Furthermore, the differentiation inhibited by the stretching was also restored by synthetic PPARγ ligand. Collectively, these results suggest that the inhibition of adipocyte differentiation in response to stretching is mainly attributable to the reduced expression of PPARγ2, which is mediated by activation of the ERK/MAPK system.
Abstract. The present study examined the combined effects of fish-oil-derived ω-3 polyunsaturated fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and cyclic stretching on the adipocyte differentiation of 3T3-L1 cells. Treatment with EPA alone did not inhibit the differentiation, although it partially suppressed the expressions of peroxisome proliferator-activated receptor (PPAR)-γ 2 and CCAAT/ enhancer-binding protein (C / EBP)α transcripts, which are considered to be indispensable for the determination of adipocyte differentiation. However, the differentiation was significantly reduced when EPA but not DHA was concomitantly applied with cyclic stretching. In addition, EPA, but not DHA, could be a substrate of cyclooxygenase (COX)-2, and we found that the stretching significantly augmented the expression of COX-2 and that a selective COX-2 inhibitor (NS-398) inhibited the combined effect of the stretching and EPA. Taken together, it appears that the stretching and EPA exhibit a synergistic effect for the inhibition of adipocyte differentiation through stretch-induced COX-2.
Polyphenols were synthesized via a horseradish peroxidase reaction from phenol, catechol, and pyrogallol for use as copper-ion adsorbents. The molecular weights of the polyphenols ranged from about 1000 to 3000 g/mol. The hydroxyl group contents in the polyphenols from phenol, catechol, and pyrogallol were 5.9, 4.0, and 0.94 mol/kg, respectively, as determined by titration. The saturation binding capacity for copper ions of the polyphenols from phenol, catechol, and pyrogallol were calculated to be 1.44, 0.88, and 0.22 mol/kg, respectively, at pH 4.5. Copper ions were efficiently adsorbed via an ion-exchange interaction by the synthesized polyphenols with vicinal hydroxyl groups, and those polyphenols could be applied to metal adsorption. Gold ions were selectively reduced by the phenol group in polypyrogallol in acid media to form gold particles. The reduced gold particles were eluted with a solution of 1.0M thiourea plus 0.5M HCl.
A systematic study is conducted to compare the performances and stability of active layers employing a high performance electron donor (PBDB‐T) combined with state‐of‐the‐art fullerene (PC71BM), nonfullerene (ITIC), and polymer (N2200) electron acceptors. The impact of the chemical nature of the acceptor on the durability of organic solar cells (OSCs) is elucidated by monitoring their photovoltaic performances under light exposure or dark conditions in the presence of oxygen. PC71BM molecules exhibit a higher resistance toward oxidation compared to nonfullerene acceptors. Unencapsulated PBDB‐T:PC71BM OSCs display relatively stable performances at room temperature when stored in air for 3 months. However, when exposed to temperatures above 80 °C, their active materials demix causing notable reductions in the short‐circuit densities. Such detrimental demixing can also be seen for PBDB‐T:ITIC active layers above 120 °C. Although N2200 chains irreversibly degrade when exposed to air, thermally induced demixing does not occur in PBDB‐T:N2200 active layers annealed up to 200 °C. In summary, fullerene OSCs may be the best currently available choice for unencapsulated room temperature applications but if oxidation of the polymer acceptors can be avoided, all polymer active layers should enable the fabrication of highly durable OSCs with lifetimes matching the requirements for OSC commercialization.
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