bluuebunny/crossref_metadata_2025_split huggingface dataset:
QSPR Study of Fluorescence Wavelengths (λex/λem) Based on the Heuristic Method and Radial Basis Function Neural Networks
Authors: Shi Jing , Luan Feng , Zhang Haixia , Liu Mancang , Guo Qingxiang , Hu Zhide , Fan Botao 
Published: October 2005

AbstractThe Quantitative Structure–Property Relationship (QSPR) method was performed to study the fluorescence excitation wavelengths (λex) and emission wavelengths (λem) of 64 fluorescent probes. The probes included the derivatives of dansyl, bimane, pyrene, benzofurazan, nonaphthalene, coumarin, anthracene and fluorescein, with the wavelength ranging from 300 nm to 600 nm. The Heuristic Method (HM) and Radial Basis Function Neural Networks (RBFNNs) were employed to construct linear and nonlinear prediction models, respectively. The proposed linear models for λex and λem contain five descriptors with the squared correlation coefficients R2 of 0.888 and 0.897, respectively. Better prediction results were obtained from RBFNN model, with the squared correlation coefficients R2 of 0.948 and 0.939 for λex and λem, respectively. The descriptors used in the models were discussed in detail too.
Estimation of Phosphate Ester Hydrolysis Rate Constants. I. Alkaline Hydrolysis
Authors: Whiteside Tad S. , Hilal S. H. , Carreira L. A. 
Published: October 2005

AbstractSPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to allow the calculation of alkaline hydrolysis rate constants of phosphate esters in water. The rate is calculated from the energy difference between the initial and transition states of a molecule. This difference is a function of the reference rate and internal and external perturbations to the reference rate. The internal perturbations are comprised of electrostatic and resonance effects. The external perturbations quantify solute‐solvent interactions based on the dielectric constant of the solvent and the steric effect of substituent groups. These perturbation models have been tested using 225 reliably measured second order hydrolysis rate constants over a variety of temperatures. The RMS deviation of the calculated versus observed values was 0.401 log M−1s−1.
Mass spectrometry of stanozolol and its analogues using electrospray ionization and collision‐induced dissociation with quadrupole‐linear ion trap and linear ion trap‐orbitrap hybrid mass analyzers
Authors: Thevis Mario , Makarov Alexander A. , Horning Stevan , Schänzer Wilhelm 
Published: October 2005

AbstractMass spectrometric identification and characterization of growth‐promoting anabolic‐androgenic steroids in biological matrices has been a major task for doping control as well as food safety laboratories. The fragmentation behavior of stanozolol, its metabolites 17‐epistanozolol, 3′‐OH‐stanozolol, 4α‐OH‐stanozolol, 4β‐OH‐stanozolol, 17‐epi‐16α‐OH‐stanozolol, 16α‐OH‐stanozolol, 16β‐OH‐stanozolol, as well as the synthetic analogues 4‐dehydrostanozolol, 17‐ketostanozolol, and N‐methyl‐3′‐OH‐stanozolol, was investigated after positive electrospray ionization and subsequent collision‐induced dissociation utilizing a quadrupole‐linear ion trap and a novel linear ion trap‐orbitrap hybrid mass spectrometer. Stable isotope labeling, H/D‐exchange experiments, MS3 analyses and high‐resolution/high mass accuracy measurements of fragment ions were employed to allow proposals for charge‐driven as well as charge‐remote fragmentation pathways generating characteristic product ions of stanozolol at m/z 81, 91, 95, 105, 119, 135 and 297 and 4‐hydroxylated stanozolol at m/z 145. Fragment ions were generated by dissociation of the steroidal A‐ and B‐ring retaining the introduced charge within the pyrazole function of stanozolol and by elimination of A‐ and B‐ring fractions including the pyrazole residue. In addition, a charge‐remote fragmentation causing the neutral loss of methanol was observed, which was suggested to be composed by the methyl residue at C‐18 and the hydroxyl function located at C‐17. Copyright © 2005 John Wiley & Sons, Ltd.
Cu(II)‐loaded iminodiacetic acid‐silica particles for protein profiling of human serum samples using surface‐enhanced affinity capture: support porosity effects
Authors: Trojer L. , Stecher G. , Feuerstein I. , Bonn G. K. 
Published: October 2005

AbstractSilica particles of different porosity were functionalised with iminodiacetic acid (IDA) and loaded with Cu(II) ions to yield Cu(II)‐IDA‐silica. These immobilised metal affinity chromatography (IMAC) materials were subjected to a comprehensive characterisation study. The Cu(II) content – determined via UV/Vis spectroscopy and atomic absorption spectroscopy (AAS) – was found to be linearly dependent on the specific surface area of the silica particles. The evaluation of protein adsorption isotherms provided information on binding properties towards biomolecules. The data fitted Langmuir's adsorption theory. Binding capacity of hen egg white lysozyme (HEWL) was highest for Cu(II)‐IDA‐silica with mean pore diameter of 120 Å, reaching nearly 350 mg/g. All derivatised materials were applied to the fractionation of human serum samples and subsequent mass spectrometric analysis (m/z: 2000–10 000) according to a surface‐enhanced affinity capture (SEAC) protocol. Pore size of the support material affected the appearance of the mass spectra to a great extent, showing that surface morphology is another parameter that has to be considered in addition to surface chemistry. Signal intensity as well as the number of detected masses were strongly dependent on the pore diameter, indicating that the carrier material has to be carefully chosen to assure best results. Copyright © 2005 John Wiley & Sons, Ltd.
Laser ablation synthesis of selenium superoxide anion SeO via selenium trioxide photolysis. Time‐of‐flight mass spectrometry and ab initio calculations
Authors: Alberti Milan , Špalt Zbyněk , Peña‐Méndez Eladia María , Ramírez‐Galicia Guillermo , Havel Josef 
Published: October 2005

AbstractLaser desorption/ionisation and laser ablation of solid selenium trioxide, as well as the gas‐phase behaviour of selenium trioxide, were studied. Selenium trioxide undergoes photochemical decomposition and, from the mass spectra obtained by laser desorption/ionisation time‐of‐flight mass spectrometry (LDI‐TOF‐MS), the following species were identified: O−, O, O, SeO−, SeO, SeO, SeO, Se2O, Se3O, and Se4O. Formation of the selenium superoxide SeO anion is described in this work for the first time. In addition, low‐abundance selenium species such as Se2O8H, Se3O11H−, and Se4O15H were also detected. The stoichiometry of all ions was confirmed via isotopic pattern modeling and/or post‐source decay (PSD) analysis. Photolysis of selenium trioxide leads partly to ozone formation. It was found that the most likely mechanisms of selenium superoxide formation are oxidation of selenium trioxide with ozone and/or reactive oxygen radicals, or photolysis of selenium trioxide tetramer (SeO3)4. Therefore, ab initio calculations were performed to support the mass spectrometric evidence and to suggest probable geometries for selenium superoxide anion SeO and diselenium superoxide anion Se2O, as well as to provide insight into and/or predict possible formation pathways. It has been found that both cyclic and non‐cyclic peroxide structures of SeO and Se2O ions are possible. In addition, the SeO4 structure was also calculated guided by thermodynamic considerations using Gaussian‐2 methodology, and the inferred stability of the SeO4 neutral molecule was supported by ab initio calculations. Copyright © 2005 John Wiley & Sons, Ltd.
Determination of microbial volatile organic compounds from Staphylococcus pasteuri against Tuber borchii using solid‐phase microextraction and gas chromatography/ion trap mass spectrometry
Authors: Barbieri E. , Gioacchini A. M. , Zambonelli A. , Bertini L. , Stocchi V. 
Published: October 2005

AbstractThe mycelium of Tuber borchii Vittad., a commercial truffle species, is used as a model system for in vitro ectomycorrhizal synthesis, infected seedling production and biotechnological applications. Our fungal cultures were accidentally contaminated with a Staphylococcus pasteuri strain, showing a strong antifungal activity against T. borchii mycelium. In order to identify the antifungal volatile agents produced by S. pasteuri, solid‐phase microextraction (SPME) with gas chromatography and mass spectrometry (GC/MS) was used. Using this method 65 microbial volatile organic compounds (MVOCs), synthesized by this bacterium in either single or in fungal‐bacterial dual culture, were identified. SPME combined with GC/MS may be a useful method for the determination of MVOCs involved in the antifungal activity. These results showed that bacteria with unusual biological activities could be a major problem during large‐scale production of inoculum for truffle‐infected seedling. Copyright © 2005 John Wiley & Sons, Ltd.
Performance of binary‐encounter‐Bethe (BEB) theory for electron‐impact ionization cross sections of molecules containing heavy elements (Z > 10)
Authors: Scott Gregory E. , Irikura Karl K. 
Published: October 2005

AbstractThe binary‐encounter‐Bethe (BEB) theory developed by Kim and coworkers has been successful for computing electron‐impact ionization cross sections of many molecules. However, some recent publications have stated that BEB theory performs poorly for molecules that contain heavier elements such as chlorine and sulfur. We have found that the BEB calculations in those publications were performed incorrectly. When performed correctly, BEB predictions are as good for heavy‐element molecules as for light‐element molecules. We recommended recently that an alternative, less‐confusing procedure be used for molecules that contain heavier elements. The alternative procedure, based upon effective core potentials (ECPs), does not require explicit kinetic energy corrections. For peak cross sections of a group of 18 molecules, the root‐mean‐square difference between BEB predictions and experimental values is 13%. Results are presented for CCl3CN, C2Cl6, C2HCl5, C2Cl4, both isomers of C2H2Cl4, CCl4, TiCl4, CBr4, CHBr3, CH2Br2, GaCl, CS2, H2S, CH3I, Al(CH3)3, Ga(CH3)3, and hexamethyldisiloxane. Incorrect BEB calculations have been reported in the literature for several of these molecules. Published in 2005 John Wiley & Sons, Ltd.
A new Monte Carlo application for complex sample geometries
Authors: Ritchie Nicholas W. M. 
Published: October 2005

AbstractNISTMonte is a new application for Monte Carlo simulation1, 2 of electron transport, X‐ray generation and transmission in complex sample geometries. NISTMonte uses the Mott cross section3, 4 to model elastic scattering and the Joy–Luo expression5 to model energy loss. The ionization cross section is modeled using the empirical expression of Casnati.6 The mass absorption coefficients are those of Heinrich,7 and the fluorescence yields are tabulated experimental values.8A defining characteristic of the application is the flexibility with which complex sample geometries may be defined. The application provides a set of basic building blocks that may be combined to build complex sample shapes. Furthermore, shapes may be embedded within shapes to model inhomogeneous samples or structured samples. The application imposes no artificial limits on the number of sample regions or on the number of elements within a material.A detailed description of the implementation and the results of various tests, including backscatter yields, will be presented to demonstrate the range of validity of the model and the implementation.The application has been developed in Java J2SE 1.4 for platform independence. The source code will be made available on the NIST web site or by contacting the author. Published in 2005 by John Wiley & Sons, Ltd.
X‐ray microanalysis of real materials using Monte Carlo simulations
Authors: Gauvin Raynald 
Published: October 2005

AbstractIn this paper, new results of Monte Carlo simulations are presented in the context of X‐ray microanalysis in the scanning electron microscope and the variable pressure scanning electron microscope. For the analysis of bulk samples in the scanning electron microscope, the simulation of X rays emitted from porous materials is covered. Modeling of electron scattering in gases is also presented in the context of X‐ray microanalysis in variable pressure scanning electron microscopy. Finally, characterization of electron trajectories from the results of Monte Carlo simulations using the concepts of fractal geometry is described with their implications for quantitative X‐ray microanalysis. Copyright © 2005 John Wiley & Sons, Ltd.
A new examination of secondary electron yield data
Authors: Lin Yinghong , Joy David C. 
Published: October 2005

AbstractA new and thorough examination of secondary electron (SE) yield as a function of primary energy (EPE) and atomic number Z for the 44 elements in the database1 is made. The principles of the semiempirical universal law for the SE yield are described and a template for Monte Carlo (MC) simulation is produced accordingly. Both universal curve fitting and MC simulation are made for the 44 elements. The resulted maximum SE yield δm, corresponding primary energy $E_{\rm {PE}}^{\rm {m}}$, SE excitation energy ε, and effective escape depth λ are tabulated and plotted as a function of atomic number Z. It is found that similarities exist in the profiles of ε and λ, δm and $E_{\rm {PE}}^{\rm {m}}$, and all of these parameters seem to have characteristics associated with atomic shell filling. Copyright © 2005 John Wiley & Sons, Ltd.
Use of Monte Carlo models in the development and validation of CD operators
Authors: Frase Carl Georg , Häßler‐Grohne Wolfgang 
Published: October 2005

AbstractIn this article, different applications of Monte Carlo simulations in scanning electron microscope (SEM) critical dimension (CD) metrology are presented. A first field of application is the analysis of image formation that leads to functional descriptions of secondary electron (SE) signal profiles. From this, algorithms are defined to evaluate the linewidth of microstructures. Monte Carlo generated images are used to validate CD operators and to estimate model‐induced contributions to the CD uncertainty budget. New challenges and new fields of application for Monte Carlo simulations in CD metrology are discussed. Copyright © 2005 John Wiley & Sons, Ltd.
A Monte Carlo model utilizing local chemical potentials for simulating segregation and diffusion. Part 1—theory
Authors: Joubert H. D. , Swart H. C. , Terblans J. J. 
Published: October 2005

AbstractBulk‐to‐surface segregation was studied with a Monte Carlo model based on the modified Darken model.1 Chemical potentials2 are used to represent the local energy of a randomly chosen atom, while the largest positive change in chemical potential directs atomic motion, complying with the conditions associated with the lowering of the Gibbs free energy. An adjustment is made to the calculations to compensate for the segregation energy associated with the surface layer.3 The current model simulates segregation in binary alloys, represented by a crystal matrix containing two constituent elements. A random selection of an atom initiates the calculation process,4 after which the energy of the selected atom, represented by the chemical potential, is calculated for an area that includes nearest and next nearest neighbours. In addition, only nearest neighbour exchanges are allowed, resulting in a maximum of four possible moves. A test move is performed to each of the four move directions, and the chemical potential for each new configuration is calculated. The change in chemical potential for all four exchanges can be calculated, and the probabilities associated with these moves can also be calculated. The exchange that represents the largest positive change in chemical potential will possess the largest probability of motion. By including the segregation energy (associated with the surface) in the calculations, the frequency of jumps from the surface to the bulk is significantly reduced. Copyright © 2005 John Wiley & Sons, Ltd.
Heterotetramers Formed by an S‐Layer–Streptavidin Fusion Protein and Core‐Streptavidin as a Nanoarrayed Template for Biochip Development
Authors: Huber Carina , Liu Jing , Egelseer Eva M. , Moll Dieter , Knoll Wolfgang , Sleytr Uwe B. , Sára Margit 
Published: October 2005

AbstractBased on the S‐layer protein SbpA of Bacillus sphaericus CCM 2177, an S‐layer–streptavidin fusion protein was constructed. After heterologous expression, isolation of the fusion protein, and refolding, functional heterotetramers were obtained that had retained the ability to recrystallize into the square‐lattice structure on plain gold chips and on gold chips precoated with secondary cell wall polymer (SCWP), which is the natural anchoring molecule for the S‐layer protein in the bacterial cell wall. Monolayers generated by recrystallization of heterotetramers on plain gold chips or on gold chips precoated with thiolated SCWP were exploited for the binding of biotinylated oligonucleotides (30‐mers). Hybridization experiments with complementary fluorescently labeled oligonucleotides carrying one mismatch or no mismatch (both 15‐mers) were performed and evaluated with surface‐plasmon‐field‐enhanced fluorescence spectroscopy. For surfaces generated by the recrystallization of heterotetramers on SCWP‐coated gold chips, a detection limit of 1.57 pM could be determined, whereas for surfaces obtained by direct recrystallization of heterotetramers on plain gold chips, a detection limit of 8.2 pM was found. Measuring the association and dissociation processes of oligonucleotides carrying no mismatch led to a dissociation constant of KD=6.3×10−10 m, whereas for oligonucleotides carrying one mismatch a dissociation constant of KD=7.9×10 −9 m was determined. This finding was confirmed by measuring the whole Langmuir isotherm, which resulted in a dissociation constant of KD=2.6×10−8 m.
Microwave‐Assisted Synthesis and Characterization of Succinate Derivatives of Cassava (Manihot esculenta Crantz) Starch
Authors: Jyothi Alummoottil N. , Rajasekharan Kallikat N. , Moorthy Subramoney N. , Sreekumar Janardhanan 
Published: October 2005

AbstractThe use of microwave heating to prepare very rapidly cassava starch succinates with high viscosity is described. A response surface design was used for the experiment and different factors affecting the succinylation of cassava starch, including concentration of succinic anhydride, reaction time, temperature and moisture content of the medium were investigated. The degrees of substitution of the modified starches increased with an increase in reaction time and were in the range 0.007 – 0.051. The products exhibited higher viscosity, lower pasting temperature, enhanced water binding capacity and reduced swelling and paste clarity than unmodified cassava starch. The results of this study indicated that succinylation of starch can be achieved in shorter reaction times, which offers a benefit to laboratories and industries involved in developing newer and more versatile uses for cassava starch.
Development of a biped walking robot actuated by a closed-chain mechanism
Authors: Choi Hyeung-Sik , Park Yong-Heon 
Published: October 2005

We developed a new type of a human-sized BWR (biped walking robot) driven by the closed-chain type of a joint actuator. Each leg of the BWR is composed of three pitch joints and one roll joint. In all, a 12 degree-of-freedom robot, including four arm joints, was developed. The BWR was designed to walk autonomously; it is actuated by small 90W DC motors/drivers and is has DC batteries and controllers. A new type of the joint actuator for the BWR is composed of the four-bar-link mechanism driven by a ball screw which has high strength and high gear ratio despite its light weight.In this paper, analyses on the four-bar-link mechanism applied to the joint actuator and on the structure of the BWR are presented. Through walking experiments of the BWR, the superior trajectory-tracking ability of the proposed joint actuator is validated.
Please – from courtesy to appeal: the role of intonation in the expression of attitudinal meaning
Authors: WICHMANN ANNE 
Published: October 2005

Intonation is known to convey many nuances of meaning, both emotional and attitudinal, but a way of explaining how these meanings arise has so far remained elusive. While some emotions may have direct correlates in a speaker's voice, such correlates are harder to find for attitudinal meanings.The word please is typically a routine expression of courtesy, but data from the International Corpus of British English (ICE GB) reveals please to be a pragmatic marker with a wide range of expressive functions. This study, which uses a quantitative approach combined with qualitative analysis, has implications for the study of other pragmatic particles, and also provides the basis for the understanding of attitudinal intonation in a wider context.
An exploratory study of physiological correlates of neurodevelopmental delay in infants with sickle cell anaemia
Authors: Hogan Alexandra M. , Kirkham Fenella J. , Prengler Mara , Telfer Paul , Lane Roderick , Vargha‐Khadem Faraneh , de Haan Michelle 
Published: October 2005

SummaryThis study aimed to investigate whether infants with sickle cell anaemia (SCA) are at risk of neurodevelopmental delay, and whether any delay is associated with SCA pathology. Twenty‐eight infants (14 SCA; 14 age‐ and ethnic‐similar controls) were assessed longitudinally with the Bayley Infant Neurodevelopmental Screener (BINS) at 3, 9 and 12 months. Transcranial Doppler (TCD) and pulse oximetry (SpO2) measures were recorded longitudinally in SCA infants, and a subgroup of controls. Haemoglobin values were obtained from SCA infants. At each age, SCA infants obtained BINS scores indicative of greater risk of neurodevelopmental delay compared with controls. The number of moderate–high BINS risk scores increased significantly between 3 and 9 months. At 9 months BINS raw scores correlated negatively with TCD velocity and positively with haemoglobin. This exploratory study suggests that SCA infants may be at greater risk of neurodevelopmental delay than previously considered, and may provide the impetus for further research into the very early precursors of cognitive impairment.
A comparison of benthic macroinvertebrate assemblages among different types of alpine streams
Authors: HIEBER MÄGGI , ROBINSON CHRISTOPHER T. , UEHLINGER URS , WARD J. V. 
Published: October 2005

Summary1. Benthic macroinvertebrate assemblages were compared among a diverse array of first‐order alpine tundra streams of the Swiss Alps.2. A principal components analysis separated sites into three main groups: rhithral streams, rhithral lake outlets, and kryal sites including outlets and streams. Rhithral streams contained the most diverse and taxon rich assemblages, being colonised by both non‐insect taxa and Ephemeroptera, Plecoptera, Trichoptera and Diptera.3. Rhithral lake outlets supported high densities of non‐insect taxa such as Oligochaeta, Nemathelminthes and crustaceans. Despite low taxon richness, kryal sites had high Ephemeroptera and Plecoptera abundances. Chironomidae were most common at all sites.4. Collector‐gatherers were dominant at all sites, whereas filter‐feeders were rare. Scrapers and shredders were more common in streams than lake outlets.5. Water temperature and algal standing crops were higher at rhithral lake outlets than rhithral streams, perhaps providing more favourable habitat for non‐insect taxa. Glacial runoff was the dominant factor influencing macroinvertebrate assemblages of kryal streams and kryal lake outlets. Alpine lakes influenced the environmental conditions of their outlets and, consequently, their macroinvertebrate assemblages unless being constrained by a glacial influence.