Insights into the solution structure of the hydrated uranyl ion from neutron scattering and EXAFS experiments.

The solution structure of 1.0 M Uranyl Chloride has been determined by the EPSR modelling of a combination of neutron scattering and EXAFS data. The experimental data show an equilibrium in solution between [UO(HO)] and [UOCl(HO)] with a stability constant of 0.

A multi-technique study of altered granitic rock from the Krunkelbach Valley uranium deposit, Southern Germany.

Herein, a multi-technique study was performed to reveal the elemental speciation and microphase composition in altered granitic rock collected from the Krunkelbach Valley uranium (U) deposit area near an abandoned U mine, Black Forest, Southern Germany. The former Krunkelbach U mine with 1-2 km surrounding area represents a unique natural analogue site with the rich accumulation of secondary U minerals suitable for radionuclide migration studies from a spent nuclear fuel (SNF) repository. Based on a micro-technique analysis using several synchrotron-based techniques such as X-ray fluorescence analysis, X-ray absorption spectroscopy, powder X-ray diffraction and laboratory-based scanning electron microscopy and Raman spectroscopy, the complex mineral assemblage was identified.

Flying Around in the Genome: Characterization of LINE-1 in Chiroptera.

L1s are transposable elements that move by a copy-and-paste mechanism that continuously increases their copy number in the genome, such that each genome has a record of the L1 history in that host lineage. They make up about 20% of the genomes of eutherian mammals and have played a major role in shaping genome evolution. Chiroptera has the lowest average genome size among mammalian orders and the only documented case of L1 extinction affecting an entire mammalian family.

A computational investigation of orbital overlap versus energy degeneracy covalency in [UE] (E = O, S, Se, Te) complexes.

The extent and nature of covalency in actinide complexes is an important and complex question. There are two main mechanisms of covalency, namely overlap of orbitals or degeneracy of the energies of the ligand and actinide metal, and computational approaches can play a significant part in rationalising the relative importance of each. In this work, we use a suite of computational approaches including Natural Bond Orbitals (NBO), Quantum Theory of Atoms in Molecules (QTAIM) and Interacting Quantum Atoms (IQA) to probe these effects in [E[double bond, length as m-dash]U[double bond, length as m-dash]E] (E = O, S, Se, Te) and [UE(HO)] compounds.

Competitive Reaction of Neptunium(V) and Uranium(VI) in Potassium-Sodium Carbonate-Rich Aqueous Media: Speciation Study with a Focus on High-Resolution X-ray Spectroscopy.

Neptunium(V) and uranium(VI) are precipitated from an aqueous potassium-sodium-containing carbonate-rich solution, and the solid phases are investigated. U/Np M-edge high-energy resolution X-ray absorption near edge structure (HR-XANES) spectroscopy and Np 3d4f resonant inelastic X-ray scattering (3d4f RIXS) are applied in combination with thermodynamic calculations, U/Np L-edge XANES, and extended X-ray absorption fine structure (EXAFS) studies to analyze the local atomic coordination and oxidation states of uranium and neptunium. The XANES/HR-XANES analyses are supported by ab initio quantum-chemical computations with the finite difference method near-edge structure code (FDMNES).

Perfluorinated phosphine and hybrid P-O ligands for Pd catalysed C-C bond forming reactions in solution and on Teflon supports.

The synthesis of two types of phosphine ligands that feature perfluorinated ponytails is reported. A bidentate (RfCHCH)PCHCHP(CHCHRf) (Rf = CF(CF) ; = 5, 7) and an alkoxyphosphine made by ring opening a fluorous epoxide, RfCHCH(OH)CHPR (Rf = CF(CF)), have been prepared and spectroscopically characterised. The electronic effects of the fluorous chains have been elucidated from either the or coupling constants in Pt(ii) or phosphine selenide compounds.

Americium incorporation into studtite: a theoretical and experimental study.

Studtite, [UO(η-O)(HO)]·2HO, and metastudtite, [UO(η-O)(HO)], are important phase alterations of UO in a spent nuclear fuel repository and have previously been shown to react with Np(v). In this work we extend the study to Am(v) on a tracer scale and show spectroscopic evidence that the Am is incorporated into the structure of studtite as Am(iii). A computational study on the possible mechanisms for the incorporation of Np and Am shows that protonation of the -yl oxygen is the favoured route and the calculated incorporation energies are large and positive.

Structure-activity relationships of new Organotin(IV) anticancer agents and their cytotoxicity profile on HL-60, MCF-7 and HeLa human cancer cell lines.

There is a growing interest in the cancer cell growth inhibitory effects of organotin (IV) compounds and, accordingly, a new series of dimethyl-, di-(n-butyl)-, diphenyl- and chloro-phenyl tin(IV) complexes with a Schiff base core were prepared. Their binding to DNA was assessed by UV thermal denaturation showing no interaction and by UV-vis titration exhibiting moderate interaction by intercalation. Complexes having n-butyl substituents were more potent and cytotoxic against human leukemia, breast and cervical cancer cell lines than other organotin(IV) complexes tested.

Oxidation of uranium(iv) thiocyanate complexes: cation-cation interactions in mixed-valent uranium coordination chains.

Oxidation of Cs4[U(NCS)8] in MeCN or DMF affords structurally characterised examples of the mixed-valent UIV/VI compound Cs14[{U(NCS)8}3{UO2(NCS)4(H2O)}]·4.5H2O, or the [UIV-UV-UIV][UVI] species [U(DMF)8(μ-O)U(NCS)5(μ-O)U(DMF)7(NCS)][UO2(NCS)5]. Vibrational and magnetism data support their oxidation state formulism, which is further corroborated by computational methodology.

Non-covalent interactions of uranyl complexes: a theoretical study.

We report a set of theoretical calculations designed to examine the potential of model uranyl complexes to participate in hydrogen- and halogen-bonding. Potential energy scans for the interaction of [UO2Cl2(H2O)3] and [UO2(NCSe)2(H2O)3] with a single water molecule demonstrate that uranyl is a weak hydrogen bond acceptor, but that equatorially coordinated water is a strong hydrogen bond donor. These predictions are supported by a survey of contacts reported in the Cambridge Structural Database.

Pseudohalide Tectons within the Coordination Sphere of the Uranyl Ion: Experimental and Theoretical Study of C-H···O, C-H···S, and Chalcogenide Noncovalent Interactions.

A series of uranyl thiocyanate and selenocyanate of the type [RN][UO(NCS)] (R = Bu, MeBz, EtBz), [PhP][UO(NCS)(NO)] and [RN][UO(NCSe)] (R = Me, Pr, EtBz) have been prepared and structurally characterized. The resulting noncovalent interactions have been examined and compared to other examples in the literature. The nature of these interactions is determined by the cation so that when the alkyl groups are small, chalcogenide···chalcogenide interactions are present, but this "switches off" when R = Pr and charge assisted U═O···H-C and S(e)···H-C hydrogen bonding remain the dominant interaction.

Dehydration of the Uranyl Peroxide Studtite, [UO(η-O)(HO)]·2HO, Affords a Drastic Change in the Electronic Structure: A Combined X-ray Spectroscopic and Theoretical Analysis.

The minerals studtite, [UO(η-O)(HO)]·2HO, and metastudtite, [UO(η-O)(HO)], are uranyl peroxide minerals that are major oxidative alteration phases of UO under conditions of geological storage. The dehydration of studtite has been studied using X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy. XPS of the U 4f region shows small but significant differences between studtite and metastudtite, with the 4f binding energy of studtite being the highest reported for a uranyl mineral studied by this technique.

Elevated mitochondrial genome variation after 50 generations of radiation exposure in a wild rodent.

Currently, the effects of chronic, continuous low dose environmental irradiation on the mitochondrial genome of resident small mammals are unknown. Using the bank vole () as a model system, we tested the hypothesis that approximately 50 generations of exposure to the Chernobyl environment has significantly altered genetic diversity of the mitochondrial genome. Using deep sequencing, we compared mitochondrial genomes from 131 individuals from reference sites with radioactive contamination comparable to that present in northern Ukraine before the 26 April 1986 meltdown, to populations where substantial fallout was deposited following the nuclear accident.

Structural Variability of 4f and 5f Thiocyanate Complexes and Dissociation of Uranium(III)-Thiocyanate Bonds with Increased Ionicity.

A series of complexes [EtN][Ln(NCS)(HO)] (Ln = Pr, Tb, Dy, Ho, Yb) have been structurally characterized, all showing the same structure, namely a distorted square antiprismatic coordination geometry, and the Ln-O and Ln-N bond lengths following the expected lanthanide contraction. When the counterion is Cs, a different structural motif is observed and the eight-coordinate complex Cs[Nd(NCS)] isolated. The thorium compounds [MeN][Th(NCS)(NO)] and [MeN][Th(NCS)(NO)] have been characterized, and high coordination numbers are also observed.

Chromosomal Evolution in Chiroptera.

Chiroptera is the second largest order among mammals, with over 1300 species in 21 extant families. The group is extremely diverse in several aspects of its natural history, including dietary strategies, ecology, behavior and morphology. Bat genomes show ample chromosome diversity (from 2n = 14 to 62).

Conflicting Evolutionary Histories of the Mitochondrial and Nuclear Genomes in New World Myotis Bats.

The rapid diversification of Myotis bats into more than 100 species is one of the most extensive mammalian radiations available for study. Efforts to understand relationships within Myotis have primarily utilized mitochondrial markers and trees inferred from nuclear markers lacked resolution. Our current understanding of relationships within Myotis is therefore biased towards a set of phylogenetic markers that may not reflect the history of the nuclear genome.

Characterisation of isothiocyanic acid, HNCS, in the solid state: trapped by hydrogen bonding.

The crystal structure of [PhP][NCS]·HNCS is reported. This is the first structural determination of isothiocyanic acid and hydrogen bonding between the NCS anion and HNCS fragment explored using computational chemistry.

Human-modified habitats change patterns of population genetic structure and group relatedness in Peter's tent-roosting bats.

Although coloniality is widespread among mammals, it is still not clear what factors influence composition of social groups. As animals need to adapt to multiple habitat and environmental conditions throughout their range, variation in group composition should be influenced by adaptive adjustment to different ecological factors. Relevant to anthropogenic disturbance, increased habitat modification by humans can alter species' presence, density, and population structure.

A Pain in the Psoas.

General medical conditions are an important part of the differential diagnosis in athletes presenting with pain or injury. A psoas abscess is a collection of pus in the iliopsoas muscle compartment and is a rare cause of hip, low back, or groin pain. Psoas abscesses may have significant morbidity and mortality, as 20% progress to septic shock.

An investigation of the interactions of Eu³⁺ and Am³⁺ with uranyl minerals: implications for the storage of spent nuclear fuel.

The reaction of a number of uranyl minerals of the (oxy)hydroxide, phosphate and carbonate types with Eu(iii), as a surrogate for Am(iii), have been investigated. A photoluminescence study shows that Eu(iii) can interact with the uranyl minerals Ca[(UO2)6(O)4(OH)6]·8H2O (becquerelite) and A[UO2(CO3)3]·xH2O (A/x = K3Na/1, grimselite; CaNa2/6, andersonite; and Ca2/11, liebigite). For the minerals [(UO2)8(O)2(OH)12]·12H2O (schoepite), K2[(UO2)6(O)4(OH)6]·7H2O (compreignacite), A[(UO2)2(PO4)2]·8H2O (A = Ca, meta-autunite; Cu, meta-torbernite) and Cu[(UO2)2(SiO3OH)2]·6H2O (cuprosklodowskite) no Eu(iii) emission was observed, indicating no incorporation into, or sorption onto the structure.

Integration of molecular cytogenetics, dated molecular phylogeny, and model-based predictions to understand the extreme chromosome reorganization in the Neotropical genus Tonatia (Chiroptera: Phyllostomidae).

Background: Defining factors that contributed to the fixation of a high number of underdominant chromosomal rearrangements is a complex task because not only molecular mechanisms must be considered, but also the uniqueness of natural history attributes of each taxon. Ideally, detailed investigation of the chromosome architecture of an organism and related groups, placed within a phylogenetic context, is required. We used multiple approaches to investigate the dynamics of chromosomal evolution in lineages of bats with considerable karyotypic variation, focusing on the different facets contributing to fixation of the exceptional chromosomal changes in Tonatia saurophila.

Rolling-circle transposons catalyze genomic innovation in a mammalian lineage.

Rolling-circle transposons (Helitrons) are a newly discovered group of mobile DNA widespread in plant and invertebrate genomes but limited to the bat family Vespertilionidae among mammals. Little is known about the long-term impact of Helitron activity because the genomes where Helitron activity has been extensively studied are predominated by young families. Here, we report a comprehensive catalog of vetted Helitrons from the 7× Myotis lucifugus genome assembly.

Thiocyanate complexes of uranium in multiple oxidation states: a combined structural, magnetic, spectroscopic, spectroelectrochemical, and theoretical study.

A comprehensive study of the complexes A4[U(NCS)8] (A = Cs, Et4N, (n)Bu4N) and A3[UO2(NCS)5] (A = Cs, Et4N) is described, with the crystal structures of [(n)Bu4N]4[U(NCS)8]·2MeCN and Cs3[UO2(NCS)5]·O0.5 reported. The magnetic properties of square antiprismatic Cs4[U(NCS)8] and cubic [Et4N]4[U(NCS)8] have been probed by SQUID magnetometry.

Multilocus Characterization of a Woodrat (Genus Neotoma) Hybrid Zone.

In order to investigate hybridization between 2 species of woodrats, Neotoma floridana and Neotoma micropus, 103 specimens were collected, in March of 1988, from a known area of sympatry, and compared with reference collections from areas of allopatry. Ten genetic markers, consisting of 7 microsatellite loci, 1 mitochondrial gene (cytochrome-b [Cytb]), and 2 nuclear introns (intron 2 of the vertebrate alcohol dehydrogenase gene [Adh1-I2] and intron 7 of the beta-fibrinogen gene [Fgb-I7]) were used to develop a composite genotype for each individual and for detection of hybridization. Six individuals were identified as pure parental N.

Dietary and flight energetic adaptations in a salivary gland transcriptome of an insectivorous bat.

We hypothesized that evolution of salivary gland secretory proteome has been important in adaptation to insectivory, the most common dietary strategy among Chiroptera. A submandibular salivary gland (SMG) transcriptome was sequenced for the little brown bat, Myotis lucifugus. The likely secretory proteome of 23 genes included seven (RETNLB, PSAP, CLU, APOE, LCN2, C3, CEL) related to M.