The paper focuses on the optimization of IEEE 802.11ax dense networks. The results were obtained with the use of the NS-3 simulator. Various network topologies were analyzed and compared. The advantage of using MSDU and MPDU aggregations in a dense network environment was shown. The process of improving the network performance for changes in the transmitter power value, CCA Threshold, and antenna gain was presented. The positive influence of BSS coloring mechanism on overal network efficiency was revealed. The influence of receiver sensitivity on network performance was determined.

Different approaches to enhance healing of hard or soft tissues include the use of cytokines and growth factors to modify cellular behaviour. Numerous growth factors are found in autologous blood concentrates – platelet-rich plasma (PRP) and platelet-rich fibrin (PRF). Enamel matrix derivative (EMD) may improve tissue healing via amelogenins. Bilayered collagen matrix (CM) is used for soft tissue augmentation.

The aim of the present study was to assess potential benefits of PRP, PRF and EMD in combination with bilayered collagen matrix or CM alone in treatment of oral mucosal defects in rabbits.

Twenty-seven New Zealand white rabbits were included in this randomized controlled trial. Artificial oral mucosal defects were treated with one of these five approaches: PRP+CM, PRF+CM, EMD+CM, CM alone, or left untreated as a negative control - CO. The animals were euthanized 1 day, 7 days, or 28 days after surgery and necropsies were harvested. Histological and molecular biological analyses were performed.

All defects were healed by day 28. No differences between PRP+CM, PRF+CM, CM alone and CO groups were recorded at any time point. Slower angiogenesis and a higher presence of inflammatory infiltrate were observed in the EMD+CM group 28 days after surgery. Molecular biological analyses did not reveal any statistically significant changes.

In conclusion, no improvement in mucosal healing of wounds covered with a collagen membrane and PRP, PRF, or EMD was observed, compared with CM alone or untreated controls.

The use of ultrasonic energy has created versatile possibilities of their applications in many areas of life, especially in hydro location and underwater telecommunications, industry and medicine. The consequence of a widespread use of high intensity ultrasonics in technology is the increased number of people who are exposed to such ultrasonic noise. Therefore it is important to determine the types of machines and other devices that are responsible for the emission of ultrasonic noise (10-40 kHz of central frequencies of one-third octave bands) as harmful and annoying hazard in the work environment. This paper presents ultrasonic noise sources frequently used in industry and preventive measures reducing the exposure to ultrasonic noise. Two types of ultrasonic noise sources have been distinguished: machines and other devices used to carry out or improve production processes, the so-called technological sources and sources in which ultrasonic noise exists as a non-intentional result of operation of many machines and systems, the so-called non-technological sources of ultrasonic noise. The emission of SPL has been determined for each groups of devices based on own measurement results.

Author presents an analytical method of calculation of unit power losses in magnetic laminations used in electrical machines and transformers. The idea of this method, based on the solution of Maxwell's equations in the lamination material, was described by the author in the previous work [3], taking into account approximation of constitutive static hysteresis loop by elliptic form of the function B = f(H) depending on magnetic saturation. In the previous formula for new isotropic and anisotropic materials it is needed to introduce so called "anomaly coefficient" deduced from the comparison of measured and calculated value of power losses in arbitrary excitation frequency for assumed induction. The method was tested by comparison with the results of experiments presented in commercial catalogues [1, 2]. Assuming superposition of harmonic power losses it is possible to enlarge this method for the estimation of overloss coefficient in dynamo sheet during axial magnetization with nonsinusoidal flux generated e.g. by PWM voltage supply.

Professor Jerzy Vetulani passed away on the 6th of April 2017. He was born on 21st January 1936 in Kraków. In 1957 he earned his B.A. in Biology and in 1963 in Chemistry from Jagiellonian University. He began to work in 1957 at the Institute of Pharmacology of the Polish Academy of Sciences in Kraków and got a PhD in 1966. Prof. Vetulani did Habiltation in Institute of Immunology and Experimental Therapy in Wrocław in 1976. His scientific career throughout all extremely active scientific life was connected with the Institute of Pharmacology. He became Head of the Department of Biochemistry in 1976 and from 1994 until 2002 he was the Deputy Director for Science Affairs and from 2002 Vice Chairman of the Scientific Council. He was elected Member of the Polish Academy of Sciences and Polish Academy of Arts and Sciences. He received a Doctor honoris causa degrees from the Medical University of Silesia and the Medical University of Łódź. He published about 240 original scientific papers in the areas of neuropharmacology and neurobiology. He was exceptional neuropharmacologist. His research, conducted together with Fridolin Sulser and his group allowed to obtain interesting data that repeatedly administered antidepressants induce adaptive changes in the noradrenergic system and to formulate a hypothesis on the mechanism of action of antidepressant drugs suggesting “downregulation” of β-adrenergic receptors. His research interests included neuropharmacology of addiction, neurodegeneration and mechanisms of memory. He was an excellent academic, admired and followed by many pharmacologists and neuroscientists. Professor Vetulani was also very active in the area of popularization of neuroscience. He was, a superb, provocative and witty speaker, someone who everybody wanted to hear. Professor Vetulani had the soul of the artist. In the late sixties, he was an announcer and one of the creators of famous Polish Kraków cabaret “Piwnica pod Baranami” (1954–1961) and more recently a regular participant in other cabaret “Gadający Pies”. Professor Jerzy Vetulani had many different talents and accompanying him always intellectual perversity and above all sense of freedom and independence.