bluuebunny/crossref_metadata_2025_split huggingface dataset:
Orientation‐Dependent Strain Relaxation and Chemical Functionalization of Graphene on a Cu(111) Foil
Authors: Li Bao‐Wen , Luo Da , Zhu Liyan , Zhang Xu , Jin Sunghwan , Huang Ming , Ding Feng , Ruoff Rodney S. 
Published: January 2018

AbstractEpitaxial graphene grown on single crystal Cu(111) foils by chemical vapor deposition is found to be free of wrinkles and under biaxial compressive strain. The compressive strain in the epitaxial regions (0.25–0.40%) is higher than regions where the graphene is not epitaxial with the underlying surface (0.20–0.25%). This orientation‐dependent strain relaxation is through the loss of local adhesion and the generation of graphene wrinkles. Density functional theory calculations suggest a large frictional force between the epitaxial graphene and the Cu(111) substrate, and this is therefore an energy barrier to the formation of wrinkles in the graphene. Enhanced chemical reactivity is found in epitaxial graphene on Cu(111) foils as compared to graphene on polycrystalline Cu foils for certain chemical reactions. A higher compressive strain possibly favors lowering the formation energy and/or the energy gap between the initial and transition states, either of which can lead to an increase in chemical reactivity.
2D PdAg Alloy Nanodendrites for Enhanced Ethanol Electroxidation
Authors: Huang Wenjing , Kang Xiaolin , Xu Cheng , Zhou Junhua , Deng Jun , Li Yanguang , Cheng Si 
Published: January 2018

AbstractThe development of highly active and stable electrocatalysts for ethanol electroxidation is of decisive importance to the successful commercialization of direct ethanol fuel cells. Despite great efforts invested over the past decade, their progress has been notably slower than expected. In this work, the facile solution synthesis of 2D PdAg alloy nanodendrites as a high‐performance electrocatalyst is reported for ethanol electroxidation. The reaction is carried out via the coreduction of Pd and Ag precursors in aqueous solution with the presence of octadecyltrimethylammonium chloride as the structural directing agent. Final products feature small thickness (5–7 nm) and random in‐plane branching with enlarged surface areas and abundant undercoordinated sites. They exhibit enhanced electrocatalytic activity (large specific current ) and excellent operation stability (as revealed from both the cycling and chronoamperometric tests) for ethanol electroxidation. Control experiments show that the improvement comes from the combined electronic and structural effects.
Iridium‐catalyzed Asymmetric Hydrogenation of Polycyclic Pyrrolo/Indolo[1,2‐a]quinoxalines and Phenanthridines
Authors: Hu Shu‐Bo , Zhai Xiao‐Yong , Shen Hong‐Qiang , Zhou Yong‐Gui 
Published: January 2018

AbstractOwing to the dehydrogenative rearomatization of hydrogenation product and poisoning effect of nitrogen atom, asymmetric hydrogenation of polycyclic nitrogen‐containing heteroaromatics is still a great challenge. Herein, through in situ protection of hydrogenation products with acetic anhydride to inhibit rearomatization and poisoning effect, a novel iridium‐catalyzed enantioselective hydrogenation of polycyclic nitrogen‐containing heteroaromatics – pyrrolo/indolo[1,2‐a]quinoxalines and phenanthridines – has been successfully developed, providing a facile access to chiral dihydropyrrolo/indolo[1,2‐a]quinoxalines and dihydrophenanthridines with up to 98% ee. The strategy features broad substrate scope, easy operation and potential medicinal application.magnified image
The Interplay of Oxygen Functional Groups and Folded Texture in Densified Graphene Electrodes for Compact Sodium‐Ion Capacitors
Authors: Zhang Jun , Lv Wei , Zheng Dequn , Liang Qinghua , Wang Da‐Wei , Kang Feiyu , Yang Quan‐Hong 
Published: January 2018

AbstractSodium‐ion capacitors (SICs) can effectively combine high energy density with high power density, and are especially appropriate for high‐power demanding applications of large‐scale stationary energy storage. Surface‐induced pseudocapacitive charge storage based on porous or nano carbon materials is regarded as the most promising candidate for SICs. Unfortunately, their ultralow packing densities severely restrict their practical applications. A novel approach toward ultrafast high‐volumetric SICs based on folded‐graphene electrodes has already been demonstrated and showed quite competitive performance. In this work, it is further proved that oxygen functional groups and folded texture are two key elements for high‐volumetric sodium storage of folded‐graphene electrodes. Through a simple and controllable method, of thermal treatment in inert atmosphere, both the oxygen functional groups and folded texture can be quantitatively manipulated to better investigate the individual contribution and mutual interplay. It is illustrated that oxygen functional groups are crucial to superior capacitive sodium storage while folded texture is not only the origin for high‐volumetric sodium storage but also beneficial for both capacitive and additional diffusion‐controlled sodium storage. Inspired by above‐mentioned conclusion, more rational designs and effective preparation of advanced structure and novel materials can be realized to better promote the development of high‐volumetric SICs.
Graphene‐Oxide‐Promoted Direct Dehydrogenative Coupling Reaction of Aromatics
Authors: Fang Jingxian , Peng Zhiyong , Yang Yun , Wang Jiawei , Guo Jiaying , Gong Hang 
Published: January 2018

AbstractGraphene oxide, which is a popular 2D carbon material, promoted a direct dehydrogenative coupling reaction of aromatics. Homo‐coupling and cross‐coupling reactions were achieved in good yields in the presence of graphene oxide. This strategy is simple and does not require any other additives, such as acid/base or ligand. The reaction can also be easily scaled up to gram level.
Stabilization of the Pentazolate Anion in a Zeolitic Architecture with Na20N60 and Na24N60 Nanocages
Authors: Zhang Wenquan , Wang Kangcai , Li Juecheng , Lin Zhien , Song Siwei , Huang Shiliang , Liu Yu , Nie Fude , Zhang Qinghua 
Published: January 2018

AbstractThe experimental detection and synthesis of pentazole (HN5) and its anion (cyclo‐N5−) have been actively pursued for the past hundred years. The synthesis of an aesthetic three‐dimensional metal–pentazolate framework (denoted as MPF‐1) is presented. It consists of sodium ions and cyclo‐N5− anions in which the isolated cyclo‐N5− anions are preternaturally stabilized in this inorganic open framework featuring two types of nanocages (Na20N60 and Na24N60) through strong metal coordination bonds. The compound MPF‐1 is indefinitely stable at room temperature and exhibits high thermal stability relative to the reported cyclo‐N5− salts. This finding offers a new approach to create metal–pentazolate frameworks (MPFs) and enables the future exploration of interesting pentazole chemistry and also related functional materials.
Divergent Pathways Involving 1,3‐Dipolar Addition and N−N Bond Splitting of an Organic Azide across a Zirconium Methylidene
Authors: Kurogi Takashi , Mane Manoj V. , Zheng Shuai , Carroll Patrick J. , Baik Mu‐Hyun , Mindiola Daniel J. 
Published: January 2018

AbstractThe zirconium methylidene (PNP)Zr=CH2(OAr) (1) reacts with N3Ad to give two products (PNP)Zr=NAd(OAr) (2) and (PNP)Zr(η2‐N=NAd)(N=CH2)(OAr) (3), both resulting from a common cycloaddition intermediate (PNP)Zr(CH2N3Ad)(OAr) (A). Using a series of control experiments in combination with DFT calculations, it was found that 2 results from a nitrene by a carbene metathesis reaction in which N2 acts as a delivery vehicle and forms N2CH2 as a side product. In the case of 3, N−N bond splitting of the azide at the α‐position allowed the isolation of a rare example of a parent ketimide complex of zirconium. Isotopic labeling studies and solid‐state X‐ray analysis are presented for 2 and 3, in addition to an independent synthesis for the former.
Seeded Polymerization through the Interplay of Folding and Aggregation of an Amino‐Acid‐based Diamide
Authors: Ogi Soichiro , Matsumoto Kentaro , Yamaguchi Shigehiro 
Published: January 2018

AbstractAmino acid based diamides are widely used as a substructure in supramolecular polymers and are also key components of polypeptides that help to understand protein folding. The interplay of folding and aggregation of a diamide was used to achieve seed‐initiated supramolecular polymerization. For that purpose, a pyrene‐substituted diamide was synthesized in which pyrene is used as a tracer to monitor the supramolecular polymerization. Thermodynamics and time‐dependent studies revealed that the folding of the diamide moiety, via the formation of intramolecular hydrogen bonds, effectively prevents a spontaneous nucleation that leads to supramolecular polymerization. Under such out‐of‐equilibrium conditions, the addition of seeds successfully initiates the supramolecular polymerization. These results demonstrate the utility of such amino acid based diamides in programmable supramolecular polymerizations.
The Advantage of Democratic Peer Punishment in Sustaining Cooperation within Groups
Authors: Pfattheicher Stefan , Böhm Robert , Kesberg Rebekka 
Published: January 2018

AbstractIn social dilemma situations, individuals benefit from uncooperative behavior while exploiting resources of the collective. One prominent solution to prevent uncooperative behavior and to increase cooperation is to establish a system of costly peer punishment, that is, the possibility for every individual involved in the dilemma to impose costly punishment on interaction partners. However, recent research revealed that, in contrast to a situation without punishment, peer punishment is inefficient and maladaptive in the sense that the total payoff is reduced and punishment of cooperative individuals (i.e., antisocial punishment) is possible. In the present work, we propose that a system ofdemocratic peer punishment, that is, direct and equal participation of each individual in the punishment decision‐making process with punishment only executed when a majority has voted for its execution, can address the shortcomings of a peer punishment system. Using iterated public goods games, we show higher cooperation levels, higher total payoffs, and reduced executed punishment in the democratic compared with a peer punishment system. Moreover, we document that fairness perceptions, satisfaction, and interpersonal trust are increased in the democratic punishment system. Implications for how cooperation and democratic punishment systems may evolve are discussed. Copyright © 2018 John Wiley & Sons, Ltd.
Effective role of medium supplementation in microalgal lipid accumulation
Authors: Fazeli Danesh Azadeh , Mooij Peter , Ebrahimi Sirous , Kleerebezem Robbert , van Loosdrecht Mark 
Published: January 2018

AbstractThe present study investigated the interaction between starch and lipid accumulation in a green microalgae enrichment culture. The objective was to optimize the lipid content by manipulation of the medium in regular batch culture. Two medium designs were evaluated: First a high ortho‐P concentration with vitamin supplementary (Pi‐vitamins supplemented medium), second normal growth medium (control). Both media contained a low amount of nitrogen which was consumed during batch growth in three days. The batch experiments continued for another 4 days with the absence of soluble nitrogen in the medium. When the mixed microalgal culture was incubated in the Pi‐vitamin supplemented medium, the lipid, and starch content of the culture increased within the first 3 days to 102.0 ± 5.2 mg/L (12.7 ± 0.6% of DW) and 31.7 ± 1.6 mg/L (4.0 ± 0.2% of DW), respectively. On the last day of the experiment, the lipid, and starch content in Pi‐vitamin medium increased to 663.1 ± 32.5 mg/L (33.4 ± 1.6% of DW) and 127.5 ± 5.2 mg/L (6.4 ± 0.3% of DW). However, the lipid and starch content in the control process, reached to 334.7 ± 16.4 mg/L (20.1 ± 1.0% of DW) and 94.3 ± 4.6 mg/L (5.7 ± 0.3% of DW), respectively. The high Pi‐vitamin medium induced storing lipid formation clearly while the starch formation was not affected. The lipid contents reported here are among the high reported in the literature, note that already under full growth conditions significant lipid levels occurred in the algal enrichment culture. The high lipid productivity of the reported mixed microalgae culture provides an efficient route for efficient algal biodiesel production.
Do Boards of Directors Influence Corporate Sustainable Development? An Attention‐Based Analysis
Authors: Galbreath Jeremy 
Published: January 2018

AbstractFollowing the attention‐based view of the firm (ABV), boards of directors’ link to corporate sustainable development (CSD) could be dependent upon certain attention structures: valuation of environmental stimuli, rules of the game and the players. Studying a sample of large Australian firms, the findings indicate that the proposed attention‐directing structures do appear to be linked to CSD in a manner consistent with the ABV. Specifically, creating awareness through scanning efforts links boards to CSD. Stakeholder debate, as a boardroom rule, is also significantly associated with CSD. Furthermore, as a so‐called ‘player’ on the board, women directors have a moderating effect on the relationships between environmental scanning, stakeholder debate and CSD. The findings are discussed along with limitations and directions for future research. Copyright © 2018 John Wiley & Sons, Ltd and ERP Environment
Recent Advances in Micro‐/Nanostructured Metal–Organic Frameworks towards Photonic and Electronic Applications
Authors: Yang Xiaogang , Lin Xianqing , Zhao Yong Sheng , Yan Dongpeng 
Published: January 2018

AbstractMicro‐ and nanometer‐sized metal–organic frameworks (MOFs) materials have attracted great attention due to their unique properties and various potential applications in photonics, electronics, high‐density storage, chemo‐, and biosensors. The study of these materials supplies insight into how the crystal structure, molecular components, and micro‐/nanoscale effects can influence the performance of inorganic–organic hybrid materials. In this Minireview article, we introduce recent breakthroughs in the controlled synthesis of MOF micro‐/nanomaterials with specific structures and compositions, the tunable photonic and electronic properties of which would provide a novel platform for multifunctional applications. Firstly, the design strategies for MOFs based on self‐assembly and crystal engineering principles are introduced. Attention is then focused on the methods of fabrication of low‐dimensional MOF micro‐/nanostructures. Their new applications including two‐photon excited fluorescence, multi‐photon pumped lasing, optical waveguides, nonlinear optical (NLO), and field‐effect transistors are also outlined. Finally, we briefly discuss perspectives on the further development of these hybrid crystalline micro‐/nanomaterials.
Controlling Selectivity in Aliphatic C−H Oxidation through Supramolecular Recognition
Authors: Vidal Diego , Olivo Giorgio , Costas Miquel 
Published: January 2018

AbstractAliphatic C−H oxidation is the most straightforward approach to functionalize hydrocarbon skeletons. The main challenge of this reaction is the control of site selectivity, given the multiple C−H bonds present in any organic molecule. Natural enzymes elegantly solve this problem through the interplay of different interactions that geometrically orient the substrate to expose a single C−H bond to the active unit, thus overriding intrinsic reactivity patterns. A combination of molecular catalysts and supramolecular receptors can be a promising way to replicate such control. This strategy indeed unlocks hydroxylation of C−H bonds that are not accessible with conventional methodologies, in which the selectivity is dictated by the geometry of the substrate–receptor adduct. Herein, we review the reports of recognition‐driven C−H oxidation reactions and highlight the key design principles that inspired these works.
N‐Terminal Cu‐Binding Motifs (Xxx‐Zzz‐His, Xxx‐His) and Their Derivatives: Chemistry, Biology and Medicinal Applications
Authors: Gonzalez Paulina , Bossak Karolina , Stefaniak Ewelina , Hureau Christelle , Raibaut Laurent , Bal Wojciech , Faller Peter 
Published: January 2018

AbstractPeptides and proteins with N‐terminal amino acid sequences NH2‐Xxx‐His (XH) and NH2‐Xxx‐Zzz‐His (XZH) form well‐established high‐affinity CuII‐complexes. Key examples are Asp‐Ala‐His (in serum albumin) and Gly‐His‐Lys, the wound healing factor. This opens a straightforward way to add a high‐affinity CuII‐binding site to almost any peptide or protein, by chemical or recombinant approaches. Thus, these motifs, NH2‐Xxx‐Zzz‐His in particular, have been used to equip peptides and proteins with a multitude of functions based on the redox activity of Cu, including nuclease, protease, glycosidase, or oxygen activation properties, useful in anticancer or antimicrobial drugs. More recent research suggests novel biological functions, mainly based on the redox inertness of CuII in XZH, like PET imaging (with 64Cu), chelation therapies (for instance in Alzheimer's disease and other types of neurodegeneration), antioxidant units, Cu transporters and activation of biological functions by strong CuII binding. This Review gives an overview of the chemical properties of Cu‐XH and ‐XZH motifs and discusses the pros and cons of the vastly different biological applications, and how they could be improved depending on the application.
Synthesis and X‐Ray Crystallographic Characterisation of Frustum‐Shaped Ligated [Cu18H16(DPPE)6]2+ and [Cu16H14(DPPA)6]2+ Nanoclusters and Studies on Their H2 Evolution Reactions
Authors: Li Jiaye , Ma Howard Z. , Reid Gavin E. , Edwards Alison J. , Hong Yuning , White Jonathan M. , Mulder Roger J. , O'Hair Richard A. J. 
Published: January 2018

AbstractWe report new structural motifs for Cu nanoclusters that conceptually represent seed crystals for large face‐centred cubic (FCC) crystal growth. Kinetically controlled syntheses, high resolution mass spectrometry experiments for determination of the dication formulae and crystallographic characterisation were carried out for [Cu18H16(DPPE)6][BF4][Cl] (DPPE=bis(diphenylphosphino)ethane) and [Cu16H14(DPPA)6][(BF4)2] (DPPA=bis(diphenylphosphino)amine) polyhydrido nanoclusters, which feature the unprecedented bifrustum and frustum metal‐core architecture in metal nanoclusters. The Cu18 nanocluster contains two Cu9 frustum cupolae and the Cu16 nanocluster has one Cu9 frustum cupola and a Cu7 distorted hexagonal‐shape base. Gas‐phase experiments revealed that both Cu18H16 and Cu16H14 cores can spontaneously release H2 upon removal of one bisphosphine capping ligand.
Microsphere Assemblies via Phosphonate Monoester Coordination Chemistry
Authors: Bladek Kamila J. , Reid Margaret E. , Nishihara Hirotomo , Akhtar Farid , Gelfand Benjamin S. , Shimizu George K. H. 
Published: January 2018

AbstractBy complexing a bent phosphonate monoester ligand with cobalt(II), coupled with in situ ester hydrolysis, coordination microspheres (CALS=CALgary Sphere) are formed whereas the use of the phosphonic acid directly resulted in a sheet‐like structure. Manipulation of the synthetic conditions gave spheres with different sizes, mechanical stabilities, and porosities. Time‐dependent studies determined that the sphere formation likely occurred through the formation of a Co2+ and ligand chain that propagates in three dimensions through different sets of interactions. The relative rates of these assembly processes versus annealing by ester hydrolysis and metal dehydration determine the growth of the microspheres. Hardness testing by nanoindentation is carried out on the spheres and sheets. Notably, no templates or capping agents are employed, the growth of the spheres is intrinsic to the ligand geometry and the coordination chemistry of cobalt(II) and the phosphonate monoester.
Hierarchy of Asymmetry at Work: Chain‐Dependent Helix‐to‐Helix Interactions in Supramolecular Polymers
Authors: Díaz‐Cabrera Sandra , Dorca Yeray , Calbo Joaquín , Aragó Juan , Gómez Rafael , Ortí Enrique , Sánchez Luis 
Published: January 2018

AbstractA detailed investigation of the hierarchy of asymmetry operating in the self‐assembly of achiral (1) and chiral ((S)‐2 and (R)‐3) 1,3,5‐triphenylbenzenetricarboxamides (TPBAs) is reported. The aggregation of these TPBAs is conditioned by the point chirality at the peripheral side chains for (S)‐2 and (R)‐3. An efficient helix‐to‐helix interaction that goes further in the organization of fibrillar bundles is experimentally detected and theoretically supported only for the achiral TPBA 1. The effective interdigitation of the achiral aliphatic side chains produces a social self‐sorting to form preferentially heterochiral macromolecular aggregates.
Production of Electricity and Liquid Fuels with Low Carbon Footprint
Authors: Machhammer Otto , Maaß Hans‐Jürgen , Bode Andreas 
Published: January 2018

AbstractDie Nutzung bestehender Kohlekraftwerke ermöglicht die Herstellung von Strom und flüssigen Kraftstoffen mit niedrigem Carbon Footprint. Drei verfahrenstechnische Prozessverbundvarianten werden miteinander verglichen. Im Kraftwerk wird Strom erzeugt und aus den Kraftwerksabgasen wird CO2 gewonnen, das mit Wasserstoff zu flüssigen Kraftstoffen hydriert wird. H2 wird durch Wasserelektrolyse oder Methanpyrolyse produziert. Gegenüber dem Vergleichsfall (Strom aus Kohlekraftwerk und Kraftstoffe aus einer Rohölraffinerie) lassen sich die CO2‐Emissionen senken, wenn der Wasserstoff aus einer mit Windstrom betriebenen Elektrolyse oder aus einer Methanpyrolyse kommt.
Targeting HER2 in colorectal cancer: The landscape of amplification and short variant mutations in ERBB2 and ERBB3
Authors: Ross Jeffrey S. , Fakih Marwan , Ali Siraj M. , Elvin Julia A. , Schrock Alexa B. , Suh James , Vergilio Jo‐Anne , Ramkissoon Shakti , Severson Eric , Daniel Sugganth , Fabrizio David , Frampton Garrett , Sun James , Miller Vincent A. , Stephens Philip J. , Gay Laurie M. 
Published: January 2018

BACKGROUNDIn contrast to lung cancer, few precision treatments are available for colorectal cancer (CRC). One rapidly emerging treatment target in CRC is ERBB2 (human epidermal growth factor receptor 2 [HER2]). Oncogenic alterations in HER2, or its dimerization partner HER3, can underlie sensitivity to HER2‐targeted therapies.METHODSIn this study, 8887 CRC cases were evaluated by comprehensive genomic profiling for genomic alterations in 315 cancer‐related genes, tumor mutational burden, and microsatellite instability. This cohort included both colonic (7599 cases; 85.5%) and rectal (1288 cases; 14.5%) adenocarcinomas.RESULTSA total of 569 mCRCs were positive for ERBB2 (429 cases; 4.8%) and/or ERBB3 (148 cases; 1.7%) and featured ERBB amplification, short variant alterations, or a combination of the 2. High tumor mutational burden (≥20 mutations/Mb) was significantly more common in ERBB‐mutated samples, and ERBB3‐mutated CRCs were significantly more likely to have high microsatellite instability (P<.002). Alterations affecting KRAS (27.3%) were significantly underrepresented in ERBB2‐amplified samples compared with wild‐type CRC samples (51.8%), and ERBB2‐ or ERBB3‐mutated samples (49.0% and 60.8%, respectively) (P<.01). Other significant differences in mutation frequency were observed for genes in the PI3K/MTOR and mismatch repair pathways.CONCLUSIONSAlthough observed less often than in breast or upper gastrointestinal carcinomas, indications for which anti‐HER2 therapies are approved, the percentage of CRC with ERBB genomic alterations is significant. Importantly, 32% of ERBB2‐positive CRCs harbor short variant alterations that are undetectable by routine immunohistochemistry or fluorescence in situ hybridization testing. The success of anti‐HER2 therapies in ongoing clinical trials is a promising development for patients with CRC. Cancer 2018;124:1358‐73. © 2018 Foundation Medicine, Inc. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.