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OTA Vertical File by Author
No full textThis document presents different types of OTA publications by author
A 10 fJ·K <sup>2</sup>Wheatstone Bridge Temperature Sensor with a Tail-Resistor-Linearized OTA
No full textThis article describes a highly energy-efficient Wheatstone bridge temperature sensor. To maximize sensitivity, the bridge is made from resistors with positive (silicided diffusion) and negative (poly) temperature coefficients. The bridge is balanced by a resistive (poly) FIR-DAC, which is part of a 2nd-order continuous-time delta-sigma modulator (CT Δ Σ M). Each stage of the modulator is based on an energy-efficient current-reuse OTA. To efficiently suppress quantization noise foldback, the 1st stage OTA employs a tail-resistor linearization scheme. Sensor accuracy is enhanced by realizing the poly arms of the bridge and the DAC from identical unit elements. Fabricated in a 180-nm CMOS technology, the sensor draws 55 μ W from a 1.8-V supply and achieves a resolution of 150 μ K rms in an 8-ms conversion time. This translates into a state-of-the-art resolution figure-of-merit (FoM) of 10 fJ · K2. Furthermore, the sensor achieves an inaccuracy of ±0.4 °C (3 σ) from -55 °C to 125 °C after a ratio-based one-point trim and systematic non-linearity removal, which improves to ±0.1 °C (3 σ) after a 1st-order fit.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
SMV-2015-25: Expertise of microorganisms by high-resolution electron microscopy and Raman spectroscopy
No full textDetail investigations of microorganisms surfaces and expertise of their ultrastructure was performed using an high-resolution scanning electron microscope as well as a specific sample preparation required for the imaging. Detailed chemical analysis of the samples was characterized using a Raman spectroscopy
Raman microspectroscopy of living cells and biological tissues
No full textTitle: Raman microspectroscopy of living cells and biological tissues Author: Šárka Moudříková Department / Institute: Institute of Physics of Charles University Supervisor of the doctoral thesis: doc. RNDr. Peter Mojzeš, CSc., Institute of Physics of Charles University Abstract: Raman microscopy combines Raman spectroscopy with optical confocal microscopy and thus provides information on chemical composition of a sample with a µm3 resolution. In this thesis, Raman microscopy has been used to study microalgae-unicellular photosynthetic organisms that are greatly relevant for the Earth's environment as well as for biotechnological applications. Raman microscopy of photosynthetic organisms struggles with a highly intensive background of the spectra, which is formed by fluorescence of cellular photosynthetic apparatus. In this thesis, we have developed a fast and reliable photobleaching method that suppresses the unwanted background; this method has enabled us to study intracellular distribution of algal biomolecules such as proteins, starch, lipids and polyphosphate. We have investigated an evolution of these structures during a cell cycle of a model microalga Desmodesmus quadricauda. Next, we have developed a method for quantitative analysis of polyphosphate in a cellular culture of a microalga Chlorella..
Production and characterization of biosurfactants
No full textThis diploma thesis deals with the microbial production of biosurfactants of selected bacterial strains. In order to test the biosurfactant production ability, screening methods were chosen to be able to review the potential of the selected strains to produce biosurfactants. With the scope of the work, 11 bacterial strains, which are used as polyhydroxyalkanoate (PHA) producers, have been tested. The ability to produce biosurfactants was tested in all strains both in complex inoculation and mineral production media. The presence of biosurfactants in Pseudomonas putida was detected on the basis of the results obtained after cultivation in inoculation and production media. The bacteria Pseudomonas fulva was put under more deep study to support their production by cultivation in different types of production media supplemented by different sources of carbon and nitrogen, and the effect of cultivation time was tested as well. Biosurfactants produced by these bacteria were subsequently identified by Fourier transform infrared spectroscopy (FTIR) on the basis of which the substances were identified as rhamnolipids. According to thin-layer chromatography result (TLC), Pseudomonas putida produces a mixture of mono- and dirhamnolipids, with monorhamnolipids being more dominant in our samples
Golden nanosystems for molecular detection of biological samples using Surface-Enhanced Raman Spectroscopy
No full textCitlivá a přesná detekce analytů nebo bakterií je klíčovým krokem při identifikaci nebezpečných sloučenin či patogenů, ať už v oblasti medicíny nebo bezpečnosti potravin. Využití pokročilých metod, jako je povrchově zesílená Ramanova spektroskopie (SERS), by pomohlo identifikovat bakterie nebo analyty s vysokou citlivostí a přesností. Tato diplomová práce zaměřuje na syntézu a charakterizaci kovových nanočástic (NČ) pro citlivou detekci bakterií pomocí SERS, přičemž NČ zvyšují Ramanův signál lokalizovanou plazmonovou rezonancí. Nejdříve jsou diskutovány nejnovější přístupy k syntéze plazmonických nanostruktur. Hlavní část experimentální práce tvoří syntéza zlatých (Au) a stříbrných (Ag) NČ, jejich charakterizace a využití pro analýzu chemických a biologických vzorků pomocí SERS. Nanočástice byly použity pro detekci molekul barviv (rhodamin 6G a methylenová modř), a patogenních bakterií Staphylococcus aureus a Escherichia coli, adsorbovaných na povrch syntetizovaných NČ. Dále byl replikován vysoce specifický sendvičový imunotest detekovatelný pomocí SERS. Tato metoda umožňuje rychlou a přesnou detekci patogenů. Na povrch nanočástic se pomocí interakce avidin-biotin vážou protilátky, které slouží k zachycení bakterií (E. coli a S. aureus). Ačkoli dílčí kroky protokolu byly úspešné, ověření funkce sendvičového imunotestu se doposud nezdařilo, pravděpodobně kvůli změnám v použitých chemikáliích a protilátkách. Kroky nezbytné k replikaci protokolu budou provedeny v budoucnu
Ota Pavels sagovärld [Elektronisk resurs] : Biografiska, narratologiska och språkliga perspektiv på Ota Pavels författarskap
No full textAbstractThe present dissertation analyzes the role of the fairy tale in the literary works of the Czech author Ota Pavel. Ota Pavel (1930–1973) started as a sports reporter and later became a popular and esteemed writer of fiction, mainly short stories. His works have been translated to many languages, among them Swedish.The study consists of a biographical reading of Ota Pavel’s texts and a discussion of the function of the fairy tale in his stories. My analysis of his literary development and use of various prose elements is based on narratological theories of the fairy tale – Karel Čapek’s motifs and fairytale characters, Gérard Genette’s paratexts and Vladimir Propp’s functions and dramatis personae – and includes remarks on the function of diminutives, etc. Ota Pavel is also viewed in the context of the literary landscape of his time – the 1960s and 1970s – and the reception of his work is discussed.Pavel’s stories contain a number of characteristic features which together form his unique style: direct allusions and references to fairy tales--for example, fairies and witches – and the linguistic markers and distinctive use of the narrator’s voice.One of the most common characters in Ota Pavel’s work is the hero, who, often with the assistance of magical objects or supernatural helpers, defeats supernatural antagonists or solves impossible tasks. Developing and growing as he – the hero is usually male–strives toward his goal, Pavel’s protagonist struggles not with dragons and giants, but with himself and his own difficulties and misfortunes.Earlier research refers to Ota Pavel’s two “genres”: sports prose and retrospective, or “memory” prose. This study shows that the boundary between the two is fluid, and that all Pavel’s work might be called memory prose. The title of this thesis – Ota Pavels sagovärld (The Fairytale World of Ota Pavel) – indicates the perspective from which the subject is approached. On the one hand, it alludes to the influence of the fairy tale on Pavel’s work, while on the other it points to the fact that his own life was such that he sometimes needed to retreat into a fantasy world of his own.Keywords: Tjeckisk litteratur, saga, Ota Pavel, narratologi, Tjeckoslovakien</p
Ota Pavels sagovärld : Biografiska, narratologiska och språkliga perspektiv på Ota Pavels författarskap
No full textAbstract The present dissertation analyzes the role of the fairy tale in the literary works of the Czech author Ota Pavel. Ota Pavel (1930–1973) started as a sports reporter and later became a popular and esteemed writer of fiction, mainly short stories. His works have been translated to many languages, among them Swedish. The study consists of a biographical reading of Ota Pavel’s texts and a discussion of the function of the fairy tale in his stories. My analysis of his literary development and use of various prose elements is based on narratological theories of the fairy tale – Karel Čapek’s motifs and fairytale characters, Gérard Genette’s paratexts and Vladimir Propp’s functions and dramatis personae – and includes remarks on the function of diminutives, etc. Ota Pavel is also viewed in the context of the literary landscape of his time – the 1960s and 1970s – and the reception of his work is discussed. Pavel’s stories contain a number of characteristic features which together form his unique style: direct allusions and references to fairy tales--for example, fairies and witches – and the linguistic markers and distinctive use of the narrator’s voice. One of the most common characters in Ota Pavel’s work is the hero, who, often with the assistance of magical objects or supernatural helpers, defeats supernatural antagonists or solves impossible tasks. Developing and growing as he – the hero is usually male–strives toward his goal, Pavel’s protagonist struggles not with dragons and giants, but with himself and his own difficulties and misfortunes. Earlier research refers to Ota Pavel’s two “genres”: sports prose and retrospective, or “memory” prose. This study shows that the boundary between the two is fluid, and that all Pavel’s work might be called memory prose. The title of this thesis – Ota Pavels sagovärld (The Fairytale World of Ota Pavel) – indicates the perspective from which the subject is approached. On the one hand, it alludes to the influence of the fairy tale on Pavel’s work, while on the other it points to the fact that his own life was such that he sometimes needed to retreat into a fantasy world of his own. Keywords: Tjeckisk litteratur, saga, Ota Pavel, narratologi, Tjeckoslovakie
Optical micromanipulation and Raman spectroscopy of cells in microfluidic systems
No full textThis diploma thesis deals with optimization of analysis process and measuring antibiotics induced changes in E. coli cells via Raman spectroscopy, LTRS and microfluidic systems. Optical micromanipulation by a laser beam allows noncontact and noninvasive manipulation of objects on scale 10^-5–10^-8 m, for example bacterial cells. Microfluidic device consists of microchannels and microchambers in transparent polymer and it is used for isolation, observation and cultivation of bacterial cells. Combination of these methods gives an effective tool for observation, manipulation and analysis of microorganisms. E. coli is a microorganism potentially pathogenic for humans and faster detection of its sensitivity to antibiotic treatment would make the whole process of diagnostics and treatment easier. We performed laser tweezer-Raman spectroscopy and conventional Raman spectroscopy of bacterial cells and cells under antibiotic stress and collected Raman spectra and characteristic areas were compared with literature to establish the reliability and usefulness of this method
Use of optical and microfluidic techniques for analysis and separation of microbial cells
No full textThe presented diploma thesis primarily focuses on Raman spectroscopy and its connections to microfluidic techniques, along with potentially biotechnologically interesting products of bacterial strains Janthinobacterium lividum and Azotobacter vinelandii. The methods were chosen for their non-destructive nature, which allows for rapid cell analysis and comparison with gas chromatography. After analysis, cells can be further cultivated or a generation with excessive production of a selected metabolite can be prepared. Janthinobacterium lividum is a bacterial strain that produces the pigment violacein, which has significant biotechnological potential as a drug, antioxidant, fluorescent probe, or dye. The ability to distinguish between cells producing and not producing violacein can have wide applications in diagnosis and identification. In the experimental part, the spectra of three strains were measured, based on which Janthinobacterium lividum CCM 160 was selected for analysis using Raman tweezers, along with Cupriavidus necator H16. By evaluating with principal component analysis, the distinguishability of pigmented cultures from non-pigmented ones was determined, and a potential sorting marker of 1 140 cm-1 (corresponding to violacein) was selected for further measurements. The biotechnological potential of the Azotobacter vinelandii strain lies in its ability to fix nitrogen from the atmosphere, produce alginate, and polyhydroxybutyrate. The experimental part of the thesis focuses on identifying Raman spectra of five strains and the extracted alginates from them. Polyhydroxybutyrate (PHB) is a biodegradable polymer that replaces petrochemical plastics. For PHB production, Azotobacter vinelandii is an adept for commercial production, as it is one of the few that produces PHB directly from atmospheric nitrogen, which can lead to reduced production costs and thus higher representation of degradable plastics in the market. The highest response for PHB in Raman spectra was measured for Azotobacter vinelandii DSM 720 and the lowest for Azotobacter vinelandii DSM 85. Quantitative information for comparison was obtained from gas chromatography, which confirmed the measurements from Raman spectroscopy. By evaluating the measured Raman spectra of pure alginates, it is possible to assume that they are heteropolymeric fractions, as the spectra showed the expression of various monomers. Depending on the composition of subunits, the properties of alginate change, so it is necessary to know the composition for its adjustment for further use in medicine or the food industry. From the five Azotobacter vinelandii strains, producers with the highest and lowest PHB content were selected, which were subsequently analysed using Raman tweezers. By evaluating with principal component analysis, the distinguishability of these strains and their separability using the sorting parameter of 1 060 cm-1 was determined
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