Verification of mathematical formulae applied to overhead stage canopy design

This paper presents a comparison of the experimental research concerning overhead stage canopies with a numerical approach based on selected mathematical models. The numerical predictions are made using the simplified asymptotic curves suggested by Rindel and modified by Skålevik. For singular cases a prediction with detailed calculations based on the Fresnel–Kirchhoff approximation is also given. The aim of the work is to verify proposed algorithms for designing reflective panels as well as to determine the conditions of conducting such procedures. It is shown that based on Rindel’s approximation one may determine some substantial information about sound reflection from the panels i.e. the value of upper limit frequency as well as the relative sound reflection level. On the other hand, the lower cut-off frequency should be calculated using Skålevik’s model as the value obtained from Rindel’s formula is undervalued. Such an approach could be applied to design reflective structures. However, it has some limitations for example for arrays of perturbed symmetry or sparse arrays as well as in the case of non-perpendicular angles of sound wave incidence. Then it may be necessary to apply more accurate numerical models.     

Thermoresponsive polymeric gel as a medium for examining interactions between dsDNA and an anticancer drug

A piece of dry N-isopropylacrylamide polymer was soaked in phosphate buffer to obtain a hydrogel which was then employed in the examination of interactions between an anticancer drug C-1311 (5-diethylaminoethyl-amino-8-hydroxyimidazoacridinone) and dsDNA. dsDNA was introduced into the polymer at the polymerization stage. The drug was added to the buffer. Using the volume phase transition of the gel at 40 °C, the unbound drug could be determined in the solution released during the transition, which made the calculations more reliable. The interaction parameters were calculated using the McGhee and von Hippel model. It appeared that in the gel medium, the interaction between the drug and dsDNA is spatially limited, since the number of binding units of the polymer chain occupied by one drug molecule was found to be one, while it was two in the regular buffer solution. Figure   The two authors Agata Kowalczyk and Anna M. Nowicka contributed equally to this work.     

Physicochemical and dissolution properties of ezetimibe–aspirin binary system in development of fixed-dose combinations

Journal of Thermal Analysis and Calorimetry - The objective of this work was to investigate binary pharmaceutical mixtures of ezetimibe (EZT) and aspirin (ASA) in order to identify whether the...     

AdipoRon,an Orally Active,Synthetic Agonist of AdipoR1 and AdipoR2 Receptors Has Gastroprotective Effect in Experimentally Induced Gastric Ulcers in Mice

Introduction: Adiponectin is a hormone secreted by adipocytes, which exhibits insulin-sensitizing and anti-inflammatory properties and acts through adiponectin receptors: AdipoR1 and AdipoR2. The aim of the study was to evaluate whether activation of adiponectin receptors AdipoR1 and AdipoR2 with an orally active agonist AdipoRon has gastroprotective effect and to investigate the possible underlying mechanism. Methods: We used two well-established mouse models of gastric ulcer (GU) induced by oral administration of EtOH (80% solution in water) or diclofenac (30 mg/kg, p.o.). Gastroprotective effect of AdipoRon (dose 5 and 50 mg/kg p.o.) was compared to omeprazole (20 mg/kg p.o.) or 5% DMSO solution (control). Clinical parameters of gastroprotection were assessed using macroscopic (gastric lesion area) and microscopic (evaluation of the gastric mucosa damage) scoring. To establish the molecular mechanism, we measured: myeloperoxidase (MPO), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) activities; glutathione (GSH) level; and IL-1β, adenosine monophosphate-activated protein kinase (AMPK), and phosphorylated AMPK expression in gastric tissue. Results: AdipoRon produced a gastroprotective effect in both GU mouse models as evidenced by significantly lower macroscopic and microscopic damage scores. AdipoRon exhibited anti-inflammatory effect by reduction in MPO activity and IL-1β expression in the gastric tissue. Moreover, AdipoRon induced antioxidative action, as demonstrated with higher GSH levels, and increased SOD and GPX activity. Conclusions: Activation of AdipoR1 and AdipoR2 using AdipoRon reduced gastric lesions and enhanced cell response to oxidative stress. Our data suggest that AdipoR1 and AdipoR2 activation may be an attractive therapeutic strategy to inhibit development of gastric ulcers.     

Composition of Selected Lipid Fractions in 13 Alpine Cryophytic Plant Species Growing in the Eastern Pamir Mountains,Tajikistan

Chemistry of Natural Compounds -     

Photostability of Terbinafine Under UVA Irradiation: The Effect of UV Absorbers

The photostability of drugs administered topically on unprotected skin is a complex phenomenon that could be connected with the loss of activity or, rather rarely, the occurrence of toxic degradation products. In this study, an in‐depth investigation of the photostability of terbinafine, in both solutions and formulations, was conducted, taking into account the presence of UV absorbers such as TiO₂, ZnO, avobenzone, 3‐(4‐methylbenzylidene)camphor, octocrylene, benzophenone‐1 and benzophenone‐2. The clear photocatalytic degradation of terbinafine in ethanol solution was observed in the presence of TiO₂ and/or ZnO. In other cases, terbinafine was stable, with the exception of, in the presence of octocrylene. The presumed degradation products of terbinafine were identified for the first time using LC/MS/MS, and transformation pathways were proposed. In the case of a cream formulation, the percentage of initial terbinafine content was almost unchanged in the presence of the UV absorbers benzophenone‐1, benzophenone‐2 and 3‐(4‐methylbenzylidene)camphor. In vitro cytotoxicity risk assessment of terbinafine based on photostability under UVA irradiation was evaluated using the human skin fibroblast BJ (ATCC^® CRL‐2522?), and this showed no statistically significant difference in cell viability for all samples analyzed.     

Determination of H2S and HCl concentration limits in the fuel for anode supported SOFC operation

Solid oxide fuel cell (SOFC) is an electric generator, operating based on electrochemical reaction converting gaseous fuel to electricity and heat. It is characterized by the high electrical efficiency of up to 70% with cogeneration and negligible emission of pollutants. Syngas from the biomass gasification is considered to be a possible fuel for solid oxide fuel cell systems. However, high level of contaminants such as H₂S, HCl, alkali metals, tars and particulates, in addition to possibility of carbon deposition and high temperature gradients due to internal reforming of hydrocarbons requires cleaning and conditioning of the syngas stream. The current status of the effect of contaminants on the SOFC performance has been reviewed and effects of single contaminants (H₂S, HCl) has been tested. It has been found that anode supported solid oxide fuel cell (AS-SOFC) with Ni/YSZ cermet anode can tolerate up to 1 ppm H₂S and up to 10 ppm HCl without significant performance degradation.      

Revision of structural properties of GdBO3 nanopowders doped with Eu3+ ions through spectroscopic studies

Monoclinic Gd(1-x)Eu(x)BO(3) nanopowders were successfully synthesized using a modified Pechini method. The crystal structure of the prepared materials was revised and confirmed using several techniques such as: IR, XRD, TEM, Raman spectroscopy and EDX analysis. The obtained material was comprised of particles, consisting of parts with the average size 350 nm. The luminescence properties of the prepared phosphors with different concentrations of Eu(3+) ions were characterized by excitation and emission spectra and its kinetic decay. The Judd-Ofelt parameters (Ω(2), Ω(4)), quantum efficiency, η, and chromaticity coordinates were also calculated.