bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bis(3,5‐dimethyl‐4‐vinylpyrazol‐1‐yl)acetic Acid: A New Heteroscorpionate Building Block for Copolymers that Mimic the 2‐His‐1‐carboxylate Facial Triad
Authors: Türkoglu Gazi , Pubill Ulldemolins Cristina , Müller Rainer , Hübner Eike , Heinemann Frank W. , Wolf Marion , Burzlaff Nicolai 
Published: May 2010

AbstractThe new N,N,O ligand bis(3,5‐dimethyl‐4‐vinylpyrazol‐1‐yl)acetic acid (Hbdmvpza) (4) suitable for copolymerisation was synthesised in a multi‐step synthesis starting from bis(3,5‐dimethylpyrazol‐1‐yl)methane (1). The κ3‐N,N,O facial coordination behaviour of 4 was verified by synthesis and characterisation of the tricarbonyl compounds [Mn(bdmvpza)(CO)3] (5) and [Re(bdmvpza)(CO)3] (6), the ruthenium bisphosphane complex [Ru(bdmvpza)Cl(PPh3)2] (7), as well as the complex [Cu(bdmvpza)2] (8). Copolymerisation of 4 with methyl methacrylate (MMA) or ethylene glycol dimethacrylate (EGDMA) led to solid phases P1a, P1b and P2 with different amounts of incorporated ligand 4. Furthermore, a homopolymer H1 of ligand 4 was successfully synthesised. Copolymer‐bound manganese and rhenium tricarbonyl complexes P1a‐Mn, P1a‐Re, P2‐Mn and P2‐Re have been obtained by reaction of P1a and P2 with the metal precursors [MnBr(CO)5] and [ReBr(CO)5], respectively. The κ3‐N,N,O coordination of the manganese and rhenium centres was verified by IR spectroscopy and the amount of incorporated metal complex was determined by AAS or ICP‐AES measurements. Treatment of the deprotonated copolymer P1a or P2 with copper(II) or iron(II) led to polymers P1a‐Cu, P1a‐Fe and P2‐Fe. A bathochromic shift in the UV spectrum of P1a‐Cu compared to the absorption maximum of the homogeneous complex 8 by 64 nm indicates copper centres with one ligand moiety bound only. AAS analysis of P1a‐Fe and P2‐Fe show that up to 64 % of the ligand sites can be accessed withiron(II). Furthermore, two 2‐oxocarboxylato complexes [Ru(bdmvpza)(BF)(PPh3)] (9) (BF = benzoylformato) and [Ru(bdmvpza)(NOG)(PPh3)] (10) (NOG = N‐oxalylglycine) have been synthesised that mimic the shape of the active sites of 2‐oxoglutarate dependent iron oxygenases. The successful copolymerisation of 9 and 10 with EGDMA was proven by UV spectroscopy.
NIR Bioimaging: Development of Liposome‐Encapsulated, Rare‐Earth‐Doped Y2O3 Nanoparticles as Fluorescent Probes
Authors: Soga Kohei , Tokuzen Kimikazu , Tsuji Kosuke , Yamano Tomoyoshi , Hyodo Hiroshi , Kishimoto Hidehiro 
Published: May 2010

AbstractNear‐infrared (NIR) bioimaging is attracting a lot of attention due to the absence of strong scattering and color fading of the phosphors, which can provide long‐term and deep imaging. For fluorescence bioimaging (FBI) in the NIR region, rare‐earth‐doped ceramic nanoparticles can be one of the best candidates. For the delivery of the ceramic particles to the biological imaging target, liposome‐encapsulating the ceramic phosphor is proposed. Liposome‐encapsulated, Er‐doped Y2O3 nanoparticles were prepared as fluorescent probes for NIR bioimaging. Their surface was modified with PEG, biotin, anionic, and cationic agents. The dispersion, surface charge, and specific interactions of the surface‐modified liposomes were characterized. Microscopic and macroscopic NIR bioimages were demonstrated by injecting the liposome‐encapsulated, Er‐doped Y2O3 nanoparticles into the body of a mouse through the blood vessels. The NIRfluorescence images of the mouse organs are presented.
Ureaphosphanes as Hybrid, Anionic or Supramolecular Bidentate Ligands for Asymmetric Hydrogenation Reactions
Authors: Meeuwissen Jurjen , Detz Remko , Sandee Albertus J. , de Bruin Bas , Siegler Maxime A. , Spek Anthony L. , Reek Joost N. H. 
Published: May 2010

AbstractWe report the coordination behavior of ureaphosphane ligand 1‐[2‐(diphenylphosphanyl)ethyl]‐3‐phenylurea (L1) towards different rhodium precursor complexes. Depending on the nature of the anion and the ligand/metal ratio, L1 acts either as a hybrid P,O‐coordinating chelate, as an anionic P,N‐coordinating chelate or as a supramolecular (hydrogen‐bonded) bidentate ligand. The different types of complexes were investigated in the asymmetric hydrogenation of three olefinic substrates using ureaphosphanes L2 and L3, which are chiral analogues of L1. For methyl 2‐acetamidoacrylate (S1) and dimethyl itaconate (S2) the neutral complex [Rh(L2‐κ2P,N)(cod)], containing an anionic P,N‐coordinating ureaphosphane ligand, provided the best enantioselectivity (69.2 and 24.3 %, respectively). For N‐(3,4‐dihydro‐2‐naphthalenyl)acetamide (S3) the best enantioselectivity was obtained with the cationic complex [Rh(L3‐κ2P,O)(nbd)]BF4, containing a hybrid P,O‐coordinating ureaphosphane ligand (86.1 %).
Palladium Chemistry with Stanna‐closo‐dodecaborate and Isocyanides
Authors: Hornung Martin , Wesemann Lars 
Published: May 2010

AbstractThe substitution equilibrium between isocyanides and stanna‐closo‐dodecaborate with palladium(II) was investigated. The mixed substituted products of type [(RNC)2Pd(SnB11H11)2]2– and [(RNC)Pd(SnB11H11)3]4– were characterized by X‐ray crystal structure analysis, elemental analysis and NMR spectroscopy. Isocyanide insertion into palladium–carbon bonds was also found. The zwitterionic complexes isolated from the reaction of [(P′2)Pd(Me)(SnB11H11)]– (P′2 = dppe, dppp, dppf) with isocyanides were characterized.
Comparative analysis of triacylglycerols from Olea europaea L. fruits using HPLC and MALDI‐TOFMS
Authors: Sakouhi Faouzi , Absalon Christelle , Kallel Habib , Boukhchina Sadok 
Published: May 2010

AbstractMALDI‐TOFMS and HPLC are two analytical methods that were used to characterize triacylglycerols (TAG) of the Meski, Sayali, and Picholine Tunisian olive varieties. The HPLC chromatograms of the oils showed the presence of 15 TAG species, among which triolein (OOO) was the most abundant (21–48%). In the Sayali cultivar, OOO was the predominant TAG species followed by POO and LOO. However, the minor TAG molecules were represented by LnLO and LnLP. MALDI mass spectra produced sodiated ([M + Na]+) and potassiated ([M + K]+) TAG molecules; only the major TAG were potassiated [OOO + K] ([OOO + K]+, [POO + K]+, and [LOO + K]+). In contrast to the HPLC chromatograms, the MALDI mass spectra showed 13 peaks of TAG. The major peak was detected at m/z 907, which corresponds to OOO with an Na+ adduct. The results from both HPLC and MALDI techniques predict the fatty acid composition and their percentages for each olive variety.Practical applications: TAG are the main components in vegetable oils. These biomolecules determine the physical, chemical, and nutritional properties of the oils. The nutritional benefits of TAG are related to DAG (moderate plasma lipid level) and esterified FA, which are intermediate biosynthetic molecules of TAG. TAG analysis is necessary to discriminate between oils of different origin, since some oils have similar FA profiles. Olive products, oils, and table olives, are the main diet sources of TAG in the Mediterranean countries. In this work, chromatographic and spectrometric methods were used for TAG analysis and characterization of Tunisian olive varieties.
Copper‐Catalyzed Multicomponent Coupling of Organoindium Reagents with Nitrogen‐Containing Aromatic Heterocycles
Authors: Beveridge Ramsay E. , Black Daniel A. , Arndtsen Bruce A. 
Published: May 2010

AbstractA mild, copper‐catalyzed coupling of organoindium reagents with nitrogen‐containing aromatic heterocycles and chloroformates is described. This reaction proceeds with a range of organoindium reagents, yielding predominately or exclusively the 1,4‐addition products with pyridine. In addition, a range of other nitrogen‐containing heterocycles can be employed in this reaction (e.g. benzoxazole, benzothiazole, phthalazine). As an illustration of the utility of this reaction, this heterocycle functionalization is coupled with a subsequent oxidation to achieve the one‐pot synthesis of functionalized pyridine and benzothiazole derivatives.
How social experience is related to children's intergroup attitudes
Authors: McGlothlin Heidi , Killen Melanie 
Published: May 2010

AbstractIntergroup attitudes were assessed in 7 and 10 years old European American and African American children from ethnically heterogeneous schools and in 7 and 10 years old European American children from ethnically homogeneous schools in order to test hypotheses about racial biases and judgments regarding cross‐race peer interactions (N = 302). Using an Ambiguous Situations Task, the findings revealed that European American children attending homogeneous schools displayed racial bias in their interpretations of ambiguous situations as well as in their evaluations of cross‐race friendship. Bias was not found, however, in the interpretations and evaluations of European American or African American children from heterogeneous schools. This study is the first to empirically demonstrate significant and direct relationships between intergroup contact in the school environment and children's intergroup biases as well as judgments about the potential for cross‐race friendships. Copyright © 2010 John Wiley & Sons, Ltd.
Intergroup bias in children: Development and persistence
Authors: Files James Sean , Casey Christopher M. , Oleson Kathryn C. 
Published: May 2010

AbstractUsing a longitudinal approach, we examined intergroup bias based on randomly assigned novel groups in fourth‐ and fifth‐grade children (roughly 9–11 years old) involved in an afterschool program. We investigated not only the development of intergroup bias but also its persistence over multiple weeks. Our intergroup bias measure assessed children's evaluations of group members uninvolved in the program to determine if intergroup bias could be applied beyond the immediate context. We found that children's intergroup bias toward group members outside their program developed when they were first segregated into classrooms based on their novel groupings and persisted over multiple weeks, adding to our understanding of the impact of categorization on the development and persistence of children's intergroup biases. We consider our findings both in terms of how categorization influences the development of intergroup bias and ways to use re‐ and cross‐categorization to defeat children's intergroup biases. Copyright © 2010 John Wiley & Sons, Ltd.
Priorities in social categories
Authors: Kinzler Katherine D. , Shutts Kristin , Correll Joshua 
Published: May 2010

AbstractIn this paper we review evidence from social, developmental, and evolutionary psychology to raise a common question: Are there priorities in how humans categorize their social world? Are some social groupings more prominent in childhood, and more resilient in adulthood than others? We review and compare evidence from each field, with a particular emphasis on exploring the relative robustness of gender, race, age, and language as social categories. We highlight the value of developmental approaches for characterizing the origins and nature of social categories in adults, and provide suggestions for how collaborative research from social, developmental, and evolutionary psychology could inform our understanding of potential priorities in social categorization. Copyright © 2010 John Wiley & Sons, Ltd.
Learning to control ethnic intergroup bias in childhood
Authors: FitzRoy Sarah , Rutland Adam 
Published: May 2010

AbstractThe aim of this research was to identify what factors deter explicit intergroup bias in childhood. Two studies were conducted to examine what facilitates the control of ethnic bias amongst 6–9‐year‐old majority children. In both studies in‐group accountability was either low (i.e., only accountable to experimenter) or high (i.e., also accountable to classmates and teachers). Study 1 (n = 287) found that only 8–9‐year‐old with low social emotions reduced their bias with increased accountability. Study 2 (n = 236) showed children with low “Theory of Social Mind” (ToSM: Abrams, Rutland, Ferrell, & Pelletier, 2009), who perceived an anti‐prejudice in‐group norm, decreased their bias when accountability increased. In both studies children high in social emotion and ToSM showed low bias irrespective of accountability. Together these studies make a novel contribution by showing for the first time affective and social‐cognitive factors that influence how children learn to control explicit bias. Copyright © 2010 John Wiley & Sons, Ltd.
Biosorption of lead by E. coli strains expressingVitreoscilla hemoglobin: Isotherm modeling with two‐and three‐parameter models
Authors: Aljundi Isam H. , Khleifat Khaled M. 
Published: May 2010

AbstractBiosorption is presented as an alternative choice to traditional physicochemical means for removing toxic metals from groundwater and wastewaters. Removal of lead (Pb) from solutions was studied using Escherichia coli (parental) and Vitreoscilla hemoglobin (VHb)‐expressing E. coli (transformed) cells. Pb biosorption was increased in bacterial hemoglobin‐expressing E. coli cells grown in Luria broth B containing different concentrations of Pb2+. The maximum Pb2+ biosorption of transformed and parental cells was determined to be 612 and 370 μg Pb/g biomass, respectively. The inhibitory effect of Pb2+ on the parental strain was determined at 10 ppm. However, in transformed cells, Pb2+ was lethal at 100 ppm. The optimum aeration required for the transformed cells was lower than that for the parental strain on a growth yield basis. A linear correlation was established between the biosorption and uptake amounts. The biosorption process was analyzed using two‐parameter (Langmuir, Freundlich, Temkin) and three‐parameter models (Sips, Redlich–Peterson, Toth). The chi‐square test was used to compare these models. It was demonstrated that the three‐parameter model is better in describing biosorption equilibria a, white the Sips equation showed the best description for both types of cells.
Possible roles of excess tryptophan metabolites in cancer
Authors: Chung King‐Thom , Gadupudi Gopi S. 
Published: May 2010

AbstractTryptophan is metabolized through serotonin, indole, and kynurenine (KN) pathways. Uptake of an excess amount of tryptophan accompanied with vitamin B6 deficiency may result in the accumulation of higher concentrations of metabolites mainly from the KN pathways in the bladder. These metabolites could interact with nitrite to become mutagenic nitrosamines. They could be a promoter in the initiator–promoter model of carcinogenesis. They produced bladder cancer when implanted in the bladder. They also interact with transition metals copper or iron to form reactive radicals or reactive oxygen species (ROS). Some metabolites, 3‐hydroxy‐anthranilic acid, were autooxidized to mutagenic cinnabarinic and anthranilyl radical intermediates. These radical intermediates could also be ligands that interact with aryl hydrocarbon receptor (AhR) and induce xenobiotic metabolizing enzymes (XMEs) to metabolize contaminated carcinogens. When tryptophan is exposed to either visible or UV light, a photoproduct of 6‐formylindolo[3,2b]‐carbazole is formed, which has a very high affinity for the AhR that plays a role in carcinogenesis. This review gives an insight into various mechanisms through which tryptophan metabolites cause carcinogenesis. It could be concluded that tryptophan metabolites play a complementary role in promoting carcinogenesis along with carcinogens like aflatoxin, CCl4, 2‐acetylaminofluorene, 4‐aminobiphenyl, 2‐naphthylamine, orN‐[4‐(5‐nitro‐2‐furyl)−2‐thiazolyl] formamide. The underlying mechanisms could be their autoxidation, exposure to either visible or UV light, interaction with nitrite or transition metals to form reactive intermediates, serving as ligands to interact with an AhR that is known to play a role in carcinogenesis through induction of XMEs. Further research is warranted.Environ. Mol. Mutagen. 52:81–104, 2011. © 2010 Wiley‐Liss, Inc.
Using sediment travel distance to estimate medium‐term erosion rates: a 16‐year record
Authors: Parsons Anthony John , Wainwright John , Fukuwara Tomomi , Onda Yuichi 
Published: May 2010

AbstractFine grained (80 µm) magnetite was introduced onto a semi‐arid grassland hillslope in 1992, as part of a set of rainfall‐simulation experiments. Using measurements of magnetic susceptibility, the median distance travelled by these magnetite grains during subsequent natural runoff events in the 16‐year period up to 2008 was estimated. Coupling this estimate to direct measurements of sediment flux obtained during the rainfall‐simulation experiments has enabled estimation of the erosion rate over this period. The estimated average erosion rate of between 2·61 × 10−2 and 4·36 × 10−2 kg m−1 year−1, is equivalent to a rate of ground lowering between 0·020 and 0·033 mm year−1. This estimate is consistent with (in the sense of being less than) an estimate of total sediment detachment over the same period. The rate of erosion measured using this travel‐distance approach is an order of magnitude less that obtained from a study based on 137Cs in a nearby catchment, and compatible with the longevity of continents. Copyright © 2010 John Wiley & Sons, Ltd.
Lead distributions and risks in New Orleans following Hurricanes Katrina and Rita
Authors: Abel Michael T. , Cobb George P. , Presley Steven M. , Ray Gary L. , Rainwater Thomas R. , Austin Galen P. , Cox Stephen B. , Anderson Todd A. , Leftwich Blair D. , Kendall Ronald J. , Suedel Burton C. 
Published: May 2010

AbstractDuring the last four years, significant effort has been devoted to understanding the effects that Hurricanes Katrina and Rita had on contaminant distribution and redistribution in New Orleans, Louisiana, USA, and the surrounding Gulf Coast area. Elevated concentrations were found for inorganic contaminants (including As, Fe, Pb, and V), several organic pollutants (polycyclic aromatic hydrocarbons, pesticides, and volatiles) and high concentration of bioaerosols, particularly Aeromonas and Vibrio. Data from different research groups confirm that some contaminant concentrations are elevated, that existing concentrations are similar to historical data, and that contaminants such as Pb and As may pose human health risks. Two data sets have been compiled in this article to serve as the foundation for preliminary risk assessments within greater New Orleans. Research from the present study suggests that children in highly contaminated areas of New Orleans may experience Pb exposure from soil ranging from 1.37 µg/d to 102 µg/d. These data are critical in the evaluation of children's health. Environ. Toxicol. Chem. 2010;29:1429–1437. © 2010 SETAC
Use of bioassays and sediment polycyclic aromatic hydrocarbon concentrations to assess toxicity at coastal sites impacted by Hurricane Katrina
Authors: Weston James , Warren Crystal , Chaudhary Amit , Emerson Beth , Argote Kate , Khan Shabana , Willett Kristine L. 
Published: May 2010

AbstractThe goal of the present study was twofold: to rapidly assess the potential environmental toxicological response following the storm surge and flooding caused by Hurricane Katrina along the Gulf Coast of Mississippi, USA, in August 2005, and to establish post-Katrina baseline toxicological profiles for three environmental matrices (water, suspended sediments, and sediments) within the intertidal zone. Sediment and water samples were collected monthly from September 2005 to 2006 from 10 sites along the Gulf Coast from Gulfport, Mississippi, to Mobile Bay, Alabama. Water samples and suspended sediment matrices were extracted, assayed, and toxic equivalent values calculated for compounds with estrogenic potential, using the yeast estrogen screen, and CYP1A induction potential, using the H4IIE rat hepatoma ethoxyresorufin-O-deethylase assay. Polycyclic aromatic hydrocarbons (PAHs) were measured in surface sediments. It was hypothesized that the more heavily storm impacted sites, those closest to Katrina's path and time of landfall (e.g., Gulfport, September–October 2005), would elicit higher bioassay responses and PAH concentrations compared to those further east or approximately a year post-Katrina (e.g., Mobile Bay, August– September 2006). Benzo[a]pyrene equivalents decreased along spatial and temporal storm intensity gradients, but estrogenic compounds and sediment PAHs did not. Estrogen equivalents (∼1 ng/L) from water and suspended sediment samples occurred primarily in samples collected within a few months post-Katrina. Site-averaged surface sediment total PAHs varied significantly between sites and were higher than the U.S. National Oceanic and Atmospheric Administration's probable effects level at the Gulfport Marina and Back Biloxi Bay, Mississippi, sites. Results from the present study suggest that CYP1A inducing compounds elicited a short-term bioassay response in the water matrix shortly (within weeks) after Katrina's passing but were quickly reduced. Environ. Toxicol. Chem. 2010;29:1409–1418. © 2010 SETAC
Sediment quality in near coastal waters of the Gulf of Mexico: Influence of Hurricane Katrina
Authors: Macauley John M. , Smith Lisa M. , Harwell Linda C. , Benson William H. 
Published: May 2010

AbstractThe results of the present study represent a synoptic analysis of sediment quality in coastal waters of Lake Pontchartrain and Mississippi Sound two months after the landfall of Hurricane Katrina. Posthurricane conditions were compared to prehurricane (2000–2004) conditions, for sediment quality data. There were no exceedances of effects range median (ERM) sediment quality guideline values for chemical contaminants in any of the sediment samples collected from the Lake Pontchartrain or the Mississippi Sound study areas following the hurricane. Lower threshold effects range low (ERL) values were exceeded for As, Cd, and Ni at several stations in both survey areas, similar to levels of contamination observed prior to the hurricane. The comparison of sediment quality indicators before and after the hurricane suggests considerable stability of these systems with respect to short-term ecological impacts. Although other studies have shown storm-related changes could be detected (e.g., effects on benthic communities associated with shifts in salinity), there were no indications of widespread sediment contamination. Environ. Toxicol. Chem. 2010;29:1403–1408. © 2010 SETAC