bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrothermal processing of rice husks: effects of severity on product distribution
Authors: Vegas Rodolfo , Kabel Mirjam , Schols Henk A. , Alonso J. L. , Parajó J.C. 
Published: March 2008

AbstractBACKGROUND: Treatment in aqueous media (hydrothermal or autohydrolysis reactions) is an environmentally friendly technology for fractionating lignocellulosic materials. Rice husks were subjected to hydrothermal processing under a variety of operational conditions to cause the selective breakdown of xylan chains, in order to assess the effects of reaction severity on the distribution of reaction products.RESULTS: The effects of severity (measured by the severity factor, R0) on the concentrations of the major autohydrolysis products (monosaccharides, xylo‐ and glucooligosaccharides, xylooligosaccharide substituents, acetic acid, acid‐soluble lignin and elemental nitrogen) were assessed. The interrelationship between the severity of treatment and molecular weight distribution was established by high‐performance size‐exclusion chromatography. Selected samples were subjected to refining treatments as ethyl acetate extraction and ion exchange for refining purposes, and the concentrates were assayed by high‐performance anion‐exchange chromatography and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry.CONCLUSIONS The protein equivalent of the products present in liquors accounted for 43 to 51% of the protein present in the raw rice husks. The concentrations of glucose (derived from starchy material) and arabinose (split from the xylan backbone) were fairly constant with severity. Even in treatments at low severity, high molecular weight compounds derived from xylan accounted for a limited part of the stoichiometric amount. Operating under harsh conditions, about 50% of the total xylan‐derived compounds corresponded to fractions with a degree of polymerization (DP) < 9. After refining, saccharides accounted for more than 90% of the non‐volatile components of the sample. The refined products showed a series of xylose oligomers up to about DP 13, and a series of acetylated xylose oligomers up to about DP 15. Copyright © 2008 Society of Chemical Industry
Kinetics of synthesis of butyl butyrate by esterification and transesterification in supercritical carbon dioxide
Authors: Varma Mahesh N. , Madras Giridhar 
Published: March 2008

AbstractBACKGROUND: The synthesis of butyl butyrate (used as a pineapple flavor) by green chemistry is of immense importance to the food industry. This study investigated the enzymatic esterification of butanol and butyric acid to butyl butyrate and transesterification of ethyl butyrate to butyl butyrate in supercritical carbon dioxide (ScCO2) with a lipase, Novozym 435.RESULTS: The effect of various parameters, such as temperature and enzyme, loading was investigated. The initial rate increased sharply up to 3% (w/w) and 7% (w/w) of enzyme loading for esterification and transesterification, respectively while further addition of enzyme did not increase the initial rate significantly. The optimum temperature for the reaction was between 45–50 °C. Because lipases can catalyze both esterification and hydrolysis, a complete kinetic model accounting for both reactions was developed and used to determine the kinetic parameters.CONCLUSION: Butyl butyrate was successfully synthesized in supercritical carbon dioxide in the presence of a lipase. The kinetic parameters for esterification, hydrolysis and transesterification were determined using the Ping‐Pong Bi‐Bi mechanism with substrate inhibition and represented by the Lineweaver and Burk plot. Copyright © 2008 Society of Chemical Industry
Separation and concentration of bilberry impact aroma compound from dilute model solution by pervaporation
Authors: García Verónica , Diban Nazely , Gorri Daniel , Keiski Riitta , Urtiaga Ane , Ortiz Inmaculada 
Published: March 2008

AbstractBACKGROUND: In the present work, the flavor compounds of natural juice of bilberries were qualitatively analyzed by GC‐MS, leading to the identification of trans‐Hex‐2‐en‐1‐ol as one of the major ‘impact aroma’ compounds of this fruit. The pervaporation of trans‐Hex‐2‐en‐1‐ol from diluted aqueous solutions was studied using commercial polydimethylsiloxane (PDMS) capillary membranes. The influences of solvent composition (water/ethanol mixtures), initial concentration of the aroma compound, flow rate and temperature of the feed were studied.RESULTS: High selectivity of the PDMS membrane towards the aroma compound was obtained, leading to enrichment factors in the range 100 < β < 200. Mass transfer resistance was found to be located in the pervaporation membrane. Experimental data showed a linear dependency of the permeation flux of trans‐Hex‐2‐en‐1‐ol on the differences in partial pressures of the compound across the pervaporation membrane. The permeability coefficient of the PDMS membrane to the transport of trans‐Hex‐2‐en‐1‐ol was calculated as Pm, Hex(50 °C) = 7.62 × 10−11 mol m−1 s−1 Pa−1.CONCLUSION: The membrane used was found to be very selective toward trans‐Hex‐2‐en‐1‐ol. A model based on the solution‐diffusion mechanism was applied. The mass transfer parameters needed for the design of a pervaporation process for aroma compound recovery were obtained. Copyright © 2008 Society of Chemical Industry
Development through integration? EU aid reform and the evolution of Mediterranean aid policy
Authors: Holden Patrick 
Published: March 2008

AbstractThe recipient states for Mediterranean aid are the middle‐income Arab countries of the Mediterranean littoral. Due to the region's importance for Europe there is a comprehensive EU strategy for the region and this has shaped Mediterranean aid policy more than the EU's generic aid policy reforms, although these have also had an impact. The EU's approach to developing these countries is to instigate liberal economic reform and integrate them economically with Europe. This takes the form of a regional free trade area and bilateral integration with the EU's single market. Mediterranean aid from 2001 to 2007 has been targeted at supporting and enabling reform in key sectors. A crude form of allocative (rewards‐based) conditionality has been applied. Assistance is thus more focused and coherent with EU policy than before. The Country Strategy Paper format and the organisational reforms of the aid programme facilitated this, but the political importance given to the Mediterranean area is the major reason. In any case, the broader reform and development strategy is not a success, as there is little sign that partial integration with Europe will enable economic development. While there is a new, post‐2006, aid instrument for the region this is not fundamentally different to its predecessor. Copyright © 2008 John Wiley & Sons, Ltd.
Loss of benzene to generate an enolate anion by a site‐specific double‐hydrogen transfer during CID fragmentation of o‐alkyl ethers of ortho‐hydroxybenzoic acids
Authors: Attygalle Athula B. , Bialecki Jason B. , Nishshanka Upul , Weisbecker Carl S. , Ruzicka Josef 
Published: March 2008

AbstractCollision‐induced dissociation of anions derived from ortho‐alkyloxybenzoic acids provides a facile way of producing gaseous enolate anions. The alkyloxyphenyl anion produced after an initial loss of CO2 undergoes elimination of a benzene molecule by a double‐hydrogen transfer mechanism, unique to the ortho isomer, to form an enolate anion. Deuterium labeling studies confirmed that the two hydrogen atoms transferred in the benzene loss originate from positions 1 and 2 of the alkyl chain. An initial transfer of a hydrogen atom from the C‐1 position forms a phenyl anion and a carbonyl compound, both of which remain closely associated as an ion/neutral complex. The complex breaks either directly to give the phenyl anion by eliminating the neutral carbonyl compound, or to form an enolate anion by transferring a hydrogen atom from the C‐2 position and eliminating a benzene molecule in the process. The pronounced primary kinetic isotope effect observed when a deuterium atom is transferred from the C‐1 position, compared to the weak effect seen for the transfer from the C‐2 position, indicates that the first transfer is the rate determining step. Quantum mechanical calculations showed that the neutral loss of benzene is a thermodynamically favorable process. Under the conditions used, only the spectra from ortho isomers showed peaks at m/z 77 for the phenyl anion and m/z 93 for the phenoxyl anion, in addition to that for the ortho‐specific enolate anion. Under high collision energy, the ortho isomers also produce a peak at m/z 137 for an alkene loss. The spectra of meta and para compounds show a peak at m/z 92 for the distonic anion produced by the homolysis of the OC bond. Moreover, a small peak at m/z 136 for a distonic anion originating from an alkyl radical loss allows the differentiation of para compounds from meta isomers. Copyright © 2008 John Wiley & Sons, Ltd.
Matrix‐free laser desorption/ionization of ions landed on plasma‐treated metal surfaces
Authors: Volný Michael , Sadílek Martin , Jackson Karl E. , Diener Matthew , Elam W. Tim , Tureček František 
Published: March 2008

AbstractWe report new experiments in which laser desorption/ionization time‐of‐flight mass spectrometry (LDI‐TOF‐MS) was applied to detection and characterization of gramicidin S and IgG pentapeptide (DSDPR) that were reactively landed on plasma‐treated stainless steel surfaces. The distributions of [M + H]+, [M + Na]+ and [M + K]+ ion species in LDI‐TOF for gramicidin S and IgG pentapeptide (DSDPR) were found to be markedly different from those in conventional MALDI‐TOF spectra of the same samples. LDI‐TOF mass spectra showed a strong preference for [M + K]+ adducts even in the presence of a large excess of sodium cations, or following surface treatment with trifluoroacetic acid. Alkali metal cations (K+ and Cs+) can be exchanged in reactively landed peptide samples to provide the corresponding cationized peptide ions by LDI. Multiple charged trypsin cations were reactively landed into a layer of 2‐(4‐hydroxyphenylazo)benzoic acid and ionized by LDI. The ionization mechanisms for LDI of surface‐deposited peptides are briefly discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Changes in the large‐scale features associated with the Indian summer monsoon in the recent decades
Authors: Yadav R. K. 
Published: March 2008

AbstractThe inter‐annual variability of the Indian summer monsoon rainfall (ISMR) has been examined in association with the variability of surface temperature, the mean sea level pressure (MSLP), the tropospheric geopotential height, and wind patterns over the globe to study the changes in the large‐scale features associated with Indian summer monsoon (ISM) in the recent decades. The data for the study have been considered from 1949–2005 (for a period of 57 years). It has been found that, during the recent decades, the El Nino‐Southern Oscillation (ENSO) relationship over ISMR has weakened while the northwest (NW) of North Atlantic sea surface temperature (SST) relationship has increased. A physical mechanism for the relationship of North Atlantic SST with ISMR is proposed, by which during the excess years of ISMR, the SST over NW of North Atlantic is above normal. The rise in SST is the consequence of intensification and a cell‐type shaped Azores high with isobars parallel to the east coast of North America, which drives a subtropical oceanic gyre (Gulf stream) transporting equatorial warm water NW of North Atlantic. The Azores high act as a source of downstream Rossby wave train over Eurasian region having barotropic structure consisting of a successive pressure trough and ridge. The Rossby wave may be associated with intensifying the low surface pressure anomaly over the Iranian landmass, which intensify the monsoon current over the Indian region. Copyright © 2008 Royal Meteorological Society
Nanocomposites based on polyolefins and functional thermoplastic materials
Authors: Ciardelli Francesco , Coiai Serena , Passaglia Elisa , Pucci Andrea , Ruggeri Giacomo 
Published: March 2008

AbstractPolyolefins are today the most used thermoplastic materials thanks to the high technology and sustainability of the polymerization process, their excellent thermomechanical properties and their good environmental compatibility, including easy recycling. In the last few decades much effort has been devoted worldwide to extend the applications of polyolefins by conferring on them new properties through mixing and blending with different materials. In this latter context, nanocomposites have recently offered new exciting possibilities. This has been made possible on the basis of the improvement of polyolefin functionalization processes with the availability of several olefin homo‐ and copolymers bearing a small (generally less than 1 mol%) amount of backbone grafted polar groups. These are indeed adequate to endow favourable interface interactions with polar macromolecules and inorganic compounds, leading first to compatible blends and then to microcomposites. The successful use of nanostructured dispersed materials has opened, on a similar basis, the way to nanocomposites as described in this review. This review provides a broad and updated description of the synthetic routes to nanostructured biphase materials having the typical structural properties of polyolefins (continuous matrix) but showing enhanced thermomechanical properties, thermostability, lower flammability, lower gas permeability and electrical and optical properties, thanks to the presence of an extended interphase interaction with very different nanodispersed species. Copyright © 2008 Society of Chemical Industry
A novel photo‐responsive organogel based on azobenzene
Authors: Zhou Yifeng , Xu Miao , Wu Junchen , Yi Tao , Han Jiantao , Xiao Shuzhang , Li Fuyou , Huang Chunhui 
Published: March 2008

AbstractA novel triarmed cis‐1, 3, 5‐cyclohexanetricarboxamides gelator, functionalized by three azobenzene moieties grafted with three long alkyl chains, was designed and synthesized. The gelator can gel most of the organic solvents in low concentration. The morphologies of the xerogels show one‐dimensional aggregated bundles or helical fibres. The azobenzene groups in the gel state form H‐type aggregation and perform expected trans–cis photoisomerization with a gel to sol phase transition upon irradiation of UV light. The main driving force for gelation is intermolecular hydrogen bonding between amides and π–π interaction of azobenzene moieties. Copyright © 2008 John Wiley & Sons, Ltd.
Dissecting the insecticide‐resistance‐ associated cytochrome P450 gene Cyp6g1
Authors: McCart Caroline , ffrench‐Constant Richard H 
Published: March 2008

AbstractBACKGROUND: The cytochrome P450 gene Cyp6g1 is overtranscribed in all field isolates of DDT‐resistant Drosophila melanogaster (Meigen) and confers a fitness advantage when inherited via the female. Overtranscription is associated with the insertion of an Accord transposable element into the 5′ end of the resistance allele. Here the authors attempt to dissect the transcription of the P450 gene in order to understand why resistance confers an advantage rather than the expected cost.RESULTS: Using a transgenic UAS:GAL4 reporter, the authors document the overexpression patterns of green fluorescent protein (GFP) in the fat body, midgut and Malpighian tubules driven by flies carrying the resistant 5′ construct. Knockout of Cyp6g1 via RNAi decreases both the level of Cyp6g1 transcript and the metabolism of the artificial substrate MROD (methyl ether resorufin, Sigma M1544). RNAi does not, however, significantly increase the susceptibility of susceptible flies to DDT. Finally, quantification of Cyp6g1 RNA in embryos laid by resistant females indicates that they pass on more Cyp6g1 RNA to their progeny than their susceptible counterparts.CONCLUSION: These results help explain why the eggs and larvae of resistant females enjoy a fitness benefit rather than a cost, and suggest that the provisioning of Cyp6g1 RNA to embryos provides a direct, but uncharacterised, fitness benefit. Copyright © 2008 Society of Chemical Industry
Unusual pentagon and hexagon geometry of three isomers (no 1, 20, and 23) of fullerene C84
Authors: Khamatgalimov Ayrat R. , Luzhetskii Andrey V. , Kovalenko Valeri I. 
Published: March 2008

AbstractThree isomers 23 (D2d), 1 (D2), and 20 (Td) of fullerene C84 have been investigated by PM3, HF/6‐31G*, and DFT methods with B3LYP functional at the 6‐31G and 6‐31G* levels. In this article we reveal for the first time that some distortion of hexagon (pentagon), measured as its maximal dihedral angles, caused by local molecular strains may serve as a new criterion of stability of fullerenes with closed shell. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Natural bond orbital‐based energy density analysis for correlated methods: Second‐order Møller–Plesset perturbation and coupled‐cluster singles and doubles
Authors: Imamura Yutaka , Baba Takeshi , Nakai Hiromi 
Published: March 2008

AbstractNatural bond orbital‐based energy density analysis (NBO‐EDA), which split energies into atomic and bonding contributions, is proposed for correlated methods such as coupled‐cluster singles and doubles (CCSD) and second‐order Møller–Plesset (MP2) perturbation. Applying NBO‐EDA for CCSD and MP2 to ethylene and the Diels–Alder reaction, we are successful in obtaining useful knowledge regarding electron correlation of π‐ and σ‐type orbitals, and clarifying the difference of the reaction barriers and heat of reaction calculated by CCSD and MP2. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Correlation between the sensorial perception and the descriptive instrumental analysis of the tackiness of silicone elastomers
Authors: Mith Setha , Carpentier Luc , Monteil Guy 
Published: March 2008

AbstractOne of the objectives of sensorial metrology devices aims to substitute or to reproduce the operating of human organs with a high accuracy. The advantage of such a device is to get rid of the subjective nature of human perceptions. Thus, a probe tack test device has been developed in order to reproduce human tactile exploration, especially the perception of tackiness (or stickiness). Such a device enables, indeed, to study and to quantify mechanically the tackiness of silicone elastomers. However, tackiness can also be considered with a qualitative approach by a touch test. The resulting sensorial analysis requires the achievement of tactile experiments. The descriptive instrumental analysis and the sensorial analysis enable to establish a correlation on the phenomena of adhesion between two different ways of studying tackiness. This report shows that the sensorial perception of tackiness is not necessarily related to the “tack” force but also depends on other characteristics of tackiness, such as the energy of adhesion or the “tack” distance, which represent respectively the energy required to separate the punch from the sample and the distance between the moment when the force is negative and the moment when the probe is completely separated from the sample. Copyright © 2008 John Wiley & Sons, Ltd.
Dynamic regression hazards models for relative survival
Authors: Cortese Giuliana , Scheike Thomas H. 
Published: March 2008

AbstractA natural way of modelling relative survival through regression analysis is to assume an additive form between the expected population hazard and the excess hazard due to the presence of an additional cause of mortality. Within this context, the existing approaches in the parametric, semiparametric and non‐parametric setting are compared and discussed. We study the additive excess hazards models, where the excess hazard is on additive form. This makes it possible to assess the importance of time‐varying effects for regression models in the relative survival framework. We show how recent developments can be used to make inferential statements about the non‐parametric version of the model. This makes it possible to test the key hypothesis that an excess risk effect is time varying in contrast to being constant over time. In case some covariate effects are constant, we show how the semiparametric additive risk model can be considered in the excess risk setting, providing a better and more useful summary of the data. Estimators have explicit form and inference based on a resampling scheme is presented for both the non‐parametric and semiparametric models. We also describe a new suggestion for goodness of fit of relative survival models, which consists on statistical and graphical tests based on cumulative martingale residuals. This is illustrated on the semiparametric model with proportional excess hazards. We analyze data from the TRACE study using different approaches and show the need for more flexible models in relative survival. Copyright © 2008 John Wiley & Sons, Ltd.
Expanding the repertoire of plasmids for PCR‐mediated epitope tagging in yeast
Authors: Moqtaderi Zarmik , Struhl Kevin 
Published: March 2008

AbstractEpitope tagging of yeast proteins provides a convenient means of tracking proteins of interest in Western blots and immunoprecipitation experiments without the need to raise and test specific antibodies. We have constructed four plasmids for use as templates in PCR‐based epitope tagging in the yeast Saccharomyces cerevisiae. These plasmids expand the range of epitopes available in a tag–URA3–tag context to include the FLAG, HSV, V5 and VSV‐G epitopes. The cloning strategy used would be easily applicable to the construction of a similar tag–URA3–tag molecule for essentially any desired epitope. Oligonucleotides designed for PCR from one plasmid may be used interchangeably with any of the other template molecules to allow tagging with different epitopes without the need for new primer synthesis. We have tagged Tfc6 with each of the triple epitope tags and assessed the efficiency of these epitopes for chromatin immunoprecipitation (ChIP). For all the tagged alleles, ChIP occupancy signals are easily detectable at known Tfc6 target genes. These new tags provide additional options in experimental schemes requiring multiple tagged proteins. Copyright © 2008 John Wiley & Sons, Ltd.
Effects of high hydrostatic pressure on the growth and β‐carotene production of Rhodotorula glutinis
Authors: Wang Sui‐Lou , Chen De‐Jing , Deng Bai‐Wan , Wu Xiao‐Zong 
Published: March 2008

AbstractThe effects of high hydrostatic pressure (HHP) on the biomass and β‐carotene biosynthesis of Rhodotorula glutinis R68 were studied. After treatment with five repeated cycles at 300 MPa for 15 min, the barotolerant mutant PR68 was obtained. After 72 h of culture, the biomass of mutant PR68 was 21.6 g/l, decreased by 8.5% compared to the parental strain R68, but its β‐carotene production reached 19.4 mg/l, increased by 52.8% compared to the parental strain R68. The result of restriction fragment length polymorphism (RFLP) analysis suggested that mutant strain PR68 was likely to change in nucleic acid level, and thus enhanced β‐carotene production in this strain as a result of gene mutation induced by HHP treatment. Copyright © 2008 John Wiley & Sons, Ltd.