bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetite and Metal‐Impregnated Magnetite Catalysts in Organic Synthesis: A Very Old Concept with New Promising Perspectives
Authors: Baeza Alejandro , Guillena Gabriela , Ramón Diego J. 
Published: December 2015

AbstractMagnetite is a well‐known material, with the impregnation of transition metals onto its surface being a very old protocol for preparing catalysts. However, only recently, the combination of both, magnetite and impregnation protocols, have been recognized as a powerful methodology to prepare catalysts. The impregnation protocol, of nearly all transition metals in the magnetite surface, has rendered the first generation of catalysts. These simple catalysts have been used in a very broad range of organic transformations. Thus, simple imine derivative formation or unknown reactions such as the direct cross β‐alkylation of primary alcohols, through dehydrogenation, oxidation, addition, hydrogen autotransfer, and multicomponent reactions has been accomplished using these catalysts. In most cases, these catalysts could be just isolated by magnetic decantation and reused several times without a detrimental effect on the initial results. In some cases, the study of the surface of the catalyst by means of several surface characterization techniques has permitted to determine the real species involved in the process and their structural changes within the reaction cycles. Furthermore, the post‐modification of the catalysts by reduction or oxidation of the immobilized metal, or by the addition of ligands, has enlarged the applicability of this type of catalysts.
A Water‐Soluble Copper–Polypyridine Complex as a Homogeneous Catalyst for both Photo‐Induced and Electrocatalytic O2 Evolution
Authors: Xiang Rui‐Juan , Wang Hong‐Yan , Xin Zhi‐Juan , Li Cheng‐Bo , Lu Ya‐Xing , Gao Xue‐Wang , Sun Hua‐Ming , Cao Rui 
Published: December 2015

AbstractThe water‐soluble polypyridine copper complex [Cu(F3TPA)(ClO4)2] [1; F3TPA=tris(2‐fluoro‐6‐pyridylmethyl)amine] catalyzes water oxidation in a pH 8.5 borate buffer at a relatively low overpotential of 610 mV. Assisted by photosensitizer and an electron acceptor, 1 also exhibits activity as a homogeneous catalyst for photo‐induced O2 evolution with a maximum turnover frequency (TOF) of (1.58±0.03)×10−1 s−1 and a maximum turnover number (TON) of 11.61±0.23. In comparison, the reference [Cu(TPA)(ClO4)2] [TPA=tris(2‐pyridylmethyl)amine] displayed almost no activity under either set of conditions, implying the crucial role of the ligand in determining the behavior of the catalyst. Experimental evidence indicate the molecular catalytic nature of 1, leading to a potentially practical strategy to apply the copper complex in a photoelectrochemical device for water oxidation.
Carboranylphosphinic Acids: A New Class of Purely Inorganic Ligands
Authors: Oleshkevich Elena , Teixidor Francesc , Choquesillo‐Lazarte Duane , Sillanpää Reijo , Viñas Clara 
Published: December 2015

AbstractPurely inorganic carboranyl phosphinates were prepared, and the influence of the cluster on the reactivity of the phosphinate group was studied. Electron‐withdrawal by the carboranyl carbon atoms, combined with space‐filling efficiency and enhanced aromaticity of the cluster cage, renders the phosphorus more difficult to oxidize. This enables carboranyl phosphinates to survive harsh oxidizing conditions, a property which is uncommon in organic phosphinates.
Use of Lanthanide‐Containing Polyoxometalates to Sensitise the Emission of Fluorescent Labelled Serum Albumin
Authors: Holmes‐Smith A. Sheila , Crisp Jacob , Hussain Firasat , Patzke Greta R. , Hungerford Graham 
Published: December 2015

AbstractMonitoring the interaction of biomolecules is important, and the use of energy transfer is a principal technique in elucidating nanoscale interactions. Lanthanide compounds are promising luminescent probes for biological samples as their emission is longer‐lived than any native autofluorescence. Polyoxometalates (POMs) are interesting structural motifs to incorporate lanthanides, offering low toxicity and a size pertinent for biological applications. Here, we employ iso‐structured POMs containing either terbium or europium and assess their interaction with serum albumin by sensitisation of a fluorescent tag on the protein via LRET (luminescence resonance energy transfer) by exciting the lanthanide. Time‐resolved measurements showed energy transfer with an efficiency of over 90 % for the POM–protein systems. The Tb–POM results were relatively straightforward, while those with the iso‐structured Eu–POM were complicated by the effect of protein shielding from the aqueous environment.
Ambient Synthesis of One‐/Two‐Dimensional CuAgSe Ternary Nanotubes as Counter Electrodes of Quantum‐Dot‐Sensitized Solar Cells
Authors: Chen Xin Qi , Bai Yang , Li Zhen , Wang Lian Zhou , Dou Shi Xue 
Published: December 2015

AbstractOne‐/two‐dimensional ternary CuAgSe nanotubes (NTs) were successfully prepared from copper selenide (Cu2−xSe) NTs at room temperature within a short reaction time by the facile cation‐exchange approach. Cation exchange leads to the transformation of the crystal structure from cubic into orthorhombic and/or tetragonal with good retention of morphology. The exchange reactions are spontaneous owing to large negative changes of the Gibbs free energy. The effects of parameters such as reaction time, precursor source, and precursor ratio on the exchange reaction were investigated. The resultant CuAgSe NTs were explored as counter electrodes (CEs) of quantum‐dot‐sensitized solar cells (QDSSCs) and achieved higher conversion efficiency (η=5.61 %) than those of QDSSCs with the gold as the CE (3.32 %).
Network utility maximization in multipath lossy wireless networks
Authors: Pham Quoc‐Viet , Hwang Won‐Joo 
Published: December 2015

SummaryThe end‐to‐end rate control in multipath wireless multihop networks has been widely studied so as to exploit path diversity and improve network performance. However, it has been recognized that the hop‐by‐hop congestion control is stable and spatially smoothed in the absence and presence of delay, respectively. As a result, we are motivated to consider the lossy features of wireless links and propose a novel utility maximization problem for multipath communication networks. In view of the fact that the considered optimization problem formulated as a multipath network utility maximization problem is in non‐convex form and hard to tackle, we first cast the underlying problem into a convex one and then solve the convex approximation problem by the Lagrangian duality technique. What is more, an efficient hop‐by‐hop rate control algorithm is proposed. In addition, we prove that the proposed two‐loop algorithm converges to the optimal solution satisfying the Karush–Kuhn–Tucker optimality conditions of the original optimization problem. We finally validate the effectiveness of the proposed algorithm through extensive simulations and compare the performance of the proposed algorithm with a hop‐by‐hop single‐path rate control algorithm and also with an end‐to‐end multipath algorithm. Copyright © 2015 John Wiley & Sons, Ltd.
The circulating microRNome demonstrates distinct lymphocyte subset‐dependent signatures
Authors: de Candia Paola , Torri Anna , Fedeli Maya , Viganò Valentina , Carpi Donatella , Gorletta Tatiana , Casorati Giulia , Pagani Massimiliano , Dellabona Paolo , Abrignani Sergio 
Published: December 2015

Upon activation, lymphocytes release vesicles containing microRNAs (miRNAs). However, little is known as to whether this release results in modulation of circulating miRNAs (the miRNome) in the serum. The present work aims to identify lymphocyte subset‐specific signatures of miRNAs within the serum circulating miRNome. We therefore assessed serum miRNA expression profiles in wild‐type mice; in mice lacking either CD4+ T cells, CD8+ T cells, invariant natural killer T (iNKT) cells, or B cells; and, as a control, in mice in which Dicer has been ablated in T lymphocytes. We found that specific serum miRNAs are differentially modulated when different lymphocyte subsets are lacking. In particular, the serum level of miR‐181b‐5p, previously demonstrated to be fundamental for the development of iNKT cells, is specifically reduced in mice in which iNKT cells are absent. Interestingly, our results indicate a direct link between the biological role of a single miRNA in lymphocyte development and its serum level, and prove that even a population composed of relatively few cells in vivo, such as iNKT lymphocytes, has a measurable effect on the serum circulating miRNome.
Valence Tautomerism in Main‐Group Complexes? Computational Modeling of Si, Ge, Sn, and Pb Bischelates with o‐Iminoquinone Ligands
Authors: Chegerev Maxim G. , Starikova Alyona A. , Piskunov Alexander V. , Cherkasov Vladimir K. 
Published: December 2015

AbstractThe potential valence tautomeric (VT) properties of bischelate complexes of group 14 elements with 2,6‐di‐tert‐butyl‐4‐[(3,5‐di‐tert‐butyl‐2‐hydroxyphenyl)imino]cyclohexa‐2,5‐dienone (I) and 4,6‐di‐tert‐butyl‐N‐(R)‐o‐aminophenol (II, R = Ph and tBu) were studied computationally. According to DFT B3LYP/6‐311++G(d,p)/SDD calculations, the silicon complexes will be present as SiIV isomers with pseudotetrahedral coordination sites. Geometry optimizations of both lead bischelates I and II result in tetragonal‐pyramidal PbII structures. In the germanium complex I, the energy difference (5.2 kcal mol–1) between the electromeric forms allows the expectation of valence tautomerism, but the large energy barrier of the spin‐forbidden reaction (20.8 kcal mol–1) will complicate the occurrence of a thermally initiated redox process. Tin complex II (R = tBu) is characterized by a narrow energy gap between the tetragonal‐pyramidal and pseudotetrahedral electromeric forms (7.0 kcal mol–1) and a low energy barrier (11.7 kcal mol–1) for their interconversion and, therefore, may be considered as a promising candidate for the observation of thermally driven VT rearrangements.
Alkylammonium Guest Induced‐Fit Recognition by a Flexible Dihomo­oxacalix[4]arene Derivative
Authors: Talotta Carmen , Gaeta Carmine , De Rosa Margherita , Ascenso José R. , Marcos Paula M. , Neri Placido 
Published: December 2015

AbstractThe conformationally mobile tetramethoxy‐dihomooxacalix[4]arene 1c is able to interact with linear and branched alkylammonium guests through an induced‐fit process mainly driven by H‐bonds and cation–π interactions. Although free 1c adopts a 1,4‐alternate conformation in solution, in the presence of linear nBuNH3+ and branched sBuNH3+ and iPrNH3+ guests, it preferentially forms endo‐complexes in a cone conformation through adaptive structural change in response to the presence of the ammonium guests. In accordance with previous results, the DFT‐optimized structures of the complexes indicate that they are mainly stabilized by H‐bonding interactions between the guest ammonium group and the host CH2OCH2 ethereal bridge.
Molybdenum Pentachloride Mediated Synthesis of Spirocyclic Compounds by Intramolecular Oxidative Coupling
Authors: Schubert Moritz , Wehming Kathrin , Kehl Anton , Nieger Martin , Schnakenburg Gregor , Fröhlich Roland , Schollmeyer Dieter , Waldvogel Siegfried R. 
Published: December 2015

AbstractThe oxidative treatment of (m)ethyl 2‐aryl cinnamates equipped with methoxy groups in position 4 of the phenyl moiety promote the formation of cyclohexadienone substructures. This dealkylative oxidative C–C coupling gives access to spirocyclic compounds and avoids the construction of the corresponding phenanthrenes. Furthermore, the transformation can be expanded to other spirocyclic systems.
Investigation of the relationship of seismic intensity measures and the accumulation of damage on concrete gravity dams using incremental dynamic analysis
Authors: Soysal Berat Feyza , Binici Baris , Arici Yalin 
Published: December 2015

SummaryNonlinear analysis tools are gaining prominence for the design and evaluation of concrete gravity dams. The performance limits of concrete gravity dams within the framework of performance based design are challenging to determine in comparison to those used for the assessments based on linear elastic analyses. The uncertainty in quantifying the behavior of these systems and the strong dependence of the behavior on the ground motion play an important role. The purpose of the study is to quantify the damage levels on a representative monolith using incremental dynamic analysis (IDA). For this purpose, the constitutive model utilized was calibrated first to the existing experimental results to verify the ability of the utilized cracking model to simulate the crack propagation process. Next, the relation between the damage levels on the monolith and the ground motion characteristics was investigated. The results of the conducted IDA showed that the engineering demand parameters (EDP) such as the crest displacement and acceleration showed weak correlation with the damage states. The spectral velocity and the peak ground acceleration were determined to be better predictors for the damage on the monolith. Copyright © 2015 John Wiley & Sons, Ltd.
Nanosized titanium dioxide influences copper-induced toxicity during aging as a function of environmental conditions
Authors: Rosenfeldt Ricki R. , Seitz Frank , Haigis Ann-Cathrin , Höger Johanna , Zubrod Jochen P. , Schulz Ralf , Bundschuh Mirco 
Published: December 2015

Abstract

Titanium dioxide nanoparticles (TiO2-NPs) adsorb co-occurring heavy metals in surface waters, modulating their toxicity for freshwater invertebrates. The processes triggering this interaction may be influenced by several environmental parameters; however, their relative importance remains unclear. The present study assessed the implications of aging on the joint acute toxicity of copper (Cu) and TiO2-NPs for Daphnia magna over a duration of up to 72 h. The influences of aging duration as well as ionic strength, pH, and presence of different qualities of organic matter during aging were assessed. The results indicated that the presence of TiO2-NPs often reduced the Cu-induced toxicity for daphnids after aging (albeit with varying extent), which was displayed by up to 3-fold higher EC50 (50% effective concentration) values compared to the absence of TiO2-NPs. Moreover, the Cu speciation, influenced by the ionic composition and the pH as well as the presence of organic additives in the medium, strongly modulated the processes during aging, with partly limited implications of the aging duration on the ecotoxicological response of D. magna. Nonetheless, the present study underpins the potential of TiO2-NPs to modify toxicity induced by heavy metals in freshwater ecosystems under various environmental conditions. This pattern, however, needs further verification using heavy metal ions with differing properties in combination with further environmental factors, such as ultraviolet irradiation. Environ Toxicol Chem 2016;35:1766–1774. © 2015 SETAC
USAT: A Unified Score‐Based Association Test for Multiple Phenotype‐Genotype Analysis
Authors: Ray Debashree , Pankow James S. , Basu Saonli 
Published: December 2015

ABSTRACTGenome‐wide association studies (GWASs) for complex diseases often collect data on multiple correlated endo‐phenotypes. Multivariate analysis of these correlated phenotypes can improve the power to detect genetic variants. Multivariate analysis of variance (MANOVA) can perform such association analysis at a GWAS level, but the behavior of MANOVA under different trait models has not been carefully investigated. In this paper, we show that MANOVA is generally very powerful for detecting association but there are situations, such as when a genetic variant is associated with all the traits, where MANOVA may not have any detection power. In these situations, marginal model based methods, however, perform much better than multivariate methods. We investigate the behavior of MANOVA, both theoretically and using simulations, and derive the conditions where MANOVA loses power. Based on our findings, we propose a unified score‐based test statistic USAT that can perform better than MANOVA in such situations and nearly as well as MANOVA elsewhere. Our proposed test reports an approximate asymptotic P‐value for association and is computationally very efficient to implement at a GWAS level. We have studied through extensive simulations the performance of USAT, MANOVA, and other existing approaches and demonstrated the advantage of using the USAT approach to detect association between a genetic variant and multivariate phenotypes. We applied USAT to data from three correlated traits collected on 5, 816 Caucasian individuals from the Atherosclerosis Risk in Communities (ARIC, The ARIC Investigators []) Study and detected some interesting associations.
Meta‐Analysis of Rare Variant Association Tests in Multiethnic Populations
Authors: Mensah‐Ablorh Akweley , Lindstrom Sara , Haiman Christopher A. , Henderson Brian E. , Marchand Loic Le , Lee Seunngeun , Stram Daniel O. , Eliassen A. Heather , Price Alkes , Kraft Peter 
Published: December 2015

ABSTRACTSeveral methods have been proposed to increase power in rare variant association testing by aggregating information from individual rare variants (MAF < 0.005). However, how to best combine rare variants across multiple ethnicities and the relative performance of designs using different ethnic sampling fractions remains unknown. In this study, we compare the performance of several statistical approaches for assessing rare variant associations across multiple ethnicities. We also explore how different ethnic sampling fractions perform, including single‐ethnicity studies and studies that sample up to four ethnicities. We conducted simulations based on targeted sequencing data from 4,611 women in four ethnicities (African, European, Japanese American, and Latina). As with single‐ethnicity studies, burden tests had greater power when all causal rare variants were deleterious, and variance component‐based tests had greater power when some causal rare variants were deleterious and some were protective. Multiethnic studies had greater power than single‐ethnicity studies at many loci, with inclusion of African Americans providing the largest impact. On average, studies including African Americans had as much as 20% greater power than equivalently sized studies without African Americans. This suggests that association studies between rare variants and complex disease should consider including subjects from multiple ethnicities, with preference given to genetically diverse groups.
SPERCS—A tool for environmental emission estimation
Authors: Reihlen Antonia , Bahr Tobias , Bögi Christian , Dobe Christopher , May Thomas , Verdonck Frederik , Wind Thorsten , Zullo Lorenzo , Tolls Johannes 
Published: December 2015

Abstract
The European Union (EU) chemicals regulation Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) requires a hazardous substance registration to identify the uses of a substance and the corresponding conditions of safe use. This requirement includes a human and an environmental safety assessment. Exposure scenarios are developed and employed for estimating emissions resulting from the uses of hazardous substances. To support the environmental assessments, the REACH guidance documents define 22 environmental release categories (ERCs) with conservative release factors (RFs) to water, air, and soil. Several industry associations target the ERCs to more specific uses and respective emission scenarios to enable more realistic emission estimations. They have developed more than 190 specific ERCs (SPERCs) as standardized descriptions of operational conditions (OCs) and risk management measures (RMMs). SPERCs reflect the current good practice and are documented in factsheets. These factsheets contain the information necessary for environmental emission modeling. Key parameters are the substance use rate, the efficiency of the risk management measures (if applicable), and the RFs. These parameters can be based on literature or measured company data or are justified by qualitative arguments. The majority of SPERCs have been implemented as realistic worst-case emission values in screening-level chemical safety assessment (CSA) tools. Three regulatory reviews in Europe have established requirements for documenting the SPERCs and for justifying the RFs. In addition, each of the reviews included recommendations for improving the SPERCs. The latest review proposed a condensed factsheet that focuses on the essentials for exposure assessment and subsequent communication in safety data sheets. It is complemented with a background document for providing details on the emission scenarios and justifications. In the EU the SPERCs will be further progressed in a consensus process using the multi-stakeholder expert network on exposure scenarios. The SPERCs have the potential to be used in environmental risk assessments within other regulatory frameworks or in other geographical regions. Integr Environ Assess Manag 2016;12:772–781. © 2015 SETAC
DNA Superresolution Structure of Reed–Sternberg Cells Differs Between Long‐Lasting Remission Versus Relapsing Hodgkin's Lymphoma Patients
Authors: Righolt Christiaan H. , Knecht Hans , Mai Sabine 
Published: December 2015

ABSTRACTRecent developments in microscopy have led to superresolution microscopy images of cells. Structured illumination microscopy was used before to reveal new details in the DNA structure and the structure of the DNA‐free space in the DAPI‐stained cell nuclei of the Hodgkin's lymphoma HDLM‐2 cell line. This study extends this technology to primary pre‐treatment classical Hodgkin's lymphoma samples of ten patients. Significant differences in both the DNA structure and the structure of the DNA‐free space were detected between lymphocytes and malignant cells. Both types of structures were similar for lymphocytes of different patients. When the patients were un‐blinded and grouped based on their clinical outcome, either non‐relapsed or relapsed, a significant difference in the DNA structure of their Reed–Sternberg (RS) cells was found. Since, RS cells develop from mono–nucleated Hodgkin (H) cells, these data suggest distinct architectural restructuring of nuclei during RS cell formation in patients going to long‐lasting remission versus relapse. J. Cell. Biochem. 117: 1633–1637, 2016. © 2015 Wiley Periodicals, Inc.