bluuebunny/crossref_metadata_2025_split huggingface dataset:
Supramolecular Immobilization of Laccase on Carbon Nanotube Electrodes Functionalized with (Methylpyrenylaminomethyl)anthraquinone for Direct Electron Reduction of Oxygen
Authors: Bourourou Mariem , Elouarzaki Kamal , Lalaoui Noémie , Agnès Charles , Le Goff Alan , Holzinger Michael , Maaref Abderrazak , Cosnier Serge 
Published: June 2013

AbstractAn efficient way of immobilizing and wiring a large amount of laccase on non‐covalently‐functionalized multi‐walled carbon nanotube (MWCNT) electrodes is reported. 1‐(2‐anthraquinonylaminomethyl)pyrene and 1‐[bis(2‐anthraquinonyl)aminomethyl]pyrene were synthesized and studied for their capability to non‐covalently functionalize MWCNT electrodes and immobilize and orientate laccase on the nanostructured electrodes. This led to high‐performance biocathodes for oxygen reduction by direct electron transfer with maximum current densities of (1±0.2) mA cm−2. The performance of the resulting bioelectrodes could be doubled simply by using the bis‐anthraquinone compound. The bioelectrodes show excellent stability over weeks and can thus be envisioned in enzymatic biofuel cells.
Rational Design of Angiotensin‐I‐Converting Enzyme Inhibitory Peptides by Integrating in silico Modeling and an in vitro Assay
Authors: Jing Tao , Feng Jian , Li De , Liu Jianping , He Guoxiang 
Published: June 2013

AbstractHuman angiotensin‐I‐converting enzyme (ACE) is a classic target of antihypertensive drugs and possesses a bulky, amphiphilic active pocket that is physicochemically compatible with a wide spectrum of small peptide ligands. Herein we describe a synthetic pipeline to directly optimize the atomic interactions between ACE in complex with its peptide ligands. By using this pipeline, we were able to derive thousands of peptides with potential ACE‐inhibitory capacity, from which 15 structurally diverse, theoretically active samples were investigated systematically with respect to the structural, energetic, and dynamic aspects of their interactions with ACE. Subsequently, ACE‐inhibitory activities of several highly promising candidates were evaluated in vitro using a standard spectrophotometric method. As might be expected, three of these candidates showed high inhibitory activities against ACE and others also significantly inhibited the enzymatic activity at low or moderate doses. Furthermore, one of these peptides, LHGPYP, was chosen for structural modification based on the details of its interaction with ACE using modeled structure data. Consequently, a Gly 3 Leu/Tyr 5 Ala double mutation on the peptide was assessed to obtain a more potent mutant LHLPAP, leading to a considerable increase in ACE‐inhibitory activity (IC50 decrease from 75.4 to 4.2 μM).
A Bipodal Dicyano Anchor Unit for Single‐Molecule Spintronic Devices
Authors: Tsuji Yuta , Semoto Takayuki , Yoshizawa Kazunari 
Published: June 2013

AbstractThe conductance through single 7,7,8,8‐tetracyanoquinodimethane (TCNQ) connected to gold electrodes is studied with the nonequilibrium Green’s function method combined with density functional theory. The aim of the study is to derive the effect of a dicyano anchor group, C(CN)2, on energy level alignment between the electrode Fermi level and a molecular energy level. The strong electron‐withdrawing nature of the dicyano anchor group lowers the LUMO level of TCNQ, resulting in an extremely small energy barrier for electron injection. At zero bias, electron transfer from electrodes easily occurs and, as a consequence, the anion radical state of TCNQ with a magnetic moment is formed. The unpaired electron in the TCNQ anion radical causes an exchange splitting between the spin‐α and spin‐β transmission spectra, allowing the single TCNQ junction to act as a spin‐filtering device.
Ozone‐Induced Band Bending on Metal‐Oxide Surfaces Studied under Environmental Conditions
Authors: Lampimäki Markus , Zelenay Veronika , Křepelová Adéla , Liu Zhi , Chang Rui , Bluhm Hendrik , Ammann Markus 
Published: June 2013

AbstractOzone adsorption and decomposition on metal oxides is of wide interest in technology and in atmospheric chemistry. Here, ozone‐adsorption‐induced band bending is observed on Ti‐ and Fe‐oxide model surfaces under dry and humid conditions. Photoelectron spectroscopic studies indicate the effect of charge transfer to O3, which limits the surface coverage of the precursor to decomposition reactions. This is also consistent with the negative pressure dependence observed in previous studies. These results contribute to our fundamental understanding of ozone adsorption and decomposition mechanisms on metal oxides of environmental and technological relevance.
Personalized cytomic assessment of vascular health: Evaluation of the vascular health profile in diabetes mellitus
Authors: Kurtzman Nicholas , Zhang Lifeng , French Benjamin , Jonas Rebecca , Bantly Andrew , Rogers Wade T. , Moore Jonni S. , Rickels Michael R. , Mohler Emile R. 
Published: June 2013

BackgroundAn inexpensive and accurate blood test does not currently exist that can evaluate the cardiovascular health of a patient. This study evaluated a novel high dimensional flow cytometry approach in combination with cytometric fingerprinting (CF), to comprehensively enumerate differentially expressed subsets of pro‐angiogenic circulating progenitor cells (CPCs), involved in the repair of vasculature, and microparticles (MPs), frequently involved in inflammation and thrombosis. CF enabled discovery of a unique pattern, involving both MPs and CPCs and generated a personalized signature of vascular health, the vascular health profile (VHP).MethodsLevels of CPCs and MPs were measured with a broad panel of cell surface markers in a population with atherosclerosis and type 2 diabetes mellitus (DM) and age‐similar Healthy controls (HC) using an unbiased computational approach, termed CF.ResultsCirculating hematopoietic stem and progenitor cell (CHSPCAng) levels were detected at significantly lower concentrations in DM (P < 0.001), whereas levels of seven phenotypically distinct MPs were present at significantly higher concentrations in DM patients and one MP subset was present at significantly lower concentration in DM patients. Collectively, the combination of CHSPCAng and MP levels was more informative than any one measure alone.ConclusionsThis work provides the basis for a personalized cytomic vascular health profile that may be useful for a variety of applications including drug development, clinical risk assessment and companion diagnostics. © 2013 International Clinical Cytometry Society
Demographic patterns of a widespread long‐lived tree are associated with rainfall and disturbances along rainfall gradients in SE Australia
Authors: Cohn Janet S. , Lunt Ian D. , Bradstock Ross A. , Hua Quan , McDonald Simon 
Published: June 2013

AbstractPredicting species distributions with changing climate has often relied on climatic variables, but increasingly there is recognition that disturbance regimes should also be included in distribution models. We examined how changes in rainfall and disturbances along climatic gradients determined demographic patterns in a widespread and long‐lived tree species, Callitris glaucophylla in SE Australia. We examined recruitment since 1950 in relation to annual (200–600 mm) and seasonal (summer, uniform, winter) rainfall gradients, edaphic factors (topography), and disturbance regimes (vertebrate grazing [tenure and species], fire). A switch from recruitment success to failure occurred at 405 mm mean annual rainfall, coincident with a change in grazing regime. Recruitment was lowest on farms with rabbits below 405 mm rainfall (mean = 0–0.89 cohorts) and highest on less‐disturbed tenures with no rabbits above 405 mm rainfall (mean = 3.25 cohorts). Moderate levels of recruitment occurred where farms had no rabbits or less disturbed tenures had rabbits above and below 405 mm rainfall (mean = 1.71–1.77 cohorts). These results show that low annual rainfall and high levels of introduced grazing has led to aging, contracting populations, while higher annual rainfall with low levels of grazing has led to younger, expanding populations. This study demonstrates how demographic patterns vary with rainfall and spatial variations in disturbances, which are linked in complex ways to climatic gradients. Predicting changes in tree distribution with climate change requires knowledge of how rainfall and key disturbances (tenure, vertebrate grazing) will shift along climatic gradients.
Method for the Preparation of Nonracemic Bis‐Cyclometalated Iridium(III) Complexes
Authors: Helms Melanie , Lin Zhijie , Gong Lei , Harms Klaus , Meggers Eric 
Published: June 2013

AbstractA practical strategy for the generation of virtually enantiomerically pure bis‐cyclometalated iridium(III) complexes is reported. Accordingly, the reactions of [Ir(μ‐Cl)(ppy)2]2 (ppy = cyclometalating 2‐phenylpyridine) with (S)‐4‐tert‐butyl‐2‐(2′‐hydroxyphenyl)‐2‐oxazoline [(S)‐1a], [Ir(μ‐Cl)(pq)2]2 (pq = cyclometalating 2‐phenylquinoline) with (S)‐2‐(2′‐hydroxyphenyl)‐4‐isopropyl‐2‐oxazoline [(S)‐1b], and [Ir(μ‐Cl)(pbt)2]2 (pbt = cyclometalating 2‐phenylbenzothiazole) with (S)‐2‐(2′‐hydroxyphenyl)‐4‐isopropyl‐2‐thiazoline [(S)‐1d] afforded diastereomeric mixtures of salicyloxazolinato or salicylthiazolinato complexes Λ/Δ‐[Ir(ppy)2{(S)‐1a–H}]PF6, Λ/Δ‐[Ir(pq)2{(S)‐1b–H}]PF6, and Λ/Δ‐[Ir(pbt)2{(S)‐1d–H}]PF6, respectively, which could be resolved by silica gel flash chromatography. With the individual diastereomers in hand, an acid‐induced substitution of the chiral auxiliaries by achiral bidentate ligands with retention of configuration afforded several iridium complexes Λ‐ or Δ‐[Ir(C∧N)2(N∧N)]PF6 (C∧N = cyclometalating ppy, pq, or pbt; N∧N = 2,2′‐bipyridine, 1,10‐phenanthroline, or 2,2′‐biquinoline) with enantiomeric ratio (er) values of 24:1 to 230:1.
Cu(OTf)2‐Catalyzed Dehydrogenative C–H Activation under Atmospheric Oxygen: An Expedient Approach to Pyrrolo[3,2‐d]pyrimidine Derivatives
Authors: Roy B. , Hazra Somjit , Mondal Biplab , Majumdar K. C. 
Published: June 2013

AbstractA new dehydrogenative C–H activation of uracil in an open atmosphere was developed to synthesize pyrrolo‐pyrimidines, which are potentially bioactive molecules. This new approach establishes the selective catalytic activity of Cu(OTf)2 to accomplish the uracil C‐6–H activation.
Magnetically Recoverable CuFe2O4 Nanoparticles: Catalyzed Synthesis of Aryl Azides and 1,4‐Diaryl‐1,2,3‐triazoles from Boronic Acids in Water
Authors: Kumar A. Suresh , Reddy M. Amarnath , Knorn M. , Reiser O. , Sreedhar B. 
Published: June 2013

AbstractMagnetically recoverable and reusable CuFe2O4 nanoparticles are shown to be highly efficient catalysts for the one‐pot synthesis of biologically important 1,4‐diaryl‐1,2,3‐triazoles starting from boronic acids, sodium azide, and acetylenes. The use of aqueous reaction medium at room temperature, the low cost and facile recovery of the catalyst by application of an external magnetic field, and consistently high catalytic efficiency for at least three consecutive cycles renders the protocol operationally attractive.
Calix[2]triazole[2]arenes; A Class of Hybrid Heterocalixarenes
Authors: Cho Jihee , Lee Seokwoo , Hwang Soonho , Kim Sang Hoon , Kim Jong Seung , Kim Sanghee 
Published: June 2013

AbstractA series of calix[2]triazole[2]arenes, which are members of the heterocalixarene family, were generated by copper(I)‐catalyzed Huisgen reaction in a one‐pot synthesis. Their various conformational structures and physical properties were characterized by a computational, NMR spectroscopic, and X‐ray structural investigation. Among six conformations, the 1,2‐alternate conformation was found to be the most stable due to two intramolecular hydrogen bonds between the phenolic hydroxyl group and the triazole nitrogen atom.
Selenium‐Promoted Intramolecular Oxidative Amidation of 2‐(Arylamino)acetophenones for the Synthesis of N‐Arylisatins
Authors: Liu Yong , Chen Hui , Hu Xiong , Zhou Wang , Deng Guo‐Jun 
Published: June 2013

AbstractA convenient method for the synthesis of N‐arylisatins from 2‐(arylamino)acetophenones by using SeO2 as an oxidant is described. Various substituted N‐arylisatins were selectively obtained in good to excellent yields. The reaction tolerates a wide range of functionalities.
Improvement in the One‐Carbon Chain Extension of Esters with Dimethylsulf­oxonium Methylide
Authors: Luong Hoa , Luss‐Lusis Eduard , Tanoury Gerald J. , Nugent William A. 
Published: June 2013

AbstractA recent report suggests that the reaction of dimethylsulfoxonium methylide with esters does not produce a chain‐extended sulfur ylide as previously reported, but rather affords the corresponding carboxylate salt. We have investigated this assertion by using a combination of ab initio molecular orbital calculations, spiking studies, and isotopic labeling. The formation of carboxylate is unambiguously demonstrated to arise through hydrolysis involving adventitious water, principally derived from moisture in commercial trimethylsulfoxonium chloride. Careful vacuum drying of this reagent diminishes the competing hydrolytic pathway resulting in higher yields for the chain‐extension reaction than previously reported.
Electrochemical Oxidation of Ibuprofen and Its Voltammetric Determination at a Boron‐Doped Diamond Electrode
Authors: Lima Amanda B. , Faria Eric O. , Montes Rodrigo H. O. , Cunha Rafael R. , Richter Eduardo M. , Munoz Rodrigo A. A. , dos Santos Wallans T. P. 
Published: June 2013

AbstractThe electrochemical oxidation of ibuprofen at a boron‐doped diamond electrode (BDDE) and its voltammetric determination is reported for the first time. A well‐defined oxidation peak was observed at around 1.6 V in 0.1 mol L−1 H2SO4 solution with 10 % (v/v) ethanol at the BDDE surface activated by either cathodic or anodic pretreatments. A differential‐pulse voltammetric method for the determination of ibuprofen in pharmaceutical formulations was optimized with a detection limit of 5 µmol L−1 and compared with the British Pharmacopeia method.
pH‐Switchable Redox Reactions and Bioelectrocatalytic Processes Using Au Nanoparticles‐Modified Electrodes
Authors: Trifonov Alexander , Yehezkeli Omer , Tel‐Vered Ran , Willner Itamar 
Published: June 2013

AbstractBoronate ester complexes generated between methylene blue (MB+)‐functionalized Au nanoparticles (NPs) and electrode surfaces are implemented to stimulate the bioelectrocatalyzed reduction of H2O2 in the presence of horseradish peroxidase (HRP). Two kinds of Au NPs are prepared: Class I includes MB+/phenylboronic acid as a modifying layer, whereas Class II includes MB+/dithiothreitol as a mixed capping layer. The Class I or II NPs form boronate ester complexes with a dithiothreitol‐ or phenylboronic acid‐functionalized Au electrodes, respectively. By the cyclic loading of the NPs on the electrodes (pH 8.1), and the removal of the NPs (pH 1.5), switchable bioelectrocatalyzed reduction of H2O2 is demonstrated.
Simultaneous Square‐Wave Voltammetric Determination of Paracetamol, Caffeine and Orphenadrine in Pharmaceutical Formulations Using a Cathodically Pretreated Boron‐Doped Diamond Electrode
Authors: Eisele Ana Paula Pires , Clausen Débora Nóbile , Tarley César Ricardo Teixeira , Dall'Antonia Luiz Henrique , Sartori Elen Romão 
Published: June 2013

AbstractAn electroanalytical method for the simultaneous determination of paracetamol (PAR), caffeine (CAF), and orphenadrine (ORPH) using the square‐wave voltammetry (SWV) and a cathodically pretreated boron‐doped diamond electrode was developed. The method exhibits linear responses to PAR, CAF, and ORPH in the concentration ranges 5.4×10−7–6.1×10−5 M, 7.8×10−7–3.5×10−5 M, and 7.8×10−7–3.5×10−5 M, respectively, with detection limits of 2.3×10−7 M, 9.6×10−8 M, and 8.4×10−8 M, respectively. The proposed method was successfully applied in the simultaneous determination of these analytes in pharmaceutical formulations.
Weather types, runoff and sediment yield in a Mediterranean mountain landscape
Authors: Nadal‐Romero E. , Cortesi N. , González‐Hidalgo J. C. 
Published: June 2013

ABSTRACTThe relationship between the synoptic weather types (WTs), runoff and sediments in a Mediterranean mountain landscape was analysed. The study was performed between 2005 and 2012 using one of the most complete and extensive daily databases of rainfall, runoff and sediment recorded in the Spanish Pyrenees, coupled with WTs defined from the National Meteorological Center/National Center for Atmospheric Research (NMC/NCAR) 40‐Year Reanalysis Project. The results show that the three wettest WTs accounted for 30% of rainy days and 46% of rainfall, but comprised only 13% of total daily records. To obtain a much more robust association between WTs and rainfall an analysis was carried out using a longer rainfall record (1989–2011). The analyses confirmed that the results obtained from the Araguás catchment are representative of a longer time span.The cyclonic, north‐westerly and westerly WTs play an important role in runoff generation, coinciding with the wettest WTs. Extreme floods are commonly associated also with south‐westerly and westerly airflows, whereas less flooding was generated under cyclonic circulations. Sediment transport was concentrated in 2.9% of total time mainly related to westerly WTs.Seasonal differences exist in WT frequency. In winter and spring north‐west and West are the most prominent WTs related to rainfall, water and sediment yield, although in spring cyclonic frequency was higher. During autumn north‐west and south‐west were the most frequent, but sediment yield was produced nearby under south‐west flow. In summer the WTs that produce sediment are north and west. A magnitude–frequency analysis shows the different behaviour of WTs according to their efficiency in producing runoff and sediment.A study with different monitored areas around the Iberian Peninsula and the Mediterranean basin would be very valuable in providing information for hydrological and sediment behaviour under the current conditions of global climate change. Copyright © 2013 John Wiley & Sons, Ltd.
Effects of pH on uranium uptake and oxidative stress responses induced in Arabidopsis thaliana
Authors: Saenen Eline , Horemans Nele , Vanhoudt Nathalie , Vandenhove Hildegarde , Biermans Geert , Van Hees May , Wannijn Jean , Vangronsveld Jaco , Cuypers Ann 
Published: June 2013

Abstract

Uranium (U) causes oxidative stress in Arabidopsis thaliana plants grown at pH 5.5. However, U speciation and its toxicity strongly depend on environmental parameters, for example pH. It is unknown how different U species determine U uptake and translocation within plants and how they might affect the oxidative defense mechanisms of these plants. The present study analyzed U uptake and oxidative stress-related responses in A. thaliana (Columbia ecotype) under contrasted U chemical speciation conditions. The 18-d-old seedlings were exposed for 3 d to 25 µM U in a nutrient solution of which the pH was adjusted to 4.5, 5.5, 6.5, or 7.5. Results indicate that there is a different rate of U uptake and translocation at the different pHs, with high uptake and low translocation at low pH and lower uptake but higher translocation at high pH. After U exposure, an increased glutathione reductase activity and total glutathione concentration were observed in U-exposed roots, pointing toward an important role for glutathione in the root defense system against U either by chelation or by antioxidative defense mechanisms. In leaves, antioxidative defense mechanisms were activated on U exposure, indicated by increased superoxide dismutase and catalase activity. As it seems that U toxicity is influenced by pH, it is important to consider site-specific characteristics when making U risk assessments. Environ Toxicol Chem 2013;32:2125–2133. © 2013 SETAC
Layered subspace codes for random network coding
Authors: Chen Chao , Xie Hongmei , Bai Baoming 
Published: June 2013

AbstractSubspace codes were introduced by Kötter and Kschischang for error control in random linear network coding. In this paper, a layered type of subspace codes is considered, which can be viewed as a superposition of multiple component subspace codes. Exploiting the layered structure, we develop two decoding methods for these codes. The first method operates by separately decoding each component code. The second method is similar to the successive interference cancellation algorithm for conventional superposition coding and further permits an iterative version. We show that both methods decode not only deterministically up to but also probabilistically beyond the error‐correction capability of the overall code. Finally, we present possible applications of layered subspace codes in several network coding scenarios. Copyright © 2013 John Wiley & Sons, Ltd.
Metallic trace elements in cereal grain – a review: how much metal do we eat?
Authors: Teklić Tihana , Lončarić Zdenko , Kovačević Vlado , Singh Bal Ram 
Published: June 2013

AbstractPlants are the first step of a metal's pathway from the soil to heterotrophic organisms such as animals and humans, so the content of metallic trace elements in edible parts of a plant represent available load of these metals that may enter the food chain through plants. Among metal elements, Cu, Fe, Mn, and Zn are micronutrients as they are essential in trace amounts for physiological processes in living organisms and therefore are a significant component of the soil–plant–food continuum. Billions of people around the world suffer from micronutrient malnutrition. This review is aimed at giving an overview of the data pertaining to the Fe, Mn, Zn, and Cu content of the grains of the globally most important cereals – wheat, rice, and maize, reported mostly during the last two decades. The prevailing opinions on their importance in the food chain, and current strategies for enrichment of cereal grains with those essential microelements are briefly summarized.
Characterization and Correction of Error in Genome‐Wide IBD Estimation for Samples with Population Structure
Authors: Morrison Jean 
Published: June 2013

ABSTRACTThe proportion of the genome that is shared identical by descent (IBD) between pairs of individuals is often estimated in studies involving genome‐wide SNP data. These estimates can be used to check pedigrees, estimate heritability, and adjust association analyses. We focus on the method of moments technique as implemented in PLINK [Purcell et al., 2007] and other software that estimates the proportions of the genome at which two individuals share 0, 1, or 2 alleles IBD. This technique is based on the assumption that the study sample is drawn from a single, homogeneous, randomly mating population. This assumption is violated if pedigree founders are drawn from multiple populations or include admixed individuals. In the presence of population structure, the method of moments estimator has an inflated variance and can be biased because it relies on sample‐based allele frequency estimates. In the case of the PLINK estimator, which truncates genome‐wide sharing estimates at zero and one to generate biologically interpretable results, the bias is most often towards over‐estimation of relatedness between ancestrally similar individuals. Using simulated pedigrees, we are able to demonstrate and quantify the behavior of the PLINK method of moments estimator under different population structure conditions. We also propose a simple method based on SNP pruning for improving genome‐wide IBD estimates when the assumption of a single, homogeneous population is violated.