bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Highly Porous Materials from Cellulose Carbamate
Authors: Pinnow Manfred , Fink Hans‐Peter , Fanter Carola , Kunze Jürgen
Published: February 2008

Highly porous cellulose was formed by gelation of cellulose carbamate solutions in caustic soda. Two methods for gel preparation were optimized for the formation of beads and bulky materials – the chemical precipitation from dilute sulfuric acid and the thermal gelation by annealing at elevated temperatures. Various methods were used for characterizing of the pores of low density materials: scanning electron microscopy, small angle X‐ray scattering, mercury intrusion and nitrogen sorption. These methods were optimized and used for characterizing the complete pore system from micro to macro pores. The effects of different preparation (cellulose carbamate concentration in caustic soda) and processing (precipitation, drying and pyrolysis) on the pore structure were studied by the set of complementary methods. Aerocell samples with a minimum density of 0.06 g/cm3 were prepared from cellulose carbamate. They are characterized by a broad pore size distribution ranging from 0.5 nm to 1 mm, specific internal surfaces of up to 660 m2/g and total pore volumes of up to 18 cm3/g.
Efficient Method for the Preparation of Pure, Water‐Soluble Cellodextrines
Authors: Liebert Tim , Seifert Marit , Heinze Thomas
Published: February 2008

An efficient method towards water soluble cellodextrine mixtures is described and detailed information on structure analysis is given. For cellulose degradation in good yield, treatment of cellulose with 85% phosphoric acid for 30 minutes at room temperature and a hydrolysis of 20 hours at 55 °C are suitable. With a work up in tetrahydrofuran (THF), a yield of almost 70% raw product is achievable. After separation of a water insoluble fraction, a yield of 53% of cellodextrines with a degree of polymerization (mean weight average, $\overline {DP} _{\rm w} $) of 7.5 and a polydispersity index of 1.7 is obtained. These cellodextrines are soluble in water, dimethyl sulfoxide (DMSO) and dimethyl acetamide (DMA)/LiCl. Detailed structure analysis by one and two‐dimensional NMR, FTIR and mass spectroscopy revealed that the substance consists only of β‐1 → 4 linked glucoses. A partial functionalization was excluded by 13C NMR‐ and 31P decoupled 1H NMR spectroscopy.
Studies into the Early Degradation Stages of Cellulose by Different Iron Gall Ink Components
Authors: Henniges Ute , Banik Gerhard , Reibke Rebecca , Potthast Antje
Published: February 2008

Selective fluorescence labelling of oxidized cellulose functionalities followed by GPC‐MALLS was used to get a deeper insight into ink‐induced degradation processes. As the method is very sensitive towards oxidation and molecular weight changes, slight variations at the very beginning of aging processes, e.g. during ink corrosion of cellulose, can be studied.

Five different ink modifications were applied on model papers and underwent mild accelerated aging at 55 °C and cycling humidity (7 days) followed by a short period of static humid aging at 80 °C (2 days). Pure ink constituents like tannic acid or iron sulphate do not result in the same degree of oxidation or chain scission as complete inks. Balanced ink degrades paper more than single compounds, but less than unbalanced inks. Interestingly, some degradation occurs already during or shortly after the application process of unbalanced inks on paper. It could be demonstrated that this oxidation proceeded in a rather high Mw area, while the subsequent aging steps affected predominantly regions of shorter cellulose chains.
New Possibilities of the Acetosulfation of Cellulose
Authors: Hettrich Kay , Wagenknecht Wolfgang , Volkert Bert , Fischer Steffen
Published: February 2008

Regioselectively substituted cellulose sulfates in C2/3‐, C2/6‐, or C6‐position of the anhydroglucose unit are accessible by certain synthesis routes. Thereby, products with different properties and various application areas are resulted. Important characteristics of cellulose sulfates regarding their applications are solubility (e.g. in water), rheological behavior, different interaction with low or high molecular cations, thermo reversible gel formation, enzymatic degradability, anticoagulant and antiviral activity. In C6‐position substituted cellulose sulfates can be synthesized in principle by acetosulfation. The acetosulfation is a quasi‐homogeneous synthesis proceeding under gradually dissolution of the cellulose by using different reactivity of the primary and secondary OH‐groups as soon as converting cellulose acetate sulfates. After precipitation of the polymer the acetyl groups are cleaved in alkaline solution. The focus of our study was firstly the investigation of the acetosulfation in different polar aprotic solvents by various sulfating and acetylating agents. In general it should be investigated if C6 substituted cellulose sulfates can be obtained by acetosulfation with different solvents and agents. The products were characterized by 13C‐NMR and Raman spectroscopy.
Improvement of Fibre‐Matrix‐Adhesion of Natural Fibres by Chemical Treatment
Authors: Reich Stefan , ElSabbagh Ahmed , Steuernagel Leif
Published: February 2008

Plastics, also called synthetic polymers, are playing an important role in daily living. To raise more applications it is necessary to modify known polymeric systems to reach improved materials/material systems.

A possibility to create new optimised materials out of neat polymers is offered by compounding them with different filling material. Besides chemical modification of polymers, mixing, combining or use of different fillers, one possibility is given by the composite technique, whereas the combination of the polymeric matrix and the embedded reinforcement (e.g. fibre) are yielding in optimised materials adjusted to the required properties. Concerning the polymeric matrix, either thermoplastic or thermoset material can be used. In case of the reinforcement, either synthetic (carbon‐, glass‐ or polymeric fibres) or natural fibres are introduced to composites.

To obtain an appropriate adhesion of the matrix to the reinforcement system, synthetic fibres are equipped with an avivage. For natural fibres, there are no such materials available and the hydrophilic property of this system surface prevents an adhesion to hydrophobic polymers, as well as to sizings.

In this paper, ways are shown to modify the natural fibres via chemical treatment to yield higher physical properties at better adhesion. Also we will explain activities on the use of natural fibres as reaction systems and processing tools as well as the attempt to isolate the different compounds of the neat fibre via selective work‐up.
Comparative Synthesis Studies Towards Methyl and Phenyl 4‐Deoxy‐β‐L‐threo‐hex‐4‐enopyranosiduronic Acid as Model Compounds of Hexenuronic Acid Moieties in Hardwood Pulps
Authors: Tot Ivana , Krainz Karin , Potthast Antje , Suess Ulrich , Rosenau Thomas
Published: February 2008

The present study describes two approaches to synthesize hexenuronic acid model compounds in which the xylan backbone is replaced by a simple substituent, either methyl or phenyl. To general pathways towards the two products are offered: the first one, starting from glucuronic acid and involving formation and reopening of the 1,6‐lactone, was especially suitable to afford the phenyl derivative 8. The second one, by contrast, is more appropriate for the methyl compound 12; it starts from galactose and involves TEMPO oxidation and conversions of the intermediate 1,3‐lactone. Both pathways were optimized on a mg scale and subsequently upscaled to afford the targets in gram amounts. The “detour” via the methyl glucopyranosiduronate – instead of using the free acid – proved to be crucial in boosting the yield in the elimination step.
One‐dimensional analysis of a poroelastic medium during freezing
Authors: Boukpeti Nathalie
Published: February 2008

A solution to the problem of freezing of a poroelastic material is derived and analysed in the case of one‐dimensional deformation. The solution is sought within the framework of thermo‐poroelasticity, with specific account of the behaviour of freezing materials. The governing equations of the problem can be combined into a pair of coupled partial differential equations for the temperature and the fluid pressure, with particular forms in the freezing and the unfrozen regions. In the freezing region, the equations are highly non‐linear, partly due to the dependence of thermal and hydraulic properties on water saturation, which varies with temperature. Consequently, the solution is obtained through numerical methods, with special attention to the propagation of the freezing front boundary. The response to one‐dimensional freezing is illustrated for the case of cement paste. Finally, the influence on the solution of varying selected parameters is analysed, such as the temperature boundary conditions, the parameters characterizing the geometry of the porous system, the ratio of fluid and thermal diffusivities, and the rate of cooling applied at the freezing end. Copyright © 2008 John Wiley & Sons, Ltd.
Simplified coupled chemo‐mechanical modeling of cement pastes behavior subjected to combined leaching and external sulfate attack
Authors: Bary B.
Published: February 2008

In the context of radioactive waste storage, underground concrete structures may be subjected to external sulfate attack due to penetration of sulfate combined with leaching. This paper proposes a coupled chemo‐mechanical modeling relying on a simplified chemical description of the solid phase composing the cement paste to address this issue. The sulfate and calcium species diffusing through the pore solution are supposed to completely control the chemical system, in particular the precipitation of gypsum and ettringite, which may lead to significant macroscopic expansions and cracking. The crystallization pressure generated by the growing crystals is introduced in the modeling through a poroelasticity analogy. Based on a representation of the cement paste of the matrix‐inclusion type, the application of the Mori–Tanaka (MT) scheme provides estimates of the mechanical and diffusive properties and of the interaction coefficient as a function of the degradation state. The obtained coupled system is applied to two‐dimensional numerical simulations of laboratory tests; the confrontation between experimental and computational results shows a good agreement in terms of both hydrated product evolutions as a function of time and macroscopic cracking appearance. Copyright © 2008 John Wiley & Sons, Ltd.
Analytical theory for one‐dimensional consolidation of clayey soils exhibiting rheological characteristics under time‐dependent loading
Authors: Xie Kang‐He , Xie Xin‐Yu , Li Xi‐Bin
Published: February 2008

This paper presents analytical solutions to the one‐dimensional consolidation problem taking into consideration the rheological properties of clayey soil under variable loadings. A four‐element rheological model is introduced, and different loading types are involved, i.e. constant loading, one‐step loading, triangular loading, rectangular loading, and isosceles–trapezoidal cyclic loading. The differential equations governing consolidation are solved by the Laplace transform. Based on the solutions obtained, the influences of the rheological parameters and loading conditions on the consolidation process are investigated. It has been shown that the consolidation behavior is mainly governed by four dimensionless parameters, a1, a2, b, and Tv0. Load shape has a great influence on the rate of consolidation. A decrease either in the modulus of the spring in the Kelvin body or in the viscosity coefficient of independent dashpot will slow down the rate of consolidation. An increase in the viscosity coefficient of the dashpot in the Kelvin body will make the rate of consolidation increase at an early stage but decrease at a later stage. For isosceles–trapezoidal cyclic loading, the consolidation rate in each cycle reaches a maximum at the end of the constant loading phase and the minimum at the end of this cycle. Copyright © 2008 John Wiley & Sons, Ltd.
Influence of size on the constitutive equations of concrete or rock dowels
Authors: Miguel Letícia Fleck Fadel , Riera Jorge Daniel , Iturrioz Ignacio
Published: February 2008

The numerical fracture analysis of non‐homogeneous rock or concrete dowels subjected to shear and compression is described in detail. The method of analysis allows the consideration of scale and rate effects due to material non‐homogeneity and fracture. The proposed approach is verified by comparing numerical predictions with experimental results reported in the literature for a series of small rock samples, since experimental evidence for large bodies is not yet available (2007). Results generated by Monte Carlo simulation using the so‐called discrete element method to model the dowels suggest that a simple three parameters law can be used to predict the relationship between tangential stress at the base and lateral distortion. It is observed that the larger the size of the cubes, the smaller both the peak tangential stress and the rupture distortion. Size effects are also evaluated in samples with vertical restraint. The influence of loading rate is likewise numerically assessed for two sample sizes. The effect is compatible with experimental evidence available for concrete using small samples. Copyright © 2008 John Wiley & Sons, Ltd.
A community‐based stress management programme for an impoverished population in South Africa
Authors: Crouch Rosemary B.
Published: February 2008

The development and evaluation of a programme for the effective management of stress in an impoverished rural community is the subject of this research study. A random sample of 160 participants was selected from the rural population of the Limpopo Province of South Africa. This population resembles in many ways other disadvantaged populations in South Africa, and the outcome may have generalizability. A quantitative, factorial experimental design was used to compare four stress management programmes. Three were conventional stress management programmes derived from the literature, and the fourth programme was a creative activity programme. Data was gathered from two questionnaires. Results from the statistical analyses of data revealed that the participants experienced significant reduction in stress in all four programmes. At post post‐testing, participants in the three conventional programmes experienced a reduction of stress by 39.5, 72.5 and 40.8%, respectively. There was a 41.6% reduction in stress in participants in the creative activity programme. Limitations of the study include differences in the severity of certain psycho‐social stressors experienced by the participants and difficulty in the control of a standardized presentation of the programmes. The most successful and sustainable stress management programme included physical methods of controlling stress such as exercise relaxation and good nutrition. Further research is recommended in combining a stress management programme with a creative activity group in reducing stress in a disadvantaged population. Copyright © 2008 John Wiley & Sons, Ltd.
Agreeableness is related to social‐cognitive, but not social‐perceptual, theory of mind
Authors: Nettle Daniel , Liddle Bethany
Published: February 2008

We hypothesise on a number of grounds that the personality dimension of Agreeableness may be associated with inter‐individual differences in theory of mind (ToM) functioning. However, it is important to distinguish social‐perceptual from social‐cognitive ToM. Previous findings on ToM in psychopathic individuals, sex differences in ToM and the associations between ToM and social relationships, all suggest that social‐cognitive ToM is more likely than social‐perceptual ToM to relate to Agreeableness. In separate empirical studies, we find that Agreeableness is substantially correlated with social‐cognitive ToM performance, but uncorrelated with social‐perceptual ToM performance. We suggest that the propensity or motivation to attend to the mental states of others may be central to the personality dimension of Agreeableness. Copyright © 2008 John Wiley & Sons, Ltd.
Proteasome subunit proteins and neuropathology in tauopathies and synucleinopathies: Consequences for proteomic analyses
Authors: Zouambia Mohamed , Fischer David F. , Hobo Barbara , De Vos Rob A. I. , Hol Elly M. , Varndell Ian M. , Sheppard Paul W. , Van Leeuwen Fred W.
Published: February 2008

Accumulation of proteins in inclusions in neurological disorders is partly due to dysfunction of the ubiquitin–proteasome system. Proteasomal dysfunction may be caused by misexpression of one or more of its subunits. A large number of antibodies reactive with proteasome subunits were screened on material from patients exhibiting tau‐ and synucleinopathies. Many antisera against proteasomal subunits (11S activator, 19S regulator ATPase/non‐ATPase, and 20S α and β resulted in a distinct nuclear and/or cytoplasmic staining of the entorhinal‐hippocampal area and the temporal cortex of Alzheimer's disease (AD) patients. In particular an antibody directed against 19S regulator ATPase subunit 6b (S6b) specifically stained the neurofibrillary tangles and dystrophic neurites in AD, Down syndrome and aged nondemented controls. In other tauopathies (Pick's disease, frontotemporal dementia, progressive supranuclear palsy and argyrophilic grain disease), neuronal and/or glial inclusions were also S6b immunoreactive. In contrast, in synucleinopathies (Lewy body disease (LBD) and multiple system atrophy) no S6b staining was seen. Real time quantitative PCR on the temporal cortex of AD patients revealed a significant increase in S6b subunit mRNA. This increase was not found in the gyrus cinguli anterior of patients with LBD. This differential expression of S6b most likely will result in different proteomic patterns. Here we present evidence to show that S6b coexists with a reporter for proteasomal dysfunction (ubiquitin+1), and we conclude that S6b transcript up‐regulation and the dysfunction in tauopathies may be functionally related.
The myth of automated, high‐throughput two‐dimensional gel analysis
Authors: Clark Brittan N. , Gutstein Howard B.
Published: February 2008

Many software packages have been developed to process and analyze 2‐D gel images. Some programs have been touted as automated, high‐throughput solutions. We tested five commercially available programs using 18 replicate gels of a rat brain protein extract. We determined computer processing time, approximate spot editing time, time required to correct spot mismatches, as well as total processing time. We also determined the number of spots automatically detected, number of spots kept after manual editing, and the percentage of automatically generated correct matches. We also determined the effect of increasing the number of replicate gels on spot matching efficiency for two of the programs. We found that for all programs tested, less than 3% of the total processing time was automated. The remainder of the time was spent in manual, subjective editing of detected spots and computer generated matches. Total processing time for 18 gels varied from 22 to 84 h. The percentage of correct matches generated automatically varied from 1 to 62%. Increasing the number of gels in an experiment dramatically reduced the percentage of automatically generated correct matches. Our results demonstrate that these 2‐D gel analysis programs are not automatic or rapid, and also suggest that matching accuracy decreases as experiment size increases.
Transcriptome and proteome analysis of early embryonic mouse brain development
Authors: Hartl Daniela , Irmler Martin , Römer Irmgard , Mader Michael T. , Mao Lei , Zabel Claus , de Angelis Martin Hrabé , Beckers Johannes , Klose Joachim
Published: February 2008

Mouse embryonic brain development involves sequential differentiation of multipotent progenitors into neurons and glia cells. Using microarrays and large 2‐DE, we investigated the mouse brain transcriptome and proteome of embryonic days 9.5, 11.5, and 13.5. During this developmental period, neural progenitor cells shift from proliferation to neuronal differentiation. As expected, we detected numerous expression changes between all time points investigated, but interestingly, the rate of alteration remained in a similar range within 2 days of development. Furthermore, up‐ and down‐regulation of gene products was balanced at each time point which was also seen at embryonic days 16–18. We hypothesize that during embryonic development, the rate of gene expression alteration is rather constant due to limited cellular resources such as energy, space, and free water. A similar complexity in terms of expressed genes and proteins suggests that changes in relative concentrations rather than an increase in the number of gene products dominate cellular differentiation. In general, expression of metabolism and cell cycle related gene products was down‐regulated when precursor cells switched from proliferation to neuronal differentiation (days 9.5–11.5), whereas neuron specific gene products were up‐regulated. A detailed functional analysis revealed their implication in differentiation related processes such as rearrangement of the actin cytoskeleton as well as Notch‐ and Wnt‐signaling pathways.
Assessing quantitative post‐mortem changes in the gray matter of the human frontal cortex proteome by 2‐D DIGE
Authors: Crecelius Anna , Götz Andrea , Arzberger Thomas , Fröhlich Thomas , Arnold Georg J. , Ferrer Isidro , Kretzschmar Hans A.
Published: February 2008

The number of proteomics studies concerning human brain samples has been increasing in recent years, in particular in the discovery of biomarkers for neurological diseases. The human brain samples are obtained from brain banks, which are interested in providing high quality human nervous tissue. In order to provide brain banks as well as scientists working in the proteomics field with measures for tissue quality, the critical factors after death, the effect of post‐mortem interval (PMI) and storage temperature on the human brain proteome were investigated. This study was focused on the gray matter of the frontal cortex. The PMI was artificially prolonged from the time of autopsy (2 h after death) by storing samples at 4°C or room temperature over 18, 24, and 48 h. The samples were analyzed by 2‐D DIGE using a pH 4–7 gradient, revealing a time course of quantitative protein changes. The degradation of three proteins, peroxiredoxin‐1, stathmin, and glial fibrillary acidic protein were further confirmed by Western‐blot analysis. Proteins vulnerable to PMI were analyzed by the 2‐D DIGE analysis of cortex samples from three donors, and were derived from a variety of functional groups, including metabolic, structural, stress response, antioxidants, synaptosomal, and neuronal proteins.
An approach to handling and interpretation of ambiguous data in transcriptome and proteome comparisons
Authors: Irmler Martin , Hartl Daniela , Schmidt Thorsten , Schuchhardt Johannes , Lach Christiane , Meyer Helmut E. , Hrabé de Angelis Martin , Klose Joachim , Beckers Johannes
Published: February 2008

A major challenge towards a comprehensive analysis of biological systems is the integration of data from different “omics” sources and their interpretation at a functional level. Here we address this issue by analysing transcriptomic and proteomic datasets from mouse brain tissue at embryonic days 9.5 and 13.5. We observe a high concordance between transcripts and their corresponding proteins when they were compared at the level of expression ratios between embryonic stages. Absolute expression values show marginal correlation. We show in examples, that poor concordance between protein and transcript expression is in part explained by the fact, that single genes give rise to multiple transcripts and protein variants. The integration of transcriptomic and proteomic data therefore requires proper handling of such ambiguities. A closer inspection of such cases in our datasets suggests, that comparing gene expression at exon level instead of gene level could improve the comparability. To address the biological relevance of differences in expression profiles, literature‐data mining and analysis of gene ontology terms are widely used. We show here, that this can be complemented by the inspection of physical properties of genes, transcripts, and proteins.
Interlocking transcriptomics, proteomics and toponomics technologies for brain tissue analysis in murine hippocampus
Authors: Bode Marcus , Irmler Martin , Friedenberger Manuela , May Caroline , Jung Klaus , Stephan Christian , Meyer Helmut E. , Lach Christiane , Hillert Reyk , Krusche Andreas , Beckers Johannes , Marcus Katrin , Schubert Walter
Published: February 2008

We have correlated transcriptomics, proteomics and toponomics analyses of hippocampus tissue of inbred C57BL/6 mice to analyse the interrelationship of expressed genes and proteins at different levels of organization. We find that transcriptome and proteome levels of function as well as the topological organization of synaptic protein clusters, detected by toponomics at physiological sites of hippocampus CA3 region, are all largely conserved between different mice. While the number of different synaptic states, characterized by distinct synaptic protein clusters, is enormous (>155 000), these states together form synaptic networks defining distinct and mutually exclusive territories in the hippocampus tissue. The findings provide insight in the systems biology of gene expression on transcriptome, proteome and toponome levels of function in the same brain subregion. The approach will lay the ground for designing studies of neurodegeneration in mouse models and human brains.
BrainProfileDB – a platform for integration of functional genomics data
Authors: Schuchhardt Johannes , Glintschert Alexander , Hartl Daniela , Irmler Martin , Beckers Johannes , Stephan Christian , Marcus Katrin , Klose Joachim , Meyer Helmut E. , Malik Arif
Published: February 2008

BrainProfileDB is a database system for integrating large sets of high throughput functional genomics data of the Human Brain Proteome Project (HBPP). Within HBPP (http://www.smp‐proteomics.de/) the molecular pathology of neurodegenerative diseases is investigated, using complementary methods from transcriptomics, proteomics, toponomics and interaction measurements. Aim of the database system is to provide a broad spectrum of scientific users joined in the consortium with a practical integrated view on their data. Employing appropriate mapping techniques and levels of data representation the user is relieved from technical details of gene identification or experimental measurement technique.
Island clustering analysis for the comparison of the membrane and the soluble protein fractions of human brain proteome
Authors: Kwon Kyung‐Hoon , Park Gun Wook , Kim Jin Young , Lee Sang Kwang , Lee Jeong Hwa , Kim Young Hye , Kim Se‐Young , Park Young Mok , Yoo Jong Shin
Published: February 2008

A protein identified in multiple separate bands of a 1‐D gel reflects variation in the molecular weight caused by alternative splicing, endoproteolytic cleavage, or PTMs, such as glycosylation or ubiquitination. To characterize such a protein distribution over the bands, we defined an entity called an ‘island’ as the band region including the bands of the same protein identified sequentially. We quantified the island distribution using a new variable called an Iscore. Previously, as described in Park et al.. (Proteomics 2006, 6, 4978–4986.), we analyzed human brain tissue using a multidimensional MS/MS separation method. Here, the new method of island analysis was applied to the previous proteome data. The soluble and membrane protein fractions of human brain tissue were reanalyzed using the island distribution. The proteome of the soluble fraction exhibited more variation in island positions than that of the membrane fraction. Through the island analysis, we identified protein modifications and protein complexes over the 1‐D gel bands.
Fluorescence and bioluminescence procedures for functional proteomics
Authors: Prinz Anke , Reither Gregor , Diskar Mandy , Schultz Carsten
Published: February 2008

This review aims to provide an overview of current optical procedures used in functional proteomics, investigating protein localization, protein–protein interaction, intracellular signaling events, and second messenger generation in living cells. Reporter assays using proteins tagged with fluorescent or bioluminescent moieties are discussed. Recently, intracellular biosensor assays, flow cytometry‐based techniques (fluorescent cell barcoding), as well as transfected cell microarray assays involving RNA interference coupled with automated imaging were introduced and have been adopted as screening platforms for annotating small molecules, investigating signaling events, or in phenotype analysis. These novel methodological advances include improved image acquisition and processing techniques and help linking in vitro observations to in vivo processes. In addition, the acquired data are increasingly quantitative in nature and will therefore pave the way for modeling of signaling cascades and other complex cellular events, an important step toward systems biology.
Inside SMP proteomics: Six years German Human Brain Proteome Project (HBPP) – A summary
Authors: Hamacher Michael , Hardt Tanja , van Hall Andre , Stephan Christian , Marcus Katrin , Meyer Helmut E.
Published: February 2008

In 2001, the German Federal Ministry of Education and Research (BMBF) initiated the National Genome Research Network (NGFN; www.ngfn.de) as a nation‐wide multidisciplinary networking platform aiming at the analysis of common human diseases and aging. Within the NGFN the Human Brain Proteome Project (HBPP; www.smp‐proteomics.de) focuses on the analysis of the human brain in health and disease. The concept is based on two consecutive steps: (i) Elaborating and establishing the necessary technology platforms. (ii) Application of the established technologies for research in Alzheimer's disease and Parkinson's disease. In the first funding period, HBPP1, running from 2001 to 2004, necessary technologies were established and optimized. In HBPP2, which started 2004 and will end in May 2008, the developed technologies are used for large‐scale experiments, offering new links for disease related research and therapies. The following overview describes structure, aims and outcome of this unique German Brain Proteome Project.
Crop losses due to olive moth mediated by ethylene
Authors: Ramos Pedro , Rosales Raquel , Sabouni Ibrahim , Garrido Dolores , Ramos Jose M
Published: February 2008

BACKGROUND:Studies for nine years in southern Spain on the olive moth, Prays oleae Bern., have tested the possibility of altering oviposition behaviour on newly formed olive fruits by means of a single ethylene application.

RESULTS:A single spraying of ethylene on the olive trees at the beginning of fruiting significantly decreased the olive moth egg populations and consequent the olive fruit fall. At the same time, no negative effect was found in the activity of natural oophagous predators of the olive moth.

CONCLUSIONS:The ethylene treatments against P. oleae yielded substantial economical benefits each year (a mean of €526 ha−1), benefits that fluctuated depending on the olive crop and on the annual fruit fall caused by this major pest. Copyright © 2008 Society of Chemical Industry
EPR study of low symmetry Er centers in congruent lithium niobate
Authors: Bodziony T. , Kaczmarek S. M.
Published: February 2008

Electron paramagnetic resonance study of congruent LiNbO3 single crystal weakly doped (0.1 wt%) with erbium is reported. The EPR lines originating both from the 167Er isotope with a hyperfine structure, as well as from the evenEr isotopes causing fine structure, are identified. Angular dependence of the EPR lines reveals the presence of several non‐equivalent centers. Deconvolution of the EPR line into several Lorentzian components in a plane perpendicular to the z‐axis (optical c‐axis) allowed us to show the Er3+ center with the lowest (C1) point group symmetry and estimate the values of g‐tensor. The obtained results confirmed the model of non‐ equivalent centers of the rare‐earth ions in lithium niobate having the lowest C1 symmetry due to the presence of intrinsic defects in the near‐neighborhood of RE3+. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Silicon nano particles: Surface characterization, defects and electronic properties
Authors: Hahn Torsten , Heimfarth Jan P. , Roewer Gerhard , Kroke Edwin
Published: February 2008

Nano scaled silicon particles (nc‐Si) having a diameter of about 3 to 9 nm were synthesized by direct reduction of SiCl4 with H2 in a LaCl3 matrix by a vapour deposition (CVD) route. The particles were characterized by diffuse reflection fourier transform spectroscopy (DR/FT‐IR), photoluminescence (PL), electron paramagnetic resonance (EPR) and microwave detected photo induced current transient spectroscopy (MD‐PICTS). EPR measurements identified dangling bond defects on the surface of as‐prepared nc‐Si particles in the LaCl3 matrix. The number of dangling bonds significantly decreases upon extraction of the nc‐Si with ethanol. As expected, the dangling bonds disappear completely after treatment with 1% HF solution. A strong correlation between presence of dangling bond defects and electronic properties was found. The temperature dependent photoconductivity in conjunction with the EPR and PL results allowed us to analyze the defect structure of the nc‐Si particles. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of hydrostatic pressure on the donor binding energy and intra donor transition matrix elements in GaAs–GaAlAs quantum wells
Authors: Panahi H. , Maleki M.
Published: February 2008

The effects of hydrostatic pressure on the donor binding energy in GaAs–Ga0.7Al0.3As quantum wells have been studied in the effective mass approximation, using a variational approach for hydrogenic ground state 1s and excited states 2s, 2px, 3px. Results obtained show that the donor binding energy variation with the well width and the position of impurity under pressure is similar to that without pressure. The intra donor squared transition matrix elements are calculated as functions of impurity position in the presence of hydrostatic pressure. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photophysics of J‐aggregate microcavities
Authors: Michetti P. , La Rocca G. C.
Published: February 2008

We have developed a model in order to account for the photo‐excitation dynamics of J‐aggregate films and strongly coupled J‐aggregate microcavities. The J‐aggregates are described as a disordered Frenkel exciton system in which relaxation occurs due to the presence of a thermal bath of molecular vibrations. The link between the J‐aggregate film and the microcavities is obtained introducing a model polariton wavefunction mixing cavity photon modes and J‐aggregate superradiant excitons. With the same approach we have calculated both absorption and luminescence spectra for the J‐aggregate film and the photoluminescence of strongly coupled organic microcavities. The model is able to explain the organic microcavities fast relaxation dynamics and polariton luminescence following non resonant pumping starting from the excitonic properties of the optically active layer. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Piezo‐voltage control of magnetization orientation in a ferromagnetic semiconductor
Authors: Goennenwein S. T. B. , Althammer M. , Bihler C. , Brandlmaier A. , Geprägs S. , Opel M. , Schoch W. , Limmer W. , Gross R. , Brandt M. S.
Published: February 2008

The possibility to control magnetic properties via electrical fields is investigated in a piezoelectric actuator/ferromagnetic semiconductor thin film hybrid structure. Using anisotropic magnetoresistance techniques, the magnetic anisotropy and the magnetization orientation within the plane of the ferromagnetic film are measured quantitatively. The experiments reveal that the application of an electrical field to the piezoelectric actuator allows to continuously and reversibly rotate the magnetization orientation in the ferromagnet by about 70°. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural characterization of synthetic poly(ester amide) from sebacic acid and 4‐amino‐1‐butanol by matrix‐assisted laser desorption ionization time‐of‐flight/time‐of‐flight tandem mass spectrometry
Authors: Rizzarelli Paola , Puglisi Concetto
Published: February 2008

Matrix‐assisted laser desorption/ionization time‐of‐flight/time‐of‐flight tandem mass spectrometry (MALDI‐TOF/TOF‐MS/MS) was employed to analyze a poly(ester amide) sample (PEA‐Bu) from the melt condensation of sebacic acid and 4‐amino‐1‐butanol. In particular, we investigated the fragmentation pathways, the ester/amide bond sequences and the structure of species derived from side reactions during the synthesis. MALDI‐TOF/TOF‐MS/MS analysis was performed on cyclic species and linear oligomers terminated by dicarboxyl groups, carboxyl and hydroxyl groups and diamino alcohol groups. The sodium adducts of these oligomers were selected as precursor ions. Different end groups do not influence the fragmentation of sodiated poly(ester amide) oligomers and similar series of product ions were observed in the MALDI‐TOF/TOF‐MS/MS spectra. According to the structures of the most abundant product ions identified, the main cleavages proceed through a β‐hydrogen‐transfer rearrangement, leading to the selective scission of the OCH2 bonds. Abundant product ions originating from CH2CH2 (β–γ) bond cleavage in the sebacate moiety were also detected. Their formation should be promoted by the presence of an α,β‐unsaturated ester or amide end group. MALDI‐TOF/TOF‐MS/MS provided structural information concerning the ester/amide sequences in the polymer chains. In the MALDI‐TOF/TOF‐MS/MS spectra acquired, using argon as the collision gas, of cyclic species and linear oligomers terminated by diamino alcohol groups, product ions in the low‐mass range, undetected in the mass spectra acquired using air as the collision gas, proved to be diagnostic and made it possible to establish the presence of random sequences of ester and amide bonds in the poly(ester amide) sample. Furthermore, MALDI‐TOF/TOF‐MS/MS provided useful information to clarify the structures of precursor ions derived from side reactions during the synthesis. Copyright © 2008 John Wiley & Sons, Ltd.
Trace level determination of trichloroethylene in biological samples by headspace solid‐phase microextraction gas chromatography/negative chemical ionization mass spectrometry
Authors: Liu Yongzhen , Muralidhara Srinivasa , Bruckner James V. , Bartlett Michael G.
Published: February 2008

A gas chromatography/negative chemical ionization mass spectrometry (GC/NCIMS) method using headspace solid‐phase microextraction (HS‐SPME) was developed for the determination of trichloroethylene (TCE) in blood, liver, kidney, lung and brain. The method was optimized with respect to several parameters including extraction time, extraction temperature, desorption time and salt addition. The method showed good linearity over the range of 0.025–25 ng/mL in blood and 0.075–75 ng/g in tissues with correlation coefficient (R2) values higher than 0.99. The precision and accuracy for intra‐day and inter‐day measurements were less than 10%. The relative recoveries of all matrices were greater than 52%. Samples showed no significant loss during 8 h in the autosampler and following three freeze/thaw cycles. Validation results demonstrated that selected‐ion monitoring of the 35Cl and 37Cl isotopes using NCI resulted in reliable and sensitive quantitation. This validated method was successfully applied to study the toxicokinetics of TCE following oral administration of extremely low doses of this potential human carcinogen to small test animals (rats). Copyright © 2008 John Wiley & Sons, Ltd.
Determination of peanut allergens in cereal‐chocolate‐based snacks: metal‐tag inductively coupled plasma mass spectrometry immunoassay versus liquid chromatography/electrospray ionization tandem mass spectrometry
Authors: Careri Maria , Elviri Lisa , Maffini Monica , Mangia Alessandro , Mucchino Claudio , Terenghi Mattia
Published: February 2008

A comparison of two methods for the identification and determination of peanut allergens based on europium (Eu)‐tagged inductively coupled plasma mass spectrometry (ICP‐MS) immunoassay and on liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) with a triple quadrupole mass analyzer was carried out on a complex food matrix like a chocolate rice crispy‐based snack. The LC/MS/MS method was based on the determination of four different peptide biomarkers selective for the Ara h2 and Ara h3/4 peanut proteins. The performance of this method was compared with that of a non‐competitive sandwich enzyme‐linked immunosorbent assay (ELISA) method with ICP‐MS detection of the metal used to tag the antibody for the quantitative peanut protein analysis in food. The limit of detection (LOD) and quantitation of the ICP‐MS immunoassay were 2.2 and 5 µg peanuts g−1 matrix, respectively, the recovery ranged from 86 ± 18% to 110 ± 4% and linearity was proved in the 5–50 µg g−1 range. The LC/MS/MS method allowed us to obtain LODs of 1 and 5 µg protein g−1 matrix for Ara h3/4 and Ara h2, respectively, thus obtaining significantly higher values with respect to the ELISA ICP‐MS method, taking into account the different expression for concentrations. Linearity was established in the 10–200 µg g−1 range of peanut proteins in the food matrix investigated and good precision (RSD <10%) was demonstrated. Both the two approaches, used for screening or confirmative purposes, showed the power of mass spectrometry when used as a very selective detector in difficult matrices even if some limitations still exist, i.e. matrix suppression in the LC/ESI‐MS/MS procedure and the change of the Ag/Ab binding with matrix in the ICP‐MS method. Copyright © 2008 John Wiley & Sons, Ltd.
The inclusion of succinylacetone as marker for tyrosinemia type I in expanded newborn screening programs
Authors: la Marca Giancarlo , Malvagia Sabrina , Pasquini Elisabetta , Innocenti Marzia , Fernandez Maira Rebollido , Donati Maria Alice , Zammarchi Enrico
Published: February 2008

In expanded newborn screening programs by liquid chromatography/tandem mass spectrometry false negatives for tyrosinemia type I are a significant problem. We describe a method for inclusion of succinylacetone in order to avoid false negatives. We studied spots from 13 000 neonates born in Tuscany (January–May 2007) and ten spots from six patients with tyrosinemia type I. The traditional screening method was modified by adding dioxooctanoid acid (or 13C2‐succinylacetone) as an internal standard to the methanolic solution of deuterated acylcarnitines and amino acids. A hydrazine solution was added to the mixture. The times of extraction, butylation and drying were only slightly prolonged. Specific multiple reaction monitoring for derivatized and labelled succinylacetone and dioxooctanoic acid was carried out. The assays were linear up to 100 µmol/L for succinylacetone. Intra‐ and inter‐day imprecision data were in the range of 1.34% to 7.09% and 3.50% to 4.49%. Limits of detection and of quantification were 0.2 µmol/L and 0.4 µmol/L, respectively. Recovery ranged from 97.02% to 100.29%. Succinylacetone levels in samples from unaffected neonates were very close to the detection limit. Of the 46 recalls, eight (17.4%) were for abnormal tyrosine levels and all these cases had succinylacetone levels within the normal range (<2.4 µmol/L). In ten spots from six affected patients succinylacetone values ranged from 3.3 to 35.0 µmol/L. Including succinylacetone in newborn screening programs for amino acids and acylcarnitines avoids false‐negative results for tyrosinemia type I. Newborn screening laboratories should consider implementing these modifications. Copyright © 2008 John Wiley & Sons, Ltd.
Confirmatory identification of sixteen non‐steroidal anti‐inflammatory drug residues in raw milk by liquid chromatography coupled with ion trap mass spectrometry
Authors: Gallo Pasquale , Fabbrocino Serena , Vinci Floriana , Fiori Maurizio , Danese Vincenzo , Serpe Luigi
Published: February 2008

The European Council Decision 2002/657/EC established that group B substances detected in foods must be identified and confirmed on the basis of their molecular structure. To this aim, we have developed a panel of methods for unambiguous determination of sixteen non‐steroidal anti‐inflammatory drugs (NSAIDs) in cattle and buffalo raw milk. A multi‐residue reversed‐phase high‐performance liquid chromatography method with photodiode array detection is described for quantitative screening analysis. For confirmatory purposes, two multi‐residue reversed‐phase ion trap liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI‐MS/MS) methods were developed: the former to identify salicylic acid, naproxen, carprofen, flurbiprofen, ibuprofen, meclofenamic acid, niflumic acid, flunixin and its metabolite 5‐hydroxyflunixin in the negative ion mode; the latter to identify ketoprofen, suxibutazone, diclofenac, mefenamic acid, tolfenamic acid, phenylbutazone and its metabolite oxyphenbutazone in the positive ion mode. These drugs are representative of different subclasses of NSAIDs not chemically related. The methods were in‐house validated, evaluating specificity and calculating the mean recoveries, repeatability, within‐laboratory reproducibility, and limits of quantification. For all the NSAIDs, apart from salicylic acid and 5‐hydroxyflunixin, mean recoveries ranging between 69.0% and 96.7% were measured. The qualitative identification of all drugs was attained by their MS/MS spectra in the concentration range studied. Similarly, at 5 µg/kg all NSAIDs, apart from flurbiprofen, were unambiguously confirmed. Copyright © 2008 John Wiley & Sons, Ltd.
Delay‐dependent robust stability for stochastic time‐delay systems with polytopic uncertainties
Authors: Li Hongyi , Chen Bing , Zhou Qi , Lin Chong
Published: February 2008

This paper considers a delay‐dependent and parameter‐dependent robust stability criterion for stochastic time‐delay systems with polytopic uncertainties. The delay‐dependent robust stability criterion, as expressed in terms of linear matrix inequalities (LMIs), is obtained by using parameter‐dependent Lyapunov functions. It is shown that the result derived by a parameter‐dependent Lyapunov functional is less conservative. Numerical examples are provided to illustrate the effectiveness of the proposed method. Copyright © 2008 John Wiley & Sons, Ltd.
Disturbance attenuation by output feedback for linear systems subject to actuator saturation
Authors: Wu Fen , Zheng Qian , Lin Zongli
Published: February 2008

In this paper, we study the problem of disturbance attenuation by output feedback for linear systems subject to actuator saturation. A nonlinear output feedback, expressed in the form of a quasi‐linear parameter‐varying system with state‐dependent scheduling parameter, is constructed that leads to the attenuation of the effect of the disturbance on the output of the system. The level of disturbance attenuation is measured in terms of the restricted ℒ︁2gain and the restricted ℒ︁2–ℒ︁∞gain over a class of bounded disturbances. Copyright © 2008 John Wiley & Sons, Ltd.