Properties of DNA-CTMA monolayers obtained by Langmuir-Blodgett technique

The complex consisting of DNA and cetyltrimethylammonium chloride (DNA-CTMA) is extensively exploited in organic electronics in form of thin films with submicron or nanometer thickness. In this work, using the Langmuir-Blodgett technique, the surface films were prepared from complexes based on different types of chromosomal and plasmid DNA. The research focused on changes in their continuity after they were transferred onto a solid substrate. It was found that only the monolayer of plasmid DNA-CTMA complex remained continuous after being transferred. The other complexes underwent a spontaneous self-assembling and created elongated linear patterns. AFM images of these patterns were analysed quantitatively with Fast Fourier Transform. It was confirmed that self-assembling occurred along one privileged direction

Optimization of the process for producing DNA-CTMA thin fims for use in organic electronic devices

Głównym celem niniejszej pracy była optymalizacja procesu wynoszenia cienkich warstw kompleksu DNA-CTMA. W ramach badań przeprowadzono charakterystykę materiału wyjściowego (DNA) metodą elektroforezy a stabilność kompleksu DNA-CTMA na granicy faz ciecz-gaz została zbadana przy użyciu wagi Langmuira. Zastosowano dwa sposoby nanoszenia cienkich warstw kompleksów DNA-CTMA: metodę Langmuir-Blodgett (LB) i warstwa po warstwie (LbL). W oparciu o grubości warstw kompleksu otrzymanego tymi dwoma metodami stwierdzono, że metoda LbL lepiej nadaje się do wynoszenia cienkich filmów DNA-CTMA o potencjalnych zastosowaniach w elektronice organicznej.The aim of present thesis was to optimize the process of formation thin films of DNA-CTMA complex, which is a promising material for organic electronic applications. The characteristics of native DNA, conducted by electrophoresis method, allowed to determine the approximate molar mass of that biomolecule. The native DNA was successfully used to synthetize DNA-CTMA complex. The monolayer of DNA-CTMA complex formed at the air/water interface was further examined using the Langmuir monolayer technique and Brewster angle microscopy (BAM). Additionaly DNA-CTMA complex was transferred on solid support and analysed by using atomic force microscopy (AFM) as well as ellipsometry

Studies of the properties of liquid crystal on the potential use in a new generation of Liquid Crystals Displays

Motywacja do podjęcia badań było zbadanie właściwości nowego ciekłego kryształu (w skrócie (S)-MHBOS5) pod katem jego zastosowania w wyświetlaczach ciekłokrystalicznych (LCD) nowej generacji. Badany związek wykazuje bogaty polimorfizm, co stwierdzono metodami różnicowej kalorymetrii skaningowej (DSC) i mikroskopii polaryzacyjnej. Dodatkowo, zmierzono wartość spontanicznej polaryzacji i czasu przełączania podczas ochładzania. Stwierdzono, że MHBOS5 wykazuje dobrą stabilność termiczną ferroelektrycznej fazy SmC*, szybkie przełączanie i dobrą wartość spontanicznej polaryzacji z punktu widzenia jej zastosowania w LCD. Z drugiej strony ferroelektryczna faza SmC* występuje w wysokim zakresie temperatur, co oznacza, że badany związek jest obiecujący jedynie jako składnik mieszaniny wieloskładnikowej do potencjalnego zastosowania w LCD nowej generacji.Motivation of this work was to study properties of new liquid crystal (in short (S)-MHBOS5) for its application in new generation of Liquid Crystal Displays (LCDs). The compound studied exhibits rich polymorphism what was detected by Differential Scanning Calorimetry (DSC) and polarizing microscopy methods. Additionally, spontaneous polarization and switching time was measured at cooling. It was finding that MHBOS5 shows good thermal stability of ferroelectric SmC* phase, fast switching and proper value of spontaneous polarization from application point of view. On the other hand the ferroelectric SmC* phase exists at high temperature range what means that compound studied is promising as component of the multi-component mixture for potential application in new generation of LCDs

Endocrine Effect of Some Mycotoxins on Humans: A Clinical Review of the Ways to Mitigate the Action of Mycotoxins

Fungi such as Aspergillus spp. and Fusarium spp., which are commonly found in the environment, pose a serious global health problem. This study aims to present the results of epidemiological studies, including clinical cases, on the relationship between human exposure to some mycotoxins, especially zearalenone and aflatoxin, and the occurrence of reproductive disorders. In addition, examples of methods to reduce human exposure to mycotoxins are presented. In March 2023, various databases (PubMed, Google Scholar, EMBASE and Web of Science) were systematically searched using Google Chrome to identify studies evaluating the association between exposure to mycotoxins and the occurrence of complications related to impaired fertility or cancer incidence. The analysed data indicate that exposure to the evaluated mycotoxins is widespread and correlates strongly with precocious puberty, reduced fertility and increased cancer incidence in women and men worldwide. There is evidence to suggest that exposure to the Aspergillus mycotoxin aflatoxin (AF) during pregnancy can impair intrauterine foetal growth, promote neonatal jaundice and cause perinatal death and preterm birth. In contrast, exposure to the Fusarium mycotoxin zearalenone (ZEA) leads to precocious sexual development, infertility, the development of malformations and the development of breast cancer. Unfortunately, the development of methods (biological, chemical or physical) to completely eliminate exposure to mycotoxins has limited practical application. The threat to human health from mycotoxins is real and further research is needed to improve our knowledge and specific public health interventions