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https://www.readbyqxmd.com/read/28079383/structure-and-interaction-in-ph-dependent-phase-behavior-of-nanoparticle-protein-systems
#1
Indresh Yadav, Sugam Kumar, Vinod K Aswal, Joachim Kohlbrecher
The pH-dependent structure and interaction of anionic silica nanoparticles (diameter 18 nm) with two globular model proteins-lysozyme and bovine serum albumin (BSA) have been studied. Cationic lysozyme adsorbs strongly on the nanoparticles and the adsorption follows an exponential growth as a function of lysozyme concentration, where the saturation value increases with pH approaching towards the isoelectric point (IEP) of lysozyme. In contrast, irrespective of the pH, anionic BSA does not show any adsorption...
January 12, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28079249/fractal-analysis-of-visual-search-activity-for-mass-detection-during-mammographic-screening
#2
Folami Alamudun, Hong-Jun Yoon, Kathleen B Hudson, Garnetta Morin-Ducote, Tracy Hammond, Georgia D Tourassi
PURPOSE: The objective of this study is to assess the complexity of human visual search activity during mammographic screening using fractal analysis and to investigate its relationship with case and reader characteristics. METHODS: The study was performed for the task of mammographic screening with simultaneous viewing of four coordinated breast views as typically done in clinical practice. Eye-tracking data and diagnostic decisions collected for 100 mammographic cases (25 normal, 25 benign, 50 malignant) and 10 readers (three board certified radiologists and seven radiology residents), formed the corpus data for this study...
January 12, 2017: Medical Physics
https://www.readbyqxmd.com/read/28075432/aggregation-and-deposition-of-in-situ-formed-colloidal-particles-in-the-presence-of-polyelectrolytes
#3
Feng Li, Dejun Sun, Tao Wu, Yujiang Li
In this work, aggregation and deposition of in situ formed magnesium hydroxide (IFM) in the presence of hydrolyzed polyacrylamide (HPAM) were investigated. Relative concentrations of interactants, as well as other experimental conditions, were changed to elucidate the interaction mechanisms from microscopic to macroscopic levels. Light scattering measurements were used to investigate the aggregation kinetics, fractal dimension, and collision efficiency of the aggregates on a microscopic level. Electrophoretic mobility and TEM were utilized to measure the charging properties and morphologies of aggregates, respectively...
January 11, 2017: Soft Matter
https://www.readbyqxmd.com/read/28072842/fractal-analysis-of-brain-blood-oxygenation-level-dependent-bold-signals-from-children-with-mild-traumatic-brain-injury-mtbi
#4
Olga Dona, Michael D Noseworthy, Carol DeMatteo, John F Connolly
BACKGROUND: Conventional imaging techniques are unable to detect abnormalities in the brain following mild traumatic brain injury (mTBI). Yet patients with mTBI typically show delayed response on neuropsychological evaluation. Because fractal geometry represents complexity, we explored its utility in measuring temporal fluctuations of brain resting state blood oxygen level dependent (rs-BOLD) signal. We hypothesized that there could be a detectable difference in rs-BOLD signal complexity between healthy subjects and mTBI patients based on previous studies that associated reduction in signal complexity with disease...
2017: PloS One
https://www.readbyqxmd.com/read/28067200/quantitative-angiography-methods-for-bifurcation-lesions-a-consensus-statement-update-from-the-european-bifurcation-group
#5
Carlos Collet, Yoshinobu Onuma, Rafael Cavalcante, Maik Grundeken, Philippe Généreux, Jeffrey Popma, Ricardo Costa, Goran Stankovic, Shengxian Tu, Johan H C Reiber, Jean-Paul Aben, Jens Flensted Lassen, Yves Louvard, Alexandra Lansky, Patrick W Serruys
Bifurcation lesions represent one of the most challenging lesions subset in interventional cardiology. The European Bifurcation Club (EBC) is an academic consortium whose goal has been to assess and recommend the appropriate strategies to manage bifurcation lesions. The quantitative coronary angiography (QCA) methods for the evaluation of bifurcation lesions has been subject to extensive research. Single vessel quantitative coronary angiography (QCA) has shown to be inaccurate to assess bifurcation lesions dimensions...
January 10, 2017: EuroIntervention
https://www.readbyqxmd.com/read/28063435/local-structure-of-percolating-gels-at-very-low-volume-fractions
#6
Samuel Griffiths, Francesco Turci, C Patrick Royall
The formation of colloidal gels is strongly dependent on the volume fraction of the system and the strength of the interactions between the colloids. Here we explore very dilute solutions by the means of numerical simulations and show that, in the absence of hydrodynamic interactions and for sufficiently strong interactions, percolating colloidal gels can be realised at very low values of the volume fraction. Characterising the structure of the network of the arrested material we find that, when reducing the volume fraction, the gels are dominated by low-energy local structures, analogous to the isolated clusters of the interaction potential...
January 7, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28059537/universal-formula-for-the-mean-first-passage-time-in-planar-domains
#7
Denis S Grebenkov
We derive a general exact formula for the mean first passage time (MFPT) from a fixed point inside a planar domain to an escape region on its boundary. The underlying mixed Dirichlet-Neumann boundary value problem is conformally mapped onto the unit disk, solved exactly, and mapped back. The resulting formula for the MFPT is valid for an arbitrary space-dependent diffusion coefficient, while the leading logarithmic term is explicit, simple, and remarkably universal. In contrast to earlier works, we show that the natural small parameter of the problem is the harmonic measure of the escape region, not its perimeter...
December 23, 2016: Physical Review Letters
https://www.readbyqxmd.com/read/28059426/the-effect-of-colloidal-aggregates-on-fat-crystal-networks
#8
Raamanand R Chauhan, Roel P A Dullens, Krassimir P Velikov, Dirk G A L Aarts
We investigate the role of a colloidal model system in the crystallization and network formation of lipids. This system consists of fractal fumed silica aggregates. We look at the influence of different solid fat concentrations and fumed silica concentrations on the resulting gel network. Oscillatory rheology shows that the addition of silica to fat-in-oil gels does not significantly affect the magnitude of the storage modulus within the linear viscoelastic region. Interestingly, the range of this region is increased...
January 6, 2017: Food & Function
https://www.readbyqxmd.com/read/28058083/simulating-the-hydrodynamics-of-self-propelled-colloidal-clusters-using-stokesian-dynamics
#9
Yousef M F El Hasadi, Martin Crapper
Self-propelled clusters are involved in many technological applications such as in material science and biotechnology, and understanding their interaction with the fluid that surrounds them is of a great importance. We present results of swimming velocity and energy dissipation obtained through Stokesian dynamics simulations of self-propelled clusters. The clusters are of diffusion limited aggregates, consisting of force- and torque-free spherical particles. The number of particles per cluster ranges from 100 to 400, and with two fractal dimensions of 2...
November 2016: Biomicrofluidics
https://www.readbyqxmd.com/read/28057576/a-stochastic-and-integrative-model-of-breathing
#10
Brett F BuSha, George Banis
Human breathing patterns contain both temporal scaling characteristics, and an innately random component. A stochastic and mathematically integrative model of breathing (SIMB) that simulated the natural random and fractal-like pattern of human breathing was designed using breath-to-breath interval (BBI) data recorded from 14 healthy subjects. Respiratory system memory was estimated with autocorrelation, and a probability density function (PDF) was created by fitting a polynomial curve to each normalized BBI sequence histogram...
January 3, 2017: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/28054690/small-angle-scattering-from-the-cantor-surface-fractal-on-the-plane-and-the-koch-snowflake
#11
Alexander Yu Cherny, Eugen M Anitas, Vladimir A Osipov, Alexander I Kuklin
The small-angle scattering (SAS) from the Cantor surface fractal on the plane and Koch snowflake is considered. We develop the construction algorithm for the Koch snowflake, which makes possible the recurrence relation for the scattering amplitude. The surface fractals can be decomposed into a sum of surface mass fractals for arbitrary fractal iteration, which enables various approximations for the scattering intensity. It is shown that for the Cantor fractal, one can neglect with good accuracy the correlations between the mass fractal amplitudes, while for the Koch snowflake, these correlations are important...
January 5, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28054317/test-retest-reliability-of-brain-morphology-estimates
#12
Christopher R Madan, Elizabeth A Kensinger
Metrics of brain morphology are increasingly being used to examine inter-individual differences, making it important to evaluate the reliability of these structural measures. Here we used two open-access datasets to assess the intersession reliability of three cortical measures (thickness, gyrification, and fractal dimensionality) and two subcortical measures (volume and fractal dimensionality). Reliability was generally good, particularly with the gyrification and fractal dimensionality measures. One dataset used a sequence previously optimized for brain morphology analyses and had particularly high reliability...
January 5, 2017: Brain Informatics
https://www.readbyqxmd.com/read/28050606/long-term-exposure-to-space-s-microgravity-alters-the-time-structure-of-heart-rate-variability-of-astronauts
#13
Kuniaki Otsuka, Germaine Cornelissen, Satoshi Furukawa, Yutaka Kubo, Mitsutoshi Hayashi, Koichi Shibata, Koh Mizuno, Tatsuya Aiba, Hiroshi Ohshima, Chiaki Mukai
BACKGROUND: Spaceflight alters human cardiovascular dynamics. The less negative slope of the fractal scaling of heart rate variability (HRV) of astronauts exposed long-term to microgravity reflects cardiovascular deconditioning. We here focus on specific frequency regions of HRV. METHODS: Ten healthy astronauts (8 men, 49.1 ± 4.2 years) provided five 24-hour electrocardiographic (ECG) records: before launch, 20.8 ± 2.9 (ISS01), 72.5 ± 3.9 (ISS02) and 152.8 ± 16...
December 2016: Heliyon
https://www.readbyqxmd.com/read/28048783/su-f-r-30-interscanner-variability-of-radiomics-features-in-computed-tomography-ct-using-a-standard-acr-phantom
#14
M Shafiq Ul Hassan, M Budzevich, G Zhang, K Latifi, D Hunt, R Gillies, E Moros
PURPOSE: A simple approach to investigate Interscanner variability of Radiomics features in computed tomography (CT) using a standard ACR phantom. METHODS: The standard ACR phantom was scanned on CT scanners from three different manufacturers. Scanning parameters of 120 KVp, 200 mA were used while slice thickness of 3.0 mm on two scanners and 3.27 mm on third scanner was used. Three spherical regions of interest (ROI) from water, medium density and high density inserts were contoured...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046757/mo-de-207b-04-impact-of-reconstruction-field-of-view-on-radiomics-features-in-computed-tomography-ct-using-a-texture-phantom
#15
M Shafiq Ul Hassan, G Zhang, K Latifi, J Oliver, D Hunt, R Guzman, Y Balagurunathan, D Mackin, L Court, R Gillies, E Moros
PURPOSE: To investigate the impact of reconstruction Field of View on Radiomics features in computed tomography (CT) using a texture phantom. METHODS: A rectangular Credence Cartridge Radiomics (CCR) phantom, composed of 10 different cartridges, was scanned on four different CT scanners from two manufacturers. A pre-defined scanning protocol was adopted for consistency. The slice thickness and reconstruction interval of 1.5 mm was used on all scanners. The reconstruction FOV was varied to result a voxel size ranging from 0...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28039830/characterization-of-silver-nanoparticle-aggregates-using-single-particle-inductively-coupled-plasma-mass-spectrometry-spicp-ms
#16
Hyun-A Kim, Byung-Tae Lee, So-Young Na, Kyoung-Woong Kim, James F Ranville, Soon-Oh Kim, Eunhye Jo, Ig-Chun Eom
The single particle-inductively coupled plasma-mass spectrometry was applied to characterize the aggregates of AgNPs. was applied to characterize the aggregates of AgNPs. Two sizes of citrate-AgNPs and PVP-AgNPs were used at relatively high and predicted environmental concentrations under various ionic strengths. Citrate-AgNP aggregated with increases in the ionic strength, whereas PVP-AgNPs were sterically stable. The critical coagulation concentrations were 85 mM and 100 mM NaNO3 for 60 nm and 100 nm citrate-AgNPs at 2 mg L(-1) as total Ag obtained by dynamic light scattering (DLS)...
December 19, 2016: Chemosphere
https://www.readbyqxmd.com/read/28033115/quantification-of-differences-between-nailfold-capillaroscopy-images-with-a-scleroderma-pattern-and-normal-pattern-using-measures-of-geometric-and-algorithmic-complexity
#17
Samuel George Urwin, Bridget Griffiths, John Allen
This study aimed to quantify and investigate differences in the geometric and algorithmic complexity of the microvasculature in nailfold capillaroscopy (NFC) images displaying a scleroderma pattern and those displaying a 'normal' pattern. 11 NFC images were qualitatively classified by a capillary specialist as indicative of 'clear microangiopathy' (CM), i.e. a scleroderma pattern, and 11 as 'not clear microangiopathy' (NCM), i.e. a 'normal' pattern. Pre-processing was performed, and fractal dimension (FD) and Kolmogorov complexity (KC) were calculated following image binarisation...
December 29, 2016: Physiological Measurement
https://www.readbyqxmd.com/read/28027466/dynamics-of-aggregate-size-and-shape-properties-under-sequenced-flocculation-in-a-turbulent-taylor-couette-reactor
#18
Léa Guérin, Carole Coufort-Saudejaud, Alain Liné, Christine Frances
This paper concerns experimental investigation of the sequenced flocculation of latex particles in a Taylor-Couette reactor. The aim of this work was to investigate the evolution of both the size and the shape of aggregates under sequenced hydrodynamics. A number of studies have focused on the evolution of the aggregate size or size distribution during steps of growth-breakage-regrowth, but aggregates generally experience steps of breakage-regrowth on repeated occasions in real operating conditions (passages near the impeller or during the transfer processes, for example)...
December 21, 2016: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28026197/what-paint-can-tell-us-a-fractal-analysis-of-neurological-changes-in-seven-artists
#19
Alex Forsythe, Tamsin Williams, Ronan G Reilly
OBJECTIVE: The notion that artistic capability increases with dementia is both novel and largely unsupported by available literature. Recent research has suggested an emergence of artistic capabilities to be a by-product of involuntary behaviour seen with dementia, as opposed to a progression in original thinking (de Souza, et al., 2010). A far more complementary explanation comes from Hannemann (2006), who suggests that art offers an outlet for dementia patients to refine and sharpen their cognitive abilities...
January 2017: Neuropsychology
https://www.readbyqxmd.com/read/28025302/micromechanics-of-sea-ice-frictional-slip-from-test-basin-scale-experiments
#20
Peter R Sammonds, Daniel C Hatton, Daniel L Feltham
We have conducted a series of high-resolution friction experiments on large floating saline ice floes in an environmental test basin. In these experiments, a central ice floe was pushed between two other floes, sliding along two interfacial faults. The frictional motion was predominantly stick-slip. Shear stresses, normal stresses, local strains and slip displacement were measured along the sliding faults, and acoustic emissions were monitored. High-resolution measurements during a single stick-slip cycle at several positions along the fault allowed us to identify two phases of frictional slip: a nucleation phase, where a nucleation zone begins to slip before the rest of the fault, and a propagation phase when the entire fault is slipping...
February 13, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
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