bluuebunny/crossref_metadata_2025_split huggingface dataset:
PCM study of the solvent and substituent effects on bond dissociation energies of the CNO bond
Authors: Li Xiao‐Hong , Tang Zheng‐Xin , Yang Xiang‐Dong 
Published: January 2009

AbstractQuantum chemical calculations are used to estimate the equilibrium CNO bond dissociation energies (BDEs) for eight XNO molecule (X = CCl3, C6F5, CH3, CH3CH2, iC3H7, tC4H9, CH2CHCH2, and C6H5CH2). These compounds are studied by employing the hybrid density functional theory (B3LYP, B3PW91, B3P86) methods together with 6‐31G** and 6‐311G** basis sets and the complete basis set (CBS‐QB3) method. The obtained results are compared with the available experimental results. It is demonstrated that B3P86/6‐31G** and CBS‐QB3 methods are accurate for computing the reliable BDEs for the XNO molecule. Considering the inevitably computational cost of CBS‐QB3 method and the reliability of the B3P86 calculations, B3P86 method with 6‐31G** basis set may be more suitable to calculate the BDEs of the CNO bond. The solvent effects on the BDEs of the CNO bond are analyzed and it is shown that the CNO BDEs in a vacuum computed by using B3PW91/6‐311G** method are the closest to the computed values in acetontrile and the average solvent effect is 1.48 kcal/mol. Subsequently, the substituent effects of the BDEs of the CNO bond are further analyzed and it is found that electron denoting group stabilizes the radical and as a result BDE decreases; whereas electron withdrawing group stabilizes the group state of the molecule and thus increases the BDE from the parent molecule. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Theoretical investigation of the adsorption of oxygen on small bimetallic LimCun (m, n ≤ 4) clusters
Authors: Padilla‐Campos Luis 
Published: January 2009

AbstractA theoretical study of the adsorption of molecular oxygen on small bimetallic LimCun (m, n ≤ 4) clusters was carried out using density functional methods, and it was compared with the adsorption of O2 on copper (Cun, n ≤ 8) clusters. The study of O2‐LimCun system is important to understand the promotion effects of the alkali atoms on the copper surface participating in the catalytic processes. Adsorption energies ranging from 7.9 to 51 kcal/mol were found, which represented values over 30% to those calculated for the adsorption of O2 on copper clusters in a previous study. Thus, the reactivity of molecular oxygen on bimetallic clusters is more favorable with high tendency being in favor of the dissociation of the O2 molecule. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Pulsed radiofrequency glow discharge time‐of‐flight mass spectrometry for molecular depth profiling of polymer‐based films
Authors: Tuccitto Nunzio , Lobo Lara , Tempez Agnès , Delfanti Ivan , Chapon Patrick , Canulescu Stela , Bordel Nerea , Michler Johann , Licciardello Antonino 
Published: January 2009

AbstractWe demonstrate the potential of an innovative technique, pulsed radiofrequency glow discharge time‐of‐flight mass spectrometry, for the molecular depth profiling of polymer materials. The technique benefits from the presence, in the afterglow of the pulsed glow discharge, of fragment ions that can be related to the structures of the polymers under study. Thin films of different polymers (PMMA, PET, PAMS, PS) were successfully profiled with retention of molecular information along the profile. Multilayered structures of the above polymers were also profiled, and it was possible to discriminate among layers having similar elemental composition but different polymer structure. Copyright © 2009 John Wiley & Sons, Ltd.
Fragmentation pathways of some benzothiophene radical cations formed by atmospheric pressure chemical ionisation
Authors: Herrera Lisandra Cubero , Ramaley Louis , Grossert J. Stuart 
Published: January 2009

AbstractPolycyclic aromatic sulfur‐containing compounds (PASHs) are commonly found in fossil fuels and are of considerable importance in environmental studies. This work presents detailed studies on the fragmentation patterns of radical cations formed from four representative PASHs, benzo[b]thiophene, dibenzothiophene, 4‐methyldibenzothiophene and 4,6‐dimethyldibenzothiophene, using tandem atmospheric pressure chemical ionization mass spectrometry (APCI‐MS/MS). Understanding these fragmentation patterns can be a useful aid in the analysis of PASHs employing APCI or electron ionization (EI‐MS/MS), either alone or in conjunction with liquid or gas chromatography. Copyright © 2009 John Wiley & Sons, Ltd.
Skeleton‐based active catheter navigation
Authors: Fu Yili , Liu Hao , Wang Shuguo , Deng Wei , Li Xianling , Liang Zhaoguang 
Published: January 2009

AbstractBackgroundThe emergence of the active catheter has prompted the development of catheterization in minimally invasive surgery. However, it is still operated using only the physician's vision; information supplied by the guiding image and tracking sensors has not been fully utilized.MethodsIn order to supply the active catheter with more useful information for automatic navigation, we extract the skeleton of blood vessels by means of an improved distance transform method, and then present the crucial geometric information determining navigation. With the help of tracking sensors' position and pose information, two operations, advancement in the proximal end and direction selection in the distal end, are alternately implemented to insert the active catheter into a target blood vessel.ResultsThe skeleton of the aortic arch reconstructed from slice images is extracted fast and automatically. A navigation path is generated on the skeleton by manually selecting the start and target points, and smoothed with the cubic cardinal spline curve. Crucial geometric information determining navigation is presented, as well as requirements for the catheter entering the target blood vessel. Using a shape memory alloy active catheter integrated with magnetic sensors, an experiment is carried out in a vascular model, in which the catheter is successfully inserted from the ascending aorta, via the aortic arch, into the brachiocephalic trunk.ConclusionsThe navigation strategy proposed in this paper is feasible and has the advantage of increasing the automation of catheterization, enhancing the manoeuvrability of the active catheter and providing the guiding image with desirable interactivity. Copyright © 2009 John Wiley & Sons, Ltd.
Development of a piezo‐actuated micro‐teleoperation system for cell manipulation
Authors: Zareinejad M. , Rezaei S. M. , Abdullah A. , Shiry Ghidary S. 
Published: January 2009

AbstractBackgroundIntracytoplasmic sperm injection (ICSI) requires long training and has low success rates, primarily due to poor control over the injection force. Making force feedback available to the operator will improve the success rate of the injection task. A macro–micro‐teleoperation system bridges the gap between the task performed at the micro‐level and the macroscopic movements of the operator. The teleoperation slave manipulator should accurately position a needle to precisely penetrate a cell membrane. Piezoelectric actuators are widely used in micromanipulation applications; however, hysteresis non‐linearity limits the accuracy of these actuators.MethodThis paper presents a novel approach for utilizing a piezoelectric nano‐stage as slave manipulator of a teleoperation system. The Prandtl–Ishlinskii (PI) model is used to model actuator hysteresis in a feedforward scheme to cancel out this non‐linearity. To deal with the influence of parametric uncertainties, unmodelled dynamics and PI identification error, a perturbation term is added to the slave model and applies a sliding mode‐based impedance control with perturbation estimation.ResultsThe stability of entire system is guaranteed by Llewellyn's absolute stability criterion. The performance of the proposed controller was investigated through experiments for cell membrane penetration.ConclusionThe experimental results verified the accurate position tracking in free motion and simultaneous position and force tracking in contact with a low stiffness environment. Copyright © 2009 John Wiley & Sons, Ltd.
Imaging organic and mineral phases in a biomineral using novel contrast techniques
Authors: Stockdale E. J. , Shaw J. A. , Macey D. J. , Clode P. L. 
Published: January 2009

AbstractChitons are marine molluscs that mineralize their teeth by the process of matrix‐mediated biomineralization. The teeth develop in a continuous manner forming hard minerals, including magnetite, making analysis of the matrix within these mineralized regions difficult. This article describes the use of charge contrast imaging techniques, rarely applied to biological samples, to simultaneously image the organic and mineral phases within the teeth of these animals. Resulting evidence demonstrates the power of this technique in delivering architectural information concerning both the matrix and mineral phases, without the need for removal of the hard mineralized material. SCANNING 31: 11–18, 2009. © 2009 Wiley Periodicals, Inc.
Magnetosensory function in rats: Localization using positron emission tomography
Authors: Frilot Clifton , Carrubba Simona , Marino Andrew A. 
Published: January 2009

AbstractThe aim of this study was to show that low‐strength electromagnetic fields (EMFs) produced evoked potentials in rats and to localize the activated region in the brain. In response to a 2.5‐G, 60‐Hz stimulus, onset‐ and offset‐evoked potentials were detected (P < 0.05 in each of the 10 animals studied); the evoked potentials had the same magnitude, latency, and nonlinear relationship to the field seen in previous studies on rabbits and human subjects. The neuroanatomical region of activation associated with the electrophysiological effect was identified by positron emission tomography using fluorodeoxyglucose. Paired emission scans (the same animal with and without field treatment) from 10 additional rats were differenced and averaged to produce a t‐statistic image using the pooled variance; the t value of each voxel was compared with a calculated critical t value to identify the activated voxels (P < 0.05). A brain volume of 13 mm3 (15 voxels) located in the posterior, central cerebellum was found to have been activated by exposure to the field. Taken together, the results indicated that magnetosensory evoked potentials in the rats were associated with increased glucose utilization in the cerebellum, thereby supporting earlier evidence that EMF transduction occurred in the brain. Synapse 63:421–428, 2009. © 2009 Wiley‐Liss, Inc.
Low dielectric and flame‐retardant properties of thermosetting redistributed poly(phenylene oxide)
Authors: Hwang Hann‐Jang , Hsu Su‐Wen , Wang Chun‐Shan 
Published: January 2009

AbstractA curable low‐molecular‐weight poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) was prepared by the redistribution of regular PPO with maleic anhydride (MA) in toluene, using benzoyl peroxide as an initiator. The redistributed PPO (MA‐PPO), which contained alkene groups, was characterized by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. The redistributed PPO oligomers with reactive double bonds were cured with triallylisocyanurate (TAIC) and/or a phosphorus‐containing allyl‐functionalized monomer (allyl‐DOPO). Electrical properties of cured resins were studied by using a dielectric analyzer. The glass transition temperatures were measured by dynamic mechanical analysis. The flame retardancy was determined by the UL‐94 vertical test. The effects of curing accelerator and the amounts of TAIC and allyl‐DOPO incorporated into the network on the dielectric properties, glass transition temperature, and flame retardancy of the resulting systems were investigated. The results indicated that MA‐PPO cured with TAIC exhibited low dielectric constants (2.23–2.58 at 1 GHz) and dissipation factors (0.0034–0.0039 at 1 GHz) but had high glass transition temperatures (171–197°C). The MA‐PPO/TAIC copolymerized with allyl‐DOPO could achieve a flame retardancy rating of UL‐94 V‐0 at about 1.35 wt % of phosphorus. The redistributed PPO/TAIC resins have potential applications in the fabrication of printed circuit boards. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers.
Demographic responses to a mild winter in enclosed vole populations
Authors: Hoset Katrine S. , Le Galliard Jean‐François , Gundersen Gry 
Published: January 2009

AbstractMild winter weather causing snow to melt and ice to accumulate on the ground has been proposed to cause the decreased survival of individuals, and less pronounced cyclicity, of small rodent populations in Fennoscandia. However, detailed data linking ice accumulation to decreased winter survival is lacking. We live‐trapped and monitored with passive integrated transponders enclosed populations of root voles (Microtus oeconomus) exposed to different amounts of ice accumulation through a mild winter. We studied how social behaviour and survival responded to snow melt and ice accumulation. Voles avoided ground ice by moving their home ranges, thus increasing home range overlap in enclosed populations experiencing more extensive ice cover. Winter survival was not affected by the amount of ice accumulation, and was only slightly reduced during ice formation in early winter. The lowest survival rates were found at the onset of snow melt in early spring. These results suggest that ice accumulation does not cause lower survival during mild winters, probably because plastic social behaviour enables root voles to reduce the negative effects of varying winter weather on survival. The mechanisms for lower survival during mild winters may operate during spring and be related to spring floods or increased susceptibility to predators.
Impairment of VGLUT2 but not VGLUT1 signaling reduces neuropathy‐induced hypersensitivity
Authors: Leo Sandra , Moechars Dieder , Callaerts‐Vegh Zsuzsanna , D'Hooge Rudi , Meert Theo 
Published: January 2009

AbstractGlutamate is the major excitatory neurotransmitter in the central nervous system with an important role in nociceptive processing. Storage of glutamate into vesicles is controlled by vesicular glutamate transporters (VGLUT). Null mutants for VGLUT1 and VGLUT2 were poorly viable, thus, pain‐related behavior was presently compared between heterozygote VGLUT1 and VGLUT2 mice and their respective wild‐type littermates using a test battery that included a variety of assays for thermal and mechanical acute nociception, and inflammatory and neuropathic pain syndromes. Behavioral analysis of VGLUT1 mutant mice did not show important behavioral changes in the pain conditions tested. Reduction of VGLUT2 also resulted in unaltered acute nociceptive and inflammatory‐induced pain behavior. Interestingly, VGLUT2 heterozygote mice showed an attenuation or absence of some typical neuropathic pain features (e.g., absence of mechanical and cold allodynia after spared nerve injury). Chronic constriction injury in VGLUT2 heterozygote mice showed also reduced levels of cold allodynia, but had no impact on mechanical thresholds. Together, these data suggest that VGLUT2, but not VGLUT1, plays a role in neuropathy‐induced allodynia and hypersensitivity, and might be a therapeutic target to prevent and/or treat neuropathic pain.
Sleep continuity and architecture: Associations with pain‐inhibitory processes in patients with temporomandibular joint disorder
Authors: Edwards R.R. , Grace E. , Peterson S. , Klick B. , Haythornthwaite J.A. , Smith M.T. 
Published: January 2009

AbstractRecent research suggests bi‐directional interactions between the experience of pain and the process of sleep; pain interferes with the ability to obtain sleep, and disrupted sleep contributes to enhanced pain perception. Our group recently reported, in a controlled experimental study, that sleep fragmentation among healthy adults resulted in subsequent decrements in endogenous pain inhibition. The present report follows up that observation by extending this line of research to a sample of patients experiencing persistent pain. Patients with chronic temporomandibular joint disorder (TMD) pain were studied using polysomnography and psychophysical evaluation of pain responses. We assessed whether individual differences in sleep continuity and/or architecture were related to diffuse noxious inhibitory controls (DNIC), a measure of central nervous system pain inhibition. Among 53 TMD patients, higher sleep efficiency and longer total sleep time were positively associated with better functioning of DNIC (r = 0.42–0.44, p < 0.01; ps < 0.05 for the multivariate analyses). These results suggest the possibility that disrupted sleep may serve as a risk factor for inadequate pain‐inhibitory processing and hint that aggressive efforts to treat sleep disturbance early in the course of a pain condition might be beneficial in reducing the severity or impact of clinical pain.
Fatty acid pattern in serum is associated with bone mineralisation in healthy 8-year-old children
Authors: Eriksson Susanne , Mellström Dan , Strandvik Birgitta 
Published: January 2009

Animal studies have shown that fatty acids (FA) are important for normal bone development. Human data are scanty and mostly related to diseases. We hypothesised that serum FA pattern might be related to bone mineralisation in healthy children. Serum phospholipid FA pattern was studied in relation to bone parameters in eighty-five healthy Caucasian 8-year-olds. Dual-energy X-ray absorptiometry and blood sampling for analysis of serum phospholipid FA by capillary GLC were performed on the same day. SFA concentrations were associated with bone mineral density (BMD) of the hip, lumbar spine and total body. There was a general trend that linoleic acid (LA; 18 : 2n-6) was negatively associated with BMD, since that was found both for the LA concentration, the total n-6 concentration and the ratio of n-6:n-3 FA. Arachidonic acid (AA; 20 : 4n-6) was positively correlated with bone mineral content (BMC) and BMD of total body, as was the corresponding z-score and the AA:LA ratio. Both saturated and polyunsaturated serum phospholipid FA were associated with BMC and BMD in healthy children. LA and AA were found to inversely influence bone mineralisation and the association with the n-6:n-3 ratio suggested that this balance might also be of importance. The general trend of a negative influence of high n-6 FA concentrations on bone mineralisation might be of concern in relation to the changes in the Western diet. Longitudinal studies are necessary to verify if different bone compartments and different grades of modelling are related to different FA patterns.
Dietary vitamin E, brain redox status and expression of Alzheimer's disease-relevant genes in rats
Authors: Gaedicke Sonja , Zhang Xiangnan , Huebbe Patricia , Boesch-Saadatmandi Christine , Lou Yijia , Wiswedel Ingrid , Gardemann Andreas , Frank Jan , Rimbach Gerald 
Published: January 2009

Oxidative stress is one of the major pathological features of Alzheimer's disease (AD). Here, we investigated whether dietary vitamin E (VE) depletion may induce adverse effects and supplementation with α-tocopherol (αT) may result in beneficial effects on redox status and the regulation of genes relevant in the pathogenesis of AD in healthy rats. Three groups of eight male rats each were fed diets with deficient ( < 1 mg αT equivalents/kg diet), marginal (9 mg αT equivalents/kg diet) or sufficient (18 mg αT equivalents/kg diet) concentrations of natural-source VE for 6 months; a fourth group was fed the VE-sufficient diet fortified with αT (total VE, 146 mg αT equivalents/kg diet). Feeding of the experimental diets dose dependently altered αT concentrations in the cortex and plasma. No significant changes in F2-isoprostane concentrations, activities of antioxidative enzymes (total superoxide dismutase, Se-dependent glutathione peroxidase) and concentrations of glutathione or the expression of AD-relevant genes were observed. In this non-AD model, depletion of VE did not induce adverse effects and supplementation of αT did not induce positive effects on the parameters related to the progression of AD.
The Relationship between Public Expenditures and Services: A Longitudinal Analysis
Authors: Peters B. Guy 
Published: January 2009

In summary, we do find that levels of services and expenditures are more closely related across time than they are in cross-sectional studies and that, further, these relationships are functionally specific. At the same time, however, it would appear from these data that the extension of services precedes the expansion of the budget. It may, therefore, be argued that the extension of services can be used as a rational means of expanding the budget available to an agency rather than as a response to the increased availability of funds. This expansion may also be seen as a function of demand creation on the part of the agencies in increasing these services.A second point to be made is the importance of differentiating different categories of service. For those indicators of service that concern output or a service rendered, expenditures and policy are positively related. For those indicators of service that are more related to impacts – or needs – there is a negative relationship – i.e. lower quality associated with higher expenditure. Therefore, we find that the policy-making system of Sweden may have been making policy in relation to important objective changes in its service environment. It further leads us to expect quite different relationships between services and expenditures dependent upon the type of service measure being used.The research site and the measures of services used here are obviously different from those of Sharkansky. However, these findings do speak to the general theoretical point of the connection between public expenditures and services. They demonstrate the need to examine this important research question within a more dynamic framework and in a variety of social and cultural settings. Sharkansky's findings for the American states should be tested, for example, in an examination of the same question for sub-national units in Sweden and other European systems. Through the gradual accretion of these findings, we can elaborate theoretically the linkages between expenditures and policy outputs.
Principled Tolerance and the American Mass Public
Authors: Sniderman Paul M. , Tetlock Philip E. , Glaser James M. , Green Donald Philip , Hout Michael 
Published: January 2009

Americans appear to be more tolerant of deviant opinions and life-styles now than they were a generation ago. Recent research by Sullivan and his colleagues suggests, however, that this apparent change is largely illusory – a product not of an increase in principled support for tolerance, but rather of shifts in public dislike for, and hence intolerance of, particular political groups. An alternative account of tolerance is proposed which shows that citizen attitudes on issues of tolerance are remarkably consistent – far more so than has been commonly appreciated. In particular, the empirical analysis distinguishes two kinds of consistency – ‘principled’ and ‘situational’. Using log-linear techniques, it demonstrates that substantial numbers of the general public now support a variety of forms of tolerance consistently; and do so, not for reasons peculiar to each, but rather on principle.The broader implications of the results for the study of public opinion and democratic theory are noted.