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A new approach for the production of microspheres from oil-in-water (O/W) emulsions using supercritical fluids is presented. The composition of the emulsions, consisting of 1-monoacylglycerol (1-MAG) and polyvinylalcohol (PVA) was first optimized, then supercritical assisted atomization (SAA) was applied to produce dried microparticles. The effect of different 1-MAG/PVA ratios and emulsion preparation method on size, stability, and morphology of microparticles was investigated using scanning electron microscopy, dynamic light scattering, differential scanning calorimetry and X-ray diffraction. The emulsion composition and emulsification method affected the sizes of microparticles and the smallest 1-MAG/PVA microparticles were obtained at lower 1-MAG (<30 mg/mL) and PVA (6 mg/mL) concentrations. Prepared 1-MAG/PVA microparticles had a spherical morphology with mean diameter ranging from 0.5 to 3 μm and a semi-crystalline structure. A maximum microparticle recovery of 55% was obtained.

Dynamic light scattering (DLS) is a non-invasive technique, capable of measuring the size of submicron particles in the submicron range. The study was focused on the applicability of DLS in measurement of colloidal particles of different types. The micelle sizes of surfactants (Tween 60, Tween 20, Igepal CA 720 and Na lauryl sarcosinate) and particle sizes of micro-and nanoemulsions were measured. The diameters of surfactant micelles were 13.0±0.1 nm, 8.4±0.1 nm, 7.1±0.2 nm and 2.7±0.1 nm for Tween 60, Tween 20, Igepal CA 720 and Na lauryl sarcosinate, respectively. Stability of nanoemulsions as a consequence of the changes of particle size distributions in storage was monitored. The results revealed the presence of uni-, bi-and trimodal distributions reflecting the occurrence of various particle populations as well as a shift of distribution curves due to the particle growth. It was confirmed that DLS can provide reliable and rapid determinations of particle sizes of micro-, nano-and classical emulsions.

Antibacterial activity of stable 1-monoacylglycerol (1-MAG) microemulsions (MEs) of capric (C10:0), undecanoic (C11:0), lauric (C12:0), and myristic (C14:0) acids against the growth of gram-positive and gram-negative bacteria was tested and their inhibition effect was compared to that of neat 1-MAG. To reveal their behavior with respect to eukaryotic cells, the cytotoxicity on mouse fibroblasts was also determined. The MEs were studied via pseudo-ternary phase diagrams in order to find out the miscibility areas of all components used. The results indicated that at 1-MAG concentrations of 1000-1900mg/L, an inhibition of gram-negative strains was improved compared to neat 1-MAG and depended on the fatty acid type; however, at lower 1-MAG concentrations, both systems showed comparable effect. The opposite trend was detected on gram-positive bacteria, where 1-MAGs showed better performance compared to corresponding MEs. The best antibacterial activity against both bacterial types was observed in 1-MAG C12:0 MEs. MTT assay revealed significant cytotoxicity of all MEs. The threshold of 10mg/L was determined as the limit for moderate toxicity, which represents 40-60% cell survival. All prepared MEs were transparent, stable during the storage period of 6 months and their particle sizes were between 15 and 20nm. Practical applications: 1-MAGs belong to safe and efficient antimicrobial agents and their application may be a convenient alternative to usage of synthetic antimicrobials; however, one of their limitations for certain applications is their insolubility in aqueous systems. This drawback can be reduced by encapsulation of 1-MAGs in suitable ME system. The presented study has confirmed that 1-MAG MEs possess suitable inhibitory activity against both gram-negative and gram-positive bacteria. Efficacy of MEs against gram-negative strains was enhanced compared to 1-MAG alone. Although the growth of gram-positive bacteria was less affected by MEs when compared to neat 1-MA

In situ polymerised thin polyaniline (PANI) films produced on polystyrene dishes were tested for their antibacterial activity with respect to Escherichia coli and Staphylococcus aureus, representing both gram-positive and gram-negative bacteria. PANI films were subsequently used for the reduction of silver ions to metallic Ag. PANI salt and base in original forms and after the deposition of Ag were studied. PANI salt showed a significant antibacterial effect against both bacteria strains while the efficacy of neat PANI base was only marginal. After the Ag deposition, the PANI base exhibited different levels of antibacterial effect depending on the type of the bacterial strain; the growth of gram-positive Staphylococcus aureus was inhibited depending on the Ag concentration on the film, while Escherichia coli remained uninfluenced. Efficacy of the PANI salt with deposited Ag against both bacteria strains was comparable with that of PANI alone and was not affected by the Ag concentration. The results show that Ag deposition can be a suitable method for the preparation of PANI base films with improved antibacterial properties. (C) 2013 Institute of Chemistry, Slovak Academy of Sciences

Předmětem této diplomové práce je navrhnout efektivní komunikaci pro subjekt podnikající v cestovním ruchu, konkrétně po restaurační zařízení hotelu Zámeček. Zaměřuje se na analýzu marketingového prostředí podniku, dále na analýzu konkurence, zákazníků a také je zde zhodnocen současný marketingový mix podniku. V neposlední řadě je provedena SWOT analýza, která shrnuje důležité poznatky, týkající se vnějšího a vnitřního prostředí hotelu. Na základě všech informací je navržen projekt pro efektivní komunikaci hotelové restaurace, který obsahuje propagační plán na zvolené období a další doporučení ke zlepšení stávající pozice restaurace, a tím i celého hotelového komplexu., The purpose of this thesis is to design an effective communication for the entity doing business in the tourism sector, specifically for the restaurant of hotel Zámeček. It focuses on the analysis of marketing environment of company, as well as the analysis of competi-tors, customers, and there is assessed also the current marketing mix of hotel. Next compo-nent of thesis is a SWOT analysis, which summarizes the important findings of the external and internal environment of the hotel. On the basis of all information is created a plan for efficient communicate the hotel's restaurant, which includes a promotional plan for a selected period and other recommendations to improve the current position of restaurant and herewith also the whole hotel complex., Ústav marketingových komunikací, obhájeno

Formation, appearance, particle size and viscosity of n-undecane in water (nano)emulsions prepared by the phase inversion method using non-ionic surfactants (Igepal, Brij) were investigated. The effects of the HLB value, oil-in-water ratio (5/95 to 30/70), surfactant type and its concentration (3 and 5%) on the physico-chemical characteristics of emulsions were studied. Emulsions were characterized by visual and microscopic observations and the particle size and distribution as well as emulsion viscosity were determined. The results showed that all the variables mentioned above considerably influenced both the particle size and the viscosity. The smallest particle sizes (lower than 250. nm) and the best emulsion stability were determined at optimum HLB of 10.5 for all the studied oil-in-water ratios, both types and concentrations of surfactants. Typically, the emulsion droplets prepared with Igepals were bigger than those prepared with Brij systems.

Polyaniline (PANI) belongs to a group of conducting polymers that show numerous properties useful in biomedical applications. Although PANT has long been studied in terms of interaction with human tissue, the published studies are mostly focused on composites of polyaniline with other polymers, not allowing for generalization of the obtained results. The present study is focused on the adhesion of human liver cells to a conducting and non-conducting polyaniline films. The ability of human liver cells to attach to both types of the tested surfaces was confirmed. Cell proliferation on the PANI surfaces was monitored in relation to material biocompatibility and to its practical applications. The results showed statistically significant differences in cell proliferation depending on the type of PANT film. The study thus points out the need to test materials in their neat forms, which allow for better generalization of the test results leading to their broader applications.

The effect of the presence of colloids on formation, stability and particle size of n-undecane in water nanoemulsions prepared by the Emulsion Inversion Point (EIP) method using nonionic surfactants (Igepals) was studied. The influence of oil-to-water ratio, the HLB value and concentration of the surfactant on their physico-chemical characteristics was also investigated. The stability of emulsions was assessed from changes in the particle size and the particle size distribution as well as through visual assessment of their appearance. The results obtained show that the anticipated positive effect of the colloids on emulsion stability was not confirmed. Phase separation of these systems usually occurred soon after preparation or during a few days of their storage. The particle size of emulsions prepared in the presence of colloids was mostly bigger in comparison with emulsions where colloids were absent. Nevertheless, nanoemulsions with the particle size smaller than 200 nm were also obtained. The best long-term stability was observed in emulsions prepared at the HLB value of 11.5, oil content of 20 and 30 wt. % stored at 4 degrees C.