The circ-PITX1 promotes non-small cell lung cancer development via the miR-30e-5p/ITGA6 axis

Non-small cell lung cancer (NSCLC) is one of the most prevalent tumors with high incidence and mortality across the globe. Recently, increasing studies have demonstrated that circular RNAs (circRNAs) exert outstanding functions in NSCLC progression. Notwithstanding, we are still in the dark about the function and exact mechanism of circ-PITX1, a newly discovered circRNA. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) confirmed the profile of circ-PITX1 in NSCLC tissues and adjacent normal tissues. Gain- and loss- of function assay verified the impact of circ-PITX1 and miR-30e-5p on the proliferation, invasion, and migration of NSCLC cells (H1975 and A549). Bioinformatics analysis corroborated the downstream mechanisms of circ-PITX1. Dual-luciferase reporter gene assay and RNA immunoprecipitation (RIP) examined the interactions between circ-PITX1 and miR-30e-5p, miR-30e-5p and ITGA6. The protein levels of ITGA6, PI3K, AKT were determined by Western blot. circ-PITX1 was substantially up-regulated in NSCLC tissues and cells, and circ-PITX1 up-regulation was correlated with NSCLC patients’ poor survival. Functionally, circ-PITX1 overexpression or miR-30e-5p inhibition markedly facilitated proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), reduced apoptosis, and enhanced ITGA6/PI3K/AKT expression in NSCLC cells, whereas circ-PITX1 knockdown or miR-30e-5p up-regulation resulted in the opposite results. Mechanistically, circ-PITX1 acted as a sponge of miR-30e-5p, which targeted the 3ʹuntranslated region (UTR) of ITGA6. Knockdown of circ-PITX1 or overexpressing miR-30e-5p reduced ITGA6/PI3K/AKT axis. circ-PITX1 modulates the miR-30e-5p/ITGA6 axis to boost NSCLC progression, hence functioning as an oncogene.</p

Correction to “Highly Efficient Inverted Circularly Polarized Organic Light Emitting Diodes”

Correction to “Highly Efficient Inverted Circularly Polarized Organic Light Emitting Diodes

Why Do Sulfone-Containing Polymer Photocatalysts Work So Well for Sacrificial Hydrogen Evolution from Water?

Many of the highest-performing polymer photocatalysts for sacrificial hydrogen evolution from water have contained dibenzo[b,d]thiophene sulfone units in their polymer backbones. However, the reasons behind the dominance of this building block are not well understood. We study films, dispersions, and solutions of a new set of solution-processable materials, where the sulfone content is systematically controlled, to understand how the sulfone unit affects the three key processes involved in photocatalytic hydrogen generation in this system: light absorption; transfer of the photogenerated hole to the hole scavenger triethylamine (TEA); and transfer of the photogenerated electron to the palladium metal co-catalyst that remains in the polymer from synthesis. Transient absorption spectroscopy and electrochemical measurements, combined with molecular dynamics and density functional theory simulations, show that the sulfone unit has two primary effects. On the picosecond timescale, it dictates the thermodynamics of hole transfer out of the polymer. The sulfone unit attracts water molecules such that the average permittivity experienced by the solvated polymer is increased. We show that TEA oxidation is only thermodynamically favorable above a certain permittivity threshold. On the microsecond timescale, we present experimental evidence that the sulfone unit acts as the electron transfer site out of the polymer, with the kinetics of electron extraction to palladium dictated by the ratio of photogenerated electrons to the number of sulfone units. For the highest-performing, sulfone-rich material, hydrogen evolution seems to be limited by the photogeneration rate of electrons rather than their extraction from the polymer

Structure–Property Relationships for the Electronic Applications of Bis-Adduct Isomers of Phenyl‑C₆₁ Butyric Acid Methyl Ester

Higher adducts of a fullerene, such as the bis-adduct of PCBM (bis-PCBM), can be used to achieve shallower molecular orbital energy levels than, for example, PCBM or C60. Substituting the bis-adduct for the parent fullerene is useful to increase the open-circuit voltage of organic solar cells or achieve better energy alignment as electron transport layers in, for example, perovskite solar cells. However, bis-PCBM is usually synthesized as a mixture of structural isomers, which can lead to both energetic and morphological disorder, negatively affecting device performance. Here, we present a comprehensive study on the molecular properties of 19 pure bis-isomers of PCBM using a variety of characterization methods, including ultraviolet photoelectron spectroscopy, thermal gravimetric analysis, differential scanning calorimetry, single crystal structure, and (time-dependent) density functional theory calculation. We find that the lowest unoccupied molecular orbital of such bis-isomers can be tuned to be up to 170 meV shallower than PCBM and up to 100 meV shallower than the mixture of unseparated isomers. The isolated bis-isomers also show an electron mobility in organic field-effect transistors of up to 4.5 × 10–2 cm2/(V s), which is an order of magnitude higher than that of the mixture of bis-isomers. These properties enable the fabrication of the highest performing bis-PCBM organic solar cell to date, with the best device showing a power conversion efficiency of 7.2%. Interestingly, we find that the crystallinity of bis-isomers correlates negatively with electron mobility and organic solar cell device performance, which we relate to their molecular symmetry, with a lower symmetry leading to more amorphous bis-isomers, less energetic disorder, and higher dimensional electron transport. This work demonstrates the potential of side chain engineering for optimizing the performance of fullerene-based organic electronic devices