Delia antiqua is a major underground agricultural pest widely distributed in Asia, Europe and North America. In this study, we sequenced and annotated the complete mitochondrial genome of this species, which is the first report of complete mitochondrial genome in the family Anthomyiidae. This genome is a double-stranded circular molecule with a length of 16,141 bp and an A+T content of 78.5%. It contains 37 genes (13 protein-coding genes, 22 tRNAs and 2 rRNAs) and a non-coding A+T rich region or control region. The mitochondrial genome of Delia antiqua presents a clear bias in nucleotide composition with a positive AT-skew and a negative GC-skew. All of the 13 protein-coding genes use ATN as an initiation codon except for the COI gene that starts with ATCA. Most protein-coding genes have complete termination codons but COII and ND5 that have the incomplete termination codon T. This bias is reflected in both codon usage and amino acid composition. The protein-coding genes in the D. antiqua mitochondrial genome prefer to use the codon UUA (Leu). All of the tRNAs have the typical clover-leaf structure, except for tRNA Ser(AGN) that does not contain the dihydrouridine (DHU) arm like in many other insects. There are 7 mismatches with U-U in the tRNAs. The location and structure of the two rRNAs are conservative and stable when compared with other insects. The control region between 12S rRNA and tRNA Ile has the highest A+T content of 93.7% in the D. antiqua mitochondrial genome. The control region includes three kinds of special regions, two highly conserved poly-T stretches, a (TA)n stretch and several G(A)nT structures considered important elements related to replication and transcription. The nucleotide sequences of 13 protein-coding genes are used to construct the phylogenetics of 26 representative Dipteran species. Both maximum likelihood and Bayesian inference analyses suggest a closer relationship of D. antiqua in Anthomyiidae with Calliphoridae, Calliphoridae is a paraphyly, and both Oestroidea and Muscoidea are polyphyletic.

DFT calculations demonstrated that An@B20 (An = U, Np, and Pu) are twenty-coordinated boron molecular drums, and the An–B bond covalency dominates the stability.

The electronic structures of a series of complexes (CpSiMe 3 ) 3 AnSi(NCHMes) 2 ([An−Si], An = Th−Am) with different oxidation states (OS = II, III, and IV) of actinides were investigated using the relativistic density functional theory to explore the actinide−silicon bonding, which was evaluated based on the analyses of quantum theory of atoms in molecules (QTAIM) and electron localization function (ELF). The An−Si bond length variation for a series of [An−Si] with different oxidation states may be attributed to the synergistic effect of the steric hindrance and the ability of the actinide atom to accept electrons. The value of An− Si Mayer bond order (MBO) decreases across the actinide series with the same oxidation state. The values of An−Si MBO for the [An II −Si] − (An = Th−Pu) are the largest in general among the complexes with three actinide oxidation states, except that for the Am−Si MBO of [Am IV − Si] + is the largest because of more covalent Am−Si bond in the [Am IV −Si] + complex. The An−Si bonds are highly polarized due to lone pair electrons located on the Si 3s orbital. Moreover, the An−Si bonds possess donor−acceptor interactions according to the analyses of QTAIM and ELF. In addition, the binding energies suggest that the tetravalent complexes [An IV −Si] + are thermodynamically accessible, of which [U IV −Si] + and [Pu IV −Si] + are the most preferable. The electron affinity analysis suggests that the reduction reaction of [An III −Si] → [An II −Si] − should become increasingly facile across the actinide series from Th to Am. This work expands the knowledge on the An−Si bonding, especially for the transuranium−silicon bonding, and guides synthesis of the actinide silicon complexes with different oxidation states.