Lower Fractal Dimension Research Articles

Study of prediction model for high-grade meningioma using fractal geometry combined with radiological features.

To establish a prediction model combining fractal geometry and radiological features, which consider the complexity of tumour morphology advancing beyond the limitations of previous models. A total of 227 patients at the First Affiliated Hospital of Harbin Medical University from July 2021 to November 2023 were included. Fractal geometry was calculated and the radiomics features were extracted from regions of interest (ROIs). Weighted Gene Co-Expression Network Analysis (WGCNA) was employed for preliminary screening to identify those that were significantly associated with high-grade meningioma. In the training cohort, the least absolute shrinkage and selection operator (LASSO) regression was employed for further screening the radiomics features. Area under curve (AUC) was to evaluate models' performance. In entire patient cohort, low-grade meningiomas had significantly lower fractal dimensions (P = 0.01), while high-grade meningiomas had higher lacunarity (P = 0.049). Fractal dimension (OR 6.8, 95% CI 1.49-36.51, P = 0.017), lacunarity (OR 3.7, 95% CI 1.36-11.75, P = 0.014), and Rscore (OR 2.8, 95% CI 1.55-5.75, P = 0.002) were independent risk factors for high-grade meningiomas. The final results demonstrated that the "fractal geometry + radiological features (semantic features + radiomics features)" model exhibited the most optimal performance in predicting high-grade meningioma, with an AUC of 0.854 in the training cohort and 0.757 in the validation cohort. Significant differences in fractal dimension and lacunarity exist between high-grade and low-grade meningiomas, which can be potential predictive factors. The developed predictive model demonstrated good performance in predicting high-grade meningiomas.

The Control of Isolated Kerogen on Pore Structure and Heterogeneity in Marine-Continental Transitional Shale: A Case Study on the Taiyuan Formation, Northern Ordos Basin

Accurately determining the pore structure and heterogeneity characteristics of marine-continental transitional shale in the Taiyuan Formation is crucial for evaluating the shale gas resources in the northern Ordos Basin. However, the studies on pore characteristics and heterogeneity of marine-continental transitional shales and isolated kerogen are limited. This study collected Taiyuan Formation shale in the northern Ordos Basin, and corresponding kerogen isolated from shale and used N2 and CO2 adsorption experiment and Frenkel–Halsey–Hill and Volume-Specific Surface Area model to investigate the pore structure and heterogeneity of both. The results show that the isolated kerogen is dominated by micropores, and the micropore’s specific surface area and volume are 4.7 and 3.5 times the corresponding shale, respectively. In addition, the microporous heterogeneity of the isolated kerogen is stronger than that of shale, while the mesoporous heterogeneity is exactly the opposite. Meanwhile, the micropores fractal dimension Dm is positively correlated with organic matter (OM) content, while mesopores fractal dimension D1 and D2 are negatively linearly correlated with TOC content and have no significant relationship with clay mineral and quartz content (but show a significant positive correlation with illite and illite/smectite mixed layer). Isolated kerogen plays an important role in the pore (especially micropores) heterogeneity of shale, while other minerals (such as clay minerals) have a controlling effect on the mesopores heterogeneity of shale. Compared with marine shale, the marine-continental transitional shale of the Taiyuan Formation has a lower fractal dimension and better connectivity, which is conducive to shale gas seepage and migration. The final result can provide a significant basis for the reserve evaluation and the optimization of desert areas in the marine-continental transitional shale gas in the northern Ordos Basin.

The influence of pore throat heterogeneity and fractal characteristics on reservoir quality: A case study of chang 8 member tight sandstones, Ordos Basin

The Chang 8 member of the Yanchang Formation in the Ordos Basin exhibits extensive development of tight sandstone reservoirs. In comparison to conventional reservoirs, these tight sandstone reservoirs demonstrate smaller pore-throat systems and stronger heterogeneity due to interactions between inherent sedimentary components and various diagenetic processes. To further investigate the influence of microscopic pore throat structure on macroscopic physical properties and oil content within the reservoir, a comprehensive study was conducted utilizing high pressure mercury injection, nuclear magnetic resonance, X-CT scanning, and other pore throat testing methods. This study was complemented by observation techniques such as polarizing microscope, scanning electron microscopy, and laser confocal imaging, to study the pore throat system of reservoirs under the influence of different sedimentary components and diagenesis. By comparison, it is observed that the radius of the primary pore throat system in the tight sandstone reservoir ranges from 0.01 to 1 μm. The structural characteristics of the pore throat system significantly impact the macroscopic physical properties of the reservoir. Due to variations in testing methods, high pressure mercury injection, nuclear magnetic resonance (NMR), and X-ray computed tomography (X-CT) reveal different fractal dimensions of the reservoir's pore throat system. Therefore, it is better to respectively utilize fractal dimension Df2, Df2-NMR, Df2-CT, and pore throat parameters to characterize the microscopic pore throat system with a radius ranging from 0.01 to 1 μm. The decrease in the average pore throat radius and the increased irregularity of pore shape contribute to heightened heterogeneity in the micro-pore throat structure within the reservoir. This negatively impacts its physical properties and oil content. Furthermore, it is important to note that the minimum threshold of pore throat radius plays a crucial role as a primary factor determining the fluid seepage capacity within this reservoir. Moreover, when isolated pores exist, reduced fluid mobility ensues, which further worsens the seepage conditions of the reservoir. The chlorite rims development reservoir shows a low fractal dimension in its micro-pore throats, contributing to superior macroscopic petrophysical properties and oil content. However, compression, siliceous cementation, and calcite cementation negatively impact the average pore throat radius by increasing micropores, inaccessible pores, and narrow throat content. This results in a stronger heterogeneity of the pore throat structure, leading to poor seepage conditions and lower oil content.

Exploring cortical morphology biomarkers of amnesic mild cognitive impairment using novel fractal dimension-based structural MRI analysis.

Amnestic mild cognitive impairment (aMCI) is considered as an intermediate stage of Alzheimer's disease, but no MRI biomarkers currently distinguish aMCI from healthy individuals effectively. Fractal dimension, a quantitative parameter, provides superior morphological information compared to conventional cortical thickness methods. Few studies have used cortical fractal dimension values to differentiate aMCI from healthy controls. In this study, we aim to build an automated discriminator for accurately distinguishing aMCI using fractal dimension measures of the cerebral cortex. Thirty aMCI patients and 30 health controls underwent structural MRI of the brain. First, the atrophy of participants' cortical sub-regions of Desikan-Killiany cortical atlas was assessed using fractal dimension and cortical thickness. The fractal dimension is more sensitive than cortical thickness in reducing dimensional effects and may accurately reflect morphological changes of the cortex in aMCI. The aMCI group had significantly lower fractal dimension values in the bilateral temporal lobes, right limbic lobe and right parietal lobe, whereas they showed significantly lower cortical thickness values only in the bilateral temporal lobes. Fractal dimension analysis was able to depict most of the significantly different focal regions detected by cortical thickness, but additionally with more regions. Second, applying the measured fractal dimensions (and cortical thickness) of both cerebral hemispheres, an unsupervised discriminator was built for the aMCI and healthy controls. The proposed fractal dimension-based method achieves 80.54% accuracy in discriminating aMCI from healthy controls. The fractal dimension appears to be a promising biomarker for cortical morphology changes that can discriminate patients with aMCI from healthy controls.

Factors Controlling Differences in Morphology and Fractal Characteristics of Organic Pores of Longmaxi Shale in Southern Sichuan Basin, China

Shale gas is a prospective cleaner energy resource and the exploration and development of shale gas has made breakthroughs in many countries. Structure deformation is one of the main controlling factors of shale gas accumulation and enrichment in complex tectonic areas in southern China. In order to estimate the shale gas capacity of structurally deformed shale reservoirs, it is necessary to understand the systematic evolution of organic pores in the process of structural deformation. In particular, as the main storage space of high-over-mature marine shale reservoirs, the organic matter pore system directly affects the occurrence and migration of shale gas; however, there is a lack of systematic research on the fractal characteristics and deformation mechanism of organic pores under the background of different tectonic stresses. Therefore, to clarify the above issues, modular automated processing system (MAPS) scanning, low-pressure gas adsorption, quantitative evaluation of minerals by scanning (QEMSCAN), and focused ion beam scanning electron microscopy (FIB-SEM) were performed and interpreted with fractal and morphology analyses to investigate the deformation mechanisms and structure of organic pores from different tectonic units in Silurian Longmaxi shale. Results showed that in stress concentration areas such as around veins or high-angle fractures, the organic pore length-width ratio and the fractal dimension are higher, indicating that the pore is more obviously modified by stress. Under different tectonic backgrounds, the shale reservoir in Weiyuan suffered severe denudation and stronger tectonic compression during burial, which means that the organic pores are dominated by long strip pores and slit-shaped pores with high fractal dimension, while the pressure coefficient in Luzhou is high and the structural compression is weak, resulting in suborbicular pores and ink bottle pores with low fractal dimension. The porosity and permeability of different forms of organic pores are also obviously different; the connectivity of honeycomb pores with the smallest fractal dimension is the worst, that of suborbicular organic pores is medium, and that of long strip organic pores with the highest fractal dimension is the best. This study provides more mechanism discussion and case analysis for the microscopic heterogeneity of organic pores in shale reservoirs and also provides a new analysis perspective for the mechanism of shale gas productivity differences in different stress–strain environments.

Blue skies: Does the visual composition of sky guide subjective judgments of naturalness in the environment?

Expanding on previous findings, that highlighted the significance of sky in environmental perception, our analysis investigated whether the visual composition of the sky shapes perceptions of environmental naturalness. The study employed a novel, free-selection task in which participants viewed a series of environmental images with varying levels of natural and urban elements, as well as different sky visibility conditions, and were asked to identify “nature” within these images. The task procedure also involved subjective ratings of each scene. Using previously gathered data, we reassessed 105 participants' selection of the sky as “nature” across 96 photos of diverse outdoor scenes to understand which visuospatial features influence these perceptions. Utilizing the Boruta feature selection algorithm, we identified key characteristics—fractal dimensions, brightness, and entropy in brightness, hue, and saturation—that significantly predicted the selection of sky as “nature”, irrespective of the environment type (urban or natural). Results indicated that lower fractal dimensions are preferred for sky selected as “nature”, inversely affecting the naturalness judgment of scenes with the additional effect of brightness. These findings enhance our understanding of how visuospatial features influence environmental perception, offering implications for future research directions and theoretical advancements in understanding environmental perception.

Tracking and modeling the movement of Queensland fruit flies, Bactrocera tryoni, using harmonic radar in papaya fields

Determining movement parameters for pest insects such as tephritid fruit flies is critical to developing models which can be used to increase the effectiveness of surveillance and control strategies. In this study, harmonic radar was used to track wild-caught male Queensland fruit flies (Qflies), Bactrocera tryoni, in papaya fields. Experiment 1 continuously tracked single flies which were prodded to induce movement. Qfly movements from this experiment showed greater mean squared displacement than predicted by both a simple random walk (RW) or a correlated random walk (CRW) model, suggesting that movement parameters derived from the entire data set do not adequately describe the movement of individual Qfly at all spatial scales or for all behavioral states. This conclusion is supported by both fractal and hidden Markov model (HMM) analysis. Lower fractal dimensions (straighter movement paths) were observed at larger spatial scales (> 2.5 m) suggesting that Qflies have qualitatively distinct movement at different scales. Further, a two-state HMM fit the observed movement data better than the CRW or RW models. Experiment 2 identified individual landing locations, twice a day, for groups of released Qflies, demonstrating that flies could be tracked over longer periods of time.

Preliminary Results of Developing Imaging Complexity Biomarkers for the Incidence of Severe Radiation Pneumonitis Following Radiotherapy in Non-Small Cell Lung Cancer Patients with Underlying Idiopathic Pulmonary Fibrosis.

Background: Idiopathic pulmonary fibrosis (IPF) has the potential to cause fatal pulmonary toxicity after radiotherapy and can increase the morbidity and mortality of non-small-cell lung cancer (NSCLC) patients. In this context, we aimed to develop imaging complexity biomarkers to predict the incidence of severe pulmonary toxicity in patients with NSCLC who have underlying IPF and are treated with radiotherapy. Methods: We retrospectively reviewed the medical records of 19 patients with NSCLC who had underlying IPF and were treated with radiotherapy at the Korea University Guro Hospital between March 2018 and December 2022. To quantify the morphometric complexity of the lung parenchyma, box-counting fractal dimensions and lacunarity analyses were performed on pre-radiotherapy simulation chest computed tomography scans. Results: Of the 19 patients, the incidence of grade 3 or higher radiation pneumonitis was observed in 8 (42.1%). After adjusting for age, sex, smoking status, histology, and diffusing capacity of the lung for carbon monoxide, eight patients with a lower fractal dimension showed a significantly higher hazard ratio of 7.755 (1.168-51.51) for grade 3 or higher pneumonitis than those with a higher fractal dimension. Patients with lower lacunarity exhibited significantly lower hazards in all models, both with and without adjustments. The lower-than-median lacunarity group also showed significantly lower incidence curves for all models built in this study. Conclusions: We devised a technique for quantifying morphometric complexity in NSCLC patients with IPF on radiotherapy and discovered lacunarity as a potential imaging biomarker for grade 3 or higher pneumonitis.

Fractal Changes of the Retinal Microvasculature in Birdshot Chorioretinopathy.

Retinal vascular disorders are associated with lower fractal dimension (FD). We analyzed FD in birdshot chorioretinopathy (BSCR). This was a retrospective cohort study. We performed optical coherence tomography angiography (OCTA) and analyzed FD of the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC) using ImageJ. For each vascular layer, we analyzed the presence of BSCR, subjects' age, sex, and presence of diabetes mellitus to determine which may predict lower FD. We compared 28 eyes (14 patients) with BSCR to 34 control eyes (17 patients). Mean FD of BSCR was lower in SCP (1.584 [± 0.126] vs 1.706 [± 0.118], P < 0.001), DCP (1.637 [± 0.134] vs 1.780 [± 0.096], P < 0.001), and CC (1.884 [± 0.063] vs 1.917 [± 0.047], P = 0.036). FD of SCP was lower per increasing year (0.005 [P = 0.014]). Male patients had lower FD-DCP (0.101 [P = 0.043]). In BSCR, fractal analysis showed significant involvement of the SCP, DCP, and to a lesser extent the CC. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].

3D fractal model with experimental analysis for assessing surface topography in EDM

This work presents a novel three-dimensional fractal model designed specifically for morphological analysis of specimens made by the EDM. Within the 3D fractal framework, an algorithm is developed to estimate fractal parameters such as fractal dimension and periodic length. AISI 316 stainless steel, dielectric media, electrode materials, and powder variations were used in experimental trials to validate the 3D fractal model. Fixed pulse time ratios were used to control the EDM process. The specimen having the lowest fractal dimension, the shortest periodic length, the least amount of surface roughness, and the least amount of ten-point height was discovered to be the one machined using kerosene oil dielectric, brass electrode, graphite powder, and 1.0 pulse ratio time. On the other hand, the specimen machined using copper electrode, graphite powder, transformer oil dielectric, and 1.5 pulse ratio time produced the largest periodic length, maximum surface roughness, fractal dimension, and ten-point height. The developed 3D fractal model evaluates the EDM process well and provides insightful information on how to improve surface properties.

Correlation between left atrial appendage morphology based on fractal dimension quantification and its hemodynamic parameters in patients with atrial fibrillation

To investigate the relationship between left atrial appendage (LAA) morphology, quantified based on fractal dimension (FD), and LAA hemodynamic parameters in patients with atrial fibrillation (AF), in an effort to reveal the effect of LAA shape on blood flow. 225 patients with AF who underwent cardiac computed tomography angiography (CTA) and transesophageal echocardiography (TEE) were enrolled. LAA morphology was quantified based on FD on cardiac CTA images, and LAA hemodynamic parameters, including injection fraction (EF), filling peak flow velocity (FV), maximum speed of emptying (PEV), and wall motion velocity (WMV), were assessed using TEE. We divided the patients with AF into two groups based on a mean LAA FD of 1.32: the low FD group (n=124) and the high FD group (n=101). Compared to the low FD group, there were more patients with LAA circulatory stasis/thrombus (P=0.008) in the high FD group, as well as lower LAA FV (P=0.004), LAA PEV (P=0.007), and LAA WMV (P=0.007). LAA FD was an independent and significant determinant of LAA EF (β=-11.755, P=0.001), LAA FV (β=-17.364, P=0.004), LAA PEV (β=-18.743, P<0.001), and LAA WMV (β=-7.740, P=0.001) in multiple linear regression analysis. LAA FD is an essential determinant of LAA hemodynamic parameters, suggesting that the relatively complex morphology of the LAA may influence its hemodynamics, which can correlate with embolic events.

Cover crops and poultry litter impact on soil structural stability in dryland soybean production in southeastern United States

AbstractThis study explored the efficacy of soil aggregate indices in quantifying soil structural development, utilizing 5‐year field experiment data from the Southeastern United States. The experiment utilized a split‐plot design with cover crops (native vegetation as control, cereal rye (Secale cereale L.), winter wheat (Triticum aestivum), hairy vetch (Vicia villosa), and mustard (Brassica rapa) plus cereal rye as the main factor and fertilizer source (no fertilizer as control, inorganic fertilizer with phosphorus, potassium, and elemental sulfur, and poultry litter) as the secondary factor. Aggregate size fractions were determined using the wet‐sieving method, and aggregate stability index (ASI), mean weight diameter (MWD), geometric mean diameter (GMD), and fractal dimension (FD) were calculated to assess soil structural stability. Main effects results indicated that cereal rye (55.11%) and poultry litter (50.97%) exhibited the highest ASI values. The highest MWD, GMD, and FD were observed under mustard plus cereal rye (1.187 mm), cereal rye (0.462 mm), and hairy vetch (2.573), respectively. Principal component analysis revealed that cover crops significantly improved soil aggregate structure and stability, overcoming limitations of sole fertilization practices. Regression analysis suggested that ASI, MWD, and GWD positively correlated with soil organic carbon, whereas FD negatively correlated with MWD, GMD, and ASI. Principal component analysis exhibited that FD decreased with increasing soil organic carbon, ASI, MWD, and GMD, demonstrating that lower FD values indicate enhanced soil aggregation and structure. Assessed indices, FD included, effectively gauged soil structural stability. These metrics should be prioritized in managerial decisions to support soil productivity and health in agricultural systems.

Investigation of Fractal Dimension Analysis and Radiomorphometric Indices in Children with Type 1 Diabetes Mellitus

Background: Diabetes mellitus (DM) disrupts bone metabolism, leading to slowed bone development, poor bone quality, and osteoporosis. Objectives: The aim of this study was to examine changes in the bones of adolescents with type-1 diabetes mellitus (T1DM) using fractal dimension (FD) analysis method and panoramic radiomorphometric indices. Methods: Fractal dimension values and radiomorphometric measurements of 36 children with T1DM and 36 healthy individuals were compared using panoramic radiographs. The panoramic mandibular index (PMI), mental index (MI), mandibular cortical width (MCW), amount of alveolar bone resorption (AABR), antegonial index (AI), and gonial index (GI) were measured. Mandibular cortical index (MCI) was recorded as C1, C2, and C3 classes. Results: For the angulus and corpus regions, the T1DM patient group had lower FD values, and there was a statistically significant difference between the T1DM patient group and the control group (P = 0.003, P = 0.029). Mental index, MCW, and AI values were higher in the control group than in the T1DM patient group and were statistically significant (P = 0.014, P = 0.001, P &lt; 0.001, respectively). Conclusions: In this study examining the mandible in pediatric patients with T1DM using radiomorphometric measurements and fractal analysis method, it can be concluded that T1DM affects bone morphology and trabecular structure

Retinal Fractal Dimension Is a Potential Biomarker for Systemic Health-Evidence From a Mixed-Age, Primary-Care Population.

To investigate whether fractal dimension (FD), a retinal trait relating to vascular complexity and a potential "oculomics" biomarker for systemic disease, is applicable to a mixed-age, primary-care population. We used cross-sectional data (96 individuals; 183 eyes; ages 18-81 years) from a university-based optometry clinic in Glasgow, Scotland, to study the association between FD and systemic health. We computed FD from color fundus images using Deep Approximation of Retinal Traits (DART), an artificial intelligence-based method designed to be more robust to poor image quality. Despite DART being designed to be more robust, a significant association (P < 0.001) between image quality and FD remained. Consistent with previous literature, age was associated with lower FD (P < 0.001 univariate and when adjusting for image quality). However, FD variance was higher in older patients, and some patients over 60 had FD comparable to those of patients in their 20s. Prevalent systemic conditions were significantly (P = 0.037) associated with lower FD when adjusting for image quality and age. Our work suggests that FD as a biomarker for systemic health extends to mixed-age, primary-care populations. FD decreases with age but might not substantially decrease in everyone. This should be further investigated using longitudinal data. Finally, image quality was associated with FD, but it is unclear whether this finding is measurement error caused by image quality or confounded by age and health. Future work should investigate this to clarify whether adjusting for image quality is appropriate. FD could potentially be used in regular screening settings, but questions around image quality remain.

Associations between unilateral amblyopia in childhood and cardiometabolic disorders in adult life: a cross-sectional and longitudinal analysis of the UK Biobank

Amblyopia is a common neurodevelopmental condition and leading cause of childhood visual impairment. Given the known association between neurodevelopmental impairment and cardiometabolic dysfunction in later life, we investigated whether children with amblyopia have increased risk of cardiometabolic disorders in adult life. This was a cross-sectional and longitudinal analysis of 126,399 United Kingdom Biobank cohort participants who underwent ocular examination. A subset of 67,321 of these received retinal imaging. Data analysis was conducted between November 1st 2021 and October 15th 2022. Our primary objective was to investigate the association between amblyopia and a number of components of metabolic syndrome and individual cardiometabolic diseases. Childhood amblyopia, dichotomised as resolved or persisting by adulthood, cardiometabolic disease and mortality were defined using ophthalmic assessment, self-reported, hospital admissions and death records. Morphological features of the optic nerve and retinal vasculature and sublayers were extracted from retinal photography and optical coherence tomography. Associations between amblyopia and cardiometabolic disorders as well as retinal markers were investigated in multivariable-adjusted regression models. Individuals with persisting amblyopia (n=2647) were more likely to be obese (adjusted odds ratio (95% confidence interval): 1.16 (1.05; 1.28)), hypertensive (1.25 (1.13; 1.38)) and diabetic (1.29 (1.04; 1.59)) than individuals without amblyopia (controls, (n=18,481)). Amblyopia was also associated with an increased risk of myocardial infarction (adjusted hazard ratio: 1.38 (1.11; 1.72)) and death (1.36 (1.15; 1.60)). On retinal imaging, amblyopic eyes had significantly increased venular caliber (0.29 units (0.21; 0.36)), increased tortuosity (0.11 units (0.03; 0.19)), but lower fractal dimension (-0.23 units (-0.30;-0.16)) and thinner ganglion cell-inner plexiform layer (mGC-IPL,-2.85 microns (-3.47;-2.22)). Unaffected fellow eyes of individuals with amblyopia also had significantly lower retinal fractal dimension (-0.08 units (-0.15;-0.01)) and thinner mGC-IPL (-1.14 microns (-1.74;-0.54)). Amblyopic eyes with a persisting visual deficit had smaller optic nerve disc height (-0.17 units (-0.25;-0.08)) and width (-0.13 units (-0.21;-0.04)) compared to control eyes. Although further research is needed to understand the basis of the observed associations, healthcare professionals should be cognisant of greater cardiometabolic dysfunction in adults who had childhood amblyopia. Differences in retinal features in both the amblyopic eye and the unaffected non-amblyopic suggest generalised versus local processes. Medical Research Council (MR/T000953/1) and the National Institute for Health and Care Research.

On the fractal dimension of carbon black particles in pyrolysis flow reactors

This study presents a numerical approach for simulating the internal morphology of carbon black particles formed in a pyrolysis reactor. The simulation process involves a two-step approach using population balance models (PBM) and detailed population balance models (DPBM), solved via sectional and stochastic methods, to simulate the arrangement of primary particles within aggregates to allow determination of their fractal dimension (FD). The outcome is a novel introduction of simulating real flow reactors that for the first time provides the fractal dimension of particles as an output, rather than an assumed input. The results of this study have practical implications for optimizing the synthesis processes in carbon black production. The effects of various production parameters, including aggregation efficiency, temperature, pressure, and acetylene concentrations, on the fractal dimension values of carbon black particles are examined. It is observed that higher temperatures lead to the formation of larger fractal shapes with lower fractal dimensions and larger primary particle diameters. Moreover, increased reactor pressure and higher aggregation efficiency enhance the formation of carbon black aggregates, but also have a time-based effect with higher compactness at longer residence times. The time-based effect reveals the importance of sintering, where high loads of small particles enhance the overall sintering of the aggregates. These findings provide insights into the interplay between temperature, pressure, and particle morphology, highlighting the dynamic nature of carbon black nanoparticles and their response to synthesis process conditions.

Structural properties of the intra- and interhelical cavities of V6-type crystalline starches

V-type crystalline starch is known for its property to enhance aroma retention. Intra- and interhelical cavities are the first-order characteristics of V-type crystalline starch, which can affect its properties from microscopic level. This work aims to provide a detailed analysis of structural attributes of intra- and interhelical cavities and their influence on the properties of V-type crystalline starches. Helix deformation was caused due to the formation of interhelical cavities, which was reflected by the downfield shift of the signals for C1 and C4 as well as the appearance of an independent signal for C3 in 13C CP/MAS NMR spectra. Unit cell and lamellar structure formed by the aggregation of intrahelical cavities exhibited relatively low cell volume and high fractal dimension at crystal cell and lamellar levels. Toward a larger crystal, d-spacing increased with the formation of interhelical cavities, causing low-angle shifts of V-type crystalline starches in X-ray diffraction profiles. Intrahelical cavities enabled V6I-type crystalline starch to show high crystallinity per unit volume and a favorable short-range order, contributing greatly to the stable thermal properties. The flavor quality improvement in starch-based food is attributed to the structural characteristics of helical cavities and their relationship with the properties of V-type crystalline starches.

Optical coherence tomography angiography macular biomarkers of peripheral retinal ischemia in diabetic macular edema: secondary endpoints from the clinical study "FOVEA".

To investigate the relationship between the macular values of fractal dimension (FD) and lacunarity (LAC) on optical coherence tomography angiography (OCTA) images and the presence of peripheral retina non-perfusion areas (NPAs) on fluorescein angiography (FA) in patients with treatment-naïve diabetic macular edema (DME). Fifty patients with treatment-naïve DME underwent a full ophthalmic examination, including best-corrected visual acuity measurement, FA, spectral-domain optical coherence tomography, and OCTA. Specifically, FA was performed to detect the presence of retinal NPAs, whereas fractal OCTA analysis was used to determine macular FD and LAC values at the level of thesuperficial and deep capillary plexus (SCP and DCP). FA montage frames of the posterior pole and peripheral retina, as well as macular OCTA slabs of the SCP and DCP, were obtained. Thirty (60%) eyes with FA evidence of peripheral retinal NPAs in at least one quadrant showed significantly lower FD and higher LAC in both SCP and DCP, when compared with eyes presenting a well-perfused peripheral retina. Furthermore, macular FD and LAC values were found to be significantly associated with the extent of retinal NPAs. Macular FD and LAC of both SCP and DCP seem to be strongly associated with the extent of peripheral retinal NPAs, thus suggesting that may be useful predictive biomarkers of peripheral ischemia in treatment-naïve DME eyes.

Analysis of the difference between Alzheimer's disease, mild cognitive impairment and normal people by using fractal dimensions and small-world network.

This research examined the distinctions in brain network characteristics among individuals with Alzheimer's disease (AD), mild cognitive impairment (MCI), and a control group. Magnetic resonance imaging (MRI) and mini-mental state examination (MMSE) data were retrieved from the Alzheimer's Disease Neuroimaging Initiative (ANDI) database, comprising 40 subjects in each group. Correlation maps for evaluating brain network connectivity were generated using fractal dimension (FD) analysis, a method capable of quantifying morphological changes in cortical and cerebral regions. Employing graph theory, each parcellated brain region was represented as a node, and edges between nodes were utilized to compute small-world network properties for each group. In the comparison between control and AD demonstrated the significantly lower FD values (P<0.05) in temporal lobe, motor cortex, part of occipital and parietal, hippocampus, amygdala, and entorhinal cortex, which present the atrophy. Similarly, comparing control group to MCIs, regions closely associated with memory, such as the hippocampus, showed significantly lower FD values. Furthermore, both AD and MCI groups displayed diminished connectivity and decreased network efficiency. In conclusion, fractal dimension (FD) analysis illustrate the progression of structural declination from mild cognitive impairment (MCI) to Alzheimer's disease (AD). Additionally, structural small-world network analysis presents itself as a potential method for assessing network efficiency and the progression of AD. Moving forward, further clinical assessments are warranted to validate the findings observed in this study.

INFLUENCE OF HEATING CONDITIONS ON TEXTURE PARAMETERS AND ADSORPTION PROPERTIES OF APRICOT KERN SHELL CARBONIZATES

Some results of a comparative analysis of the textural parameters and sorption characteristics of carbonizates obtained by microwave and traditional heating of apricot kernel shells are presented. It has been shown that sorbent samples obtained by microwave carbonization of shells, in comparison with sorbents obtained by traditional heating, are characterized by a more uniform distribution of pore sizes, greater adsorption capacity and low fractal dimension of the surface.