bluuebunny/crossref_metadata_2025_split huggingface dataset:
Segmentally arranged somatotopy within the face representation of human primary somatosensory cortex
Authors: Moulton Eric A. , Pendse Gautam , Morris Susie , Aiello‐Lammens Matthew , Becerra Lino , Borsook David 
Published: February 2008

AbstractThough somatotypic representation within the face in human primary somatosensory cortex (S1) to innocuous stimuli is controversial; previous work suggests that painful heat is represented based on an “onion‐skin” or segmental pattern on the face. The aim of this study was to determine if face somatotopy for brush stimuli in S1 also follows this segmental representation model. Twelve healthy subjects (nine men: three women) underwent functional magnetic resonance imaging to measure blood oxygen level dependent signals during brush (1 Hz, 15 s) applied to their faces. Separate functional scans were collected for brush stimuli repetitively applied to each of five separate stimulation sites on the right side of the face. These sites were arranged in a vertical, horizontal, and circular manner encompassing the three divisions of the trigeminal nerve. To minimize inter‐individual morphological differences in the post‐central gyrus across subjects, cortical surface‐based registration was implemented before group statistical image analysis. Based on activation foci, somatotopic activation in the post‐central gyrus was detected for brush, consistent with the segmental face representation model. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Photocatalytic degradation of 2,2‐bis(4‐hydroxy‐3‐methylphenyl) propane (BPP) based on molecular recognition interaction
Authors: Wang Guanghui , Huang Lei , Yu Rong , Deng Nansheng 
Published: February 2008

AbstractBACKGROUND: Endocrine disruptors in the aquatic environment and their potential adverse effects are currently issues of concern. One of these endocrine disruptors is 2,2‐bis(4‐hydroxy‐3‐methylphenyl)propane (BPP). In this work the molecular recognition interaction of BPP with β‐cyclodextrin (β‐CD) was studied using IR spectroscopy and steady state fluorescence spectroscopy, and the photocatalytic degradation behaviour of BPP based on molecular recognition interaction was investigated in a TiO2/UV–visible (λmax = 365 nm) system. This might provide a new method for the treatment of some organic pollutants in wastewater.RESULTS: β‐CD reacts with BPP to form a 1:1 inclusion complex, the formation constant of which is 4.94 × 103 L mol−1. The photodegradation rate constant of BPP after molecular recognition by β‐CD showed a 1.42‐fold increase in the TiO2/UV–visible (λmax = 365 nm) system. The photodegradation of BPP depended on the concentration of β‐CD, the pH value, the gaseous medium and the initial concentration of BPP. The photodegradation efficiency of BPP with molecular recognition was higher than that without molecular recognition. After 100 min of irradiation the mineralisation efficiency of BPP after molecular recognition by β‐CD reached 94.8%, whereas the mineralisation efficiency of BPP before molecular recognition by β‐CD was only 40.6%.CONCLUSION: The photocatalytic degradation of BPP after molecular recognition by β‐CD can be enhanced in the TiO2/UV‐visible (λmax = 365 nm) system. This enhancement is dependent on the enhancement of the adsorption of BPP, the moderate inclusion depth of BPP in the β‐CD cavity and the increase in the frontier electron density of BPP after molecular recognition. Copyright © 2008 Society of Chemical Industry
Production of thermostable alkaline lipase on vegetable oils from a thermophilic Bacillus sp. DH4, characterization and its potential applications as detergent additive
Authors: Bora Limpon , Kalita Mohan C 
Published: February 2008

AbstractBACKGROUND: The alkaline lipase production on vegetable oils as sole carbon source, its characterization and effect of different commercial detergents and surfactants on enzymatic activity from thermophilic Bacillus sp. DH4 was investigated.RESULTS: The organism grew on mannose, but the amount of lipase secreted was significantly less than on vegetable oils. This study identified a simple substrate for lipase production and established the utility of groundnut oil for increasing the lipase yield. The enzyme was compatible with various ionic and non‐ionic surfactants as well as commercial detergents. Lipase activity was strongly inhibited by sodium dodecyl sulfate (SDS), but not by Triton X‐100 or Triton X‐114. The best assay conditions observed for this lipase was found to be pH 9.0 and 50 °C. The enzyme was stable at alkaline pH and considerable activity was observed at pH 10 and it retained 93% of the residual activity at 60 °C. The lipase showed a novel property of marked activation at alkaline pH. Wash performance analysis of commercial detergent for removal of fatty stains improved upon addition of lipase.CONCLUSION: The production on cheap vegetable oils, novel properties and resistance towards various surfactants and tolerance to commercial detergents make this lipase a potential additive for detergent formulations. Significance and impact of the study: Bacillus sp. produces alkaline and thermostable lipase on cheap vegetable oils and its compatibility can find use in the detergent industry. Copyright © 2008 Society of Chemical Industry
The macrophage–biomaterial interface: a proteomic analysis of the conditioned medium environment
Authors: Dinnes Donna Lee M , Marçal Helder , Raftery Mark J , Labow Rosalind S , Mahler Stephen M 
Published: February 2008

AbstractBACKGROUND: Proteomic techniques provide an approach for exploration of intracellular structure and function as well as extracellular microenvironments. However, proteomics has not been extensively applied to examine cell–material interface dynamics or the conditioned medium (CM) that ensues. Monocyte‐derived macrophages (MDM) are of particular interest as they are the predominant cell type contributing to chronic inflammation at long‐term implant sites. The current study compares the CM generated when MDM were adherent to tissue culture polystyrene (TCPS) or a model polycarbonate–urethane (PCNU). Two‐dimensional electrophoresis and either matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry or liquid chromatography Fourier transform mass spectrometry were used for protein identification to begin to assess how the CM is altered when MDM are in contact with a degradable PCNU material relative to a typical tissue culture surface.RESULTS: Proteomic analysis of CM samples identified regulatory molecules associated with specific activation pathways, such as interferon‐γ, and degradative proteins, such as matrix metalloproteinases and chitinase‐like proteins, suggesting their involvement in the MDM response to PCNU materials. Furthermore, this study illustrates the challenges in analysing CM protein profiles against a background of intracellular protein, originating from lysed cells or cell fragments, and cell culture additives such as fetal bovine serum.CONCLUSIONS: The microenvironment surrounding an MDM–biomaterial interface is complex, containing proteins that relate to intracellular signalling pathways, cytoskeletal remodelling, degradation as well as the presence of serum factors necessary for cell attachment. The use of proteomics to determine the CM protein profile should continue to aid in the elucidation of cell–material interactions. Copyright © 2008 Society of Chemical Industry
Clarification of a wheat straw‐derived medium with ion‐exchange resins for xylitol crystallization
Authors: Canilha Larissa , Carvalho Walter , Giulietti Marco , Felipe Maria Das Graças Almeida , Almeida E Silva João Batista 
Published: February 2008

AbstractBACKGROUND: Xylitol bioproduction from lignocellulosic residues comprises hydrolysis of the hemicellulose, detoxification of the hydrolysate, bioconversion of the xylose, and recovery of xylitol from the fermented hydrolysate. There are relatively few reports on xylitol recovery from fermented media. In the present study, ion‐exchange resins were used to clarify a fermented wheat straw hemicellulosic hydrolysate, which was then vacuum‐concentrated and submitted to cooling in the presence of ethanol for xylitol crystallization.RESULTS: Sequential adsorption into two anion‐exchange resins (A‐860S and A‐500PS) promoted considerable reductions in the content of soluble by‐products (up to 97.5%) and in medium coloration (99.5%). Vacuum concentration led to a dark‐colored viscous solution that inhibited xylitol crystallization. This inhibition could be overcome by mixing the concentrated medium with a commercial xylitol solution. Such a strategy led to xylitol crystals with up to 95.9% purity. The crystallization yield (43.5%) was close to that observed when using commercial xylitol solution (51.4%).CONCLUSION: The experimental data demonstrate the feasibility of using ion‐exchange resins followed by cooling in the presence of ethanol as a strategy to promote the fast recovery and purification of xylitol from hemicellulose‐derived fermentation media. Copyright © 2008 Society of Chemical Industry
Advanced oxidation processes for water treatment: advances and trends for R&D
Authors: Comninellis Christos , Kapalka Agnieszka , Malato Sixto , Parsons Simon A , Poulios Ioannis , Mantzavinos Dionissios 
Published: February 2008

AbstractAdvanced oxidation comprises a range of similar but different chemical processes aimed at tackling pollution in water, air and soil. Over the past few decades, multidisciplinary research has been carried out to study a broad spectrum of topics such as understanding of process fundamentals, elucidation of kinetics and mechanisms, development of new materials, modelling, process integration and scale‐up. This article identifies and discusses certain directions that seem to advance R&D on advanced oxidation for water/wastewater treatment. Copyright © 2008 Society of Chemical Industry
Production of organic solvent tolerant lipase by Staphylococcus caseolyticus EX17 using raw glycerol as substrate
Authors: Volpato Giandra , Rodrigues Rafael Costa , Heck Júlio Xandro , Ayub Marco Antônio Záchia 
Published: February 2008

AbstractBACKGROUND: In this work we used Plackett–Burman statistical design and central composite design in order to optimize culture conditions for lipase production by Staphylococcus caseolyticus strain EX17 growing on raw glycerol, which was obtained as a by‐product of the enzymatic synthesis of biodiesel. The stability of lipase was verified over several organic solvents, such as methanol, ethanol and n‐hexane.RESULTS: Optimal culture conditions for lipase production were found to be 36 °C, initial pH 8.12, glycerol 30 g L−1, olive oil 3.0 g L−1, and soybean oil 2.5 g L−1, with 145.8 U L−1 of enzyme activity. When commercial glycerol was substituted by the raw glycerol from biodiesel synthesis, lipolytic activity was 127.3 U L−1. Experimental validation of enzyme production matched values predicted by the mathematical model, which was 138.3 U L−1. Stability tests showed that lipase from S. caseolyticus EX17 was stable in methanol, ethanol, and n‐hexane.CONCLUSIONS: Results obtained in this work suggest that raw glycerol can be used for lipase production by S. caseolyticus EX17 and that this enzyme has a potential application in the synthesis of biodiesel. Copyright © 2008 Society of Chemical Industry
Efficient syntheses of benzyl and n‐octyl [1,3‐13C2]acetoacetates, and their application to syntheses of 13C‐labelled pyrrole and 13C‐labelled hymecromone
Authors: Iida Katsumi , Ohtaka Kuniaki , Komatsu Takayuki , Makino Tomoe , Kajiwara Masahiro 
Published: February 2008

AbstractBenzyl [1‐13C]acetate (2a) was prepared via esterification of sodium [1‐13C]acetate (1) with benzyl bromide in the presence of 18‐crown‐6‐ether in 97% yield. n‐Octyl [1‐13C]acetate (2b) was rapidly obtained by microwave irradiation of 1‐bromooctane and potassium [1‐13C]acetate (obtained by salt exchange of 1) absorbed on Al2O3 in 82% yield. Solvent‐free Claisen condensation of benzyl or n‐octyl [1‐13C]acetate (2a or 2b) in the presence of potassium tert‐butoxide efficiently gave benzyl or n‐octyl [1,3‐13C2]acetoacetate (3a or 3b) in 51 or 68% yield, respectively. Dibenzyl 2,4‐dimethyl[2,4‐13C2]pyrrole‐3,5‐di[13C]carboxylate (4) was synthesized from benzyl [1,3‐13C2]acetoacetate (3a) in 54% yield. [2,4‐13C2]Hymecromone (6) (7‐hydroxy‐4‐methyl[2,4‐13C2]coumarin) was obtained from n‐octyl [1,3‐13C2]acetoacetate (3b) and 1,3‐benzenediol (5) in 73% yield. Copyright © 2008 John Wiley & Sons, Ltd.
Stereoselective synthesis of L‐[15N] amino acids with glucose dehydrogenase and galactose mutarotase as NADH regenerating system
Authors: Chiriac Maria , Lupan Iulia , Bucurenci N. , Popescu O. , Palibroda N. 
Published: February 2008

AbstractWe have developed an efficient stereospecific enzymatic synthesis of L‐[15N]‐valine, L‐[15N]‐leucine, L‐[15N]‐norvaline, L‐[15N]‐norleucine and L‐[15N]‐isoleucine from the corresponding α‐keto acids by coupling the reactions catalysed by leucine dehydrogenase and glucose dehydrogenase/galactose mutarotase. Giving high yields of L‐amino acids, the procedure is economical and easy to perform and to monitor at a synthetically useful scale (1–10 g). Copyright © 2008 John Wiley & Sons, Ltd.
Gallium metal affinity capture tandem mass spectrometry for the selective detection of phosphopeptides in complex mixtures
Authors: Blacken Grady R. , Sadílek Martin , Tureček František 
Published: February 2008

AbstractMetal affinity capture tandem mass spectrometry (MAC‐MSMS) is evaluated in a comparative study of a lysine‐derived nitrilotriacetic acid (Nα, Nα‐bis‐(carboxymethyl)lysine, LysNTA) and an aspartic‐acid‐related iminodiacetic acid (N‐(4‐aminobutyl)aspartic acid, AspIDA) as selective phosphopeptide detection reagents. Both LysNTA and AspIDA spontaneously form ternary complexes with GaIII and phosphorylated amino acids and phosphopeptides upon mixing in solution. Collision‐induced dissociation of positive complex ions produced by electrospray produces common fragments (LysNTA + H)+ or (AspIDA + H)+ at m/z 263 and 205, respectively. MSMS precursor scans using these fragments as reporter ions allow one to selectively detect multiple charge states of phosphopeptides in mixtures. It follows from this comparative study that LysNTA is superior to AspIDA in detecting phosphopeptides, possibly because of the higher coordination number and greater stability constant for GaIII—phosphopeptide complexation of the former reagent. In a continuing development of MAC‐MSMS for proteomics applications, we demonstrate its utility in a post‐column reaction format. Using a simple post‐column‐reaction ‘T’ and syringe pump to deliver our chelating reagents, α‐casein tryptic phosphopeptides can be selectively analyzed from a solution containing a twofold molar excess of bovine serum albumin. The MAC‐MSMS method is shown to be superior to the commonly used neutral loss scan for the common loss of phosphoric acid. Copyright © 2008 John Wiley & Sons, Ltd.
Hydration, charge, size, and shape characteristics of peptides from their CZE analyses
Authors: Peirotti Marta B. , Piaggio Maria V. , Deiber Julio A. 
Published: February 2008

AbstractA CZE model is presented for peptide characterization on the basis of well‐established physicochemical equations. The effective mobility is used as basic data in the model to estimate relevant peptide properties such as, for instance, hydration, net and total electrical charge numbers, hydrodynamic size and shape, particle average orientation, and pH‐microenvironment from the charge regulation phenomenon. Therefore 102 experimental effective mobilities of different peptides are studied and discussed in relation to previous work. An equation for the estimation of peptide hydration as a function of ionizing, polar, and non‐polar amino acid residues is included in the model. It is also shown that the shape‐orientation factor of peptides may be either lower or higher than one, and its value depends on a complex interplay among total charge number, molar mass, hydration, and amino acid sequence.
Conus ventricosus venom peptides profiling by HPLC‐MS: A new insight in the intraspecific variation
Authors: Romeo Cristina , Di Francesco Laura , Oliverio Marco , Palazzo Paola , Massilia Gabriella Raybaudi , Ascenzi Paolo , Polticelli Fabio , Schininà Maria Eugenia 
Published: February 2008

AbstractConus is a genus of predatory marine gastropods that poison the prey with a complex mixture of compounds active on muscle and nerve cells. An individual cone snail's venom contains a mixture of pharmacological agents, mostly short, structurally constrained peptides. This study is focused on the composition of the venom employed by Conus ventricosus Gmelin, 1791, a worm‐hunting cone snail living in the Mediterranean Sea. For this purpose, LC coupled to MS techniques has been successfully used to establish qualitative and quantitative differences in conopeptides from minute amounts of venom ducts. We were able to prove variability in the venom conopeptide complement, possibly related to different trophic habits of the species in the Mediterranean Sea. Moreover, the information‐rich MS techniques enabled us to identify two novel C. ventricosus peptides, here named Conotoxin‐Vn and α‐Conotoxin‐Vn. On the basis of the structural data collected so far, we suggest that Conotoxin‐Vn is a conopeptide belonging to the ω‐family that recognizes calcium channels through a specific pharmacophore. Similarly, molecular modeling data suggest that α‐Conotoxin‐Vn should represent a competitive antagonist of neuronal nicotinic acetylcholine receptors (nAChRs).
Peptide profile of human acquired enamel pellicle using MALDI tandem MS
Authors: Vitorino Rui , Calheiros‐Lobo Maria João , Duarte José A. , Domingues Pedro M. , Amado Francisco M.L. 
Published: February 2008

AbstractThe present study proposes a strategy for human in vivo acquired enamel pellicle (AEP) peptidome characterisation based on sequential extraction with guanidine and TFA followed by MALDI‐TOF/TOF identification. Three different nanoscale analytical approaches were used: samples were subjected to tryptic digestion followed by nano‐HPLC and mass spectrometry (MS and MS/MS) analysis. Undigested samples were analysed by LC‐MS (both linear and reflector modes) and LC‐MS/MS analysis, and samples were subjected to nano‐HPLC followed by on‐plate digestion and mass spectrometry (MS and MS/MS) analysis. The majority of the identifications corresponded to peptide/protein fragments of salivary protein, belonging to the classes: acidic PRPs, basic PRPs, statherin, cystatins S and SN and histatin 1 (all also identified in intact form). Overall, more than 90 peptides/proteins were identified. Results clearly show that peptides with acidic groups are enriched in the TFA fraction while peptides with no acidic or phosphate groups are prevalent on the guanidine extract. Also, phosphorylated peptides were observed mainly on the TFA fraction. Fragments present in the AEP show a predominance of cleavage points located at Arg, Tyr and Lys residues. Obtained data suggest that proteolytic activity could influence AEP formation and composition.
CASPT2 investigation of ethane dissociation and methyl recombination using canonical variational transition state theory
Authors: Li Hua , Chen Bo‐Zhen , Huang Ming‐Bao 
Published: February 2008

AbstractEthane dissociation and the reverse recombination reactions were investigated based on CASPT2 and CASSCF calculations. The CASPT2 (partial) geometry optimization calculations and the CASSCF frequency calculations provided geometrical parameters, potential energies, and vibrational frequencies along the reaction pathway. For determining dissociation and recombination rate constants at a temperature range from 200 to 2000 K, two models (models 1 and 2) were used on the basis of the canonical variational transition state theory. The different methods for accounting for the five transitional modes were proposed in the two models. Dissociation activation parameters evaluated using the two models are in good agreement with the data available in the literature. Model 1 predicts reasonable rate constant values for methyl recombination at high temperature, and model 2 predicts reasonable values in both high‐ and low‐temperature ranges. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 161–173, 2008
Hydroxyl radical reactions with halogenated ethanols in aqueous solution: Kinetics and thermochemistry
Authors: Morozov I. , Gligorovski S. , Barzaghi P. , Hoffmann D. , Lazarou Y. G. , Vasiliev E. , Herrmann H. 
Published: February 2008

AbstractLaser flash photolysis combined with competition kinetics with SCN− as the reference substance has been used to determine the rate constants of OH radicals with three fluorinated and three chlorinated ethanols in water as a function of temperature. The following Arrhenius expressions have been obtained for the reactions of OH radicals with (1) 2‐fluoroethanol, k1(T) = (5.7 ± 0.8) × 1011 exp((−2047 ± 1202)/T) M−1 s−1, (2) 2,2‐difluoroethanol, k2(T) = (4.5 ± 0.5) × 109 exp((−855 ± 796)/T) M−1 s−1, (3) 2,2,2‐trifluoroethanol, k3(T) = (2.0 ± 0.1) × 1011 exp((−2400 ± 790)/T) M−1 s−1, (4) 2‐chloroethanol, k4(T) = (3.0 ± 0.2) × 1010 exp((−1067 ± 440)/T) M−1 s−1, (5) 2, 2‐dichloroethanol, k5(T) = (2.1 ± 0.2) × 1010 exp((−1179 ± 517)/T) M−1 s−1, and (6) 2,2,2‐trichloroethanol, k6(T) = (1.6 ± 0.1) × 1010 exp((−1237 ± 550)/T) M−1 s−1. All experiments were carried out at temperatures between 288 and 328 K and at pH = 5.5–6.5. This set of compounds has been chosen for a detailed study because of their possible environmental impact as alternatives to chlorofluorocarbon and hydrogen‐containing chlorofluorocarbon compounds in the case of the fluorinated alcohols and due to the demonstrated toxicity when chlorinated alcohols are considered. The observed rate constants and derived activation energies of the reactions are correlated with the corresponding bond dissociation energy (BDE) and ionization potential (IP), where the BDEs and IPs of the chlorinated ethanols have been calculated using quantum mechanical calculations. The errors stated in this study are statistical errors for a confidence interval of 95%. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 174–188, 2008
Detailed chemical kinetic modeling of pyrolysis of ethylene, acetylene, and propylene at 1073–1373 K with a plug‐flow reactor model
Authors: Norinaga Koyo , Janardhanan Vinod M. , Deutschmann Olaf 
Published: February 2008

AbstractThis study examines the predictive capability of our recently proposed reaction mechanism (Norinaga and Deutschmann, Ind Eng Chem Res 2007, 46, 3547) for hydrocarbon pyrolysis at varying temperature. The conventional flow reactor experiments were conducted at 8 kPa, over the temperature range 1073–1373 K, using ethylene, acetylene, and propylene as reactants to validate the mechanism. More than 40 compounds were identified and quantitatively analyzed by on‐ and off‐line gas chromatography. The chemical reaction schemes consisting of 227 species and 827 reactions were coupled with a plug‐flow reactor model that incorporated the experimentally measured axial temperature profile of the reactor. Comparisons between the computations and the experiments are presented for more than 30 products including hydrogen and hydrocarbons ranging from methane to coronene as a function of temperature. The model can predict the compositions of major products (mole fractions larger than 10−2) in the pyrolysis of three hydrocarbons with satisfactory accuracies over the whole temperature range considered. Mole fraction profiles of minor compounds including polycyclic aromatic hydrocarbons (PAHs) up to three ring systems, such as phenanthrene, anthracene, and phenylnaphthalene, are also fairly modeled. At temperatures lower than 1273 K, larger PAHs were underpredicted and the deviation became larger with decreasing temperature and increasing molecular mass of PAHs, while better agreements were found at temperatures higher than 1323 K. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 199–208, 2008