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Room Modes in Rectangular Rooms with Complex Impedance Boundaries
Jun, David ; Plasek, Josef ; Rychtarikova, Monika ; Glorieux, Christ
In many calculation approaches in room acoustics, one models the reflection of surfaces via a positive, real absorption coefficient, neglecting the fact that the reflection coefficient can have a non-zero phase. For some sound-absorbing structures such as resonators, this simplification leads to erroneous results, e.g. when room modes are of interest.
This contribution presents an approach for the calculation of room mode frequencies in a rectangular room with complex and frequency-dependent acoustic impedance wall boundary conditions. The results are to be used for auralizations of different scenarios in which the modal behaviour of a room is modified, and for evaluation by listening tests.
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Design of Acoustic Absorbers Using Perforated Boards
Jun, David ; Stejskal, Pavel (referee) ; Kalousek, Lubor (advisor)
Perforated boards are one of the most commonly used elements for the construction of acoustic resonators in the form of walls or ceilings. This diploma thesis focuses on some aspects of the design of these perforated resonators. The main factor considered was the shape of the holes in the plate and its influence on the measured course of the sound absorption coefficient and also on its prediction by commonly available methods. The first aspect of resonator design is to measure the sound absorption coefficient. Within the work, common measurement methods are thoroughly compared and the reverberation room method, which is further used for measuring the produced samples, is presented in more detail. For the purposes of this part, our own hardware and software solution of the measuring set is also developed. Service scripts were written in the Python programming language. The second aspect of the design treated in this work is the choice of the porous infill of the resonator based on its value of airflow resistivity. This value is determined here by the static airflow method and based on the relevant standards, our own measuring device was developed for these purposes. This device was made mainly by FDM 3D printing and was operated by scripts in Python. The third and last of the design aspects described here is the prediction of the course of the sound absorption coefficient of perforated resonators. In this part, the method of electro-acoustic analogy is presented together with the transfer matrix method as described in the literature, which is further supplemented by the introduction of an equivalent radius including the effect of hole elongation in the calculation. The results obtained by the calculation are finally compared with the measurement and the optimization of the calculation is proposed in the form of adjusting the relationship for the end correction factor and for the combination of acoustic impedances of individual layers.
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Recording Studio with Accommodation in Proseč
Jun, David ; Remeš, Josef (referee) ; Kalousek, Lubor (advisor)
The thesis deals with designing a recording studio with accommodation. The object is drafted as a three-level construction built on a slightly sloping terrain. The purpose of the studio is to record primarily artificial chamber music and the accommodation space ought to be provided preferentially to the musicians involved. Attention is paid especially to the space layout and structure of the recording studio. The thesis is based on foreign literature and focuses on unique approaches to designs of absorbent and diffuse elements.
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Investigation of compouds affecting the neoplastic cell changes
Andrš, Martin ; Jun, Daniel (advisor) ; Šinkorová, Zuzana (referee) ; Vávrová, Jiřina (referee)
Radiation and genotoxic drugs after more than 70 years since their discovery still belong to the cornerstones of cancer treatment. However, these types of therapy often suffer from severe adverse effects and resistance caused by DNA repair mechanisms. The basic feature of cancer cells is genome instability, leading to various mutations and upregulated or otherwise defective DNA repair, making the cancer cells vulnerable to additional interference with the DNA damage response (DDR) mechanisms. This is the fundamental idea behind the DDR targeted therapy, which has been thoroughly studied for almost two decades. The main goals of this therapy is an improvement of the efficacy of DNA damaging treatments leading to lesser doses and adverse effects but also enabling selective targeting of defective cancer cells. The development of this area of research was very slow at the onset, but last few years it finally brought the first compound into therapy and several others into clinical trials. Among the plethora of signal and effector proteins involved in DDR, three related kinases ATM (ataxia telangiectasia mutated), ATR (ATM and Rad3-related) and DNA-PK (DNA- dependent protein kinase) play the principal roles in initiation and regulation of signaling pathways in response to DNA double and single strand...
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Synthesis and biological evaluation of purine inhibitors of phosphatidylinositol 3-kinases and related protein kinases I.
Poledníková, Michaela ; Opletalová, Veronika (advisor) ; Jun, Daniel (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Drug Control Student: Michaela Poledníková Supervisor: Assoc. Prof. RNDr. Veronika Opletalová, Ph.D. Consultant: Mgr. Martin Andrš Title of diploma thesis: Synthesis and biological evaluation of purine inhibitors of phosphatidylinositol 3-kinases and related protein kinases I. Cancer is a group of diseases characterized by the uncontrolled, abnormal growth of cells. Anticancer chemotherapy is one of the basic methods for treatment, but its mechanism of action is not specific and targets rapidly dividing cells, including cancer cells as well as certain normal tissues. In recent years one of the most studied ways to improve cancer treatment is inhibition of DNA repair mechanisms. This process can lead to potentially higher efficacy of cytotoxic therapy and thus lower doses of cytostatic agents with benefit of less adverse side effects for the patient. Suitable candidate for this purpose is family of phosphatidylinositol 3-kinase- related protein kinases (PIKK). In this diploma thesis, sixteen purine analogs of nonselective inhibitor PIKK LY294002 were prepared. We also analyzed chemo-sensitizing properties of these newly synthesized inhibitors in combination with a chemotherapeutic agent doxorubicin in...
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STUDY OF POTENTIAL PHARMACOLOGICAL PROTECTION OF CARDIAC CELLS AGAINST OXIDATIVE STRESS AND ANTRACYCLINE ANTICANCER DRUGS
Jansová, Hana ; Šimůnek, Tomáš (advisor) ; Hrdina, Radomír (referee) ; Jun, Daniel (referee)
CHARLES UNIVERSITY IN PRAGUE FACULTY OF PHARMACY IN HRADEC KRÁLOVÉ DEPARTMENT OF BIOCHEMICAL SCIENCES Candidate: Mgr. Hana Jansová Supervisor: Doc. PharmDr. Tomáš Šimůnek, Ph.D. Title of Doctoral Thesis: STUDY OF POTENTIAL PHARMACOLOGICAL PROTECTION OF CARDIAC CELLS AGAINST OXIDATIVE STRESS AND ANTRACYCLINE ANTICANCER DRUGS Development of cardiovascular disorders is associated with various risk factors and oxidative stress plays an important role in many of them. Iron-catalysed production of highly toxic and reactive hydroxyl radicals may contribute to oxidative stress. Chelation of free iron seems to be a promising strategy to prevent the propagation of oxidative stress. However, the use of classic iron chelators in pathological conditions without iron overload is associated with the risk of toxicity due to the iron depletion. Hence, this study deals with cardioprotective properties of iron chelators as well as prochelators derived from them. We focused on prochelators with almost no affinity for iron ions until they are activated under disease-specific oxidative stress conditions. For a long time, it has been assumed that oxidative stress is also the main denominator in an anthracycline-induced cardiotoxicity. However, the previous studies suggested alternative mechanism(s). Therefore in the...
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Muskarinové receptory v regulaci mechanizmů vaskulární perfúze u potkanů
Soukup, Ondřej ; Tilšer, Ivan (advisor) ; Jun, Daniel (referee)
Muscarinic receptors in the regulation of vascular perfusion mechanisms in the rat and sheep salivary glands Author: Ondřej Soukup Supervisor: Gunnar Tobin, Sahgrenska Academy,Goteborg University, Sweden Formal supervisor: Ivan Tilšer, Faculty of Pharmacy, Charles University, Czech Republic This study constists of the functional experiments, the assesment of VIP in plasma and the immunohistochemistry. Functional experiments include investigation of muscarinic receptors subtypes, their occurence and function in the rat carotid artery and jugular vein using tissue bath and muscarinic receptors agonist (carbachol) and antagonists ( pirenzepine, methoctramine, 4-DAMP). Assesment of VIP was done in the sheep plasma samples collected during 8 Hz stimulation of chorda lingual using ELISA. Immunohistochemistry of rat carotid artery and jugular vein was done using specific muscarinic antibodies and evaluated udner the fluorescence microscope. Statistical significance was determined by Student's t-test for paired data. ANOVA test in cases of multiple comparisons and post-hoc test according to Bonferoni were applied. P-values of 0.05 or less were regarded as statistically significant. The results show that muscarinic receptors have direct and indirect effect on vessels affecting the blood flow over the...
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