bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors that influenced county system leaders to implement an evidence-based program: a baseline survey within a randomized controlled trial
Authors: Wang Wei , Saldana Lisa , Brown C Hendricks , Chamberlain Patricia
Published: October 2010

Background

Despite the burgeoning number of well-validated interventions that have been shown in randomized trials to produce superior outcomes compared to usual services, it is estimated that only 10% of public systems deliver evidence-based mental health services. In California, for example, more than 15,000 children are placed in group homes or residential centers with some evidence of iatrogenic effects. The present study evaluates the willingness among county leaders of child public service systems to adopt a new evidence-based model, Multidimensional Treatment Foster Care, (MTFC), as a way to decrease the prevalence of out-of-home placements. Specifically, the study examines how county-level socio-demographic factors and child public service system leaders' perceptions of their county's organizational climate influence their decision of whether or not to consider adopting MTFC.

Methods

Two levels were examined in this study: Stable and historical factors from 40 California counties gathered from public records including population size, number of entries into out-of-home care, financing of mental health services, and percent minority population; and system leaders' perceptions of their county's organizational climate and readiness for change measured via a web-based survey. The number of days-to-consent was the primary outcome variable defined as the duration of time between being notified of the opportunity to implement MTFC and the actual signing of a consent form indicating interest in considering implementation. Survival analysis methods were used to assess the predictors of this time-to-event measure. The present study is part of a larger randomized trial comparing two methods of implementation where counties are randomized to one of three time cohorts and two implementation conditions.

Results

The number of entries into care was the primary predictor of days-to-consent. This variable was significantly correlated to county size. System leader's perceptions of positive climate and organizational readiness for change also contributed to but did not mediate or moderate the days-to-consent.

Conclusions

System leaders' decision to consider implementing a new evidence-based model was influenced most by their objective need for the program and next by their perception of the county's organizational climate and motivation to change. These findings highlight the importance of understanding the fit between the needs of the systems or agencies and the potential for addressing those needs with the proposed new program.
Edelfosine-induced metabolic changes in cancer cells that precede the overproduction of reactive oxygen species and apoptosis
Authors: Selivanov Vitaly A , Vizán Pedro , Mollinedo Faustino , Fan Teresa WM , Lee Paul WN , Cascante Marta
Published: October 2010

Background

Metabolic flux profiling based on the analysis of distribution of stable isotope tracer in metabolites is an important method widely used in cancer research to understand the regulation of cell metabolism and elaborate new therapeutic strategies. Recently, we developed software Isodyn, which extends the methodology of kinetic modeling to the analysis of isotopic isomer distribution for the evaluation of cellular metabolic flux profile under relevant conditions. This tool can be applied to reveal the metabolic effect of proapoptotic drug edelfosine in leukemia Jurkat cell line, uncovering the mechanisms of induction of apoptosis in cancer cells.

Results

The study of 13C distribution of Jukat cells exposed to low edelfosine concentration, which induces apoptosis in ≤5% of cells, revealed metabolic changes previous to the development of apoptotic program. Specifically, it was found that low dose of edelfosine stimulates the TCA cycle. These metabolic perturbations were coupled with an increase of nucleic acid synthesis de novo, which indicates acceleration of biosynthetic and reparative processes. The further increase of the TCA cycle fluxes, when higher doses of drug applied, eventually enhance reactive oxygen species (ROS) production and trigger apoptotic program.

Conclusion

The application of Isodyn to the analysis of mechanism of edelfosine-induced apoptosis revealed primary drug-induced metabolic changes, which are important for the subsequent initiation of apoptotic program. Initiation of such metabolic changes could be exploited in anticancer therapy.
Integrin α2-deficient mice provide insights into specific functions of collagen receptors in the kidney
Authors: Girgert Rainer , Martin Maria , Kruegel Jenny , Miosge Nicolai , Temme Johanna , Eckes Beate , Müller Gerhard-Anton , Gross Oliver
Published: October 2010

Background

Integrins are important cellular receptors for collagens. Within the glomerulus, podocytes regulate the integrity of the glomerular basement membrane (GBM) by sensing the presence of collagen and regulating collagen IV synthesis. The present study evaluates the role of integrin α2 (ITGA2) in cell-matrix interaction.

Methods and Results

ITGA2-deficient mice had normal renal function but moderate proteinuria and enhanced glomerular and tubulointerstitial matrix deposition. Electron microscopy demonstrated irregular podocyte-matrix interaction, causing pathological protrusions towards the urinary (podocyte) side of the GBM. These characteristic subepithelial bulges mimic the renal phenotype of mice, which are deficient in another collagen receptor, discoidin domain receptor (DDR)1. Using immunogold staining, ITGA2 expression was found to localize to the basolateral site of the podocyte foot processes. ITGA2-deficient mice overexpressed transforming growth factor (TGF)β and connective tissue growth factor (CTGF) compared with wild-type mice. Using in situ hybridization, tubular cells were found to be the primary site of TGFβ synthesis and podocytes the source of CTGF in ITGA2-deficient mice.

Conclusion

These findings support our hypothesis that both these collagen receptors (ITGA2 and DDR1) play a similar role within the kidney. Further, cell-matrix interaction via collagen receptors seems to be crucial for maintenance of normal GBM architecture and function. Targeting collagen receptors such as ITGA2 might be a new form of treatment for progressive fibrotic diseases.
Trend of Entamoeba histolytica infestation in Kolkata
Authors: Mukherjee Avik K , Das Kaushik , Bhattacharya Mihir K , Nozaki Tomoyoshi , Ganguly Sandipan
Published: October 2010

Background

Entamoeba histolytica infection is found almost all over the world and is highly endemic and a major cause of parasitic diarrhoea particularly in the developing countries.

Methods

A systemic surveillance was set up at the Infectious Disease hospital, Kolkata, India between November 2007 and October 2009 for understanding the trend of E. histolytica infection in Kolkata. Fecal samples were collected from diarrhoeal patients attending the hospital, under the surveillance system and processed for detection of E. histolytica.

Results

During the last two years about 2500 diarrhoeal samples were collected and screened for E. histolytica. About 3.6% were positive for E. histolytica. As compared to the earlier years, E. histolytica infection was observed to be less amongst patients screened during the last two years. No seasonality was observed in Kolkata although in the neighboring tropical country Bangladesh, a typical seasonality of E. histolytica infection was noticed.

Conclusion

The study indicates that the detection rate of E. histolytica infection amongst diarrhoeal patients in Kolkata is decreasing during the last two years than that of Bangladesh.
Factors associated with access to HIV care and treatment in a prevention of mother to child transmission programme in urban Zimbabwe
Authors: Muchedzi Auxilia , Chandisarewa Winfreda , Keatinge Jo , Stranix‐Chibanda Lynda , Woelk Godfrey , Mbizvo Elizabeth , Shetty Avinash K
Published: October 2010

Background

This cross‐sectional study assessed factors affecting access to antiretroviral therapy (ART) among HIV‐positive women from the prevention of mother to child transmission HIV programme in Chitungwiza, Zimbabwe.

Methods

Data were collected between June and August 2008. HIV‐positive women attending antenatal clinics who had been referred to the national ART programme from January 2006 until December 2007 were surveyed. The questionnaire collected socio‐demographic data, treatment‐seeking behaviours, and positive or negative factors that affect access to HIV care and treatment.

Results

Of the 147 HIV‐positive women interviewed, 95 (65%) had registered with the ART programme. However, documentation of the referral was noted in only 23 (16%) of cases. Of the 95 registered women, 35 (37%) were receiving ART; 17 (18%) had not undergone CD4 testing. Multivariate analysis revealed that participants who understood the referral process were three times more likely to access HIV care and treatment (OR = 3.21, 95% CI 1.89‐11.65) and participants enrolled in an HIV support group were twice as likely to access care and treatment (OR = 2.34, 95% CI 1.13‐4.88). Those living with a male partner were 60% less likely to access care and treatment (OR = 0.40, 95% CI 0.16‐0.99). Participants who accessed HIV care and treatment faced several challenges, including long waiting times (46%), unreliable access to laboratory testing (35%) and high transport costs (12%). Of the 147 clients surveyed, 52 (35%) women did not access HIV care and treatment. Barriers included perceived long queues (50%), competing life priorities, such as seeking food or shelter (33%) and inadequate referral information (15%).

Conclusions

Despite many challenges, the majority of participants accessed HIV care. Development of referral tools and decentralization of CD4 testing to clinics will improve access to ART. Psychosocial support can be a successful entry point to encourage client referral to care and treatment programmes.
Stacking-velocity inversion with borehole constraints for tilted TI media
Authors: Wang Xiaoxiang , Tsvankin Ilya
Published: October 2010

Transversely isotropic models with a tilted symmetry axis (TTI) play an increasingly important role in seismic imaging, especially near salt bodies and in active tectonic areas. Here, we present a 2D parameter-estimation methodology for TTI media based on combining P-wave normal-moveout (NMO) velocities, zero-offset traveltimes, and reflection time slopes with borehole data that include check-shot traveltimes as well as the reflector depths and dips. For a dipping TTI layer with the symmetry axis confined to the dip plane of the reflector, simultaneous estimation of the symmetry-direction velocity [Formula: see text], the anisotropy parameters [Formula: see text] and [Formula: see text], and the tilt [Formula: see text] of the symmetry axis proves to be ambiguous despite the borehole constraints. If the symmetry axis is orthogonal to the reflector, [Formula: see text] and [Formula: see text] can be recovered with high accuracy, even when the symmetry axis deviates by [Formula: see text] from the reflector normal. The parameter [Formula: see text], however, cannot be constrained for dips smaller than 60° without using nonhyperbolic moveout. To invert for the interval parameters of layered TTI media, we apply 2D stacking-velocity inversion supplemented with the same borehole constraints. The dip planes in all layers are assumed to be aligned, and the symmetry axis is set orthogonal to the reflector in each layer. Information about reflector dips can be replaced with near-offset walkaway vertical seismic profiling (VSP) traveltimes. Tests on noise-contaminated data demonstrate that the algorithm produces stable estimates of the interval parameters [Formula: see text] and [Formula: see text], if the range of dips does not exceed 30°. Our method can be used to build an accurate initial TTI model for post-migration reflection tomography and other techniques that employ migration velocity analysis.
Facilitative glucose transporter Glut1 is actively excluded from rod outer segments
Authors: Gospe Sidney M. , Baker Sheila A. , Arshavsky Vadim Y.
Published: October 2010

Photoreceptors are among the most metabolically active cells in the body, relying on both oxidative phosphorylation and glycolysis to satisfy their high energy needs. Local glycolysis is thought to be particularly crucial in supporting the function of the photoreceptor's light-sensitive outer segment compartment, which is devoid of mitochondria. Accordingly, it has been commonly accepted that the facilitative glucose transporter Glut1 responsible for glucose entry into photoreceptors is localized in part to the outer segment plasma membrane. However, we now demonstrate that Glut1 is entirely absent from the rod outer segment and is actively excluded from this compartment by targeting information present in its cytosolic C-terminal tail. Our data indicate that glucose metabolized in the outer segment must first enter through other parts of the photoreceptor cell. Consequently, the entire energy supply of the outer segment is dependent on diffusion of energy-rich substrates through the thin connecting cilium that links this compartment to the rest of the cell.
Clathrin recruits phosphorylated TACC3 to spindle poles for bipolar spindle assembly and chromosome alignment
Authors: Fu Wenxiang , Tao Wei , Zheng Puwei , Fu Jingyan , Bian Minglei , Jiang Qing , Clarke Paul R. , Zhang Chuanmao
Published: October 2010

Transforming acidic coiled-coil-containing protein 3 (TACC3) has been implicated in mitotic spindle assembly, although the mechanisms involved are largely unknown. Here we identify that clathrin heavy chain (CHC) binds specifically to phosphorylated TACC3 and recruits it to spindle poles for proper spindle assembly and chromosome alignment. Phosphorylation of Xenopus TACC3 at serine 620 (S620) and S626, but not S33, is required for its binding with CHC. Knockdown of CHC by RNA interference (RNAi) abolishes the targeting of TACC3 to spindle poles and results in abnormal spindle assembly and chromosome misalignment, similar to the defects caused by TACC3 knockdown. Furthermore, the binding of CHC with phosphorylated TACC3 is inhibited by importin β and this inhibition is reversed by the presence of the GTP-binding nuclear protein Ran in the GTP-bound state. Together, these results indicate that the recruitment of phosphorylated TACC3 to spindle poles by CHC ensures proper spindle assembly and chromosome alignment, and is regulated by Ran.
Teaching Retail Operations in Business and Engineering Schools
Authors: Van Woensel Tom , Fisher Marshall L. , Fransoo Jan C.
Published: October 2010

This paper describes the organization and teaching of retail operations at The Wharton School at the University of Pennsylvania and the School of Industrial Engineering at Eindhoven University of Technology. We present the course outlines and discuss how differences in the schools' environments affect the way retail operations is taught at each school.
Rosuvastatin-Induced Thrombocytopenia: Lisinopril-Induced Nightmares: Valproate Sodium-Associated Hypotension: Gabapentin-Induced Delusions of Parasitosis: Piperacillin/Tazobactam-Induced Petechial Rash: Adverse Events Associated with Testosterone: Chloroquine-Induced Hair Hypopigmentation: Scoring System to Assess ADR Risk among In-Hospital Elderly Patients
Authors: Shuster Joel
Published: October 2010

The purpose of this feature is to heighten awareness of specific adverse drug reactions (ADRs), discuss methods of prevention, and promote reporting of ADRs to the US Food and Drug Administration's (FDA's) MedWatch program (800-FDA-1088). If you have reported an interesting, preventable ADR to MedWatch, please consider sharing the account with our readers.
Safety Concerns Involving Transdermal Patches and Magnetic Resonance Imaging (MRI)
Authors: Hong Irene , Gabay Michael , Lodolce Amy
Published: October 2010

Transdermal drug delivery systems have become more prevalent since their initial introduction in the 1980s. Recently, safety concerns have arisen regarding the continued application of transdermal patches during magnetic resonance imaging (MRI) procedures. Case reports have revealed that serious burns may occur in patients undergoing MRI who have transdermal patches with metallic content applied to their skin. The metallic component of these patches acts as a conductor for the radiofrequency pulses of the MRI, inducing an electric current and thereby resulting in intense heat and burns. Currently, over 20 brand and generic transdermal drug delivery systems are available. Not all available patches contain metallic components that necessitate removal prior to MRI. This review provides information related to the metallic content of available transdermal patches and also provides recommendations regarding reapplication of transdermal therapy after a scan. Health care professionals should be aware that published information regarding transdermal therapy and risk of burns appears to vary from source to source as the primary reference for such information is verbal communication with manufacturers. Given this issue, it may be often easier to err on the side of caution and remove the patch prior to MRI.
Stability of Sodium Nitroprusside and Sodium Thiosulfate 1:10 Intravenous Admixture
Authors: Schulz Lucas T. , Elder Edmund J. , Jones Karen J. , Vijayan Ashwanth , Johnson Benjamin D. , Medow Joshua E. , Vermeulen Lee
Published: October 2010

Purpose

Thiosulfate has been shown to reduce the risk of cyanide toxicity during nitroprusside administration. Admixtures containing both agents may provide a safe and effective alternative to more expensive agents used to reduce blood pressure in the critically ill patient. This study determined the physical and chemical stability of a 1:10 nitroprusside:thiosulfate admixture, stored up to 48 hours. The economic consequences of a shift toward using thiosulfate and nitroprusside, and away from higher cost alternatives, are considered.

Methods

Seven samples of 50 mg nitroprusside and 500 mg thiosulfate were prepared and stored away from light, at room temperature, and in a refrigerator prepared in D5W and NS. Each sample was analyzed via a novel high-performance liquid chromatographic (HPLC) method at time 0, 8, 24, and 48 hours. The method was tested and passed specifications for linearity, reproducibility, and accuracy. A visual inspection by 9 licensed pharmacists was used to demonstrate physical stability. A cost evaluation comparing nitroprusside and thiosulfate to alternative agents was completed.

Results

The concentration of both nitroprusside and thiosulfate remain greater than 95% of the initial concentration through 48 hours. Physical compatibility was confirmed in all samples tested through 72 hours.

Conclusion

The combination of nitroprusside and thiosulfate is chemically and physically stable as a single compounded dose for up to 48 hours when stored at room temperature and protected from light. The admixture represents an inexpensive option to other higher cost alternatives such as nicardipine or clevidipine.
Recent Publications on Medications and Pharmacy
Authors: Russett Flint
Published: October 2010

Hospital Pharmacy presents this feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest regarding a broad scope of topics are abstracted monthly.
Association Between Cancer and Immunosuppressive Therapy—Analysis of Selected Studies in Pemphigus and Pemphigoid
Authors: Mabrouk Dalia , Gürcan Hakan M , Keskin Derin B , Christen William G , Ahmed A Razzaque
Published: October 2010

Objective:

To determine whether there is an association between the use of immunosuppressive agents (ISAs) and cancer in patients with pemphigus and pemphigoid—rare, potentially fatal diseases of the skin and mucous membranes, often requiring long-term use of ISAs.

Data Source:

Literature was accessed through PubMed (all years available), using the search terms cancer, immunosuppressive agents, pemphigoid, and pemphigus.

Study Selection and Data Extraction:

A retrospective review of the literature was conducted. Inclusion criteria for studies were: (1) English language, (2) diagnosis of pemphigus and/or pemphigoid based on histology and immunopathology, (3) more than 10 patients evaluated, (4) investigators had a high index of suspicion of cancer and patients were monitored for it, (5) follow-up information was provided for at least 1 year after initiation of therapy, and (6) absence of diagnosis of cancer before initiation of an ISA. Case reports were not included in the analysis.

Data Synthesis:

A total of 929 patients diagnosed with either pemphigus or pemphigoid in 17 studies were identified. Patients were divided into 2 groups. Group A comprised patients treated with azathioprine, cyclophosphamide, cyclosporins, or mycophenolate mofetil in combination with prednisone. In Group A. 22 cases of cancer were reported in 21 of the 218 patients (9.6%). Group B comprised patients treated with systemic corticosteroids only. In this group, cancer was reported in 11 of the 711 patients (1.5%). In this study there was no control group (untreated patients) and the sample sizes were small.

Conclusions:

Preliminary data suggest a possible association between the use of azathioprine, cyclophosphamide, and cyclosporine and increased susceptibility to cancer in patients with pemphigus and pemphigoid.
Education…A Must in All Levels of Pharmacy Practice
Authors: Keresztes Jan M
Published: October 2010

Public perception of a profession is extremely important, but even more vital is the actual worth the profession provides to those who partake of its services. As pharmacy recreates itself as a consultative profession, many changes are occurring in the college of pharmacy students' education. The onset of the Introductory Pharmacy Practice Experience (IPPE), the continued rotations in the Advanced Pharmacy Practice Experience (APPE), and the proposal to have mandatory residencies occurring by 2020 show the steps that pharmacy will take to move forward. But pharmacy continues to miss the first rung of the ladder as the profession climbs to its future success by not addressing the mandatory education of the primary workforce in day-to-day activities: that of standardized education and training of pharmacy technicians. While IPPE, APPE, and residencies will strengthen the pharmacy “dwelling,” its foundation does not have solid ground. A deadline needs to be established for mandatory education, training, and certification for all technicians entering the profession today and, only after achieving these goals, should the pharmacy technicians be licensed to practice. With even more forethought, pharmacy might require that potential college of pharmacy students, as well as those not fortunate enough to be admitted to a college of pharmacy, become pharmacy technicians first. Only then can the pharmacy profession conquer the top rung of the ladder in a strong, upright fashion.
Microsystem Light Source at 488 nm for Shifted Excitation Resonance Raman Difference Spectroscopy
Authors: Maiwald Martin , Schmidt Heinar , Sumpf Bernd , Güther Reiner , Erbert Götz , Kronfeldt Heinz-Detlef , Tränkle Günther
Published: October 2010

A microsystem light source emitting at 488 nm was tested and applied as a light source for shifted excitation resonance Raman difference spectroscopy (SERRDS). A nonlinear frequency conversion using a distributed feedback (DFB) diode laser emission at 976 nm and a periodically poled lithium niobate (PPLN) waveguide crystal was realized on a micro-optical bench with a footprint of 25 mm × 5 mm. Joint temperature management via the microbench is used for wavelength tuning. Two emission lines at 487.61 nm and 487.91 nm are used for the SERRDS experiments. The Raman spectra of the test sample polystyrene demonstrate that a laser bandpass filter did not need to be implemented. Resonance Raman spectra of Tartrazine (FD&C Yellow 5, E 102) in distilled water are presented to demonstrate the suitability of this light source for SERRDS in, e.g., food safety control.
Raman Chemical Imaging of Explosive-Contaminated Fingerprints
Authors: Emmons E. D. , Tripathi A. , Guicheteau J. A. , Christesen S. D. , Fountain A. W.
Published: October 2010

Raman chemical imaging (RCI) has been used to detect and identify explosives in contaminated fingerprints. Bright-field imaging is used to identify regions of interest within a fingerprint, which can then be examined to determine their chemical composition using RCI and fluorescence imaging. Results are presented where explosives in contaminated fingerprints are identified and their spatial distributions are obtained. Identification of explosives is obtained using Pearson's cosine cross-correlation technique using the characteristic region (500–1850 cm−1) of the spectrum. This study shows the ability to identify explosives nondestructively so that the fingerprint remains intact for further biometric analysis. Prospects for forensic examination of contaminated fingerprints are discussed.
Balmer-β Line Asymmetry Characteristics in a High Pressure, Microwave-Produced Argon Plasma
Authors: Palomares J. M. , Torres J. , Gigosos M. A. , Van Der Mullen J. J. A. M. , Gamero A. , Sola A.
Published: October 2010

This paper presents a study on the asymmetry of the Balmer Hβ profile in plasmas produced by microwaves at high pressure with the help of some functions of asymmetry for the whole profile, as well as by means of some specific parameters characterizing only its central dip. The study shows how this asymmetry—very low in our case—depends on the electron density and flux of gases and how the existence of inhomogeneities in the plasma can affect the shape and symmetry of this line. Also, limitations on the determination of the asymmetry are pointed out and the use of this profile for plasma diagnosis is discussed.
Characterization of Yeast Species Using Surface-Enhanced Raman Scattering
Authors: Sayin Ismail , Kahraman Mehmet , Sahin Fikrettin , Yurdakul Dilsad , Culha Mustafa
Published: October 2010

Surface-enhanced Raman scattering (SERS) is used for the characterization of six yeast species and six isolates. The sample for SERS analysis is prepared by mixing the yeast cells with a four times concentrated silver colloidal suspension. The scanning electron microscopy (SEM) images show that the strength of the interaction between silver nanoparticles and the yeast cells depends on the biochemical structure of the cell wall. The SERS spectra are used to identify the biochemical structures on the yeast cell wall. It is found that the density of –SH and –NH2 groups might be higher on certain yeast cell walls. Finally, the obtained SERS spectra from yeast is used for the classification of the yeast.
Detection of Uranium Using Laser-Induced Breakdown Spectroscopy
Authors: Chinni Rosemarie C. , Cremers David A. , Radziemski Leon J. , Bostian Melissa , Navarro-Northrup Claudia
Published: October 2010

The goal of this work is a detailed study of uranium detection by laser-induced breakdown spectroscopy (LIBS) for application to activities associated with environmental surveillance and detecting weapons of mass destruction (WMD). The study was used to assist development of LIBS instruments for standoff detection of bulk radiological and nuclear materials and these materials distributed as contaminants on surfaces. Uranium spectra were analyzed under a variety of different conditions at room pressure, reduced pressures, and in an argon atmosphere. All spectra displayed a high apparent background due to the high density of uranium lines. Time decay curves of selected uranium lines were monitored and compared to other elements in an attempt to maximize detection capabilities for each species in the complicated uranium spectrum. A survey of the LIBS uranium spectra was conducted and relative emission line strengths were determined over the range of 260 to 800 nm. These spectra provide a guide for selection of the strongest LIBS analytical lines for uranium detection in different spectral regions. A detection limit for uranium in soil of 0.26% w/w was obtained at close range and 0.5% w/w was achieved at a distance of 30 m. Surface detection limits were substrate dependent and ranged from 13 to 150 μg/cm2. Double-pulse experiments (both collinear and orthogonal arrangements) were shown to enhance the uranium signal in some cases. Based on the results of this work, a short critique is given of the applicability of LIBS for the detection of uranium residues on surfaces for environmental monitoring and WMD surveillance.
A Study of Electric Field Standing Waves on Reflection Microspectroscopy of Polystyrene Particles
Authors: Brooke Heather , Bronk B. V. , McCutcheon J. N. , Morgan S. L. , Myrick M. L.
Published: October 2010

We have been investigating the mid-infrared (MIR) reflection spectrum of microparticles on mirrored substrates. Gold-coated porous alumina filters were used as a substrate to layer the particles and provide consistent reflection spectra. Polystyrene spheres with measured diameters of 0.42 μm were studied using Fourier transform infrared (FT-IR) reflection microspectroscopy, and spectra are shown for coverages in the range 0.5–6 monolayers (ML). Results show that absorption has a nonlinear, stairstep-like dependence on particle coverage and a wavelength dependence that can be explained by electric field standing waves (EFSW) caused by the mirrored substrate. The same effect is found to cause progressive weakening of the observed spectra as a function of increasing wavelength in sub-monolayer coverage measurements. Scattering effects in the spectra are consistent with surface scattering at the antinodes of the EFSW. These observations provide explanations for differences seen between optical properties of particles calculated using the specular-reflection method versus those calculated using traditional aerosol methods. A simple multilayer method for estimating particle absorption coefficients is demonstrated that compares well with values reported using ellipsometry for bulk polystyrene. Another simple method based on sub-monolayer coverage spectra provides spectra suitable for classification analysis but is only semi-quantitative at determining absorption coefficients.
Experimental Determination of the Raman Sampling Depth in Zirconia Ceramics
Authors: Presser V. , Keuper M. , Berthold C. , Nickel K. G.
Published: October 2010

This study provides experimentally determined values for the actual μ-Raman spectroscopy sampling depth in zirconia ceramics (ZrO,2) via line scans on a wedge-shaped sample. Common instrumental settings with metallurgical objective lenses in dry air, argon-ion, and helium-neon laser radiation of approximately 10 mW were chosen. Under those conditions effective sampling depths, defined as the depth at which 99% of the information is recorded, range from 20 to more than 50 μm, depending on the numerical aperture of the lens and the laser wavelength. These results elucidate the pitfalls of the investigation of surface phenomena in zirconia ceramics such as low-temperature degradation or mechanically induced phase transformations by Raman spectroscopy.
Fluorescence Spectroscopy for Rapid Detection and Classification of Bacterial Pathogens
Authors: Sohn Miryeong , Himmelsbach David S. , Barton Franklin E. , Fedorka-Cray Paula J.
Published: October 2010

This study deals with the rapid detection and differentiation of Escherichia coli, Salmonella, and Campylobacter, which are the most commonly identified commensal and pathogenic bacteria in foods, using fluorescence spectroscopy and multivariate analysis. Each bacterial sample cultured under controlled conditions was diluted in physiologic saline for analysis. Fluorescence spectra were collected over a range of 200–700 nm with 0.5 nm intervals on the PerkinElmer Fluorescence Spectrometer. The synchronous scan technique was employed to find the optimum excitation (λex) and emission (λem) wavelengths for individual bacteria with the wavelength interval (Δλ) being varied from 10 to 200 nm. The synchronous spectra and two-dimensional plots showed two maximum λex values at 225 nm and 280 nm and one maximum λem at 335–345 nm (λem=λex + Δλ), which correspond to the λex=225 nm, Δλ=110–120 nm, and λex=280 nm, Δλ=60–65 nm. For all three bacterial genera, the same synchronous scan results were obtained. The emission spectra from the three bacteria groups were very similar, creating difficulty in classification. However, the application of principal component analysis (PCA) to the fluorescence spectra resulted in successful classification of the bacteria by their genus as well as determining their concentration. The detection limit was approximately 103–104 cells/mL for each bacterial sample. These results demonstrated that fluorescence spectroscopy, when coupled with PCA processing, has the potential to detect and to classify bacterial pathogens in liquids. The methology is rapid (<10 min), inexpensive, and requires minimal sample preparation compared to standard analytical methods for bacterial detection.
Application of Small-Spot Energy Dispersive X-ray Fluorescence Instrumentation in Phytoremediation Activities around Metal Mines
Authors: Marguí E. , Jurado A. , Hidalgo M. , Pardini G. , Gispert M. , Queralt I.
Published: October 2010

In view of the considerable number of analyses necessary in phytoremediation and plant biology studies, it is important that the analytical procedures used for elemental determination in plant tissues should be fast and cheap, with simple sample preparation, and of adequate accuracy and precision. The aim of the present work was focused on the possibilities and drawbacks of a low-cost benchtop energy dispersive X-ray fluorescence (EDXRF) instrument to be used as an analytical technique for studying the potential use of sunflowers ( Helianthus annuus) for the phytoremediation of an abandoned Pb/Zn mining area. The simplicity and the ability to operate at room temperature and open air conditions provides a flexible setup for the rapid analysis of vegetation material without complicated previous sample pretreatments. With the help of different collimator caps, a modest lateral resolution (from 200 μm to 1 mm) was achieved and it was thought to be small enough to study the accumulation of Pb and Zn and its distribution between parts of the vegetation specimens (roots, stems, and leaves); the limits of detection achieved (0.6 ng for Zn and 3.0 ng for Pb) proved to be suitable for the intended purpose. Therefore, obtained data revealed that EDXRF spectrometry could be a useful tool to better understand the metal uptake, translocation, and tolerance mechanisms in vegetation species related to biomonitoring and phytoremediation studies.
In Situ Orientation Studies of a Poly(3-hydroxybutyrate)/Poly(ε-caprolactone) Blend by Rheo-Optical Fourier Transform Infrared Spectroscopy and Two-Dimensional Correlation Spectroscopic Analysis
Authors: Unger Miriam , Siesler Heinz W.
Published: October 2010

In the present study, the orientation of a poly(3-hydroxybutyrate) (PHB)/poly(ε-caprolactone) (PCL) blend was monitored during uniaxial elongation by rheo-optical Fourier transform infrared (FT-IR) spectroscopy and analyzed by generalized two-dimensional correlation spectroscopy (2D-COS). The dichroism of the δ(CH2) absorption bands of PHB and PCL was employed to determine the polymer chain orientation in the PHB/PCL blend during the elongation up to 267% strain. From the PHB and PCL specific orientation functions it was derived that the PCL chains orient into the drawing direction while the PHB chains orient predominantly perpendicular to the applied strain. To extract more detailed information about the polymer orientation during uniaxial elongation, 2D-COS analysis was employed for the dichroic difference of the polarization spectra recorded during the drawing process. In the corresponding synchronous and asynchronous 2D correlation plots, absorption bands characteristic of the crystalline and amorphous regions of PHB and PCL were separated. Furthermore, the 2D-COS analysis revealed that during the mechanical treatment the PCL domains orient before the PHB domains.
A Chemometric Analysis of Ligand-Induced Changes in Intrinsic Fluorescence of Folate Binding Protein Indicates a Link between Altered Conformational Structure and Physico-Chemical Characteristics
Authors: Bruun Susanne W. , Holm Jan , Hansen Steen Ingemann , Andersen Charlotte M. , Nørgaard Lars
Published: October 2010

Ligand binding alters the conformational structure and physico-chemical characteristics of bovine folate binding protein (FBP). For the purpose of achieving further information we analyzed ligand (folate and methotrexate) -induced changes in the fluorescence landscape of FBP. Fluorescence excitation and emission two-dimensional (2D) spectra were recorded over a wide range of wavelengths on a Perkin-Elmer LS 55 spectrofluorometer at varying pH in different buffers, and the resulting three-dimensional data were subjected to a chemometric analysis, parallel factor analysis (PARAFAC). The most important finding was the occurrence of two maximum intensity emission wavelengths of tryptophan, 350 nm (component one) and 330 nm (component two). In contrast to the first component, the score of the short wavelength component increased with increasing ligation of FBP. Since the emission wavelengths of indole groups in tryptophan shorten with increasing distance from the solvent surface of proteins, an increasing number of the 11 tryptophan residues seem to reorientate from the solvent surface to the interior of FBP with increasing ligation. The sharp decrease in hydrophobicity at pI=7–8 following binding of folate accords fairly well with the disappearance of strongly hydrophobic tryptophan residues from the solvent-exposed surface of FBP. The PARAFAC has thus proven useful to establish a hitherto unexplained link between parallel changes in conformational structure and physico-chemical characteristics of FBP induced by folate binding. Parameters for ligand binding derived from PARAFAC analysis of the fluorescence data were qualitatively and quantitatively similar to those obtained from binding of radiofolate to FBP. Herein, methotrexate exhibited a higher affinity for FBP than in competition with radiofolate. This could suggest a rapid and firm complexation of folate to FBP, blocking access of competing ligands.
Study on the Genotoxic Interaction of Methyl Violet with Calf Thymus DNA
Authors: Chi Zhenxing , Liu Rutao , Zhao Xingchen , Sun Yajing , Yang Bingjun , Gao Canzhu
Published: October 2010

By utilizing ultraviolet (UV)-visible absorption spectroscopy, circular dichroism (CD), resonance light scattering (RLS), and transmission electron microscope (TEM) techniques, the toxic interaction of methyl violet (MV) with calf thymus DNA (ctDNA) was investigated at the molecular level. The UV-visible absorption spectra results showed that MV intercalated into ctDNA base pairs at low MV concentrations, while MV was attached to the negative charged phosphate groups at higher concentrations and the binding constant ( Kθ25°C) was 1.80 × 103 L mol−1. The absorbency results showed that the genotoxic interaction of MV with ctDNA is under the electrostatic binding mode. MV had strong toxic interaction with ctDNA at 4.0 × 10−5 mol L−1 MV and pH 6.5. The toxic interaction of MV with ctDNA can result in the formation of massive aggregates and change of the ctDNA conformation, which showed a significant linear dose-response relationship.
Study of Air-Induced Paper Discolorations by Infrared Spectroscopy, X-ray Fluorescence, and Scanning Electron Microscopy
Authors: Ferreira Adriana , Figueira Francisca , Pessanha Sofia , Nielsen Ingelise , Carvalho Maria Luisa
Published: October 2010

Air-induced paper discoloration is described as being different from other discoloration morphologies. It seems to be the result of prolonged exposure to air in a humid and polluted environment without appropriate protecting coverage. In this work, three folios from the same eighteenth century book, presenting three degrees of discoloration and opacity and subjected to different environmental conditions, were examined and compared. Samples were analyzed and compared by three different instrumental techniques, mid-infrared spectroscopy, X-ray fluorescence (XRF), and scanning electron microscopy (SEM). Chemical and physical changes were confirmed from the data collected by these techniques. The absence of the secondary amide band characteristic of proteins in the infrared spectra of the two discolored folios, accompanied by the appearance and increase of white mineral-like deposits visible in the SEM micrographs, support the idea that oxidation reactions occurred and that these two folios were subjected to more severe degradation hazard.
Temperature-Dependent Raman Study of the Smectic to Nematic Phase Transition and Vibrational Analysis Using Density Functional Theory of the Liquid Crystalline System 4-Decyloxy Benzoic Acid
Authors: Vikram K. , Tarcea Nicolae , Popp J. , Singh Ranjan K.
Published: October 2010

Room-temperature Raman spectra of the thermotropic liquid crystalline system, 4-decyloxy benzoic acid (4DBA) have been recorded and the experimentally observed bands are assigned by density functional theory (DFT) for the first time. The C–O and C–C stretching and C–H in-plane bending modes of the phenyl ring and C=O stretching modes of the -COOH group are the marker bands for the smectic (S) → nematic (N) and nematic (N) → isotropic (I) transitions for this system. The temperature-dependent Raman spectra for these bands in the heating cycle clearly characterize the S→N and the N→I transition over a range <1 °C, which is much better than the earlier range of 23 °C for S→N and 26 °C for the N→I transition. The ∼773, ∼807, ∼881, and ∼1146 cm−1 bands disappear, whereas a band at ∼830 cm−1 appears at the S→N transition. The relative intensity of the ∼1257 and ∼1280 cm−1 bands distinguishes the three phases, namely smectic, nematic, and isotropic, in 4DBA. The variation of line width and peak wavenumber of the ∼1128 and ∼1168 cm−1 bands also clearly shows the two transitions. The molecular reorientation at the transition and the effect of local fields present in the liquid crystalline mesophases are also briefly discussed on the basis of changes in intensity, linewidth and peak wavenumber with temperature.
Surface-Controlled Electroless Deposition Method in the Preparation of Stacked Silver Nanoparticles on Germanium for Surface-Enhanced Infrared Absorption Measurements
Authors: Chang Ruo-Lan Joan , Yang Jyisy
Published: October 2010

A new method to prepare highly sensitive sensing elements for surface-enhanced infrared absorption (SEIRA) measurements was investigated. A surface-controlled procedure was employed to grow round and stacked silver nanoparticles (Ag-NPs) on germanium substrates. In this method, an initial layer of Ag-NPs was prepared using a common method of electroless deposition. After subsequently placing a controlled layer of p-aminothiophenol ( pATP) on the surface of the initial layer of Ag-NPs, the substrates were placed in a silver nitrate solution to grow a second layer of Ag-NPs. By repeating these growing procedures, multi-layers of stacked Ag-NPs can be obtained. To examine the influence of morphology of the formed Ag-NPs on the resulting SEIRA signals, the factors affecting the reactions were systematically examined. These factors included the concentrations of silver nitrates, the reaction times to prepare both the initial layer and the second layer of Ag-NPs, and the coverage of pATP. Results indicate that the Ag-NPs making up the second layer were round in shape and much more densely distributed than those in the initial layer. The observed SEIRA spectra did not show derivative-shaped absorption bands for pATP on the Ag-NPs after re-growth, indicating that pATP was sandwiched between the two layers of Ag-NPs, preventing the nanoparticles from coming into direct contact with one another. Also, the SEIRA signals of the controlled molecules between the particles were found to be two to five times more intense than the signals before growing another layer of Ag-NPs. The reaction conditions can be adjusted to vary the morphology and thickness of the Ag-NP layers, and, by repeating the growing procedures, a thick layer of stacked Ag-NPs with suitable size for SEIRA measurements can be obtained that is highly suited to chemical sensing applications.
Instantaneous Temperature Imaging of Diffusion Flames Using Two-Line Atomic Fluorescence
Authors: Medwell Paul R. , Chan Qing N. , Kalt Peter A. M. , Alwahabi Zeyad T. , Dally Bassam B. , Nathan Graham J.
Published: October 2010

This work investigates the first demonstration of nonlinear regime two-line atomic fluorescence (NTLAF) thermometry in laminar non-premixed flames. The results show the expediency of the technique in the study of the reaction zone and reveals interesting findings about the indium atomization process. Indium fluorescence is observed to be strongest at the flame-front, where the temperature exceeds 1000 K. The uncertainty in the deduced temperature measurement is ∼6%. The temperature profile across the reaction zone shows good agreement with laminar flame calculations. The advantages and inherent limitations of the technique are discussed.
Characterization of Thio Compounds for a Surface-Controlled Electroless Deposition Method in the Preparation of Silver Nanoparticles on Germanium for Surface-Enhanced Infrared Absorption Measurements
Authors: Chang Ruo-Lan Joan , Yang Jyisy
Published: October 2010

An electroless re-growing method has been developed to prepare silver nanoparticles (Ag-NPs) on substrates for surface-enhanced infrared absorption (SEIRA) measurements. To understand the roles of specific molecules in controlling the properties of Ag-NPs on germanium substrates, thio compounds bearing different functional groups were examined systematically. Four classes of thio compounds were examined in this work, including aromatic thio compounds with second functional group, alkyl thio compounds with second functional group, structural isomers of aromatic thio compounds, and alkyl thio compounds with different alkyl chain lengths. By correlating SEIRA signals with the observed morphologies of the Ag-NPs, it was found that thio compounds bearing amine polar functional groups produced Ag-NPs that were the most regular in shape and size. Also, aromatic thio compounds provided better performance than did alkyl thio compounds in terms of producing suitable shapes and sizes for SEIRA. The Ag-NPs prepared in this work were generally around 50 nm in diameter and round in shape. To examine the prepared substrates for chemical sensing purposes, the enhancement factors were determined by deposition of para-nitrothiophenol ( pNTP) on the Ag-NP substrates produced by this surface-controlled electroless deposition method. Results indicated that the surface of the newly formed Ag-NPs actively interacted with pNTP, and the enhancement factors obtained ranged from 50 to 150.