bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regiocontrolled Gold‐Catalyzed [2+2+2] Cycloadditions of Ynamides with Two Discrete Nitriles to Construct 4‐Aminopyrimidine Cores
Authors: Karad Somnath Narayan , Liu Rai‐Shung 
Published: July 2014

AbstractReported herein is the novel gold‐catalyzed intermolecular [2+2+2] cycloaddition of ynamides with two discrete nitriles to form monomeric 4‐aminopyrimidines, which are pharmaceutically important structural motifs. The utility of this new cycloaddition is demonstrated by the excellent regioselectivity obtained using a variety of ynamides and nitriles.
Polyaniline salts as polymer‐based solid acid catalyst for low molecular weight poly(lactic acid)
Authors: Rajender Boddula , Palaniappan Srinivasan 
Published: July 2014

ABSTRACTPolymer‐based solid acid catalyst, polyaniline (PANI) salt, is used for the first time to synthesize polymer. In continuation of our work to synthesize organic chemicals using PANI‐based solid acid catalyst, in this work, polylactic acid is synthesized by the condensation polymerization of lactic acid using PANI salts. PANI salts are characterized by FTIR, FE‐SEM, and TGA analyses. Polymerization of lactic acid in xylene solvent at 140°C for 24 h with the use of very low amount of PANI catalysts gave polylactic acid (PLLA) in the order: PANI‐MSA (46%) > PANI‐TFA (33%) > PANI‐Bi(OTf)3 (27%) > PANI‐Cu(OTf)2 (20%) > PANI‐Yb(OTf)3 (15%). Molecular weights of PLLA synthesized using PANI‐MSA and PANI‐TFA are found to be 4385 and 4830, respectively. This methodology gives highly crystalline polymer with mushroom cap‐like morphology. Advantage of this methodology is the use of easily synthesizable, recyclable, easily handlable, cheaper, and eco‐friendly nature of the catalyst. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41147.
Competitive adsorption of acid dyes from aqueous solution on diethylenetriamine‐modified chitosan beads
Authors: Yan Yikai , Xiang Bo , Yi Xiaowei , Li Yijiu , Jia Qian 
Published: July 2014

ABSTRACTThe interaction between two dyes (AO7 and AG25) during adsorption was studied in detail with diethylenetriamine‐modified chitosan beads (CTSN‐beads) as the adsorbent. Results indicate that the adsorption capacities and rates were directly related to the molecular size of the dye. The adsorption capacity and rate of AO7 could be greatly weakened by interaction with AG 25 during adsorption, which has a larger molecular size. The adsorption followed the pseudo‐second‐order kinetic equation and Freundlich model gave a satisfying correlation with the equilibrium data both in the single and binary component system. Adsorption could be divided into three stages, each controlled by different mechanisms. Temperature experiments showed high temperature was beneficial to the mass transfer of dyes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41168.
Signal crayfish (Pacifastacus leniusculus) predation upon Atlantic salmon (Salmo salar) eggs
Authors: Findlay John D. S. , Riley William D. , Lucas Martyn C. 
Published: July 2014

Abstract

The signal crayfish (Pacifastacus leniusculus) is a large, polytrophic crustacean which has invaded waterways across much of Europe. Crayfish prey on the eggs of several fish species and egg predation, especially by invasive crayfish, is cited as a likely cause of population decline and a serious concern for the conservation of some fish species including at least one salmonid.
Numerically, crayfish populations may be dominated by small individuals, but most studies have investigated egg predation by large crayfish. Evidence for crayfish gaining access to buried fish eggs is equivocal.
The ability of signal crayfish of a range of age groups (and hence, sizes) to prey on unburied and buried Atlantic salmon (Salmo salar) eggs was investigated in laboratory experiments.
Only Age 2+ and older crayfish (24–43 mm carapace length (CL)) significantly reduced egg survival in unburied egg experiments, although some evidence of egg predation was observed with Age 1+ crayfish (16–22 mm CL). Age 0+ crayfish (8–14 mm CL) did not prey on salmon eggs. No evidence of substantial excavations or predation upon buried eggs by crayfish of any size class was observed. Binomial logistic regression of egg survival against crayfish CL indicated that mean egg recovery fell below control levels when CL exceeded 16.3 mm.
These results suggest that large signal crayfish are likely to pose the greatest threat to salmonid eggs, but that crayfish larger than 16.3 mm CL have the potential to prey on eggs.
Further research is needed before manual removal or harvesting of signal crayfish are used as conservation measures for Atlantic salmon spawning areas in which signal crayfish occur. Restoration of high‐quality salmonid spawning habitat might, however, help to prevent signal crayfish predation of salmonid eggs in addition to broader benefits for salmonid conservation. © 2014 Crown copyright. Aquatic Conservation: Marine and Freshwater Ecosystems © 2014 John Wiley & Sons, Ltd.
Projections of the impacts of gear‐modification on the recovery of fish catches and ecosystem function in an impoverished fishery
Authors: Condy Michelle , Cinner Joshua E. , McClanahan Tim R. , Bellwood David R. 
Published: July 2014

ABSTRACT

The regulation of fishing gear is a widely accepted fisheries management solution that requires further research to improve the chances of achieving sustainable yields, maintaining ecological integrity, and assisting fishers to escape from poverty. Fishing traps are a good candidate for modification because they are used widely, represent one of the most profitable gears, and often catch key species known to promote ecological resilience.
The ecological and economic implications of modifying fishing traps with escape slots were examined in a heavily fished and poor artisanal Kenyan fishery. Catches of fish from traps with four escape slot sizes (2, 4, 6, and 8 cm,) were examined for differences in the catch rates and composition and to calibrate a simulation model. The simulation model was used to predict how the ecological and economic outcomes will change as the standing stock responds to the new size selectivity of the fishing traps.
The results suggest a fishery's wide implementation of the 2 cm escape slots could provide an immediate benefit to the ecosystem by reducing the catch of juvenile fishes and algal browsers, which could help avoid or reverse coral–macroalgal phase shifts that can reduce reef biodiversity. However, the model predicts a decline in per trap profits in the first year that the 2 cm escape slot is implemented. This period would be followed by profitability increasing by a factor of 1.6 and 2.2 in the second year for the 2 cm and 4 cm escape slots respectively.
Sequential implementation of 2 cm slots followed by 4 cm slots in the fourth year reduces the total economic cost of implementing the 4 cm slots by 34%. Consequently, sequential implementation of these traps is suggested as a potential way to simultaneously conserve key ecosystem functions and reduce poverty. Copyright © 2014 John Wiley & Sons, Ltd.
A Comparative Study of Size Effects in the Au‐Catalyzed Oxidative and Non‐Oxidative Dehydrogenation of Benzyl Alcohol
Authors: Chen Jiashu , Fang Wenhao , Zhang Qinghong , Deng Weiping , Wang Ye 
Published: July 2014

AbstractA hydrotalcite‐supported gold catalyst has been found to be efficient for both oxidative and non‐oxidative conversions of benzyl alcohol into benzaldehyde. In both cases, the reaction rates were dependent on the size of the Au particles, but the size dependence for the non‐oxidative reaction was more pronounced. Our analyses on the intrinsic rates of different sites suggested that all of the atoms on the Au surfaces participated in the oxidative reaction, whereas the edge and corner Au atoms predominantly contributed to the non‐oxidative reaction, and that the terrace atoms were at least two orders of magnitude less active than the edge or corner atoms. In both cases, the rate‐determining step was CH bond cleavage. The presence of oxygen significantly enhanced the reaction rate. Herein, we propose that the non‐oxidative reaction proceeds through a β‐H elimination step by the low‐coordination‐number edge and corner Au atoms, whereas the active oxygen species, which are even generated on the terrace Au atoms, might assist CH bond cleavage under oxidative conditions.
Integration of [(Co(bpy)3]2+ Electron Mediator with Heterogeneous Photocatalysts for CO2 Conversion
Authors: Lin Jinliang , Hou Yidong , Zheng Yun , Wang Xinchen 
Published: July 2014

AbstractAn efficient chemical system for electron generation and transfer is constructed by the integration of an electron mediator ([Co(bpy)3]2+; bpy=2,2′‐bipyridine) with semiconductor photocatalysts. The introduction of [Co(bpy)3]2+ remarkably enhances the photocatalytic activity of pristine semiconductor photocatalysts for heterogeneous CO2 conversion; this is attributable to the acceleration of charge separation. Of particular interest is that the excellent photocatalytic activity of heterogeneous catalysts can be developed as a universal photocatalytic CO2 reduction system. The present findings clearly demonstrate that the integration of an electron mediator with semiconductors is a feasible process for the design and development of efficient photochemical systems for CO2 conversion.
Pd/Cu‐Cocatalyzed Aerobic Oxidative Carbonylative Homocoupling of Arylboronic Acids and CO: A Highly Selective Approach to Diaryl Ketones
Authors: Ren Long , Jiao Ning 
Published: July 2014

AbstractA highly selective Pd/Cu‐cocatalyzed aerobic oxidative carbonylative homocoupling of arylboronic acids has been developed. This method employs a simple catalytic system, readily available boronic acids as the substrates, molecular oxygen as the oxidant, and 1 atm of CO/O2, which makes this method practical for further applications.
Untersuchung vorgespannter Brückenplatten unter Verkehr mit zerstörungsfreien Prüfverfahren
Authors: Diersch Norman , Kind Thomas , Taffe Alexander , Kurz Jochen 
Published: July 2014

AbstractDer Untersuchung von vorgespannten Brückenplatten bzw. Fahrbahnplatten kommt angesichts ihrer direkten Belastung durch Verkehr und der Gefahr durch Tausalzeintrag infolge von Schäden an der Abdichtung eine tragende Rolle bei der Planung von Instandsetzungsarbeiten zu. Da diese Bauteile direkt befahren werden, ist der Einsatz zerstörungsfreier Prüfverfahren (ZfPBau‐Verfahren) sinnvoll, wobei deren Anwendung nur einen begrenzten Eingriff in den Verkehr verursachen sollte. In diesem Beitrag werden neben dem großflächigen Einsatz von Radar von der Brückenoberseite aus, d. h. durch den Fahrbahnbelag hindurch, Detailuntersuchungen von der Brückenunterseite mithilfe von Bauwerkscannern beschrieben. Diese Scanner verwenden sowohl Radar als auch Ultraschall mit ihren komplementären Verfahrenseigenschaften, wobei deren Möglichkeiten und Grenzen aufgezeigt werden. Abschließend wird eine Strategie zur Kombination von ZfPBau‐Verfahren sowie deren gezielter großflächiger Einsatz in Abgrenzung zu kleinflächigen Detailuntersuchungen beschrieben.Investigation of prestressed bridgedecks under traffic using non‐destructive‐testing methodsThe investigations of pre‐stressed bridge decks and carriageway slabs, considering their direct exposure to traffic and threat of ingress of de‐icing salt as a result of damage of the seal, plays a major role in the planning of repair work. Since these building elements are driven directly, the usage of non‐destructive testing (NDT methods) is useful where the application should cause only a limited intervention into traffic. In this paper, in addition to the large‐scale measurements with radar from the outer side of the bridge, which is through the road surface, detailed studies of the bridge base with the help of on‐site scanners are described. These scanners use radar and ultrasonic with their complementary properties. The possibilities and limitations are discussed here. Finally, a strategy for combining NDT methods and their specific large‐scale applications in a distinction to small‐scale detailed studies is described.
DGZfP‐Merkblatt B08 zur seismischen Baugrunderkundung
Authors: Niederleithinger Ernst 
Published: July 2014

AbstractSeismische Methoden, die mithilfe elastischer Wellen Informationen über den Untergrund liefern, spielen in der Baugrunderkundung eine immer größere Rolle. Die einschlägigen Regelwerke weisen zwar auf diese Methoden hin, geben aber keine näheren Hinweise zu Methodenauswahl oder Einsatzbereichen. Das neue Merkblatt B08 “Seismische Baugrunderkundung”, das seit Kurzem bei der DGZfP (Deutsche Gesellschaft für Zerstörungsfreie Prüfung) online und gedruckt auf Deutsch und Englisch erhältlich ist, will diese Lücke schließen. Die Grundlagen der Seismik werden kurz und knapp beschrieben, ebenso wie die zahlreichen Einzelmethoden mit ihren Anwendungsmöglichkeiten und Grenzen. Dabei wird sowohl auf Anwendungen von der Erdoberfläche aus wie auch auf Bohrlochmethoden und Offshore‐Techniken eingegangen. Eine Applikationsmatrix hilft bei der Methodenauswahl. Hinweise zu Ausschreibungen fehlen ebenso wenig wie Maßnahmen zur Qualitätssicherung. Das Merkblatt richtet sich an alle, die seismische Messungen zur Baugrunderkundung ausschreiben oder anbieten bzw. mit den Ergebnissen arbeiten.DGZfP recommendations for seismic site characterizationInformation on methods, applications, contracting and quality assurance: Seismic methods, which are acquiring information about the subsurface using elastic waves, are more and more used in site investigation. These techniques and their fields of application are mentioned in standards and regulations but not described or explained in detail. The new guideline B08 ”Site Investigation by Seismic methods" has been published by DGZFP (German Society for Non‐Destructive Testing) recently and is available in print and online in German and English. Basic concepts of seismic exploration are described shortly as well as the numerous techniques including fields of application and limitations. This includes surface, borehole and offshore methods. Hints on fields of application are given in a matrix like structure. Comments on tendering and bidding are included as well as measures for quality assurance. This guideline is for all, who need or offer geophysical services.
Regulation mechanisms in mixed and pure culture microbial fermentation
Authors: Hoelzle Robert D. , Virdis Bernardino , Batstone Damien J. 
Published: July 2014

ABSTRACTMixed‐culture fermentation is a key central process to enable next generation biofuels and biocommodity production due to economic and process advantages over application of pure cultures. However, a key limitation to the application of mixed‐culture fermentation is predicting culture product response, related to metabolic regulation mechanisms. This is also a limitation in pure culture bacterial fermentation. This review evaluates recent literature in both pure and mixed culture studies with a focus on understanding how regulation and signaling mechanisms interact with metabolic routes and activity. In particular, we focus on how microorganisms balance electron sinking while maximizing catabolic energy generation. Analysis of these mechanisms and their effect on metabolism dynamics is absent in current models of mixed‐culture fermentation. This limits process prediction and control, which in turn limits industrial application of mixed‐culture fermentation. A key mechanism appears to be the role of internal electron mediating cofactors, and related regulatory signaling. This may determine direction of electrons towards either hydrogen or reduced organics as end‐products and may form the basis for future mechanistic models. Biotechnol. Bioeng. 2014;111: 2139–2154. © 2014 Wiley Periodicals, Inc.
Nitrite accumulation from simultaneous free‐ammonia and free‐nitrous‐acid inhibition and oxygen limitation in a continuous‐flow biofilm reactor
Authors: Park Seongjun , Chung Jinwook , Rittmann Bruce E. , Bae Wookeun 
Published: July 2014

ABSTRACTTo achieve nitrite accumulation for shortcut biological nitrogen removal (SBNR) in a biofilm process, we explored the simultaneous effects of oxygen limitation and free ammonia (FA) and free nitrous acid (FNA) inhibition in the nitrifying biofilm. We used the multi‐species nitrifying biofilm model (MSNBM) to identify conditions that should or should not lead to nitrite accumulation, and evaluated the effectiveness of those conditions with experiments in continuous flow biofilm reactors (CFBRs). CFBR experiments were organized into four sets with these expected outcomes based on the MSNBM as follows: (i) Control, giving full nitrification; (ii) oxygen limitation, giving modest long‐term nitrite build up; (iii) FA inhibition, giving no long‐term nitrite accumulation; and (iv) FA inhibition plus oxygen limitation, giving major long‐term nitrite accumulation. Consistent with MSNBM predictions, the experimental results showed that nitrite accumulated in sets 2–4 in the short term, but long‐term nitrite accumulation was maintained only in sets 2 and 4, which involved oxygen limitation. Furthermore, nitrite accumulation was substantially greater in set 4, which also included FA inhibition. However, FA inhibition (and accompanying FNA inhibition) alone in set 3 did not maintained long‐term nitrite accumulation. Nitrite‐oxidizing bacteria (NOB) activity batch tests confirmed that little NOB or only a small fraction of NOB were present in the biofilms for sets 4 and 2, respectively. The experimental data supported the previous modeling results that nitrite accumulation could be achieved with a lower ammonium concentration than had been required for a suspended‐growth process. Additional findings were that the biofilm exposed to low dissolved oxygen (DO) limitation and FA inhibition was substantially denser and probably had a lower detachment rate. Biotechnol. Bioeng. 2015;112: 43–52. © 2014 Wiley Periodicals, Inc.
Anti‐HIV Small‐Molecule Binding in the Peptide Subpocket of the CXCR4:CVX15 Crystal Structure
Authors: Cox Bryan D. , Prosser Anthony R. , Katzman Brooke M. , Alcaraz Ana A. , Liotta Dennis C. , Wilson Lawrence J. , Snyder James P. 
Published: July 2014

AbstractThe CXC chemokine receptor 4 (CXCR4) is involved in chemotaxis and serves as a coreceptor for T‐tropic HIV‐1 viral entry, thus making this receptor an attractive drug target. Recently, crystal structures of CXCR4 were reported as complexes with the small molecule IT1t and the CVX15 peptide. Follow‐up efforts to model different antagonists into the small molecule CXCR4:IT1t crystal structure did not generate poses consistent with either the X‐ray crystal structure or site‐directed mutagenesis (SDM). Here, we compare the binding pockets of the two CXCR4 crystal structures, revealing differences in helices IV, V, VI, and VII, with major differences for the His203 residue buried in the binding pocket. The small molecule antagonist AMD11070 was docked into both CXCR4 crystal structures. An AMD11070 pose identified from the CXCR4:CVX15 model presented interactions with Asp171, Glu288, Trp94, and Asp97, consistent with published SDM data, thus suggesting it is the bioactive pose. A CXCR4 receptor model was optimized around this pose of AMD11070, and the resulting model correlated HIV‐1 inhibition with MM‐GBSA docking scores for a congeneric AMD11070‐like series. Subsequent NAMFIS NMR results successfully linked the proposed binding pose to an independent experimental structure. These results strongly suggest that not all small molecules will bind to CXCR4 in a similar manner as IT1t. Instead, the CXCR4:CVX15 crystal structure may provide a binding locus for small organic molecules that is more suitable than the secondary IT1t site. This work is expected to provide modeling insights useful for future CXCR4 antagonist and X4‐tropic HIV‐1 based drug design efforts.
Dicer Nuclease‐Promoted Production of Let7a‐1 MicroRNA Is Enhanced in the Presence of Tryptophan‐Containing Amphiphilic Peptides
Authors: Hyun Soonsil , Han Areum , Jo Myung Hyun , Hohng Sungchul , Yu Jaehoon 
Published: July 2014

AbstractA library of Trp‐containing amphiphilic peptides was synthesized and screened for the ability to bind to pre‐miRNA targets. Two members of this family, peptides Ac‐WKKLLKWLKKLLKLAG‐NH2 (2 b) and Ac‐WKKLLKWLKKLLDabLAG‐NH2 (4 b) were found to have nanomolar binding affinities to pre‐let7a‐1. Peptides 2 b and 4 b caused an increase in the in vitro Dicer cleavage of pre‐let7a‐1. This observation was confirmed by a cell‐based assay, the results of which show an up to 50 % increase in Dicer activity. Enhanced expression of let7a‐1 promoted by the peptides results in specific reductions of target mRNAs. The results of a microarray study show that lower amount of fluctuating genes are generated in the presence of 2 b or 4 b, relative to that from exogenous delivery of let7a‐1. Because peptides 2 b and 4 b promote enhanced formation of mature let7a‐1 only at the endogenous miRNA level, this specifically controls genes related to let7a‐1.
Chiral Bifunctional Squaramide‐Catalyzed Highly Enantioselective Michael Addition of Allomaltol to β,γ‐Unsaturated α‐Ketoesters
Authors: Liu Yunting , Wang Qiaohui , Wang Youming , Song Haibin , Zhou Zhenghong 
Published: July 2014

AbstractA highly enantioselective Michael addition of allomaltol (5‐hydroxy‐2‐methyl‐4H‐pyran‐4‐one) to both aromatic and aliphatic β,γ‐unsaturated α‐ketoesters has been realized. Under the catalysis of a chiral bifunctional tertiary amine‐squaramide that bears a (1R,2R)‐1,2‐diphenylethane‐1,2‐diamine scaffold, the reaction proceeded smoothly with high levels of enantioselectivity to give the desired products in acceptable yields with 86–>99 % enantiomeric excess. This methodology provided an efficient process for the enantioselective synthesis of optically active kojic acid derivatives.
A Remarkable Catalyst Combination to Widen the Operating Temperature Window of the Selective Catalytic Reduction of NO by NH3
Authors: Zhang Runduo , Liu Ning , Luo Zhen , Yang Wei , Liang Xin , Xu Ruinian , Chen Biaohua , Duprez Daniel , Royer Sébastien 
Published: July 2014

AbstractOn the basis of the idea of combining high selective catalytic reduction (SCR) activity, high N2 selectivity, and broad operating temperature window, we developed a combined catalyst process that was found to be a convenient way to design a highly efficient SCR process for NO with NH3. The single catalysts of MnOx–CeO2/TiO2 and V2O5–WO3/TiO2 as well as combined catalysts with different configurations were fully characterized by XRD, temperature‐programmed reduction of H2, and temperature‐programmed desorption of NO/O2. In addition, they were tested for the oxidation of NO or NH3 as well as the SCR of NO with NH3. The correlations between combining configurations and SCR activity results were also revealed. Furthermore, fundamental evidences were given for the rational design of the process and its efficiency maximization (assembly order and catalytic bed volume). An adequate configuration, with MnOx–CeO2/TiO2 and V2O5–WO3/TiO2 active materials, ensures an excellent SCR performance (NO conversion >85 %, N2 yield >70 %, and decreased N2O production) over a wide operating temperature window (from 150 to 400 °C).