Wyniki wyszukiwania - BazTech

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Spektrometria mas w analizie białek i peptydów : znaczniki jonizacyjne

Bąchor R., Biernat M., Cebrat M., Kijewska M., Kluczyk A., Kuczer M., Paluch A., Waliczek M., Wierzbicka M., Stefanowicz P., Szewczuk Z.

Wiadomości Chemiczne

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2018

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[Z] 72, 7-8

609--633

EN

High sensitivity, accuracy, and ability to provide structural information makes mass spectrometry (MS) the method of choice for both qualitative and quantitative analysis in proteome research. Peptide sequencing by tandem mass spectrometry (MS/MS) was successfully applied to discover new peptide sequences and modifications. Insufficient ionization of some peptides is one of the main limitations of MS- based peptide identification. The development of sensitive detection techniques for the efficient analysis of such samples is very important. Differences in ionizability cause difficulties in quantification studies, which could be overcome by derivatization of peptides to improve both the detectability and the selectivity of an analysis. Incorporation of ionization markers and isotopic labels (particularly the isobaric tags) is often used for this reason. Isobaric labeling reagents (including commercially available iTRAQ, TMT, DiLeu and DiART) have found a wide application in quantitative proteomics. Mass spectrometry is a very good tool for the determination of posttranslational modifications (PTMs), but the modified proteins are usually present in low concentrations. The development of ionization tags specific to a particular PTM and suitable for sensitive analysis of the modified proteins is required. For the analysis of phosphorylated peptides, a combination of β-elimination and the reaction of resulting α,β-dehydroamino acid residues with the nucleophilic thiol group could be used to detect a labile PTM. Such reaction may be used to introduce derivatizing reagents at the original site of phosphorylation, to enhance ionization in MS analysis. Glycation and glycosylation of proteins are other very important PTMs associated with many natural processes as well as diseases. We have designed and synthesized bifunctional quaternary ammonium salt derivatives of phenylboronic acids for selective detection of carbohydrates and peptide-derived Amadori products by ESI-MS. The attachment of a fixed charge (e.g. in a form of a quaternary ammonium salt) to the amino groups in peptides leads to the enhancement of a precursor ion signal in mass spectra. We have developed several new QAS-containing ionization reagents including bicyclic tags with DABCO, ABCO or azoniaspiro groups. It is worth noting that 2,4,6-substituted pyrylium salts react with amino groups in peptides introducing a stable positive charge and improve peptide detection by MS. The newly developed ionization tags were successfully applied for the analysis of OBOC combinatorial libraries as well as for studying possible biomarkers of preeclampsia, a pregnancy disorder.

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The new stand for aging of biocomponents and biofuels process testing at relatively short time

Dzięgielewski W., Kaźmierczak U., Kulczycki A., Okniński R., Stefanowicz P.

Journal of KONES

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2016

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Vol. 23, No. 2

105--112

EN

In the paper, the concept of a model bench for accelerated ageing of bio-components and biofuels was presented. It is used to simulate the ageing process of biofuels and components of vegetable or animal origin, taking place during storage in the storage tanks. The construction of the bench’s essential elements and its equipment were designed and implemented in such a way as to mostly reflect actual storage conditions in large capacity tanks. An additional and unprecedented function of the bench includes the possibility to simulate the product transport conditions. Furthermore, a method of the test, with the use of simultaneously performed traditional tests on the physical and chemical properties monitored in the process of storage was presented. An analysis of the relation between values of the parameters obtained with different methods (on the model bench and under laboratory conditions) was conducted. In addition, their usefulness to assess the impact of logistic processes on the product quality was presented. In the paper, the results of the work executed within the framework of the project “Development of a prototype of the monitoring system the ageing rate and degree of bio-components and biofuels” within the Program Innovative Economy Operational Programme, Measure 1.4. “Support for goal-oriented projects” were used.

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The method, based on storage simulator and IR – VIS spectroscopy, for predicting the allowable time of storage of biocomponents for CI engines

Dzięgielewski W., Kaźmierczak U., Kulczycki A., Okniński R., Stefanowicz P.

Journal of KONES

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2016

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Vol. 23, No. 1

115--121

EN

The paper presents the results of investigations concerning a new method used for predicting the allowable time of storage of biocomponents – FAME. The method was based on laboratory research carried out with the use of a storage tank simulator. The aging process was carried out in the conditions increasing the reaction rate – at high temperature. There are several methods/procedures used for predicting the allowable time of storage of fuels and biocomponents – FAME, but all of them are based on tests at the temperature so high that the mechanism of aging process is different than the one observed in storage tanks. It was assumed that the aging process could be divided into two stages: at the first stage, the aging precursors are created and at the second stage, precursors are converted into the fuel aging products. These products lead to changes in fuel properties. The kinetics of precursor creation determines the rate of all reactions, which lead to the final aging products. It was found that the rate of reaction at the first stage of fuel aging can be effectively increased by an increase in temperature and even relatively high temperature does not change the mechanism of the creation of aging precursors. The method that has been worked out makes it possible to control the mechanism of aging process during quick laboratory tests. The products of aging processes were detected with the use of the IR-VIS spectrometry. The allowable time of storage was determined for several FAME samples on the basis of quick laboratory tests. The results of laboratory quick tests were verified by comparing them with the results of the aging process of FAME in storage tanks. On the basis of the test results, the algorithm of allowable time of FAME storage calculation was worked out.

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Procesy starzenia chemicznego biokomponentów do paliw silnikowych w warunkach przechowywania w zbiornikach magazynowych

Dzięgielewski W., Karp G., Kaźmierczak U., Kulczycki A., Okniński R., Stefanowicz P.

TTS Technika Transportu Szynowego

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2015

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R. 22, nr 12

473--477, CD

PL

artykule omówiony został problem starzenia chemicznego biokomponentów do paliw silnikowych. Problem ten stał się ważny dla jakości benzyn i oleju napędowego w sytuacji powszechnego dodawania bioetanolu i FAME. Badaniami objęto bioetanol i FAME przechowywane w różnych warunkach w laboratorium. Zastosowano do oce-ny stopnia zestarzenia biokomponentów standardowe metody badań oraz analizę spektroskopową w zakresie IR i chromatografię gazową. Przedstawiono wyniki badań bioetanolu i FAME przechowywanych przez 1 rok oraz wyniki analiz próbek bioetanolu i FAME przechowywanych w warunkach laboratoryjnych w różnych warunkach. W wyniku przeprowadzonych badań stwierdzono, że proces starzenia bioetanolu przebiega poprzez aldehyd octowy i acetal, a FAME trójetapowo poprzez epitlenki i nadtlenki. Stwierdzono także, że zanieczyszczenia biokomponentów, tj. woda i stałe produkty korozji zbiorników magazynowych przyspieszają procesy starzenia biokomponentów.

EN

The article explains the chemical processes responsible for aging of biocomponents during their storage. This problem is import ant for quality of gasolines and diesel fuel. The study involved bioethanol and FAME stored under different conditions in the laboratory. The standard methods and IR spectroscopy as well as gas chromatography were use for aging processes assessment. The obtained results showed that aging process of bioethanol runs through aldehyde and acetal. Aging of FAME runs through three stages which comprise epioxides and peroxides. It was found that water as well as solid contaminants increase the ratio of aging processes of bioethanol and FAME.