(2-Amino-5-chloro­benzene­sulfonato)bis­(triphenyl­phosphine)silver(I)

The asymmetric unit of the title mononuclear compound, [Ag(C6H5ClNO3S)(C18H15P)2], contains four independent mol­ecules. In each of the mol­ecules, the AgI cation is three-coordinated by two triphenyl­phosphine ligands, and one N atom from a 2-amino-5-chloro­benzene­sulfonate anion. The mol­ecules are linked into a one-dimensional supra­molecular structure by N—H⋯O hydrogen bonds

Evolution of pore structure, submaceral composition and produced gases of two Chinese coals during thermal treatment

This research was funded by the Research Program for Excellent Doctoral Dissertation Supervisor of Beijing (grant no. YB20101141501), the Fundamental Research Funds for Central Universities (grant no. 35832015136) and Key Project of Coal-based Science and Technology in Shanxi Province-CBM accumulation model and reservoir evaluation in Shanxi province (grant no. MQ2014-01).Peer reviewedPostprin

Effects of Termites on Soil pH and Its Application for Termite Control in Zhejiang Province, China

Soil dwelling termites dig nests in the ground that have a significant impact on the soil environment. Activities of termites can result in accumulation of organic matter and enrichment of nutrients and minerals in the soil. Samples from the nest/surrounding soils of two termite species (Odontotermes formosanus (Shiraki) and Reticulitermes flaviceps (Oshima)) and termite non-invaded soils in the seawall of the Qiantang River, Zhejiang Province, China were collected and analysed for soil pH. The results show that the observed termites prefer an acidic environment and that their activities elevate the pH of termite mound soil compared with surrounding soil. Considering the differences in the distribution areas, termite species, and properties of termite mounds and surrounding soils, this paper also examines the literature concerning the effects of termites on soil pH. After summarizing the pH of the termite survival soil environment, the feasibility of termite control by modifying the soil pH is addressed. Finally, some topics for future research are discussed

Comparative and phylogenomic studies on the mitochondrial genomes of Pentatomomorpha (Insecta: Hemiptera: Heteroptera)

<p>Abstract</p> <p>Background</p> <p>Nucleotide sequences and the gene arrangements of mitochondrial genomes are effective tools for resolving phylogenetic problems. Hemipteroid insects are known to possess highly reorganized mitochondrial genomes, but in the suborder Heteroptera (Insecta: Hemiptera), there was only one complete mitochondrial genome sequenced without gene rearrangement and the phylogeny of infraorder Pentatomomorpha in Heteroptera was still uncertain.</p> <p>Results</p> <p>Fifteen mitochondrial genomes of the suborder Heteroptera were sequenced. Gene rearrangements were found as follows: 1) <it>tRNA-I </it>and <it>tRNA-Q </it>switched positions in Aradidae, 2) <it>tRNA-T </it>and <it>tRNA-P </it>switched positions in Largidae and Pyrrhocoridae. Two recombination events were found in Alydidae and Malcidae. The other mt-genomes were organized in the same way as observed in <it>Drosophila yakuba</it>. The phylogenetic analyses of infraorder Pentatomomorpha based on the nucleotide sequence raised the hypothesis of (Aradoidea + (Pentatomoidea + (Pyrrhocoroidea + (Lygaeoidea + Coreoidea)))). The rearrangement of <it>tRNA-T </it>and <it>tRNA-P </it>also linked Largidae and Pyrrhocoridae together. Furthermore, the conserved sequence block in the unusual intergenic spacers between <it>tRNA-H </it>and <it>ND4 </it>favored the monophyly of Lygaeoidea. Tetranucleotide ATCA was inferred to be the initiation codon of <it>ND2 </it>in Cydnidae. No correlation was found between the rates of nucleotide substitution and gene rearrangement. CG content was significantly correlated with the nucleotide substitution rate of each gene. For ND1, there was a positive correlation (<it>P </it>< 0.01) between amino acids variations and hydrophobicity, but a negative correlation (<it>P </it>< 0.01) for ND6. No conserved sequence was found among the control regions and these regions were not always the most AT-rich region of the mt-genome.</p> <p>Conclusion</p> <p>Heteropteran insects are extremely complex groups worthy of further study because of the unusual tetranucleotide initiation codon and their great mt-genomic diversity, including gene rearrangements and recombinations. The mt-genome is a powerful molecular marker for resolving phylogeny at the level of the superfamily and family. Gene rearrangements were not correlated with nucleotide substitution rates. CG content variation caused the different evolutionary patterns among genes. For ND1, in many polar or nonpolar regions the specific identity of the amino acid residues might be more important than maintaining the polarity of these regions, while the opposite is true for ND6. Most sequences of the control regions did not appear to be important for regulatory functions. Finally, we suggest that the term "AT-rich regions" should not be used.</p

Diaqua­bis(1,10-phenanthroline)magnesium dichromate(VI) 1,10-phenanthroline disolvate

In the title compound, [Mg(C12H8N2)2(H2O)2][Cr2O7]·2C12H8N2, the cation and anion are situated on a twofold rotation axis. The MgII ion is coordinated by four N atoms from two 1,10-phenanthroline ligands and two O atoms from coordinated water mol­ecules in a distorted octa­hedral geometry. Inter­molecular O—H⋯N and O—H⋯O hydrogen bonds and π–π inter­actions between the aromatic rings [shortest centroid–centroid separation = 3.527 (2) Å] link the cations, anions and 1,10-phenanthroline solvent mol­ecules into a hydrogen-bonded cluster

Phylogenetic analysis of the true water bugs (Insecta: Hemiptera: Heteroptera: Nepomorpha): evidence from mitochondrial genomes

<p>Abstract</p> <p>Background</p> <p>The true water bugs are grouped in infraorder Nepomorpha (Insecta: Hemiptera: Heteroptera) and are of great economic importance. The phylogenetic relationships within Nepomorpha and the taxonomic hierarchies of Pleoidea and Aphelocheiroidea are uncertain. Most of the previous studies were based on morphological characters without algorithmic assessment. In the latest study, the molecular markers employed in phylogenetic analyses were partial sequences of 16S rDNA and 18S rDNA with a total length about 1 kb. Up to now, no mitochondrial genome of the true water bugs has been sequenced, which is one of the largest data sets that could be compared across animal taxa. In this study we analyzed the unresolved problems in Nepomorpha using evidence from mitochondrial genomes.</p> <p>Results</p> <p>Nine mitochondrial genomes of Nepomorpha and five of other hemipterans were sequenced. These mitochondrial genomes contain the commonly found 37 genes without gene rearrangements. Based on the nucleotide sequences of mt-genomes, Pleoidea is not a member of the Nepomorpha and Aphelocheiroidea should be grouped back into Naucoroidea. Phylogenetic relationships among the superfamilies of Nepomorpha were resolved robustly.</p> <p>Conclusion</p> <p>The mt-genome is an effective data source for resolving intraordinal phylogenetic problems at the superfamily level within Heteroptera. The mitochondrial genomes of the true water bugs are typical insect mt-genomes. Based on the nucleotide sequences of the mt-genomes, we propose the Pleoidea to be a separate heteropteran infraorder. The infraorder Nepomorpha consists of five superfamilies with the relationships (Corixoidea + ((Naucoroidea + Notonectoidea) + (Ochteroidea + Nepoidea))).</p

Piperazine-1,4-diium bis­(3,5-dicarboxy­benzoate)

The asymmetric unit of the title salt, C4H12N2 2+·2C9H5O6 −, comprises one half of the piperazine-1,4-diium dication lying on an inversion centre and one 3,5-dicarboxy­benzoate anion. In the crystal, the ions are linked into a two-dimensional framework parallel to (101) by N—H⋯O and O—H⋯O hydrogen bonds

N-Cyclo­hexyl-2-(2,3-dichloro­phen­oxy)acetamide

In the crystal structure of title compound, C14H17Cl2NO2, the cyclo­hexyl ring is in a chair conformation and the mol­ecules are connected via N—H⋯O hydrogen bonding into chains

3,3′-(p-Phenyl­enedimethyl­ene)di-1H-imidazol-1-ium bis­(4-nitro­benzoate)–4-nitro­benzoic acid (1/2)

The asymmetric unit of the title compound, C14H16N4 2+·2C7H4NO4 −·2C7H5NO4, comprises one-half of the 3,3′-(p-phenyl­enedimethyl­ene)di-1H-imidazol-1-ium dication, which lies on an inversion centre, one 4-nitro­benzoate anion and one 4-nitro­benzoic acid mol­ecule. In the crystal, the components are linked into a two-dimensional network parallel to (110) by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds

Poly[μ2-aqua-diaqua­(μ8-3-nitro­benzene-1,2-dicarboxylato)(μ6-3-nitro­benzene-1,2-dicarboxylato)tetra­sodium]

In the title layered coordination polymer, [Na4(C8H3NO6)2(H2O)3]n, the doubly deprotonated 3-nitro­benzene-1,2-dicarboxyl­ate ligands exhibit μ8- and μ6-coordination modes to the sodium ions, generating sheets lying parallel to (001). The coordination environments of the sodium ions are distorted octa­hedral, distorted trigonal-bipyramidal and moncapped trigonal-prismatic. One of the nitro groups is disordered over two sets of sites with site-occupancy factors 0.580 (8):0.419 (2). A network of O—H⋯O and O—H⋯N hydrogen bonds helps to establish the packing