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https://www.readbyqxmd.com/read/28535065/silica-polymerization-from-supersaturated-dilute-aqueous-solutions-in-the-presence-of-alkaline-earth-salts
#1
Marina Kley, Andreas Kempter, Volodymyr Boyko, Klaus Huber
The early stages of silica polymerization in aqueous solution proceeds according to a mechanism based on three steps: nucleation, particle growth and agglomeration of the particles. Application of time-resolved static and dynamic light scattering as a powerful in-situ technique in combination with spectrophotometric analysis of the monomer consumption based on the molybdenum blue method was carried out to further investigate this 3-step process. Experiments were carried out at four different initial silicic acid contents covering a range between 350 ppm and 750 ppm in the presence of either 10 mM NaCl or 5 mM of a mixture of CaCl2 and MgCl2...
May 23, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28522831/scaling-of-average-receiving-time-on-weighted-polymer-networks-with-some-topological-properties
#2
Dandan Ye, Song Liu, Jia Li, Fei Zhang, Changling Han, Wei Chen, Yingze Zhang
In this paper, a family of the weighted polymer networks is introduced depending on the number of copies f and a weight factor r. The topological properties of weighted polymer networks can be completely analytically characterized in terms of the involved parameters and/or of the fractal dimension. Moreover, assuming that the walker, at each step, starting from its current node, moves to any of its neighbors with probability proportional to the weight of edge linking them, namely weight-dependent walk. Then, we calculate the average receiving time (ART) with weighted-dependent walks, which is the sum of mean first-passage times (MFPTs) for all nodes absorpt at the trap located at the central node as a recursive relation...
May 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28514702/nanoscale-morphological-analysis-of-soft-matter-aggregates-with-fractal-dimension-ranging-from-1-to-3
#3
REVIEW
Francesco Valle, Marco Brucale, Stefano Chiodini, Eva Bystrenova, Cristiano Albonetti
While the widespread emergence of nanoscience and nanotechnology can be dated back to the early eighties, the last decade has witnessed a true coming of age of this research field, with novel nanomaterials constantly finding their way into marketed products. The performance of nanomaterials being dominated by their nanoscale morphology, their quantitative characterization with respect to a number of properties is often crucial. In this context, those imaging techniques able to resolve nanometer scale details are clearly key players...
May 4, 2017: Micron: the International Research and Review Journal for Microscopy
https://www.readbyqxmd.com/read/28513853/association-between-textural-and-morphological-tumor-indices-on-baseline-pet-ct-and-early-metabolic-response-on-interim-pet-ct-in-bulky-malignant-lymphomas
#4
Fayçal Ben Bouallègue, Yassine Al Tabaa, Marilyne Kafrouni, Guillaume Cartron, Fabien Vauchot, Denis Mariano-Goulart
PURPOSE: We investigated whether metabolic, textural and morphological tumoral indices evaluated on baseline PET-CT were predictive of early metabolic response on interim PET-CT in a cohort of patients with bulky Hodgkin and non-Hodgkin malignant lymphomas. METHODS: This retrospective study included 57 patients referred for initial PET-CT examination. In-house dedicated software was used to delineate tumor contours using a fixed 30% threshold of SUV max and then to compute tumoral metabolic parameters (SUV max, mean, peak, standard deviation, skewness and kurtosis, metabolic tumoral volume (MTV), total lesion glycolysis, and area under the curve of the cumulative histogram), textural parameters (Moran's and Geary's indices, energy, entropy, contrast, correlation derived from the gray-level co-occurrence matrix, area under the curve of the power spectral density, auto-correlation distance, and granularity), and shape parameters (surface, asphericity, convexity, surfacic extension, and 2D and 3D fractal dimensions)...
May 17, 2017: Medical Physics
https://www.readbyqxmd.com/read/28510430/nanoarchitecturing-of-natural-melanin-nanospheres-by-layer-by-layer-assembly-macroscale-anti-inflammatory-conductive-coatings-with-optoelectronic-tunability
#5
Taesik Eom, Kyungbae Woo, Whirang Cho, Jaeeun Heo, Daseul Jang, Jae In Shin, David Charles Martin, Jeong Jae Wie, Bong Sup Shim
Natural melanins are biocompatible conductors with versatile functionalities. Here, we report fabrication of multifunctional poly(vinyl alcohol)/melanin nanocomposites by layer-by-layer (LBL) assembly using melanin nanoparticles (MNPs) directly extracted from sepia officinalis inks. The LBL assembly offers facile manipulation of nanotextures as well as nm-thickness control of the macroscale film by varying solvent qualities. The time-resolved absorption was monitored during the process and quantitatively studied by fractal dimension and lacunarity analysis...
May 16, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28509723/determinants-of-retinal-microvascular-features-and-their-relationships-in-two-european-populations
#6
Mirna Kirin, Reka Nagy, Thomas J MacGillivray, Ozren Polašek, Caroline Hayward, Igor Rudan, Harry Campbell, Sarah Wild, Alan F Wright, James F Wilson, Veronique Vitart
OBJECTIVES: To examine factors influencing retinal vasculature in two environmentally contrasted, cross-sectional studies of adult participants of European descent and to estimate the extent and specificity of genetic contributions to each retinal vasculature feature. METHODS: Retinal images from 1088 participants in the Orkney Complex Disease Study and 387 in the CROATIA-Korčula study, taken using the same nonmydriatic camera system and graded by the same person, were evaluated...
May 13, 2017: Journal of Hypertension
https://www.readbyqxmd.com/read/28505839/explosive-percolation-on-a-scale-free-multifractal-weighted-planar-stochastic-lattice
#7
M M Rahman, M K Hassan
In this article, we investigate explosive bond percolation (EBP) with the product rule, formally known as the Achlioptas process, on a scale-free multifractal weighted planar stochastic lattice. One of the key features of the EBP transition is the delay, compared to the corresponding random bond percolation (RBP), in the onset of the spanning cluster. However, when it happens, it happens so dramatically that initially it was believed, although ultimately proved wrong, that explosive percolation (EP) exhibits a first-order transition...
April 2017: Physical Review. E
https://www.readbyqxmd.com/read/28505817/fractal-dimension-and-universality-in-avascular-tumor-growth
#8
Fabiano L Ribeiro, Renato Vieira Dos Santos, Angélica S Mata
For years, the comprehension of the tumor growth process has been intriguing scientists. New research has been constantly required to better understand the complexity of this phenomenon. In this paper, we propose a mathematical model that describes the properties, already known empirically, of avascular tumor growth. We present, from an individual-level (microscopic) framework, an explanation of some phenomenological (macroscopic) aspects of tumors, such as their spatial form and the way they develop. Our approach is based on competitive interaction between the cells...
April 2017: Physical Review. E
https://www.readbyqxmd.com/read/28503981/platelet-reactivity-influences-clot-structure-as-assessed-by-fractal-analysis-of-viscoelastic-properties
#9
Rebecca B Knowles, Matthew J Lawrence, Plinio M Ferreira, Melissa A Hayman, Lindsay A D'Silva, Sophie N Stanford, Ahmed Sabra, Arthur T Tucker, Karl M Hawkins, Phylip R Williams, Timothy D Warner, Phillip A Evans
Despite the interwoven nature of platelet activation and the coagulation system in thrombosis, few studies relate both analysis of protein and cellular parts of coagulation in the same population. In the present study, we use matched ex vivo samples to determine the influences of standard antiplatelet therapies on platelet function and use advanced rheological analyses to assess clot formation. Healthy volunteers were recruited following fully informed consent then treated for 7 days with single antiplatelet therapy of aspirin (75 mg) or prasugrel (10 mg) or with dual antiplatelet therapy (DAPT) using aspirin (75 mg) plus prasugrel (10 mg) or aspirin (75 mg) plus ticagrelor (90 mg)...
May 15, 2017: Platelets
https://www.readbyqxmd.com/read/28499160/predicting-settling-performance-of-anammox-granular-sludge-based-on-fractal-dimensions
#10
Zhiyao Wang, Ping Zheng
The settling performance of ANAMMOX granular sludge determines the biomass retention in reactors, and finally determines the potential reaction capacity. In this paper, Stokes equation was modified by fractal dimensions to describe the settling performance of ANAMMOX granular sludge. A new method was developed to obtain fractal dimensions, and a fractal settling model was established for ANAMMOX granular sludge. The fractal settling model was excellent with only a small deviation of 0.8% from the experimental data...
March 30, 2017: Water Research
https://www.readbyqxmd.com/read/28487830/automated-and-erp-based-diagnosis-of-attention-deficit-hyperactivity-disorder-in-children
#11
Hossein R Jahanshahloo, Mousa Shamsi, Elham Ghasemi, Abolfazl Kouhi
Event-related potential (ERP) is one of the most informative and dynamic methods of monitoring cognitive processes, which is widely used in clinical research to deal with a variety of psychiatric and neurological disorders such as attention-deficit/hyperactivity disorder (ADHD). In this study, there were 60 participants including 30 patients with ADHD and 30 subjects as a control group. Their ERP signals were recorded by three electrodes in two modalities. After a preprocessing step, several features such as band power, fractal dimension, autoregressive (AR) model coefficients and wavelet coefficients were extracted from recorded signals...
January 2017: Journal of Medical Signals and Sensors
https://www.readbyqxmd.com/read/28486198/mutation-of-spirulina-sp-by-nuclear-irradiation-to-improve-growth-rate-under-15-carbon-dioxide-in-flue-gas
#12
Jun Cheng, Hongxiang Lu, Xin He, Weijuan Yang, Junhu Zhou, Kefa Cen
Spirulina sp. was mutated by γ-rays from (60)Co nuclear irradiation to improve growth and CO2 fixation rate under 15vol.% CO2 (in flue gas from a power plant). Mutants with enhanced growth phenotype were obtained, with the best strain exhibiting 310% increment in biomass yield on day 4. The mutant was then domesticated with elevated CO2 concentration, and the biomass yield increased by 500% after domestication under 15vol.% CO2, with stable inheritance. Ultrastructure of Spirulina sp. shows that the fractal dimension of Spirulina cells decreased by 23% after mutation...
April 29, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28486140/improving-the-understanding-of-fullerene-nc60-aggregate-structures-fractal-dimension-characterization-by-static-light-scattering-coupled-to-asymmetrical-flow-field-flow-fractionation
#13
Julien Gigault, Bruno Grassl
Fullerene (C60) aggregation mechanisms in aqueous media require considerable attention in the near future due to the heavy use and application of fullerene-based products within the context of nanotechnology. Such intensive development will result in the release of massive amounts of C60 in aqueous environmental systems in the aggregate form (nC60). In that sense, the aggregation mechanisms need to be fully determined to better evaluate the environmental fate and behavior of C60. To fulfil these needs, the aim of this work was to extensively characterize the aggregation mechanisms of fullerene aggregates in aqueous media by asymmetrical flow field fractionation (AF4) coupled to static light scattering (SLS)...
May 3, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28483356/evaluation-of-a-breast-software-model-for-2d-and-3d-x-ray-imaging-studies-of-the-breast
#14
Yanka Baneva, Kristina Bliznakova, Lesley Cockmartin, Stoyko Marinov, Ivan Buliev, Giovanni Mettivier, Hilde Bosmans, Paolo Russo, Nicholas Marshall, Zhivko Bliznakov
INTRODUCTION: In X-ray imaging, test objects reproducing breast anatomy characteristics are realized to optimize issues such as image processing or reconstruction, lesion detection performance, image quality and radiation induced detriment. Recently, a physical phantom with a structured background has been introduced for both 2D mammography and breast tomosynthesis. A software version of this phantom and a few related versions are now available and a comparison between these 3D software phantoms and the physical phantom will be presented...
May 5, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28481194/primary-rectal-cancer-repeatability-of-global-and-local-regional-mr-imaging-texture-features
#15
Sofia Gourtsoyianni, Georgia Doumou, Davide Prezzi, Benjamin Taylor, J James Stirling, N Jane Taylor, Musib Siddique, Gary J R Cook, Robert Glynne-Jones, Vicky Goh
Purpose To assess the day-to-day repeatability of global and local-regional magnetic resonance (MR) imaging texture features derived from primary rectal cancer. Materials and Methods After ethical approval and patient informed consent were obtained, two pretreatment T2-weighted axial MR imaging studies performed prospectively with the same imaging unit on 2 consecutive days in 14 patients with rectal cancer (11 men [mean age, 61.7 years], three women [mean age, 70.0 years]) were analyzed to extract (a) global first-order statistical histogram and model-based fractal features reflecting the whole-tumor voxel intensity histogram distribution and repeating patterns, respectively, without spatial information and (b) local-regional second-order and high-order statistical texture features reflecting the intensity and spatial interrelationships between adjacent in-plane or multiplanar voxels or regions, respectively...
May 5, 2017: Radiology
https://www.readbyqxmd.com/read/28480566/cranial-suture-complexity-in-caviomorph-rodents-rodentia-ctenohystrica
#16
Guido Buezas, Federico Becerra, Aldo Vassallo
Due to their flexibility, sutures are regions that experience greater strains than the surrounding rigid cranial bones. Cranial sutures differ in their degree of interdigitation or complexity. There is evidence indicating that a more convoluted suture better enables the absorption of high stresses coming from dynamic masticatory forces, and other functions. The Order Rodentia is an interesting clade to study this because of its taxa with diverse chewing modes. Due to repeated loading resulting from gnawing and grinding, energy absorption by the sutures might be a crucial factor in these mammals...
May 7, 2017: Journal of Morphology
https://www.readbyqxmd.com/read/28474902/kinetics-of-vapor-solid-phase-transitions-structure-growth-and-mechanism
#17
Jiarul Midya, Subir K Das
The kinetics of the separation between low and high density phases in a single component Lennard-Jones model is studied via molecular dynamics simulations, at very low temperatures, in the space dimension d=2. For densities close to the vapor branch of the coexistence curve, disconnected nanoscale clusters of the high density phase exhibit essentially ballistic motion. Starting from nearly circular shapes, at the time of nucleation, these clusters grow via sticky collisions, gaining filamentlike nonequilibrium structure at a later time, with a very low fractal dimensionality...
April 21, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28472211/progressive-retinal-vasodilation-in-patients-with-type-1-diabetes-a-longitudinal-study-of-retinal-vascular-geometry
#18
Gerald Liew, Paul Benitez-Aguirre, Maria E Craig, Alicia J Jenkins, Lauren A B Hodgson, Annette Kifley, Paul Mitchell, Tien Y Wong, Kim Donaghue
Purpose: Retinal vessels can be used to noninvasively monitor changes in microvasculature. These changes in retinal vascular geometry (RVG) may predict chronic diabetes complications. We evaluated longitudinal RVG changes in adolescents with type 1 diabetes. Methods: We followed 102 adolescents (baseline: 47.1% male, mean [SD] age 14.4 [1.6] years, diabetes duration 7.2 [3.1] years, HbA1c 8.1% [1.3%] [65 (9.3) mmol/mol]) over three visits, with a mean follow-up of 2...
May 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28466380/differences-of-temporal-dynamics-and-signal-complexity-of-gamma-band-oscillations-in-first-episode-psychosis-during-a-working-memory-task
#19
Pascal Missonnier, Logos Curtis, Joseph Ventura, François R Herrmann, Marco C G Merlo
Gamma band oscillations participate in the temporal binding needed to synchronize cortical networks, involved in early sensory and short term memory processes. In earlier studies, alterations of these neurophysiological parameters have been found in psychotic disorders. To date no study has explored the temporal dynamics and signal complexity of gamma band oscillations in first episode psychosis (FEP). To address this issue, gamma band analysis was performed in 15 FEP patients and 18 healthy controls who successfully performed an adapted 2-back working memory task...
May 2, 2017: Journal of Neural Transmission
https://www.readbyqxmd.com/read/28460932/nature-of-protein-protein-interactions-during-the-gelation-of-canola-protein-isolate-networks
#20
Jae He Kim, Natallia V Varankovich, Andrea K Stone, Michael T Nickerson
The nature of interactions involved during the gelation of a canola protein isolate was investigated using rheology and fractal imaging at neutral pH as a function of protein concentration (5.0-9.0% w/w). The onset of denaturation and the denaturation temperature by differential scanning calorimetry for canola protein isolate (CPI; 98.2% protein) was 78.6°C and 87.1°C, respectively. Rheological testing determined the gelation temperature (Tgel) to be ~87-90°C for all concentrations. The log % strain at break increased from 1...
November 2016: Food Research International
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