Alveolar bone healing patterns in chronic kidney failure and kidney transplant recipients: A pixel intensity and fractal analyses.

AIMS: To assess and compare radiographically the alveolar bone after tooth extractions in individuals with chronic kidney failure undergoing hemodialysis (CKFh), those submitted to kidney transplantation (KT), and those without kidney disease (CG) by using fractal analysis (FA) and pixel intensity (PI). METHODS AND RESULTS: Periapical radiographs of 48 CKFh individuals (87 extracted teeth), 12 KT individuals (26 extracted teeth and 29 control individuals [76 extracted teeth] were analyzed at 7 and 60 days after tooth extraction. Fractal dimension (FD) and PI were assessed to evaluate the alveolar trabecular bone structural complexity and mineral content. The difference in FD values between the 7th and 60th postoperative days in KT individuals (0.03 ± 0.08) was significantly lower compared to those of CKFh individuals (0.09 ± 0.10) and controls (0.15 ± 0.06). As for the difference in PI values, KT (4.55 ± 10.24) and CKFh groups (9.88 ± 15.90) showed significantly lower values compared to those of the control group (17.93 ± 11.86) in the same period. These results indicate a lower gain in the trabecular bone complexity and bone density in the alveolus of KT individuals compared to the other groups. CONCLUSIONS: Overall mineral content and thickness of the bone in the plane of the x-ray beam were lower in KT and CKFh individuals compared to controls, reflecting the need for careful consideration in recommending rehabilitation with dental implants for these patients. Particular attention should be given to the potential challenges in oral rehabilitation of KT patients.

Radiographic texture of the trabecular bone of the proximal phalanx in horses with metacarpophalangeal osteoarthritis.

Osteoarthritis (OA) is a prevalent condition in horses, leading to changes in trabecular bone structure and radiographic texture. Although fractal dimension (FD) and lacunarity have been applied to quantify these changes in humans, their application in horses remains nascent. This study evaluated the use of FD, bone area fraction (BA/TA), and lacunarity in quantifying trabecular bone differences in the proximal phalanx (P1) in 50 radiographic examinations of equine metacarpophalangeal joints with varying OA degrees. In the dorsopalmar view, regions of interest were defined in the trabecular bone of the proximal epiphysis, medial and lateral to the sagittal groove of P1. Lower BA/TA values were observed medially in horses with severe OA (P=0.003). No significant differences in FD and lacunarity were found across OA degrees (P>0.1). FD, BA/TA, and lacunarity were not effective in identifying radiographic texture changes in the P1 trabecular bone in horses with different metacarpophalangeal OA degrees.

Evaluating the roughness dynamics of kefir biofilms grown on Amazon cupuaçu juice: a monofractal and multifractal approach.

We conducted a comprehensive analysis of the surface microtexture of kefir biofilms grown on Theobroma grandiflorum Shum (cupuaçu) juice using atomic force microscopy. Our goal was to investigate the unique monofractal and multifractal spatial patterns of these biofilms to complement the existing limited literature. The biofilms were prepared dispersing four different concentrations of kefir grains in cupuaçu juice. Our morphological analysis showed that the surface of the obtained biofilms is essentially formed by the presence of cupuaçu fibers and microorganisms like lactobacilli and yeast. The topographic height-based parameter analysis reveals that there is a dependence between surface roughness and the concentration of kefir grains used. The strongly anisotropic well-centralized topographical height distribution of the biofilms also exhibited a quasi-symmetrical and platykurtic pattern. The biofilms exhibit comparable levels of spatial complexity, surface percolation and surface homogeneity, which can be attributed to their similar topographic uniformity. This aspect was further supported by the presence of similar multifractality in the biofilms, suggesting that despite their varying topographic roughness, their vertical growth dynamics follow a similar pattern. Our findings demonstrate that the surface roughness of kefir biofilms cultivated on cupuaçu juice is influenced by the concentration of kefir grains in the precursor solution. However, this dependence follows a consistent pattern across different concentrations. Graphical Abstract.

Alternative Controlling Agent of Theobroma grandiflorum Pests: Nanoscale Surface and Fractal Analysis of Gelatin/PCL Loaded Particles Containing Lippia origanoides Essential Oil.

A new systematic structural study was performed using the Atomic Force Microscopy (AFM) reporting statistical parameters of polymeric particles based on gelatin and poly-ε-caprolactone (PCL) containing essential oil from Lippia origanoides. The developed biocides are efficient alternative controlling agents of Conotrachelus humeropictus and Moniliophtora perniciosa, the main pests of Theobroma grandiflorum. Our results showed that the particles morphology can be successfully controlled by advanced stereometric parameters, pointing to an appropriate concentration of encapsulated essential oil according to the particle surface characteristics. For this reason, the absolute concentration of 1000 µg·mL-1 (P1000 system) was encapsulated, resulting in the most suitable surface microtexture, allowing a faster and more efficient essential oil release. Loaded particles presented zeta potential around (-54.3 ± 2.3) mV at pH = 8, and particle size distribution ranging from 113 to 442 nm. The hydrodynamic diameter of 90% of the particle population was found to be up to (405 ± 31) nm in the P1000 system. The essential oil release was evaluated up to 80 h, with maximum release concentrations of 63% and 95% for P500 and P1000, respectively. The best fit for the release profiles was obtained using the Korsmeyer-Peppas mathematical model. Loaded particles resulted in 100% mortality of C. humeropictus up to 48 h. The antifungal tests against M. perniciosa resulted in a minimum inhibitory concentration of 250 µg·mL-1, and the P1000 system produced growth inhibition up to 7 days. The developed system has potential as alternative controlling agent, due to its physical stability, particle surface microtexture, as well as pronounced bioactivity of the encapsulated essential oil.

Investigation of the morphological and fractal behavior at nanoscale of patterning lines by scratching in an atomic force microscope.

In this work, the topographical effect of the scratching trajectory and the feed direction on the formation of lithographed lines on the (001) InP surface was investigated using an atomic force microscope (AFM) tip-based nanomachining approach. Nanoscratching tests were carried out using the sharp face of a diamond AFM tip in contact mode. From the topographic maps obtained by AFM, several morphological and fractal parameters were obtained and analyzed. Surface morphology presented a surface smoothing for surfaces with scratches produced in [011] and [001] directions. The height parameters confirmed this behavior because scratches in [001] direction exhibited lower roughness. Moreover, this scratch direction promoted the height distribution most symmetrical and platykurtic. The other morphological parameters revealed that this direction provided a more irregular surface (smaller Smc and Sxp ), peak distribution, denser and pointed, smaller portion of material in the core, less deep furrows, higher spatial frequency components, and high isotropy. Fractal parameters revealed that FRE90 has the highest spatial complexity, it is dominated by higher spatial frequencies, and has the lowest surface percolation. Furthermore, all samples exhibited high topographic uniformity.

Nanoscale morphology and fractal analysis of TiO2 coatings on ITO substrate by electrodeposition.

In this paper, we introduced an advanced discussion of the 3D morphology of TiO2 coatings deposited on ITO substrate by electrodeposition under different deposition times. Atomic force microscopy was applied for obtaining topographic images of the samples. The images were processed using the MountainsMap 8.0 commercial software according to ISO 25178-2:2012. Moreover, fractal theory was applied to study the surface microtexture of coatings. The morphology was affected by the deposition time, where the grain size decreased with the increase of the time, making film's surfaces smoother. In addition, the surface roughness exhibited a random behaviour, but does not presented significant difference between samples. The fractal dimension showed similar values for all coatings. In contrast, surface texture isotropy also exhibited random behaviour. However, advanced fractal parameters revealed that when the deposition time increased, the coatings microtexture has become uniform and less porous. Furthermore, all coatings presented high topographic uniformity, regardless of deposition time. These results revealed that the morphology and microtexture of TiO2 -based coatings can be controlled by the deposition time. LAY DESCRIPTION: An advanced characterization on the micromorphology of 3D morphology, using AFM images, of Titanium dioxide (TiO2 ) coatings deposited on ITO substrate by electrodeposition under different deposition times. TiO2 is one of the most studied semiconductors to make photovoltaic devices. The versatility of this semiconductor is associated with low toxicity, high photochemical stability, abundance, and the facility to obtain by conventional synthesis routes. The obtention of a homogeneous and stable layer in the semiconductor TiO2 film deposition is a crucial stage in the assembly of sensitized photovoltaic devices. Atomic Force Microscopy (AFM) is a technique which can magnify up to a billion times and it uses a tip or probe which touches the sample surface point by point. The tip deflection is interpreted as the surface topography by the software, producing 2D or 3D images that generate several tribological parameters such as roughness in respect to a scanned area, has been a technique widely reported in the morphological characterization, determination of thickness, roughness, and particle size in thin films. Therefore, in this paper, the morphology was studied by atomic force microscopy using MountainsMap commercial software. The main goal was to study the influence of the deposition time on the morphology and microtexture of the material. New parameters such as surface entropy, fractal succolarity and fractal lacunarity were obtained for studying coatings microtexture's complexity.

3D micromorphology evaluation of kefir microbial films loaded with extract of Amazon rainforest fruit Cupuaçu.

We performed qualitative and quantitative analysis of surfaces of kefir biofilms loaded with Amazon rainforest fruit extract. Scanning electron microscopy and atomic force microscopy were used to evaluate the micromorphology of the biofilms. The films surface displayed a lower density of microorganisms (∼ 0.061 microorganisms/µm2) for the lowest concentration of fruit extract, however, a greater density (∼0.220 microorganisms/µm2) was observed for the higher concentration. Height stereometric parameters revealed that the biofilms with the highest concentration presented the highest roughness. However, almost all the stereometric parameters related to texture showed no significant difference. Furthermore, the Hurst coefficients of the average power spectrum density were similar for all biofilms. Fractal parameters confirmed that higher concentrations of fruit extract induced a superior topographic irregularity. However, fractal lacunarity does not show any significant difference confirming the similarity of the microtextures. Moreover, fractal succolarity and surface entropy exhibited values that suggested ideal percolation and strong topographic uniformity, respectively, indicating that these films can uniformly adhere to other surfaces. Our results confirm that the stereometric and fractal parameters can be relevant for the surface characterization of microbial films, which can be of great importance to the biomedical field.

Chronic Undernutrition Differentially Changes Muscle Fiber Types Organization and Distribution in the EDL Muscle Fascicles.

Fiber type composition, organization, and distribution are key elements in muscle functioning. These properties can be modified by intrinsic and/or extrinsic factors, such as undernutrition and injuries. Currently, there is no methodology to quantitatively analyze such modifications. On one hand, we propose a fractal approach to determine fiber type organization, using the fractal correlation method in software Fractalyse. On the other hand, we applied the kernel methodology from machine learning to build radial-basis functions for the spatial distribution of fibers (distribution functions), by dividing into square cells a two-dimensional binary image for the spatial distribution of fibers from a muscle fascicle and mounting on each cell a radial-basis function in such a way that the sum of all cell functions creates a smooth version of the fiber histogram on the cell grid. The distribution functions thus created belong in a reproducing kernel Hilbert space which permits us to regard them as vectors and measure distances and angles between them. In the present study, we analyze fiber type organization and distribution in fascicles (F2, F3, F4, and F5) of the extensor digitorum longus muscle (EDLm) from control and undernourished male rats. Fibers were classified according to the ATPase activity in slow, intermediate, and fast. Then, (x, y) coordinates of fibers were used to build binary images and distribution functions for each fiber type and both conditions. The fractal organization analysis showed that fast and intermediate fibers, from both groups, had a fractal organization within the four fascicles, i.e., the fiber assembly is distributed in clusters. We also show that chronic undernutrition altered the organization of fast fibers in the F3, although it still is considered a fractal organization. Distribution function analysis showed that each fiber type (slow, intermediate, and fast) has a unique distribution within the fascicles, in both conditions. However, chronic undernutrition modified the intra-fascicular fiber type distributions, except in the F2. Altogether, these results showed that the methodology herein proposed allows for analyzing fiber type organization and distribution modifications. On the other side, we show that chronic undernutrition alters not only the fiber type composition but also the organization and distribution, which could affect the muscle functioning, and ultimately, its behavior (e.g., locomotion).

Mandibular Regional Odontodysplasia in an 8-year-old Boy showing Teeth Disorders, Gubernaculum Tracts, and Altered Bone Fractal Pattern.

Regional odontodysplasia (RO) is a rare nonhereditary developmental condition usually affecting maxilla and female patients. A few number of articles have used the cone beam computed tomography (CBCT) to describe imaging findings in RO. Thus, this article aims to report unusual imaging findings in a Brazilian child who presented with mandibular RO. A healthy 8-year-old boy was referred for evaluation of an anterior mandibular gingival enlargement. Radiographically, all right mandibular teeth showed wide pulp chambers and shortened roots with thin dentinal walls and open apices, featuring a "ghost teeth" appearance, which indicated a diagnosis of RO. Missing teeth and altered radiopacity were observed. Cone beam computed tomography provided great insight into RO, allowing to identify gubernaculum tracts (GTs) associated with RO teeth. Fractal analysis of the bone surrounding RO teeth revealed an altered trabecular pattern. CLINICAL SIGNIFICANCE: This case describes a rare developmental teeth-related pathology in a boy who showed unusual features on imaging exams. The CBCT provided the observation of RO tooth-related GTs, probably a new finding added to the international literature regarding RO, as well as the pulp chamber volume characterization of an affected tooth not published yet. In addition, it was observed an altered fractal pattern of the mandibular bone adjacent to RO teeth, which has not been described to date.How to cite this article: de Sa Cavalcante D, Fonteles CSR, Ribeiro TR, Kurita LM, Pimenta AVM, Carvalho FSR, Costa FWG. Mandibular Regional Odontodysplasia in an 8-year-old Boy showing Teeth Disorders, Gubernaculum Tracts, and Altered Bone Fractal Pattern. Int J Clin Pediatr Dent 2018;11(2):128-134.

Fractal analysis of skeletal muscle tissue of rats subjected to stretch injury / Análisis fractal de tejido muscular esquelético en ratas sometidas a lesión por estiramiento

The aim of this study was to analyze changes in the skeletal muscle tissue of rats after muscle stretch injury using fractal analysis. Nineteen rats were divided into three groups, Control (n= 5) (C), Lesion two days (n= 7) (L2), and Lesion seven days (n= 7) (L7). Histological slides of the gastrocnemius muscle of the animals were prepared and stained with Hematoxylin and eosin for analysis of the inflammatory process, and picrosirius for the demonstration of collagen. The stained slides were subsequently analyzed using Fractal Dimension (FD). The results showed high FD values of the inflammatory process in the experimental groups L2 and L7 in relation to C (p= 0.000). The analysis of collagen in the picrosirius stained slides showed high FD in the L2 group compared to the L7 (p= 0.0001), with no statistically significant difference among other groups. In summary, the present study demonstrated that fractal analysis was able to identify changes in the inflammatory process in injured skeletal muscle tissue.

El objetivo de la investigación fue observar las modificaciones en tejido muscular esquelético en ratas después de la lesión por estiramiento muscular con análisis fractal. En el estudio se incluyeron 19 ratas, divididas en tres grupos, Control (n= 5) (C), lesión dos días (n= 7) (L2) y lesión siete días (L7). Los cortes histológicos del músculo gastrocnemio fueron coloreados con hematoxilina-eosina para el análisis de la inflamación y picrosirius para la determinación del colágeno. Los cortes histológicos fueron posteriormente analizados por medio de dimensión fractal (FD). Los resultados mostraron valores elevados de FD en proceso inflamatorio en los grupos experimentales L2 y L7, en comparación con grupo C (p= 0,000). El análisis de colágeno mostró mayor FD en grupo L2 comparado con L7 (p= 0,0001), se observó diferencia estadísticamente significativa con los demás. En resumen, esta investigación ha demostrado que el análisis fractal fue capaz de identificar las alteraciones del proceso inflamatorio en tejido muscular esquelético después de la lesión.

The spatial distribution of ß-carotene impregnated in apple slices determined using image and fractal analysis.

Changes in the concentration profiles of ß-carotene caused by diffusion through parenchymatic dried apple tissue were characterized by image and fractal analysis. Apple slices were dried by convection, and then impregnated with an aqueous ß-carotene solution. Scanning electron microscopy images of dried apple slices were captured and the fractal dimension (FD) values of the textures of the images were obtained (FDSEM). It was observed that the microstructure of the foodstuff being impregnated have an important effect on the impregnation phenomenon, generating irregular concentration profiles of ß-carotene, which are numerically described by the fractal dimension FDPROFILES and are related to the diffusion process during impregnation in dried edible tissue.

Physical characterization of freeze-dried foam prepared from Aloe Vera gel and guar gum / Caracterización de espumas liofilizadas preparadas a partir de gel de Aloe vera y goma guar

Background: Foams are colloidal dispersions of a gas suspended in a dispersing phase, which consisting of a semi-freeze-dried or viscous liquid phase. The physical properties of food foams are the result of the bubble characteristics and their spatial arrangement. Objectives: The aim of this work was to obtain foams of A. vera gel and guar gum and describe the changes in their physical properties and microstructure during freeze-drying using the fractal dimension concept and image analysis techniques. Methods: The porosity, density, and volume expansion factor of the fresh foams that were based on the A. vera foams were determined. The kinetics of foam texture, color, porosity and microstructure of the freeze-dried foams were obtained. The fractal texture dimension of surface (FDSDBC) and microstructure (FDESEM) of the foams were determined as indicators of structural changes after freeze-drying. The guar gum concentrations used to obtain the A. vera prefoam were expressed in w/w as F1 (control sample without gum), F2 (2%), F3 (4%) and F4 (6%). Results: We obtained stable freeze-dried foams of Aloe vera gel and guar gum. The porosity, density and volume expansion factor of the fresh and freeze-dried foams were affected by the addition of the guar gum. Changes in the topology of the freeze-dried foam surface during the drying process resulted in a high rugosity compared with the original smooth surface. The microstructure of the dried foam samples suggested a relationship between the gum concentration of the prefoam A. vera gel mixture and the physical properties before and after freeze-drying, such as an increase in the microstructural alterations and surface roughness during freeze-drying. The roughness of the freeze-dried foam surface, described by the FDSDBC represented the macroscopic physical changes of the samples and correlated with the changes in the foam microstructure, which were described by the fractal dimension of the Environmental Scanning Electron Microscopy ESEM microphotographs (FDESEM). Conclusions: The digital analysis of the structure and porosity of the freeze-dried foam can be used to quantify the effect of gum concentrations on the morphological features and physical properties of foams during freeze-drying.

Antecedentes: Las espumas son dispersiones coloidales de un gas en una fase líquida viscosa. Las propiedades físicas de las espumas alimentarias son el resultado de las características de sus burbujas y su disposición espacial. Objetivos: El objetivo de este trabajo fue obtener espumas de gel de A. vera y goma guar y describir los cambios en sus propiedades físicas y su microestructura durante el secado por liofilización utilizando el concepto de dimensión fractal y las técnicas de análisis de imagen. Métodos: Se determinó la porosidad, densidad, factor de expansión volumétrico de las espumas frescas de A. vera. Así como la cinética de liofilización, textura, isotermas de sorción, color, porosidad y la microestructura las espumas liofilizadas. La dimensión fractal de la textura (FDSDBC) y microestructural (FDESEM) de las espumas de gel de A. vera y goma guar liofilizadas se determinó como un indicador de los cambios estructurales después de la liofilización. Las concentraciones de goma de guar utilizados para obtener la solución de clara de huevo preespuma se expresaron en w/w como F1 (muestra de control sin goma), F2 (2%), F3 (4%) y F4 (6%). Resultados: Fue posible obtener espumas liofilizadas estables de gel de A. vera y goma guar. La porosidad, densidad, factor de expansión volumétrico de las espumas se vieron afectadas con la adición de goma guar. Los cambios en la topología de la superficie de la espuma liofilizada durante todo el proceso de secado dieron lugar a alta rugosidad en comparación con la superficie lisa original. La microestructura de las muestras de espuma secas sugirió una relación entre la concentración de goma de las espumas de A. vera y las propiedades físicas antes y después de la liofilización como un aumento en las alteraciones microestructurales y rugosidad de la superficie durante el secado por congelación. La rugosidad de la superficie de la espuma liofilizada, se describió por la relación FDSDBC que representa los cambios físicos macroscópicos de las muestras y se correlacionó con los cambios en la microestructura de espuma, que fueron descritos por la dimensión fractal de las micrografías ESEM (FDESEM). Conclusiones: El análisis digital de la estructura y la porosidad de la espuma liofilizada se puede utilizar para cuantificar el efecto de las concentraciones de goma guar en las características morfológicas de las espumas durante el secado por congelación.