bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical integrin stress and magnetic forces induce biological responses in mesenchymal stem cells which depend on environmental factors
Authors: Kasten Annika , Müller Petra , Bulnheim Ulrike , Groll Jürgen , Bruellhoff Kristina , Beck Ulrich , Steinhoff Gustav , Möller Martin , Rychly Joachim
Published: November 2010

The control of mesenchymal stem cells (MSC) by physical cues is of great interest in regenerative medicine. Because integrin receptors function as mechanotransducers, we applied drag forces to β1 integrins on the apical surface of adherent human MSC. In addition to mechanical forces, the technique we used involved also the exposure of the cells to an inhomogeneous magnetic field. In order to assess the influence of the substrate on cell adhesion, cells were cultured on plain tissue culture polystyrene (TCP) or on coated well plates, which allowed only adhesion to embedded fibronectin or RGD peptides. We found that the expression of collagen I, which is involved in osteogenesis, and VEGF, a factor which stimulates angiogenesis, increased as a result of short‐term mechanical integrin stress. Whereas, collagen I expression was stimulated by mechanical forces when the cells were cultured on fibronectin and RGD peptides but not on TCP, VEGF expression was enhanced by physical stimulation on TCP. The study further revealed that magnetic forces enhanced Sox 9 expression, a marker of chondrogenesis, and reduced the expression of ALP. Concerning the intracellular mechanisms involved, we found that the expression of VEGF induced by physical forces depended on Akt activation. Together, the results implicate that biological functions of MSC can be stimulated by integrin‐mediated mechanical forces and a magnetic field. However, the responses of cells depend strongly on the substrate to which they adhere and on the cross‐talk between integrin‐mediated signals and soluble factors. J. Cell. Biochem. 111: 1586–1597, 2010. © 2010 Wiley‐Liss, Inc.
Sonodynamic effects of hematoporphyrin monomethyl ether on CNE‐2 cells detected by atomic force microscopy
Authors: Jin Hua , Zhong Xing , Wang Zhiyong , Huang Xun , Ye Hongyan , Ma Shuyuan , Chen Yong , Cai Jiye
Published: November 2010

Hematoporphyrin monomethyl ether (HMME) has been effectively used to treat solid tumors of some types. However, its application in nasopharyngeal carcinoma has not been studied yet. In this paper, the detailed sonodynamic effects of HMME‐SDT (sonodynamic therapy) on CNE‐2 cells including cell growth inhibition, apoptosis induction, and membrane toxicity were investigated. It was found that HMME alone had less cytotoxicity whereas HMME‐SDT could suppress the cell proliferation in a dose‐dependent manner as detected by MTT assay. The annexin V‐based flow cytometric data indicated that upon SDT, different concentrations of HMME induce distinct types of cell death, apoptosis by low concentration (60 µg/ml) of HMME and necrosis by higher concentration (120 µg/ml). The immunofluorescence of cytoskeleton and nuclei morphology showed that upon HMME‐SDT, the cells became rounding and the cytoskeletal network disappeared, and, the nuclei represented a total fragmented morphology of nuclear bodies. These alternations showed the apoptosis induction by HMME‐SDT. Further AFM study showed that the cell membrane structure and cytoskeleton networks were destroyed, and, the Young's modulus, tip‐cell‐surface adhesion force decreased to 0.22 ± 0.11 Mpa, 35.4 ± 12.8 pN of cells with 120 µg/ml HMME‐SDT from 0.48 ± 0.21 Mpa, 69.6 ± 22.3 pN of native cells, respectively. These membrane changes caused the collapse of mitochondrial transmembrane potential and disturbance of intracellular calcium homeostasis, which was consistent with the results detected by flow cytometry. Therefore, membrane toxicity and cytoskeleton disrupture induced by HMME‐SDT maybe important factors to induce cell apoptosis, and, the disturbance of mitochondrial transmembrane potential and calcium channels might be the apoptosis mechanisms. J. Cell. Biochem. 112: 169–178, 2011. © 2010 Wiley‐Liss, Inc.
Cell‐cycle‐dependent localization of human cytomegalovirus UL83 phosphoprotein in the nucleolus and modulation of viral gene expression in human embryo fibroblasts in vitro
Authors: Arcangeletti Maria‐Cristina , Rodighiero Isabella , Mirandola Prisco , De Conto Flora , Covan Silvia , Germini Diego , Razin Sergey , Dettori Giuseppe , Chezzi Carlo
Published: November 2010

The nucleolus is a multifunctional nuclear compartment widely known to be involved in several cellular processes, including mRNA maturation and shuttling to cytoplasmic sites, control of the cell cycle, cell proliferation, and apoptosis; thus, it is logical that many viruses, including herpesvirus, target the nucleolus in order to exploit at least one of the above‐mentioned functions. Recent studies from our group demonstrated the early accumulation of the incoming ppUL83 (pp65), the major tegument protein of human cytomegalovirus (HCMV), in the nucleolus. The obtained results also suggested that a functional relationship might exist between the nucleolar localization of pp65, rRNA synthesis, and the development of the lytic program of viral gene expression. Here we present new data which support the hypothesis of a potentially relevant role of HCMV pp65 and its nucleolar localization for the control of the cell cycle by HCMV (arrest of cell proliferation in G1–G1/S), and for the promotion of viral infection. We demonstrated that, although the incoming pp65 amount in the infected cells appears to be constant irrespective of the cell‐cycle phase, its nucleolar accumulation is prominent in G1 and G1/S, but very poor in S or G2/M. This correlates with the observation that only cells in G1 and G1/S support an efficient development of the HCMV lytic cycle. We propose that HCMV pp65 might be involved in regulatory/signaling pathways related to nucleolar functions, such as the cell‐cycle control. Co‐immunoprecipitation experiments have permitted to identify nucleolin as one of the nucleolar partners of pp65. J. Cell. Biochem. 112: 307–317, 2011. © 2010 Wiley‐Liss, Inc.
Radiosynthesis, biodistribution and scintigraphy of the 99mTc‐Teicoplanin complex in artificially infected animal models
Authors: Shah Syed Qaiser , Khan Aakif Ullah , Khan Muhammad Rafiullah
Published: November 2010

Radiocomplexation of Teicoplanin (TIN), a new glycopeptide antibiotic with technetium‐99m, was investigated. The 99mTc‐TIN complex was assessed for its radiochemical permanence, in vitro stability in serum, binding with methicillin‐resistant Staphylococcus aureus (MRSA), biodistribution in Model Rats (MRT) and for scintigraphic precision in Model Rabbit (MRB). Radiochemically, a stable 99mTc‐TIN was observed with 98.90±0.50% yield and remained staunch more than 90% up to 120 min, by mixing TIN, 1.5 mg in 0.5 ml of saline with 2.5 mCi sodium pertechnetate and 150 µl of stannous chloride dihydrate at pH 5.4. The 99mTc‐TIN was found stable in serum with an insignificant undesirable yield of free and unhydrolyzed technetium (5.25±0.10 and 13.5±0.14%, n = 10) up to 120 min of incubation. The 99mTc‐TIN showed in vitro binding with MRSA in the range of 55–65%. The 99mTc‐TIN showed almost six‐fold elevated uptake in the infected (IFT) muscle of the MRT as compared with the inflamed (IFM) and normal (NL) muscles. This higher uptake of the 99mTc‐TIN in the IFT was scintigraphically confirmed after the whole body scanning of the MRB. The radiochemical eternalness with high yield, in vitro stability in serum, binding with MRSA, significant biodistribution performance, and scintigraphic precision posed the 99mTc‐TIN, a new glycopeptide radiotracer for the infection imaging. Copyright © 2010 John Wiley & Sons, Ltd.
Characterization of calcium sulfate grounds and fillings of applied tin‐relief brocades by Raman spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy
Authors: Rodríguez Ainhoa , Eremin Katherine , Khandekar Narayan , Stenger Jens , Newman Richard , Bazeta Fernando , Escohotado María Teresa
Published: November 2010

Applied tin‐relief brocade (commonly called applied brocade) refers to a decorative painting technique using tin leaf applied over a supporting relief mass (filling) which is glued to the artwork to simulate gold and silver textile brocades. This originated in Germany ca 1415–1430 and spread across Europe from the mid‐15th century to the mid‐16th century. This study focuses on six early 16th century altarpieces in the Basque country in the present province of Guipúzcoa, Spain. Cross sections of the ground and applied brocade were initially examined with optical microscopy and staining tests for proteins and lipids to assess the layering structure and materials present. Further examination with Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy dispersive X‐ray spectroscopy identified the inorganic and organic components of the various layers. Raman spectroscopic mapping was used to image the location of phases in selected cross sections. Five altarpieces from Spain had calcium sulfate grounds, whereas one thought to come from Flanders had a calcium carbonate ground. Raman and FTIR spectra showed that the thick, coarse lower ground layer (yeso grueso) is anhydrous calcium sulfate (anhydrite) whereas the fine, thin upper ground layer (yeso fino) is calcium sulfate dihydrate (gypsum). The filling masses consisted of different mixtures of inorganic (chiefly gypsum or anhydrite but occasionally with other pigments or additives) and organic (protein and/or oil or beeswax) materials. Comparison of the documented historical techniques with the materials found provides insight into local variations of the technique. Copyright © 2010 John Wiley & Sons, Ltd.
Feeling happier when paying more: Dysfunctional counterfactual thinking in consumer affect
Authors: Yoon Sukki , Vargas Patrick T.
Published: November 2010

In this research the authors examine whether counterfactual thinking, the process of imagining alternatives to reality, can have a detrimental impact on consumers' feelings. Five studies examine the dysfunctional role of counterfactual thinking in the presence of Minimum Purchase Requirement conditional message framing (“X% off all purchases if you spend at least $Y”), and its affective consequences. Results show that the presence or absence of the minimum amount restriction (Studies 1A and 1B), success or failure to meet the restriction (Studies 2A and 2B), and perceived closeness (i.e., outcome proximity) to success or failure in meeting the restriction (Study 3), drastically influence consumer affect to the extent that participants receiving an inferior deal exhibited higher satisfaction than those receiving a superior deal. It is suggested that such promotion‐induced counterfactual thinking polarizes consumer satisfaction, which may impede consumers from arriving at optimal conclusions. © 2010 Wiley Periodicals, Inc.
Photochemical activation of endosomal escape of MRI‐Gd‐agents in tumor cells
Authors: Gianolio Eliana , Arena Francesca , Strijkers Gustav J. , Nicolay Klaas , Högset Anders , Aime Silvio
Published: November 2010

Endocytosis is a common internalization pathway for cellular labeling with MRI contrast agents. However, the entrapment of the Gd(III) complexes into endosomes results in a “quenching” of the attainable relaxivity when the number of Gd(III) complexes reaches the number of ca. 1 × 109/cell. Herein we show that the use of the newly developed photochemical internalization technique provides an efficient method for attaining the endosomal escape of GdHPDO3A molecules entrapped by pinocytosis into different kind of cells. Furthermore, it has been found that a new “quenching” limit is observed when the number of Gd‐HPDO3A complexes is ca. five times higher than the value observed for the endosome entrapped conditions. The observed behavior is explained in terms of the attainment of the conditions in which the difference in proton relaxation rates between the cytoplasmic and the extracellular compartment is higher than the exchange rate of water molecules across the cellular membrane. The experimental data points have been reproduced by using a properly designed theoretical compartment T1‐relaxation model. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Two‐dimensional radial acquisition technique with density adaption in sodium MRI
Authors: Konstandin Simon , Nagel Armin M. , Heiler Patrick M. , Schad Lothar R.
Published: November 2010

Conventional 2D radial projections suffer from losses in signal‐to‐noise ratio efficiency because of the nonuniform k‐space sampling. In this study, a 2D projection reconstruction method with variable gradient amplitudes is presented to cover the k‐space uniformly. The gradient is designed to keep the average sampling density constant. By this, signal‐to‐noise ratio is increased, and the linear form of the radial trajectory is kept. The simple gradient design and low hardware requirements in respect of slew rate allow an easy implementation at MR scanners. Measurements with the density‐adapted 2D radial trajectory were compared with the conventional projection reconstruction method. It is demonstrated that the density‐adapted 2D radial trajectory technique provides higher signal‐to‐noise ratio (up to 28% in brain tissue), less blurring, and fewer artifacts in the presence of magnetic field inhomogeneities than imaging with the conventional 2D radial trajectory scheme. The presented sequence is well‐suited for electrocardiographically gated sodium heart MRI and other applications with short relaxation times. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Poly(N‐vinylimidazole) based hydrogen bonded side chain liquid crystalline polymer
Authors: Gursel Yeşim H. , Senkal Bahire Filiz , Kandaz Mehmet , Yakuphanoglu Fahrettin
Published: November 2010

A new poly(N‐vinylimidazole) (PVI) based side chain liquid crystalline polymer (HB‐PLC) was prepared from PVI as a hydrogen bond acceptor polymer and 11‐(4‐cyanobiphenyl‐4′‐oxy)undekan‐1‐ol (LC11) by molecular self‐assembly processes via hydrogen bond formation between nitrogen of PVI and hydroxyl group of the LC11. The formation of H‐bond was confirmed by using FTIR spectroscopy. The liquid crystalline behavior of the HB‐PLC was investigated by differential scanning calorimeter (DSC) and polarized optical microscopy. The thermal behaviors of the H‐bonded liquid crystalline polymer were investigated by DSC measurements under various heating rates. The HB‐PLC shows a transition temperature of 97°C with an relatively high enthalpy change of 140.6 J/g corresponding to the transition from liquid crystalline nematic phase to isotropic phase. The activation energy required for liquid crystal phase transformation was found to be 551.75 kJ/mol. Copyright © 2010 John Wiley & Sons, Ltd.
Identification and evaluation of progressive thermal degradation caused by carbamate formation in cyanate ester resin‐based composites
Authors: Zaldivar Rafael J. , Nokes James P.
Published: November 2010

The effect of moisture during cure on the mechanical and thermal performance was evaluated for a series of cyanate ester composite laminates. Data presented in our investigation show that the amount of carbamate formation is inversely proportional to the glass transition temperature (Tg) of the cured composite and is typically localized on the outer surface plies adjacent the moisture source. Even though the majority of the composite may remains largely unaffected, the Tg of the localized areas will show sharp decreases which correlate with strength as verified by flatwise tensile tests. Additionally, our test data show that performing just one Tg measurement after cure will not necessarily provide a valid assessment of the state of the composite since additional degradation may occur with subsequent thermal exposure. Accordingly, a second dynamic mechanical analysis (DMA) measurement should be performed after an extended, elevated temperature, post‐treatment thereby allowing direct assessment of carbamate degradation. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.
Effects of PBO fiber and clay on the mechanical, morphological, and dynamic mechanical properties of NR/HDPE blends
Authors: Ahmad Ishak , Ismail Ramli , Abdullah Ibrahim
Published: November 2010

Poly(p‐phenylene‐2,6‐benzobisoksazole) (PBO) and natural rubber (NR)/high density polyethylene (HDPE) composites were melt‐blended in a Haake internal mixer. The tensile strength, tensile modulus, and impact strength increased with fiber loading and optimized at 20%. Incorporation of clay into the NR/HDPE/PBO composites resulted in an improvement of tensile strength for NR/HDPE/PBO composites compared to the systems without clay. However, addition of clay was only effective at low contents (5–7.5%). Additional improvement of tensile strength, tensile modulus, and impact strength of the hybrid composite was observed on addition of liquid natural rubber (LNR). Scanning electron micrographs of the samples had indicated that the presence of clay decreased the domain size of the dispersed phase. Results on dynamic response showed that incorporation of clay and LNR into the composites had increased the storage modulus and reduced the tan δ. The shift of glass transition temperature (Tg) to higher values for composites also indicated good interaction between the fiber and the matrix. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.
Numerical analysis of defect formation during fabrication of high temperature polymer electrolyte membrane solutions
Authors: Bhamidipati Kanthi Latha , Harris Tequila A.L.
Published: November 2010

Previous studies have shown that defects like pin‐holes and air entrainment are common during polymer electrolyte membrane (PEM) manufacturing. For mass production of defect‐free membranes, an optimized manufacturing process is required. The objective of this work is to understand the nature of defect generation during the manufacturing process of high‐temperature PEM membranes and the factors influencing them. An extrusion process is simulated using a multiphase, laminar model using computational fluid dynamics (CFD) techniques. The effects of processing conditions on quality of the cast and pressure drop are analyzed. The results showed that for a constant inlet to substrate velocity ratio, both the substrate velocity and temperature will have an insignificant effect on the entrained air height. However, their effect on pressure drop is found to be substantial. Further, it is shown that the inlet velocity and slot gap width have significant effect on the entrained air height and pressure drop. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers.
Calculated polar substituent effects on the stability of 4‐substituted(X) ‐ cub‐1‐yl and ‐bicyclo[2.2.2]oct‐1‐yl cations: a DFT study
Authors: Adcock William
Published: November 2010

The effects of substituents on the stability of 4‐substituted(X) cub‐1‐yl cations (2), as well as the benchmark 4‐substituted(X) bicyclo[2.2.2]oct‐1‐yl cation systems (7), for a set of substituents (X = H, NO2, CN, NC, CF3, COOH , F, Cl, HO, NH2, CH3, SiH3, Si(CH3)3, Li, O−, and NH) covering a wide range of electronic substituent effects were calculated using the DFT theoretical model at the B3LYP/6‐311 + G(2d,p) level of theory. Linear regression analysis was employed to explore the relationship between the calculated relative hydride affinities (ΔE, kcal/mol) of the appropriate isodesmic reactions for 2/7 and polar field/group electronegativity substituent constants (σF and σχ, respectively). The analysis reveals that the ΔE values of both systems are best described by a combination of both substituent constants. This highlights the distinction between through‐space and through‐bond electronic influences characterized by σF and σχ, respectively. Copyright © 2010 John Wiley & Sons, Ltd.
Luminescent mesogen jacketed poly(1‐alkyne) bearing lateral terphenyl with hexyloxy tail
Authors: Peng Hongxia , Chen Yiwang , Chen Lie , He Xiaohui , Li Fan
Published: November 2010

Mesogen jacketed liquid crystalline poly(1‐alkyne) and poly(1‐phenyl‐1‐alkyne) linked pendants of terphenyl mesogens with hexyloxy tails at the waist position ({RCC [(CH2)3OOC‐terpheyl‐(OC6H13)2]}n, where RH, PHATP(OC6)2; RC6H5, PPATP(OC6)2) were synthesized. The influences of structural variations on the thermal, mesomorphic, and luminescent properties were investigated. Polymerizations of all monomers are carried out by WCl6‐Ph4Sn catalysts successfully. The polymers are stable (Td ≥ 340 °C) and soluble in common solvents. The monomers and polymers show enantiotropic SmA phases in the heating and cooling processes, and the lateral side chains of the mesogenic units are perpendicular to the main chain. The “jacket effect” of chromophoric terphenyl core “shell” around the main chain also contributes to polymers with high photoluminescence, and the pendant‐to‐backbone energy transfer path is involved in the luminescence process of this polymers. In comparison with monosubstituted polyacetylene PHATP(OC6)2, the disubstituted polyacetylene PPATP(OC6)2 shows better photoluminescence in both THF solution and film, and exhibited about 40 nm red‐shifted than PHATP(OC6)2, indicating that the “jacket effect” of terphenyl mesogens forces poly(1‐phenyl‐1‐alkyne) backbone to extend in a more planar conformation with a better conjugation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Role of resource gap and value appropriation: effect of reputation gap on price premium in online auctions
Authors: Obloj Tomasz , Capron Laurence
Published: November 2010

In this study, we draw on the resource‐based view of the firm and on value‐based models of strategy to examine when firms appropriate value from their superior resources. We argue for the need to take into account the role of the resource gap between competitors rather than the absolute resource stock of the focal firm when examining the resource‐performance relationship. In particular, we investigate whether the ability of a reputable seller to command a price premium is influenced by the reputation gap (i.e., the reputation differences between the focal seller and its closest competitor standardized by the reputation stock of both sellers). We test our hypotheses on 72 matched pairs of online transactions screened from more than 2,000 auctions of new mobile phones on the Polish Internet auction site Allegro. We find that the ability of a reputable seller to command a price premium (1) increases with the size of the reputation gap between the focal seller and its matched competitor, and (2) becomes increasingly smaller for each additional unit of the seller reputation gap. Copyright © 2010 John Wiley & Sons, Ltd.
Entropy and dynamics of water in hydration layers of a bilayer
Authors: Debnath Ananya , Mukherjee Biswaroop , Ayappa K. G. , Maiti Prabal K. , Lin Shiang-Tai
Published: November 2010

We compute the entropy and transport properties of water in the hydration layer of dipalmitoylphosphatidylcholine bilayer by using a recently developed theoretical scheme [two-phase thermodynamic model, termed as 2PT method; S.-T. Lin et al., J. Chem. Phys. 119, 11792 (2003)] based on the translational and rotational velocity autocorrelation functions and their power spectra. The weights of translational and rotational power spectra shift from higher to lower frequency as one goes from the bilayer interface to the bulk. Water molecules near the bilayer head groups have substantially lower entropy (48.36 J/mol/K) than water molecules in the intermediate region (51.36 J/mol/K), which have again lower entropy than the molecules (60.52 J/mol/K) in bulk. Thus, the entropic contribution to the free energy change (TΔS) of transferring an interface water molecule to the bulk is 3.65 kJ/mol and of transferring intermediate water to the bulk is 2.75 kJ/mol at 300 K, which is to be compared with 6.03 kJ/mol for melting of ice at 273 K. The translational diffusion of water in the vicinity of the head groups is found to be in a subdiffusive regime and the rotational diffusion constant increases going away from the interface. This behavior is supported by the slower reorientational relaxation of the dipole vector and OH bond vector of interfacial water. The ratio of reorientational relaxation time for Legendre polynomials of order 1 and 2 is approximately 2 for interface, intermediate, and bulk water, indicating the presence of jump dynamics in these water molecules.
Three-dimensional simulations of the orientation and structure of reconnection X-lines
Authors: Schreier R. , Swisdak M. , Drake J. F. , Cassak P. A.
Published: November 2010

This letter employs Hall magnetohydrodynamic simulations to study X-lines formed during the reconnection of magnetic fields with differing strengths and orientations embedded in plasmas of differing densities. Although random initial perturbations trigger the growth of X-lines with many orientations, a few robust X-lines sharing an orientation consistent with the direction of maximal outflow speed, as predicted by Swisdak and Drake [Geophys. Res. Lett. 34, L11106 (2007)] eventually dominate the system. Reconnection in the geometry examined here contradicts the suggestion of Sonnerup [J. Geophys. Res. 79, 1546 (1974)] that it occurs in a plane normal to the equilibrium current. At late time, the X-lines' growth stagnates, leaving them shorter than the simulation domain.
Stochastic solutions of Navier–Stokes equations: An experimental evidence
Authors: Djurek Ivan , Djurek Danijel , Petošić Antonio
Published: November 2010

An electrodynamic loudspeaker has been operated in anharmonic regime indicated by the nonlinear ordinary differential equation when spring constant γ in restoring term, as well as, viscoelasticity of the membrane material, increases with displacement. For driving currents in the range of 2.8–3.3 A, doubling of the vibration period appears, while for currents in the range of 3.3–3.6 A, multiple sequences of subharmonic vibrations begin with f/4 and 3f/4. An application of currents higher than 3.6 A results in a spectrum, characteristic for the chaotic state. The loudspeaker was then operated in a closed chamber, and subharmonic vibrations disappeared by an evacuation. Subsequent injection of air revoked them again at ∼120 mbar (Re′=476) when air viscous forces dominate the Morse convection. At 430 mbar (Re=538) single vibration state was restored, and the phenomenon is in an agreement with prediction of the five mode truncation procedure applied to the Navier–Stokes equations describing a two-dimensional incompressible fluid.
Plasma response to nonlinear time-periodic electric fields in one dimension
Authors: Shah Kushal
Published: November 2010

Plasma response to spatially nonuniform time-periodic electric fields is of importance in many applications. For the case of a spatially linear monochromatic electric field in Paul traps, exact analytic expressions for the time-dependent plasma distribution function have been recently obtained [K. Shah and H. S. Ramachandran, Phys. Plasmas 15, 062303 (2008)]. In this paper, the problem of plasma response to a one-dimensional time-periodic electric field with a general spatial dependence is considered and analytic expressions for the time-averaged plasma distribution function and density are derived by solving the Vlasov equation under two limiting cases of high and low frequencies. Under this approximation, it is shown that the time-averaged plasma density is a function of the square of the oscillatory electric potential.
Hard x-ray phase contrast imaging using single absorption grating and hybrid semiconductor pixel detector
Authors: Krejci Frantisek , Jakubek Jan , Kroupa Martin
Published: November 2010

A method for x-ray phase contrast imaging is introduced in which only one absorption grating and a microfocus x-ray source in a tabletop setup are used. The method is based on precise subpixel position determination of the x-ray pattern projected by the grating directly from the pattern image. For retrieval of the phase gradient and absorption image (both images obtained from one exposure), it is necessary to measure only one projection of the investigated object. Thus, our method is greatly simplified compared with the phase-stepping method and our method can significantly reduce the time-consuming scanning and possibly the unnecessary dose. Furthermore, the technique works with a fully polychromatic spectrum and gives ample variability in object magnification. Consequently, the approach can open the way to further widespread application of phase contrast imaging, e.g., into clinical practice. The experimental results on a simple testing object as well as on complex biological samples are presented.
Optical temperature measurements on thin freestanding silicon membranes
Authors: Schmotz Markus , Bookjans Patrick , Scheer Elke , Leiderer Paul
Published: November 2010

We report on a contactless, all-optical method to derive thermal properties of 340 nm thin, 640×640 μm2 wide, freestanding silicon membranes. Exploiting the temperature dependent optical transmissivity of 4×10−3/K between 300 and 470 K, we are able to measure the temperature of the membrane with millikelvin thermal, micrometer lateral, and nanosecond temporal resolution. Experiments such as the decay of a transient thermal grating with spacings between 5 and 30 μm, measured in first order of diffraction, as well as heat diffusion in a statically heated membrane are reported in this letter. For the latter case an example of a nanostructured membrane by means of focused ion beam milling is given.
Topographic anisotropy in continuous magnetic films with two-dimensional surface nanomodulation
Authors: Li S. P. , Godsell Jeffrey F. , Roy Saibal
Published: November 2010

Artificial and local control of spin-configuration in nanoscale in continuous magnetic films could enable new spin-based electronics and precision sensor technologies. Extensive theoretical research has recently been devoted to examination of surface nanovariation mediated magnetism and its utility, which has been demonstrated only in one-dimensional surface modulation. However, a realization of engineered spin configuration using two-dimensional (2D) nanomodulation is limited by local vortex formation induced by magnetostatic energy. In this work we demonstrate for the first time, an ability to control the anisotropy in continuous magnetic films by periodic surface nanomodulation in two-dimensions (2D). Magnetic properties of NiFe films with nanomodulated surfaces have been studied as a function of both film thickness and modulation amplitude. For films with a patterned square array (without breaking the film continuity), a clear fourfold symmetry of anisotropy field and coercivity was observed with rotation angle. An experimental phase diagram of anisotropy with respect to film thickness and modulation amplitude has been produced which delineates that the observed fourfold anisotropy is induced by the magnetostatic effect. The observed dependence of anisotropy field on film thickness and surface modulation amplitude agrees well with the developed theory.
Using rf impedance probe measurements to determine plasma potential and the electron energy distribution
Authors: Walker D. N. , Fernsler R. F. , Blackwell D. D. , Amatucci W. E.
Published: November 2010

Earlier work has demonstrated the usefulness of a network analyzer in plasma diagnostics using spherical probes in the thin sheath limit. The rf signal applied to the probe by the network analyzer is small in magnitude compared to probe bias voltages, and the instrument returns both real and imaginary parts of the complex plasma impedance as a function of frequency for given bias voltages. This information can be used to determine sheath resistance, sheath density profiles, and a technique for measuring electron temperature. The present work outlines a method for finding plasma potential and the electron energy distribution within a limited energy range. The results are compared to those using conventional Langmuir probe techniques. The rf method has general application to diverse areas of plasma investigations when the plasma is uniform and probe dimensions are much less than the size of the plasma. These applications include laboratory and space environments.
Tilt-over mode in a precessing triaxial ellipsoid
Authors: Cébron D. , Le Bars M. , Meunier P.
Published: November 2010

The tilt-over mode in a precessing triaxial ellipsoid is studied theoretically and numerically. Inviscid and viscous analytical models previously developed for the spheroidal geometry by Poincaré [Bull. Astron. 27, 321 (1910)] and Busse [J. Fluid Mech. 33, 739 (1968)] are extended to this more complex geometry, which corresponds to a tidally deformed spinning astrophysical body. As confirmed by three-dimensional numerical simulations, the proposed analytical model provides an accurate description of the stationary flow in an arbitrary triaxial ellipsoid, until the appearance at more vigorous forcing of time dependent flows driven by tidal and/or precessional instabilities.
Suppression of edge-localized modes by magnetic field perturbations
Authors: Kleva Robert G. , Guzdar Parvez N.
Published: November 2010

Transport bursts in simulations of edge-localized modes (ELMs) in tokamaks are suppressed by the application of magnetic field perturbations. The amplitude of the applied magnetic field perturbations is characterized by a stochasticity parameter S. When S>1, magnetic flux surfaces are destroyed and the magnetic field lines diffuse in minor radius. As S increases in the simulations, the magnitude of the ELM bursts decreases. The size of bursts is reduced to a very small value while S is still less than unity and most of the magnetic flux surfaces are still preserved. Magnetic field line stochasticity is not a requirement for the stabilization of ELMs by the magnetic field perturbations. The magnetic field perturbations act by suppressing the growth of the resistive ballooning instability that underlies the ELM bursts.
Prediction of thermal radiative properties (300–1000 K) of La2NiO4+δ ceramics
Authors: Ta M. T. , Rolland J. Y. , Echegut P. , Rousseau B. , Zaghrioui M. , Giovannelli F. , Gomart H. , Lenormand P. , Ansart F.
Published: November 2010

A multiscale numerical model is developed to predict the thermal radiative properties (TRP) of rough La2NiO4+δ coatings. The model integrates intrinsic and extrinsic contributions related to the chemical composition and the texture, respectively. High-temperature infrared reflectivity and thermogravimetric measurements on a La2NiO4+δ single crystal make it possible to understand the role of the excess oxygen in the intrinsic TRP. We show that dense ceramics with thicknesses higher than 4 μm are optically thick, and that one can adjust the surface roughness parameters to predict their TRP.
Efficient growth of high-quality graphene films on Cu foils by ambient pressure chemical vapor deposition
Authors: Gao Libo , Ren Wencai , Zhao Jinping , Ma Lai-Peng , Chen Zongping , Cheng Hui-Ming
Published: November 2010

We developed an ambient pressure chemical vapor deposition (CVD) for rapid growth of high-quality graphene films on Cu foils. The quality and growth rate of graphene films are dramatically increased with decreasing H2 concentration. Without the presence of H2, continuous graphene films are obtained with a mean sheet resistance of <350 Ω/sq and light transmittance of 96.3% at 550 nm. Because of the ambient pressure, rapid growth rate, absence of H2 and readily available Cu foils, this CVD process enables inexpensive and high-throughput growth of high-quality graphene films.
Phosphorylation-independent dual-site binding of the FHA domain of KIF13 mediates phosphoinositide transport via centaurin α1
Authors: Tong Yufeng , Tempel Wolfram , Wang Hui , Yamada Kaori , Shen Limin , Senisterra Guillermo A. , MacKenzie Farrell , Chishti Athar H. , Park Hee-Won
Published: November 2010

Phosphatidylinositol 3,4,5-triphosphate (PIP3) plays a key role in neuronal polarization and axon formation. PIP3-containing vesicles are transported to axon tips by the kinesin KIF13B via an adaptor protein, centaurin α1 (CENTA1). KIF13B interacts with CENTA1 through its forkhead-associated (FHA) domain. We solved the crystal structures of CENTA1 in ligand-free, KIF13B-FHA domain-bound, and PIP3 head group (IP4)-bound conformations, and the CENTA1/KIF13B-FHA/IP4 ternary complex. The first pleckstrin homology (PH) domain of CENTA1 specifically binds to PIP3, while the second binds to both PIP3 and phosphatidylinositol 3,4-biphosphate (PI(3,4)P
2
). The FHA domain of KIF13B interacts with the PH1 domain of one CENTA1 molecule and the ArfGAP domain of a second CENTA1 molecule in a threonine phosphorylation-independent fashion. We propose that full-length KIF13B and CENTA1 form heterotetramers that can bind four phosphoinositide molecules in the vesicle and transport it along the microtubule.
THE IMPACT OF FAMILY POLICY AND CAREER INTERRUPTIONS ON WOMEN'S PERCEPTIONS OF THE NEGATIVE OCCUPATIONAL CONSEQUENCES OF FULL-TIME HOME CARE
Authors: Ejrnæs Anders
Published: November 2010

This article examines the role of family policy in shaping mothers’ choice between work and care and the perceived occupational consequences of that choice. A central question concerns how parental/maternal leave and childcare policies affect the occupational consequences for mothers who spend time on full-time caring. Using comparative data from the second round of the 2004/05 European Social Survey, the analysis shows that the duration of career interruption due to care-giving and different care policies influence mothers’ subjective feelings about caring for children having negative consequences for their careers. On the one hand, our findings confirm the hypothesis that long-term absence from the labour market due to full-time care has negative consequences for women's occupational careers. On the other hand, our findings show that countries with well paid leave schemes combined with access to high quality childcare reduce the perceived negative occupational consequences of the time spent on full-time care. This is the case independently of the duration of the career interruption due to care-giving.
Effects of starting score‐line, game location, and quality of opposition in basketball quarter score
Authors: Sampaio Jaime , Lago Carlos , Casais Luis , Leite Nuno
Published: November 2010

In several team sports, the game starting score‐line may be understood as a measure of performance accomplishment and hence might have an effect on players' subsequent efforts. The aim of this study was to identify the effect of the starting score‐line, game location, and quality of opposition on basketball game quarter final score. The sample comprised 504 game quarters from the Spanish Basketball Professional League and these were classified as balanced (difference in scores equal of 8 points or less,n=194) and unbalanced (difference in scores of more than 8 points,n=310) usingk‐means cluster procedures. The effects of the predictor variables on game quarter outcome (difference between points scored and points received) in the whole game and in the second, third, and fourth game quarters were analysed using linear regression analysis. The starting game quarter score‐line was only significant in unbalanced situations with very similar effects among different game quarters. The greater the difference in accumulated score at the beginning of each quarter, the more points recovered by the teams who were losing. A small effect from the quality of the opponent was found in the second and third quarters, whereas game location only had an effect when analysing the whole game and second quarter using balanced and unbalanced game quarters combined.
Peak aerobic power and paddling efficiency in recreational and competitive junior male surfers
Authors: Loveless Danielle J. , Minahan Clare
Published: November 2010

The purpose of the present study was to measure and compare peak oxygen uptake and paddling efficiency in recreational and competitive junior male surfers. Eight male recreational surfers (mean age 18 years, s=2; mass 66.8 kg, s=13.0; height 1.75 m, s=0.10) and eight male competitive surfers (mean age 18 years, s=1; mass 68.0 kg, s=11.7; height 1.72 m, s=0.10) performed an incremental paddling test consisting of four 3‐min constant load work stages followed by a ramp increase in power output of 20 W · 30 s−1 until exhaustion. The oxygen uptake–power output relationship of the four constant load work stages and peak values obtained during the incremental paddling test were used to calculate paddling efficiency. No differences (P>0.05) were observed between the recreational and competitive surfers for peak oxygen uptake (recreational: 2.52 litres · min−1, s=0.5; competitive: 2.66 litres · min−1, s=0.35) or efficiency (recreational: 24%, s=3; competitive: 21%, s=4). Blood lactate concentration was significantly greater in recreational (2.4 mmol · l−1, s=0.9) than competitive surfers (1.6 mmol · l−1, s=0.5) during submaximal paddling. There were no differences in peak oxygen uptake or paddling efficiency between recreational and competitive surfers suggesting that peak oxygen uptake and efficiency are not sensitive to differences in surfing ability. The increase in blood lactate concentration during submaximal paddling in recreational compared with competitive surfers suggests that other determinants of paddling endurance, such as blood lactate threshold, might be better at distinguishing surfers of differing ability.
Prognostic Factors for Persistence of Chronic Abdominal Pain in Children
Authors: Gieteling Marieke J , Bierma‐Zeinstra Sita MA , van Leeuwen Yvonne , Passchier Jan , Berger Marjolein Y
Published: November 2010

Objectives:

The aim of the study was to identify prognostic factors for the persistence of chronic abdominal pain (CAP) in children.

Materials and Methods:

For this systematic review, MEDLINE, EMBASE, and PsycINFO were searched up to June 2008 for prospective follow‐up studies of pediatric CAP as defined by the criteria of Apley, von Baeyer, or the Rome committee. The outcome measure of interest was persistence of CAP. Persistent CAP was considered only when the abdominal pain of children with CAP persisted during follow‐up at the same level of frequency and severity. For each study the risk for bias was assessed. The evidence for prognostic factors was summarized according to a best‐evidence synthesis.

Results:

Eight studies, which examined 17 prognostic factors, were included. Moderate evidence was found that having a parent with gastrointestinal symptoms predicts the persistence of CAP. Strong evidence was found for no association between female sex and the duration of CAP, and moderate evidence that the severity of abdominal pain does not predict persistence of CAP. There is conflicting evidence as to whether psychological factors prevent, or have no relation with, persistence of CAP.

Conclusions:

Because there are few prognostic follow‐up studies on pediatric CAP, the evidence for prognostic factors is limited. Physicians should ask about parental gastrointestinal problems because this is a risk factor for persistence of CAP in children. The hypothesis that psychological factors of the child predict persistence of CAP is not supported by evidence from the follow‐up studies.
Usefulness of a real-time PCR platform for G+C content and DNA–DNA hybridization estimations in vibrios
Authors: Moreira Ana Paula B. , Pereira Nei , Thompson Fabiano L.
Published: November 2010

The aim of this study was to evaluate the utility of a real-time PCR platform to estimate the DNA G+C content (mol%) and DNA–DNA hybridization (DDH) values in the genus Vibrio. In total, nine vibrio strains were used to determine the relationship between genomic DNA G+C content and T
m (°C). The T
m and HPLC datasets fit a linear regression curve with a significant correlation coefficient, corroborating that this methodology has a high correlation with the standard methodology based on HPLC (R2 = 0.94). Analysis of 31 pairs of vibrios provided a wide range of ΔT
m values, varying between 0.72 and 12.5 °C. Pairs corresponding to strains of the same species or strains from sister species showed the lowest ΔT
m values. For instance, the ΔT
m of the sister species Vibrio harveyi LMG 4044T and Vibrio campbellii LMG 11216T was 5.2 °C, whereas the ΔT
m of Vibrio coralliilyticus LMG 20984T and Vibrio neptunius LMG 20536T was 8.75 °C. The mean ΔT
m values corresponding to pairs of strains with DDH values lower than 60 % or higher than 80 % were, respectively, 8.29 and 2.21 °C (significant difference, P<0.01). The high correlation between DDH values obtained in previous studies and the ΔT
m values (R2 = 0.7344) indicates that the fluorimetric methodology is a reliable alternative for the estimation of both DNA G+C content and ΔT
m in vibrios. We suggest that strains of the same Vibrio species will have less than 4 °C ΔT
m. The use of a real-time PCR platform represents a valuable alternative for the development of the taxonomy of vibrios.
Asanoa hainanensis sp. nov., isolated from rhizosphere soil of Acrostichum speciosum in a mangrove, and emended description of the genus Asanoa
Authors: Xu Xiao-Xiong , Qu Zhi , Wang Hailong , Lin Hai-Peng , Wang Cheng , Xie Qing-Yi , Ruan Ji-Sheng , Hong Kui
Published: November 2010

A Gram-reaction-positive, non-motile actinobacterium, designated strain 210121T, was isolated from rhizosphere soil of the mangrove fern Acrostichum speciosum. 16S rRNA gene sequence analysis showed that the isolate belonged to the genus Asanoa. DNA–DNA relatedness values between strain 210121T and the type strains of the three recognized species of the genus Asanoa were below the 70 % threshold recommended for distinguishing bacterial genomic species. The novel isolate contained glutamic acid, glycine, alanine and meso-A2pm as cell-wall amino acids, indicating peptidoglycan type A1γ. The characteristic whole-cell sugars were xylose, ribose, glucose and mannose. The predominant menaquinones were MK-9(H4), MK-9(H6) and MK-9(H8). The major fatty acids were iso-C16 : 0 (30.9 %), C17 : 0 (23.0 %), anteiso-C15 : 0 (14.9 %) and iso-C15 : 0 (12.3 %). The phospholipid profile comprised phosphatidylethanolamine, phosphatidylinositol mannosides and phospholipids of unknown structure containing glucosamine. The G+C content of the DNA was 70.3 mol%. On the basis of the phenotypic and genotypic data, strain 210121T ( = CGMCC 4.5593T  = DSM 45427T) represents a novel species of the genus Asanoa, for which the name Asanoa hainanensis sp. nov., is proposed. An emended description of the genus Asanoa is also proposed.