bluuebunny/crossref_metadata_2025 huggingface dataset:
Management of venous malformations in Klippel–Trenaunay syndrome with ultrasound-guided foam sclerotherapy
Authors: McDonagh B , Sorenson S , Cohen A , Eaton T , Huntley D E , La Baer S , Campbell K , Guptan R C
Published: June 2005

Objective: To study the clinical profile of Klippel–Trenaunay syndrome (KTS) and the management of venous malformations (VMs) with ultrasound-guided foam sclerotherapy using the compass technique.

Methods: In this open prospective series, 11 consecutive patients with KTS seeking therapy at a phlebology group practice were included. Seven (64%) of them were post-surgical recurrences.

Results: Pain was the commonest presenting complaint (100%), accompanied with VMs/ varicose veins in all except one (91%). Chronic venous insufficiency (CVI) was seen in seven (64%). Soft tissue and bone deformity was present in all (100%). Limb lengthening was frequent and detected in eight (73%), thickening in six (54%); unusually, one patient (9%) presented with severe thinning and shortening of the leg. Venous malformation was the primary vascular problem in nine patients (82%), with capillary malformation (CM)/port wine stain in seven (64%) and isolated lymphatic malformation (LM) in two (18%). The lateral embryonic/Klippel–Trenaunay (KT) vein was detected in 10 patients (91%). Deep vein deformity was not detected in any of them. All the deformities were of the lower limb (100%), while two (18%) had deformities of the thorax and one (9%) had gastrointestinal (GI) malformation. None of the patients gave family history of KTS, while five (45%) had history of varicosities in the family. Eight patients (73%) completed the therapeutic plan with a mean follow-up of 5±3.9 years. An excellent to good type result could be documented in six of the eight cases (75%). These patients had an event-free, good quality of life. Follow-up duplex studies revealed the evolving refluxing tracts requiring sequential therapies.

Conclusions: The results in this series demonstrate the utility of foam sclerotherapy using the compass technique in the management of KTS. Chronicity of the VMs in KTS necessitates strict clinical monitoring and sequential therapies.
Objective non-invasive technique for quantification of superficial varicose veins
Authors: de Zeeuw R , Noordmans H J , Verdaasdonk R M , Wittens C H A
Published: June 2005

Introduction: Non-invasive methods for imaging varicose veins allow quantification and evaluation of venous diseases. This paper will describe a technique to visualize superficial (subdermal) varicose veins using digital infrared imaging and analysis with special software.

Method: After image acquisition, the pictures were analysed with special software that segmented the varicose veins and calculated the surface area (per gridblock) occupied by varicose veins. By comparing the surfaces occupied by varices before and after a specific treatment, one can establish which treatment method performs the best.

Aim for the future: Validation of this technique and quantification of the effects of treatment modalities for superficial (subdermal) varicose veins.

We also investigate the use of this technique for the other clinical CEAP stages and the potential resemblance with duplex scanning.
The use of email in a child and adolescent mental health service: are staff ready?
Authors: Cartwright Matthew , Gibbon Peter , McDermott Brett M , Bor William
Published: June 2005

All staff members of a child and adolescent mental health service were invited to participate in a survey about the use of email. Sixty-two of the 105 staff members responded to the survey, a participation rate of 59%. Of the respondents, 32 were allied health staff, 10 were nurses, seven were administrative staff, six were medical staff, three were operational staff and four were acting in a combination of these roles. The respondents reported extensive work-related email usage and considered that they were confident in using email despite low levels of training. However, they did not feel that they understood the legal and ethical issues involved. Furthermore, there was limited incorporation of email into standard record keeping. The majority of respondents thought that increased use of email would lead to a greater workload, a consequence they considered would probably increase over time. Many commented on the quick and practical use of this medium, but were wary about using email with individuals outside the service organization, especially if it were to contain clinical material. There was low use of email directly with clients, and clinicians were ambivalent about incorporating email into therapy. The results suggest that it is timely to consider the utility and appropriateness of email communication with clients and external service providers, and to formulate guidelines and procedures to ensure the confidentiality of client information and the safety of clients and staff.
Emerging trends in ocular telemedicine: the diabetic retinopathy model
Authors: Cavallerano Jerry , Aiello Lloyd M
Published: June 2005

Diabetes mellitus is a leading cause of vision loss in industrialized countries. Diabetic retinopathy has features which make it ideal for disease management by telemedicine. The American Telemedicine Association (ATA) has recently established consensus recommendations for ocular telemedicine for diabetic retinopathy, in cooperation with the US National Institute of Standards and Technology. The guiding principle is that it would be inappropriate to use telemedicine to provide anything less than the accepted standard of clinical care. The ATA practice recommendations delineate performance standards for the clinical, technical and administrative elements of ocular telemedicine for diabetic retinopathy. Four clinical categories of assessment were identified. Category 4 validation, for example, indicates that a system matches or exceeds the ability of current photographs to identify lesions of diabetic retinopathy. To create the practice recommendations, workshops were held to address each of the three components: (1) clinical, (2) technical, and (3) operational and business. Ocular telemedicine programmes will need to demonstrate sustainability and cost-effectiveness, and respect a patient's right to privacy. Nevertheless, ocular telemedicine seems poised to become an integral part of eye health care, as long as programmes meet or exceed present clinical standards of care, and patient and provider expectations are clearly defined.
Use of telephone interviews to follow up patients after total hip replacement
Authors: Sharma Sanjeev , Shah Ravi , Draviraj Kingsley Paul , Bhamra M S
Published: June 2005

We studied the feasibility of telephone interviews to assess hip function in patients who had had a total hip replacement. One hundred patients attending the orthopaedic clinic for follow-up after undergoing total hip replacement were studied. A modified Harris hip score was used. Since range of motion and deformity cannot be assessed by telephone, only pain and function were assessed. The maximum possible score was 100. Patients attending follow-up clinics were contacted by telephone one to two weeks prior to their appointment and a telephone assessment was completed. This was then compared with a face-to-face assessment in the subsequent clinic. The mean hip score obtained with the telephone interview was 85.2 and the mean hip score at face-to-face assessment was 86.1. The mean of the differences between the individual scores was −0.9 (SD 5.5). This difference was not significant ( P=0.11). Only three patients had a clinically significant difference (>20 points) between the two methods. Telephone questionnaires may be a useful adjunct to face-to-face assessment for patient follow-up after total hip replacement.
A cost analysis of participation via personal attendance versus telemedicine at a head and neck oncology multidisciplinary team meeting
Authors: Stalfors Joacim , Björholt Ingela , Westin Thomas
Published: June 2005

Multidisciplinary team (MDT) meetings are used for establishing diagnosis, for tumour, node, metastasis (TNM) classification and for treatment in head and neck tumour patients in the western region of Sweden. Because of the distances, telemedicine was introduced to link the regional hospital to two of the three district general hospitals (DGHs). We evaluated the costs of presenting patients face to face (FTF) versus via telemedicine. Cost analyses were based on questionnaires completed by patients presented at the MDT meeting. A total of 39 patients were included in the FTF group and 45 patients in the telemedicine group. The cost analysis showed that FTF presentation cost SEK 2267 versus SEK 2036 by telemedicine (difference not significant). The small difference was explained by the fact that the responsible physician accompanied only six of 39 patients when presented FTF, but when presented via telemedicine the DGH physician always participated. A sensitivity analysis revealed that if the responsible physician always accompanied his/her patient for presentation FTF, the cost would be SEK 5366 per patient. This study shows that costs may be saved by carrying out MDT meetings by means of telemedicine instead of FTF.
Low-bandwidth telemedicine for pre- and postoperative evaluation in mobile surgical services
Authors: Rodas Edgar , Mora Francisco , Tamariz Francisco , Cone Stephen W , Merrell Ronald C
Published: June 2005

Low-bandwidth telemedicine was used for the pre- and postoperative evaluation of patients treated by a mobile surgery service in remote Ecuador. Realtime and store-and-forward telemedicine was employed, using PCs connected via the ordinary telephone network. Between February 2002 and July 2003, 144 patients were studied preoperatively and 50 postoperatively. It was possible to establish 20 satisfactory preoperative realtime connections, which allowed good-quality, simultaneous audiovisual transmission. Thus, there were 124 preoperative assessments done by store-and-forward telemedicine and 50 postoperative assessments. Diagnoses and management plans made by a surgeon using telemedicine were compared with those made independently by a second surgeon, who saw the patient face to face. Due to poor quality of the transmitted images, 43 patients were excluded from the preoperative study and 13 from the postoperative study. In the 101 preoperative evaluations, there was agreement in 78 cases (77%); in the 37 postoperative evaluations, there was agreement in 36 cases (97%). Telemedicine may reduce the time required on site for preoperative planning, and may provide reliable postoperative surveillance, thus improving the efficiency of mobile surgery services.
Telephonic transmission of 12-lead electrocardiograms during acute myocardial infarction
Authors: Mischke K , Zarse M , Perkuhn M , Knackstedt C , Markus K , Koos R , Schimpf T , Graf J , Hanrath P , Schauerte P
Published: June 2005

To test the feasibility of a small and simple system for telephonic transmission of 12-lead electrocardiograms (ECGs), 70 patients with acute coronary syndrome admitted to the cardiac care unit (CCU) were included in a feasibility study. The transmission system consisted of a belt with multiple electrodes, which was positioned around the chest. The ECG signal was sent to a call centre via a standard telephone line. In parallel, a standard 12-lead ECG was recorded on site. In a retrospective analysis, each lead of the transmitted ECG was compared with the on-site 12-lead ECG with regard to ST-segment changes and final diagnosis. In all 37 patients with acute ST-elevation myocardial infarction, the diagnosis was correctly established on the basis of telephone-transmitted ECGs. In 96% of limb and 88% of chest leads, ST elevations which were visible in standard ECGs were correctly displayed on telephonically transmitted ECGs. In the remaining 33 patients no false-positive diagnosis was made using transtelephonic ECG analysis. A control group of 31 patients without apparent heart disease showed high concordance between standard ECGs and telephonically transmitted ECGs. Telephonically transmitted 12-lead ECGs interpreted by a hospital-based internist/cardiologist might allow a rapid and accurate diagnosis of ST-elevation myocardial infarction and may increase diagnostic safety for the emergency staff during prehospital decision making and treatment of acute myocardial infarction.
An intelligent emergency response system: preliminary development and testing of automated fall detection
Authors: Lee Tracy , Mihailidis Alex
Published: June 2005

We have designed an intelligent emergency response system to detect falls in the home. It uses image-based sensors. A pilot study was conducted using 21 subjects to evaluate the efficacy and performance of the fall-detection component of the system. Trials were conducted in a mock-up bedroom setting, with a bed, a chair and other typical bedroom furnishings. A small digital videocamera was installed in the ceiling at a height of approximately 2.6 m. The digital camera covered an area of approximately 5.0 m × 3.8 m. The subjects were asked to assume a series of postures, namely walking/standing, sitting/lying down in an inactive zone, stooping, lying down in a 'stretched' position, and lying down in a 'tucked' position. These five scenarios were repeated three times by each subject in a random order. These test positions totalled 315 tasks with 126 fall-simulated tasks and 189 non-fall-simulated tasks. The system detected a fall on 77% of occasions and missed a fall on 23%. False alarms occurred on only 5% of occasions. The results encourage the potential use of a vision-based system to provide safety and security in the homes of the elderly.
Evaluating telemedicine systems and services
Authors: Taylor Paul
Published: June 2005

The evaluation of telemedicine involves attempts to answer a wide range of questions involved in making decisions about safety, about practicality and about utility. Roughly speaking, if we wish to provide a telemedicine service we should first establish that it is safe, next that it is practical and finally that it is worthwhile. In establishing safety, most laboratory studies of telemedicine have a common structure, and consist of the following steps: (1) selection of cases; (2) interpretation; (3) comparison with a gold standard; (4) statistical analyses. Most of the studies to establish the practicality of telemedicine have been carried out as demonstrations, to show that a proposed application can be implemented in a chosen setting. In terms of utility, telemedicine has been used to improve the efficiency of an existing service or to make an existing service available to a new community. One of the difficulties is that the vendors of relatively expensive telemedicine systems and services disseminate much of the information on the topic. We have to focus not on the glamorous technology but on the underlying issue of how the participants in health care (patients, general practitioners, specialists) can communicate more effectively, using the range of technological options open to them. Ensuring that the most appropriate technology is used in the most effective way should be the primary aim of telemedicine research. There is now sufficient evidence for us to be confident that telemedicine is a safe alternative to conventional care in a variety of situations and for a number of clinical conditions. Reliable evidence that it is a practical and cost-effective alternative is, at the time of writing, harder to find.
Evaluation of the benefits for the patient arising from an inter-hospital teleradiology network in a French administrative area
Authors: Daucourt Valentin , Petitjean Marie-Edith , Chateil Jean-François , Michel Philippe
Published: June 2005

We conducted a prospective study of the teleradiology network which connects 15 hospitals in the Aquitaine area. All transmissions sent over a one-year period were examined (data transmitted at the time of the remote consultation and health outcomes of patients from their medical records). For emergency cases, the main outcome measure of effectiveness was the proportion of avoided transfers. For non-emergency cases, the main outcome measure of effectiveness was the proportion of transfers, hospitalizations and consultations avoided. There were 737 transmissions, of which 664 (90%) met the inclusion criteria. Of these, 562 (85%) were for emergency care and 102 (15%) for non-emergency care. In emergency care, the pathologies most often associated with a remote consultation were cerebral pathologies (88%) and traumatic spinal pathologies (8%); the proportion of avoided transfers was 48%. In non-emergency care, the specialties most often concerned with remote consultations were neurology/neurosurgery (36%), cardiology and pulmonary diseases (17%) and gastroenterology (14%). Transfer was avoided for 37% of the patients and hospitalization for 12%. An additional consultation occurred after remote consultation for 2% of the patients. The results confirm the effectiveness of an inter-hospital teleradiology network.
A Novel Application of FT-IR Spectroscopy for the Kinetics of High-Temperature Reaction of SO2 with CaO
Authors: Gopalakrishnan R.
Published: June 2005

FT-IR spectroscopy has been used to investigate the kinetics of SO2/CaO reaction at high temperatures, 700 to 1000°C. The estimated kinetic parameters, namely the activation energy (34.7 kcal/mole) and the order with respect to SO2 partial pressure (∼0.60 ± 0.02) are in excellent agreement with the earlier reports where thermogravimetric and chemical analysis methods were used, thus supporting FT-IR spectroscopy as a viable tool for the kinetics of gas/solid reaction at high temperatures.
The Assessment of Laser Photoacoustic Spectroscopy as the Analytical Tool for Studying the Potato Sprout Suppressants Carvone and Pulegone
Authors: Bićanić Dane , Zuidberg Ben , Jalink Henk , Miklós András , Hartmans Klaasje , Van Es Andre
Published: June 2005

CO2 laser photoacoustic spectroscopy in combination with the resonant cell has been used to determine the absorption cross sections of the sprouting suppressants pulegone and carvone in order to evaluate the prospects of this technique for practical application during the storage of harvested potatoes. Maximal values found at room temperature are 0.06 atm−1 cm−1 and 0.04 atm−1 cm−1 for pulegone and carvone respectively, corresponding to detection limits of 200 and 150 ppbv. At CO laser wavelengths, a 1 ppb detection limit has been derived.
Quantification of Overlapping VIS-Absorption Bands by Fourier-Domain Fitting of a Generalized Band Shape Function
Authors: Jørgensen Bo M.
Published: June 2005

Parameter estimation of overlapping (near-)symmetrical absorption bands with reference to quantitative determination may advantageously be performed by a new procedure that involves fitting a generalized four-parameter band shape function to the Fourier-domain representation of the second-derivative spectrum. Important features of the method are: insensitivity to linear and weakly curved baselines, inherent noise reduction, fast calculation of objective function, and band simulation capability much better than that with the Gauss or Lorentz shapes.
Measurement of Stray Light in Atomic Absorption Spectrometry
Authors: Black Sador S. , Robarge Wayne P. , Boss Charles B.
Published: June 2005

An equation which accounts for the phenomenon of stray light has been derived from Beer's law. The equation has three adjustable parameters: the fraction of stray light and the absorption coefficients of both the primary and stray light. The parameters derived from fits of the equation to flame atomic absorption data are quantitative indicators of the amount of stray light in an atomic absorption experiment. In addition, the proposed equation could be used for calibration of experimental determinations.
A Fiber-Optic FT-NIR Evanescent Field Absorbance Sensor
Authors: Degrandpre Michael D. , Burgess Lloyd W.
Published: June 2005

A polymer-clad fiber optic is used as an evanescent field absorbance sensor for solvents that penetrate into the polymer cladding. The sensor is coupled to an FT-NIR spectrometer for spectral measurements from 1.0 to 2.2 μm. A 400- μm core fiber optic, 1.5 m in length, was coiled with a 1.5-cm radius on a Teflon® support. The coiled sensor was then immersed in various nonpolar organic liquids which partitioned into the hydrophobic polysiloxane cladding. The evanescent-field near-infrared spectra of pure hexane, chloroform, and carbon tetrachloride are shown along with ethanol in chloroform. Various amounts of chloroform in carbon tetrachloride and toluene in cyclohexane were used to test the quantitative response. This sensor data are compared with data from a conventional NIR spectrometer using principal component regression.
Fiber Structure Study by Polarized Infrared Attenuated Total Reflection Spectroscopy
Authors: Samanta S. R. , Lanier W. W. , Miller R. W. , Gibson M. E.
Published: June 2005

Attenuated total reflection (ATR) spectroscopy has been shown to eliminate many of the difficulties encountered in the past with the sample presentation for infrared analysis. Yarn orientation behavior at different draw ratios was studied by analysis of polarized infrared spectra. The data demonstrate that the α conformation increases with drawing for nylon 6,6 fibers. The chain conformation and crystallite orientation which occur during drawing of nylon 6,6 fibers are also demonstrated. The structural changes observed by the present technique seem to agree well with x-ray diffraction data.
Polycyclic Aromatic Hydrocarbon Solute Probes. Part VI: Effect of Dissolved Oxygen and Halogenated Solvents on the Emission Spectra of Select Probe Molecules
Authors: Tucker Sheryl A. , Cretella Lisa E. , Waris Riaz , Street Kenneth W. , Acree William E. , Fetzer John C.
Published: June 2005

Fluorescence emission properties of pyrene, benzo[ ghi]perylene, coronene, and ovalene dissolved in carbon tetrachloride, chloroform, and dichloromethane are reported. Measurements indicate that the emission intensities of select solutes are time dependent, and suggest that the polycyclic aromatic hydrocarbon molecule undergoes a photochemical reaction with the chlorinated solvent. The effect of dissolved oxygen on the experimental ratio of emission intensities is also reported.
Characterization of Synthetic Organic Superconductors by Use of Vibrational Spectroscopy
Authors: Ferraro John R. , Williams Jack M.
Published: June 2005

The use of vibrational spectroscopy in characterizing synthetic organic superconductors is reviewed. The electron-donor molecules tetramethyltetraselena-fulvalene (TMTSF) and bis(ethylenedithio)tetrathia-fulvalene (BEDT-TTF or ET), which provide superconducting salts when combined with anions, are highlighted. Special emphasis is given to the microreflectance technique and its usefulness in the study of these materials.
On the Mean-Square Error of Various Spectrum-Recovery Techniques in Hadamard Transform Spectrometry
Authors: Park J. B. , Johnson T. W. , Dyer S. A. , Harms B. K. , Dyer R. A.
Published: June 2005

The multiplexing inherent in the Hadamard transform (HT) spectrometer can result in an improved spectrum-estimate when the detector is the major source of noise. A spectrum-estimate may be further improved by taking into account any nonidealities in the system. In this paper, observations concerning the errors associated with such estimates are presented, with the use of results obtained from computer simulations. Three spectrum-recovery techniques for an HT spectrometer having a nonideal electro-optic mask are considered in terms of the mean-square error (MSE) associated with a given estimate. The discussion of the MSE is with respect to the input spectrum to be estimated, the detector noise, the transmittances of the nonideal mask, and the use of coaddition. Included is a review of the computational efficiency and the statistical bias of each method. The relative performances of the spectrum-recovery methods are presented with examples to help identify the sources of error for each of the techniques.
Reinvestigation of Molten Fluoroaluminate Raman Spectra: The Question of the Existence of AlF52− Ions
Authors: Gilbert B. , Materne T.
Published: June 2005

The structure of molten NaF-AlF3 mixtures has been reinvestigated by Raman spectroscopy, with the use of a captive liquid windowless cell. The previously observed intensity variation of the 555-cm−1 and 622-cm−1 bands with the melt composition has been confirmed. However, by recording spectra of NaF-Na3AlF6 molten mixtures, one can clearly observe a new band located at 515 cm−1. This band increases in intensity with the melt basicity and is not due to an oxide contamination. The most probable explanation is to consider, in addition to the usual AlF63- and AlF4− ions, the existence of a new species, AlF52-. Consequently, the previous assignment of the main Raman bands has been changed as follows: v1 AlF63- = 515 cm−1, v1 AlF52- = 555 cm−1, v1 AlF4− = 622 cm−1. This new assignment has been checked by comparison of spectra of similar mixtures with different cations (Li, K). A quantitative analysis of the various components, as a function of the NaF-AlF3 melts molar ratio, has been performed by deconvoluting the Raman-bands envelope. The calculated equilibrium constants (expressed in mole fraction units) for AlF63- ⇌ AlF52- + F− and A1F52- ⇌ A1F4− + F− are KB = 0.29 ± 0.05 and KA = (1.65 ± 0.1).10−2 respectively. Considering the experimental errors, the value of α F−, the activity in free fluorides [estimated with these constants for molten cryolite ( α F− = 0.41 ± 0.02)], is in good agreement with values found from electrochemical measurements ( α F− = 0.375 ± 0.015) or from vapor pressure measurements ( α F− = 0.38 ± 0.04). Finally, on the basis of this new ionic model for MF-AlF3 mixtures, an explanation for the variation of alumina solubility in M3AlF6 melts is proposed.
Monitoring of Polyphenyl Ether Lubricants Using Fluorescence Spectroscopy
Authors: Keller Michael A. , Saba Costandy S.
Published: June 2005

Fluorescence spectroscopy has been investigated to determine its suitability for condition monitoring of oxidized polyphenyl ether lubricants. Oxidative degradation of the lubricant was shown to induce specific changes in its fluorescence properties. Excitation/emission wavelengths with monitoring potential were identified and were found to yield a useful correlation between emission intensity and viscosity increases of the degraded lubricant for two different formulations. Application of this technique on neat thin films of the degraded fluids yields similar correlations.
Infrared Spectra of Monolayers Adsorbed on Mica
Authors: Guzonas D. A. , Hair M. L. , Tripp C. P.
Published: June 2005

The infrared spectrum of an adsorbed monolayer of octadecyltrichlorosilane (OTS) on mica has been recorded in the transmission mode. The problem of interference fringes has been reduced by cleaving mica to thicknesses of ∼1 μm so that the period of the fringes is much greater than the bandwidth of the bands due to adsorbed molecules. In addition, mica of this thickness has the added advantage of being transparent below 1200 cm−1, which allows observation of bands arising from adsorbed species in this spectral region. An improvement in signal-to-noise ratio can be obtained by placing the thin mica sheets in series. We have also demonstrated that Attenuated Total Reflection (ATR) can be used to measure spectra of material deposited on the exposed surface of a thin mica sheet in contact with the ATR crystal.
Effect of Scattering Coefficient on Diffuse Reflectance Infrared Spectra
Authors: Fraser David J. J. , Griffiths Peter R.
Published: June 2005

The application of Kubelka-Munk theory for thin samples for which the Kubelka-Munk function would not be expected to yield a quantitative relationship between reflectance and analyte concentration is examined. For thin samples, the effective penetration depth of radiation is dependent on both the absorption and the scattering coefficients. Different penetration depths result in inaccurate relative reflectance values being measured, with the magnitude of the error being dependent on the absorption coefficient of the sample and the scattering coefficient and thickness of the reference. For diffusely reflecting samples, previous experimental results are explained on the basis of the magnitude of the scattering coefficient for the surrounding matrix. The scattering coefficient of ground potassium chloride was determined experimentally to be approximately 50 cm−1. It is shown that “infinite depth” for nonabsorbing diffusely reflecting materials would not be achieved with thicknesses less than 1 mm, necessitating the use of the full Kubelka-Munk equations to explain band intensities of thin samples.
An Efficient and Inexpensive Ultrasonic Nebulizer for Atomic Spectrometry
Authors: Jin Qinhan , Zhu Chu , Brushwyler Kevin , Hieftje Gary M.
Published: June 2005

A new and inexpensive batch-type ultrasonic nebulizer which is based on a common room humidifier has been developed. The aerosol generation rate is shown to be much higher than that of pneumatic nebulizers and hence the detection capabilities of ICP and microwave plasma-AES are significantly enhanced when they are combined with this new nebulization system. Under optimal conditions the stability and precision of the system are comparable with those of commercial ultrasonic nebulizers.
Studies of Carbonyl-Containing Compounds in Mixed Solvent Systems by Application of Infrared Spectroscopy
Authors: Nyquist R. A. , Chrzan V. , Kirchner T. , Yurga L. , Putzig C. L.
Published: June 2005

The carbonyl stretching vibrations decrease in frequency in the order of solvent polarity (acetonitrile and nitromethane are exceptions) and in the increasing mole concentration of the more polar solvent of a solvent pair. Intermolecular hydrogen bonding between the chloroform proton and the carbonyl oxygen atom of the solute shifts vC=O to lower frequency. Polar solvents such as dimethyl sulfoxide cause vC=O to shift to lower frequency by interacting with the solute in a manner which induces a canonical form which lengthens and weakens the C=O bond. Steric factors of α-halo or oxy groups of carboxylic acids or ketones prevent close solute/solvent interaction in the gauche rotational isomer compared to the cis rotational isomer; thus, gauche vC=O has a lesser contribution from the induced canonical form due to solute/solvent interaction, and gauche vC=O shifts less to lower frequency than does cis vC=O. The rotational isomer concentration distribution also changes with change in solvent polarity. Thus, physical factors of the solute play a role in solvent-induced chemical shifts of IR group frequencies.
A Spectroscopic Study of Gaseous Products of Soot-Oxides of Nitrogen/Water Reactions
Authors: Chughtai A. R. , Welch W. F. , Akhter M. S. , Smith D. M.
Published: June 2005

The simultaneous evolution of CO, CO2, N2O, and NO, detected and estimated by both infrared spectroscopy and chemiluminescence during the reaction of soot and NO2/N2O4 over a range of temperatures, suggests that, in addition to the previously described chemisorption reaction, there also is a redox process occurring in the initial stages of the reaction. Estimations of these gases suggest that the redox reaction also includes reactive components other than the olefinic segment of soot, and occurs under all conditions examined. Infrared studies show that gaseous NO, produced immediately on the introduction of NO2/N2O4 into a reactor containing soot and water vapor, subsequently decreases with the accompanying formation of N2O.
A Novel Approach in the Structure Determination of an Impurity in the Presence of a Pharmaceutical Compound
Authors: Cholli Ashok L. , Rafalko P. White , Ezell E. F. , Kosarych Z. , Ellgren A. J.
Published: June 2005

There are several techniques and methods used to quantify the presence of low-level impurities in pharmaceutical compounds. At present it is a difficult task to determine their molecular structure unless the impurity is isolated from the pharmaceutical compound. A procedure, based on crystallization and nuclear magnetic resonance (NMR) analysis, is described for determining the molecular structure and concentration of an impurity in the presence of pharmaceutical compound, even though that impurity has not been isolated. Slow crystallization is done in order to enrich the impurity concentration to usable levels in either the solution or in some extracted powder or crystallites. High-resolution one- and two-dimensional NMR analysis of the original and enriched materials may then allow determination of the impurity's structure and its concentration in the original sample. A specific example illustrating the technique is described.
Continuous Hydride Generation for Simultaneous Multielement Detection with Inductively Coupled Plasma Mass Spectrometry
Authors: Heitkemper Douglas T. , Caruso Joseph A.
Published: June 2005

A continuous hydride generation system is described for sample introduction to an inductively coupled plasma mass spectrometer. The system allows for the simultaneous determination of hydride-forming elements with elements which do not form volatile hydrides. Detection limits for volatile hydrides show an improvement of one order of magnitude over results for conventional sample introduction employing pneumatic nebulization. Calibration plots for volatile-hydride-forming elements are linear over 2 to 3.5 orders of magnitude, and relative standard deviations are generally less than 5% over a 30-minute period. The accuracy of the technique is demonstrated by the analyses of two commercial reference materials.
Determination of Enantiomeric Excess in Deuterated Chiral Hydrocarbons by Vibrational Circular Dichroism Spectroscopy
Authors: Spencer Kevin M. , Cianciosi Steven J. , Baldwin John E. , Freedman Teresa B. , Nafie Laurence A.
Published: June 2005

An improved procedure using vibrational circular dichroism spectroscopy for high-precision determinations of enantiomeric excess (ee) in chiral samples is described. Chiral trans-dideuteriocyclopropane is employed in the gas phase for percent ee measurements. This molecule is a member of the class of simple hydrocarbons made chiral by virtue of isotopic substitution for which no convenient and accurate alternative method of percent ee measurement is available. Percent ee determinations to within 1% are demonstrated for several ee values with and without contamination by the achiral cis-dideuteriocyclopropane species.
The Direct Measurement of Magnetically Induced Optical Rotation in Atomic Vapors
Authors: Monnig Curtis A. , Madison Richard T. , Hieftje Gary M.
Published: June 2005

A new instrument has been developed for directly monitoring magnetically induced optical rotation in atomic vapors. The polarization rotation induced by the atomic vapor is measured by manually rotating one of the polarizers until a minimum in transmitted intensity is recorded. The angle of this rotation is then linear with analyte concentration. Detection limits for Ag, Ca, Cu, and Li are comparable to those reported for atomic absorption spectrometry under similar analysis conditions. The new measurement approach enjoys relative immunity from background spectral interferences caused by molecular absorption and scattering.
Measurement of the Circular Polarization of the Luminescence of Photoselected Samples under Artifact-Free Conditions
Authors: Blok P. M. L. , Dekkers H. P. J. M.
Published: June 2005

The measurement of the Circular Polarization of the Luminescence (CPL) in viscous solvents is hampered by the occurrence of artifacts. These arise when the emitted radiation is partially linearly polarized due to the photoselection effect. It is shown that there are two configurations of the CPL spectrometer in which such linear polarization artifacts are virtually negligible: one requires perpendicular excitation and emission channels as well as horizontally polarized incident radiation; the other involves a 180° geometry and unpolarized excitation light. In both options, essentially artifact-free CPL data are obtained, enabling the study of the directional dependence of the optical activity in emission. This is illustrated for the case of the 3ππ* → S0 phosphorescence of the cross-conjugated dienone α-santonin.
Application of a Dual-Mode Detection System for ICP-MS. Part I: Determination of Majors, Minors, and Traces in Geostandards
Authors: Hutton Robert C. , Eaton Andrew N. , Gosland Raymond M.
Published: June 2005

The high-gain pulse-counting detection systems currently used in ICP-MS, although exhibiting excellent characteristics for trace analysis, have only a finite gain. At count rates of the order of 106 cps, gain suppression occurs, thus effectively limiting the upper measurable concentration ranges to a few μg mL−1. It is possible to utilize such detections in an analogue mode, whereby the output signal is a direct function of the applied voltage. In this paper, the applicability of a detection system employing both analogue and pulse-counting detection is evaluated, with particular emphasis on the determination of majors, minors, and traces in geological reference materials. In addition, two sample preparation modes are compared; in the first, a conventional lithium metaborate fusion is utilized, while alternatively, a rapid slurry technique is found to be particularly effective for some more volatile elements.
An Investigation of the Signal Obtained from a Flame Infrared Emission (FIRE) Detector
Authors: Lam Christopher K. Y. , Tilotta David C. , Busch Kenneth W. , Busch Marianna A.
Published: June 2005

The effect of temperature on the atmospheric asymmetric stretching vibration of carbon dioxide is studied by flame/furnace infrared emission (FIRE) spectroscopy, and a mathematical expression is developed for the resulting infrared emission signal produced by the FIRE detector. This theoretical model, which can easily be extended to other species besides carbon dioxide, is used to calculate the signal obtained for propane when the FIRE system is used as a detector for gas chromatography. Comparison of the calculated (70 μV) and experimentally observed (75.8 μV) chromatographic signal shows that the theoretical model should be of great value in improving and optimizing the FIRE detector.
Multichannel Hadamard Transform Raman Microscopy
Authors: Treado Patrick J. , Morris Michael D.
Published: June 2005

Spatial multiplexing is combined with multichannel detection in a Hadamard transform Raman microscope which provides 127 × 128 pixel images with 12 cm−1 spectral resolution. Spatial resolution of 0.6 μm per pixel has been achieved. A spatial multiplex advantage of better that 104 is demonstrated. Instrumental design details and spectroscopic images are presented.
Raman Spectroscopy of Potassium Titanates: Their Synthesis, Hydrolytic Reactions, and Thermal Stability
Authors: Bamberger Carlos E. , Begun George M. , MacDougall C. Sue
Published: June 2005

The majority of the potassium titanates described in the literature were synthesized, and their Raman spectra recorded. The identity of the compounds K2TiO3, K2Ti2O5, K2Ti4O9, K2Ti6O13, and K2Ti8O17 was confirmed by x-ray diffraction. Raman spectroscopy was then used to study the hydrolysis, under different conditions, of K2Ti2O5 and of K2Ti4O9. On drying of the hydrolysis products, the following species were found to form: K2(H2O)0.66 Ti8O16(OH)2, K1.33(H2O)0.33Ti4O8.33(OH)0.67, and H2Ti8O17. On ignition at temperatures of 500–600°C these species converted, respectively, to K2Ti8O17, K2Ti6O13, and TiO2(B). Raman spectroscopy was used to establish that (1) K6Ti4O11 consists of a mixture of K2TiO3 and a new compound K4Ti3O8; (2) K2Ti3O7 consists of a mixture of K2Ti2O5 and K2Ti4O9, and (3) K2Ti5O11 consists of a mixture of K2Ti4O9 and K2Ti6O13. The temperature of decomposition and the identity of the products of the thermal decomposition of K2Ti8Ol7, K2Ti4O9, K2Ti2O5, and K4Ti3O8 were determined by Raman spectroscopy. The XRD data of the newly identified compounds are reported.
In situ Raman Spectroscopy Study of the Nickel Oxyhydroxide Electrode (NOE) System
Authors: Johnston C. , Graves P. R.
Published: June 2005

An in situ analysis using laser Raman microprobe spectroscopy was undertaken for an operating nickel oxyhydroxide electrode (NOE), which showed that the NOE was fully oxidized to γ-NiOOH, at positive polarizations, under the experimental conditions employed. A limited spectral library was constructed by preparing model compounds of the different phases of the hydroxides and oxyhydroxides of nickel and characterizing them with the use of laser Raman microprobe spectroscopy. A factor group analysis for the fundamental building block of all the polymorphs, β-Ni(OH)2, was also performed, and mode assignments were made for the infrared and Raman spectra.
Fourier Transform Infrared Photopyroelectric Spectroscopy of Solids: A New Technique
Authors: Mandelis A. , Boroumand F. , Solka H. , Highfield J. , Van Den Bergh H.
Published: June 2005

A novel analytical technique, Fourier transform infrared photopyroelectric spectroscopy (FT-IR-P2ES) is demonstrated and applied to spectroscopic investigations of solid materials. The salient features of the technique and its advantages over other conventional FT-IR photothermal methods are discussed. A few selected quantitative applications are presented as examples of the versatility and sensitivity of the new technique.
Structure and Dynamics of a Magnetron DC Arc Plasma
Authors: Slinkman David , Sacks Richard
Published: June 2005

A direct-current arc plasma generator is described which uses a concentric electrode configuration and a magnetic field parallel to the electrode axis to obtain rotation of the arc current channel at a frequency in the 1–3 kHz range. The anode is a hollow graphite cylinder, and the cathode is a thoriated tungsten wire. A magnetic field of several hundred gauss is obtained from one or more ring-shaped permanent ceramic magnets. For a 5-mm anode diameter, the plasma is diffuse, and the current channel has the form of a thin radial sheet which undergoes relatively small periodic perturbations at the rotational frequency. Design features, performance data, and plasma structure are considered.
The Vibrational Spectrum of 2,3-Pyrazinedicarboxamide
Authors: Delgado M. J. Martín , Márquez F. , Suero M. I. , Marcos J. I.
Published: June 2005

2,3-Pyrazinedicarboxamide and its 2H and 15N isotopic derivatives were synthesized with an isotopic content of 99.4%. The molecular geometry has been optimized by the MONSTERGAUSS ab initio method. Infrared and Raman spectra were recorded and assigned on the basis of isotopic shifts. The proposed assignments are fully in accordance with the Cs symmetry that was predicted by means of the theoretical calculations.
Simultaneous Determination of Br− and I− with a Multiple Fiber-Optic Fluorescence Sensor
Authors: Zhu Chu , Bright Frank V. , Hieftje Gary M.
Published: June 2005

A dual fiber-optic sensor for the simultaneous determination of bromide and iodide is successfully demonstrated. The device is based upon the dependence of quenching effects on individual fluorophores (quinine and harmane) and quenchers (bromide and iodide). From the point of view of practical application, n unknown analyte species should be able to be determined with a sensor array which contains n sensor elements on which n fluorophores are immobilized. The relative error of the new sensors for the determination of bromide and iodide is less than 5%. The sensor combination is reversible and exhibits an overall response time of 2 minutes. The interference of several ions on the sensors has been studied.
Two-Photon-Induced Chemical Reactions in Liquids
Authors: Chen C. H. , McCann M. P.
Published: June 2005

The two-photon absorption process was used to obtain the first observation of particle precipitation in liquids between halogen-containing organic compounds and silver-containing inorganic compounds. Photo-detachment of an electron from negative ions was found to be one important mechanism that led to these chemical reactions. Similar processes may lead to many new multiphoton-induced chemical reactions between organic and inorganic compounds.
Measurement of Vibrational Circular Dichroism Using a Polarizing Michelson Interferometer
Authors: Ragunathan N. , Lee N. S. , Freedman T. B. , Nafie L. A. , Tripp C. , Buijs H.
Published: June 2005

Fourier transform infrared (FT-IR) vibrational circular dichroism (VCD) has been observed for the first time with the use of a polarizing Michelson interferometer (PMI). VCD spectra have been recorded for (–)- α-pinene between 900 and 1350 cm−1 at 4 cm−1 resolution with excellent signal-to-noise ratio. The FT-VCD spectra are virtually the same as those recorded for (–)- α-pinene under the same conditions with the use of the more conventional double modulation FT-IR approach.
Determination of Gallium in Pure Aluminum by Isotope Dilution Analysis with Solvent Extraction Using Inductively Coupled Plasma Mass Spectrometry
Authors: Makishima Akio , Inamoto Isamu , Chiba Koichi
Published: June 2005

Isotope dilution analysis with inductively coupled plasma mass spectrometry (ICP-MS) was applied to the determination of gallium in pure aluminum. Furthermore, a solvent extraction procedure was combined with isotope dilution analysis as a preconcentration technique in order to determine ultra-trace levels of gallium with high precision. The accuracy and the precision of isotope dilution analysis using ICP-MS were compared with those of conventional standard addition analysis using ICP-MS. Isotope dilution analysis gave more accurate and precise results than did standard addition analysis. Isotope dilution analysis with solvent extraction made it possible to measure 0.029 µg/g gallium in 99.999% aluminum with analytical errors at less than 3%.
Phase-Resolved Fiber-Optics Fluoroimmunosensor
Authors: Vo-Dinh T. , Nolan T. , Cheng Y. F. , Sepaniak M. J. , Alarie J. P.
Published: June 2005

This paper describes the development and application of a phase-resolved fiber-optics fluoroimmunosensor (PR-FIS), which combines the biochemical specificity of antigen-antibody reaction, the high sensitivity of laser excitation, the versatility of fiber-optics sensors, and the selectivity of phase-resolved detection. The PR-FIS device can differentiate benzo(a)pyrene and benzo(a)pyrene tetrol, a DNA-adduct product of the carcinogen benzo(a)pyrene. Benzo(a)pyrene tetrol can be detected at femtomole levels in the presence of an amount of interfacing benzo(a)pyrene that is 50-fold more concentrated.
Time-Resolved Fluorescence Microscopy Using Multichannel Photon Counting
Authors: Wang Xue Feng , Kitajima Shigeki , Uchida Teruo , Coleman David M. , Minami Shigeo
Published: June 2005

A new measurement system is reported which combines fluorescence microscopy with multichannel photon-counting detection. The prototype instrument can be operated in normal fluorescence and in fluorescence lifetime modes. Multichannel photon detection was used in order to enhance the rate of data collection. The feasibility of rapid two-dimensional mapping of samples was indicated. The technique may prove especially valuable in situations where multicomponent samples display similar spectral features but differing lifetime characteristics. By increases in the measurement dimensionality, enhanced sample evaluation is possible. Applications involving model and practical biological systems are discussed.
Surface-Enhanced Raman Scattering Fiber-Optic Sensor
Authors: Bello J. M. , Vo-Dinh T.
Published: June 2005

A fiber-optic system was developed for exciting and collecting surface-enhanced Raman scattering (SERS) signals generated from a sensing plate tip having silver-coated microparticles deposited on a glass support. Various fiber parameters, such as fiber type, fiber-substrate geometry, and other experimental parameters, were investigated to obtain the optimum conditions for the SERS fiber-optic device. In addition, analytical figures of merit relevant to the performance of the SERS fiber-optic sensor, such as SERS spectral characteristics, reproducibility, linear dynamic range, and limit of detection, were also investigated.