GLYCOGEN AND ATRIAL FIBRILLATION ATRIAL MYOCYTES CONTRACTILITY AS MECHANICAL FACTOR SHIFTING INTRACELLULAR GLYCOGEN AGAINST INTERCALATED DISCS

The purpose of this communication is to introduce in the medical literature an additional factor until now hypothesized action of atrial cells depolarization as factor in intracellular flow of glycogen molecules coalescing against the gap junctions. The demonstrated effect of gap junction blockers on paired cells contractility combined with gap junction’s selectivity towards glycogen molecules; and the visualization of contrasting intracellular glycogen images during atrial fibrillation are shown. Published data supporting atrial myocytes contraction as a mechanism in intracellular glycogen molecules migration and its deleterious effects leading into atrial fibrillation (AF) is proposed.

A Periprosthetic Femoral Fracture with Characteristics of Atypical Femoral Fracture

Although the definition of atypical femoral fracture (AFF) excludes periprosthetic femoral fracture (PFF), the number of reports about PFF with characteristics of AFF is increasing. We present the case of such a fracture in this report. An 87-year-old woman who underwent bipolar hip arthroplasty for a femoral neck fracture 38 months prior reported left thigh pain with no history of trauma. Radiographs showed a simple transverse fracture at the level of the stem distal end with features of AFF: periosteal thickening of the lateral cortex, a medial spike, and a noncomminuted fracture. She presented other features resembling AFF: history of bisphosphonate use, prodromal symptoms, no associated trauma, and lateral bowing of the contralateral femur. The fracture showed nonunion after the initial osteosynthesis, and a revision surgery of the arthroplasty and osteosynthesis was performed. Nine months after the surgery, bony union was achieved and she regained the ability to walk. It is supposed that the fracture was influenced by a stress force related to implants and lateral bowing concentrating on the fracture site as a mechanical factor in addition to bisphosphonates as a biological factor. It would be important to recognize that AFF could occur at the peri-implant location, and early detection and treatment are essential.

Limitations and potential in people on the autism spectrum in the area of mathematical skills in the light of available scientific research

The article presents basic autism terminology and the current diagnostic criteria. Then, the author focuses on presenting the findings of research on the limitations and potential of people on the autism spectrum in the area of cognitive functions and mathematical skills. The question about the abilities of people with autism remains an unsettled issue. Are the abilities of people on the autism spectrum mechanically learned skills where purely and simply a mechanical factor dominates, or is it possible to see a creative factor in this type of skills? The author is interested in children with autism learning to count. It is an important element of the development of adults and children with autism, but it has not been fully studied. There has not been enough research conducted in this area. The deliberations presented will possibly allow interested people and future researchers to take up this topic with its various aspects and areas.

Efficiency of stabilization of slag suspensions by polycarboxylate

The paper describes the method of stabilization of slag suspensions prepared on the basis of finely ground slag (FGS) with a predominant particle size of 1-7 μm, a plasticizer based on polycarboxylate (polycarboxylate). In suspension, FGS particles form two types of micelles with negative and positive surface charges. It has been established that stabilization with polycarboxylate, which is an anionic long-chain surfactant, affects slag particles with a positive surface charge. The formation of strong and elastic gel-like films on the surface of FGS leads to an increase in the structural and mechanical factor of aggregative stability of slag suspensions. Thus, the stabilization of slag particles by polycarboxylate is ensured by electrostatic, structural and mechanical factors of aggregative stability. It was established experimentally that the introduction of polycarboxylate into the aqueous dispersion medium increases the aggregative and sedimentation stability of slag suspensions. In the first period of particle sedimentation, on average, stability of slag suspensions is increased by 36 times, in the second period - 19 times, in the third period - 4 times. To ensure stability of slag suspensions, the protective number and the optimal concentration of the polycarboxylate are determined. The protective number of the suspension was 0,016 g/l; the optimal concentration of polycarboxylate - 4 g/l.

The Outburst Risk as a Function of the Methane Capacity and Firmness of a Coal Seam

In most coal basins that are currently being exploited, gas and rock outbursts pose a considerable safety threat. The risk of their occurrence is frequently assessed by means of a parameter known as the methane capacity of coal. In a lot of countries, the evaluation of the mechanical properties of coal is conducted by means of another parameter: the firmness of coal. Due to the laboratory investigations and in situ observations carried out by the authors of this paper, it was possible to determine a function space in which the outburst risk can be described as a function of the methane capacity and firmness of a coal seam. This, in turn, made it possible to link the „gas factor” to the „mechanical factor”, and thus provide a more comprehensive risk analysis.