bluuebunny/crossref_metadata_2025 huggingface dataset:
(Phthalocyaninato)copper(II) Complexes Fused with Different Numbers of 15‐Crown‐5 Moieties – Synthesis, Spectroscopy, Supramolecular Structures, and the Effects of Substituent Number and Molecular Symmetry
Authors: Sheng Ning , Zhang Yuexing , Xu Hui , Bao Meng , Sun Xuan , Jiang Jianzhuang
Published: May 2007

Symmetrical (phthalocyaninato)copper(II) complexes Cu(Pc′) [Pc′ = Pc(15C5), Pc(opp‐15C5)2, Pc(adj‐15C5)2, Pc(15C5)3; Pc = unsubstituted phthalocyaninate, Pc(15C5) = 2,3‐(15‐crown‐5)phthalocyaninate, Pc(opp‐15C5)2 = 2,3,16,17‐bis(15‐crown‐5)phthalocyaninate, Pc(adj‐15C5)2 = 2,3,9,10‐bis(15‐crown‐5)phthalocyaninate, Pc(15C5)3 = 2,3,9,10,16,17‐tris(15‐crown‐5)phthalocyaninate] (2–5) have been prepared by the reaction of corresponding heteroleptic bis(phthalocyaninato)europium complexes Eu(Pc)(Pc′) [Pc′ = Pc(15C5), Pc(opp‐15C5)2, Pc(adj‐15C5)2, Pc(15C5)3, Pc(15C5)4; Pc = unsubstituted phthalocyaninate] with Cu(OAc)2 in dry dmf at 100 °C. For the purpose of comparative studies, the symmetrical counterparts CuPc (1) and CuPc(15C5)4 [Pc(15C5)4 =2,3,9,10,16,17,24,25‐tetrakis(15‐crown‐5)phthalocyaninate](7) have also been prepared. These monomeric complexes have been characterized by spectroscopic methods in addition to elemental analysis. Having a series of closely related phthalocyanines with a different number and/or disposition of 15‐crown‐5 groups at the peripheral positions, the effects of 15‐crown‐5 substituent number and molecular symmetry on the electronic absorption spectra, infra‐red (IR) spectra, and supramolecular structure formation induced by K+ ions have been investigated. Systematic studies on the formation of dimeric supramolecular structures of the series of monomers 2–6 reveal and confirm the previously proposed two‐step three‐stage process of K+‐induced dimerization of phthalocyanines with three or four 15‐crown‐5 moieties.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Coordination Assemblies of Metallacyclic, Prismatic and Tubular Molecular Architectures Based on the Non‐rigid Ligands
Authors: Chen Chun‐Long , Zhang Jian‐Yong , Su Cheng‐Yong
Published: May 2007

This microreview covers recent advances in the assembly of coordination molecular architectures showing cyclic, prismatic and tubular structures based on the semi‐rigid or flexible ligands. Four assembly routes are outlined depending on the symmetry interactions between specific ligands and metal ions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Generation of [2×2] Grid Metallosupramolecular Architectures from Preformed Ditopic Bis(acylhydrazone) Ligands and through Component Self‐Assembly
Authors: Cao Xiao‐Yu , Harrowfield Jack , Nitschke Jonathan , Ramírez Juan , Stadler Adrian‐Mihail , Kyritsakas‐Gruber Nathalie , Madalan Augustin , Rissanen Kari , Russo Luca , Vaughan Gavin , Lehn Jean‐Marie
Published: May 2007

Ditopic bis(acylhydrazone) ligands, derived from the reactions of carbohydrazides with 2‐phenylpyrimidine‐4,6‐dicarbaldehyde and designed for grid formation with octahedrally coordinating transition‐metal ions, exhibit a varied coordination chemistry depending upon the degree of their deprotonation. The neutral acylhydrazones are relatively poor ligands and are seemingly involved in multiple, labile complexation equilibria varying with the solvent and the particular metal salt in solution; nevertheless, grid complexes of different forms can be isolated in the solid state. Although only limited study has been made of the singly deprotonated ligands, grid species appear to be much more readily isolated. With the doubly deprotonated ligands, grid formation is strongly favoured in both the solution and solid states. As a consequence, the grid structures form spontaneously in the presence of a base by self‐assembly from their components without need to preform the ditopic ligands. Extensive structural studies have been carried out both to establish the grid structures and to analyse the nature of the supramolecular interactions possible for neutral and charged grid species. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Differential effects of obesity on acetoacetyl‐CoA synthetase gene in rat adipose tissues
Authors: Yamasaki Masahiro , Hasegawa Shinya , Kitani Tetsuya , Hidai Kensuke , Fukui Tetsuya
Published: May 2007

In order to investigate the physiological role of the ketone body‐utilizing enzyme acetoacetyl‐CoA synthetase (AACS) in obesity‐induced metabolic derangements, we examined the mRNA levels of AACS and other lipogenic enzymes in white adipose tissues (WAT) in the different types of obesity, genetic (Zucker fatty) and high‐fat diet (HFD)‐induced obesity. Plasma ketone body levels and gene expression levels of AACS and acetyl‐CoA carboxylase‐2 (ACC‐2) in WAT were lower in Zucker fatty rats than in lean rats. On the contrary, in HFD‐induced obese rats, these levels were increased. Moreover, AACS mRNA expression was affected only in subcutaneous WAT by each type of obesity. Our data suggest that AACS mRNA expression is related to obesity‐induced alteration of plasma ketone body levels, and that AACS in subcutaneous WAT plays an important role in the regulation of lipogenesis and ketone body utilization in various obese conditions.
Are natural antioxidants better – and safer – than synthetic antioxidants?
Authors: Pokorný Jan
Published: May 2007

Antioxidants are necessary in the Western diet as it is rich in polyenoic fatty acids, which are easily oxidized with formation of free radicals that are harmful if present in higher amounts. Consumers prefer natural antioxidants to synthetic antioxidants, mainly for emotional reasons. The common Western daily diet contains about 1 g natural antioxidants even if no natural antioxidants have been added for lipid stabilization. Their main sources are cereals, fruits, vegetables, and beverages. Only a part of the natural antioxidants is absorbed and used as free‐radical scavengers in vivo. Natural antioxidants should be added to food in larger amounts than synthetic antioxidants as they are less active, but the actual activity depends very much on particular conditions and food composition. Nevertheless, the addition of additional antioxidants is still negligible in comparison with the dietary supply of native antioxidants. The safety limits of natural antioxidants are mostly not known, but they are hardly safer than synthetic antioxidants. The best protection would be to replace high‐polyenoic oils in the diet with high‐oleic oils, and to use alternative methods of food protection against autoxidation.
Stereoselective Synthesis of 2‐Deoxy‐2‐phenylselenenyl Glycosides from Furanoses: Implication of the Phenylselenenyl Group in the Stereocontrolled Preparation of 2‐Deoxy‐ribo‐ and 2‐Deoxy‐xylo‐oligosaccharides
Authors: Boutureira Omar , Rodríguez Miguel A. , Benito David , Matheu M. Isabel , Díaz Yolanda , Castillón Sergio
Published: May 2007

A series of 2‐deoxy‐2‐phenylselenenyl‐1‐thioglycosides were evaluated as a class of glycosyl donors that provide access to 2‐deoxyglycosides from furanoses. This short synthetic route involves olefination, selenonium ion mediated 6‐endo cyclization and glycosylation reactions. The cyclization reaction proceeds with complete regio‐ and stereoselectivity, which are enhanced by employing 3,4‐O‐isopropylidene as a cyclic bifunctional protecting group. The implication of the phenylselenenyl group at C‐2 in the stereocontrolled preparation of 2‐deoxyoligosaccharides is discussed. Its presence gives some insights into the likely pathway of glycosylation reactions by using 2‐deoxy‐2‐phenylselenenyl‐1‐thioglycosyl donors in comparison with the previously described 2‐deoxy‐2‐iodo derivatives. We also demonstrated that the glycosylation of 2‐deoxy‐2‐phenylselenenyl‐1‐thioglycosides is highly substrate dependent, as well as particularly effective in providing 2‐deoxy‐2‐phenylselenenyl‐β‐D‐gulo‐ and ‐β‐D‐allo‐glycosides. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthesis of (S)‐Nonacosan‐10‐ol, the Major Component of Tubular Plant Wax Crystals
Authors: Dommisse Aarnoud , Wirtz Jennifer , Koch Kerstin , Barthlott Wilhelm , Kolter Thomas
Published: May 2007

(S)‐Nonacosan‐10‐ol [(+)‐Ginnol] is the main component of the tubular wax aggregates, which are found on many plant leaves. To investigate the role of this lipid for the formation of super hydrophobic self‐cleaning plant surfaces, both enantiomers of the title compound were prepared in six steps. Key steps are the resolution of the allylation product of decanal with (R)‐O‐methylmandelic acid, and a chain elongation by cross metathesis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Development in Synthesis, Electrochemistry, LB Moieties of Phenothiazine Based Units
Authors: Doskocz Jacek , Sołoducho Jadwiga , Cabaj Joanna , Łapkowski Mieczysław , Golba Sylwia , Palewska Krystyna
Published: May 2007

A convenient and higher yielding synthetic route to N‐alkyl‐bis(thiophene)phenothiazine derivatives is reported and their aggregation, electrochemical properties and polymerization are characterized. The key step in the synthesis of this group of compounds has been the Stille type coupling reaction between the N‐alkyldibromophenothiazine and tin derivatives of thiophene as the best way for preparation of conjugated N‐alkylphenothiazine derivatives. For this group of compounds we also present an electrochemical polymerization effect and widely adopted approach to prepare structurally ordered thin, electroconducting films by Langmuir–Blodgett technique.
Electroaddressable Selective Functionalization of Electrode Arrays: Catalytic NADH Detection Using Aryl Diazonium Modified Gold Electrodes
Authors: Harper Jason C. , Polsky Ronen , Dirk Shawn M. , Wheeler David R. , Brozik Susan M.
Published: May 2007

We report the application of 4‐nitrophenyl diazonium modified electrodes towards the electrochemical detection of NADH. Selective activation of individual electrodes on a 5 element array by electro‐addressable conversion of nitro groups to amines and subsequent EDC/NHS crosslinking to the NADH oxidant, pyrroloquinoline quinone (PQQ), is demonstrated. Inactivated electrodes retained nitro functionality and were protected against non‐specific adsorption and mild chemical reactions. Electrodeposition conditions were used to control nitrophenyl film thickness and showed that while increased film thickness leads to greater functionalization density of PQQ, it also results in decreased electron transfer kinetics. The electrodeposition protocol can therefore serve as a method to control electrode functionalization density and film electron transfer kinetics. We believe this simple technique for selective electrode functionalization may facilitate the development of next generation multianalyte electrochemical sensors.
Acetylcholinesterase Immobilization on 3‐Mercaptopropionic Acid Self Assembled Monolayer for Determination of Pesticides
Authors: Pedrosa Valber A. , Caetano Josiane , Machado Sergio A. S. , Freire Renato S. , Bertotti Mauro
Published: May 2007

Studies on the immobilization of acetylcholinesterase onto a SAM gold electrode and the use of the fabricated biosensor for the determination of carbaryl and parathion are presented. The influence of pH, ionic strength, enzyme loading and concentration of glutaraldehyde on the response of the biosensor was investigated . The amperometric biosensor developed in this study provided linearity to parathion and carbaryl in the 2.0 a 30.0×10−6 mol L−1 concentration range. The detection limits under the optimum working conditions were found to be 9.3 μg L−1 for parathion and 9.0 μg L−1 for carbaryl. The enzyme electrode was found to be stable for 7 days.
Anodic Stripping Voltammetry Using a Vibrating Electrode
Authors: Chapman Conrad S. , van den Berg Constant M. G.
Published: May 2007

This work proposes a vibrating microwire electrode as working electrode in stripping voltammetry. The vibration was found to maintain a constant and thin (1–2 μm) diffusion layer during the deposition step. The electrode vibration eliminated the need for external stirring of the solution, thus facilitating in situ detection in the environment. The vibration was effected by fixing a low‐voltage (3 V), asymmetric, electrical rotor to the working electrode (a gold microwire of either 5 or 25 μm). The sensitivity of the vibrated electrode was ca. 22×greater than stationary. Measurements of copper (4 nM) by anodic stripping voltammetry using the vibrating electrode had a low standard deviation (1% for n=6) indicating that the diffusion layer had only minor variability. The agitation mechanism was unaffected by water moving at >2 m s−1 and by water pressure equivalent to a depth of >40 m, indicating its suitability for in situ measurements. The vibrating probe was used for in situ detection of copper by anodic stripping voltammetry to a depth of 6 m. Using a 5 min deposition time, the limit of detection for labile copper was 38 pM.
A Versatile System for Arbitrary Function Large‐Amplitude Fourier Transformed Voltammetry
Authors: Wang Lishi , Huang Xinjian
Published: May 2007

A novel low‐cost instrument for arbitrary function large‐amplitude Fourier transformed voltammetry was developed. Description of both hardware and software was given in detail in this paper. A micro‐control‐unit (MCU) in combination with a field programmable gate array (FPGA) was designed to act as the controller of the instrument. Profiting from the built‐in USB2.0 standard interface of the MCU, vast amount of data to/from the high resolution digital‐to‐analog converter (DAC)/analog‐to‐digital converter (ADC) then could be exchanged with computer in real‐time, instead of being temporarily stored at the capacity limited memory of the instrument which always restricted the length of sampling time and the size of the collected data set. In the [Fe(CN)6]4+/3+ system, by superimposing a sinusoidal waveform with an amplitude of 120 mV onto a triangular potential and then applying to a macro electrode through the instrument, voltammograms up to the eighth harmonic could be well resolved by FT‐IFT method. Excellent agreement was attained with Bond's similar experiment [Anal. Chem. 76 (2004) 3619] in respect of the shape and relative peak height of each harmonic. With the simply structured instrument, stable performance, flexible and versatile function was achieved. Arbitrary forms of AC perturbation which may not necessarily be sinusoidal or square‐wave or other regular formed periodic signal could be synthesized and superimposed onto a DC potential as the excitation signal with this instrument. Some more useful electrode process information was expected to unveil by utilizing the FT‐IFT algorithm to dissect the response signal.
Voltammetry as an Alternative Tool for Trace Metal Detection in Peloid Marine Sediments
Authors: Ciglenečki Irena , Bura‐Nakić Elvira , Inzelt György
Published: May 2007

Here was demonstrated for the first time a possible application of abrasive stripping voltammetry in the direct measurement of trace metals in anoxic, sulfidic marine sediments (peloid mud) from a small and shallow (0.2–1 m) marine lagoon in Central Dalmatia, Croatia. Trace amounts of sample compounds are transferred to the graphite electrode surface and electrochemical reduction or oxidation processes are followed by the cyclic voltammetry in seawater or 0.55 M NaCl as electrolyte. After a preelectrolysis at potentials ranging from −1.0 to −1.5 V (vs. SCE) a well‐defined anodic stripping peak corresponding to the oxidation of metal deposits generated at deposition potentials is obtained around −0.74 V (vs. SCE). The same samples were studied by anodic stripping voltammetry at the Hg electrode and inductively coupled plasma‐mass spectrometer (ICP‐MS). ICP‐MS showed higher concentrations of trace metals such as Al, Fe, Mo, Mn. A relatively high concentration of reduced sulfur species (RSS) (10−3 M) is determined electrochemically in porewater of the peloid mud, indicating that the magnitude of metal enrichment in the sediments is probably controlled by precipitation with sulfide.
Fast Simultaneous Adsorptive Stripping Voltammetric Determination of Ni(II) and Co(II) at Lead Film Electrode Plated on Gold Substrate
Authors: Tyszczuk Katarzyna , Korolczuk Mieczyslaw
Published: May 2007

A fast adsorptive stripping voltammetric procedure for simultaneous determination of Ni(II) and Co(II) in the presence of nioxime as a complexing agent at an in situ plated lead film electrode was described. The time of determination of these ions was shortened due to the application of gold as a substrate for lead film. At gold substrate lead film formation and accumulation of Ni(II) and Co(II) complexes with nioxime proceeds simultaneously. To obtain a stable signals for both ions a simple procedure of activation of the electrode was proposed. Calibration graphs for an accumulation time of 20 s were linear from 5×10−9 to 1×10−7 mol L−1 and from 5×10−10 to 1×10−8 mol L−1 for Ni(II) and Co(II), respectively. The procedure with the application of a lead film electrode on a gold substrate was validated in the course of Ni(II) and Co(II) determination in certified reference materials.
Comparison of DNA Hybridization at Rotating and Heated Gold Disk Electrodes
Authors: Peter Jörg , Reske Thomas , Flechsig Gerd‐Uwe
Published: May 2007

This paper reports about the influence of temperature, hybridization time and convection upon the detection of osmium tetroxide bipyridine‐labeled target oligonucleotides at rotating gold disk (RDE) and heated low temperature co‐fired ceramics (LTCC) gold disk electrodes. We used mixed self‐assembled monolayers of hexathiol‐linked probe oligonucleotides and mercaptohexanol on the gold surface of the electrodes for the hybridization detection of the labeled targets by means of square‐wave voltammetry. Due to protective strands, the osmium tetroxide‐modified target strands were still able to hybridize with the immobilized probe strands. The hybridization of such osmium tetroxide bipyridine‐modified target strands with thiol‐linked probe strands immobilized on gold yielded large reversible square‐wave‐voltammetric signals. Rotation speed and, hence, mass transport due to convection has only marginal effects. On the other hand, temperature affects greatly the hybridization step as indicated by both heated LTCC electrode in cold and RDE in warm hybridization solution. Calculated detection limits of 3.6 and 3.1 nM targets at the RDE and the LTCC electrode, respectively, have been almost the same at both types of electrodes. Applying an appropriate temperature during hybridization is more important than mechanically enhanced mass transport.
Electroanalytical Determination of Some Phenolic Acids by High‐Performance Liquid Chromatography at Gold Electrodes
Authors: Casella Innocenzo G. , Colonna Chiara , Contursi Michela
Published: May 2007

The electrochemical and amperometric behavior of a gold electrode was investigated towards the oxidation of several common phenolic acids in neutral phosphate solutions. Au electrodes show an appreciable stability and reproducibility of the amperometric signals by using a constant applied potential of 1.0 V vs. Ag/AgCl. Separations of selected phenolic acids using a reverse phase C18 analytical column with a mobile phase containing 10 mM NaH2PO4 plus 10 mM Na2HPO4 (pH 7) and methanol as organic modifier, are achieved isocratically in less than 30 min. The detection limits at the level of nmol/L and linear ranges of four‐five orders of magnitude are generally achieved. The proposed chromatographic strategy coupled with the electrochemical detection at the Au electrode was successful tested for the quantitative determination of phenolic acids in beer, red wine and brandy with good sensitivity and recovery.
Room Temperature Ionic Liquid Carbon Nanotube Paste Electrodes: Overcoming Large Capacitive Currents Using Rotating Disk Electrodes
Authors: Kachoosangi Roohollah Torabi , Wildgoose Gregory G. , Compton Richard G.
Published: May 2007

The voltammetric response of graphite or carbon nanotube paste electrodes, which incorporate the room temperature ionic liquid, N‐butyl‐N‐methyl pyrrolidinium bis(trifluoromethylsulfonyl) imide or [C4mpyrr][NTf2], (RTIL‐CNTPE and RTIL‐CPE respectively) as the binder, towards anionic, cationic and neutral redox probes is examined and compared to conventional paste electrodes which use mineral oil as the binder. The RTIL paste electrodes are found to suffer from very large background currents due to capacitive charging. This is exacerbated further when CNTs are combined with RTILs in the paste. The large charging currents obscure any Faradaic processes of interest, especially at low analyte concentrations. By employing steady state voltammetry at a rotating disk electrode made of the RTIL pastes this problem can be overcome. This allows the electroanalytical properties of these interesting electrode substrates, which combine the attractive properties of CNTs with RTILs to be further explored and developed.
Characterization of transferrin glycoforms in human serum by CE‐UV and CE‐ESI‐MS
Authors: Sanz‐Nebot Victoria , Balaguer Elvira , Benavente Fernando , Neusüß Christian , Barbosa José
Published: May 2007

Human transferrin (Tf) is a model glycoprotein for congenital disorders of glycosylation (CDG) diagnosis. In the last few years, new CE‐UV methods for intact Tf glycoforms analysis have been developed using nonvolatile BGEs and organic modifiers. However, the use of these BGEs does not allow the coupling of these procedures with electrospray MS (ESI‐MS). In this study, a new CE‐UV separation method of Tf glycoforms is developed, using a double‐layer stable coating and a volatile BGE based on ammonium acetate. The separation method is optimized using standard Tf and their potential is demonstrated applying the method to the analysis of sera Tf from healthy individuals and CDG patients. The CE‐UV separation method has been coupled to ESI‐MS detection. Main parameters such as sheath liquid composition are optimized in order to obtain a good sensitivity. The CE‐ESI‐MS method has also been used in serum samples obtaining the separation of the different proteins present in serum and partial separation of Tf glycoforms. Different mass spectra and deconvoluted molecular masses were obtained for each sialoform, allowing unequivocal glycoform identification.
pI‐based phosphopeptide enrichment combined with nanoESI‐MS
Authors: Hung Chien‐Wen , Kübler Dieter , Lehmann Wolf D.
Published: May 2007

IEF is introduced as a new principle for enrichment and separation of phosphopeptides as obtained after digestion of phosphoproteins by trypsin. Tryptic peptides and phosphopeptides exhibit pI values, which overlap in the range of about 4–6. However, after methyl esterification of all carboxyl functions, the pI values of tryptic peptides and phosphopeptides regroup in discrete clusters. In addition, mono‐ and diphosphorylated peptides show different but very homogeneous pI values, with variations when internal Arg, Lys, or His residues are present. Experimentally, this new concept was applied for separation of model peptides on IPG strips pH 3–10 as used in the first dimension of 2‐DE. After IEF of methyl‐esterified peptides, the IPG strip was cut into pieces followed by peptide extraction, desalting and MS analysis by nanoESI‐MS. Phosphopeptides were found to focus in good agreement with their calculated pI values. This analytical strategy showed a resolution of about 0.2 pI units, and thus turned out to be capable of detecting minor differences in pI values, such as those occurring between pSer, pThr and pTyr residues. Using IPG strips with a pI range of 3–10, methyl esterified nonphosphorylated tryptic peptides are concentrated in the basic part of the IPG strip or even leave the strip. Thus, efficient enrichment of phosphopeptides and their subfractionation according to pI is obtained in one step. Minor hydrolytic side reactions including deamidation of Asn and partial hydrolysis of methyl esters are observed. The results show that IEF opens attractive avenues for the further advancement of analytical phosphoproteomics.
Applicability of different fluorescent dyes for isoform quantification on linear IPG gels
Authors: Schriebl Kornelia , Trummer Evelyn , Weik Robert , Lattenmayer Christine , Müller Dethardt , Kunert Renate , Katinger Hermann , Vorauer‐Uhl Karola
Published: May 2007

For biotechnological research, development, and production various analytical methods are required to determine the quality of the target product. In this context, the determination of isoforms is state‐of‐the‐art; however, the majority of applied techniques are more qualitative than quantitative. To address this fact, we evaluated different post‐ and pre‐electrophoretic staining dyes for their applicability on linear IPG gels using recombinant human erythropoietin as a model protein. Each evaluated dyes was able to detect all isoforms reproducibly, but CyDyes were found to be the most promising. Using CyDyes, up to three samples can be focused on the same lane under identical electrophoretic conditions, thus, a fast, reproducible, sensitive and quantitative isoform determination can be performed. To illustrate the practical relevance, quantitative CyDye technique was used for the characterization of our model protein, recombinant human Epo‐Fc. This method makes it possible to determine the isoform pattern of nonpurified supernatants as well as purified proteins. We conclude that quantitative pre‐electrophoretic staining IEF using CyDyes is a fast, simple, accurate method to determine isoforms, which can be used in research, development, and manufacturing for product quality analysis, e.g., clone screening, process optimization, and purification monitoring.
Nuclear protein profiling of Jurkat cells during heat stress‐induced apoptosis by 2‐DE and MS/MS
Authors: Yuan Xiaoqin , Kuramitsu Yasuhiro , Furumoto Hiroko , Zhang Xiulian , Hayashi Eiko , Fujimoto Masanori , Nakamura Kazuyuki
Published: May 2007

Heat stress causes severe constraints on numerous physiological functions of cells, such as the repression of splicing of mRNA precursors. In this study, we performed proteomic profiling of a nuclear fraction of Jurkat cells during heat stress using 2‐DE and LC‐MS/MS. We found 10 protein spots whose expression had changed after heat stress at 43°C for 30 min. Seven of those protein spots, periodic tryptophan protein 1 homolog (PWP1), importin β‐1 subunit, sumoylated protein, splicing factor 3a subunit 3 (SF3a3), TAR DNA‐binding protein 43, U2 small nuclear ribonucleoprotein auxiliary factor 35 kDa subunit (U2AF35) and small ubiquitin‐related modifier‐1 (SUMO‐1) were downregulated, while three other protein spots, Protein SET, 40S ribosomal protein SA and 60S acidic ribosomal protein P0 were upregulated by the heat stress. We focused on the downregulation of two splicing factors, which might participate in the repression of pre‐mRNA processing by heat stress, leading to cell apoptosis.
Rapid isoelectric trapping in a micropreparative‐scale multicompartment electrolyzer
Authors: Lim Peniel , North Robert , Vigh Gyula
Published: May 2007

A multicompartmental electrolyzer called membrane‐separated wells for isoelectric focusing and trapping (MSWIFT) has been developed and tested for micropreparative‐scale isoelectric trapping separations. In the MSWIFT, the length of the heat conduction path from the center of the compartments to the wall is less than 1 mm. The compartments are made from 99.8% nonporous alumina that has a high heat conductivity and a high specific heat capacity, leading to adequate Joule heat dissipation even at power loads as high as 5 W. The length of any compartment parallel to the electric field (the intermembrane distance) can be selected to be multiples of 1.5 mm, leading to compartment volumes that are multiples of about 60 μL. A maximum of 20 (1.5 mm long) separation compartments can be readily assembled in the current version of MSWIFT. The MSWIFT has been used to desalt samples, isolate small ampholytic components (amino acids, peptides, and dyes), prefractionate complex protein mixtures and enrich minor components; these separations were achieved in 20–60 min.
Scanning copy number and gene expression on the 18q21‐qter chromosomal region by the systematic multiplex PCR and reverse transcription‐PCR methods
Authors: Yamamoto Fumiichiro , Yamamoto Miyako
Published: May 2007

We examined differences in copy number and expression of 127 genes located on the 18q21‐qter chromosomal region of the breast and prostate cancer cell lines, using the systematic multiplex PCR and reverse transcription‐PCR (SM PCR and SM RT‐PCR) methods that we developed. Semi‐quantitative data were obtained that were comparable in quality, but not in quantity, to data from DNA microarray hybridization analysis. In the chromosomal region where losses are frequent in breast, prostate, and other cancers, we detected a homozygous deletion of the SMAD4 gene in the MDA‐MB‐468 breast cancer cell line. We also observed partial or entire loss of expression in genes such as CCBE1, CCDC11, CD226, NP_115536.1, NP_689683.2, RNF152, SERPINB8, and TCF4 in certain breast and/or prostate cancer cell lines. An increase in gene expression was rare, but found with the transcription factor ONECUT2 gene in all of the cancer cell lines examined. Real‐time qRT‐PCR experiments confirmed these SM RT‐PCR results. Further analysis of clinical specimens of breast cancer by real‐time qRT‐PCR demonstrated that the gene expression of CCBE1, TCF4, NP_115536.1, and NP_689683.2 was downregulated in the majority of clinical cases of breast cancer.
Cushioning the pressure vibration of a zeolite concentrator system using a decoupled balancing duct system
Authors: Chang Feng‐Tang , Lin Yu‐Chih
Published: May 2007

A honeycomb Zeolite Rotor Concentrator (HZRC) is the main air pollution control device utilized by many semiconductor and optoelectronics manufacturers. Various plant exhaust streams are collected and then transferred to the HZRC for decontamination. In a conventional HZRC, the exhaust fan movement and the switching between different air ducts can cause significant duct pressure variations resulting in production interruption. The minimization of pressure fluctuations to ensure continuous operation of production lines while maintaining a high volatile organic compounds (VOCs) removal efficiency is essential for exhaust treatment in these high technology manufactures. The article introduces a decoupled balancing duct system (DBDS) for controlling the airflows to achieve a balanced pressure in the HZRC system by adding a flow rate control device to the VOCs loaded stream bypass duct of a conventional system. Performance comparisons of HZRC with DBDS and other air flow control systems used by the wafer manufacturers in Hsinchu Science Park, Taiwan are presented. DBDS system had been proved effectively to stabilize the pressure in the airflow ducts, and thus avoided pressure fluctuations; it helped to achieve a high VOCs removal efficiency while ensuring the stability of the HZRC. © 2007 American Institute of Chemical Engineers Environ Prog, 2007
Initiation of motion of a free‐standing body to base excitation
Authors: Tung C. C.
Published: May 2007

This study is concerned with the conditions for the initiation of various modes of response of a free‐standing rigid body, initially at rest, placed on a frictional horizontal base which undergoes earthquake‐like accelerations in both the horizontal and vertical directions. These conditions are derived using equations of motion appropriate for each mode of motion. The analysis shows that an equivalent horizontal base acceleration may be constructed by dividing the time history of horizontal base acceleration by the sum of gravitational acceleration and the time history of vertical base acceleration. The criteria governing each mode of response of a body of given aspect ratio are then presented graphically with the magnitude of the equivalent base acceleration as abscissa and the coefficient of friction between the body and the base as ordinate. The study shows that a body is more stable while the vertical base acceleration is upwards than when it is absent as expected. When the vertical base acceleration is downwards, although the body is very likely to be lifted off the base, it is nevertheless possible to rock, and slide and rock simultaneously provided the value of coefficient of friction is sufficiently high and the downward vertical base acceleration is not too different from gravitational acceleration. Copyright © 2007 John Wiley & Sons, Ltd.
Distributed object‐based software environment for urban system integrated simulation under urban‐scale hazard—Part I: Infrastructure
Authors: Hassanien Serror M. , Inoue Junya , Hori Muneo , Fujino Yozo
Published: May 2007

In this paper, a distributed object‐based software environment (DOSE) has been developed to facilitate the integrated simulation of an urban system under the risk of urban‐scale hazards such as earthquakes. It is understood that individual simulation participants perform their simulation services in separate environments, bartering service exchange relationships to get what they need to resolve their part of the problem. This is the communication gap between the scientists on one side and the end users who need to understand knowledge and employ it on the other side. The authors envision a distributed simulation service software environment running in parallel with the activities of simulation participants. DOSE has lent itself to integrate interdisciplinary participants through an infrastructure that has three basic building blocks, namely: modularity, scalability, and interoperability. The modular, object‐based, design of DOSE architecture is described in terms of key functionalities of four distinct layers, namely: resource, core, domain, and interface layers. DOSE scalability in terms of urban system size and participant third‐party application complexity is enabled through the interface layer. A message passing model is developed using the Message Passing Interface standard and a control room is provided to schedule the interaction/communication among model processes. DOSE interoperability with the vulnerability analysis third‐party applications is enabled through the Industry Foundation Classes (IFC) standard. An adopted analogy between DOSE and construction industry is employed to provide interpretation and implementation for DOSE interoperability. While interfacing IFC object model to solve DOSE interoperability questions, an extension model for the structural view of IFC is proposed and accepted by the International Alliance for Interoperability. The DOSE application for real‐world urban systems is beyond the scope of this paper and is presented in an accompanying paper work. Copyright © 2007 John Wiley & Sons, Ltd.
An analytic model to simulate leakage current of a snow‐covered insulator
Authors: Javadi H. , Farzaneh M. , Hemmatjou H. , Fofana I.
Published: May 2007

In this paper an analytic model allowing simulating the electrical characteristics and the leakage current of a snow‐covered insulator is proposed. For that purpose, leakage current through a snow‐covered insulator was monitored under high alternative voltage at a temperature of −12°C. From the measured voltage–current characteristics, it was found that the voltage across snow and the leakage current flowing through the snow‐covered insulator were almost in the same phase. However, the resistance of snow was found to be non‐linear, as it decreases with an increase in voltage across snow. Based on the experimental results, a mathematical model enabling to simulate the leakage current was elaborated. This model shows that the leakage current through snow can be expressed as an exponential function of the voltage across snow, depending on the density and conductivity of the water melted from the snow. The comparison of results obtained by the analytical model and those by experiment shows a good correlation. Copyright © 2007 John Wiley & Sons, Ltd.
Ad‐CoopPositioning System (ACPS): positioning for cooperative users in hybrid cellularad‐hocnetworks
Authors: Frattasi Simone , Monti Marco
Published: May 2007

In this paper, we propose an innovative solution for positioning determination in fourth generation (4G) wireless networks by introducing theAd‐CoopPositioning System (ACPS). The ACPS is supported by a hybrid cellularad‐hocarchitecture, where the cellular network has a centralised control over thead‐hocconnections among pairs of mobiles. Specifically, peer‐to‐peer (P2P) communications are exploited in a mesh fashion within cellular‐established clusters for cooperation‐aided localisation purposes (from that, the wordad‐coopis derived). The major contribution of this work is the design of the data fusion method for the ACPS which appropriately combines and weights the long‐ and short‐range location information in a non‐linear least square (NLLS) minimisation procedure. The numerical results shown in the paper demonstrate that the ACPS enhances the location estimation accuracy with respect to conventional hybrid positioning techniques in cellular networks. Copyright © 2007 John Wiley & Sons, Ltd.
On a useful property of the complementary error function
Authors: Ermolova N. Y.
Published: May 2007

This paper presents a property of the complementary error function that to the best of our knowledge has not been widely recognised. Meanwhile, this property can be useful for solving some practical problems in communications. Some examples where it can be utilised are problems of bit error rate (BER) performance evaluation in multi‐hop communication systems and low‐complexity adaptive power allocation in orthogonal frequency division multiplexing (OFDM). Copyright © 2007 John Wiley & Sons, Ltd.
Algorithms and applications of channel impulse response length estimation for MIMO‐OFDM
Authors: Krondorf M. , Liang T. J. , Goblirsch M. , Fettweis G.
Published: May 2007

The performance of the widely applied time‐domain channel estimation for SISO‐ and MIMO‐OFDM systems strongly depends on the preciseness of information regarding maximum channel impulse response (CIR) length. In practice the required CIR length is usually approximated by the length of the cyclic prefix (CP) which is an upper bound for most of the actual instantaneous CIR length. In this article, we introduce an appropriate channel length estimation method—named as Frequency Domain Channel Length Indicator (FCLI) which estimates the CIR length minimising the estimated mean square error (MSE) of an instantaneous channel estimate. The simulation results present that the FCLI outperforms the approximation of CP length. In addition, we investigate two applications of FCLI on (1) CP adaptation OFDM systems in which we minimise the overhead of the CP by the estimated CIR length and (2) CP‐free OFDM systems in which we directly re‐construct the structure of cyclic repetition with reduced error. Compared to the traditional channel estimation with the approximation of CP length, the overall system throughput of either CP adaptation or CP‐free OFDM transmission scheme is significantly enhanced regardless of perfect synchronisation or practical distribution of time offsets. Copyright © 2007 John Wiley & Sons, Ltd.
Resource allocation with minimum rates for OFDM broadcast channels
Authors: Huppert Carolin , Stender Boris
Published: May 2007

Downlink transmissions with minimum rate requirements over orthogonal frequency division multiplexing (OFDM) channels are commonly done by means of scheduling algorithms. However, regarding it from an information theoretical point of view, this is not optimal since broadcast techniques can achieve higher rates. The drawbacks of the optimum broadcast algorithm are that the signalling overhead is larger than for scheduling and also the computational complexity is much higher. In this paper we propose an algorithm which overcomes these points. This algorithm is a hybrid algorithm combining scheduling and broadcast approaches. Thus, it combines advantages of both methods. Furthermore, we present modifications to this algorithm to avoid irresolvable decoding dependencies. We show by means of simulation results that the proposed algorithm operates close to the optimum performance and that it outperforms a pure scheduling approach. Copyright © 2007 John Wiley & Sons, Ltd.
Spatial multiplexing in pulse based ultrawideband communications
Authors: Sibille A. , Tran V. P.
Published: May 2007

The performance of various spatial multiplexing (SM) schemes in ultrawideband pulse based (UWB) binary antipodal modulations is investigated. It is shown that the favourable spatial decorrelation properties of UWB signals allow to decouple spatial channels very effectively, and to reach excellent performance under moderate complexity at the receiver. The work presented here considers several detection methods such as zero forcing (ZF), minimum mean square error (MMSE) and maximum likelihood (ML) in order to cope with inter channel interference (ICI). Inter symbol interference (ISI) is investigated as well, and is shown to be moderate unless for extreme rates. In addition partial ISI suppression by iterative decision‐aided interference cancellation over a block of symbols is investigated in order to further increase the data rate. Simulations based on a double directional channel model exemplify these results. Copyright © 2007 John Wiley & Sons, Ltd.
The effect of accelerated ageing of building wires
Authors: Emanuelsson Viktor , Simonson Margaret , Gevert Thomas
Published: May 2007

The fire performance of two electric cables (building wires) designed for indoor use has been tested, both as new products and after accelerated thermooxidative ageing. The cables were aged for a maximum time of 16.5 weeks at 80°C. The cables are commercially available, and were constructed using a PVC material in one case and a non‐halogenated polyolefin‐based material, called Casico, in the other. The effects of ageing on the fire performance of the cables, and the chemical changes that have caused the observed fire behaviour, have been investigated and are discussed. Special attention is paid to the behaviour of the plasticizers that are used in the PVC cable, and how the fire behaviour is affected by the loss of plasticizers from the cable and by the migration of plasticizers between the parts of the cable (insulation, bedding and sheathing). Copyright © 2007 John Wiley & Sons, Ltd.
Spontaneous ignition in storage and production lines: Investigation on wood pellets and protein powders
Authors: Pauner Martin Ankjer , Bygbjerg Henrik
Published: May 2007

Three materials were tested in small‐scale baskets of cubic dimensions and analyses were performed based upon the results according to the Frank‐Kamenetskii (FK) method and the crossing point (CP) method. Comparison of the FK method and the CP method results was performed additionally. The activation energy E and the QA value were found. The relationship between critical ambient temperature and the storage size was determined as well as the relationship between CAT and time to maximum thermal runaway for the materials. Copyright © 2007 John Wiley & Sons, Ltd.
Flammability characteristics at applied heat flux levels up to 200 kW/m2
Authors: Beaulieu Patricia A. , Dembsey Nicholas A.
Published: May 2007

This paper documents the first of the two interrelated studies that were conducted to more fundamentally understand the scalability of flame heat flux, the motivation being that it has been reported that flame heat flux back to the burning surface in bench‐scale experiments is not the same as for large‐scale fires. The key aspect was the use of real scale applied heat flux up to 200kW/m2 which is well beyond that typically considered in contemporary testing. The main conclusions are that decomposition kinetics needs to be included in the study of ignition and the energy balance for steady burning is too simplistic to represent the physics occurring.

An unexpected non‐linear trend is observed in the typical plotting methods currently used in fire protection engineering for ignition and mass loss flux data for several materials tested and this non‐linearity is a true material response. Using measured temperature profiles in the condensed phase shows that viewing ignition as an inert material process is
inaccurate at predicting the surface temperature at higher heat fluxes. The steady burning temperature profiles appear to be invariant with applied heat flux. This possible inaccuracy was investigated by obtaining the heat of gasification via the ‘typical technique’ using the mass loss flux data and comparing it to the commonly considered ‘fundamental’ value obtained from differential scanning calorimetry measurements. This comparison suggests that the ‘typical technique’ energy balance is too simplified to represent the physics occurring for any range of applied heat flux. Observed bubbling and melting phenomena provide a possible direction of study. Copyright © 2007 John Wiley & Sons, Ltd.
The effectiveness of magnesium carbonate‐based flame retardants for poly(ethylene‐co‐vinyl acetate) and poly(ethylene‐co‐ethyl acrylate)
Authors: Morgan Alexander B. , Cogen Jeffrey M. , Opperman Robert S. , Harris Joseph D.
Published: May 2007

In this report we outline recent work on the evaluation of magnesium carbonate‐based flame retardants for polymers commonly used in halogen‐free flame retardant wire and cable applications: poly(ethylene‐co‐vinyl acetate) (EVA) and poly(ethylene‐co‐ethyl acrylate) (EEA). Natural magnesium carbonate (magnesite), synthetic magnesium carbonate (hydromagnesite), and hydromagnesite/huntite blends were combined with EVA or EEA and tested for flame retardancy effectiveness with the cone calorimeter. The flammability results showed that the effectiveness of these carbonates was polymer dependent, suggesting that polymer degradation chemistry played a role in the flammability reduction mechanism. Hydromagnesites were, in general, more effective in reducing flammability, being comparable in performance to magnesium hydroxide. Finally, we report some polymer–clay (organically treated montmorillonite and magadiite) + magnesium carbonate flame retardant results which showed that the nanocomposite yielded mixed results. Specifically, the polymer–clay nanocomposite samples did not always yield the greatest reductions in peak heat release rate. Copyright © 2007 John Wiley & Sons, Ltd.
Correlations of flow maldistribution parameters in an air cooled heat exchanger
Authors: Habib M. A. , Ben‐Mansour R. , Said S. A. M. , Al‐Bagawi J. J. , Al‐Mansour K. M.
Published: May 2007

The present paper provides correlations of flow maldistribution parameters in air‐cooled heat exchangers. The flow field in the inlet header was obtained through the numerical solution of the governing partial differential equations including the conservation equations of mass and momentum in addition to the equations of the turbulence model. The results were obtained for different number of nozzles of 2–4, different inlet flow velocities of 1–2.5m/s and different nozzle geometries in addition to incorporation of a second header. The results are presented in terms of mass flow rate distributions in the tubes of the heat exchanger and their standard deviations. The results indicate that the inlet flow velocity has insignificant influence on maldistribution while the nozzle geometry shape has a slight effect. Also, the results indicate that reducing the nozzle diameter results in an increase in the flow maldistribution. A 25% increase is obtained in the standard deviation as a result of decreasing the diameter by 25%. Increasing the number of nozzles has a significant influence on the maldistribution. A reduction of 62.5% in the standard deviation of the mass flow rate inside the tubes is achieved by increasing the number of nozzles from 2 to 4. The results indicate that incorporating a second header results in a significant reduction in the flow maldistribution. A 50% decrease in the standard deviation is achieved as a result of incorporation of a second header of seven holes. It is also found that the hole‐diameter distribution at the exit of the second header has a slight influence on the flow maldistribution. Correlations of the flow maldistribution in terms of the investigated parameters are presented. Copyright © 2007 John Wiley & Sons, Ltd.