bluuebunny/crossref_metadata_2025_split huggingface dataset:
β‐Functionalized Push–Pull Porphyrin Sensitizers in Dye‐Sensitized Solar Cells: Effect of π‐Conjugated Spacers
Authors: Ishida Masatoshi , Hwang Daesub , Zhang Zhan , Choi Yung Ji , Oh Juwon , Lynch Vincent M. , Kim Dong Young , Sessler Jonanthan L. , Kim Dongho 
Published: March 2015

AbstractA series of new β‐functionalized push–pull‐structured porphyrin dyes were synthesized so as to investigate the effect of the π‐conjugated spacer on the performance of dye‐sensitized solar cells (DSSCs). Suzuki‐ and Heck‐type palladium‐catalyzed coupling methodologies were used to obtain various β‐functionalized porphyrins and β‐benzoic acid (ZnPHn) and β‐vinylbenzoic acid (ZnPVn) derivatives from β‐borylated porphyrin precursors. Photophysical studies of the resulting porphyrins revealed a clear dependence on the nature of the β linker. In particular, it was found that a β‐vinylene linkage perturbs the electronic structure of the porphyrin core; this is less true for a β‐phenyl linkage. Theoretical analyses provided support for the intrinsic intramolecular charge‐transfer character of the β‐functionalized, push–pull porphyrins of this study. The extent of charge transfer depends on the nature of the β‐conjugated linkage. The photovoltaic performances of the cells sensitized with β‐phenylenevinylene ZnPVn exhibited higher power conversion efficiency values than those bearing β‐phenyl linkages (ZnPHn). This was ascribed to differences in light‐harvesting efficiency. Furthermore, compared to the use of a standard iodine‐based electrolyte, the DSSC performance of cells made from the present porphyrins was improved by more than 1 % upon using a cobalt(II/III)‐based electrolyte. Under standard AM 1.5 illumination, the highest efficiency, 8.2 %, was obtained by using cells made from the doubly β‐butadiene‐linked porphyrin.
Does natural selection explain the fine scale genetic structure at the nuclear exon Glu‐5′ in blue mussels from Kerguelen?
Authors: Gérard Karin , Roby Charlotte , Bierne Nicolas , Borsa Philippe , Féral Jean‐Pierre , Chenuil Anne 
Published: March 2015

AbstractThe Kerguelen archipelago, isolated in the Southern Ocean, shelters a blue mussel Mytilus metapopulation far from any influence of continental populations or any known hybrid zone. The finely carved coast leads to a highly heterogeneous habitat. We investigated the impact of the environment on the genetic structure in those Kerguelen blue mussels by relating allele frequencies to habitat descriptors. A total sample comprising up to 2248 individuals from 35 locations was characterized using two nuclear markers, mac‐1 and Glu‐5′, and a mitochondrial marker (COI). The frequency data from 9 allozyme loci in 9 of these locations were also reanalyzed. Two other nuclear markers (EFbis and EFprem's) were monomorphic. Compared to Northern Hemisphere populations, polymorphism in Kerguelen blue mussels was lower for all markers except for the exon Glu‐5′. At Glu‐5′, genetic differences were observed between samples from distinct regions (FCT = 0.077), as well as within two regions, including between samples separated by <500 m. No significant differentiation was observed in the AMOVA analyses at the two other markers (mac‐1 and COI). Like mac‐1, all allozyme loci genotyped in a previous publication, displayed lower differentiation (Jost's D) and FST values than Glu‐5′. Power simulations and confidence intervals support that Glu‐5′ displays significantly higher differentiation than the other loci (except a single allozyme for which confidence intervals overlap). AMOVA analyses revealed significant effects of the giant kelp Macrocystis and wave exposure on this marker. We discuss the influence of hydrological conditions on the genetic differentiation among regions. In marine organisms with high fecundity and high dispersal potential, gene flow tends to erase differentiation, but this study showed significant differentiation at very small distance. This may be explained by the particular hydrology and the carved coastline of the Kerguelen archipelago, together with spatially variable selection at Glu‐5′.
Nutrient levels within leaves, stems, and roots of the xeric species Reaumuria soongorica in relation to geographical, climatic, and soil conditions
Authors: He Mingzhu , Zhang Ke , Tan Huijuan , Hu Rui , Su Jieqiong , Wang Jin , Huang Lei , Zhang Yafeng , Li Xinrong 
Published: March 2015

AbstractBesides water relations, nutrient allocation, and stoichiometric traits are fundamental feature of shrubs. Knowledge concerning the nutrient stoichiometry of xerophytes is essential to predicting the biogeochemical cycling in desert ecosystems as well as to understanding the homoeostasis and variability of nutrient traits in desert plants. Here, we focused on the temperate desert species Reaumuria soongorica and collected samples from plant organs and soil over 28 different locations that covered a wide distributional gradient of this species. Carbon (C), nitrogen (N), and phosphorus (P) concentrations and their stoichiometry were determined and subsequently compared with geographic, climatic, and edaphic factors. The mean leaf C, N, and P concentrations and C/N, C/P, and N/P ratios were 371.6 mg g−1, 10.6 mg g−1, 0.73 mg g−1, and 59.7, 837.9, 15.7, respectively. Stem and root C concentrations were higher than leaf C, while leaf N was higher than stem and root N. Phosphorus concentration and N/P did not differ among plant organs. Significant differences were found between root C/N and leaf C/N as well as between root C/P and leaf C/P. Leaf nutrient traits respond to geographic and climatic factors, while nutrient concentrations of stems and roots are mostly affected by soil P and pH. We show that stoichiometric patterns in different plant organs had different responses to environmental variables. Studies of species‐specific nutrient stoichiometry can help clarify plant–environment relationships and nutrient cycling patterns in desert ecosystems.
Heteroleptic Phenanthroline Complexes of Trinuclear Molybdenum Clusters with Luminescent Properties
Authors: Recatalá David , Llusar Rosa , Galindo Francisco , Brylev Konstantin A. , Gushchin Artem L. 
Published: March 2015

AbstractNeutral Mo3(μ3‐S)(μ‐S2)3X3(diimine) (X = Cl–, Br–) heteroleptic cluster complexes containing the 1,10‐phenanthroline ligands 1H‐imidazo[4,5‐f][1,10]phenanthroline‐2‐[3,4‐bis(dodecyloxy)phenyl] (IPDOP), 4,7‐diphenyl‐1,10‐phenanthroline (BPhen), and 3,4,7,8‐tetramethyl‐1,10‐phenanthroline (tmphen) were prepared in high yields by straightforward ligand‐substitution reactions starting from the [Mo3(μ3‐S)(μ‐S2)3X6]2– cluster anion. The complexes Mo3S7X4(BPhen) [X = Br– (for 3) and Cl– (for 4)] and Mo3S7X4(tmpphen) [X = Br– (for 5) and Cl– (for 6)] crystallized as tetra‐n‐butylammonium salts of anionic aggregates (3–6·X)–, in which neutral Mo3S7X3(diiimine)3 cluster molecules participate in non‐valence interactions between the axial sulfur atoms, Sax, and a halide anion. The complexes Mo3S7Br4(IPDOP) (1) and Mo3S7Cl4(IPDOP) (2) are luminescent when excited at 330 nm and have maximum emission intensities around 450 nm in DMF and around 435 nm in dichloromethane. The maximum fluorescence quantum yield and the maximum emission lifetime were achieved for complex 2 in DMF(φF = 0.15 and τ = 7.5 ns, respectively). The most important property of complexes 1 and 2 is the shift of their emission spectra in the presence of proton‐abstractor anions, such as F–, OH–, and AcO–. When these anions are added to solutions of complexes 1 or 2 in DMF or dichloromethane, the maximum emission wavelength shifts by approximately 90 nm to higher wavelengths.
PEPPSI‐Effect on Suzuki–Miyaura Reactions Using 4,5‐Dicyano‐1,3‐dimesitylimidazol‐2‐ylidene‐Palladium Complexes: A Comparison between trans‐Ligands
Authors: Baier Heiko , Kelling Alexandra , Holdt Hans‐Jürgen 
Published: March 2015

AbstractThe PEPPSI (Pyridine Enhanced Precatalyst Preparation, Stabilization and Initiation) complexes 12–15 with the structure [PdCl2{(CN)2IMes}(3‐R‐py)] (12: R = H; 13: R = Cl; 14: R = Br; 15: R = CN) bearing the maleonitrile‐based N‐heterocyclic carbene (NHC) (CN)2IMes ({(CN)2IMes}: 4,5‐dicyano‐1,3‐dimesitylimidazol‐2‐ylidene) were prepared. Solid state structures of 14 and 15 were obtained. Complexes 14 and 15 adopt a slightly distorted square‐planar coordination geometry in the solid state with the substituted pyridine ligand trans to the NHC. Catalytic activities of precatalysts 12–15 were studied and subsequently compared to complexes [PdCl2{(CN)2IMes}(PPh3)] (4) and [PdCl(dmba){(CN)2IMes}] (5) recently reported by our group in the Suzuki–Miyaura reaction of various aryl halides and phenylboronic acid. Reactions using previously reported [PdCl2(IMes)(py)] (IMes: 1,3‐dimesitylimidazol‐2‐ylidene) (1) were also carried out and their results contrasted to those involving 12–15, 4 and 5. Differences in initiation rates and the catalytically active species related to the seven complexes in regards to the “throw away ligand” were investigated. Poisoning experiments with mercury show that palladium nanoparticles are responsible for the catalytic activity.
Chiral Radical‐Cation Salts of BEDT‐TTF Containing a Single Enantiomer of Tris(oxalato)aluminate(III) and ‐chromate(III)
Authors: Martin Lee , Akutsu Hiroki , Horton Peter N. , Hursthouse Michael B. , Harrington Ross W. , Clegg William 
Published: March 2015

AbstractRadical‐cation salts of BEDT‐TTF with chiral anions provide the opportunity to combine chirality with conductivity in the same molecular material. We report here two salts, (BEDT‐TTF)3NaAl(C2O4)3·nitromethane and (BEDT‐TTF)3(NH4)0.83Cr1.17(C2O4)3·nitromethane. The former crystallises in space group P21 and the latter in P212121. The use of nitromethane alone as the electrolyte for electrocrystallisation produces no crystals, but the addition of chiral (R)‐(–)‐carvone yields crystals of these two new chiral radical‐cation salts of BEDT‐TTF through chiral induction from racemic tris(oxalato)aluminate(III) and tris(oxalato)chromate starting materials. The honeycomb anion layers in these salts contain a single enantiomer of tris(oxalato)metallate and creates hexagonal cavities that are smaller than those found in the superconducting β″ salts in this tris(oxalate)metallate family, which gives preference for smaller solvents to be included, such as nitromethane. The chromium salt has a non‐stoichiometric composition of the anion layer, which provides an electron doping effect to the donor layer.
Samarium Diiodide Mediated Coupling of 2‐Pyridylsulfonyl Furanosides with Aldehydes and Ketones: A General Synthesis of C‐Furanosides
Authors: Wang Jin , Gasc Fabien , Prandi Jacques 
Published: March 2015

AbstractDiiodosamarium‐mediated coupling of anomeric 2‐pyridyl sulfones derived from furanosides with carbonyl compounds, aldehydes, and ketones gave α‐hydroxylated 2,5‐trans‐dialkylated tetrahydrofurans with good yields and useful stereoselectivities. The main control element of the reaction is the substituent on the 4‐position or the starting furanosyl sulfone. C‐Furanosides of D‐arabinose and of D‐ribose were obtained from sulfones prepared from the corresponding furanosides. Finally, a di‐C‐arabinofuranoside, a C‐disaccharide analogue of a major motif of the arabinogalactan from the mycobacterial cell wall, was prepared.
Reactions of Alkynyl‐ and 1,1′‐Dialkynylferrocenes with Tetracyanoethylene – Unanticipated Addition at the Less Electron‐Rich of Two Triple Bonds
Authors: Krauße Nico , Kielmann Marc , Ma Jingxiang , Butenschön Holger 
Published: March 2015

AbstractAlkynylferrocenes react with tetracyanoethylene (TCNE) to form 2‐ferrocenyl‐1,1,4,4‐tetracyanobutadienes. These reactions occur under mild reaction conditions in almost quantitative yields if the triple bond is electron‐rich. Systems with more than one triple bond, namely, 1,1′‐dialkynylferrocenes or diynylferrocenes, react once at the more electron‐rich triple bond, and the second reaction cannot be achieved, even under more‐forcing reaction conditions. For a diyne with the reactivity switched by oxidation of the ferrocenyl moiety to the corresponding ferrocenium salt, the addition of TCNE occurred at the less electron‐rich triple bond. This unprecedented reactivity is explained by the resonance stabilization of a diradical intermediate. A push–pull 1,1′‐dialkynylferrocene with a [4‐(dimethylamino)phenyl]ethynyl and a (4‐nitrophenyl)ethynyl substituent reacted exclusively at the [4‐(dimethylamino)phenyl]ethynyl triple bond.
Palladium‐Catalyzed Amination of Aryl Sulfides with Aliphatic Amines
Authors: Gao Ke , Yorimitsu Hideki , Osuka Atsuhiro 
Published: March 2015

AbstractConditions for the palladium–NHC‐catalyzed amination of aryl sulfides with aliphatic as well as aromatic amines were established. The KHMDS‐mediated amination of heteroaryl sulfides could proceed without palladium. Based on the distinct difference in reactivity of C–Br and C–S bonds, a sequential amination of bromothioanisole can take place to install two different alkylamino groups onto the aromatic ring in one pot.
HIV‐related stigma in social interactions: Approach and avoidance behaviour in a virtual environment
Authors: Toppenberg Henna L. , Bos Arjan E. R. , Ruiter Robert A. C. , Wigboldus Daniël H. J. , Pryor John B. 
Published: March 2015

AbstractPeople living with HIV are a stigmatized group in our society, especially homosexual people living with HIV. One of the behavioural manifestations of stigmatization is an increased interpersonal distance kept during social interactions. Immersive virtual environment technology enables the experimental study of social interactions in an accurate and relatively unobtrusive manner. Using a virtual hospital room, we measured to what extent diagnosis (HIV, cancer or broken leg) and sexual orientation (homosexual or heterosexual) were related to approach behaviour (based on the interpersonal distance and the speed of approach), and the degree patients were looked at (as was obtained from an additional exploration of our head orientation data). Moreover, implicit and explicit attitudes were predicted to moderate this relationship. Participants (N = 50) were healthy, heterosexual students. A main effect of diagnosis revealed larger interpersonal distances from patients with HIV than from patients with cancer. Also, an interaction effect demonstrated that distances were largest when the HIV patient was homosexual. Furthermore, a main effect of diagnosis showed that HIV and cancer patients were approached more slowly than broken leg patients, an effect that was larger for HIV than for cancer patients. In addition, head orientation analyses revealed that patients with HIV were relatively ‘looked at’ more often as well as relatively ‘looked away from’ less often than patients with cancer and patients with a broken leg. None of these effects however were found to be moderated by implicit and explicit attitudes. These findings provide behavioural evidence for the stigmatization of people living with HIV and homosexuals with HIV in particular. Copyright © 2015 John Wiley & Sons, Ltd.
Scanning Electrochemical Microscopy Applied to the Investigation of Lithium (De‐)Insertion in TiO2
Authors: Zampardi Giorgia , Ventosa Edgar , La Mantia Fabio , Schuhmann Wolfgang 
Published: March 2015

AbstractThe electrochemical insertion of lithium ions in anatase TiO2 nanoparticles was investigated by scanning electrochemical microscopy in the feedback mode of operation using ferrocene as reporting redox couple at different potentials in presence and absence of lithium ions. By fixing the position of the tip while performing cyclic voltammetry at the TiO2 paste electrode, the formation of the solid electrolyte interphase (SEI) on the surface of titania was followed in situ. Different scan rates have been used to study the kinetics of SEI formation.
Electron Transfer Rates in an Adsorbed C60‐Porphyrin Dyad
Authors: Fortgang Philippe , Urbani Maxence , Holler Michel , Nierengarten Jean‐François , Moreau Alain , Delavaux‐Nicot Béatrice , Maisonhaute Emmanuel 
Published: March 2015

AbstractAssociation of C60 and porphyrin entities to build light harvesting systems is a promising alternative for future photovoltaic devices. Herein, we determine the electron transfer rates in a C60‐porphyrin dyad anchored onto a gold ultramicroelectrode via the porphyrin core. Similar rates are observed for both redox entities, suggesting a tilt of the molecules allowing an efficient through‐space communication between C60 and the electrode.
The Mechanism of Mediated Electron Transfer at Redox Active Surfaces
Authors: Lyons Michael E. G. 
Published: March 2015

AbstractTheoretical models describing transport and kinetic processes involved in heterogeneous redox catalysis of solution phase reactants at RDE surfaces modified with catalytically active layers are presented. Model A regards the interaction between the surface immobilized redox active mediator and substrate being described in terms of bimolecular reaction kinetics. Model B assumes the interaction involves the formation of an adduct. Both consider the processes of heterogeneous electron transfer between immobilized mediator and support electrode, chemical reaction between redox mediator/reactant, and reactant diffusive mass transport, and expressions for the net reaction flux are derived. Kinetic case diagrams are constructed.
Electrohydrodynamically Printed, Flexible Energy Harvester Using In Situ Poled Piezoelectric Nanofibers
Authors: Ding Yajiang , Duan Yongqing , Huang YongAn 
Published: March 2015

AbstractThis article presents the fabrication of electrohydrodynamically printed energy harvesters based on piezoelectric polyvinylidene fluoride (PVDF) nanofibers. PVDF nanofibers with β phase formation are fabricated by mechano‐electrospinning to realize in situ electric poling and mechanical stretching. By directly depositing the poled nanofibers onto flexible or prestrained elastomeric substrates, bendable or stretchable energy harvesters with high efficiency were fabricated. The flexible energy harvesters generate electricity under bending, stretching, and compression, and the generated current is characterized by a linear ratio to the stretching frequency/strain as well as the number of fibers. Additionally, the vertical pressure enables the stretchable energy harvesters with in‐surface buckled fibers to generate electricity stably even if the harvesters exist in different stretching statuses. The printed energy harvesters pave the way for a cost‐effective, high‐efficiency manufacturing pathway in wearable, bio‐integrated electronics with large deformability.
Room Temperature Ionic Liquid‐based Electrolytes as an Alternative to Carbonate‐based Electrolytes
Authors: Yim Taeeun , Kwon Mi‐Sook , Mun Junyoung , Lee Kyu Tae 
Published: March 2015

AbstractThe issue of the safety of Li‐ion batteries is becoming more critical with the increase in their size for applications in large energy storage devices, such as hybrid electric vehicles (HEVs), and energy storage systems (ESSs) for smart grids. The thermal runaway of Li‐ion batteries is considered to be caused by their flammable components, such as the volatile carbonate solvents of electrolytes. Room temperature ionic liquids (RTILs) have recently received much attention because of their characteristics of non‐flammability and non‐volatility. In addition, RTILs show high ionic conductivity and a wide electrochemical stability window. Therefore, RTIL‐based electrolytes are considered one of the most promising candidates to improve the safety of Na‐ion, as well as Li‐ion batteries; indeed, RTIL‐based electrolytes have shown excellent improvements in terms of thermal stability and electrochemical performance. This review provides a comprehensive overview of selected RTIL materials, including their physicochemical and electrochemical properties. Moreover, we discuss the failure mechanisms of certain RTIL‐based electrolytes with various electrodes to suggest alternative strategies for improving their electrochemical performance.
Potential of biofluid components to modify silver nanoparticle toxicity
Authors: Murphy Anna , Sheehy Kate , Casey Alan , Chambers Gordon 
Published: March 2015

AbstractEstablishing realistic exposure scenarios is critical for cytotoxic investigation of silver nanoparticles (AgNP) in the gastrointestinal tract. This study investigated the potential interaction with and effect of biofluid components, namely cholic acid, deoxycholic acid and ursodeoxycholic acid, on AgNP toxicity. Two cell lines corresponding to organs related to the biofluid components were employed. These were HepG‐2 a hepatocellular carcinoma derived from liver tissue and Hep2 an epithelial cell line. Physiochemical and cytotoxic screening was performed and the ability of biofluid components to modify AgNP cytotoxicity was explored. No alteration to the physiochemical characteristics of AgNP by biofluid components was demonstrated. However, biofluid component addition resulted in alteration of AgNP toxicity. Greater reactive oxygen species induction was noted in the presence of cholic acid and deoxycholic acid. Ursodeoxycholic acid demonstrated no modification of toxicity in HepG‐2 cells; however, significant modification was noted in Hep2 cells. It is concluded that biofluid components can modify AgNP toxicity but this is dependent on the biofluid component itself and the location where it acts. Copyright © 2015 John Wiley & Sons, Ltd.
Fluorescence life‐time imaging and steady state polarization for examining binding of fluorophores to gold nanoparticles
Authors: Schwartz Shmulik , Fixler Dror , Popovtzer Rachela , Shefi Orit 
Published: March 2015

Nanocomposites as multifunctional agents are capable of combing imaging and cell biology technologies. The conventional methods used for validation of the conjugation process of nanoparticles (NPs) to fluorescent molecules such as spectroscopy analysis and surface potential measurements, are not sufficient. In this paper we present a new and highly sensitive procedure that uses the combination of (1) fluorescence spectrum, (2) fluorescence lifetime, and (3) steady state fluorescence polarization measurements. We characterize and analyze gold NPs with Lucifer yellow (LY) surface coating as a model. We demonstrate the ability to differentiate between LY‐GNP (the conjugated complex) and a mixture of coated NP and free dyes. We suggest the approach for neuroscience applications where LY is used for detecting and labeling cells, studying morphology and intracellular communications.
Histograms of Fluorescence lifetime imaging (FLIM) of free LY dye (Left) in comparison to the conjugated dye to gold nanoparticles, LY‐GNP (Middle) enable the differentiation between LY‐GNP (the conjugated complex) and a mixture of coated NP and free dyes (Right).magnified imageHistograms of Fluorescence lifetime imaging (FLIM) of free LY dye (Left) in comparison to the conjugated dye to gold nanoparticles, LY‐GNP (Middle) enable the differentiation between LY‐GNP (the conjugated complex) and a mixture of coated NP and free dyes (Right).