bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymmetric Hydrogenation of Quinolines Catalyzed by Iridium Complexes of Monodentate BINOL‐Derived Phosphoramidites
Authors: Mršić Nataša , Lefort Laurent , Boogers Jeroen A. F. , Minnaard Adriaan J. , Feringa Ben L. , de Vries Johannes G.
Published: April 2008

The monodentate BINOL‐derived phosphoramidite PipPhos is used as ligand for the iridium‐catalyzed asymmetric hydrogenation of 2‐ and 2,6‐substituted quinolines. If tri‐ortho‐tolylphosphine and/or chloride salts are used as additives enantioselectivities are strongly enhanced up to 89%. NMR indicates that no mixed complexes are formed upon addition of tri‐ortho‐tolylphosphine.
Inclusions of amyotrophic lateral sclerosis–linked superoxide dismutase in ventral horns, liver, and kidney
Authors: Jonsson P. Andreas , Bergemalm Daniel , Andersen Peter M. , Gredal Ole , Brännström Thomas , Marklund Stefan L.
Published: April 2008

Mutant superoxide dismutases type 1 (SOD1s) cause amyotrophic lateral sclerosis by an unidentified toxic property. In a patient carrying the G127X truncation mutation, minute amounts of SOD1 were found in ventral horns using a mutant‐specific antibody. Still, both absolute levels and ratios versus wild‐type SOD1 were considerably greater than in other central nervous system areas and peripheral organs. Inclusions of mutant SOD1 were abundant in motoneurons but were also seen in hepatocytes and kidney epithelium. This first examination of mutant SOD1 in both central nervous system and peripheral organs supports the notion that enrichment of misfolded SOD1s might explain the particular vulnerability of motor areas. Ann Neurol 2008
Body mass index and magnetic resonance markers of brain integrity in adults
Authors: Gazdzinski Stefan , Kornak John , Weiner Michael W. , Meyerhoff Dieter J.
Published: April 2008

Objective

Obesity and being overweight during adulthood have been consistently linked to increased risk for development of dementia later in life, especially Alzheimer's disease. They have also been associated with cognitive dysfunction and brain structural alterations in otherwise healthy adults. Although proton magnetic resonance spectroscopy may distinguish between neuronal and glial components of the brain and may point to neurobiological mechanisms underlying brain atrophy and cognitive changes, no spectroscopic studies have yet assessed the relationships between adiposity and brain metabolites.

Methods

We have utilized magnetic resonance imaging and proton magnetic resonance spectroscopic imaging data from 50 healthy middle‐aged participants (mean age, 41.7 ± 8.5 years; 17 women), who were scanned as control subjects for another study.

Results

After adjustment for age and sex, greater body mass indices (BMIs) correlated with: (1) lower concentrations of N‐acetylaspartate (spectroscopic marker of neuronal viability) in frontal (p = 0.001), parietal (p = 0.006), and temporal (p = 0.008) white matter; (2) lower N‐acetylaspartate in frontal gray matter (p = 0.01); and (3) lower concentrations of choline‐containing metabolites (associated with membrane metabolism) in frontal white matter (p = 0.05).

Interpretation

These results suggest that increased BMI at midlife is associated with neuronal and/or myelin abnormalities, primarily in the frontal lobe. Because white matter in the frontal lobes is more prone to the effects of aging than in other lobes, our results may reflect accelerated aging in individuals with high levels of adiposity. Thus, greater BMI may increase the odds of developing an age‐related disease, such as Alzheimer's disease. Ann Neurol 2008
Electrospun nanofibers from crosslinked poly(vinyl alcohol) and its filtration efficiency
Authors: Qin Xiao‐Hong , Wang Shan‐Yuan
Published: April 2008

Nanoscaled crosslinked poly(vinyl alcohol) PVA fibers were prepared by electrospinning. This study described its electrospinning process, structure, and filtration applications. The fibers were found to be efficiently crosslinked by maleic acid. Vitriolic acid was used as a catalyst activator during crosslinking. Scanning electron micrograph and differential scanning calorimetric techniques as well as infrared reflection–absorption spectroscopy (FTIR) were employed to characterize the morphology and structure of crosslinking of PVA fibers, PVA fibers as well as PVA powder. Moreover, the filtration properties of crosslinked PVA nanofibers were tested. During the experiments, crosslinked PVA nanofibers layers with different area weight were placed on the spunbond or meltblown sublayers. The result shows that the filtration efficiency increases sharply when crosslinked PVA nanofibers layers were added to the sublayers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Studies of influence of naphthalene mono/disulfonic acid dopant on thermal stability of polypyrrole
Authors: Liu Jing , Wang Xiaocong , Hu Xiangzheng , Xiao Anqinq , Wan Meixiang
Published: April 2008

Thermal stability of polypyrrole (PPY) synthesized by in situ doping polymerization in the presence of different naphthalene mono/disulfonic acid dopant like α‐naphthalene sulfonic acid (α‐NSA), β‐naphthalene sulfonic acid (β‐NSA), and 1,5‐naphthalene disulfonic acid (1,5‐NDSA) has been systematically investigated by thermogravimetric analysis (TG). It was found that the thermal stability of as‐resulted PPY was greatly affected by type and concentration of dopant. In general, the order of their thermal stability was PPY‐(β‐NSA) > PPY‐(α‐NSA) ≈ PPY‐(1,5‐NDSA). And high concentration of dopant (e.g., 1.2 mol/L) had a negative effect on the thermal stability. Among those three dopants, 1,5‐NDSA had a unique influence on thermal stability and crystallinity of as‐resulted PPY. In addition, all of room‐temperature conductivity and crystallinity of PPY‐(1,5‐NDSA) changed dramatically after aging for 9 h under N2 atmosphere and at 230°C, which may be due to a partly dedoping process. These results were confirmed by elemental analysis, FTIR, X‐ray photoelectron spectroscopy (XPS), and X‐ray powder diffraction (XRD). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Rheological behavior of a microcellular, oil‐extended ethylene–propylene–diene rubber compound: Effects of the blowing agent curing agent, and conductive carbon black filler
Authors: Mahapatra S. P. , Tripathy D. K.
Published: April 2008

The rheological behavior of microcellular, oil‐extended ethylene–propylene–diene rubber (EPDM) compounds was studied in extrusions containing a blowing agent. The cell morphology development and rheological properties were studied for unfilled and conductive carbon black (Vulcan XC72, Cabot Corp., Ltd., Alpharetta, GA) filled compounds with variations of the blowing agent, extrusion temperature, and shear rate. The apparent shear stress, apparent viscosity, die swell (%), and total extrusion pressure of the Vulcan XC72 filled, oil‐extended EPDM compounds were determined with a Monsanto processability tester (St. Louis, MO). The effects of the curing agent and blowing agent on the rheological properties of the compounds were also studied. A significant reduction in the stress and viscosity with the blowing agent was observed in the compound in the presence of the curing agent in comparison with those without the curing agent. The viscosity reduction factor was found to be dependent on the blowing agent loading, shear rate, and temperature. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Copolymerization of methyl methacrylate with N‐(methoxyphenyl) itaconimides
Authors: Chauhan Rashmi , Choudhary Veena
Published: April 2008

This article describes the synthesis and characterization of N‐(3‐methoxyphenyl) itaconimide (MAI) and N‐(4‐methoxyphenyl) itaconimide (PAI) obtained by the reaction of itaconic anhydride with m‐anisidine and p‐anisidine, respectively. Structural and thermal characterization of MAI and PAI monomers was performed with Fourier transform infrared (FTIR), 1H‐NMR, differential scanning calorimetry (DSC), and thermogravimetric analysis. Copolymerization of methyl methacrylate (MMA) with various amounts of MAI or PAI ranging from 0.1 to 0.5 was performed in solution with azobisisobutyronitrile as an initiator. Structural and molecular characterization of copolymers was performed with FTIR, 1H‐NMR, elemental analysis, and gel permeation chromatography. The nitrogen percentage was used to calculate the copolymer composition. The monomer reactivity ratios for MMA–MAI copolymers were found to be 1.00 ± 0.01 for MMA and 0.99 ± 0.07 for MAI; those for MMA–PAI copolymers were 0.93 ± 0.02 for MMA and 1.11 ± 0.10 for PAI. The molecular weights of the copolymers were in the range of 0.94–9.7 × 103 (number‐average molecular weight) and 3.3–101.8 × 103 (weight‐average molecular weight), with polydispersity indices in the range of 1.5–4.1. The molecular weight decreased with the increasing molar fraction of imide in the polymer backbone. The glass‐transition temperature, as determined from DSC scans, increased with increasing amounts of itaconimides in the copolymers. A significant improvement in the char yield, as determined by thermogravimetry, was observed upon copolymerization. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Influence of the diene monomer on devulcanization of EPDM rubber
Authors: Verbruggen M. A. L. , van der Does L. , Noordermeer J. W. M. , van Duin M.
Published: April 2008

Ethylene–propylene–diene rubbers (EPDM) with 2‐ethylidene‐5‐norbornene (ENB), dicyclopentadiene (DCPD), and 1,4‐hexadiene (HD) as third monomers have been vulcanized with peroxide and with a conventional sulfur vulcanization recipe, and their devulcanization was subsequently investigated for recycling purposes. The behavior of these vulcanizates during pure thermal devulcanization depends on the EPDM third monomer and the crosslinker used. Peroxide vulcanizates of ENB‐EPDM devulcanize only to a small extent and predominantly by random scission, whereas peroxide vulcanizates of HD‐EPDM devulcanize by crosslink scission. In contrast, sulfur vulcanizates of ENB‐EPDM, devulcanize mainly by crosslink scission. During devulcanization of sulfur‐cured HD‐EPDM, scission of both crosslinks and main chains occurs. Sulfur‐cured DCPD‐EPDM cannot be devulcanized but shows further crosslinking instead. In those cases, where purely thermal devulcanization is already effective to a certain extent, diphenyldisulfide as devulcanization agent increases the effectivity during thermochemical devulcanization. Hexadecylamine as an alternative devulcanization agent is effective for ENB‐EPDM but does not contribute to thermochemical devulcanization of HD‐EPDM. In summary, devulcanization proceeds by different mechanisms in ENB‐EPDM, DCPD‐EPDM, and HD‐EPDM. Explanations are given in terms of the chemical structures of the third monomers, the corresponding crosslinks, and devulcanization agents. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Antimicrobial finishing of regular and modified polyethylene terephthalate fabrics
Authors: Shalaby S. E. , Al‐Balakocy N. G. , Beliakova M. K. , Abdel‐Fatah O. M. , Elshafei A. M.
Published: April 2008

An effective two‐stage method has been developed for imparting antimicrobial properties to regular polyethylene terephthalate (R‐PET), polyethylene glycol modified polyethylene terephthalate (PEG‐M‐PET), R‐PET/Cotton blend (R‐PET/C) and PEG‐M‐PET/Cotton blend (PEG‐M‐PET/C) fabrics. The method consists of partial hydrolysis of the fabrics to create carboxylic groups in PET macromolecules followed by subsequent reaction with dimethylalkylbenzyl ammonium chloride (DMABAC) under alkaline conditions. The reaction conditions such as pH, reaction temperature and time, carboxylic content, and DMABAC concentration were studied. Characterization of the finished fabrics was carried out through scanning electron microscopy (SEM) and Fourier transform infrared spectra (FTIR). All the modified PET fabrics showed excellent antibacterial activity towards Gram‐positive (Bacillus mycoides), Gram‐negative (Escherichia coli), and nonfilamentous fungus (Candida albicans). The achieved antimicrobial functions on the PET fabrics are durable in repeated laundering processes. Even after laundering 10 times the fabrics could still provide more than 85% of its antimicrobial activity against B. mycoides, E. coli, and C. albicans. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and Biological Activity of Functionalized Indole‐2‐carboxylates, Triazino‐ and Pyridazino‐indoles
Authors: El‐Gendy Adel A. , Said Mohamed M. , Ghareb Nagat , Mostafa Yasser M. , El‐Ashry El Sayed H.
Published: April 2008

Condensation of aryl hydrazines with ethyl pyruvate gave the respective hydrazones 4–6; Fischer indolization led to substituted‐1H‐indole‐2‐carboxylic acid ethyl esters 7–9. The Mannich reaction of these compounds with formaldehyde and morpholine yielded ethyl 3‐(morpholinomethyl)‐substituted‐1H‐indole‐2‐carboxylates 10‐12. The 5,7‐dichloro‐1H‐indole‐2‐carbohydrazide 13 was cyclized with methyl orthoformate in DMF to give 6,8‐dichloro[1,2,4]triazino[4,5‐a]indol‐1(2H)‐one 14. Vilsmeier–Haack formylation of 7–9 gave ethyl 3‐formyl‐substituted‐1H‐indole‐2‐carboxylates 15–17 whose 2,2′‐((5‐chloro‐2‐(ethoxycarbonyl)‐1H‐indol‐3‐yl)methylene)bis‐(sulfanediyl) diacetic acid 18 was prepared. The reaction of 15 and 16 with substituted anilines by conventional and microwave methods gave ethyl 3‐(N‐aryliminomethyl)‐5‐halo‐1H‐indole‐2‐carboxylates 19–29. In a cyclocondensation reaction of 19–25 with thiolactic acid or thioglycolic acid substituted indolylthiazolidinones 30–33 were prepared. Reaction of hydrazine hydrate with 15–17 did not give the respective hydrazones but directly led to the cyclized products substituted‐3H‐pyridazino[4,5‐b]indol‐4(5H)‐ones 34–36, while a reaction with 2,4‐dichlorophenylhydrazine yielded the uncyclized hydrazones. The chlorination of 35 and 36 with POCl3 gave pyridazino[4,5‐b]indoles 39 and 40, respectively; reaction of the latter compounds with morpholine gave 4‐(substituted‐5H‐pyridazino[4,5‐b]indol‐4‐yl)morpholine 41 and 42. Mannich reaction of 34 with formaldehyde and N‐ethylpiperazine gave 8‐chloro‐3‐((4‐ethylpiperazin‐1‐yl)methyl)‐3H‐pyridazino[4,5‐b]indol‐4(5H)‐one 43. The microwave assistance of selected reactions has a profound effect on the reaction speed. The structures of the new compounds were confirmed by both analytical and spectral data. Some compounds were subjected to investigations concerning their antimicrobial, tranquilizing, and anticonvulsant activities.
Analysis of the Tetronomycin Gene Cluster: Insights into the Biosynthesis of a Polyether Tetronate Antibiotic
Authors: Demydchuk Yuliya , Sun Yuhui , Hong Hui , Staunton James , Spencer Jonathan B. , Leadlay Peter F.
Published: April 2008

The biosynthetic gene cluster for tetronomycin (TMN), a polyether ionophoric antibiotic that contains four different types of ring, including the distinctive tetronic acid moiety, has been cloned from Streptomyces sp. NRRL11266. The sequenced tmn locus (113 234 bp) contains six modular polyketide synthase (PKS) genes and a further 27 open‐reading frames. Based on sequence comparison to related biosynthetic gene clusters, the majority of these can be assigned a plausible role in TMN biosynthesis. The identity of the cluster, and the requirement for a number of individual genes, especially those hypothesised to contribute a glycerate unit to the formation of the tetronate ring, were confirmed by specific gene disruption. However, two large genes that are predicted to encode together a multifunctional PKS of a highly unusual type seem not to be involved in this pathway since deletion of one of them did not alter tetronomycin production. Unlike previously characterised polyether PKS systems, oxidative cyclisation appears to take place on the modular PKS rather than after transfer to a separate carrier protein, while tetronate ring formation and concomitant chain release share common mechanistic features with spirotetronate biosynthesis.
Redilation of e‐PTFE covered CP stents
Authors: Butera Gianfranco , Gaio Gianpiero , Carminati Mario
Published: April 2008

Objectives: To evaluate the possibility to redilate covered Cheatham‐Platinum stents during follow‐up, in particular in growing children with aortic coarctation. Background: There are no data in the literature about the redilation of ePTFE covered CP stents. Methods: Sixty covered CP stents were implanted in patients with aortic coarctation or recoarctation between January 2004 and October 2007. Seven patients (mean age 14.2 ± 3.7 years) needed to repeat the hemodynamic study due to somatic growth and increase of aortic gradient with the occurrence of systemic hypertension. Two had near‐atretic aortic coarctation, three had postsurgical recoarctation and aneurysm formation, one had native aortic coarctation associated with aneurysm of the arterial wall, and one had severe native aortic coarctation. Results: Procedures were performed a mean of 20 ± 5 months (range, 12–24 months) after the primary stent implantation. Fluoroscopy time ranged between 7 and 15 min (median, 10 min) whereas procedure time ranged between 60 and 75 min (median, 65 min). After redilation the gradient across the stenosis decreased from a median value of 35 mm Hg to a median value of 5 mm Hg. The stent diameter increased of 20–50% the predilation value. No complications occurred and angiographic controls showed that the stenoses have been relieved. Follow‐up: During a median follow‐up of 12 months (6–30 months) the results were stable without complications. Conclusion: Covered Cheatham‐Platinum stents can be easily redilated © 2008 Wiley‐Liss, Inc.
Effects of Peripheral Chloro Substitution on the Photophysical Properties and in vitro Photodynamic Activities of Galactose‐Conjugated Silicon(IV) Phthalocyanines
Authors: Lo Pui‐Chi , Fong Wing‐Ping , Ng Dennis K. P.
Published: April 2008

A series of silicon(IV) phthalocyanines with two axial isopropylidene‐protected galactose moieties and one, two, or eight chloro group(s) on the periphery of the macrocycle have been synthesised and spectroscopically characterised. The photophysical properties and in vitro photodynamic activities of these compounds have been studied and compared with those of the nonchlorinated analogue. All the compounds, with the exception of the octachlorinated counterpart which has a limited solubility, are essentially nonaggregated in N,N‐dimethylformamide. The fluorescence quantum yield decreases and the singlet oxygen quantum yield increases as the number of chloro substituent increases, which is in accord with the heavy‐atom effect. The non‐, mono‐, and dichlorinated phthalocyanines formulated with Cremophor EL are all photodynamically active against HT29 human colon adenocarcinoma and HepG2 human hepatocarcinoma cells with IC50 values ranging from 0.03 to 1.05 μM. The photocytotoxicity as well as the efficiency to generate intracellular reactive oxygen species decrease along this series because of the increase in aggregation tendency upon chloro substitution. The nonchlorinated analogue exhibits the highest potency and can target the lysosomes of HT29 cells, whereas the monochlorinated counterpart is not localised in the lysosomes.
Stable Non‐IPR C60 and C70 Fullerenes Containing a Uniform Distribution of Pyrenes and Adjacent Pentagons
Authors: Zettergren Henning , Alcamí Manuel , Martín Fernando
Published: April 2008

The most abundant fullerenes, C60 and C70, and all the pure carbon fullerenes larger than C70, follow the isolated‐pentagon rule (IPR). Non‐IPR fullerenes containing adjacent pentagons (APs) have been stabilized experimentally in cases where, according to Euler’s theorem, it is topologically impossible to isolate all the pentagons from each other. Surprisingly, recent experiments have shown that a few endohedral fullerenes, for which IPR structures are possible, are stabilized in non‐IPR cages. We show that, apart from strain, the physical property that governs the relative stabilities of fullerenes is the charge distribution in the cage. This charge distribution is controlled by the number and location of APs and pyrene motifs. We show that, when these motifs are uniformly distributed in the cage and well‐separated from one other, stabilization of non‐IPR endohedral and exohedral derivatives, as well as pure carbon fullerene anions and cations, is the rule, rather than the exception. This suggests that non‐IPR derivatives might be even more common than IPR ones.
Time‐mode circuits for analog computation
Authors: Ravinuthula Vishnu , Garg Vaibhav , Harris John G. , Fortes José A. B.
Published: April 2008

We introduce time‐mode circuits, a set of basic circuit building blocks for analog computation using a temporal step function representation for the inputs and outputs. These novel time‐mode circuits are low power, provide good noise performance and offer improved dynamic range. The design, IC implementation and detailed theoretical signal‐to‐noise ratio (SNR) analysis of a prototype time‐mode circuit—a weighted average computation circuit—are discussed. This new way of computation is studied with respect to existing conventional voltage‐mode and current‐mode circuits. Two possible applications of these time‐mode circuits are presented: an edge detection circuit for 16 pixels and a 3‐tap FIR filter that provides an SNR of 64 dB. Copyright © 2008 John Wiley & Sons, Ltd.
Autoregulatory loop and retinoic acid repression regulate pou2/pou5f1 gene expression in the zebrafish embryonic brain
Authors: Parvin Mst. Shahnaj , Okuyama Noriko , Inoue Fumitaka , Islam Md. Ekramul , Kawakami Atsushi , Takeda Hiroyuki , Yamasu Kyo
Published: April 2008

Zebrafish pou5f1, also known as pou2, encodes a POU‐family transcription factor that is transiently expressed in the prospective midbrain and anterior hindbrain during gastrulation, governing brain development. In the present study, we found that the main regulatory elements reside in the proximal upstream DNA sequence from −2.2 to −0.12 kb (the −2.2/−0.1 region). The electrophoretic gel mobility shift assay (EMSA) revealed four functional octamer sequences that can associate with zebrafish Pou2/Pou5f1. The expression of mutated reporter constructs, as well as EMSA, suggested that these four octamer sequences operate in a cooperative manner to drive expression in the mid/hindbrain. We also identified a retinoic acid (RA) ‐responsive element in this proximal region, which was required to repress transcription in the posterior part of the embryo. These data provide a scheme wherein pou2/pou5f1 expression in zebrafish embryos is regulated by both an autoregulatory loop and repression by RA emanating from the posterior mesoderm. Developmental Dynamics 237:1373‐1388, 2008. © 2008 Wiley‐Liss, Inc.
Spatial planning for biodiversity in Europe's changing climate
Authors: Wilson Elizabeth , Piper Jake
Published: April 2008

Climate change is already having impacts on biodiversity within Europe, with habitats and species needing to change and adapt to rising global temperatures and shifts in bio‐climatic zones.

Spatial planning represents an important intervention to further European, national and local biodiversity objectives for climate change adaptation. Drawing on case‐studies of plans for inland and coastal areas, and involving stakeholder workshops, this paper reports on a trans‐national study examining the scope of spatial plans in the Netherlands, England and France in addressing the impact of climate change. It concludes that spatial planning is making provision for biodiversity and dynamic natural processes. However, while good practice in planning for biodiversity under conditions of climate change is developing, systematic use is not being made of available procedures. The paper examines some of the barriers to implementation of this new policy commitment to climate change adaptation. Recommendations are made covering policy development to include climate change impacts upon biodiversity, modified procedures for plan‐making and the appraisal of plans and projects. Amongst the specific measures recommended are the climate‐proofing of projects and plans through the use of EIA and SEA; the integration of plans through adoption of common objectives and review of time horizons and boundaries; and an ecosystem‐based planning approach. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment.
Voltammetric Studies of Cadmium‐ and Zinc‐Containing Metallothioneins at Nafion‐Coated Mercury Thin Film Electrodes
Authors: Fu Ying , Xu Maotian , Li Xue , Du Ming , Wang Jianxiu , Zhou Feimeng
Published: April 2008

Voltammetric studies of rabbit liver metallothioneins (MTs, containing both Zn and Cd ions) and Zn7‐MT were carried out at Nafion‐coated mercury film electrodes (NCMFEs). The accumulation of MT molecules into the NCMFEs enhances the voltammetric signals and the electrostatic interaction between the Nafion membrane and MT facilitates facile electron transfer reactions. Two well‐defined redox waves, with reduction potential (Epc) values at −0.740 and −1.173 V, respectively, were observed. The peak at Epc =−0.740 V is attributable to the reduction of the Cd‐MT complex, whereas that at Epc=−1.173 V was assigned to the reduction of the Zn‐MT complex. Zn7‐MT exhibits only one redox wave with Epc=−1.198 V. The NCMFE was found to be more advantageous than thin mercury film electrode (MFE), because the pristine metal ions in MTs (e.g., Cd2+ and/or Zn2+) are not significantly replaced by Hg2+. The NCMFE is also complementary to Nafion‐coated bismuth film electrode in that it has a greater hydrogen overpotential, which allows the reduction of the Zn‐MT complex to be clearly observed. Moreover, intermetallic compound formation between Cd and Zn appears to be less serious at NCMFEs. Consequently, the amounts of Cd and Zn deposited into the electrode upon the reduction reactions can be quantified more accurately.
Capillary electrophoresis‐electrospray‐mass spectrometry in peptide analysis and peptidomics
Authors: Herrero Miguel , Ibañez Elena , Cifuentes Alejandro
Published: April 2008

In the present work, an exhaustive review of the main developments and applications of CE‐MS for peptide analysis is given. This review includes the use of different CE separation modes, MS analyzers, capillary coatings, preconcentration techniques, on‐chip applications as well as other different multidimensional strategies for peptide analysis. Key applications are critically discussed and relevant works published from January 2000 to May 2007 are summarized including information concerning the type of sample, CE‐MS parameters as well as some figures of merit of the different CE‐MS procedures developed for peptide analysis and peptidomics.
Validation of chiral capillary electrophoresis‐electrospray ionization‐mass spectrometry methods for ecstasy and methadone in plasma
Authors: Schappler Julie , Guillarme Davy , Prat Josiane , Veuthey Jean‐Luc , Rudaz Serge
Published: April 2008

Due to its selectivity and sensitivity, CE coupled to MS (CE‐MS) has evolved as a useful analytical tool for determining drugs and metabolites in biological samples. A generic CE‐ESI/MS method was developed for the enantioselective determination of basic compounds in plasma. The use of protein precipitation (PP) prior to a hydrodynamic injection (HD) was well adapted to high‐concentration samples (>1 ppm) and allowed high throughput. In contrast, the combination of liquid–liquid extraction (LLE) and electrokinetic injection (EK) was time‐consuming but did allow detection at the ppb level. Both approaches were fully validated according to ICH guidelines and SFSTP protocols for two pharmaceutical compounds (ecstasy and methadone (MTD)). Deuterated internal standards (IS) in the analytical procedures were used and good quantitative performance was obtained in terms of trueness and precision (repeatability and intermediate precision) since accuracy profiles were within the acceptance limits (30% for biological assay). Methods were linear over the concentration range of 0.50–175 ng/mL and 0.25–5 μg/mL for LLE‐EK and PP‐HD procedures, respectively. The LLE‐EK methodology was finally successfully applied to quantitation of ecstasy and MTD in real cases obtained from toxicology.
Effect of Co‐Substrates on Aerobic Phenol Degradation by Acclimatized and Non‐acclimatized Enrichment Cultures
Authors: Bajaj M. , Gallert C. , Winter J.
Published: April 2008

Aerobic degradation of 7 mmol/L phenol in the presence of alternative carbon sources (7 mmol/L glucose or acetate or 1–2 mmol/L 2‐chlorophenol) was investigated using non‐acclimatized and acclimatized sewage sludges and enrichment cultures. The substrates represented an intermediate of phenol degradation (acetate), an independent substrate (glucose) or a “precursor‐substrate” of phenol degradation (2‐chlorophenol). Bacteria from sewage sludge, not pre‐adapted to phenol (2 mmol/L), rapidly respired acetate and glucose in the presence of phenol, whereas phenol was only bioconverted to any unknown aromatic metabolite after 24 h. In the presence of phenol and 2‐chlorophenol, no removal of both substances was observed when using the unacclimatized sludge. Sludge that was acclimatized to the degradation of phenol showed an initial preference for easily degradable co‐substrates such as glucose or acetate with only a slow concomitant respiration of phenol. Respiration of phenol increased rapidly after the co‐substrates were depleted. The highest phenol degradation rates were 51.6 mmol/L d, when phenol was the sole carbon substrate. Vice versa, phenol was preferentially respired in the presence of a less easily degradable co‐substrate such as 2‐chlorophenol at a rate of around 7 mmol/L d. Further studies with an enrichment culture that was obtained after 7 successive transfers of phenol‐adapted sludge into mineral medium with phenol as the only carbon source indicated that the acetate and glucose‐degrading capabilities were diminished or almost completely lost. In these enrichment cultures, phenol degradation was not affected by the presence of glucose, but glucose was not degraded. In contrary, the presence of acetate slightly slowed down the phenol degradation rate of the enrichment culture. Growth of the microorganisms apparently occurred at the expense of phenol and acetate respiration. The result of this work may be of practical importance in determining the feeding strategy, which is the key factor for most biological wastewater treatment systems. When acetate was present together with phenol in a wastewater, the phenol degradation rates were influenced by acetate, since acetate was an intermediate of phenol degradation. Glucose as an “independent substrate” was apparently degraded by other bacteria via acetate, and in this way it also influenced the phenol degradation rates. Glucose‐degrading bacteria could be “washed out” from the acclimatized sludge during several transfers into mineral medium with phenol as the sole carbon source. If later on, glucose was added again, it remained undegraded and did not influence phenol degradation. 2‐Chlorophenol degradation also requires other bacteria than phenol degraders.
Reaction Pattern in Vertebrate Cells (RiV): Studies of the Course of Tumor Therapy using an anti‐RiV ELISA (Initial Results)
Authors: Liebermann H. E. H. , Müller H.
Published: April 2008

Detection of anti‐RiV antibodies by ELISA can be used to follow a patient's response to treatments such as cancer surgery or RiV therapy. The initial results of the authors demonstrated that it is necessary to optimize the sensitivity of the ELISA. Known tumor markers such as prostate specific antigen (PSA), especially the ratio of free PSA (fPSA)/total PSA (tPSA) or neurones‐specific enolase (NSE) detect the therapeutic effect of treatment with RiV particle preparation (RiV‐PP) more rapidly and with greater sensitivity than does the anti‐RiV antibody assay. However, a continuous decrease of anti‐RiV‐antibody titers seems to indicate a good prognosis. RiV therapy improved the quality of life and achieved an apparent prolongation of life of cancer patients. After treatment with 12 mL of RiV‐PP, a patient with a prostate hyperplasia of uncertain genesis became free of symptoms. This monotherapy with an adequate dose of RiV‐PP resulted in a decrease of tPSA and an increase of fPSA in the first 200 days. The general value of RiV ELISA is emphasized by the fact that it could detect RiV antigen in urinary samples offering a simple means of early diagnosis and monitoring. Since chemo‐ or/and radiotherapy, both of which are immunosuppressive, are frequently used to treat cancer patients, an ELISA for the detection of RiV (particles as) antigen may be more informative than one designed to detect anti RiV antibodies.
Strategies and Practices for Sustainable Use of Water in Industrial Papermaking Processes
Authors: Gavrilescu M. , Teodosiu C. , Gavrilescu D. , Lupu L.
Published: April 2008

The problem of water use in industrial sectors is analyzed in the context of sustainability, and the manufacturing process as one of the most important water consumers is scrutinized. Some practices of water conservation and reduction of water consumption, as well as the implementation of advanced treatment processes for wastewater recycling are considered under the general aspect of process integration and control in order to minimize environmental discharges. Reduction of effluents in papermaking processes are discussed as well as preventative approaches. It is emphasized that four groups of methods can be applied in order to minimize water consumption: process changes, water reuse, regeneration reuse and regeneration recycling. Minimizing the water consumption and thus reducing the hydraulic load may help to improve effluent treatment, reduce operating costs and, when subsequent disposal is to sewers, minimize effluent disposal charges. The data presented show that initially producing less effluents will reduce the demands on the effluent treatment plant and thus save both money and efforts. Separation techniques for minimizing effluents and effluent loads are presented, as well as potential practices to ensure a sustainable use of water, grouped as short term and long term measures. Prevention measures for water consumption in a Romanian paper mill are considered and discussed in relation with best available techniques (BAT), taking into account both economical and environmental benefits.
Commercial quality and analytical parameters of cured vanilla beans (Vanilla planifolia) from different origins from the 2006–2007 crop
Authors: Gassenmeier K. , Riesen B. , Magyar B.
Published: April 2008

An overview on the vanilla bean production and commercial grades from the major vanilla producing areas is given. More than 90 samples of cured vanilla beans from the 2006–2007 crop were obtained and the samples were classified into commercial grades. The concentration of vanillin, vanillic acid, p‐hydroxybenzaldehyde and p‐hydroxybenzoic acid was determined and related to shape, length and colour of the beans. Huge differences in analytical parameters between origins and from batch to batch were found. From Madagascar beans only 50% meet all values of the so‐called ‘ratios’. Many samples contained less vanillin than required by some authorities. The average vanillin content of all Madagascar samples was 1.76 g/100 g. Sensory evaluation of extracts showed no clear relationship between vanillin content and sensory profile of the vanilla extracts. Copyright © 2008 John Wiley & Sons, Ltd.
Institutional research's role in strategic planning
Authors: Voorhees Richard A.
Published: April 2008

Data‐driven strategic plans yield significant returns for institutions. The author gives an overview of strategic planning and useful techniques that yield meaningful results.
Extraction of native collagen from limed bovine split wastes through improved pretreatment methods
Authors: Li Dong , Yang Wei , Li Guo‐ying
Published: April 2008

BACKGROUND: The large amount of limed bovine split wastes discharged by the leather industry has raised concerns regarding their environmental effect. The objective of this work was to perform pilot plant trials to extract high‐value native collagen from these wastes through improved pretreatment methods.

RESULTS: EDTA‐ and HCl‐pretreatment gave similar removal percentages of inorganic substances. Owing to the open structure of fibers, the collagen yield of HCl‐pretreated splits (HPS) (41.31%) was higher than that of EDTA‐pretreated splits (EPS) (10.42%). Furthermore, HCl‐pretreated split collagen (HPC) had a more acidic isoelectric point, lower content of primary amino groups, larger Z‐average particle size and higher relative viscosity than EDTA‐pretreated split collagen (EPC). Electrophoretic analysis and circular dichroism spectra revealed the maintenance of polypeptide and triple helix conformation, respectively. In addition, the transition temperatures of EPC (34.7 °C) and HPC (34.6 °C) detected by differential scanning calorimetry (DSC) were close to that of commercial collagen from calfskin (CCC) (35.7 °C).

CONCLUSION: A process of native collagen extraction from limed bovine split wastes was proposed. While both EPC and HPC represented similar physicochemical properties to those of CCC, the collagen yield of HPS was much higher than that of EPS. Copyright © 2008 Society of Chemical Industry
Wastewater treatment for production of H2S‐free biogas
Authors: Ahammad Sk Z , Gomes J , Sreekrishnan TR
Published: April 2008

BACKGROUND: In anaerobic wastewater treatment processes, the presence of sulfate‐reducing bacteria (SRB) produces H2S. Many techniques are being used to remove H2S from biogas to obtain H2S‐free biogas but none of those are cost effective or efficient enough to remove the H2S completely. The objective of the present study was to introduce some changes/modifications to the process parameters of the wastewater treatment operation to eliminate SRB from the system.

RESULTS: The growth of SRB was found to be completely suppressed under thermophilic conditions (55 °C) but not at 37 °C. H2S‐free biogas containing 56.5% methane was obtained at 55 °C after 180 days of treatment. The effect of higher concentrations of volatile fatty acids (VFAs) on the growth of SRB and methanogens at 37 °C and 55 °C were also studied. At higher VFA concentrations, SRB outgrew the methanogens at 37 °C but at 55 °C the situation was found to be reversed. For continuous operation at 55 °C and low dilution rate (0.0075 h−1), SRB was suppressed and biogas having 29% methane but free of H2S was obtained.

CONCLUSION: Operating the reactor at high temperature (550C) and low hydraulic retention time (HRT) can result in the production of H2S‐free biogas, with a high concentration of methane. Copyright © 2008 Society of Chemical Industry
Synthesis of p‐aminophenol from the hydrogenation of nitrobenzene over metal–solid acid bifunctional catalyst
Authors: Wang Shufang , Ma Yuanhui , Wang Yanji , Xue Wei , Zhao Xinqiang
Published: April 2008

BACKGROUND: A single‐step conversion of nitrobenzene (NB) to p‐aminophenol (PAP) through catalytic hydrogenation is a widely used synthesis route for PAP. The main shortcoming of this route is the use of sulfuric acid for rearrangement of the phenylhydroxylamine (PHA) intermediate. In this paper, S2O82−/ZrO2 (PSZ) solid acid and Pt‐S2O82−/ZrO2 (Pt‐PSZ) bifunctional catalysts were prepared for the synthesis of PAP in non‐acid medium.

RESULTS: Calcination temperature has a substantial effect on the acidity, structure and activity for PHA rearrangement of PSZ. The highest PAP yield was 33.8% over PSZ calcined at 823 K when the reaction was carried out in water at 423 K. A high PAP yield of 23.9% was achieved by a single‐step reaction of nitrobenzene over Pt‐PSZ bifunctional catalysts.

CONCLUSION: PSZ solid acid exhibits high activity for PHA rearrangement. Perfect tetragonal ZrO2 and much stronger acid sites play important roles in catalytic activity. Inhibiting the hydrogenation activity by reducing the amount of Pt loading on Pt‐PSZ can improve the competition of PHA rearrangement on acid sites with hydrogenation of PHA on metal active sites, resulting in better selectivity to PAP. Copyright © 2008 Society of Chemical Industry
Yeast‐mediated enantioselective synthesis of chiral R‐(+)‐ and S‐(−)‐1‐phenyl‐1‐butanol from prochiral phenyl n‐propyl ketone in hexane–water biphasic culture
Authors: Cheng Cheanyeh , Tsai Hsiang‐Rong
Published: April 2008

BACKGROUND: The hydrophobic phenyl n‐propyl ketone was used as a model compound to examine alcohol dehydrogenase activity in Saccharomyces cerevisiae mediated cell culture. Parameters such as pH, hexane‐to‐water volume percentage, and the amount of cofactor Zn2+ ion for either cell growth or reduction were studied to see their effect on the enantioselectivity toward the product R‐(+)‐ or S‐(−)‐1‐phenyl‐1‐butanol.

RESULTS: The pH for cell growth in aqueous culture was 7.0, while the pH for reduction in the aqueous portion of the biphasic culture was 5.0. Without Zn2+ ion the biphasic cultures of middle to high hexane‐to‐water volume percentage exhibited an R‐(+)‐1‐phenyl‐1‐butanol enantiomeric excess of 53.7% to > 99%. Without Zn2+ ion the biphasic cultures at low hexane‐to‐water volume percentage possessed an S‐(−)‐1‐phenyl‐1‐butanol enantiomeric excess of 14.5–46.5%. Exclusively, the enantioselectivity for biphasic cultures containing Zn2+ ion was an S‐(−)‐1‐phenyl‐1‐butanol enantiomeric excess of 27.5% to > 99%. Reduction mediated in aqueous culture with varied amount of Zn2+ ion by the yeast Candida utilis also showed an S‐(−)‐1‐phenyl‐1‐butanol enantiomeric excess of 79.2–95.4%.

CONCLUSION: The enantioselectivity of S. cerevisiae mediated biphasic culture reduction of phenyl n‐propyl ketone can be manipulated through the cofactor Zn2+ ion and the hexane volume percentage of the biphasic culture. Copyright © 2008 Society of Chemical Industry
Oxidation of 4‐nitrophenol in water over Fe(III), Co(II), and Ni(II) impregnated MCM41 catalysts
Authors: Chaliha Suranjana , Bhattacharyya Krishna Gopal , Paul Parimal
Published: April 2008

BACKGROUND: Nitrophenols are toxic constituents of the effluents of petroleum, textile, dye, iron and steel, foundries, pharmaceutical and electrical manufacturing industries. Aromatic nitro compounds are particularly resistant to normal chemical or biological oxidation making them environmentally persistent. Advanced oxidation using appropriate catalysts mineralize these organics to harmless final products. In this work, MCM41‐based catalysts incorporating Fe(III)‐, Co(II)‐ and Ni(II)‐ cations were used for oxidizing 4‐nitrophenol in water under variable conditions of reaction time, pH, mole ratio of the reactant and the oxidant, catalyst load, feed concentration, and temperature.

RESULTS: The catalysts prepared were characterized with X‐ray diffraction (XRD) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), cation exchange capacity (CEC) and atomic absorption spectrometry (AAS) measurements. In typical reaction conditions of temperature 353 K, time 300 min, catalyst load 2 g L−1 and 10−3 mol L−1 4‐nitrophenol, the oxidation was 48.7, 52.2 and 55.2% with H2O2 and 42.5, 56.6 and 60.2% without H2O2 for Fe(III)‐, Co(II)‐ and Ni(II)‐MCM41, respectively. Pseudo‐first‐order kinetics with kinetic constant of 2.0 × 10−3 to 5.5 × 10−3 Lg−1 min−1 was proposed along with a possible mechanism. 4‐nitrocatechol, 4‐nitropyrogallol, 1,2,4‐trihydroxybenzene, hydroquinone, acrylic acid, malonic acid, and oxalic acid were identified in the oxidation products.

CONCLUSION: Introduction of Fe(III)‐, Co(II)‐ and Ni(II)‐ into MCM‐41 by impregnation produced effective catalysts for wet oxidation of 4‐nitrophenol. The catalysts were able to oxidize 4‐NP even without the presence of an oxidizing agent. The results suggest that the transition metal loaded MCM41 brings about a more effective interaction between 4‐NP molecules and OH radicals. Copyright © 2008 Society of Chemical Industry
Kinematics of turning maneuvers in the southern flying squirrel,Glaucomys volans
Authors: Bishop Kristin L. , Brim‐DeForest Whitney
Published: April 2008

The ability to change direction is essential to any animal that moves around in a complex, 3D environment. In this study we present the first 3D description of body positions during gliding turns in a mammalian gliding specialist, the southern flying squirrel,Glaucomys volans. In addition, we used these kinematic data to estimate the aerodynamic forces generated by the animals and rotational velocities and accelerations of the body while turning. These results were compared with similar measurements of flying squirrels during straight glides. The two individuals used in this study differed significantly in limb position asymmetries between the two sides of their bodies and also were significantly different in measures of turning performance. The individual with better performance used limb positions consistent with a primarily lift‐based turning mechanism (banked turn), whereas the individual with poorer performance used limb positions consistent with a primarily drag‐based turning mechanism (crabbed turn). Both individuals employed limb movements continuously through the gliding turn, but these movements did not have any consistent relationships with body rotations or lateral acceleration. As compared with straight glides, squirrels used significantly higher angles of attack and had lower lift‐to‐drag ratios, but did not differ in glide angle. Contrary to the typical view of maneuvering during gliding as a simple, static form of locomotion, the results presented here indicate that mammalian gliding is a complex behavior comprising the interplay of many components of limb position and wing shape that affect the balance of forces that control the turn.J. Exp. Zool. 309A:225–242, 2008. © 2008 Wiley‐Liss, Inc.
Two‐point dixon fat–water separation: Improving reliability and accuracy in phase correction algorithms
Authors: Schmidt Maria A. , Fraser Karlene M.
Published: April 2008

Purpose

To propose an advanced phase‐correction region‐growing algorithm for two‐point fat–water separation suitable for parotid assessment, and to evaluate the general performance of phase‐correction algorithms.

Materials and Methods

Two region‐growing algorithms were evaluated in test objects and in head images: the original phase‐correction algorithm (OPC) and the advanced phase‐correction algorithm with voxel size manipulation (VSM) which includes: 1) starting the region‐growing process from images of lower resolution and subsequently stepping toward the original matrix size, and 2) limiting the use of low‐pass filters to fat–water interfaces with partial volume effects

Results

Fundamental problems relate to biological tissue spectrum being poorly approximated by two discrete peaks for fat and water. The VSM algorithm was shown to be less noise‐sensitive, faster, and to produce a better approximation for the field inhomogeneity map. In head images (6 volunteers, 10 slices each) 43 errors were found with the OPC algorithm and only 6 errors with the VSM algorithm. Only the OPC algorithm produced errors surrounding the parotids (10 errors).

Conclusion

The VSM algorithm provides a more accurate and less noise‐sensitive fat–water separation. This highly significant performance improvement allows the application of phase‐correction algorithms to a wider range of clinical applications. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.