bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raman and mid‐IR spectroscopic study of the magnesium carbonate minerals—brugnatellite and coalingite
Authors: Frost Ray L. , Bahfenne Silmarilly 
Published: December 2008

AbstractTwo hydrated hydroxy magnesium carbonate minerals brugnatellite and coalingite with a hydrotalcite‐like structure were studied by Raman spectroscopy. Intense bands are observed at 1094 cm−1 for brugnatellite and at 1093 cm−1 for coalingite attributed to the CO32−ν1 symmetric stretching mode. Additional low intensity bands are observed at 1064 cm−1. The existence of two symmetric stretching modes is accounted for in terms of different anion structural arrangements. Very low intensity bands at 1377 and 1451 cm−1 are observed for brugnatellite, and the Raman spectrum of coalingite displays two bands at 1420 and 1465 cm−1 attributed to the (CO3)2−ν3 antisymmetric stretching modes. Very low intensity bands at 792 cm−1 for brugnatellite and 797 cm−1 for coalingite are assigned to the CO32− out‐of‐plane bend (ν2). X‐ray diffraction studies by other researchers have shown that these minerals are disordered. This is reflected in the difficulty of obtaining Raman spectra of reasonable quality and explains why the Raman spectra of these minerals have not been previously or sufficiently described. A comparison is made with the Raman spectra of other hydrated magnesium carbonate minerals. Copyright © 2008 John Wiley & Sons, Ltd.
Vibrational spectroscopic study of the hydrated platinum(II), palladium(II) and cis‐diammineplatinum(II) ions in acidic aqueous solutions
Authors: Kocsis L. , Mink J. , Jalilehvand F. , Laffin L. J. , Berkesi O. , Hajba L. 
Published: December 2008

AbstractMid infrared, far‐infrared and Raman spectroscopic studies, combined with force field analyses, were performed for the hydrated platinum(II) and palladium(II) ions and cis‐diammineplatinum(II) complex in acidic aqueous solutions. Simplified Density Functional Theory (DFT) calculations were made for the equatorial plane of the platinum complexes. Careful subtraction of solvent spectra allowed a number of ‘internal’ modes of coordinated H2O and NH3 to be determined as weak residual bands. The [Pt(OH2)6]2+ and [cis‐Pt(NH3)2(OH2)4]2+ complexes were found to be six‐coordinated with four ligands strongly bound in an equatorial plane. The assignments of the vibrational modes in the equatorial plane could be performed on the basis of the experimental observations and by comparison with metal–ligand vibrations of square‐planar complexes, aided by normal coordinate calculations. For the weakly coordinated axial aqua ligands, the low wavenumber range and the polarizibility properties allowed the assignments of the bands at about 365 and 325 cm−1 to the stretching modes of one short and one longer Pt— O* bound to axial aqua ligands, respectively. A similar picture with even less strongly bound axial water molecules emerges from Raman spectroscopy data for the hydrated palladium(II) ion, [Pd(OH2)6]2+. The results are consistent with a description of the [Pt(OH2)6]2+ and [Pd(OH2)6]2+ aqua ions in C4v symmetry, and with the [cis‐Pt(NH3)2(OH2)4]2+ complex in the Cs point group, and also in qualitative agreement with the structures devised from previous extended X‐ray absorption fine structure (EXAFS) measurements. Copyright © 2008 John Wiley & Sons, Ltd.
FT‐Raman and FT‐IR spectral and quantum chemical studies on some flavonoid derivatives: Baicalein and Naringenin
Authors: Unsalan Ozan , Erdogdu Yusuf , Gulluoglu M. Tahir 
Published: December 2008

AbstractIn this study, the experimental and theoretical results on the molecular structures of some flavonoid derivatives (Baicalein and Naringenin) are presented. The FT‐IR and FT‐Raman spectra of the compounds have been recorded together for the first time between 4000–400 cm−1 and 3500–5 cm−1 regions, respectively. The molecular geometry and vibrational wavenumbers of the compounds have been also calculated in their ground states by using ab initio HF and DFT/B3LYP functional with 6‐31G(d,p) basis set used in calculations. The calculations were utilized to the C1 symmetries of the molecules. All calculations were performed with Gaussian 98 software. The obtained vibrational wavenumbers and optimized geometric parameters were seen to be in good agreement with the experimental data. Scale factors have been used in order to compare how the calculated and experimental data are in agreement. Theoretical infrared intensities were also reported. Copyright © 2008 John Wiley & Sons, Ltd.
Characterization and optimization of AuNPs labeled by Raman reporters on glass based on silver enhancement
Authors: Wang Yuling , Ren Wen , Dong Shaojun , Wang Erkang 
Published: December 2008

AbstractIn this report, gold nanoparticles (AuNPs) labeled by Raman reporters (AuNPs‐R6G) were assembled on glass and used as the seeds to in situ grow silver‐coated nanostructures based on silver enhancer solution, forming the nanostructures of AuNPs‐R6G@Ag, which were characterized by scanning electron microscopy (SEM) and UV‐visible spectroscopy. More importantly, the obtained silver‐coated nanostructures can be used as a surface enhancement Raman scattering (SERS) substrate. The different SERS activities can be controlled by the silver deposition time and assembly time of AuNPs‐R6G on glass. The results indicate that the maximum SERS activity could be obtained on AuNPs‐R6G when these nanostructures were assembled on glass for 2 h with silver deposition for 2 min. In addition, the reproducibility of SERS signal on the fabricated nanostructures is very high with the intensity error lower than 15%, which has great promise as a probe for application in bioanalysis. Copyright © 2008 John Wiley & Sons, Ltd.
The gas‐phase elimination kinetics of ethyl 2‐furoate and ethyl 2‐thiophenecarboxylate
Authors: Espitia Liliany , Meneses Ruby , Dominguez Rosa M. , Tosta Maria , Herize Armando , Lezama Jesus , Lafont Jennifer , Chuchani Gabriel 
Published: December 2008

AbstractThe gas‐phase elimination kinetics of ethyl 2‐furoate and 2‐ethyl 2‐thiophenecarboxylate was carried out in a static reaction system over the temperature range of 623.15–683.15 K (350–410°C) and pressure range of 30–113 Torr. The reactions proved to be homogeneous, unimolecular, and obey a first‐order rate law. The rate coefficients are expressed by the following Arrhenius equations: ethyl 2‐furoate, log k1 (s−1) = (11.51 ± 0.17)–(185.6 ± 2.2) kJ mol−1 (2.303 RT)−1; ethyl 2‐thiophenecarboxylate, log k1 (s−1) = (11.59 ± 0.19)–(183.8 ± 2.4) kJ mol−1 (2.303 RT)−1. The elimination products are ethylene and the corresponding heteroaromatic 2‐carboxylic acid. However, as the reaction temperature increases, the intermediate heteroaromatic carboxylic acid products slowly decarboxylate to give the corresponding heteroaromatic furan and thiophene, respectively. The mechanisms of these reactions are suggested and described. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 145–152, 2009
Solvent effects on kinetics of an aromatic nucleophilic substitution reaction in mixtures of an ionic liquid with molecular solvents and prediction using artificial neural networks
Authors: Habibi‐Yangjeh Aziz , Jafari‐Tarzanag Yahya , Banaei Ali Reza 
Published: December 2008

AbstractKinetics of the reaction between 1‐chloro‐2,4‐dinitrobenzene and aniline was studied in mixtures of 1‐ethyl‐3‐methylimidazolium ethylsulfate ([EMIM][EtSO4]) with methanol, chloroform, and dimethylsulfoxide at 25°C. Single‐parameter correlations of log kA versus normalized polarity parameter (ENT), hydrogen‐bond acceptor basicity (β), hydrogen‐bond donor acidity (α), and dipolarity/polarizability (π*) of media do not give acceptable results. Multiparameter linear regression (MLR) of log kA versus the solvatochromic parameters demonstrates that the reaction rate constant increases with ENT, π*, and β and decreases with α parameter. To predict accurately solvent effects on the rate constant, optimized artificial neural network with three inputs (including α, π*, and β parameters) was applied for prediction of the log kA values in the prediction set. It was found that properly selected and trained neural network could fairly represent the dependence of the reaction rate constant on solvatochromic parameters. Mean percent deviation of 5.023 for the prediction set by the MLR model should be compared with the value of 0.343 by the artificial neural network model. These improvements are due to the fact that the reaction rate constant shows nonlinear correlations with the solvatochromic parameters. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 153–159, 2009
Studies on the oxygen atom transfer reactions of peroxomonosulfate: Oxidation of glycolic acid
Authors: Shailaja S. , Ramachandran M. S. 
Published: December 2008

AbstractThe kinetics of oxidation of glycolic acid, an α‐hydroxy acid, by peroxomonosulfate (PMS) was studied in the presence of Ni(II) and Cu(II) ions and in acidic pH range 4.05–5.89. The metal glycolate, not the glycolic acid (GLYCA), is oxidized by PMS. The rate is first order in [PMS] and metal ion concentrations. The oxidation of nickel glycolate is zero‐order in [GLYCA] and inverse first order in [H+]. The increase of [GLYCA] decreases the rate in copper glycolate, and the rate constants initially increase and then remain constant with pH. The results suggest that the metal glycolate ML+ reacts with PMS through a metal‐peroxide intermediate, which transforms slowly into a hydroperoxide intermediate by the oxygen atom transfer to hydroxyl group of the chelated GLYCA. The effect of hydrogen ion concentrations on kobs suggests that the structure of the metal‐peroxide intermediates may be different in Ni(II) and Cu(II) glycolates. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 160–167, 2009
Experimental and quantum‐chemical studies of 1H, 13C and 15N NMR coordination shifts in Au(III), Pd(II) and Pt(II) chloride complexes with picolines
Authors: Pazderski Leszek , Toušek Jaromír , Sitkowski Jerzy , Maliňáková Kateřina , Kozerski Lech , Szłyk Edward 
Published: December 2008

Abstract1H, 13C and 15N NMR studies of gold(III), palladium(II) and platinum(II) chloride complexes with picolines, [Au(PIC)Cl3], trans‐[Pd(PIC)2Cl2], trans/cis‐[Pt(PIC)2Cl2] and [Pt(PIC)4]Cl2, were performed. After complexation, the 1H and 13C signals were shifted to higher frequency, whereas the 15N ones to lower (by ca 80–110 ppm), with respect to the free ligands. The 15N shielding phenomenon was enhanced in the series [Au(PIC)Cl3] < trans‐[Pd(PIC)2Cl2] < cis‐[Pt(PIC)2Cl2] < trans‐[Pt(PIC)2Cl2]; it increased following the Pd(II) → Pt(II) replacement, but decreased upon the trans → cis‐transition. Experimental 1H, 13C and 15N NMR chemical shifts were compared to those quantum‐chemically calculated by B3LYP/LanL2DZ + 6‐31G**//B3LYP/LanL2DZ + 6‐31G*. Copyright © 2008 John Wiley & Sons, Ltd.
Preimplantation genetic diagnosis for fragile X syndrome: is there increased transmission of abnormal FMR1 alleles among female heterozygotes?
Authors: Reches Adi , Malcov Mira , Ben‐Yosef Dalit , Azem Foad , Amit Ami , Yaron Yuval 
Published: December 2008

AbstractBackgroundFragile X syndrome is caused by a CGG triplet‐repeat expansion mutation in the FMR1 gene. Previous studies have shown increased transmission of abnormal alleles in the 51–60 repeat range. This study was undertaken to evaluate the performance of preimplantation genetic diagnosis (PGD) for fragile X, and to assess the transmission rate of the abnormal FMR1 alleles in this setting.MethodThe study included 18 fragile X carriers who applied for PGD. FMR1 CGG repeats ranged from 70 to 300. PGD was performed using multiplex‐nested PCR, with simultaneous amplification of the CGG repeat region and several polymorphic markers, and sex chromosome markers.ResultsFour patients had a poor ovarian response, and could not undergo PGD. The remaining 14 patients underwent 47 PGD cycles. A total of 565 oocytes were aspirated. Of the 386 embryos that were successfully biopsied, 18 (6.4%) could not be analyzed due to amplification failure, and 12 (4.3%) had sex chromosomal abnormalities. Of the remaining 250 embryos, the abnormal allele was transmitted to 124 embryos (49.6%) compared to 126 (50.4%) for the normal allele. This difference was not statistically significant. Only embryos carrying the normal allele were transferred, resulting in 7 clinical pregnancies (18% per embryo transfer).ConclusionsOur results demonstrate that PGD for fragile X is feasible, and that carriers transmit the abnormal allele at the same frequency as the normal allele. Copyright © 2008 John Wiley & Sons, Ltd.
Promises and pitfalls of first trimester sonographic markers in the detection of fetal aneuploidy
Authors: Borrell Antoni 
Published: December 2008

AbstractFirst trimester sonographic markers are the only markers achieving detection rates above 50% in the prenatal detection of fetal aneuploidy. Although potentially they are the best markers, some concerns have arisen about its clinical application. Pitfalls may be due to inability to examine the markers, incorrect assessment, or incorrect interpretation of the findings. Markers may be unable to be examined due to maternal (maternal body habitus, previous surgery) or fetal reasons (incompatible fetal position or fetal movements). Causes of incorrect interpretation may be insufficient image magnification, incorrect caliper placement (nuchal translucency), incorrect insonation angle (nasal bone), venous contamination (ductus venosus), or arterial contamination (tricuspid regurgitation), among others. Venous contamination in ductus venosus waveforms may mimic an abnormal blood flow when it is normal, and the opposite can also occur. Finally, incorrect interpretation of a substantially increased nuchal translucency may lead to a false impression of an ominous fetal prognosis or may be confounded with a cystic hygroma. Copyright © 2008 John Wiley & Sons, Ltd.
First‐trimester contingent screening for Down syndrome can reduce the number of nuchal translucency measurements required
Authors: Vadiveloo Thenmalar , Crossley Jennifer A. , Aitken David A. 
Published: December 2008

AbstractBackgroundTo assess the performance of a two‐stage screening protocol for Down syndrome based on initial serum marker analysis for all women and nuchal translucency (NT) measurement only in women with intermediate risks.MethodsBiochemical marker and NT data in 10 189 women who had had combined ultrasound and biochemical (CUB) screening, were re‐analysed using the contingent model. A risk was calculated from the results of the pregnancy‐associated plasma protein A (PAPP‐A) and free β human chorionic gonadotrophin (FβhCG) measurements and maternal age. For risks between 1 in 42 and 1 in 1000, the likelihood ratio from the NT measurement was incorporated and assessed against a final cut‐off risk of 1 in 250.ResultsA total of 3.1% unaffected and 61.4% Down syndrome pregnancies had risks ≥ 1: 42. In women with risks < 1 in 42 and > 1 in 1000 (29%), a further 2.7% unaffected pregnancies and 27.3% Down syndrome pregnancies had risks above 1 in 250 when NT was incorporated. Overall detection rate was 88.6%, and false positive rate 5.8% (compared with 90.9% and 6.4% for CUB screening). NT measurements were required in 29% of women.ConclusionsWithin first‐trimester, contingent screening provides good sensitivity and specificity with the potential for considerable saving in ultrasound resources. Copyright © 2008 John Wiley & Sons, Ltd.
Planar aqueous electrode technique for polymer impedance spectroscopy
Authors: Bai T. , Bradshaw R.D. , Ramanathan T. , Nunalee F.N. , Shull K.R. , Mason T.O. , Brinson L.C. 
Published: December 2008

AbstractIn this article, we develop an aqueous electrode technique that can adapt to complex sample geometries while maintaining perfect contact between the electrodes and the measured sample. In contrast to surface deposited electrodes, the aqueous electrode technique measures the ionic conduction of the polymer sample instead of the inherent dielectric properties of the polymer. Polymer ionic conduction is often related to the polymer thermodynamic state, which itself is closely linked to many other polymer properties. As such, the aqueous electrode method provides an approach to conduct in situ monitoring of polymer samples subjected to degradation; changes in the impedance provide an indication of polymer sample degradation. This article presents the aqueous electrode setup and discusses experimental results obtained using it. Changes in the impedance response of PVC and polyimide films due to moisture absorption, ionic conduction, pinholes, chemical degradation, and temperature are presented. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Cephalosporins – do they still have a role in primary care?
Authors: Thompson Angus 
Published: December 2008

AbstractCephalosporins are barely mentioned in the HPA's guidance on treating infection and there is rising concern over their role in the development of C. difficile. Angus Thompson argues that, with suitable alternatives available, there is little reason to continue prescribing them. Copyright © 2008 Wiley Interface Ltd
Characterization of silver selenide thin films grown on Cr‐covered Si substrates
Authors: Mohanty Bhaskar Chandra , Malar P. , Osipowicz Thomas , Murty B. S. , Varma Shikha , Kasiviswanathan S. 
Published: December 2008

AbstractThermal stability of silver selenide thin films formed from the solid‐state reaction of Ag‐Se diffusion couples on Si substrates covered with a thin Cr film, is investigated. Glancing angle X‐ray diffraction (GXRD), XPS, atomic force microscopy (AFM) and Rutherford backscattering spectrometry (RBS) are used to characterize the as‐deposited films and those annealed at 100, 200, 300, and 400 °C. The results reveal the formation of polycrystalline orthorhombic silver selenide films that remain stable without compositional change upon thermal annealing, in marked contrast to the agglomeration exhibited by silver selenide films deposited on Si without Cr film. The improvement in the thermal stability is attributed to compressive stress relief by a grainy morphology with large surface area, the formation of which is promoted by partially oxidized Cr adhesion film. Copyright © 2008 John Wiley & Sons, Ltd.
Overlayer thickness determination by XPS using the multiline approach
Authors: Jablonski A. , Zemek J. 
Published: December 2008

AbstractAn important analytical application of x‐ray photoelectron spectroscopy is the possibility of determining the overlayer thickness in the nanometer range. The relevant procedure should be based on a realistic theoretical model relating the photoelectron signal intensities, measured for the overlayer and for the substrate, to the overlayer thickness. In the most frequently used procedure, we derive the thickness from the ratio of intensity measured for the overlayer and intensity measured for the substrate. We may expect that the resulting thickness depends on the pair of intensities selected for analysis. This is due to the fact that each calculated intensity has a certain systematic error associated with accuracy of parameters used in calculations.We consider here a possibility of using more than two intensities, for a given element, in the procedure of thickness determination. In this way, we expect that the analysis is more accurate due to the fact that the systematic errors are averaged. In the past, similar approach has been successfully applied to the procedure of surface composition determination. To test the proposed multiline approach, the Au 4f, Ni 2p, and Ni 3p intensities were measured for a series of Ni overlayers deposited on the Au substrate. It has been found that the proposed approach well performs at relatively large overlayer thicknesses. It provides values that are averages of values obtained from other methods. At small overlayer thicknesses, we observe a scatter of thicknesses obtained from different methods which can be due to the discontinuity of the overlayer. Copyright © 2008 John Wiley & Sons, Ltd.
Fear‐avoidance‐ and endurance‐related responses to pain: Development and validation of the Avoidance‐Endurance Questionnaire (AEQ)
Authors: Hasenbring Monika I. , Hallner Dirk , Rusu Adina C. 
Published: December 2008

ABSTRACTAim of investigation: Recent research indicated wide variability regarding pain‐related cognitive/affective and behavioral responses to pain, showing that fear‐avoidance responses (FAR) and endurance‐responses (ER) play a prominent role in the maintenance of low back pain (LBP). Until now, there is a lack of reliable and valid instruments covering FAR and ER.Methods: A pool of 60 items, derived from the Kiel Pain Inventory was answered by 191 LBP patients. Principle components analyses (PCA) was used to explore the factor structure creating the Avoidance‐Endurance Questionnaire (AEQ). Validity was calculated using the criteria variables pain intensity, disability, chronic pain grades (CPG) and number of sick days, further self‐report measures (Fear‐Avoidance Beliefs Questionnaire FABQ, Pain Anxiety Symptoms Scale PASS, Tampa Scale of Kinesiophobia TSK and Beck Depression Inventory BDI) evaluating construct validity.Results: PCA revealed five AEQ–FAR scales with anxiety/depression, catastrophizing, help‐/hopelessness, avoidance of social activities, avoidance of physical activities, and four AEQ–ER scales with positive mood, thought suppression, pain persistence behavior and humor/distraction. All scales revealed high internal consistency. As expected, FAR scales showed positive associations with pain, disability and other FAR variables (correlations between r=.26 and r=.58), whereas ER scales showed negative associations (between r=−.19 and −.48). The only exception referred to positive correlations between both, FAR and ER and pain intensity.Conclusions: The AEQ has shown as a reliable and valid measure to assess pattern of fear‐avoidance and endurance‐related responses to pain. Both aspects seem to play a role in the maintenance of LBP.
Cortical changes in complex regional pain syndrome (CRPS)
Authors: Swart C.M.A. Karin , Stins John F. , Beek Peter J. 
Published: December 2008

ABSTRACTRecent research suggests that changes in cortical structures can contribute to the pathophysiology of Complex Regional Pain Syndrome (CRPS). This review provides an overview of studies showing cortical involvement in CRPS, including mislocalizations of tactile stimuli, changes in size and organization of the somatosensory map, changes in motor cortex representation and body perception disturbances. In addition, we review experimental treatment approaches, such as mirror therapy and motor imagery programs, aimed at restoring the integrity of neural processing in the sensory‐motor cortex in individuals with CRPS. The intervention effects are promising and can be theoretically motivated on the basis of established principles of neural organization, although important questions concerning the precise neural mechanisms of action remain unanswered.