bluuebunny/crossref_metadata_2025_split huggingface dataset:
Matrices Progresivas de Raven: efecto Flynn y actualización de baremos
Authors: Rossi-Casé Lilia , Neer Rosa , Lopetegui Susana , Doná Stella , Biganzoli Bruno , Garzaniti Ramiro 
Published: July 2015

Este trabajo presenta los resultados obtenidos en la construcción de normas válidas y actualizadas del Test de Matrices Progresivas de Raven, Escala General, para la ciudad de La Plata, Argentina; y realiza una comparación con las normas obtenidas en 1964 y 2000 a fin de observar la tendencia de los puntajes. Se seleccionó una muestra de 1001 estudiantes de ambos sexos y provenientes de distintos establecimientos de educación secundaria, con edades comprendidas entre los 13 y 18 años. El instrumento fue administrado de manera colectiva, en grupos-clase, con presencia del examinador, sin límite de tiempo para su ejecución, de manera tal que permitiera evaluar la capacidad intelectual sin la intervención de la velocidad en la tarea. Los resultados obtenidos se analizaron dividiéndolos en tres grupos por edad (i.e., 13-14 años, 15-16 años, 17-18 años), y se compararon con los baremos de 1964 y 2000. Se observó un leve descenso de los puntajes directos necesarios para alcanzar el rendimiento promedio, respecto de las puntuaciones obtenidas en la tipificación del año 2000, en la que se constató el efecto Flynn respecto de las normas de 1964. Esta tendencia está en consonancia con investigaciones recientes realizadas en otros países, que muestran un amesetamiento de los puntajes. Un segundo aspecto observado, fue que a medida que aumenta la edad de los sujetos, el rendimiento es mejor. La variabilidad de los puntajes es similar entre los tres grupos de edad analizados.
Control of coupling mass balance error in a process‐based numerical model of surface‐subsurface flow interaction
Authors: Fiorentini Marcello , Orlandini Stefano , Paniconi Claudio 
Published: July 2015

AbstractA process‐based numerical model of integrated surface‐subsurface flow is analyzed in order to identify, track, and reduce the mass balance errors affiliated with the model's coupling scheme. The sources of coupling error include a surface‐subsurface grid interface that requires node‐to‐cell and cell‐to‐node interpolation of exchange fluxes and ponding heads, and a sequential iterative time matching procedure that includes a time lag in these same exchange terms. Based on numerical experiments carried out for two synthetic test cases and for a complex drainage basin in northern Italy, it is shown that the coupling mass balance error increases during the flood recession limb when the rate of change in the fluxes exchanged between the surface and subsurface is highest. A dimensionless index that quantifies the degree of coupling and a saturated area index are introduced to monitor the sensitivity of the model to coupling error. Error reduction is achieved through improvements to the heuristic procedure used to control and adapt the time step interval and to the interpolation algorithm used to pass exchange variables from nodes to cells. The analysis presented illustrates the trade‐offs between a flexible description of surface and subsurface flow processes and the numerical errors inherent in sequential iterative coupling with staggered nodal points at the land surface interface, and it reveals mitigation strategies that are applicable to all integrated models sharing this coupling and discretization approach.
Age of theLavaCreek supereruption and magma chamber assembly at Yellowstone based on40Ar/39Ar andU‐Pb dating of sanidine and zircon crystals
Authors: Matthews Naomi E. , Vazquez Jorge A. , Calvert Andrew T. 
Published: July 2015

AbstractThe last supereruption from the Yellowstone Plateau formed Yellowstone caldera and ejected the >1000 km3of rhyolite that composes the Lava Creek Tuff. Tephra from the Lava Creek eruption is a key Quaternary chronostratigraphic marker, in particular for dating the deposition of mid Pleistocene glacial and pluvial deposits in western North America. To resolve the timing of eruption and crystallization history for the Lava Creek magma, we performed (1)40Ar/39Ar dating of single sanidine crystals to delimit eruption age and (2) ion microprobe U‐Pb and trace‐element analyses of the crystal faces and interiors of single zircons to date the interval of zircon crystallization and characterize magmatic evolution. Sanidines from the two informal members composing Lava Creek Tuff yield a preferred40Ar/39Ar isochron date of 631.3 ± 4.3 ka. Crystal faces on zircons from both members yield a weighted mean206Pb/238U date of 626.5 ± 5.8 ka, and have trace element concentrations that vary with the eruptive stratigraphy. Zircon interiors yield a mean206Pb/238U date of 659.8 ± 5.5 ka, and reveal reverse and/or oscillatory zoning of trace element concentrations, with many crystals containing high U concentration cores that likely grew from highly evolved melt. The occurrence of distal Lava Creek tephra in stratigraphic sequences marking the Marine Isotope Stage 16–15 transition supports the apparent eruption age of ∼631 ka. The combined results reveal that Lava Creek zircons record episodic heating, renewed crystallization, and an overall up‐temperature evolution for Yellowstone's subvolcanic reservoir in the 103−104year interval before eruption.
MIS 3 to MIS 1 temporal and LGM spatial variability in Arctic Ocean sea ice cover: Reconstruction from biomarkers
Authors: Xiao Xiaotong , Stein Ruediger , Fahl Kirsten 
Published: July 2015

AbstractUsing the sea ice proxy IP25 and phytoplankton‐derived biomarkers (brassicasterol and dinosterol), Arctic sea ice conditions were reconstructed for Marine Isotope Stage (MIS) 3 to 1—with special emphasis on the Last Glacial Maximum (LGM)—in sediment cores from the northern Barents Sea continental margin across the central Arctic Ocean to the southern Mendeleev Ridge. Our results suggest more extensive sea ice cover than present day during the latter part of MIS 3, increasing sea ice growth during MIS 2 and decreased sea ice cover during the last deglacial. The summer ice edge remained north of the Barents Sea even during extremely cold (i.e., Last Glacial Maximum (LGM)) as well as warm periods (i.e., Bølling‐Allerød). During the LGM, the western Svalbard margin and the northern Barents Sea margin areas were characterized by high concentrations of both IP25 and phytoplankton biomarkers, interpreted as a productive ice edge situation caused by the inflow of warm Atlantic water. In contrast, the LGM central Arctic Ocean (north of 84°N) was covered by thick permanent sea ice throughout the year with rare breakup, indicated by zero or near‐zero biomarker concentrations. The spring/summer sea ice margin significantly extended southward to the Laptev Sea shelf (southern Lomonosov Ridge) and southern Mendeleev Ridge during the LGM. Our proxy reconstructions are very consistent with published model results based on the North Atlantic/Arctic Ocean Sea Ice Model.
Climatic and landscape controls on water transit times and silicate mineral weathering in the critical zone
Authors: Zapata‐Rios Xavier , McIntosh Jennifer , Rademacher Laura , Troch Peter A. , Brooks Paul D. , Rasmussen Craig , Chorover Jon 
Published: July 2015

AbstractThe critical zone (CZ) can be conceptualized as an open system reactor that is continually transforming energy and water fluxes into an internal structural organization and dissipative products. In this study, we test a controlling factor on water transit times (WTT) and mineral weathering called Effective Energy and Mass Transfer (EEMT). We hypothesize that EEMT, quantified based on local climatic variables, can effectively predict WTT within—and mineral weathering products from—the CZ. This study tests whether EEMT or static landscape characteristics are good predictors of WTT, aqueous phase solutes, and silicate weathering products. Our study site is located around Redondo Peak, a rhyolitic volcanic resurgent dome, in northern New Mexico. At Redondo Peak, springs drain slopes along an energy gradient created by differences in terrain aspect. This investigation uses major solute concentrations, the calculated mineral mass undergoing dissolution, and the age tracer tritium and relates them quantitatively to EEMT and landscape characteristics. We found significant correlations between EEMT, WTT, and mineral weathering products. Significant correlations were observed between dissolved weathering products (Na+ and DIC), 3H concentrations, and maximum EEMT. In contrast, landscape characteristics such as contributing area of spring, slope gradient, elevation, and flow path length were not as effective predictive variables of WTT, solute concentrations, and mineral weathering products. These results highlight the interrelationship between landscape, hydrological, and biogeochemical processes and suggest that basic climatic data embodied in EEMT can be used to scale hydrological and hydrochemical responses in other sites.
Label‐Free, Electrochemical Quantitation of Potassium Ions from Femtomolar Levels
Authors: Zhu Bicheng , Booth Marsilea A. , Woo Han Young , Hodgkiss Justin M. , Travas‐Sejdic Jadranka 
Published: July 2015

AbstractIn this communication, a label‐free and sensitive electrochemical method to detect potassium ions is proposed. The conducting polymer polypyrrole was used as both an anchor for the probe and a transducer of the detection event. A K+‐specific G‐rich aptamer was applied as a recognition element, which folded into the G‐quadruplex structure in the presence of K+, and this resulted in an increase in the electrode impedance. The combination of the K+‐selective aptamer and the porous conducting polymer as a signal transducer afforded a successful sensor platform. The sensor responded approximately logarithmically over a wide dynamic range of K+ concentrations from 20 fm to 1 mm, with a very low detection limit of 14.7 fm and excellent discrimination against other ions. Additionally, electrochemical impedance spectroscopy was used to study the kinetics of K+ binding at the conducting polymer–immobilized aptamer surface, which indicated strong binding between the two. This work demonstrates a powerful approach for the sensitive, selective, and direct electrochemical detection of metal ions based on the switching conformation of G‐rich aptamers attached to a porous conducting polymer surface. This assay scheme can be expanded to the detection of a wide range of targets by modifying the aptamer structure as a recognizing moiety.
Engineering a branch of the UDP‐precursor biosynthesis pathway enhances the production of capsular polysaccharide in Escherichia coli O5:K4:H4
Authors: Cimini Donatella , Carlino Elisabetta , Giovane Alfonso , Argenzio Ottavia , Dello Iacono Ileana , De Rosa Mario , Schiraldi Chiara 
Published: July 2015

AbstractEscherichia coli K4 produces a capsule with a chemical structure that resembles chondroitin, a molecule with established chondro protective properties. The endogenous genes pgm and galU are involved in the biosynthesis of UDP‐glucose which is a critical intermediate in carbohydrate metabolism and biochemical precursor of UDP‐glucuronic acid. Together with UDP‐N‐acetylgalactosamine, UDP‐glucuronic acid is used as sugar donor for capsule biosynthesis. The aim of the study was to evaluate how a change in the pathways leading to UDP‐glucuronic acid biosynthesis affected capsular polysaccharide production. One additional copy of pgm and galU was introduced in E. coli K4 and in the previously described recombinant strain EcK4r3. A microbioreactor was used to analyse strain performance with parallel batch experiments, demonstrating increased polysaccharide concentrations and providing data that are comparable to those obtained in larger fermenters. Further experiments on a glutamine enriched medium showed an additional 45% increase of capsule production, maybe indicating the need to balance both branches leading to polymer biosynthesis in order to maximize yields. In the effort towards the establishment of a feasible bio‐chondroitin production process this study provides information on how the availability of sugar precursors impacts polysaccharide biosynthesis in E. coli K4, a complex unexplored aspect of a multifaceted process.
Recent therapeutic approaches for spinal cord injury
Authors: Raspa Andrea , Pugliese Raffaele , Maleki Mahboubeh , Gelain Fabrizio 
Published: July 2015

ABSTRACTA spinal cord injury (SCI) often causes permanent changes in strength and sensation functions below the site of the injury and affects thousands of people each year. Transplantation of stem cells is a promising approach in acute SCI as it may support spinal cord repair. However, in case of chronic SCI greater amounts of nervous tissue have to be regenerated, leaving scaffold transplantation the only feasible option for cellular engraftment and nervous bridging. The aim of regenerative medicine, specifically tissue engineering, is to create a microenvironment that mimics native extracellular matrix (ECM), capable of promoting specific cell‐matrix interactions, coaxing cell behavior, and fostering host tissue regeneration. In this regard, nanostructured scaffolds are currently the most promising advanced substrates capable of supporting nervous fiber ingrowth and delivery of neurotrophic drugs. Among them, electrospinning technique and Self‐Assembling Peptides (SAPs) have recently attracted lots of attention for their reproducible synthesis and high tailorability. This review highlights clinical trials and recent encouraging strategies for spinal cord repair comprising both cell therapy and nanomedicine. Biotechnol. Bioeng. 2016;113: 253–259. © 2015 Wiley Periodicals, Inc.
Improving fold activation of small transcription activating RNAs (STARs) with rational RNA engineering strategies
Authors: Meyer Sarai , Chappell James , Sankar Sitara , Chew Rebecca , Lucks Julius B. 
Published: July 2015

ABSTRACTRegulatory RNAs have become integral components of the synthetic biology and bioengineering toolbox for controlling gene expression. We recently expanded this toolbox by creating small transcription activating RNAs (STARs) that act by disrupting the formation of a target transcriptional terminator hairpin placed upstream of a gene. While STARs are a promising addition to the repertoire of RNA regulators, much work remains to be done to optimize the fold activation of these systems. Here we apply rational RNA engineering strategies to improve the fold activation of two STAR regulators. We demonstrate that a combination of promoter strength tuning and multiple RNA engineering strategies can improve fold activation from 5.4‐fold to 13.4‐fold for a STAR regulator derived from the pbuE riboswitch terminator. We then validate the generality of our approach and show that these same strategies improve fold activation from 2.1‐fold to 14.6‐fold for an unrelated STAR regulator, opening the door to creating a range of additional STARs to use in a broad array of biotechnologies. We also establish that the optimizations preserve the orthogonality of these STARs between themselves and a set of RNA transcriptional repressors, enabling these optimized STARs to be used in sophisticated circuits. Biotechnol. Bioeng. 2016;113: 216–225. © 2015 Wiley Periodicals, Inc.
ChemInform Abstract: Crystal Structure Refinement of the Electron‐Transfer‐Active Potassium Manganese Hexacyanoferrates and Isomorphous Potassium Manganese Hexacyanocobaltates.
Authors: Rykov Alexandre I. , Li Xuning , Wang Junhu 
Published: July 2015

AbstractThe compounds KMn4 [Fe1‐xCox(CN)6] 3·12H2O (0 ≤ x ≤ 1) are synthesized from aqueous solutions containing excess K3[Fe(CN)6] and K3[Co(CN)6], Mn(NO3)2, and excess KCl (50 °C, 10 min).
ChemInform Abstract: Stabilization of the Ti3Co5B2‐Type Structure for Ti3‐xSixRu5B2 Through Si—Ti Substitution.
Authors: Xie Weiwei , Fuccillo M. K. , Phelan B. F. , Luo H. , Cava R. J. 
Published: July 2015

AbstractTi3‐xSixRu5B2 (x = 0.25, 0.50, 0.75, 1.00, 1.25) phases are prepared by arc melting of the elements and characterized by single crystal XRD, magnetization and resistivity measurements, and electronic structure calculations at the TB‐LMTO‐ASA and extended Hueckel level of theory.
ChemInform Abstract: Crystal Structure and Thermal Expansion of a CsCe2Cl7 Scintillator.
Authors: Zhuravleva M. , Lindsey A. , Chakoumakos B. C. , Custelcean R. , Meilleur F. , Hughes R. W. , Kriven W. M. , Melcher C. L. 
Published: July 2015

AbstractCrystals of the title compound are grown from stoichiometric mixtures of CsCl and CeCl3 by the vertical Bridgman method.
ChemInform Abstract: Luminescent Nitridophosphates CaP2N4:Eu2+, SrP2N4:Eu2+, BaP2N4:Eu2+, and BaSr2P6N12:Eu2+.
Authors: Pucher Florian J. , Marchuk Alexey , Schmidt Peter J. , Wiechert Detlef , Schnick Wolfgang 
Published: July 2015

AbstractMP2N4:Eu2+ (M: Ca, Sr, Ba) and BaSr2P6N12:Eu2+ are prepared by hot pressing the corresponding azides and P3N5 with 1—2 mol% EuCl2 (multianvil press, 5—8 GPa, 1100—1300 °C, 10 min).
ChemInform Abstract: Photocatalytic Water Splitting and CO2 Reduction over KCaSrTa5O15 Nanorod Prepared by a Polymerized Complex Method.
Authors: Takayama Tomoaki , Iwase Akihide , Kudo Akihiko 
Published: July 2015

AbstractPolycrystalline KCaSrTa5O15 is prepared by calcination of a mixture of the metal carbonates and Ta2O5 in air (K:Ca:Sr:Ta = 1.05:1:1:5; 1423 K, 10 h).
ChemInform Abstract: Modulation of Framework and Centricity: Cation Size Effect in New Quaternary Selenites, ASc(SeO3)2 (A: Na, K, Rb, and Cs).
Authors: Song Seung Yoon , Ok Kang Min 
Published: July 2015

AbstractThe new title compounds are hydrothermally synthesized from aqueous mixtures of A2CO3 (A: Na, K, Rb, Cs), Sc(NO3)3 (or ScO3), and SeO2 (autoclave, 180—230 °C, 3—4 d, 66, 69, 57, and 73% yield for the Na‐, K‐, Rb‐, and Cs‐containing compound, respectively).
ChemInform Abstract: Facile Sonochemical Synthesis of Near Spherical Barium Zirconate Titanate (BaZr1‐yTiyO3; BZT); Perovskite Stability and Formation Mechanism.
Authors: Wirunchit Supamas , Charoonsuk Thitirat , Vittayakorn Naratip 
Published: July 2015

AbstractNanospheres of Ba(ZryTi1‐y)O3 (y = 0‐0.6) are prepared by high‐intensity pulsed ultrasonication (20 kHz, 750 W, 2 second pulse, 1 second pause) of stoichiometric mixtures of aqueous solutions of TiCl4, ZrOCl2, and BaCl2 slowly given to NaOH as the precipitant.
ChemInform Abstract: Syntheses, Characterization, and Optical Properties of Centrosymmetric Ba3(BS3)1.5(MS3)0.5 and Noncentrosymmetric Ba3(BQ3)(SbQ3).
Authors: Li Yan‐Yan , Li Bing‐Xuan , Zhang Ge , Zhou Liu‐Jiang , Lin Hua , Shen Jin‐Ni , Zhang Cheng‐Yi , Chen Ling , Wu Li‐Ming 
Published: July 2015

AbstractThe new compounds Ba3(BS3)1.5(MS3)0.5 (I) with M: Sb, Bi and Ba3(BQ3)(SbQ3) (II) with Q: S, Se are synthesized by solid state reaction of stoichiometric mixtures of the elements (graphite crucible in an evacuated silica tube, 820—920 °C).
ChemInform Abstract: New Ag(F1‐xClx) Phases for Energy Storage Applications.
Authors: Adamczyk Wojciech , Polczynski Piotr , Mika Andrzej , Jaron Tomasz , Mazej Zoran , Fijalkowski Karol J. , Jurczakowski Rafal , Grochala Wojciech 
Published: July 2015

AbstractMixed‐halide phases of Ag(I) with stoichiometries close to AgF0.5Cl0.5 and AgF0.75Cl0.25 are prepared by reactions of AgF (or AgF2, resp.) and AgCl in an 1:1 molar ratio (sealed PTFE reactor, 400 °C resp.
ChemInform Abstract: Bipyridine‐ and Phenanthroline‐Based Metal—Organic Frameworks for Highly Efficient and Tandem Catalytic Organic Transformations via Directed C—H Activation.
Authors: Manna Kuntal , Zhang Teng , Greene Francis X. , Lin Wenbin 
Published: July 2015

AbstractA series of robust and porous bipyridyl‐ and phenanthryl‐based metal—organic frameworks (MOFs) of UiO topology is prepared and metalated with [Ir(cod)(OMe)]2 to provide Ir—MOF complexes which are highly active catalysts for tandem hydrosilylation of aryl ketones and aldehydes followed by dehydrogenative ortho‐silylation as well as C—H boration of arenes.
ChemInform Abstract: Robustness Screen in Enantioselective Catalysis Enabled Generation of Enantioenriched Heterocyclic Scaffolds in One Pot.
Authors: Bagle Pradip N. , Shinde Valmik S. , Patil Nitin T. 
Published: July 2015

AbstractThe reaction of aminoaromatics, e.g. (I) and (VI), with up to five alkynols, such as (II) and (III), in one pot affords mixtures of the corresponding enantioenriched aza‐heterocyclic scaffolds (IV)/(V) and (VII)/(VIII) in good yields and enantioselectivities.
ChemInform Abstract: NMO·TPB: A Selectivity Variation on the Ley‐Griffith TPAP Oxidation.
Authors: Moore Peter W. , Mirzayans Paul M. , Williams Craig M. 
Published: July 2015

AbstractA novel NMO complex is discovered, which modulates the Standard Ley—Griffith oxidation such that benzylic and allylic alcohols are oxidized with considerable selectivity over primary and secondary alcohols.
ChemInform Abstract: Catalytic Asymmetric Hydrogenation Using a [2.2]Paracyclophane Based Chiral 1,2,3‐Triazol‐5‐ylidene—Pd Complex under Ambient Conditions and 1 Atmosphere of H2.
Authors: Dasgupta Ayan , Ramkumar Venkatachalam , Sankararaman Sethuraman 
Published: July 2015

AbstractThe triazolylidene—Pd complex PCP bearing a [2.2]paracyclophane moiety is found to be an excellent catalysts for the chemoselective hydrogenation of alkynes and alkenes under abient conditions.
ChemInform Abstract: Application of Nanoparticle Mediated N‐Arylation of Amines for the Synthesis of Pharmaceutical Entities Using vit‐E Analogues as Amphiphiles in Water.
Authors: Kumar Atul , Bishnoi Ajay Kumar 
Published: July 2015

AbstractThe CuI‐nanoparticles catalyze the inter‐ and intramolecular N‐arylation of various amines using vitamin E analogues (TPGS) as amphiphiles in water.
ChemInform Abstract: N‐(1‐Oxy‐2‐picolyl)oxalamic Acids as a New Type of O,O‐Ligands for the Cu‐Catalyzed N‐Arylation of Azoles with Aryl Halides in Water or Organic Solvent.
Authors: Wang Yongbin , Zhang Yu , Yang Beibei , Zhang Ao , Yao Qizheng 
Published: July 2015

AbstractA green process for the cross‐coupling of azoles and aryl halides in water with low catalyst loading is reported.
ChemInform Abstract: Insight into the Copper‐Catalyzed Borylation of Strained Alkenes.
Authors: Parra Alejandro , Lopez Aurora , Diaz‐Tendero Sergio , Amenos Laura , Ruano Jose Luis Garcia , Tortosa Mariola 
Published: July 2015

AbstractThe Cu(II)‐catalyzed hydro‐ and carboboration of strained alkenes, such as (I), (IV), and (VI) is reported.
ChemInform Abstract: Vinylogy in Nitronates: Utilization of α‐Aryl Conjugated Nitroolefins as a Nucleophile for a Highly Stereoselective aza‐Henry Reaction.
Authors: Oyaizu Keigo , Uraguchi Daisuke , Ooi Takashi 
Published: July 2015

AbstractThe relief of the steric repulsion between cis‐oriented substituents of the nitroolefins seems to assist the facile generation of the vinylogous nitronates, which react with N‐Boc aldimines at the sterically more congested α‐position exclusively, thus establishing the contiguous tertiary‐quaternary stereocenters.
ChemInform Abstract: C—H Activation/Functionalization Catalyzed by Simple, Well‐Defined Low‐Valent Cobalt Complexes.
Authors: Fallon Brendan J. , Derat Etienne , Amatore Muriel , Aubert Corinne , Chemla Fabrice , Ferreira Franck , Perez‐Luna Alejandro , Petit Marc 
Published: July 2015

AbstractAn optimized method is developed which demonstrates the utility of low‐valent Co‐phosphine catalyst to allow the direct C—H alkenylation of aromatic imines using internal alkynes as coupling partners.
ChemInform Abstract: AlCl3‐Catalyzed Insertion of Isocyanides into Nitrogen—Sulfur Bonds of Sulfenamides.
Authors: Shiro Daisuke , Fujiwara Shin‐ichi , Tsuda Susumu , Iwasaki Takanori , Kuniyasu Hitoshi , Kambe Nobuaki 
Published: July 2015

AbstractA simple and convenient reaction for the synthesis of isothioureas by Lewis acid‐catalyzed insertion of isocyanides into the N—S bond of sulfenamides is developed.