bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural, 103Rh NMR and DFT Studies of a Bis(phosphane)RhIII–Porphyrin Derivative
Authors: Munro Orde Q. , Camp Greville L. , Carlton Laurence 
Published: April 2009

AbstractThe synthesis and characterisation of a novel bis(phosphane)rhodium(III)–porphyrin, [Rh(TPP)(PEtPh2)2]SbF6 (compound 1; TPP = dianion of 5,10,15,20‐tetraphenylporphyrin) is described. The X‐ray structure of the bis(dichloromethane) solvate of the complex has a moderately ruffled porphyrin core conformation, which is primarily determined by the relative orientations of the axial phosphane ligands and their steric interaction with the porphyrin phenyl rings. The mean Rh–N and Rh–P bond lengths for 1 are 2.036(5) and 2.401(3) Å, respectively. The mean absolute perpendicular displacements of the porphyrin α‐, β‐ and meso‐carbon atoms from the 24‐atom porphyrin mean plane measure 0.15(3), 0.11(8) and 0.27(2) Å, respectively. The 103Rh NMR chemical shifts of 1, determined by means of indirect detection through polarisation transfer from 31P, were δ = 2480, 2558 and 2590 ppm at 213, 300 and 333 K, respectively. The 31P chemical shifts measured δ = 10.68, 10.79 and 10.84 ppm at the same temperatures. Ruffled and planar porphyrin conformations are possible for 1 and were modelled by using DFT simulations at the PBE1PBE/3‐21G** level of theory with the cation [Rh(TPP)(PEtPh2)2]+. Accurate structural parameters (calculated bond lengths and out‐of‐plane porphyrin core atom displacements within 2 % and 0.02 Å of the experimental values, respectively) and moderately accurate 103Rh isotropic shielding tensors (δRhcalcd. within 13 % of δRhexp. at 0 K using the GIAO method) were calculated with this hybrid functional and relatively small all‐electron basis set. The DFT simulations indicate unusually high fractional electron populations for the formally antibonding 4d and 4d orbitals of both the ruffled and planar conformers of [Rh(TPP)(PEtPh2)2]+, consistent with the relatively low energies of these metal‐character orbitals that are evidently well‐mixed with ligand orbitals.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A Quantum Chemical Study of the Structure, Bonding Characteristics and Nonlinear Optical Properties of Aryloxido and Salicylaldehydo Derivatives of [XW5O18]3– (X = Zr or Ti)
Authors: Zhuang Jia , Yan Likai , Liu Chunguang , Su Zhongmin 
Published: April 2009

AbstractThe bonding characteristics, first hyperpolarizabilities, and origin of the nonlinear optical (NLO) properties of aryloxido and salicylaldehydo derivatives of [XW5O18]3– (X = Zr or Ti) have been investigated using density functional theory (DFT). The flexible bonding behavior of the linkage oxygen (OL) atom attracted our attention initially, and NBO analysis revealed that there aret two different kinds of π‐interactions involving the OL atom in these systems. In two aryloxido derivatives (systems 1 and 2), OL–metal π‐interactions are largely OL–M p‐d in character, whereas in the salicylaldehydo derivatives (system 3) we observed another kind of π‐interaction, namely OL–C p‐p π‐bonding. The differences in molecular composition in our studied systems are very slight. However, the β0 values differ significantly. Thus, system 3 has the largest β0 value(559.27 × 10–30 esu), which is 170 times larger than that of system 1. This variation can be traced to the different electronic transitions and charge‐transfer characteristics. The heteropolyanion cluster and organic ligand are both electron‐rich groups. A small change in molecular composition or architecture can therefore significantly modify the configuration and overlapping of molecular orbitals, thus causing a “butterfly effect” upon the electronic transitions and charge‐transfer characteristics.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Analysis of the Interaction between Adenine Nucleobase and Metal‐Malonato Complexes
Authors: Pérez‐Yáñez Sonia , Castillo Oscar , Cepeda Javier , García‐Terán Juan P. , Luque Antonio , Román Pascual 
Published: April 2009

AbstractThe synthesis, crystal structure and variable‐temperature magnetic measurements of compounds [M2(μ‐Hade)2(μ‐mal)2(H2O)2]·2H2O [M = Ni (1), Co (2)], [Co2(μ‐Hade)2(μ‐mal)2(H2O)2] (3), {(H2ade)2[Cu(μ‐mal)2]·2H2O}n (4) and (H2ade)2[Cu(mmal)2(H2O)] (5; H2ade = adeninium, Hade = adenine, mal = malonato, mmal = methylmalonato) are reported. Compounds 1–3 contain neutral paddle‐wheel [M2(μ‐Hade)2(μ‐mal)2(H2O)2] [M = Ni (1), Co (2 and 3)] units where the 7H‐tautomeric form of the nucleobase and the malonate dianion act as μ‐κN3:κN9 and μ‐κ2O1,O2:κO1 bridging ligands, respectively. The supramolecular crystal structures of 1–3 are essentially maintained by hydrogen‐bonding interactions involving the nucleobases, the carboxylate groups and crystallisation water molecules (in compounds 1 and 2). Compounds 4 and 5 show a hybrid inorganic‐organic lamellar structure containing layers of anionic metal‐malonato complexes and supramolecular aggregates of the 1H,9H‐adeninium cation. Their overall three‐dimensional architectures are controlled, in addition to electrostatic forces, by supramolecular recognition processes between the inorganic and organic frameworks. Compound 4 contains one‐dimensional anionic copper‐malonato chains in which the copper atoms are doubly bridged by μ‐κ2O1,O2:κO2′ malonato ligands and the cationic nucleobases form dimeric entities sustained by Hoogsteen‐Hoogsteen hydrogen‐bonding interactions. Compound 5 is built up of anionic [Cu(mmal)2(H2O)]2– monomeric entities and planar, hydrogen‐bonded, one‐dimensional, ribbon‐like aggregates of protonated adenine. Variable‐temperature magnetic susceptibility measurements of compounds 1–4 show the preponderance of ferromagnetic interactions between the paramagnetic centres. DFT calculations have been performed to evaluate the magnetic behaviour of these compounds and to analyze the interaction between two adeninium cations in compound 4. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Water‐Soluble Ultra Small Paramagnetic or Superparamagnetic Metal Oxide Nanoparticles for Molecular MR Imaging
Authors: Park Ja Young , Choi Eun Sook , Baek Myung Ju , Lee Gang Ho , Woo Seungtae , Chang Yongmin 
Published: April 2009

AbstractA simple and general one‐pot synthesis for water‐soluble ligand‐coated ultra small paramagnetic or superparamagnetic metal oxide nanoparticles with average particle diameters (dav.) that range from 1–3 nm has been developed and used in molecular magnetic resonance (MR) imaging. The iron oxide, manganese oxide, and gadolinium oxide nanoparticles are coated with various hydrophilic and biocompatible ligands. We found that the ligand‐coated ultra small gadolinium oxide nanoparticles are the superior candidates for use as T1 MRI contrast agents. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of 9‐Substituted‐1,8‐Dioxooctahydroxanthenes by an Efficient Iodine‐Catalyzed Cyclization
Authors: Luna Liliana E. , Cravero Raquel M. , Faccio Ricardo , Pardo Helena , Mombrú Álvaro W. , Seoane Gustavo 
Published: April 2009

AbstractNew 1,8‐dioxooctahydroxanthenes with substituents in the 2‐, 3‐, and 9‐positions were obtained by cyclization with iodine from tandem Michael/Michael adducts. The X‐ray molecular structure of the methyl 2‐(1,8‐dioxo‐2,3,4,5,6,7,8,9‐octahydro‐1H‐xanthen‐9‐yl)acetate (3a) was solved and shows the parallel laminae packing of these molecules. Furthermore, we reported the structure of intermediate 4 isolated from this reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis and Characterization of Highly Fluorinated Gemini Pyridinium Surfactants
Authors: Quagliotto Pierluigi , Barolo Claudia , Barbero Nadia , Barni Ermanno , Compari Carlotta , Fisicaro Emilia , Viscardi Guido 
Published: April 2009

AbstractA series of fluorinated gemini pyridinium amphiphiles have been prepared, purified and fully characterized. The synthesis was performed using alkyl trifluoromethanesulfonates as the quaternizing agents, provided very good yields and overcame problems arising with other less powerful alkylating agents. The use of different characterization techniques, such as conductivity and surface tension measurements, shed light on the aggregation process. The title products showed interesting, unusual properties, which could be interpreted in view of a peculiar aggregating behaviour. This family of compounds is very interesting for their possible transfection activity and application in gene therapy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Intramolecular Nonbonded Interactions Between Divalent Selenium Centers with Donor and Acceptor Substituents
Authors: Lari Alberth , Bleiholder Christian , Rominger Frank , Gleiter Rolf 
Published: April 2009

AbstractTo investigate the intramolecular van der Waals interactions between two divalent selenium centers in the solid state and in solution, we have prepared methyl 2‐(methylselenyl)benzyl selenide (1), ethynyl 2‐(methylselenyl)benzyl selenide (2), and 2‐(methylselenyl)benzyl selenocyanate (3). By means of NMR spectroscopic studies we have determined the 77Se NMR chemical shifts of the signals of the Se centers of 1–3 and their long‐range 4JSe,Se coupling constants. These results, and the X‐ray structural studies of single crystals of 3 and 11, a quasi‐dimer of 2, point to an Se···Se van der Waals interaction and short Se···H distances in 1–3. These measurements were supported by quantum chemical calculations on 1–3 at the MP2/6‐311+g(d)//B98/6‐311+g(d) level of theory, which showed a preference for the endoX and endoH conformations of 1–3. This finding was confirmed by calculations of the 77Se NMR chemical shifts of 1–3 by GIAO‐B98 and GIAO‐PBE calculations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Molecularly Imprinted Polymerized Methylene Green as a Platform for Electrochemical Sensing of Aptamer–Thrombin Interactions
Authors: Evtugyn Gennady , Porfireva Anna , Ivanov Alexey , Konovalova Olga , Hianik Tibor 
Published: April 2009

AbstractThe biosensors based on DNA aptamers immobilized by electrostatic adsorption onto electropolymerized Methylene Green (MG)) imprinted with DNA have been developed and examined for thrombin detection in the range from 1 nM to 1 μM using electrochemical impedance spectroscopy (EIS) and potentiometry. The participation of DNA in MG electropolymerization and imprints formation was proved by measurements of EIS and redox signals of neutral and charged indicators. Changes in the morphology of the layers were examined using atomic force microscopy (AFM). The addition of DNA at the electropolymerization stage followed by acidic treatment of the coating significantly improved the efficiency of electrostatic adsorption of the DNA aptamer and provided sensitive detection of thrombin with limit of detection 0.5 nM.
Impedimetric or Ion‐Sensitive Field‐Effect Transistor (ISFET) Aptasensors Based on the Self‐Assembly of Au Nanoparticle‐Functionalized Supramolecular Aptamer Nanostructures
Authors: Sharon Etery , Freeman Ronit , Tel‐Vered Ran , Willner Itamar 
Published: April 2009

AbstractTwo electrical methods (Faradaic impedance spectroscopy and ion‐sensitive field‐effect transistor (ISFET)) are applied to sense aptamer‐substrate complexes. The methods utilize anticocaine aptamer fragments that self‐assemble, in the presence of cocaine, to a supramolecular aptamer fragments/cocaine complex on the electrode surface or ISFET gate. One of the aptamer fragments is assembled on a Au electrode or the ISFET gate. The second thiolated aptamer fragment is used to modify Au NPs that are used as amplifying labels for the two detection schemes. The impedimetric and ISFET methods enabled the analysis of cocaine with detection limits of 1×10−5 M and 1×10−6 M, respectively.
Reduction of hexamminecobalt (III) catalyzed by coconut activated carbon
Authors: Long Xiang‐li , Cheng Hua , Yuan Wei‐kang 
Published: April 2009

AbstractThe wet ammonia desulphurization process can be retrofitted to remove NO and SO2 simultaneously by adding soluble cobalt (II) salt into the aqueous ammonia solution. The hexamminecobalt (II), Co(NH3), is the active constituent in the removal of nitric oxide with the hexamminecobalt ammonia solution. To maintain the capability of removing NO with the hexamminecobalt solution, activated carbon is used to catalyze the reduction of hexamminecobalt (III) to hexamminecobalt (II). In this study, the study on the investigation into the intrinsic kinetics of the hexamminecobalt (III) conversion has been performed. The reduction of hexamminecobalt (III) catalyzed by coconut activated carbon has been studied in a batch stirred cell without the external or internal mass transfer resistances. The experimental results show that the reaction rate increases with the activated carbon mass and the concentration of hexamminecobalt (III). pH affects the reaction greatly. A best Co(NH3)63+ conversion is obtained at pH of 2.74. A high temperature is favorable to such reaction. The reaction is first order with respect to Co(NH3)63+. The intrinsic activation energy of 56.73 ± 1.82 kJ mol−1 has been obtained. A kinetic model for such catalytic reaction can be expressed as follow:

© 2009 American Institute of Chemical Engineers Environ Prog, 2010
Rethinking climate change impacts on subsurface temperatures in a sub‐Antarctic mire affected by synoptic scale processes
Authors: Nel Werner , van der Merwe Barend J. , Meiklejohn K. Ian 
Published: April 2009

AbstractThis paper presents the first high resolution temperature data from a small Agrostis magellanica mire on subantarctic Marion Island as part of an ongoing island‐wide monitoring project on subsurface ground temperature variability. Variations in ground temperatures were found to be directly linked to the passage of synoptic scale weather systems that influence thermal characteristics and heat fluxes especially in the upper 30 cm of the mire. Preliminary data published here suggest that shallow temperatures will be most affected by changes in synoptic climate that Marion Island is currently experiencing with an increase in average temperatures and a reduction in temperature variability with depth. This study proposes that to effectively detect the ecosystem responses to climate change in a maritime sub‐Antarctic environment the temporal scale of measurement needs to be at least on a diurnal scale to be effective. Copyright © 2009 John Wiley & Sons, Ltd.
Developing a unified FVE‐ALE approach to solve unsteady fluid flow with moving boundaries
Authors: Naderi A. , Darbandi M. , Taeibi‐Rahni M. 
Published: April 2009

AbstractIn this study, an arbitrary Lagrangian–Eulerian (ALE) approach is incorporated with a mixed finite‐volume–element (FVE) method to establish a novel moving boundary method for simulating unsteady incompressible flow on non‐stationary meshes. The method collects the advantages of both finite‐volume and finite‐element (FE) methods as well as the ALE approach in a unified algorithm. In this regard, the convection terms are treated at the cell faces using a physical‐influence upwinding scheme, while the diffusion terms are treated using bilinear FE shape functions. On the other hand, the performance of ALE approach is improved by using the Laplace method to improve the hybrid grids, involving triangular and quadrilateral elements, either partially or entirely. The use of hybrid FE grids facilitates this achievement. To show the robustness of the unified algorithm, we examine both the first‐ and the second‐order temporal stencils. The accuracy and performance of the extended method are evaluated via simulating the unsteady flow fields around a fixed cylinder, a transversely oscillating cylinder, and in a channel with an indented wall. The numerical results presented demonstrate significant accuracy benefits for the new hybrid method on coarse meshes and where large time steps are taken. Of importance, the current method yields the second‐order temporal accuracy when the second‐order stencil is used to discretize the unsteady terms. Copyright © 2009 John Wiley & Sons, Ltd.
1‐D numerical modelling of shallow flows with variable horizontal density
Authors: Leighton Feifei Zhang , Borthwick Alistair G. L. , Taylor Paul H. 
Published: April 2009

AbstractA1‐D numerical model is presented for vertically homogeneous shallow flows with variable horizontal density. The governing equations represent depth‐averaged mass and momentum conservation of a liquid–species mixture, and mass conservation of the species in the horizontal direction. Here, the term ‘species’ refers to material transported with the liquid flow. For example, when the species is taken to be suspended sediment, the model provides an idealized simulation of hyper‐concentrated sediment‐laden flows. The volumetric species concentration acts as an active scalar, allowing the species dynamics to modify the flow structure. A Godunov‐type finite volume scheme is implemented to solve the conservation laws written in a deviatoric, hyperbolic form. The model is verified for variable‐density flows, where analytical steady‐state solutions are derived. The agreement between the numerical predictions and benchmark test solutions illustrates the ability of the model to capture rapidly varying flow features over uniform and non‐uniform bed topography. A parameter study examines the effects of varying the initial density and depth in different regions. Copyright © 2009 John Wiley & Sons, Ltd.
Integrated genomic and transcriptional analysis of the in vitro evolution of telomerase‐immortalized urothelial cells (TERT‐NHUC)
Authors: Chapman Emma J. , Williams Sarah V. , Platt Fiona M. , Hurst Carolyn D. , Chambers Philip , Roberts Paul , Knowles Margaret A. 
Published: April 2009

AbstractMuch progress has been made in identifying the molecular genetic alterations that occur in bladder cancer. However, in many cases the genes targeted by these alterations are not known. Telomerase immortalized human urothelial cells (TERT‐NHUC) are a useful resource for in vitro studies of genes involved in urothelial transformation. When cultured under standard conditions they remain genetically stable but when cultured under low‐density conditions they exhibit genetic instability and acquire chromosomal alterations. TERT‐NHUC from three donors were cultured at low plating density and examined at four time‐points during a culture period of 600 days. Analyses included population doubling kinetics, array‐based CGH (aCGH), chromosome counts, fluorescence in situ hybridization (FISH), mutation analysis, Affymetrix gene expression analysis, Western blotting for p16, anchorage‐independent growth and tumorigenicity assays. Alterations acquired during continued culture of TERT‐NHUC at low density (TERT‐NHUC‐L) included some observed in urothelial carcinoma (UC) cell lines and primary UC. Examination of gene expression in TERT‐NHUC with distinct acquired genetic aberrations may pinpoint genes targeted by these alterations. Data from an aCGH study of UC cell lines and primary tumors were examined for changes in chromosomal regions that also showed alterations in TERT‐NHUC‐L. Loss of a region on 2q including BOK was identified in UC cell lines and primary tumors. DNER and FRAS1 were identified as potential candidate genes, whose expression is altered independently of the acquisition of any genetic event. © 2009 Wiley‐Liss, Inc.
When the solution is part of the problem: problem solving in elderly suicide attempters
Authors: Gibbs Lawrence M. , Dombrovski Alexandre Y. , Morse Jennifer , Siegle Greg J. , Houck Patricia R. , Szanto Katalin 
Published: April 2009

AbstractObjectivesDepression, loss, and physical illness are associated with suicide in the elderly. However, the nature of individual vulnerability remains poorly understood. Poor problem solving has been suggested as a risk factor for suicide in younger adults. Unresolved problems may create an accumulation of stressors. Thus, those with perceived deficits in problem‐solving ability may be predisposed to suicidal behavior. To test this hypothesis, we investigated whether elderly suicide attempters perceived their problem solving as deficient.MethodsSixty‐four individuals aged 60 and older participated in the study including depressed suicide attempters, depressed non‐attempters, and non‐depressed controls. The social problem solving inventory‐revised: short‐version was used to measure participants' perceived social problem solving, assessing both adaptive problem‐solving dimensions (positive problem orientation and rational problem solving) and dysfunctional dimensions (negative problem orientation, impulsivity/carelessness, and avoidance).ResultsDepressed elderly who had attempted suicide perceived their overall problem solving as deficient, compared to non‐suicidal depressed and non‐depressed elderly. Suicide attempters perceived their problems more negatively and approached them in a more impulsive manner. On rational problem solving and avoidant style sub‐scales, suicide attempters did not differ from non‐suicidal depressed. However, both depressed groups reported lower rational problem solving and higher avoidance compared to non‐depressed controls.ConclusionsA perception of life problems as threatening and unsolvable and an impulsive approach to problem solving appear to predispose vulnerable elderly to suicide attempts. Copyright © 2009 John Wiley & Sons, Ltd.
Reductions in neuronal density in elderly depressed are region specific
Authors: Van Otterloo Eric , O'Dwyer Gillian , Stockmeier Craig A. , Steffens David C. , Krishnan Ranga R. , Rajkowska Grazyna 
Published: April 2009

AbstractObjectiveFrontal regions, including the orbitofrontal cortex (ORB) and dorsolateral prefrontal cortex (dlPFC) have been implicated in the neuropathology of geriatric depression. Prominent reductions in pyramidal neuron density have been recently reported in the ORB of older depressed subjects. However, the cellular pathology of the dlPFC has not yet been examined in these subjects.MethodsPostmortem tissue from the dlPFC (Brodmann's area 9, BA9) was collected from 10 older (>60 years old) subjects diagnosed with major depression and 10 age‐matched non‐psychiatric controls (CTRL). The majority of the subjects were the same as those used for our previous study on neuronal reductions in the ORB in older depressed. Overall (all six layers combined), and laminar density of pyramidal (presumably glutamatergic), and non‐pyramidal (GABAergic) neurons as well as cortical and laminar width were measured using linear optical disector of Stereoinvestigator software.ResultsNeither the overall nor laminar density of pyramidal or non‐pyramidal neurons was significantly different between groups. The cortical and laminar widths were also not affected.ConclusionsThese results suggest that neuronal prefrontal pathology in elderly depressed is region specific. No significant changes were detected in the density of any type of neurons in the dlPFC of elderly depressed subjects (present study) whereas, prominent reductions in the density of pyramidal glutamatergic neurons were observed previously in the ORB. Copyright © 2009 John Wiley & Sons, Ltd.