bluuebunny/crossref_metadata_2025 huggingface dataset:
Precipitation Polymerization in Ethanol and Ethanol/Water to Prepare Uniform Microspheres of Poly(TMPTA‐styrene)
Authors: Kong Xiang Zheng , Gu Xiang Ling , Zhu Xiaoli , Zhang Lina
Published: March 2009

The precipitation polymerization of styrene‐trihydroxymethyl propane triacrylate has been carried out using ethanol and an ethanol/water mixture as the solvent. Uniform microspheres with high monomer conversion are achieved within 4 h, a much shorter polymerization time than that reported for the precipitation polymerization of divinyl benzene‐styrene in acetonitrile. The results clearly demonstrate that use of water as a co‐solvent is indeed very effective to promote the polymerization to high conversion and to obtain uniform microspheres. With no water under the otherwise same experimental conditions, only about 57% of monomer conversion is obtained; while the monomer conversion is remarkably increased to 96% when 12 vol.‐% of water is used.

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A direct method for a regularized least‐squares problem
Authors: Elfving Tommy , Skoglund Ingegerd
Published: March 2009

We consider a linear system of the form A1x1+ A2x2+η=b1. The vector η consists of identically distributed random variables all with mean zero. The unknowns are split into two groups x1 and x2. In the model usually there are more unknowns than observations and the resulting linear system is most often consistent having an infinite number of solutions. Hence some constraint on the parameter vector x is needed. One possibility is to avoid rapid variation in, e.g. the parameters x2. We formulate the problem as a partially regularized least‐squares problem, and propose a direct solution method based on the QR decomposition of matrix blocks. Further we consider regularizing using one and two regularization parameters, respectively. We also discuss the choice of regularization parameters, and extend Reinsch's method to the case with two parameters. Also the cross‐validation technique is treated. We present test examples taken from an application in modelling of the substance transport in rivers. Copyright © 2009 John Wiley & Sons, Ltd.
A mixed finite element method for non‐linear and nearly incompressible elasticity based on biorthogonal systems
Authors: Lamichhane Bishnu P.
Published: March 2009

We present a finite element method for non‐linear and nearly incompressible elasticity. The formulation is based on Petrov–Galerkin discretization for the pressure and is closely related to the average nodal pressure formulation presented earlier in the context of incompressible and nearly incompressible dynamic explicit applications (Commun. Numer. Meth. Engng 1998; 14:437–449). Some numerical examples are presented to show the efficiency of the approach. Copyright © 2009 John Wiley & Sons, Ltd.
Preparation and properties of water‐soluble chitosan and polyvinyl alcohol blend films as potential bone tissue engineering matrix
Authors: Ma Guiping , Yang Dongzhi , Su Dandan , Mu Xueyan , Kennedy John F , Nie Jun
Published: March 2009

The blend film was prepared by casting solutions of water‐soluble hydroxyethyacryl‐chitosan (HEA‐CS) and polyvinyl alcohol (PVA) and cross‐linked by glutaraldehyde. The structure and properties of the blend films were estimated by wide‐angle X‐ray diffraction (WXRD), contact angle measurements with water, and scanning electron microscopy (SEM). The tensile properties of the blend films were investigated and the tensile strength (TS) and the elongation increased with the increased amount of PVA. The thermal stability (thermogravimetric (TG) and derivative thermogravimetric (DTG)) was evaluated and HEA‐CS was more thermally‐stable than that of PVA. The water swelling properties analysis indicated that HEA‐CS in the blends promoted the water absorption owing to its porous structure and the antimicrobial ability of the blend films was retained. Indirect cytotoxicity assessment of the blend films with human bone sarcoma cell (SW1353) indicated that the biomaterials were non‐toxic and did not release substances harmful to living cells. Copyright © 2009 John Wiley & Sons, Ltd.
Genomic and phenotypic analysis reveals a key role for CCN1 (CYR61) in BAG3—modulated adhesion and invasion
Authors: Kassis Jareer N , Virador Victoria M , Guancial Elizabeth A , Kimm Daniel , Ho Allen S , Mishra Mark , Chuang Eric Y , Cook John , Gius David , Kohn Elise C
Published: March 2009

Chaperone protein quantity may regulate the balance of proteins involved in invasion and malignancy. BAG3 is a co‐chaperone and pro‐survival protein that has been implicated in adhesion, migration, and metastasis. We reported that BAG3 overexpression in MDA435 human breast cancer cells results in a significant decrease in migration and adhesion to matrix molecules that is reversed upon deletion of the BAG3 proline‐rich domain (dPXXP). We now hypothesize that transcriptional analysis would identify proteins involved in matrix‐related processes that are regulated by BAG3 and/or its PXXP domain mutant. Expression array analysis of MDA435 cells overexpressing either wild‐type BAG3 (FL) or dPXXP identified CCN1 as a BAG3 target protein. CCN1 is a known AP‐1 target. Increased AP‐1 transcriptional activity and AP‐1 DNA‐binding was found in MDA435 dPXXP cells. Consistent with these findings, CCN1 quantity and secretion were increased in dPXXP mutants but suppressed in FL cells; both BAG3 forms resulted in up‐regulated CCN1 in HeLa cells. CCN1 silencing in the BAG3 FL overexpressors reduced the already low phospho‐integrin β1 in response to attachment on collagen IV. Matrigel invasion of HeLa cells engineered with the BAG3 constructs was enhanced in FL cells and minimal in dPXXP cells. CCN1 silencing blocked a greater percentage of the serum‐induced invasion in FL cells than in dPXXP cells. This implies a context‐dependent function of BAG3 on CCN1 and thus mesenchymal behaviour. CCN1 may be necessary for adhesion and matrix‐related signalling in FL cells, abrogating a negative signal of the PXXP domain when BAG3 is intact. We propose that BAG3 regulates CCN1 expression to regulate tumour cell adhesion and migration. Published in 2009 by John Wiley & Sons, Ltd.
Ovarian tumor in a 12‐year old female with severe hypothyroidism: A case of Van Wyk and Grumbach syndrome
Authors: Hunold Andrea , Alzen Gerhard , Wudy Stefan A. , Bluetters‐Sawatzki Renate , Landmann Eva , Reiter Alfred , Wagner Hans‐Joachim
Published: March 2009

We report a 12‐year‐old female presenting with an abdominal tumor. Diagnostic workup revealed giant bilateral ovarian cysts, severe hypothyroidism as well as an elevation of CA 125. We refrained from ovariectomy, which would be necessary for a malignant tumor, in view of an evident Van Wyk and Grumbach syndrome. The patient promptly responded to L‐thyroxine with complete regression of all symptoms. Hypothyroidism should be considered in the evaluation of ovarian cysts. Although the Van Wyk and Grumbach syndrome is rare, it is crucial to rule it out in order to avoid unnecessary ovarian surgery when thyroid replacement is completely sufficient. Pediatr Blood Cancer 2009;52:677–679. © 2009 Wiley‐Liss, Inc.
Qualitative and quantitative determination of hydrolysable tannins and other polyphenols in herbal products from meadowsweet and dog rose
Authors: Fecka Izabela
Published: March 2009

Introduction

Meadowsweet and dog rose are used as herbal medicines and foodstuffs. Their biological and pharmacological properties are mainly attributed to vitamins, flavonoids and tannins known to be effective antioxidants.

Objective

To evaluate the distribution of hydrolysable tannins and other polyphenols in commercially available products of Filipendula ulmaria and Rosa canina.

Methodology

In order to evaluate the distribution of polyphenols, the isolation and structure elucidation of six ellagitannins (tellimagrandins I and II, rugosins A, B, D and E) along with other well‐known compounds was performed. Further high‐performance chromatographic methods (HPLC, HPTLC) were developed for qualitative and quantitative studies of phenolic acids, flavonoids and tannins in meadowsweet flowers and dog rose fruits. The analysis of linearity, limits of detection and quantification, precision and accuracy showed that the HPLC assay was sufficiently precise for content evaluation. Selection of a suitable solvent and optimisation of the sample extraction procedure were also carried out.

Results

Amounts of more than 20 polyphenols were estimated in the studied pharmaceuticals (27 products of meadowsweet and 10 products of dog rose) using a Chromolith Performance RP‐18e column and UV detection. Methyl gallate 3‐O‐β‐glucoside was identified for the first time in dog rose, while rugosins A, B and E are new meadowsweet constituents.

Conclusion

The results showed that meadowsweet flowers and rose hips with seeds yielded 55.53–124.8 and 0.43–1.26 mg/g of ellagitannins, respectively. The sum of detected polyphenols was 83.88–165.68 mg/g for Filipendulae ulmariae flos and 1.21–2.66 mg/g for Rosae pseudo‐fructus cum fructibus. Copyright © 2009 John Wiley & Sons, Ltd.
Preparation and reflectance properties of new cholesteric liquid crystalline copolymers containing cholesteryl group
Authors: Guo Jinbao , Liu Fang , Zhang Lipei , Cao Hui , Yang Huai
Published: March 2009

In this study, a new family of side‐chain cholesteric liquid crystal copolymers derived from cholesterol substituents were synthesized. The chemical structures of the copolymers were validated by FTIR and1H NMR. A wide‐band reflective polarizer from the above copolymers with stable optical properties was developed. The pitch gradient was formed by molecular diffusion between adjacent liquid crystal layers based on these cholesteric copolymers with different pitch lengths, and the pitch gradient was further stabilized by UV crosslinking of the polymerizable monomers during the diffusion process. The stability of these systems as a function of time was investigated. The polymer network was validated by scanning electron microscopy and this network played an important role in stabilizing the pitch gradient of the system. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Use of porous ion exchange film for glucose sensing
Authors: Hotta Saori , Miyano Kazuki , Aoki Hidemitsu , Fujiwara Nobuaki , Masui Akihiko , Yano Daisaku , Sano Kazuhiko , Yamanaka Koji , Kimura Chiharu , Sugino Takashi
Published: March 2009

A rapid response biological and chemical sensor capable of detection to the micromolar level is required for health and environmental monitoring. We have investigated the glucose sensing by using a porous ion exchanger with a three‐dimensional open‐cellular monolith structure. Glucose oxidase (GOD), a typical enzyme, is effectively immobilized on the porous anion exchange film. Addition of glucose to the immobilized GOD results in the production of gluconic acid. The impedance of the ion exchange film increases linearly with glucose concentration, which can be indirectly detected by monitoring gluconic acid concentration. The results demonstrate the potential of the porous anion exchanger as a high performance device for sensitive detection of biological substances. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Thermal conductivity and mechanical properties of aluminum nitride filled linear low‐density polyethylene composites
Authors: Gu Junwei , Zhang Qiuyu , Dang Jing , Zhang Junping , Yang Zhaoying
Published: March 2009

To acquire polymer composites with high thermal conductivity and mechanical properties, the aluminum nitride (AlN) microparticles modified with titanate coupling reagent of isopropyltrioleictitanate (NDZ‐105) were employed to blend linear low‐density polyethylene (LLDPE) via powder mixing method. Thermal conductive coefficient of the AlN/LLDPE composites was measured using hot disk thermal analyzer, and the thermal stability characteristics of AlN/LLDPE composites were mainly investigated via thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC). The results indicated that the use of AlN particles modified by NDZ‐105 significantly enhanced thermal conductivity and mechanical properties of AlN/LLDPE composites. The thermal conductivity coefficient λ was 1.0842 W/mk with 30% volume fraction of AlN, about three times higher than that of native LLDPE. The tensile strength of composites was maximum (17.42 MPa) with 20% mass fraction of AlN. DSC analyses results indicated that AlN had an influence on the melting temperature and the crystallinity of LLDPE. Additionally, TGA analyses showed that the thermal stability of LLDPE was significantly increased with addition of AlN. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Thermodynamic characterization of hybrid polymer blend systems
Authors: Ophir Amos , Zonder Lior , Rios Pablo F.
Published: March 2009

A thermodynamic model was used to predict the morphology of hybrid multicomponent polymer blend systems. Two systems were studied, both including two noncompatible polymers, a third compatibilizer polymer and layered, organo‐treated clays. The polar and nonpolar contributions of the surface energies of the components of the systems were calculated using measurements of the contact angles. The morphology of the multicomponent systems and the relative position of the organo‐clays within them, were predicted by calculating the interaction energies between the different components of the system and evaluating these values according to the Vaia and Giannelis thermodynamic model for polymer melt intercalation in organically modified layered silicates. The experimental results show good correlation with the prediction that the organo‐clays will have higher affinity to the compatibilizer polymer component situated at the interface between the two noncompatible blend components. In addition, the presence of the organo‐clays in this interface was found to have a significant additional compatibilizing effect between the two polymer phases. The results presented in this work support the idea that hybrid formation via polymer melt intercalation depends mostly on energetic factors that can be determined from surface energies of polymers and organo‐modified layered silicates, also in the case of multiphase polymer system. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Synthesis of poly (vinylcatechols)
Authors: Daly William H. , Moulay Saad
Published: March 2009

Five vinylcatechol precursors have been synthesized by either alcohol dehydration or Wittig coupling techniques. Dehydration of the appropriate sec‐phenethyl alcohol is the most efficient synthetic approach: the following monomers (yields) are reported: 5‐vinyl‐1,3‐benzodioxole, I (63%); 3,4‐dimethoxystyrene, II (45%); 2,3‐dimethoxystyrene, III (85%);6‐vinyl‐1,4‐benzodioxane.IV(65%); and4‐vinyl‐l,3‐benzodioxole, V(50%). The monomers can be converted by free‐radical techniques to polymers with molecular weights up to 95,000. Monomers I, II, IV, and V polymerized in the presence of stannic chloride; monomers I, III, and IV yielded polymers upon treatment with butyllithium. With the exception of poly IV, the blocking groups can be removed by treatment with boron trichloride followed by methanolysis to liberate poly(3‐vinyl‐ or 4‐vinylcatechol). Suprisingly, the stability of the catechol polymers depends upon the substituent distribution; poly(3‐vinylcatechol) is more stable than any polycatechol previously reported. It is soluble in methanol, autooxidizes very slowly, but can be oxidized by ceric ammonium nitrate to poly(3‐vinyl‐1,2‐benzoquinone).
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

Standard 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

Nature'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

Fusarium 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

BACKGROUND: 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

The 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

Select 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

Arrays 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

Nanoporous 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

Mesosphere – 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

Monosaccharide 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

The 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

The 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

The 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

Genetic 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

Kin 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.
Large-Scale Assessment of Change in Student Achievement: Dutch Primary School Students’ Results on Written Division in 1997 and 2004 as an Example
Authors: van den Heuvel-Panhuizen Marja , Robitzsch Alexander , Treffers Adri , Köller Olaf
Published: March 2009

This article discusses large-scale assessment of change in student achievement and takes the study by Hickendorff, Heiser, Van Putten, and Verhelst (2009) as an example. This study compared the achievement of students in the Netherlands in 1997 and 2004 on written division problems. Based on this comparison, they claim that there is a performance decline in this subdomain of mathematics, and that there is a move from applying the digit-based long division algorithm to a less accurate way of working without writing down anything. In our discussion of this study, we address methodological challenges that come in when investigating long-term trends in student achievements, such as the need for adequate operationalizations, the influence of the time of measurement and the necessity of the comparability of assessments, the effect of the assessment format, and the importance of inclusion relevant covariates in item response models. All these issues matter when assessing change in student achievement.
On Insensitivity of the Chi-Square Model Test to Nonlinear Misspecification in Structural Equation Models
Authors: Mooijaart Ab , Satorra Albert
Published: March 2009

In this paper, we show that for some structural equation models (SEM), the classical chi-square goodness-of-fit test is unable to detect the presence of nonlinear terms in the model. As an example, we consider a regression model with latent variables and interactions terms. Not only the model test has zero power against that type of misspecifications, but even the theoretical (chi-square) distribution of the test is not distorted when severe interaction term misspecification is present in the postulated model. We explain this phenomenon by exploiting results on asymptotic robustness in structural equation models. The importance of this paper is to warn against the conclusion that if a proposed linear model fits the data well according to the chi-quare goodness-of-fit test, then the underlying model is linear indeed; it will be shown that the underlying model may, in fact, be severely nonlinear. In addition, the present paper shows that such insensitivity to nonlinear terms is only a particular instance of a more general problem, namely, the incapacity of the classical chi-square goodness-of-fit test to detect deviations from zero correlation among exogenous regressors (either being them observable, or latent) when the structural part of the model is just saturated.
The Tag Test for Dupuytren's Surgery
Authors: Charalambous C. P. , Mills S. P. , Hayton M. J.
Published: March 2009

Digital nerve injury is a well-recognised complication of surgical treatment for Dupuytren's disease. We describe a simple test, the Tag test, that can be used intra-operatively to help identification of the digital nerves.
Synthesis and Characterization of Glomerate GaN Nanowires
Authors: Qin Lixia , Xue Chengshan , Duan Yifeng , Shi Liwei
Published: March 2009

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

Purpose

Sudden 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.

Methods

Male 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.

Results

The 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.

Conclusions

The 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.
The heliospheric magnetic field and the solar wind during the solar cycle
Authors: Fisk Lennard A. , Zhao Liang
Published: March 2009

The heliospheric magnetic field and the solar wind are behaving differently in the current solar minimum, compared to the previous minimum. The radial component of the heliospheric magnetic field, and thus the average value of the component of the solar magnetic field that opens into the heliosphere, the so-called open magnetic flux of the Sun, is lower than it was in the previous solar minimum; in fact, lower than in any previous solar minimum for which there are good spacecraft observations. The mass flux, the ram pressure, and the coronal electron temperature as measured by solar wind charge states are also lower in the current minimum compared to the previous one. This situation provides an opportunity to test some of the concepts for the behavior of the heliospheric magnetic field and the solar wind that have been developed; to improve these theories, and to construct a theory for the solar wind that accounts for the observed behavior throughout the solar cycle, including the current unusual solar minimum.
Magnetic helicity of solar active regions
Authors: Nindos A.
Published: March 2009

Magnetic helicity is a quantity that describes the linkage and twistedness/shear in the magnetic field. It has the unique feature that it is probably the only physical quantity which is approximately conserved even in resistive MHD. This makes magnetic helicity an ideal tool for the exploration of the physics of eruptive events. The concept of magnetic helicity can be used to monitor the whole history of a CME event from the emergence of twisted magnetic flux from the convective zone to the eruption and propagation of the CME into interplanetary space. In this article, I discuss the sources of the magnetic helicity injected into active regions and the role of magnetic helicity in the initiation of solar eruptions.
Three-dimensional MHD modeling of waves in active region loops
Authors: Ofman Leon , Selwa Małgorzata
Published: March 2009

Observations show that MHD waves are one of the most important universal processes in the heliosphere. These waves are likely to play an important role in energy transfer in the heliosphere, and they can be used as a diagnostic tool of the properties of the local magneto-fluid environment. Recent observations by TRACE and Hinode satellites provide ample evidence of oscillations in coronal active region loops. The oscillations were interpreted as fast (kink), slow, and Alfvén modes, and the properties of the waves were used for coronal seismology. However, due to the complex interactions of the various modes in the inhomogeneous active region plasma, and due to nonlinearity, idealized linear theory is inadequate to properly describe the waves. To overcome this theoretical shortcoming we developed 3D MHD models of waves in active region loops. We investigated the effects of 3D active region magnetic and density structure on the oscillations and the wave dissipation, and we investigated the oscillation of individual loops. Some loops were constructed to contain several threads and twist. Here, we present the results of our models, and show how they can be used to understand better the properties of the waves, and of the active regions.
Stellar mass ejections
Authors: Jardine Moira , Donati Jean-Francois , Gregory Scott G.
Published: March 2009

It has been known for some time now that rapidly-rotating solar-like stars possess the stellar equivalent of solar prominences. These may be three orders of magnitude more massive than their solar counterparts, and their ejection from the star may form a significant contribution to the loss of angular momentum and mass in the stellar wind. In addition, their number and distribution provide valuable clues as to the structure of the stellar corona and hence to the nature of magnetic activity in other stars.

Until recently, these “slingshot prominences” had only been observed in mature stars, but their recent detection in an extremely young star suggests that they may be more widespread than previously thought. In this review we will summarise our current understanding of these stellar prominences, their ejection from their stars and their role in elucidating the (sometimes very non-solar) behaviour of stellar magnetic fields.
Statistical relationship between solar flares and coronal mass ejections
Authors: Yashiro Seiji , Gopalswamy Nat
Published: March 2009

We report on the statistical relationships between solar flares and coronal mass ejections (CMEs) observed during 1996-2007 inclusively. We used soft X-ray flares observed by the Geostationary Operational Environmental Satellite (GOES) and CMEs observed by the Large Angle and Spectrometric Coronagraph (LASCO) on board the Solar and Heliospheric Observatory (SOHO) mission. Main results are (1) the CME association rate increases with flare's peak flux, fluence, and duration, (2) the difference between flare and CME onsets shows a Gaussian distribution with the standard deviation σ = 17 min (σ = 15 min) for the first (second) order extrapolated CME onset, (3) the most frequent flare site is under the center of the CME span, not near one leg (outer edge) of the CMEs, (4) a good correlation was found between the flare fluence versus the CME kinetic energy. Implications for flare-CME models are discussed.