Ultrahigh-Temperature Long-Persistent Luminescence from B2O3-Confined Polycyclic Aromatic Compounds.

Organic molecules and polymers have recently been intensively explored for afterglow materials owing to their low cost and flexible design. However, they normally fail to generate long-persistent luminescence at elevated temperatures, mostly due to the fast deactivation of triplet excited states. Here, we report that polycyclic aromatic compounds (PACs) individually confined in a B2O3 crystalloid emit long-persistent luminescence at high temperatures up to 400 °C. This is facilely accomplished by dispersing a series of aromatic derivatives in an aqueous solution of boric acid, followed by drying, melting, and dehydrating. The resulting highly rigid and thermostable B2O3 crystalloid network provides a matched ultrastrong confinement effect and completely restricts the vibration and rotation of the molecularly distributed PACs even at ultrahigh temperatures and thereby prevents the nonradiative dissipation of triplet excitons and promotes the generation of ultrahigh-temperature long-persistent luminescence. The afterglow colors are responsive to both temperature and time, spanning from ultraviolet to near-infrared regions over a wide temperature range, which is substantially modulated by the subtle balance of phosphorescence and thermally activated delayed fluorescence. These features favor the creation of advanced afterglow materials for visual 3D temperature probing, anticounterfeiting, and data encryption in extreme environments.

Next-Generation Sequencing of the Complete Huaibei Grey Donkey Mitogenome and Mitogenomic Phylogeny of the Equidae Family.

The Huaibei grey donkey (HGD) is an endangered species and a vital native breed in Anhui Province, China. However, its complete mitogenome, phylogeny, and maternal origin remain unclear. The objectives of this study were to detect the genetic diversity of the HGD and investigate its phylogenetic relationship with other breeds to inform conservation management. The complete mitogenome of the HGD was sequenced through next-generation sequencing, and the most variable region in the mitochondrial DNA displacement-loop (D-loop) was amplified via a polymerase chain reaction (PCR). Next, we used the median-joining network (MJN) to calculate the genetic relationships among populations and the neighbor-jointing method to build a phylogenetic tree and speculate as to its origin. The results showed that the mitogenome contains 22 tRNAs, 2 rRNAs, 13 PCGs, and 1 D-loop region. Analyzing the D-loop region of the HGDs, we identified 23 polymorphic sites and 11 haplotypes. The haplotype and nucleotide diversity were 0.87000 (Hd) and 0.02115 (Pi), respectively. The MJN analysis indicated that the HGD potentially has two maternal lineages, and phylogenetic analysis indicated that the Somali lineage could be the most probable domestication center for this breed. Therefore, our mitogenome analysis highlights the high genetic diversity of the HGD, which may have originated from the Somali wild ass, as opposed to the Asian wild ass. This study will provide a useful resource for HGD conservation and breeding.

Tailored Fabrication of Carbon Dot Composites with Full-Color Ultralong Room-Temperature Phosphorescence for Multidimensional Encryption.

Ultralong room-temperature phosphorescence (RTP) is highly useful for information encryption, organic electronics, bioelectronics, etc. However, the preparation of related metal-free materials with multiple colors across the full spectrum remains a major challenge. Herein, a facile method is developed to fabricate boron-doped carbon dot (B-CD) composites with full-color long lifetime RTP continuously tailorable in the range of 466-638 nm simply by pyrolysis of the citric acid and boric acid precursors with various mass ratios at different temperatures. This leads to the formation of luminescent B-CD centers in a rigid polycrystalline B2 O3 matrix, which effectively stabilizes the triplet excited states of B-CDs. Thus, the composites become phosphorescent over a relatively long period (5-12 s) after the removal of the irradiation source. Meanwhile, the increased particle size and oxidation degree of B-CDs obtained at larger citric acid feeding or higher pyrolysis temperature continuously shift the phosphorescence from blue to red. Due to the formation of multiple luminescence centers, the RTP can also be finely modulated by the excitation wavelength. The resulting B-CD composites with highly tunable long lifetime RTP further allow a variety of distinctive applications in multidimensional encryption handily utilizing space, time, and color variations.