bluuebunny/crossref_metadata_2025 huggingface dataset:
Purification and characterization of natural Ara h 8, the Bet v 1 homologous allergen from peanut, provides a novel isoform
Authors: Riecken Susanne , Lindner Buko , Petersen Arnd , Jappe Uta , Becker Wolf-Meinhard
Published: January 2008

The peanut allergen Ara h 8 is an important allergen for birch pollen allergic patients because of the cross-reactivity to the homologous Bet v 1. As the existence of Ara h 8 has been shown at the cDNA level so far (AY328088) and the allergen has indirectly been detected as natural protein, it was the aim of our study to identify natural Ara h 8 in peanut extract and to develop a purification strategy. This was achieved using a unique combination of purification steps, including optimized extraction conditions, size exclusion and ion exchange chromatography and treatment of the interfering contaminants with iodo-acetic acid. A characterization of the protein by microsequencing showed discrepancies to the deduced amino acid sequence of AY328088. For this reason, we cloned and expressed a new Ara h 8 isoform from cDNA (EU046325). This IgE-reactive protein corresponds to the results of microsequencing, ESI-FTICR-MS and trypsin fingerprinting analysis of the authentic and purified nAra h 8. Apart from the ultimate use of recombinant allergens for diagnostic procedures, there is also a scientific need for the natural counterpart, as it represents an excellent reference point by which to compare protein characteristics and to standardize diagnostic and therapeutic allergens.
p53-dependent repression of the human MCL-1 gene encoding an anti-apoptotic member of the BCL-2 family: the role of Sp1 and of basic transcription factor binding sites in the MCL-1 promoter
Authors: Pietrzak Maciej , Puzianowska-Kuznicka Monika
Published: January 2008

p53 regulates transcription of one anti-apoptotic and four pro-apoptotic members of the BCL-2 family, but nothing is known about the regulation of MCL-1, another anti-apoptotic member of this family, by p53. Confocal microscopic analysis of COS1, HEK 293 and HeLa cells transfected with a p53 expression plasmid demonstrated a decrease in the signal of endogenous MCL-1 compared to neighboring non-transfected cells. Transcription regulation assays showed that the 1826 bp human MCL-1 promoter fragment was repressed up to 30-fold by wild-type p53 in a dose-dependent manner. As shown by electrophoretic mobility shift assays, Sp1 binding to the sites located in the -295 to +16 MCL-1 promoter fragment was decreased in the presence of p53. However, the MCL-1 promoter devoid of all Sp1 binding sites was still repressed by p53, albeit 2-fold weaker than the wild-type promoter. Overexpression of Sp1 reduced p53-dependent repression of the MCL-1 promoter only up to 2.2-fold. Transcription regulation assays performed with MCL-1 promoter deletion mutants showed that most of the p53 inhibitory effect was mediated by the -41 to +16 bp promoter fragment containing binding sites only for TATA-binding protein and other basal transcription factors. We propose a novel, promoter-based mechanism by which p53 down-regulates expression of the anti-apoptotic MCL-1 protein.
Disentanglement of protease substrate repertoires
Authors: Van Damme Petra , Vandekerckhove Joel , Gevaert Kris
Published: January 2008

Identification of protease substrates and detailed characterization of processed sites are essential for understanding the biological function of proteases. Because of inherent complexity reasons, this however remains a formidable analytical challenge, illustrated by the fact that the majority of the more than 500 human proteases are uncharacterized to date. Recently, in addition to conventional genetic and biochemical approaches, diverse quantitative peptide-centric proteomics approaches, some of which selectively recover N-terminal peptides, have emerged. These latter proteomic technologies in particular allow the identification of natural protease substrates and delineation of cleavage sites in a complex, natural background of thousands of different proteins. We here review current biochemical, genetic and proteomic methods for global analysis of substrates of proteases and discuss selected applications.
Die Bilirubinbestimmung – Eine aktuelle Übersicht / Bilirubin measurement – An updated survey
Authors: Thaler Markus , Luppa Peter B. , Schlebusch Harald
Published: January 2008

Die präzise, richtige und spezifische Bestimmung des Bilirubins und seiner Fraktionen im Serum ist im klinisch-chemischen Laboratorium trotz einer Vielzahl unterschiedlicher Methoden immer noch nicht problemlos möglich. Neben den klassischen fotometrischen Diazo-Verfahren etablierten sich trockenchemische Methoden, direkte Spektrofotometrie in Serum und Vollblut und für wissenschaftliche Zwecke Trennungen mittels HPLC. Auch für das Point-of-Care-Testing stehen neuerdings mehrere Verfahren zur Verfügung. Die vorliegende Arbeit gibt einen Überblick über die wichtigsten Methoden und beschreibt ihre jeweiligen Vor- und Nachteile.
Diagnostik und Resistenztestung bei Pneumocystis jirovecii / Diagnostic features and resistance testing of Pneumocystis jirovecii
Authors: Riebold D. , Löbermann M. , Reisinger E.C.
Published: January 2008

Die durch den Pilz Pneumocystis jirovecii (P. jirovecii) ausgelöste Pneumocystis Pneumonie (PCP) ist vor allem bei HIV-Infizierten bekannt. In den letzten Jahren sind jedoch vermehrt Patienten nach Organtransplantationen und andere Immunsupprimierte betroffen. Die Labordiagnostik der PCP wird oft mit klassischen Färbemethoden durchgeführt, die wenig sensitiv sind. Ein Nachweis von P. jirovecii mit molekularbiologischen Methoden (PCR) erreicht eine Sensitivität von über 95% und kann – je nach untersuchtem Gen – auch für die Resistenztestung und Aufklärung von Infektionsketten herangezogen werden.
Effects of retrieval practice on conceptual explicit and implicit consumer memory
Authors: Parker Andrew , Dagnall Neil
Published: January 2008

Two experiments are reported that investigate the effects of retrieval practice on explicit and implicit memory for brand names. In Experiment 1, participants were exposed to a set of brand names pertaining to a range of product categories. Following this, participants practiced retrieving a subset of the brands before taking an explicit or implicit test for the brands. The explicit test, required recall of the brands in response to product category cues. The implicit test required the generation of the first brand names that came to mind. In both tests, prior retrieval produced retrieval‐induced forgetting of the non‐practiced brands. Experiment 2 replicated this effect under conditions designed to reduce explicit contamination. In addition, Experiment 2 found that increasing the amount of retrieval practice also increased the magnitude of retrieval‐induced forgetting on the explicit but not the implicit test. Implications for advertising and marketing are considered. Copyright © 2008 John Wiley & Sons, Ltd.
Visualization of quality parameters for classification of spectra in shooting crimes
Authors: Knauthe Björn , Steffen Sylvia , Barth Martin , Niewoehner Ludwig , Otto Matthias
Published: January 2008

X‐ray emission spectra from gunshot residues (GSR) are evaluated in order to assign them to a certain ammunition brand. Classification is based on regularized discriminant analysis (RDA) providing class information as well as additional parameters for judging the quality of an assignment. For visualization of measures such as the posterior probability, distance to centre or inverse Mahalanobis distances different approaches are explored and their common interpretation is evaluated. Copyright © 2008 John Wiley & Sons, Ltd.
Molecular and Electronic Structures of One‐Electron Oxidized NiII–(Dithiosalicylidenediamine) Complexes: NiIII–Thiolate versus NiII–Thiyl Radical States
Authors: Stenson Philip A. , Board Ashley , Marin‐Becerra Armando , Blake Alexander J. , Davies E. Stephen , Wilson Claire , McMaster Jonathan , Schröder Martin
Published: January 2008

The dithiosalicylidenediamine NiII complexes [Ni(L)] (R=tBu, R′=CH2C(CH3)2CH2 1, R′=C6H4 2; R=H, R′=CH2C(CH3)2CH2 3, R′=C6H4 4) have been prepared by transmetallation of the tetrahedral complexes [Zn(L)] (R=tBu, R′=CH2C(CH3)2CH2 7, R′=C6H4 8; R=H, R′=CH2C(CH3)2CH2 9, R′=C6H4 10) formed by condensation of 2,4‐di‐R‐thiosalicylaldehyde with diamines H2N‐R′‐NH2 in the presence of ZnII salts. The diamagnetic mononuclear complexes [Ni(L)] show a distorted square‐planar N2S2 coordination environment and have been characterized by 1H‐ and 13C NMR and UV/Vis spectroscopies and by single‐crystal X‐ray crystallography. Cyclic voltammetry and coulombic measurements have established that complexes 1 and 2, incorporating tBu functionalities on the thiophenolate ligands, undergo reversible one‐electron oxidation processes, whereas the analogous redox processes for complexes 3 and 4 are not reversible. The one‐electron oxidized species, 1+ and 2+, can be generated quantitatively either electrochemically or chemically with 70 % HClO4. EPR and UV/Vis spectroscopic studies and supporting DFT calculations suggest that the SOMOs of 1+ and 2+ possess thiyl radical character, whereas those of 1(py)2+ and 2(py)2+ possess formal NiIII centers. Species 2+ dimerizes at low temperature, and an X‐ray crystallographic determination of the dimer [(2)2](ClO4)2⋅2 CH2Cl2 confirms that this dimerization involves the formation of a SS bond (S⋅⋅⋅S=2.202(5) Å).
Positive‐ion ESI mass spectrometry of regioisomeric nonreducing oligosaccharide fatty acid monoesters: In‐source fragmentation of sodium adducts
Authors: Pérez‐Victoria Ignacio , Zafra Alberto , Morales Juan Carlos
Published: January 2008

Structural characterization and differentiation of a novel group of regioisomeric monolaurate esters of the nonreducing trisaccharides raffinose and melezitose, and the nonreducing tetrasaccharide stachyose has been obtained using positive electrospray ionization (ESI) mass spectrometry with in‐source fragmentation. The surfactant nature and high polarity of these compounds make them appropriate analytes for being studied by conventional ESI‐MS. The position of the acyl chain in each particular regioisomer has been used as a reporter group that allows unambiguous rationalization of the fragmentation routes of the corresponding natriated molecular ions [M + Na]+. In all cases, the main fragment ions were produced through cleavage of the glycosidic bond involving two anomeric carbons, the C‐1′ and C‐2″ of the α‐D‐Glcp‐(1–2)‐β‐D‐Fruf bond, and it was observed that sodium cation retention occurred on the heavier mass fragment of the two formed fragments, (e.g. di‐ or trisaccharide type vs monosaccharide type). Our results may help to better understand the fragmentation behavior of nonreducing oligosaccharides (as sodium adducts) in positive ESI mass spectrometry. Copyright © 2008 John Wiley & Sons, Ltd.
On‐target derivatization of keratan sulfate oligosaccharides with pyrenebutyric acid hydrazide for MALDI‐TOF/TOF‐MS
Authors: Zhang Yuntao , Iwamoto Takeo , Radke Gary , Kariya Yutaka , Suzuki Kiyoshi , Conrad Abigail H. , Tomich John M. , Conrad Gary W.
Published: January 2008

In the present work, a rapid and novel method of on‐target plate derivatization of keratan sulfate (KS) oligosaccharides for subsequent analysis by matrix‐assisted laser desorption and ionization (MALDI) mass spectrometry is described. MALDI‐(time‐of‐flight)‐TOF spectra of labeled KS oligosaccharides revealed that significantly improved ionization can be accomplished through derivatization with pyrenebutyric acid hydrazide (PBH), and the most abundant peak in each spectrum corresponds to the singly charged molecular ion [M − H]− or [M + (n − 1)Na − nH]−, where n = the number of sulfates (n = 1, 2, 3…). The high‐energy collision‐induced dissociation (heCID) spectra of labeled KS oligosaccharides displayed fragments of compounds similar to those observed with laser‐induced dissociation (LID) analysis, suggesting that both heCID and LID fragmentations can be used to analyze KS oligosaccharides. Moreover, fragmentation analysis of all labeled KS oligosaccharides was performed by MALDI‐TOF/TOF‐MS. With LID mode, sodium adducts showed fragmentation of glycosidic linkages with mainly Y/B/C ions, as well as various cross‐ring cleavages providing exact information for the positions of sulfate groups along the KS oligosaccharide chains. This one‐step on‐target derivatization method makes MALDI‐TOF/TOF‐MS identification of KS fast, simple and highly throughput for trace amounts of biological samples. Copyright © 2008 John Wiley & Sons, Ltd.
Structural and dynamical properties of glucose aqueous solutions by depolarized Rayleigh scattering
Authors: Paolantoni Marco , Comez Lucia , Fioretto Daniele , Gallina Maria Elena , Morresi Assunta , Sassi Paola , Scarponi Filippo
Published: January 2008

Depolarized Rayleigh scattering (DRS) spectra of glucose aqueous solutions measured from 0.01 to 1000 cm−1 reveal the presence of two distinct relaxation processes, in addition to the intermolecular Raman modes of the water network. The slow relaxation process with a characteristic time of tens of picoseconds is due to the glucose rotational diffusion and is spectrally separated from the fast relaxation process at picosecond time scales commonly attributed to the hydrogen‐bond lifetime; this latter time clearly increases with increase in glucose concentration. This suggests the formation of stable sugar hydration shells where the water dynamics is slower than the bulk. The destructuring effect on the tetrahedral hydrogen bonding of water induced by the sugar is also clearly evidenced when comparing the intermolecular Raman spectra at different molar ratios. Copyright © 2008 John Wiley & Sons, Ltd.
Matrix‐assisted laser desorption/ionization‐MS‐based relative quantification of peptides and proteins using iodoacetamide and N‐methyliodoacetamide as labeling reagents
Authors: Sun Mei‐Chuan , Chen Cheng‐Dong , Huang Yu‐Shan , Wu Zhong‐Siang , Ho Yen‐Peng
Published: January 2008

The use of iodoacetamide (IAA) and N‐methyliodoacetamide (MIAA) as labeling agents for the relative measurements of proteins using MALDI‐MS is described herein. These reagents, which alkylate the thiol groups of cysteine residues in proteins, were introduced during the alkylation step of a common protein denaturation and digestion process. This approach is simpler and cheaper than those involving isotope labeling agents. The labeling agents described herein displayed good dynamic ranges and correlation coefficients for protein quantification analyses when the proteins were treated through either in‐solution or in‐gel digestion. The best dynamic ranges (in the molar ratio) for proteins lysozyme, transferrin, and BSA (in‐solution digestion) are 0.1–10, 0.1–8, and 0.1–8, respectively. The corresponding correlation coefficients are greater than 0.99. The IAA/MIAA labeling is a useful method for the relative quantification of peptides and digested proteins when the chromatographic isotope effect is not a major concern.
Separating stereoisomers of di‐, tri‐, and tetrapeptides using capillary electrophoresis with contactless conductivity detection
Authors: Gong Xiao Yang , Dobrunz Dominik , Kümin Michael , Wiesner Markus , Revell Jefferson D. , Wennemers Helma , Hauser Peter C.
Published: January 2008

The separation and detection of small oligopeptides in CE with contactless conductivity detection were demonstrated. A strongly acidic separation buffer (0.5 M acetic acid) was employed in order to render the species cationic. Separation of the stereoisomers was achieved in typically 10–15 min by using either dimethyl‐β‐CD (DM‐β‐CD), (+)‐(18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid (18C6H4), a combination of the two substances, or of histidine, as buffer additives. Calibration curves were determined for isomers of Gly‐Asp and H‐Pro‐Asp‐NH2, in the range of 0.05–0.5 mM and 0.1–1 mM, respectively, and were found to be linear. LODs were determined to be in the order of 1.0 μM. The determination of isomeric impurities down to about 1% was found possible. Species showing good separation could also be successfully determined on an electrophoretic lab‐on‐chip device, with analysis times of a few minutes.
Malondialdehyde tagging improves the analysis of arginine oligomers and arginine‐containing dendrimers by HPLC‐MS
Authors: Onofrejova Lucia , Leitner Alexander , Lindner Wolfgang
Published: January 2008

The selective modification of arginine residues by malondialdehyde (MDA) was used to improve the mass spectrometric analysis of arginine oligomers (Argx, x = 4, 6, 7, 8, 9) and an arginine‐containing dendrimeric peptide. MDA tagging significantly increased the hydrophobicity of the arginine side‐chain and resulted in improved retention in RP HPLC of the oligoarginines using formic acid as mobile phase additive. This avoided the use of TFA to generate sufficient retention, as TFA was shown to lead to a dramatically reduced sensitivity (up to ten‐fold for Arg8 and Arg9) as a result of the strong signal suppression by ion pairing with multiple basic residues. MDA modification of Arg oligomers not only resulted in improved detection sensitivity for most of the peptides studied (e. g., more than six‐fold for Arg7), but also greatly enhanced the quality of MS/MS spectra, in line with previous results for other peptides. Furthermore, MDA modification helped to identify major side products in a sample of a dendrimeric peptide, a class of peptides that is typically difficult to analyze by MS.
Atom Transfer Radical Polymerization of Styrene Using Multifunctional Iniferter Reagents as Initiators
Authors: Zhang Wei , Wang Chengchao , Li Daoguang , Song Qing , Cheng Zhenping , Zhu Xiulin
Published: January 2008

Summary: Two multifunctional iniferters, 1,4‐bis‐(α‐N,N‐diethyldithiocarbamyl‐isobutyryloxy)‐benzene (BDCIB) and 1,3,5‐tris‐(α‐N,N‐diethyldithiocarbamyl‐isobutyryloxy)‐benzene (TDCIB), were successfully synthesized and used as initiators to initiate the polymerization of styrene in the presence of a CuBr/PMDETA complex. The polymerization results demonstrated that the kinetic plots in all cases were first‐order to the monomer, the molecular weight of the polymers increased linearly with the monomer conversion; meanwhile, the molecular weight distribution of the polymer was kept to a very low value (Mw/Mn ≤ 1.35). Furthermore, the measured molecular weights were very close to the calculated values, which indicated the high efficiency of the initiator for the polymerization of styrene. The effect of catalyst concentration and initiator concentration was not obvious and the influence of polymerization temperature was apparent, and the polymerization rate increased with the polymerization temperature. The results of chain‐extension and 1H NMR analysis proved that the polymer obtained was capped with diethylthiocarbamoylthiy (DC) group.
Copolymerization of N‐Vinylcarbazole and Vinyl Acetate via Reversible Addition‐Fragmentation Chain Transfer (RAFT) Polymerization
Authors: Zhu Jian , Zhu Xiulin , Cheng Zhenping , Zhang Zhengbiao
Published: January 2008

Summary: The reversible addition–fragmentation chain transfer (RAFT) random copolymerization of N‐vinylcarbazole (NVC) and vinyl acetate (VAc) was carried out using s‐benzyl‐o‐ethyl dithiocarbonate (BED) as the chain transfer agent and 2,2′‐azoisobutyronitrile (AIBN) as the initiator in 1,4‐dioxane solution at 70 °C. The polymerization showed the characteristics of ‘living’ free radical polymerization behaviors: first order kinetics, linear relationships between molecular weight and conversion, and narrow polydispersity of the polymers. The reactivity ratios of NVC and VAc were calculated via the Kelen–Tudos (KT) and non‐linear error in variable (EVM) methods and showed as r1 = 1.938 ± 0.191, r2 = 0.116 ± 0.106. The thermal behavior of the copolymers with different content of NVC and VAc was investigated by DSC and TGA. The results showed that the introduction of a VAc segment into copolymer significantly reduced the Tg of the NVC homopolymers. FT‐IR spectra, fluorescence spectra, and cyclic voltammetric behavior of these copolymers were also measured and compared with those of NVC homopolymers. The copolymers showed similar oxidative behavior to the NVC homopolymer. However, there was only one reductive potential peak shown for the copolymers at about 0.058 V.
Characterization of Polymer Architectures by Multidetection Size Exclusion Chromatography
Authors: Puskas Judit E. , Foreman Elizabeth A. , Dos Santos Lucas M. , Soytaş Serap Hayat
Published: January 2008

Summary: This paper discusses the analysis of star‐branched and dendritic polyisobutylenes (PIBs) using branching parameters based on radii of gyration Rg,z and hydrodynamic radii Rh,z. Rg,z and Rh,z were measured by Size Exclusion Chromatography equipped with a Wyatt Technology Viscostar viscometer (VIS), a Wyatt Optilab DSP RI detector, a Wyatt DAWN EOS 18 angle Multiangle Light Scattering (MALS) detector and a Wyatt Quasi‐elastic Light Scattering QELS detector. Branching parameters were calculated from these measurements and compared with those computed for these architectures.
Approximation of the Navier–Stokes system with variable viscosity by a system of Cauchy–Kowaleska type
Authors: de Araújo G. M. , de Menezes S. B. , Gúzman R. B.
Published: January 2008

In this paper, we study the existence of weak solutions when n⩽4 of the mixed problem for the Navier–Stokes equations defined in a bounded domain Q using approximation by a system of Cauchy–Kowaleska type. Periodical solutions are also analyzed. Copyright © 2008 John Wiley & Sons, Ltd.
1H NMR spectroscopy of ascitic fluid: discrimination between malignant and benign ascites and comparison of the results with conventional methods
Authors: Bala Lakshmi , Sharma Abhinav , Yellapa Radha Krishna , Roy Raja , Choudhuri G. , Khetrapal C. L.
Published: January 2008

It is often difficult to distinguish benign ascites from malignant ascites by conventional examination of ascitic fluid. Therefore, 1H NMR spectroscopy of ascitic fluid specimens was explored as a one‐shot experiment to identify potentially interesting metabolic indices that might help to differentiate between the two. Seventy ascitic fluid specimens (15 cytologically positive for malignant cells, eight cytologically negative for malignant cells but remaining suspicious for malignant ascites, and 47 due to liver cirrhosis) were subjected to 1H NMR spectroscopy for quantitative estimation of 14 metabolites. Mean concentrations of the metabolites were compared with the Mann–Whitney U test. Multivariate discriminant function analysis was performed to determine important descriptors in the discrimination process. The sensitivity and specificity of the proposed model were compared with conventional methods using ascitic fluid protein and serum ascitic albumin gradient. Then, probable predictions for the doubtful cases were made using the proposed model. Patients with malignant ascites had significantly higher mean concentrations (µM) of β‐hydroxybutyrate (594 vs 61), lactate (5384 vs 2104), acetone (136 vs 69), and acetoacetate (122 vs 48) than patients with cirrhotic ascites, and significantly lower concentrations of glutamine (359 vs 615), citrate (62 vs 118), glucose (4933 vs 8411), tyrosine (44 vs 124), and phenylalanine (51 vs 93) (P < 0.05 for all). In the discriminant function analysis model, the best discrimination (P < 0.001) was achieved when β‐hydroxybutyrate, lactate, citrate and tyrosine were considered together as markers. Sensitivity and specificity of the proposed model, ascitic fluid protein and serum ascitic albumin gradient were found to be 100% and 97.9%, 53.3% and 76.6%, and 60% and 87.2%, respectively. The proposed model put five of the eight doubtful cases in the malignant group. This is encouraging and may provide useful information for clinical purposes. Copyright © 2008 John Wiley & Sons, Ltd.
A general solution to the identification of moving vehicle forces on a bridge
Authors: González A. , Rowley C. , OBrien E. J.
Published: January 2008

Bridge weigh‐in‐motion systems measure bridge strain caused by the passing of a truck to estimate static axle weights. For this calculation, they commonly use a static algorithm that takes the bridge influence line as reference. Such a technique relies on adequate filtering to remove bridge dynamics and noise. However, filtering can lead to the loss of a significant component of the underlying signal in bridges where the vibration does not have time to complete sufficient number of cycles and in cases of closely spaced axles traveling at high vehicle speeds. In order to overcome these limitations and also to provide additional information on the dynamics of the applied forces, this paper presents an algorithm based on first‐order Tikhonov regularization and dynamic programming. First, strain measurements are simulated using an elaborate three‐dimensional vehicle and orthotropic bridge interaction system. Then, strain is contaminated with noise and input into the moving force identification algorithm. The procedure to implement the algorithm and to derive the applied forces from the simulated strain record is described. Vehicle axle forces are shown to be accurately predicted for smooth and rough road profiles and a range of speeds. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of collision‐activated dissociation gas and collision energy on the fragmentation of dipyridamole and its rapid and sensitive liquid chromatography/electrospray ionization tandem mass spectrometric determination in human plasma
Authors: Yadav Manish , Patel Dharmesh , Singhal Puran , Prasad Rajendra , Goswami Sailendra , Shrivastav Pranav S. , Pande Umesh C.
Published: January 2008

The effect of nitrogen as the collision‐activated dissociation (CAD) gas on the fragmentation of dipyridamole was investigated in the range of 10–90 eV collision energy. The results support the collision model reported elsewhere, that the degree of ion fragmentation increases with the increasing mass of the collision gas. A simple, sensitive and high‐throughput liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed for the determination of dipyridamole, a platelet aggregation inhibitor in human plasma, using granisetron as internal standard (IS). The method involved liquid–liquid extraction of the analyte and IS from 0.5 mL human plasma with diethyl ether. The chromatographic separation was achieved under isocratic conditions and the ion transitions for dipyridamole (m/z 505.40 → 429.60) and the IS (m/z 313.10 → 138.20) were monitored on a triple quadrupole mass spectrometer, operating in positive ion multiple reaction monitoring (MRM) mode. The method was validated over the concentration range 5.1–4499.1 ng/mL for dipyridamole. The method was rugged and rapid with a total run time of 1.2 min. It was successfully applied to a pivotal bioequivalence study in 67 healthy human subjects after oral administration of a 75 mg extended release formulation under fasting condition. Copyright © 2008 John Wiley & Sons, Ltd.
The interaction of human serum albumin with titanium studied by means of atomic force microscopy
Authors: Van De Keere Isabel , Willaert Ronnie , Tourwé Els , Hubin Annick , Vereecken Jean
Published: January 2008

Titanium is frequently used as a biomaterial for implants in orthopaedics and cardiovascular devices. Understanding the biocompatibility, which is strongly influenced by the adsorption of proteins onto the surface, is very important to improve implants. The surface chemistry of an implant material and its influence on the interaction with body fluid is crucial in that perspective. The main goal of this study was to investigate the conformation of human serum albumin (HSA) with commercially pure titanium (CP Ti) on a molecular level. Both ex situ and in situ AFM imaging showed the conformation of HSA on CP Ti and on mica, which was used as a reference material. Single molecules and aggregates of albumin were observed. HSA can be recognised by the globular shape. The conformation of the adsorbed HSA molecules was different on titanium and mica, for both the ex situ and in situ imaging. The difference in wettability between both substrates caused a larger spread of the protein on the CP Ti surface and thus resulted in a larger perturbation of the native structure of HSA as compared to mica. Copyright © 2008 John Wiley & Sons, Ltd.
Electroless deposition of polyaniline: synthesis and characterization
Authors: Attout A. , Yunus S. , Bertrand P.
Published: January 2008

Polyaniline (PANi), as conductive polymer, constitutes an attractive material for electronic and optical applications. Different from electropolymerization and chemical oxidative polymerization, electroless deposition is another method for synthesizing PANi. Aniline can polymerize slowly and spontaneously on platinum or palladium surface in an aqueous acid solution of the monomer. This reaction proceeds via an electrochemical mechanism that involves the reduction of dissolved oxygen as cathodic and oxidation of aniline as anodic half‐reactions at the metal/solution interface. PANi, obtained by electroless synthesis, was compared to chemical oxidative and electropolymerized ones by XPS and SEM. The product of electroless deposition is found to be chemically similar to the others but its morphology is different. The PANi film growth and morphology are studied as a function of time and temperature. Copyright © 2008 John Wiley & Sons, Ltd.
Pyrite oxidation in acidic medium: overall reaction pathway
Authors: Demoisson Frédéric , Mullet Martine , Humbert Bernard
Published: January 2008

This study investigated the oxidation processes of pyrite by dissolved oxygen. Synthetic pyrite suspensions have reacted with dissolved oxygen in a closed‐thermostated system for 20 h and at pH values of 2.0 and 3.5. Special emphasis was made on the characterization of the solid phase formed during the reaction process, using X‐ray photoelectron spectroscopy (XPS) and confocal Raman microspectrometry. The results revealed a strong heterogeneity of the samples with the identification of two different micrometric areas. Eg and Ag Raman pyrite modes were characterized by wavenumber drifts, from 0 to 6, correlated with the shine changes of the micrometric probed area. XPS analyses provided evidence of the distribution of iron and sulfur species at the reacted pyrite surface. The Fe(2p3/2) signals showed an increase in the binding energy range typical of Fe(III)S and Fe(III)O compounds. The S(2p) XPS signals included contribution from disulfide, monosulfide, elemental sulfur, and sulfate. Elemental sulfur should be protected from sublimation under ultrahigh vacuum, possibly by an overlaying of other species such as Fe(III) (oxyhydr)oxide species. An overall reaction pathway of the pyrite in oxidizing (Cr(VI), dissolved oxygen, Fe(III)), and acidic media (pH ⩽3.5) has been established from the present results and previous papers. Copyright © 2008 John Wiley & Sons, Ltd.
Immobilization stress suppresses cutaneous delayed‐type hypersensitivity reaction induced by gastrointestinal sensitization in mice: association with Langerhans cell of the forestomach
Authors: Tamiya Hisashi , Kobayashi Hiromi , Yamanaka Kazuhoshi , Fujita Naoko , Tsuruta Daisuke , Mizuno Nobuyuki , Ishii Masamitsu
Published: January 2008

Psychological stress (PS) has various influences on allergic diseases. Although gastrointestinal sensitization induces hypersensitivity reactions in the skin, such as urticaria and dermatitis, due to food or drug allergy, the effect of PS on the gastrointestinal sensitization phase remains unclear. We administered 2,4,6‐trinitrochlorobenzene (TNCB) to BALB/c mice intragastrically (gastrointestinal sensitization). After 4 days, we elicited a cutaneous delayed‐type hypersensitivity (DTH) reaction by applying TNCB to the ear. We examined the effects of immobilization stress (IS) before gastrointestinal sensitization and elicitation on the cutaneous DTH (CDTH) by measurement of the thickness of the swollen ear, morphological changes and the number of Ia molecule‐positive Langerhans cells (Ia + LC) in the forestomach, and serum corticosterone (CORT) concentration. In addition, we studied the effect of pre‐administration of a glucocorticoid receptor antagonist (RU486). CDTH was suppressed significantly with application of IS for more than 6 h prior to gastrointestinal sensitization. Simultaneously, Ia + LC became smaller and round in shape and decreased in number. The serum CORT concentration doubled following IS for more than 2 h, and these changes were suppressed by pre‐administration of RU486. The results indicate that IS suppresses gastrointestinal sensitization, probably in association with suppression of the antigen‐presenting function of the Ia + LC by elevation of steroid hormones. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis, Crystal Structure and Characterization of Hexakis[2‐methoxy‐4‐formylphenoxy]cyclotriphosphazene
Authors: Tümer Yasemin , Bati Hümeyra , Çalişkan Nezihe , Yüksektepe Çi˘dem , Büyükgüngör Orhan
Published: January 2008

The new cyclotriphosphazene derivative N3P3(OC6H3OCH3COH)6 (1) was synthesized from hexachlorocyclotriphosphazene, N3P3Cl6, and 4‐hydroxy‐3‐methoxybenzaldehyde in acetonitrile in the presence of K2CO3. The structure of 1 was verified by means of elemental analysis, IR, 1H NMR, 13C NMR, 31P NMR spectra, thermal analysis and X‐ray diffraction.
A New Supramolecular Assembly Formed by Melamine and Sulfuric Acid
Authors: Heine Axel , Gloe Kerstin , Doert Thomas , Gloe Karsten
Published: January 2008

Polymeric melaminium sulfate [(LH2)2(SO4)2]n has been synthesized by reaction of melamine L with sulfuric acid in aqueous solution. The compound was characterized by elemental analysis, 1H NMR, ESI MS and a single crystal X‐ray diffraction analysis. The architecture of the assembly formed is based on hydrogen bonded dimers of diprotonated melaminium cations (LH2)2+ which are linked by a hydrogen bonded network with sulfate ions forming 2D sheets. A 3D polymeric structure results from the presence of mutual hydrogen bonds between sulfate ions and melaminium cations in different sheets. Significant π‐π stacking is also present between the aromatic cations in this supramolecular arrangement.
Hydrated Zinc p‐Aminobenzoate [Zn(p‐H2NC6H4COO)2(H2O)]·H2O from a Layered Zinc Hydroxide
Authors: v. Prondzinski Nina , Merz Klaus
Published: January 2008

A new pillard crystal packing of a hydrated [Zn(PABA)2(H2O)]·H2O (PABA = p‐aminobenzoate) (1) was obtained starting from a layered zinc hydroxide with PABA as organic substrate. Compound 1 was characterized in the solid state by crystal structure analysis and in solution by 13C‐ and 1H‐NMR spectroscopy. In contrast to the known hydrate of [Zn(PABA)2]·1.5H2O the water molecules of crystal packing of 1 are involved in the coordination sphere of the zinc atoms, forming hydrogen bonding interactions between amino groups of PABA and water molecules.
Synthesis and Crystal Structures of Two New Layered Manganese(II) Diphosphonates: Mn2[{(O3PCH2)2NHR}(H2O)F]·H2O
Authors: Meng Lei , Li Jing , Sun Zhen‐Gang , Zheng Xue‐fang , Dong Da‐Peng , Chen Hui , Zhu Yan‐Yu , Zhao Yan , Zhang Jing
Published: January 2008

Two manganese phosphonates Mn2[{(O3PCH2)2NHR}(H2O)F]·H2O (R = −C6H11 (1), −CH2C5H4N (2)) have been synthesized by hydrothermal reaction and characterized by single–crystal X–ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. The two isomorphous compounds feature layered structures in ab plane, in which the tetramers comprised of two MnO4F2 and two MnO5F polyhedra are cross–linked via phosphonate oxygen atoms to form MnII phosphonate layers. The organic groups of the ligands are orientated toward the interlayer space.
Disparities in Surgical Care: Strategies for Enhancing Provider–Patient Communication
Authors: Bigby JudyAnn , Ashley Stanley W.
Published: January 2008

Patient–provider communication is critical to eliminating disparities in healthcare. Both the patient and the physician bring a variety of assumptions to the therapeutic partnership. As illustrated in a surgical case, these are based not only on race and ethnicity but also on a host of other factors, which may affect both partners’ perceptions of reality and their subsequent behavior. Communication is an essential component of quality and is necessary to improve patients’ understanding of the content of their care, their ability to make informed choices, and their ability to adhere to recommended therapies. There are a variety of practical strategies to enhance awareness of these issues and improve communication that we need to begin to incorporate into surgical culture.
Impact of Adenoma Weight and Ectopic Location of Parathyroid Adenoma on Localization Study Results
Authors: Erbil Yeşim , Barbaros Umut , Tükenmez Mustafa , İşsever Halim , Salmaslıoğlu Artür , Adalet Işık , Özarmağan Selçuk , Tezelman Serdar
Published: January 2008

Although the sensitivity of preoperative localization techniques is high for solitary parathyroid adenomas, negative imaging study results are inevitable. The weight and location of the parathyroid adenoma may contribute to the negative results. We aimed to study the impact of adenoma weight and ectopic location of the parathyroid adenoma on ultrasonography and sestamibi scan results.
The patients were divided into two groups according to adenoma location. Group 1 consisted of 36 patients with ectopic location, and group 2 consisted of 149 patients with normal location. Parathyroid adenoma weight and the results of imaging studies were determined in all patients.
Of 185 patients operated on for hyperparathyroidism, 36 (19.4%) had ectopic parathyroid glands. There was a positive correlation between adenoma weight and positive imaging studies, whereas ectopic location did not correlate with negative imaging study results. There was no significant difference between the ectopic adenoma ratio of patients with negative and positive imaging study results. The weight of the ectopic parathyroid adenoma was significantly lower in patients with negative imaging study results than in patients with positive imaging study results (p = 0.001). According to the analysis of variance, patients with higher‐weight adenomas have positive imaging study results irrespective of ectopic location.
For both normal and ectopic adenoma locations, adenoma weight was found only to be a factor that positively influences imaging study results.
Amniotic fluid iodine concentrations do not vary in pregnant women with varying iodine intake
Authors: García-Fuentes Eduardo , Gallo Manuel , García Laureano , Prieto Stephanie , Alcaide-Torres Javier , Santiago Piedad , Velasco Inés , Soriguer Federico
Published: January 2008

Iodine deficiency is an important clinical and public health problem. Its prevention begins with an adequate intake of iodine during pregnancy. International agencies recommend at least 200 μg iodine per d for pregnant women. We assessed whether iodine concentrations in the amniotic fluid of healthy pregnant women are independent of iodine intake. This cross-sectional, non-interventional study included 365 consecutive women who underwent amniocentesis to determine the fetal karyotype. The amniocentesis was performed with abdominal antisepsis using chlorhexidine. The iodine concentration was measured in urine and amniotic fluid. The study variables were the intake of iodized salt and multivitamin supplements or the prescription of a KI supplement. The mean level of urinary iodine was 139·0 (sd94·5) μg/l and of amniotic fluid 15·81 (sd7·09) μg/l. The women who consumed iodized salt and those who took a KI supplement had significantly higher levels of urinary iodine than those who did not (P = 0·01 andP = 0·004, respectively). The urinary iodine levels were not significantly different in the women who took a multivitamin supplement compared with those who did not take this supplement, independently of iodine concentration or multivitamin supplement. The concentrations of iodine in the amniotic fluid were similar, independent of the dietary iodine intake. Urine and amniotic fluid iodine concentrations were weakly correlated, although the amniotic fluid values were no higher in those women taking a KI supplement. KI prescription at recommended doses increases the iodine levels in the mother without influencing the iodine levels in the amniotic fluid.
Memory and metamemory in schizophrenia: a liberal acceptance account of psychosis
Authors: Moritz S. , Woodward T. S. , Jelinek L. , Klinge R.
Published: January 2008

Background

In previous studies we suggested that liberal acceptance (LA) represents a fundamental cognitive bias in schizophrenia and may explain why patients are more willing to accept weak response alternatives and display overconfidence in incorrect responses. The aim of the present study was to test a central assumption of the LA account: false alarms in schizophrenia should be particularly increased when the distractor–target resemblance is weak relative to a control group.

Method

Sixty-eight schizophrenia patients were compared to 25 healthy controls on a visual memory task. At encoding, participants studied eight complex displays, each consisting of a unique pairing of four stimulus attributes: symbol, shape, position and colour. At recognition, studied items were presented along with distractors that resembled the targets to varying degrees (i.e. the match between distractors and targets ranged from one to three attributes). Participants were required to make old/new judgements graded for confidence.

Results

The hypotheses were confirmed: false recognition was increased for patients compared to controls for weakly and moderately related distractors only, whereas strong lure items induced similar levels of false recognition for both groups. In accordance with prior research, patients displayed a significantly reduced confidence gap and enhanced knowledge corruption compared to controls. Finally, higher neuroleptic dosage was related to a decreased number of high-confident ratings.

Conclusions

These data assert that LA is a core mechanism contributing to both enhanced acceptance of weakly supported response alternatives and metamemory deficits, and this may be linked to the emergence of positive symptomatology.
One-year follow-up results of a randomized controlled clinical trial on internet-based cognitive behavioural therapy for subthreshold depression in people over 50 years
Authors: Spek V. , Cuijpers P. , Nyklíček I. , Smits N. , Riper H. , Keyzer J. , Pop V.
Published: January 2008

Background

Internet-based cognitive behaviour therapy (CBT) is a promising new approach for the treatment of depressive symptoms. The current study had two aims: (1) to determine whether, after 1 year, an internet-based CBT intervention was more effective than a waiting-list control group; and (2) to determine whether the effect of the internet-based CBT differed from the group CBT intervention, 1 year after the start of treatment.

Method

A total of 191 women and 110 men (mean age=55 years, s.d.=4.6) with subthreshold depression were randomized into internet-based treatment, group CBT (Lewinsohn's Coping with Depression Course), or a waiting-list control condition. The main outcome measure was treatment response after 1 year, defined as the difference in pretreatment and follow-up scores on the Beck Depression Inventory (BDI). Missing data were imputed using the multiple imputation procedure of data augmentation. Analyses were performed using multiple imputation inference.

Results

In the waiting-list control group, we found a pretreatment to follow-up improvement effect size of 0.69, which was 0.62 in the group CBT condition and 1.22 with the internet-based treatment condition. Simple contrasts showed a significant difference between the waiting-list condition and internet-based treatment (p=0.03) and no difference between both treatment conditions (p=0.08).

Conclusions

People aged over 50 years with subthreshold depression can still benefit from internet-based CBT 1 year after the start of treatment.
The acceptability to patients of computerized cognitive behaviour therapy for depression: a systematic review
Authors: Kaltenthaler E. , Sutcliffe P. , Parry G. , Beverley C. , Rees A. , Ferriter M.
Published: January 2008

Background

Cognitive behaviour therapy (CBT) is widely used to treat depression. However, CBT is not always available to patients because of a shortage of therapists and long waiting times. Computerized CBT (CCBT) is one of several alternatives currently available to treat patients with depression. Evidence of its clinical effectiveness has led to programs being used increasingly within the UK and elsewhere. However, little information is available regarding the acceptability of CCBT to patients.

Method

A systematic review of sources of information on acceptability to patients of CCBT for depression.

Results

Sources of information on acceptability included: recruitment rates, patient drop-outs and patient-completed questionnaires. We identified 16 studies of CCBT for the treatment of depression that provided at least some information on these sources. Limited information was provided on patient take-up rates and recruitment methods. Drop-out rates were comparable to other forms of treatment. Take-up rates, when reported, were much lower. Six of the 16 studies included specific questions on patient acceptability or satisfaction although information was only provided for those who had completed treatment. Several studies have reported positive expectancies and high satisfaction in routine care CCBT services for those completing treatment.

Conclusions

Trials of CCBT should include more detailed information on patient recruitment methods, drop-out rates and reasons for dropping out. It is important that well-designed surveys and qualitative studies are included alongside trials to determine levels and determinants of patient acceptability.
Asymptotic representation of weighted L∞- and L1-minimal polynomials
Authors: KROÓ ANDRÁS , PEHERSTORFER FRANZ
Published: January 2008

In 1858 Chebyshev, and some years later his students Korkin and Zolotarev, determined the polynomial which deviates least from zero among all polynomials of degree n with leading coefficient one with respect to the maximum- and the L1-norm, respectively; these are now called the Chebyshev polynomial of first and second kind.

The next natural step which is to find, at least asymptotically, the minimal polynomial with respect to a given weight function has not been settled until today. Indeed, Bernstein gave asymptotics for the minimum deviation of weighted minimal polynomials, Fekete and Walsh found nth root asymptotics and, recently, Lubinsky and Saff provided asymptotics outside [−1, 1]. But the main point of interest: the asymptotic representation of the weighted minimal polynomials on the interval of approximation [−1, 1] remained open. Here we settle this problem with respect to the maximum norm for weight functions whose second derivative is Lipα, α ∈ (0, 1), and with respect to the L1-norm under somewhat stronger differentiability conditions.
On ϕ-amenability of Banach algebras
Authors: KANIUTH EBERHARD , LAU ANTHONY T. , PYM JOHN
Published: January 2008

Generalizing the notion of left amenability for so-called F-algebras [12], we study the concept of ϕ-amenability of a Banach algebra A, where ϕ is a homomorphism from A to ℂ. We establish several characterizations of ϕ-amenability as well as some hereditary properties. In addition, some illuminating examples are given.