bluuebunny/crossref_metadata_2025 huggingface dataset:
Confined suspension jet and long-range hydrodynamic interactions: A destabilization scenario
Authors: Alvarez Alejandra , Clement Eric , Soto Rodrigo
Published: September 2006

The collective dynamics of a quasi-two-dimensional suspension jet, of non-Brownian particles, confined in a thin cell and driven by gravitational force is studied both numerically and theoretically. We present a theoretical scheme aimed to describe such a system in the Stokes regime. We focus on the dynamics of the interface between the suspension and the pure fluid. Numerical simulations solving Newton’s equations for all particles show that the jet free surface becomes unstable: the fastest growing modes at small sizes coarsen up to the largest structures reaching the jet lateral scale. In the bulk, structural waves develop and travel at slightly slower speed than the jet average fall. An analytical model, based on hydrodynamic-like equations for the suspension, is derived and predicts the development of the interfacial instability. It captures in essence the collective effects driving the interface destabilization, i.e., the long-range hydrodynamic interactions coupled with the abrupt interface, and no relation to surface tension is found.
Soft elasticity is not necessary for striping in nematic elastomers
Authors: Fried Eliot , Sellers Shaun
Published: September 2006

The neoclassical model for nematic elastomers, which displays soft elasticity, predicts striping in stretched sheets. Thus the experimental observation of striped domains has been suggested as evidence for soft elasticity. Here we show that the postulated director rotations and shears in the domain regions are also predicted by more general constitutive models that do not involve any notion of softness. Striping in nematic elastomers may therefore be a more general phenomenon that is not necessarily an indication of soft elasticity. Furthermore, constitutive models more general than the neoclassical model may also explain the behavior of some nematic elastomers that do not appear to exhibit striping.
Towards ultrahigh-contrast ultraintense laser pulses—complete characterization of a double plasma-mirror pulse cleaner
Authors: Wittmann T. , Geindre J. P. , Audebert P. , Marjoribanks R. S. , Rousseau J. P. , Burgy F. , Douillet D. , Lefrou T. , Phuoc K. Ta , Chambaret J. P.
Published: September 2006

The effects of small amounts of energy delivered at times before the peak intensity of ultrahigh-intensity ultrafast-laser pulses have been a major obstacle to the goal of studying the interaction of ultraintense light with solids for more than two decades now. We describe implementation of a practical double-plasma-mirror pulse cleaner, built into a f=10m null telescope and added as a standard beamline feature of a 100 TW laser system for ultraintense laser-matter interaction. Our measurements allow us to infer a pulse-height contrast of 5×1011—the highest contrast generated to date—while preserving ∼50% of the laser intensity and maintaining excellent focusability of the delivered beam. We present a complete optical characterization, comparing empirical results and numerical modeling of a double-plasma-mirror system.
Microstructural evolution and mechanical properties of SnAgCu alloys
Authors: Fouassier O. , Heintz J.-M. , Chazelas J. , Geffroy P.-M. , Silvain J.-F.
Published: September 2006

Lead containing solder paste is now considered as an environmental threat. In order to eliminate this undesirable environmental impact associated to their production, a family of lead-free solder joint, Sn-3.8Ag-0.7Cu, is proposed. Microstructural and mechanical data of this solder joint have been acquired and compared with the most common used SnPb solder paste. The evolution of the microstructure as well as the failure mode and the mechanical properties of SnAgCu solder joint are discussed as a function of strain rate, annealing treatments, and testing temperature. Tensile tests have been performed, at temperatures ranging from −50to+150°C, on bulk samples. Changes of the mechanical properties of bulk tested samples are actually correlated with microstructural changes, as shown by transmission electronic microscopy investigations.
Real-time, in situ spectroscopic ellipsometry for analysis of the kinetics of ultrathin oxide-film growth on MgAl alloys
Authors: Vinodh M. S. , Jeurgens L. P. H. , Mittemeijer E. J.
Published: September 2006

A procedure has been developed to determine the growth kinetics of thin (<3nm) oxide films on bare binary alloys from the measured changes of the ellipsometric amplitude-ratio and phase-shift dependent parameters, ψ and Δ, versus wavelength, as function of oxidation time, as recorded by real-time, in situ spectroscopic ellipsometry. The approach has been applied to the dry, thermal oxidation of Mg-based MgAl substrates of low (2.63at.%) and high (7.31at.%) bulk Al content at 304K within the partial pressure of oxygen range of 10−6–10−4Pa. Various models have been developed to describe the time dependences of the spectra of ψ(λ) and/or Δ(λ) for the initial and subsequent stages of oxidation. It followed that the initial oxide-film growth kinetics can be accurately described by adopting a three-node graded oxide layer using the Maxwell-Garnet effective medium approximation to assess the optical properties of the compositionally inhomogeneous, Al-doped MgO film developing on the MgAl alloy surface. The specific complications that arise in the ellipsometric analysis of the oxidation of binary alloys (as compared to that of pure metals), such as due to the concurrent processes of selective oxidation and (oxidation-induced) chemical segregation, have been discussed.
Real-time quantitative investigation of photochemical reaction using thermal lens measurements: Theory and experiment
Authors: Pedreira P. R. B. , Hirsch L. R. , Pereira J. R. D. , Medina A. N. , Bento A. C. , Baesso M. L. , Rollemberg Maria C. , Franko Mladen , Shen Jun
Published: September 2006

In this work the time-resolved mode-mismatched thermal lens method is applied to investigate Cr(VI) species in water. An abnormal behavior of the thermal lens transient induced by a photochemical reaction was observed during optical excitation. With the purpose of better understanding this phenomenon, the existing theoretical model of thermal lens effect was generalized in order to take the time dependence of the absorbance of the sample into account due to the changes in concentration resulting from photochemical reaction and diffusion of absorbing species. Consequently, the photochemical reaction rate can be quantitatively evaluated by this technique with the generalized model. The adopted procedure demonstrates the usefulness of the time-resolved thermal lens method for the study of photochemical reactions under the presence of absorbing species diffusion with the advantage of monitoring the processes in a quantitative way and with a temporal resolution of a few milliseconds.
Doping effects on the electrical conductivity of bismuth layered Bi3TiNbO9-based ceramics
Authors: Zhou Zhiyong , Dong Xianlin , Yan Haixue , Chen Heng , Mao Chaoliang
Published: September 2006

Single phase Bi3TiNbO9 (BTNO)-based ceramics, with Sr2+ replacing Bi3+ as an acceptor dopant and Nb5+ and W6+ replacing Ti4+ as donor dopants, were prepared by conventional solid-state reaction method. The conductivity increased with acceptor dopant and decreased with donor dopant. These results indicate that the dominant conduction mechanism of pure BTNO is p type at low temperature range. Detailed investigations about the W6+ donor doped BTNO ceramics showed that when the doping amount x>0.01, the conductivity increases with increasing donor doping amount, suggesting that the extrinsic conductivity changes from p type to n type at the low temperature region. The extrinsic conductivity range extends to higher temperature with the increase of donor doping amount. At high temperature range the intrinsic electrical conductivity activation energy is about 1.8eV. This value is equal to half the band gap energy.
Heat-kernel expansion on noncompact domains and a generalized zeta-function regularization procedure
Authors: Cognola Guido , Elizalde Emilio , Zerbini Sergio
Published: September 2006

Heat-kernel expansion and zeta function regularization are discussed for Laplace-type operators with discrete spectrum in noncompact domains. Since a general theory is lacking, the heat-kernel expansion is investigated by means of several examples. It is pointed out that for a class of exponential (analytic) interactions, generically the noncompactness of the domain gives rise to logarithmic terms in the heat-kernel expansion. Then, a meromorphic continuation of the associated zeta function is investigated. A simple model is considered, for which the analytic continuation of the zeta function is not regular at the origin, displaying a pole of higher order. For a physically meaningful evaluation of the related functional determinant, a generalized zeta function regularization procedure is proposed.
Statistical quantum probabilities in coherent bosonic and fermionic states
Authors: Ali Abdulmuhsen H.
Published: September 2006

A derivation of the statistical nature of quantum probabilities is presented by considering a system of bosonic particles in a coherent state. A comparison between the current approach and a former derivation is also discussed. The current approach, which is an evaluation of the field operator matrix in the coherent Glauber state, proved to be a concise method which can be applied to relativistic particles as well. An extension of the coherent state method to the fermionic type of particles is also presented and thus the generality of the coherent state method is established.
Optical emission spectroscopic studies on laser ablated zinc oxide plasma
Authors: Saji K. J. , Joshy N. V. , Jayaraj M. K.
Published: September 2006

Optical emission spectroscopic studies were carried out on the plasma produced by ablation of zinc oxide target using the third harmonic (355nm) of Q-switched Nd:YAG laser, in vacuum and at three different ambient gas (oxygen) pressures. The spatial variations of electron density (Ne) and electron temperature (Te) were studied up to a distance of 20mm from the target surface. The kinematics of the emitted particles and the expansion of the plume edge are discussed. The optimum conditions favorable for the formation of high quality zinc oxide thin films are thereby suggested.
Structural transformations of double-walled carbon nanotube bundle under hydrostatic pressure
Authors: Yang Xiaoping , Wu Gang , Dong Jinming
Published: September 2006

Three kinds of the response mechanisms to the external pressure have been found for double-walled carbon nanotube (DWCNT) bundle, depending strongly on their average radius and symmetry. The small-diameter DWCNT bundle undergoes a small discontinuous volume change, and then deform continuously. The intermediate-diameter DWCNT bundle collapses completely after a structure phase transition (SPT). Significantly, two SPTs exist for the larger-diameter DWCNT bundle if the outer tube has no C6 or C3 symmetry. It would be interesting to search for signatures of these different structural transformations by experimentally investigating mechanical, optical, and thermal response functions of DWCNT bundle.
Optochemical sensor for water monitoring based on SnO2 particle layer deposited onto optical fibers by the electrospray pyrolysis method
Authors: Cusano A. , Consales M. , Pisco M. , Pilla P. , Cutolo A. , Buosciolo A. , Viter R. , Smyntyna V. , Giordano M.
Published: September 2006

In this letter, experimental results on the capability of a tin dioxide (SnO2)-based silica optical fiber (SOF) sensor to detect sub-ppm ammonia concentrations in water environments, at room temperature, are presented. SnO2 sensitive layers have been deposited on the fiber end by using the simple and low cost electrostatic spray pyrolysis deposition technique. The surface morphology of the deposited SnO2 layers as well as its influence on the near field profile of the emergent electromagnetic field from the fiber coating have been investigated by means of atomic force microscopy and scanning near field optical microscopy. The room temperature adsorption measurements reveal the excellent sensor resolution of 80ppb, good recovery features, high repeatability, and fast response times (a few minutes). The results obtained demonstrate the strong potentiality of the proposed SnO2-based SOF sensor to be employed for water quality monitoring applications.
Microstructure and electromechanical responses in semicrystalline ferroelectric relaxor polymer blends
Authors: Zhang Shihai , Neese Bret , Ren Kailiang , Chu Baojin , Zhang Q. M.
Published: September 2006

Ferroelectric relaxor poly(vinylidene fluoride-trifluoroethylene-1,1-chlorofluoroethylene) [P(VDF-TrFE-CFE)] terpolymer with VDF/TrFE/CFE composition of 59.2∕34.6∕7.2 (mole %) exhibits a high dielectric constant (∼50) around room temperature and strong electromechanical response. It can form miscible blends with poly(methyl methacrylate) (PMMA). This paper reports the results of a systematic investigation of the influence of PMMA on the microstructure and electromechanical responses of the terpolymer blends with PMMA content up to 10wt%. It was found that the crystallinity of the blends decreases nearly linearly with increased PMMA content. Since the dielectric constant and polarization response of P(VDF-TrFE-CFE) terpolymer are mainly from the crystalline region, these properties accordingly exhibit proportional reduction with increased PMMA concentration. Nevertheless, a small amount (∼5wt%, for instance) of PMMA can raise the elastic modulus of the blend quite markedly while the field-induced strain level is not affected very much. Consequently, the elastic energy density can be enhanced in the blends. As a result, the electromechanical efficiency of blends in the composition range investigated is also significantly improved. In addition, the mechanical loss factor is dramatically decreased at room temperature by blending with PMMA.
Solitary electrostatic waves are possible in unmagnetized symmetric pair plasmas
Authors: Dubinov Alexander E. , Dubinova Irina D. , Gordienko Victor A.
Published: September 2006

A possibility of stationary solitary electrostatic waves with large amplitude in symmetric unmagnetized symmetric pair plasmas (e−e+ plasma, C60−C60+ plasma or e−h+ plasma) is proven. The main idea of the work is a thermodynamic unequilibrium of plasma species which may be created in low-density ideal pair plasmas. Ranges of parameters (Mach number M and a nonequilibrium degree τ=T+∕T−) which lead to the possibility of solitary waves are found.
Contact-lens type of micromachined hydrogenated amorphous Si fluorescence detector coupled with microfluidic electrophoresis devices
Authors: Kamei Toshihiro , Wada Takehito
Published: September 2006

A 5.8-μm-thick SiO2∕Ta2O5 multilayer optical interference filter was monolithically integrated and micromachined on a hydrogenated amorphous Si (a-Si:H) pin photodiode to form a fluorescence detector. A microfluidic electrophoresis device was mounted on a detection platform comprising a fluorescence-collecting half-ball lens and the micromachined fluorescence detector. The central aperture of the fluorescence detector allows semiconductor laser light to pass up through the detector and to irradiate an electrophoretic separation channel. The limit of detection is as low as 7nM of the fluorescein solution, and high-speed DNA fragment sizing can be achieved with high separation efficiency. The micromachined a-Si:H fluorescence detector exhibits high sensitivity for practical fluorescent labeling dyes as well as integration flexibility on various substances, making it ideal for application to portable microfluidic bioanalysis devices.
The effect of an external magnetic field on the structure of liquid water using molecular dynamics simulation
Authors: Chang Kai-Tai , Weng Cheng-I.
Published: September 2006

Through a series of molecular dynamics simulations based on the flexible three-centered water model, this study analyzes the structural changes induced in liquid water by the application of a magnetic field with a strength ranging from 1to10T. It is found that the number of hydrogen bonds increases slightly as the strength of the magnetic field is increased. This implies that the size of a water cluster can be controlled by the application of an external magnetic field. The structure of the water is analyzed by calculating the radial distribution function of the water molecules. The results reveal that the structure of the water is more stable and the ability of the water molecules to form hydrogen bonds is enhanced when a magnetic field is applied. In addition, the behavior of the water molecules changes under the influence of a magnetic field; for example, the self-diffusion coefficient of the water molecules decreases.
Well-oriented nanowell array metrics for integrated digital nanobiosensors
Authors: Lee HeaYeon , Park JongWan , Kim JongMin , Jung HoSup , Kawai Tomoji
Published: September 2006

Nanofabrication technologies should be useful for developing highly sensitive, reproducible nanobiosensors. This letter presents a nanometric system that is composed of well-oriented nanowells. The geometry permits only one or a few biomolecules to enter and become attached to nanosized gold dots. This nanoarray is easily fabricated using current nanolithography technology. When the authors applied this array to highly sensitive electrochemical DNA detection, they obtained a two-orders-of-magnitude enhancement in sensitivity. This nanometric system could be applied to numerous other integrated digital biosensors.
Terahertz photonic mixers as local oscillators for hot electron bolometer and superconductor-insulator-superconductor astronomical receivers
Authors: Cámara Mayorga I. , Muñoz Pradas P. , Michael E. A. , Mikulics M. , Schmitz A. , van der Wal P. , Kaseman C. , Güsten R. , Jacobs K. , Marso M. , Lüth H. , Kordoš P.
Published: September 2006

A pump experiment of two astronomical heterodyne receivers, a superconductor- insulator-superconductor (SIS) receiver at 450GHz and a hot-electron-bolometer (HEB) receiver at 750GHz, is reported. A low-temperature-grown GaAs metal-semiconductor-metal photonic local oscillator (LO) was illuminated by two near infrared semiconductor lasers, generating a beat frequency in the submillimeter range. I-V junction characteristics for different LO pump power levels demonstrate that the power delivered by the photomixer is sufficient to pump a SIS and a HEB mixer. SIS receiver noise temperatures were compared using a conventional solid-state LO and a photonic LO. In both cases, the best receiver noise temperature was identical (Tsys=170K).
Stability of liquid rope coiling
Authors: Ribe N. M. , Habibi M. , Bonn Daniel
Published: September 2006

A thin “rope” of viscous fluid falls from a sufficient height of coils as it approaches a rigid surface. Here we perform a linear stability analysis of steady coiling, with particular attention to the “inertio-gravitational” regime in which multiple states with different frequencies exist at a fixed fall height. The basic states analyzed are numerical solutions of asymptotic “thin-rope” equations that describe steady coiling. To analyze their stability, we first derive in detail a set of more general equations for the arbitrary time-dependent motion of a thin viscous rope. Linearization of these equations about the steady coiling solutions yields a boundary-eigenvalue problem of order 21 which we solve numerically to determine the complex growth rate. The multivalued portion of the curve of steady coiling frequency vs height comprises alternating stable and unstable segments whose distribution agrees closely with high-resolution laboratory experiments. The dominant balance of (perturbation) forces in the instability is between gravity and the viscous resistance to bending of the rope; inertia is not essential, although it significantly influences the growth rate.
Gyro-kinetic simulation of global turbulent transport properties in tokamak experiments
Authors: Wang W. X. , Lin Z. , Tang W. M. , Lee W. W. , Ethier S. , Lewandowski J. L. V. , Rewoldt G. , Hahm T. S. , Manickam J.
Published: September 2006

A general geometry gyro-kinetic model for particle simulation of plasma turbulence in tokamak experiments is described. It incorporates the comprehensive influence of noncircular cross section, realistic plasma profiles, plasma rotation, neoclassical (equilibrium) electric fields, and Coulomb collisions. An interesting result of global turbulence development in a shaped tokamak plasma is presented with regard to nonlinear turbulence spreading into the linearly stable region. The mutual interaction between turbulence and zonal flows in collisionless plasmas is studied with a focus on identifying possible nonlinear saturation mechanisms for zonal flows. A bursting temporal behavior with a period longer than the geodesic acoustic oscillation period is observed even in a collisionless system. Our simulation results suggest that the zonal flows can drive turbulence. However, this process is too weak to be an effective zonal flow saturation mechanism.
Interpolation of multidimensional diabatic potential energy matrices
Authors: Godsi Oded , Evenhuis Christian R. , Collins Michael A.
Published: September 2006

A method for constructing diabatic potential energy matrices by interpolation of ab initio quantum chemistry data is described and tested. This approach is applicable to any number of interacting electronic states, and relies on a formalism and a computational procedure that are more general than those presented previously for the case of two electronic states. The method is tested against an analytic model for three interacting electronic states of NH3+.
Local CC2 electronic excitation energies for large molecules with density fitting
Authors: Kats Danylo , Korona Tatiana , Schütz Martin
Published: September 2006

A new local method for the computation of electronic excitation energies of singlet states in extended molecular systems is presented. It is based on the CC2 model and local approximations to the wave functions. In the proposed method the singles excitations are treated nonlocally and local restrictions are imposed on doubles amplitudes only. The accuracy of the new method was tested by calculating several lowest excited states for 14molecules and comparing them with canonical CC2 values. Deviations of the local excitation energies from the canonical reference values do not exceed 0.05eV for all test molecules and all states in the lower energy range investigated in this work. The method uses the density-fitting approximation for all two-electron integrals, which considerably simplifies the computational complexity of the individual diagrams. A combination of the local approximations and the powerful density-fitting technique leads to a low-scaling method, capable to treat molecular systems comprised of 100 atoms and more in a basis of a polarized double zeta quality. A test calculation for a system consisting of 127 atoms and 370 active electrons without symmetry is presented to show the efficiency of the new method.
Reactions of mixed silver-gold cluster cations AgmAun+ (m+n=4,5,6) with CO: Radiative association kinetics and density functional theory computations
Authors: Neumaier Marco , Weigend Florian , Hampe Oliver , Kappes Manfred M.
Published: September 2006

Near thermal energy reactive collisions of small mixed metal cluster cations AgmAun+ (m+n=4, 5, and 6) with carbon monoxide have been studied in the room temperature Penning trap of a Fourier transform ion-cyclotron-resonance mass spectrometer as a function of cluster size and composition. The tetrameric species AgAu3+ and Ag2Au2+ are found to react dissociatively by way of Au or Ag atom loss, respectively, to form the cluster carbonyl AgAu2CO+. In contrast, measurements on a selection of pentamers and hexamers show that CO is added with absolute rate constants that decrease with increasing silver content. Experimentally determined absolute rate constants for CO adsorption were analyzed using the radiative association kinetics model to obtain cluster cation-CO binding energies ranging from 0.77to1.09eV. High-level ab initio density functional theory (DFT) computations identifying the lowest-energy cluster isomers and the respective CO adsorption energies are in good agreement with the experimental findings clearly showing that CO binds in a “head-on” fashion to a gold atom in the mixed clusters. DFT exploration of reaction pathways in the case of Ag2Au2+ suggests that exoergicities are high enough to access the minimum energy products for all reactive clusters probed.
Diacylglycerol kinase δ regulates protein kinase C and epidermal growth factor receptor signaling
Authors: Crotty Tracy , Cai Jinjin , Sakane Fumio , Taketomi Akinobu , Prescott Stephen M. , Topham Matthew K.
Published: October 2006

Diacylglycerol kinases (DGKs) phosphorylate diacylglycerol (DAG) to terminate its signaling. To study DGKδ, we disrupted its gene in mice and found that DGKδ deficiency reduced EGF receptor (EGFR) protein expression and activity. Similar to EGFR knockout mice, DGKδ-deficient pups were born with open eyelids and died shortly after birth. PKCs are activated by DAG and phosphorylate EGFR to reduce its expression and activity. We found DAG accumulation, increased threonine phosphorylation of EGFR, enhanced phosphorylation of other PKC substrates, and increased PKC autophosphorylation in DGKδ knockout cells, indicating that DGKδ regulates EGFR by modulating PKC signaling.
TimeTree: a public knowledge-base of divergence times among organisms
Authors: Hedges S. Blair , Dudley Joel , Kumar Sudhir
Published: October 2006

Summary: Biologists and other scientists routinely need to know times of divergence between species and to construct phylogenies calibrated to time (timetrees). Published studies reporting time estimates from molecular data have been increasing rapidly, but the data have been largely inaccessible to the greater community of scientists because of their complexity. TimeTree brings these data together in a consistent format and uses a hierarchical structure, corresponding to the tree of life, to maximize their utility. Results are presented and summarized, allowing users to quickly determine the range and robustness of time estimates and the degree of consensus from the published literature.

Availability: TimeTree is available at

Contact:  sbh1@psu.edu
Experimental studies on the nature of sensitive skin
Authors: Kligman A. M. , Sadiq Iqbal , Zhen Yaxian , Crosby Marilyn
Published: October 2006

Background: In the USA, Europe and Japan 40 to 50% of women report that they have sensitive skin, defined as abnormal sub‐clinical sensory responses to drugs, cosmetics and toiletries in the absence of visible signs of irritation. Itching, burning, stinging and tightness are the commonest complaints, which mainly afflict women. Manufacturers of skin care products have made available a large variety of products which are designed for persons with sensitive skin. Such products are not required by regulatory agencies to submit evidence of safety and efficacy, allowing marketers to make claims that are often exaggerated, irrational and even preposterous. The consumer with self‐assessed sensitive skin has no way of judging which products are likely to be most beneficial and least harmful. The marketplace is awash with products for which there is no evidence that the rosy claims have been substantiated by appropriate testing procedures. There is no internationally accepted consensus regarding the criteria which define sensitive skin. Many papers have been published in the last 15 years, mainly originating from industry, which express widely differing views regarding what constitutes sensitive skin. For some, any adverse reaction to a product topically applied to sensitive skin, including breakouts, redness, scaling etc., a panoply of adverse reactions which is virtually meaningless. Others include environmental factors as causative, including cold, dry wind, heat and high humidity, solar radiation, etc., which add to the manifest complexities of the subject.

Methods: This is the first paper in a series which provides a comprehensive review of the subject, emphasizing the all too many controversies and confusions arising from the lack of a consensus regarding the identification, classification, epidemiology, prevalence and pathogenesis of sensitive skin. Sensitive skin is a biologic reality and not a psychological, fashionable fantasy on the part of impressionable women.

Result/Conclusion: There is an urgent necessity to establish rigorous methodologies for estimating the quality and severity of sensitive skin, a heterogeneous condition involving multi‐factorial factors. Subsequent papers in this series will describe in detail the experimental approach our group has used to bring some clarity and credibility to this querulous, but important subject.
Association between vasopressor dependence and early outcome in patients after cardiac surgery
Authors: Weis F. , Kilger E. , Beiras‐Fernandez A. , Nassau K. , Reuter D. , Goetz A. , Lamm P. , Reindl L. , Briegel J.
Published: September 2006

Arterial hypotension with vasopressor dependence is a major problem after cardiac surgery. We evaluated the early postoperative course of 1558 consecutive patients scheduled for cardiac surgery, and compared the outcome of patients with and without vasopressor dependence (defined as the need for > 0.1 μg.kg−1.h−1 noradrenaline for > 3 h in the face of normovolaemia). Vasopressor dependence was diagnosed in 424 patients (27%) and was associated with a higher incidence of postoperative renal failure (67 (15.7%) vs 7 (0.6%), respectively; p < 0.0001), a longer duration of ventilation (median IQR [range]) 14 (8–26 [6–39]) h vs 8 (5–11 [4–32]) h; p < 0.0001), a greater need for red cell transfusion (3 (1–5 [0–10]) units vs 1 (0–2 [0–4]) units; p < 0.001) and a longer length of stay in the ICU (4 (2–6 [2–9] days) vs 2 (1–3 [1–6] days; p < 0.001). Vasopressor dependence could be predicted from a combination of factors, including pre‐operative ejection fraction < 37%, cardiopulmonary bypass lasting > 94 min, and postoperative interleukin‐6 > 837 pg.ml−1.
The LMA CTrachTM in airway resuscitation: six case reports
Authors: Goldman A. J. , Rosenblatt W. H.
Published: September 2006

We report six patients with unexpected difficult airways who underwent tracheal intubation using the Laryngeal Mask Airway CTrach™. All these patients had failed orotracheal intubation using direct laryngoscopy and gum elastic bougie placement. Fibreoptic bronchoscopy failed in two of these patients due to blood and secretions in the airway. This report describes the successful use of this new intubating laryngeal mask in these cases, all of whom were intubated on the first attempt with this new device.
Fentanyl and clonidine as adjunctive analgesics with levobupivacaine in paravertebral analgesia for breast surgery
Authors: Burlacu C. L. , Frizelle H. P. , Moriarty D. C. , Buggy D. J.
Published: September 2006

The addition of fentanyl or clonidine to levobupivacaine was evaluated in patients undergoing breast surgery under general anaesthesia with intra‐ and postoperative paravertebral analgesia. Patients were randomly allocated to four groups: Group L received 19 ml bolus levobupivacaine 0.25% plus 1 ml saline followed by an infusion of levobupivacaine 0.1%; Group LF received 19 ml bolus levobupivacaine 0.25% plus fentanyl 50 μg followed by an infusion of levobupivacaine 0.05% with fentanyl 4 μg.ml−1; Group LC received 19 ml bolus levobupivacaine 0.25% plus clonidine 150 μg followed by an infusion of levobupivacaine 0.05% with clonidine 3 μg.ml−1; Group C (control) received general anaesthesia without paravertebral analgesia. All groups received postoperative i.v. morphine patient controlled analgesia (PCA). Although mean (SD) postoperative PCA morphine consumption was decreased in LF [7.9 (4.1) mg] and LC [5.9 (3.5) mg]vs L [27.7 (8.6) mg] or C patients [21.7 (5.5) mg], p < 0.01, paravertebral fentanyl and clonidine were associated with significantly increased vomiting and hypotension, respectively.
High incidence of the ETV6/RUNX1 fusion gene in paediatric precursor B‐cell acute lymphoblastic leukaemias with trisomy 21 as the sole cytogenetic change: a Nordic series of cases diagnosed 1989–2005
Authors: Karrman Kristina , Forestier Erik , Andersen Mette K. , Autio Kirsi , Borgström Georg , Heim Sverre , Heinonen Kristina , Hovland Randi , Kerndrup Gitte , Johansson Bertil ,   the Nordic Society of Paediatric Haematology and Oncology (NOPHO) and the NOPHO Leukaemia Cytogenetic Study Group (NLCSG)
Published: September 2006

Trisomy 21 is common in ETV6/RUNX1‐positive acute lymphoblastic leukaemia (ALL); both these aberrations are associated with a favourable outcome. The prognostic impact of +21 as a sole cytogenetic change could be due to a cryptic t(12;21)(p13;q22). The occurrence of ETV6/RUNX1 was determined in 66 childhood ALLs with an acquired +21 and a chromosome number <51. ETV6/RUNX1 was found in 45% of cases and in the majority (10/18; 56%) of ALLs with sole +21. Event‐free survival did not differ between the t(12;21)‐positive and ‐negative cases. Thus, the prognostic impact of +21 is not attributable to cryptic ETV6/RUNX1.
A comparative study on the disinfection potentials of bioactive glass S53P4 and calcium hydroxide in contra‐lateral human premolars ex vivo
Authors: Zehnder M. , Luder H. U. , Schätzle M. , Kerosuo E. , Waltimo T.
Published: September 2006

Aim  To evaluate the effects of bioactive glass S53P4 versus calcium hydroxide when used as dressings in contra‐lateral human premolars infected with Enterococcus faecalis ATCC 29212.

Methodology  Pairs of contra‐lateral premolar teeth plus single control premolars were obtained from 23 individuals aged 10–26 years undergoing orthodontic treatment. Root canals of teeth with fully formed apices (nine contra‐lateral pairs, seven controls) were instrumented using a size 60 FlexoFiles 2 mm short of canal length. Canals with open apices (six contra‐lateral pairs, four controls) were circumferentially instrumented using a FlexoFile. Root canals were rinsed with 1% sodium hypochlorite and 10% citric acid. Teeth were then suspended in tryptic soy broth (TSB) and autoclaved. Positive controls and study teeth were infected with E. faecalis ATCC 29212 for 2 weeks in TSB, while negative controls were kept in sterile TSB. Subsequently, contra‐lateral premolars were dressed with bioactive glass S53P4 (BAG) or calcium hydroxide suspensions for 10 days. Dentine samples were obtained from teeth with fully formed apices using ISO‐size 70, 80 and 90 FlexoFiles to working length and cultured. Teeth with open apices were fixed, fractured and examined using scanning electron microscopy (SEM).

Results  Calcium hydroxide had a strong antibacterial effect and was significantly more effective than BAG in preventing residual bacterial growth (P < 0.01). SEM analysis revealed apparent substance‐specific modes of action.

Conclusions  Calcium hydroxide was an effective disinfectant in human teeth.
Multicolour CCD photometry of the variable stars in globular cluster M3
Authors: Benkő J. M. , Bakos G. Á. , Nuspl J.
Published: October 2006

We present time-series data on the variable stars of the galactic globular cluster Messier 3 (M3). We give BVIC light curves for 226 RR Lyrae, 2 SX Phe and 1 W Vir type variables, along with estimated fundamental photometric parameters such as intensity and magnitude-averaged brightness and pulsation periods. In some cases, the periods we have found significantly differ from the previously published ones. This is the first published light curve and period determination for variable V266. The I-band light curve has not been observed previously for numerous (76) variables. Three new RR Lyrae variables have been discovered. Groups of RR Lyrae variables that belong to different evolutionary stages and have been separated previously on the basis of V data were found here for all colours and colour indices by cluster analysis. The I-band period–luminosity relation is also discussed. From the 66 modulated (Blazhko type) RR Lyrae stars we investigated, six are newly identified and two of them are first overtone pulsators. In the case of 13 RR Lyrae, the period of Blazhko cycle has been estimated for the first time. V252 is identified as a new RRd variable. Amplitude ratios of RRd stars have been investigated to search possible mode content changes. In contrast to previous publications no changes have been found. Problems with the sampling of the time-series of typical cluster variability surveys are demonstrated.
Sedimentological and marine eogenetic control on porosity distribution in Upper Cretaceous carbonate turbidites (central Albania)
Authors: DEWEVER B. , BREESCH L. , MEZINI A. , SWENNEN R.
Published: October 2006

Results of a detailed petrographic and stable isotope study illustrate that sedimentological differences and eogenetic dissolution/precipitation processes controlled porosity distribution within carbonate turbidites of the Ionian basin (central Albania). Based on lithology characteristics and porosity distribution observed in outcrop, individual turbidite beds can be subdivided into four distinct intervals, i.e. from base to top: (A) a non‐porous wackestone/floatstone or packstone followed by (B) porous packstone–grainstone that grades into (C) wackestone and (D) non‐porous mudstone with pelagic foraminifera. Wackestone interval C is characterized by an alternation of porous and non‐porous laminae. Changes in turbidity current flow regime controlled the initial presence of matrix micrite giving rise to both matrix‐ and grain‐supported lithologies within turbidite sequences. These are non‐porous and porous, respectively. Four eogenetic diagenetic processes (dissolution, cementation, neomorphism and compaction) acted shortly after deposition and modified primary porosity characteristics and distribution. Alteration by meteoric water is excluded based on the continuous burial until the Oligocene of the studied deep marine carbonates. Moreover, the stable isotope data with values between −2·1‰ and +0·7‰ for δ18OV‐PDB and between +1‰ and +3‰ for δ13CV‐PDB, favour alteration by marine‐derived pore‐waters. Compaction and aggrading neomorphism occurred dominantly in intervals characterized by higher matrix micrite content, i.e. the floatstone base and the wackestone–mudstone upper turbidite part. Framework‐stabilizing cementation occurred dominantly in the packstone–grainstone middle part of the turbidite beds. In the latter porous lithologies, matrix micrite was not compacted because of the grain fabric and the framework‐stabilizing cements. Here, neomorphism of micrite into microrhombic euhedral calcite occurred and microporosity was preserved.
Additive contribution of AMT1;1 and AMT1;3 to high‐affinity ammonium uptake across the plasma membrane of nitrogen‐deficient Arabidopsis roots
Authors: Loqué Dominique , Yuan Lixing , Kojima Soichi , Gojon Alain , Wirth Judith , Gazzarrini Sonia , Ishiyama Keiki , Takahashi Hideki , Von Wirén Nicolaus
Published: October 2006

In Arabidopsis four root‐expressed AMT genes encode functional ammonium transporters, which raises the question of their role in primary ammonium uptake. After pre‐culturing under nitrogen‐deficiency conditions, we quantified the influx of 15N‐labeled ammonium in T‐DNA insertion lines and observed that the loss of either AMT1;1 or AMT1;3 led to a decrease in the high‐affinity ammonium influx of approximately 30%. Under nitrogen‐sufficient conditions the ammonium influx was lower in Columbia glabra compared with Wassilewskija (WS), and AMT1;1 did not contribute significantly to the ammonium influx in Col‐gl. Ectopic expression of AMT1;3 under the control of a 35S promoter in either of the insertion lines amt1;3‐1 or amt1;1‐1 increased the ammonium influx above the level of their corresponding wild types. In transgenic lines carrying AMT‐promoter–GFP constructs, the promoter activities of AMT1;1 and AMT1;3 were both upregulated under nitrogen‐deficiency conditions and were localized to the rhizodermis, including root hairs. AMT gene–GFP fusions that were stably expressed under the control of their own promoters were localized to the plasma membrane. The double insertion line amt1;1‐1amt1;3‐1 showed a decreased sensitivity to the toxic ammonium analog methylammonium and a decrease in the ammonium influx of up to 70% relative to wild‐type plants. These results suggest an additive contribution of AMT1;1 and AMT1;3 to the overall ammonium uptake capacity in Arabidopsis roots under nitrogen‐deficiency conditions.
An open label randomized comparison of mefloquine–artesunate as separate tablets vs. a new co‐formulated combination for the treatment of uncomplicated multidrug‐resistant falciparum malaria in Thailand
Authors: Ashley Elizabeth A. , Lwin Khin Maung , McGready Rose , Simon Win Htay , Phaiphun Lucy , Proux Stephane , Wangseang Nantawan , Taylor Walter , Stepniewska Kasia , Nawamaneerat Wimon , Thwai Kyaw Lay , Barends Marion , Leowattana Wattana , Olliaro Piero , Singhasivanon Pratap , White Nicholas J. , Nosten François
Published: October 2006

Background  Delivering drugs in a fixed combination is essential to the success of the strategy of artemisinin‐based combination therapy. This prevents one drug being taken without the protection of the other, reducing the chance of emergence and spread of drug resistant strains of Plasmodium falciparum. A lower tablet burden should also facilitate adherence to treatment. A new fixed combination of mefloquine plus artesunate has been developed. This was compared with the conventional regimen of separate tablets for the treatment of uncomplicated multidrug‐resistant falciparum malaria.

Methods  On the north‐western border of Thailand 500 adults and children with uncomplicated falciparum malaria were randomized to receive either the new fixed combination or separate tablets. They were followed up weekly for 63 days.

Results  The day 63 polymerase chain reaction‐adjusted cure rates were 91.9% (95% CI 88.2–95.6) in the fixed combination group and 89.2% (85.0–93.4) in the loose tablets group (P = 0.3). There was a lower incidence of early vomiting in the group receiving the fixed combination.

Conclusion  This new fixed combination of mefloquine and artesunate was efficacious, well tolerated and convenient to administer.

Keywords  artemisinin , fixed combination , malaria , mefloquine
EFNS guidelines on pharmacological treatment of neuropathic pain
Authors: Attal N. , Cruccu G. , Haanpää M. , Hansson P. , Jensen T. S. , Nurmikko T. , Sampaio C. , Sindrup S. , Wiffen P.
Published: September 2006

Neuropathic pain treatment remains unsatisfactory despite a substantial increase in the number of trials. This EFNS Task Force aimed at evaluating the existing evidence about the pharmacological treatment of neuropathic pain. Studies were identified using first the Cochrane Database then Medline. Trials were classified according to the aetiological condition. All class I and II controlled trials (according to EFNS classification of evidence) were assessed, but lower‐class studies were considered in conditions that had no top level studies. Only treatments feasible in an outpatient setting were evaluated. Effects on pain symptoms/signs, quality of life and comorbidities were particularly searched for. Most of the randomized controlled trials included patients with postherpetic neuralgia (PHN) and painful polyneuropathies (PPN) mainly caused by diabetes. These trials provide level A evidence for the efficacy of tricyclic antidepressants, gabapentin, pregabalin and opioids, with a large number of class I trials, followed by topical lidocaine (in PHN) and the newer antidepressants venlafaxine and duloxetine (in PPN). A small number of controlled trials were performed in central pain, trigeminal neuralgia, other peripheral neuropathic pain states and multiple‐aetiology neuropathic pains. The main peripheral pain conditions respond similarly well to tricyclic antidepressants, gabapentin, and pregabalin, but some conditions, such as HIV‐associated polyneuropathy, are more refractory. There are too few studies on central pain, combination therapy, and head‐to‐head comparison. For future trials, we recommend to assess quality of life and pain symptoms or signs with standardized tools.
RHETORIC OF FAITH AND PATTERNS OF PERSUASION IN BERKELEY'S ALCIPHRON
Authors: BRADATAN COSTICA
Published: September 2006

In this article I consider George Berkeley's Alciphron (1732) from the standpoint of the literary techniques and rhetorical procedures employed, as evidence for placing this composition within the tradition of Christian apologetic rhetoric. The argument develops around three main issues: 1) Berkeley's employment of the traditional rhetorical tool of attacking his opponents using their own weapons; 2) Berkeley's resort to a perennial tradition of pre‐Christian or non‐Christian wisdom, in order to validate his Christian‐theistic claims; and 3) Berkeley's ‘argument from utility’ (considering the beneficial effects that accepting Christianity has had over the centuries on people's lives, making them better, wiser, happier, and more virtuous, as well as the social peace and harmony that living by Christian standards brings about – it is preferable to adopt the Christian faith than not). These three theses are discussed in light of the history of Christian apologetic rhetoric, with references to the works of St. Augustine, St. Justin Martyr, Origen, St. Thomas Aquinas and other Christian authors.
ACT AND POTENCY IN WITTGENSTEIN?
Authors: KLEIN TERRANCE W.
Published: September 2006

The philosophy of language pioneered by Ludwig Wittgenstein, far from being inimical to the metaphysical concerns of philosophy, can be understood as complementing and perhaps even deepening the approach to metaphysics first employed by the Belgian Jesuit philosopher Joseph Marèchal: a ‘metaphysics of knowledge’ illuminating the deeper‐than‐conceptualist movement in the thought of Thomas Aquinas. The relationship of words and reality was radically reconfigured in the linguistic turn inaugurated in the work of Wittgenstein, but that work itself still presupposes what might be called the existential act of judgement, which was the foundation of Marèchal's Thomistic retrieval.
REGIONAL DISTRIBUTION OF γ‐AMINOBUTYRIC ACID (GABA) IN BRAIN OF THE RHESUS MONKEY*
Authors: Fahn S. , Ccote L. J.
Published: October 2006

—The concentrations of γ‐aminobutyric acid (GABA) in twenty different regions of Rhesus monkey brain were studied. The highest levels were found in the substantia nigra, globus pallidus, and hypothalamus. Regions of the cerebral cortex and thalamus contained low amounts and white matter the lowest. Indirect evidence supporting an inhibitory transmitter role for GABA is discussed.
LOCALIZATION OF γ‐AMINOBUTYRIC‐α‐OXOGLUTARIC ACID TRANSAMINASE IN MOUSE BRAIN*
Authors: Waksman A. , Rubinstein M. K. , Kuriyama K. , Roberts E.
Published: October 2006

The distribution of γ‐aminobutyric‐α‐oxoglutarate transaminase (GABA‐T) has been studied in mouse brain by histochemical visualization on sections, quantitative determination in grossly dissected brain regions, and in subcellular fractions prepared from whole brain homogenates. The results indicate that GABA‐T is predominantly a mitochondrial enzyme and that its concentration is particularly high in brain stem areas. The results are discussed in relation to the overall function of the GABA system in the CNS.