bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flux Bridgman growth and the influence of annealing temperatures on PL properties of ZnO single crystals
Authors: Xu Jiayue , He Qingbo , Shen Hui , Jin Min , Zhang Yan , Li Xinhua 
Published: September 2011

AbstractTransparent ZnO crystals were obtained by the flux Bridgman method from high temperature solution of 22 mol% ZnO‐78 mol% PbF2 system. The influence of annealing temperatures on the photoluminescence (PL) of ZnO crystal was investigated. An ultraviolet emission peak at about 379 nm was observed in PL spectra and the peak position has a weak blueshift for annealed samples. A green band centered at 523 nm appeared in the annealed samples and its intensity enhanced with the increase of annealing temperatures, while the intensity of the ultraviolet peak decreased considerably. However, the ultraviolet emission peak became the strongest after annealing at 1000 °C. This phenomenon was considered to be associated with oxygen vacancy and F‐ impurities induced by the PbF2 flux. The results show that high temperature annealing in air seems helpful for improving the PL properties of ZnO crystal. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Conspecific brood parasitism in the tropics: an experimental investigation of host responses in common moorhens and American purple gallinules
Authors: McRae Susan B. 
Published: September 2011

AbstractSpecies occupying a broad latitudinal range may show greater phenotypic plasticity in behavior than species with smaller ranges or more specific habitat requirements. This study investigates for the first time the occurrence of conspecific brood parasitism (CBP) in sympatric tropical populations of the common moorhen (Gallinula chloropus pauxillaBangs) and the American purple gallinule (Porphyrula martinicaL.). CBP occurred in at least 20% (N= 76) of common moorhen nests on the Rio Chagres in Panama. Half (N= 20) of the parasitic eggs were accepted, but 10 were destroyed or ejected from host nests. Introductions of experimental eggs into nests revealed hosts were more likely to accept parasitism later in the host's laying period and during incubation, consistent with expectation of an adaptive response. CBP was not detected in a small sympatric population of American purple gallinules. Members of this population did not eject experimental eggs, suggesting a lack of experience with costly CBP. Contrasting ecological factors help explain why these two species of rail (Family Rallidae) differ in regard to CBP. Purple gallinule territories were sparse, owing to the distribution of preferred habitat. Moorhens flocked outside of the breeding season. They nested more synchronously, at higher densities, and primarily in ephemeral floating vegetation. Further, moorhens suffered a rate of nest loss nearly double that of American purple gallinules, and this increased over the course of the breeding season. Moorhen clutches were larger on average, and more variable in size than those of purple gallinules. Reproductive effort and rate (seasonality) constitute important life history differences between these species that may constrain the evolution of reproductive tactics. Comparing these sympatric populations, and others differing in life‐history traits and ecological constraints, highlights the role of risk management in the evolution of CBP.
Strong Charge‐Transfer Chromophores from [2+2] Cycloadditions of TCNE and TCNQ to Peripheral Donor‐Substituted Alkynes
Authors: Chen Songhua , Li Yongjun , Liu Chao , Yang Wenlong , Li Yuliang 
Published: September 2011

AbstractPeripheral donor‐substituted N,N‐dimethyl‐4‐[(7‐nitrobenzo[c][1,2,5]thiadiazol‐4‐yl)ethynyl]aniline (1a), 4‐(benzo[c][1,2,5]thiadiazol‐4‐ylethynyl)‐N,N‐dimethylaniline (1b), and 4,4′‐{benzo[c][1,2,5]thiadiazole‐4,7‐diylbis(ethyne‐2,1‐diyl)}bis(N,N‐dimethylaniline) (2) were prepared by Sonogashira cross‐coupling reactions. Compounds 1a, 1b, and 2 subsequently reacted with tetracyanoethylene (TCNE) or 7,7,8,8‐tetracyanoquinodimethane (TCNQ) to afford the charge‐transfer chromophores 3–8. X‐ray crystallographic analysis revealed the nonplanarity of these donor–acceptor (D–A) chromophores. Cyclic voltammetry (CV) exhibited a multistep reduction wave. UV/Vis spectra and theoretical calculations identified efficient intramolecular charge‐transfer interactions. Moreover, scanning electron microscopy (SEM) showed the morphology transition and reconstruction process of 5 from 0D hollow nanospheres to 1D tubular microstructures.
A simple and rapid pre‐confirmation method to distinguish endogenous human haemoglobin from synthetic haemoglobin‐based oxygen carriers in doping control
Authors: Donati Francesco , Mazzarino Monica , de la Torre Xavier , Botrè Francesco , Islam Nazia , Cowan David 
Published: September 2011

AbstractA specific, sensitive and rapid analytical procedure based on capillary electrophoresis with UV/Vis detection at 405 and 415 nm was developed and validated to detect human haemoglobin and haemoglobin‐based oxygen carriers (Hemopure®, Oxyglobin® and Polyheme®) in blood samples collected for doping control. The electrophoretic separation, based on capillary dynamic coating, was achieved in less than 10 min. The effects of capillary temperature, injection conditions and initial ramping were investigated. The optimum separation voltage was 25 kV with a capillary temperature of 20°C, initial ramping of 1 kV/s and an injection pressure of 0.5 psi for 10 s. The removal of haptoglobin using anti‐human haptoglobin antibody prior to the analysis was mandatory to increase the specificity of the analysis. Sufficient resolution between endogenous haemoglobin variants and the three haemoglobin‐based oxygen carriers here investigated was obtained, thus allowing discrimination between a normal haemolysed sample and a sample in which Oxyglobin®, Hemopure® or Polyheme® is present. Good repeatability of migration times (CV% less than 1), peak resolution and adequate sensitivity (limit of detection: 2.5 mg/mL) was obtained.
Single‐phase transformer modeling for inrush ‎currents simulation using differential evolution
Authors: Ketabi Abbas , Naseh Mojtaba 
Published: September 2011

SUMMARYAccurate modeling of transformer saturation characteristics is essential for analyzing inrush currents and ‎harmonic overvoltages. This paper outlines a straightforward method for correct estimation of the transformer's inrush current where the residual flux effect is considered. The Ι–Λ nonlinear characteristic of transformer core is estimated by the sum of ‎two exponential functions. The differential evolution optimization method is used to identify the parameters of ‎the iron core ‎model including the current flux nonlinear function and the core loss resistance. The ‎objective function to be minimized is the root mean square difference between the measured and calculated ‎inrush currents. The experimental iron characteristic is obtained from the secondary winding voltage ‎and primary winding current waveforms produced during transformer energization. The performance and accuracy of the proposed method have been verified by a close ‎agreement between simulation and measured inrush waveforms for a single‐phase transformer. Copyright © 2011 John Wiley & Sons, Ltd.
Production and hedging under state‐dependent preferences
Authors: Wong Kit Pong 
Published: September 2011

AbstractThis study examines the behavior of the competitive firm under output price uncertainty and state‐dependent preferences. When there is a futures market for hedging purposes, the firm's optimal production decision is independent of the output price uncertainty and of the state‐dependent preferences. If the futures contracts are unbiased, the firm's optimal futures position is an over‐hedge or an under‐hedge, depending on whether the firm is correlation averse or correlation loving, and on whether the output price is positively or negatively expectation dependent on the state variable. When the firm has access not only to the unbiased futures but also to fairly priced options, sufficient conditions are derived under which the firm's optimal hedge position includes both hedging instruments. This study thus establishes a hedging role of options, which is over and above that of futures, in the case of state‐dependent preferences. © 2011 Wiley Periodicals, Inc. Jrl Fut Mark 32:945–963, 2012
Fitting and testing for the implied volatility curve using parametric models
Authors: Chang Chuang‐Chang , Chou Pin‐Huang , Liao Tzu‐Hsiang 
Published: September 2011

AbstractNumerous issues have arisen over the past few decades relating to the implied volatility smile in the options market; however, the extant literature reveals that relatively little effort has thus far been placed into comparing the various implied volatility models, essentially as a result of the lack of any theoretical foundation on which to base such comparative analysis. In this study, we use a comprehensive options database and employ methods of combining the various hypothesis tests to compare the different implied volatility models. To the best of our knowledge, this is the first study of its kind to address this issue using combination tests. Our empirical results reveal that the linear piecewise model is the most appropriate model for capturing the implied volatility smile, with additional robustness checks confirming the validity of this finding.
Effects of eastern redcedar encroachment on soil hydraulic properties along Oklahoma's grassland‐forest ecotone
Authors: Wine Michael L. , Ochsner Tyson E. , Sutradhar Apurba , Pepin Rachael 
Published: September 2011

AbstractIn north‐central Oklahoma eastern redcedar (Juniperus virginiana), encroachment into grassland is widespread and is suspected of reducing streamflow, but the effects of this encroachment on soil hydraulic properties are unknown. This knowledge gap creates uncertainty in understanding the hydrologic effects of eastern redcedar encroachment and obstructs fact‐based management of encroached systems. The objective of this study was to quantify the effects of eastern redcedar encroachment into tallgrass prairie on soil hydraulic properties. Leaf litter depth, soil organic matter, soil water repellency, soil water content, sorptivity, and unsaturated hydraulic conductivity were measured near Stillwater, OK, along 12 radial transects from eastern redcedar trunks to the center of the grassy intercanopy space. Eastern redcedar encroachment in the second half of the 20th century caused the accumulation of 3 cm of hydrophobic leaf litter near the trunks of eastern redcedar trees. This leaf litter was associated with increased soil organic matter in the upper 6 cm of soil under eastern redcedar trees (5.96% by mass) relative to the grass‐dominated intercanopy area (3.99% by mass). Water repellency was more prevalent under eastern redcedar than under grass, and sorptivity under eastern redcedar was 0.10 mm s−1/2, one seventh the sorptivity under adjacent prairie grasses (0.68 mm s−1/2). Median unsaturated hydraulic conductivity under grass was 2.52 cm h−1, four times greater than under eastern redcedar canopies (0.57 cm h−1). Lower sorptivity and unsaturated hydraulic conductivity would tend to decrease infiltration and increase runoff, but other factors such as rainfall interception by the eastern redcedar canopy and litter layer, and preferential flow induced by hydrophobicity must be examined before the effects of encroachment on streamflow can be predicted. Copyright © 2011 John Wiley & Sons, Ltd.
Origin and dynamics of groundwater salinity in the alluvial plains of western Delhi and adjacent territories of Haryana State, India
Authors: Lorenzen Gunnar , Sprenger Christoph , Baudron Paul , Gupta Dinesh , Pekdeger Asaf 
Published: September 2011

AbstractGroundwater salinity is a widespread problem and a challenge to water resources management. It is an increasing concern in the alluvial plains of Delhi and neighbouring Haryana state as well as a risk for agricultural production water supply and sustainable development. This study aims to identify potential sources of dissolved salts and the driving mechanisms of salinity ingress in the shallow aquifer. It combines a comprehensive review of environmental conditions and the analysis of groundwater samples from 25 sampling points. Major ions are analysed to describe the composition and distribution of saline groundwater and dissolution/precipitation dynamics. Density stratification and local upconing of saline waters were identified by multilevel monitoring and temperature logging. Bromide–chloride ratios hold information on the formation of saline waters, and nitrate is used as an indicator for anthropogenic influences. In addition, stable isotope analysis helps to identify evaporation and to better understand recharge processes and mixing dynamics in the study region. The results lead to the conclusion that surface water and groundwater influx into the poorly drained semiarid basin naturally results in the accumulation of salts in soil, sediments and groundwater. Human‐induced changes of environmental conditions, especially the implementation of traditional canal and modern groundwater irrigation, have augmented evapotranspiration and led to waterlogging in large areas. In addition, water‐level fluctuations and perturbation of the natural hydraulic equilibrium favour the mobilisation of salts from salt stores in the unsaturated zone and deeper aquifer sections. The holistic approach of this study demonstrates the importance of various salinity mechanisms and provides new insights into the interference of natural and anthropogenic influences. Copyright © 2011 John Wiley & Sons, Ltd.
Combined effects of FLT3 and NF‐κB selective inhibitors on acute myeloid leukemia in vivo
Authors: Wang Chunmei , Lu Jie , Wang Yumei , Bai Songting , Wang Yingchao , Wang Lu , Sheng Guangyao 
Published: September 2011

AbstractFMS‐like tyrosine kinase 3 (FLT3) is an independent poor prognostic marker of acute myeloid leukemia (AML), and strategies that specifically target FLT3 are therefore of substantial interest. However, previous studies with FLT3 inhibitors as single agents in patients with AML showed few clinical responses. In the present study, combined effects of FLT3 selective inhibitor (SC‐203048) and NF‐κB selective inhibitor (Parthenolide, PTL) on AML xenograft tumor growth in vivo were examined, and the possible antitumor mechanisms by which SC‐203048 and PTL affect AML xenograft tumor growth were also detected. Results showed that the tumor growth was strongly inhibited, and increased cell apoptosis was also observed after treatments, especially in the combination group; meanwhile, the expressions of FLT3, p65, cyclin D1, and Bc1‐2 decreased significantly, and the expression of nuclear Silencing mediator for retinoic acid and thyroid hormone receptors (SMRT) increased notably. All results indicate that synergism exists between FLT3 and NF‐κB inhibitors, and inhibitors combination treatment may be a potential strategy for AML. © 2011 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:35–43 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.20411
Fractional dimension of binary Knuth semifield planes
Authors: Polverino Olga , Trombetti Rocco 
Published: September 2011

AbstractWe prove that semifield planes π(𝕂2m) coordinatized by the commutative binary Knuth semifield 𝕂2m, m=nk (m odd) are fractional dimensional with respect to a subplane isomorphic to PG(2, 4) if either n=9 or n≡\0(mod 3) and one of the trinomials xn+xs+1, s∈{1, 2, 3, 5}, is irreducible over the Galois field 𝔽2. © 2012 Wiley Periodicals, Inc. J. Combin. Designs 20: 317–327, 2012
Activity of matrix metallo proteinases (MMPs) and the tissue inhibitor of MMP (TIMP)‐1 in electromagnetic field‐exposed THP‐1 cells
Authors: Patruno Antonia , Pesce Mirko , Marrone Alessandro , Speranza Lorenza , Grilli Alfredo , De Lutiis Maria Anna , Felaco Mario , Reale Marcella 
Published: September 2011

AbstractMatrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) are the main determinants of tissue remodeling in both physiological and pathological processes. Metabolic processes, which generate oxidants and antioxidants can be influenced by environmental factors such as electromagnetic fields (EMF). We analyzed the effects of EMF on the activity and expression of MMPs in THP‐1 cells. Cells were exposed to a 50 Hz, 1 mT EMF for 24 h and incubated with or without LPS. Our data indicate that THP‐1 cells exposed to EMF causes a reduction of anti‐oxidant enzyme activity and an enhancement of nitrogen intermediates involving the iNOS pathway. We then analyzed the role of nitration of TIMP‐1 in increasing the activity of MMPs in EMF exposed cells. Molecular modeling tools were employed to identify the most plausible sites in the active conformation of TIMP‐1; at least two protein sites, Y120 and Y38 and/or Y72 were identified. Reactive nitrogen species (RNS) may affect protein targets, such as TIMP‐1, which are crucial for the regulation of MMP activities by oxidation of sulfydryl groups, or by nitration of tyrosine residues. These results may suggest a pathway connecting an imbalance of MMPs and their cognate inhibitor TIMP‐1. J. Cell. Physiol. 227: 2767–2774, 2012. © 2011 Wiley Periodicals, Inc.
Histone deacetylase inhibitors induce mitochondrial elongation
Authors: Lee Jee Suk , Yoon Young Geol , Yoo Seung Hee , Jeong Na Young , Jeong Seung Hun , Lee Sang Yeob , Jung Dai‐il , Jeong Seon‐Yong , Yoo Young Hyun 
Published: September 2011

AbstractAlthough various stimuli‐inducing cell demise are known to alter mitochondrial morphology, it is currently debated whether alteration of mitochondrial morphology is per se responsible for apoptosis execution or prevention. This study was undertaken to examine the effect of histone deacetylase (HDAC) inhibitors on mitochondrial fusion–fission equilibrium. The mechanism underlying HDAC inhibitor‐induced alteration of mitochondrial morphology was examined in various cells including primary cultured cells and untransformed and cancer cell lines treated with seven different HDAC inhibitors. Suberoylanilide hydroxamic acid (SAHA)‐induced mitochondrial elongation in both Hep3B and Bcl‐2‐overexpressing Hep3B cells, apart from its apoptosis induction function. SAHA significantly decreased the expression of mitochondrial fission protein Fis1 and reduced the translocation of Drp1 to the mitochondria. Fis1 overexpression attenuated SAHA‐induced mitochondrial elongation. In addition, depletion of mitochondrial fusion proteins, Mfn1 or Opa1, by RNA interference also attenuated SAHA‐induced mitochondrial elongation. All of the HDAC inhibitors we examined induced mitochondrial elongation in all the cell types tested at both subtoxic and toxic concentrations. These results indicate that HDAC inhibitors induce mitochondrial elongation, irrespective of the induction of apoptosis, which may be linked to alterations of mitochondrial dynamics regulated by mitochondrial morphology‐regulating proteins. Since mitochondria have recently emerged as attractive targets for cancer therapy, our findings that HDAC inhibitors altered mitochondrial morphology may support the rationale for these agents as novel therapeutic approaches against cancer. Further, the present study may provide insight into a valuable experimental strategy for simple manipulation of mitochondrial morphology. J. Cell. Physiol. 227: 2856–2869, 2012. © 2011 Wiley Periodicals, Inc.
PEG coating reduces NMR relaxivity ofMn0.5Zn0.5Gd0.02Fe1.98O4hyperthermia nanoparticles
Authors: Issa Bashar , Qadri Shahnaz , Obaidat Ihab M. , Bowtell Richard W. , Haik Yousef 
Published: September 2011

AbstractPurpose:To investigate both T1 and T2 MR relaxation enhancement of Gd substituted Zn‐Mn ferrite magnetic nanoparticles. Both uncoated and polyethylene glycol (PEG) coated particles were used.Materials and Methods:Chemical co‐precipitation was used to synthesize particles in the formMn0.5Zn0.5Gd0.2Fe1.98O4suitable for hyperthermia applications. Physical characterization of the magnetic nanoparticles included SEM, TEM, ICP, and SQUID. T1 and T2 measurements were performed at 1.5 Tesla (T).Results:The saturation magnetization was 12.86 emu/g while the particle's magnetic moment was 1.86 × 10−19J/T. The particle size increased due to coating, while 1/T1 and 1/T2 relaxivities (26°C) decreased from 2.5 to 0.7 and from 201.3 to 76.6 s−1mM−1, respectively, at a magnetic field 1.5T.Conclusion:The reduction in both 1/T1 and 1/T2 is attributed to increased distance of closest approach between the protons and the magnetic core caused by the shielding provided by the high molecular weight PEG. 1/T2 data are compared with existing theoretical models using a modified radius that takes into account both possible agglomeration of the particles and increased inter‐particle separation induced by PEG coating. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Dexamethasone indirectly induces Ndrg2 expression in rat astrocytes
Authors: Takahashi Kou , Saitoh Akiyoshi , Yamada Misa , Iwai Takashi , Inagaki Masatoshi , Yamada Mitsuhiko 
Published: September 2011

AbstractN‐myc downstream‐regulated gene 2 (Ndrg2) has been associated with cell proliferation, differentiation, and apoptosis. Ndrg2 expression in the brain is induced by glucocorticoid treatment or chronic stress in vivo. It has been postulated that glucocorticoid‐induced Ndrg2 expression in astrocytes is regulated by the glucocorticoid response element half‐site (GRE1/2) upstream of the Ndrg2 transcription site. Here we examined the mechanisms of dexamethasone‐induced Ndrg2 expression in rat astrocytes. Ndrg2 mRNA expression in primary astrocytes was significantly increased after 24 hr of exposure to dexamethasone in a concentration‐dependent manner. Dexamethasone‐induced Ndrg2 mRNA and protein expression was blocked by pretreatment with RU486, a glucocorticoid receptor antagonist. Moreover, dexamethasone‐induced Ndrg2 mRNA expression was reduced by pretreatment with the protein synthesis inhibitor cycloheximide. The Ndrg2 reporter assay showed that deletion of a putative GRE1/2, located upstream of Ndrg2, did not affect induction by dexamethasone. A region between –755 and –701 bp from the transcription start site was shown to regulate induction by dexamethasone using promoter constructs progressively deleted from the 5′ to 3′ ends. This region contained the predicted transcription factor binding sites for early B‐cell factor 1 (Ebf1), nuclear factor‐κB (NFκB), and paired box gene 5 (Pax5). Mutation at the NFκB‐ or Pax5‐binding site, but not the Ebf1 binding site, abolished dexamethasone‐induced promoter activation. These results indicate that Ndrg2 expression was indirectly induced by dexamethasone at the DNA level, potentially by the binding of NFκB or Pax5 to the transcription factor binding sites, and GRE1/2 was not involved in this induction. © 2011 Wiley Periodicals, Inc.