RETRACTED: Metallic Ions Encapsulated in Electrospun Nanofiber for Antibacterial and Angiogenesis Function to Promote Wound Repair

Electrospun nanofiber is an attractive biomaterial for skin tissue engineering because it mimics the natural fibrous extracellular matrix structure and creates a physical structure suitable for skin tissue regeneration. However, endowing the nanofibrous membranes with antibacterial and angiogenesis functions needs to be explored. In the current study, we aimed to fabricate gelatin/polycaprolactone (GT/PCL) (GT/PCL-Ag-Mg) nanofibers loaded with silver (Ag) and magnesium (Mg) ions for antibacterial activity and pro-angiogenesis function for wound repair. The fabricated GT/PCL membranes had a nanofibrous structure with random arrangement and achieved sustained release of Ag and Mg ions. In vitro results indicated that the GT/PCL-Ag-Mg membranes presented satisfactory cytocompatibility with cell survival and proliferation. In addition, the membranes with Ag demonstrated good antibacterial capacity to both gram-positive and gram-negative bacteria, and the Mg released from the membranes promoted the tube formation of vascular endothelial cells. Furthermore, in vivo results demonstrated that the GT/PCL-Ag-Mg membrane presented an accelerated wound healing process compared with GT/PCL membranes incorporated with either Ag or Mg ions and pure GT/PCL alone. Superior epidermis formation, vascularization, and collagen deposition were also observed in GT/PCL-Ag-Mg membrane compared with the other membranes. In conclusion, a multifunctional GT/PCL-Ag-Mg membrane was fabricated with anti-infection and pro-angiogenesis functions, serving as a potential metallic ion-based therapeutic platform for applications in wound repair

miRNA transcriptome reveals key miRNAs and their targets contributing to the difference in Cd tolerance of two contrasting maize genotypes

Soil cadmium (Cd) contamination is a global environmental and food safety production issue. microRNAs (miRNAs) are proven to be involved in plant growth and development, and abiotic/biotic stress response, but their role in Cd tolerance is largely unknown in maize. To understand the genetic basis of Cd tolerance, two maize genotypes differing in Cd tolerance (L42, a sensitive genotype and L63, a tolerant genotype) were selected, and miRNA sequencing was carried out at nine-day-old seedlings exposed to 24 h Cd stress (5 μM CdCl2). A total of 151 differentially expressed miRNAs were identified, including 20 known miRNAs and 131 novel miRNAs. The results revealed that 90 and 22 miRNAs were up-regulated and down-regulated by Cd in Cd-tolerant genotype L63, and there were 23 and 43 miRNAs in Cd-sensitive genotype L42, respectively. Twenty-six miRNAs were up-regulated in L42 and unchanged or down-regulated in L63, or unchanged in L42 and down-regulated in L63. There were 108 miRNAs that were up-regulated in L63 and unchanged or down-regulated in L42, or unchanged in L63 and down-regulated in L42. Their target genes were enriched mainly in peroxisomes, glutathione (GSH) metabolism, ABC transporter, and ubiquitin-protease system. Among them, target genes involved in the peroxisome pathway and GSH metabolism might play key roles in Cd tolerance in L63. Besides, several ABC transporters which might involve in Cd uptake and transport were identified. The differentially expressed miRNAs or target genes could be used for breeding low grain Cd accumulation and high Cd tolerance cultivars in maize

Metabolome Analysis Revealed the Mechanism of Exogenous Glutathione to Alleviate Cadmium Stress in Maize (<i>Zea mays</i> L.) Seedlings

Cadmium (Cd) is one of the major heavy metal pollutants in the environment and imposes severe limitations on crop growth and production. Glutathione (GSH) plays an important role in plant Cd tolerance which is able to scavenge stresses-induced reactive oxygen species (ROS) and is involved in the biosynthesis of phytochelatins (PCs). Our previous study revealed that Cd stress affects maize growth, and the GSH treatment could relieve Cd stress in maize seedlings. In this study, we attempted to characterize the metabolomics changes in maize leaves and roots under Cd stress and exogenous GSH conditions. We identified 145 and 133 metabolites in the leaves and roots, respectively. Cd stress decreased the tricarboxylic acid cycle (TCA cycle) metabolism and increased the amino acid contents in the leaves, while it decreased the amino acid contents, increased the TCA cycle metabolism, the sugar contents, and shikimic acid metabolism in the roots. On the other hand, exogenous GSH increased the GSH content, changed the production of metabolites related to antioxidant systems (such as ascorbic acid-related metabolites and flavonoid-related metabolites), and alleviated lipid peroxidation, thereby alleviating the toxic effect of Cd stress on maize. These findings support the idea that GSH alleviates Cd-induced stress in maize and may help to elucidate the mechanism governing Cd-induced stress and the GSH-driven alleviation effect

Accelerated prediction of Cu-based single-atom alloy catalysts for CO2 reduction by machine learning

Various strategies, including controls of morphology, oxidation state, defect, and doping, have been developed to improve the performance of Cu-based catalysts for CO2 reduction reaction (CO2RR), generating a large amount of data. However, a unified understanding of underlying mechanism for further optimization is still lacking. In this work, combining first-principles calculations and machine learning (ML) techniques, we elucidate critical factors influencing the catalytic properties, taking Cu-based single atom alloys (SAAs) as examples. Our method relies on high-throughput calculations of 2669 CO adsorption configurations on 43 types of Cu-based SAAs with various surfaces. Extensive ML analyses reveal that low generalized coordination numbers and valence electron number are key features to determine catalytic performance. Applying our ML model with cross-group learning scheme, we demonstrate the model generalizes well between Cu-based SAAs with different alloying elements. Further, electronic structure calculations suggest surface negative center could enhance CO adsorption by back donating electrons to antibonding orbitals of CO. Finally, several SAAs, including PCu, AgCu, GaCu, ZnCu, SnCu, GeCu, InCu, and SiCu, are identified as promising CO2RR catalysts. Our work provides a paradigm for the rational design and fast screening of SAAs for various electrocatalytic reactions

Synthesis of 1,3-Azaphospholes with Pyrrolo[1,2‑<i>a</i>]quinoline Skeleton and Their Optical Applications

A facile synthesis of 1,3-azaphospholes with a pyrrolo­[1,2-<i>a</i>]­quinoline skeleton has been described. These new annulated 1,3-azaphospholes exhibit good photoelectric performance and can be used as the emitting dopant in organic light-emitting diodes (OLEDs) and dye for bioimaging