bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glycosyltransferase cascades for natural product glycosylation: Use of plant instead of bacterial sucrose synthases improves the UDP‐glucose recycling from sucrose and UDP
Authors: Gutmann Alexander , Lepak Alexander , Diricks Margo , Desmet Tom , Nidetzky Bernd 
Published: April 2017

AbstractNatural product glycosylations by Leloir glycosyltransferases (GTs) require expensive nucleotide‐activated sugars as substrates. Sucrose synthase (SuSy) converts sucrose and uridine 5'‐diphosphate (UDP) into UDP‐glucose. Coupling of SuSy and GT reactions in one‐pot cascade transformations creates a UDP cycle, which regenerates the UDP‐glucose continuously and so makes it an expedient donor for glucoside production. Here we compare SuSys with divergent kinetic characteristics for UDP‐glucose recycling in the synthesis of the natural C‐glucoside nothofagin. Development of a fast reversed‐phase ion‐pairing HPLC method, quantifying all relevant reactants from the coupled conversion in a single run, was key to dissect the main factors of recycling efficiency. Limitations due to high KM, both for UDP and sucrose, were revealed for the bacterial SuSy from Acidithiobacillus caldus. The L637M‐T640V double mutant of this SuSy with a 60‐fold reduced KM for UDP substantially improved UDP‐glucose recycling. The SuSy from Glycine max (soybean) was nevertheless the most active enzyme at the UDP (≤ 0.5 mM) and sucrose (≤ 1 M) concentrations used. It was also unexpectedly stable at up to 50°C where spontaneous decomposition of UDP‐glucose started to become problematic. The herein gained in‐depth understanding of requirements for UDP‐glucose regeneration supports development of efficient GT‐SuSy cascades.
UHPLC‐Q‐TOF‐MS/MS‐based screening and characterization of metabolites of cnidilin in human liver microsomes
Authors: Yuan Lin , Zhang Yuqian , Liao Man , Liu Yanyan , Wan Changchen , Zhang Lantong 
Published: April 2017

AbstractCnidilin is an active natural furocoumarin ingredient originating from well‐known traditional Chinese medicine Radix Angelicae Dahuricae. In the present study, an efficient approach was developed for the screening and identification of cnidilin metabolites using ultra‐high‐performance liquid chromatography coupled to quadrupole time‐of‐flight mass spectrometry. In this approach, an on‐line data acquisition method multiple mass defect filter combined with dynamic background subtraction was developed to trace all probable metabolites. Based on this analytical strategy, a total of 24 metabolites of cnidilin were detected in human liver microsomal incubation samples and the metabolic pathways were proposed. The results indicated that oxidation was the main biotransformation route for cnidilin in human liver microsomes. In addition, the specific cytochrome P450 (CYP) enzymes involved in the metabolism of cnidilin were identified using chemical inhibition and CYP recombinant enzymes. The results showed that CYP1A2 and CYP3A4 might be the major enzymes involved in the metabolism of cnidilin in human liver microsomes. The relationship between cnidilin and the CYP450 enzymes could provide us a theoretical basis of the pharmacological mechanism.
ALET: Agents Learning their Environment through Text
Authors: Balint J. Timothy , Allbeck Jan 
Published: April 2017

AbstractFor intelligent virtual humans to interact in a rich environment, connections between the usable actions and objects must be defined. For scenarios consisting of hundreds of object types and many actions, having a simulation author create these connections by hand becomes and difficult. This limitation causes the simulation to have only a few object connections, whereas the rest of the objects are static and cannot be acted upon. Automated methods to connect objects to actions are promising but incomplete as they still miss key interactions and are unable to determine important characteristics of each action such as the manner of the action. We present Agents Learning their Environment through Text (ALET) to connect graphical objects to actions and provide an understanding of the actions. Observing that text contains descriptions of actions and connections to objects, ALET leverages large text corpora, and knowledge bases to provide candidate connections and descriptions for the actions and objects available in a simulation. The candidate connections and descriptions populate a representation that describes the graphical models and animations. We test ALET against other semantic generation methods, and find it more accurately determines object roles in actions, as well as determines semantic information about the action.
A comparative study of k‐nearest neighbour techniques in crowd simulation
Authors: Vermeulen Jordi L. , Hillebrand Arne , Geraerts Roland 
Published: April 2017

AbstractThe k‐nearest neighbour (kNN) problem appears in many different fields of computer science, such as computer animation and robotics. In crowd simulation, kNN queries are typically used by a collision‐avoidance method to prevent unnecessary computations. Many different methods for finding these neighbours exist, but it is unclear which will work best in crowd simulations, an application which is characterised by low dimensionality and frequent change of the data points. We therefore compare several data structures for performing kNN queries. We find that the nanoflann implementation of a k‐d tree offers the best performance by far on many different scenarios, processing 100,000 agents in about 35 ms on a fast consumer PC.
Electrochemical Water Oxidation Catalyzed by an In Situ Generated α‐Co(OH)2 Film on Zeolite‐Y Surface
Authors: Bose Suranjana , Debgupta Joyashish , Ramsundar Rani M. , Das Samar K. 
Published: April 2017

AbstractThe design and synthesis of an efficient and robust water‐oxidation catalyst with inexpensive materials remains an important challenge in the context of artificial photosynthesis. Herein, a simple but unique technique is reported to in situ generate a thin‐film of α‐Co(OH)2 on the surface of zeolite‐Y [hereafter referred to as Y‐α‐Co(OH)2] that acts as an efficient and stable catalyst for electrochemical water oxidation in alkaline medium. Catalyst Y‐α‐Co(OH)2 is so stable that it retains its catalytic activity even after 2000 cyclic voltammetric cycles of water oxidation. Expectedly, the chemical composition of α‐Co(OH)2 on the surface of zeolite‐Y remains same as that of parent Y‐α‐Co(OH)2 after 2000 electrocatalytic cycles. A Tafel slope as low as 59 mV decade−1 in 0.1 m KOH (pH 13) suggests faster oxygen evolution kinetics (overpotential=329 mV; turnover frequency=0.35 mol O2 (mol Co)−1 s−1 at 1 mA cm−2) than the existing α‐Co(OH)2‐based electrocatalysts operating in alkaline medium.
One‐Step Fabrication of Monolithic Electrodes Comprising Co9S8 Particles Supported on Cobalt Foam for Efficient and Durable Oxygen Evolution Reaction
Authors: Xiong Dehua , Zhang Qingqing , Thalluri Sitaramanjaneya Mouli , Xu Junyuan , Li Wei , Fu Xiuli , Liu Lifeng 
Published: April 2017

AbstractA very easy and cost‐effective approach to the fabrication of monolithic Co9S8 water oxidation electrodes (Co@Co9S8), fabricated by one‐step hydrothermal treatment of commercially available cobalt foam in the presence of thiourea, is reported. The morphology, crystal structure, microstructure, and composition of as‐fabricated Co@Co9S8 electrodes were examined by using scanning electron microscopy (SEM), powder X‐ray diffractometry (XRD), transmission electron microscope (TEM), and X‐ray photoelectron spectroscopy (XPS), and their electrochemical properties were investigated by cyclic voltammetry (CV), chronopotentiometry (CP), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). When used to catalyze the oxygen evolution reaction (OER) in alkaline solution, the Co@Co9S8 electrode with an optimal Co9S8 loading exhibits outstanding catalytic activity, requiring a low overpotential of 350 mV to deliver an anodic current density of 10 mA cm−2 and showing fast kinetics for OER with a small Tafel slope (55 mV dec−1) and charge‐transfer resistance (0.44 Ω cm−2), which outperforms many sulfide‐based OER catalysts and some state‐of‐the‐art noble metal catalysts recently reported in the literature. Importantly, the electrodes show excellent long‐term stability, and are capable of operating at both a low current density and a high current density relevant to industrial water electrolysis up to 100 hours.
Thermo‐Chromium: A Contactless Optical Molecular Thermometer
Authors: Otto Sven , Scholz Norman , Behnke Thomas , Resch‐Genger Ute , Heinze Katja 
Published: April 2017

AbstractThe unparalleled excited‐state potential‐energy landscape of the chromium(III)‐based dye [1]3+ ([Cr(ddpd)2]3+; ddpd=N,N′‐dimethyl‐N,N′‐dipyridin‐2‐yl‐pyridin‐2,6‐diamine) enables a strong dual emission in the near infrared region. The temperature dependence of this dual emission allows the use of [1]3+ as an unprecedented molecular ratiometric thermometer in the 210–373 K temperature range in organic and in aqueous media. Incorporation of [1]3+ in biocompatible nanocarriers, such as 100 nm‐sized polystyrene nanoparticles and solutol micelles, provides nanodimensional thermometers operating under physiological conditions.
Synthesis of l‐threitol‐based crown ethers and their application as enantioselective phase transfer catalyst in Michael additions
Authors: Rapi Zsolt , Nemcsok Tamás , Pálvölgyi Ádám , Keglevich György , Grün Alajos , Bakó Péter 
Published: April 2017

AbstractA few new l‐threitol‐based lariat ethers incorporating a monoaza‐15‐crown‐5 unit were synthesized starting from diethyl l‐tartrate. These macrocycles were used as phase transfer catalysts in asymmetric Michael addition reactions under mild conditions to afford the adducts in a few cases in good to excellent enantioselectivities. The addition of 2‐nitropropane to trans‐chalcone, and the reaction of diethyl acetamidomalonate with β‐nitrostyrene resulted in the chiral Michael adducts in good enantioselectivities (90% and 95%, respectively). The substituents of chalcone had a significant impact on the yield and enantioselectivity in the reaction of diethyl acetoxymalonate. The highest enantiomeric excess (ee) values (99% ee) were measured in the case of 4‐chloro‐ and 4‐methoxychalcone. The phase transfer catalyzed cyclopropanation reaction of chalcone and benzylidene‐malononitriles using diethyl bromomalonate as the nucleophile (MIRC reaction) was also developed. The corresponding chiral cyclopropane diesters were obtained in moderate to good (up to 99%) enantioselectivities in the presence of the threitol‐based crown ethers.
Quantitative segmental analysis of myocardial perfusion to differentiate stress cardiomyopathy from acute myocardial infarction: A myocardial contrast echocardiography study
Authors: Min Sun‐Yang , Song Jong‐Min , Shin Yewon , Sin Min‐Jung , Kim Dae‐Hee , Kang Duk‐Hyun , Song Jae‐Kwan 
Published: April 2017

BackgroundBoth stress cardiomyopathy (SCMP) and acute myocardial infarction (AMI) present with similar clinical symptoms and signs, and apical akinesis.
Hypothesis: Quantitative segmental analysis of myocardial contrast echocardiography (MCE) helps to differentiate AMI from SCMP.MethodsReal‐time MCE was performed in 33 consecutive patients who presented with an acute symptom/sign and a new apical akinesis on echocardiography. In 18 left ventricular (LV) myocardial segments, a replenishment curve was obtained in each segment to measure peak plateau myocardial contrast intensity (MCI) (A) and the replenishment curve slope (β). The calibrated MCI was also measured in each segment.ResultsAmong 33 patients, 22 were diagnosed with SCMP and 11 were diagnosed with AMI according to comprehensive diagnostic criteria. A, β, Aβ, and the calibrated MCI were lower in akinetic than in normokinetic segments in both the SCMP and AMI groups. In the akinetic segments, A, β, Aβ, and the calibrated MCI in SCMP patients were each higher than those in AMI patients. In patient‐based analyses, areas under the ROC curves of A, β, Aβ, and the calibrated MCI for diagnosing AMI were 0.769, 0.607, 0.822, and 0.934, respectively. The optimal cutoff values to diagnose AMI were Aβ < 3.7 dB/sec (sensitivity 82%, specificity 82%) and a calibrated MCI < −23 dB (sensitivity 91%, specificity 95%).ConclusionsAlthough myocardial perfusion is relatively reduced in the akinetic segments of SCMP, a quantitative segmental analysis of myocardial perfusion using MCE helps to discriminate AMI from SCMP.
Simplified electrical modelling of power LEDs for DC–DC converter analysis and simulation
Authors: Osorio R. , Alonso J.M. , Pinto S.E. , Martínez G. , Vázquez N. , Ponce‐Silva M. , Martínez A.J. 
Published: April 2017

SummaryThis paper presents a model of power light emitting diodes (LEDs) based on electrical variables and considering the concept of LED ‘equivalent resistance’, which has previously been used in discharge lamp modelling and is suitable to achieve fast simulations of LED converter systems. The model can be obtained with only some simple electrical measurements, thus making its implementation quite straightforward. The proposed model is oriented to the electronic engineering area, and it has special application for the simulation of the electrical behaviour of LEDs and dc–dc converter systems by using software like Simulink. In addition, the proposed model can also be employed for the theoretical analysis and design of LED drivers. Experimental and simulation results are obtained proving the feasibility of the proposed model. Copyright © 2017 John Wiley & Sons, Ltd.
The effects of cognitive‐behavioral therapy for eating disorders on quality of life: A meta‐analysis
Authors: Linardon Jake , Brennan Leah 
Published: April 2017

AbstractObjectiveMeta‐analyses have documented the efficacy of cognitive‐behavioral therapy (CBT) for reducing symptoms of eating disorders. However, it is not known whether CBT for eating disorders can also improve quality of life (QoL). This meta‐analysis therefore examined the effects of CBT for eating disorders on subjective QoL and health‐related quality of life (QoL).MethodStudies that assessed QoL before and after CBT for eating disorders were searched in the PsycInfo and Medline database. Thirty‐four articles met inclusion criteria. Pooled within and between‐groups Hedge's g were calculated at post‐treatment and follow‐up for treatment changes on both subjective and HRQoL using a random effects model.ResultsCBT led to significant and modest improvements in subjective QoL and HRQoL from pre to post‐treatment and follow‐up. CBT led to greater subjective QoL improvements than inactive (i.e., wait‐list) and active (i.e., a combination of bona fide therapies, psychoeducation) comparisons. CBT also led to greater HRQoL improvements than inactive, but not active, comparisons. Prepost QoL improvements were larger in studies that delivered CBT individually and by a therapist or according to the cognitive maintenance model of eating disorders (CBT‐BN or CBT‐E); though this was not replicated at follow‐upConclusionsFindings provide preliminary evidence that CBT for eating disorders is associated with modest improvements in QOL, and that CBT may be associated with greater improvements in QOL relative to comparison conditions.
Reindeer habitat use in relation to two small wind farms, during preconstruction, construction, and operation
Authors: Skarin Anna , Alam Moudud 
Published: April 2017

AbstractWorldwide there is a rush toward wind power development and its associated infrastructure. In Fennoscandia, large‐scale wind farms comprising several hundred windmills are currently built in important grazing ranges used for Sámi reindeer husbandry. In this study, reindeer habitat use was assessed using reindeer fecal pellet group counts in relation to two relatively small wind farms, with 8 and 10 turbines, respectively. In 2009, 1,315 15‐m2plots were established and pellet groups were counted and cleaned from the plots. This was repeated once a year in May, during preconstruction, construction, and operation of the wind farms, covering 6 years (2009–2014) of reindeer habitat use in the area. We modeled the presence/absence of any pellets in a plot at both the local (wind farm site) and regional (reindeer calving to autumn range) scale with a hierarchical logistic regression, where spatial correlation was accounted for via random effects, using vegetation type, and the interaction between distance to wind turbine and time period as predictor variables. Our results revealed an absolute reduction in pellet groups by 66% and 86% around each wind farm, respectively, at local scale and by 61% at regional scale during the operation phase compared to the preconstruction phase. At the regional, scale habitat use declined close to the turbines in the same comparison. However, at the local scale, we observed increased habitat use close to the wind turbines at one of the wind farms during the operation phase. This may be explained by continued use of an important migration route close to the wind farm. The reduced use at the regional scale nevertheless suggests that there may be an overall avoidance of both wind farms during operation, but further studies of reindeer movement and behavior are needed to gain a better understanding of the mechanisms behind this suggested avoidance.
Population structure and regeneration dynamics ofQuercus variabilisalong latitudinal and longitudinal gradients
Authors: Gao Wen‐Qiang , Ni Yan‐Yan , Xue Ze‐Min , Wang Xiao‐Fei , Kang Feng‐Feng , Hu Jun , Gao Zhong‐Hai , Jiang Ze‐Ping , Liu Jian‐Feng 
Published: April 2017

AbstractThe upcoming climatic variability is expected to influence the population dynamics of tree species, but few empirical studies have been performed over broad geographical scales, which may be more convincing to address tree range shift under climate change. In the present study, the population structure and regeneration dynamics ofQuercus variabiliswere investigated along latitudinal and longitudinal gradients over its full range in China. The size structure, density, mortality rate (b), conversion rate (CR), initial recruitment (y0), and survival from birth to the highest class of regeneration (survival rate [SR]) were analyzed. The results showed the following: (1) The population structure ofQ. variabilisexhibited an inverse‐J shape throughout the latitudinal gradient, and the relative seedling density was significantly higher in the middle populations than in the north and the south. In addition, they0andSRexhibited the highest values in the middle, but no significant differences in the density and total basal area of adults were found across latitudes. (2) Along the longitudinal gradient, an inverse‐J‐type population structure was present in the west populations, but was not observed in the east due to the scarcity of individuals in regenerated populations. The total basal area and density of adults were similar across longitudes, but both the seedling density and the relative seedling density, along with they0andSR, were higher in the middle than in the east and the west. Thebof adults was lower in the middle‐longitude populations than in the west and the east. (3) Climate (annual average temperature) was identified as the primary factor affecting regeneration. In addition, local factors, including the soil and stand conditions, were also found to play a significant role in determining the regeneration dynamics. Based on these results, we speculate that populations ofQ. variabilisat the range edges would decline in the context of climate change, particularly in the south and the east.
Fire regimes and environmental gradients shape vertebrate and plant distributions in temperate eucalypt forests
Authors: Kelly Luke T. , Haslem Angie , Holland Greg J. , Leonard Steven W. J. , MacHunter Josephine , Bassett Michelle , Bennett Andrew F. , Bruce Matthew J. , Chia Evelyn K. , Christie Fiona J. , Clarke Michael F. , Di Stefano Julian , Loyn Richard , McCarthy Michael A. , Pung Alina , Robinson Natasha , Sitters Holly , Swan Matthew , York Alan 
Published: April 2017

AbstractFire is a global driver of ecosystem structure, function, and change. Problems common to fire scientists and managers worldwide include a limited knowledge of how multiple taxonomic groups within a given ecosystem respond to recurrent fires, and how interactions between fire regimes and environmental gradients influence biodiversity. We tested six hypotheses relating to fire regimes and environmental gradients in forest ecosystems using data on birds (493 sites), mammals (175 sites), and vascular plants (615 sites) systematically collected in dry eucalypt forests in southeastern Australia. We addressed each of these hypotheses by fitting species distribution models which differed in the environmental variables used, the spatial extent of the data, or the type of response data. We found (1) as predicted, fire interacted with environmental gradients and shaped species distributions, but there was substantial variation between species; (2) multiple characteristics of fire regimes influenced the distribution of forest species; (3) common to vertebrates and plants was a strong influence of temperature and rainfall gradients, but contrary to predictions, inter‐fire interval was the most influential component of the fire regime on both taxonomic groups; (4) mixed support for the hypothesis that fire would be a stronger influence on species occurrence at a smaller spatial extent; only for vertebrates did scale have an effect in the direction expected; (5) as predicted, vertebrates closely associated with direct measures of habitat structure were those most strongly influenced by fire regimes; and (6) the modeled fire responses for birds were sensitive to the use of either presence–absence or abundance data. These results underscore the important insights that can be gained by modeling how fire regimes, not just fire events, influence biota in forests. Our work highlights the need for management of fire regimes to be complemented by an understanding of the underlying environmental gradients and key elements of habitat structure that influence resource availability for plants and animals. We have demonstrated that there are general patterns in biotic responses to fire regimes and environmental gradients, but landscape management must continue to carefully consider species, scale, and the quality of biodiversity data to achieve biodiversity conservation in fire‐prone forests.