Read by QxMD icon Read

fractal dimension

Eva Déli, Arturo Tozzi, James F Peters
Brain electric activity exhibits two important features: oscillations with different timescales, characterized by diverse functional and psychological outcomes, and a temporal power law distribution. In order to further investigate the relationships between low- and high- frequency spikes in the brain, we used a variant of the Borsuk-Ulam theorem which states that, when we assess the nervous activity as embedded in a sphere equipped with a fractal dimension, we achieve two antipodal points with similar features (the slow and fast, scale-free oscillations)...
December 2017: Cognitive Neurodynamics
Omid Rahmani Seryasat, Javad Haddadnia
BACKGROUND: Mammography is the most common screening method for diagnosis of breast cancer. MATERIALS AND METHODS: In this study, a computer-aided system for diagnosis of benignity and malignity of the masses was implemented in mammogram images. In the computer aided diagnosis system, we first reduce the noise in the mammograms using an effective noise removal technique. After the noise removal, the mass in the region of interest must be segmented and this segmentation is done using a deformable model...
May 22, 2017: Clinical Breast Cancer
Ruben Pauwels, Somchai Sessirisombat, Soontra Panmekiate
PURPOSE: To evaluate the relationship between mandibular bone structure parameters measured on preimplant cone beam computed tomography (CBCT) images and primary implant stability. MATERIALS AND METHODS: Twenty-one hemimandibles were scanned on the 3D Accuitomo 170 CBCT. Next, an implant was placed in each hemimandible, after which insertion torque and implant stability quotient (ISQ) measurements were acquired. The following measurements were performed on the preimplant CBCT scans: bone surface, bone volume, fractal dimension, connectivity, trabecular thickness and spacing, and skeleton analysis...
November 2017: International Journal of Oral & Maxillofacial Implants
Haoxuan Li, Yili Wang, Huaili Zheng
The feasibility of using Fe(0)/S2O8(2-) conditioning (zero valence iron (ZVI)/persulfate (ps)) integrated with horizontal electro-dewatering (HED) to improve the dewaterability of activated sludge (AS) was evaluated. The removal and migration of free and bound water in the ZVI/ps-HED process were determined, along with the organic matter migration between the solid and liquid phases of AS biosolids. Results showed that the optimum conditioning dosages were determined as 0.35 g ZVI/g dry solids (DS) and 0.15 g ps/g DS on the basis of capillary suction time variation...
November 6, 2017: Water Research
Mila Pajevic, Marija Aleksic, Igor Golic, Milica Markelic, Vesna Otasevic, Aleksandra Jankovic, Ana Stancic, Bato Korac, Aleksandra Korac
The effect of insulin on the endocrine pancreas has been the subject of extensive study, but quantitative morphometric investigations of the exocrine pancreas are scarce. This study was therefore undertaken to investigate the effect of acute and chronic insulin administration (two doses, 0.4 IU and 4 IU) on the morphology of rat pancreas acini. Semi-fine sections stained with methylene blue and basic fuchsine or hematoxylin- and eosin-stained 5-micrometer thick paraffin sections were used for fractal and stereological analysis of exocrine acini...
November 13, 2017: Folia Morphologica (Warsz)
Di Wu, Tai Min, Jian Zhou, Chen Li, Guobin Ma, Gaotian Lu, Minggang Xia, Zhengbin Gu
In van der Waals epitaxial growth, the substrate plays a particularly important role in the crystal morphology. Here, we synthesized MoS2 by chemical vapour deposition on silicon carbide (SiC). The obtained MoS2 dendritic crystals show six-fold symmetry, which are different from the conventional triangular shapes on SiO2 substrate and from those with three-fold symmetry on SrTiO3 substrate. Interestingly, these MoS2 dendritic crystals on SiC exhibit an average fractal dimension 1.76, which is slightly larger than the classical Diffusion-limited-Aggregation fractal dimension 1...
November 9, 2017: Scientific Reports
Noor Kamal Al-Qazzaz, Sawal Hamid Bin Mohd Ali, Siti Anom Ahmad, Mohd Shabiul Islam, Javier Escudero
Stroke survivors are more prone to developing cognitive impairment and dementia. Dementia detection is a challenge for supporting personalized healthcare. This study analyzes the electroencephalogram (EEG) background activity of 5 vascular dementia (VaD) patients, 15 stroke-related patients with mild cognitive impairment (MCI), and 15 control healthy subjects during a working memory (WM) task. The objective of this study is twofold. First, it aims to enhance the discrimination of VaD, stroke-related MCI patients, and control subjects using fuzzy neighborhood preserving analysis with QR-decomposition (FNPAQR); second, it aims to extract and investigate the spectral features that characterize the post-stroke dementia patients compared to the control subjects...
November 8, 2017: Medical & Biological Engineering & Computing
Christoph Redies, Anselm Brachmann
Several statistical image properties have been associated with large subsets of traditional visual artworks. Here, we investigate some of these properties in three categories of art that differ in artistic claim and prestige: (1) Traditional art of different cultural origin from established museums and art collections (oil paintings and graphic art of Western provenance, Islamic book illustration and Chinese paintings), (2) Bad Art from two museums that collect contemporary artworks of lesser importance (© Museum Of Bad Art [MOBA], Somerville, and Official Bad Art Museum of Art [OBAMA], Seattle), and (3) twentieth century abstract art of Western provenance from two prestigious museums (Tate Gallery and Kunstsammlung Nordrhein-Westfalen)...
2017: Frontiers in Neuroscience
Katherine Yh Chen, Ling-Jun Li, Tien Y Wong, Carol Y Cheung, Nigel Curtis, Michael Cheung, David P Burgner
Whether individuals who had toxic shock syndrome (TSS) in childhood have differences in macro- and retinal microvascular parameters indicative of increased cardiovascular risk is unknown. We found no evidence of adverse macrovascular changes in 22 TSS participants compared to 60 control participants. Microvascular comparisons showed a reduction in retinal total fractal dimension which has been associated with cardiovascular risk factors in children.
November 3, 2017: Pediatric Infectious Disease Journal
Hwabin Jung, Won Byong Yoon
The effect of water activity (aw ) or the relative humidity (RH) on the tensile rupture properties of dried laver (DL) associated with structures formed with phycocolloids was investigated. The morphological characteristics of tensile ruptured DL samples at various relative humidities were evaluated by multifractal analysis. The RH of the microclimate was controlled from 10% to 90% at 25 °C using supersaturated salt solutions. The sorption isotherm of DL was experimentally obtained and quantitatively analyzed using mathematical models...
November 7, 2017: Journal of Food Science
Aleksandar Kalauzi, Aleksandra Vuckovic, Tijana Bojić
A number of measures, stemming from nonlinear dynamics, exist to estimate complexity of biomedical objects. In most cases they are appropriate, but sometimes unconventional measures, more suited for specific objects, are needed to perform the task. In our present work, we propose three new complexity measures to quantify complexity of topographic closed loops of alpha carrier frequency phase potentials (CFPP) of healthy humans in wake and drowsy states. EEG of ten adult individuals was recorded in both states, using a 14-channel montage...
November 7, 2017: Medical & Biological Engineering & Computing
Thorsten Frenzel, Bertin Hoffmann, Rüdiger Schmitz, Anja Bethge, Udo Schumacher, Gero Wedemann
BACKGROUND: Tumor vasculature is critical for tumor growth, formation of distant metastases and efficiency of radio- and chemotherapy treatments. However, how the vasculature itself is affected during cancer treatment regarding to the metastatic behavior has not been thoroughly investigated. Therefore, the aim of this study was to analyze the influence of hypofractionated radiotherapy and cisplatin chemotherapy on vessel tree geometry and metastasis formation in a small cell lung cancer xenograft mouse tumor model to investigate the spread of malignant cells during different treatments modalities...
2017: PloS One
Goran J Djuričić, Marko Radulovic, Jelena P Sopta, Marina Nikitović, Nebojša T Milošević
The prediction of induction chemotherapy response at the time of diagnosis may improve outcomes in osteosarcoma by allowing for personalized tailoring of therapy. The aim of this study was thus to investigate the predictive potential of the so far unexploited computational analysis of osteosarcoma magnetic resonance (MR) images. Fractal and gray level cooccurrence matrix (GLCM) algorithms were employed in retrospective analysis of MR images of primary osteosarcoma localized in distal femur prior to the OsteoSa induction chemotherapy...
2017: Frontiers in Oncology
Tristan Van de Moortele, Christine H Wendt, Filippo Coletti
The accurate representation of the human airway anatomy is crucial for understanding and modeling the structure-function relationship in both healthy and diseased lungs. The present knowledge in this area is based on morphometric studies of excised lung casts, partially complemented by in vivo studies in which computed tomography (CT) was used on a small number of subjects. In the present study, we analyze CT scans of a cohort of healthy subjects and obtain comprehensive morphometric information down to the seventh generation of bronchial branching, including airway diameter, length, branching angle, and rotation angle...
November 2, 2017: Journal of Applied Physiology
Qiuyan Wang, Wenxiang Zhao, Zhiqiang Liang, Xibin Wang, Tianfeng Zhou, Yongbo Wu, Li Jiao
The wear behaviors of grinding wheel have significant influence on the work-surface topography. However, a comprehensive and quantitative method is lacking for evaluating the wear conditions of grinding wheel. In this paper, a fractal analysis method is used to investigate the wear behavior of resin-bonded diamond wheel in Elliptical Ultrasonic Assisted Grinding (EUAG) of monocrystal sapphire, and a series of experiments on EUAG and conventional grinding (CG) are performed. The results show that the fractal dimension of grinding wheel topography is highly correlated to the wear behavior, i...
October 16, 2017: Ultrasonics
Minyu Chen, Lin Yu, Yixin Zhang
The random fluctuation of the refractive index is an important factor that affects the light transmission in a biological tissue. Here we have derived an expression of signal/noise ratio or equivalent intensity of the orbital angular momentum (OAM) mode for the partially coherent modified Bessel-correlated beam in a turbulent biological tissue. Effects of specific parameters of the biological tissue on it have been studied, such as the outer scale of the tissue index inhomogeneities, the fractal dimension of the particle size distribution, temperature fluctuation strength, and the cutoff correlation length...
November 1, 2017: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
Robert A Byers, Matthew Fisher, Nicola J Brown, Gillian M Tozer, Stephen J Matcher
Subcutaneously implanted experimental tumors in mice are commonly used in cancer research. Despite their superficial location, they remain a challenge to image non-invasively at sufficient spatial resolution for microvascular studies. Here we evaluate the capabilities of optical coherence tomography (OCT) angiography for imaging such tumors directly through the murine skin in-vivo. Data sets were collected from mouse tumors derived from fibrosarcoma cells genetically engineered to express only single splice variant isoforms of vascular endothelial growth factor A (VEGF); either VEGF120 or VEGF188 (fs120 and fs188 tumors respectively)...
October 1, 2017: Biomedical Optics Express
Giovanni Ferraro, Emiliano Fratini, Riccardo Rausa, Piero Baglioni
HYPOTHESIS: Soot is a black powder-like substance consisting of carbonaceous amorphous particles, formed by incomplete combustion of hydrocarbons. In the last decades, industrial research on lubricant oils has grown to develop more efficient formulations, mainly to reduce the formation of soot in oil so to increase engine lifetime. The comprehension of the mechanism of soot formation and particles growth/aggregation in times during real applications is of fundamental importance for the design of better performing lubricants...
October 10, 2017: Journal of Colloid and Interface Science
Zhiqiang Wu, Wangcai Yang, Bolun Yang
In this work, the influence of Nannochloropsis and Chlorella on the thermal behavior and surface morphology of char during the co-pyrolysis process were explored. Thermogravimetric and iso-conversional methods were applied to analyzing the pyrolytic and kinetic characteristics for different mass ratios of microalgae and low-rank coal (0, 3:1, 1:1, 1:3 and 1). Fractal theory was used to quantitatively determine the effect of microalgae on the morphological texture of co-pyrolysis char. The result indicated that both the Nannochloropsis and Chlorella promoted the release of volatile from low-rank coal...
October 9, 2017: Bioresource Technology
Marcel Moura, Knut Jørgen Måløy, Eirik Grude Flekkøy, Renaud Toussaint
In this Letter we give experimental grounding for the remarkable observation made by Furuberg et al. [Phys. Rev. Lett. 61, 2117 (1988)PRLTAO0031-900710.1103/PhysRevLett.61.2117] of an unusual dynamic scaling for the pair correlation function N(r,t) during the slow drainage of a porous medium. Those authors use an invasion percolation algorithm to show numerically that the probability of invasion of a pore at a distance r away and after a time t from the invasion of another pore scales as N(r,t)∝r^{-1}f(r^{D}/t), where D is the fractal dimension of the invading cluster and the function f(u)∝u^{1...
October 13, 2017: Physical Review Letters
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"