Characterization of Eighty-Eight Single-Nucleotide Polymorphism Markers in the Manila Clam <i>Ruditapes philippinarum</i> Based on High-Resolution Melting (HRM) Analysis

Single-nucleotide polymorphisms (SNPs) are the most commonly used DNA markers in population genetic studies. We used the Illumina HiSeq4000 platform to develop single-nucleotide polymorphism (SNP) markers for Manila clam Ruditapes philippinarum using restriction site-associated DNA sequencing (RAD-seq) genotyping. Eighty-eight SNP markers were successfully developed by using high-resolution melting (HRM) analysis, with a success rate of 44%. SNP markers were analyzed for genetic diversity in two clam populations. The observed heterozygosity per locus ranged from 0 to 0.9515, while the expected heterozygosity per locus ranged from 0.0629 to 0.4997. The value of FIS was estimated to be from −0.9643 to 1.0000. The global Fst value was 0.1248 (p p < 0.0006). These SNP markers provide a valuable resource for population and conservation genetics studies in this commercially important species

Comparative Expression Profiling Reveals the Regulatory Effects of Dietary Mannan Oligosaccharides on the Intestinal Immune Response of Juvenile <i>Megalobrama amblycephala</i> against <i>Aeromonas hydrophila</i> Infection

Mannan oligosaccharides (MOS) are functional oligosaccharides with beneficial effects on the non-specific immunity of Megalobrama amblycephala, but systematic studies on the immunomodulatory mechanisms of MOS are still lacking. To investigate the protective mechanisms of three different levels of dietary MOS supplementation on the intestinal immunity of juvenile M. amblycephala, comparative digital gene expression (DGE) profiling was performed. In this study, 622 differentially expressed genes (DEGs) were identified, while the similar expression tendency of 34 genes by qRT-PCR validated the accuracy of the DGE analyses. Gene Ontology (GO) enrichment revealed that the DEGs were mainly enriched in two functional categories of biological process and molecular function. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the DEGs were mainly related to complement and coagulation cascades, coagulation cascades, platelet activation, natural killer cell mediated cytotoxicity, Fc gamma R-mediated phagocytosis and antigen processing and presentation. In addition, the pro-inflammatory, apoptosis and tight junction-related genes were more significantly up-regulated upon infection in the dietary MOS groups to enhance host immune functions and maintain the stability of the intestinal barrier. These results will be helpful to clarify the regulatory mechanism of MOS on the intestinal immunity of M. amblycephala and lay the theoretical foundation for the prevention and protection of fish bacterial diseases

Highly efficient mass production of boron nitride nanosheets via a borate nitridation method

Boron nitride nanosheets (BNNSs) have attracted intensive attention because of their fantastic properties, including excellent electrical insulating ability, splendid thermal conductivity, and outstanding oxidation resistance. However, facing the rising demand for versatile applications, the cost-effective mass production of BNNSs, similar to graphene, remains a huge challenge. Here, we provide a highly effective strategy for BNNS synthesis via a borate nitridation method utilizing solid borate precursors, producing gram-scale yields with efficiencies up to 88%. Combined with density functional theory (DFT) calculations, a vapor–solid–solid (VSS) mechanism was proposed in which ammonia vapor reacts with the solid borates, producing solid BNNSs at the vapor–solid interfaces. The strategy proposed herein, together with the diversity of borate compounds, allows numerous choices for the facile mass production of BNNSs at low cost. In addition, the remarkably enhanced thermal conductivity in composite materials demonstrated good quality and huge potential for these BNNSs in thermal management. This work reveals a cost-efficient method for the large-scale production of BNNSs, which should promote practical applications in various fields

Elaborately Designed Micro–Mesoporous Graphitic Carbon Spheres as Efficient Polysulfide Reservoir for Lithium–Sulfur Batteries

Hybrid micro–mesoporous graphitic carbon spheres (M-MGCSs) featuring ordered mesoporous graphene-like cores and uniform microporous carbon shells are designed by transformation of self-assembled Fe₃O₄ nanoparticle supraparticles and are used as an efficient, dual spatially confined sulfur reservoir for lithium–sulfur (Li–S) batteries. Such rationally designed M-MGCSs synergistically combine the merits of micro- and mesoporous carbons when used as the sulfur host in Li–S batteries: the core having interconnected spherical mesopores of 9.0 nm provides sufficient space for loading S₈ molecules, while the shell having micropores of 0.6 nm can entrap only small S_2–4 molecules, which are converted into electrolyte-insoluble polysulfides during discharge, minimizing the outward diffusion of long-chain polysulfides from the core. These advantageous structural features, combined with the highly graphitic nature and mesoscale spherical morphology of M-MGCSs, enable Li–S cathodes with greatly improved performance even at high sulfur areal loadings

Highly Efficient Mass Production of Boron Nitride Nanosheets via a Borate Nitridation Method

Boron nitride nanosheets (BNNSs) have attracted intensive attention because of their fantastic properties, including excellent electrical insulating ability, splendid thermal conductivity, and outstanding oxidation resistance. However, facing the rising demand for versatile applications, the cost-effective mass production of BNNSs, similar to graphene, remains a huge challenge. Here, we provide a highly effective strategy for BNNS synthesis via a borate nitridation method utilizing solid borate precursors, producing gram-scale yields with efficiencies up to 88%. Combined with density functional theory (DFT) calculations, a vapor–solid–solid (VSS) mechanism was proposed in which ammonia vapor reacts with the solid borates, producing solid BNNSs at the vapor–solid interfaces. The strategy proposed herein, together with the diversity of borate compounds, allows numerous choices for the facile mass production of BNNSs at low cost. In addition, the remarkably enhanced thermal conductivity in composite materials demonstrated good quality and huge potential for these BNNSs in thermal management. This work reveals a cost-efficient method for the large-scale production of BNNSs, which should promote practical applications in various fields