiber column eliminates humoral mediators and improves pulmonary oxygenation
Authors: Kushi Hidehiko , Miki Takahiro , Okamaoto Kazuhiko , Nakahara Jun , Saito Takeshi , Tanjoh Katsuhisa
Published: October 2005

Introduction

The objective of this study was to clarify the efficacy and mechanism of action of direct hemoperfusion with an immobilized polymyxin B fiber column (DHP-PMX) in patients with acute lung injury or acute respiratory distress syndrome caused by sepsis.

Method

Thirty-six patients with sepsis were included. In each patient a thermodilution catheter was inserted, and the oxygen delivery index and oxygen consumption index were measured. DHP-PMX was performed in patients with a normal oxygen delivery index and oxygen consumption index (> 500 ml/minute per m2 and >120 ml/minute per m2, respectively). The Acute Physiology and Chronic Health Evaluation II score was used as an index of the severity of sepsis, and survival was assessed after 1 month. The humoral mediators measured were the chemokine IL-8, plasminogen activator inhibitor-1, and neutrophil elastase (NE). These mediators were measured before DHP-PMX treatment, and at 24, 48, and 78 hours after the start of treatment. The arterial oxygen tension (PaO2)/fractional inspired oxygen (FiO2) ratio was measured before DHP-PMX treatment and at 24, 48, 72, 92, and 120 hours after the start of treatment.

Results

All patients remained alive after 1 month. Before DHP-PMX treatment, the Acute Physiology and Chronic Health Evaluation II score was 24 ± 2.0, the IL-8 level was 54 ± 15.8 pg/ml, plasminogen activator inhibitor-1 was 133 ± 28.1 ng/ml, and NE was 418 ± 72.1 μg/l. These three humoral mediators began to decrease from 24 hours after DHP-PMX treatment, and the decline became significant from 48 hours onward. The PaO2/FiO2 ratio was 244 ± 26.3 before DHP-PMX treatment but improved significantly from 96 hours onward. There were significant negative correlations between the PaO2/FiO2 ratio and blood levels of NE and IL-8.

Conclusion

The mechanism of action of DHP-PMX is still not fully understood, but we report the following findings. The mean blood levels of plasminogen activator inhibitor-1, NE, and IL-8 were significantly decreased from 48 hours after DHP-PMX treatment. The mean PaO2/FiO2 ratio was significantly improved from 96 hours after DHP-PMX treatment. Improvement in the PaO2/FiO2 ratio appeared to be related to the decreases in blood NE and IL-8 levels.
Endocrine Effects of Relaxin Overexpression in Mice
Authors: Feng Shu , Bogatcheva Natalia V. , Kamat Aparna A. , Truong Anne , Agoulnik Alexander I.
Published: October 2005

Relaxin is a small peptide hormone with a variety of biological functions. To investigate the systemic endocrine effects of relaxin, we produced mice with transgenic overexpression of the Rln1 gene, Tg(Rln1), driven by rat insulin 2 promoter. The expression of relaxin was detected in the pancreas of the transgenic animals. An analysis of the sera from the transgenic animals revealed at least 20-fold elevation of the level of bioactive relaxin. Transgenic animals had normal viability and fertility in both sexes. Transgenic overexpression of Rln1 did not rescue the undescended testis phenotype in Insl3-deficient males, suggesting that in vivo relaxin does not interact with the insulin-like 3 factor receptor, leucine-rich repeats-containing G protein-coupled receptor 8, Lgr8. Phenotypically, the excess of relaxin resulted in hypertrophic nipple development in virgin female mice. Deletion of the relaxin receptor, leucine-rich repeats-containing G protein-coupled receptor 7, Lgr7, in Tg(Rln1) animals abrogated the development of enlarged nipples in females, indicating that relaxin exerts its effect through Lgr7 alone. The levels of previously defined targets of relaxin signaling, such as matrix metalloproteinases 2 and 9, vascular endothelial growth factor, or nitric oxide, were similar in the sera of the transgenic and wild-type mice. However, the total plasma protein concentration in male Tg(Rln1) mice was lower than that in control animals. The livers of male Tg(Rln1) mice exhibited significantly higher hydroxyproline content, indicative of increased collagen deposition. Our results indicate that relaxin overexpression causes gender-specific changes in liver collagen metabolism.
Cholesterol facilitates the native mechanism of Ca2+-triggered membrane fusion
Authors: Churchward Matthew A. , Rogasevskaia Tatiana , Höfgen Jana , Bau Jason , Coorssen Jens R.
Published: October 2005

The process of regulated exocytosis is defined by the Ca2+-triggered fusion of two apposed membranes, enabling the release of vesicular contents. This fusion step involves a number of energetically complex steps and requires both protein and lipid membrane components. The role of cholesterol has been investigated using isolated release-ready native cortical secretory vesicles to analyze the Ca2+-triggered fusion step of exocytosis. Cholesterol is a major component of vesicle membranes and we show here that selective removal from membranes, selective sequestering within membranes, or enzymatic modification causes a significant inhibition of the extent, Ca2+ sensitivity and kinetics of fusion. Depending upon the amount incorporated, addition of exogenous cholesterol to cholesterol-depleted membranes consistently recovers the extent, but not the Ca2+ sensitivity or kinetics of fusion. Membrane components of comparable negative curvature selectively recover the ability to fuse, but are unable to recover the kinetics and Ca2+ sensitivity of vesicle fusion. This indicates at least two specific positive roles for cholesterol in the process of membrane fusion: as a local membrane organizer contributing to the efficiency of fusion, and, by virtue of its intrinsic negative curvature, as a specific molecule working in concert with protein factors to facilitate the minimal molecular machinery for fast Ca2+-triggered fusion.
Interaction between secretogranin III and carboxypeptidase E facilitates prohormone sorting within secretory granules
Authors: Hosaka Masahiro , Watanabe Tsuyoshi , Sakai Yuko , Kato Takeshi , Takeuchi Toshiyuki
Published: October 2005

Secretogranin III (SgIII) and carboxypeptidase E (CPE) bind specifically to cholesterol-rich secretory granule (SG) membranes. We previously showed that SgIII binds chromogranin A (CgA) and targets CgA to the SGs in endocrine cells. We investigated the binding of SgIII and CPE because they frequently localize close to the periphery of SGs, and they bind each other in mouse corticotrope-derived AtT-20 cells. In Cpefat mouse corticotropes, which have defective CPE, proopiomelanocortin (POMC)-derived adrenocorticotrophin hormone (ACTH)-containing peptides were distributed over the entire surface of the SGs, and displayed a regulated secretion by secretagogues. The Cpefat pituitary exhibited elevated levels of SgIII and CgA, which suggests that they compensate for a sorting function of CPE for POMC and its intermediates to ACTH. Indeed, both SgIII and CgA were able to bind POMC-derived intermediates. In a competitive pull-down assay, excessive SgIII led to a decrease in CPE-bound POMC-derived intermediate molecules, and SgIII pulled-down by anti-ACTH antibody increased proportionately. We suggest that SgIII and CPE form the separate functional sorting complex by anchoring to cholesterol-rich SG membranes, and POMC-derived peptides are transferred from CPE to SgIII, and subsequently to CgA.
Usher I syndrome: unravelling the mechanisms that underlie the cohesion of the growing hair bundle in inner ear sensory cells
Authors: El-Amraoui Aziz , Petit Christine
Published: October 2005

Defects in myosin VIIa, the PDZ-domain-containing protein harmonin, cadherin 23 and protocadherin 15 (two cadherins with large extracellular regions), and the putative scaffolding protein Sans underlie five genetic forms of Usher syndrome type I (USH1), the most frequent cause of hereditary deafness-blindness in humans. All USH1 proteins are localised within growing stereocilia and/or the kinocilium that make up the developing auditory hair bundle, the mechanosensitive structure receptive to sound stimulation. Cadherin 23 has been shown to be a component of fibrous links interconnecting the growing stereocilia as well as the kinocilium and the nearest tall stereocilia. A similar function is anticipated for protocadherin 15. Multiple direct interactions between USH1 proteins have been demonstrated. In particular, harmonin b can bind to the cytoplasmic regions of cadherin 23 and protocadherin 15, and to F-actin, and thus probably anchors these cadherins to the actin filaments filling the stereocilia. Myosin VIIa and Sans are both involved in the sorting and/or targeting of harmonin b to the stereocilia. Together, this suggests that the disorganisation of the hair bundles observed in mice mutants lacking orthologues of USH1 proteins may result from a defect of hair-bundle-link-mediated adhesion forces. Moreover, several recent evidences suggest that some genes defective in Usher type II syndrome also encode interstereocilia links, thus bridging the pathogenic pathways of USH1 and USH2 hearing impairment. Additional functions of USH1 proteins in the inner ear and the retina are evident from other phenotypic abnormalities observed in these mice. In particular, myosin VIIa could act at the interface between microtubule- and actin-based transport.
Use of the MODIS imager to help deal with AIRS cloudy radiances
Authors: Dahoui Mohamed , Lavanant Lydie , Rabier Florence , Auligne Thomas
Published: October 2005

The assimilation of the Atmospheric InfraRed Sounder (AIRS) data is expected to improve the quality of NWP products. Currently, operational use of such data is limited to the cloud‐free pixels or to the channels far above the clouds for cloudy pixels. This paper focuses on the validation of various cloud‐detection schemes applied to AIRS data. The clouds are detected and characterized, in cloud‐top and cover, by using the NESDIS, ECMWF, CO2‐slicing and MLEV schemes. These four different AIRS cloud descriptions are evaluated by independent information retrieved with the Météo‐France cloud mask applied to MODIS data and taken as our reference. The validation for a ten‐day period over the North‐east Atlantic is presented. The use of satellite cloudy radiances is a great challenge for numerical weather prediction. Work is in progress to assimilate such data by using enhanced observation operators dealing with clouds. In this work, we try to contribute to this effort by investigating the linearity assumption of an observation operator, with a simple diagnostic cloud scheme, for different cloud types. Copyright © 2005 Royal Meteorological Society
The Role of Smart Power Technologies in Global Electrification
Authors: Yeager Kurt , Gehl Stephen , Barker Brent
Published: October 2005

This paper explores trends in global electrification through 2050, and the shift in technology dominance from supply-side to demand-side as the electricity delivery system becomes integrated with communications to form a new mega-infrastructure with new functions. This ‘energy web’ will be a smart, interactive, and self-healing electricity delivery system fully capable of supporting the precision power needs of the digital society of the 21st century. The demand side employs billions and ultimately trillions of microprocessor agents negotiating for specialised services on behalf of their owners. The traditional electricity meter will be replaced by a two-way energy/information portal, through which information, power and services can flow. Because of the resulting optimisation opportunities, substantial efficiency gains are possible throughout the entire energy chain, from end user to producer. Another advantage is an improvement in economic productivity through the use of advanced digital technologies in all sectors of the economy.

A balanced focus on the technologies of supply and the technologies of demand is needed to meet global electrification goals. The paper shows that the sustainable growth of the global economy will be increasingly reliant on ‘digital quality’ electricity (perfectly reliable and free of spikes, voltage sags and frequency fluctuations) to power computers, advanced electro-technologies for business and industry, the internet and its successor networks, and the knowledge-based industries of the future. Examples include semiconductor manufacturing, pharmaceuticals, advanced materials, nanotechnology applications and biotechnology. These applications are already well established in the developed world, and they will become increasingly important in the LDCs as these countries seek to expand the technology base of their economies.

>Finally, the paper points out that a balanced implementation of the technologies of supply and demand offers an optimal approach to improving worker productivity and thereby addressing the issues of an ageing (and shrinking) work force in many parts of the globe.
Rapid Access to Modern Energy Services Using Lp Gas
Authors: Venn John
Published: October 2005

Modern energy is not universally available. An estimated two billion people in the world do not yet have access to modern fuels and around one quarter of all energy consumed in developing countries is derived from the burning of wood, charcoal, crop residues and animal dung. Yet a modern energy carrier exists that can meet the thermal energy needs of many of these people from both developing and developed countries. This energy carrier is available now, at low marginal cost. It can rapidly provide a critical step up on the energy ladder from traditional fuels to modern fuels whilst accelerating the socio-economic development of urban and rural regions in a sustainable manner. This modern energy carrier is LP Gas.

LP Gas (Liquefied Petroleum Gas) is a by-product of natural gas production and / or crude oil refining. With an annual demand of approximately 250 million tonnes of oil equivalent, LP Gas consumption is now equivalent to approximately 10% of global natural gas consumption. Due to its versatile characteristics, LP Gas has found uses in many applications from being a thermal fuel in domestic applications to being essential in industrial and agricultural uses. LP Gas is now also the world's most popular alternative automotive fuel.

Energy demand generally increases with population growth but in many developing countries, the rate of population growth far exceeds the rate of modern energy provision with a result that energy poverty in developing countries is extremely high. Lack of modern energy prevents the socio-economic development necessary to allow communities to move up the energy ladder from traditional fuels to fuels that can support and stimulate a greater level of economic activities.

LP Gas is the ideal transition fuel to modern energy carriers such as natural gas. Access can be achieved at relatively low marginal cost through a well-developed global LP Gas industry. Barriers to LP Gas use can often be overcome through effective government policies. The case for government support to the LP Gas sector is based on the positive contribution the fuel can make to sustainable development. Experience from several countries shows that active government support can catalyse the development of the LP Gas market and lead to a virtuous circle of growing market potential, increased investment and expanded availability.

LP Gas is available now. There is nothing exotic to invent or improve. The transportation system that moves it is in place and the tanks that store it are available today.
A Mixed Complementarity-Based Equilibrium Model of Natural Gas Markets
Authors: Gabriel Steven A. , Kiet Supat , Zhuang Jifang
Published: October 2005

We present a new multiseasonal, multiyear, natural gas market equilibrium model based on the concept of a competitive equilibrium involving the market participants: producers, storage reservoir operators, peak gas operators, pipeline operators, marketers, and consumers. The first three classes are depicted as price-takers consistent with perfect competition. The pipeline operations are described with regulated tariffs, but also involve “congestion pricing” as a mechanism to allocate scarce pipeline capacity. The marketers are price-takers in all markets except in sales to consumers, in which they compete as Nash-Cournot players. Finally, consumers are described by demand curves for each of the four sectors: residential, commercial, industrial, and electric power. We show that the equilibrium model is an instance of a mixed nonlinear complementarity problem (NCP) and provide sufficient detail not generally seen in previous complementarity models of natural gas. The NCP formulation is derived from considering the Karush-Kuhn-Tucker optimality conditions of the optimization problems faced by these participants. Under mild conditions, we show that this NCP has a solution, and under additional reasonable conditions, we show that the market prices are unique. We also validate the model on a representative sample network with nine market participants and three seasons, using four scenarios.
Simultaneous Multielement and Multiline Atomic Absorption Analysis Using a Computer-Coupled Photodiode Array Spectrometer
Authors: Horlick Gary , Codding Edward G.
Published: October 2005

Development of simultaneous multielement atomic absorption analysis has been hampered by a lack of effective multichannel spectrochemical measurement systems. In this study a computer-coupled photodiode array spectrometer is applied to atomic absorption measurements. Using a multielement hollow cathode lamp source and this spectrometer system, a complete “atomic absorption spectrum” can be measured over a range of 130 Å. Both quantitative and qualitative absorption information can be simultaneously acquired for lines of several elements and several lines of one element. Results are presented for multiline atomic absorption of Cr and multielement atomic absorption of Ni and Cr, and Cr and Fe.
A High Speed Method of Continuous Background Correction in Atomic Absorption Spectrometry
Authors: Donnelly T. H. , Eccleston A. J.
Published: October 2005

The need for background correction in atomic absorption spectrometry (AAS), particularly when graphite furnaces are used to generate the atomic vapor, is discussed. It is shown that a Beckman hydrogen arc lamp is suitable as a continuum source from the point of view of noise, extent of its useful broad band absorption, and light intensity for background-corrected absorption (BCA) measurements over the wavelength range examined (200 to 460 nm). The standard method of determining tin present in rock samples as cassiterite, by extraction as the volatile tin iodide, was examined by flameless AAS with BCA. The method corrects for the large nonatomic absorption present, it is rapid, and it enables easier examination of solutions containing low concentrations of tin (detection limit for a 1 g starting sample is ∼1 jug tin).
A Simple Directly Combined Gas Chromatographic-Infrared Spectrometric System for Identification of Low Molecular Weight Hydrocarbons
Authors: Louw C. W. , Richards J. F.
Published: October 2005

A simple directly combined gas chromatographic-infrared spectrometric system suitable for the identification of low molecular weight hydrocarbon-type compounds is reported. It incorporates a 30-m × 0.5-mm i.d. SCOT Silicone DC-550 column and a micro light pipe gas cell (volume 0.6 ml) fitted on a kinematic mounting into the sample compartment of a conventional ir spectrophotometer. Sensitivity is enhanced by a gas chromatographic fraction concentrator, a 10-cm × 1.0-mm i.d. 10% Silicone SE-30/Chromport A (80 to 100 mesh) column, situated upstream of the gas cell. The performance of the system is demonstrated for synthetic mixtures of C6 — C10 paraffinic, olefinic, and aromatic types of hydrocarbons. Infrared spectra can be taken at 5- to 6-min intervals at levels of 14 to 19 µg per sample component. This system has potential for application in the field of trace analysis, e.g., air pollution.
Signal-to-Noise Ratio Comparison for Dispersive and Non-Dispersive Flame Atomic Fluorescence Measurements
Authors: Muscat V. I. , Vickers T. J. , Rippetoe J W. E. , Johnson E. R.
Published: October 2005

Signal-to-noise ratios achievable with dispersive and nondispersive atomic fluorescence systems are compared. In this comparison particular attention has been devoted to considerations affecting optimization of the dispersive system with low and high background flames. Relative signal and noise values are reported for Hg and Fe atomic fluorescence with dispersive, solar-blind nondispersive, and filter nondispersive systems with C2H2-air, separated C2H2-air, H2-air, and H2-O2-Ar flames. It is concluded that, when due consideration is given to optimization of the dispersive system for atomic fluorescence measurements, use of a nondispersive system will not generally provide an improvement in the measurement signal-to-noise ratio and may result in a decreased signal-to-noise ratio with an atomizer of even moderate background emission, such as the separated C2H2-air flame.
Molecules We Have Recently Met
Authors: Miller Foil A.
Published: October 2005

Brief summaries are given of work on the vibrational spectra of the following compounds. (1) N(SiH3)3. A Raman study of the 14N−15N isotopic shift of the totally symmetric NSi3 stretching mode confirms that the heavy atom skeleton is planar in the gas phase. In condensed phases it is slightly distorted from D3h in some undetermined manner. (2) Si(NCO)4, Ge(NCO)4, and Ge(Na)4. Each of these molecules has some Raman bands with depolarization ratios between 0 and 0.75, showing that the molecules are not tetrahedral. (3) Cyclopropenone-d0 and -d2. A good assignment of the fundamentals has been made, and the forms of the normal modes calculated. The bands at 1483 cm−1 (d0) and 1409 cm−1 (d2) are nearly pure =C stretches, making them the lowest such modes known. (4, 5) Tetramethylenecyclobutane and its perchloro derivative. The former is planar (D4h); the latter is not. (6) F2C=C=C=CF2. This is planar (D2d). (7) B4Cl4. This has an unusual B4 tetrahedral cage. A reliable set of assignments has been made and force constants determined. (8) Trithiadiborolanes. The B2S3 ring is planar.
Accuracy of Graphical Slope Method versus Deconvolution for the Evaluation of Luminescent Lifetimes Using Various Pulsed Sources
Authors: Shaver L. A. , Love L. J. Cline
Published: October 2005

A quantitative evaluation has been made of the errors in luminescent lifetime calculations obtained by the graphical slope method when the data are distorted by the pulsed light source decay characteristics. The fluorophore lifetimes were calculated directly by the graphical slope method and were then deconvoluted to obtain the lifetimes undistorted by the pulsed source decay function. The percent error of the graphical slope method becomes significant (>5%) at luminescent-source lifetime differences of 2 nsec or less for pulsed sources having 1- to 3-nsec lifetimes. As the pulsed source lifetime increases, the percent errors will be greater at the same luminescent-source lifetime differences. As the luminescent lifetime approaches the pulsed source lifetime the percent error of the graphical method increases exponentially. The computer simulation procedure and a quantitative error analysis of the graphical slope and deconvolution methods are presented for a range of pulsed source decay values.
The Vibrational Spectra of α-Bromoacetaldehyde Dimethyl Acetal and Related Molecules
Authors: Katon J. E. , Miller Philip D.
Published: October 2005

The complete vibrational spectra of α-bromoacetaldehyde dimethyl acetal and α-bromoacetaldehyde dimethyl s6 have been recorded on the pure liquids, and a tentative vibrational assignment has been proposed. The infrared spectra of both compounds in the crystal state have also been recorded at low temperatures. There is no apparent evidence of a conformational equilibrium in the liquid phase. The infrared spectra of three other acetals have been recorded, and the data from all of the compounds are discussed in terms of previously proposed group frequencies of acetals in both the infrared and Raman.
Determination of Antimony, Tin, and Arsenic in High Antimonial Lead Alloys by Vacuum X-ray Fluorescence
Authors: McAlpin Donald L. , Kenner Charles T.
Published: October 2005

A method of x-ray fluorescence analysis for high antimonial lead alloys has been developed to cover antimony concentrations between 6 and 18%, a range not covered in previously published x-ray methods. The proposed method utilizes a General Electric XRD 6 VS spectrometer, chill-cast mold, and a special cutting bit to produce a smooth surface. Ten separate 10-sec counts are taken at 120° intervals to offset nonhomogeneity of the surface. Average counts vs concentration are plotted to obtain calibration curves and percentage concentration. The precision and accuracy of the proposed method compare favorably with the classical wet method. The average standard deviation of the proposed method in terms of the amount present is 1.19% for antimony, 2.03% for tin, and 2.37% for arsenic. These values are within the limits required in the specifications of most high antimonial lead alloys. A time saving of 2 h per sample is realized by the x-ray method over the classical wet method.
Baseline Modeling with a Computerized Raman System
Authors: Bulmer J. T. , Irish D. E. , Grossman F. W. , Herriot G. , Tseng M. , Weerheim A. J.
Published: October 2005

A PDP-11-to-Raman spectrometer interface for data acquisition and plotting is described. The background correction problem, which occurs in the transition from data acquisition to the data analysis of chemical interest, has been studied for the nontrivial case of considerable curvature near the Rayleigh wing. The conflict between a baseline function with sufficient freedom to compensate properly for the background and sufficient constraint to achieve uniqueness and reproducibility has been demonstrated. A comparative study has shown the superiority of an exponential-quadratic baseline function over common interpolation procedures such as the cubic spline, the fitting of simple shape-functions to the background, or polynomial expansions.
The Use of Ratio-Recording Interferometry for the Measurement of Infrared Emission Spectra: Applications to Oxide Films on Copper Surfaces
Authors: Kember D. , Sheppard N.
Published: October 2005

Infrared emission spectra from metal samples with oxide surface layers are shown to be very advantageously studied using the spectrum-ratioing facility of a recording infrared interferometer. The emission from a given sample is ratioed against that from a black-body emitter at the same temperature so as to give emittance as a function of wavenumber directly. This method has very useful application to irregularly shaped metal emitters. In the absence of selective reflection there is a direct correspondence between emission and absorption spectra for thin layers of an emitting substance. However, the presence of selective reflection leads to reduced emission and to considerable differences in the appearance of “absorption” and emission spectra in regions of strong absorption. Emission spectra obtained from copper plates heated, above 150°C, for different periods in air are shown clearly to indicate the presence of cuprous, Cu(I), and cupric, Cu(II), oxides in the surface layer.
An Automated Technique for the Analysis of Total Inorganic Iron by Atomic Absorption Spectroscopy
Authors: Pierce F. D. , Brown H. R. , Fraser R. S.
Published: October 2005

A fully automated method for the preparation of surface water specimens for total inorganic iron analysis by atomic absorption spectroscopy and a method for the aspiration of prepared specimens are described. The automated specimen preparation technique is compared with a standard method used for total iron analysis and is applied to iron, manganese, zinc, and copper. Standard Technicon AutoAnalyzer components and standard atomic absorption spectrophotometers were used. The automated specimen preparation technique will handle 60 samples per hour and is totally flexible as to sampling rates, sample ratios, added chemicals, and time for particulate settling.
The Analysis of Discrete Fine Particles by Raman Spectroscopy
Authors: Rosasco G. J. , Etz E. S. , Cassatt W. A.
Published: October 2005

A conventional laser Raman spectrometer has been modified and used to obtain useful Raman spectra from discrete solid particles as small as 0.7 µm in linear dimensions. Spectra obtained from single, micrometer-sized particles of several inorganic and organic compounds are reported. Simplified calculations are discussed which provide an estimate of detectability levels and other problems associated with these measurements. Certain parameters that must be considered in the design of an instrument especially intended for use in the chemical characterization of single fine particles are reviewed in the light of this work.
Review of Multielement Atomic Spectroscopic Methods
Authors: Winefordner J. D. , Fitzgerald J. J. , Omenetto N.
Published: October 2005

A comparison of multielement atomic spectroscopic methods is given. The atomic spectroscopic methods, including atomic absorption flame and nonflame spectrometry, atomic fluorescence flame and nonflame spectrometry, and atomic emission spectrometry (including sources consisting of flames, inductively coupled plasmas, and microwave plasmas) are reviewed and compared especially with respect to their inherent advantages and disadvantages for multielement analysis. The types of optical detection systems, including temporal devices, spatial devices, and multiplex devices whether the spectral information is collected sequentially, simultaneously in parallel mode, or simultaneously in multiplexed mode are also compared with respect to their advantages and limitations for measuring atomic spectra and for multielement analysis. In this review, a comparison of atomic spectroscopic methods and optical detection devices is given. The comparison is given with respect to signal-to-noise ratio, experimental limits of detection, and other practical analytical figures of merit. It is hoped that this review will aid the analyst in selecting a multielement atomic method for trace analysis and especially make the analyst aware of the unavoidable tradeoffs in such a selection.
Determination of Sodium and Potassium in Blood of Oceanic Fish by Emission Flame Spectrometry Using an Exponential Extrapolation with Multiple Standard Additions
Authors: Folsom T. R. , Hansen N. , Weitz W. E. , Parks G. J.
Published: October 2005

A method is described for using multiple standard additions to determine sodium and potassium in samples of digested but unpurified blood of oceanic tuna fish whose flame emission responses are nonlinear. An exponential curve is fit in a rational manner to signals of the unknown and two or more spiked unknowns. Evidences are given suggesting that higher precision can be obtained in determination of these and similar elements in biological materials in a direct and simple manner.
Measurement of the Infrared Rotatory Dispersion of Cholesteric Liquid Crystals
Authors: Korte E. H. , Schrader B.
Published: October 2005

A polarimeter for the infrared region is described, which is used to measure the optical rotation due to the helical arrangement of molecules in cholesteric mesophases. The rotatory dispersion of mixtures of cholesteric liquid crystals and of liquid crystals in which the cholesteric structure is induced by a small amount of a chiral solute is discussed.
Raman Addition Spectroscopy with a Rotating Cell
Authors: Covington Arthur K. , Thain Jennifer M.
Published: October 2005

A new technique is described for obtaining quantitative relative intensity measurements, in the study of solution equilibria by laser-Raman spectroscopy, without the necessity for adding an internal standard to the sample. A rotating cylindrical double cell with separate compartments for sample and reference is used to superimpose the Raman spectra of sample and reference and hence avoid any uncertainties arising from the displacement of the equilibrium by reference substance addition.
Application of Fourier Transform Infrared Spectroscopy to Chemical Systems
Authors: Koenig Jack L.
Published: October 2005

The advantages of Fourier transform infrared spectroscopy (FTIR) over dispersive infrared spectroscopy are outlined. The use of data processing with specific reference to difference spectroscopy is discussed in light of these advantages. Applications of FTIR to identification, quality control, and quantitative infrared analysis arc indicated. The use of difference spectroscopy to improve the quality of the spectra of the desired components is illustrated for a variety of chemical systems. The role of FTIR is thus illustrated in the analytical chemical laboratory.
Direct Recording of Intermolecular Interaction Perturbation Spectra by Fourier Transform Spectroscopy
Authors: Hirschfeld Tomas , Kizer Kenneth
Published: October 2005

The symbiosis of the Fourier transform spectrometer with the computer permits the development of novel procedures for handling spectroscopic data. Two such procedures are here described. The first one produces directly the spectrum of the intermolecular interaction perturbation in solutions, while the second obtains the spectrum of pressure broadening coefficients of a gas sample. The interpretation of these techniques are discussed in the light of experimental results and shown to be critically dependent on a constant, well denned slit function and on nearly perfect spectral and intensity registration.
Integral Reflection Coefficient of X-ray Spectrometer Crystals
Authors: Gilfrich J. V. , Brown D. B. , Burkhalter P. G.
Published: October 2005

Analyzing crystals used in x-ray spectrometers have widely varying diffraction efficiencies. When employed in x-ray fluorescence analysis, the parameter which defines the efficiency is the integral reflection coefficient. This parameter has been measured using a single crystal spectrometer, as a function of wavelength, for a number of crystals commonly used. A recent adaptation of an existing diffraction theory is shown to make possible the calculation of integral reflection coefficients which agree with measured values.
Mass Spectral Intensities of Inorganic Fluorine-Containing Compounds
Authors: Beattie Willard H.
Published: October 2005

Mass spectral intensities and sensitivities of 24 fluorine-containing gases and vapors have been measured on a time-of-flight mass spectrometer at an ionizing voltage of 70 eV. Apparatus and techniques for handling fluorine compounds are described. The relative sensitivities and relative abundances are tabulated for the following gases: BF3, BrFs, CF4, CF3Cl, CF2Cl2, CF3I, C2F4, C2F6, ClF, ClF3, F2, HF, IF5, IF7, MoF6, NF3, N2F4, PF3, SF4, SF6, SO2F2, SiF4, UF6, and XeF4.
Accurate Calibration of Efficiencies of X-ray Detectors: Flow-Proportional and Scintillation Counters
Authors: Loomis T. C. , Keith H. D.
Published: October 2005

Direct methods have been devised for calibrating the quantum efficiencies of two x-ray detectors: a Siemens flow-proportional counter in the energy range 2.6 to 11.2 keV, and a General Electric SPG 5 scintillation counter in the range 5.9 to 50.4 keV. Literature values for x-ray attenuation coefficients of detector components are used only to estimate small corrections for x-ray scattering. The largest known errors in the measurements are statistical errors in photon counting and range from 0.03 to 0.23%. In the energy range 5.9 to 11.2 keV, efficiencies of a lithium-drifted silicon detector measured by comparison with the two calibrated detectors as references agree satisfactorily. Linear attenuation coefficients have been measured for argon, methane and P-10 gas (90% Ar; 10% CH4) in the energy range 2 to 12 keV; these can be used to calculate the efficiency of any flow-proportional counter of known geometry when used with counter gas consisting of a known mixture of argon and methane.
A Computerized Television Spectrometer for Emission Analysis
Authors: Wood D. L. , Dargis A. B. , Nash D. L.
Published: October 2005

A computerized direct reading emission spectrometer has been constructed to perform rapid spectrochemical analyses. The four essential components include a prism-echelle spectrograph to disperse light from the source, a proximity-focus image intensifier to convert ultraviolet radiation to visible, a random-access digital television camera to measure the intensities of many wavelengths simultaneously, and a dedicated minicomputer for control, data processing, and output. At the present stage of development, the intensities of 400 analytical lines can be measured every second during the excitation of a sample and the results can be summed, averaged, or displayed as intensity vs time. Analytical working curves can be automatically constructed and displayed for inspection by the operator. Analyses are reported for Fe in beryl using a graphite powder method and a dc arc, as well as for Zn, Sn, and Pb in Cu alloys using a glow-discharge sputtering source. The analyses yield values comparable to those from more conventional equipment.
Raman Spectral Characterization of Pure and Doped Fused Silica Optical Fibers
Authors: Walrafen G. E. , Stone J.
Published: October 2005

The utility of Raman spectroscopy as a means of characterizing the properties of pure and doped fused silica has been investigated. Laser-Raman spectra were obtained by forward scattering from solid optical fibers ∼35 to 85 m in length using 514.5 nm excitation with an “image slicer” and a Cary model 81 instrument. Clad and unclad fibers of fused silica and doped fibers having SiO2-GeO2 and SiO2-GeO2-B2O3 cores were examined. Raman spectra were also obtained from bulk samples of glasses, including pure GeO2, pure B2O3, and various compositions of SiO2-GeO2, SiO2-B2O3, and SiO2-GeO2-B2O3.

The addition of dopants to fused silica was found to alter the Raman spectrum both by the appearance of new bands, roughly proportional to dopant concentration and not common either to the fused silica or to the dopant alone, and by the marked alteration of other Raman bands, which is indicative of changes in the local intermolecular order. Thus, addition of GeO2 produces new Raman bands at ∼675 and ∼1000 cm−1; and of B2O3, new bands at ∼940 and ∼1350 cm−1. Addition of GeO2 and/or B2O3 weakens the relatively sharp Raman lines near 485 and 600 cm−1 (and a similar but small effect was also noted with increasing OH content). GeO2 and B2O3 together also produce observable narrowing of the broad intense 440 cm−1 Raman contour. These spectral effects are interpreted, respectively, in terms of a decrease in the concentrations of [Formula: see text] and [Formula: see text] defects produced by dopant addition and of a concomitant reordering of the silica structure. Raman spectroscopy thus appears to be a useful optical technique for elucidating the properties of dopants that have been especially chosen for good optical transmission and hence are not easily detectable by absorption measurements.
Application of the Rapid Scan Fourier Transform Infrared Spectrometer to Kinetics
Authors: Lephardt J. O. , Vilcins G.
Published: October 2005

The properties of a rapid scanning Fourier transform infrared spectrometer (FT-IR) which permit its effective utilization in acquiring kinetics information are described. Experiments which would be lengthy and difficult to perform by conventional infrared procedures can be performed quickly and more reliably with an FT-IR system. The detection of all spectral frequencies simultaneously, inherent to the interferometer spectrometer, enables these advances to be achieved. The computer, which is essential for Fourier transformation, can also be utilized to provide absorbance profiles, differential profiles, and other display formats which can simplify the analysis and improve the reliability of kinetic measurements. Spectra and profiles obtained for a gas-solid adsorption process and a gas phase reaction of butadiene with an NO2-N2O4 mixture are presented to illustrate the potentials of an FT-IR system.
A Comparison of Two Discriminant Functions for Classifying Binary Infrared Data
Authors: Woodruff H. B. , Lowry S. R. , Isenhour T. L.
Published: October 2005

Some form of information compression is essential if one is to be able to utilize effectively the increasingly large data compilations. One approach is to eliminate the intensity information, leaving spectra packed in a peak/no peak format. This paper reports the comparison of two simple discriminant functions for classifying binary infrared data. For the multicategory problem of 13 classes used in this investigation, random guessing would achieve about 8% correct classification. A dot product calculation produces 49.1% correct classification, while a distance measurement produces 58.7%. The results from this investigation are also qualitatively compared to previous work using infrared data which retained some intensity information. It is found that the binary packing of spectral data shows great promise in the area of infrared analysis.
A Miniature, Low Energy Spark Discharge System for Emission Spectrochemical Analysis of Solutions
Authors: Zynger J. , Crouch S. R.
Published: October 2005

A miniature spark discharge system is described for solution analysis by emission spectroscopy. Samples are introduced as dry particles formed by nebulization into a heated desolvation chamber. The spark is formed by the discharge of a coaxial capacitor through a stream of argon which transports the desolvated aerosol. A photoelectric, time-resolved detection system for mechanistic studies and analytical applications is described. The detection system consists of a synchronous integrator controlled by a digital timing and sequencing system. The time-resolved spectral characteristics of the source are discussed, and time resolution is shown to provide enhanced sensitivity. Analytical results are reported for a variety of elements.
Spectrographic Analysis of Geological Materials with an Argon Plasma Jet
Authors: Golightly D. W. , Harris J. L.
Published: October 2005

An argon plasma jet source of recent design is applied to multiple element spectrographic analysis of geological materials. The source is characterized in terms of accuracy of analysis and repeatability of measurements obtained from spectra from a large region of the plasma. Results of analyses for Al, Ca, Fe, Mg, Si, and Ti in geochemical reference samples, for Ti in lunar basalts, gabbros, and soils, and for the SiO2/Al2O3 ratio in mordenite from geodes are presented. The effective temperature of the plasma region used for analytical measurements is 4670 ± 50°K. Use of control samples is recommended to improve accuracy of analysis.
Slitwidth Dependence of Depolarization Ratios
Authors: Fini Giancarlo , Mirone Paolo
Published: October 2005

The dependence of the depolarization ratio on the slitwidth has been investigated for some polarized Raman bands. It is found that the ratio of the peak intensities depends on the slitwidth, whereas the ratio of the integrated strengths does not. This behavior is explained in a general way by considering the different contributions of the isotropic and the anisotropic spectrum to the two terms of the depolarization ratio.
Growth, Fecundity, and Diets of Newly Established Silver Carp in the Middle Mississippi River
Authors: Williamson Christopher J. , Garvey James E.
Published: October 2005

The silver carp Hypophthalmichthys molitrix has spread throughout the Mississippi River drainage. During 2003, we determined its population status and potential impact in the middle Mississippi River (MMR), the conduit between the lower Mississippi River and the upper Mississippi, Missouri, and Illinois rivers. We quantified growth, age structure, fecundity, and diets of silver carp sampled with trammel nets and AC electrofishing in main‐channel areas. Mean length at age in the MMR exceeded that of populations in Asia by as much as 26%. Individuals were typically more than 1 year old and 230 mm total length, suggesting that small, young fish were absent. Individuals in this population matured earlier (age 2) than in the species' native range. Regardless of phytoplankton variation (using chlorophyll a as a surrogate) and zooplankton concentration at MMR sites, phytoplankton was consistently most abundant in diets. Silver carp are finding suitable resources within the MMR, allowing individuals to grow rapidly during early life, persist as adults, and successfully disperse upstream.
Swimming Performance of Juvenile Florida Pompano after Sublethal Exposure to Ethylene Glycol and Methanol: Synergistic Effects
Authors: Stead M. A. , Baltz D. M. , Chesney E. J. , Tarr M. A. , Kolok A. S. , Marx B. D.
Published: October 2005

Chemical additives for enhancing deepwater (>305‐m) petrochemical production, such as ethylene glycol and methanol, are used to prevent the formation of gas hydrates in deepwater wells and pipelines and pose threats to marine faunas. Juvenile Florida pompano Trachinotus carolinus were used in controlled experiments to test the effects of 3.0% (volume per volume) ethylene glycol, 1.07% methanol, and a combination of the two chemicals on the swimming performance of individuals. We quantified the sublethal effects of contaminants by comparing differences in pre‐ and postexposure critical swimming speeds (Ucrit) among treatment and control groups. In juvenile swimming performance tests, single exposure to ethylene glycol and to the combination of ethylene glycol and methanol significantly reduced mean Ucrit by 13.4% and 41.1%, respectively. No detectable difference in Ucrit was found for control groups or juveniles exposed solely to methanol. The sublethal effects of single exposures to ethylene glycol and methanol were increased synergistically more than threefold when juveniles were exposed to the contaminants in combination. The reduced ability to sustain high and prolonged performance levels could affect an individual's ability to avoid predators and feed effectively.