ABSTRACT
Water-based adsorption chillers (ADC) driven by low-grade thermal energy are environment-friendly alternatives to the traditional compression ones to realize the net zero carbon target. Aluminophosphates molecular sieve (AlPOs) is an excellent material for water-based adsorption applications. However, AlPOs suffers from relatively high cost attributed to the extensive use of expensive structure direct agents (SDAs). This study employed a dual-template method, using cheap organic amine as a dual-template, to synthesize low-cost and excellent adsorbent AlPOs with SFO topology (AlPO-SFO). AlPO-SFO synthesized with dual templates shows high crystallinity, large micropore volume, excellent water uptake, and low regeneration temperature. AlPO-SFO guided by 4-dimethylaminopyridine (4-DMAPy) and diethanolamine (DEOA) molar composition of 0.4 and 0.1 exhibits large microporous volume (0.30 ml g-1), high water uptake (0.26 g g-1 at P/P0 = 0.25) and low regeneration temperature (65 °C). Importantly, this AlPO-SFO exhibits a high coefficient of performance (COP) of 0.89 for cooling at a low driven temperature of 64 °C. The additive amine providing alkaline medium ensures the practical synthesis of AlPO-SFO when expensive 4-DMAPy decreases, endowing the 42 % reduction of the raw material cost. The results provide a cheaper synthesis route of AlPO-SFO, which is conducive to its large-scale production as a distinguished adsorbent for adsorption chillers.
ABSTRACT
Thermally driven water-based sorption refrigeration is considered a promising strategy to realize near-zero-carbon cooling applications by addressing the urgent global climate challenge caused by conventional chlorofluorocarbon (CFC) refrigerants. However, developing cost-effective and high-performance water-sorption porous materials driven by low-temperature thermal energy is still a significant challenge. Here, we propose a zeolite-like aluminophosphate with SFO topology (EMM-8) for water-sorption-driven refrigeration. The EMM-8 is characterized by 12-membered ring channels with large accessible pore volume and exhibits high water uptake of 0.28 g·g-1 at P/P0 = 0.2, low-temperature regeneration of 65 °C, fast adsorption kinetics, remarkable hydrothermal stability, and scalable fabrication. Importantly, the water-sorption-based chiller with EMM-8 shows the potential of achieving a record coefficient of performance (COP) of 0.85 at an ultralow-driven temperature of 63 °C. The working performance makes EMM-8 a practical alternative to realize high-efficient ultra-low-temperature-driven refrigeration.
ABSTRACT
It is of great importance to correlate the water adsorption performance of MOFs to their physicochemical features in order to design and prepare MOFs for applications in adsorption heat transformation. In this work, both data analysis from existing studies and Grand Canonical Monte Carlo molecular simulation investigations were carried out. The results indicated that the highest water adsorption capacity was determined by the pore volume of MOF adsorbents, while there was a linear correlation interrelationship between isosteric heats of adsorption and the water adsorption performance at a low relative pressure. More detailed analysis showed that the charge distribution framework and pore size of MOFs contributed together to the hydrophilicity. Electrostatic interaction between water molecules and the framework atoms played a key role at low relative water pressure. A quantitative structure-property relationship model that can correlate the hydrophilicity of MOFs to their pore size and atomic partial charge was established. Along with some qualitative considerations, the screening methodology is proposed and is used to screen proper MOFs in the CoRE database. Seven MOFs were detected, and four of them were synthesized to validate the screening principle. The results indicated that these four MOFs possessed outstanding water adsorption performance and could be considered as promising candidates in applications for adsorption heating and cooling.
ABSTRACT
OBJECTIVE: Numerous studies suggested autophagy was involved in temozolomide (TMZ) resistance in glioma. Long non-coding RNA (lncRNA) CASC2 was shown to be downregulated in glioma tissues and cell lines, and was related to the TMZ resistance. However, whether CASC2 affects TMZ resistance through regulating autophagy is unknown. The aim of this study was to assess the role and mechanism of CASC2 in TMZ-induced drug resistance in glioma cells. METHODS: Glioma and the adjacent non-cancerous tissues from 32 patients were collected. The expressions of CASC2 and miR-193a-5p were determined by PCR, and their correlation was analyzed. The correlation between CASC2 expression and the clinical characteristics of patients was also studied. Glioma cells were treated with TMZ to acquire the TMZ-resistant cell lines in which the expressions of CASC2, miR-193a-5p, and mTOR were measured. The regulatory roles of CASC2, miR-193a-5p, and mTOR were defined through the loss of function and luciferase reporter assays. Autophagy was inhibited by autophagy inhibitor 3-MA, CASC2 and mTOR overexpression, or miR-193a-5p inhibitor, and the effect of which on cell viability, apoptosis, and migration of TMZ-resistant glioma cells was evaluated. RESULTS: CASC2 downregulation and miR-193a-5p upregulation was found to be associated with advanced clinical stage and TMZ response in patients with glioma. CASC2 negatively regulates miR-193a-5p expression by direct interaction in glioma cells. Overexpression of CASC2 or inhibition of miR-193a-5p reduced TMZ-induced autophagy via mTOR upregulation, which makes the glioma cells become sensitive to TMZ cytotoxicity. CONCLUSION: CASC2 is downregulated in gliomas, resulting in increased miR-193a-5p level and a decrease in mTOR expression, which further induces protective autophagy, leading to TMZ resistance. Inhibition of autophagy helps to increase the efficacy of TMZ.
