bluuebunny/crossref_metadata_2025_split huggingface dataset:
Color Tuning in Garnet Oxides: The Role of Tetrahedral Coordination Geometry for 3 d Metal Ions and Ligand–Metal Charge Transfer (Band‐Gap Manipulation)
Authors: Bhim Anupam , Laha Sourav , Gopalakrishnan Jagannatha , Natarajan Srinivasan 
Published: September 2017

AbstractWe explored garnet‐structured oxide materials containing 3d transition‐metal ions (e.g., Co2+, Ni2+, Cu2+, and Fe3+) for the development of new inorganic colored materials. For this purpose, we synthesized new garnets, Ca3Sb2Ga2ZnO12 (I) and Ca3Sb2Fe2ZnO12 (II), that were isostructural with Ca3Te2Zn3O12. Substitution of Co2+, Ni2+, and Cu2+ at the tetrahedral Zn2+ sites in I and II gave rise to brilliantly colored materials (different shades of blue, green, turquoise, and red). The materials were characterized by optical absorption spectroscopy and CIE chromaticity diagrams. The Fe3+‐containing oxides showed band‐gap narrowing (owing to strong sp–d exchange interactions between Zn2+ and the transition‐metal ion), and this tuned the color of these materials uniquely. We also characterized the color and optical absorption properties of Ca3Te2Zn3−xCoxO12 (0<x≤2.0) and Cd3Te2Zn3−xCoxO12 (0<x≤1.0), which display brilliant blue and green‐blue colors, respectively. The present work brings out the role of the distorted tetrahedral coordination geometry of transition‐metal ions and ligand–metal charge transfer (which is manifested as narrowing of the band gap) in producing brilliantly colored garnet‐based materials.
Ultra‐performance liquid chromatography–tandem mass spectrometry assay for determination of plasma nomegestrol acetate and estradiol in healthy postmenopausal women
Authors: Nair Sneha G. , Patel Daxesh P. , Sanyal Mallika , Singhal Puran , Shrivastav Pranav S. 
Published: September 2017

AbstractA highly sensitive and selective ultra‐performance liquid chromatography–tandem mass spectrometry method is described for the simultaneous determination of nomegestrol acetate (NOMAC), a highly selective progestogen, and estradiol (E2), a natural estrogen in human plasma. NOMAC was obtained from plasma by solid‐phase extraction, while E2 was first separated by liquid–liquid extraction with methyl tert‐butyl ether followed by derivatization with dansyl chloride. Deuterated internal standards, NOMAC‐d5 and E2‐d4 were used for better control of extraction conditions and ionization efficiency. The assay recovery of the analytes was within 90–99%. The analytes were separated on UPLC BEH C18 (50 × 2.1 mm, 1.7 μm) column using a mobile phase comprising of acetonitrile and 3.0 mm ammonium trifluoroacetate in water (80:20, v/v) with a resolution factor (Rs) of 3.21. The calibration curves were linear from 0.01 to 10.0 ng/mL for NOMAC and from 1.00 to 1000 pg/mL for E2, respectively. The intra‐ and inter‐batch precision was ≤5.8% and the accuracy of quality control samples ranged from 96.7 to 103.4% for both analytes. The practical applicability of the method is demonstrated by analyzing samples from 18 healthy postmenopausal women after oral administration of 2.5 mg nomegestrol acetate and 1.5 mg estradiol film‐coated tablets under fasting.
The Intersectionality of Gender and Race—Programs to Support Men of Color in Education
Authors: Person Dawn , Dawson Robert , García Yvonne , Jones Andrew 
Published: September 2017

AbstractThis chapter reports on three research studies conducted by the Center for Research on Educational Access and Leadership (C‐REAL) at California State University, Fullerton (CSUF) that are designed to help higher education institutions enhance their practices in serving men of color, namely Black and Latino men.
First‐Principles Computational Screening of Dopants to Improve the Deacon Process over RuO2
Authors: Yao Zhen , Reuter Karsten 
Published: September 2017

AbstractDoping of metal oxides is a promising route to further optimize their catalytic performance. To guide corresponding experimental endeavors, we performed a DFT‐based computational screening study for a wide range of metal dopant atoms in rutile RuO2. With a focus on the Deacon process, that is, the catalytic oxidation of HCl to chlorine and water, we used the rate‐controlling Cl desorption energy as a reactivity descriptor. As stability descriptors, we employed the dopant surface segregation energy and as the dopant thermodynamic stability against precipitation into the metal oxide or bulk oxide grains. In the oxygen‐rich conditions of the Deacon process, particularly the instability against oxide precipitation, represents a strong limitation. In this respect, doping with Cu appears as an optimum compromise between stability and catalytic activity enhancement.
Specific Inhibition of the Hydrogenolysis of Benzylic C−O Bonds Using Palladium Nanoparticles Supported on Nitrogen‐Doped Carbon Nanofibers
Authors: Motoyama Yukihiro , Morii Koshi , Ishizuka Shoya , Inomoto Sou , Zhang Zhenzhong , Yoon Seong‐Ho 
Published: September 2017

AbstractPalladium nanoparticles supported on 5 %‐nitrogen‐doped, herringbone‐type carbon nanofibers (Pd/N‐CNF‐H), which are prepared by thermally decomposing [Pd2(dba)3⋅CHCl3] (dba=dibenzylideneacetone) in toluene in the presence of N‐CNF‐H, were found to be an efficient catalyst for the chemoselective hydrogenation of alkenyl and nitro moieties in benzyl‐protected alcohols and carboxylic acid derivatives with high turnover frequencies: the hydrogenation reactions of these functional groups proceeded smoothly even at ambient temperature under atmospheric H2 pressure, and the benzyl protecting groups in the molecules remained intact. Moreover, the recovered Pd/N‐CNF‐H catalyst could be reused without loss of its catalytic activity or chemoselectivity. The Pd/N‐CNF‐H catalyst also acted as an effective hydrogenation catalyst for the reduction of aromatic ketones to the corresponding benzyl alcohol derivatives with good to high product selectivity.
Bioelectrocatalysis of Sulfite Dehydrogenase from Sinorhizobium meliloti with Its Physiological Cytochrome Electron Partner
Authors: Kalimuthu Palraj , Hsiao Ju‐Chun , Nair Remya Purushothaman , Kappler Ulrike , Bernhardt Paul V. 
Published: September 2017

AbstractWe demonstrate electrochemically driven catalytic voltammetry of the Mo‐dependent sulfite dehydrogenase (SorT) from the α‐Proteobacterium Sinorhizobium meliloti with its physiological electron acceptor, the c‐type cytochrome (SorU), with both proteins co‐adsorbed on a chemically modified Au working electrode. Both SorT and SorU were constrained under a perm‐selective dialysis membrane with the biopolymer chitosan as a co‐adsorbate, while the electrode was modified with a 3‐mercaptopropionate self‐assembled monolayer cast on the Au electrode. Cyclic voltammetry of the SorU protein reveals a well‐defined quasireversible FeIII/II redox couple at +130 mV versus NHE in 100 mM phosphate buffer solution (pH 7.0). Introduction of wild‐type sulfite dehydrogenase (SorTWT) and sulfite transforms this transient SorU voltammetric response into a sigmoidal catalytic wave, which increases with sulfite concentration before eventually saturating. In addition to the wild‐type enzyme, the variants SorTR78K, SorTR78M, and SorTR78Q were also examined electrochemically in an effort to better understand the role of amino acid residue Arg78, which is in the vicinity of the Mo active site of SorT.
Exposed N and S Active Sites: An Indicator for Oxygen Reduction on Metal‐Free Yam‐Derived Porous Carbons
Authors: Fan Hao , Dong Zhen , Zhao Jianshe 
Published: September 2017

AbstractExploring efficient and low‐cost catalysts for the oxygen reduction reaction (ORR) is a key issue in the development of renewable energy devices such as fuel cells and metal−air batteries. The design and construct of advanced catalysts can be guided by identifying the sites with high activity. In this study, an indicative research study on the ORR of yam‐derived N and S self‐doped porous carbons (NSDCs) is presented. The NSDC optimized at 800 °C (NSDC800) with more exposed intrinsic N and S active sites shows a comparable ORR activity to the commercial Pt/C and sets the top level for metal‐free carbons, as well as high stability and tolerance to CO and methanol. Consequently, a homemade primary Al−air battery with NSDC800 demonstrates an open‐circuit potential of 1.66 V and a peak power density of 83 mW cm−2. With a series of NSDCs, the exposed intrinsic N and S sites (pyrrolic‐N, graphitic‐N, and thiophene‐S) are synergistically identified as the activity indicators for the ORR. This finding may provide an insight into the analysis of active sites and open an avenue for the synthesis and volume production of carbon‐based ORR catalysts with low cost and high activity.
Sequence Engineering to Control the Helix Handedness of Peptide Foldamers
Authors: Rudzińska‐Szostak Ewa , Berlicki Łukasz 
Published: September 2017

AbstractPeptide foldamers have been studied for over two decades and numerous sequence patterns have been shown to form well‐defined three‐dimensional arrangements in solution. In particular, helices of various geometries have been described. In this article, different concepts concerning the construction of helical foldameric peptides, for which the possibility of governing the sense of the formed helix was evidenced, are presented and discussed.
Aerosols: A Sustainable Route to Functional Materials
Authors: Powell Michael J. , Carmalt Claire J. 
Published: September 2017

AbstractSustainability is an increasingly important topic in the design and manufacture of materials, with the need to reduce the environmental impact of producing materials being of paramount significance. A competing interest to this is the ability to produce functional materials in large volumes from a fast, on‐line process, which can be integrated easily into existing industrial setups. Herein, we present aerosol‐assisted chemical vapour deposition (AACVD) routes to advanced functional materials. We will show that by careful design of precursors and manipulation of deposition conditions, it is possible to achieve high sustainability whilst maintaining fast growth rates and large scale production of thin film functional materials.
Structural Analysis of Uranyl Complexation by the EF‐Hand Motif of Calmodulin: Effect of Phosphorylation
Authors: Sauge‐Merle Sandrine , Brulfert Florian , Pardoux Romain , Solari Pier Lorenzo , Lemaire David , Safi Samir , Guilbaud Philippe , Simoni Eric , Merroun Mohamed Larbi , Berthomieu Catherine 
Published: September 2017

AbstractBetter understanding of uranyl–protein interactions is a prerequisite to predict uranium chemical toxicity in cells. The EF‐hand motif of the calmodulin site I is about thousand times more affine for uranyl than for calcium, and threonine phosphorylation increases the uranyl affinity by two orders of magnitude at pH 7. In this study, we confront X‐ray absorption spectroscopy with Fourier transform infrared (FTIR) spectroscopy, time‐resolved laser‐induced fluorescence spectroscopy (TRLFS), and structural models obtained by molecular dynamics simulations to analyze the uranyl coordination in the native and phosphorylated calmodulin site I. For the native site I, extended X‐ray absorption fine structure (EXAFS) data evidence a short U−Oeq distance, in addition to distances compatible with mono‐ and bidentate coordination by carboxylate groups. Further analysis of uranyl speciation by TRLFS and thorough investigation of the fluorescence decay kinetics strongly support the presence of a hydroxide uranyl ligand. For a phosphorylated site I, the EXAFS and FTIR data support a monodentate uranyl coordination by the phosphoryl group and strong interaction with mono‐ and bidentate carboxylate ligands. This study confirms the important role of a phosphoryl ligand in the stability of uranyl–protein interactions. By evidencing a hydroxide uranyl ligand in calmodulin site I, this study also highlights the possible role of less studied ligands as water or hydroxide ions in the stability of protein–uranyl complexes.
Synthesis and Reactivity of a Scandium Terminal Hydride: H2 Activation by a Scandium Terminal Imido Complex
Authors: Han Xianghao , Xiang Li , Lamsfus Carlos A. , Mao Weiqing , Lu Erli , Maron Laurent , Leng Xuebing , Chen Yaofeng 
Published: September 2017

AbstractDihydrogen is easily activated by a scandium terminal imido complex containing the weakly coordinated THF. The reaction proceeds through a 1,2‐addition mechanism, which is distinct from the σ‐bond metathesis mechanism reported to date for rare‐earth metal‐mediated H2 activation. This reaction yields a scandium terminal hydride, which is structurally well‐characterized, being the first one to date. The reactivity of this hydride is reported with unsaturated substrates, further shedding light on the existence of the terminal hydride complex. Interestingly, the H2 activation can be reversible. DFT investigations further eludciate the mechanistic aspects of the reactivity of the scandium anilido‐terminal hydride complex with PhNCS but also on the reversible H2 activation process.
Electrocatalytic Water Oxidation by MnOx/C: In Situ Catalyst Formation, Carbon Substrate Variations, and Direct O2/CO2 Monitoring by Membrane‐Inlet Mass Spectrometry
Authors: Melder Jens , Kwong Wai Ling , Shevela Dmitriy , Messinger Johannes , Kurz Philipp 
Published: September 2017

AbstractLayers of amorphous manganese oxides were directly formed on the surfaces of different carbon materials by exposing the carbon to aqueous solutions of permanganate (MnO4−) followed by sintering at 100–400 °C. During electrochemical measurements in neutral aqueous buffer, nearly all of the MnOx/C electrodes show significant oxidation currents at potentials relevant for the oxygen evolution reaction (OER). However, by combining electrolysis with product detection by using mass spectrometry, it was found that these currents were only strictly linked to water oxidation if MnOx was deposited on graphitic carbon materials (faradaic O2 yields >90 %). On the contrary, supports containing sp3‐C were found to be unsuitable as the OER is accompanied by carbon corrosion to CO2. Thus, choosing the “right” carbon material is crucial for the preparation of stable and efficient MnOx/C anodes for water oxidation catalysis. For MnOx on graphitic substrates, current densities of >1 mA cm−2 at η=540 mV could be maintained for at least 16 h of continuous operation at pH 7 (very good values for electrodes containing only abundant elements such as C, O, and Mn) and post‐operando measurements proved the integrity of both the catalyst coating and the underlying carbon at OER conditions.
Anodic Dissolution of Al Current Collectors in Unconventional Solvents for High Voltage Electrochemical Double‐Layer Capacitors
Authors: Krummacher Jakob , Heß Lars‐Henning , Balducci Andrea. 
Published: September 2017

AbstractThis study investigated the anodic dissolution of Al current collectors in unconventional electrolytes for high voltage electrochemical double‐layer capacitors (EDLCs) containing adiponitrile (ADN), 3‐cyanopropionic acid methyl ester (CPAME), 2‐methyl‐glutaronitrile (2‐MGN) as solvent, and tetraethylammonium tetrafluoroborate (Et4NBF4) and tetraethylammonium bis(trifluoromethanesulfonyl)imide (Et4NTFSI) as conductive salts. To have a comparison with the state‐of‐the‐art electrolytes, the same salts were also used in combination with acetonitrile (ACN). The chemical–physical properties of the electrolytes were investigated. Furthermore, their impact on the anodic dissolution of Al was analyzed in detail as well as the influence of this process on the performance of high voltage EDLCs. The results of this study indicated that in the case of Et4NBF4‐based electrolytes, the use of an alternative solvent is very beneficial for the realization of stable devices. When Et4NTFSI is used, the reduced solubility of the complex Al(TFSI)3 appears to be the key for the realization of advanced electrolytes.
Improvement of Electrochemical Water Oxidation by Fine‐Tuning the Structure of Tetradentate N4 Ligands of Molecular Copper Catalysts
Authors: Shen Junyu , Wang Mei , Gao Jinsuo , Han Hongxian , Liu Hong , Sun Licheng 
Published: September 2017

AbstractTwo copper complexes, [(L1)Cu(OH2)](BF4)2 [1; L1=N,N′‐dimethyl‐N,N′‐bis(pyridin‐2‐ylmethyl)‐1,2‐diaminoethane] and [(L2)Cu(OH2)](BF4)2 [2, L2=2,7‐bis(2‐pyridyl)‐3,6‐diaza‐2,6‐octadiene], were prepared as molecular water oxidation catalysts. Complex 1 displayed an overpotential (η) of 1.07 V at 1 mA cm−2 and an observed rate constant (kobs) of 13.5 s−1 at η 1.0 V in pH 9.0 phosphate buffer solution, whereas 2 exhibited a significantly smaller η (0.70 V) to reach 1 mA cm−2 and a higher kobs (50.4 s−1) than 1 under identical test conditions. Additionally, 2 displayed better stability than 1 in controlled potential electrolysis experiments with a faradaic efficiency of 94 % for O2 evolution at 1.58 V, when a casing tube was used for the Pt cathode. A possible mechanism for 1‐ and 2‐catalyzed O2 evolution reactions is discussed based on the experimental evidence. These comparative results indicate that fine‐tuning the structures of tetradentate N4 ligands can bring about significant change in the performance of copper complexes for electrochemical water oxidation.
Hybrid Deep Eutectic Solvents with Flexible Hydrogen‐Bonded Supramolecular Networks for Highly Efficient Uptake of NH3
Authors: Li Yuhui , Ali Mohammad Chand , Yang Qiwei , Zhang Zhiguo , Bao Zongbi , Su Baogen , Xing Huabin , Ren Qilong 
Published: September 2017

AbstractInvited for this month′s cover is the group of Qiwei Yang at the Zhejiang University. The image shows the effective capture of NH3 molecules by hybrid deep eutectic solvents comprising choline chloride, resorcinol, and glycerol. The Full Paper itself is available at 10.1002/cssc.201701135.
Deciphering the enigma of undetected species, phylogenetic, and functional diversity based on Good‐Turing theory
Authors: Chao Anne , Chiu Chun‐Huo , Colwell Robert K. , Magnago Luiz Fernando S. , Chazdon Robin L. , Gotelli Nicholas J. 
Published: September 2017

AbstractEstimating the species, phylogenetic, and functional diversity of a community is challenging because rare species are often undetected, even with intensive sampling. The Good‐Turing frequency formula, originally developed for cryptography, estimates in an ecological context the true frequencies of rare species in a single assemblage based on an incomplete sample of individuals. Until now, this formula has never been used to estimate undetected species, phylogenetic, and functional diversity. Here, we first generalize the Good‐Turing formula to incomplete sampling of two assemblages. The original formula and its two‐assemblage generalization provide a novel and unified approach to notation, terminology, and estimation of undetected biological diversity. For species richness, the Good‐Turing framework offers an intuitive way to derive the non‐parametric estimators of the undetected species richness in a single assemblage, and of the undetected species shared between two assemblages. For phylogenetic diversity, the unified approach leads to an estimator of the undetected Faith's phylogenetic diversity (PD, the total length of undetected branches of a phylogenetic tree connecting all species), as well as a new estimator of undetected PD shared between two phylogenetic trees. For functional diversity based on species traits, the unified approach yields a new estimator of undetected Walker et al.'s functional attribute diversity (FAD, the total species‐pairwise functional distance) in a single assemblage, as well as a new estimator of undetected FAD shared between two assemblages. Although some of the resulting estimators have been previously published (but derived with traditional mathematical inequalities), all taxonomic, phylogenetic, and functional diversity estimators are now derived under the same framework. All the derived estimators are theoretically lower bounds of the corresponding undetected diversities; our approach reveals the sufficient conditions under which the estimators are nearly unbiased, thus offering new insights. Simulation results are reported to numerically verify the performance of the derived estimators. We illustrate all estimators and assess their sampling uncertainty with an empirical dataset for Brazilian rain forest trees. These estimators should be widely applicable to many current problems in ecology, such as the effects of climate change on spatial and temporal beta diversity and the contribution of trait diversity to ecosystem multi‐functionality.
Increased consumer density reduces the strength of neighborhood effects in a model system
Authors: Merwin Andrew C. , Underwood Nora , Inouye Brian D. 
Published: September 2017

AbstractAn individual's susceptibility to attack can be influenced by conspecific and heterospecifics neighbors. Predicting how these neighborhood effects contribute to population‐level processes such as competition and evolution requires an understanding of how the strength of neighborhood effects is modified by changes in the abundances of both consumers and neighboring resource species. We show for the first time that consumer density can interact with the density and frequency of neighboring organisms to determine the magnitude of neighborhood effects. We used the bean beetle, Callosobruchus maculatus, and two of its host beans, Vigna unguiculata and V. radiata, to perform a response‐surface experiment with a range of resource densities and three consumer densities. At low beetle density, damage to beans was reduced with increasing conspecific density (i.e., resource dilution) and damage to the less preferred host, V. unguiculata, was reduced with increasing V. radiata frequency (i.e., frequency‐dependent associational resistance). As beetle density increased, however, neighborhood effects were reduced; at the highest beetle densities neither focal nor neighboring resource density nor frequency influenced damage. These findings illustrate the importance of consumer density in mediating indirect effects among resources, and suggest that accounting for consumer density may improve our ability to predict population‐level outcomes of neighborhood effects and our use of them in applications such as mixed‐crop pest management.