bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Flexible Bis‐Intercalating Ruthenium(II) Complexes
Authors: Brodie Craig R. , Aldrich‐Wright Janice R. 
Published: September 2007

AbstractWe report the synthesis, resolution and characterisation of a number of novel ruthenium(II) complexes. Four mononuclear complexes, [Ru(dpq)2(3‐Br‐phen)]2+, [Ru(dpq)2(4‐Cl‐phen)]2+, [Ru(dpq)2(5‐Cl‐phen)]2+and [Ru(dpq)2(phen)]2+were synthesised (dpq = dipyrido[3,2‐d:2′,3′‐f]quinoxaline, phen = 1,10‐phenanthroline, 3‐Br‐phen = 3‐bromo‐1,10‐phenanthroline, 4‐Cl‐phen = 4‐chloro‐1,10‐phenanthroline, 5‐Cl‐phen = 5‐chloro‐1,10‐phenanthroline). These complexes were resolved using the chiral TRISPHAT anion, [tris(tetrachlorocatecholato)phosphate(V)]–. Racemic mononuclear complexes were used in the synthesis of the racemic dinuclear complexes, [{Ru(dpq)2}2μ‐(phen‐n‐SOS‐n‐phen)]4+(SOS = 2‐mercaptoethyl ether,n= 3, 4 or 5). Resolved mononuclear complexes were used to synthesise stereoselectively the ΔΔ‐ and ΛΛ‐enantiomers of their respective dinuclear complexes. All metal complexes were characterised by1H NMR, ESI‐MS, UV/Vis and luminescence spectroscopy. Resolved metal complexes were further characterised using CD spectroscopy and chiral1H NMR titrations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
A Tris‐Cyclometalated Iridium(III) Complex of 2‐(5,5‐Dioxido‐dibenzothiophen‐3‐yl)pyridine: Synthesis, Structural, Redox and Photophysical Properties
Authors: Tavasli Mustafa , Bettington Sylvia , Perepichka Igor F. , Batsanov Andrei S. , Bryce Martin R. , Rothe Carsten , Monkman Andrew P. 
Published: September 2007

AbstractThe first cyclometalated dibenzothiophene S,S‐dioxide derivative, namely [fac‐2‐(5,5‐dioxidodibenzothiophen‐3‐yl)pyridine]iridium(III) (3) has been synthesised in high yield and characterised by X‐ray crystallography, solution electrochemistry, absorption and emission spectroscopy. The Ir atom has a fac‐octahedral coordination with three chelating ligands (A, B and C); each Ir–N bond is in trans position to an Ir–C bond. In cyclic voltammetry experiments in dichloromethane, complex 3 undergoes a reversible metal‐centred IrIII/IrIV oxidation at E1/2ox = +1.04 V vs. Ag/Ag+ reference electrode. Complex 3 exhibits bright green photoluminescence (λmax = 525 nm in toluene) from mixed 3MLCT/3π→π* states with quantum yield (ΦPL) of 0.26 in toluene solution. The phosphorescence emission decay follows first order kinetics, with a lifetime of 4.9 μs. A comparison of complex 3 with analogues 1 and 2, where the dibenzothiophene S,S‐dioxide unit is replaced by 9,9‐dihexylfluorene and N‐hexylcarbazole respectively, establish that the substituent para to the Ir metal atom, i.e. CR2 in 1, NR in 2 and SO2 in 3, has a major influence on the redox and emission properties in this series. Organic light‐emitting diodes (OLEDs) were fabricated by spin‐coating techniques using a polyspirobifluorene copolymer (PSBF) as a host and complex 3 as dopant.In a single‐layer blend configuration ITO/PEDOT:PSS/PSBF:3(8 wt.‐%)/Ba/Al OLEDs showed pale blue/white light emission (CIE coordinates: x = 0.29, y = 0.31) arising from a combination of fluorescence from the host copolymer (λmax = 450 nm) and phosphorescence from 3 (λmax = 530 nm). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Chiral Calix[4]arene‐Based Diphosphites as Ligands in the Asymmetric Hydrogenation of Prochiral Olefins
Authors: Marson Angelica , Freixa Zoraida , Kamer Paul C. J. , van Leeuwen Piet W. N. M. 
Published: September 2007

AbstractChiral calixarene‐based diphosphite ligands 3a–d have been obtained via lower‐rim functionalisation of the p‐tert‐butylcalix[4]arene core. High enantiomeric excesses (up to 94 %) and good activities were obtained in the rhodium‐catalyzed asymmetric hydrogenation of prochiral olefins withTADDOL‐containing diphosphites 3c,d. This is the firstexample of chiral calix[4]arene‐modified ligands that induce high enantioselectivity in metal‐catalysed asymmetric reactions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Voltammetry: An In Situ Tool to Monitor the Health of Ecosystems
Authors: Ma Shufen , Luther George W. , Scarborough Robert W. , Mensinger Michael G. 
Published: September 2007

AbstractA solid‐state Au/Hg voltammetric microelectrode was used to monitor the development of seasonal anoxia in Delaware coastal bays which have deep holes with stratification. Since fish kills and harmful algal blooms have occurred over the years here, water circulators were installed in October 2003 to improve water quality. We conducted in situ determination of temperature, salinity, pH, dissolved O2 and H2S to document the circulators' function which was evaluated by comparing in situ data obtained before and after their installation. Stratification at both sites was similar in 2004 to that in previous years. Furthermore, the circulators did not oxygenate the water column but did bring some H2S to the surface waters. We found that O2 concentrations in the surface waters and H2S concentrations in the bottom waters were similar in different years. Thus, the H2S conditions were not abated and water quality was still a problem.
Determination of phosphate in seawater by CZE with on‐line transient ITP
Authors: Okamoto Takaaki , Fukushi Keiichi , Takeda Sahori , Wakida Shin‐ichi 
Published: September 2007

AbstractWe developed CZE with indirect UV detection for the determination of phosphate in seawater using transient ITP as an on‐line concentration procedure. The following optimum conditions were established: BGE, 5 mM 2,6‐pyridinedicarboxylic acid (PDC) containing 0.01% hydroxypropylmethylcellulose (HPMC) adjusted to pH 3.5; detection wavelength, 200 nm; vacuum injection period of sample, 3 s (45 nL); terminating ion solution, 500 mM MES adjusted to pH 4.0; vacuum injection period of the terminating ion solution, 30 s (450 nL); applied voltage, 30 kV with the sample inlet side as the cathode. The LOD for phosphate was 16 μg/L ($ \displaystyle {{PO}}_{{4}}^{{{3}} -}$–P) at S/N of 3. The respective values of the RSD of the peak area, peak height, and migration time for phosphate were 2.6, 2.3, and 0.34%. The proposed method was applied to the determination of phosphate in a seawater certified reference material for nutrients, MOOS‐1, distributed by the National Research Council of Canada (NRC). The results were very similar to certified values. The method was also applied to the determination of phosphate in coastal seawaters. The results agreed with those obtained using a conventional spectrophotometric method.
Anisotropic mesh refinement for discontinuous Galerkin methods in two‐dimensional aerodynamic flow simulations
Authors: Leicht Tobias , Hartmann Ralf 
Published: September 2007

AbstractWe derive and implement two types of anisotropic indicators which can be used within an anisotropic refinement algorithm for second but also for higher‐order discontinuous Galerkin discretizations. Although the first type of indicator employs the possible inter‐element discontinuities of the discrete functions, the second type of indicator estimates the approximation error in terms of second but possibly also higher‐order derivatives. We implement a simple extension of these indicators to systems of equations which performs similar to the so‐called metric intersection used to combine the metric information of several solution components and is applicable to higher‐order discretizations as well. The anisotropic indicators are incorporated into an adaptive refinement algorithm which uses state‐of‐the‐art residual‐based or
adjoint‐based indicators for goal‐oriented refinement to select the elements to be refined, whereas the anisotropic indicators determine which anisotropic case the selected elements shall be refined with. We demonstrate the performance of the anisotropic refinement algorithm for sub‐, trans‐ and supersonic, inviscid and viscous compressible flows around a NACA0012 airfoil. Copyright © 2007 John Wiley & Sons, Ltd.
Multi‐method global sensitivity analysis (MMGSA) for modelling floodplain hydrological processes
Authors: Cloke H. L. , Pappenberger F. , Renaud J.‐P. 
Published: September 2007

AbstractWhen studying hydrological processes with a numerical model, global sensitivity analysis (GSA) is essential if one is to understand the impact of model parameters and model formulation on results. However, different definitions of sensitivity can lead to a difference in the ranking of importance of the different model factors. Here we combine a fuzzy performance function with different methods of calculating global sensitivity to perform a multi‐method global sensitivity analysis (MMGSA). We use an application of a finite element subsurface flow model (ESTEL‐2D) on a flood inundation event on a floodplain of the River Severn to illustrate this new methodology. We demonstrate the utility of the method for model understanding and show how the prediction of state variables, such as Darcian velocity vectors, can be affected by such a MMGSA. This paper is a first attempt to use GSA with a numerically intensive hydrological model. Copyright © 2007 John Wiley & Sons, Ltd.
Hyporheic and total transient storage in small, sand‐bed streams
Authors: Stofleth John M. , Shields Jr F. Douglas , Fox Garey A. 
Published: September 2007

AbstractKey processes in stream ecosystems are linked to hydraulic retention, which is the departure of stream flow from ideal ‘plug flow’, and reflects fluid movement through surface and hyporheic storage zones. Most existing information about hyporheic exchange is based on flume studies or field measurements in relatively steep streams with beds coarser than sand. Stream tracer studies may be used to quantify overall hydraulic retention, but disaggregation of surface and hyporheic retention remains difficult. A stream tracer approach was used to compute the rates at which stream water is exchanged with water in storage zones (total storage) in short reaches of two small, sand‐bed streams under free and obstructed flow conditions. Tracer curves were fit to the one‐dimensional transport with inflow storage model OTIS‐P. Networks of piezometers were used to measure specific discharge between the stream and the groundwater. In the sand‐bed streams studied, parameters describing total retention were in the upper 50% of data compiled from the literature, most of which represented streams with beds coarser than sand. However, hyporheic storage was an insignificant component of total hydraulic retention, representing only 0·01–0·49% of total exchange, and this fraction did not increase after installation of flow obstructions. Total retention did not vary systematically with bed material size, but increased 50–100% following flow obstruction. Removal of roughness elements, such as large wood and debris dams, is detrimental to processes dependent upon transient storage in small, sand‐bed streams. Copyright © 2007 John Wiley & Sons, Ltd.
Bank lending in Germany and the UK: are there differences between a bank‐based and a market‐based country?
Authors: Kaufmann Sylvia , Valderrama Maria Teresa 
Published: September 2007

AbstractWe estimate Markov switching vector autoregressive systems for loans to firms and loans to households to investigate their relationship to interest rates and investment and consumption, respectively. We find evidence for different reactions of lending to shocks in real variables and interest rates across regimes both within countries and across countries for a given regime. We find evidence for a procyclical effect of lending during specific growth periods in both countries. Copyright © 2007 John Wiley & Sons, Ltd.
Integrated activation of MAP3Ks balances cell fate in response to stress
Authors: Winter‐Vann Ann M. , Johnson Gary L. 
Published: September 2007

AbstractIn vivo, tissues and organs are exposed to numerous stressors that require cells to respond appropriately for viability and homeostasis. Cells respond to these stressors, which range from UV irradiation, heat shock, chemicals, and changes in osmolality, to oxidative stress and inflammatory cytokines, by activating pathways that protect cells from damage. If the stress is too great, cells commit to undergo apoptosis. Such cell fate decisions involve the stress‐mediated activation of mitogen‐activated protein kinase (MAPK) networks, ultimately under the control of MAPK kinase kinases, or MAP3Ks. It is the MAP3Ks that coordinate the localization, duration and magnitude of MAPK activation in response to cell stress. A single stressor may activate several MAP3Ks, each of which impacts the balance between survival and apoptotic signaling. In this prospect article, we review the specific MAP3Ks that integrate the physiological response to cell stressors. The interrelationships among different stressors are discussed, with an emphasis on how the balance of signaling through MAP3Ks controls the MAPK response to determine cell fate. J. Cell. Biochem. 102: 848–858, 2007. © 2007 Wiley‐Liss, Inc.
Sperm binding glycoprotein (SBG) produces calcium and bicarbonate dependent alteration of acrosome morphology and protein tyrosine phosphorylation on boar sperm
Authors: Teijeiro Juan M. , Cabada Marcelo O. , Marini Patricia E. 
Published: September 2007

AbstractThe oviduct is a dynamic organ which modulates gamete physiology. Two subpopulations of sperm have been described in the oviduct of sows, a majority with normal appearance in the deep furrows and a minority, centrally located, and showing damaged membranes. Sperm–oviduct interaction provides the formation of a sperm storage and allows the selection of sperm with certain qualities. Pig (Sus scrofa) oviductal sperm binding glycoprotein (SBG) binds to sperm and exposes Galβ1‐3GalNAc. This disaccharide may be recognized by boar spermadhesin AQN1, which seems to be involved in sperm interaction with the oviduct. SBG is present at the apical surface of the epithelial cells that surround the lumen of the oviduct rather than at the bottom of the crypts. These characteristics imply it could be involved in sperm interaction with this organ. In this study, we evaluate the effect of SBG over boar sperm. We show that the presence of SBG produces alterations of the acrosome morphology of sperm only when they are incubated in capacitating conditions. SBG binds to the periacrosomal region of sperm undergoing capacitation. Its presence induces an increase on the tyrosine‐phosphorylation of a polypeptide of apparent molecular mass 97 kDa, as occurs with a 95 kDa protein in other mammalian sperm upon acrosomic reaction. Altogether, these results suggest that SBG might be involved in sperm selection by alteration of the acrosome of sperm that have already begun the capacitation process when they arrive to the oviduct. J. Cell. Biochem. 103: 1413–1423, 2008. © 2007 Wiley‐Liss, Inc.
Ab initio direct dynamics studies on the reactions of chlorine atom with CH3−nFnCH2OH (n = 1–3)
Authors: Wang Ying , Liu Jing‐Yao , Li Ze‐Sheng 
Published: September 2007

AbstractThe hydrogen abstraction reactions of Cl atom with a series of fluorinated alcohols, i.e., CH3−nFnCH2OH + Cl (n = 1–3) (R1–R3) have been studied systematically by ab initio direct dynamics method and the canonical variational transition state theory (CVT). The potential energy surface information is calculated at the MP2/6‐311G(d,p) level. Energies along the minimum energy paths are improved by a series of single‐point calculations at the higher modified GAUSSIAN‐2 (G2M) level of theory. Theoretical analysis shows that three kinds of hydrogen atoms can be abstracted from the reactants CH2FCH2OH and CHF2CH2OH, and for CF3CH2OH, two possible pathways are found. The rate constants for each reaction channel are evaluated by CVT with the small‐curvature tunneling correction (SCT) over a wide range of temperature from 200 to 2000 K. The calculated CVT/SCT rate constants are in good agreement with the available experimental values for the reactions CHF2CH2OH + Cl and CF3CH2OH + Cl. However, for the reaction CH2FCH2OH + Cl, there is negative temperature dependence below 500 K, which is different from the experimental fitted. It is shown that in the low temperature ranges, the three reactions all proceed predominantly via H‐abstraction from the methylene positions, and with the increase of the temperature the H‐abstraction channels from the fluorinated‐methyl positions should be taken into account, while the H‐abstraction channels from the hydroxyl groups are negligible over the whole temperature ranges. Also, the reactivity decreases substantially with fluorine substitution at the methyl position of alcohol. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Numerical characterization of the conformation of cyclic peptides and its application
Authors: Liu Xiaoqing , Xiu Zhilong , Li Xiaohui 
Published: September 2007

AbstractMany classes of functional cyclic peptide molecules are determined by experimental techniques, but few similarities of cyclic peptides are detectable. We propose three numerical characterizations of conformations of cyclic peptides. By incorporating the information on atomic coordinates of cyclic peptides, the coordinates are transformed into a characteristic sequence. Then we calculate its center of gravity, the eigenvalues of its Euclidean and L/L matrices, and regard them as descriptors to numerically characterize the conformations of cyclic peptides. Finally, the method is tested by analyzing the similarities of cyclic peptides presented in Table . © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Sugar sensing by enterocytes combines polarity, membrane bound detectors and sugar metabolism
Authors: Le Gall Maude , Tobin Vanessa , Stolarczyk Emilie , Dalet Véronique , Leturque Armelle , Brot‐Laroche Edith 
Published: September 2007

AbstractSugar consumption and subsequent sugar metabolism are known to regulate the expression of genes involved in intestinal sugar absorption and delivery. Here we investigate the hypothesis that sugar‐sensing detectors in membranes facing the intestinal lumen or the bloodstream can also modulate intestinal sugar absorption. We used wild‐type and GLUT2‐null mice, to show that dietary sugars stimulate the expression of sucrase‐isomaltase (SI) and L‐pyruvate kinase (L‐PK) by GLUT2‐dependent mechanisms, whereas the expression of GLUT5 and SGLT1, did not rely on the presence of GLUT2. By providing sugar metabolites, sugar transporters, including GLUT2, fuelled a sensing pathway. In Caco2/TC7 enterocytes, we could disconnect the sensing triggered by detector from that produced by metabolism, and found that GLUT2 generated a metabolism‐independent pathway to stimulate the expression of SI and L‐PK. In cultured enterocytes, both apical and basolateral fructose could increase the expression of GLUT5, conversely, basolateral sugar administration could stimulate the expression of GLUT2. Finally, we located the sweet‐taste receptors T1R3 and T1R2 in plasma membranes, and we measured their cognate Galpha Gustducin mRNA levels. Furthermore, we showed that a T1R3 inhibitor altered the fructose‐induced expression of SGLT1, GLUT5, and L‐PK. Intestinal gene expression is thus controlled by a combination of at least three sugar‐signaling pathways triggered by sugar metabolites and membrane sugar receptors that, according to membrane location, determine sugar‐sensing polarity. This provides a rationale for how intestine adapts sugar delivery to blood and dietary sugar provision. J. Cell. Physiol. 213:834–843. © 2007 Wiley‐Liss, Inc.
Mitogenic signaling pathways induced by G protein‐coupled receptors
Authors: Rozengurt Enrique 
Published: September 2007

AbstractG protein‐coupled receptor (GPCR) agonists, including neurotransmitters, hormones, chemokines, and bioactive lipids, act as potent cellular growth factors and have been implicated in a variety of normal and abnormal processes, including development, inflammation, and malignant transformation. Typically, the binding of an agonistic ligand to its cognate GPCR triggers the activation of multiple signal transduction pathways that act in a synergistic and combinatorial fashion to relay the mitogenic signal to the nucleus and promote cell proliferation. A rapid increase in the activity of phospholipases C, D, and A2 leading to the synthesis of lipid‐derived second messengers, Ca2+ fluxes and subsequent activation of protein phosphorylation cascades, including PKC/PKD, Raf/MEK/ERK, and Akt/mTOR/p70S6K is an important early response to mitogenic GPCR agonists. The EGF receptor (EGFR) tyrosine kinase has emerged as a transducer in the signaling by GPCRs, a process termed transactivation. GPCR signal transduction also induces striking morphological changes and rapid tyrosine phosphorylation of multiple cellular proteins, including the non‐receptor tyrosine kinases Src, focal adhesion kinase (FAK), and the adaptor proteins CAS and paxillin. The pathways stimulated by GPCRs are extensively interconnected by synergistic and antagonistic crosstalks that play a critical role in signal transmission, integration, and dissemination. The purpose of this article is to review recent advances in defining the pathways that play a role in transducing mitogenic responses induced by GPCR agonists. J. Cell. Physiol. 213:589–602. © 2007 Wiley‐Liss, Inc.
The osmotic sensitivity of rat growth plate chondrocytes in situ; clarifying the mechanisms of hypertrophy
Authors: Bush Peter G. , Parisinos Constantinos A. , Hall Andrew C. 
Published: September 2007

AbstractBone elongation is predominantly driven by the volume expansion of growth plate chondrocytes. This mechanism was initially believed to be “hypertrophy”, describing a proportional increase of cell water and organelles. However, morphometrical analysis subsequently assumed the increase to be “swelling”, resulting in a disproportionate increase of cell water (osmotically active fraction). Histological approaches were performed on fixed tissue, and for the “swelling” assumption to be valid, the osmotic sensitivity of living cells before and during volume increase should differ. To test this, analysis of images acquired by 2‐photon laser scanning microscopy (2PLSM) were used to determine the osmotic sensitivity, and osmotically active/inactive proportions of in situ chondrocytes from 15 living rat growth plates exposed to varying media osmolarities (∼0–580 mOsm). The dimensions of cell volume swelling in hypotonic media were different to the preferential lengthening seen in vivo, confirming the complexity of directional cell volume increase. Boyle–van't Hoff analysis of cell volume over the range of media osmolarity indicated no significant difference (Student's t‐test) in the osmotically inactive fraction, 39.5 ± 2.9% and 47.0 ± 4.3% (n = 13) for proliferative and hypertrophic zones, respectively, or the sensitivity of volume to changes in media osmolarity (proliferative 15.5 ± 0.8 and hypertrophic zone 15.5 ± 1.2%volume · Osm). The osmotic fractions did not change as chondrocytes progress from proliferative to hypertrophic regions of the growth plate. Our data suggest cell volume increase by hypertrophy may play a greater role in cell enlargement than swelling, and should be re‐evaluated as a mechanism responsible for growth plate chondrocyte volume increase and hence bone elongation. J. Cell. Physiol. 214: 621–629, 2008. © 2007 Wiley‐Liss, Inc.