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  • Pozycja
    The impact of transcription factors Znf1, Sip4, Adr1, Tup1, and Hap4 on xylose alcoholic fermentation in the engineered yeast Saccharomyces cerevisiae
    (Springer Nature, 2021-06-15) Dzanaeva, Ljubov; Kruk, Barbara; Ruchala, Justyna; Sibirny, Andriy; Dmytruk Kostyantyn
    Lignocellulosic biomass is an attractive sustainable platform for fuel ethanol production. Xylose is a second after glucose most abounded sugar in lignocellulosic hydrolysates. Effective conversion of xylose to ethanol is one of key prerequisite for the development of an efficient conversion of biomass to ethanol. Engineered Saccharomyces cerevisiae strains are able to xylose fermentation. However, the yield and productivities of xylose fermentation remains lower in comparison with glucose fermentation. In this work, we studied impact of transcription factors Znf1, Sip4, Adr1, Tup1, and Hap4 on xylose catabolism. We have isolated znf1Δ, adr1Δ, tup1Δ and hap4Δ mutants, and strains overexpressing SIP4, ADR1 and HAP4 genes on the background of xylose-fermenting strain of S. cerevisiae aiming to explore involvement of these transcription factors in regulation of xylose growth and fermentation. It was shown that hap4Δ reveal 1.8-fold increase of ethanol production from xylose as compared to that of parental strain. The hap4Δ mutant accumulates 10.38 g l−1 of ethanol with an overall ethanol yield reaching 0.41 g g−1 of consumed xylose. While the other constructed strains revealed a decrease in ethanol production from this pentose.
  • Pozycja
    Non-targeting siRNA-mediated responses are associated with apoptosis in chemotherapy-induced senescent skin cancer cells
    (Chemico-Biological Interactions, 2023-01-05) Betlej, Gabriela; Błoniarz, Dominika; Lewińska, Anna; Wnuk, Maciej
    It is widely accepted that siRNA transfection can promote some off-target effects in the genome; however, little is known about how the cells can respond to the presence of non-viral dsRNA. In the present study, non-targeting control siRNA (NTC-siRNA) was used to evaluate its effects on the activity of pathogen and host-derived nucleic acid-associated signaling pathways such as cGAS-STING, RIG-I, MDA5 and NF-κB in A431 skin cancer cells and BJ fibroblasts. NTC-siRNA treatment promoted cytotoxicity in cancer cells. Furthermore, NTC-siRNA-treated doxorubicin-induced senescent cancer cells were more prone to apoptotic cell death compared to untreated doxorubicin-induced senescent cancer cells. NTC-siRNA stimulated the levels of NF-κB, APOBECs, ALY, LRP8 and phosphorylated STING that suggested the involvement of selected components of nucleic acid sensing pathways in NTC-siRNA-mediated cell death response in skin cancer cells. NTC-siRNA-mediated apoptosis in cancer cells was not associated with IFN-β-based pro-inflammatory response and TRDMT1-based adaptive response. In contrast, in NTC-siRNA-treated fibroblasts, an increase in the levels of RIG-I and IFN-β was not accompanied by affected cell viability. We propose that the use of NTC-siRNA in genetic engineering may provoke a number of unexpected effects that should be carefully monitored. In our experimental settings, NTC-siRNA promoted the elimination of doxorubicin-induced senescent cancer cells that may have implications in skin cancer therapies.
  • Pozycja
    Review of the development of copper oxides with titanium dioxide thin-film solar cells
    (2020) Sawicka-Chudy, Paulina; Sibiński, Maciej; Rybak-Wilusz, Elżbieta; Cholewa, Marian; Wisz, Grzegorz; Yavorskyi, Rostyslav
    Copper oxide-titanium dioxide (TiO2) p–n junctions are promising materials for photovoltaic devices and may reduce production costs due to their low cost and inexpensive production methods compared with silicon solar cells. The present review compares solar cells made with copper oxides combined with TiO2–TiO2/Cu2O and TiO2/CuO heterojunctions, and “cascade heterojunction systems.” First, we describe the main properties of titanium (iv) dioxide (TiO2), cuprous oxide (Cu2O), and cupric oxide (CuO), and their potential applications. Next, we explain the concept of copper oxide and TiO2 heterojunctions. We summarize and present the photovoltaic characteristics (efficiency, fill factor, circuit current density, and open circuit voltage), thickness, preparation method, and electrode type for solar cells comprising copper oxide and TiO2. The efficiency of the solar cells ranged from 0.0005% to 1.62%. The thickness of the TiO2 and cupric oxide layers ranged from 0.06 to 16 µm, and from 0.18 to 1.5 µm, respectively, depending on the fabrication method. Additionally, we review and discuss the available combinations of copper oxide with other materials (Cu2O with ZnO, CuO with ZnO, and CuO with Si), as well as the effect of the thickness of the copper (i) oxide and copper (ii) oxide on the solar cell performance. Finally, we present aspects to improve the conversion efficiency of heterojunction solar cells with copper oxides combined with TiO2. This review will be useful for the construction and further development of thin-film solar cells.
  • Pozycja
    Characteristics of TiO2, Cu2O, and TiO2/Cu2O thin films for application in PV devices
    (AIP Advance, 2019) Sawicka-Chudy, Paulina; Sibiński, Maciej; Pawełek, Ryszard; Wisz, Grzegorz; Cieniek, Bogumił; Potera, Piotr; Szczepan, Patryk; Adamiak, Stanisław; Cholewa, Marian; Głowa, Łukasz
    Several Cu2O and TiO2 thin films and four additional TiO2/Cu2O structures were fabricated by direct current (DC) magnetron sputtering. The process parameters were selected on the basis of earlier studies and numerical simulations. We examined the morphology of a cross-section of the PV structures, roughness and topography, and the transmission spectra of the thin films. Additionally, the properties of the samples were determined by X-ray diffraction. Next, the morphology cross-sectional and layer compositions of the solar cells was evaluated by scanning electron microscopy. Only one of the TiO2/Cu2O structures appeared smooth and homogeneous with columnar-type growth. For the as-grown films, diffraction peaks were observed and identified as brookite, rutile, CuO, and Cu2O and the average roughness of the samples was 0.5, 1.2, 5.4, and 4.0 nm, respectively. Finally, the transmission spectra of the thin films were recorded. Transmission and reflection spectra of ultraviolet-visible spectroscopy were analyzed, and the optical band gap and absorption coefficient of the oxidized layers were calculated. In the region of 400 to 1000 nm, transmittance varied from 5% to 70% in the TiO2 samples, and from 15% to 40% in the Cu2O samples, and reflectance of the TiO2 and Cu2O samples ranged from 20% to 90%. In the region of 1.5 eV to 3.5 eV, the mean absorption coefficient varied from ∼105 1/cm to ∼3 · 105 1/cm for TiO2 thin film, and from ∼2 · 105 to ∼6 · 105 1/cm for Cu2O thin film. The optical band gap values of the samples shifted slightly toward bulk anatase-3.5 eV, bulk rutile-3.1 eV, and copper(I) oxide. Finally, silver contacts were used for the electrodes. One of the fabricated TiO2/Cu2O PV structures was found to be sensitive to electromagnetic radiance during the experiment.
  • Pozycja
    Comparison of Solar Tracking System Solar Tracking System and Fixed Photovoltaic Modules in Lodz
    (Journal of Solar Energy Engineering, 2018-01) Sawicka-Chudy, Paulina; Sibiński, Maciej; Cholewa, Marian; Pawełek, Ryszard
    The world energy consumption has exhibited high growth over the last several decades. Alternative energy sources like photovoltaic (PV) systems generate electricity, reduce pollution air, and have little environmental impact. The commonly used fixed-tilt solar panels, however, have low efficiency and high production cost. Thus, it takes a long time to obtain a return on the investment. Solar trackers increase the efficiency of PV systems and are therefore more attractive from a financial point of view. In order to design tracking systems that will be efficient, it is necessary to analyze the results during various periods during the year and over their lifespan. Thus, we performed a comparative study between fixed-tilt panels and the tracking system installed in Lodz, Poland. Fixed-tilt panels are at normal to the Earth's surface (90 deg from horizontal plane) and are attached to a building façade, azimuth 180 deg (S direction) with 15 cm ventilation gap so slight efficiency drop may be presumed. We performed short- and long-term analyses of the solar tracking and fixed-tilt systems, which allowed us to conclude that the panels tracking the sun had an additional gain of energy during the year as compared to the fixed-tilt panels. During some months, however, the solar tracking system did not produce as much energy as the fixed-tilt, vertically positioned panels. These results might be useful in designing and constructing solar tracking PV systems.