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Interaction of platinum-based cytostatics and platinum nanoparticles with metallothionein - potencial source of the antitumor drug resistence
(TANGER, 2018-03-31) Zelníčková, Jaroslava; Nejdl, Lukáš; Richtera, Lukáš; Kopel, Pavel; Adam, Vojtěch
Platinum-based cytostatic represent a unique class of DNA-damaging antitumor agents and they are one the most frequently used drugs in oncology. Problem is that some kind of cancer is resistant against this type of cytostatics. This resistance can be potentially caused by metalloproteins such as metallothioneins. MTs belong to the group of intracellular cystine-rich, metal-binding proteins and hold a number of functions in body. One of them is detoxification of heavy metals. This ability of MTs can cause a decreased therapeutic effect of platinum-based cytostatics. In this work, the interaction between two isoforms of MTs (MT3 and MT2a) and several types of platinum cytostatics (oxaliplatin, carboplatin and cisplatin) as well as platinum nanoparticles (size of 10 and 40 nm) was examined by fluorimetric analysis using a fluorescence zinc indicator (Fluozin-3). Both, stationary fluorescence spectrometry and capillary electrophoresis with laser-induced fluorescence detection (ex - 488 nm, em - 530 nm) was used in the study.
Investigation of ammonia gas sensing properties of graphite oxide
(Elsevier, 2016-09-04) Bannov, Alexander G.; Prášek, Jan; Jašek, Ondřej; Shibaev, Alexander A.; Zajíčková, Lenka
In this paper a graphite oxide is investigated as a possible sensing layer of room temperature ammonia chemiresistive gas sensor. The sensing properties were tested in a wide range of ammonia concentrations in air (10-1000 ppm) and under different humidity levels (3-65 %). It was concluded that the graphite oxide based sensor possessed high response to NH3 in synthetic air (R/R0 ranged from 2.5 to 7.4 % for concentrations of 100-500 ppm and 3 % relative humidity) with negligible cross-sensitivity towards H2 and CH4. It was determined that the sensor recovery rate was improved with ammonia concentration growth. Increasing of ambient relative humidity led to increase of sensor response. The highest response of 22.2 % for 100 ppm of ammonia was achieved at 65 % relative humidity level.
Microfluidic Technology for Clinical Applications of Exosomes
(MDPI, 2019-06-12) Iliescu, Florina Silvia; Vrtačnik, Danilo; Neužil, Pavel; Iliescu, Ciprian
Exosomes, a type of nanovesicle, are distinct cellular entities specifically capable of carrying various cargos between cells. It has been hypothesized that exosomes, as an enriched source of biomolecules, may serve as biomarkers for various diseases. This review introduces general aspects of exosomes, presents the challenges in exosome research, discusses the potential of exosomes as biomarkers, and describes the contribution of microfluidic technology to enable their isolation and analysis for diagnostic and disease monitoring. Additionally, clinical applications of exosomes for diagnostic purposes are also summarized.
0.3V Bulk-driven current conveyor
(IEEE, 2019-05-15) Khateb, Fabian; Kulej, Tomasz; Kumngern, Montree
This paper presents the design and the experimental results of a sub 0.5 V bulk-driven (BD) current conveyor (CCII) using 0.18 µm TSMC CMOS technology with total chip area of 0.0134 mm2. All transistors are biased in subthreshold region for low-voltage low-power operation and the input transistors are controlled from their bulk terminals for rail-to-rail input voltage range. The circuit is designed to work with voltage supply (VDD = 0.3V) which is much lower than the threshold voltage of the MOS transistor (VTH=0.5V) while consuming 19 nW of power. The measurement results confirm the proper function of the proposed circuit.
Amalgam electrode-based electrochemical detector for on-site direct determination of cadmium(II) and lead(II) from soils
(MDPI, 2017-08-01) Nejdl, Lukáš; Kynický, Jindřich; Brtnický, Martin; Vaculovičová, Markéta; Adam, Vojtěch
Toxic metal contamination of the environment is a global issue. In this paper, we present a low-cost and rapid production of amalgam electrodes used for determination of Cd(II) and Pb(II) in environmental samples (soils and wastewaters) by on-site analysis using difference pulse voltammetry. Changes in the electrochemical signals were recorded with a miniaturized potentiostat (width: 80 mm, depth: 54 mm, height: 23 mm) and a portable computer. The limit of detection (LOD) was calculated for the geometric surface of the working electrode 15 mm(2) that can be varied as required for analysis. The LODs were 80 ng.mL(-1) for Cd(II) and 50 ng.mL(-1) for Pb(II), relative standard deviation, RSD <= 8% (n = 3). The area of interest (Dolni Rozinka, Czech Republic) was selected because there is a deposit of uranium ore and extreme anthropogenic activity. Environmental samples were taken directly on-site and immediately analysed. Duration of a single analysis was approximately two minutes. The average concentrations of Cd(II) and Pb(II) in this area were below the global average. The obtained values were verified (correlated) by standard electrochemical methods based on hanging drop electrodes and were in good agreement. The advantages of this method are its cost and time effectivity (approximately two minutes per one sample) with direct analysis of turbid samples (soil leach) in a 2 M HNO3 environment. This type of sample cannot be analyzed using the classical analytical methods without pretreatment.

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