bluuebunny/crossref_metadata_2025_split huggingface dataset:
Engineering a Diverse Ligase Toolbox for Peptide Segment Condensation
Authors: Nuijens Timo , Toplak Ana , Quaedflieg Peter J. L. M , Drenth Jeroen , Wu Bian , Janssen Dick B. 
Published: December 2016

AbstractThe substrate profile of peptiligase, a stable enzyme designed for peptide ligation in aqueous environments, was mapped using six different peptide libraries. The most discriminating substrate binding pocket proved to be the first nucleophile binding subsite (S1′), which is crucial for the peptide ligation yield. Two important amino acids shaping the S1′ pocket are M213 and L208. A site‐saturation library of the M213 position yielded two variants with a significantly broadened substrate profile, i.e., M213G and M213P. Next, examination of two libraries with M213G+L208X and M213P+L208X (with X being any proteinogenic amino acid) resulted in a toolbox of enzymes which can accommodate any proteinogenic amino acid in the S1′ pocket, except proline. The applicability of a particular enzyme variant in chemoenzymatic peptide synthesis was demonstrated by coupling at the gram scale of two peptide segments to yield exenatide, a 39‐mer therapeutic peptide used in the treatment of diabetes type II. The overall yield of 43% is at least 2‐fold higher than yields reported for conventional syntheses of exenatide by full solid‐phase peptide synthesis; large‐scale production costs are expected to be significantly reduced if the enzymatic coupling process is employed to manufacture this peptide.magnified image
A Palladium/Light System Combined with Hanztsch Ester: Radical Vinylation of Alkyl Iodides with Vinyl Bromides
Authors: Sumino Shuhei , Ryu Ilhyong 
Published: December 2016

AbstractRadical vinylation of alkyl iodides with vinyl bromides proceeds smoothly with a combined Pd/light/Hanztsch ester system. In this reaction system, the Hanztsch ester acts as an effective reducing reagent of PdII to Pd0 that generates key alkyl radicals via single electron transfer (SET) with alkyl iodides upon photo‐excitation.
Dark Photocatalysis: Storage of Solar Energy in Carbon Nitride for Time‐Delayed Hydrogen Generation
Authors: Lau Vincent Wing‐hei , Klose Daniel , Kasap Hatice , Podjaski Filip , Pignié Marie‐Claire , Reisner Erwin , Jeschke Gunnar , Lotsch Bettina V. 
Published: December 2016

AbstractWhile natural photosynthesis serves as the model system for efficient charge separation and decoupling of redox reactions, bio‐inspired artificial systems typically lack applicability owing to synthetic challenges and structural complexity. We present herein a simple and inexpensive system that, under solar irradiation, forms highly reductive radicals in the presence of an electron donor, with lifetimes exceeding the diurnal cycle. This radical species is formed within a cyanamide‐functionalized polymeric network of heptazine units and can give off its trapped electrons in the dark to yield H2, triggered by a co‐catalyst, thus enabling the temporal decoupling of the light and dark reactions of photocatalytic hydrogen production through the radical′s longevity. The system introduced here thus demonstrates a new approach for storing sunlight as long‐lived radicals, and provides the structural basis for designing photocatalysts with long‐lived photo‐induced states.
Surfactant‐free Fabrication of Fullerene C60 Nanotubules Under Shear
Authors: Vimalanathan Kasturi , Shrestha Rekha Goswami , Zhang Zhi , Zou Jin , Nakayama Tomonobu , Raston Colin L. 
Published: December 2016

AbstractA method for controlling the self‐assembly of fullerene C60 molecules into nanotubules in the fcc phase, devoid of entrapped solvent, has been established in a thin film microfluidic device. The micron length C60 nanotubules, with individual hollow diameters of 100 to 400 nm, are formed under continuous flow processing during high shear micromixing of water and a toluene solution of the fullerene, in the absence of surfactant, and without the need for further down‐stream processing. TEM revealed pores on the surface of the nanotubes, and the isolated material has a much higher response to small molecule sensing than that for analogous material formed using multistep batch processing.
Self‐Healing Behavior in a Thermo‐Mechanically Responsive Cocrystal during a Reversible Phase Transition
Authors: Liu Guangfeng , Liu Jie , Ye Xin , Nie Lina , Gu Peiyang , Tao Xutang , Zhang Qichun 
Published: December 2016

AbstractThe molecular‐level motions of a coronene‐based supramolecular rotator are amplified into macroscopic changes of crystals by co‐assembly of coronene and TCNB (1,2,4,5‐tetracyanobenzene) into a charge‐transfer complex. The as‐prepared cocrystals show remarkable self‐healing behavior and thermo‐mechanical responses during thermally‐induced reversible single‐crystal‐to‐single‐crystal (SCSC) phase transitions. Comprehensive analysis of the microscopic observations as well as differential scanning calorimetry (DSC) measurements and crystal habits reveal that a thermally‐reduced‐rate‐dependent dynamic character exists in the phase transition. The crystallographic studies show that the global similarity of the packing patterns of both phases with local differences, such as molecular stacking sequence and orientations, should be the origin of the self‐healing behavior of these crystals.
Adsorptive removal of biophenols from olive mill wastewaters (OMW) by activated carbon: mass transfer, equilibrium and kinetic studies
Authors: Senol A. , Hasdemir İ.M. , Hasdemir B. , Kurdaş İ. 
Published: December 2016

AbstractIn this study, the removal of biophenols from olive mill wastewater by activated carbon of different particle sizes has been carried out using the batch adsorption technique. The effects of the sorbent specific surface area and concentration, temperature, initial biophenols concentration, and contact time on the adsorption efficiency have been analyzed independently. The sorbent yields higher removal efficiency of biophenols as its specific surface area increases. When increasing the sorbent concentration from 10 to 50 g L−1, the sorbent uptake capacity increases from 20% to 41%, and it reaches a maximum value of 65 mg g−1 at 298.2 K. Adsorption of olive mill wastewater biophenols is moderately rapid, being about 38% to 40% of the initial phenolic content after 120 min. Kinetic analysis shows that the adsorption process can be approximated by a pseudo‐second‐order model for which pore diffusion is the essential rate‐controlling step. Equilibrium modeling by linearized adsorption isotherms reveals that a Langmuir‐type isotherm with a preferable monolayer sorption would likely proceed. Calculated thermodynamic parameters such as Gibbs energy, enthalpy, entropy, activation energy, and sticking probability indicate that adsorption is a typical endothermic yet spontaneous process with a preferable physisorption mechanism. An external mass transfer coefficient model has been developed to determine the rate of adsorption controlled initially by the boundary layer film, with particular focus on its predictive performance. Copyright © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.
Enhancing Market Valuation of ESG Performance: Is Integrated Reporting Keeping its Promise?
Authors: Mervelskemper Laura , Streit Daniel 
Published: December 2016

AbstractThis paper studies the effectiveness of a firm's strategy to report on its ESG activities with regard to the extent and direction in which the firm's ESG performance is valued by capital market investors. It is the first to disentangle the moderating effects of different types of ESG reporting on market valuation of ESG performance and to analyze whether following the current integrated reporting trend is worth the effort. Results indicate that ESG performance is valued more strongly and in the (desired) positive direction when firms publish an ESG report, irrespective of its type (stand‐alone or integrated). Furthermore, integrated reporting is associated with superior outcomes compared with a stand‐alone report for composite ESG and corporate governance performance. Our findings are important for corporate managers, as they help to understand market valuation of ESG performance in dependence on the reporting type and provide guidance for formulating and evaluating the reporting strategy. Copyright © 2016 John Wiley & Sons, Ltd and ERP Environment
Isolation and Characterization of RNA Aptamers against a Proteasome‐Associated Deubiquitylating Enzyme UCH37
Authors: Lee Jung Hoon , Lee Min Jae 
Published: December 2016

AbstractDeubiquitylating (DUB) enzymes antagonize ubiquitin‐dependent protein degradation both before and after the substrates are engaged with proteasomes. UCH37 is one of three proteasome‐associated DUB enzymes in mammals and the only protease among them from the ubiquitin carboxyl‐terminal hydrolase (UCH) family. Here, we report the identification of specific RNA aptamers for UCH37 through in vitro selection, and we describe their inhibitory effects on the DUB activity of UCH37. The RNA aptamers significantly delayed RPN13‐mediated UCH37 activation and lowered total DUB activity of proteasomes, as measured by the hydrolysis of ubiquitin‐rhodamine 110. In addition, the UCH37 aptamers efficiently facilitated the hydrolysis of peptide‐based reporter substrates of proteasomes. Thus, the UCH37 aptamers might offer a possible strategy for removing toxic cellular proteins through enhancing proteasome activity.
Brominated Luciferins Are Versatile Bioluminescent Probes
Authors: Steinhardt Rachel C. , Rathbun Colin M. , Krull Brandon T. , Yu Jason M. , Yang Yuhang , Nguyen Brian D. , Kwon Jake , McCutcheon David C. , Jones Krysten A. , Furche Filipp , Prescher Jennifer A. 
Published: December 2016

AbstractWe report a set of brominated luciferins for bioluminescence imaging. These regioisomeric scaffolds were accessed by using a common synthetic route. All analogues produced light with firefly luciferase, although varying levels of emission were observed. Differences in photon output were analyzed by computation and photophysical measurements. The brightest brominated luciferin was further evaluated in cell and animal models. At low doses, the analogue outperformed the native substrate in cells. The remaining luciferins, although weak emitters with firefly luciferase, were inherently capable of light production and thus potential substrates for orthogonal mutant enzymes.
Borinic Acid Catalysed Reduction of Tertiary Amides with Hydrosilanes: A Mild and Chemoselective Synthesis of Amines
Authors: Chardon Aurélien , Mohy El Dine Tharwat , Legay Rémi , De Paolis Michaël , Rouden Jacques , Blanchet Jérôme 
Published: December 2016

AbstractA reduction of various aryl, alkyl, and α,β‐unsaturated amides with phenylsilane, catalysed by a borinic acid, is reported. The unprecedented reaction was carried out under very mild conditions and led to useful amines. Furthermore, the reaction tolerates a variety of functional groups. Initial investigations implicated that an intermediate diarylhydroborane is involved in the reaction mechanism.
Nutrient limitation in tropical secondary forests following different management practices
Authors: Nagy R. Chelsea , Rastetter Edward B. , Neill Christopher , Porder Stephen 
Published: December 2016

AbstractSecondary forests now make up more than one‐half of all tropical forests, and constraints on their biomass accumulation will influence the strength of the terrestrial carbon (C) sink in the coming decades. However the variance in secondary tropical forest biomass for a given stand age and climate is high and our understanding of why is limited. We constructed a model of terrestrial C, nitrogen (N), and phosphorus (P) cycling to examine the influence of disturbance and management practices on nutrient limitation and biomass recovery in secondary tropical forests. The model predicted that N limited the rate of forest recovery in the first few decades following harvest, but that this limitation switched to P approximately 30–40 yr after abandonment, consistent with field data on N and P cycling from secondary tropical forest chronosequences. Simulated biomass recovery agreed well with field data of biomass accumulation following harvest (R2 = 0.80). Model results showed that if all biomass remained on site following a severe disturbance such as blowdown, regrowth approached pre‐disturbance biomass in 80–90 yr, and recovery was faster following smaller disturbances such as selective logging. Field data from regrowth on abandoned pastures were consistent with simulated losses of nutrients in soil organic matter, particularly P. Following any forest disturbance that involved the removal of nutrients (i.e., except blowdown), forest regrowth produced reduced biomass relative to the initial state as a result of nutrient loss through harvest, leaching and/or sequestration by secondary minerals. Differences in nutrient availability accounted for 49–94% of the variance in secondary forest biomass C at a given stand age. Management lessons from this study are the importance of strategies that help retain nutrients on site, recognizing the role of coarse woody debris in immobilization and subsequent release of nutrients, and the potential for nutrient additions to enhance biomass growth and recovery in secondary tropical forests.
Early Response to treatment in Eating Disorders: A Systematic Review and a Diagnostic Test Accuracy Meta‐Analysis
Authors: Nazar Bruno Palazzo , Gregor Louise Kathrine , Albano Gaia , Marchica Angelo , Coco Gianluca Lo , Cardi Valentina , Treasure Janet 
Published: December 2016

AbstractObjectiveEarly response to eating disorders treatment is thought to predict a later favourable outcome. A systematic review of the literature and meta‐analyses examined the robustness of this concept.MethodThe criteria used across studies to define early response were summarised following the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. Diagnostic Test Accuracy methodology was used to estimate the size of the effect.ResultsFindings from 24 studies were synthesized and data from 14 studies were included in the meta‐analysis. In Anorexia Nervosa, the odds ratio of early response predicting remission was 4.85(95%CI: 2.94–8.01) and the summary Area Under the Curve (AUC) = .77. In Bulimia Nervosa, the odds ratio was 2.75(95%CI:1.24–6.09) and AUC = .67. For Binge Eating Disorder, the odds ratio was 5.01(95%CI: 3.38–7.42) and AUC = .71.ConclusionEarly behaviour change accurately predicts later symptom remission for Anorexia Nervosa and Binge Eating Disorder but there is less predictive accuracy for Bulimia Nervosa. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.
Seek and decode: Random access with physical‐layer network coding and multiuser detection
Authors: Cocco Giuseppe , Pfletschinger Stephan , Navarro Monica 
Published: December 2016

AbstractWe present a novel scheme for Slotted ALOHA random access systems that combines physical‐layer network coding (PLNC) with multiuser detection (MUD). The PLNC and MUD are applied jointly at the physical layer to be able to extract any linear combination of messages experiencing a collision within a slot. The set of combinations extracted from a whole frame is then processed by the receiver to recover the original packets. A simple precoding stage at the transmitting terminals allows the receiver to further decrease the packet loss rate. We present results for the decoding at the physical layer as well as several performance measures at frame level, namely, throughput, packet loss rate, and energy efficiency. The results we present are promising and suggest that a cross‐layer approach leveraging on the joint use of PLNC and MUD can significantly improve the performance of random access systems in the presence of slow fading.
Impact of Land Use Change and Dam Construction on Soil Erosion and Sediment Yield in the Black Soil Region, Northeastern China
Authors: Fang Haiyan 
Published: December 2016

AbstractSince the 1960s, the implemented soil conservation measures on steep slopes and the densely planted shelterbelts as well as the constructed reservoirs and ponds in Baiquan County, northeastern China have dramatically altered the landscape and would greatly influence soil erosion and sediment yield (SY). However, how these land use changes and the constructed dams affected soil erosion and SY still remained unclear. A physically distributed soil erosion model WaTEM/SEDEM that has been calibrated and validated using 25 reservoir SYs in the study area was applied using nine land use scenarios (land uses in 1954, 1975 and 2010, each with 8, 32 and without dams) to assess their impacts on sediment delivery at the Shuangyang catchment (915 km2). The results show that land use changes as well as the increased dam numbers progressively decreased catchment sediment delivery and the impact of dams on sediment delivery was more efficient under the intensified land use condition (1954 land use without reservoirs). With respect to 1954 land use without dams, current land use condition (2010 land use with 32 dams) was simulated to decrease SY by 61·8%. Soil conservation measures (terrace and contour tillage as well as shelterbelts) on the slopes greatly influenced SY and over 80% of the reduced SY were caused by land use changes. This study indicates that soil conservation measures are sustainable sediment control measures for the black soil region because the accumulation of sediment in dams causes shortening of the useful life in reservoirs and ponds and implies increasing financial costs. Copyright © 2016 John Wiley & Sons, Ltd.
Mixotrophy in Heterocapsa rotundata: A mechanism for dominating the winter phytoplankton
Authors: Millette N. C. , Pierson J. J. , Aceves A. , Stoecker D. K. 
Published: December 2016

AbstractHeterocapsa rotundata is a mixotrophic dinoflagellate that can ingest picoplankton, including bacteria, and is known to form large blooms in temperate estuaries during wet winters, particularly when grazing pressure on phytoplankton is low. We hypothesized that phagotrophy gives H. rotundata an advantage over other phytoplankton species during low light conditions. We used laboratory and field experiments to investigate changes in phagotrophy by H. rotundata in response to changes in light availability. Prey removal experiments with a non‐axenic culture of H. rotundata were used to determine changes in H. rotundata's ingestion rates in response to changes in irradiance. Fluorescent microspheres were used to measure in situ ingestion rates of H. rotundata collected on 20 different occasions from the Choptank River during the winter of 2016. In situ H. rotundata ingestion rates were tested for correlation with inorganic nutrient concentrations and irradiance levels. Ingestion rates measured with cultured and in situ H. rotundata followed similar patterns and ingestion rates increased as irradiance decreased. H. rotundata has the potential to obtain nutrients from multiple nutrient sources, switching from phototrophy to partial heterotrophy as irradiance decreases. This response may allow H. rotundata to survive and to potentially form blooms when growth rates of most other estuarine phytoplankton species is low.
Alleviating VLDL overproduction is an important mechanism for Laminaria japonica polysaccharide to inhibit atherosclerosis in LDLr−/− mice with diet‐induced insulin resistance
Authors: Zha Xue‐Qiang , Zhang Wei‐Nan , Peng Fu‐Hua , Xue Lei , Liu Jian , Luo Jian‐Ping 
Published: December 2016

ScopeThe overproduction of very low density lipoprotein (VLDL) is an important cause for initiation and development of atherosclerosis, which is highly associated with insulin signaling. The aim of this work is to verify whether the inhibition of VLDL overproduction is an underlying mechanism for a Laminaria japonica polysaccharide (LJP61A (where LJP is L. japonica)) to resist atherosclerosis.Methods and resultsLJP61A (50 and 200 mg/kg/day) was orally administered to a high‐fat diet (HFD)‐fed LDL receptor deficient mice for 14 weeks. LJP61A significantly attenuated insulin resistance, hepatic steatosis, atherosclerosis, and dyslipidemia. Meanwhile, LJP61A ameliorated the HFD‐induced impairment of hepatic insulin signaling and reduced VLDL overproduction via regulating the expression of genes involved in the assembly and secretion of VLDL. To study the possibility that the inhibition of mammalian target of rapamycin complex 1 and stimulation of Forkhead box protein O1 (Foxo1) nuclear exclusion is a result of LJP61A via regulating insulin signaling, LJP61A was administrated to HepG2 cells in the presence or absence of mTOR inhibitor and Foxo1 inhibitor. Results showed that LJP61A alleviated VLDL overproduction via regulating insulin receptor substrate mediated phosphatidylinositide 3‐kinase AKT mammalian target of rapamycin complex 1 and phosphatidylinositide 3‐kinase AKT‐Foxo1 signaling pathways.ConclusionThese results suggested that LJP61A ameliorated HFD‐induced insulin resistance to attenuate VLDL overproduction possibly via regulating insulin signaling, leading to the inhibition of atherosclerosis.
Fast Fourier‐based simulation of off‐resonance artifacts in steady‐state gradient echo MRI applied to metal object localization
Authors: Zijlstra Frank , Bouwman Job G. , Braškutė Ieva , Viergever Max A. , Seevinck Peter R. 
Published: December 2016

PurposeTo accelerate simulation of off‐resonance artifacts in steady‐state gradient echo MRI by using fast Fourier transforms and demonstrate its applicability to metal object localization.Theory and MethodsBy exploiting the repetitive nature of steady‐state pulse sequences it is possible to use fast Fourier transforms to calculate the MR signal. Based on this principle, a method for fast simulation of off‐resonance artifacts was designed. The method was validated against Bloch simulations and MRI scans. Its clinical relevance was demonstrated by employing it for template matching‐based metal object localization, as applied to a titanium cylinder, an oxidized zirconium knee implant, and gold fiducials.ResultsThe fast simulations were accurate compared with actual MRI scans of the objects. The differences between the fast simulations and Bloch simulations were minor, while the acceleration scaled linearly with the number of phase‐encoding lines. The object localization method accurately localized the various metal objects.ConclusionThe proposed simulation methodology provided accurate 3D simulations of off‐resonance artifacts with a lower computational complexity than Bloch simulations. The speed of the simulations opens up possibilities in image reconstructions involving off‐resonance phenomena that were previously infeasible due to computational limitations, as demonstrated for metal object localization. Magn Reson Med 78:2035–2041, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.