bluuebunny/crossref_metadata_2025_split huggingface dataset:
Termite digestomes as sources for novel lignocellulases
Authors: Scharf Michael E. , Tartar Aurélien 
Published: October 2008

AbstractFor most animals, lignocellulose is a nutritionally poor food source that is highly resistant to enteric degradation. Termites, however, have the unique ability to digest lignocellulose with high efficiency, often using it as a sole food source. Another interesting aspect of termite biology is their symbiotic associations with prokaryotic and eukaryotic gut symbionts. Termite symbionts contribute to lignocellulose digestion efficiency, but by no means are they responsible for 100% of lignocellulose digestion in the termite gut. The termite digestome can be defined as the pool of genes, both termite and symbiont, that contribute to lignocellulose depolymerization and digestion, as well as simple sugar fermentation, nutrient transport, and nutrient assimilation. A central goal of termite digestomics research is to define/understand the relative contributions of termite and symbiont gene products to collaborative lignocellulose digestion. While efficient microbial cellulases have already been identified and are presently being used in industrial applications, efficient and inexpensive pre‐treatments for lignin and hemicellulose depolymerization are not yet well developed. In this respect, termite digestomics has already offered significant insights, and can continue to identify relevant enzymes, as well as reveal how to optimally combine and utilize these enzymes for maximum synergy. The topics covered in this review are as follows: lignocellulose structure with emphasis on its potential for depolymerization by termite and gut endosymbiont‐derived digestive enzymes; termite biology and ecology from the perspectives of termite nutrition, gut physiology, and lignocellulose digestion; and trends identified through recent termite digestomics research. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd
Implications of an interpretive understanding of LCA practice
Authors: Rex Emma , Baumann Henrikke 
Published: October 2008

AbstractDespite the desirability of a life cycle perspective and many attempts to facilitate life cycle assessment (LCA), industry has been relatively slow to adopt LCA. In this research, we thus set out to investigate the underpinnings of LCA practice in industry. A literature review shows that the present understanding is that ‘structural’ conditions such as location and sector determine the use of LCA in industry. However, a field study of two companies in the Swedish forest product industry (thus in the same sector and country) indicates that LCA practice is shaped more by individual preferences and chance events. Our results imply a more interpretive understanding of LCA practice than has been put forward by previous research. The two types of understanding are discussed and their implications for practitioners in industry, organizations promoting the use of LCA and further research are presented. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment.
Global supply chains and social requirements: case studies of labour condition auditing in the People's Republic of China
Authors: Kortelainen Ketty 
Published: October 2008

AbstractThe purpose of this paper is to (1) discuss the usability of labour condition auditing as a tool, (2) identify main differences between quality and environmental auditing and labour condition auditing and (3) define typical improvement areas in a high technology supply chain in the People's Republic of China (hereafter ‘China’). The increased interest in labour conditions of global supply chains has driven companies to integrate corporate social responsibility (CSR) into supply chain management (SCM) practices. Companies face legal requirements as well as voluntary social requirements. This paper focuses on the empirical part of labour condition auditing at selected factories during 2003 and 2004. Findings from these audits include non‐conformances in health and safety, remuneration, working hours and disciplinary practices. Based on the experiences of the case studies, labour condition auditing is seen as a beneficial tool for inducing continuous improvement in supply chain management, but it requires a new set of skills from the auditors. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment.
Antimicrobial activity of endemic Crataegus tanacetifolia (Lam.) Pers and observation of the inhibition effect on bacterial cells
Authors: Benli Mehlika , Yiğit Nazife , Geven Fatmagül , Güney Kerim , Bingöl Ümit 
Published: October 2008

AbstractUp to now an increasing number of antibiotic‐resistant bacteria have been reported and thus new natural therapeutic agents are needed in order to eradicate these pathogens. Through the discovery of plants such as Crataegus tanacetifolia (Lam.) Pers that have antimicrobial activity, it will be possible to discover new natural drugs serving as chemotherapeutic agents for the treatment of nosocomial pathogens and take these antibiotic‐resistant bacteria under control. The objective of the present study was to determine antimicrobial activity and the activity mechanism of C. tanacetifolia plant extract. The leaves of C. tanacetifolia, which is an endemic plant, were extracted using methanol and tested against 10 bacterial and 4 yeast strains by using a drop method. It was observed that the plant extract had antibacterial effects on Bacillus subtilis, Shigella, Staphylococcus aureus, and Listeria monocytogenes among the microorganisms that were tested. Minimum inhibitory concentration (MIC) results obtained at the end of an incubation of 24 h were found to be ≥6.16 mg ml−1 for B. subtilis, <394 mg ml−1 for Shigella, and ≥3.08 mg ml−1 for L. monocytogenes and S. aureus and minimum bactericidal concentration (MBC) were found as ≥24.63 mg ml−1 for B. subtilis, ≥394 mg ml−1 for Shigella, ≥6.16 mg ml−1 for L. monocytogenes, and ≥98.5 mg ml−1 for S. aureus. According to the MBC results, it was found that the plant extract had bactericidal effects and in order to explain the activity mechanism and cell deformation of bacterial strains treated with plant extract, the scanning electron microscopy (SEM) was used. The results of SEM showed that the treated cells appeared shrunken and there was degradation of the cell walls. This study, in which the antibacterial effect of C. tanacetifolia was demonstrated, will be a base for further investigations on advanced purification and effect mechanism of action of its active compounds. Copyright © 2008 John Wiley & Sons, Ltd.
Calcium‐Induced Membrane Microdomains Trigger Plant Phospholipase D Activity
Authors: Kuppe Konstantin , Kerth Andreas , Blume Alfred , Ulbrich‐Hofmann Renate 
Published: October 2008

AbstractPlant α‐type phospholipase D proteins are calcium‐dependent, lipolytic enzymes. The morphology of the aggregates of their phospholipid substrate fundamentally defines the interaction between the enzyme and the surface. Here we demonstrate that the Ca2+‐induced generation of membrane microdomains dramatically activates α‐type phospholipase D from white cabbage. 500‐fold stimulation was observed upon incorporation of 10 mol % 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphate (POPA) into 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine (POPC) vesicles in the presence of Ca2+ ions. Enhanced association of PLDα2 with phospholipid surfaces containing anionic components was indicated by lag phase analysis and film balance measurements. Differential scanning calorimetry showed that the POPA‐specific activation correlates with the phase behavior of the POPC/POPA vesicles in the presence of Ca2+ ions. We conclude from the results that the Ca2+‐induced formation of POPA microdomains is the crucial parameter that facilitates the binding of PLD to the phospholipid surface and suggest that this effect serves as a cellular switch for controlling PLD activity.
Melectin: A Novel Antimicrobial Peptide from the Venom of the Cleptoparasitic Bee Melecta albifrons
Authors: Čeřovský Václav , Hovorka Oldřich , Cvačka Josef , Voburka Zdeněk , Bednárová Lucie , Borovičková Lenka , Slaninová Jiřina , Fučík Vladimír 
Published: October 2008

AbstractA novel antimicrobial peptide designated melectin was isolated from the venom of the cleptoparasitic bee Melecta albifrons. Its primary sequence was established as H‐Gly‐Phe‐Leu‐Ser‐Ile‐Leu‐Lys‐Lys‐Val‐Leu‐Pro‐Lys‐Val‐Met‐Ala‐His‐Met‐Lys‐NH2 by Edman degradation and ESI‐QTOF mass spectrometry. Synthetic melectin exhibited antimicrobial activity against both Gram‐positive and ‐negative bacteria and it degranulated rat peritoneal mast cells, but its hemolytic activity was low. The CD spectra of melectin measured in the presence of trifluoroethanol and sodium dodecyl sulfate showed a high content α‐helices, which indicates that melectin can adopt an amphipathic α‐helical secondary structure in an anisotropic environment such as the bacterial cell membrane. To envisage the role of the proline residue located in the middle of the peptide chain on biological activity and secondary structure, we prepared several melectin analogues in which the Pro11 residue was either replaced by other amino acid residues or was omitted. The results of biological testing suggest that a Pro kink in the α‐helical structure of melectin plays an important role in selectivity for bacterial cells. In addition, a series of N‐ and C‐terminal‐shortened analogues was synthesized to examine which region of the peptide is related to antimicrobial activity.
Nanoparticle‐Based Electrochemical Immunosensor for the Detection of Phosphorylated Acetylcholinesterase: An Exposure Biomarker of Organophosphate Pesticides and Nerve Agents
Authors: Liu Guodong , Wang Jun , Barry Richard , Petersen Catherine , Timchalk Charles , Gassman Paul L , Lin Yuehe 
Published: October 2008

AbstractA nanoparticle‐based electrochemical immunosensor has been developed for the detection of phosphorylated acetylcholinesterase (AChE), which is a potential biomarker of exposure to organophosphate (OP) pesticides and chemical warfare nerve agents. Zirconia nanoparticles (ZrO2 NPs) were used as selective sorbents to capture the phosphorylated AChE adduct, and quantum dots (ZnS@CdS, QDs) were used as tags to label monoclonal anti‐AChE antibody to quantify the immunorecognition events. The sandwich‐like immunoreactions were performed among the ZrO2 NPs, which were pre‐coated on a screen printed electrode (SPE) by electrodeposition, phosphorylated AChE and QD‐anti‐AChE. The captured QD tags were determined on the SPE by electrochemical stripping analysis of its metallic component (cadmium) after an acid‐dissolution step. Paraoxon was used as the model OP insecticide to prepare the phosphorylated AChE adducts to demonstrate proof of principle for the sensor. The phosphorylated AChE adduct was characterized by Fourier transform infrared spectroscopy (FTIR) and mass spectroscopy. The binding affinity of anti‐AChE to the phosphorylated AChE was validated with an enzyme‐linked immunosorbent assay. The parameters (e.g., amount of ZrO2 NP, QD‐anti‐AChE concentration,) that govern the electrochemical response of immunosensors were optimized. The voltammetric response of the immunosensor is highly linear over the range of 10 pM to 4 nM phosphorylated AChE, and the limit of detection is estimated to be 8.0 pM. The immunosensor also successfully detected phosphorylated AChE in human plasma. This new nanoparticle‐based electrochemical immunosensor provides an opportunity to develop field‐deployable, sensitive, and quantitative biosensors for monitoring exposure to a variety of OP pesticides and nerve agents.
Synthesis of Compounds Presenting Three and Four Anthracene Units as Potential Connectors To Mediate Infinite Lateral Growth at the Air/Water Interface
Authors: Münzenberg Cindy , Rossi Antonella , Feldman Kirill , Fiolka Reto , Stemmer Andreas , Kita‐Tokarczyk Katarzyna , Meier Wolfgang , Sakamoto Junji , Lukin Oleg , Schlüter A. Dieter 
Published: October 2008

AbstractWe report the synthesis of molecular sheets based on the photochemically initiated dimerization of monomers with lateral anthracene units. The film thickness and composition were investigated by ellipsometry and X‐ray photoelectron spectroscopy (XPS). The mechanical stability of the film was sufficient to span it over 45×45 μm‐sized holes. Several model reactions were performed to illustrate the underlying chemistry and to assist in analysis. The reported experiments are considered first steps towards the ultimate goal of the rational synthesis of laterally “infinite”, one‐monomer‐unit‐thick molecular sheets with a long‐range positional order and a periodic covalent‐bonding pattern. Such sheets are referred to as 2D polymers and are considered a prime goal of chemical synthesis with intriguing applications.
Three‐Dimensional Encapsulation of Live Cells by Using a Hybrid Matrix of Nanoparticles in a Supramolecular Hydrogel
Authors: Ikeda Masato , Ueno Shiori , Matsumoto Shinji , Shimizu Yusuke , Komatsu Harunobu , Kusumoto Ken‐ichi , Hamachi Itaru 
Published: October 2008

AbstractFrom a library of glyco‐lipid mimics with muconic amide as the spacer, we found that 1, a glyco‐lipid that has N‐acetyl glucosamine and methyl cyclohexyl groups as its hydrophilic head and hydrophobic tails, respectively, formed a stable hydrogel (0.05 wt %) through hierarchical self‐assembly of the lipid molecules into supramolecular nanofibers. The formation of the supramolecular hydrogel was verified by rheological measurements, and the supramolecular nanofiber was characterized as the structural element by transmission electron microscopy and atomic force microscopy observations. Absorption and circular dichroism spectroscopic measurements revealed that the muconic amide moieties of 1 are arranged in a helical, stacked fashion in the self‐assembled nanofibers. Moreover, we unexpectedly found that the homogeneous distribution of the supramolecular nanofibers of 1 was greatly facilitated by the addition of polystyrene nanobeads (100–500 nm in diameter), as evaluated by confocal laser scanning microscopic observations. It is interesting that the obtained supramolecular hybrid matrix can efficiently encapsulate and distribute live Jurkat cells in three dimensions under physiological conditions. This supramolecular hybrid matrix is intriguing as a unique biomaterial.
Coordination Behaviour of Gold and Silver Towards Pyrazole Ligands
Authors: Crespo Olga , Concepción Gimeno M. , Jones Peter G. , Laguna Antonio , Naranjo Mar , Villacampa M. Dolores 
Published: October 2008

AbstractTreatment of pyrazole ligands HL (HL = pyrazole or 3,5‐dimethylpyrazole) with the gold(I) compound [Au(C6F5)(tht)] (tht = tetrahydrothiophene) gives either the complexes [Au(C6F5)(HL)] or, if the reaction is carried out in a molar ratio of 1:2 and in the presence of a base, the pyrazolate compound [NBu4][{Au(C6F5)}2(μ‐L)]. Binuclear derivatives with bridging pyrazolate ligands have been obtained by treatment of the ligands with [O(AuPPh3)3][ClO4] or [Au2Cl2(μ‐dppf)] (dppf = 1,1′‐bis(diphenylphosphanyl)ferrocene) and Na2CO3, to give [(AuPPh3)2(μ‐L)][ClO4] or [Au2(μ‐L)(μ‐dppf)]Cl. Treatment of [Ag(OTf)(PPh3)] with the pyrazole ligands affords the dimeric species [Ag2(μ‐OTf)2(HL)2(PPh3)2]. Gold(III) derivatives have been accessed by treatment of the pyrazole ligands with [Au(C6F5)3(OEt2)] or [Au(C6F5)2(OEt2)2][ClO4], affording the species [Au(C6F5)3(HL)] or [Au(C6F5)2(HL)2][ClO4]. Gold(III) pyrazolate derivatives of the form trans‐[NBu4][Au(C6F5)2Cl(L)] or [{Au(C6F5)2}2(μ‐L)2] have been prepared from [NBu4][Au(C6F5)2Cl2] or [Au(acac)(C6F5)2]. X‐ray structural characterization has been carried out for eight compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Germylenes and Stannylenes with Chelating Anilido–Imine Ligands: Syntheses, Structures and Reactivity
Authors: Mcheik Ali , Katir Nadia , Castel Annie , Gornitzka Heinz , Massou Stéphane , Rivière Pierre , Hamieh Tayssir 
Published: October 2008

AbstractGermylenes and stannylenes with anilido–imine ligands were synthesized in high yields by the reaction of group 14 dichlorides (Cl2Ge·dioxane, Cl2Sn) and the lithium salts of the ligands. Complexes were characterized by 1H and 13C NMR spectroscopy, and the molecular structure of methoxygermylene was determined by X‐ray crystallography. These data indicate the formation of N,N′‐chelate complexes having three‐coordinate germanium or tin atoms and quasiplanar six‐membered heterocycles. In the germanium series, cycloaddition reactions with o‐quinone were performed, and the structures of the cycloadducts were determined by X‐ray structure analyses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Pyrenylamino Acids: Synthesis, Photophysical and Electrochemical Studies
Authors: Abreu Ana S. , Castanheira Elisabete M. S. , Ferreira Paula M. T. , Monteiro Luís S. , Pereira Goreti , Queiroz Maria‐João R. P. 
Published: October 2008

AbstractSeveral β‐pyrenyldehydroamino acids and a pyrenylalanine derivative have been synthesized in good‐to‐high yields from dehydroamino acids by several types of reactions. A β‐[(pyren‐1‐yl)methylamino]alanine was prepared by treating the methyl ester of N,N‐(di‐tert‐butoxycarbonyl)dehydroalanine with (pyren‐1‐yl)methylamine hydrochloride in the presence of an excess of potassium carbonate. The E isomer of the methyl esters of N‐(tert‐butoxycarbonyl)‐β‐(1,2,4‐triazol‐1‐yl)dehydroalanine and dehydroaminobutyric acid were treated with (pyren‐1‐yl)methylamine hydrochloride in the presence of triethylamine to give the E isomers of the β‐aminomethylpyrene dehydroalanine and dehydroaminobutyric acid derivatives. β‐(Pyren‐1‐yl)dehydrophenylalanine and dehydroaminobutyric acid derivatives were obtained from the pure stereoisomer of the corresponding β‐bromodehydroamino acids and (pyren‐1‐yl)boronic acid by Suzuki cross‐coupling. This reaction was also applied successfully to β‐bromodehydrodipeptides. The electrochemical behaviour of some of the compounds prepared was studied by cyclic voltammetry. The peak potentials for the oxidation and reduction of pyrenylalanines were similar to those reported for pyrene. However, it was found that when the pyrene ring was conjugated with the dehydroamino acid moiety, the compounds had higher oxidation and reduction peak potentials than pyrene. The fluorescence properties of four of the pyrenylamino acids synthesized were evaluated in cyclohexane and alcohols. The methyl ester of N,N‐bis(tert‐butoxycarbonyl)‐β‐[(pyren‐1‐yl)methylamino]alanine presented high fluorescence quantum yields in cyclohexane and ethanol (ΦF = 0.45 and 0.35, respectively). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis of Hybrids of D‐Glucose and D‐Galactose with Pyrrolidine‐Based Iminosugars as Glycosidase Inhibitors
Authors: Doddi Venkata Ramana , Kokatla Hari Prasad , Pal A. P. John , Basak Ranjan K. , Vankar Yashwant D. 
Published: October 2008

AbstractSugar–iminosugar hybrid molecules made up of D‐glucose and D‐galactose with pyrrolidine‐based iminosugars, viz. 1,4‐dideoxy‐1,4‐imino‐L‐xylitol and 1,4‐dideoxy‐1,4‐imino‐L‐lyxitol, are synthesized from glycal epoxides and found to be moderate glycosidase inhibitors. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
In Situ Fabrication of Noble Metal Nanoparticles Modified Multiwalled Carbon Nanotubes and Related Electrocatalysis
Authors: Qu Jianying , Chen Hongjun , Dong Shaojun 
Published: October 2008

AbstractUsing multiwalled carbon nanotubes (MWNTs) as templates, noble metal (Au, Ag, Pt or Pd) nanoparticles (NPs) were fabricated in situ by electrochemistry with a diameter of 40–60 nm. Further, catalytic behaviors of these composite materials were investigated. Experiments showed that such carbon nanotubes decorated with Pd NPs modified glassy carbon electrodes exhibited higher electrocatalytic ability to some molecules such as evolution of hydrogen, reduction of oxygen and oxidation of ascorbic acid. Atomic force microscopy, X‐ray photoelectron spectroscopy and cyclic voltammetry were used to characterize the film formation and their properties.
Electrochemical Behavior of Thalidomide at a Glassy Carbon Electrode
Authors: Oliveira S. Carlos B. , Vivan Marilene , Oliveira – Brett Ana Maria 
Published: October 2008

AbstractThalidomide is an oral drug marketed in the 1950s as a sedative and an anti‐emetic during pregnancy that was removed from the market when its teratogenic side effects appeared in new born children due to inadequate tests to assess the drug's safety. Recent studies evaluating the use of thalidomide in cancer and HIV diseases have sparked renewed interest. The electrochemical behavior of thalidomide on a glassy carbon electrode has been investigated using cyclic, differential and square‐wave voltammetry in aqueous media at different pHs. The oxidation mechanism of thalidomide is an irreversible, adsorption‐controlled process, pH dependent up to values close to the pKa and occurs in two consecutive charge transfer reactions. A mechanism of oxidation of thalidomide involving one electron and one proton to produce a cation radical, which reacts with water and yields a final hydroxylated product is proposed. The reduction of thalidomide is also a pH dependent, irreversible process and occurs in a single step, with the same number of electrons and protons transferred. The reduction mechanism involves the protonation of the nitrogen that bridges the two cyclic groups, and the product of the protonation reaction causes irreversible dissociation. Both thalidomide and the non electroactive oxidation and reduction products are strongly adsorbed on the glassy carbon electrode surface.
Amperometric Detection of 4‐Chlorophenol on Two Types of Expanded Graphite Based Composite Electrodes
Authors: Pop Aniela , Manea Florica , Radovan Ciprian , Malchev Plamen , Bebeselea Adriana , Proca Cristina , Burtica Georgeta , Picken Stephen , Schoonman Joop 
Published: October 2008

AbstractThe assessment of an expanded graphite‐Ag‐zeolite‐epoxy composite (EG‐Z‐Ag‐Epoxy) electrode for the determination of 4‐chlorophenol (4‐CP) is described and compared to the corresponding expanded graphite‐epoxy composite (EG‐Epoxy) electrode. Cyclic voltammetry was used to characterize the electrochemical behavior and determination of 4‐CP at both electrodes in 0.1 M Na2SO4 and 0.1 M NaOH supporting electrolytes. A substantial enhancement of sensitivity for the determination of 4‐CP at the EG‐Z‐Ag‐Epoxy electrode was reached by applying a chemical preconcentration step prior to voltammetric quantification. Also, under these last conditions the lowest limit of detection of 1 μM illustrates the analytical versatility of this electrode in a concentration range where aquatic 4‐chlorophenol pollution is known to occur.
Separation of multiphosphorylated peptide isomers by CZE
Authors: Muetzelburg Marika V. , Hoffmann Ralf 
Published: October 2008

AbstractA separation of mono, doubly and triply phosphorylated isomers was developed with CZE with an aqueous electrolyte containing 3.9 mol/L formic acid and 30% v/v trifluoroethanol. Thus a mixture of ten phosphopeptides corresponding to the human tau sequence 226–240 was separated within 70 min. Although peptides with different phosphorylation degrees, i.e. 0–3 phosphate groups, were well separated, some of the phosphopeptide isomers containing one or two phosphate groups were only partially separated. The electrolyte system is compatible with both MALDI‐ and ESI‐MS, allowing a direct coupling, and thus could have some interesting applications in proteomics.