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https://www.readbyqxmd.com/read/28535518/extracorporeal-sorbent-technologies-basic-concepts-and-clinical-application
#1
William R Clark, Fiorenza Ferrari, Gaetano La Manna, Claudio Ronco
Limitations imposed by the characteristics of some solutes and the structure of dialysis membranes have spurred new interest in the use of mechanisms beyond diffusion and convection for extracorporeal solute removal. Sorbents have been utilized for more than 50 years in extracorporeal blood treatments for specific purposes, and better understanding of their basic aspects may further expand the potential for their clinical application. In this chapter, the basic principles applying to sorbents are discussed, including composition and structure, along with the fundamental mechanisms of solute removal...
2017: Contributions to Nephrology
https://www.readbyqxmd.com/read/28535066/marangoni-flow-induced-evaporation-enhancement-on-binary-sessile-drops
#2
Pin Chen, Souad Harmand, Safouene Ouenzerfi, Jesse Schiffler
The evaporation processes of pure water, pure 1-butanol, and 5% 1-butanol aqueous solution drops on heated hydrophobic substrates are investigated to determine the effect of temperature on the drop evaporation behavior. The evolution of the parameters (contact angle, diameter, and volume) during evaporation measured using a drop shape analyzer and the infrared thermal mapping of the drop surface recorded by an infrared camera were used in investigating the evaporation process. The pure 1-butanol drop does not show any thermal instability at different substrate temperatures, while the convection cells created by the thermal Marangoni effect appear on the surface of the pure water drop from 50°C...
May 23, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28534055/experimental-determination-of-surface-heat-transfer-coefficient-in-a-dry-ice-ethanol-cooling-bath-using-a-numerical-approach
#3
M V Santos, M Sansinena, N Zaritzky, J Chirife
  BACKGROUND: Dry ice-ethanol bath (-78 degree C) have been widely used in low temperature biological research to attain rapid cooling of samples below freezing temperature. The prediction of cooling rates of biological samples immersed in dry ice-ethanol bath is of practical interest in cryopreservation. The cooling rate can be obtained using mathematical models representing the heat conduction equation in transient state. Additionally, at the solid cryogenic-fluid interface, the knowledge of the surface heat transfer coefficient (h) is necessary for the convective boundary condition in order to correctly establish the mathematical problem...
March 2017: Cryo Letters
https://www.readbyqxmd.com/read/28525826/formation-and-stability-of-manganese-doped-zns-quantum-dot-monolayers-determined-by-qcm-d-and-streaming-potential-measurements
#4
Magdalena Oćwieja, Katarzyna Matras-Postołek, Julia Maciejewska-Prończuk, Maria Morga, Zbigniew Adamczyk, Svitlana Sovinska, Adam Żaba, Marta Gajewska, Tomasz Król, Klaudia Cupiał, Michael Bredol
Manganese-doped ZnS quantum dots (QDs) stabilized by cysteamine hydrochloride were successfully synthesized. Their thorough physicochemical characteristics were acquired using UV-Vis absorption and photoluminescence spectroscopy, X-ray diffraction, dynamic light scattering (DLS), transmission electron microscopy (HR-TEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared (FT-IR) spectroscopy. The average particle size, derived from HR-TEM, was 3.1nm, which agrees with the hydrodynamic diameter acquired by DLS, that was equal to 3-4nm, depending on ionic strength...
May 10, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28524852/surface-chemistry-governs-cellular-tropism-of-nanoparticles-in-the-brain
#5
Eric Song, Alice Gaudin, Amanda R King, Young-Eun Seo, Hee-Won Suh, Yang Deng, Jiajia Cui, Gregory T Tietjen, Anita Huttner, W Mark Saltzman
Nanoparticles are of long-standing interest for the treatment of neurological diseases such as glioblastoma. Most past work focused on methods to introduce nanoparticles into the brain, suggesting that reaching the brain interstitium will be sufficient to ensure therapeutic efficacy. However, optimized nanoparticle design for drug delivery to the central nervous system is limited by our understanding of their cellular deposition in the brain. Here, we investigated the cellular fate of poly(lactic acid) nanoparticles presenting different surface chemistries, after administration by convection-enhanced delivery...
May 19, 2017: Nature Communications
https://www.readbyqxmd.com/read/28522846/effect-of-compressibility-and-non-uniformity-in-flow-on-the-scattering-pattern-of-acoustic-cloak
#6
Hyeonbin Ryoo, Wonju Jeon
During the last decade, most of acoustic cloak research has been done within a theoretical framework in which the medium is at rest. However, such an acoustic cloak cannot preserve its unique properties or functions to make an object acoustically invisible in the presence of flow. In this study, we propose a theoretical framework to accurately investigate the effect of compressibility and non-uniformity in flow on the scattering pattern of acoustic cloak. In the formulation, the wave operator is coupled with the non-uniform velocity vector, and the equivalent source terms due to mean flow are divided into the compressibility effect and the non-uniformity effect with their own physical meanings...
May 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28514847/electric-field-assisted-assembly-of-colloidal-particles-into-ordered-non-close-packed-arrays
#7
Jingjing Gong, Ning Wu
Non-close packed colloidal arrays have many potential applications ranging from plasmonic sensors, light trapping for photovoltaics, to transparent electrodes. However, scalable fabrication of those structures remains a challenge. In this paper, we investigate the robustness of an electric-field assisted approach systematically. A monolayer of non-close packed crystalline array is first created under a low-frequency alternating-current electric field in solution. We then apply a sequence of direct current pulses to fix the particle array onto the substrate so that it remains intact even after both field removal and solvent evaporation...
May 17, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28513143/interactive-effects-of-corrosion-copper-and-chloramines-on-legionella-and-mycobacteria-in-hot-water-plumbing
#8
William J Rhoads, Amy Pruden, Marc A Edwards
Complexities associated with drinking water plumbing systems can result in undesirable interactions among plumbing components, undermining engineering controls for opportunistic pathogens (OPs). In this study, we examine the effects of plumbing system materials and two commonly applied disinfectants, copper and chloramines, on water chemistry and the growth of Legionella and mycobacteria across a transect of bench- and pilot-scale hot water experiments carried out with the same municipal water supply. We discovered that copper released from corrosion of plumbing materials can initiate evolution of >1,100 times more hydrogen (H2) from water heater sacrificial anode rods than does presence of copper dosed as soluble cupric ions...
May 17, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28510453/influence-of-local-heating-on-marangoni-flows-and-evaporation-kinetics-of-pure-water-drops
#9
Alexandros Askounis, Yutaku Kita, Masamichi Kohno, Yasuyuki Takata, Vasileios Koutsos, Khellil Sefiane
The effect of localized heating on the evaporation of pure sessile water drops was probed experimentally by a combination of infrared thermography and optical imaging. In particular, we studied the effect of three different heating powers and two different locations, directly below the center and edge of the drop. In all cases, four distinct stages were identified according to the emerging thermal patterns. In particular, depending on heating location, recirculating vortices emerge which either remain pinned or move azimuthally within the drop...
May 16, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28509843/modeling-the-footprint-and-equivalent-radiance-transfer-path-length-for-tower-based-hemispherical-observations-of-chlorophyll-fluorescence
#10
Xinjie Liu, Liangyun Liu, Jiaochan Hu, Shanshan Du
The measurement of solar-induced chlorophyll fluorescence (SIF) is a new tool for estimating gross primary production (GPP). Continuous tower-based spectral observations together with flux measurements are an efficient way of linking the SIF to the GPP. Compared to conical observations, hemispherical observations made with cosine-corrected foreoptic have a much larger field of view and can better match the footprint of the tower-based flux measurements. However, estimating the equivalent radiation transfer path length (ERTPL) for hemispherical observations is more complex than for conical observations and this is a key problem that needs to be addressed before accurate retrieval of SIF can be made...
May 16, 2017: Sensors
https://www.readbyqxmd.com/read/28507295/self-assembled-levitating-clusters-of-water-droplets-pattern-formation-and-stability
#11
Alexander A Fedorets, Mark Frenkel, Evgeny Shulzinger, Leonid A Dombrovsky, Edward Bormashenko, Michael Nosonovsky
Water forms ordered hexagonally symmetric structures (snow crystals) in its solid state, however not as liquid. Typically, mists and clouds are composed of randomly moving small droplets lacking any ordered structure. Self-organized hexagonally patterned microdroplet clusters over locally heated water surfaces have been recently observed. However, many aspects of the phenomenon are far from being well understood including what determines droplets size, arrangement, and the distance between them. Here we show that the Voronoi entropy of the cluster tends to decrease indicating to their self-organization, while coupling of thermal effects and mechanical forces controls the stability of the clusters...
May 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28506514/a-novel-cooling-method-and-comparison-of-active-rewarming-of-mildly-hypothermic-subjects
#12
Mark L Christensen, Grant S Lipman, Dennis A Grahn, Kate M Shea, Joseph Einhorn, H Craig Heller
OBJECTIVE: To compare the effectiveness of arteriovenous anastomosis (AVA) vs heated intravenous fluid (IVF) rewarming in hypothermic subjects. Additionally, we sought to develop a novel method of hypothermia induction. METHODS: Eight subjects underwent 3 cooling trials each to a mean core temperature of 34.8±0.6 (32.7 to 36.3°C) by 14°C water immersion for 30 minutes, followed by walking on a treadmill for 5 minutes. Core temperatures (Δtes) and rates of cooling (°C/h) were measured...
May 11, 2017: Wilderness & Environmental Medicine
https://www.readbyqxmd.com/read/28505837/electrophoresis-of-a-polarizable-charged-colloid-with-hydrophobic-surface-a-numerical-study
#13
Somnath Bhattacharyya, Partha Sarathi Majee
We consider the electrophoresis of a charged colloid for a generalized situation in which the particle is considered to be polarizable and the surface exhibits hydrophobicity. The dielectric polarization of the particle creates a nonlinear dependence of the electrophoretic velocity on the applied electric field, and the core hydrophobicity amplifies the fluid convection in the Debye layer. Thus, a linear analysis is no longer applicable for this situation. The present analysis is based on the numerical solution of the nonlinear electrokinetic equations based on the Navier-Stokes-Nernst-Planck-Poisson equations coupled with the Laplace equation for the electric field within the dielectric particle...
April 2017: Physical Review. E
https://www.readbyqxmd.com/read/28505732/thermohydrodynamics-of-an-evaporating-droplet-studied-using-a-multiphase-lattice-boltzmann-method
#14
Ahad Zarghami, Harry E A Van den Akker
In this paper, the thermohydrodynamics of an evaporating droplet is investigated by using a single-component pseudopotential lattice Boltzmann model. The phase change is applied to the model by adding source terms to the thermal lattice Boltzmann equation in such a way that the macroscopic energy equation of multiphase flows is recovered. In order to gain an exhaustive understanding of the complex hydrodynamics during evaporation, a single droplet is selected as a case study. At first, some tests for a stationary (non-)evaporating droplet are carried out to validate the method...
April 2017: Physical Review. E
https://www.readbyqxmd.com/read/28504262/density-structure-of-earth-s-lowermost-mantle-from-stoneley-mode-splitting-observations
#15
Paula Koelemeijer, Arwen Deuss, Jeroen Ritsema
Advances in our understanding of Earth's thermal evolution and the style of mantle convection rely on robust seismological constraints on lateral variations of density. The large-low-shear-wave velocity provinces (LLSVPs) atop the core-mantle boundary beneath Africa and the Pacific are the largest structures in the lower mantle, and hence severely affect the convective flow. Here, we show that anomalous splitting of Stoneley modes, a unique class of free oscillations that are perturbed primarily by velocity and density variations at the core-mantle boundary, is explained best when the overall density of the LLSVPs is lower than the surrounding mantle...
May 15, 2017: Nature Communications
https://www.readbyqxmd.com/read/28500352/whole-mantle-convection-with-tectonic-plates-preserves-long-term-global-patterns-of-upper-mantle-geochemistry
#16
T L Barry, J H Davies, M Wolstencroft, I L Millar, Z Zhao, P Jian, I Safonova, M Price
The evolution of the planetary interior during plate tectonics is controlled by slow convection within the mantle. Global-scale geochemical differences across the upper mantle are known, but how they are preserved during convection has not been adequately explained. We demonstrate that the geographic patterns of chemical variations around the Earth's mantle endure as a direct result of whole-mantle convection within largely isolated cells defined by subducting plates. New 3D spherical numerical models embedded with the latest geological paleo-tectonic reconstructions and ground-truthed with new Hf-Nd isotope data, suggest that uppermost mantle at one location (e...
May 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28495871/embryonic-hypoxia-programmes-postprandial-cardiovascular-function-in-adult-common-snapping-turtles-chelydra-serpentina
#17
Oliver H Wearing, Justin Conner, Derek Nelson, Janna Crossley, Dane A Crossley
Reduced oxygen availability (hypoxia) is a potent stressor during embryonic development, altering the trajectory of trait maturation and organismal phenotype. We previously documented that chronic embryonic hypoxia has a lasting impact on the metabolic response to feeding in juvenile snapping turtles (Chelydra serpentina). Turtles exposed to hypoxia as embryos (10% O2, H10) exhibited an earlier and increased peak postprandial oxygen consumption rate, compared to control turtles (21% O2, N21). In the current study, we measured central blood flow patterns to determine whether the elevated postprandial metabolic response in H10 turtles is linked to lasting impacts on convective transport...
May 11, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28493093/insights-from-mathematical-modeling-for-convection-enhanced-intraputamenal-delivery-of-gdnf
#18
Elena Belova, Christopher L Shaffer, Patrick E Trapa
Glial cell line-derived neurotrophic factor (GDNF) is a potential therapy for Parkinson's disease (PD) promoting survival and functional recovery of dopaminergic neurons when delivered to the degenerated striatum. To study the aspects of intraputamenal delivery of GDNF, a mathematical model of recombinant methionyl human GDNF (r-metHuGDNF) convection in the human putamen has been developed. The convection-enhanced delivery infusions of r-metHuGDNF were simulated at rates up to 5 μL/min. The high-rate infusions (≥1 μL/min) permit rapid and uniform distribution of drug with up to 75% of the distribution volume having a concentration within 5% of the infusate concentration...
May 11, 2017: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/28492649/identifying-electrochemical-effects-in-a-thermal-electrochemical-co-driven-system-for-co2-capture
#19
Guang X Liu, Yun S Yu, Ying T Hong, Zao X Zhang, Jin J Wei, Geoff G X Wang
Currently, the most promising amine absorption system for CO2 capture still faces the challenges of heavy steam consumption and a high energy penalty. Thus, a new thermal-electrochemical co-driven system (TECS) for CO2 capture was developed to resolve these problems. In the TECS, unknown electrochemical behaviors are quite essential to assess the CO2 capture performance. Electrochemical experiments were designed using response surface methodology (RSM) to identify electrochemical effects. The results show that the cathode process is slow and difficult, which is the main limitation in improving the performance of the TECS...
May 11, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28492625/thermal-convection-in-electrochemical-cells-boundaries-with-heterogeneous-thermal-conductivity-and-implications-for-scanning-electrochemical-microscopy
#20
Javor K Novev, Richard G Compton
We investigate the heat transfer in a cylinder-shaped electrochemical cell with solid, thermally insulating walls. The cell is filled with a liquid and a solid substrate that is thermostated from below is situated at its base. The initial temperature of the liquid is different from that of the substrate so as to mimic imperfect thermostating in an electrochemical experiment; as heat transfer acts to diminish the temperature difference between the two, natural convection ensues. The influence of inhomogeneities in the thermal conductivity of the solid is studied - numerical simulations of the heat transfer in the system are conducted for substrates that are comprised of a thermally conductive material, an insulating one or a combination thereof...
May 11, 2017: Physical Chemistry Chemical Physics: PCCP
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