Evaluation of repeated measurements on 3D measuring machine Wenzel LH 54

katedra: KVS; přílohy: CD ROM; rozsah: 39 sThe diploma thesis is focused on repeated measurements of the same parts on 3D measuring co-ordinal machine Wenzel LH 54. Exploration of the effect of single indicators on accuracy of measurement, for example, temperature during measurement, cleanness of measured parts, measuring sounds and calibration of measuring sonds. Measurement in order to assesment of the process competence and production machine.Bakalářská práce pojednává o opakovaných měření stejných součástí na 3D měřícím souřadnicovém stroji Wenzel LH 54. Prozkoumání vlivu jednotlivých ukazatelů na přesnost měření, jako jsou teplota při měření, čistota měřených součástí a měřících sond a přesnost (kalibrace) měřících sond. Dalším bodem práce je provádění měření za účelem stanovení způsobilosti procesu a výrobního stroje

THE BIOELECTRIC ACTIVITY OF MUSCLE PECTORALIS MAJOR IN PRESSING FROM A LYING POSITION

The bioelectric activity of muscle pectoralis major was recorded with the help of surface EMG. The aim of this work was to determine participation of three parts of this muscle in motor task realization i.e. the pressing of a barbell in a lying position. Despite a suitable competitors’ selection (the first class) and a similar way of task realization (the 'bridge' technique) some competitors indicated a large activity in central part of the muscle whereas the others in lower or upper part. Average bioelectric activity of three parts of muscle together, in all subjects, was larger in pressing phase than in lowering phase during the press in a lying position. It may mean, that the way of trial realization is also affected by other factors, i.e. the radius of “bridge” curvature or trajectory motion of barbell

A comparison of different measurement methods of mechanical properties of Al thin films

The paper compares two different methods for testing of metallic thin films: microcompression test and nanoindentation. Microcompression test is one possibility how to perform mechanical tests on a very small scale. This method requires preparation of a small cylindrical specimen (micropillar) of micrometric size by FIB and execution of a compression test using nanoindenter device equipped with a flat diamond punch. Stressstrain curves of the thin films were obtained from such tests. Nanoindentation tests were then conducted to compare the results on the same films. Two different metal thin films - AlCuW, AlCuSi with thickness 2 mu m and grain size 3.8 mu m in average were prepared by PVD method. In this paper, we announce the results of measurements, a comparison of the results obtained by each method and identify advantages and limitations of the methods

Creation of workflows for design processes

Diplomová práce se zabývá analýzou konstrukčních procesů ve firmě Siempelkamp Bohemia. S využitím vhodného programu zmapovat procesy a pomocí vybrané metody zlepšit konstrukční procesy. Cílem práce je odhalit plýtvání v nevýrobních procesech, nalezená plýtvání eliminovat a zlepšit procesy v podniku.ObhájenoDiploma thesis deals with the analysis of design processes in the company Siempelkamp Bohemia. Using a suitable program, map the processes and use selected method to improve engineer processes. The aim of the work is reveal waste in non-production processes, eliminate wastes found and improve processe in the company

Design of MO-SPR sensor element with photonic crystal

Magneto-plasmonic response in planar multilayer with prism coupling composed from Fe/Au bi-layer supplied by photonic crystal (Ta2O5/SiO2 bi-layers) is studied. Modeled structure is intended as a sensor unit combining magneto-optical (MO) and surface-plasmon-resonance (SPR) effects. The sensitivity of MO-SPR system by small variations of analyte refractive index is tested to obtain optimal resolution ability. The non-reciprocal MO-SPR response is studied by means of the function p(phi) = (R-p((+))- R-p((-)))/(R-p((+)) + R-p((-))), where the reflectance Rp depends on the incidence angle phi and external magnetic field orientation by a fixed wavelength. The detection ability is characterized by the angular shift Delta phi(o) between the null-points of the function p that corresponds to the change Delta n(a) of analyte refractive index. Besides the key role of metallic layers thicknesses the number and size of Ta2O5/SiO2 bi-layers of photonic crystal are discussed. The magneto-plasmonic response in planar multilayer with prism coupling composed from Fe and Au bilayer supplied by photonic crystal (Ta2O5/SiO2) is studied. Modeled structure is intended as a sensor unit combining MO and SPR effects.Web of Science31807

R468A mutation in perfringolysin O destabilizes toxin structure and induces membrane fusion

Perfringolysin O (PFO) belongs to the family of cholesterol-dependent cytolysins. Upon binding to a cholesterol-containing membrane, PFO undergoes a series of structural changes that result in the formation of a β-barrel pore and cell lysis. Recognition and binding to cholesterol are mediated by the D4 domain, one of four domains of PFO. The D4 domain contains a conserved tryptophan-rich loop named undecapeptide (E458CTGLAWEWWR468) in which arginine 468 is essential for retaining allosteric coupling between D4 and other domains during interaction of PFO with the membrane. In this report we studied the impact of R468A mutation on the whole protein structure using hydrogen-deuterium exchange coupled with mass spectrometry. We found that in aqueous solution, compared to wild type (PFO), PFOR468A showed increased deuterium uptake due to exposure of internal toxin regions to the solvent. This change reflected an overall structural destabilization of PFOR468A in solution. Conversely, upon binding to cholesterol-containing membranes, PFOR468A revealed a profound decrease of hydrogen-deuterium exchange when compared to PFO. This block of deuterium uptake resulted from PFOR468A-induced aggregation and fusion of liposomes, as found by dynamic light scattering, microscopic observations and FRET measurements. In the result of liposome aggregation and fusion, the entire PFOR468A molecule became shielded from aqueous solution and thereby was protected against proteolytic digestion and deuteration. We have established that structural changes induced by the R468A mutation lead to exposure of an additional cholesterol-independent liposome-binding site in PFO that confers its fusogenic property, altering the mode of the toxin action

Crucial role of perfringolysin O D1 domain in orchestrating structural transitions leading to membrane-perforating pores: a hydrogen-deuterium exchange study.

Perfringolysin O (PFO) is a toxic protein that binds to cholesterol-containing membranes, oligomerizes, and forms a β-barrel transmembrane pore, leading to cell lysis. Previous studies have uncovered the sequence of events in this multistage structural transition to a considerable detail, but the underlying molecular mechanisms are not yet fully understood. By measuring hydrogen-deuterium exchange patterns of peptide bond amide protons monitored by mass spectrometry (MS), we have mapped structural changes in PFO and its variant bearing a point mutation during incorporation to the lipid environment. We have defined all regions that undergo structural changes caused by the interaction with the lipid environment both in wild-type PFO, thus providing new experimental constraints for molecular modeling of the pore formation process, and in a point mutant, W165T, for which the pore formation process is known to be inefficient. We have demonstrated that point mutation W165T causes destabilization of protein solution structure, strongest for domain D1, which interrupts the pathway of structural transitions in other domains necessary for proper oligomerization in the membrane. In PFO, the strongest changes accompanying binding to the membrane focus in D1; the C-terminal part of D4; and strands β1, β4, and β5 of D3. These changes were much weaker for PFO(W165T) lipo where substantial stabilization was observed only in D4 domain. In this study, the application of hydrogen-deuterium exchange analysis monitored by MS provided new insight into conformational changes of PFO associated with the membrane binding, oligomerization, and lytic pore formation

Identifying purine nucleoside phosphorylase as the target of quinine using cellular thermal shift assay

Mechanisms of action (MoAs) have been elusive for most antimalarial drugs in clinical use. Decreasing responsiveness to antimalarial treatments stresses the need for a better resolved understanding of their MoAs and associated resistance mechanisms. In the present work, we implemented the cellular thermal shift assay coupled with mass spectrometry (MS-CETSA) for drug target identification in Plasmodium falciparum, the main causative agent of human malaria. We validated the efficacy of this approach for pyrimethamine, a folic acid antagonist, and E64d, a broad-spectrum cysteine proteinase inhibitor. Subsequently, we applied MS-CETSA to quinine and mefloquine, two important antimalarial drugs with poorly characterized MoAs. Combining studies in the P. falciparum parasite lysate and intact infected red blood cells, we found P. falciparum purine nucleoside phosphorylase (PfPNP) as a common binding target for these two quinoline drugs. Biophysical and structural studies with a recombinant protein further established that both compounds bind within the enzyme's active site. Quinine binds to PfPNP at low nanomolar affinity, suggesting a substantial contribution to its therapeutic effect. Overall, we demonstrated that implementation of MS-CETSA for P. falciparum constitutes a promising strategy to elucidate the MoAs of existing and candidate antimalarial drugs.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)Nanyang Technological UniversityNational Medical Research Council (NMRC)This work was supported by NMRC MS-CETSA platform grant MOH/IAFCAT2/004/2015 to Z.B., P.N., A.L., and R.M.S.; Singapore Ministry of Education, Tier 2, MOE2015-T2-2-108 grant to Z.B.; Young Investigator Grant (YIG2015 A-STAR) to R.M.S.; Startup grant from NTU to P.N.; and grants from the Swedish Research Council and the Knut och Alice Wallenberg Foundation to P.N