bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the magmatic record of the Makran arc, southeastern Iran: Insights from zircon U‐Pb geochronology and bulk‐rock geochemistry
Authors: Pang Kwan‐Nang , Chung Sun‐Lin , Zarrinkoub Mohammad Hossein , Chiu Han‐Yi , Li Xian‐Hua 
Published: May 2014

AbstractTwenty‐one magmatic rocks were analyzed for major and trace elements, and a subset of them for Sr‐Nd isotopes and zircon U‐Pb isotopes, to constrain magma genesis and tectonic evolution of the Makran arc, southeastern Iran. Representative samples from the Bazman and Taftan volcanoes yield zircon U‐Pb ages from ∼0.84 to ∼7.5 Ma, consistent with published ages ranging from the Late Miocene to Late Pleistocene. The Mirabad granitic pluton adjacent to and geochemically similar to the Taftan volcano was dated at ∼19 Ma, indicating that arc magmatism might have started earlier than commonly thought in the Early Miocene. The studied rocks show basaltic to rhyolitic compositions, calc‐alkaline affinity, and an orogenic signature involving enrichments in large ion lithophile elements, light rare earth elements, Th and Pb, and depletions in high field strength elements and P, relative to elements of similar incompatibilities. The trace element ratios in a subset of relatively primitive samples are consistent with derivation from a mantle source that underwent subduction‐related enrichment. The covariations of Sr and Nd isotopic ratios, and of these ratios and MgO and SiO2, are consistent with combined assimilation and fractional crystallization. The process is modeled using covariations of 87Sr/86Sr and Sr concentration in the studied rocks given that Sr behaves as neutral or slightly incompatible. We propose, in light of published and our new data, that the Makran represents a window of continental collision between the India‐Eurasia collision zone to the east and the Arabia‐Eurasia collision zone to the west.
Rhizon sampler alteration of deep ocean sediment interstitial water samples, as indicated by chloride concentration and oxygen and hydrogen isotopes
Authors: Miller Madeline D. , Adkins Jess F. , Hodell David A. 
Published: May 2014

AbstractDespite their potential to inform past ocean salinity, δ18O, and temperature, high‐resolution depth profiles of interstitial water chloride concentration and hydrogen and oxygen isotopes exist in very few locations. One of the primary limitations to the recovery of these depth profiles is that traditional interstitial water sampling requires 5–10 cm whole rounds of the sediment core, which has the potential to interfere with stratigraphic continuity. The Rhizon sampler, a nondestructive tool developed for terrestrial sediment interstitial water extraction, has been proposed for efficient and nondestructive sampling of ocean sediment pore waters. However, there exists little documentation on the reliability and performance of Rhizon samplers in deep ocean sediments, particularly in regard to their effect on chloride concentration and oxygen and hydrogen isotopic measurements. We perform an intercomparison of chloride concentration and oxygen and hydrogen isotopic composition in samples taken using traditional squeezing versus those taken with Rhizon samplers. We find that samples taken with Rhizons have positive biases in both chloride concentration and stable isotopic ratios relative to those taken by squeezing water from sediments in a hydraulic press. The measured offsets between Rhizon and squeeze samples are consistent with a combination of absorption by and diffusive fractionation through the hydrophilic membrane of the Rhizon sampler. These results suggest caution is needed when using Rhizons for sampling interstitial waters in any research of processes that leave a small signal‐to‐noise ratio in dissolved concentrations or isotope ratios.
The wavelet transform function to analyze interplanetary scintillation observations
Authors: Aguilar‐Rodriguez E. , Rodriguez‐Martinez M. , Romero‐Hernandez E. , Mejia‐Ambriz J. C. , Gonzalez‐Esparza J. A. , Tokumaru M. 
Published: May 2014

AbstractInterplanetary scintillation (IPS) observations are useful to remotely sense the inner heliosphere. We present a new technique to analyze IPS observations using a wavelet transform (WT) function. This technique allows us to derive, in a straightforward way, a simple method to obtain the scintillation index (m). We tested this WT technique to analyze IPS observations obtained by the Solar‐Terrestrial Environment Laboratory (STEL) radio telescope. The analysis of themindex of the radio source 3C48 detected by STEL over the year 2012 shows the expected decrease with solar elongation reported in previous studies. The WT technique has a great potential for future solar wind studies using IPS observations from contemporary radio telescopes.
Isolating the anthropogenic component of Arctic warming
Authors: Chylek Petr , Hengartner Nicholas , Lesins Glen , Klett James D. , Humlum Ole , Wyatt Marcia , Dubey Manvendra K. 
Published: May 2014

AbstractStructural equation modeling is used in statistical applications as both confirmatory and exploratory modeling to test models and to suggest the most plausible explanation for a relationship between the independent and the dependent variables. Although structural analysis cannot prove causation, it can suggest the most plausible set of factors that influence the observed variable. We apply structural model analysis to the annual mean Arctic surface air temperature from 1900 to 2012 to find the most effective set of predictors and to isolate the anthropogenic component of the recent Arctic warming by subtracting the effects of natural forcing and variability from the observed temperature. We find that anthropogenic greenhouse gases and aerosols radiative forcing and the Atlantic Multidecadal Oscillation internal mode dominate Arctic temperature variability. Our structural model analysis of observational data suggests that about half of the recent Arctic warming of 0.64 K/decade may have anthropogenic causes.
Strong ionospheric field‐aligned currents for radial interplanetary magnetic fields
Authors: Wang Hui , Lühr Hermann , Shue Jih‐Hong , Frey Harald. U. , Kervalishvili Guram , Huang Tao , Cao Xue , Pi Gilbert , Ridley Aaron J. 
Published: May 2014

AbstractThe present work has investigated the configuration of field‐aligned currents (FACs) during a long period of radial interplanetary magnetic field (IMF) on 19 May 2002 by using high‐resolution and precise vector magnetic field measurements of CHAMP satellite. During the interest period IMF By and Bz are weakly positive and Bx keeps pointing to the Earth for almost 10 h. The geomagnetic indices Dst is about −40 nT and AE about 100 nT on average. The cross polar cap potential calculated from Assimilative Mapping of Ionospheric Electrodynamics and derived from DMSP observations have average values of 10–20 kV. Obvious hemispheric differences are shown in the configurations of FACs on the dayside and nightside. At the south pole FACs diminish in intensity to magnitudes of about 0.1 μA/m2, the plasma convection maintains two‐cell flow pattern, and the thermospheric density is quite low. However, there are obvious activities in the northern cusp region. One pair of FACs with a downward leg toward the pole and upward leg on the equatorward side emerge in the northern cusp region, exhibiting opposite polarity to FACs typical for duskward IMF orientation. An obvious sunward plasma flow channel persists during the whole period. These ionospheric features might be manifestations of an efficient magnetic reconnection process occurring in the northern magnetospheric flanks at high latitude. The enhanced ionospheric current systems might deposit large amount of Joule heating into the thermosphere. The air densities in the cusp region get enhanced and subsequently propagate equatorward on the dayside. Although geomagnetic indices during the radial IMF indicate low‐level activity, the present study demonstrates that there are prevailing energy inputs from the magnetosphere to both the ionosphere and thermosphere in the northern polar cusp region.
Interseismic coupling, seismic potential, and earthquake recurrence on the southern front of the Eastern Alps (NE Italy)
Authors: Cheloni D. , D'Agostino N. , Selvaggi G. 
Published: May 2014

AbstractHere we use continuous GPS observations to document the geodetic strain accumulation across the South‐Eastern Alps (NE Italy). We estimate the interseismic coupling on the intracontinental collision thrust fault and discuss the seismic potential and earthquake recurrence. We invert the GPS velocities using the back slip approach to simultaneously estimate the relative angular velocity and the degree of interseismic coupling on the thrust fault that separates the Eastern Alps and the Venetian‐Friulian plain. Comparison between the rigid rotation predicted motion and the shortening observed across the area indicates that the South‐Eastern Alpine thrust front absorbs about 70% of the total convergence between the Adria and Eurasia plates. The coupling is computed on a north dipping fault following the continuous external seismogenic thrust front of the South‐Eastern Alps. The modeled thrust fault is currently locked from the surface to a depth of ≈10 km. The transition zone between locked and creeping portions of the fault roughly corresponds with the belt of microseismicity parallel and to the north of the mountain front. The estimated moment deficit rate is 1.3 ± 0.4 × 1017Nm/yr. The comparison between the estimated moment deficit and that released historically by the earthquakes suggests that to account for the moment deficit the following two factors or their combination should be considered: (1) a significant part of the observed interseismic coupling is released aseismically and (2) infrequent “large” events with long return period (> 1000 years) and with magnitudes larger than the value assigned to the largest historical events (Mw≈ 6.7).
Preparation and properties of novel boric acid modified poly(aryl ether sulfone) membranes
Authors: Wang Yongpeng , Zhang Haibo , Liu Mengzhu , Zhu Ye , Cui Zengduo , Lin Yingjian , Zhu Xuanbo , Jiang Zhenhua 
Published: May 2014

ABSTRACTIn this article, boric acid‐modified poly(aryl ether sulfone) (PES‐B) membranes were prepared by solution blending, solution casting, evaporation, and programmed temperature curing method for the first time. The chemical modification of poly(aryl ether sulfone) was accomplished by the curing of poly(aryl ether sulfone) with pendent phenyl hydroxide (PES‐OH) under the function of boric acid. The reaction mechanisms and the effects of boric acid content were thoroughly investigated. Processing conditions and structures of PES‐B were determined by FT‐IR spectra. It has been found that the B(OH)3/PES composite membranes were completely cured after treatment at 300°C for 4 h. When boric acid content was over 4.7%, PES‐B membranes presented phase separation and full cross‐linking structures. DSC measurements demonstrated that the addition of boric acid had influenced the glass transition temperature of PES‐B, which provided the proof of the appearance of cross‐linking network structure. TGA results confirmed that the thermal stability of the prepared PES‐B composites was improved. Furthermore, the cross‐linked composite membranes exhibited excellent mechanical property and solvent resistance. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40860.
Europium‐containing cholesteric liquid crystalline polymers in the side chain
Authors: Zhao Wen‐Zhi , Cong Yue‐Hua , Zhang Bao‐Yan , Gu Wei‐Min 
Published: May 2014

ABSTRACTEuropium‐containing cholesteric liquid crystalline polymers were graft copolymerized using poly(methylhydrogeno)siloxane, cholesteryl 4‐(allyloxy)benzoate (M1), cholesteryl acrylate (M2), and a europium complexes monomer (M3). The chemical structures of the monomers were characterized by Fourier transform infrared and 1H‐nuclear magnetic resonance. The mesomorphic properties and phase behavior were investigated by differential scanning calorimetry, thermo gravimetric analysis, polarizing optical microscopy, and X‐ray diffraction. With an increase of europium complexes units in the polymers, the glass transition temperature (Tg) did not change significantly; the isotropic temperature (Ti) and mesophase temperature range (ΔT) decreased. All polymers showed typical cholesteric Grandjean textures, which was confirmed by X‐ray diffraction. The temperatures at which 5% weight loss occurred (Td) were greater than 300°C for the polymers. The introduction of europium complexes units did not change the liquid crystalline state of polymer systems; on the contrary, the polymers were enabled with the significant luminescent properties. With Eu3+ ion contents ranging between 0 and 1.5 mol %, luminescent intensity of polymers gradually increased and luminescent lifetimes were longer than 0.45 ms for the polymers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40866.
Multigeneration Reproduction and Male Developmental Toxicity Studies on Atrazine in Rats
Authors: DeSesso John M. , Scialli Anthony R. , White Tacey E. K. , Breckenridge Charles B. 
Published: May 2014

BACKGROUNDReproductive toxicity of Atrazine (ATR) was evaluated in two rat multigenerational studies. Development of male reproductive parameters was evaluated in separate studies after prenatal or postnatal exposure.METHODSIn multigenerational studies, rats received dietary concentrations of 0, 10, 50, 100 or 500 ppm ATR. In separate studies in female rats, ATR was administered by gavage at 0, 1, 5, 25 or 125 mg/kg/day during pregnancy (GD6–21) or lactation (LD2–21). Plasma testosterone concentration, testicular and epididymal weights, and sperm counts were measured in male offspring on PND70 and 170.RESULTSIn the multigenerational studies, parental systemic toxicity occurred at 500 ppm (38.7 mg/kg/day), but reproductive endpoints were unaffected. In the prenatal study, maternal toxicity and embryo‐fetal mortality occurred at 125 mg/kg/day. In male offspring, testosterone levels and sperm counts were unaffected, although the percentage of abnormal sperm increased at 125 mg/kg/day (PND 70) and 25 mg/kg/day (PND170). In the postnatal study, maternal toxicity and reduced body weights of male offspring occurred at 125 mg/kg/day. Additionally, reduced testicular (PND70, PND170) and epididymal (PND70) weights and increased numbers of abnormal sperm (PND70, PND170) were seen, but no changes in plasma testosterone or sperm counts.CONCLUSIONSDietary administration of ATR did not affect rat reproduction up to a parentally toxic dose of 38.7 mg/kg/day. Some effects on male reproductive system development occurred after high dose, bolus administration to dams, but doses were much higher than expected under normal use conditions. Thus, oral RfDs for ATR would be protective for reproductive effects
Size‐Controlled Synthesis of Tetrametallic Ag@CoNiFe Core–Shell Nanoparticles Supported on Graphene: A Highly Efficient Catalyst for the Hydrolytic Dehydrogenation of Amine Boranes
Authors: Yang Lan , Su Jun , Luo Wei , Cheng Gongzhen 
Published: May 2014

AbstractTetrametallic core–shell Ag@CoNiFe nanoparticles (NPs) supported on graphene have been synthesized by a facile one‐step in situ procedure for the first time. We tuned the reducing ability of the reductants to control the structure and particle size of the as‐synthesized NPs. The use of weaker reducing agents, such as ammonia borane (AB) and methylamine borane (MeAB), result in the core–shell structure, whereas the stronger reducing agent NaBH4 results in alloy NPs. The as‐synthesized core–shell NPs reduced by MeAB possess a smaller particle size and exhibit a superior catalytic activity compared to the core–shell NPs reduced by AB and alloy NPs reduced by NaBH4 for the hydrolytic dehydrogenation of AB. Moreover, the turnover frequency of the as‐synthesized tetrametallic core–shell NPs is 118.5 mol min−1 molAg−1, which is higher than that of Ag‐based trimetallic, bimetallic core–shell, and alloy counterparts and even higher than that of most reported noble‐metal‐based NPs. Kinetic studies indicate that the catalytic hydrolysis of AB and MeAB by the Ag@CoNiFe/graphene NPs is a first‐order reaction. Furthermore, the as‐prepared NPs exert good catalytic activities and recycle stabilities towards the hydrolysis of AB. Additionally, the as‐prepared NPs display magnetic recyclability, which makes the practical recycling of the NPs more convenient.
Aerobic Oxidation of Alcohols on Au Nanocatalyst: Insight to the Roles of the Ni–Al Layered Double Hydroxides Support
Authors: Wang Jiang , Lang Xianjun , Zhaorigetu Bao , Jia Meilin , Wang Jun , Guo Xiaofang , Zhao Jincai 
Published: May 2014

AbstractAu nanoparticles (NPs) supported on Ni–Al layered double hydroxides (LDHs) were shown to be efficient heterogeneous catalysts for the highly selective oxidation of alcohols to the corresponding aldehydes or ketones under base‐free or even solvent‐free conditions with O2 as the sole oxidant. The Au NPs can be uniformly distributed on Ni–Al LDHs support, which is beneficial to the catalytic activity. In addition, the weak Brønsted basic property of the support enables the aerobic oxidation of alcohols under base‐free conditions. More importantly, unlike Al2O3, which is inert, Ni–Al–LDHs are redox‐actively involved in prompting the electron transfer to O2 via the Au nanocatalyst because of the presence of NiII. Both of the basic and the redox properties of Ni–Al–LDHs can be tuned by adjusting the ratio of Ni:Al to achieve the best synergistic effects between Au NPs and the supports. The activity of the obtained Au catalysts was found to be structurally associated with the arrangements of NiO6 and AlO6 octahedra in the surface hydroxide layers which were different from the bulk Ni:Al ratio.
Sensitive and Selective Detection of Imidacloprid by Graphene‐Oxide‐Modified Glassy Carbon Electrode
Authors: Lei Wu , Han Zhen , Si Weimeng , Hao Qingli , Zhang Yuehua , Xia Mingzhu , Wang Fengyun 
Published: May 2014

AbstractBased on the enhancement effect of graphene oxide (GO), a GO‐modified glassy carbon electrode (GO/GCE) is prepared for the fast and sensitive electrochemical detection of the imidacloprid (IMI) insecticide, with high selectivity and stability, for the first time. The electrochemical behavior of imidacloprid on GO/GCE is investigated by using cyclic voltammetry, and graphene oxide is found to have a strong affinity towards IMI. The reduction peak current varies linearly with the concentration of IMI over the 0.8–10 μM range and the limit of detection is 0.36 μM.
A Langevin Canonical Approach to the Dynamics of Chiral Systems: Thermal Averages and Heat Capacity
Authors: Peñate‐Rodríguez Helen C. , Dorta‐Urra Anais , Bargueño Pedro , Rojas‐Lorenzo German , Miret‐Artés Salvador 
Published: May 2014

ABSTRACTA Langevin canonical framework for a chiral two‐level system coupled to a bath of harmonic oscillators was developed within a coupling scheme different from the well‐known spin‐boson model. Thermal equilibrium values were reached at asymptotic times by solving the corresponding set of nonlinear coupled equations in a Markovian regime. In particular, phase difference thermal values (or, equivalently, the so‐called coherence factor) and heat capacity through energy fluctuations were obtained and are discussed in terms of tunneling rates and asymmetries. Chirality 26:319–325, 2014. © 2014 Wiley Periodicals, Inc.
Hyperglycemia in Patients Referred for Cardiac Catheterization Is Associated With Preexisting Diabetes Rather Than a Stress‐Related Phenomenon: A Prospective Cross‐Sectional Study
Authors: Arbel Yaron , Shmueli Hezzy , Halkin Amir , Berliner Shlomo , Shapira Itzhak , Herz Itzhak , Havakuk Ofer , Shacham Yacov , Rabinovich Itay , Keren Gad , Finkelstein Ariel , Banai Shmuel 
Published: May 2014

ABSTRACTBackgroundAn increased serum glucose level in patients with acute coronary syndrome (ACS) is associated with adverse clinical outcome. This hyperglycemia has been attributed, at least in part, to acute stress reaction. Our objective was to determine whether hyperglycemia is a stress‐related phenomenon or whether it represents a more sustained and possibly significant background dysglycemia.HypothesisHyperglycemia in patients undergoing coronary angiography is related to background dysglycemia.MethodsBlood samples were obtained at the time of cardiac catheterization. Patients with hemoglobin A1c >6.5% were excluded to avoid patients with chronic glucose levels above 135 mg/dL. A logistic regression model was created to assess the influence of different variables on hyperglycemia (glucose levels above 140 mg/dL). We also evaluated the effect of glucose levels above 140 mg/dL on major adverse cardiovascular events (MACEs) up to 36 months.ResultsThere were 2554 consecutive patients prospectively recruited. Serum glucose levels above 140 mg/dL was a strong predictor of MACE (hazard ratio: 2.2, 95% confidence interval [CI]: 1.3‐3.6, P = 0.002). Both diabetes mellitus and ACS were associated with hyperglycemia (glucose levels above 140 mg/dL). Nevertheless, the incidence of hyperglycemia was doubled in diabetic patients (odds ratio [OR]: 9.4, 95% CI: 3.9‐22.4, P < 0.001) compared with patients with ACS (OR: 4.6, 95% CI: 2.3‐9.0, P < 0.001). Combining both conditions was associated with a high likelihood of elevated glucose levels (OR: 15.5, 95% CI: 7.4‐32.9, P < 0.001).ConclusionsHyperglycemia in patients undergoing cardiac catheterization is a strong predictor of adverse outcome. It is mainly related to background dysglycemia and to a lesser extent to the acute stress accompanying ACS.
DNA Binding Dynamics and Energetics of Cobalt, Nickel, and Copper Metallopeptides
Authors: Galindo‐Murillo Rodrigo , Cheatham Thomas E. 
Published: May 2014

AbstractWe present molecular dynamics (MD) and Quantum Theory of Atoms in Molecules (QTAIM) analysis of the DNA binding properties of three metallopeptides to the Drew–Dickerson dodecamer DNA: CoII‐Gly1‐Gly2‐His, NiII‐Gly1‐Gly2‐His and CuII‐Gly1‐Gly2‐His. Fairly extensive MD simulations were run on each system until a stable binding mode for each ligand was sampled. Clustering analysis was used in an attempt to find representative structures for the most populated clusters sampled during the MD, and a QTAIM analysis was performed. Additionally, MM‐PBSA analysis was performed to obtain approximate binding energies for each complex. The results suggest that stable DNA–metallopeptide complexes are formed with each of the three ligands, and that the most stable interaction is with Co(GGH), then Ni(GGH), and finally Cu(GGH). Bond Critical Points (BCP) information between the minor groove of the DNA and the metallopeptides shows an increase in electronic density between Gly1, the His residues, and the oxygen atoms of the thymine nucleotide. Overall, we present a detailed theoretical study of the specific interactions involved and the binding properties of each complex formed.