|
|
Biochemical analyses of the DNA interaction partners
Valchová, Michaela ; Coufal,, Jan (referee) ; Brázda, Václav (advisor)
This thesis was focused on DNA analysis. The fluorescently labelled oligonucleotides were at first hybridised and subsequently analysed by HRM analysis to determine the melting temperatures of the oligonucleotides depending on the environment. This thesis describes the change of melting temperature of oligonucleotides in environments containing mono and bivalent ions and the influence of protein binding on the stability of these DNA structures. From determined melting points, it was specified whether the ion/protein stabilised or destabilised the oligonucleotide. Furthermore, plasmids were isolated and analyzed by atomic force microscopy.
|
|
|
P53 protein isoforms production and purification in the bacterial expression system
Vadovičová, Natália ; Obruča, Stanislav (referee) ; Brázda, Václav (advisor)
Apart from the p53 protein, the TP53 tumor-suppressor gene is expressed as another eleven protein isoforms with the use of alternative splicing, alternative promotors and alternative translational initiation sites. Abnormal expression of these isoforms has been observed in tumor tissues. The binding properties as well as the biological functions are also modulated, due to sequential and therefore structural differences from the p53 protein. p53 is regulated by these isoforms in both suppressive and supportive manner. Explanation of the p53 isoform regulation mechanism in cells could lead to desired alternative splicing of the chosen isoforms, and modulation of isoform expression could be used in cancer treatment based on p53 therapy. Basic information about p53 protein is summarised in the theoretical part of this master thesis, supplemented with recent advances in the field of p53 isoforms, as well as the Gateway cloning method. The main goal of the experimental part was p53 isoform production in a bacterial expression system. Prior to the protein production, DNA sequences coding twelve p53 isoforms were prepared using PCR and Gateway cloning. In total, twelve entry clones and eight expression clones were prepared by cloning the isoforms’ sequences. After the protein production and purification, the detection using SDS-PAGE and Western Blotting was performed with five p53 protein isoforms: p53, 40p53, 40p53 and 40p53. DNA binding properties of p53 protein isoforms will be tested in subsequent research.
|
|
|
Biological effects of substances isolated from Isoptera species
Dušková, Simona ; Hrstka, Miroslav (referee) ; Brázda, Václav (advisor)
This thesis was focused on monitoring the viability of eukaryotic and prokaryotic cells after exposure of termites-isolated chemicals. Recently, evidence of antibacterial and antifungal properties of these defense substances has grown, and they can find a wide range of uses not only in the pharmaceutical industry. In this work, three defensive substances from termites were studied: nerolidol, nitropentadecene and methylanthranilate. Their antibacterial effects, minimal inhibitory concentrations and minimal bactericidal concentrations against Escherichia coli STBL3 strain were monitored. Further, their cytotoxic effects on eukaryotic non-tumor (HEK293FT) and tumor cells (MCF7) as well as their effect on plasmid DNA were studied. Antibiotic ampicillin and cytostatic cisplatin were used as control substances for antibacterial and cytotoxic effects, respectively. In the case of the action of nerolidol, nitropentadecene and methylanthranilate on the STBL3 strain, antibacterial activity was not demonstrated. Cytotoxic effects were observed nerolidol and nitropentadecene. None of the examined substances modified the plasmid DNA.
|
|
|
Earth-space path propagation characteristics in the climatic conditions of the Czech Republic from Alphasat Ka/Q band experiment
Fišer, Ondřej ; Brázda, Vladimír ; Pešice, Petr ; Grabner, M.
The objective of the activity is to prepare, realize and conduct experimental research of the influence of atmospheric phenomena on the Earth-space path propagation characteristics at 20 and 40 GHz (Ka/Q) bands in the specific climatic conditions of the Czech Republic (CR). The scientific approach is based on the comprehensive measurements of physical parameters of atmosphere together with concurrent measurements of propagation characteristics on the Earth-space path and on 10 collocated terrestrial paths with star configuration. The proposed activity will utilize the ESA Alphasat Mission Ka/Q experiment that is designed to investigate the propagation characteristics on slant paths in Europe and elsewhere.
|
|
| |
|
|
On Forward and Backward Scattering from Fog and Rain Drops
Fišer, O. ; Rejfek, Luboš ; Brázda, Vladimír
This contribution deals with the backward and forward scattering on dielectrical spheres. The well-known Rayleigh, Mie and Optical regions are discussed for frequencies regions 0.05 to 70 GHz and for optical wavelength of 830 nm. Some of our results fit the published one, some of them are different and the explanation of possible reasons is added. Also the formulas necessary to compute the radar reflectivity or attenuation due to fog and rain are presented.
|
|
|
Device for Measurement of Optical Visibility
Rejfek, L. ; Brázda, V. ; Fišer, Ondřej
This paper is about a proposed device for the optical visibility measurement. This device is usable for monitoring of the fog mightiness. The principle of device is based on comparison of attenuation on two optical links. The fog mightiness is determined by the using of the Beer-Lambert Law. The philosophy of electrical arrangement is also explained.
|
|
|
Applied research at the Institute of Atmospheric Physics Prague
Fišer, Ondřej ; Jaroš, J. ; Brázda, V.
This article describes the research performed at the Milesovka observatory. The base of this research is the measurement of the signal attenuation on the experimental free space optic link. Concurrently the pertinent meteorological parameters are measured and compared to the attenuation. First of all, visibility, liquid water content, wind speed + other wind parameters and rain rate are sampled and statistically evaluated including diurnal variations.
|
|
|
Rain impact on FSO link attenuation based on theory and measurement
Brázda, V. ; Schejbal, V. ; Fišer, Ondřej
The FSO link becomes a usual mean of modern wireless communications. But it suffers from atmospheric particles causing attenuation. That´s why this random attenuation must be carefully considered by the FSO link design. As it is known the most serious atmospheric phenomenon is fog, and low cloudiness. But the rain attenuation (night mare of mm wave links) is not negligible on optical links, too. In this contribution we focus on rain attenuation from theoretical as well as experimental point of view. Statistics and rain event analysis are shown. There is an overview and a comparison of several formulas for rain attenuation derived from DSD or rain rate. Rain is not the worst phenomena for the transmission but we can’t neglect its influence on FSO. Only full understanding of influence of real atmosphere can lead to solution of a high availability of FSO systems.
|
|
| |
guest ::
