Osteosarcoma remains a significant clinical challenge, with poor outcomes in metastatic cases and slow progress in the development of novel therapies. In this work, a previously developed 3D osteosarcoma model, comprising bone-mimicking macroporous alginate scaffolds with hydroxyapatite particles and a perfusion bioreactor, was evaluated as a tool for anticancer drug testing. Murine osteosarcoma cells (K7M2-wt) were seeded onto the scaffolds (15× 10^{6} cells per cm^{3} ) and cultured statically for 1 day. In two experimental series, scaffolds were then exposed to doxorubicin (1μg cm^{-3} ) under perfusion for 1 or 3 days (40 μm s^{-1} superficial velocity), modelling post-resection conditions with predominantly individual or loosely aggregated cells. In two additional series, the same treatments were applied after 7 days of perfusion, when compact spheroids had formed, mimicking established tumours. Histological analysis and MTT assay were used to assess cell morphology and metabolic activity. Short-term treatment had negligible effects, while prolonged exposure significantly reduced metabolic activity of individual cells, but spheroid-like structures exhibited increased doxorubicin resistance. To rationalize the results from the first two series, a mathematical model was developed describing drug transport, intracellular accumulation, cell proliferation, and cell death. The model captured the initial treatment phase, but overestimated the effect of prolonged treatment, suggesting additional resistance mechanisms. Overall, the results demonstrate the potential of this 3D model for anticancer drug evaluation.
Extraction of aliphatic hydrocarbons from demineralized coal using superheated steam is a promising method for reducing the industrial production costs. In the present study, extractions were performed at superheated steam temperatures without a catalyst (373 to 473 K; 2-20 h). The greatest yield of extracted organic matter was obtained during the first 2 h (4.0 to 6.1 % of the initial sample mass). At longer times, solubility values varied, suggesting that the release of aliphatic hydrocarbons depends on their location within different structural domains of the organic matrix. The high maturity of the organic matter indicates that the anthracite sample is in the metagenesis phase. Gas chromatography with flame ionization detection showed that extraction yielded n-paraffins, primarily the energetically significant C12 to C19 homologues, comprising 50 to 61 % of extracted compounds after 20 h. Comparison with less mature coals (lignite and brown coal) from the same area revealed a similar trend, though, with increasing coalification, the proportion of n-paraffins decreased and terpenes increased. Fourier transform infrared spectroscopy of the dry residue after extraction showed that methyl groups (2972 cm-1) were lost after 2 hours at all temperatures, while complete removal of aliphatic structures, including ethyl groups (2924, 2852 and 1377 cm-1), occurred after 20 h. The detected paraffins and terpenes originated from methyl and ethyl groups extracted from the organic matrix. Additionally, while lignite and brown coal gave nearly identical results, lignite lacked independently bound methyl groups.
Wastewater from chemical, petrochemical, and metallurgical industries contains different dissolved pollutants, characterized with high toxicity. In recent decades, industrial water treatment to remove heavy metal ions has become increasingly important due to their toxicity and the potential risk of accumulation in the food chain. This requires the application of various methods to reduce heavy metal ion concentrations to acceptable levels. In this respect, adsorption processes based on different sorbents are widely used for industrial wastewater treatment. For this investigation, apricot pits were pyrolyzed and chemically activated with potassium hydroxide to produce activated carbon. The adsorption capacity of the resulting material for removing Cu(II) ions from aqueous solutions was then investigated. The results have shown that these carbon-based adsorbents possess a high surface area and favourable textural characteristics, making them promising candidates for the removal of copper ions from aqueous solutions.
This paper provides a concise and accessible overview of commonly used methods for measuring the thermal conductivity of liquids. Both steady-state and transient techniques are briefly outlined, including guarded hot plate methods, laser flash analysis, and approaches based on time-dependent thermal response. Particularfocus is placed on the transient hot wire method, recognized for its simplicity, versatility, and its proven suitability for liquid samples. In addition, a recently developed patented approach based on the transient hot wire technique is presented in a more illustrative manner. The concept relies on improvements in sensor design and data interpretation, aimed at enhancing measurement stability and reducing typical sources of error in liquid measurements. Rather than a detailed technical validation, the emphasis is on explaining the idea and its potential benefits in practical applications.
Due to greater awareness of environmental and social issues, as well as stricter environmental regulations, there is a rising demand for green materials to replace fossil-based resources and raw materials. With its excellent mechanical properties, biodegradability, and low cost, nettle fibre has the potential to become a sustainable fibre for technical applications. Dyeability, antimicrobial properties, renewability, and wrinkle resistance make this fibre suitable for textile applications. Due to its low density, it may be used in a wide array of applications such as woven and non-woven fabrics, blends, and composite materials. This paper aims to critically review nettle fibre in various textile applications and provide directions for future research.
