Effect of a static magnetic field on the fractal complexity of bursting activity of the Br neuron in the snail detected by factor analysis

In the present work we report a new combination of fractal analysis and some advanced statistical methods and their application for the quantitative detection of the effects of a static magnetic field of 2.7 mT on fractal complexity changes of Br neuron activity in the subesophageal ganglia of the garden snail Helix pomatia. We used factor analysis (FA) in the analysis of the empirical distribution of fractal dimension (FD). FA showed that there are two factors in the empirical distribution of FD. Results indicated that the significant changes in the fractal complexity of Br neuron activity occurred during treatment with a magnetic field, were extended to the post exposure period

Health Risk Assessment for Residents and Workers Based on Toxic and Carcinogenic Element Content from PM2.5 in Belgrade Suburban Area

Particulate matter of diametar 1) and carcinogenic (R≥1×10-5) risks for the residents from this area. The residents spent the most of their time in this ambient and they are most at the risk caused by the measured PM2.5 pollution (HImedian: 2.28; Rmedian: 1.25 × 10-4). Observing the scenarios for workers, the risk mostly depends on the time that workers spent outside during working hours. Similar non-carcinogenic risks were observed for outdoor, indoor and composite workers, slightly higher risk was observed for construction workers, while the lowest risk was obtained for an excavation worker who is less exposed to the PM2.5 atmospheric deposition than soil dust resuspension. The same was observed for the carcinogenic risk, while the similar risks were observed for all workers. Only for an excavation worker, the carcinogenic risk was significantly lower than for other workers. The most significant contributor to the non-carcinogenic risk in all scenarios was the concentration of Mn, and then the concentration of Be, while the most significant contributor to the carcinogenic risk was Cr6+. Observing the risks among the investigated period the highest non-carcinogenic and carcinogenic risks were observed in April and October based on the toxic and carcinogenic elements in PM2.5. In these months beside the influence of the industrial activities, dust episodes or activity of heating sorces possibly caused the increase of the toxic and carcinogenic elements in PM2.5

Structure and mineral element composition of the lyophilised freshwater bryozoan Hyallinela punctata

Structure of the lyophilised colonies of the freshwater bryozoan Hyalinella punctata (Hancock, 1850) and their mineral element composition were studied by X ray diffraction, scanning electron microscopy (SEM) and inductively coupled plasma (ICP) spectrometry for the first time ever. The X ray measurements showed amorphous structure of the bryozoan, while SEM indicated porous connected structure without regular structural motifs. Considerable presence of phosphorus (7949.69 μg/ml), sulphur (6204.7 μg/ml) and calcium (6139.58 μg/ml), as well as low heavy metal content was found by ICP. The obtained results jointly indicate the potential of the investigated animal species as a base for bioscaffolds and nanocompositesPhysical chemistry 2012 : 11th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 201

The effect of single-pulse transcranial magnetic stimulation and peripheral nerve stimulation on complexity of EMG signal: fractal analysis

The aim of this study was to examine whether single-pulse transcranial magnetic stimulation (spTMS) affects the pattern of corticospinal activity once voluntary drive has been restored after spTMS-induced EMG silence. We used fractal dimension (FD) to explore the 'complexity' of the electromyography (EMG) signal, and median frequency of the spectra (MDF) to examine changes in EMG spectral characteristics. FD and MDF of the raw EMG epochs immediately before were compared with those obtained from epochs after the EMG silence. Changes in FD and MDF after spTMS were examined with three levels of muscle contraction corresponding to weak (20-40 %), moderate (40-60 %) and strong (60-80 % of maximal voluntary contraction) and three intensities of stimulation set at 10, 20 and 30 % above the resting motor threshold. FD was calculated using the Higuchi fractal dimension algorithm. Finally, to discern the origin of FD changes between the CNS and muscle, we compared the effects of spTMS with the effects of peripheral nerve stimulation (PNS) on FD and MDF. The results show that spTMS induced significant decrease in both FD and MDF of EMG signal after stimulation. PNS did not have any significant effects on FD nor MDF. Changes in TMS intensity did not have any significant effect on FD or MDF after stimulation nor had the strength of muscle contraction. However, increase in contraction strength decreased FD before stimulation but only between weak and moderate contraction. The results suggest that the effects of spTMS on corticospinal activity, underlying voluntary motor output, outlast the TMS stimulus. It appears that the complexity of the EMG signal is reduced after spTMS, suggesting that TMS alters the dynamics of the ongoing corticospinal activity most likely temporarily synchronizing the neural network activity. Further studies are needed to confirm whether observed changes after TMS occur at the cortical level

Review of the Hard-Facing Technology Application for Reparation of the Given Parts in Various Branches of Industry

This paper deals with the problem of defining the optimal procedure for reparation of the machine parts of large dimensions and complex shapes. The procedure consists of establishing the causes of the part's damages, definition of the reparation technology, with selection of its parameters and ways of execution. The reparation is done by hard-facing, with heat treatment that consists of preheating, additional heating and the post hard-facing tempering. The process parameters' selection includes choosing the right filler metal(s), ways and order of depositing the hard-faced layers, ways of reaching and maintaining the preheating temperatures, checking of the base metal's chemical composition and mechanical properties and deciding on the post-process heat and mechanical processing of the executed hard-facing. The executed reparation of the forging hammer's mallet, presented in details, serves as an example how the reparation can successfully serve as a substitute for procuring the new part and thus producing the savings both directly in lower costs and indirectly in shortening the down-time of the damaged part operation

Variability Estimation of the Protein and Phenol Total Content in Honey Using Front Face Fluorescence Spectroscopy Coupled with MCR–ALS Analysis

It has been explored to what extent the ratio of the two main fluorophores in honey, originating from proteins and phenolic compounds, change between the honey extraction stage and packaging in the jars. Fluorescence spectroscopy combined with multivariate curve resolution–alternating least squares (MCR–ALS) was used to determine the ratio of the spectral components originating from phenol and proteins (Ph/Pr) fl , as a ratiometric indicator of variability in selected Lime tree (Tilia L.) honey samples. Spectrophotometric quantification of phenols and proteins in the honey samples was also performed and their ratio (Ph/Pr) sp was calculated. The values of the (Ph/Pr) fl ratio and honey protein content after packaging depended on the quality of homogenization before packaging in jars. Colorimetric and fluorometric results for phenols and proteins were in compliance. The examples are the values 3.34, 3.30, and 9, 3.14 for (Ph/Pr) fl and corresponding values 2.64, 2.18, and 12.75, 2.31 for (Ph/Pr) sp , in all pairs, the first value presenting the sample after extraction and the second value the sample after packaging in jars. Both methods show that in the former case there is no change in the phenol/protein ratio, and in the latter case the ratio decreased

Error estimates of Gaussian-type quadrature formulae for analytic functions on ellipses-a survey of recent results. ETNA - Electronic Transactions on Numerical Analysis

This paper presents a survey of recent results on error estimates of Gaussian-type quadrature formulas for analytic functions on confocal ellipses

Synthesis of europium-doped fluorapatite as a promising luminescent biomaterial

Lanthanide-doped apatite biomaterials are highly promising in medicine because of their excellent chemical and optical properties. In this study, Eu(III)-doped fluorapatite particles have been successfully synthesized by a wet method at room temperature. The characterization study from XRD showed that obtained powder is monophasic fluorapatite. Biomaterials based on fluorapatite (Ca10(PO4)5F2) doped with lanthanide elements are ideal contrast agents for a variety of biomedical applications, e.g. detection, imaging, cell tracking, and therapy [1]. Eu(III) received a great deal of interest because of several desirable properties like emission in the visible region, long luminescent lifetime, and less sensitivity to quenching by singlet oxygen [2].IX International School and Conference on Photonics : PHOTONICA2023 : book of abstracts; August 28 - September 1, 2023; Belgrad