bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiple linear regression and artificial neural network retention prediction models for ginsenosides on a polyamine‐bonded stationary phase in hydrophilic interaction chromatography
Authors: Quiming Noel S. , Denola Nerissa L. , Saito Yoshihiro , Jinno Kiyokatsu 
Published: April 2008

AbstractThe development of retention prediction models for the seven ginsenosides Rf, Rg1, Rd, Re, Rc, Rb2, and Rb1 on a polyamine‐bonded stationary phase in hydrophilic interaction chromatography (HILIC) is presented. The models were derived using multiple linear regression (MLR) and artificial neural network (ANN) using the logarithm of the retention factor (log k) as the dependent variable for four temperature conditions (0, 10, 25, and 40°C). Using stepwise MLR, the retention of the analytes in all the temperature conditions was satisfactorily described by a two‐predictor model wherein the predictors were the percentage of ACN (%ACN) in the mobile phase and local dipole index (LDI) of the compounds. These predictors account for the contribution of the solute‐related variable (LDI) and the influence of the mobile phase composition (%ACN) on the retention behavior of the ginsenosides. A comparison of the models derived from both MLR and ANN revealed that the trained ANNs showed better predictive abilities than the MLR models in all temperature conditions as demonstrated by their higher R2 values for both training and test sets and lower average percentage deviation of the predicted log k from the observed log k of the test compounds. The ANN models also showed excellent performance when applied to the prediction of the seven ginsenosides in different sample matrices.
Fiberlaser: Beam Sources and Applications
Authors: Hoult Tony , Gabzdyl Jack 
Published: April 2008

AbstractThe worldwide acceptance of anthropogenic global warming has brought a dramatically increased interest in renewable energy resources. This trend led to some interesting developments related to photovoltaics. Firstly, current manufacturing capacity using bulk silicon has grown significantly and caused a worldwide shortage of silicon. Secondly, newer thin film PV (photovoltaic) technology has been pushed forward dramatically, not at least due to the rising cost of silicon. But beside that, the rapid growth of the photovoltaics industry requires new processes where laser technology may obtain a crucial role.
Health benefits of omega‐3 fatty acids from Neptune krill oil
Authors: Massrieh Wael 
Published: April 2008

AbstractOver the last few decades, natural health ingredients have gained the interest and support of both science and industry. The increasing incidence of adverse events associated with synthetic drugs has created a demand for effective and safe alternative treatments. The few natural health ingredients that have been rigorously researched for their safety and efficacy and have passed both peer and regulatory scrutiny can provide a solution to this problem. Neptune krill oil® (NKO®) fulfills these criteria by supporting solid scientifically validated research proving safety and efficacy. Furthermore, the company is involved in several novel clinical trials to further expand its proprietary and innovative portfolio.
Jatropha curcas: A potential source for tomorrow' s oil and biodiesel
Authors: Becker Klaus , Makkar H. P. S. 
Published: April 2008

AbstractGreenhouse gas emission (GHG) is the driving force for global climate change. Deforestation accounts for over 20% of the world's GHG emission and leaves behind deforested areas. It is of utmost importance to revert these areas in a way that carbon is sequestered again. Jatropha curcas, a perennial tree or shrub, is capable of growing on such degraded land and eventually reclaim it. In addition to providing biodiesel of high quality it has several other uses of economic importance. There is an edible genotype of J. curcas that exclusively grows in Mexico. Fatty acid composition of both toxic and non‐toxic genotypes mirrors that of most conventional plant oils used for biodiesel production. Biodiesel produced from J. curcas oil meets all the requirements stipulated by the EU‐Standard EN‐14214. As J. curcas is still a wild plant, initiation of systematic selection and breeding programmes is a prerequisite for sustainable utilization of this plant for oil and biodiesel production.
Olfactory pathogenesis of idiopathic Parkinson disease revisited
Authors: Lerner Alicja , Bagic Anto 
Published: April 2008

AbstractIdiopathic Parkinson disease (PD) is traditionally considered a movement disorder with hallmark lesions located in the substantia nigra pars compacta (SNpc). However, recent histopathological studies of some PD cases suggest the possibility of a multisystem disorder which progresses in a predictable sequence as described in Braak's staging criteria. The disease process starts in the dorsal motor nucleus of the vagus (dmX) and anterior olfactory nucleus and bulb, and from there, spreads through the brainstem nuclei to ultimately reach the SNpc, which then presents as symptomatic PD. In this article, we would like to revisit the olfactory pathogenesis of PD based on Braak's staging system and review anatomical pathways supporting such a possibility. We also suggest some biomarkers for early stages of PD. Additionally, we present and discuss the possibility that a prion‐like process underlies the neurodegenerative changes in PD. © 2008 Movement Disorder Society
The diet‐derived sulforaphane inhibits matrix metalloproteinase‐9‐activated human brain microvascular endothelial cell migration and tubulogenesis
Authors: Annabi Borhane , Rojas‐Sutterlin Shanti , Laroche Mathieu , Lachambre Marie‐Paule , Moumdjian Robert , Béliveau Richard 
Published: April 2008

AbstractHuman brain microvascular endothelial cells (HBMECs) play an essential role as structural and functional components of the blood–brain barrier (BBB). While disruption of the BBB by the brain tumor‐secreted matrix metalloproteinase‐9 (MMP‐9) favors tumor invasion, the role and regulation of MMP‐9 secretion by HBMEC themselves in response to carcinogens or brain tumor‐derived growth factors has received little attention. Our study delineates a unique brain endothelial phenotype in that MMP‐9 secretion is increased upon phorbol 12‐myristate 13‐acetate (PMA) treatment of HBMEC. Sulforaphane (SFN), an isothiocyanate present in broccoli which exhibits chemopreventive properties, selectively inhibited the secretion of MMP‐9 but not that of MMP‐2. The decrease in MMP‐9 gene expression correlated with a decrease in the expression of the mRNA stabilizing factor HuR protein triggered by SFN. PMA‐induced HBMEC migration was also antagonized by SFN. Silencing of the MMP‐9 gene inhibited PMA‐induced MMP‐9 secretion, cell migration, and in vitro tubulogenesis on Matrigel. While SFN inhibited the chemoattractive abilities of brain tumor‐derived growth factors, it failed to inhibit PMA‐induced tubulogenesis. Our data are indicative of a selective role for SFN to inhibit MMP‐9‐activated, but not basal, HBMEC migration, and tubulogenesis whose actions could add to SFN's antitumor properties.
Relative signs of 29Si13C couplings
Authors: Blechta Vratislav , Schraml Jan 
Published: April 2008

AbstractTwo pulse sequences applicable to the determination of relative signs of coupling constants, gHSQC‐RELAY(P) and gHSQC‐RELAY(D), were developed and tested. These sequences are suitable for determination of relative signs of long‐range coupling constants (<2 Hz) between two heteronuclei of low abundance (such as 29Si and 13C), and are applicable even to cases in which one of the heteronuclei (29Si) does not exhibit coupling with some of the detected protons (1H). The two sequences differ in the manner in which they suppress undesirable homonuclear coherence transfers. Each of the sequences can be combined with an isotope filter for better suppression of the centerlines arising from more abundant NMR‐inactive isotopes. The sequences were tested on ethoxytrimethylsilane and (E)‐(buta‐1,3‐dienyloxy)trimethylsilane, and we conclude that 2J(29Si‐O‐13C) is positive while 3J(29Si‐O‐C‐13C) is negative in both compounds. Copyright © 2008 John Wiley & Sons, Ltd.
Frequency‐dependent tactile responses in rat brain measured by functional MRI
Authors: Sanganahalli Basavaraju G. , Herman Peter , Hyder Fahmeed 
Published: April 2008

AbstractWe measured frequency‐dependent functional MRI (fMRI) activations (at 11.7 T) in the somatosensory cortex with whisker and forepaw stimuli in the same α‐chloralose anesthetized rats. Whisker and forepaw stimuli were attained by computer‐controlled pulses of air puffs and electrical currents, respectively. Air puffs deflected (±2 mm) the chosen whisker(s) in the right snout in the rostral to caudal direction, and electrical currents (2 mA amplitude, 0.3 ms duration) stimulated the left forepaw with subcutaneous copper electrodes placed between the second and fourth digits. In the same subject, unimodal stimulation of whisker and forepaw gave rise to significant blood oxygen level‐dependent (BOLD) signal increases in corresponding contralateral somatosensory areas of whisker barrel field (S1BF) and forelimb (S1FL), respectively, with no significant spatial overlap between these regions. The BOLD responses in S1BF and S1FL regions were found to be differentially variable with frequency of each stimulus type. In the S1BF, a linear increase in the BOLD response was observed with whisker stimulation frequency of up to ∼12 Hz, beyond which the response seemed to saturate (and/or slightly attenuate) up to the maximum frequency studied (i.e. 30 Hz). In the S1FL, the magnitude of the BOLD response was largest at forepaw stimulation frequency between 1.5 and 3 Hz, beyond which the response diminished with little or no activity at frequencies higher than 20 Hz. The volume of tissue activated by each stimulus type followed a similar pattern to that of the stimulation frequency dependence. These results of bimodal whisker and forepaw stimuli in the same subject may provide a framework to study interactions of different tactile modules, with both fMRI and neurophysiology (i.e. inside and outside the magnet). Copyright © 2008 John Wiley & Sons, Ltd.
Connection and comparison between frequency shift time integration and a spectral transformation preconditioner
Authors: Meerbergen Karl , Coyette Jean‐Pierre 
Published: April 2008

AbstractThe numerical study of exterior acoustics problems is usually carried out in the frequency domain. Finite element analyses often require the solution of large‐scale algebraic linear systems. For very large problems, sometimes the time domain is used. Implicit time integration requires linear system solves, but these are often far easier than those from the frequency domain. This paper shows a connection between a spectral transformation preconditioner and a frequency shift time integration. This preconditioner is close to the shifted Laplace preconditioner. The preconditioned iterative method appears to be faster than time integration. Copyright © 2008 John Wiley & Sons, Ltd.
Approximating second‐order vector differential operators on distorted meshes in two space dimensions
Authors: Hermeline F. 
Published: April 2008

AbstractA new finite volume method is presented for approximating second‐order vector differential operators in two space dimensions. This method allows distorted triangle or quadrilateral meshes to be used without the numerical results being too much altered. The matrices that need to be inverted are symmetric positive definite; therefore, the most powerful linear solvers can be applied. The method has been tested on a few second‐order vector partial differential equations coming from elasticity and fluids mechanics areas. These numerical experiments show that it is second‐order accurate and locking‐free. Copyright © 2008 John Wiley & Sons, Ltd.
On the computation of the coupled thermo‐electromagnetic response of continua with particulate microstructure
Authors: Zohdi T. I. 
Published: April 2008

AbstractRecently, several applications, primarily driven by micro‐technology, have emerged where the use of materials with tailored electromagnetic properties is necessary for a successful design. The ‘tailored’ properties are achieved by doping an easily moldable base matrix with particles having dielectric constants that are chosen to give overall desired properties. In many cases, the analysis of such materials requires the simulation of the macroscopic and microscopic electromagnetic response, as well as its resulting coupled thermal response, which can be important to determine possible failure in ‘hot spots’. In this study, a model and a solution strategy are developed to compute the response of a class of fully coupled electro‐magneto‐thermal systems composed of heterogeneous materials, involving the absorption of electromagnetic energy, its conversion to heat and changes in the electromagnetic material properties. The algorithm involves recursive staggering, whose convergence is dependent on the discretized time‐step size. The multifield system coupling can change, becoming weaker, stronger or alternating back and forth. Therefore, it is quite difficult to determine a priori the time‐step size needed to meet a prespecified tolerance on the staggering error, i.e. the incomplete resolution of the coupling between the fields. The presented solution process involves time‐step size adaptivity to control the contraction mapping constant of the multifield system operator in order to induce desired staggering rates of convergence within each time step and to control the staggering error. Three‐dimensional numerical experiments are performed to illustrate the behavior of the model and the solution strategy. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and characterization of chiral liquid‐crystalline polysiloxanes containing fluorinated units and sulfonic acid groups
Authors: Meng Fan‐Bao , Sun Yan‐Hui , Gao Yong‐Mei , Song Xian‐Gen , Zhang Bao‐Yan 
Published: April 2008

AbstractChiral side‐chain liquid‐crystalline polysiloxanes (PS‐1, PS‐2, PS‐3, PS‐4, PS‐5, PS‐6) bearing fluorinated units and sulfonic acid groups were synthesized with poly(methylhydrogeno)siloxane, cholest‐5‐en‐3‐ol(3β)‐4‐(2‐propenyloxy)benzoate, and 3‐trifluoromethyl‐phenyl 3‐sulfo‐4‐undec‐10‐ enoyloxy‐benzoate. The effects of fluorinated units and sulfonic acid groups on characteristic of liquid‐crystalline properties were studied. PS‐1, PS‐2, and PS‐3 exhibited both smectic and cholesteric mesophases, while PS‐4, PS‐5, and PS‐6 exhibited only cholesteric mesophase. As the polymers contained more fluorinated units and sulfonic acid groups, segregation of the fluorinated segment to the surface and aggregation of hydrogen bonding should occur. Therefore, the highly ordered lamellar mesogen–siloxane matrix systems should be disturbed severely, suggesting that PS‐4, PS‐5, and PS‐6 show no smectic phase. The maximum reflection bands become broad and shifted slightly to long wavelength from PS‐1 to PS‐6. Copyright © 2008 John Wiley & Sons, Ltd.
Chitosan‐induced synthesis of magnetite nanoparticles via iron ions assembly
Authors: Wang Yongliang , Li Baoqiang , Zhou Yu , Jia Dechang 
Published: April 2008

AbstractSuperparamagnetic magnetite nanoparticles were synthesized induced by chitosan hydrogel under ambient conditions via iron ions assembly, and the inducing effect of chitosan hydrogel was discussed. Results of X‐ray diffraction and transmission electron microscopy indicate that the nanoparticles were inverse cubic spinel structure magnetite with diameter about 16 nm, and the superparamagnetic nanoparticles with narrow size distribution dispersed uniformly in chitosan. The magnetization measurements indicated that the nanoparticles showed the typical superparamagnetic behavior. The crystallinity, morphology, and magnetic properties of magnetite nanoparticles were remarkably influenced by the pH values of iron ion solutions. The interaction between magnetite and chitosan was illustrated by FT‐IR and thermogravimetric analysis, which concluded that the magnetite nanoparticles were coated by a chitosan layer via the amino groups of chitosan. The chitosan hydrogel assisted in the synthesis of superparamagnetic magnetite nanoparticles through chelation by amino groups. Copyright © 2008 John Wiley & Sons, Ltd.
Simultaneous determination of ten active components in traditional Chinese medicinal products containing both Gegen (Pueraria lobata) and Danshen (Salvia miltiorrhiza) by high‐performance liquid chromatography
Authors: Chang Qi , Sun Lan , Zhao Run‐Huai , Chow Moses S. S. , Zuo Zhong 
Published: April 2008

AbstractIn order to facilitate the quality control of Traditional Chinese Medicine (TCM) products containing both Gegen (Pueraria lobata) and Danshen (Salvia miltiorrhiza), a new and simple HPLC method for the simultaneous determination of 10 active components in these products has been developed. The chromatographic separation was carried out on a C18 column eluted with a mobile phase consisting of 0.1% acetic acid in water and 0.1% acetic acid in acetonitrile with gradient elution. The eluent was monitored by a photodiode array UV detector at a wavelength of 250 nm for Gegen components including puerarin, daidzein 8‐C‐apiosyl‐glucoside, daidzin and daidzein, and at 270 nm for Danshen components including danshensu, protocatechuic aldehyde, salvianolic acid B, cryptotanshinone, tanshinone I and tanshinone IIa. Excellent chromatographic separation was achieved for all studied compounds with good linearity (r2 > 0.999) over the studied concentration ranges. The developed method has been applied to the simultaneous determination of the 10 studied compounds in commercially available products containing both Gegen and Danshen. The TCM product samples were extracted by sonication with a mixture of methanol:water (80:20) containing 0.5% acetic acid. Extraction recoveries for all studied compounds were in the range of 96.01–106.18%. The intra‐day and inter‐day variations were less than 7.25 and 5.44%, respectively, for all studied compounds. The developed method has not only proved to be effective in the simultaneous determination of the 10 components, but also provides a convenient quality control approach for TCM products containing both Gegen and Danshen. Copyright © 2008 John Wiley & Sons, Ltd.
Separation and measurement of plant alkaloid enantiomers by RP‐HPLC analysis of their Fmoc‐Alanine analogs
Authors: Lee Stephen T. , Gardner Dale R. , Tom Chang Cheng‐Wei , Panter Kip E. , Molyneux Russell J. 
Published: April 2008

AbstractIntroduction. Ammodendrine (1), anabasine (2) and coniine (3) can cause congenital malformations in livestock. They appear naturally in both enantiomeric forms, and can cause variable physiological responses. A method to measure the enantiomeric ratio of these natural toxins is needed.Objective. To develop a simple and economical method in order to determine the enantiomeric ratios of piperidine and pyrrolidine alkaloids in small samples of plant material.Methodology. Mixtures of isolated or purified plant alkaloids were converted to their Fmoc‐l‐Ala‐alkaloid analogues forming diastereomeric mixtures, which were then analysed by high pressure liquid chromatography (HPLC) with mass spectrometry (MS) and ultraviolet (UV) detection to determine enantiomeric ratios. Results. The diastereomeric analogs for ammodendrine, anabasine and nornicotine could be separated and the enantiomeric ratios determined. The Fmoc‐l‐Ala‐coniine analogue was not resolved under the HPLC conditions studied. The enantiomeric ratios of the selected plant alkaloids were measured and found to differ between both location within a species and location between species.Conclusion. A low‐cost HPLC method to analyse the enantiomeric ratio of plant alkaloids containing primary or secondary amine nitrogens via conversion to their respective diastereomeric analogues has been developed. Published in 2008 by John Wiley & Sons.
Simulation of losses in thin‐film silicon modules for different configurations and front contacts
Authors: Brecl Kristijan , Topič Marko 
Published: April 2008

AbstractA simulation tool for the quantification of electrical losses in thin‐film modules using a one‐ and two‐dimensional electrical PSpice model is presented. Two main sources of electrical losses are examined: monolithic contacts (MC) and front contacts made of a transparent conductive oxide (TCO) layer with or without a metal finger grid. Our study was focussed on amorphous and micromorph silicon modules in substrate or superstrate configuration. Results show that front contact losses (TCO losses and finger losses) prevail. While, under assumption that their subcell performances are the same, performance of amorphous silicon (a‐Si) modules do not depend on the configuration, the superstrate micromorph silicon module has a relatively slight (below 2%) advantage over the substrate counterpart due to lower electrical losses in the MC. Losses of the front contact made of a thick TCO layer or of thin TCO layer and metal finger grid on top were studied for both modules in substrate configuration and optimisation results are presented. Use of thin TCO layer and optimised finger grid and solar cell geometry is competitive and these modules can even outperform the optimised amorphous or micromorph silicon module with thick TCO front contact. In all optimised cases under standard test conditions, total relative losses can be minimised to around 10%. Copyright © 2008 John Wiley & Sons, Ltd.
Fabrication of poly(aniline‐co‐pyrrole) hollow nanospheres with Triton X‐100 micelles as templates
Authors: Zhou Chuanqiang , Han Jie , Song Genping , Guo Rong 
Published: April 2008

AbstractA one‐step route has been reported for the fabrication of poly(aniline‐co‐pyrrole) (PACP) copolymer hollow nanospheres via the oxidation polymerization of a mixture of aniline and pyrrole in the presence of Triton X‐100. It was found that the variations in polymerization conditions, such as the concentrations of Triton X‐100 and comonomers, and [pyrrole]/[aniline] molar ratios, could change the size and uniformity of copolymer hollow nanospheres. The result of DLS has attested the presence of the spherical Triton X‐100 micelles swelled by the comonomers in reaction system, and such micelles might play template for the formation of hollow nanospheres, followed by developing a possible formation mechanism. The chemical structures and crystallinity of products were characterized by FTIR, UV–visible, 1H NMR spectra, and XRD patterns, respectively, to prove the copolymer chemical structures of hollow nanospheres. The thermal‐stability and solubility of PACP were improved compared with homopolymers (polyaniline and pyrrole). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3563–3572, 2008