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Wyniki wyszukiwania dla: antitumor unsymmetrical bisacridine
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The role of glucuronidation in drug resistance
PublikacjaThe final therapeutic effect of a drug candidate, which is directed to a specific molecular target strongly depends on its absorption, distribution, metabolism and excretion (ADME). The disruption of at least one element of ADME may result in serious drug resistance. In this work we described the role of one element of this resistance: phase II metabolism with UDP-glucuronosyltransferases (UGTs). UGT function is the transformation...
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CYP3A4 overexpression enhances apoptosis induced by anticancer agent imidazoacridinone C-1311, but does not change the metabolism of C-1311 in CHO cells
PublikacjaWe examine whether CYP3A4 overexpression influences the rate and pattern of antitumor imidazoacridinone C-1311 metabolism, in relation to the impact of this overexpression on cell cycle progression and final cellular response of CHO cells following C-1311 treatment. Methods: Three CHO cell lines: CHO-WT, wild type, CHO-HR, overexpressing cytochrome P450 reductase (CPR) and CHO-HR-3A4, coexpressing CPR and CYP3A4 were applied....
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DNA-damaging imidazoacridinone C-1311 induces autophagy followed by irreversible growth arrest and senescence in human lung cancer cells
PublikacjaImidazoacridinone 5-diethylaminoethylamino-8-hydroxyimidazoacridinone (C-1311) is an antitumor inhibitor of topoisomerase II and FMS-like tyrosine kinase 3 receptor. In this study, we describe the unique sequence of cellular responses to C-1311 in human non-small cell lung cancer (NSCLC) cell lines, A549 and H460. In A549 cells, C-1311 (IC80 = 0.08 µM) induced G1 and G2/M arrests, whereas H460 cells (IC80 = 0.051 µM) accumulated...
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Pin Angle Thermal Effects on Friction Stir Welding of AA5058 Aluminum Alloy: CFD Simulation and Experimental Validation
PublikacjaThe friction stir welding (FSW) of tool pin geometry plays a critical role in the final properties of the produced joint. The tool pin geometry directly affects the generation of heat and the flow of internal materials during the FSW process. The effects of the FSW tool pin angle on heat generation and internal flow have not been quantitatively investigated in detail. In this manuscript, a validated Computational Fluid Dynamic...
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Impact of strontium non-stoichiometry of SrxTi0.3Fe0.7O3-δ on structural, electrical, and electrochemical properties for potential oxygen electrode of intermediate temperature solid oxide cells
PublikacjaThis work presents the results of a comprehensive study on the impact of the A-site non-stoichiometry of SrxTi0.3Fe0.7O3-δ (x = 0.90, 0.95, 1.00, 1.05) ceramics on their physicochemical properties. The materials were fabricated by the conventional solid-state reaction method and their structure was determined by X-ray diffractometry, X-ray photoelectron spectroscopy and electron microscopy. Their sintering and thermal expansion...
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PRESSURE DROP OF HFE7000 AND HFE7100 IN FLOW CONDENSATION IN MINICHANNELS WITH ACCOUNT OF NON-ADIABATIC EFFECTS
PublikacjaFlow boiling and flow condensation are often regarded as two opposite or symmetrical phenomena involving the change of phase. There is a temptation to describe both these phenomena with one only correlation. From amongst the structures present in flow boiling and flow condensation at least the annular flow structure seems to be mostly appropriate to the common modeling. However, the shear stress acting between vapor phase and liquid...
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Explanation of Reduction of Pressure Forces in Turbine Chamber Seals
PublikacjaThe paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....
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Explanation of Reduction of Pressure Forces in Turbine Chamber Seals
PublikacjaThe paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....
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A Broadband Circularly Polarized Wide-Slot Antenna with a Miniaturized Footprint
PublikacjaThis letter presents a novel and simple feeding technique for exciting orthogonal components in a wide-slot antenna. In this technique, a rectangular bracket-shape parasitic strip is placed at the open end of the straight microstrip line to excite the fundamental horizontal and vertical components of the circular polarization (CP). The proposed technique—when employed in conjunction with the asymmetrical geometry of coplanar waveguide...
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Influence of hydrochloric acid concentration and type of nitrogen source on the electrochemical performance of TiO2/N-MoS2 for energy storage applications
PublikacjaIn this work, nitrogen-doped molybdenum sulfide was directly deposited on titanium dioxide nanotubes substrate (TiO2/N-MoS2) during hydrothermal synthesis. The study focuses on the influence of hydrochloric acid concentration used for the synthesis, with the results indicating its essential role in thioacetamide hydrolysis and thus in the effectiveness of the N-MoS2 deposition. The electrode material itself is characterized by...
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Proposal of New Tracer Concentration Model in Lung PCT Study Comparison with Commonly Used Gamma-variate Model
PublikacjaPerfusion computed tomography (pCT) is one of the methods that enable non-invasive imaging of the hemodynamics of organs and tissues. On the basis of pCT measurements, perfusion parameters such as blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS) are calculated and then used for quantitative evaluation of the tissue condition. To calculate perfusion parameters it is necessary to approximate...
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New 2-[(4-Amino-6-N-substituted-1,3,5-triazin-2-yl)methylthio]-N-(imidazolidin-2-ylidene)-4-chloro-5-methylbenzenesulfonamide Derivatives, Design, Synthesis and Anticancer Evaluation
PublikacjaIn the search for new compounds with antitumor activity, new potential anticancer agents were designed as molecular hybrids containing the structures of a triazine ring and a sulfonamide fragment. Applying the synthesis in solution, a base of new sulfonamide derivatives 20–162 was obtained by the reaction of the corresponding esters 11–19 with appropriate biguanide hydrochlorides. The structures of the compounds were confirmed...
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DNA methylation in cancer development, diagnosis and therapy-multiple opportunities for genotoxic agents to act as methylome disruptors or remediators
PublikacjaThe role of DNA methylation and recently discovered hydroxymethylation in the function of the human epigenome is currently one of the hottest topics in the life sciences. Progress in this field of research has been further accelerated by the discovery that alterations in the methylome are not only associated with key functions of cells and organisms, such as development, differentiation and gene expression, but may underlie a number...
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Porównanie działania transformatora symetryzującego (zygzak) z aktywnym energoelektronicznym symetryzatorem prądów fazowych linii niskiego napięcia
PublikacjaNa potrzeby planowania sieci niskiego napięcia operatorzy systemów dystrybucyjnych (OSD) zakładają symetryczne warunki obciążenia linii. Z roku na rok, rośnie liczba rozproszonych systemów fotowoltaicznych (PV) zainstalowanych w sieciach niskiego napięcia, których większość to małe jednofazowe systemy dachowe. Dodatkowo, do niesymetrii obciążenia przyczyniają się instalowane masowo pompy ciepła i ładowane jednofazowo samochody...
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Design and Optimization of Metamaterial-Based 5G Millimeter Wave Antenna for Gain Enhancement
PublikacjaIn this brief, a low profile, broadband, high-gain antenna array based on optimized metamaterials (MMs) with dual-beam radiation is reported for 5G millimeters wave (mm-wave) applications. The design is a simple bow tie operating at a 5G band of 28 GHz. It consists of two bow ties with substrate integrated waveguide (SIW)-based power splitter. A broad impedance bandwidth of 26.3−29.8 GHz is obtained by appropriately combining the...
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SFEM Analysis of Beams with Scaled Lengths including Spatially Varying and Cross-Correlated Concrete Properties
PublikacjaThis paper presents the results obtained for plain concrete beams under four-point bending with spatially varying material properties. Beams of increasing length but constant depth were analyzed using the stochastic finite element method. Spatial fluctuation of a uniaxial tensile strength, fracture energy and elastic modulus was defined within cross-correlated random fields. The symmetrical Gauss probability distribution function...
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Determination of pressure drop in flow condensation of HFE7000 in minichannels with account of non-adiabatic effects
PublikacjaFlow boiling and flow condensation are often regarded as two opposite or symmetrical phenomena involving the change of phase. There is a temptation to describe both these phenomena with one only correlation, however such method has yet to be suggested. From amongst the structures present in flow boiling and flow condensation at least the annular flow structure seems to be mostly appropriate to the common modeling. However, the shear...
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Endothelial dysfunction due to eNOS uncoupling: molecular mechanisms as potential therapeutic targets
PublikacjaNitric oxide (NO) is one of the most important molecules released by endothelial cells, and its antiatherogenic properties support cardiovascular homeostasis. Diminished NO bioavailability is a common hallmark of endothelial dysfunction underlying the patho‑ genesis of the cardiovascular disease. Vascular NO is synthesized by endothelial nitric oxide synthase (eNOS) from the substrate L‑arginine (L‑Arg), with tetrahydrobiopterin...
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Problem of aggregation in dye-DNA interaction, calorimetry studies
PublikacjaNucleic acids are the biological target for many antimicrobial, antitumor and antiviral drugs. Ligand-DNA interactions can be classified into two major categories: 1. covalent binding, which can provide to intermolecular adducts, 2. physico-chemical interactions, which can be divided into intercalation (e.g. adriamycin) or groove binding (e.g. dystamycin). There are several methods to investigate interactions between drug and DNA....
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Muramyl dipeptide-based analogs as potential anticancer compounds: Strategies to improve selectivity, biocompatibility, and efficiency
PublikacjaAccording to the WHO, cancer is the second leading cause of death in the world. This is an important global problem and a major challenge for researchers who have been trying to find an effective anticancer therapy. A large number of newly discovered compounds do not exert selective cytotoxic activity against tumorigenic cells and have too many side effects. Therefore, research on muramyl dipeptide (MDP) analogs has attracted interest...
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Anti-cancer effect of Rumex obtusifolius in combination with arginase/nitric oxide synthase inhibitors via downregulation of oxidative stress, inflammation, and polyamine synthesis
PublikacjaCancer continues to be a leading cause of death worldwide, making the development of new treatment methods crucial in the fight against it. With cancer incidence rates increasing worldwide, ongoing research must focus on identifying new and effective ways to prevent and treat the disease. The combination of herbal extracts with chemotherapeutic agents has gained much interest as a novel strategy to combat cancer. Rumex obtusifolius...
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Improvement of Oxygen Electrode Performance of Intermediate Temperature Solid Oxide Cells by Spray Pyrolysis Deposited Active Layers
PublikacjaIntermediate temperature solid oxide fuel cells oxygen electrodes are modified by active interfacial layers. Spray pyrolysis is used to produce thin (≈500 nm) layers of mixed ionic and electronic conductors: Sm0.5Sr0.5CoO3−δ (SSC), La0.6Sr0.4CoO3−δ (LSC), La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF), and Pr6O11 (PrOx) on the electrode–electrolyte interface. The influence of the annealing temperature on the electrode polarization (area specific...
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Relatively high-Seebeck thermoelectric cells containing ionic liquids supplemented by cobalt redox couple
PublikacjaMeanwhile no general and reliable equation determining the Seebeck coefficient (S e ) and involving electro-chemical reaction effects was derived for solutions. We reported the database of 15,000 ionic liquids supplemented by three different redox couple systems: 0.01 mol/l Co 3+/2+ (bpy) 3 , 0.01 mol/l I 3-/3I- and 0.2 mol/l 3- /3I- , and the corresponding estimated Seebeck coefficients. We also reported methods for estimating...
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A novel one-variable first-order shear deformation theory for biaxial buckling of a size-dependent plate based on Eringen’s nonlocal differential law
PublikacjaPurpose – This paper aims to present a new one-variable first-order shear deformation theory (OVFSDT) using nonlocal elasticity concepts for buckling of graphene sheets. Design/methodology/approach – The FSDT had errors in its assumptions owing to the assumption of constant shear stress distribution along the thickness of the plate, even though by using the shear correction factor (SCF), it has been slightly corrected, the errors...
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Corrosion damage identification based on the symmetry of propagating wavefield measured by a circular array of piezoelectric transducers: Theoretical, experimental and numerical studies
PublikacjaThe article investigates the results obtained from numerical simulations and experimental tests concerning the propagation of guided waves in corroded steel plates. Developing innovative methodologies for assessing corrosion-induced degradation is crucial for accurately diagnosing offshore and ship structures exposed to harsh environmental conditions. The main aim of the research is to analyze how surface irregularities affect...
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Novel Versatile Topologies and Design Optimization of Wide-Bandstop Frequency Selective Surfaces for X-Band, Ku-Band and Millimeter-Wave Applications
PublikacjaNovel designs of frequency selective surface (FSS) are presented for wideband applications in X, Ku and mmWave (millimeter Wave) bands. Two identical metallic layers of FSS are imprinted on both sides of the RO4003 substrate. The geometry parameters are optimized to maximize the bandstop at the specified in-band maximum transmission level of –10 dB; satisfaction of the latter condition is enforced through appropriate formulation...
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Tensile modulus of human orbital wall bones cut in sagittal and coronal planes
PublikacjaIn the current research, 68 specimens of orbital superior and/or medial walls taken from 33 human cadavers (12 females, 21 males) were subjected to uniaxial tension untill fracture. The samples were cut in the coronal (38 specimens) and sagittal (30 specimens) planes of the orbital wall. Apparent density (ρapp), tensile Young’s modulus (E-modulus) and ultimate tensile strength (UTS) were identified. Innovative test protocols were...
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Metamaterial-Based Series-Fed Antenna with High Gain and Wideband Performance for Millimeter Wave Spectrum Applications
PublikacjaThis paper presents a high-gain, wideband series-fed antenna designed for 5G millimeter-wave (MMW) applications. The structure employs a substrate-integrated waveguide (SIW)-based power splitter and metamaterials (MMs). The power divider functions effectively at 27.5 GHz, exhibiting an impedance bandwidth from 26.9–28.6 GHz. The series-fed dipole is assembled on the SIW-based power splitter, incorporating four dipoles with varying...
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Genetic Algorithm Approach for Gains Selection of Induction Machine Extended Speed Observer
PublikacjaThe subject of this paper is gains selection of an extended induction machine speed observer. A high number of gains makes manual gains selection difficult and due to nonlinear equations of the observer, well-known methods of gains selection for linear systems cannot be applied. A method based on genetic algorithms has been proposed instead. Such an approach requires multiple fitness function calls; therefore, using a quality index...
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Improving the Performance of a Graphite Foil/Polyaniline Electrode Material by a Thin PEDOT:PSS Layer for Application in Flexible, High Power Supercapacitors
PublikacjaIn this study, we present a novel strategy for enhancing polyaniline stability and thus obtaining an electrode material with practical application in supercapacitors. A promising (graphite foil/polyaniline/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) GF/PANI/PEDOT:PSS) electrode material was characterized and used in the construction of a symmetric supercapacitor that provides an outstanding high power density. For this...
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Comparative analysis of mechanical conditions in bone union following first metatarsophalangeal joint arthrodesis with varied locking plate positions: A finite element analysis
PublikacjaFirst metatarsophalangeal joint arthrodesis is a typical medical treatment performed in cases of arthritis or joint deformity. The gold standard for this procedure is arthrodesis stabilisation with the dorsally positioned plate. However, according to the authors’ previous studies, medially positioned plate provides greater bending stiffness. It is worth to compare the mechanical conditions for bone formation in the fracture callus...
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Unequally-Spaced Slot Strategy for Radiation Null Reduction in Single SIW-Embedded Antenna Element
PublikacjaThe incorporation of higher-order modes (HOMs) can substantially augment the antenna gain and bandwidth, but this improvement is typically accompanied by compromised radiation performance including radiation nulls and higher side lobe levels. In this study, an inventive strategy is introduced to reduce the radiation nulls and the side lobe levels of a single antenna element by positioning multiple slots of the radiating element...
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DNA restriction analysis as a supportive tool in mechanistic studies carried out by 32P-postlabelling
PublikacjaNumerous antitumor and carcinogenic compounds are able to modify DNA by forming covalent bonds with its constituents, while some anticarcinogenic compounds are known to prevent such a modification. All these processes are of vital biological import_ance, though deeper inside into factors influencing formation of DNA adducts is difficult due to the low level of their occurrence. 32P-Postlabelling approach ensures very sensitive...
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Anticancer imidazoacridinone C-1311 inhibits hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF) and angiogenesis
PublikacjaAntitumor imidazoacridinone C-1311 is a DNA-reactive topoisomerase II and FLT3 receptor tyrosine kinase inhibitor. Here, we demonstrate the mechanism of C-1311 inhibitory action on novel targets: hypoxia-inducible factor-1α (HIF-1α), vascular-endothelial growth factor (VEGF), and angiogenesis. In a cell-free system, C-1311 prevented HIF-1α binding to an oligonucleotide encompassing a canonical hypoxia-responsive element (HRE),...
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Mass spectrometry based identification of geometric isomers during metabolic stability study of a new cytotoxic sulfonamide derivatives supported by quantitative structure-retention relationships
PublikacjaA set of 15 new sulphonamide derivatives, presenting antitumor activity have been subjected to a metabolic stability study. The results showed that besides products of biotransformation, some additional peaks occurred in chromatograms. Tandem mass spectrometry revealed the same mass and fragmentation pathway, suggesting that geometric isomerization occurred. Thus, to support this hypothesis, quantitative structure-retention relationships...
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Optymalizacja doboru prawa konstytutywnego membrany o strukturze plecionej
PublikacjaCelem niniejszej dysertacji jest opracowanie zagadnienia optymalizacyjnego pozwalającego dobrać model konstytutywny opisujący mechaniczne zachowanie membrany technicznej. Do analizy wybrano membrany plecione, stosowane w medycynie, tzw. siatki chirurgiczne. W celu wykonania identyfikacji praw konstytutywnych, wykonano dwuosiowe rozciąganie próbek materiałów, otrzymując wskazanie na nieliniowe anizotropowe zachowanie materiałów....
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Design of a Coplanar Waveguide-Fed Wideband Compact-Size Circularly Polarized Antenna and polarization-sense alteration
PublikacjaThis paper presents the design and validation of a geometrically simple circularly polarized(CP) structure featuring flat gain in the sub-6 GHz 5th generation spectrum. The proposed structure is based on coplanar-waveguide-fed, modified wide slot etched in the ground plane. For generating CP waves, the coplanar ground planes are designed with slight asymmetry in both the horizontal and vertical directions. Furthermore, the ground...
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Implementation of spatial/polarization diversity for improved-performance circularly polarized multiple-input-multiple-output ultra-wideband antenna
PublikacjaIn this paper, spatial and polarization diversities are simultaneously implemented in an ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna to reduce the correlation between the parallel-placed radiators. The keystone of the antenna is systematically modified coplanar ground planes that enable excitation of circular polarization (CP). To realize one sense of circular polarization as well as ultra-wideband operation,...
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Derivation of motor mean phase currents in PMSM drives operating with low switching-to-fundamental frequency ratio
PublikacjaPulse width modulation (PWM) of inverter output voltage causes the waveforms of motor phase cur-rents to consist of distinctive ripples. In order to provide suitable feedback for the motor current con-trollers, the mean value must be extracted from the currents’ waveforms in every PWM cycle. A com-mon solution to derive the mean phase currents is to sample their value at the midpoint of a symmetrical PWM cycle. Using an assumption...
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Możliwości wydłużania krzywych przejściowych w układach geometrycznych torów
PublikacjaW pracy przedstawiono analizę problemu wydłużania krzywych przejściowych, wykorzystując do tego celu analityczną metodę projektowania. Podstawę analizy stanowiły obliczenia numeryczne przeprowadzone dla zestawu parametrów charakteryzujących standardowy układ geometryczny: krzywa przejściowa – łuk kołowy – krzywa przejściowa (w wersji niesymetrycznej). Ocenie poddano różnice rzędnych poziomych układu istniejącego oraz układu z...
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Caffeine Inhibits Differentiation Of Lung Cancer Stem Cells By Modulating Their Respiratory Metabolism
PublikacjaIt is ell established that many tumor types contain a fraction of cells, with stem cell-like properties, called cancer stem cells (CSCs), that are resistant to apoptosis induced by therapeutic agents. The presence of CSCs may explain why a standard anticancer treatment, that eliminates only differentiated cancer cells, does not lead to cancer cure.We previously showed the existence of caffeine-sensitive mechanism that controls...
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Electrochemistry meets enzymes: Investigation of the biotransformation pathway of C-1311 based on electrochemical simulation in comparison to in vitro methods.
PublikacjaThe knowledge of the metabolic pathways and the biotransformation of new drugs is one of the major challenges in pharmaceutical research. It is crucial for elucidation of degradation routes of the new biologically active compounds, especially in the area of possible toxicity. Conventional in vitro drug metabolism studies are based on incubating drug candidate with e.g. hepatocytes or, most importantly, liver cell microsomes and...
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Dietary intervention with beetroot juice during doxorubicin cancer chemotherapy in vivo reduces markers of oxidative stress
PublikacjaCancer chemotherapy with doxorubicin, despite high antitumor activity and broad spectrum of this drug, is on decline due to toxic side effects. The clinical efficacy of anthracyclines have continuously prompted the search for new adjuvants to alleviate undesirable side toxicity incurred by this group of cytostatics. The recent approaches involve the application of synthetic or purified natural antioxidants in combination with doxorubicin...
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Tacit Knowledge Sharing and Personal Branding. How to Derive Innovation From Project Teams?
PublikacjaInnovation, relationships, cooperation, and knowledge are key factors which determine a competitive advantage in the networked economy. A network serves as a contemporary form of market process coordination. Network economy, according to the idea of prosumerism, is founded on collaboration of individual creators based on a network of values instead of hierarchical dependencies. Another feature of a network is that it imposes symmetry...
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Carotid Artery Stenting and Blood–Brain Barrier Permeability in Subjects with Chronic Carotid Artery Stenosis
PublikacjaFailure of the blood-brain barrier (BBB) is a critical event in the development and progression of diseases such as acute ischemic stroke, chronic ischemia or small vessels disease that affect the central nervous system. It is not known whether BBB breakdown in subjects with chronic carotid artery stenosis can be restrained with postoperative recovery of cerebral perfusion. The aim of the study was to assess the short-term effect...
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Optimizing CO2 Purification in a Negative CO2 Emission Power Plant
PublikacjaIn the pursuit of mitigating CO2 emissions, this study investigates the optimisation of CO2 purification within a Negative CO2 Emission Power Plant using a spray ejector condenser (SEC) coupled with a separator. The approach involves direct-contact condensation of vapour, primarily composed of an inert gas (CO2), facilitated by a subcooled liquid spray. A comprehensive analysis is presented, employing a numerical model to simulate...
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Effects of Ni-NCAL and Ni–Ag electrodes on the cell performances of low-temperature solid oxide fuel cells with Sm0.2Ce0·8O2-δ electrolyte at various temperatures
PublikacjaThree low-temperature solid oxide fuel cells are built using Sm0.2Ce0·8O2-δ (SDC) as the electrolyte. Cell A is symmetrical and features Ni–LiNi0.8Co0·15Al0·05O2 (Ni–NCAL) electrodes, Cell B comprises a Ni–NCAL anode and a Ni–Ag cathode, and Cell C is fabricated using a Ni–NCAL cathode and a Ni–Ag anode. The ohmic resistance and polarization resistance (Rp) of Cells B and C are significantly higher than those of Cell A. The reduction...