bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymorphisms in the 5α reductase type 2 gene and urologic measures of BPH
Authors: Roberts Rosebud O. , Bergstralh Erik J. , Farmer Sara A. , Jacobson Debra J. , McGree Michaela E. , Hebbring Scott J. , Cunningham Julie M. , Anderson Sarah A. , Thibodeau Stephen N. , Lieber Michael M. , Jacobsen Steven J. 
Published: September 2004

AbstractBACKGROUNDThe objective of the study was to examine associations between SRD5A2 polymorphisms and measures of benign prostatic hyperplasia (BPH).METHODSParticipants were 510 Caucasian men (median age 60 years), randomly selected from the Olmsted County, MN community to participate in a longitudinal study of BPH. From 1990 through 2000, biennial measurements of lower urinary tract symptom severity (assessed from the American Urological Association Symptom Index, AUASI), peak urinary flow rates (Qmax), and prostate volume were made. Genotyping of SRD5A2 V89L, A49T, and TA repeat polymorphisms were performed.RESULTSCompared with the VV genotype, the LL genotype was associated with an enlarged prostate (Hazard ratio (HR) = 1.62, 95% confidence interval (CI) = 1.06, 2.43) but not with AUASI, Qmax, or PSA. The A49T and TA repeat polymorphisms were not associated with BPH. When the LL/VL, AT/TT, and TA(0)/TA(0) genotypes were considered high risk, the number of high risk genotypes increased with increasing prostate volume (32.3, 30.7, 34.1, and 38.7, respectively, P for trend = 0.04).CONCLUSIONSThese findings do not demonstrate consistent associations between SRD5A2 genotypes and BPH. However, they suggest that the associations of V89L polymorphisms and prostate volume should be investigated further. © 2004 Wiley‐Liss, Inc.
Spatial and temporal distribution of imidacloprid and thiamethoxam in citrus and impact on Homalodisca coagulata populations
Authors: Castle Steven J , Byrne Frank J , Bi Jian L , Toscano Nick C 
Published: September 2004

AbstractTiters of two systemic neonicotinoid insecticides in citrus trees were measured in conjunction with conventional evaluations of their impact on glassy‐winged sharpshooter (Homalodisca coagulata (Say); GWSS) populations. Xylem fluid samples were collected at regular intervals and from multiple locations within field‐grown citrus trees to determine imidacloprid and thiamethoxam concentrations using commercial ELISA kits. Uptake profiles varied considerably with peak mean titers of imidacloprid occurring 6–8 weeks after application compared with 2 weeks for thiamethoxam. The persistence of each compound also varied as near‐peak levels of imidacloprid were sustained for another 6–10 weeks before gradually declining. In contrast, thiamethoxam titers declined more rapidly after the initial peak, possibly reflecting an application rate only one‐quarter of that used for imidacloprid. Within‐tree distributions were more similar for the two compounds, with no significant effect due to height of the sample (upper or lower half) or to the quadrant location within the tree, with the exception of one quadrant in the thiamethoxam‐treated trees. Substantial reductions in GWSS nymphs and adults were observed in imidacloprid‐treated trees during the 2001 trial and were sustained for 4–5 months after treatment. Treatment effects on nymphs were not as well pronounced in the 2002 trial, when overall GWSS infestations were much reduced from the previous year. However, consistently lower adult infestations were still observed in 2002 for both treatments compared with untreated trees. Information on the spatial and temporal profiles in citrus trees was obtained for both compounds to complement field impact data and improve understanding of their pest management potential. Copyright © 2004 Society of Chemical Industry
Structural analysis of thick GaN films grown by hydride vapour phase epitaxy
Authors: Ruterana Pierre , Chen Jun , Nouet Gérard , Lei Benliang , Ye Haohua , Yu Guanghui , Qi Ming , Li Aizhen 
Published: September 2004

AbstractThick GaN films were deposited on sapphire substrate by hydride vapour phase epitaxy (HVPE) in two steps at 1050 °C. The substrate was first nitridated for different times between 1 and 10 minutes before deposition of a 12 μm thick layer. X‐ray rocking curves show a minimum for 5 and 7 minutes of nitridation. The shift of the photoluminescence peak (PL) at room temperature from 3.328 to 3.405 eV is consistent with the evolution of the microstructure which is characterised by non‐compact layers for the shortest times of nitridation. The nitridation of the sapphire surface results in the formation of a damaged layer with a thickness varying with the nitridation times. In this interfacial area, flat interfaces are present, but AlN nanocrystals may be observed as well as an amorphous zones containing Al, O and N. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman spectroscopy with UV excitation on untwinned single crystals of YBa2Cu3O7–δ
Authors: Bahrs S. , Reich S. , Zwick A. , Goñi A. R. , Bacsa W. , Nieva G. , Thomsen C. 
Published: September 2004

AbstractRecent reflectance anisotropy studies on the material showed a photobleaching effect in the in‐plane components of the dielectric function around 2.2 and 4.1 eV [1]. We present Raman spectra of oxygen deficient YBa2Cu3O7–δ detwinned single crystals taken with laser excitation of 3.7 eV, close to the UV feature in the dielectric function, in search for a signal from the defect‐induced Raman modes. While two groups of defect‐induced mode at 230 cm–1 and 600 cm–1 behave very similar at the 2.2 eV resonance, we find clear differences for UV excitation. A peak at 600 cm–1 is identified as a copper‐oxygen‐chain related, defect‐induced modes by its Raman selection rules. While this mode is enhanced beyond the strength of the Raman‐allowed modes, the group at 230 cm–1 is absent. Low temperature experiments showed no change of the peak height under illumination, though the peaks are known to photobleach in the visible. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical study of hydrogen bonds between acetylene and selected proton donor systems
Authors: Bende A. , Vibók Á. , Halász G. J. , Suhai S. 
Published: September 2004

AbstractThe equilibrium structures, the binding energies, and the second‐order energy components of a series of hydrogen‐bonded complexes involving acetylene are studied. The strength of the binding energy of the selected systems (HF … HCCH, HCl … HCCH, HCN … HCCH, and HCCH … HCCH) was different, ranging from a very weak interaction to a strong interaction. Calculations have been carried out at both the Hartree–Fock and correlated (second‐order Møller–Plesset perturbation theory) levels of theory, using several different basis sets [6‐31G(d,p), 6‐311G(d,p), 6‐31G++(d,p), 6‐311G++(d,p), 6‐31++G(2d,2p) and 6‐311++G(2d,2p)]. The widely used a posteriori Boys–Bernardi counterpoise (CP) correction scheme has been compared with the a priori CHA/CE, CHA–MP2, and CHA–PT2 methods, using the chemical Hamiltonian approach (CHA). The results show that at both levels the CP and the appropriate CHA results are very close to each other. Only the monomer‐based CHA‐PT2 theory gives slightly overcorrected results, reflecting that the charge transfer and polarization effects are not taken into account in this method up to second order. We have also applied our earlier developed energy decomposition scheme in order to decompose the second‐order energy contribution into different physically meaningful components. The results show that at large and intermediate intermolecular distances, the second‐order intermolecular contribution is almost equal to the sum of different physically meaningful components (e.g., polarization, charge transfer, dispersion), while at shorter distances the slightly strong overlap effects fairly disturb this simple additivity. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Structures and isomerization of neutral and zwitterion serine–water clusters: Computational study
Authors: Jeon In‐Sun , Ahn Doo‐Sik , Park Sung‐Woo , Lee Sungyul , Kim Bongsoo 
Published: September 2004

AbstractCalculations are presented for the structure and the isomerization reaction of various conformers of the bare serine, neutral serine–(H2O)n and serine zwitterion–(H2O)n (n = 1, 2) clusters. The effects of binding water molecules on the relative stability and the isomerization processes are examined. Hydrogen bonding between serine and the water molecule(s) may significantly affect the relative stability of conformers of the neutral serine–(H2O)n (n = 1, 2) clusters. The sidechain (OH group) in serine is found to have a profound effect on the structure and isomerization of serine–(H2O)n (n = 1, 2) clusters. Conformers with the hydrogen bonding between water and the hydroxyl group of serine are predicted. A detailed analysis is presented of the isomerization (proton transfer) pathways between the neutral serine–(H2O)2 and serine zwitterion–(H2O)2 clusters by carrying out the intrinsic reaction coordinate analysis. At least two water molecules need to bind to produce the stable serine zwitterion–water cluster in the gas phase. The isomerization for the serine–(H2O)2 cluster proceeds by the concerted double and triple proton transfer mechanism occurring via the binding water molecules, or via the hydroxyl group. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Erratum: Fillmore Freeman, Nina Asgari, Behrooz Entezam, Faranak Gomarooni, Jolene Mac, Monet H. Nguyen, Nhu N. T. Nguyen, Thao P. Nguyen, Ngoc B. Pham, Perveen Sultana, Timothy S. Welch, Bagrat A. Shainyan, “Computational study of sulfoxides of thiacyclohexane, 4‐silathiacyclohexane, 4‐fluoro‐4‐silathiacyclohexane, and 4,4‐difluoro‐4‐silathiacyclohexane: Relative energies of conformations and sulfinyl oxygen stabilized pentacoordinate silicon in boat and twist structures,” International Journal of Quantum Chemistry (2004)
Authors: Freeman Fillmore , Asgari Nina , Entezam Behrooz , Gomarooni Faranak , Mac Jolene , Nguyen Monet H. , Nguyen Nhu N. T. , Nguyen Thao P. , Pham Ngoc B. , Sultana Perveen , Welch Timothy S. , Shainyan Bagrat A. 
Published: September 2004

AbstractThe original article to which this Erratum refers was published in International Journal of Quantum Chemistry (2004)The above affiliations were printed incorrectly. The correct affiliations are as follows.1 Department of Chemistry, University of California, Irvine, California 92697‐20252 A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Division of Russian Academy of Science, 1 Favorsky Street, Irkutsk 664033, Russian FederationWe apologize for any inconvenience this may have caused.
Selective detection of monohydroxy metabolites of polycyclic aromatic hydrocarbons in urine using liquid chromatography/triple quadrupole tandem mass spectrometry
Authors: Xu Xu , Zhang Junfeng , Zhang Lin , Liu Weili , Weisel Clifford P. 
Published: September 2004

AbstractPolycyclic aromatic hydrocarbons (PAHs) are ubiquitously present in the environment and associated with a variety of adverse health effects. Monohydroxylated PAHs (OH‐PAHs), metabolites of PAHs, have been employed as biomarkers for human exposure assessment of PAHs. This manuscript describes new, selective detection methods for OH‐PAHs using liquid chromatography and tandem mass spectrometry (LC/MS/MS). Electrospray ionization was operated in the negative ion mode to detect the deprotonated PAH metabolites ([MH]−). Hydroxylated metabolites of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, benzo[c]phenanthrene, chrysene, benzo[a]anthracene, and benzo[a]pyrene were selected for the method development. Based on the collision‐induced dissociation MS/MS spectra of the selected OH‐PAHs, a characteristic ion fragmentation, loss of 28 Da from the [MH]− ion, was identified for all of these OH‐PAHs. This characteristic fragmentation was exploited for selective screening for OH‐PAHs in human urine by incorporating a constant neutral loss (CNL) scan with data‐dependent scanning, using a triple quadruple mass spectrometer. Selected reaction monitoring (SRM) was also used to tentatively identify isomers of the target OH‐PAHs in human urine. The excellent linearity (3–4 orders of magnitude) and signal‐to‐noise performance provided by the SRM method allowed development of a sensitive LC/MS/MS method for measuring OH‐PAHs in urine samples. The limits of detection of the SRM method ranged from approximately 0.1–5 pg on column for a suite of OH‐PAHs tested in the study. The LC‐SRM method was applied, following enzymatic deconjugation and solid‐phase extraction of the urine, to preliminarily determine the OH‐PAH concentrations in urine specimens from six Chinese non‐occupationally exposed workers and seven Chinese coke oven workers. Copyright © 2004 John Wiley & Sons, Ltd.
Identification of monovinyl tripropionic acid porphyrins and metabolites from faeces of patients with hereditary coproporphyria by high‐performance liquid chromatography/electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry
Authors: Danton Malcolm , Lim Chang Kee 
Published: September 2004

AbstractHarderoporphyrin (2‐vinyl‐4,6,7‐tripropionic acid porphyrin) and its metabolites in faeces of patients with hereditary coproporphyria (HCP) have been separated and characterized by high‐performance liquid chromatography/electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry (HPLC/ESI‐Q‐TOFMS/MS). The metabolites identified were 2‐ethyl‐4,6,7‐tripropionic acid porphyrin, 2‐hydro‐4,6,7‐tripropionic acid porphyrin, 2‐methoxyethyl‐4,6,7‐tripropionic acid porphyrin and 2‐acetyl‐4,6,7‐tripropionic acid porphyrin. Isomers of harderoporphyrin derived from isomerization of harderoporphyrinogen were also detected. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of humic substances by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Mugo Samuel M. , Bottaro Christina S. 
Published: September 2004

AbstractMatrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) and laser desorption/ionization (LDI‐)TOFMS have been used to characterize Suwannee River humic substances, obtained from the International Humic Substances Society (IHSS), and Armadale soil fulvic acid (ASFA). An array of MALDI matrices were tested for use with humic substances, including α‐cyano‐4‐hydroxycinammic acid (CHCA), 2‐(4‐hydroxyphenylazo)benzoic acid (HABA), 2,5‐dihydroxybenzoic acid (DHBA), sinapinic acid, dithranol and norharmane. DHBA yielded the best results, exhibiting superior ionization efficiency, low noise, broad applicability to the analytes of interest, and most importantly producing an abundance of high mass ions, the highest observed being m/z 1848. A number of sample preparation modes were investigated; the overlayer method improved sample/matrix homogeneity and hence shot‐to‐shot reproducibility. The choice of the matrix, mass ratio of analyte to matrix, and the sample preparation protocol, were found to be the most critical factors governing the quality of the mass spectra. Matrix suppression was greatly enhanced by ensuring good mixing of matrix and analyte in the solid phase, proper optimization of the matrix/analyte ratio, and optimizing delayed extraction to ensure complete matrix–analyte reaction in the plume before ions are moved to the flight tube. A number of common features, in particular specific ions which could not be attributed to the matrices or to contaminants, were present in the spectra of all the humic substances, regardless of origin or operational definition. Additionally, a prominent repeating pattern of peaks separated by 55, 114 and 169 Da was clearly observed in both LDI and MALDI, suggesting that the humic compounds studied here may have quasi‐polymeric or oligomeric features. Copyright © 2004 John Wiley & Sons, Ltd.
Online measurement of rheological properties of PVC/wood‐flour composites
Authors: Shah Bhavesh L. , Matuana Laurent M. 
Published: September 2004

AbstractBy using a factorial design approach, this study examined the effect of the component materials on the viscoelastic properties of PVC/wood‐flour composites. Statistical analysis was performed to determine the effects of wood‐flour content, acrylic modifier content, and plasticizer content on the die swell ratio and viscosity of the composites measured online on a conical twin‐screw extrusion capillary rheometer. The viscoelastic properties of the samples also were measured using dynamic mechanical analyzer (DMA). Wood‐flour content and acrylic modifier content were the two important variables affecting the die swell ratio, whereas the addition of a low level of plasticizer did not affect this ratio. The die swell increased with the increased acrylic modifier content, but it was reduced considerably by adding wood flour into the PVC matrix. The true viscosity of neat PVC and PVC/wood‐flour composites decreased with the plasticizer content, irrespective of the acrylic modifier content. However, the addition of acrylic modifier significantly increased the viscosity of unfilled PVC, while an opposite trend was observed for the composites, owing to the differing effect of acrylic modifier on the melt elasticity and viscosity of these materials. J. Vinyl Addit. Technol. 10:121–128, 2004. © 2004 Society of Plastics Engineers.
Performance benefits of TPE inter‐material substitution using metallocene ethylene elastomers
Authors: Weaver Laura B. , Vercuski Phil , Waszeciak Doug 
Published: September 2004

AbstractThermoplastic elastomers (TPEs) are one of the fastest‐growing segments of the plastic compounding market and are projected to grow at an annual rate of 5%–6% (1). By offering additional options and benefits on the price‐performance curve, thermoplastic olefins (TPOs) are expected to grow at higher rates than many styrenics and thermoplastic vulcanizates (TPVs) in automotive, durables and construction market sectors. Traditionally, these markets initially specify materials that may be over‐engineered in an application to ensure they fully meet the required properties. Over time, however, specifiers are often forced to shift their focus to reduce costs via new material substitution, provided they can continue to meet the required properties. Likewise, inter‐material substitution is a common trend based on the product delivering improved performance over the incumbent material at comparable costs, such as the movement to replace f‐PVC compounds with soft TPOs in automotive interior thermoformed sheeting. The soft TPOs based on metallocene ethylene elastomers offer improved cold‐temperature‐impact performance, lower part weight, and extended lifetime durability over f‐PVC at essentially the same part cost. This paper offers a comparison of emerging soft TPO compounds based on metallocene ethylene elastomers with styrene tri‐block polymer (SEBS), TPVs and f‐PVC compounds. J. Vinyl Addit. Technol. 10:129–136, 2004. © 2004 Society of Plastics Engineers.
Layout and first XRF applications of the BAMline at BESSY II
Authors: Riesemeier H. , Ecker K. , Görner W. , Müller B.R. , Radtke M. , Krumrey M. 
Published: September 2004

AbstractThe first hard x‐ray beamline at BESSY II has been installed by BAM and PTB at a superconducting 7 T wavelength shifter. The main optical elements of the beamline are a double‐multilayer monochromator and a double‐crystal monochromator. Depending on the application, the two devices are used separately or in‐line. The main applications of the monochromatic radiation with photon energies up to 60 keV are x‐ray fluorescence analysis, micro computed tomography, x‐ray topography, detector calibration and reflectometry. Calculable undispersed radiation up to 200 keV is available for radiometric applications. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of pulsed versus conventional radiofrequency current on rabbit dorsal root ganglion morphology
Authors: Erdine Serdar , Yucel Aysen , Cimen Ali , Aydin Salih , Sav Aydin , Bilir Ayhan 
Published: September 2004

AbstractLesioning using radiofrequency (RF) current has been increasingly used in clinical practice for the treatment of pain syndromes. Although formation of heat causing “thermocoagulation” of the nervous tissues is thought to be responsible of the clinical outcome, a more recent modality of RF application named pulsed radiofrequency (PRF) delivers the RF current without producing destructive levels of heat. In our study, we compared the effects of conventional RF (CRF) and PRF on rabbit dorsal root ganglion (DRG) morphology, including also control and sham operated groups. The setting of the experiment and the RF parameters used were similar to those used in current clinical practice. The specimens were analyzed both with light microscopy and electron microscopy, two weeks after the procedure. At the light microscopic level, all groups had preserved the normal DRG morphology and no differences were observed between them. In the electron microscopic analysis there were no pathological findings in the control and sham operated groups. But the ganglion cells in the RF groups had enlarged endoplasmic reticulum cisterns and increased number of cytoplasmic vacuoles which were more evident in the CRF group. Some of the ganglion cells in the CRF group had mitochondrial degeneration, nuclear membrane disorders or loss of nuclear membrane and neurolemma integrity. The myelinated and unmyelinated nerve fibers were of normal morphology in all groups. Our results suggest that PRF application is less destructive of cellular morphology than CRF at clinically used “doses”. Before making certain judgements, more experimental and clinical studies should be planned.
Population genetic structure of the kuruma prawn (Penaeus japonicus) in East Asia inferred from mitochondrial DNA sequences
Authors: Tzeng Tzong-Der , Yeh Shean-Yeh , Hui Cho-Fat 
Published: September 2004

AbstractSequence analyses on the complete mitochondrial DNA (mtDNA) control region (992 bp) were conducted to elucidate the population structure of kuruma prawns (Penaeus japonicus) in East Asia. Five populations including 95 individuals were collected. They are separated into the Japan Sea (JS), the north and south of the East China Sea (NECS and SECS), the Taiwan Strait (TS), and the north of the South China Sea (NSCS) populations. There are 292 variable sites without any insertions and deletions. Nucleotide diversity in the total populations is 2.51 ± 0.07%, and the variations within populations ranged from 2.61 ± 0.93% (SECS) to 2.29 ± 0.16% (JS). FST values between the JS and the rest of the populations, between the NECS and NSCS populations, and between the SECS and NSCS populations show significant differences. The UPGMA tree of these five populations shows three distinct clusters; one includes the JS population; another includes the NECS population; the third includes populations from the rest of the areas. The analysis of molecular variance (AMOVA) shows clear genetic difference between the JS and the rest of the populations. Additional AMOVA analysis excluding the JS population indicates significant variation between the NECS population and the other three populations. We, therefore, conclude that three distinct populations exist in East Asia; one is in the JS; another is in the NECS; and the third is distributed in SECS, TS and NSCS.