50 research outputs found

    FireProt(DB): database of manually curated protein stability data

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    The majority of naturally occurring proteins have evolved to function under mild conditions inside the living organisms. One of the critical obstacles for the use of proteins in biotechnological applications is their insufficient stability at elevated temperatures or in the presence of salts. Since experimental screening for stabilizing mutations is typically laborious and expensive, in silico predictors are often used for narrowing down the mutational landscape. The recent advances in machine learning and artificial intelligence further facilitate the development of such computational tools. However, the accuracy of these predictors strongly depends on the quality and amount of data used for training and testing, which have often been reported as the current bottleneck of the approach. To address this problem, we present a novel database of experimental thermostability data for single-point mutants FireProt(DB). The database combines the published datasets, data extracted manually from the recent literature, and the data collected in our laboratory. Its user interface is designed to facilitate both types of the expected use: (i) the interactive explorations of individual entries on the level of a protein or mutation and (ii) the construction of highly customized and machine learning-friendly datasets using advanced searching and filtering. The database is freely available at https://loschmidt.chemi.muni.cz/fireprotdb

    Speciation Analysis of Arsenic by Selective Hydride Generation-Cryotrapping-Atomic Fluorescence Spectrometry with Flame-in-Gas-Shield Atomizer: Achieving Extremely Low Detection Limits with Inexpensive Instrumentation

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    This work describes the method of a selective hydride generation-cryotrapping (HG-CT) coupled to an extremely sensitive but simple in-house assembled and designed atomic fluorescence spectrometry (AFS) instrument for determination of toxicologically important As species. Here, an advanced flame-in-gas-shield atomizer (FIGS) was interfaced to HG-CT and its performance was compared to a standard miniature diffusion flame (MDF) atomizer. A significant improvement both in sensitivity and baseline noise was found that was reflected in improved (4 times) limits of detection (LODs). The yielded LODs with the FIGS atomizer were 0.44, 0.74, 0.15, 0.17 and 0.67 ng L–1 for arsenite, total inorganic, mono-, dimethylated As and trimethylarsine oxide, respectively. Moreover, the sensitivities with FIGS and MDF were equal for all As species, allowing for the possibility of single species standardization with arsenate standard for accurate quantification of all other As species. The accuracy of HG-CT-AFS with FIGS was verified by speciation analysis in two samples of bottled drinking water and certified reference materials, NRC CASS-5 (nearshore seawater) and SLRS-5 (river water) that contain traces of methylated As species. As speciation was in agreement with results previously reported and sums of all quantified species corresponded with the certified total As. The feasibility of HG-CT-AFS with FIGS was also demonstrated by the speciation analysis in microsamples of exfoliated bladder epithelial cells isolated from human urine. The results for the sums of trivalent and pentavalent As species corresponded well with the reference results obtained by HG-CT-ICPMS (inductively coupled plasma mass spectrometry)

    Selective hydride generation-cryotrapping-ICP-MS for arsenic speciation analysis at picogram levels: analysis of river and sea water reference materials and human bladder epithelial cells

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    An ultra sensitive method for arsenic (As) speciation analysis based on selective hydride generation (HG) with preconcentration by cryotrapping (CT) and inductively coupled plasma- mass spectrometry (ICP-MS) detection is presented. Determination of valence of the As species is performed by selective HG without prereduction (trivalent species only) or with L-cysteine prereduction (sum of tri- and pentavalent species). Methylated species are resolved on the basis of thermal desorption of formed methyl substituted arsines after collection at −196°C. Limits of detection of 3.4, 0.04, 0.14 and 0.10 pg mL−1 (ppt) were achieved for inorganic As, mono-, di- and trimethylated species, respectively, from a 500 μL sample

    XXIV. mezinárodní kolokvium o regionálních vědách

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    Title in English: 24th International Colloquium on Regional Sciences: Conference proceedings. The conference proceedings consists of papers presented at the 24rd International Colloquium on Regional Sciences that was organized by Department of Regional Economics and Administration FEA MU. It contains 79 articles arranged by topic. The individual articles deal with e.g. socioeconomic disparities among regions, regional policy, territory attractiveness, tourism or regional public administration

    Gold chemical vapor generation by tetrahydroborate reduction for AAS: Radiotracer efficiency study and characterization of gold species

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    The main objective was to assess the generation efficiency in the optimized method of chemical vapor generation of gold by means of 198,199Au radioindicator. We also intended to characterize the volatile Au species formed by tetrahydroborate reduction

    Contributions to Volatile Compound Generation of Arsenic, Silver and

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    (EN) The presented dissertation thesis summarizes the results contained in five original research papers that were published in prestigious international scientific journals in the field of analytical chemistry and atomic spectrometry. It is devoted to the method of generation of volatile compounds using a tetrahydroborate reaction and detection in a quartz multiatomizer by atomic absorption spectrometry. The thesis can be divided into two thematic parts - speciation analysis of arsenic based on hydride generation technique with collection and separation in a cryogenic trap and generation of volatile species of transition metals. In the first thematic part pre-reduction of pentavalent inorganic and methylated arsenicals has been studied. A simple setup for on-line pre-reduction employing thioglycolic acid as a fast pre-reductant has been developed, connected with a current hydride generator and applied/verified to oxidation state specific arsenic speciation analysis of human urine samples. In the same method the possibility of drying the gaseous phase from water vapor has been investigated to avoid incidental blocking the cryogenic trap by frozen water and to decrease fluctuations of signal baseline. Pronounced losses of methylated species have been discovered on Nafion tube dryer currently used in..

    Former Monastery of Order of Minims nearby Nová Bystřice

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    This thesis deals with the establishment of the Paulans order, and his activities at Czech, establishment of the Paulans monastery of the Holy Trinity by Nová Bystřice. It describes the important circumstances of the paulans monkery arrival to this convent. Thesis also observe the termination of the convent in 1533 and his new establishment in 1626 and following 200 years of this greatest properity. Then it also describes the final termination of the convent in 1785, caused by the reforms of emperor Josef II
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