This work presents a segment of research results of mechanical stability of the Sarafix external fixation system, applied to a tibia, in the case of an unstable fracture. The research has been conducted using structural analysis of one of the Sarafix fixator configurations by application of the finite element method (FEM) and experimental testing. 3D geometrical and FEM model of fixator configuration have been formed, whence a structural analysis has been performed using CATIA V5 software system. Structural analysis and experimental testing of Sarafix fixator have been performed under axial compression. Values of bone segments displacements at the point of load and fracture gap have been analyzed based on which values of axial construct stiffness and fracture gap stiffness have been determined. Verification of the results obtained from a structural analysis through experimental testing has been carried out by comparing values of an appropriate component of displacement at the point of load. 1. INTRODUCTION External fixator systems are medical devices for stabilization of bone fractures, and their compliance aims at producing an interfragmentary motion that promotes rapid and successful healing. The aim of the fixation technique is anatomical reduction and immobilization of the bone segments, as well as maintenance of this anatomical stabilization concept throughout the treatment by external stiffening of the fracture gap separating the bone segments. This aim is achieved by an external frame that is connected percutaneously to the bone segments by pins or wires. Directions and intensity of interfragmentary motions have the crucial importance on rapid bone healing [3]. It is possible to control interfragmentary 3D displacement of the fracture gap using FEM model. Optimal mechanical environment, which promotes bone healing, has not been completely defined yet. Both excessively high and excessively low interfragmentary motions were shown to have adverse effects on bone fracture healing. Moreover, interfragmentary displacements parallel to the fracture surfaces were shown to result in pseudo-arthrosis instead of fracture healing. This work presents results of structural and experimental analysis of one of the most used configuration of Sarafix external fixator system in the case of an unstable tibial fracture (configuration C, type 4+4). Fixator Sarafix presents unilateral biplanar external fixator of high flexibility, enabling its application on complete human skeleton. Unstable fractures at the middle of tibia have been analyzed with fracture gap of 20 and 50 mm (severe extensive injuries with a considerable defect of bone structure).

The decision process of artificial intelligence is elusive. We proposed a new method that by combining an attention-based convolutional neural network (GAMER-MRI) with the modified Layer-wise Relevance Propagation could reveal relevant regions on quantitative imaging maps in differentiating multiple sclerosis patients with mild-moderate and severe disabilities. The assessment of the relevant regions included the impact of inverting values within the regions and the heatmap on the MNI152 template. Our results show good network performance and identify brain regions relevant to the corticospinal tract. The proposed method might be useful to further explore patterns of brain microstructural alterations associated with disability.

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In recent work we have developed a general one-speed transport theory model for the calculation of the multiplicity moments, used in nuclear safeguards. Quantitative results were obtained for spheres, cylinders of various shapes, and shells. In all these works, similarly to the point model, the only neutron reaction was assumed to be fission. Since the quantitative results for highly multiplicative systems were not in agreement with recent experiments, we extended the model to include isotropic elastic scattering without energy loss of the neutrons. In the present work, we generalise the model further, to include inelastic scattering, which requires the introduction of energy dependence and anisotropic scattering. In the paper, the significance of the elastic scattering, as well as the need for including inelastic scattering is demonstrated, and the extension to energy dependent transport theory is described and illustrated with one example.

phenolic content was determined by the Folin-Ciocalteu method expressed as mg GAE/L. Antioxidant activity was determined by FRAP (mmol/L Fe2+) and Briggs-Rauscher (expressed as inhibitory time) methods, while antiradical activity was determined by the DPPH method (expressed as IC50). Results: Sweet cherry wine analysis conducted by UPLC TQ-MS/MS showed the presence of phenolic acids and flavonoids. The most dominant compound was chlorogenic acid, with a content of 232.77 to 317.34 µg/ml. Among other phenolic acids were detected: vanillic (7.62-11.58 µg/ml) and protocatehuic (12.81-22.37 µg/ml). Flavonoids detected in sweet cherry wines were catechin (11.23-21.83 µg/ml), epicatechin (75.81-110.43 µg/ml), quercetin (22.31-47.72 µg/ml) and kaempferol (2.87-7.53 µg/ml). Total phenolic content was in interval 1281.43-1721.52 mg GAE/L. Antioxidant activity detected by the FRAP method indicates that results were from 53.21-61.53 mmol/L Fe2+. Briggs-Rauscher and DPPH methods indicated significant inhibitory activity in sweet cherry wine. It is important to highlight that wines produced with the addition of sugar and enzymatic preparation showed higher contents of selected phenolic compounds and higher antioxidant and antiradical activity.

In the flood frequency assessment, engineers often face the problem of mixed peak data in the data record: some peaks are instantaneous daily flows (IDF), while the others are mean daily flows (MDF). If the problem is recognized, correction factor to the MDFs in the dataset is usually applied. In our research, we use flood flow datasets from 8 hydrologic stations with catchment area up to 1000 km 2 in the Sava River basin. Four hydrologic stations are located in Bosnia and Herzegovina (BiH) and four in Serbia. We apply Sangal’s procedure to establish a correction factor for a single station analysis to produce the IDFs from MDFs. We use three annual maxima datasets at each hydrologic station, comprising: 1) IDF only, 2) MDF only, and 3) mixed IDF and MDF (officially available). We subject each dataset to flood frequency assessment using USACE HEC-SSP Bulletin 17b and 17c analysis. The results show the diversity of flood quantile estimates at each station, with the most significant differences obtained according to expected probability curve in Bulletin 17b analysis. The highest uncertainty shown as mean square error of skewness coefficient is observed at stations with large data gaps, and large number of detected low outliers. The case study revealed a potential for significant underestimation or overestimation of flood

. A truly important challenge in flood frequency assessment (FFA) in Bosnia and Herzegovina is lack of continuous gaged flow data, because the reliability of FFA results depends on the length and quality of flow records. At the case study location - hydrologic station (HS) Maglaj on the river Bosna the reference period for flow record is 1961-1990. The research goal in this paper is to exploit the water stage gauge data and information (1933-1960) for the extension of flow dataset from 30 to 58 years. We apply the original rating curve from the period 1960-1970 to the water table record to generate daily flow datasets. Anticipating three rating curve change developments, we generate six longer flow datasets -with and without instantaneous maxima, for the period 1933-1990 at HS Maglaj - Poljice. Together with two reference period flow datasets we arrive at the total of eight datasets/scenarios and subject these datasets to FFA on the annual maxima series and partial duration series. For the former, we use conventional statistical analysis (CSA) and for the latter, the peak over threshold (POT) method. The FFA results show no significant difference in the values of the selected quantiles for scenarios involving time extrapolation. The quantiles for the reference period 1961-1990 are generally higher, among both CSA and POT results. We find the absence of instantaneous maxima a major influence on FFA.

Progression independent of relapse activity (PIRA) has been described in patients with multiple sclerosis (MS) even in the earliest disease stages. Patients with PIRA show increased atrophy rates in multiple brain regions compared to stable patients. Here, we investigated whether patients with PIRA exhibit loss of integrity in WM tracts compared to stable patients. We studied 62 RRMS patients, 27 PIRA and 35 stable patients using a clinical DW-MRI protocol. Our results showed that PIRA patients present smaller FA values in areas of corpus callosum and along corticosprinal tract. These differences suggest neurodegeneration in major WM tracts of PIRA patients.

We explored the value of multiple longitudinal quantitative MRI (qMRI) measures in detecting microstructural changes occurring in normal-appearing tissue of patients with multiple sclerosis (PwMS). While no differences in qMRI longitudinal changes were measured between PwMS and healthy controls, progressive PwMS showed accelerated T1-relaxometry increase in normal-appearing tissue with respect to both healthy controls and relapsing-remitting PwMS, reflecting increased micro/macrostructural damage. In PwMS the rates of qMRI changes during follow-up were associated with the severity of clinical disability, with higher neurological impairment being associated with qMRI changes reflecting accelerated micro/macrostructural damage, demyelination, and axon/dendrite loss.

The utility of advanced quantitative MRI for assessment of spinal cord tissue damage in multiple sclerosis has not yet been established. In this work, we used T1-mapping as well as quantitative magnetization transfer saturation and echo-planar imaging to quantify the extent of pathologic changes in the cervical cord of multiple sclerosis patients. Our results point to extensive demyelination and axonal loss both in the normal-appearing and lesional cervical cord, as well as to and chronic inflammation of cSCWM lesions in secondary progressive multiple sclerosis. Hence, quantitative spinal cord MRI may provide valuable information about the pathologic substrate of this disease.

We performed an extensive assessment of the clinical relevance of a method that we had previously developed, which provides personalized quantitative MRI abnormality maps of individual multiple sclerosis (MS) patients. Specifically, we assessed the relationships between quantitative T1 (qT1), myelin water fraction (MWF), neurite density index (NDI), magnetization transfer saturation (MTsat) abnormality maps and clinical disability in a cohort of 102 MS patients and 98 healthy subjects. We found that qT1 and NDI alterations in white matter lesions were strongly related to patients' clinical disability, supporting the use of those personalized maps for patient stratification and follow-up in clinical practice.

Damage to the myelin sheath and the neuroaxonal unit are features of multiple sclerosis, as well as reparative processes for both. However, a detailed characterization of the dynamics of those in vivo is challenging. In this longitudinal study, we applied a multi-contrast quantitative MRI approach to disentangle lesion progression in vivo in patients with MS. The microstructural measures were compared between multiple sclerosis groups (55 relapsing-remitting, 24 progressive) and 34 healthy controls. Our results indicate changes in microstructural MRI measures in white matter lesions and normal appearing tissue related to myelin and axonal integrity in RRMS and PMS.