bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coexistence of Two Thermally Induced Intramolecular Electron Transfer Processes in a Series of Metal Complexes [M(Cat‐N‐BQ)(Cat‐N‐SQ)]/[M(Cat‐N‐BQ)2] (M=Co, Fe, and Ni) bearing Non‐Innocent Catechol‐Based Ligands: A Combined Experimental and Theoretical Study
Authors: Evangelio Emi , Bonnet Marie‐Laure , Cabañas Miquel , Nakano Motohiro , Sutter Jean‐Pascal , Dei Andrea , Robert Vincent , Ruiz‐Molina Daniel 
Published: April 2010

AbstractThe different thermally induced intermolecular electron transfer (IET) processes that can take place in the series of complexes [M(Cat‐N‐BQ)(Cat‐N‐SQ)]/[M(Cat‐N‐BQ)2], for which M=Co (2), Fe (3) and Ni(4), and Cat‐N‐BQ and Cat‐N‐SQ denote the mononegative (Cat‐N‐BQ−) or dinegative (Cat‐N‐SQ2−) radical forms of the tridentate Schiff‐base ligand 3,5‐di‐tert‐butyl‐1,2‐quinone‐1‐(2‐hydroxy‐3,5‐di‐tert‐butylphenyl)imine, have been studied by variable‐temperature UV/Vis and NMR spectroscopies. Depending on the metal ion, rather different behaviors are observed. Complex 2 has been found to be one of the few examples so far reported to exhibit the coexistence of two thermally induced electron transfer processes, ligand‐to‐metal (IETLM) and ligand‐to‐ligand (IETLL). IETLL was only found to take place in complex 3, and no IET was observed for complex 4. Such experimental studies have been combined with ab initio wavefunction‐based CASSCF/CASPT2 calculations. Such a strategy allows one to solicit selectively the speculated orbitals and to access the ground states and excited‐spin states, as well as charge‐transfer states giving additional information on the different IET processes.
Peptide Nanofibers Modified with a Protein by Using Designed Anchor Molecules Bearing Hydrophobic and Functional Moieties
Authors: Miyachi Ayaka , Takahashi Tsuyoshi , Matsumura Sachiko , Mihara Hisakazu 
Published: April 2010

AbstractSelf‐assembly of peptides and proteins is a key feature of biological functions. Short amphiphilic peptides designed with a β‐sheet structure can form sophisticated nanofiber structures, and the fibers are available as nanomaterials for arranging biomolecules. Peptide FI (H‐PKFKIIEFEP‐OH) self‐assembles into nanofibers with a coiled fine structure, as reported in our previous work. We have constructed anchor molecules that have both a binding moiety for the fiber structure and a functional unit capable of capturing target molecules, with the purpose of arranging proteins on the designed peptide nanofibers. Designed anchors containing an alkyl chain as a binding unit and biotin as a functional moiety were found to bind to peptide fibers FI and F2i (H‐ALEAKFAAFEAKLA‐NH2). The surface‐exposed biotin moiety on the fibers could capture an anti‐biotin antibody. Moreover, hydrophobic dipeptide anchor units composed of iminodiacetate connected to Phe–Phe or Ile–Ile and a peptide composed of six histidine residues connected to biotin could also connect FI peptide fibers to the anti‐biotin antibody through the chelation of Ni2+ ions. This strategy of using designed anchors opens a novel approach to constructing nanoscale protein arrays on peptide nanomaterials.
Bipyridyl Derivatives as Photomemory Devices: A Comparative Electronic‐Structure Study
Authors: Ortiz‐Sánchez Juan Manuel , Gelabert Ricard , Moreno Miquel , Lluch José M. , Anglada Josep M. , Bofill Josep M. 
Published: April 2010

AbstractThe two isoelectronic bipyridyl derivatives [2,2′‐bipyridyl]‐3,3′‐diamine (BP(NH2)2) and [2,2′‐bipyridyl]‐3,3′‐diol (BP(OH)2) are experimentally known to undergo very different excited‐state double proton transfer processes that result in fluorescence quantum yields that differ by four orders of magnitude. Such differences have been theoretically explained in terms of topographical features in the potential energy surface and the likely presence of conical intersections. The hypothetical hybrid compound [2,2′‐bipyridyl]‐3‐amin‐3′‐ol (BP(OH)(NH2)) presents intermediate photochemical features of its “ancestors”. In this report we analyze the photochemical properties of a whole family of “dark” (not fluorescent) states that can be accessed from each bipyridyl derivative upon irradiation of light of a given wavelength and their potential application as photomemory devices. In the light of our density functional theory (DFT), time‐dependent DFT (TDDFT), and complete active space self‐consistent field (CASSCF) calculations, BP(NH2)2 is the more likely candidate to become a photomemory device.
Ir‐Catalysed Asymmetric Allylic Substitutions with Cyclometalated (Phosphoramidite)Ir Complexes—Resting States, Catalytically Active (π‐Allyl)Ir Complexes and Computational Exploration
Authors: Raskatov Jevgenij A. , Spiess Stephanie , Gnamm Christian , Brödner Kerstin , Rominger Frank , Helmchen Günter 
Published: April 2010

AbstractMechanistic aspects of allylic substitutions with iridium catalysts derived from phosphoramidites by cyclometalation were investigated. The determination of resting states by 31P NMR spectroscopy led to the conclusion that the cyclometalation process is reversible. A novel, one‐pot procedure for the preparation of (π‐ allyl)Ir complexes was developed, and these complexes were characterised by X‐ray crystal structure analyses and spectral data. They are fully active catalysts of the allylic substitution reaction. DFT calculations on the allyl complexes, transition states of the allylic substitution and product olefin complexes gave further mechanistic insight.
Methane Activation by Platinum: Critical Role of Edge and Corner Sites of Metal Nanoparticles
Authors: Viñes Francesc , Lykhach Yaroslava , Staudt Thorsten , Lorenz Michael P. A. , Papp Christian , Steinrück Hans‐Peter , Libuda Jörg , Neyman Konstantin M. , Görling Andreas 
Published: April 2010

AbstractComplete dehydrogenation of methane is studied on model Pt catalysts by means of state‐of‐the‐art DFT methods and by a combination of supersonic molecular beams with high‐resolution photoelectron spectroscopy. The DFT results predict that intermediate species like CH3 and CH2 are specially stabilized at sites located at particles edges and corners by an amount of 50–80 kJ mol−1. This stabilization is caused by an enhanced activity of low‐coordinated sites accompanied by their special flexibility to accommodate adsorbates. The kinetics of the complete dehydrogenation of methane is substantially modified according to the reaction energy profiles when switching from Pt(111) extended surfaces to Pt nanoparticles. The CH3 and CH2 formation steps are endothermic on Pt(111) but markedly exothermic on Pt79. An important decrease of the reaction barriers is observed in the latter case with values of approximately 60 kJ mol−1 for first CH bond scission and 40 kJ mol−1 for methyl decomposition. DFT predictions are experimentally confirmed by methane decomposition on Pt nanoparticles supported on an ordered CeO2 film on Cu(111). It is shown that CH3 generated on the Pt nanoparticles undergoes spontaneous dehydrogenation at 100 K. This is in sharp contrast to previous results on Pt single‐crystal surfaces in which CH3 was stable up to much higher temperatures. This result underlines the critical role of particle edge sites in methane activation and dehydrogenation.
Cross‐Coupling/Cyclization Reactions of Two Different Allenic Moieties
Authors: Alcaide Benito , Almendros Pedro , Martínez del Campo Teresa 
Published: April 2010

AbstractThe allene moiety represents an excellent building block for allene cross‐coupling cyclization reactions, affording heterocyclic skeletons in a single step. This strategy is of particular interest when two different allene derivatives are involved in a series of metal‐catalyzed cross‐coupling heterocyclization processes. This Concept article is focused on the Pd‐catalyzed union of two different allenic moieties, with cyclization of at least one of them by intramolecular cyclometalation. These new, versatile, and highly effective transformations are complex multistep processes leading to potential privileged structures that could find wide applications in related medicinal chemistry.
Nanoparticle transport in a realistic model of the tracheobronchial region
Authors: Comerford A. , Bauer G. , Wall W. A. 
Published: April 2010

AbstractThe transport and deposition of nanoparticles in the human lung has important health consequences for both hazardous and non‐hazardous reasons. Example scenarios are inhalation of toxic pollutants from the surrounding environment and novel targeted drug delivery to the lung epithelial surface. In this paper, we develop a method to simulate the time‐dependent transport of nanoparticles in CT‐based models of the human tracheobronchial region. We consider the transport in a seven generation model based on an Euler–Euler approach for particles ranging from 1.5 to 11 nm, i.e. in a range considered important for the tracheobronchial region. The results indicate that the deposition of smaller particles are affected more by the non‐uniformity of the realistic geometry. In particular, we observe spatial variations in wall deposition directly resulting from the complex air flow patterns. Time‐dependent effects tend to be less significant compared with the geometric effects. Copyright © 2010 John Wiley & Sons, Ltd.
Distributed reachability testing of concurrent programs
Authors: Carver Richard H. , Lei Yu 
Published: April 2010

AbstractReachability testing is an approach to verifying concurrent programs. During reachability testing, every partially ordered synchronization sequence of a program with a given input is exercised exactly once. In this paper, we present the design and implementation of a distributed reachability testing algorithm for a cluster of workstations. This algorithm allows different test sequences to be exercised concurrently by different workstations without any synchronization, and without any duplication of sequences among workstations. Dynamic load balancing is performed using a work‐stealing scheme. A novel aspect of this scheme is that work‐stealing requests progress in rounds. This round‐based structure identifies overloaded workstations to target for work stealing. Empirical studies show good speedup for four benchmark Java programs and one Lotos specification. Copyright © 2010 John Wiley & Sons, Ltd.
Global‐scale distributed I/O with ParaMEDIC
Authors: Balaji P. , Feng W. , Lin H. , Archuleta J. , Matsuoka S. , Warren A. , Setubal J. , Lusk Ewing , Thakur R. , Foster I. , Katz D. S. , Jha S. , Shinpaugh K. , Coghlan S. , Reed D. 
Published: April 2010

AbstractAchieving high performance for distributed I/O on a wide‐area network continues to be an elusive holy grail. Despite enhancements in network hardware as well as software stacks, achieving high‐performance remains a challenge. In this paper, our worldwide team took a completely new and non‐traditional approach to distributed I/O, calledParaMEDIC: Parallel Metadata Environment for Distributed I/O and Computing, by utilizing application‐specifictransformationof data to orders of magnitude smaller metadata before performing the actual I/O. Specifically, this paper details our experiences in deploying a large‐scale system to facilitate the discovery of missing genes and constructing a genome similarity tree by encapsulating the mpiBLAST sequence‐search algorithm into ParaMEDIC. The overall project involved nine computational sites spread across the U.S. and generated more than a petabyte of data that was ‘teleported’ to a large‐scale facility in Tokyo for storage. Copyright © 2010 John Wiley & Sons, Ltd.
Optimization of process parameters by Taguchi method in the recovery of lactose from whey using sonocrystallization
Authors: Patel S. R. , Murthy Z. V. P. 
Published: April 2010

AbstractAnti‐solvent crystallization of lactose in the presence of ultrasound will reduce crystal size and the level of agglomeration as compared to the commercial cooling crystallization. It offers a potential route to enhance the physical properties as well as the rapid recovery of lactose. Since lactose recovery itself can reduce biological oxygen demand of whey by more then 80%, recovery of lactose from dairy waste stream (whey) solves the problems of dairy industries by improving economics of whey utilization and pollution reduction. In the present study, recovery of lactose from partially deproteinated whey using an anti‐solvent (acetone) by sonocrystallization was optimized for finding the most influencing operating parameters; such as sonication time, anti‐solvent concentration, initial lactose concentration in the whey and initial pH of sample mixture at three levels using L9‐orthogonal method. The responses were analyzed for recovery of lactose from whey. The anti‐solvent concentration and the sonication time were found to be most influencing parameters for the recovery of lactose and the recovery of lactose was found to be 89.03% at the identified optimized level. The crystal size distribution of recovered lactose was found to be narrower (2.5 – 6.5 μm) as compared to the commercial lactose crystals (3.5 – 9.5 μm). (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermal transformations of the mineral component of composite biomaterials based on chitosan and apatite
Authors: Danilchenko S. N. , Kalinkevich O. V. , Kuznetsov V. N. , Kalinkevich A. N. , Kalinichenko T. G. , Poddubny I. N. , Starikov V. V. , Sklyar A. M. , Sukhodub L. F. 
Published: April 2010

AbstractComposite biomaterials based on chitosan and calcium apatite with different chitosan/apatite ratio were prepared by chemical synthesis of apatite in chitosan solution using one‐step co‐precipitation method. Initial and annealed samples were characterized by X‐ray diffraction, FTIR spectroscopy and scanning electron microscopy coupled to energy‐dispersive electron X‐ray spectroscopy. The data obtained suggest that the formation of the calcium‐phosphate mineral in chitosan solution is substantially modulated by the chemical interaction of the components; apparently, a part of calcium is captured by chitosan and does not participate in the formation of the main mineral phase. The apatite in the composite is calcium‐deficient, carbonate‐substituted and is composed of dispersed nano‐sized crystallites, i.e. has properties that closely resemble those of bone mineral. Varying synthesis, drying and lyophilization conditions, the composite materials can be produced with the desirable chitosan/apatite ratio, both in the dense and porous form. The structural analysis of composite samples after annealing at certain temperatures is examined as an approach to elucidate the mechanism of co‐precipitation by one‐step method. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Altered vascular expression of EphrinB2 and EphB4 in a model of oxygen‐induced retinopathy
Authors: Davies Michael H. , Stempel Andrew J. , Hubert Kristin E. , Powers Michael R. 
Published: April 2010

AbstractEphrinB2 ligands and EphB4 receptors are expressed on endothelial cells (EC) of arteries and veins, respectively, and are essential for vascular development. To understand how these molecules regulate retinal neovascularization (NV), we evaluated their expression in a model of oxygen‐induced retinopathy (OIR). EphrinB2 and EphB4 were expressed on arterial and venous trunks, respectively, and on a subset of deep capillary vessels. EphB4 expression was reduced following hyperoxia, while ephrinB2 expression remained unaltered. In addition, a subset of EphB4‐positive veins regressed in a caspase‐3‐dependent manner during hyperoxia. Arteriovenous malformations were also observed with loss of arterial‐venous boundaries. Finally, both ephrinB2 and EphB4 were expressed on a subset of neovascular tufts following hyperoxia. These data confirm the contribution of ECs from both venous and arterial origins to the development of retinal NV. Developmental Dynamics 239:1695–1707, 2010. © 2010 Wiley‐Liss, Inc.
Permanent Encapsulation or Host–Guest Behavior of Aromatic Molecules in Hexanuclear Arene Ruthenium Prisms
Authors: Freudenreich Julien , Barry Nicolas P. E. , Süss‐Fink Georg , Therrien Bruno 
Published: April 2010

AbstractCationic arene ruthenium metallaprisms of the general formula [Ru6(p‐cymene)6(tpt)2(OO∩OO)3]6+ {tpt = 2,4,6‐tris(4‐pyridyl)‐1,3,5‐triazine; OO∩OO = 9,10‐dioxo‐9,10‐dihydroanthracene‐1,4‐diolato [1]6+, 6,11‐dioxo‐6,11‐dihydronaphthacene‐5,12‐diolato [2]6+} have been obtained from the corresponding dinuclear arene ruthenium complexes [Ru2(p‐cymene)2(OO∩OO)Cl2] by reaction with tpt and silver trifluoromethanesulfonate. Aromatic molecules (phenanthrene, pyrene, triphenylene, coronene) present during the synthesis of these metallaprisms are permanently encapsulated to give carceplex systems. All empty cages ([1]6+ and [2]6+) and carceplex systems ([guest⊂1]6+ and [guest⊂2]6+) were isolated in good yield as trifluoromethanesulfonate salts and characterized by NMR, UV, and IR spectroscopy. The host–guest properties of [1]6+ and [2]6+ were studied in solution in the presence of small aromatic molecules (phenanthrene andpyrene). The stability constant of association (Ka) wasestimated by NMR spectroscopy for the following host–guest systems: [phenanthrene⊂1]6+, [pyrene⊂1]6+ and [phenanthrene⊂2]6+, [pyrene⊂2]6+. All Ka values were found to be larger than 2.0 × 104 M–1 for these host–guest systems ([D3]acetonitrile, 21 °C).
SOFA database temporarily out of order
Authors: Aitzetmüller Kurt 
Published: April 2010

AbstractReaders are informed about temporary problems with the database “Seed Oil Fatty Acids” (SOFA). Because industrial oil crops with unusual fatty acids are currently a hot research field, many requests for information reached the author, particularly often from ICON‐Partners worldwide (http://icon.slu.se/ICON/Part icon.htm). SOFA should be online again later in 2010. The nature of SOFA and some potential applications of SOFA are briefly discussed.
Evaluation of the performance of single‐walled carbon nanohorns in capillary electrophoresis
Authors: Jiménez‐Soto Juan Manuel , Moliner‐Martínez Yolanda , Cárdenas Soledad , Valcárcel Miguel 
Published: April 2010

AbstractThis paper describes for the first time the use of single‐walled carbon nanohorns (SWNHs) as pseudostationary and stationary phases for EKC and CEC, respectively, taking advantage of their characteristic features, such as conical‐end termination, formation of spherical assemblies dahlia‐flower like superstructure and easy functionalization. The use of SWNHs as pseudostationary phase for EKC required the study of their dispersion in different surfactants as well as their compatibility with the electrophoretic system. The carboxylation and subsequent immobilization of carboxylated SWNHs in fused‐silica capillary to obtain useful, reproducible and stable stationary phases for CEC has also been investigated, with promising results. The electrophoretic separations obtained for water‐soluble vitamins in both modalities (EKC and CEC) have been systematically compared with those obtained with single‐walled carbon nanotubes.
Highly sensitive non‐isotopic restriction endonuclease fingerprinting of nucleotide variability in the gp60 gene within Cryptosporidium species, genotypes and subgenotypes infective to humans, and its implications
Authors: Pangasa Aradhana , Jex Aaron R. , Nolan Matthew J. , Campbell Bronwyn E. , Haydon Shane R. , Stevens Melita A. , Gasser Robin B. 
Published: April 2010

AbstractThe high‐resolution analysis of genetic variation has major implications for the identification of parasites and micro‐organisms to species and subspecies as well as for population genetic and epidemiological studies. In this study, we critically assessed the effectiveness of a PCR‐based restriction endonuclease fingerprinting (REF) method for the detection of mutations in the 60 kDa glycoprotein gene (gp60) of Cryptosporidium, a genus of parasitic protists of major human and animal health importance globally. This gene displays substantial intraspecific variability in sequence, particularly in a TCA (perfect and imperfect) microsatellite region, is present as a single copy in the nuclear genome and is used widely as a marker in molecular epidemiological studies of Cryptosporidium hominis and C. parvum, the two predominant species that infect humans. The results of this study demonstrated an exquisite capacity of REF to detect nucleotide variability in the gp60 gene within each of the two species. The differentiation of genotypes/subgenotypes based on REF analysis was supported by targeted sequencing, allowing the detection of levels of variation as low as a single‐nucleotide transversion for amplicons of ∼1 kb in size. The high‐throughput potential and relatively low‐cost of REF make it a particularly useful tool for large‐scale genetic analyses of C. hominis and C. parvum. REF could also be utilized for comparative surveys of genetic variability across large nuclear genomic regions. Such analyses of Cryptosporidium in clinical and environmental samples by REF have important implications for identifying sources of infection, modes of transmission and/or possible infectivity to humans, thus assisting in the surveillance and control of cryptosporidiosis. Given its excellent mutation detection capacity, REF should find broad applicability to various single‐copy genes as well as a wide range of other protozoan and metazoan parasites. (The nucleotide sequences reported in this article are available in the GenBank database under accession numbers GU214343–GU214371).
Holocene flood histories in south‐western USA
Authors: Harden Tessa , Macklin Mark G. , Baker Victor R. 
Published: April 2010

AbstractRiver basins in south‐western USA are some of the most extensively studied arid land fluvial systems in the world. Since the early 1960s their hydro‐climatic histories have been reconstructed from the analysis of alluvial cut‐and‐fill cycles, while from the late 1970s there have been investigations of slackwater deposits and palaeostage indicators for large floods in stable‐boundary bedrock reaches. However, no studies have regionally integrated Holocene fluvial histories from these two different types of fluvial environments. The current study combines the alluvial archive with flood records from bedrock reaches to generate a probability‐based 12,000 year record of flooding in south‐western USA. Using more than 70014C‐dated fluvial units, the analysis produces a high resolution (centennial) flood record. Seven episodes of increased flooding occurred at 11,250–10,400, 8800–8350, 8230–7600, 6700–5700, 5600–4820, 4550–3320 and 2000–0 cal. BP. Bedrock reaches are found to record more frequent floods during the middle to late Holocene, while in alluvial rivers more flood units are dated to the early and middle Holocene. These differences are primarily the result of selective preservation with alluvial reaches tending to erode during periods characterised by very large floods. Episodes of major Holocene flooding recorded in slackwater deposits within bedrock systems correspond with periods of increased precipitation in the region and lower temperatures. In contrast, within alluvial rivers above‐average flooding probabilities, as well as regionally extensive channel entrenchment episodes, match with reduced annual precipitation and lower temperatures. The results of this study clearly demonstrate the value of the Holocene fluvial archive for reconstructing regional, short‐term hydro‐climatic change in south‐western USA. Copyright © 2010 John Wiley & Sons, Ltd.