A Wind Tunnel Experimental Study of Icing on NACA0012 Aircraft Airfoil with Silicon Compounds Modified Polyurethane Coatings

Ice formation on the aerodynamic surfaces of an aircraft is regarded as a major problem in the aerospace industry. Ice accumulation may damage parts, sensors and controllers and alter the aerodynamics of the airplane, leading to a range of undesired consequences, including flight delays, emergency landings, damaged parts and increased energy consumption. There are various approaches to reducing ice accretion, one of them being the application of icephobic coatings. In this work, commercially available polyurethane-based coatings were modified and deposited on NACA 0012 aircraft airfoils. A hybrid modification of polyurethane (PUR) topcoats was adopted by the addition of nanosilica and three-functional spherosilicates (a variety of silsesqioxane compound), which owe their unique properties to the presence of three different groups. The ice accretion on the manufactured nanocomposites was determined in an icing wind tunnel. The tests were performed under three different icing conditions: glaze ice, rime ice and mixed ice. Furthermore, the surface topography and wetting behavior (static contact angle and contact angle hysteresis) were investigated. It was found that the anti-icing properties of polyurethane nanocomposite coatings strongly depend on the icing conditions under which they are tested. Moreover, the addition of nanosilica and spherosilicates enabled the reduction of accreted ice by 65% in comparison to the neat topcoat.     

A blinded study assessment of the efficacy of an original formula with retinol in combination with sonophoresis

An appropriately designed cosmetic product and regimen of treatment can improve facial skin appearance and provide good tolerability. The aim of the study was to evaluate the effect of 0.3 and 0.5% retinol in liquid crystal formula, applied with sonophoresis, on mature skin. Serum with various concentrations of retinol was applied to the left and right sides of the face and treated with ultrasound. The treatments were performed once a week for a period of 7 weeks. The skin condition before and after treatment was compared using the Fotomedicus system. The Visual Analogue Scale method enabled the results to be assessed by three independent specialists. The Multi Probe Adapter system was used to evaluate the efficacy of a series of treatments. Subjective assessment of volunteers identified perceived improvement of skin conditions. In addition, treatment was associated with greater skin moisture level, reduced wrinkling and decreased skin discoloration. Mild side effects appeared mainly after the first treatment and on the left side of the face with 0.5% retinol. More significant results may be obtained by extending the treatment duration in longer‐term studies. Nonetheless, the findings confirmed the effectiveness of the procedures.     

Etiopathogenesis of Recurrent Aphthous Stomatitis and the Role of Immunologic Aspects: Literature Review

Recurrent aphthous stomatitis (RAS; recurrent aphthous ulcers; canker sores) belongs to the group of chronic, inflammatory, ulcerative diseases of the oral mucosa. Up to now, the etiopathogenesis of this condition remains unclear; it is, however, considered to be multifactorial. The results of currently performed studies indicate that genetically mediated disturbances of the innate and acquired immunity play an important role in the disease development. Factors that modify the immunologic response in RAS include: food allergies, vitamin and microelement deficiencies, hormonal and gastrointestinal disorders (e.g., celiac disease, Crohn’s disease, ulcerative colitis), some viral and bacterial infections, mechanical injuries and stress. In this paper, we presented the main etiopathogenetic factors of RAS with a special emphasis on the mechanisms of the immune response modification. Moreover, we discussed the crucial clinical symptoms and types of RAS together with epidemiologic data based on the current medical literature reports and our own observations.     

A simply and sensitive fluorometric method for determination of gentamicin in liposomal suspensions

A new method for measuring gentamicin in liposomes fluorometrically is described. The assay is based on the reaction between the amino groups in the gentamicin molecule and o-phthaldialdehyde (OPA), under basic pH conditions; the product's fluorescence can be read directly on a simple fluorimeter. The effects of several factors (time of reaction, volume of the OPA reagent, and product stability) were investigated. The standard curve was linear in the concentration range of 0.5-4.0microg, showing an excellent determination coefficient of r(2)=0.99. Additionally, the influence of different liposomal lipids on gentamicin determination was tested. Liposomal lipids containing no free amino groups (PC, Chol, DOTAP) have no influence on the reaction when present in the reaction mixture. In contrast, amino groups containing lipid (SA) showed intense method interference. Therefore, a method of lipid extraction was adapted to remove undesired lipids. The described method was successfully utilised during 2 years of liposomal gentamicin experiments.     

Cochlear implantation in autistic children with profound sensorineural hearing loss

Introduction

Cochlear implants have become the method of choice for the treatment of severe-to-profound hearing loss in both children and adults. Its benefits are well documented in the pediatric and adult population. Also deaf children with additional needs, including autism, have been covered by this treatment.

Interleukin-1 beta affects the macrophage recruitment and proliferation in the injured brain of 6-day-old rat

Six-day-old male rats received a mechanical lesion in the left cerebral hemisphere. Thereafter, a single dose of either 5, 50 or 500 units (U) of recombinant rat interleukin-1 beta (IL-1 beta) was injected into the lesion cavity. One or 2 days after the injury, the rats were injected with 3H-thymidine. Brain sections were subjected to BSI-B4 lectin histochemistry and autoradiography to visualise proliferating and non-proliferating macrophages located within the region of injury. A mitogenic effect of IL-1 beta on macrophages was observed on day 2 in brains injected with the lowest 5 U dose of cytokine. Following administration of higher 50 U and 500 U doses, infiltration of the injured tissue by macrophages was significantly intensified on day 1. However, on day 2, dose-dependent reductions of the total number of macrophages as well as their proliferative activity were recorded. The findings suggest that the higher the initial quantity of macrophages, the sooner they disappeared from the injury site. It may therefore be hypothesised that IL-1 beta-induced increase in macrophage recruitment at the beginning of the inflammatory response speeded the removal of tissue debris and, therefore, accelerated healing of the injured nervous tissue.     

A method to estimate synaptic conductances from membrane potential fluctuations

In neocortical neurons, network activity can activate a large number of synaptic inputs, resulting in highly irregular subthreshold membrane potential (V(m)) fluctuations, commonly called "synaptic noise." This activity contains information about the underlying network dynamics, but it is not easy to extract network properties from such complex and irregular activity. Here, we propose a method to estimate properties of network activity from intracellular recordings and test this method using theoretical and experimental approaches. The method is based on the analytic expression of the subthreshold V(m) distribution at steady state in conductance-based models. Fitting this analytic expression to V(m) distributions obtained from intracellular recordings provides estimates of the mean and variance of excitatory and inhibitory conductances. We test the accuracy of these estimates against computational models of increasing complexity. We also test the method using dynamic-clamp recordings of neocortical neurons in vitro. By using an on-line analysis procedure, we show that the measured conductances from spontaneous network activity can be used to re-create artificial states equivalent to real network activity. This approach should be applicable to intracellular recordings during different network states in vivo, providing a characterization of the global properties of synaptic conductances and possible insight into the underlying network mechanisms.