Antiproliferative and Cytotoxic Activities of Fluorescein—A Diagnostic Angiography Dye

Fluorescein is a fluorescent dye used as a diagnostic tool in various fields of medicine. Although fluorescein itself possesses low toxicity, after photoactivation, it releases potentially toxic molecules, such as singlet oxygen (¹O₂) and, as we demonstrate in this work, also carbon monoxide (CO). As both of these molecules can affect physiological processes, the main aim of this study was to explore the potential biological impacts of fluorescein photochemistry. In our in vitro study in a human hepatoblastoma HepG2 cell line, we explored the possible effects on cell viability, cellular energy metabolism, and the cell cycle. We observed markedly lowered cell viability (≈30%, 75–2400 μM) upon irradiation of intracellular fluorescein and proved that this decrease in viability was dependent on the cellular oxygen concentration. We also detected a significantly decreased concentration of Krebs cycle metabolites (lactate and citrate < 30%; 2-hydroxyglutarate and 2-oxoglutarate < 10%) as well as cell cycle arrest (decrease in the G2 phase of 18%). These observations suggest that this photochemical reaction could have important biological consequences and may account for some adverse reactions observed in fluorescein-treated patients. Additionally, the biological activities of both ¹O₂ and CO might have considerable therapeutic potential, particularly in the treatment of cancer.     

Recovery of Hydrochloric Acid from Industrial Wastewater by Diffusion Dialysis Using a Spiral-Wound Module

In the present study, the possibility of using a spiral-wound diffusion dialysis module was studied for the separation of hydrochloric acid and Zn²⁺, Ni²⁺, Cr³⁺, and Fe²⁺ salts. Diffusion dialysis recovered 68% of free HCl from the spent pickling solution contaminated with heavy-metal-ion salts. A higher volumetric flowrate of the stripping medium recovered a more significant portion of free acid, namely, 77%. Transition metals (Fe, Ni, Cr) apart from Zn were rejected by >85%. Low retention of Zn (35%) relates to the diffusion of negatively charged chloro complexes through the anion-exchange membrane. The mechanical and transport properties of dialysis FAD-PET membrane under accelerated degradation conditions was investigated. Long-term tests coupled with the economic study have verified that diffusion dialysis is a suitable method for the treatment of spent acids, the salts of which are well soluble in water. Calculations predict significant annual OPEX savings, approximately up to 58%, favouring diffusion dialysis for implementation into wastewater management.     

Mixtures of l-Amino Acids as Reaction Medium for Formation of Iron Nanoparticles: The Order of Addition into a Ferrous Salt Solution Matters

Owing to Mössbauer spectroscopy, an advanced characterization technique for iron-containing materials, the present study reveals previously unknown possibilities using l-amino acids for the generation of magnetic particles. Based on our results, a simple choice of the order of l-amino acids addition into a reaction mixture containing ferrous ions leads to either superparamagnetic ferric oxide/oxyhydroxide particles, or magnetically strong Fe⁰-Fe₂O₃/FeOOH core-shell particles after chemical reduction. Conversely, when ferric salts are employed with the addition of selected l-amino acids, only Fe⁰-Fe₂O₃/FeOOH core-shell particles are observed, regardless of the addition order. We explain this phenomenon by a specific transient/intermediate complex formation between Fe²⁺ and l-glutamic acid. This type of complexation prevents ferrous ions from spontaneous oxidation in solutions with full air access. Moreover, due to surface-enhanced Raman scattering spectroscopy we show that the functional groups of l-amino acids are not destroyed during the borohydride-induced reduction. These functionalities can be further exploited for (i) attachment of l-amino acids to the as-prepared magnetic particles, and (ii) for targeted bio- and/or environmental applications where the surface chemistry needs to be tailored and directed toward biocompatible species.     

Ductile/brittle PA6/PS system: Effect of carbon nanoplatelets-modified interface on performance

Addition of rigid PS to ductile PA6 can lead to higher toughness provided plastic deformation of PS is achieved. The current study deals with upgrading of this system by graphene, graphene oxide (GO), and GO with grafted polystyrene (GO-g-PS). Low amount of these carbon nanoplatelets can enhance performance of the PA/PS 90/10 system with the best-balanced properties achieved with GO-g-PS by unique combination of reinforcement with the favorable effect of the GO-g-PS-modified interface on plastic deformation of the PS phase causing higher impact resistance. Simultaneous linking of PA chains and hydrogen bonding causes “anchoring” of PS inclusions in the PA6 phase. This results in support of hydrostatic pressure evolution during loading and thus extensive yielding of PS. Another positive effect is reduction of pullout of in situ formed fibrous inclusions, which is different from rigid short-fiber composites. The study highlights high potential of GO modified with polymer chains to upgrade polymer systems via tailoring the interface.     

Two-Step Preparation of Benzylacetone

Two-step preparation of benzylacetone has been investigated using layered double hydroxides (LDHs) as catalysts for aldol condensation of benzaldehyde and acetone and Ni supported catalysts for consecutive hydrogenation of benzylideneacetone. Activity and selectivity of LDHs of various Mg/Al ratios to desired product, benzylideneacetone, have been compared in the liquid phase at 333 K. An aldol condensation yield at 100 % conversion of benzaldehyde was 78 % using catalyst HT-2.0. In the following, optimal hydrogenation conditions—temperature of 353 K, hydrogen pressure of 5 MPa and 5 wt% of catalyst NiSAT^® 320 were found. At 95 % conversion of benzylideneacetone the selectivity to desired product was 99 %.     

System Condition Estimation Based on Selected Tribodiagnostic Data

The aim of the paper is to estimate a system‐soft failure occurrence and residual technical life. When estimating a residual technical life statistically, usually a big amount of tribodiagnostic data is used. Data include the information about particles contained in oil that testifies to oil and system conditions. We focus here on the particles that we consider to be interesting. They are ferrum (Fe) and lead (Pb) as contact degradation product. By modelling the occurrence of particles in oil, we expect to determine the expected moment for soft failure occurrence or adequate moment to perform preventive maintenance. The way of our modelling is based on the specific characteristics of diffusion processes, namely the Wiener process with positive drift and Ornstein–Uhlenbeck process. Following the modelling results, we could judge hazard rate and set‐up principles of ‘CBM ‐ Condition Based Maintenance’ (CBM). However, the possibilities are much wider, because we can also plan operation, mission and reduce life cost. Copyright © 2015 John Wiley & Sons, Ltd.     

Chemical Composition and Mechanical Characteristic of Nitrogen Ion Beam Mixed Carbon Nanolayer

Ion beam methods for modification of nanohardness of surface nanolayers of the titanium alloy Ti6AI4V were applied. After deposition of carbon nanolayers by electron beam evaporation, the ion implantation of nitrogen into samples was carried out. The chemical composition of the modified surface area was investigated by AES （auger electron spectroscopy）. The nanohardness of resulted ion beam modified surface nanolayers were investigated by nanoindentation testing. The measured concentration profiles indicate the atomic mixing of carbon into the substrate. It was found that the modified samples had a markedly higher nanohardness than the unmodified samples. The increased nanohardness is attributed to the newly created phases in the surface area.