The Rice Pentatricopeptide Repeat Protein PPR756 Is Involved in Pollen Development by Affecting Multiple RNA Editing in Mitochondria.

In land plants, the pentatricopeptide repeat (PPR) proteins form a large family involved in post-transcriptional processing of RNA in mitochondria and chloroplasts, which is critical for plant development and evolutionary adaption. Although studies showed a number of PPR proteins generally influence the editing of organellar genes, few of them were characterized in detail in rice. Here, we report a PLS-E subclass PPR protein in rice, PPR756, loss of function of which led to the abolishment of RNA editing events among three mitochondrial genes includin

Room Temperature Light-Mediated Long-Range Coupling of Excitons in Perovskites

Perovskites have been the focus of attention due to their multitude of outstanding optoelectronic properties and structural versatility. Two-dimensional halide perovskite such as (C_6H_5C_2H_4NH_3)_2PbI_4, or simply PEPI, forms natural multiple quantum wells with enhanced light-matter interactions, making them attractive systems for further investigation. This work reports tunable splitting of exciton modes in PEPI resulting from strong light-matter interactions, manifested as multiple dips (modes) in the reflection spectra. While the origin of the redder mode is well understood, that for the bluer dip at room temperature is still lacking. Here, it is revealed that the presence of the multiple modes originates from an indirect coupling between excitons in different quantum wells. The long-range characteristic of the mediated coupling between excitons in distant quantum wells is also demonstrated in a structure design along with its tunability. Moreover, a device architecture involving an end silver layer enhances the two excitonic modes and provides further tunability. Importantly, this work will motivate the possibility of coupling of the excitonic modes with a confined light mode in a microcavity to produce multiple exciton-polariton modes.Comment: 12 pages, 11 figure

A β-cyclodextrin modified graphitic carbon nitride with Au co-catalyst for efficient photocatalytic hydrogen peroxide production

Photocatalytic hydrogen peroxide (H2O2) production has attracted considerable attention as a renewable and environment-friendly method to replace other traditional production techniques. The performance of H2O2 production remains limited by the inertness of graphitic carbon nitride (CN) towards the adsorption and activation of O2. In this work, a photocatalyst comprising of β-cyclodextrin (β-CD)-modified CN with supporting Au co-catalyst (Au/β-CD-CN) has been utilized for effective H2O2 production under visible light irradiation. The static contact angle measurement suggested that β-CD modification increased the hydrophobicity of the CN photocatalyst as well as its affinity to oxygen gas, leading to an increase in H2O2 production. The rate of H2O2 production reached more than 0.1 mM/h under visible-light irradiation. The electron spin resonance spectra indicated that H2O2 was directly formed via a 2-electron oxygen reduction reaction (ORR) over the Au/β-CD-CN photocatalyst

Hot carrier extraction in CH3NH3PbI3 unveiled by pump-push-probe spectroscopy

Halide perovskites are promising materials for development in hot carrier (HC) solar cells, where the excess energy of above-bandgap photons is harvested before being wasted as heat to enhance device efficiency. Presently, HC separation and transfer processes at higher-energy states remain poorly understood. Here, we investigate the excited state dynamics in CH3NH3PbI3 using pump-push-probe spectroscopy. It has its intrinsic advantages for studying these dynamics over conventional transient spectroscopy, albeit complementary to one another. By exploiting the broad excited-state absorption characteristics, our findings reveal the transfer of HCs from these higher-energy states into bathophenanthroline (bphen), an energy selective organic acceptor far above perovskite's band edges. Complete HC extraction is realized only after overcoming the interfacial barrier formed at the heterojunction, estimated to be between 1.01 and 1.08 eV above bphen's lowest unoccupied molecular orbital level. The insights gained here are essential for the development of a new class of optoelectronics