bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pharmacists' attitudes towards the reporting of suspected adverse drug reactions in Norway
Authors: Granas Anne G. , Buajordet Marit , Stenberg‐Nilsen Hanne , Harg Pernille , Horn Anne M. 
Published: September 2006

AbstractBackgroundIn Scandinavian countries, pharmacists have not reported adverse drug reactions (ADRs), either due to legislative restrictions or because of lack of tradition. From 1 January 2005, Norwegian pharmacists have been encouraged by the Norwegian Medicines Agency to take a larger role in the reporting of ADRs.ObjectiveTo explore pharmacists' attitudes towards pharmacovigilance and their experiences with ADR reporting, to evaluate the effect of an educational programme and to compare these findings to the attitudes in a control group.MethodsFrom September 2004, pharmacies in two of Norway's five health regions were invited to attend a 3‐month ADR reporting study, and 39 pharmacies were recruited. One pharmacist from each pharmacy participated in a 1 day pre‐study educational programme and a 1 day post‐study evaluation meeting. Pharmacists involved in the study answered a questionnaire (A) regarding their attitudes to ADR reporting (active group). A control group answered the same questionnaire. One reminder was sent. The active group evaluated the study by answering questionnaire A once more and an evaluation questionnaire (B). Qualitative aspects of ADR reporting were discussed with the active group post‐study.ResultsThe response rate for questionnaire A was 97% (n = 158) in the active group, 74% (n = 184) in the control group and the response rate for questionnaire A and B post‐study was 68% (n = 105) in the active group. Pharmacists in the active group had more positive attitudes to ADR reporting after taking part in the study than the control group (p < 0.001). Lack of time, confidence and knowledge of reporting rules could potentially prevent them from reporting ADRs.ConclusionsThe pharmacists had positive attitudes towards pharmacovigilance, but very little experience with reporting. The educational programme clarified their role and increased their knowledge about the reporting requirements. Copyright © 2006 John Wiley & Sons, Ltd.
The impact of over‐the‐counter simvastatin on the number of statin prescriptions in the United Kingdom: a view from the General Practice Research Database
Authors: Filion Kristian B. , Chris Delaney J. A. , Brophy James M. , Ernst Pierre , Suissa Samy 
Published: September 2006

AbstractPurposeThe United Kingdom (UK) government changed the prescription policy of statins, making low‐dose simvastatin (10 mg) available as an over‐the‐counter (OTC) drug in August 2004. We assessed the impact of this policy change on statin prescribing.MethodsWe examined all statin prescriptions in the General Practice Research Database (GPRD), a well‐validated database of approximately 3.5 million patients, from the first quarter of 2001 to the second quarter of 2005.ResultsFrom 2001, the number of statin prescriptions written for GPRD patients was increasing by approximately 437 prescriptions per 100,000 people per quarter until the time of the policy change. Over the four quarters post‐policy implementation, however, this trend changed abruptly (p < 0.0001) with a decrease of 281 prescriptions per 100,000 people per quarter. This decrease was not restricted to prescriptions of 10 mg statins but was also observed for statin prescriptions of ≥20 mg. Several other cardiovascular medications displayed a similar trend as that observed in the number of statin prescriptions. This trend was not observed among non‐cardiovascular control medications.ConclusionsOur study suggests that the policy allowing the OTC sale of 10 mg simvastatin has had a significant impact on statin prescriptions by general practitioners. However, this new policy may also be leading to less aggressive statin therapy. An alternative explanation for the observed decrease in statin prescriptions may be related to the unknown factors responsible for the overall decrease observed with other cardiovascular prescription drugs. Copyright © 2006 John Wiley & Sons, Ltd.
Thickness‐dependent reduction of the glass‐transition temperature in thin polymer films with a free surface
Authors: Peter Simone , Meyer Hendrik , Baschnagel Jörg 
Published: September 2006

AbstractWe present results of molecular dynamics simulations for free‐standing and supported thin films of a nonentangled polymer melt using a coarse‐grained (bead‐spring) model. Our discussion is mainly concerned with the equilibrium properties of the films above the critical temperature (Tc) of mode‐coupling theory, although we also determine the glass‐transition temperature (Tg) by measurements of the film thickness h upon cooling. We explore the influence of confinement on the structure and dynamics of the polymer films. We find that the dynamics in the films is accelerated compared to the bulk, that this enhanced mobility originates from the surfaces, and that the effect is larger at the free than at the supported surface. Thus, the films have lower Tc values relative to the bulk. Tc depends on film thickness h; this dependence can be well parametrized by Tc(h) = T/(1 + h0/h), a function proposed by experiments on supported polystyrene films. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2951–2967, 2006
Polymer–nanoparticle interfacial interactions in polymer nanocomposites: Confinement effects on glass transition temperature and suppression of physical aging
Authors: Rittigstein Perla , Torkelson John M. 
Published: September 2006

AbstractThe effects of confinement on glass transition temperature (Tg) and physical aging are measured in polystyrene (PS), poly(methyl methacrylate) (PMMA), and poly(2‐vinyl pyridine) (P2VP) nanocomposites containing 10‐ to 15‐nm‐diameter silica nanospheres or 47‐nm‐diameter alumina nanospheres. Nanocomposites are made by spin coating films from sonicated solutions of polymer, nanofiller, and dye. The Tgs and physical aging rates are measured by fluorescence of trace levels of dye in the films. At 0.1–10 vol % nanofiller, Tg values can be enhanced or depressed relative to neat, bulk Tg (Tg,bulk) or invariant with nanofiller content. For alumina nanocomposites, Tg increases relative to Tg,bulk by as much as 16 K in P2VP, decreases by as much as 5 K in PMMA, and is invariant in PS. By analogy with thin polymer films, these results are explained by wetted P2VP–nanofiller interfaces with attractive interactions, nonwetted PMMA–nanofiller interfaces (free space at the interface), and wetted PS–nanofiller interfaces lacking attractive interactions, respectively. The presence of wetted or nonwetted interfaces is controlled by choice of solvent. For example, 0.1–0.6 vol % silica/PMMA nanocomposites exhibit Tg enhancements as large as 5 K or Tg reductions as large as 17 K relative to Tg,bulk when films are made from methyl ethyl ketone or acetic acid solutions, respectively. A factor of 17 reduction of physical aging rate relative to that of neat, bulk P2VP is demonstrated in a 4 vol % alumina/P2VP nanocomposite. This suggests that a strategy for achieving nonequilibrium, glassy polymeric systems that are stable or nearly stable to physical aging is to incorporate well‐dispersed nanoparticles possessing attractive interfacial interactions with the polymer. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2935–2943, 2006
Controlling the thermomechanical properties of polymer nanocomposites by tailoring the polymer–particle interface
Authors: Bansal Amitabh , Yang Hoichang , Li Chunzhao , Benicewicz Brian C. , Kumar Sanat K. , Schadler Linda S. 
Published: September 2006

AbstractWe show that the thermomechanical properties of polymer nanocomposites are critically affected by polymer‐particle wetting behavior. Silica nanoparticles grafted with dense polystyrene brushes of degree of polymerization 1050 are blended with polystyrene melts to form nanocomposites. It was found that low molecular weight (MW) polystyrene melts with lengths <880 wet these particles. Concurrently, the glass transition temperature (Tg) of the nanocomposite increases. At higher MW, the matrix does not wet the particles and the Tg decreases. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2944–2950, 2006
Bioactivity of extracts and isolated compounds from Vitex polygama (Verbenaceae) and Siphoneugena densiflora (Myrtaceae) against Spodoptera frugiperda (Lepidoptera: Noctuidae)
Authors: Gallo Margareth BC , Rocha Waldireny C , da Cunha Uemerson S , Diogo Fernanda A , da Silva Fernando C , Vieira Paulo C , Vendramim José D , Fernandes João B , da Silva M Fátima das GF , Batista‐Pereira Luciane G 
Published: September 2006

AbstractThe effects of crude extracts, fractions and isolated compounds from Vitex polygama Cham. and Siphoneugena densiflora Berg were evaluated on the development of Spodoptera frugiperda JE Smith, a destructive insect pest of corn and several other crops. The extracts and fractions were incorporated into an artificial diet at 1 mg g−1 and offered to the insect during its larval stage. Length and viability of larval and pupal stages as well as pupal weight were assessed. Isolated compounds were tested through superficial contamination of the diet at 0.1 mg g−1. Weight and viability of ten‐day‐old larvae were determined. Methanolic and hydroalcoholic S. densiflora extracts caused 100% larval mortality, while leaf and fruit hydroalcoholic extracts from V. polygama were the most active. Among the isolated compounds, flavonoids presented the best insecticidal results, and tannins the best larval growth inhibition. Copyright © 2006 Society of Chemical Industry
Activities of mixtures of soil‐applied herbicides with different molecular targets
Authors: Kaushik Shalini , Inderjit  , Streibig Jens Carl , Cedergreen Nina 
Published: September 2006

AbstractThe joint action of soil‐applied herbicide mixtures with similar or different modes of action has been assessed by using the additive dose model (ADM). The herbicides chlorsulfuron, metsulfuron‐methyl, pendimethalin and pretilachlor, applied either singly or in binary mixtures, were used on rice (Oryza sativa L.). The growth (shoot) response curves were described by a logistic dose–response model. The ED50 values and their corresponding standard errors obtained from the response curves were used to test statistically if the shape of the isoboles differed from the reference model (ADM). Results showed that mixtures of herbicides with similar molecular targets, i.e. chlorsulfuron and metsulfuron (acetolactate synthase (ALS) inhibitors), and with different molecular targets, i.e. pendimethalin (microtubule assembly inhibitor) and pretilachlor (very long chain fatty acids (VLCFAs) inhibitor), followed the ADM. Mixing herbicides with different molecular targets gave different results depending on whether pretilachlor or pendimethalin was involved. In general, mixtures of pretilachlor and sulfonylureas showed synergistic interactions, whereas mixtures of pendimethalin and sulfonylureas exhibited either antagonistic or additive activities. Hence, there is a large potential for both increasing the specificity of herbicides by using mixtures and lowering the total dose for weed control, while at the same time delaying the development of herbicide resistance by using mixtures with different molecular targets. Copyright © 2006 Society of Chemical Industry
Development of electronic nose method for evaluation of HDPE flavour characteristics, correlated with organoleptic testing
Authors: Das Rajarshi , Selke Susan , Harte Janice 
Published: September 2006

AbstractA method for analysing food‐grade high‐density polyethylene (HDPE) resins was developed using the electronic nose (E‐nose) system. Eight different HDPE resin grades were analysed using the E‐nose. The E‐nose system with principal component analysis was found to be capable of discriminating between the resin grades. The resin samples were soaked in ultra‐pure water at 40 ±2°C for 1 week. Water samples stored in contact with the resins were organoleptically evaluated at different concentrations by untrained discrimination sensory panels and the resins were ranked based on the degree of off‐flavour perceived. The E‐nose was used to correlate the sensory data and the sensor responses for the various resin grades, using multivariate statistical techniques. A good correlation was obtained between the E‐nose sensor responses and the human sensory analysis data, when the resins were analysed using standardized experimental run conditions. The method is capable of predicting the quality of an unknown food‐grade HDPE resin sample, in terms of its possibility of producing an off‐flavour in drinking water, which could be a result of migration of low molecular weight compounds from the polymer. Copyright © 2006 John Wiley & Sons, Ltd.
Electron transport in Nano‐Gold–Silicon interfaces
Authors: Yan Liuming , Seminario Jorge M. 
Published: September 2006

AbstractThe electron transport characteristics of gold–silicon interfaces are studied using a combined ab initio approach of the Green's function for electron transfer and quantum density functional theory (DFT) for finite and extended systems. The Kohn–Sham Hamiltonian of an extended cluster or molecule and the density of states (DOS) of bulk Si and Au are used to construct the interface Hamiltonian to obtain the DOS, electron transmission, and current–voltage characteristics of the interface. Diode behavior is observed with electron conduction when the gold side is positively biased with a threshold of 0.8 V. The presence of molecules trapped at the interface and the geometry of the metal atoms strongly affect the conductance, implying difficult or even impossible theory–experiment validations. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Experimental and theoretical IR, Raman, NMR spectra of 2‐, 3‐, and 4‐nitrobenzoic acids
Authors: Samsonowicz M. , Świsłocka R. , Regulska E. , Lewandowski W. 
Published: September 2006

AbstractThe influence of the position of nitro group toward the carboxylic group on the vibration structure of the molecule was estimated. Optimized geometrical structures were calculated (HF, B3PW91, B3LYP). Experimental and theoretical FT‐IR, FT‐Raman, and nuclear magnetic resonance (NMR) spectra of the title compounds were recorded and analyzed. The most important vibrational bands of nitro and carboxyl groups and the benzene ring were assigned. Wavenumbers and intensities for the three acids studied were compared and discussed. Data of chemical shifts in 1H and 13C NMR spectra of 2‐, 3‐, and 4‐nitrobenzoic acids were analyzed in comparison with benzoic acid molecule. The calculated parameters are compared with experimental characteristics of these molecules. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Nonrigid group theory for 1,3,5‐trimethylbenzene
Authors: Darafsheh Mohammad Reza , Darafsheh Arash , Ashrafi Ali Reza 
Published: September 2006

AbstractUsing nonrigid group theory, the full nonrigid (f‐NRG) group of 1,3,5‐trimethylbenzene (TMB) is shown to be isomorphic to the group S3[C3] = C3
S3 of order 162, where denotes the wreath product of groups, and C3 is the cyclic group of order three and S3 is the symmetric group of order six on three letters. This group has 22 conjugacy classes and irreducible representations. The character table of the full nonrigid TMB is then derived for the first time. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Electronic structure calculations on multiply charged anions containing MS bonds (M = Cr, Mo, W) and their heterobimetallic cluster complexes
Authors: Gili Pedro , Tsipis Athanassios C. 
Published: September 2006

AbstractMolecular and electronic structures of multiply charged mononuclear [CrS4]2−/3−, [MoOxS4−x]2−/3− (x = 0–4) and [WS4]2−/3− anionic species, and their heterobimetallic dinuclear and trinuclear clusters formulated as [MoOS3(CuCl)]2−, [WOS3(CuCl)]2−, [MoS4{Cu(CN)}]2−, [(CN)Cu(μ‐CrS4)Cu(CN)]2−, [(CN)Cu(μ‐MoS4)Cu(CN)]2−, [ClCu(μ‐MoS4)CuCl]2−, [Cl2Fe(μ‐MoS4)CuCl2]2−, and [(CN)Cu(μ‐WS4)Cu(CN)]2− have been investigated using electronic structure calculation (HF, MP4SDQ and DFT) methods. For the discrete mononuclear anions HF/lanl2dz(M)∪6‐31+G*(S,O) method provided the best description of their molecular structures, while for the heterobimetallic dinuclear and trinuclear clusters the B3LYP/lanl2dz(M)∪6‐31+G* method gave equilibrium geometries closely resembling the experimental ones. Electronic and spectroscopic (IR, UV‐Vis) properties of the thiometalates are discussed in relation to their structures, while the bonding mechanism was analyzed in the framework of the natural bond orbital (NBO) approach. The nature of the highest occupied molecular orbitals (HOMOs) of all thiometalates indicated their ability to act as ligands coordinated with metal centers and forming clusters of higher nuclearity. The lowest‐lying vertical one‐electron detachment processes from the ground state of the [CrS4]2/3−, [MoOxS4−x]2/3− (x = 0–4) and [WS4]2/3− anions have been calculated using the outer valence Green's function (OVGF) method. Interestingly, in the heterobimetallic dinuclear and trinuclear clusters intemetallic M…M′ interactions exist corresponding to d10 → d0 dative bonding. Finally, the complete energetic and geometric profile of the successive acid‐catalyzed formation reactions:

equation image

and the reverse hydrolysis reactions have been delineated and details of the mechanism have been furnished. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Symmetric ring puckering potential in thietane‐1,1‐dioxide compared with experiment and analysis of theoretical vibrational spectra
Authors: Förner Wolfgang , Badawi Hassan M. 
Published: September 2006

AbstractWe studied the ring puckering potential in thietane‐1,1‐dioxide with different methods, using a suitable basis set, 6‐311+G**. We obtained a barrier to ring puckering of 153 cal/mol with the DFT/B3LYP (Becke3 exchange–Lee, Yang, Parr correlation functional) method, ∼60% too small compared with experiment. However, using MP2, MP3, and MP4 we obtained values around 200% too large. The MP series turned out to converge far too slowly to the experimental barrier value, showing no sign of convergence even at MP4, while higher orders are out of our reach for such a system. Obviously, of all methods used, DFT worked best despite some shortcomings. The barrier corresponds to 77 K; thus, there should be rapid interconversion over the barrier at room temperature, a phenomenon actually observed at room temperature, the measured barrier corresponding to 201 K. Thus, we decided to use the DFT/6‐311+G** calculations to predict reasonable vibrational spectra and assignments of the lines found. The ring puckering mode is found at 80 cm−1 in DFT in good agreement with the experimental value of 78.3 cm−1 for this vibration. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Generalized electronic diabatic approach to structural similarity and the Hammond postulate
Authors: Arteca Gustavo A. , Tapia O. 
Published: September 2006

AbstractWe revisit the notion of structural similarity along a reaction path within the context of a generalized electronic diabatic (GED) molecular model. In this approach, a reaction involving two closed‐shell stable species is described as the evolution of a quantum state that superimposes at least three diabatic electronic species (reactant, product, and an open‐shell transition state) coupled by an external electromagnetic field. Reactant and product amplitudes in this general state are also modulated by changing the geometry of a system of classical positive charges interacting with the electrons. By mapping these amplitudes over nuclear configurational space, we can follow the total quantum state along a reaction coordinate and establish its similarity to each of the diabatic species. As a result, chemical processes, and useful notions such as those of energy barriers and the Hammond postulate, emerge as consequence of Franck–Condon‐like transitions between quantum states. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Comparative study of electrostatic solvent response by RISM and PCM methods
Authors: Chiodo S. , Chuev G. N. , Erofeeva S. E. , Fedorov M. V. , Russo N. , Sicilia E. 
Published: September 2006

AbstractThe solvent response on the solute is calculated by the reference interaction site model (RISM) and by the polarizable continuum model (PCM) methods. The linearized RISM technique is developed to treat free energies of atomic and polyatomic ions in water. An empirical repulsive bridge is used for the RISM calculations. The solvent electrostatic potential is approximated by a linear dependence on the solute atomic charges. For a series of monovalent polyatomic cations and anions, the method provides free energies deviating by few percent from the experimental data. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Development of a liquid chromatography/electrospray selected reaction monitoring method for the determination of organoarsenic species in marine and freshwater samples
Authors: Schaeffer Richard , Fodor Peter , Soeroes Csilla 
Published: September 2006

AbstractCation‐ and anion‐exchange high‐performance liquid chromatography/electrospray selected reaction monitoring (HPLC/ES‐SRM) methods were developed for the determination of 15 organoarsenic compounds in marine and freshwater samples. The results demonstrate that the developed HPLC/ES‐SRM methods are powerful approaches for the identification of organoarsenic species in crude sample extracts. The detection limits, linearity as well as reproducibility for most of the species are comparable or even better than those measured by the HPLC/inductively coupled plasma mass spectrometry (ICPMS) technique. The qualitative analysis of the extracts shows that the developed methods allow for the identification of arsenicals which were not detectable by ICPMS.It was also demonstrated that the signal suppression caused by matrix effects means a significant limitation in the quantification of arsenicals by ES‐SRM detection. This drawback is manifested especially in the case of the slightly retained species. The three sample‐cleanup chromatographic methods including off‐line size‐exclusion, on‐line reversed‐phase and on‐line oppositely charged ion‐exchange approaches proved to be ineffective for separation of the signal‐suppressive matrix from the analytes. The standard addition calibration seems to be a suitable solution for such problems. Copyright © 2006 John Wiley & Sons, Ltd.
Reduction of nitriles to amines in positive ion electrospray ionization mass spectrometry
Authors: Gu Zhe‐ming , Ma Jiyuan , Zhao Xian‐guo , Wu Jinn , Zhang Donglu 
Published: September 2006

AbstractSome compounds readily form [M+46]+ adduct ions during positive ion electrospray ionization mass spectrometry ((+)ESI‐MS) analysis. These [M+46]+ ions were characterized as [M+CH3CH2NH2+H]+ by accurate mass determination. Ethylamine involved in the adduct was proposed to be the reduction product of acetonitrile and this was confirmed using deuterated acetonitrile. Other nitrile‐containing compounds tested, including isobutyronitrile and benzonitrile, also formed the adduct ions of the respective amine forms under (+)ESI‐MS conditions. Hydrogen/deuterium exchange experiments demonstrated that the reductive hydrogen originated from water. Reduction of nitriles (R‐CN) to their respective amines (R‐CH2NH2) under (+)ESI‐MS conditions expands the ability to identify nitrile‐containing chemical unknowns. Copyright © 2006 John Wiley & Sons, Ltd.