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Eline Willemse, Kees van Uffelen, Britta Brix, Sebastiaan Engelborghs, Hugo Vanderstichele, Charlotte Teunissen
INTRODUCTION: We aimed to investigate factors defining amyloid-β (1-42) (Aβ1-42) adsorption during preanalytical workup of cerebrospinal fluid (CSF). METHODS: CSF was transferred to new tubes ≤4 times. Variables tested were different polypropylene tube brands, volumes, CSF Aβ1-42 concentrations, incubation times, pipettes, vortex intensities, and other CSF proteins, including hyperphosphorylated tau and IL-1RAcP. An enquiry assessed the number of transfers in current practice...
February 18, 2017: Alzheimer's & Dementia: the Journal of the Alzheimer's Association
E Alshwaimi
AIM: To compare the cyclic fatigue properties of a novel file made using controlled memory NiTi technology with those of files made from M-wire. METHODOLOGY: Twelve files with similar cross-sectional geometry and tip size from each of the following groups were tested: Proflexendo made from CMT (PE; size 30 .04) (Nexden, Houston, Tx, USA), ProFile Vortex made from M-wire (PV; size 30 .04) (Dentsply Tulsa Dental, Tulsa, OK, USA), and ProTaper Universal made from regular alloy (PU; F3) (Dentsply Tulsa Dental)...
February 20, 2017: International Endodontic Journal
D Pengel, S Kerbstadt, D Johannmeyer, L Englert, T Bayer, M Wollenhaupt
Multiphoton ionization of potassium atoms with a sequence of two counter-rotating circularly polarized femtosecond laser pulses produces vortex-shaped photoelectron momentum distributions in the polarization plane describing Archimedean spirals. The pulse sequences are produced by polarization shaping and the three-dimensional photoelectron distributions are tomographically reconstructed from velocity map imaging measurements. We show that perturbative ionization leads to electron vortices with c_{6} rotational symmetry...
February 3, 2017: Physical Review Letters
Zhen Zhang, Wei Yu, Jing Wang, Dan Luo, Xuezhi Qiao, Xiaoyun Qin, Tie Wang
Surface-enhanced Raman scattering (SERS) is expected as a technique that even theoretically detected chemicals at the single molecule level by surface plasmon phenomena of noble metal nanostructures. Insensitivity of detecting Raman weak-intensity molecules and low adsorptivity of gaseous molecules on solid substrates are two main factors hindering the application of SERS in gas detectors. In this manuscript, we demonstrated an operational SERS strategy to detect gaseous Raman weak-intensity aldehydes that have been considered as a biomarker of lung cancer for abnormal content was measured in volatile organic compounds (VOCs) of lung cancer patients...
February 7, 2017: Analytical Chemistry
Nora Warshawsky, Diane Andrews, Cynthia Thornton Bacon, Barbara Cherry, Karren Kowalski, Heather Nelson-Brantley, Rose O Sherman
The 2016 International Nursing Administration Research Conference, Leading in a Healthcare Vortex, was held in Orlando, Florida. The program drew 116 attendees with representation from Canada and Brazil. Participants from practice, education, and research discussed leadership in our turbulent healthcare climate, which are highlighted in this column. The conference was dedicated to the memory of Dr Heather S. Laschinger in recognition of her distinguished research legacy of empowering nursing work environments and mentorship of prominent nursing administration researchers...
March 2017: Journal of Nursing Administration
Jonasz Słomka, Jörn Dunkel
Classical turbulence theory assumes that energy transport in a 3D turbulent flow proceeds through a Richardson cascade whereby larger vortices successively decay into smaller ones. By contrast, an additional inverse cascade characterized by vortex growth exists in 2D fluids and gases, with profound implications for meteorological flows and fluid mixing. The possibility of a helicity-driven inverse cascade in 3D fluids had been rejected in the 1970s based on equilibrium-thermodynamic arguments. Recently, however, it was proposed that certain symmetry-breaking processes could potentially trigger a 3D inverse cascade, but no physical system exhibiting this phenomenon has been identified to date...
February 13, 2017: Proceedings of the National Academy of Sciences of the United States of America
Rodrigo Papai, Roseli Hiromi Sato, Lidiane Cristina Nunes, Francisco José Krug, Ivanise Gaubeur
This work proposes a new development in the use of melted paraffin wax as a new extractant in a procedure designed to aggregate the advantages of liquid phase extraction (extract homogeneity, fast, and efficient transfer, low cost and simplicity) to solid phase extraction. As proof of concept, copper(II) in aqueous samples was converted into a hydrophobic complex of copper(II) diethyldithiocarbamate and subsequently extracted into paraffin wax. Parameters which affect the complexation and extraction (pH, DDTC, and Triton X-100 concentration, vortex agitation time and complexation time) were optimized in a univariate way...
February 16, 2017: Analytical Chemistry
S Eley, M Miura, B Maiorov, L Civale
Superconductors are excellent testbeds for studying vortices, topological excitations that also appear in superfluids, liquid crystals and Bose-Einstein condensates. Vortex motion can be disruptive; it can cause phase transitions, glitches in pulsars, and losses in superconducting microwave circuits, and it limits the current-carrying capacity of superconductors. Understanding vortex dynamics is fundamentally and technologically important, and the competition between thermal energy and energy barriers defined by material disorder is not completely understood...
February 13, 2017: Nature Materials
Tiffany M Mott, Jennifer L Shoe, Melissa Hunter, Amber M Woodson, Kristen A Fritts, Christopher P Klimko, Avery V Quirk, Susan L Welkos, Christopher K Cote
AIMS: In an attempt to devise decontamination methods that are both effective and minimally detrimental to the environment, we evaluated germination-induction as an enhancement to strategies for Bacillus anthracis spore decontamination. To determine an optimal method for the recovery of germinating spores from different matrices it was critical to ensure that the sampling procedures did not negatively impact the viability of the germinating spores possibly confounding the results and downstream analyses of field trial data...
February 12, 2017: Journal of Applied Microbiology
Luciana Costa Dos Reis, Lorena Vidal, Antonio Canals
A fast, simple, economical, and environmentally friendly magnetic solid-phase extraction (MSPE) procedure has been developed to preconcentrate 2,4,6-trinitrotoluene (TNT) from water samples prior to determination by liquid chromatography-UV-Vis employing graphene oxide/Fe3O4 nanocomposite as sorbent. The nanocomposite synthesis was investigated, and the MSPE was optimized by a multivariate approach. The optimum MSPE conditions were 40 mg of nanocomposite, 10 min of vortex extraction, 1 mL of acetonitrile as eluent, and 6 min of desorption in an ultrasonic bath...
February 10, 2017: Analytical and Bioanalytical Chemistry
Xiangyun Liao, Weixin Si, Zhiyong Yuan, Hanqiu Sun, Jing Qin, Qiong Wang, Pheng-Ann Heng
Turbulent vortices in smoke flows are crucial for a visually interesting appearance. Unfortunately, it is challenging to efficiently simulate these appealing effects in the framework of vortex filament methods. The vortex filaments in grids scheme allows to efficiently generate turbulent smoke with macroscopic vortical structures, but suffers from the projection-related dissipation, and thus the small-scale vortical structures under grid resolution are hard to capture. In addition, this scheme cannot be applied in wall-bounded turbulent smoke simulation, which requires efficiently handling smoke-obstacle interaction and creating vorticity at the obstacle boundary...
February 7, 2017: IEEE Transactions on Visualization and Computer Graphics
Jérôme Gateau, Hervé Rigneault, Marc Guillon
Intensity maxima and zeros of speckle patterns obtained behind a diffuser are experimentally interchanged by applying a spiral phase delay of charge ±1 to the impinging coherent beam. This transform arises from the expectation that tightly focused beams, which have a planar wave front around the focus, are so changed into vortex beams and vice versa. The statistics of extrema locations and the intensity distribution of the so-generated "complementary" patterns are characterized by numerical simulations. It is demonstrated experimentally that the incoherent superposition of the three "complementary speckle patterns" yield a synthetic speckle grain size enlarged by a factor of sqrt[3]...
January 27, 2017: Physical Review Letters
Lina Hamouche, Soumaya Laalami, Adrian Daerr, Solène Song, I Barry Holland, Simone J Séror, Kassem Hamze, Harald Putzer
: Bacteria adopt social behavior to expand into new territory, led by specialized swarmers, before forming a biofilm. Such mass migration of Bacillus subtilis on a synthetic medium produces hyperbranching dendrites that transiently (equivalent to 4 to 5 generations of growth) maintain a cellular monolayer over long distances, greatly facilitating single-cell gene expression analysis. Paradoxically, while cells in the dendrites (nonswarmers) might be expected to grow exponentially, the rate of swarm expansion is constant, suggesting that some cells are not multiplying...
February 7, 2017: MBio
Nuša Pukšič, Monika Jenko, Matjaž Godec, Paul J McGuiness
While a lot is known about the deformation of metallic surfaces from experiments, elasticity theory and simulations, this investigation represents the first molecular-dynamics-based simulation of uniaxial deformation for the vicinal surfaces in a comparison of copper and nickel. These vicinal surfaces are composed of terraces divided by equidistant, mono-atomic steps. The periodicity of vicinals makes them good candidates for the study of the surface steps' influences on surface dynamics. The simulations of tensile and compressive uniaxial deformations were performed for the (1 1 19) vicinal surfaces...
February 7, 2017: Scientific Reports
Jijil Jj Nivas, Filippo Cardano, Zhenming Song, Andrea Rubano, Rosalba Fittipaldi, Antonio Vecchione, Domenico Paparo, Lorenzo Marrucci, Riccardo Bruzzese, Salvatore Amoruso
In the last few years femtosecond optical vortex beams with different spatial distributions of the state of polarization (e.g. azimuthal, radial, spiral, etc.) have been used to generate complex, regular surface patterns on different materials. Here we present an experimental investigation on direct femtosecond laser surface structuring based on a larger class of vector beams generated by means of a q-plate with topological charge q = +1/2. In fact, voltage tuning of q-plate optical retardation allows generating a family of ultrashort laser beams with a continuous spatial evolution of polarization and fluence distribution in the focal plane...
February 7, 2017: Scientific Reports
K Deguchi, P Hall
The present work is based on our recent discovery of a new class of exact coherent structures generated near the edge of quite general boundary layer flows. The structures are referred to as free-stream coherent structures and were found using a large Reynolds number asymptotic approach to describe equilibrium solutions of the Navier-Stokes equations. In this paper, first we present results for a new family of free-stream coherent structures existing at relatively large wavenumbers. The new results are consistent with our earlier theoretical result that such structures can generate larger amplitude wall streaks if and only if the local spanwise wavenumber is sufficiently small...
March 13, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
Li-Yaung Kuo, Yi-Jia Huang, JenYu Chang, Wen-Liang Chiou, Yao-Moan Huang
Ferns and lycophytes produce spores to initiate the gametophyte stage for sexual reproduction. Approximately 10% of these seedless vascular plants are apomictic, and produce genomic unreduced spores. Genome size comparisons between spores and leaves are a reliable, and potentially easier way to determine their reproductive mode compared to traditional approaches. However, estimation of the spore genome sizes of these plants has not been attempted. We attempted to evaluate the spore genome sizes of ferns and lycophytes using flow cytometry, collected spores from selected species representing different spore physical properties and taxonomic groups, and sought to optimize bead-vortexing conditions...
March 2017: New Phytologist
Nathan Phillips, Kevin Knowles, Richard J Bomphrey
The wings of many insect species including crane flies and damselflies are petiolate (on stalks), with the wing planform beginning some distance away from the wing hinge, rather than at the hinge. The aerodynamic impact of flapping petiolate wings is relatively unknown, particularly on the formation of the lift-augmenting leading-edge vortex (LEV): a key flow structure exploited by many insects, birds and bats to enhance their lift coefficient. We investigated the aerodynamic implications of petiolation P using particle image velocimetry flow field measurements on an array of rectangular wings of aspect ratio 3 and petiolation values of P = 1-3...
February 6, 2017: Interface Focus
Alexander Widmann, Cameron Tropea
The impact of chord-based Reynolds number on the formation of leading-edge vortices (LEVs) on unsteady pitching flat plates is investigated. The influence of secondary flow structures on the shear layer feeding the LEV and the subsequent topological change at the leading edge as the result of viscous processes are demonstrated. Time-resolved velocity fields are measured using particle image velocimetry simultaneously in two fields of view to correlate local and global flow phenomena in order to identify unsteady boundary-layer separation and the subsequent flow structures...
February 6, 2017: Interface Focus
Xiaoyu Weng, Luping Du, Peng Shi, Xiaocong Yuan
We propose a method to generate uniform optical cages with adjustable number and position along the optical axis in a low numerical aperture (NA) optical system. The uniform optical cages are the superposition of multiple dark and bright spots, which are of x- and y-polarized electric fields with the neglected axial component obtained, respectively, by focusing a quasi-x-polarized vortex beam with topological charge 1 and a quasi-y-polarized beam. By adjusting the number and position of the dark and bright spots with reversal radiation theory, valuable optical cages with uniformity up to 1, such as multiple optical cages, optical chain, and optical tube, can be realized...
February 1, 2017: Applied Optics
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