bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sodium Borohydride Hydrolysis as Hydrogen Generator: Issues, State of the Art and Applicability Upstream from a Fuel Cell
Authors: Demirci U. B. , Akdim O. , Andrieux J. , Hannauer J. , Chamoun R. , Miele P. 
Published: May 2010

AbstractToday there is a consensus regarding the potential of NaBH4 as a good candidate for hydrogen storage and release via hydrolysis reaction, especially for mobile, portable and niche applications. However as gone through in the present paper two main issues, which are the most investigated throughout the open literature, still avoid NaBH4 to be competitive. The first one is water handling. The second one is the catalytic material used to accelerate the hydrolysis reaction. Both issues are objects of great attentions as it can be noticed throughout the open literature. This review presents and discusses the various strategies which were considered until now by many studies to manage water and to improve catalysts performances (reactivity and durability). Published studies show real improvements and much more efforts might lead to significant overhangs. Nevertheless, the results show that we are still far from envisaging short‐term commercialisation.
Stable ‘Floating' Air Diffusion Biocathode Based on Direct Electron Transfer Reactions Between Carbon Particles and High Redox Potential Laccase
Authors: Shleev S. , Shumakovich G. , Morozova O. , Yaropolov A. 
Published: May 2010

AbstractWe report on the assembly and characterisation of a high potential, stable, mediator‐less and cofactor free biocathode based on a fungal laccase (Lc), adsorbed on highly dispersed carbonaceous materials. First, the stability and activity of Trametes hirsuta Lc immobilised on different carbon particles were studied and compared to the solubilised enzyme. Based on the experimental results and a literature analysis, the carbonaceous material BM‐4 was chosen to design efficient and stable biocatalysts for the production of a ‘floating' air diffusion Lc‐based biocathode. Voltammetric characteristics and operational stability of the biocathode were investigated. The current density of oxygen reduction at the motionless biocathode in a quiet, air saturated citrate buffer (100 mM, pH 4.5, 23 °C) reached values as high as 0.3 mA cm–2 already at 0.7 V versus NHE. The operational stability of the biocathode depended on the current density of the device. For example, at low current density (20 μA cm–2), the biocathode lost only 5× of its initial power after 1 month of continuous operation. However, when the device was polarised at 150 mV it lost more than 32× of its initial power in just 10 min. We also found that co‐immobilisation of Lc and peroxidase on highly dispersed carbon materials could protect the biocatalyst from rapid inactivation by hydrogen peroxide produced during electrocatalytic reactions at high‐current densities.
Effects of caffeine and glucose, alone and combined, on cognitive performance
Authors: Adan Ana , Serra‐Grabulosa Josep Maria 
Published: May 2010

AbstractObjectiveTo study the effects of consuming caffeine and glucose, alone and combined, on cognitive performance.MethodsSeventy‐two healthy subjects (36 women; age range 18–25) were tested early in the morning, having fasted overnight. Using a double‐blind, randomised design, subjects received one of the following beverages: water (150 ml); water plus 75 mg of caffeine; water plus 75 g of glucose; water plus and 75 mg of caffeine and 75 g of glucose. Attention, manual dexterity, visuo‐spatial and frontal functions, memory (immediate, consolidation and working) and subjective state were all assessed.ResultsThe combination of caffeine and glucose had beneficial effects on attention (sequential reaction time tasks) and on learning and consolidation of verbal memory, effects not being observed when either substance was administered alone. Caffeine only showed improvement in simple reaction time and glucose in simple and one sequential reaction time tasks and in the manual dexterity assembly task.ConclusionsThe results indicate that the synergistic effects of caffeine and glucose can benefit sustained attention and verbal memory, even with adequate levels of activation of the subjects. However, further studies are required, controlling for different levels of cognitive effort and also considering measurements of neural activity. Copyright © 2010 John Wiley & Sons, Ltd.
Use of an acute challenge with d‐amphetamine to model cognitive improvement in chronic schizophrenia
Authors: Pietrzak Robert H. , Snyder Peter J. , Maruff Paul 
Published: May 2010

AbstractThere is general agreement that pharmacologic improvement of cognition in chronic schizophrenia is a worthwhile therapeutic goal. Accordingly, there has been careful consideration about how neuropsychological methods can be used to detect improvement in cognition in people with schizophrenia. However, little data are available on the nature and magnitude of cognitive improvement that can occur with adjunctive therapeutic interventions.This double‐blind, placebo‐controlled crossover study examined the nature and magnitude of cognitive enhancement associated with a single‐dose administration of d‐amphetamine in 32 adult men with schizophrenia using a set of tasks developed specifically for detecting treatment‐related change in cognitive function. Relative to placebo, acute d‐amphetamine administration was associated with clinically meaningful improvement on measures of executive function and visual attention and vigilance, and with modest improvements on a measure of speed of processing. These results suggest that a brief computerized cognitive test battery designed for repeat administration, in combination with a statistical approach that emphasizes individual‐level change, provides a sensitive approach to detecting the effect of cognitive‐enhancing medications in people with chronic schizophrenia. Copyright © 2010 John Wiley & Sons, Ltd.
Assessing the functional significance of ecstasy‐related memory deficits using a virtual paradigm
Authors: Montgomery Catharine , Hatton Nicholas P. , Fisk John E. , Ogden Ruth S. , Jansari Ashok 
Published: May 2010

AbstractRationale/ObjectivesPrevious research shows that the use of ecstasy results in working memory and executive impairments in some users. The present study sought to assess the functional significance of such deficits using a virtual reality task.MethodsTwenty‐three ecstasy‐polydrug users and 26 nonusers were recruited. Individuals completed a drug use questionnaire measures of sleep quality and fluid intelligence. Participants also completed a virtual reality executive function task in which they play the role of an office worker for the day completing predefined tasks such as prioritising different activities according to their importance, organising the physical office environment and managing the outgoing mail in accordance with a delivery schedule.ResultsMANOVA revealed that ecstasy users performed worse on the virtual reality task overall, and this was due to poorer performance on the planning and selection subscales. Contrary to expectations, ecstasy‐polydrug users performed better on the time‐based prospective memory subscale. Indices of ecstasy use were correlated with the planning subscale of the virtual task.ConclusionsThe present study provides further support for ecstasy/polydrug related deficits in executive functioning. As it is possible that this task is more ecologically valid and relevant to day‐to‐day activities of many users, previous research finding null results on executive function tasks may have underestimated the impact of ecstasy‐polydrug use on executive functioning. Copyright © 2010 John Wiley & Sons, Ltd.
A comparison of statistical approaches used to evaluate change in cognitive function following pharmacologic challenge: an example with lorazepam
Authors: Pietrzak Robert H. , Fredrickson Amy , Snyder Peter J. , Maruff Paul 
Published: May 2010

AbstractBackgroundNeuropsychological tests are commonly used in psychopharmacological research to understand the nature and the magnitude of cognitive effects of licensed and novel compounds. While the science of cognitive change assessment has advanced considerably, statistical techniques used to guide inferences about differences in cognitive change have not been considered in the same detail, especially in light of recent advances in modeling repeated data.MethodsData from a randomized, placebo‐controlled, crossover study of the effect of an acute dose of lorazepam on cognitive function in healthy adults were analyzed using five statistical approaches (paired sample t‐test, area under curve (AUC), repeated measures analysis of variance (ANOVA), change from baseline, and linear mixed models (LMM)). Results of significance tests and effect sizes were compared at maximum concentration (Cmax) and over the ascending slopes of cognitive performance.ResultsLMM approaches were superior to other statistical approaches with respect to results of significance testing and magnitudes of estimated effect size change.ConclusionsResults of this study suggest that employment of LMM, which permit examination of specific fixed effects (e.g., time, treatment, treatment × time) and that are not confounded by between‐subject variability, provide a sensitive approach to detecting the cognitive effects of pharmacologic challenges, even with small samples. Copyright © 2010 John Wiley & Sons, Ltd.
The relationship between the daily dose, the plasma concentration of blonanserin, and its plasma anti‐dopamine D2and anti‐serotonin 5‐HT2Aactivity
Authors: Suzuki Hidenobu , Gen Keishi 
Published: May 2010

AbstractObjectiveBlonanserin (BNS) possesses anti‐serotonin 5‐HT2Aactivity in addition to anti‐dopamine D2activity, which is characteristic of second‐generation antipsychotics, little information is available on its pharmacologic profilein vivo. We investigated the BNS daily dose, plasma concentration, plasma anti‐D2activity, and plasma anti‐5‐HT2Aactivity in schizophrenia in a total of 14 subjects.MethodsBlood samples were taken 14 days after the BNS dose was fixed, and the plasma concentration was measured by means of high‐performance liquid chromatographic (HPLC) method. In addition, the plasma anti‐D2activity and anti‐5‐HT2Aactivity were measured by means of radioreceptor assays in which [3H]‐spiperone and [3H]‐ketanserin were used.ResultsThe results revealed a statistically significant correlation between the daily dose and the plasma concentration (p = 0.04). Statistically significant correlations were also observed between the plasma concentration and the anti‐D2activity and between the plasma concentration and the anti‐5‐HT2Aactivity (p = 0.003 and 0.04).ConclusionsIt is therefore believed that both the anti‐D2activity in plasma and the anti‐5‐HT2Aactivity in plasma are regulated almost solely by the unchanged principal. Moreover, the mean plasma serotonin/dopamine (S/D) ratio was 0.9 and BNS exhibited both anti‐D2activity and also anti‐5‐HT2Aactivityin vivo, as well, so it was clear that thein vitropharmacological profile was retainedin vivo. Copyright © 2010 John Wiley & Sons, Ltd.
Identification and determination of the saikosaponins in Radix bupleuri by accelerated solvent extraction combined with rapid‐resolution LC‐MS
Authors: Yang Yun‐Yun , Tang You‐Zhi , Fan Chun‐Lin , Luo Hui‐Tai , Guo Peng‐Ran , Chen Jian‐Xin 
Published: May 2010

AbstractA method based on accelerated solvent extraction combined with rapid‐resolution LC–MS for efficient extraction, rapid separation, online identification and accurate determination of the saikosaponins (SSs) in Radix bupleuri (RB) was developed. The RB samples were extracted by accelerated solvent extraction using 70% aqueous ethanol v/v as solvent, at a temperature of 120°C and pressure of 100 bar, with 10 min of static extraction time and three extraction cycles. Rapid‐resolution LC separation was performed by using a C18 column at gradient elution of water (containing 0.5% formic acid) and acetonitrile, and the major constituents were well separated within 20 min. A TOF‐MS and an IT‐MS were used for online identification of the major constituents, and 27 SSs were identified or tentatively identified. Five major bioactive SSs (SSa, SSc, SSd, 6″‐O‐acetyl‐SSa and 6″‐O‐acetyl‐SSd) with obvious peak areas and good resolution were chosen as benchmark substances, and a triple quadrupole MS operating in multiple‐reaction monitoring mode was used for their quantitative analysis. A total of 16 RB samples from different regions of China were analyzed. The results indicated that the method was rapid, efficient, accurate and suitable for use in the quality control of RB.
Amino acids stimulate Akt phosphorylation, and reduce IL‐8 production and NF‐κB activity in HepG2 liver cells
Authors: van Meijl Leonie E. C. , Popeijus Herman E. , Mensink Ronald P. 
Published: May 2010

AbstractHepatic insulin resistance and inflammatory cytokine production contribute to the manifestation of the metabolic syndrome. As amino acids have been implicated in modulating insulin signaling and inflammation, we have investigated the effects of glutamine, leucine and proline on markers of inflammation and insulin sensitivity in HepG2 liver cells. Cells were incubated with IL‐1β (5 ng/mL) to stimulate IL‐8 production. After 24 h, glutamine inhibited IL‐8 production significantly (p<0.05) at 2, 5 and 10 mM (to 82, 73 and 72% of control), whereas leucine reduced IL‐8 production significantly only at 10 mM (66%) and proline at 5 and 10 mM (71 and 52%). Glutamine, leucine and proline all reduced NF‐κB activity after 3 h of IL‐1β stimulation at 2, 5 and 10 mM (p<0.001). Insulin‐induced (1 nM) Akt phosphorylation was reduced in cells treated with tumour necrosis factor‐α (10 ng/mL) for 24 h, but was partly restored by simultaneous incubation with glutamine, leucine and proline (25 mM). Phosphorylation of glycogen synthase kinase‐3β was unaffected by insulin stimulation and amino acid treatment. Our results indicate that glutamine, leucine and proline attenuate IL‐8 production, probably through inhibition of NF‐κB, and that they increase Akt phosphorylation in HepG2 cells.
Craniocervical posture and bruxism in children
Authors: Motta Lara Jansiski , Martins Manoela Domingues , Fernandes Kristianne Porta Santos , Mesquita‐Ferrari Raquel Agnelli , Biasotto‐Gonzalez Daniela Aparecida , Bussadori Sandra Kalil 
Published: May 2010

AbstractAim. The aim of this study was to investigate, using photogrammetry, the relationship between head posture and bruxism in children with complete deciduous dentition. Material and Methods. Forty‐two children aged between 3 and 6 years, with complete deciduous dentition, participated in the study. Twenty‐one children diagnosed with bruxism according to the diagnostic criteria of the American Academy of Sleep Medicine were selected for the bruxism group, and 21 children without bruxism were selected for the control group. Markers were placed on three anatomical landmarks (spinous process of the seventh cervical vertebra, manubrium of the sternum and mental protuberance) and photographic measurements were made to evaluate head posture. Angles between markers were determined using the ALCimagem® software for quantitative image analysis. The Student's t‐test was used at a significance level of 0.05 for the comparison of head posture (mean cervical angle) between the bruxism and control groups. Results. There was a significant difference (p < 0.005) in the mean cervical angle between the control (89.58° ± 8.03°) and bruxism (98.99° ± 8.15°) groups. Conclusion. In the present study, children with bruxism showed greater alterations in head posture than controls. Copyright © 2010 John Wiley & Sons, Ltd.
Role of a‐Si:H bulk in surface passivation of c‐Si wafers
Authors: Illiberi A. , Sharma K. , Creatore M. , van de Sanden M. C. M. 
Published: May 2010

AbstractThe low thermal stability of hydrogenated amorphous silicon (a‐Si:H) thin films limits their widespread use for surface passivation of c‐Si wafers on the rear side of solar cells. We show that the thermal stability of a‐Si:H surface passivation is increased significantly by a hydrogen rich a‐Si:H bulk, which acts as a hydrogen reservoir for the a‐Si:H/c‐Si interface. Based on this mechanism, an excellent lifetime of 5.1 ms (at injection level of 1015 cm–3) is achieved after annealing at 450 °C for 10 min. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence properties of GaAs nanowire ensembles with zincblende and wurtzite crystal structure
Authors: Novikov B. V. , Serov S. Yu. , Filosofov N. G. , Shtrom I. V. , Talalaev V. G. , Vyvenko O. F. , Ubyivovk E. V. , Samsonenko Yu. B. , Bouravleuv A. D. , Soshnikov I. P. , Sibirev N. V. , Cirlin G. E. , Dubrovskii V. G. 
Published: May 2010

AbstractSelf‐standing III–V nanowires (NWs) are promising building blocks for future optoelectronic devices such as LEDs, lasers, photodetectors and solar cells. In this work, we present the results of low temperature photoluminescence (PL) characterization of GaAs NWs grown by Au‐assisted molecular beam epitaxy (MBE), coupled with the transmission electron microscopy (TEM) structural analysis. PL spectra contain exci‐ ton peaks from zincblende (ZB) and wurtzite (WZ) crystal structures of GaAs. The peaks are influenced by the quantum confinement effects. PL bands corresponding to the exciton emission from ZB and WZ crystal phases are identified, relating to the PL peaks at 1.519 eV and 1.478 eV, respectively. The obtained red shift of 41 meV for WZ GaAs should persist in thin NWs as well as in bulk materials. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Kinematics of a robotic 3UPS1S spherical wrist designed for laparoscopic applications
Authors: Navarro Jose Sabater , Garcia Nicolas , Perez Carlos , Fernandez Eduardo , Saltaren Roque , Almonacid Miguel 
Published: May 2010

AbstractBackgroundCurrent robotic orientation surgical devices used to be large, in order to cover the needed workspace and to be rigid enough to resist the forces that occur during surgery. The disadvantages of the large size of the devices are the ergonomics, collisions and interference with the surgeons. This paper presents the first steps that have been carried out on the development of a small spherical wrist for laparoscopic applications.MethodsScrew theory for kinematic analysis and the design of parallel robots have been used for choosing the kinematic architecture of the first prototype of the laparoscopic wrist. The kinematic equations of the platform are described and the Jacobian matrix calculated.ResultsThe kinematics of this device is a 3UPS‐1S parallel architecture. The work presented here shows the concept of the device, its design, that it was made under intrinsic safety criteria, its kinematic analysis and the first results and images of the built prototype. The kinematic analysis is made using screw theory and it is used to verify the optimization of the design.ConclusionsA new design for a smart and small spherical wrist is developed. Ergonomics for the surgical team is a design criterion that should be introduced to the design process for an operating‐room robotic tool. Parallel robots architecture can contribute to new devices that fit this criterion. Copyright © 2010 John Wiley & Sons, Ltd.
Predicting employees' well‐being using work–family conflict and job strain models
Authors: Karimi Leila , Karimi Hamidreza , Nouri Aboulghassem 
Published: May 2010

AbstractThe present study examined the effects of two models of work–family conflict (WFC) and job‐strain on the job‐related and context‐free well‐being of employees. The participants of the study consisted of Iranian employees from a variety of organizations. The effects of three dimensions of the job‐strain model and six forms of WFC on affective well‐being were assessed. The results of hierarchical multiple regression analysis revealed that the number of working hours, strain‐based work interfering with family life (WIF) along with job characteristic variables (i.e. supervisory support, job demands and job control) all make a significant contribution to the prediction of job‐related well‐being. On the other hand, strain‐based WIF and family interfering with work (FIW) significantly predicted context‐free well‐being. Implications are drawn and recommendations made regarding future research and interventions in the workplace. Copyright © 2010 John Wiley & Sons, Ltd.
Separation recall: psychophysiological response‐patterns in an attachment‐related short‐term stressor
Authors: Ehrenthal Johannes C. , Friederich Hans‐Christoph , Schauenburg Henning 
Published: May 2010

AbstractAttachment theory is a conceptual framework for emotional‐motivational behaviour and stress regulation in social relationships. However, few experimental studies have investigated attachment‐related autonomic stress responses in adults. In a sample of 50 healthy subjects, we investigated autonomic cardiovascular reactions and subjective stress‐load to a newly developed, attachment‐related short‐term stressor (separation recall, SR). The overall magnitude of the cardiovascular response to SR was comparable to the well established mental arithmetic (MA) stress test. However, the SR induced higher levels of sadness and impaired diastolic blood pressure recovery, whereas MA was associated with higher levels of anger and greater heart rate increase. Recovery scores to the attachment‐stressor but not the mental arithmetic were related to attachment avoidance as measured by self‐report, especially when taking into account the content of the reported episodes of the SR. In sum, our newly developed attachment‐related short‐term stressor has proven good performance in a first study. Copyright © 2010 John Wiley & Sons, Ltd.
Linking household income and work–family conflict: a moderated mediation study
Authors: Ford Michael T. 
Published: May 2010

AbstractResearch on the work–family interface has not often explored the role of structural characteristics such as income in the associations among work stressors, work–family conflict and family stressors. The goal of this study was to examine household income as a moderator of the relations among these variables. Results from a nationally (US) representative sample of 1472 employed individuals who were married with children indicate that the relations between work‐to‐family interference and family strain were stronger for individuals with lower household incomes than for those with higher household incomes. Furthermore, family strain was more strongly associated with family‐to‐work interference for individuals in low‐income households. Household income did not moderate other relations examined in the study. Potential explanations for these moderating effects are discussed, along with their implications for the generalizability of findings in the work–family literature across contexts. Copyright © 2010 John Wiley & Sons, Ltd.