bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hyperpolarization of Amino Acids in Water Utilizing Parahydrogen on a Rhodium Nanocatalyst
Authors: Kaltschnee Lukas , Jagtap Anil P. , McCormick Jeffrey , Wagner Shawn , Bouchard Louis‐S. , Utz Marcel , Griesinger Christian , Glöggler Stefan 
Published: June 2019

AbstractNMR offers many possibilities in chemical analysis, structural investigations, and medical diagnostics. Although it is broadly used, one of NMR spectroscopies main drawbacks is low sensitivity. Hyperpolarization techniques enhance NMR signals by more than four orders of magnitude allowing the design of new contrast agents. Parahydrogen induced polarization that utilizes the para‐hydrogen's singlet state to create enhanced signals is of particular interest since it allows to produce molecular imaging agents within seconds. Herein, we present a strategy for signal enhancement of the carbonyl 13C in amino acids by using parahydrogen, as demonstrated for glycine and alanine. Importantly, the hyperpolarization step is carried out in water and chemically unmodified canonical amino acids are obtained. Our approach thus offers a high degree of biocompatibility, which is crucial for further application. The rapid sample hyperpolarization (within seconds) may enable the continuous production of biologically useful probes, such as metabolic contrast agents or probes for structural biology.
Speech emotion recognition using emotion perception spectral feature
Authors: Jiang Lin , Tan Ping , Yang Junfeng , Liu Xingbao , Wang Chao 
Published: June 2019

SummarySpeech emotion recognition is an important technique for human‐computer interface applications. Due to contain rich information of emotion, the spectral feature is widely used for emotion recognition. However, the recognition performance is limited because of imprecise extracted rule and uncertain size of resolution of spectral feature. To address this issue, motivated by speech coding, we introduced psychoacoustics model, provided a perception spectral subband partition method for obtaining more precise frequency resolution. Moreover, we also provided a new spectral feature on the divided subband frequency signals. The proposed feature includes emotional perception entropy, spectral inclination, and spectral flatness. Then, a Support Vector Machine classifier is used to recognize emotion categories. The experiment results show that the proposed spectral feature is superior to the traditional MFCC feature, and also better than the state‐of‐the‐art Fourier feature and multi‐resolution amplitude feature.
Carbon Corrosion in Proton‐Exchange Membrane Fuel Cells: Spectrometric Evidence for Pt‐Catalysed Decarboxylation at Anode‐Relevant Potentials
Authors: Maillard Frédéric , O. Silva Wanderson , Castanheira Luis , Dubau Laetitia , Lima Fabio H. B. 
Published: June 2019

AbstractThe carbon oxidation reaction (COR) is a critical issue in proton‐exchange membrane fuel cells (PEMFCs), as carbon in various forms is the most used electrocatalyst support material. The COR is thermodynamically possible above the C/CO2 standard potential, but its rate becomes significantly important only at high overpotential (e. g. PEMFC cathode potential). Herein, using on‐line differential electrochemical mass spectrometry, we show that oxygen‐containing carbon surface groups present on high‐surface aera carbon, Vulcan XC72 or reinforced graphite are oxidized at PEMFC anode‐relevant potential (E=0.1 V vs. the reversible hydrogen electrode, RHE), but not at E=0.4 V vs. RHE. We rationalized our findings by considering a Pt‐catalysed decarboxylation mechanism in which Pt nanoparticles provide adsorbed hydrogen species to the oxygen‐containing carbon surface groups, eventually leading to evolution of carbon dioxide and carbon monoxide. These results shed fundamental light on an unexpected degradation mechanism and facilitate the understanding of the long‐term stability of PEMFC anode nanocatalysts.
Recent Strategies in Resveratrol Delivery Systems
Authors: Machado Noelia D. , Fernández Mariana A. , Díaz David Díaz 
Published: June 2019

AbstractResveratrol, a natural polyphenolic stilbenoid widely found in grapes and wines, displays beneficial properties such as cardio‐protective, antioxidant and anti‐inflammatory activities. Trans‐resveratrol (RSV) is the most bioactive and more abundant stereoisomer found in nature. Despite the positive properties of RSV, there are various factors that limit its effectiveness, including low aqueous solubility, low oral bioavailability and chemical instability. During the last years, an increasing number of strategies such as nano and micro encapsulation have been developed in order to overcome these limitations and enhance the use of RSV in nutritional and pharmaceutical applications. This Review summarizes the advances and main properties of several RSV carriers and delivery systems reported during the last 5 years.
Understanding the Role of Protic Ionic Liquids (PILs) in Reactive Systems: Rational Selection of PILs for the Design of Green Synthesis Strategies for Allylic Amines and β‐Amino Esters
Authors: Bravo María V. , Fernández José L. , Adam Claudia G. , Della Rosa Claudia D. 
Published: June 2019

AbstractThe reactive behaviour of protic ionic liquids (PILs) has been shown to be governed not only by their chemical structures but also by their global compositions, which include the presence of free acids and bases at equilibrium with ionic pairs. Six PILs composed of primary, secondary, or tertiary alkyl ammonium cations with two couterions, nitrate or acetate, were tested in model reactions with unsaturated substrates. The free species that were naturally present in these liquids were identified by cyclic voltammetry. Only tributylammonium nitrate was found to be mostly composed just of the ionic pair; the other five PILs also contain variable amounts of free acid and amine. In reactive systems, these free species determine the products of the reaction. In particular, allylic amines and β‐amino esters were obtained in good yields (91 and 75 %, respectively) by reaction of conjugated dienes and acrylates in the presence of PILs. By taking into account the actual composition of each PIL, it was possible to direct the reaction path towards a specific product with good yields, to ensure acid catalysis, to avoid polymerization of the substrate, and to promote phase transfer of products. These results establish some useful guidelines for the rational design of new PIL‐based one‐step synthetic strategies.
Loss of functional connectivity in migration networks induces population decline in migratory birds
Authors: Xu Yanjie , Si Yali , Wang Yingying , Zhang Yong , Prins Herbert H. T. , Cao Lei , de Boer Willem F. 
Published: June 2019

AbstractMigratory birds rely on a habitat network along their migration routes by temporarily occupying stopover sites between breeding and non‐breeding grounds. Removal or degradation of stopover sites in a network might impede movement and thereby reduce migration success and survival. The extent to which the breakdown of migration networks, due to changes in land use, impacts the population sizes of migratory birds is poorly understood. We measured the functional connectivity of migration networks of waterfowl species that migrate over the East Asian‐Australasian Flyway from 1992 to 2015. We analysed the relationship between changes in non‐breeding population sizes and changes in functional connectivity, while taking into account other commonly considered species traits, using a phylogenetic linear mixed model. We found that population sizes significantly declined with a reduction in the functional connectivity of migration networks; no other variables were important. We conclude that the current decrease in functional connectivity, due to habitat loss and degradation in migration networks, can negatively and crucially impact population sizes of migratory birds. Our findings provide new insights into the underlying mechanisms that affect population trends of migratory birds under environmental changes. Establishment of international agreements leading to the creation of systematic conservation networks associated with migratory species’ distributions and stopover sites may safeguard migratory bird populations.
Climate outweighs native vs. nonnative range‐effects for genetics and common garden performance of a cosmopolitan weed
Authors: Rosche Christoph , Hensen Isabell , Schaar Adrian , Zehra Uzma , Jasieniuk Marie , Callaway Ragan M. , Khasa Damase P. , Al‐Gharaibeh Mohammad M. , Lekberg Ylva , Nagy Dávid U. , Pal Robert W. , Okada Miki , Schrieber Karin , Turner Kathryn G. , Lachmuth Susanne , Erst Andrey , Tsunoda Tomonori , Sheng Min , Schmidt Robin , Peng Yanling , Luo Wenbo , Jäschke Yun , Reshi Zafar A. , Shah Manzoor A. 
Published: June 2019

AbstractComparing genetic diversity, genetic differentiation, and performance between native and nonnative populations has advanced our knowledge of contemporary evolution and its ecological consequences. However, such between‐range comparisons can be complicated by high among‐population variation within native and nonnative ranges. For example, native vs. nonnative comparisons between small and non‐representative subsets of populations for species with very large distributions have the potential to mislead because they may not sufficiently account for within‐range adaptation to climatic conditions, and demographic history that may lead to non‐adaptive evolution. We used the cosmopolitan weed Conyza canadensis to study the interplay of adaptive and demographic processes across, to our knowledge, the broadest climatic gradient yet investigated in this context. To examine the distribution of genetic diversity, we genotyped 26 native and 26 nonnative populations at 12 microsatellite loci. Furthermore, we recorded performance traits for 12 native and 13 nonnative populations in the field and in the common garden. To analyze how performance was related to range and/or climate, we fit pedigree mixed‐effects models. These models weighed the population random effect for co‐ancestry to account for the influence of demographic history on phenotypic among‐population differentiation. Genetic diversity was very low, selfing rates were very high, and both were comparable between native and nonnative ranges. Nonnative populations out‐performed native populations in the field. However, our most salient result was that both neutral genetic differentiation and common garden performance were far more correlated with the climatic conditions from which populations originated than native vs. nonnative range affiliation. Including co‐ancestry of our populations in our models greatly increased explained variance and our ability to detect significant main effects for among‐population variation in performance. High propagule pressure and high selfing rates, in concert with the ability to adapt rapidly to climatic gradients, may have facilitated the global success of this weed. Neither native nor nonnative populations were homogeneous groups but responded comparably to similar environments in each range. We suggest that studies of contemporary evolution should consider widely distributed and genotyped populations to disentangle native vs. nonnative range effects from varying adaptive processes within ranges and from potentially confounding effects of demographic history.
Effects of silicate application on CH4 and N2O emissions and global warming potentials in paddy soil under enhanced UV‐B radiation
Authors: Lou Yunsheng , Ren Lixuan , Zhao Sidi , Shi Yifan , Zhang Yiwei , Zhu Huaiwei 
Published: June 2019

AbstractEnhanced ultraviolet‐B (UV‐B) radiation is induced by the depletion of the stratospheric ozone layer. Silicate is beneficial to rice growth and can increase the resistance of rice plant to UV‐B radiation, but so far few reports have been available on whether silicate application can reduce CH4 and N2O emissions from paddy soils under enhanced UV‐B radiation. A field experiment was conducted to investigate the effects of silicate application on CH4 and N2O emissions and global warming potentials (GWPs) under enhanced UV‐B radiation in a paddy soil. The experiment with rice was designed with two UV‐B radiation levels, that is, ambient UV‐B (A, ambient) and enhanced UV‐B radiation (E, enhanced by 20%); and two silicate application levels, that is, control (Si0, 0 kg SiO2·ha−1) and silicate application (Si1, 200 kg SiO2·ha−1). CH4 and N2O fluxes were determined by closed chamber method at one‐week interval during rice growth period. The results show that, compared with ambient UV‐B radiation, enhanced UV‐B radiation clearly decreased the dry matter weights of shoot, root, and whole plant by 13.12%, 53.31%, and 25.85%, respectively, in the treatment without silicate application, and by 1.47%, 34.49%, and 11.12%, respectively, in the treatment with silicate application. Enhanced UV‐B radiation significantly increased the flux and cumulative emission of N2O and stimulated the GWPs of CH4 and N2O. Silicate application significantly reduced flux and cumulative emission of CH4, promoted the flux and cumulative emission of N2O, and reduced the GWPs of CH4 and N2O. This study suggests that silicate application can reduce the contribution of enhanced UV‐B radiation to global warming potentials.
A Hybrid Individual-Based and Food Web–Ecosystem Modeling Approach for Assessing Ecological Risks to the Topeka Shiner (Notropis topeka): A Case Study with Atrazine
Authors: Bartell Steven M. , Schmolke Amelie , Green Nicholas , Roy Colleen , Galic Nika , Perkins Dan , Brain Richard 
Published: June 2019

Abstract
A hybrid model was used to characterize potential ecological risks posed by atrazine to the endangered Topeka shiner. The model linked a Topeka shiner individual-based bioenergetics population model (TS-IBM) to a comprehensive aquatic system model (CASMTS) to simulate Topeka shiner population and food web dynamics for an Iowa (USA) headwater pool. Risks were estimated for monitored concentrations in Iowa, Missouri, and Nebraska (USA), and for monitored concentrations multiplied by 2, 4, and 5. Constant daily atrazine concentrations of 10, 50, 100, and 250 µg/L were assessed. Exposure–response functions were developed from published atrazine toxicity data (median effect concentrations [EC50s] and no-observed-effect concentrations). Two toxicity scenarios were developed: the first included sensitive and insensitive species of algae, and the second reduced algal EC50 values to increase atrazine sensitivity. Direct and indirect effects of atrazine on Topeka shiner prey were modeled; direct effects on Topeka shiner were not assessed. Risks were characterized as differences between population biomass values of 365-d baseline and exposure simulations. The results indicated no discernable food web effects for monitored atrazine concentrations or constant exposures of 10 µg/L on Topeka shiner populations for either toxicity scenario. Magnified monitored concentrations and higher constant concentrations produced greater modeled indirect effects on Topeka shiners. The hybrid model transparently combines species-specific and surrogate species data to estimate food web responses to environmental stressors. The model is readily updated by new data and is adaptable to other species and ecosystems. Environ Toxicol Chem 2019;38:2243–2258. © 2019 SETAC.
Toward the Development and Application of an Environmental Risk Assessment Framework for Microplastic
Authors: Gouin Todd , Becker Richard A. , Collot Anne-Gaelle , Davis John W. , Howard Brett , Inawaka Kunifumi , Lampi Mark , Ramon Blanca Serrano , Shi Jay , Hopp Philipp W. 
Published: June 2019

Abstract
Emissions of plastic waste to the environment and the subsequent degradation into microplastic particles that have the potential to interact with biological organisms represent a concern for global society. Current understanding of the potential impacts on aquatic and terrestrial population stability and ecosystem structure and function associated with emissions of microplastic particles is limited and insufficient to fully assess environmental risks. Multistakeholder discussions can provide an important element in helping to identify and prioritize key knowledge gaps in assessing potential risks. In the present review, we summarize multistakeholder discussions from a 1-d International Council of Chemical Associations–sponsored symposium, which involved 39 scientists from 8 countries with representatives from academia, industry, and government. Participants were asked to consider the following: discuss the scientific merits and limitations of applying a proposed conceptual environmental risk assessment (ERA) framework for microplastic particles and identify and prioritize major research needs in applying ERA tools for microplastic particles. Multistakeholder consensus was obtained with respect to the interpretation of the current state of the science related to effects and exposure to microplastic particles, which implies that it is unlikely that the presence of microplastic in the environment currently represents a risk. However, the quality and quantity of existing data require substantial improvement before conclusions regarding the potential risks and impacts of microplastic particles can be fully assessed. Research that directly addresses the development and application of methods that strengthen the quality of data should thus be given the highest priority. Activities aimed at supporting the development of and access to standardized reference material were identified as a key research need. Environ Toxicol Chem 2019;38:2087–2100. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.
Energy‐efficient and delay‐aware multitask offloading for mobile edge computing networks
Authors: Chanyour Tarik , El Ghmary Mohamed , Hmimz Youssef , Cherkaoui Malki Mohammed Ouçamah 
Published: June 2019

AbstractMobile edge computing (MEC) is a recent technology that intends to free mobile devices from computationally intensive workloads by offloading them to a nearby resource‐rich edge architecture. It helps to reduce network traffic bottlenecks and offers new opportunities regarding data and processing privacy. Moreover, MEC‐based applications can achieve lower latency level compared to cloud‐based ones. However, in a multitask multidevice context, the decision of the part to offload becomes critical. Actually, it must consider the available communication resources, the resulting delays that have to be met during the offloading process, and particularly, both local and remote energy consumption. In this paper, we consider a multitask multidevice scenario where smart mobile devices retain a list of heavy offloadable tasks that are delay constrained. Therefore, we formulated the corresponding optimization problem, and we derive an equivalent multiple‐choice knapsack problem formulation. Because of the short decision time constraint and the NP‐hardness of the obtained problem, the optimal solution implementation is infeasible. Hence, we propose a solution that provides, in pseudopolynomial time, the optimal or near‐optimal solutions depending on the problem's settings. In order to evaluate our solution, we carried out a set of simulation experiments to evaluate and compare the performances of the different components of this solution. Finally, the obtained results in terms of execution's time as well as energy consumption are satisfactory and very encouraging.
Effects of different proteases enzymatic extraction on the lipid yield and quality of Antarctic krill oil
Authors: Wang Linlin , Yang Feng , Rong Yali , Yuan Yuan , Ding Yatao , Shi Wenzheng , Wang Zhihe 
Published: June 2019

AbstractThis study was investigated the effects of six proteases (papain, compound proteinase, acidic protease, neutrase, pancreatin, and alcalase) on the lipid yield and quality of krill oil. The result shown that the krill oil extracted by alcalase and compound proteinase led to comparatively higher lipid yields (5.29% and 4.90%, respectively), Content of tocopherols and vitamin A, the content of omega‐3 polyunsaturated fatty acids (PUFAs) and phospholipids extracted by alcalase was relatively higher. Control and alcalase had comparatively higher concentration of astaxanthin. On the whole, compared with the extraction of solvent, enzymatic hydrolysis could improve the quality and the lipid yield of krill oil. Therefore, enzymatic hydrolysis could be used as a better method to extract krill oil.
Do cancer treatments have option value? Real‐world evidence from metastatic melanoma
Authors: Li Meng , Basu Anirban , Bennette Caroline S. , Veenstra David L. , Garrison Louis P. 
Published: June 2019

AbstractA change in the expectations about future treatments may change the option value of a current treatment, thereby affecting its utilization.We conducted an interrupted time series analysis using a large administrative claims database to test whether the utilization of existing cancer treatments changed after the disclosures of the then‐investigational drug ipilimumab's Phase II and Phase III results among metastatic melanoma patients from 2008 to 2011. We used a multinomial logistic regression to analyze the temporal probability of receiving antineoplastic systemic therapy, surgical resection of metastasis, or both, relative to no treatment, in the first 3 months following the first metastasis diagnosis.One thousand eight hundred forty‐six metastatic melanoma patients were included. After adjusting for clinical and sociodemographic variables and the underlying time trend, the disclosure of ipilimumab's Phase II result was associated with a nearly twofold immediate increase in the probability of receiving surgical resection of metastasis relative to no treatment, which was significant at 5% level. No significant effect was observed for the time trend. No significant effects were found for the announcement of the Phase III result.Our findings in metastatic melanoma provide the first empirical evidence of the impact of option value in cancer treatment decision making.
Variable power‐law scaling of hillslope Hortonian rainfall–runoff processes
Authors: Wu Songbai , Chen Li , Wang Ninglian , Xu Shaohui , Bagarello Vincenzo , Ferro Vito 
Published: June 2019

AbstractHydrological studies focused on Hortonian rainfall–run‐off scaling have found that the run‐off depth generally declines with the plot length in power‐law scaling. Both the power‐law proportional coefficient and the scaling exponent show great variability for specific conditions, but why and how they vary remain unclear. In the present study, the scaling of hillslope Hortonian rainfall–run‐off processes is investigated for different rainfall, soil infiltration, and hillslope surface characteristics using the physically based cell‐based rainfall‐infiltration‐run‐off model. The results show that both temporally intermittent and steady rainfalls can result in prominent power‐law scaling at the initial stage of run‐off generation. Then, the magnitude of the power‐law scaling decreases gradually due to the decreasing run‐on effect. The power‐law scaling is most sensitive to the rainfall and soil infiltration parameters. When the ratio of rainfall to infiltration exceeds a critical value, the magnitude of the power‐law scaling tends to decrease notably. For different intermittent rainfall patterns, the power‐law exponent varies in the range of −1.0 to −0.113, which shows an approximately logarithmic increasing trend for the proportional coefficient as a function of the run‐off coefficient. The scaling is also sensitive to the surface roughness, soil sealing, slope angle, and hillslope geometry because these factors control the run‐off routing and run‐on infiltration processes. These results provide insights into the variable scaling of the Hortonian rainfall–run‐off process, which are expected to benefit modelling of large‐scale hydrological and ecological processes.