bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparing 6 and 10 sec exhalation time in exhaled nitric oxide measurements in children
Authors: Koopman M. , Arets H.G.M. , Uiterwaal C.S.P.M , van der Ent C.K. 
Published: March 2009

AbstractStandard exhalation time for Fractional exhaled Nitric Oxide (FeNO) measurements is 10 sec but this is difficult for young children. Recommended exhalation time for children is 6 sec, but this was never substantiated in literature. We aimed to investigate the agreement between FeNO values measured with exhalation times of 6 and 10 sec and the preference of children for either method. The study population comprised children aged 5–17 years visiting the Pediatric Pulmonology outpatient clinic. FeNO values, measured during 6 (FeNO‐6) and 10 (FeNO‐10) sec (random order) using the single‐breath online (SBOL) technique, were compared. Preferences for exhalation times were related to FVC values. Ninety‐eight children (mean age 10.6 years) were included. Median FeNO‐6 (15.2 ppb) and FeNO‐10 (13.6 ppb) did not differ significantly (P = 0.259). Mean difference between FeNO‐6 and FeNO‐10 was −0.3 ppb, limits of agreement ranging from −5.8 ppb to +5.3 ppb. Sixty percent of children with a Forced Vital Capacity (FVC) less than 3 L preferred the FeNO‐6 method. We found good agreement between FeNO‐6 and FeNO‐10, so they can be used interchangeably. An exhalation time of 6 sec was preferred by the majority of subjects with a FVC below 3 L. Pediatr Pulmonol. 2009; 44:340–344. © 2009 Wiley‐Liss, Inc.
Engineered disulfides improve mechanical properties of recombinant spider silk
Authors: Grip S. , Johansson J. , Hedhammar M. 
Published: March 2009

AbstractNature's high‐performance polymer, spider silk, is composed of specific proteins, spidroins, which form solid fibers. So far, fibers made from recombinant spidroins have failed in replicating the extraordinary mechanical properties of the native material. A recombinant miniature spidroin consisting of four poly‐Ala/Gly‐rich tandem repeats and a nonrepetitive C‐terminal domain (4RepCT) can be isolated in physiological buffers and undergoes self assembly into macrofibers. Herein, we have made a first attempt to improve the mechanical properties of 4RepCT fibers by selective introduction of AA → CC mutations and by letting the fibers form under physiologically relevant redox conditions. Introduction of AA → CC mutations in the first poly‐Ala block in the miniature spidroin increases the stiffness and tensile strength without changes in ability to form fibers, or in fiber morphology. These improved mechanical properties correlate with degree of disulfide formation. AA → CC mutations in the forth poly‐Ala block, however, lead to premature aggregation of the protein, possibly due to disulfide bonding with a conserved Cys in the C‐terminal domain. Replacement of this Cys with a Ser, lowers thermal stability but does not interfere with dimerization, fiber morphology or tensile strength. These results show that mutagenesis of 4RepCT can reveal spidroin structure‐activity relationships and generate recombinant fibers with improved mechanical properties.
Structural and functional characterization of TRI3 trichothecene 15‐O‐acetyltransferase from Fusarium sporotrichioides
Authors: Garvey Graeme S. , McCormick Susan P. , Alexander Nancy J. , Rayment Ivan 
Published: March 2009

AbstractFusarium head blight is a devastating disease of cereal crops whose worldwide incidence is increasing and at present there is no satisfactory way of combating this pathogen or its associated toxins. There is a wide variety of trichothecene mycotoxins and they all contain a 12,13‐epoxytrichothecene skeleton but differ in their substitutions. Indeed, there is considerable variation in the toxin profile across the numerous Fusarium species that has been ascribed to differences in the presence or absence of biosynthetic enzymes and their relative activity. This article addresses the source of differences in acetylation at the C15 position of the trichothecene molecule. Here, we present the in vitro structural and biochemical characterization of TRI3, a 15‐O‐trichothecene acetyltransferase isolated from F. sporotrichioides and the “in vivo” characterization of Δtri3 mutants of deoxynivalenol (DON) producing F. graminearum strains. A kinetic analysis shows that TRI3 is an efficient enzyme with the native substrate, 15‐decalonectrin, but is inactive with either DON or nivalenol. The structure of TRI3 complexed with 15‐decalonectrin provides an explanation for this specificity and shows that Tri3 and Tri101 (3‐O‐trichothecene acetyltransferase) are evolutionarily related. The active site residues are conserved across all sequences for TRI3 orthologs, suggesting that differences in acetylation at C15 are not due to differences in Tri3. The tri3 deletion mutant shows that acetylation at C15 is required for DON biosynthesis even though DON lacks a C15 acetyl group. The enzyme(s) responsible for deacetylation at the 15 position of the trichothecene mycotoxins have not been identified.
The influence of simulated immigration and chemical persistence on recovery of macroinvertebrates from cypermethrin and 3,4‐dichloroaniline exposure in aquatic microcosms
Authors: Maund Steve , Biggs Jeremy , Williams Penny , Whitfield Mercia , Sherratt Thomas , Powley Will , Heneghan Phil , Jepson Paul , Shillabeer Nigel 
Published: March 2009

AbstractBACKGROUND: Chemical dissipation and organism immigration are considered important factors that influence recovery potential from perturbation of aquatic macroinvertebrates. Experiments were conducted to investigate the effect of simulated immigration on recovery of aquatic macroinvertebrates exposed in outdoor microcosms to ecotoxicologically similar concentrations of the rapidly dissipating pyrethroid insecticide cypermethrin (70 ng L−1) or the more persistent herbicide intermediate and degradate 3,4‐dichloroaniline (10 mg L−1). Microcosms were covered with light‐permeable mesh to prevent recolonisation. Immigration was simulated by the regular addition of organisms after treatment.RESULTS: Microcosms exposed to 3,4‐dichloroaniline treatment suffered substantial loss of taxon richness and by 10 months after treatment had only recovered where invertebrates had been added. Those treated with cypermethrin underwent an initial decline in certain crustacean and insect populations. These populations showed some signs of recovery over a period of 5 months through internal processes alone. However, rate of recovery was further enhanced where immigration was simulated, and in this case recovery had occurred around 100 days after treatment.CONCLUSION: Although not the only factors involved, simulated immigration and chemical fate clearly influence the ability of communities to recover from chemical exposure. Consideration of immigration processes and development of models will help to increase the realism of risk assessments. Copyright © 2009 Society of Chemical Industry
Hydrogen and carbon interaction in a FeNi alloy with a vacancy
Authors: Gonzalez Estela , Jasen Paula , Gonzalez Gabriel , Moro Lilian , Juan Alfredo 
Published: March 2009

AbstractThe bonding of hydrogen and carbon to Fe and Ni in a 50:50 alloy is analysed using density functional calculations. The changes in the electronic structure of a L10 alloy upon C and H introduction at a vacancy region are addressed and a comparison with H or C in pure metals is drawn. H in bulk FeNi alloy with a vacancy locates at a tetrahedral site shifted towards the vacancy. Instead, C prefers an octahedral site (Fe based). The vacancy acts as strong traps of both C and H. Fe–Ni atoms are initially more strongly bonded to each other due to the vacancy formation. Consequently, the Fe–Fe, Fe–Ni and Ni–Ni bond strengths are diminished as new metal–C or metal–H bonds are formed. The most affected bond is the Fe–Ni, whose overlap population decreases by 72%. An analysis of the orbital interaction reveals that the Fe–H bonding involves mainly the Fe 4s, H 1s and Ni 4s orbitals. In the case of the sequential absorption, the C–H interaction is almost zero at a distance of 2.72 Å. The main interactions of these interstitials are developed with either Fe or Ni. We also consider the absorption sequence (H first or C first) and its influence on the electronic structure. Our results could be relevant to understand some steps of the carburization process during thermal cracking operations where hydrogen atoms are present. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Active microfiltered sensor interfaces, photocatalytic reactors, and microbatteries using combined micro/nanoporous interfaces
Authors: Gole James L. , Corno James , Ozdemir Serdar , Prokes Sharka , Shin Heon‐Cheol 
Published: March 2009

AbstractSelect active micro/nanoporous porous silicon (PS) interfaces have been formed and treated to form the scaffolding for sensors, photocatalysis‐based microreactors, and PS‐based lithium ion batteries. The introduction of active nanostructures is used to form sensitive and selective sensors. The introduction of TiO2‐xNx visible light absorbing nanophotocatalysts to the PS structure for the purpose of creating a microreactor, the concomitant metal ion seeding of these nanostructures to promote infrared spectral enhancement, introduce rapid room temperature phase transformation, and provide the potential for a novel active photovoltaic response are outlined. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
ZnO/CdSe nanowires and nanotubes: formation, properties and applications
Authors: Lévy‐Clément Claude , Elias Jamil , Tena‐Zaera Ramon 
Published: March 2009

AbstractArrays of vertically aligned ZnO nanotubes were obtained in two steps by combining the electrochemical deposition and chemical dissolution of the nanowire core. In the first step arrays of nanowires (diameter ∼ 200 nm, length ∼ 1.5 μm) were electrodeposited from O2 reduction in aqueous zinc chloride solutions. In the second step, the chemical dissolution of the nanowire core in a neutral pH chloride solution led to the formation of arrays of ZnO nanotubes with the same external dimensions and a wall thickness of ∼ 35 nm. Nanowires and nanotubes exhibited single‐crystalline nature and no spurious phases were detected. The light scattering in both types of arrays was studied, emphasizing its influence on the sensitization of ZnO to solar light, by using a CdSe nanocrystalline coating as a light absorber. For a constant amount of CdSe deposited, the ZnO/CdSe nanowire arrays had a slightly higher effective absorption of the solar light (86% in the 400–725 nm range of (AM1.5) solar spectrum) than the ZnO/CdSe nanotubes (84%). However, ZnO/CdSe nanotubes exhibit a more attractive morphology for the transfer of electrical charge carriers and arrays of ZnO nanotubes appear to be very promising building blocks for nanostructured solar cells. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Manufacture and investigation of nanoporous titanium oxide photoelectrodes
Authors: Aroutiounian Vladimir , Arakelyan Valeri , Shahnazaryan Gohar , Khachaturyan Emma , Stepanyan Gnel 
Published: March 2009

AbstractNanoporous titanium oxide thin films were manufactured at room temperature by anodization of commercial titanium plate in the aqueous solution containing 0.5% hydrofluoric acid at constant voltage (10, 15, 20, 25 and 30 V) during 20 minutes. The subsequent annealing immediately after growing in air at temperature 550 °C during one hour was carried out for manufacture of semiconductor crystalline thin film photoelectrodes made of TiO2‐x.The element analysis and surface structure of produced titanium oxide films were investigated. Thickness of films, the average diameter and wall thicknesses of pores were determined. The current‐voltage characteristics of manufactured nanostructure titanium oxide photoelectrodes were measured. The dependences of photoelectrolysis current density on technological modes of preparing of the titanium oxide films were investigated. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mesosphere–stratosphere transport during Southern Hemisphere autumn deduced from MIPAS observations
Authors: Lahoz W.A. , Orsolini Y.J. , Geer A.J. , Choi W. , Allen D.R. 
Published: March 2009

AbstractMesosphere – stratosphere transport during Southern Hemisphere autumn (March–June 2003) is studied using a pole‐centred approach of along‐orbit sequences of vertical profiles of methane observations from the Envisat MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) instrument suppl1emented by meteorological analyses from ECMWF and the Met Office. We hypothesize that the methane distribution can be explained as a combination of two transport processes: (1) isentropic transport in the lower mesosphere and upper stratosphere of methane‐rich air from low/mid latitudes to high latitudes during early autumn, and (2) diabatic descent at high latitudes of methane‐poor air from the lower mesosphere during autumn. Calculations of stratospheric effective diffusivity provide broad support for this hypothesis. The along‐orbit data are shown to provide more information than studies using spatial and temporal averages of the same MIPAS methane data, and to explain anomalous features in the methane distribution, where the vertical gradient is reversed, reported by studies using MIPAS and ILAS‐II data. Copyright © 2009 Royal Meteorological Society
Electron impact ion fragmentation pathways of peracetylated C‐glycoside ketones derived from cyclic 1,3‐diketones
Authors: Adeuya Anthony , Price Neil P. J. 
Published: March 2009

AbstractMonosaccharide C‐glycoside ketones have been synthesized by aqueous‐based Knoevenagel condensation of isotopically labeled and unlabeled aldoses with cyclic diketones, 5,5‐dimethyl‐1,3‐cyclohexanedione (dimedone) and 1,3‐cyclohexanedione (1,3‐CHD). The reaction products and their corresponding acetylated analogs produce characteristic molecular adduct ions by matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐TOF MS). Analysis of the peracetylated C‐glycosides by electron ionization (EI) gas chromatography/mass spectrometry (GC/MS) revealed diagnostic fragment ions that have been used to deduce the EI fragmentation pathways and the structure of each C‐glycoside ketone. Characteristic gluco‐ and ribo‐specific ions were observed at m/z 350 and 278, respectively. Ions common to both carbohydrate fragmentation pathways were observed at m/z 193 and 169 for the dimedone‐C‐glycosides, and m/z 165 and 141 for the 1,3‐CHD‐C‐glycosides. Ions with m/z 169 and 141 retain the anomeric carbon (carbon‐1) of the original sugar, while m/z 193 and 165 are shown to retain carbons‐1, 2, and 3. Published in 2009 by John Wiley & Sons, Ltd.
Influence of extreme drawdown on water quality downstream of a large water storage reservoir
Authors: Baldwin D. S. , Wilson J. , Gigney H. , Boulding A. 
Published: March 2009

AbstractThe Serial Discontinuity Concept (SDC) proposes that dams have the potential to affect the downstream ecological condition of rivers. While the SDC was developed principally around changes to physical habitat or temperature, reservoirs also have the potential to impact on downstream water quality, including algal community structure. In the current study we examined the impacts of an extreme drawdown event on nutrient loads and algal community structure downstream of a large water storage reservoir in south‐eastern Australia—Lake Hume. The lake was a net exporter of carbon, nitrogen, phosphorus and iron during the study period and was a net sink for manganese. Most of the carbon, nitrogen and phosphorus exported from the lake was in the form of algal biomass. Processes in the lake also influenced the downstream algal community structure. Upstream of the reservoir green algae were the most dominant species; within and downstream of the reservoir cyanobacteria dominated. Much of the algal biomass found at the downstream sites appeared to originate in Lake Hume and was physically transported downstream. Copyright © 2009 John Wiley & Sons, Ltd.
Thermokinetic studies of the groups on TiO2 surface
Authors: Liu Peng , Duan Wenli , Liang Wuzhen , Li Xi 
Published: March 2009

AbstractThe properties of groups on TiO2 surface were evaluated by infrared (IR) spectra and thermal analysis. It could be found that water and ethanol are removed mainly between 343 and 363 K and the process is accompanied by an endothermic change. The results also show that ethanol could be removed completely below 673 K and the physically bonded or hydrogen‐bonded water could be removed almost completely above 873 K. The exothermic peaks ranging from 573 to 773 K are caused by the changes that chemisorbed water (Ti‐O‐H) on the surface condenses and evolves into water. There appears broad and unstable endothermic process in all temperature ranges due to the adhesions or transformations among the crystal particles. Thermogravimetry (TG) results show that with heat treatment at increasing temperatures, the groups on TiO2 surface decreases gradually. The half peak breadth of X‐ray diffractometer (XRD) results suggest that TiO2 crystallize better with higher temperature calcination. The photo‐catalytic efficiency was evaluated by UV‐Vis spectrophotometer. TiO2 with heat treatment at higher temperature shows more effective photo‐catalytic property. Copyright © 2009 John Wiley & Sons, Ltd.
Determination of optical constants of sol‐gel derived Zn0.9Mg0.1O films by spectroscopic ellipsometry with various models
Authors: Yang Shenghong , Liu Ying , Zhang Yueli , Mo Dang 
Published: March 2009

AbstractThe Zn0.9Mg0.1O thin films were prepared on Si (100) substrates by the sol‐gel method. The structural and the optical properties of Zn0.9Mg0.1O thin films, submitted to an annealing treatment in the 400–700 °C ranges, are studied by X‐ray diffraction (XRD) and ultraviolet (UV)‐visible spectroscopic ellipsometry (SE). The thickness, refractive index, and extinction coefficient of these films have been determined by analyzing the SE spectra using parameterized dispersion model. Moreover, we made a detailed comparison among various dispersion models and found that the Sellmeier model was superior to others in fitting the ellipsometric spectra in the transparent region. In the interband transition region, point‐by‐point fit was used. The spectral dependence of the refractive index and extinction coefficient was obtained in the photon energy range of 1.5–4.71 eV. The influence of annealing temperature on the refractive index, the extinction coefficient, and the optical bandgap energy was also discussed. We found that the refractive index and the extinction coefficient increase with increasing the annealing temperature, meaning the optical quality of Zn0.9Mg0.1O films is improved by annealing. Copyright © 2009 John Wiley & Sons, Ltd.
Inborn errors of purine and pyrimidine metabolism
Authors: Jurecka A. 
Published: March 2009

SummaryGenetic disorders of purine and pyrimidine (PP) metabolism are under‐reported and infrequently mentioned in the general literature, as well as in reviews dedicated to other inborn errors of metabolism. Owing to limited awareness, relatively recent recognition, as well as considerable phenotypic variation, these disorders may often be misdiagnosed or remain undiagnosed. Disorders that arise as a result of dysfunction in PP metabolism represent some of the most challenging diagnostic problems in medicine. In addition to their low prevalence rates, they also present with extremely variable signs and symptoms. They may affect any system in a variety of manners, and often mimic other, more recognizable disorders. The diagnostic problem is compounded by the fact that some biochemically affected patients are symptom‐free. Rapidly evolving laboratory techniques such as high‐performance liquid chromatography coupled to tandem mass spectrometry are now well established as the preferred method for detection for these defects, but currently the most important step in diagnosis consists of suspecting the disorder. Diagnosis is vital because genetic counselling can be provided and, in some cases, specific treatment can be offered that may slow or even reverse clinical symptoms. If undiagnosed, these disorders can be devastating to patients and their families, resulting in early death or institutionalization for the rest of patient's life. This article describes the current state of knowledge about inborn errors of purine and pyrimidine metabolism, focusing on the varying clinical presentations, the laboratory findings and discusses indications for selective screening for these disorders.
Effective paternity in natural colonies of Japanese native bumble bees
Authors: Kokuvo Nozomu , Toquenaga Yukihiko , Goka Koichi 
Published: March 2009

AbstractKin selection theory predicts a high coefficient of genetic relatedness among nestmates, explaining the frequent evolution of eusociality in a social hymenopteran colony. The bumble bee is a primitively eusocial hymenoptera whose colonies are founded by a single queen. In such a monogynous colony, mating frequency of the queen is the sole factor that affects genetic relatedness among nestmates. Although the queens of most bumble bee species are known to be monandrous, there are some species that are known to be polyandrous. Here, we estimated the effective paternity in the native colonies of Japanese bumble bees, Bombus ardens, B. diversus, and B. honshuensis, using genetic polymorphic data of microsatellites. We found no evidence for polyandry in any investigated colonies, which suggests that within‐colony genetic relatedness is very high for all of these colonies.
Synthesis and Characterization of Glomerate GaN Nanowires
Authors: Qin Lixia , Xue Chengshan , Duan Yifeng , Shi Liwei 
Published: March 2009

Abstract
Glomerate GaN nanowires were synthesized on Si(111) substrates by annealing sputtered Ga2O3/Co films under flowing ammonia at temperature of 950 °C. X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy and Fourier transformed infrared spectra were used to characterize the morphology, crystallinity and microstructure of the as-synthesized samples. Our results show that the samples are of hexagonal wurtzite structure. For the majority of GaN nanowires, the length is up to tens of microns and the diameter is in the range of 50–200 nm. The growth process of the GaN nanowires is dominated by Co–Ga–N alloy mechanism.
Time‐dependent changes in cardiovascular function during copulation in male rats
Authors: Terada Misao , Matsumura Atsufumi , Kromkhun Pudcharaporn , Taniguchi Kazumi , Sato Fumio , Sakurai Fujiro , Yokosuka Makoto , Nagy Gyorgy M. , Saito Toru R. 
Published: March 2009

AbstractPurposeSudden cardiac death after ejaculation has been reported in humans and highlights the important relationship between sexual behavior and the heart. The rat is an extremely useful animal model for investigating reproductive function in male mammals. In this study, we examined the relationship between autonomic nervous system activity and the circulatory system during sexual behavior in male rats.MethodsMale Wistar–Imamichi rats were exposed to female rats in estrous and heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and plasma noradrenaline (NA) and adrenaline (Ad) concentrations were measured by telemetry during copulation.ResultsThe resting HR was 365.5 ± 18.4 beats/min (mean ± SE), which increased to 531.2 ± 21.1 beats/min at ejaculation and decreased to 404.6 ± 30.7 beats/min 1 min after ejaculation. At rest, SBP and DBP were 123.8 ± 6.6 and 81.5 ± 4.1 mmHg, respectively, which increased to 154.5 ± 5.9 and 112.1 ± 7.3 mmHg at ejaculation. Baseline plasma Ad and NA concentrations were 151.6 ± 32.0 and 248.5 ± 22.5 pg/ml, respectively, and these increased to 393.8 ± 89.9 and 792.7 ± 154.0 pg/ml at ejaculation, after which they decreased to resting levels. The rate of increase in NA at ejaculation differed significantly from that of Ad.ConclusionsThe load on the circulatory and autonomic nervous systems is controlled by a rapid decrease in HR and NA concentration immediately after ejaculation, such that the male rat is prepared for the next copulation.