Intermittent renewable energy sources such as solar and wind necessitate energy storage methods like employing phase change materials (PCMs) for latent heat thermal energy storage (LHTES). However, the low thermal conductivity of PCMs limits their thermal response rate. This paper reviews recent progress in active heat transfer augmentation methods for improving LHTES system performance, encompassing mechanical aids, vibrations, jet impingement, injection, and external fields. It compiles findings concerning the optimization of PCM charging and discharging processes. Proposals for future research directions are provided, highlighting the significance of extra energy input for storage. The study highlights how changing the mushy zone constant from 103 to 108 affects a PCM's melt fraction and heat storage. The article also overviews studies using fins and coils to enhance heat transfer in PCM-based LHTES systems. It discusses how geometric and material constraints influence the melting and solidification processes and the heat transfer surface orientation within the storage tank. Various PCMs with different melting temperatures are examined. A broad range of test cases was examined to determine how geometry and orientation-dependent convection affect the phase-changing process. This overview of heat transfer principles offers guidelines for system designers to optimize the geometry of heat transfer fluid (HTF) flow paths and the confinement of PCM to enhance heat transfer efficiency and overall system performance. The results also indicate research gaps for certain PCM melting temperature ranges. Few experimental studies exist for melting temperatures above 60 °C; most focus only on melting rather than solidification. More standardized studies using non-dimensional parameters for coil geometries are advocated.
A library of novel 2-(het)arylpyrrolidine-1-carboxamides were obtained via a modular approach based on the intramolecular cyclization/Mannich-type reaction of N-(4,4-diethoxybutyl)ureas. Their anti-cancer activities both in vitro and in vivo were tested. The in vitro activity of some compounds towards M-Hela tumor cell lines was twice that of the reference drug tamoxifen, whereas cytotoxicity towards normal Chang liver cell did not exceed the tamoxifen toxicity. In vivo studies showed that the number of surviving animals on day 60 of observation was up to 83% and increased life span (ILS) was up to 447%. Additionally, some pyrrolidine-1-carboxamides possessing a benzofuroxan moiety obtained were found to effectively suppress bacterial biofilm growth. Thus, these compounds are promising candidates for further development both as anti-cancer and anti-bacterial agents.
Combining two pharmacophores in a molecule can lead to useful synergistic effects. Herein, we show hybrid systems that combine sterically hindered phenols with dinitrobenzofuroxan fragments exhibit a broad range of biological activities. The modular assembly of such phenol/benzofuroxan hybrids allows variations in the phenol/benzofuroxan ratio. Interestingly, the antimicrobial activity only appears when at least two benzofuroxan moieties are introduced per phenol. The most potent of the synthesized compounds exhibit high cytotoxicity against human duodenal adenocarcinoma (HuTu 80), human breast adenocarcinoma (MCF-7), and human cervical carcinoma cell lines. This toxicity is associated with the induction of apoptosis via the internal mitochondrial pathway and an increase in ROS production. Encouragingly, the index of selectivity relative to healthy tissues exceeds that for the reference drugs Doxorubicin and Sorafenib. The biostability of the leading compounds in whole mice blood is sufficiently high for their future quantification in biological matrices.
The work presents the results of a comprehensive study on obtaining compositions based on polypropylene and natural fillers modified by enzymatic preparations under high-shear forces. The experiment protocol includes determining the modification time and the ratio of water volume to the mass of natural filler (hydro modulus) during modification, which turned out to be different for each type of filler. Physical and mechanical analyses were conducted to evaluate the operational characteristics of the obtained composites, with particular attention given to comparing the modified compositions with their unmodified counterparts. The time and hydro module of the enzymatic modification of the natural fillers under consideration were investigated, which turned out to be different for each type of filler. It was found that surface modification of natural fillers improves mechanical properties; namely, the tensile strength of composites with wood and sunflower fillers increases by 10%, and the impact viscosity of composites also increases by 12% with wood and sunflower fillers. Water absorption decreases in composites, after 2 h boiling, with wood flour by 30% and with rice husk by 10%. After a 14-day test at room temperature, water absorption decreases by more than 30% in composites with rice husk. When determining the free surface energy of composites, it was found that the modification of the filler reduces the polarity of the composites in all samples, which can be interpreted as an improvement in the interaction between the filler and the polymer matrix. The findings of this research have important implications for the development of advanced polymeric materials that can be used in a wide range of applications, including automotive, aerospace, and construction industries. The results underscore the importance of surface modifications to optimize the properties of polymeric composites and provide valuable insights into the role of natural fillers in enhancing the performance of these materials.
In recent years, researchers have often encountered the significance of the aberrant metabolism of tumor cells in the pathogenesis of malignant neoplasms. This phenomenon, known as the Warburg effect, provides a number of advantages in the survival of neoplastic cells, and its application is considered a potential strategy in the search for antitumor agents. With the aim of developing a promising platform for designing antitumor therapeutics, we synthesized a library of conjugates of 3,5-bis(arylidene)-4-piperidone and sesquiterpene lactones. To gain insight into the determinants of the biological activity of the prepared compounds, we showed that the conjugates of 3,5-bis(arylidene)-4-piperidone and sesquiterpene lactones, which are cytotoxic agents, demonstrate selective activity toward a number of tumor cell lines with glycolysis-inhibiting ability. Moreover, the results of molecular and in silico screening allowed us to identify these compounds as potential inhibitors of the pyruvate kinase M2 oncoprotein, which is the rate-determining enzyme of glycolysis. Thus, the results of our work indicate that the synthesized conjugates of 3,5-bis(arylidene)-4-piperidone and sesquiterpene lactones can be considered a promising platform for designing selective cytotoxic agents against the glycolysis process, which opens new possibilities for researchers involved in the search for antitumor therapeutics among compounds containing piperidone platforms.