bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Electrochemical Behaviour of Organonickel Complexes: Mono‐, Di‐ and Trivalent Nickel
Authors: Klein Axel , Kaiser André , Sarkar Biprajit , Wanner Matthias , Fiedler Jan 
Published: January 2007

AbstractThe redox properties of organometallic nickel complexes of the type [(α‐diimine)Ni(Mes)Br], [(α‐diimine)Ni(Mes)2] and the complexes trans‐[(PPh3)2Ni(Mes)Br] and trans‐[(PPh3)2Ni(Fmes)Br] [Mes = mesityl (2,4,6‐trimethylphenyl); Fmes = tris(2,4,6‐trifluoromethyl)phenyl] have been studied in detail by various electrochemical and spectroelectrochemical (UV/Vis/NIR and EPR) methods. Upon electrochemical reduction, the bromido mesityl derivatives undergo cleavage of the bromide ligand. The resulting reactive species and their products from follow‐up reactions are investigated. Electrochemical oxidation leads to formally trivalent nickel species. The metal contribution to the unpaired electron for the formally monovalent and trivalent nickel species can be estimated from EPR spectroscopy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Methanolysis of triacylglycerols by organic basic catalysts
Authors: Peter Siegfried , Weidner Eckhard 
Published: January 2007

AbstractMethanolysis of rapeseed and soybean oil was studied using organic basic catalysts at boiling with reflux. The molar ratio methanol/free fatty acids (FFA) amounted to approx 2.8 : 1. The catalyst (guanidine carbonate) is used at concentrations between 0.5 and 1.3 wt‐% with respect to the oil. During boiling at reflux, guanidine carbonate disintegrates into guanidine and gaseous carbon dioxide. This is a very special reaction; other alcohols such as ethanol, propanol, etc. do not react in this way with guanidine carbonate. Under these conditions, the reaction mixture consists of two phases. The catalyst is mainly dissolved in the methanol phase. The rate of the phase transfer reaction is increased by stirring. With guanidine carbonate as a catalyst, neutralized rapeseed oil yielded, within 45 min and in one step, a product that meets the European Norm for biodiesel. Degummed and dried crude rapeseed oil contains ca. 1 wt‐% FFA, whereas crude degummed and dried soybean oil contains 0.3–0.7 wt‐% FFA. During catalysis with guanidine carbonate, the FFA are transformed into their methyl esters to about 60–70% at low concentrations in the crude oil (approximately up to 1–1.5%). Neutralization of the degummed and dried crude oil proved to be unnecessary in such cases.
Comparison of near‐infrared emission spectroscopy and the Rancimat method for the determination of oxidative stability
Authors: Gonzaga Fabiano B. , Pasquini Celio , Rodrigues Christianne E. C. , Meirelles Antônio J. A. 
Published: January 2007

AbstractThis work presents a comparison between a new method for the determination of the oxidative stability of edible oils at frying temperatures, based on near‐infrared emission spectroscopy (NIRES), and the Rancimat method at 110  °C. In the NIRES‐based method, the induction time (IT) is determined by means of the variation of the emission band at 2900 nm during heating at 160  °C. The comparison between the IT values obtained with the two methods for 12 samples of edible oils shows some correlation for samples of the same type once there is an agreement on the sequence of highest to lowest IT values between the methods, but a poor correlation considering all samples (correlation coefficient of 0.78). This lack of correlation demonstrates that the results obtained with the Rancimat method cannot be used as an indication of the oxidative stability, or the resistance to degradation, of edible oils at frying temperatures. The difference in the heating temperatures used in the two methods leads to 20–36 times higher IT values for the Rancimat method in relation to the NIRES‐based method, but with similar repeatabilities (2.0 and 2.8%, respectively).
Synthesis of Substrates and Biochemical Probes for Study of the Peptidoglycan Biosynthetic Pathway
Authors: Narayan Radha S. , VanNieuwenhze Michael S. 
Published: January 2007

AbstractSeveral widely used antibiotics such as β‐lactams, glycopeptides, and lipoglycopeptides exhibit their activity by interfering with peptidoglycan biosynthesis. Ever‐increasingresistance to these and other agents has placed a renewed emphasis on the need to understand the reactions in this biosynthetic pathway at the molecular level. While efficientaccess to many of the biosynthetic enzymes has been gained, the isolation of their natural substrates has proven difficult. Chemical synthesis has provided valuable tools to circumvent this problem and has allowed convenient access to several key intermediates and analogs thereof. Recent advances in the synthesis of the late‐stage intermediates, including the Park nucleotide, lipid I, lipid II, fragments of the bacterial cell wall, along with other biochemical probes are reviewed. A brief discussion on the use of these substrates in study of this important biosynthetic pathway is also included. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Instrumental activities of daily living in the screening of dementia in population studies: a systematic review and meta‐analysis
Authors: Castilla‐Rilo Juan , López‐Arrieta Jesús , Bermejo‐Pareja Felix , Ruiz Miguel , Sánchez‐Sánchez Fernando , Trincado Rocío 
Published: January 2007

AbstractBackgroundDespite the fact that the current definitions of dementia in the DSM‐IV and ICD‐10 require functional deterioration for the diagnosis of dementia, it is not necessary a formal evaluation of functional capacity.ObjectivesTo examine the efficiency of functional assessment as a method of screening dementia in population studies.MethodsThis systematic review was based on information from MEDLINE, EMBASE, Index Médico Español (IME), and related articles. The studies included are population studies of patients over 65, in which normal and demented (established diagnosis) subjects are compared. In all of them, subjects were evaluated using the instrumental activities of daily living scale (IADL) as the method of screening for dementia.ResultsTwo thousand three hundred and three abstracts and bibliographical references were reviewed. The authors of the selected studies were contacted and asked about other ongoing studies or indexes not included in our review in order to complete a meta‐analysis. Finally, five studies were selected (n = 11.960). A meta‐analysis was performed, with a statistical Q* value of 0.88 (SE 0.26).ConclusionsThe functional assessment of the IADL showed an acceptable efficiency for the screening of dementia in the population studies included in this review, although few studies have verified this efficiency (sensitivity and specificity of the scales used). Further research is necessary in this field to be able to draw definitive conclusions. Copyright © 2007 John Wiley & Sons, Ltd.
Assessing risk for imminent violence in the elderly: the Brøset Violence Checklist
Authors: Almvik Roger , Woods Phil , Rasmussen Kirsten 
Published: January 2007

AbstractObjectiveThe Brøset Violence Checklist (BVC) assesses confusion, irritability, boisterousness, verbal threats, physical threats and attacks on objects as either present or absent. It is hypothesised that an individual displaying two or more of these behaviours is more likely to be violent in the next twenty‐four hour period. This study aims to test the validity of the instrument in geriatric settings and to report on the predictive value of an easy‐to‐use risk assessment instrument.MethodEight thousand eight hundred and thirty‐five BVC observations were completed in two psychogeriatric wards (n = 42 patients) and two special care units for patients with dementia (n = 40 residents). To measure violent incidents the study group was monitored using the Staff Observation Aggression Scale‐Revised (SOAS‐R).ResultsThis study disclosed that patients in geriatric wards and residents in nursing homes who are aggressive have higher BVC scores than the non‐violent subjects indicating that the BVC does predict violent episodes in these settings.ConclusionFrom a clinical perspective, it is most important that a prediction aid has good sensitivity, so that most cases are detected and have a high negative predictive value so that most non‐cases on the measure are indeed non‐cases. Our results indicate that the BVC was able to achieve this goal. Copyright © 2007 John Wiley & Sons, Ltd.
The application of hydrogen peroxide in composite repair
Authors: Papacchini Federica , Monticelli Francesca , Radovic Ivana , Chieffi Nicoletta , Goracci Cecilia , Tay Franklin R. , Polimeni Antonella , Ferrari Marco 
Published: January 2007

AbstractThis study examined the influence of different surface conditioning methods on composite‐to‐composite microtensile bond strength. Thirty two‐year old composite resin discs were randomly divided into three groups according to the different mechanical/chemical surface pretreatment tested: (1) 38% hydrogen peroxide (H2O2)‐treatment; (2) 50‐μm aluminum oxide sandblasting; (3) no treatment. Depending on the intermediate agent applied, two subgroups were created: (A) three‐step adhesive system; (B) prehydrolyzed silane coupling agent + three‐step adhesive system. Microtensile bond strength measurements were performed and the data were statistically analyzed with Kruskall–Wallis Analysis of Variance and Dunn's multiple range test for post hoc comparisons (p < 0.05). Failure mode was evaluated with a scanning electron microscope. Changes in composite surface topography after H2O2 treatment were also investigated. Composite repair strength did not benefit from H2O2 treatment and adhesive application. Preliminary sandblasting significantly improved interfacial bond strength regardless of the intermediate agent applied. No changes in surface texture were produced after H2O2 treatment. An atypical fracture pattern was detected at the interfacial level between H2O2‐treated composite surfaces and the overlying adhesive and composite. H2O2 treatment affected the composite‐to‐composite repair strength: a compromised resin polymerization may occur, resulting in a poor interfacial quality and a weak bond. Sandblasting still remains a reliable technique for composite repair. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Modulated photoactivation methods—Effect on marginal and internal gap formation of restorations using different restorative composites
Authors: Alonso Roberta C. B. , Correr Gisele M. , Cunha Leonardo G. , De Moraes Souto Pantoja Carlos A. , Puppin‐Rontani Regina M. , Sinhoreti Mário A. C. 
Published: January 2007

AbstractThis study evaluated the effect of modulated photoactivation methods on gap formation of restorations using different composites. Methods: Sixty human third molars were selected, sectioned (two fragments), and ground to expose a flat enamel area. A cavity (5 mm long × 2 mm wide × 2 mm deep—outer margins in enamel and inner margins in dentin) was prepared on the central area of flattened surface. Single bond adhesive system was applied according to manufacturer's instructions. The specimens were assigned into 12 groups (n = 10), according to the restorative composite (Filtek Z250, Herculite XRV, and Heliomolar) and the photoactivation method [continuous light (CL); soft‐start (SS); pulse delay (PD); and intermittent light (IL)]. Outer margins were stained using Caries Detector, observed under stereomicroscope, and images were transferred to a computer measurement program. Then, the specimens were sectioned in slices and the internal gaps were assigned using the same method. The length of gaps was expressed as a percentage of total length of the margins. Data (internal adaptation) were submitted to ANOVA and Tukey's test. Results: All restorations showed perfect seal of the enamel outer margins. Modulated photoactivation methods (SS, PD, and IL) showed a significant reduction on internal gap formation when compared with CL, regardless of the composite. Filtek Z250 showed the best internal adaptation, regardless of the photoactivation method. Conclusion: Modulated photoactivation methods decrease the internal gap formation of composite restorations, and should be encouraged on clinical practice. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Tracking the urinary excretion of high molar mass poly(vinyl alcohol)
Authors: Besheer Ahmed , Mäder Karsten , Kaiser Sergej , Kressler Jörg , Weis Christine , Odermatt Erich K. 
Published: January 2007

AbstractThe fate of poly(vinyl alcohol) (PVA) of weight average molar mass of 125,000 g/mol after administration into the peritoneum of rabbits has bean studied by various methods. PVA was spin‐labeled with a nitroxide radical and then detected in urine using electron spin resonance (ESR) spectroscopy. Furthermore, unlabeled polymer was also administered to rabbits, then the urine was collected, dialyzed, precipitated, and the excretion of PVA was confirmed by size exclusion chromatography (SEC), FTIR spectroscopy, and 1H NMR spectroscopy. ESR and SEC results show that, despite its relatively high molar mass, PVA is excreted through the kidneys without significant molar mass changes. Nevertheless, NMR and FTIR spectra show slight differences between the excreted and neat PVA. Possible causes of these discrepancies are discussed. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Improved grid‐based algorithm for Bader charge allocation
Authors: Sanville Edward , Kenny Steven D. , Smith Roger , Henkelman Graeme 
Published: January 2007

AbstractAn improvement to the grid‐based algorithm of Henkelman et al. for the calculation of Bader volumes is suggested, which more accurately calculates atomic properties as predicted by the theory of Atoms in Molecules. The CPU time required by the improved algorithm to perform the Bader analysis scales linearly with the number of interatomic surfaces in the system. The new algorithm corrects systematic deviations from the true Bader surface, calculated by the original method and also does not require explicit representation of the interatomic surfaces, resulting in a more robust method of partitioning charge density among atoms in the system. Applications of the method to some small systems are given and it is further demonstrated how the method can be used to define an energy per atom inab initiocalculations. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Electric field effects on the performance of a candidate multipole molecular switch: A quantum computational study
Authors: Sabzyan Hassan , Farmanzadeh Davood 
Published: January 2007

AbstractStructural and electronic responses of the organic molecule di(4‐nitro‐2‐methylenamine phenyl) diazene a candidate molecular switch, as an active device in a nanoelectronic circuit, to the external electric fields with strengths 5 × 10−4 – 1.8 × 10−2 a.u. included explicitly in the Hamiltonian are studied using B3LYP/6‐31G* method. This study shows that thermodynamic formation functions are not affected significantly by the applied field. Electronic spatial extent show a negligibly small change (<2%) over the studied range of the electric field strength. Calculated electric dipole moments show significant sensitivity to the external electric field, which result consequently in much stronger interactions with the electrodes (poles) of the mother nanoelectronic circuit at higher electric field strengths. Natural bond orbital atomic charges analysis shows different field effects on different atoms depending on their positions with respect to the direction of the field. The applied field increases HOMO, LUMO, and the Fermi level energies; however, decreases the HOMO–LUMO gap (HLG) values. Results of this study show that it is possible to control field‐induced charge redistribution over the molecule by using push–pull effects of different substitution via their connection points to the extended π‐system. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Benign glandular inclusions a rare cause of a false positive sentinel node
Authors: Norton Laura E. , Komenaka Ian K. , Emerson Robert E. , Murphy Colleen , Badve Sunil 
Published: January 2007

AbstractAn 84‐year‐old female underwent a wire‐guided lumpectomy and sentinel lymph node biopsy. Two sentinel nodes were identified and sent for immediate pathological evaluation. One of the nodes was reported as “glandular epithelium consistent with metastatic adenocarcinoma.” Permanent sections of the sentinel node initially considered positive revealed glandular structures primarily within the fibrous capsule of the involved lymph node. These glands were lined by tall columnar epithelial cells, which had cilia on the luminal surface and did not show significant cytologic atypia. The limitations of intra‐operative evaluation of sentinel nodes make differentiation of uncommon pathology difficult. A conservative approach should be taken with these lesions as permanent sections will often elucidate the diagnosis. J. Surg. Oncol. 2007;95:593–596. © 2007 Wiley‐Liss, Inc.
Nicotinic acid receptor subtypes and their ligands
Authors: Soudijn Willem , van Wijngaarden Ineke , IJzerman Adriaan P. 
Published: January 2007

AbstractHalf a century ago, nicotinic acid (niacin) was introduced into the clinic as the first orally available drug to treat high cholesterol levels and to improve the balance between (V)low density lipoproteins (LDL) and high density lipoproteins (HDL). Remarkably, its putative mechanism of action has only been recently elucidated, particularly because of the cloning of a G protein‐coupled receptor (HM74A or GPR109A). This receptor responds to both nicotinic acid and the ketone body β‐hydroxybutyrate, the latter thought to be the more probable endogenous ligand for HM74A. In this review, we will discuss the pharmacology and medicinal chemistry of this receptor subtype and a related one (HM74 or GPR109B). Although still in its infancy, the ligand repertoire is developing, and a number of compound classes have now been described, among which are both full and partial agonists. Antagonists, however, are still lacking, thus compromising thorough pharmacological studies. Mutagenesis experiments have provided clues regarding the ligand binding site; in particular, an arginine residue in transmembrane domain 3 of the receptor seems to recognize the acidic moiety present in nicotinic acid and related substances. HM74A has also been linked to one of the major side effects of nicotinic acid, that is, flushing, since this receptor subtype also occurs in skin immune cells. It is not known yet whether HM74 is also present on these cells. Since nicotinic acid is one of the few available medicines that raise HDL (“good cholesterol”) levels, HM74A and HM74 appear promising targets for future pharmacotherapy. © 2007 Wiley Periodicals, Inc. Med Res Rev, 27, No. 3, 417–433, 2007
Contribution of central and peripheral factors to residual fatigue in Guillain–Barré syndrome
Authors: Garssen Marcel P.J. , Schillings Maartje L. , Van Doorn Pieter A. , Van Engelen Baziel G.M. , Zwarts Machiel J. 
Published: January 2007

AbstractMany patients with Guillain–Barré syndrome (GBS) suffer from severe residual fatigue that has an uncertain basis. We determined the relative contribution of peripheral and central factors during a 2‐min fatiguing sustained maximal voluntary contraction (MVC) in 10 neurologically well‐recovered GBS patients and 12 age‐ and sex‐matched healthy controls. Physiological fatigue was defined as the decline of voluntary force during an MVC of the biceps brachii. Relative amounts of peripheral fatigue and central activation failure were determined combining voluntary force and force responses to electrical stimulation. Surface electromyography was used to determine muscle‐fiber conduction velocity. During the first minute of sustained MVC, peripheral fatigue developed more slowly in patients than in controls. Central fatigue only occurred in patients. The muscle‐fiber conduction velocity was higher in patients. The initial MVC, decrease of MVC, initial force response, and initial central activation failure did not significantly differ between the groups. Although peripheral mechanisms cannot be excluded in the pathogenesis of residual fatigue after GBS, these results suggest that central changes are involved. This study thus provides further insight into the factors contributing to residual fatigue in GBS patients. Muscle Nerve, 2007
Antecedents of political market orientation in Britain and Sweden: analysis and future research propositions
Authors: Strömbäck Jesper 
Published: January 2007

AbstractDuring the last 20 years, political marketing has become a widespread phenomenon around the world. However, most of the research concerning political marketing has been carried out in countries such as the United States and Britain. Thus, in order to understand the antecedents of political marketing, as well as its effectiveness as an electoral strategy, there is a need for comparative research including countries that differ significantly from the U.S. and Britain.One such country is Sweden. Thus, the purpose of this article is to compare and analyze Sweden and Britain with regard to two analytical research questions: (1) What differences are there between Britain and Sweden that might be relevant in understanding why parties choose to be sales‐ or market‐oriented? (2) What are the implications with regards to differencesbetweencountries and between parties within countries that might help to explain why some parties in some countries are more likely than others to be market‐oriented?Copyright © 2007 John Wiley & Sons, Ltd.
Interest group strategies in multi‐level Europe
Authors: Constantelos John 
Published: January 2007

AbstractThis article analyzes the political responses of French and Italian business associations to Economic and Monetary Union (EMU) in the EU. I propose and test the empirical relevance of a multi‐level lobbying model for multi‐tiered systems, a model assumed by, but never systematically examined in, the pluralism literature. Data for this ten‐sector cross‐national panel study come from personal interviews with the presidents of French and Italian business associations. The interviews were held at the beginning and the end of the euro implementation process. The research shows that organized groups routinely overstep their territorial jurisdictions to lobby across multiple levels of government in multi‐level Europe. The degree of state political decentralization is a statistically significant variable in explaining the choice of lobbying target. This ‘crucial comparative case study’ finds that, in adjusting to deeper economic integration, regional associations in France focus their energy on the central government, while Italian groups favour the regional government.Copyright © 2007 John Wiley & Sons, Ltd.
Flow Structure in a Technical Scale Reactor with an Internal Reboiler
Authors: Biwański Tomasz , Baars Albert , Kowalczyk Wojciech , Delgado Antonio 
Published: January 2007

AbstractIn this contribution, results of experimental flow investigations in a technical scale cylindrical reactor with centrally located internal reboiler are presented. The fluid motion in the kettle is induced by natural circulation. Two different geometrical configurations are considered. First, the liquid level is set below the evaporator's outlet. Thus, only the liquid phase penetrates the liquid surface. The second configuration characterizes the a direct injection of the two phase mixture into bulk liquid. In both cases the liquid leaves the evaporator radially and horizontally towards the cylindrical wall. Gathered results reveal the presence of the big, toroidal vortex in the kettle annulus. Independently on the boundary conditions, self similarity of velocity profiles in the near wall region is observed. In contrast, investigations of the momentum transfer between the jet and the bulk liquid reveal strong dependency on the geometrical configuration of the setup. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)