bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Synthetic and X‐ray Crystallographic Study of Zinc and Platinum Complexes of 4,5‐Diazafluoren‐9‐one (Dafone) and Dicobalt Hexacarbonyl Derivatives of 9‐Phenylethynyl‐4,5‐Diazafluoren‐9‐ol: Chelation versus Monocoordination
Authors: Maguire Linda , Seward Corey M. , Baljak Sladjana , Reumann Thea , Ortin Yannick , Banide Emilie , Nikitin Kirill , Müller‐Bunz Helge , McGlinchey Michael J. 
Published: June 2009

AbstractReaction of 4,5‐diazafluoren‐9‐one (dafone, 6) and zinc dichloride yields [(dafone)ZnCl2(H2O)] (11) in which the ZnCl2 moiety is coordinated to a single nitrogen atom and also to a molecule of water. Hydrogen bonding, not only to the uncomplexed nitrogen atom of dafone but also to the ketonic oxygen atom of a neighbouring molecule, leads to a zigzag chain structure. In contrast, reaction with anhydrous zinc iodide forms cis‐(dafone)2ZnI2 (12) in which the metal–nitrogen distances – 2.170(5) and 2.456(5) Å – are significantly different. Dafone, in the presence of dimethyl sulfoxide, reacts with K2PtCl4 to produce square‐planar (dafone)PtCl2(dmso) (13), whereas with K2PtBr6 the octahedral complex (dafone)PtBr4 (14) is formed in which the ligand chelates in a symmetrical fashion. Treatment of dafone with phenylethynyllithium furnishes 9‐phenylethynyl‐4,5‐diazafluoren‐9‐ol (7), which forms a square‐planar nitrogen‐bonded PtCl2 complex, 15. Reaction of 7 with Co2(CO)8 yields the (μ‐alkyne)hexacarbonyldicobalt cluster 17, which undergoes protonation at the nitrogen atom to form 20 rather than at the alcohol to form a cobalt‐complexed propargyl cation. Alkynol 7 also reacts with HBr by addition across the triple bond to form Z‐9‐[(2‐bromo‐2‐phenyl)ethenyl]‐4,5‐diazafluoren‐9‐ol (10). X‐ray crystal structures are reported for 6, 7, 10–15, 17 and 20, and their differing hydrogen‐bonding motifs are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Unconventional Spin Crossover in Dinuclear and Trinuclear Iron(III) Complexes with Cyanido and Metallacyanido Bridges
Authors: Šalitroš Ivan , Boča Roman , Dlháň L'ubor , Gembický Milan , Kožíšek Jozef , Linares Jorge , Moncol' Ján , Nemec Ivan , Perašínová Lucia , Renz Franz , Svoboda Ingrid , Fuess Hartmut 
Published: June 2009

AbstractA nonsymmetrical triamine, 1,6‐diamino‐4‐azahexane, was Schiff‐condensed with (X‐substituted) o‐salicylaldehyde to yield pentadentate ligands X‐L5: salpet and MeBu‐salpet. These ligands form mononuclear, dinuclear, and trinuclear FeIII complexes, whose structures were determined by single‐crystal X‐ray analysis. Of the mononuclear complexes, [FeIII(salpet)Cl] and [FeIII(MeBu‐salpet)Cl] are high spin (S = 5/2), whereas [FeIII(salpet)CN]·MeOH is low spin (S = 1/2). The dinuclear and trinuclear complexes show a kind ofthermally induced spin crossover. The dinuclear complex [L5FeIII(CN)FeIIIL5](ClO4)·2H2O (L5 = salpet) is a mixed‐spin assembly: the C‐coordinated FeIII center is low spin (L) and the N‐coordinated FeIII center is high spin (H) at low temperature; an antiferromagnetic interaction occurs between them. This LH reference state is mixed with the LL one. Upon heating, the system shows an increasing content of the HH state. Also, the dinuclear complex [L5FeIII(CN)FeIIIL5](BPh4)·2MeCN (L5 = MeBu‐salpet) exhibits a spin transition between LH and HH spin pairs. The mixed‐valence trinuclear complex [L5FeIII{FeII(CN)5(NO)}FeIIIL5]·0.5MeOH·3.75H2O (L5 = salpet) shows spin crossover with a residual high‐spin fraction at liquid He temperature owing to the LL + LH ground state. The metallacyanido‐bridged complex [L5FeIII{Ni(CN)4}FeIIIL5]·2MeOH (L5 = MeBu‐salpet) contains a high‐spin pair, HH, over the whole temperature interval with a ferromagnetic exchange interaction. A theoretical model was outlined that allows simultaneous fitting of all available experimental data (magnetic susceptibility, magnetization, high‐spin mole fraction obtained from the Mössbauer spectra) on a common set of parameters. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Pyridine‐Functionalised (Vinylenedithio)tetrathiafulvalene (VDT–TTF) Derivatives and Their Dithiolene Analogues
Authors: Brooks Andrew C. , Day Peter , Dias Sandra I. G. , Rabaça Sandra , Santos Isabel C. , Henriques Rui T. , Wallis John D. , Almeida Manuel 
Published: June 2009

AbstractThe synthesis and characterisation of a group of vinylenedithio–TTFs bearing two or four 2‐ or 4‐pyridyl groups are described, along with related nickel and gold bidithiolene, as potential substrates for preparing multifunctional materials. In spite of the pyridyl groups not being coplanar with the vinylenedithio–TTF cores and the significant chair‐type distortions of the cores, because of the flexing of the dithiin rings, these substituted donors preserve the stacking ability of the unsubstituted donors in the solid state. The pyridyl substitution does not significantly change the redox potentials of these donors. Electrocrystallisation of a bis(2‐pyridyl) donor with perrhenate gave a dicationic salt in which the donor is both protonated and oxidized, and the pyridinium group makes a hydrogen bond to a perrhenate ion. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A New Trigonal‐Bipyramidal [CuII(pytBuN3)Cl2] Complex: Synthesis, Structure and Ligand Substitution Behaviour
Authors: Shaban Shaban Y. , Heinemann Frank W. , van Eldik Rudi 
Published: June 2009

AbstractThe synthesis, structure and ligand substitution mechanism of a new five‐coordinate copper(II) complex with a sterically constrained pytBuN3 chelate ligand [pytBuN3 = 2,6‐bis(3,5‐di‐tert‐butylphenyliminomethyl)pyridine] are reported. In the crystal structure of the complex the [Cu(pytBuN3)Cl2] chromophore possesses a distorted trigonal‐bipyramidal coordination geometry. The kinetics and mechanism of chloride substitution by thiourea (TU) and N,N,N′,N′‐tetramethylthiourea (TMTU) were studied in detail as a function of nucleophile concentration, temperature and pressure in methanol as solvent. The kinetics showed that the substitution reaction of [Cu(pytBuN3)Cl2] is a biphasic process that involves the subsequent displacement of both chloride ligands. The substitution of the first chloride by TU, k1296 = 918 ± 30 M–1 s–1, is 570 times faster than the substitution of the second chloride, k2296 = 1.62 ± 0.06 M–1 s–1. Substitution of chloride by TU is characterized by the activation parameters: ΔH# = 42 ± 2 and 58 ± 2 kJ mol–1, ΔS# = –46 ± 7 and –47 ± 6 J K–1 mol–1, and ΔV# = –6.5 ± 0.2 and –5.3 ± 0.7 cm3 mol–1, for the first and second substitution reactions, respectively. It is concluded from the activation parameters that both reactions follow an associative interchange (Ia) mechanism. When the substitution reaction was carried out with the sterically hindered nucleophile TMTU, the rate constant for the displacement of the first chloride, k2296 = 6.9 ± 0.5 M–1 s–1, was more than 133 times slower than for the reaction with TU, which further supports the Ia nature of the substitution mechanism.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Chemistry and Physical Properties of the Phosphide Telluride Zr2PTe2
Authors: Tschulik Kristina , Ruck Michael , Binnewies Michael , Milke Edgar , Hoffmann Stefan , Schnelle Walter , Fokwa Boniface P. T. , Gilleßen Michael , Schmidt Peer 
Published: June 2009

AbstractThe synthesis of the phosphide telluride Zr2PTe2 by solid‐state reaction from the elements at 850 °C or by thermite‐type reaction of Zr and Te8O10(PO4)4 was accomplished. Crystals were grown by chemical vapour transport by using iodine from 800 °C in the direction of higher temperatures up to 900 °C. The chemical bonding in Zr2PTe2 was investigated by the linear muffin‐tin orbital (LMTO) method. The non‐vanishing DOS of zirconium and tellurium states at the Fermi level (EF) complies with the metallic conductivity (ρ ≈ 40 μΩ cm at 300 K) and temperature‐independent Pauli paramagnetism.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
BINBAM – A New Motif for Strong and Chiral Brønsted Acids
Authors: Treskow Marcel , Neudörfl Jörg , Giernoth Ralf 
Published: June 2009

AbstractWe are reporting the first synthesis of the new chiral Brønsted acid BINBAM [(R)‐1,1′‐binaphthyl‐2,2′‐bis(sulfon)amide, 2], which can be obtained in four steps from commercially available BINOL (5). The compound is expected to be an alternative for established catalysts like phosphoric acids of BINOL 4 or TRIP and to show stronger Brønsted acidity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Single and multigrain quartz‐luminescence dating of irrigation‐channel features in Santa Fe, New Mexico
Authors: Berger Glenn W. , Post Stephen , Wenker Chris 
Published: June 2009

AbstractAcequias (irrigation channels and ditches) were used by Spanish settlers, their descendants, and Native Americans in New Mexico. Several such features were recently excavated in Santa Fe, but material for numeric dating was difficult to find. Therefore, for this high‐energy‐deposition irrigation‐feature setting we applied optically stimulated luminescence (OSL) sediment dating methods to determine the timing of last filling of some of these acequias. We report multigrain single‐aliquot quartz (MGSAQ) OSL dating results and the first single‐grain quartz (SGQ) OSL dating results for irrigation features. One sample yielded an average age of 96 ± 13 yr, consistent with the maximum expected age of 127 yr (before 2007). An OSL age of 175 ± 15 yr for another sample delimits a sedimentation event since the first construction of that feature ca. 300 yr ago. A sample known to be younger than 400–450 yr but predating the mid‐19th century gave an SGQ age of 376 ±31 yr. These results indicate that: (1) Regional quartz in New Mexico is highly favorable to OSL dating; (2) in this setting, SGQ OSL dating is preferred to MGSAQ dating; and (3) for the last 500–600 yr, SGQ OSL dating in such settings is preferred to14C dating because OSL dating lacks those ambiguities inherent in converting14C ages to calendar years. © 2009 Wiley Periodicals, Inc.
Soil properties and stable carbon isotope analysis of landscape features in the Petexbatún region of Guatemala
Authors: Wright David R. , Terry Richard E. , Eberl Markus 
Published: June 2009

AbstractSoil properties and stable carbon isotope ratios contained in the soil organic matter (SOM) were used to investigate the change in vegetative history of land cleared anciently for maize (Zea maysL.) agriculture in the Petexbatún region of Guatemala. Maize and other C4plants associated with land clearance leave a carbon isotopic signature in the SOM different from the C3plants of native forest vegetation. Soil profiles were collected from various landscape features around the Classic Maya site of Aguateca: control locations (areas likely not used in ancient agriculture), defensible locations (areas near defensive walls),rejolladas(natural karst depressions), upland locations (well‐drained soils atop the Aguateca escarpment), andbajos(seasonal and perennial wetlands). The chemical and physical properties of the profiles were examined and the soils were taxonomically classified to the great group level. The changes in d13C with soil depth were determined and compared statistically. The13C enrichment of the SOM inbajoandrejolladaprofiles were similar and were significantly (p< 0.05) greater than the control, defensible, and upland soils. This isotopic signature of sustained C4vegetation was likely associated with forest clearance and ancient Maya agriculture. Both thebajoandrejolladalandscape features appear to have been valuable agricultural resources for ancient Maya. © 2009 Wiley Periodicals, Inc.
Sources of social capital: Effects of altruistic citizenship behavior and job involvement on advice network centrality
Authors: Zhang Mian , Zheng Wei , Wei Jun 
Published: June 2009

AbstractSocial capital has been receiving increasing attention in HRD research. However, the sources of social capital have received inadequate attention. Little has been done to reveal how people obtain their social capital in the workplace. This study investigated the effects of employees' altruistic citizenship behavior and job involvement on their advice network centrality. Advice network centrality was used as an indicator of social capital. The results suggest that altruistic citizenship behavior and job involvement are positively associated with employees' advice network centrality. Furthermore, our findings suggest that job involvement moderates the effect of altruistic citizenship behavior on advice network centrality. Theoretical and practical implications for HRD are discussed and future directions are drawn.
Stream nitrate levels in a small catchment in south west England over a period of 35 years (1970–2005)
Authors: Burt Tim P. , Worrall Fred 
Published: June 2009

AbstractThis study considers a 35‐year record of streamwater nitrate concentration in a small agricultural catchment in south west England (Slapton Wood). The study revisits earlier work to assess whether upward trends have been maintained and how the controls upon streamwater concentration have been altered. The study has shown that (1) the catchment has reached a new position of equilibrium and increases in nitrate concentration have lessened; (2) the occurrence of severe drought in the record means that records of less than a decade are misleading and only long‐term records can illustrate changes of state; (3) the change of state observed in the catchment is illustrated in the switching of long‐term memory effects from a negative to a positive annual memory and (4) several significant long‐term impulsivity relationships with rainfall that become insignificant over the course of the study period. The study shows the importance of long‐term records in understanding changes in state in catchments and understanding the time constants of a range of driving processes. Copyright © 2009 John Wiley & Sons, Ltd.
Spatial variation of snowmelt and sublimation in a high‐elevation semi‐desert basin of western Canada
Authors: Jackson Scott I. , Prowse Terry D. 
Published: June 2009

AbstractThe Okanagan Basin, a semi‐desert region of western Canada, is currently experiencing rapidly increasing pressure on its water resources from development and population increases, exacerbated by changes in climate. The major source of freshwater in the region originates from the melt of high‐elevation snowpacks, about which little is currently known, including the proportion of the peak snowpack lost to sublimation. To better understand the hydrologic regime of this snow resource, a detailed field program was conducted during the 2007 snowmelt season. Specifically, peak annual snow distribution, ablation‐season surface‐energy exchange and mass balance were measured in a forested high‐elevation catchment of the Okanagan Basin. During the snowmelt period, 1–4% of the peak annual snow‐water equivalent (SWE) was lost to sublimation in open sites—averaging 0·4 mm d−1. Melt and sublimation rates increased significantly with elevation, and were observed to be higher and more variable in the open sites than under forest canopies. The largest sublimation events (>0·25 mm d−1) were associated with low atmospheric vapour pressure, temperatures below 0 °C, and higher than average wind speeds. Condensation occurred under highly stable conditions in the boundary layer when sensible heat fluxes exceeded net radiative inputs to the snow surface. Melt rates were driven almost entirely by sensible heat fluxes and exceeded 30 mm d−1 during large‐scale advection events. The results from this study will allow water managers to better predict the amount of water available for ecological, agricultural and municipal needs. This work also provides the basis for assessing changes in snow surface energetics due to ongoing salvage cutting in forested areas affected by the current mountain pine‐beetle outbreak. Copyright © 2009 John Wiley & Sons, Ltd and Her Majesty the Queen in right of Canada.
The influence of spatial variability in snowmelt and active layer thaw on hillslope drainage for an alpine tundra hillslope
Authors: Quinton William L. , Bemrose Robert K. , Zhang Yinsuo , Carey Sean K. 
Published: June 2009

AbstractIn alpine tundra, hillslope drainage occurs predominantly below the ground surface, between the relatively impermeable frost table and the water table above it. The saturated hydraulic conductivity decreases by two to three orders of magnitude between the ground surface and the top of the mineral substrate at 0·2–0·3 m depth. Consequently, the rate of sub‐surface conveyance from hillslopes strongly depends on the degree of active layer thaw. In addition, although rarely examined, the volume and timing of hillslope drainage and streamflow in alpine tundra are strongly influenced by the spatial pattern of active layer thaw in the runoff‐contributing hillslopes. The spatial and temporal pattern of soil thaw was modelled on a 25 535 m2 area of interest (AOI) on a north‐facing alpine tundra hillslope in southern Yukon, Canada. Daily oblique photographs were used to pixilate the AOI and measure the snow cover depletion for the AOI. Transects of thaw depth through selected snow‐free patches within or adjacent to the AOI were used to provide spatial representation of thaw depth and saturated hydraulic conductivity. To compute thaw depth for each pixel within the AOI as it became snow‐free, a finite element geothermal model was driven from meteorological forcing and soil hydro‐thermal data. Daily maps of snow‐free area and thaw depth were generated for the AOI, which were then combined with information on flowpath tortuosity and depth‐integrated saturated hydraulic conductivity for snow‐free areas to provide a drainage rate for the AOI. This drainage rate varied with the spatial arrangement of the snowpack and soil thaw depth. At the beginning of melt, the lack of hydrological connectivity for the AOI inhibited drainage. The drainage rate was maximized during the mid‐melt period since sub‐surface connections among snow‐free patches were widespread, and the hydraulic conductivity of the sub‐surface flow zone was still relatively high, owing to shallow soil thaw depths. Drainage was low at the end of the melt period because the frost table was at a depth where the hydraulic conductivity was very low. The results of this study indicate that to accurately simulate runoff at the hillslope scale during snowmelt, both the spatial pattern of snowmelt and ground thaw should be considered. Copyright © 2009 John Wiley & Sons, Ltd.
MicroRNA‐10b is overexpressed in malignant glioma and associated with tumor invasive factors, uPAR and RhoC
Authors: Sasayama Takashi , Nishihara Masamitsu , Kondoh Takeshi , Hosoda Kohkichi , Kohmura Eiji 
Published: June 2009

AbstractMicroRNAs (miRNAs) are effective post‐transcriptional regulators of gene expression and are important in many biological processes. Although the oncogenic and tumor suppressive functions of several miRNAs have been characterized, the role of miRNAs in mediating tumor invasion and migration remains largely unexplored. Recently, miR‐10b was identified as an miRNA highly expressed in metastatic breast cancer, promoting cell migration and invasion. Here, we performed real‐time reverse transcriptase polymerase chain reaction (RT‐PCR) assays on 43 glioma samples (17 glioblastoma, 6 anaplastic astrocytoma, 10 low‐grade astrocytoma, 6 oligodendroglioma and 4 ependymoma) and 6 glioma cell lines. We found that miR‐10b expression was upregulated in all glioma samples compared to non‐neoplastic brain tissues. The expression levels of miR‐10b were associated with higher grade glioma. In addition, mRNA expressions of RhoC and urokinase‐type plasminogen activator receptor (uPAR), which were thought to be regulated by miR‐10b via HOXD10, were statistically significantly correlated with the expression of miR‐10b (p < 0.001, p = 0.001, respectively). Also, protein expression levels of RhoC and uPAR were associated with expression levels of miR‐10b (p = 0.009, p = 0.014, respectively). Finally, multifocal lesions on enhanced MRI of 7 malignant gliomas were associated with higher expression levels of miR‐10b (p = 0.02). Our data indicated that miR‐10b might play some role in the invasion of glioma cells. © 2009 UICC
Identification of a chemokine receptor profile characteristic for mediastinal large B‐cell lymphoma
Authors: Rehm Armin , Anagnostopoulos Ioannis , Gerlach Kerstin , Broemer Meike , Scheidereit Claus , Jöhrens Korinna , Hübler Michael , Hetzer Roland , Stein Harald , Lipp Martin , Dörken Bernd , Höpken Uta E. 
Published: June 2009

AbstractMediastinal large B‐cell lymphomas (MLBCLs) are considered as a subtype of diffuse large B‐cell lymphoma; however, they exhibit completely different patterns of dissemination. Since they share a number of surface markers with thymic B cells, a close relationship was assumed. MLBCLs arise extranodally within the anterior mediastinum and have a low propensity to metastasize. To address the preferential positioning of MLBCL, we focused on homeostatic chemokines involved in B‐cell compartmental homing in secondary lymphoid organs, which are also capable of shaping lymphoid niches in ectopic sites. Here, we applied immunohistochemistry to assess chemokine receptor and ligand expression in situ. Flow cytometry was used to identify the chemokine receptor profile on an MLBCL‐derived cell line, Karpas1106 and on thymic B cells. Migration assays were performed to examine functionality of chemokine receptors. Electrophoretic mobility shift assay was applied to score for NF‐κB activity. Using immunohistochemistry, we obtained an unexpectedly low‐expression frequency for the chemokine receptors CXCR5 and CCR7 in primary lesions. Although the mature B‐cell marker CCR6 was absent in most cases, the lineage aberrant marker CCR9 emerged in the majority of MLBCL cases. Given the role of NF‐κB in the transcriptional activation of CCR7, we identified the involvement of the noncanonical activation pathway in MLBCLs. MLBCLs exhibit a diagnostic chemokine receptor profile that is instrumental in the discrimination from diffuse large B‐cell lymphoma not otherwise specified and classical Hodgkin lymphoma. Furthermore, we suggest that low‐abundance expression of CCR7 and CXCR5 may hinder lymphoma cells from nodal dissemination. © 2009 UICC
Specific thermal ablation of tumor cells using single‐walled carbon nanotubes targeted by covalently‐coupled monoclonal antibodies
Authors: Marches Radu , Chakravarty Pavitra , Musselman Inga H. , Bajaj Pooja , Azad Robert N. , Pantano Paul , Draper Rockford K. , Vitetta Ellen S. 
Published: June 2009

AbstractCD22 is broadly expressed on human B cell lymphomas. Monoclonal anti‐CD22 antibodies alone, or coupled to toxins, have been used to selectively target these tumors both in SCID mice with xenografted human lymphoma cell lines and in patients with B cell lymphomas. Single‐walled carbon nanotubes (CNTs) attached to antibodies or peptides represent another approach to targeting cancer cells. CNTs convert absorbed near‐infrared (NIR) light to heat, which can thermally ablate cells that have bound the CNTs. We have previously demonstrated that monoclonal antibodies (MAbs) noncovalently coupled to CNTs can specifically target and kill cells in vitro. Here, we describe the preparation of conjugates in which the MAbs are covalently conjugated to the CNTs. The specificity of both the binding and NIR‐mediated killing of the tumor cells by the MAb‐CNTs is demonstrated by using CD22+CD25− Daudi cells, CD22−CD25+ phytohemagglutinin‐activated normal human peripheral blood mononuclear cells, and CNTs covalently modified with either anti‐CD22 or anti‐CD25. We further demonstrate that the stability and specificity of the MAb‐CNT conjugates are preserved following incubation in either sodium dodecyl sulfate or mouse serum, indicating that they should be stable for in vivo use. © 2009 UICC