Construction of a Spatial-Confined Self-Stacking Catalytic Circuit for Rapid and Sensitive Imaging of Piwi-Interacting RNA in Living Cells.

Piwi-interacting RNAs (piRNAs) are small noncoding RNAs that repress transposable elements to maintain genome integrity. The canonical catalytic hairpin assembly (CHA) circuit relies on random collisions of free-diffused reactant probes, which substantially slow down reaction efficiency and kinetics. Herein, we demonstrate the construction of a spatial-confined self-stacking catalytic circuit for rapid and sensitive imaging of piRNA in living cells based on intramolecular and intermolecular hybridization-accelerated CHA. We rationally design a 3WJ probe that not only accelerates the reaction kinetics by increasing the local concentration of reactant probes but also eliminates background signal leakage caused by cross-entanglement of preassembled probes. This strategy achieves high sensitivity and good specificity with shortened assay time. It can quantify intracellular piRNA expression at a single-cell level, discriminate piRNA expression in tissues of breast cancer patients and healthy persons, and in situ image piRNA in living cells, offering a new approach for early diagnosis and postoperative monitoring.

Complete Organelle Genome of the Desiccation-Tolerant (DT) Moss Tortula atrovirens and Comparative Analysis of the Pottiaceae Family.

Tortula atrovirens (Sm.) Lindb. is an important component of biological soil crusts and possesses an extraordinary tolerance against desiccation in dryland habitats. However, knowledge of the organelle genome of this desiccation-tolerant (DT) moss is still lacking. Here, we assembled the first reported Tortula organelle genome and conducted a comprehensive analysis within the Pottiaceae family. T. atrovirens exhibited the second largest chloroplast genome (129,646 bp) within the Pottiaceae, whereas its mitogenome (105,877 bp) and those of other mosses were smaller in size compared to other land plants. The chloroplast and mitochondrial genomes of T. atrovirens were characterized by the expansion of IR boundaries and the absence of homologous recombination-mediated by large repeats. A total of 57 RNA editing sites were detected through mapping RNA-seq data. Moreover, the gene content and order were highly conserved among the Pottiaceae organelle genomes. Phylogenetic analysis showed that bryophytes are paraphyletic, with their three lineages (hornworts, mosses, and liverworts) and vascular plants forming successive sister clades. Timmiella anomala is clearly separated from the monophyletic Pottiaceae, and T. atrovirens is closely related to Syntrichia filaris within the Pottioideae. In addition, we detected four hypervariable regions for candidate-molecular markers. Our findings provide valuable insights into the organelle genomes of T. atrovirens and the evolutionary relationships within the Pottiaceae family, facilitating future discovery of DT genetic resources from bryophytes.

Improving bioelectrochemical performance by sulfur-doped titanium dioxide cooperated with Zirconium based metal-organic framework (S-TiO2@MOF-808) as cathode in microbial fuel cells.

The sulfur-doped titanium dioxide (S-TiO2) cooperated with Zirconium based on a kind of metal-organic framework (MOF-808) was successfully prepared as cathode catalyst (S-TiO2@MOF-808) of microbial fuel cell (MFC) by two-step hydrothermal reaction. The particle size was approximately 5 µm, and the spherical S-TiO2 particle was attached to the surface of MOF-808 as irregular block solid. Zr-O, C-O and O-H bond were indicated to exist in S-TiO2@MOF-808. When n (Zr4+): n(Ti4+) was 1: 5, S-TiO2@MOF-808 showed better oxygen reduction reaction (ORR). The introduction of S-TiO2 restrained the framework collapse of MOF-808, S-TiO2@MOF-808 showed much higher catalytic stability in reaction. The recombination of sulfur and TiO2 reduced the charge transfer resistance, accelerated the electron transfer rate, and improved ORR greatly. The maximum power density of S-TiO2@MOF-808-MFC was 84.05 mW/m2, about 2.17 times of S-TiO2-MFC (38.64 mW/m2). The maximum voltage of S-TiO2@MOF-808-MFC was 205 mV, and the stability was maintained for 6 d.