bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cloning and characterization of two cytochrome P450 CYP6AX1 and CYP6AY1 cDNAs from Nilaparvata lugens Stål (Homoptera: Delphacidae)
Authors: Yang Zhifan , Yang Haiyuan , He Guangcun 
Published: January 2007

AbstractTwo full‐length P450 cDNAs, CYP6AX1 and CYP6AY1, were cloned from the brown planthopper Nilaparvata lugens Stål (Homoptera: Delphacidae). Both CYP6AX1 and CYP6AY1 are typical microsomal P450s and their deduced amino acid sequences share common characteristics with other members of the insect P450 CYP6 family. CYP6AX1 and CYP6AY1 show the highest percent identity (36%) of amino acid to each other; both of them have 31–33% amino acid identity with CYP6B1 from Papilio polyxenes (Lepidoptera: Papilionidae), CYP6B4 from Papilio glaucus (Lepidoptera: Papilionidae), and CYP6B8 from Helicoverpa zea (Lepidoptera: Noctuidae). Phylogenetic analysis showed the clustering of CYP6AX1 and CYP6AY1 was in the clade including CYP6AE1 from Depressaria pastinacella (Lepidoptera: Oecophoridae) and the CYP6B family members from Helicoverpa and Papilio species. Northern blot analysis revealed that both of the P450s were induced by the resistant rice variety B5 (Oryza sativa L), and CYP6AY1 was expressed at a higher level than CYP6AX1. The results suggest that more than one P450s are likely involved in metabolism of rice allelochemicals and that they are possibly important components in adaptation of Nilaparvata lugens to host rice. Arch. Insect Biochem. Physiol. 64:88–99, 2007. © 2007 Wiley‐Liss, Inc.
Histone H1‐like, lysine‐rich low complexity amino acid extensions in mosquito ribosomal proteins RpL23a and RpS6 have evolved independently
Authors: Hernandez Vida P. , Fallon A.M. 
Published: January 2007

AbstractHistone H1‐like amino acid extensions have been described at the amino terminus of Drosophila RpL22 and RpL23a, and at the carboxyl terminus of mosquito ribosomal protein RpS6. An in silico search suggested that RpL23a, but not RpL22, in Anopheles gambiae has an amino‐terminal extension. Because low complexity amino acid extensions are not common on eukaryotic ribosomal proteins, and their functions are unknown, we cloned cDNAs encoding RpL23a from Aedes albopictus and Anopheles stephensi mosquito cell lines. RpL23a proteins in Aedes and Anopheles mosquitoes are rich in lysine (∼25%), alanine (∼21%), and proline (∼8%), have a mass of ∼40 kDa, a pI of 11.4 to 11.5, and contain an N‐terminal extension of approximately 260 amino acid residues. The N‐terminal extension in mosquito RpL23a is about 100 amino acids longer than that in the Drosophila RpL23a homolog, and contains several repeated amino acid motifs. Analysis of exon‐intron organization in the An. gambiae and in D. melanogaster genes suggests that a short first exon encodes a series of 11 amino acid residues conserved in RpL23a proteins from Drosophila, mosquitoes, and the moth, Bombyx mori. The histone H1‐like sequence in RpL23a is encoded entirely within the second exon. The C‐terminal 126 amino acid residues of the RpL23a protein, encoded by exon 3 in Drosophila, and by exons 3 and 4 in Anopheles gambiae, are well conserved, and correspond to Escherichia coli RpL23 with the addition of the eukaryotic N‐terminal nuclear localization sequence. Sequence comparisons indicate that the histone H1‐like extensions on mosquito RpS6 and RpL23a have evolved independently of each other, and of histone H1 proteins. Arch. Insect Biochem. Physiol. 64:100–110, 2007. © 2007 Wiley‐Liss, Inc.
Copper Oxide – Graphite Composite Electrodes: Application to Nitrite Sensing
Authors: Šljukić Biljana , Banks Craig E. , Crossley Alison , Compton Richard G. 
Published: January 2007

AbstractA simple method for the modification of carbon powder with copper oxides is presented. Carbon powder is impregnated with copper(II) nitrate by stirring carbon powder in copper(II) nitrate solution for 1 hour and subsequently thermally treated at 823 K. The modified carbon powder was characterized using electrochemical and spectroscopic techniques. The existence of both copper(I) and copper(II) oxides have been established. The copper oxide modified carbon powder was used for preparation of composite electrodes, and the electrochemical and electrocatalytic behavior of the resulting composite electrodes was studied. The copper oxide modified carbon powder – epoxy composite electrodes showed a high electrocatalytic activity for the nitrite detection in aqueous media, with the detection limit comparable or lower than detection limits obtained with other electrochemical sensors.
Electrocatalytic Properties of a Novel Poly‐1‐Naphthylamine‐Modified Electrode Using Ascorbic Acid as Molecule Probe
Authors: D'Eramo Fabiana , Sereno Leonides E. , Arévalo Alejandro H. 
Published: January 2007

AbstractA glassy carbon electrode was modified with an electropolymerized film of 1‐naphthylamine in aqueous solution. The electrocatalytic properties of this modified electrode (ME) were investigated using ascorbic acid (AA) as probe molecule. The electrochemical behavior of AA in buffer solution was examined by voltammetry and amperometry. The results showed that the ME exhibited good electrocatalytic activity towards the oxidation of AA, as a consequence, it can be used as amperometric sensor of this analyte in a flow injection system with good sensitivity. Calibration curves were linear over the concentration range 0.05–1.50 mM with a phosphate buffer solution pH 3 as the carrier, the detection limit was 1 ppm (S/N=3). The methods were applied to the determination of AA in beverages and pharmaceutical products. A good correlation with a reference method was attained.
Electrochemical Behavior of Catecholamines and Related Compounds at In Situ Surfactant Modified Carbon Paste Electrodes
Authors: Blanco‐López M.Carmen , Lobo‐Castañón M. Jesús , Ordieres Arturo J. Miranda , Tuñón‐Blanco Paulino 
Published: January 2007

AbstractThe voltammetric characteristics of catecholamines: epinephrine (E) and norepinephrine (NE) and related compounds: isoproterenol, metanephrine, L‐dopa, methyldopa, vanillylmandelic acid (VMA), and homovanillic acid (HVA) at unmodified and in situ surfactant‐ modified carbon paste electrodes were comparatively evaluated. For the basic and amphoteric compounds the modification of the electrode surface with submicellar concentrations of anionic surfactants (sodium dodecylsulfate, sodium decylsulfate or sodium dodecylsulfonate) produce an important current enhancement in its oxidation and reduction peak current together with the improvement in the reversibility of the processes. These effects were explained in basis on electrostatic and hydrophobic interactions. On the other hand, the oxidation of acidic metabolites, HVA and VMA, was studied at electrodes modified in situ with cationic surfactants. Under certain conditions the surfactant could stabilise some of the electrochemical reaction intermediates, thus explaining the different voltammetric behaviour of HVA and VMA.
Bismuth Film Electrode for Analysis of Tetracycline in Flow Injection System
Authors: Sattayasamitsathit Sirilak , Thavarungkul Panote , Kanatharana Proespichaya 
Published: January 2007

AbstractA bismuth film was prepared on glassy carbon electrode (GCE) and used in a flow injection amperometric system to analyze tetracycline. Bismuth film electrode (BiFE) preparation and flow injection amperometric parameters were optimized. System performances of BiFE were compared to GCE. BiFE was validated with three different lots of real sample, 250 mg tetracycline capsules, the results showed good agreement, i.e., between 240 and 260 mg per capsule. Good relative recoveries were also obtained in the range of 86–106%.
Chronoamperometric and Voltammetric Characterization of Gold Ultramicroelectrode Arrays
Authors: González‐García Olga , Ariño Cristina , Díaz‐Cruz José Manuel , Esteban Miquel 
Published: January 2007

AbstractSome prototypes of photolithographic‐built arrays of gold ultramicroelectrodes (UMEAs) have been electrochemically characterized and compared with a normal‐size electrode. The achievement of steady‐state conditions, effects of supporting electrolyte and the role of conditioning and activation have been considered. The results obtained show that it is possible to monitor the effective area of those devices by chronoamperometry, which confirms the convenience of using the internal auxiliary and reference electrodes and this evidences that steady‐state currents are holding in a wide range of scan rates. Additionally, some preliminary tests show the promising features of gold UMEAs in flow systems like FIA or HPLC.
Capacitive Sensing of Amino Acids Using Caliraxene‐Coated Silicon Transducers
Authors: Ijeri Vijaykumar , Vocanson Francis , Martelet Claude , Jaffrezic‐Renault Nicole 
Published: January 2007

AbstractThe possibility of using capacitance and flat band voltage as measurable quantities for determining amino acids that are neither electroactive nor with strong UV‐vis absorption has been explored. The sensors were fabricated by immobilizing calixarene derivatives on Si/SiO2/Si3N4 transducers. The measurements were made in sulfuric acid media of ca. pH 1 and in physiological buffer of pH 7.4. The different calixarene derivatives showed varying sensitivities to the amino acids ranging from 8 to 137 mV/decade.
Electroanalytical Exploitation of Nitroso Phenyl Modified Carbon‐Thiol Interactions: Application to the Low Voltage Determination of Thiols
Authors: Abiman Poobalasingam , Wildgoose Gregory G. , Compton Richard G. 
Published: January 2007

AbstractThe electrochemical generation of nitrosophenyl groups covalently attached to graphite powder (nitrosophenylcarbon) from carbon powder chemically modified with nitrophenyl groups and their subsequent reaction with thiols (glutathione, cysteine and homocysteine) has been investigated as a method by which the later can be quantified. The modified carbon powder was immobilized onto a basal plane pyrolytic graphite electrode and characterized by cyclic voltammetry by scanning between 1.0 V and −1.0 V vs. SCE in phosphate buffer (pH 7). Square wave voltammetry (SWV) was used for the determination of thiols and the SWV parameters were optimized. The nitrosophenylcarbon is electrogenerated from nitrophenylcarbon and can chemically oxidize thiols to disulfides. Subsequent reduction of nitrosophenylcarbon to phenylhydroxylaminecarbon during the square wave voltammetric process leads to a decrease in the reductive current. This can be correlated to the concentration of thiol present within the medium. The cyclic voltammetric responses of basal plane pyrolytic graphite electrode, edge plane pyrolytic graphite electrode, glassy carbon electrode and boron‐doped diamond electrode in the direct oxidation of thiols were also investigated and all were found to have a significantly higher overpotential compared to the described method using nitrosophenylcarbon.
The evolution of problem and social competence behaviors during toddlerhood: A prospective population‐based cohort survey
Authors: Baillargeon Raymond H. , Normand Claude L. , Séguin Jean R. , Zoccolillo Mark , Japel Christa , Pérusse Daniel , Wu Hong‐Xing , Boivin Michel , Tremblay Richard E. 
Published: January 2007

AbstractResearch in developmental psychopathology has long been preoccupied with rather broad categories of behavior, but we know little about the specific behaviors that comprise these categories. The objective of this study was to: (a) estimate the prevalence of problem and social competence behaviors in the general population of children at 17 months of age, and (b) describe the continuity and discontinuity in the degree to which children exhibit these behaviors between 17 and 29 months of age. The results show that frequent problem behaviors are not typical of children under two years of age. Further, the results suggest that it is possible to distinguish between different types of problem behaviors before two years of age. In addition, the results show that gender differences in some problem behaviors are already present before two years of age, and increase in magnitude during toddlerhood. Finally, the results show that interindividual differences in problem behaviors observed before two years of age are stable. The predictive accuracy of frequent problem behaviors in children at 17 months of age was limited, however, with often a majority of toddlers not behaving this way a year later. Overall, our results suggest that toddlerhood represents a critical period when behavioral and emotional problems of potentially clinical significance emerge. Pediatricians should routinely ask parents to report the frequency of their young children's problem behaviors during child health supervision visits so that children whose frequent problem behaviors persist over time can be identified and possibly referred for treatment.
Peripheral white blood cell toxicity induced by broad spectrum cyclin‐dependent kinase inhibitors
Authors: Jessen Bart A. , Lee Leo , Koudriakova Tatiana , Haines Morgan , Lundgren Karen , Price Sharon , Nonomiya Jim , Lewis Cristina , Stevens Gregory J. 
Published: January 2007

AbstractCyclin‐dependent kinases (CDKs) have been pursued for more than a decade for the treatment of cancer. CDK inhibitors are expected to slow the rate of cell division and potentially increase the apoptotic fraction of rapidly dividing cells. Although CDK activity is often increased in tumors, normal dividing tissues are also susceptible to the cytostatic and cytotoxic effects of CDK inhibitor action. Therefore the typical toxicity profile associated with cytotoxic anti‐cancer therapy, bone marrow suppression and gastrointestinal toxicity, is expected with CDK inhibitors. Bone marrow toxicity and the ensuing delayed peripheral leukocyte suppression often limit the therapeutic application of cytotoxic anticancer drugs. Here we characterize an unusual bone marrow‐independent acute toxicity toward leukocytes from broad spectrum CDK inhibitors in monkeys and rodents. The potential combination of both acute and delayed immunosuppression would likely further restrict the application of these particular compounds. Since the cells targeted were non‐proliferating, it was assumed that the toxicity was not driven by the intended pharmacological mechanism thereby facilitating the development of a testing strategy to identify compounds with a reduced potential for acute leukocyte toxicity. This testing strategy resulted in a CDK inhibitor void of bone marrow‐independent leukocyte toxicity that is currently undergoing clinical testing. Copyright © 2007 John Wiley & Sons, Ltd.
Hyperglycemia and hyperinsulinemia have additive effects on activation and proliferation of pancreatic stellate cells: Possible explanation of islet‐specific fibrosis in type 2 diabetes mellitus
Authors: Hong Oak‐Kee , Lee Seung‐Hwan , Rhee Marie , Ko Seung‐Hyun , Cho Jae‐Hyoung , Choi Yoon‐Hee , Song Ki‐Ho , Son Ho‐Young , Yoon Kun‐Ho 
Published: January 2007

AbstractPancreatic islet fibrosis observed in Type 2 diabetes is one of the major factors leading to progressive β‐cell loss and dysfunction. Despite its importance, the mechanism of islet‐restricted fibrogenesis associated with pancreatic stellate cell (PSC) activation and proliferation remains to be defined. Therefore, we studied whether the islet‐specific environment represented by hyperglycemia and hyperinsulinemia had additive effects on the activation and proliferation of cultured rat PSCs. Cells were stimulated to activate and proliferate with glucose and insulin, either individually or concomitantly. Both stimuli promoted PSC proliferation and extracellular signal‐regulated kinase (ERK) 1/2 phosphorylation independently, but an additive effect was also demonstrated. Blockade of ERK signaling by the mitogen‐activated protein kinase kinase (MEK) inhibitor, U0126, suppressed both glucose‐ and insulin‐induced ERK 1/2 phosphorylation and PSC proliferation. Glucose and insulin‐induced ERK 1/2 phosphorylation also stimulated connective tissue growth factor gene expression. Thus, hyperglycemia and hyperinsulinemia are two crucial mitogenic factors that activate and proliferate PSCs, and the presence of both states will amplify this response. J. Cell. Biochem. 101: 665–675, 2007. © 2007 Wiley‐Liss, Inc.
Hydrogen uptake by structural steels at cathodic protection in sea water inoculated with sulfate reducing bacteria
Authors: Lunarska E. , Birn J. , Domżalicki P. 
Published: January 2007

AbstractThe effect of sulfate reducing bacteria (SRB) on the hydrogen permeation rate through ferrite‐pearlite and sorbite steels of quite similar chemical composition was studied using a specially designed facility. Tests were carried out in synthetic sea water, sterile or inoculated with bacteria, at potentials corresponding to cathodic protection (− 800 mV to − 1400 mVNCE). Cathodic polarization within the studied potential range did not stop the metabolism of SRB. Presence of SRB was found to increase the hydrogen permeation rate, to form S2− ions, to increase the polarization current, to modify the impedance spectrum and to change the appearance of cathodic deposits in comparison with sterile conditions. The promoting effect of SRB on the hydrogen uptake was concluded to be the result of the increase in polarization current due to the formation of the less protective layer of cathodic deposits on the steel surface, the presence of S2− ions and the possible decrease in pH. Despite the similar tendencies, the effect of SRB on hydrogen uptake was more pronounced in the case of sorbite steel. The bacteria action can cause hydrogen deterioration of steel at potentials, recognized as safe ones at cathodic protection.
Effects of Na3PW12O40 on the corrosion behavior of carbon steel in 55 %LiBr solution
Authors: Liang C.H. , Hu X.Q. , Ma L. 
Published: January 2007

AbstractElectrochemical technologies, chemical immersion tests and surface detection technologies were adopted to study the inhibition performance of Na3PW12O40 inhibitor on carbon steel in 55 % LiBr + 0.07 mol/L LiOH solution, and the inhibition mechanism was discussed. Results indicated that Na3PW12O40 inhibitor caused the decrease of both anodic and cathodic polarization current density and a widening of the passive potential region. It behaved as a mixed inhibitor. When the concentration of Na3PW12O40 in 55 % LiBr + 0.07 mol/L LiOH solution was 300 mg/L, excellent inhibition performance on carbon steel was obtained. When the solution temperature were 145°C, 160°C, 180°C and 200°C, respectively, the corrosion rates of carbon steel were 13.07 μm/y, 17.74 μm/y, 24.55 μm/y and 73.52 μm/y accordingly. Na3PW12O40 inhibitor exhibited an excellent inhibition performance at high temperature. Na3PW12O40 is a strong oxidant. Fe was oxidized to Fe2O3 and itself was deoxidized to heteropoly blue. By this mechanism, an integrate compact passive film mainly comprising Fe2O3 may be formed on the carbon steel surface, and the corrosion of carbon steel in 55 % LiBr solution may be retarded by this passive film.
Explicit algebras with the Leibniz–Mellin translation product
Authors: Witt Ingo 
Published: January 2007

AbstractA sub‐calculus of the calculus (“algebra”) of all complete conormal symbols arising in the edge pseudodifferential calculus is constructed. This calculus of complete conormal symbols is suitable for constructing sub‐calculi of the general edge pseudodifferential calculus, for which the edge‐degenerate pseudodifferential operators involved map conormal asymptotics of distributions near the edges in a prescribed manner. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of electrical stimulation pattern on the force responses of paralyzed human quadriceps muscles
Authors: Scott Wayne B. , Lee Samuel C. K. , Johnston Therese E. , Binkley Jennifer , Binder‐MacLeod Stuart A. 
Published: January 2007

AbstractMost studies examining the effect of electrical stimulation pattern on the force response of muscle have been done in able‐bodied persons. The purpose of this study was to examine the electrically elicited force responses of the paralyzed quadriceps femoris muscles of persons with spinal cord injuries (SCI) to see whether stimulation patterns that increase the force response in non‐paralyzed muscle will do so in paralyzed muscle. Thirteen subjects ranging in age from 11 to 24 years old with motor‐complete SCI were studied. Isometric muscle performance was tested using 6‐pulse constant‐frequency trains (CFTs), variable‐frequency trains (VFTs), and doublet‐frequency trains (DFTs) delivered at mean frequencies of 10, 20, 33, 50, and 100 HZ. In the non‐fatigued and fatigued condition, the VFT and DFT peak forces were greater than the CFT peak forces at 10 HZ. In addition, in the fatigued condition the 20‐HZ VFT peak forces were greater than the CFT peak forces, and there was a trend for the DFT peak forces to be greater than the CFT peak forces. In the non‐fatigued condition, the 33‐HZ and 50‐HZ DFT force–time integrals were greater than both the CFT and VFT force–time integrals. In the fatigued condition, there was no significant effect of train‐type on the force–time integrals. These results differ from those previously reported from studies using able‐bodied persons and indicate that findings from studies of the electrically elicited force responses of the muscles of able‐bodied persons do not apply to the paralyzed muscles of persons with SCI. Muscle Nerve, 2007
The 2D hydro‐mechanically coupled response of a rock mass with fractures via a mixed BEM–FEM technique
Authors: Fidelibus C. 
Published: January 2007

AbstractThis paper describes the essential features of a numerical technique for the simulation of the coupled fluid flow and deformation in a 2D assembly of poroelastic blocks and transmissive fractures. The boundary element method (BEM) is applied to each block to reduce Navier and diffusion equations to a set of integral equations involving block boundary terms, whereas a Galerkin weighted‐residuals finite element method (FEM) is applied to the fracture diffusion equations. In addition, fracture local equilibrium is rendered through spring‐like equations relating the stresses to the relative displacements of the fracture walls. A time‐marching process is implemented leading to an algebraic system where the right‐hand side vector is built based on the collected solutions of the previous time steps. The technique requires the meshing of the fracture network only. The accuracy of the results is adequate even with relatively coarse meshes without the resort to small time steps at the beginning of the simulation. It furnishes outputs that focus only on the salient features of the response. The efficiency of the technique is demonstrated through the illustration of the results of three examples. Copyright © 2007 John Wiley & Sons, Ltd.
The bridges of Königsberg—A historical perspective
Authors: Gribkovskaia Irina , Halskau Øyvind , Laporte Gilbert 
Published: January 2007

AbstractThe Bridges of Königsberg is one of the most famous problems in graph theory. In the summer of 2005, two of the authors visited Königsberg, now called Kaliningrad. This article provides geographical and historical information on Königsberg and its bridges, as well as updated information on the current day situation. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 49(3), 199–203 2007