Kai Zhang

1 month ago | nature.com | Kai Zhang |Yuxuan Zhang |Ye Tian |Bin Xu |Li Lin |Zhendong Qin | +2 more

The American bullfrog (Aquarana catesbeiana) is both an economically important aquaculture species and a globally distributed invasive organism with high environmental adaptability. In this study, we present a high-quality chromosome-level genome assembly for the species, comprising 13 chromosomes with a total length of 6.32 Gb and a scaffold N50 of 691.8 Mb. Genome completeness was evaluated at 95.5% using BUSCO and 99.9% using Merqury. Repetitive sequences accounted for 79.51% of the genome. Through a combination of RNA-seq, Ab initio and homology-based gene prediction, we identified 32,382 protein-coding genes, with 98.96% of these genes functionally annotated. This chromosome-level assembly provides an important resource for future studies on the evolution, functional genomics and molecular breeding of the American bullfrog.

Feb 26, 2024 | nature.com | Kai Zhang |Yan Gao |Hongguang Meng |Zhengjie Zhu |Wei Peng |Zhenhuang Su | +1 more

The manufacturing of perovskite solar cells under ambient conditions is desirable, yet the efficiency of p–i–n perovskite solar cells fabricated in air still lags behind those made in an inert atmosphere. Here we introduce an ionic pair stabilizer, dimethylammonium formate (DMAFo), into the perovskite precursor solution to prevent the degradation of perovskite precursors. DMAFo inhibits the oxidization of iodide ions and deprotonation of organic cations, improving the crystallinity and reducing defects in the resulting perovskite films. We show the generation of additional p-type defects during ambient air fabrication that suggests the need for improving bulk properties of the perovskite film beyond surface passivation. Upon addition of DMAFo, we demonstrate that the efficiency of inverted p–i–n solar cells based on perovskite layers with 1.53-eV and 1.65-eV bandgaps fabricated under ambient conditions (25–30 °C, 35–50% relative humidity) increases by 15–20%. We achieve a certified stabilized efficiency of 24.72% for the 1.53-eV cell, on a par with state-of-the-art counterparts fabricated in an inert atmosphere. Manufacturing of perovskite solar cells under ambient conditions is desirable. Meng et al. show that dimethylammonium formate suppresses halide oxidation and deprotonation of organic cations, enabling air-processed inverted solar cells with 24.7% efficiency.