bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical structure‐switching sensing using nanoplasmonic devices
Authors: Patskovsky Sergiy , Dallaire Anne‐Marie , Blanchard‐Dionne Andre‐Pierre , Vallée‐Bélisle Alexis , Meunier Michel 
Published: October 2015

In this article, the implementation of electrochemical plasmonic nanostructures functionalized with DNA‐based structure‐switching sensors is presented. eNanoSPR devices with open and microfluidic measurement cells are developed on the base of nanohole arrays in 100 nm gold film and applied for combined microscopic and electrochemical surface plasmon (eSPR) visualization. eSPR voltammograms and spectroscopy are performed using planar three electrode schematic with plasmonic nanostructure operated as working electrode. Limit of detection of eNanoSPR devices for oligonucleotide hybridization is estimated in the low nanomolar and applications for structure‐switching electro‐plasmonic sensing in complex liquids are discussed.
Methyl‐, Ethenyl‐, and Ethynyl‐Bridged Cationic Digold Complexes Stabilized by Coordination to a Bulky Terphenylphosphine Ligand
Authors: Espada María F. , Campos Jesús , López‐Serrano Joaquín , Poveda Manuel L. , Carmona Ernesto 
Published: October 2015

AbstractReactions of the gold(I) triflimide complex [Au(NTf2)(PMe2Ar${{^{{\rm Dipp}{_{2}}}}}$)] (1) with the gold(I) hydrocarbyl species [AuR(PMe2Ar${{^{{\rm Dipp}{_{2}}}}}$)] (2 a–2 c) enable the isolation of hydrocarbyl‐bridged cationic digold complexes with the general composition [Au2(μ‐R)(PMe2Ar${{^{{\rm Dipp}{_{2}}}}}$)2][NTf2], where Ar${{^{{\rm Dipp}{_{2}}}}}$=C6H3‐2,6‐(C6H3‐2,6‐iPr2)2 and R=Me (3), CHCH2 (4), or CCH (5). Compound 3 is the first alkyl‐bridged digold complex to be reported and features a symmetric [Au(μ‐CH3)Au]+ core. Complexes 4 and 5 are the first species of their kind that contain simple, unsubstituted vinyl and acetylide units, respectively. In the series of complexes 3–5, the bridging carbon atom systematically changes its hybridization from sp3 to sp2 and sp. Concomitant with this change, and owing to variations in the nature of the bonding within the [Au(μ‐R)Au]+ unit, there is a gradual decrease in aurophilicity, that is, the strength of the Au⋅⋅⋅Au bonding interaction decreases. This change is illustrated by a monotonic increase in the Au–Au distance by approximately 0.3 Å from R=CH3 (2.71 Å) to CHCH2 (3.07 Å) and CCH (3.31 Å).
Confinement of Ionic Liquids in Nanocages: Tailoring the Molecular Sieving Properties of ZIF‐8 for Membrane‐Based CO2 Capture
Authors: Ban Yujie , Li Zhengjie , Li Yanshuo , Peng Yuan , Jin Hua , Jiao Wenmei , Guo Ang , Wang Po , Yang Qingyuan , Zhong Chongli , Yang Weishen 
Published: October 2015

AbstractFine‐tuning of effective pore size of microporous materials is necessary to achieve precise molecular sieving properties. Herein, we demonstrate that room temperature ionic liquids can be used as cavity occupants for modification of the microenvironment of MOF nanocages. Targeting CO2 capture applications, we tailored the effective cage size of ZIF‐8 to be between CO2 and N2 by confining an imidazolium‐based ionic liquid [bmim][Tf2N] into ZIF‐8’s SOD cages by in‐situ ionothermal synthesis. Mixed matrix membranes derived from ionic liquid‐modified ZIF‐8 exhibited remarkable combinations of permeability and selectivity that transcend the upper bound of polymer membranes for CO2/N2 and CO2/CH4 separation. We observed an unusual response of the membranes to varying pressure, that is, an increase in the CO2/CH4 separation factor with pressure, which is highly desirable for practical applications in natural gas upgrading.
Experimental and theoretical investigation of sound transmission loss for polycarbonate, poly(methyl methacrylate), and glass
Authors: Sabet Seyed Mohammad , Ohadi Abdolreza 
Published: October 2015

ABSTRACTIn this study, the effects of the soundproofing properties of polycarbonate (PC), poly(methyl methacrylate) (PMMA), and glass were investigated. We fabricated the specimens into 3 mm thick sheets by direct hot compression molding as a monolithic sample and also by gluing three thin sheets together into a multilayer. Sound transmission loss (STL) was measured by an impedance tube over the frequency range 63–1600 Hz. The results indicate that because of the close density, the STLs for PC and PMMA were almost the same above 1200 Hz. Also, PMMA had a greater STL than PC in the range 63–300 Hz. In a comparison of the monolithic and multilayered samples, we demonstrated that the epoxy‐based adhesive interlayers had more efficient bonding than the silicone‐based ones. The multilayered polymer/silicone specimens showed a sharp drop in the STL values compared to the monolithic samples. However, the multilayered polymer/epoxy specimens revealed similar behavior to the monolithic polymers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42988.
Effect of double percolation on the electrical properties and electromagnetic interference shielding effectiveness of carbon‐black‐loaded polystyrene/ethylene vinyl acetate copolymer blends
Authors: Soares Bluma G. , Touchaleaume François , Calheiros Loan F. , Barra Guilherme M. O. 
Published: October 2015

ABSTRACTIn this study, the concept of double percolation and selective location of a conducting additive was used to develop conducting polymer composites composed of polystyrene (PS) and ethylene vinyl acetate copolymer (EVA) filled with carbon black (CB). Scanning and transmission electron microscopy suggested that the CB was preferentially located in the EVA phase. By combining a cocontinuous morphology and selective location of CB in the EVA phase, we achieved the highest conductivity values and better electromagnetic interference shielding effectiveness in the X‐band frequency range for the 70:30 w/w PS/EVA blend. Electromagnetic attenuation occurred by both reflection and absorption mechanisms, although the first was predominant for composites with a higher amount of CB. The percolation thresholds of the PS, EVA, and 70:30 w/w PS/EVA blend loaded with CB were estimated from the dependence of the alternating‐current and direct‐current conductivities. The rheological properties were also used to relate the electrical behavior to the microstructure of the composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43013.
Amidoximated poly(acrylonitrile) particles for environmental applications: Removal of heavy metal ions, dyes, and herbicides from water with different sources
Authors: Ajmal Muhammad , Demirci Sahin , Siddiq Mohammad , Aktas Nahit , Sahiner Nurettin 
Published: October 2015

ABSTRACTMonodispersed poly(acrylonitrile) [p(AN)] particles were prepared by surfactant free emulsion polymerization and the hydrophobic nitrile groups were converted to hydrophilic amidoxime groups by treatment with hydroxylamine hydrochloride (NH2OH.HCl) in water. The p(AN) and amidoximated p(AN) [amid‐p(AN)] particles were characterized by Fourier transformation infrared (FT‐IR) spectroscopy, thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM). The prepared particles were used as adsorbents in the removal from aqueous media of three different types of pollutants; organic dyes methylene blue (MB), and rhodamine 6 G (R6G), a heavy metal ion Cd (II), and a herbicide paraquat (PQ). The effects of various parameters such as amidoximation, pH of solution, amount of particles, and the initial concentration of solution were investigated. Upon amidoximation, a great increase in the adsorption capacity of the prepared particles was observed as the adsorbed amounts were increased to 87, 91, 74, and 91 mg/g from 5, 1.54, 1.06, and 1.22 mg/g for Cd (II), MB, R6G, and PQ, respectively. The amid‐p(AN) particles were also able to remove considerable amounts of these pollutants from tap, river, and sea water. Langmuir, Freundlich, and Temkin adsorption isotherms were applied and it was found that the adsorption of Cd (II) and PQ followed the Langmuir adsorption model, whereas the adsorption of MB was found to obey the Freundlich adsorption isotherm. Pseudo first‐order and pseudo second‐order kinetics were also applied and the results showed that the adsorption processes of Cd (II), PQ, MB, and R6G follow pseudo second‐order kinetics. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43032.
An ambipolar polymer additive for enhanced open circuit voltage in a bulk heterojunction solar cells
Authors: Khan Mahmood Alam , Kang Yong Mook 
Published: October 2015

ABSTRACTOpen circuit voltage (VOC) of organic bulk heterojunction solar cell is extended by the addition of a 20 wt % of F8TBT, an ambipolar polymer in the active layer matrixes (P3HT:PCBM) and then spin casted (1000 rpm/30 s) in the optimized devices on the PEDOT:PSS layer of the ITO glass. A substantial increase in the open circuit voltage from approximately 0.61–0.88 V (44.26%) has been observed with slight increase in efficiency up to 1.91% in the fabricated devices. However, further increment of F8TBT content to 40 wt % reduces the photovoltaic efficiency and affects the JSC values remarkably, possibly due the excess amount of resistance developed. The enhancement of VOC is attributed to the ambipolar nature of F8TBT polymer which facilitates the generated electron and hole transfer at the respective electrodes, enhanced π–π* conjugation in polymer matrix, a superior nanoscale separation, and better molecular conformation at the film interface, thus giving an ample opportunities to explore the impact of blending of materials rather than depositing a thin buffer layer by expensive vapor phase technologies. The details of electrical and microstructure characterization of the film were analyzed by AFM, SEM, UV–Vis, J–V characteristics, and EQE techniques. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43042.
Formation, antimicrobial activity, and controlled release from cotton fibers with deposited functional polymers
Authors: Kim Suyeon , Nakamatsu Javier , Maurtua Dora , Oliveira Fernando 
Published: October 2015

ABSTRACTChitosan and alginate are biopolymers with interesting bioactivity that can be transferred to cotton fibers for medical and health care applications. These polymers in solution can be attached onto cotton fibers by a layer‐by‐layer technique. Confirmation of polymer deposition onto fibers was verified by morphology analysis, coomassie blue dye coloration, and contact angle of water on fibers. Also, weight gain and level of whiteness after each layer deposition were determined. Antimicrobial activity on treated cotton samples against E. coli and S. aureus was evaluated after each layer deposition and high inhibition rate of bacteria growth was observed in samples with chitosan outer layer (∼ 100%). Polyelectrolyte layers on cotton fibers not only provide interesting bioactivity by themselves, but can also serve as a matrix for small bioactive molecules. In this regard, a model molecule was added during sample preparation to study its release behaviors in a buffer solution by monitoring with UV–vis spectroscopy. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43054.
Pedagogical view of model metabolic cycles
Authors: García‐Herrero Victor , Sillero Antonio 
Published: October 2015

AbstractThe main purpose of this study was to present a simplified view of model metabolic cycles. Although the models have been elaborated with the Mathematica Program, and using a system of differential equations, the main conclusions were presented in a rather intuitive way, easily understandable by students of general courses of Biochemistry, and without any need of mathematical support. A change in any kinetic constant (Km or Vmax) of only one enzyme affected the metabolic profile of all the substrates of the cycle. In addition, it is shown how an increase in the Km or a decrease in the Vmax values of any particular enzyme promoted an increase of its substrate; the contrary occurred decreasing the Km or increasing the Vmax values. © 2015 by The International Union of Biochemistry and Molecular Biology, 43:468–475, 2015.
Adsorptive Separation of Acetylene from Light Hydrocarbons by Mesoporous Iron Trimesate MIL‐100(Fe)
Authors: Yoon Ji Woong , Lee Ji Sun , Lee Sukyung , Cho Kyoung Ho , Hwang Young Kyu , Daturi Marco , Jun Chul‐Ho , Krishna Rajamani , Chang Jong‐San 
Published: October 2015

AbstractA reducible metal–organic framework (MOF), iron(III) trimesate, denoted as MIL‐100(Fe), was investigated for the separation and purification of methane/ethane/ethylene/acetylene and an acetylene/CO2 mixtures by using sorption isotherms, breakthrough experiments, ideal adsorbed solution theory (IAST) calculations, and IR spectroscopic analysis. The MIL‐100(Fe) showed high adsorption selectivity not only for acetylene and ethylene over methane and ethane, but also for acetylene over CO2. The separation and purification of acetylene over ethylene was also possible for MIL‐100(Fe) activated at 423 K. According to the data obtained from operando IR spectroscopy, the unsaturated FeIII sites and surface OH groups are mainly responsible for the successful separation of the acetylene/ethylene mixture, whereas the unsaturated FeII sites have a detrimental effect on both separation and purification. The potential of MIL‐100(Fe) for the separation of a mixture of C2H2/CO2 was also examined by using the IAST calculations and transient breakthrough simulations. Comparing the IAST selectivity calculations of C2H2/CO2 for four MOFs selected from the literature, the selectivity with MIL‐100(Fe) was higher than those of CuBTC, ZJU‐60a, and PCP‐33, but lower than that of HOF‐3.
Microwave‐Assisted Organocatalyzed Rearrangement of Propargyl Vinyl Ethers to Salicylaldehyde Derivatives: An Experimental and Theoretical Study
Authors: Tejedor David , Cotos Leandro , Márquez‐Arce Daniel , Odriozola‐Gimeno Mikel , Torrent‐Sucarrat Miquel , Cossío Fernando P. , García‐Tellado Fernando 
Published: October 2015

AbstractThe microwave‐assisted imidazole‐catalyzed transformation of propargyl vinyl ethers (PVEs) into multisubstituted salicylaldehydes is described. The reaction is instrumentally simple, scalable, and tolerates a diverse degree of substitution at the propargylic position of the starting PVE. The generated salicylaldehyde motifs incorporate a broad range of topologies, spanning from simple aromatic monocycles to complex fused polycyclic systems. The reaction is highly regioselective and takes place under symmetry‐breaking conditions. The preparative power of this reaction was demonstrated in the first total synthesis of morintrifolin B, a benzophenone metabolite isolated from the small tree Morinda citrifolia L. A DFT study of the reaction was performed with full agreement between calculated values and experimental results. The theoretically calculated values support a domino mechanism comprising a propargyl Claisen rearrangement, a [1,3]‐H shift, a [1,7]‐H shift (enolization), a 6π electrocyclization, and an aromatization reaction.
Gold(I)‐Catalyzed Dearomative [2+2]‐Cycloaddition of Indoles with Activated Allenes: A Combined Experimental–Computational Study
Authors: Ocello Riccardo , De Nisi Assunta , Jia Minqiang , Yang Qing‐Qing , Monari Magda , Giacinto Pietro , Bottoni Andrea , Miscione Gian Pietro , Bandini Marco 
Published: October 2015

AbstractThe gold‐catalyzed synthesis of methylidene 2,3‐cyclobutane‐indoles is documented through a combined experimental/computational investigation. Besides optimizing the racemic synthesis of the tricyclic indole compounds, the enantioselective variant is presented to its full extent. In particular, the scope of the reaction encompasses both aryloxyallenes and allenamides as electrophilic partners providing high yields and excellent stereochemical controls in the desired cycloadducts. The computational (DFT) investigation has fully elucidated the reaction mechanism providing clear evidence for a two‐step reaction. Two parallel reaction pathways explain the regioisomeric products obtained under kinetic and thermodynamic conditions. In both cases, the dearomative CC bond‐forming event turned out to be the rate‐determining step.
Relayed Regioselective Alkynylation/Olefination of Unsymmetrical Cyclic Diaryliodonium Species Catalyzed by Cu and Pd: Affording Fluorescent Cytotoxic Benzoxazoles
Authors: Zhu Daqian , Liu Panpan , Lu Wenhua , Wang Haiwen , Luo Bingling , Hu Yumin , Huang Peng , Wen Shijun 
Published: October 2015

AbstractAlthough cyclic diaryliodonium species have the potential to act as valuable synthons for cascade transformations, they still remain largely unexplored. The regioselectivity associated with unsymmetrical cyclic diaryliodonium species has previously been known to pose a challenge. A regioselective relayed alkynylation and olefination of unsymmetrical cyclic diaryliodonium species has been achieved by installation of a directing amido group. These relayed transformations were delayed until an oxazole ring had formed, delivering a series of unique fluorescent benzoxazoles. Moreover, some of these synthetic benzoxazoles showed apparent inhibitory activity against malignant cancer cells. Further confocal visualization revealed that benzoxazoles targeted cell nuclei. These findings might provide a novel structural scaffold to develop desirable anticancer agents.
Seasonal changes in pollen limitation and femaleness along the snowmelt gradient in a distylous alpine herb,Primula modesta
Authors: Kameyama Yoshiaki , Watanabe Manami , Kurosawa Hideki , Nishimori Takuya , Matsue Daisuke , Takyu Masaaki 
Published: October 2015

AbstractFlowering phenology of alpine plants is strongly determined by the timing of snowmelt, and the conditions of pollination of widely distributed plants vary greatly during their flowering season. We examined the reproductive success of the distylous alpine herb,Primula modesta, along the snowmelt gradient under natural conditions, and compared it with the result of artificial pollination experiments. In addition, the compositions and visit frequencies of pollinators to the flower ofP. modestawere examined during the flowering period. The pin and thrum plants ofP. modestagrowing at the same site have an equal ability to produce seeds if a sufficient amount of legitimate pollen grains are deposited on the stigma surface. However, under natural conditions, their seed‐set success was often (even if not always) restricted by pollen limitation, and the functional gender of the pin and thrum plants biased to the female and male, respectively, associated with their growing sites. These variations were not ascribed to resource limitation nor biased morph ratio but to the seasonal changes in pollination situations, a replacement of pollinator types from long‐ to short‐tongued pollinators resulted in unidirectional pollen transfer from long stamens (thrum plants) to long styles (pin plants). The functional gender specialization may enhance the evolution of dioecy from heterostyly, but the severe pollen limitation may cause the breakdown of heterostyly into homostyly. To consider the evolutionary pathway of heterostylous plants, an accumulation of the empirical data is required demonstrating how phenological synchrony between plants and pollinators is decided and to what degree this relationship is stable over years, along with estimates of selection and gene flow in individual plants.
The concrete evidence of flexistyly in Plagiostachys: pollination biology of a wild ginger on Hainan Island, China
Authors: Jia Xiao‐Cheng , Li Jia , Lu Guo‐Hui , Wang Ying‐Qiang 
Published: October 2015

AbstractFlexistyly in Plagiostachys was first reported by Takano et al., while they provided no detailed study on pollination biology and breeding system. In this study, we tested this suspicion in one species of Plagiostachys (Plagiostachys austrosinensis). Field observations suggested that flexistyly was present in this species, and stigmatic behavior was similar to that reported for Alpinia and Amomum species. Two phenotypes (anaflexistylous and cataflexistylous) occurred in a ratio of 1:1 in natural populations. Anthesis began around 1530–1600 h and lasted for about 24 h. Pollen viability and stigma receptivity remained high throughout the flowering process. Mean nectar volume (4.15–11.30 μL) and mean sugar concentration (>32%) also remained at a high level during the flowering process. No fruit set occurred in unpollinated bagged plants. Two pollinators (Bombus pyrosoma and Vespidae spp.) and one pollen robber (Mutillidae spp.) were found as flower visitors. Fruit set following self‐pollination and cross‐pollination did not differ significantly in the cataflexistylous morph. Partial self‐incompatibility was apparent in the anaflexistylous morph. These results provide the concrete evidence of flexistyly in Plagiostachys and a more thorough understanding of its evolutionary origin in gingers.
ECG as a first step in the detection of left ventricular systolic dysfunction in the elderly
Authors: Olesen Line Lisbeth , Andersen Andreas 
Published: October 2015

AbstractAimsDue to the demographic development there is an increasing number of senior citizens with left ventricular systolic dysfunction (LVSD), defined as ejection fraction (EF) < 40%. Unfortunately there are under‐diagnosis and under‐treatment in the elderly of this serious condition. Echocardiography is the gold standard to diagnose LVSD, but access is limited. Simple screening methods may ensure reduction of undetected cases, and this study investigates if electrocardiogram (ECG) can be used to screen for LVSD in the geriatric population.Methods and resultsA total of 260 persons aged 75 to 92 years had an echocardiography, a 12 leads ECG, and NT‐proBNP; 61 had EF < 40%, and of these 60 had an abnormal ECG. EF < 40% was significantly related to atrial fibrillation (A), pacing (P), LBBB (L), Q‐waves (Q), and QRS duration ≥ 120 ms (D). EF < 40%, atrial fibrillation, pacing, and LBBB were related to NT‐proBNP > 35 pmol/L. When APL was absent, NT‐proBNP had discriminatory value regarding LVSD in the presence of Q‐waves or QRS duration > 120 ms. Algorithms to screen for LVSD had sensitivity >90% and specificity >80% and claimed at least one of five (A/P/L/Q/D), one of 4 (A/P/L/Q), or one of three (A/Q/D) ECG changes. The optimal algorithm to reduce the need for diagnostic echocardiographies included four (A/P/L/Q) ECG changes and measurement of NT‐proBNP when Q‐waves were the only ECG change present.ConclusionsNinety percent of LVSD may be detected, and when there is atrial fibrillation, pacing or LBBB, or QRS ≥ 120 ms/Q‐waves and NT‐proBNP>35 pmol/L, a diagnostic echocardiography should be considered.