bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of alternative specimens in toxicological analysis
Authors: Gallardo E. , Queiroz J. A. 
Published: May 2008

AbstractThe use of alternative specimens in the field of toxicology was first described in 1979, when hair analysis was used to document chronic drug exposure. Since then, the use of these ‘alternative’ samples has gained tremendous importance in forensic toxicology, as well as in clinic toxicology, doping control and workplace drug testing. It is not surprising, therefore, that a large number of papers dealing with the determination of several classes of drugs in saliva, sweat, meconium and hair have been published ever since, owing to the fact that chromatographic equipment is becoming more and more sensitive, mass spectrometry (and tandem mass spectrometry) being the most widely used analytical tool, combined with gas or liquid chromatography. ‘Alternative’ specimens present a number of advantages over the ‘traditional’ samples normally used in toxicology (e.g. blood, urine and tissues), namely the fact that their collection is not invasive, their adulteration is difficult, and they may allow increased windows of detection for certain drugs. The main disadvantage of this kind of samples is that drugs are present in very low concentrations, and therefore high‐sensitivity techniques are required to accomplish the analysis. This paper reviews a series of publications on the use of alternative specimens, with special focus on the main analytical and chromatographic problems that these samples present, as well on their advantages and disadvantages over traditional samples in documenting drug exposure. Copyright © 2008 John Wiley & Sons, Ltd.
Identification of differentially expressed proteins in the heart of translationally controlled tumor protein over‐expressing transgenic mice
Authors: Cheon Myeong Sook , Suh Jae‐kyung , Kim Min‐Jeong , Kim Seong Hwan , Lee Kyunglim 
Published: May 2008

AbstractWe previously reported that transgenic (TG) mice over‐expressing translationally controlled tumor protein (TCTP) developed systemic arterial hypertension at about 6 weeks after birth. In the present study, we identified, using proteomics technologies, 24 other proteins that were differentially expressed in the heart of TCTP over‐expressing TG mice. These 24 proteins are involved in a variety of biological processes such as reactive oxygen species metabolism, cytoskeleton organization, fatty acid metabolism, amino acid metabolism and energy metabolism. We determined protein expression levels of the peroxiredoxin (Prx)2, Prx3, myosin light chain 1, stress protein (heat shock protein) 25K, and T‐complex protein 1 alpha subunit by western blot analysis. Over‐expression of TCTP probably regulates the expression of other proteins which play a pivotal role in a variety of cellular functions in TCTP over‐expressing TG mice. Copyright © 2008 John Wiley & Sons, Ltd.
Characterization of a new norfloxacin metabolite monitored during a bioequivalence study by means of mass spectrometry and quantum computation
Authors: Medvedovici Andrei , Sora Daniela Iuliana , Ionescu Sorana , Hillebrand Mihaela , David Victor 
Published: May 2008

AbstractA bioequivalence study of two formulations containing norfloxacin was used for identification and assay of the metabolite of norfloxacin in human serum samples. The bioequivalence study was based on an analytical method using liquid chromatography with fluorescence detection. The plasmatic profile of metabolite was similar to norfloxacin for both formulations. Three plasma fractions of norfloxacin metabolite from a volunteer were isolated by liquid chromatography and investigated by atmospheric‐pressure chemical ionization mass‐spectrometry. The structure of norfloxacin metabolite (7‐aminoethylenamino‐6‐fluoro‐4‐hydroxy quinoline‐3‐carboxylic acid) was identified taking into account also the mass spectrometry investigations achieved for norfloxacin and ciprofloxacin (used as internal standard for the analytical method). A theoretical procedure based on quantum chemical calculations has been also used to explain the mass fragmentation in molecules of norfloxacin metabolite that differ from the molecule of norfloxacin. Copyright © 2008 John Wiley & Sons, Ltd.
Screening and mechanism study of components targeting DNA from the Chinese herb Lonicera japonica by liquid chromatography/mass spectrometry and fluorescence spectroscopy
Authors: Zhou Jian‐Liang , Qian Zheng‐Ming , Luo Yong‐Dong , Tang Dan , Chen Hong , Yi Ling , Li Ping 
Published: May 2008

AbstractA method which involves combination of centrifugal ultrafiltration sampling with high‐performance liquid chromatography coupled with diode array detection and mass spectrometry (HPLC‐DAD‐MS) analysis was established for screening bioactive compounds binding to calf thymus deoxyribonucleic acid (ct‐DNA) from the extracts of Lonicera japonica. Four compounds were screened out and identified as rutin, quercetin‐3‐O‐glucoside, luteolin‐7‐O‐glucoside and lonicerin, based on the comparison of retention time, UV spectra and MS data with those of standards. The DNA‐binding capabilities of the latter three flavonoids were found for the first time. The binding mechanisms of rutin, quercetin‐3‐O‐glucoside and luteolin‐7‐O‐glucoside with ct‐DNA at the molecular level were explored using acridine orange (AO) as a fluorescence probe. Groove binding is the most appropriate binding mode of these three flavonoids to DNA, according to ultraviolet absorption and fluorescence spectra, as well as melting temperature (Tm) curves and viscosity measurements. The binding constants of rutin, quercetin‐3‐O‐glucoside and luteolin‐7‐O‐glucoside with DNA–AO complex were 3.81 × 103, 3.37 × 103 and 5.50 × 103 L/mol, respectively. Copyright © 2008 John Wiley & Sons, Ltd.
The role of cognition and affect in the formation of customer satisfaction judgements concerning service recovery encounters
Authors: Schoefer Klaus 
Published: May 2008

Abstract

It is widely accepted that justice perceptions play an important role in shaping customers' evaluations of service recovery experiences. However, this stream of justice research has evolved with little cross‐reference to emotion research. The current paper seeks to address this issue by explicitly considering the role of perceived justice in the elicitation of recovery‐specific consumer emotions. Specifically, we develop and test a model suggesting that perceived justice represents a cognitive appraisal dimension, which helps to explain the elicitation of positive and negative emotions during and/or after service recovery encounters. Furthermore, we argue that customer satisfaction with service recovery (i.e. recovery satisfaction) is based partly on cognitive (i.e. perceived justice based) and partly on affective responses. Support for the proposed model is provided through findings from an empirical study showing that both cognitive and affective influences work to create the recovery satisfaction judgement. This finding has significant implications for the theory and practice of service recovery management.
Copyright © 2008 John Wiley & Sons, Ltd.
The influence of evidence type and product involvement on message‐framing effects in advertising
Authors: Dardis Frank E. , Shen Fuyuan 
Published: May 2008

Abstract

Extrapolating from prior research that describes the persuasive effects of gain‐ versus loss‐framed messages via the heuristic‐systematic model (HSM), the current study incorporated two advertising‐related factors – evidence type (informational vs. exemplar) and product involvement – and examined their influence on message‐framing effects in advertisements for commonplace consumer products. A significant interaction in Experiment 1 indicated that loss‐framed messages were persuasive in a higher‐involvement context only when coupled with informational evidence, which enhanced systematic processing among participants and thereby elicited the framing effect. No interaction effects occurred in the lower‐involvement context of Experiment 2, in which the hypothesized thought‐processing patterns did not evince. Consistent with recent theoretical advancements, these results indicate that message‐framing effects can be attenuated when both systematic and heuristic processing occur simultaneously. Practical implications are discussed.
Copyright © 2008 John Wiley & Sons, Ltd.
Being the same and different: A model explaining new product adoption
Authors: Timmor Yaron , Katz‐Navon Tal 
Published: May 2008

Abstract

The study suggests an alternative conceptualization for understanding adoption behavior over time, based on Optimal Distinctiveness Theory. This theory states that social identity derives from a fundamental tension between human needs for validation and similarity to others—the need for assimilation—and a countervailing need for uniqueness and individuation—the need for differentiation. The present study proposes that the effect of the size of the group of consumers who have already adopted a new product on an individual consumer's decision to adopt this product is contingent upon the consumer's two predispositions: the need for assimilation and the need for distinctiveness. Results of empirical research suggested that differently perceived subgroup sizes fulfill consumers' dual needs for distinctiveness and assimilation differently. The influence of the adopters' group size on a consumer's decision to adopt a new product varied among individuals with different levels of needs for distinctiveness and assimilation: when need for distinctiveness was low, the higher was the need for assimilation and the larger was the perceived group size, the higher was the probability of adopting the product. When the need for distinctiveness was high, the lower was the need for assimilation and the larger was the perceived group size, the lower was the probability of adopting the product. In addition, when the need for both distinctiveness and assimilation were high, the probability of adopting the product rose as the perceived group size increased. Implications for product variation, marketing communication, and target groups are discussed.
Copyright © 2008 John Wiley & Sons, Ltd.
Effects of sodium fluoride (NaF) on the cilia and microtubular system of Tetrahymena
Authors: Kovács P. , Pállinger É. , Csaba G. 
Published: May 2008

AbstractThe effect of the nucleophilic reagent NaF on the microtubular system of Tetrahymena was studied by using scanning electron microscopy (SEM), confocal microscopy, and flow cytometry. Treatments with 40 mM NaF significantly reduced the amount of α‐tubulin while 80 mM treatment did not alter its quantity. One possible explanation for this α‐tubulin overexpression is that the higher amount of α‐tubulin enables this organism to carry out the appropriate function of the cytoskeleton under this undesirable influence of higher amounts of 80 nM NaF. However, the amount of acetylated tubulin increased in a dose‐dependent manner. The cilia became fragile under the effect of 80 mM NaF. Confocal microscopy revealed that after 40 mM NaF treatment transversal microtubule bands (TMs) and longitudinal microtubule bands (LMs) as well as basal bodies (BBs) were extremely strong decorated with anti‐acetylated tubulin antibody and TM‐localization abnormalities were visible. In the 80 mM NaF‐treated cells, the deep fiber of oral apparatus was very strongly labeled, while the TMs and LMs were less decorated with anti‐acetylated tubulin antibody, and LM deformities were visible. It is supposed that post‐translational tubulin modifications (e.g., acetylation) defend the microtubules against the NaF‐induced injury. NaF is able to influence the activity of several enzymes and G‐proteins, therefore is capable to alter the structure, metabolism, and the dynamics of microtubular system. The possible connection of signaling and cytoskeletal system in Tetrahymena is discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Nitric oxide‐mediated activation of NADPH oxidase by salbutamol during acute asthma in children
Authors: Owayed Abdullah , Dhaunsi Gursev S. , Al‐Mukhaizeem Fahad 
Published: May 2008

AbstractA wide variety of reactive oxygen species (ROS) such as superoxide anion, hydroxyl radical and hydrogen peroxide, and reactive nitrogen species such as nitric oxide (NO) and peroxynitrite are known to be involved in pathophysiology of bronchial asthma. We have investigated, in this study, the status of NADPH oxidase (NOX), a major source of superoxide anion production, in peripheral blood lymphocytes (PBL) from asthmatic patients in relation to salbutamol treatment. PBL isolated from patients with bronchial asthma were found to have a significantly increased activity of NOX. Plasma levels of malondialdehyde (MDA), an index of lipid peroxidation, and NO were also markedly elevated in asthmatic patients compared to control samples. A significantly decreased catalase activity observed in PBL from our patients underscored the severity of oxidative stress during asthma. Treatment of PBL with salbutamol (10 µg ml−1), prevented the attenuation of catalase activity but significantly increased the levels of NO and NOX activity. Levels of NOX‐1 mRNA were significantly (p < 0.001) increased in PBL following treatment with NO donor (500 µM), S‐nitroso‐N‐acetyl penicillamine (SNAP). Western blot analysis revealed that gp91phox protein was also significantly (twofold–threefold) increased following treatment with SNAP. The observed transcriptional regulation of NOX‐1 and gp91phox by NO was observed to result in an increased NOX activity as well. This study concludes that salbutamol treatment enhances superoxide anion production in asthma patients through NO‐mediated mechanisms, however it exerts beneficial antioxidant effects through activation of catalase and attenuation of lipid peroxidation. Copyright © 2008 John Wiley & Sons, Ltd.
A Highly Efficient Procedure for the Extraction of Soluble Proteins from Bacterial Cells with Mild Chaotropic Solutions
Authors: Danilevich V. N. , Petrovskaya L. E. , Grishin E. V. 
Published: May 2008

AbstractThe development of methods for rapid and effective isolation of proteins from Escherichia coli is of considerable interest for biotechnology. The ability of buffer solutions containing low concentrations of detergents and chaotropic agents to extract intracellular proteins of E. coli cells was studied. We have shown that the solutions containing Triton X‐100 or sodium deoxycholate and the mixtures of these detergents with urea are the most effective for this purpose. During the extraction of proteins from bacterial cells under the conditions studied, the release of RNA into solution also occurs, while DNA mostly remains inside the cells. The proposed treatment does not break the bacterial cell walls; proteins probably are supposed to penetrate through the pores of the murein network. In efficiency, our buffer mixtures are comparable to the commercial reagent, CelLytic B, and can be used in different scale purification projects.
Crystalline Proteins as an Alternative to Standard Formulations
Authors: Hekmat D. , Hebel D. , Weuster‐Botz D. 
Published: May 2008

AbstractCrystalline proteins may offer superior properties for drug delivery compared to standard protein formulations such as aqueous solutions or amorphous precipitated lyophilisates. In this study, a new approach using biocompatible, hydrophilic, substituted alkylammonium‐based ionic liquids (ILs) as additives for the advanced crystallization of two exemplary proteins, lysozyme and lipase, was investigated. Sitting‐drop vapor diffusion crystallization experiments revealed that the addition of some of the ILs resulted in less crystal polymorphism and precipitation was consistently avoided, even at larger concentrations of the conventional crystallization agent. The kinetics of lysozyme crystallization were significantly enhanced by a factor of up to 5.5 using ILs with strongly hydrated anions, i.e., formate or glycolate. In contrast, ILs with weakly hydrated anions, i.e., nitrate, led to undesirable spontaneous precipitation. In addition, lipase was crystallized preferentially using an IL with a strongly hydrated anion, i.e. dihydrogenphosphate. Large, sturdy crystals were formed at rates which were enhanced by a factor of up to 4.
A Review of the Thermodynamics of Protein Association to Ligands, Protein Adsorption, and Adsorption Isotherms
Authors: Mollerup J. M. 
Published: May 2008

AbstractThe application of thermodynamic models in the development of chromatographic separation processes is discussed. The paper analyses the thermodynamic principles of protein adsorption. It can be modeled either as a reversible association between the adsorbate and the ligands or as a steady‐state process where the rate of adsorption is equal to the rate of desorption. The analysis includes the competitive Langmuir isotherm and the exponentially modified Langmuir isotherm. If the adsorbate binds to one ligand only, the different approaches become identical. When the adsorbate acts as a ligand, dimerization takes place and will give rise to a sigmoid isotherm. A model that accounts for dimerization is discussed and a sample calculation shows the behavior of this isotherm. Insulin is known to have a concave isotherm at low concentrations. The calculation of the standard Gibbs energy change of adsorption is discussed. Hydrophobic and reversed phase chromatography are useful techniques for measuring solute activity coefficients at infinite dilution.
Purification of Bionanoparticles
Authors: Pedro L. , Soares S. S. , Ferreira G. N. M. 
Published: May 2008

AbstractThe recent demand for nanoparticulate products such as viruses, plasmids, protein nanoparticles, and drug delivery systems have resulted in the requirement for predictable and controllable production processes. Protein nanoparticles are an attractive candidate for gene and molecular therapy due to their relatively easy production and manipulation. These particles combine the advantages of both viral and non‐viral vectors while minimizing the disadvantages. However, their successful application depends on the availability of selective and scalable methodologies for product recovery and purification. Downstream processing of nanoparticles depends on the production process, producer system, culture media and on the structural nature of the assembled nanoparticle, i.e., mainly size, shape and architecture. In this paper, the most common processes currently used for the purification of nanoparticles, are reviewed.
Generalization of multivariate optical computations as a method for improving the speed and precision of spectroscopic analyses
Authors: Boysworth Marc K. , Banerji Soame , Wilson Denise M. , Booksh Karl S. 
Published: May 2008

AbstractMultivariate optical computations (MOCs) offer improved analytical precision and increased speed of analysis via synchronous data collection and numerical computation with scanning spectroscopic systems. The improved precision originates in the redistribution of integration time from spurious channels to informative channels in an optimal manner for increasing the signal‐to‐noise ratio with multivariate analysis under the constraint of constant total analysis time. In this work, MOCs perform the multiplication and addition steps of spectral processing by adjusting the integration parameters of the optical detector or adjusting the scanning profile of the tunable optical filter. Improvement in the precision of analysis is achieved via the implicit optimization of the analytically useful signal‐to‐noise ratio. The speed improvements are realized through simpler data post‐processing, which reduces the computation time required after data collection. Alternatively, the analysis time may be significantly truncated while still seeing an improvement in the precision of analysis, relative to competing methods. Surface plasmon resonance (SPR) spectroscopic sensors and visible reflectance spectroscopic imaging were used as test beds for assessing the performance of MOCs. MOCs were shown to reduce the standard deviation of prediction by 15% compared to digital data collection and analysis with the SPR and up to 45% for the imaging applications. Similarly, a 30% decrease in the total analysis time was realized while still seeing precision improvements. Copyright © 2008 John Wiley & Sons, Ltd.
ChemInform Abstract: Ordered Distribution of I and Cl in the Low‐Temperature Crystal Structure of Mutnovskite, Pb4As2S6ICl: An X‐Ray Single‐Crystal Study.
Authors: Bindi Luca , Garavelli Anna , Pinto Daniela , Pratesi Giovanni , Vurro Filippo 
Published: May 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Magnetic Properties of Mn2V2O7 Single Crystals.
Authors: He Zhangzhen , Ueda Yutaka 
Published: May 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Low‐Temperature Specific Heat Study of Antiferromagnetic Transition in Ternary Rare‐Earth Metal Silicide R5Ir4Si10 (R: Tb, Dy, Ho, Er).
Authors: Tsutsumi Kitomi , Takayanagi Shigeru , Maezawa Kunihiko , Kitazawa Hideaki 
Published: May 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Syntheses, Crystal Structures and Optical Properties of the First Strontium Selenium(IV) and Tellurium(IV) Oxychlorides: Sr3(SeO3)(Se2O5)Cl2 and Sr4(Te3O8)Cl4.
Authors: Jiang Hai‐Long , Mao Jiang‐Gao 
Published: May 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Metal—Oxygen Isopolyhedra Assembled into Fullerene Topologies.
Authors: Forbes Tori Z. , McAlpin J. Gregory , Murphy Rachel , Burns Peter C. 
Published: May 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Hydrothermal Syntheses, Structural, Raman, and Luminescence Studies of Cm[M(CN)2]3×3H2O and Pr[M(CN)2]3×3H2O (M: Ag, Au). Part 2. Hetero‐bimetallic Coordination Polymers Consisting of trans‐Plutonium and Transition Metal Elements.
Authors: Assefa Zerihun , Haire Richard G. , Sykora Richard E. 
Published: May 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.