bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterisation of melt‐processed poly(ethylene terephthalate)/synthetic mica nanocomposite sheet and its biaxial deformation behaviour
Authors: Soon Kok H , Harkin‐Jones Eileen , Rajeev Rajvihar S , Menary Gary , McNally Tony , Martin Peter J , Armstrong Cecil 
Published: July 2009

AbstractBACKGROUND: Poly(ethylene terephthalate) (PET) is widely used in the packaging industry. In order to enhance the mechanical and barrier properties, nanoscale fillers are added to PET matrices to form nanocomposites. In the work reported here, a melt‐processed PET/synthetic mica nanocomposite sheet was characterised to determine the effect of the incorporation of synthetic mica on the sheet properties and also to see if these properties are an indicator of subsequent performance under high‐speed, high‐temperature biaxial deformation, typical of processes such as stretch blow moulding.RESULTS: The incorporation of synthetic mica was found to enhance the modulus, particularly above the glass transition temperature, and barrier properties of the extruded sheet and it significantly altered the deformation behaviour of PET under biaxial deformation. The plastic flow of PET during biaxial deformation was found to diminish for the nanocomposites, and strain hardening occurred earlier.CONCLUSION: The modulus and barrier properties of PET were enhanced by the incorporation of synthetic mica. Clay loading also altered the biaxial deformation behaviour of PET. Copyright © 2009 Society of Chemical Industry
Wheezing, sleeping, and worrying: The hidden risks of asthma and obesity in school‐age children
Authors: Fiese Barbara H. , Everhart Robin S. , Wildenger Leah 
Published: July 2009

AbstractThe present study investigated the co‐occurrence of asthma and obesity in a sample of 193 children (mean age = 7.76 years). Specifically, this study was interested in delineating the associated comorbidities of internalizing symptoms and sleep disruptions among younger (younger than 7 years) and older elementary age children with asthma who were also overweight. Information about child internalizing symptoms (among other areas of functioning) was collected from teacher ratings of child behavior. Data regarding nighttime waking, morning symptoms, and school days missed were obtained from parent reports. Findings suggest that older elementary age children with asthma who are overweight are more likely to experience internalizing symptoms and more nighttime waking than their average weight peers. Implications include the important role of teachers in identifying these children who might be at increased risk for internalizing symptoms and the consequences of such symptoms. © 2009 Wiley Periodicals, Inc.
Reactivity of mixed organozinc and mixed organocopper reagents. Part 4: a kinetic study of group transfer selectivity in CC coupling of mixed diorganocuprates
Authors: Erdik Ender , Özkan Duygu 
Published: July 2009

AbstractThe competitive rate data and Taft relationships for the coupling of bromomagnesium n‐butyl (substituted phenyl) cuprates with alkyl bromides show that selective n‐butyl transfer can be explained by an oxidative addition mechanism. Taft reaction constants also show that the residual group FG‐C6H4 in the mixed cuprate n‐Bu(FG‐C6H4)CuMgBr changes the ability of the copper nucleophile to react with the electrophile RBr. These results provide support for the commonly accepted hypothesis regarding the dependence of the R1 group transfer ability on the strength of R2Cu bond in reactions of R1R2CuMgBr reagents. Copyright © 2009 John Wiley & Sons, Ltd.
A proteomic approach combining MS and bioinformatic analysis for the detection and identification of biomarkers of administration of exogenous human growth hormone in humans
Authors: Boateng Joshua , Kay Richard , Lancashire Lee , Brown Pamela , Velloso Cristiana , Bouloux Pierre , Teale Phil , Roberts Jane , Rees Robert , Ball Graham , Harridge Stephen , Goldspink Geoffrey , Creaser Colin 
Published: July 2009

AbstractAn integrated MS‐based proteomic approach is described that combines MALDI‐MS and LC‐MS with artificial neural networks for the identification of protein and peptide biomarkers associated with recombinant human growth hormone (rhGH) administration. Serum from exercised males administered with rhGH or placebo was analysed using ELISA to determine insulin‐like growth factor‐I concentrations. Diluted serum from rhGH‐ and placebo‐treated subjects was analysed for protein biomarkers by MALDI‐MS, whereas LC‐MS was used to analyse tryptically digested ACN‐depleted serum extracts for peptide biomarkers. Ion intensities and m/z values were used as inputs to artificial neural networks to classify samples into rhGH‐ and placebo‐treated groups. Six protein ions (MALDI‐MS) correctly classified 96% of samples into their respective groups, with a sensitivity of 91% (20 of 22 rhGH treated) and specificity of 100% (24 of 24 controls). Six peptide ions (LC‐MS) were also identified and correctly classified 93% of samples with a sensitivity of 90% (19 of 21 rhGH treated) and a specificity of 95% (20 of 21 controls). The peptide biomarker ion with the highest significance was sequenced using LC‐MS/MS and database searching and found to be associated with leucine‐rich α‐2‐glycoprotein.
Proteomics‐based characterization of hemagglutinins in different strains of influenza virus
Authors: Getie‐Kebtie Melkamu , Chen David , Eichelberger Maryna , Alterman Michail 
Published: July 2009

AbstractInfection with influenza A (subtypes H1N1 and H3N2) or B viruses results in over half a million deaths worldwide every year. Frequent antigenic changes (drift) in two major viral surface proteins hemagglutinin (HA) and neuraminidase lead to the constant emergence of antigenically distinct virus strains against which there is sub‐optimal immunity in the population. Consequently the suitability of the viral strains included in the trivalent influenza vaccine (TIV) has to be re‐evaluated annually. While virus seeds selected for vaccine manufacture are very well characterized, there is no assay in place to identify the source of HA in the formulated trivalent vaccine. Our study describes a proteomics‐based method to identify the HA strain (not just subtype) and more fully characterize the final vaccine product. Unique and shared tryptic peptides of HAs were predicted by in silico tryptic digest of different influenza A and B virus strains. Recombinant HA and whole virus preparations of selected strains were then digested to identify the peptides detected by MS. Both subtype and strain‐specific peptides were observed. The feasibility of this method to accurately identify HA strains in an inactivated TIV was tested using a 2006/2007 formulation. Each of the three HAs in the vaccine was identified in addition to a number of other viral and non‐viral proteins. In summary, MS is a powerful method that is both specific and inclusive; in a single analysis, HAs of individual virus strains can be identified and the composition of the TIV fully characterized.
Effect of Leucine and Lysine substitution on the antimicrobial activity and evaluation of the mechanism of the HPA3NT3 analog peptide
Authors: Gopal Ramamourthy , Park Seong‐Cheol , Ha Kyeoung‐Ju , Cho Seung Joo , Kim Si Wouk , Song Peter I. , Nah Jae‐Woon , Park Yoonkyung , Hahm Kyung‐Soo 
Published: July 2009

AbstractIn this study, a HPA3NT3‐analog (FKKLKKLFKKILKLK‐NH2) peptide was designed. In this analog, two Trp residues (positions 12, 14) were replaced with Leu, and Arg and Asn (positions 3, 13) were replaced with Lys to investigate the role of amino acid substitution and increased cationicity on antimicrobial and hemolytic activities. In fungal and Gram‐negative bacterial cells, HPA3NT3‐analog activity was unchanged or slightly enhanced when compared to the HPA3NT3 peptide. In addition, a twofold decrease in activity against Gram‐positive bacteria was observed. The HPA3NT3‐analog also induced less hemolysis (4.2%) than the HPA3NT3 peptide (71%) at 200 µM. Circular dichroism (CD) spectra revealed that the HPA3NT3‐analog peptide had an unordered structure in buffer and egg yolk L‐2‐phosphatidyl choline (EYPC), but adapted an α‐helical conformation in 50% 2,2,2‐trifluoroethanol (TFE) and negatively charged egg yolk L‐2‐phosphatidyl glycerol (EYPG), while the parent peptide showed an ordered structure in the EYPC. Additionally, the HPA3NT3‐analog peptide induced the leakage of calcein from egg yolk L‐2‐phosphatidyl ethanolamine (EYPE)/EYPG (7:3 w/w) large unilamellar vesicles (LUVs); however, the activity was slightly weaker than that of the HPA3NT3 peptide. The molecular dynamics (MD) structures revealed that the amino acid substitutions induced a significant variation in peptide structure. These results suggest that the substitutions of Arg and Asn with Lys and two Trp with Leu resulted in small changes in HPA3NT3‐analog activity and significant decreases in hemolytic activity. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Electron momentum distribution in SnS
Authors: Sharma G. , Sharma M. , Mishra M. C. , Joshi K. B. , Kothari R. K. , Sharma B. K. 
Published: July 2009

AbstractA study of electron momentum density distribution in SnS by means of Compton profiles is presented. The measurement on polycrystalline sample of SnS is performed employing 59.54 keV gamma‐rays emanating from an Am241 radioisotope. The calculations are performed on the basis of density‐functional theory based ab‐initio linear combination of atomic orbitals method embodied in the CRYSTAL program. The correlation scheme proposed by von Barth and Hedin is adopted. The generalized gradient approximation proposed by Perdew and Wang is also considered to treat the correlation. The exchange is treated following the Becke scheme. Both the correlation schemes are in good agreement with the measurement. The better agreement with experimental result is, however, observed with the von Barth and Hedin correlation that also gives lower ground‐state energy than the Perdew–Wang generalized gradient approximation. Ionic model calculations for a number of configurations of Sn+xS−x (0.0 ≤ x ≤ 2) are also performed utilizing free‐atom profiles. The ionic model suggests transfer of 2.0 electrons from the valence 5p state of Sn to the 3p state of S.
Temperature dependence of the noise amplitude in graphene and graphene oxide
Authors: Goldsmith B. R. , Lu Ye , Luo Zhengtang , Johnson A. T. 
Published: July 2009

AbstractGraphene and related materials such as carbon nanotubes and graphene oxide are promising materials for future applications in chemical sensing and electronics. Electronic noise in these materials is typically very high due to the low number of carriers and the inverse dependence of 1/f noise on the number of carriers. We have investigated the changes in 1/f noise amplitude with temperature in exfoliated graphene and reduced graphene oxide devices. We show that using reduced graphene oxide results in an intriguing environmental coupling to noise amplitude. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theory of chemical bonds in metalloenzymes XIII: Singlet and triplet diradical mechanisms of hydroxylations with iron‐oxo species and P450 are revisited
Authors: Yamaguchi Kizashi , Yamanaka Syusuke , Isobe Hiroshi , Shoji Mitsuo , Saito Toru , Kitagawa Yasutaka , Okumura Mitsutaka , Shimada Jiro 
Published: July 2009

AbstractElectronic structures of the Compound I (CpdI) in P450 are investigated on the basis of spin coupling forms of iron‐oxo (Fe(IV)O) cores and radical ligand (•L) groups to generalize previous singlet and triplet diradical (TD) mechanisms for oxygenations of alkanes with Fe( IV)O. Orbital interaction schemes for four lower‐lying spin configurations of CpdI with HC bond of substrate are examined to elucidate how magnetic coupling modes correlate with radical reaction pathways for hydroxylation reactions on the basis of the broken symmetry (BS) molecular orbital (MO) model. The configuration correlation diagrams for the four configurations model are depicted on the basis of the isoelectronic analogy among O, O2, and Fe( IV)O, in addition to Coulomb exchange energy on the iron site, which determines its local spin configuration. Important role of ligand spin (•L) of CpdI for regulation of hydroxylation mechanisms is clarified with the aid of the spin coupling forms. Transition states for one quartet and three doublet configurations under the BS MO approximation are examined on the basis of potential curve crossings along reaction pathways. The four transition structures and corresponding radical intermediates for methane and trimethyl methane with CpI are located by the BS hybrid Kohn–Sham density functional theory (DFT) (B3LYP) method to confirm the orbital interaction schemes. Spin density populations obtained by the BS B3LYP calculations are found to be consistent with the theoretical predictions based on the four configurations model. The configuration and state correlation diagrams by BS B3LYP before and after spin projection are also consistent with the BS MO interaction schemes, which provide local SD and TD mechanisms of hydroxylation with CpdI. The present BS MO‐theoretical framework is useful for systematic understanding of a lot of recent BS hybrid DFT computational results for hydroxylation reactions with CpdI and configuration correlation diagrams reported by several groups. Implications of the present theoretical and computational results are discussed in relation to several experimental characteristics of hydroxylation reactions with iron‐oxo species and P450. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
The host‐defence skin peptide profiles of Peron's Tree Frog Litoria peronii in winter and summer. Sequence determination by electrospray mass spectrometry and activities of the peptides
Authors: Bilusich Daniel , Jackway Rebecca J. , Musgrave Ian F. , Tyler Michael J. , Bowie John H. 
Published: July 2009

AbstractPositive and negative ion electrospray mass spectrometry together with Edman sequencing (when appropriate) has been used to sequence the host‐defence peptides secreted from skin glands of the tree frog Litoria peronii. The peptide profiles are different in winter and summer. In winter, the frog produces small amounts of the known caerin 1.1 [GLLSVLGSVAKHVLPHVVPVIAEHL‐NH2] (a wide‐spectrum antibiotic) and caerin 2.1 [GLVSSIGRALGGLLADVVKSKQPA‐OH], a narrow‐spectrum antibiotic and an inhibitor of neuronal nitric oxide synthase. The major peptides produced throughout the year are the pGlu‐containing peroniins 1.1 to 1.5 (e.g. peroniin 1.1 [pEPWLPFG‐NH2], a smooth muscle contractor from 10−7 M), and caerulein [pEQDY(SO3H)TGWMDF‐NH2], a known and potent smooth muscle contractor from 10−10 M. There are also some precursors to the peroniin 1 peptides, only detected in the skin secretion in summer, which are inactive and appear to be all (or part) of the spacer peroniin 1 peptides, e.g. peroniin 1.1b [SEEEKRQPWLPFG‐NH2]. There are three members of the Litoria peronii Group of tree frogs classified in Australia, namely, L. peronii, L. rothii and L.tyleri. A comparison of the skin peptide profiles of L. peronii with those reported previously for L. rothii suggests that either these two species of tree frog are not as closely related as determined previously on morphological grounds, or that skin peptide divergence in tree frogs of this Group is more extensive than in others that have been studied. Copyright © 2009 John Wiley & Sons, Ltd.
Efficient rekeying algorithms for WiMAX networks
Authors: Brown Jeremy , Du Xiaojiang , Guizani Mohsen 
Published: July 2009

AbstractIn this paper, we study the rekeying issue in IEEE 802.16e WiMAX networks. The existing rekeying scheme—the Multicast and Broadcast Rekeying Algorithm (MBRA) unicasts new keys to each subscriber station (SS). This scheme does not scale well since it incurs large communication overheads when the number of SSs increase. In our work, first we propose a general tree‐based rekeying scheme, which is more efficient than the MBRA. We also formulate an optimization problem to determine the optimal tree structure for given number of SSs. Furthermore, we present a novel and efficient rekeying scheme for WiMAX networks. Our new rekeying scheme utilizes efficient security schemes and the WiMAX network application feature. Both analysis and performance evaluation show that our rekeying scheme can significantly reduce the communication overheads. Copyright © 2009 John Wiley & Sons, Ltd.
Year of birth determination using radiocarbon dating of dental enamel
Authors: Buchholz B. A. , Spalding K. L. 
Published: July 2009

AbstractRadiocarbon dating is typically an archaeological tool rather than a forensic one. Recently, however, we have shown that the amount of radiocarbon present in tooth enamel, as a result of nuclear bomb testing during the cold war, is a remarkably accurate indicator of when a person is born. Enamel isolated from human teeth is processed to form graphite, and carbon‐14 (14C) levels are measured using accelerator mass spectrometry. Since there is no turnover of enamel after it is formed, 14C levels in the enamel represent 14C levels in the atmosphere at the time of its formation. In this paper, we describe the strategy used to determine the date of birth of an individual based on radiocarbon levels in tooth enamel, focusing on the methodology of this strategy. Year of birth information can significantly assist police investigators when the identity of a deceased individual is unknown. In such cases, police will try to match particulars of the unidentified individual, which is often only gender and/or an estimate of age, with particulars from missing persons lists. Copyright © 2009 John Wiley & Sons, Ltd.
A hierarchical model for binary data with dependence between the design and outcome success probabilities
Authors: Todem David , Williams Karen Patricia 
Published: July 2009

AbstractStatistical theory requires that analysis of study outcomes be conducted conditional on the design process. Ignoring this process may result in severely biased estimates, leading to false inferences, especially when the outcome variable is associated with design variables. We propose in this paper a class of hierarchical models to investigate the dependence between the design process and the study outcomes of primary interest. We discuss a fully parametric and a semi‐parametric formulation of the hypothesized model and propose the EM algorithm to obtain maximum likelihood estimates. Our numerical results show that the semi‐parametric approach outperforms the fully parametric model with respect to some key features of the model. The methodology is used to gain insight into the mechanism that generates breast cancer literacy outcomes in a study conducted among medically underserved females in Michigan. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of fidelity of implementation on science achievement gains among english language learners
Authors: Lee Okhee , Penfield Randall , Maerten‐Rivera Jaime 
Published: July 2009

AbstractThis study examined the effect of fidelity of implementation (FOI) on the science achievement gains of third grade students broadly and students with limited literacy in English specifically. The study was conducted in the context of a professional development intervention with elementary school teachers to promote science achievement of ELL students in urban schools. As the criterion for measuring FOI, we focused on the quality of instructional delivery in teaching science to ELL students. We measured FOI using both teachers' self‐reports and classroom observations during the first year of the intervention. Science achievement was measured by a pretest and posttest over the school year. The results indicate that none of the measures of FOI using teachers' self‐reports or classroom observations had significant effects on science achievement gains. The results are discussed in terms of issues about conceptualization and measurement of FOI in educational interventions. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 836–859, 2009
Keyhole sign: how specific is it for the diagnosis of posterior urethral valves?
Authors: Bernardes L. S. , Aksnes G. , Saada J. , Masse V. , Elie C. , Dumez Y. , Lortat‐Jacob S. L. , Benachi A. 
Published: July 2009

AbstractObjectivesPosterior urethral valves (PUV) are the most common cause of renal impairment in boys during early childhood. Although antenatal suspicion of this pathology has become quite common in recent years, prenatal diagnosis remains challenging. The aim of this study was to evaluate the predictive value of different ultrasound criteria currently used to diagnose PUV.MethodsWe reviewed the antenatal and postnatal files of 54 male patients referred to our center from 2000 to 2006 after detection of fetal bilateral hydronephrosis. The following ultrasound criteria were evaluated in relation to the postnatal diagnosis of PUV: amniotic fluid volume, bladder wall thickness, bladder dilatation and the presence of the ‘keyhole sign’.ResultsForty‐two fetuses (77.8%) were suspected to have PUV on prenatal examination. Out of these, 29 (69.0%) had PUV confirmed postnatally. The sensitivity and specificity of the antenatal diagnosis of PUV were 94% and 43%, respectively. Increased bladder wall thickness and bladder dilatation were highly associated with the diagnosis of PUV (P < 0.001). However, a thick‐walled bladder was observed in 39.1% and a dilated bladder in 47.8% of the infants with a postnatal diagnosis other than PUV. The presence of the keyhole sign was not found to predict a diagnosis of PUV (P = 0.27).ConclusionIn this series the use of classical prenatal ultrasound signs to diagnose PUV showed high sensitivity but low specificity. The best diagnostic indicators were increased bladder wall thickness and dilatation of the bladder. The keyhole sign was not found to be a reliable predictor of PUV. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Performance study for HARQ–ARQ interaction of LTE
Authors: Chuang Ching‐Hsiang , Lin Phone 
Published: July 2009

AbstractThe 3GPP working group proposes the Long‐Term Evolution (LTE) system as the 4G mobile communications technology. To reduce the transmission latency in the radio access network, Evolved Universal Terrestrial Radio Access Network (E‐UTRAN), of LTE, the base station and radio network controller are merged into a single network node, namely eNB. In E‐UTRAN, the Stop‐And‐Wait Hybrid ARQ (SAW‐HARQ) protocol in the Media Access Control (MAC) layer deals with transmission errors without the need to engage the ARQ protocol in the Radio Link Control (RLC) layer. The HARQ and ARQ protocols interact only in case of dealing HARQ residual errors. In this paper, we propose an analytical model to model the behavior of the HARQ–ARQ Interaction. Our analytical model is validated against the simulation experiments that provide more performance metrics (which cannot be obtained through our analytical model). Finally, we investigate the impacts of the HARQ–ARQ Interaction on the Protocol Data Unit (PDU) transmission delay based on our simulation experiments. Copyright © 2009 John Wiley & Sons, Ltd.
The Methyl Group at C2 Carbon in {(2‐C4H3S)–C2(Me)=N–NH–C1(=S)NH2} Alters Iodide‐Bridging to Sulfur‐Bridging in Copper(I) Iodide Complexes
Authors: Lobana Tarlok S. , Sharma Rekha 
Published: July 2009

AbstractThe presence of methyl group at C2 carbon in {(2‐C4H3S)–C2(Me)=N–NH–C1(=S)NH2} leads to the formation of a sulfur‐bridged dinuclear complex [Cu2(μ‐S–Hattsc)2(η1‐I)2(Ph3P)2]·2H2O (1), in reaction of copper(I) iodide with the 2‐acetylthiophene thiosemicarbazone (Hattsc), unlike the usual iodo‐bridging in the absence of methyl substituent at C2 carbon. Water molecules are entrapped in eighteen membered cavities of 1D network.