8 research outputs found

    Utilizing of Square Wave Voltammetry to Detect Flavonoids in the Presence of Human Urine

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    About biological affecting of flavonoids on animal organisms is known less,thus we selected flavonoids, flavanones and flavones, and their glycosides, which wereexamined as potential inducers of cytochrome(s) P450 when administrated by gavages intoexperimental male rats. The study was focused on induction of CYP1A1, the majorcytochrome P450 involved in carcinogen activation. The data obtained demonstrate thenecessity of taking into account not only ability of flavonoids to bind to Ah receptor(induction factor) but also to concentrate on their distribution and metabolism (includingcolon microflora) in the body. After that we examined certain flavonoids as potential inducers of cytochrome P450, we wanted to suggest and optimize suitable electrochemical technique for determination of selected flavonoids (quercetin, quercitrin, rutin, chrysin and diosmin) in body liquids. For these purposes, we selected square wave voltannetry using carbon paste electrode. Primarily we aimed on investigation of their basic electrochemical behaviour. After that we have optimized frequency, step potential and supporting electrolyte. Based on the results obtained, we selected the most suitable conditions for determination of the flavonoids as follows: frequency 180 Hz, step potential 1.95 mV/s and phosphate buffer of pH 7 as supporting electrolyte. Detection limits (3 S/N) of the flavonoids were from units to tens of nM except diosmin, where the limit were higher than μM. In addition, we attempted to suggest a sensor for analysis of flavonoids in urine. It clearly follows from the results obtained that flavonoids can be analysed in the presence of animal urine, because urine did not influence much the signals of flavonoids (recoveries of the signals were about 90 %)

    ELECTROCHEMICAL SCIENCE Femtogram Electroanalytical Detection of Prostatic Specific Antigen by Brdicka Reaction

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    Prostatic-specific antigen is considered as the best marker for prostate cancer. Due to the importance of PSA for diagnostic purposes it is not surprising that there are tested and optimized various methods for its determination. In spite of such intensive research in the field of electrochemical detection of some by-products connected with concentration of PSA, electrochemical behaviour of PSA has not been studied yet. The aim of this study was to investigate electrochemical catalytic signals of PSA using differential pulse voltammetry Brdicka reaction. The catalytic signals were studied using adsorptive transfer stripping technique as well as directly in the electrochemical cell. Nevertheless, we primarily tested detection of PSA by standard immunoanalysis and by gel and capillary chip electrophoresis to investigate behaviour of this protein in electric field. Both electrophoretic methods showed that the most intensive band of PSA was determined at 37 kDa under reducing conditions and at 26 kDa under non-reducing. Band at 37 kDa corresponds to a reduced, and at 26 kDa to non-reduced PSA. Studying of basic electrochemical behaviour of PSA was primarily carried out using standard electrochemical cell and HMDE as a working electrode. Co(NH 3

    Chování komplexů zinku a nanočástic a nanočástic sulfidu zinečnáteho s použitím tištěných elektrod a spektrometrie

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    In this study, we focused on microfluidic electrochemical analysis of zinc complexes (Zn(phen)(his)Cl-2, Zn(his)Cl-2) and ZnS quantum dots (QDs) using printed electrodes. This method was chosen due to the simple (easy to use) instrumentation and variable setting of flows. Reduction signals of zinc under the strictly defined and controlled conditions (pH, temperature, flow rate, accumulation time and applied potential) were studied. We showed that the increasing concentration of the complexes (Zn(phen)(his)Cl-2, Zn(his)Cl-2) led to a decrease in the electrochemical signal and a significant shift of the potential to more positive values. The most likely explanation of this result is that zinc is strongly bound in the complex and its distribution on the electrode is very limited. Changing the pH from 3.5 to 5.5 resulted in a significant intensification of the Zn(II) reduction signal. The complexes were also characterized by UV/VIS spectrophotometry, chromatography, and ESI-QTOF mass spectrometry.V této studii jsme se zaměřili na mikrofluidní elektrochemickou analýzu komplexů zinku (Zn (fenyl) (jeho) Cl-2, Zn (jeho) Cl-2) a ZnS kvantové tečky (QDS) za použití tištěných elektrod. Tato metoda byla zvolena z důvodu jednoduchému (snadné použití přístrojového vybavení) a variabilnímu nastavení toků. Byly studovány signály Redukční zinku v rámci přísně definovaných a kontrolovaných podmínek (pH, teplota, průtok, doba akumulace a aplikované potenciál). Ukázali jsme, že zvyšující se koncentrace komplexů (Zn (phen) (jeho) Cl-2, Zn (jeho) Cl-2) vede ke snížení elektrochemického signálu a významný posun potenciálu na více pozitivních hodnot. Nejpravděpodobnějším vysvětlením tohoto výsledku je, že zinek je silně vázána v komplexu a jeho rozložení na elektrodě je velmi omezený. Změna pH 3,5-5,5 vedlo k významnému zesílení Zn (II) signálu snížení. Komplexy byly také charakterizovány pomocí UV spektrofotometrie / VIS, chromatografie a ESI-QTOF hmotnostní spektrometrií. (Přeloženo strojově

    Benchmarking of survival outcomes following Haematopoietic Stem Cell Transplantation (HSCT): an update of the ongoing project of the European Society for Blood and Marrow Transplantation (EBMT) and Joint Accreditation Committee of ISCT and EBMT (JACIE)

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    From 2016 EBMT and JACIE developed an international risk-adapted benchmarking program of haematopoietic stem cell transplant (HSCT) outcome to provide individual EBMT Centers with a means of quality-assuring the HSCT process and meeting FACT-JACIE accreditation requirements relating to 1-year survival outcomes. Informed by previous experience from Europe, North America and Australasia, the Clinical Outcomes Group (COG) established criteria for patient and Center selection, and a set of key clinical variables within a dedicated statistical model adapted to the capabilities of the EBMT Registry. The first phase of the project was launched in 2019 to test the acceptability of the benchmarking model through assessment of Centers’ performance for 1-year data completeness and survival outcomes of autologous and allogeneic HSCT covering 2013–2016. A second phase was delivered in July 2021 covering 2015–2019 and including survival outcomes. Reports of individual Center performance were shared directly with local principal investigators and their responses were assimilated. The experience thus far has supported the feasibility, acceptability and reliability of the system as well as identifying its limitations. We provide a summary of experience and learning so far in this ‘work in progress’, as well as highlighting future challenges of delivering a modern, robust, data-complete, risk-adapted benchmarking program across new EBMT Registry systems
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