bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, characterization, and thermal properties of phosphorylated chitin for biomedical applications
Authors: Jayakumar R. , Egawa T. , Furuike T. , Nair S.V. , Tamura H. 
Published: March 2009

AbstractThe present study investigates a suitable material, which is expected to have biocompatibility and to promote tissue regeneration. For this purpose, we have chosen chitin that was chemically modified by phosphorylation with high degree of substitution. The phosphorylated chitin (P‐chitin) was synthesized using the H3PO4/P2O5/ET3PO4/hexanol method. The structure of P‐chitin was analyzed by FTIR, 31P‐ and 13C‐NMR spectroscopic studies, scanning electron microscopy, and X‐ray diffraction. The thermal properties of the P‐chitin were also characterized by thermogravimetric analyses. The highly phosphorylated chitin derivatives prepared by this method were soluble in water and amorphous in nature. Thus, H3PO4/P2O5/ET3PO4/hexanol method provides a versatile and alternative route for synthesis of P‐chitin, which would be useful for biomedical applications. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Colorimetric quantification of amino groups in linear and dendritic structures
Authors: Coussot Gaëlle , Nicol Edith , Commeyras Auguste , Desvignes Isabelle , Pascal Robert , Vandenabeele‐Trambouze Odile 
Published: March 2009

AbstractBACKGROUND: The aim of the work reported was to develop a procedure using 96‐well microtiter plates for the easy determination of protonated groups of compounds including linear poly(amino acid)s and dendritic polymers divided into dendrigraft and dendrimeric structures. This study is a prerequisite step for the quantification of protonated groups in a macromolecule grafted onto a solid surface.RESULTS: The procedure was developed from the modified Bradford protein assay and incorporates several modifications that enable one to determine available amino groups (or even other cationic groups) present on the polyresidues backbone, all within five minutes. Based on the Atherton mathematical model, we evaluated the maximal number of Coomassie blue binding sites on linear, dendrigraft or even dendrimeric structures.CONCLUSION: The mean calculated percentage of occupied sites on a given macromolecule led us to demonstrate that one Coomassie blue molecule interacts with only one single protonated group. Consequently, the developed method using Coomassie blue binding can be used for the quantification of cationic groups in a macromolecule grafted onto a solid surface. Copyright © 2009 Society of Chemical Industry
The influence of gender on the likelihood of using soft social power strategies in school consultation
Authors: Getty Kimberly C. , Erchul William P. 
Published: March 2009

AbstractThe social power typology developed originally by French and Raven in 1959 and revised by Raven in 1965 and 1992 was applied to study school consultation. Specifically, we investigated how the gender of school psychologist consultants and teacher consultees influence how likely consultants are to use soft power strategies, identified as those drawing on expert, referent, informational, legitimate dependency, and legitimate position power. A modified version of the Interpersonal Power Inventory was mailed to 1,000 Nationally Certified School Psychologists. Results obtained from 352 respondents indicated that, when consulting with female teachers: (a) male psychologists are more likely to use expert power than the other four soft strategies combined, and (b) female psychologists are less likely to use referent power than the other four soft strategies combined. Findings suggest that consultant gender plays an important role in determining influence strategies used by school consultants. © 2009 Wiley Periodicals, Inc.
Pharmacologic intervention targeting glycolytic‐related pathways protects against retinal injury due to ischemia and reperfusion
Authors: Zheng Ling , Liu Shuqing , Sun Ming‐Zhong , Chang Jinsook , Chance Mark R. , Kern Timothy S. 
Published: March 2009

AbstractRetinal ischemia contributes to multiple ocular diseases while aminoguanidine (AMG) treatment significantly inhibits the neuronal and vascular degeneration due to acute retinal ischemia and reperfusion (I/R) injury. In the present study, 2‐D DIGE was applied to profile global protein expression changes due to retinal I/R injury, and the protection effects mediated by AMG. Retinal ischemia was induced by elevated intraocular pressure to 80–90 mmHg for 2 h, and reperfusion was established afterward. Retinal tissues were collected 2 days after I/R injury. After 2‐D DIGE analysis, a total of 96 proteins were identified. Among them, 28 proteins were identified within gel spots whose intensities were normalized by AMG pretreatment, pathway analysis indicated that most were involved in glycolysis and carbohydrate metabolism. Selected enzymes identified by MS/MS within these pathways, including transketolase, triosephosphate isomerase 1, aldolase C, total enolase, and pyruvate kinase were validated by quantitative Western blots. Glycolytic enzymes and other differentially regulated proteins likely play previously unrecognized roles in retinal degeneration after I/R injury, and inhibition of the resulting metabolic changes, using pharmacologically agents such as AMG, serve to inhibit the changes in metabolism and mitigate retinal degeneration. Select glycolytic enzymes may provide novel therapeutic targets for inhibiting the neuronal and vascular degeneration after retinal I/R injury.
Highly stable trypsin‐aggregate coatings on polymer nanofibers for repeated protein digestion
Authors: Kim Byoung Chan , Lopez‐Ferrer Daniel , Lee Sang‐Mok , Ahn Hye‐Kyung , Nair Sujith , Kim Seong H. , Kim Beom Soo , Petritis Konstantinos , Camp David G. , Grate Jay W. , Smith Richard D. , Koo Yoon‐Mo , Gu Man Bock , Kim Jungbae 
Published: March 2009

AbstractA stable and robust trypsin‐based biocatalytic system was developed and demonstrated for proteomic applications. The system utilizes polymer nanofibers coated with trypsin aggregates for immobilized protease digestions. After covalently attaching an initial layer of trypsin to the polymer nanofibers, highly concentrated trypsin molecules are crosslinked to the layered trypsin by way of a glutaraldehyde treatment. This process produced a 300‐fold increase in trypsin activity compared with a conventional method for covalent trypsin immobilization, and proved to be robust in that it still maintained a high level of activity after a year of repeated recycling. This highly stable form of immobilized trypsin was resistant to autolysis, enabling repeated digestions of BSA over 40 days and successful peptide identification by LC‐MS/MS. This active and stable form of immobilized trypsin was successfully employed in the digestion of yeast proteome extract with high reproducibility and within shorter time than conventional protein digestion using solution phase trypsin. Finally, the immobilized trypsin was resistant to proteolysis when exposed to other enzymes (i.e., chymotrypsin), which makes it suitable for use in “real‐world” proteomic applications. Overall, the biocatalytic nanofibers with trypsin aggregate coatings proved to be an effective approach for repeated and automated protein digestion in proteomic analyses.
Kinetic study of Orange II oxidation using peroxynitrous acid
Authors: Poblete F. J. , Corrochano P. , Cabañas B. 
Published: March 2009

AbstractThe reaction of Orange II with peroxynitrous acid has been studied by a spectrophotometrical method. The reaction rate is complex because the order changes from zero to one in function of substrate and oxidant concentration. The influence of pH and ionic strength has been investigated, but their effect on the reaction rate appears to be negligible under the experimental conditions used. A reaction mechanism based on the experimental results is proposed, involving a radical cage solvent attack from peroxynitrous acid to Orange II. Copyright © 2009 John Wiley & Sons, Ltd.
Can the Distress Thermometer be improved by additional mood domains? Part I. Initial validation of the Emotion Thermometers tool
Authors: Mitchell Alex J. , Baker‐Glenn Elena A. , Granger Lorraine , Symonds Paul 
Published: March 2009

AbstractPurpose: To examine the value of a new screening instrument in a visual‐analogue format.Methods: We report the design and validation of a new five‐dimensional tool called the Emotion Thermometers (ET). This is a combination of five visual‐analogue scales in the form of four predictor domains (distress, anxiety, depression, anger) and one outcome domain (need for help). Between March and August 2007, 130 patients attending the chemotherapy suite for their first chemotherapy treatment were asked to complete several questionnaires with validation for distress, anxiety and depression.Results: Of 81 with low distress on the Distress Thermometer (DT), 51% recorded emotional difficulties on the new ET tool, suggesting added value beyond the DT alone. Of those with a broadly defined emotional complication, 93.3% could be identified using the Anxiety Thermometer (AnxT) alone, compared with 54.4% who would be recognized using the DT alone. Using a cut‐off of 3v4 on all thermometers against the total Hospital Anxiety and Depression Scale (HADS) score (cut‐off 14v15), the optimal thermometer was the Anger Thermometer (sensitivity 61%, specificity 92%). Against HADS anxiety scale, the optimal thermometer was AnxT (sensitivity 92%, specificity 61%) and against the HADS depression scale, the optimal thermometer was the Depression Thermometer (DepT; sensitivity 60%, specificity 78%). Finally, against DSM‐IV major depression, the optimal thermometer was the DepT (sensitivity 80%, specificity 79%). Further improvements may be possible by using a combination of thermometers or by repeating the screen.Conclusion: The diagnostic accuracy of the DT can be improved by the inclusion of simple addition linear domains without substantially increasing the time needed to apply the test. Copyright © 2009 John Wiley & Sons, Ltd.
A Stochastic Pocket Model for Aluminum Agglomeration in Solid Propellants
Authors: Gallier Stany 
Published: March 2009

AbstractA new model is derived to estimate the size and fraction of aluminum agglomerates at the surface of a burning propellant. The basic idea relies on well‐known pocket models in which aluminum is supposed to aggregate and melt within pocket volumes imposed by largest oxidizer particles. The proposed model essentially relaxes simple assumptions of previous pocket models on propellant structure by accounting for an actual microstructure obtained by packing. The use of statistical tools from stochastic geometry enables to determine a statistical pocket size volume and hence agglomerate diameter and agglomeration fraction. Application to several AP/Al propellants gives encouraging results that are shown to be superior to former pocket models.
Integrating Fusarium oxysporum f. sp. strigae into cereal cropping systems in Africa
Authors: Venne Julien , Beed Fen , Avocanh Adolphe , Watson Alan 
Published: March 2009

AbstractBACKGROUND: Striga hermonthica (Del.) Benth. (witchweed) poses the greatest biological constraint to food production in sub‐Saharan Africa (SSA). Control options for Striga are currently largely ineffective or unavailable to farmers, and other management possibilities are urgently needed. Biological control obviates some of the problems of several of the other techniques and provides a management option that is durable and environmentally responsive. The efficacy of S. hermonthica control using different formulations of three isolates of Fusarium oxysporum Schlecht. emend. Synder & Hans f. sp. strigae was tested on Striga‐resistant and Striga‐susceptible varieties of sorghum and maize under African field conditions for the first time.RESULTS: Isolates PSM197 and Foxy 2 were effective in witchweed repression, especially when applied as pesta granules. Isolate M12‐4A was less effective under the field conditions investigated. Application of the fungi was generally more beneficial in maize than in sorghum for the varieties tested. Application of the biocontrol agent caused significant decreases in the number of flowering Striga plants, and hence deposition of seeds with impact of enhancing future crop yield.CONCLUSIONS: Synergistic effects between the Striga‐resistant maize line and Fusarium oxysporum f. sp strigae led to over 90% reduction in Striga emergence. These results will further encourage the distribution of the isolates tested or selection of country‐specific relatives as viable and environmentally safe biocontrol agents to be used against Striga. Pesta was the most effective formulation, while seed coating may be more cost effective. Copyright © 2009 Society of Chemical Industry
Synthesis of the C‐terminal penta‐ peptide of the peptaibol culicinins
Authors: Zhang Wei , Sun Tian‐Tian , Li Ying‐Xia 
Published: March 2009

AbstractThe synthesis of the C‐terminal pentapeptide of culicinins has been achieved using [4 + 1] protocol and reduction‐coupling strategy. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Investigating nanoporous silicon explosive devices
Authors: du Plessis Monuko 
Published: March 2009

AbstractThe explosive properties of nanoporous silicon, impregnated with an oxidant, were researched. A structural model was used to extract the pore and crystallite dimensions from gravimetric measurements, as well as the specific surface area, porosity and statistical distribution of crystallite diameters. The properties of three different oxidants were investigated. It was found that there is an optimum pore size for the most energetic explosion. It was also demonstrated that the nano‐explosion could be initiated within 100 μs using NaClO4 as oxidant and a thin film aluminium fuse as heating element. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron structure of iron and cobalt nanocomposites on the basis of porous silicon
Authors: Kashkarov Vladimir , Lenshin Alexander , Agapov Boris , Turishchev Sergey , Domashevskaya Evelina 
Published: March 2009

AbstractMorphology and phase composition of porous silicon with electrochemically deposited Fe and Co particles as well as the particles of their mixtures were investigated by scanning electron microscopy (SEM) and X‐ray emission and absorption spectroscopy. Iron was shown to cover the surface of porous silicon while cobalt penetrates inside the pores in the form of nanoparticles. Iron Iron is present in the form of the phase of Fe2O3 with an admixture of FeO and Fe3O4. Cobalt forming nanoparticles is involved as metallic Co and Co2O3. Under co‐deposition of these metals from solution of their salts mixture cobalt favored penetration of iron inside the pores. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling macroscopic elasticity of porous silicon
Authors: Magoariec Hélène , Danescu Alexandre 
Published: March 2009

AbstractIn this paper we present a model able to predict the elastic properties of nano‐porous silicon (nano‐PSi). Initially developed by Keating [1] for the elastic response of nonprimitive lattices in the harmonic regime, the model accounts for near neighbors (NN) and next‐near‐neighbors (NNN) interactions and leads to numerical results in very good agreement with existent experimental data.We performed numerical tests covering a wide range of porosities between bulk silicon and 90% porosity.We also evidence the significant interplay between the cubic symmetry of the bulk silicon and the shape of the pores. This is of special interest in the case of nano‐PSi due to directional electrochemical etching process and leads, in general, to macroscopic anisotropic elastic response. Our method can be easily extended to cover other porous materials and/or more surface effects like, for example, the back‐bond oxidation (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Buried spongy‐like layers in silicon implanted with He+, annealed and treated in D+ plasma
Authors: Misiuk Andrzej , Ulyashin Alexander , Barcz Adam , Bak‐Misiuk Jadwiga , Romanowski Przemyslaw , Prujszczyk Marek 
Published: March 2009

AbstractImplantation of silicon with He+ ions (energy 300 keV, dose 5×1015 cm–2) and subsequent processing of Si:He structures at high temperature (HT) up to 1270 K under Ar hydrostatic pressure (HP) up to 1.2 GPa results in a creation of spongy‐like buried layer at the projected range of He ions, which is about 1.4 μm depth. Upon subsequent treatment of Si:He structures at 573 K in deuterium plasma under 3×102 Pa, deuterium is accumulated with concentrations up to about 1019 cm–3 at two different well pronounced local regions: (i) subsurface region with the width of about 0.5 μm and (ii) region‐around the projected range of He ions. As follows from TEM, X‐Ray and SIMS measurements, microstructure of nano‐structured spongy‐like layer and D concentration are dependent on HT, HP and processing time. It is established that further annealing of plasma treated Si:He,D at 723 K under 105 Pa/1.1 GPa for 1 h leads to a release of deuterium from both mentioned above local regions of the Si:He,D structures. It is concluded that spongy‐like buried layer created by He+ implantation can be used for gettering / accumulation of deuterium, which can be of interest for ion cut based technology. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and analysis of porous silicon multilayers for spectral encoding applications
Authors: Chen Michelle Y. , Meade Shawn O. , Sailor Michael J. 
Published: March 2009

AbstractThis paper compares two methods used to encode information into the optical spectrum of a porous Si film using a modulated current‐time waveform. In the first approach, a waveform consisting of a sequence of current steps is used to produce a porous silicon multilayer structure. Each layer in the multilayer acts as a Fabry‐Perot interference film, and the superposition of their contributions results in a complicated reflectivity spectrum. The spectrum can be deconvoluted by means of a Fast Fourier Transformation (FFT), which yields the optical thickness of each of the individual layers and their combinations.The second type of waveform consists of several superimposed cosine waves of differing frequencies. The resulting reflectivity spectrum consists of a series of peaks, each of whose position in the spectrum (frequency at which a peak is at maximum amplitude) corresponds to the frequency of a cosine wave component in the current‐time waveform. The two methods of encoding information are compared in terms of repeatability, tunability, and information capacity. The superimposed cosinusoidal waves are found to provide greater information density and a simpler means of decoding. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Porosity dependence of the acoustic longitudinal velocity in heavily doped p++ porous silicon layers
Authors: Aliev Gazi N. , Goller Bernhard , Kovalev Dmitry , Snow Paul A. 
Published: March 2009

AbstractThe longitudinal acoustic velocity for 1 GHz waves propagating along the 100 direction in p++ porous silicon layers has been measured using an acoustic wave transmission technique. The velocities obtained are significantly higher than those previously observed for p+ samples. The porosity dependence is measured to be VL = 8.43(l – P)0.58 km/s, where VL is longitudinal velocity and P is porosity. The low value of the exponent (0.58) is an indication of a relatively well‐ordered pore structure. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron invariants and excited state structural analysis for electronic transitions within CIS, RPA, and TDDFT models
Authors: Luzanov A. V. , Zhikol O. A. 
Published: March 2009

AbstractWe revisit the interpretative scheme (Luzanov et al., Theor Exp Chem 1974, 10, 354) of singly excited configuration interaction (CIS) model given earlier at semiempirical level. Detailed computations and spectral (natural orbital) treatment of the CIS density matrices of various types are presented. The corresponding hole‐particle densities and related excitation localization indices are described. All the quantities are extended to the excited states calculated in the random phase approximation and closely related time‐dependent density functional theory (TDDFT). The localization indices and charge transfer numbers which are invoked to describe interfragment interactions provide a basis for our scheme which is referred to as the excited state structural analysis for electronic transitions. The proposed analysis is exemplified by various moderate and large‐size conjugated molecules treated within ab initio TDDFT and the Parizer–Parr–Pople approximation. Finally, we propose a possible generalization to the electronic transitions between CIS‐like states followed by applications to singlet organic biradicals treated within the π‐electron spin‐flip CIS. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Simultaneous measurement of 13C‐ and 15N‐isotopic enrichments of threonine by mass spectrometry
Authors: Godin Jean‐Philippe , Mermoud Anne‐France , Rémond Didier , Faure Magali , Breuille Denis , Williamson Gary , Peré‐Trepat Emma , Ramadan Ziad , Fay Laurent‐Bernard , Kochhar Sunil 
Published: March 2009

AbstractUnder conditions of high isotopic dilution, e.g. in a tracer study, the ability to determine accurately and quantitatively small variations in isotopic enrichments of differently labelled chemical compounds (e.g. 13C and 15N in threonine) in a single run by gas chromatography/mass spectrometry (GC/MS) is desirable but remains a technological challenge. Here, we report a new, rapid and simple GC/MS method for simultaneously measuring the isotopic enrichments of doubly labelled threonine ([U13C] and 15N) with isotopic enrichment lower than 1.5 Molar Percent Excess (MPE). The long‐term reproducibility measured was around 0.09 MPE for both tracers (throughout a 6 week period). The intra‐day repeatability was lower than 0.05 and 0.06 MPE for [U13C]‐Thr and 15N‐Thr, respectively. To calculate both isotopic enrichments, two modes of calculations were used: one based on work by Rosenblatt et al. in 1992 and the other one using a matrix approach. Both methods gave similar results (ANOVA, P >0.05) with close precision for each mode of calculation. The GC/MS method was then used to investigate the differential utilization of threonine in different organs according to its route of administration in minipigs after administration of both tracers. In plasma samples, the lowest isotopic enrichment measured between two successive time points was at 0.01 and 0.02 MPE for [U13C]‐Thr and 15N‐Thr, respectively. Moreover, the accuracy of GC/MS 13C‐isotopic enrichment measured was validated by analyzing the same plasma samples by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). Statistical analysis showed that both techniques gave the same results (ANOVA, P >0.05). This new GC/MS method offers the possibility to measure 13C‐ and 15N‐isotopic enrichments with higher throughput, and using a lower amount of sample, than using GC/C/IRMS. Copyright © 2009 John Wiley & Sons, Ltd.