944 research outputs found

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

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    <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

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    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

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    <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

    A study of health effects of long-distance ocean voyages on seamen using a data classification approach

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    Background: Long-distance ocean voyages may have substantial impacts on seamen’s health, possibly causing malnutrition and other illness. Measures can possibly be taken to prevent such problems from happening through preparing special diet and making special precautions prior or during the sailing if a detailed understanding can be gained about what specific health effects such voyages may have on the seamen. Methods: We present a computational study on 200 seamen using 41 chemistry indicators measured on their blood samples collected before and after the sailing. Our computational study is done using a data classification approach with a support vector machine-based classifier in conjunction with feature selections using a recursive feature elimination procedure. Results: Our analysis results suggest that among the 41 blood chemistry measures, nine are most likely to be affected during the sailing, which provide important clues about the specific effects of ocean voyage on seamen’s health. Conclusions: The identification of the nine blood chemistry measures provides important clues about the effects of long-distance voyage on seamen’s health. These findings will prove to be useful to guide in improving the living and working environment, as well as food preparation on ships

    1,1′-[1,4-Phenyl­enebis(methyl­ene)]bis­(2-methyl-1H-imidazol-3-ium) 2,4-dicarb­oxy­benzene-1,5-dicarboxyl­ate monohydrate

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    In the dication of the title compound, C16H20N4 2+·C10H4O8 2−·H2O, the dihedral angles formed by mean planes of the imidazolium rings and the benzene ring are 69.05 (18) and 89.1 (2)°. In the crystal, the components are linked into a three-dimensional network by inter­molecular N—H⋯O and O—H⋯O hydrogen bonds

    Organocatalyzed Asymmetric Reaction Using α-Isothiocyanato Compounds

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    Organocatalyzed asymmetric reaction using α-isothiocyanato compounds has received much attention in the past 5 years, and significant progress has been made for three types of isothiocyanato compounds, including α-isothiocyanato amides, esters, and phosphonates. This chapter covers the recent advances of α-isothiocyanato compounds in the organocatalytic asymmetric reaction

    Hexa­kis­(1-benzyl-1H-imidazole-κN 3)manganese(II) bis­(perchlorate)

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    In the title compound, [Mn(C10H10N2)6](ClO4)2, the MnII ion, located on an inversion center, is coordinated by six N atoms from three pairs of symmetry-related 1-benzyl-1H-imidazole ligands in a distorted octa­hedral geometry. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds link the complex cations and perchlorate anions

    Bis(2-propyl-1H-imidazol-3-ium) bis­(pyridine-2,6-dicarboxyl­ato-κ3 O 2,N,O 6)cadmate(II)

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    The title salt, (C6H11N2)2[Cd(C7H3NO4)2], displays a discrete mononuclear structure, in which the central CdII atom is six-coordinated in a distorted octa­hedral coordination geometry by two N and four O atoms from two different pyridine-2,6-dicarboxyl­ate anions in an O 2,N,O 6-tridentate chelation mode. The crystal packing is stabilized by N—H⋯O hydrogen bonds and π–π inter­actions [centroid–centroid distance = 3.576 (5) Å]

    Clinical comparison between a percutaneous hydraulic pressure delivery system and balloon tamp system using high-viscosity cement for the treatment of osteoporotic vertebral compression fractures

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    OBJECTIVES: Osteoporotic vertebral compression fractures (OVCFs) affect the elderly population, especially postmenopausal women. Percutaneous kyphoplasty is designed to treat painful vertebral compression fractures for which conservative therapy has been unsuccessful. High-viscosity cement can be injected by either a hydraulic pressure delivery system (HPDS) or a balloon tamp system (BTS). Therefore, the purpose of this study was to compare the safety and clinical outcomes of these two systems. METHODS: A random, multicenter, prospective study was performed. Clinical and radiological assessments were carried out, including assessments of general surgery information, visual analog scale, quality of life, cement leakage, and height and angle restoration. RESULTS: Using either the HPDS or BTS to inject high-viscosity cement effectively relieved pain and improved the patients’ quality of life immediately, and these effects lasted at least two years. The HPDS using high-viscosity cement reduced cost, surgery time, and radiation exposure and showed similar clinical results to those of the BTS. In addition, the leakage rate and the incidence of adjacent vertebral fractures after the HPDS treatment were reduced compared with those after treatment using the classic vertebroplasty devices. However, the BTS had better height and angle restoration abilities. CONCLUSIONS: The percutaneous HPDS with high-viscosity cement has similar clinical outcomes to those of traditional procedures in the treatment of vertebral fractures in the elderly. The HPDS with high-viscosity cement is better than the BTS in the treatment of mild and moderate OVCFs and could be an alternative method for the treatment of severe OVCFs

    The association between serum levels of oxLDL-lgG and oxLDL-lgM autoantibody with adult acute myeloblastic leukaemia

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    <p>Abstract</p> <p>Aim</p> <p>To evaluate the relationship between serum antibodies against ox-LDL levels and adult acute myeloblastic leukemia (AML).</p> <p>Methods</p> <p>Forty three patients with AML and 52 normal controls were enrolled in this study in the Department of Hematology, Tumor Center of Qilu Hospital of Shandong University from Feb. 2008 to Mar.2009. Serum lgG and lgM antibodies versus the oxLDL levels were evaluated by ELISA method. Data was analyzed by covariance and binary Logistic regression.</p> <p>Results</p> <p>Serum mean levels of oxLDL-lgG in patients (38.92 ± 21.1259 ug/ml) were significantly lower than in control subjects (78.88 ± 9.3705 ug/ml); Meanwhile, Serum mean levels of oxLDL-lgM in patients (20.53 ± 10.2990 IU/L) were significantly higher than in control subjects (10.29 ± 10.5771 IU/L). Binary logistic regression showed the odds ratios of association of oxLD-lgG and oxLD-lgM with adult AML were 0.72(95%CI: 0.55-0.94) and 1.11(95%CI: 1.01-1.21) respectively after adjusted for potential confounders.</p> <p>Conclusion</p> <p>In the preliminary investigation we found a descensive oxLDL- lgG and an elevated oxLDL-lgM serum levels for the adult AML. Future studies need to confirm the hypothesis whether they related to the development and progression of adult AML.</p
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