National Repository of Grey Literature 9 records found  Search took 0.01 seconds. 
Preparation and characterization of food and cosmetic products containing selected vitamins
Kubošová, Jana ; Pavelková, Renata (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis deals with the preparation and characterization of encapsulated forms of lipophilic vitamins in model conditions, focusing on cosmetic and food applications. The theoretical part describes the individual vitamins, their physiological effects, physical and chemical properties, sources and sequels of hypo/hypervitaminoses. Furthermore, their contribution in medicine, food industry and cosmetics, methods of determination and in the last part of the encapsulation method are discussed. Special attention is dedicated to the technique of particles encapsulation using liposomes, which was used in the practical part. The experimental part is focused on the study of liposomes of selected substances of vitamin nature. Namely, the issue of cholecalciferol, tocopherol and -carotene was addressed, for which a suitable method of determination was introduced. Subsequently, encapsulation of these substances and characterization of the prepared liposomes took place. Their size, stability and encapsulation efficiency, which reached high percentages, were determined. Liposomes were further put to the stability tests in digestive juices and model medium simulating cosmetic products. During the measured time, the release of encapsulated substances into the surroundings and their gradual degradation was monitored. At the end of the work, analytes were extracted from real foods and cosmetic products and the measured concentrations were compared with the declared values.
Evaluation of the stability of cosmetic products
Kunertová, Aneta ; Pavelková, Renata (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with methods and parameters of evaluation of the stability of cosmetic products and application of selected tests on group of products. In the theoretical part, there are described basic types of cosmetic products. Definition of stability and characterization of two main testing types – long-term and accelerated are introduced. Selected tests are described in more detail. Another part deals with group of parameters categorized according to physical, chemical, sensory and microbiological properties observed during testing. Last parts are concentrated on influence of packaging on product stability and on evaluation. The experimental part focuses on preparation of cosmetic emulsion, its stability testing and comparison with 17 commercially available products. Among accelerated tests the cyclic test, thermal test, centrifugal test and microbial stress test are performed. It was determined that commercially available peeling C + citrus Planeta Organica has the highest stability. Satisfactory results were observed with the prepared emulsion.
Application of natural antibiotics components in hygienic gels
Kubišová, Veronika ; Pavelková, Renata (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis was focused on the preparation and characterization of gels containing a natural component exhibiting an antifungal effect. A part of this work was the research, which was focused on the description of superficial and systemic fungal diseases, antifungal drugs and plant products with a potential antifungal effect. Moreover, biologically active substances found in selected plants was described. Liposome particles that were part of the experimental part were also described and characterized. Considering the subject of this thesis was the preparation of antifungal gel, the basic characteristics of gels such as their drug delivery systems were described. Descriptions of basic methods for the determination of active substances and antifungal activity were not omitted. In the experimental part, three types of extracts (aqueous, ethanolic and lipidic) were prepared from selected plants, which were subsequntly characterized. Also, all kinds of prepared extracts were encapsulated into liposome particles, in which encapsulation efficiency, size and stability by electrokinetic potential were subsequently determined. Prepared extracts in free and encapsulated form were tested for antifungal activity, when testing was performed on Candida glabrata yeast. Moreover, the antimycotic effect of these natural substances was compared with a commercially available antifungal drug, where the drug was also tested in free and encapsulated form. Extracts in which higher active compound content and higher percent inhibitory activity of C. glabrata cells were determined were selected for incorporation into the prepared gels. The result of this work are natural-based gels that could be used to treat infectious fungal diseases. An example of a prepared gel is a gel containing a lipidic extract of marigold or containing liposomes prepared from a lipidic extract of elm pincushion.
Plant-based cosmetic products
Horváthová, Iveta ; Pavelková, Renata (referee) ; Skoumalová, Petra (advisor)
The aim of this bachelor thesis was studying an antimicrobial activity of selected herbal extracts and their encapsulated forms as liposomes. Furthemore, the thesis focuses on determonation of biologically active compounds, natural pigments and antioxidant activity. 6 kinds of herbs were studied - Humulus lupulus, Matricaria chamomilla, Taraxum officinale, Bellis Perennis, Cymbopogon citratus and Rubus Fruticosus. In teoretical part, the general characteristics of herbs and their use are described, it also includes the description of active compounds, microorganisms and used methods. Practical part is focused on characterisation of herbs from the perspective of antioxidant activity, determination of totaly phenolic content and flavonoids, chlorophyll and carotenoids. For analysis of antioxidant activity, concentration of phenolic compounds and flavonoids and antimicrobial activity aqueous and 20% ethanol extracts were prepared. Based on the obtained results, selected extracts were encapsulated into various types of liposomes consisting egg yolk, soy or sunflower lecithin. Generally, ethanol extracts showed higher content of active compounds. For chlorophyll and total carotenoid content determination the highest content of natural pigments was found in Taraxum officinale. Furthemore, antimicrobial activity of extracts and liposomes against 6 strains were determined - Micrococcus luteus, Serratia marcescens, Escherichia coli, Propionibacterium acnes, Staphylococcus epidermidis and Candida glabrata. The highest inhibitory effect was found in Matricaria chamomilla and Cymbopogon citratus samples. Encapsulation effectivity, size, stability and long-term stability of liposomes after a week and two months were determined. From the perspective of zeta potential all the particles were stable and reached a good encapsulation effectivity. It turned out that after two monts of storage the particles decomposed and active compounds into surroundings were released. Selected herbs generally had high content of antioxidants and active compouds. The most suitable lecithin for encapsulation was shown to be sunflower lecithin.
History and present state of the landscape of the former fish pond system in the drainage basin of the Opatovický kanál channel (Central and Eastern Bohemia)
Leglerová, Anna ; Lipský, Zdeněk (advisor) ; Pavelková, Renata (referee)
This work is focused on the dynamics of landscape change of fish pond system in Polabí region, specifically the drainage basin of the channel Opatovický kanál. Theoretical part provides information about origin, development and present state of fish pond system. Experimental part provides the mapping of ponds in five time periods covering the epoch between the 18th and the 21st century. Information about ponds in the 16th and the 17th century are provided as well but without pond areas. The reason for their absence is insufficiency of sources. Development of the area and quantity of ponds is discussed as well as land use and land cover change on the extinct pond areas. Finally, application of the fish pond development knowledge in landscape planning and revitalization are discussed based on the information gained by the mapping and research. Key words: fish pond systems, land cover, land use, landscape changes, Polabí region, drainage basin of the channel Opatovický kanál
Preparation and characterization of biomaterials with natural UV filtres
Pavelková, Renata ; Čarnecká, Martina (referee) ; Márová, Ivana (advisor)
This presented diploma thesis is focuses on preparation and characterization of biomaterials with natural UV filters. The theoretical part is aimed at effects of sunlight on the skin and how to avoid these effects by using cosmetic products. The materials and methods for extraction of lipid part of the selected vegetable and microorganism species and methods for preparation and characterization of nanoparticles and emulsions were characterized. The practical part deals with extraction of lipid part of selected vegetable and microorganism species. The liposome particles with encapsulated active compounds were prepared. The particle size, polydispersity index, colloidal stability, encapsulation efficiency, SPF, antioxidant capacity, phospholipid content and cytotoxic effect on human keratinocytes were observed. These particles were used for preparation of the resulting emulsions. Their protection level on UV light were set and stability were tested by using analytical centrifugation.
Application of nanoparticles and nanofibers with active compound in cosmetics
Pavelková, Renata ; Obruča, Stanislav (referee) ; Márová, Ivana (advisor)
Presented bachelor thesis is focused on application of nanoparticles and nanofibers with active compound in cosmetics. The theoretical part is aimed at effect of UV radiation on the skin and compounds that are used in photo protection of the skin. The materials and methods used in nanoparticle and nanofiber preparing were characterized. The experimental part deals with preparing of liposomes and marinosomes with active compound. Particles size, stability measured using zeta potential and stability in model environment were observed. Finally, pilot experiments of optimization of nanofibers preparation using electrospinning were carried out.
Přeměna právní formy společnosti z s.r.o. na a.s.
Pavelková, Renata ; Pelák, Jiří (advisor) ; Marešová, Zuzana (referee)
Tato diplomová práce popisuje přeměny společností se zaměřením na jednu konkrétní formu přeměny, a to na změnu právní formy společnosti. Je zde zobrazen celý proces transformace včetně popisu všech kroků. Teoretická část je doplněna ilustrací změny právní formy na společnosti Casus Direct Mail, s.r.o.

See also: similar author names
4 Pavelková, Radka
1 Pavelková, Růžena
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