bluuebunny/crossref_metadata_2025 huggingface dataset:
Facile Synthesis of Nanoporous Pt‐Encapsulated Ir Black as a Bifunctional Oxygen Catalyst via Modified Polyol Process at Room Temperature
Authors: Fang Dahui , Zhang Hongjie , He Liang , Geng Jiangtao , Song Wei , Sun Shucheng , Shao Zhigang , Yi Baolian
Published: June 2019

The exploitation of a bifunctional oxygen catalyst with high efficiency is crucial for a high‐performance unitized regenerative fuel cell (URFC). However, the existing bifunctional oxygen catalysts still suffer from low catalytic efficiency due to sluggish oxygen electrode reactions toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, we report on a facile synthesis of nanoporous Pt‐encapsulated Ir black with Pt/Ir mass ratio of 55/45 (Pt55@Ir45) via a newly modified polyol process at room temperature with the aid of water. The resulting Pt55@Ir45 catalyst demonstrated to be highly efficient and robust for both ORR and OER, relative to a mixture of commercial Pt and Ir black with Pt/Ir mass ratio of 50/50 (Pt50/Ir50). Mass activity of Pt55@Ir45 presented an 8.7‐ and 1.6‐fold increase toward ORR and OER, respectively, compared with the Pt50/Ir50 catalyst. The enhanced bifunctional performance was rationalized in terms of the maximized Pt utilization, achieved by the excellent dispersion of Pt nanoparticles, and the nanoporous Pt layer constructing a conductive network without impeding the transport of oxygen and water molecules. Our work demonstrates an effective means to encapsulate nanoporous Pt layers on Ir black for the fabrication of bifunctional oxygen catalysts.
Influence of Lithium and Lanthanum Treatment on TiO2 Nanofibers and Their Application in n‐i‐p Solar Cells
Authors: Ambroz Filip , Sathasivam Sanjayan , Lee Roxanna , Gadipelli Srinivas , Lin Chieh‐Ting , Xu Shengda , Poduval Radhika K. , Mclachlan Martyn A. , Papakonstantinou Ioannis , Parkin Ivan P. , Macdonald Thomas J.
Published: June 2019

Invited for this month's cover picture is the group of Dr. Macdonald from the Department of Chemistry at University College London (UK). The cover picture shows a scanning electron microscopy image of lanthanum‐treated TiO2 nanofibers rendered to show a three‐dimensional representation of the nanostructured solar cell. This work shows that the addition of lithium and lanthanum cations causes minimal substitutional or interstitial doping of TiO2 nanofibers. In a solar cell, photovoltaic characteristics reveal that lanthanum treatment is beneficial, whereas lithium treatment is found to be detrimental to the device performance for both dye‐sensitized and perovskite solar cells. Read the full text of the Article at 10.1002/celc.201900532.
Asymmetric Hydrogenation of Aryl Perfluoroalkyl Ketones Catalyzed by Rhodium(III) Monohydride Complexes Bearing Josiphos Ligands
Authors: Brüning Fabian , Nagae Haruki , Käch Daniel , Mashima Kazushi , Togni Antonio
Published: June 2019

The asymmetric hydrogenation of 2,2,2‐trifluoroacetophenones and aryl perfluoroalkyl ketones was developed using a unique, well‐defined chloride‐bridged dinuclear rhodium(III) complex bearing Josiphos‐type diphosphine ligands. These complexes were prepared from [RhCl(cod)]2, Josiphos ligands, and hydrochloric acid. As catalyst precursors, they allow for the efficient and enantioselective synthesis (up to 99 % ee) of chiral secondary alcohols with perfluoroalkyl groups. This system does not require an activating base for the hydrogenation of 2,2,2‐trifluoroacetophenones. Additionally, the enantioselective C=O hydrogenations of 2‐phenyl‐3‐(haloacetyl)‐indoles, a class of privileged structures in medicinal chemistry, is reported for the first time.
Preparation and Characterisation of a Bis‐μ‐Hydroxo‐NiIII2 Complex
Authors: Spedalotto Giuseppe , Gericke Robert , Lovisari Marta , Farquhar Erik R. , Twamley Brendan , McDonald Aidan R.
Published: June 2019

Hydroxide‐bridged high‐valent oxidants have been implicated as the active oxidants in methane monooxygenases and other oxidases that employ bimetallic clusters in their active site. To understand the properties of such species, bis‐μ‐hydroxo‐NiII2 complex (1) supported by a new dicarboxamidate ligand (N,N′‐bis(2,6‐dimethyl‐phenyl)‐2,2‐dimethylmalonamide) was prepared. Complex 1 contained a diamond core made up of two NiII ions and two bridging hydroxide ligands. Titration of the 1 e− oxidant (NH4)2[CeIV(NO3)6] with 1 at −45 °C showed the formation of the high‐valent species 2 and 3, containing NiIINiIII and NiIII2 diamond cores, respectively, maintaining the bis‐μ‐hydroxide core. Both complexes were characterised using electron paramagnetic resonance, X‐ray absorption, and electronic absorption spectroscopies. Density functional theory computations supported the spectroscopic assignments. Oxidation reactivity studies showed that bis‐μ‐hydroxide‐NiIII2 3 was capable of oxidizing substrates at −45 °C at rates greater than that of the most reactive bis‐μ‐oxo‐NiIII complexes reported to date.
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

NMR 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

Speech 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

The 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

Resveratrol, 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

The 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.
Light on Molecular Devices
Authors: Credi Alberto
Published: June 2019

Alberto Credi
is a Professor of Chemistry at the Università di Bologna (Italy) and an Associate Research Director at the Consiglio Nazionale delle Ricerche. He is a current member of the ChemPhotoChem Editorial Board.
Court issues ruling on web access complaint against Harvard
Authors: Charmatz Marc
Published: June 2019

A Massachusetts federal court has denied in part and granted in part Harvard University's Motion for Judgment on the Pleadings in National Association of the Deaf, et al. v. Harvard University, et al., a case regarding web accessibility. A March 28, 2019, ruling grants Harvard immunity for third‐party content embedded on its sites but hosted elsewhere. But the court rejected other arguments in Harvard's Motion for Judgment on the Pleadings, and the case will move forward.
Rebrand to emphasize self‐advocacy, independence
Authors: Sutton Halley
Published: June 2019

Andrea Allison, Ed.D., started out as a counselor before she became the director of accessibility and the Program for Alternative Learning Styles at Limestone College. Allison shared how a rebranding of PALS will lead to greater independence on campus for her students, and how her institution's transition from a college to a university will change her office.
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

Migratory 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

Comparing 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.
Synthesis and Characterization of Heterobimetallic Carbonyl Clusters with Direct Au‐Fe and Au···Au Interactions Supported byN‐Heterocyclic Carbene and Phosphine Ligands
Authors: Berti Beatrice , Bortoluzzi Marco , Cesari Cristiana , Femoni Cristina , Iapalucci Maria Carmela , Mazzoni Rita , Vacca Federico , Zacchini Stefano
Published: June 2019

The reaction of Collman's reagent Na2[Fe(CO)4]·2thf with one equivalent of Au(NHC)Cl (NHC = IMes, IPr; IMes = C3N2H2(C6H2Me3)2; IPr = C3N2H2(C6H3iPr2)2) in dmso resulted in the [Fe(CO)4(AuNHC)]–(NHC = IMes,1; IPr,2) mono‐anions.1–2further reacted with Au(NHC)Cl or Au(PPh3)Cl affording the neutral complexes Fe(CO)4(AuNHC)2(NHC = IMes,3; IPr,4), Fe(CO)4(AuIMes)(AuIPr) (5) and Fe(CO)4(AuNHC)(AuPPh3) (NHC = IMes,6; IPr,7).1–7have been spectroscopically characterized by IR,1H,13C{1H} and31P{1H} NMR techniques. Moreover, the molecular structures of1,2,4,6and7have been determined through single‐crystal X‐ray diffraction as their [NMe4][Fe(CO)4(AuIMes)], [NEt4][Fe(CO)4(AuIMes)], [NEt4][Fe(CO)4(AuIPr)], Fe(CO)4(AuIPr)2·1.5toluene, Fe(CO)4(AuIPr)(AuPPh3), Fe(CO)4(AuIMes)(AuPPh3)·0.5CH2Cl2salts and solvates. The nature of the bonds in1and2was elucidated on the basis of atoms‐in molecules (AIM) analyses on the DFT‐optimized structures and compared with the corresponding compounds3and4.1–7contained strong Fe‐CO, Fe‐Au, Au‐P and Au–NHC bonds as well as weak Au···Au interactions. The different stability and reactivity of IMes‐derivatives vs. IPr‐ones was rationalized on the basis of steric effects.
Consider the impact of China's economy on international recruitment
Authors: Dennis Marguerite J.
Published: June 2019

Let's examine some aspects of the Chinese economy and the implications for future international recruitment and enrollment of Chinese students.
University finds success in blending traditional, new approaches
Authors: Enos Gary
Published: June 2019

As a relatively early entrant into offering online learning, Weber State University already has a 20‐ year history of understanding the ways technology alternatives can benefit adult learners. Online and hybrid classes have helped the Utah university grow graduate programs that are tailored to older students, and these options are helping faculty become more at ease with communicating in an online format.
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

Enhanced 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

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

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

Mobile 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

This 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.
Differential exhumation of Jiaodong Peninsula during Early Cretaceous: Evidence from detrital zircon U–Pb isotopic dating
Authors: Gao Biao , Li Zhong
Published: June 2019

The significant Late Mesozoic thinning of lithospheric mantle in eastern China caused the formation of many basins and intensive volcanism. Crust exhumation process is a crucial part of supracrust response of lithosphere destruction. It has been studied in order to constrain the model of Late Mesozoic thinning of lithospheric mantle. The Sulu orogenic belt and the Jiaobei Terrane underwent a substantial exhumation process in Early Cretaceous, and though many studies have been carried out to investigate its exhumation history, it is still lacking understanding. Extensional terrestrial domain of the Jiaolai Basin was formed along with the Early Cretaceous exhumation of the Jiaobei Terrane and the Sulu orogenic belt. It provides an ideal research object for studying the exhumation process of Jiaodong Peninsula in Early Cretaceous because of the continuous sedimentary record in the basin. In this study, we analysed detrital zircon geochronology of three sandstone samples from Early Cretaceous sediments in north‐eastern part of the Jiaolai Basin. Detrital zircon age spectrums indicate that zircon ages consist mainly of six clusters, and they comprise Neoarchean ages, Palaeoproterozoic ages, Neoproterozoic ages, Triassic ages, Jurassic ages, and Early Cretaceous ages. The study shows that the Jiaobei Terrane and the Sulu orogenic belt served as source areas that provided detrital materials for Early Cretaceous strata in the Jiaolai Basin. Our results, along with those of previous studies, suggest that Jiaobei Terrane and the Sulu orogenic belt in Jiaodong Peninsula had discrepant exhumation history in Early Cretaceous.
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

A 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

Hydrological 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.
The Links Between Social and Emotional Learning and Literacy
Authors: Fisher Douglas , Frey Nancy
Published: June 2019

This forum highlights research that literacy teachers, students, and others can explore, use, or adapt as they provide literacy instruction and develop related programs and research agendas.
Mostly harmless simulations? Using Monte Carlo studies for estimator selection
Authors: Advani Arun , Kitagawa Toru , Słoczyński Tymon
Published: June 2019

We consider two recent suggestions for how to perform an empirically motivated Monte Carlo study to help select a treatment effect estimator under unconfoundedness. We show theoretically that neither is likely to be informative except under restrictive conditions that are unlikely to be satisfied in many contexts. To test empirical relevance, we also apply the approaches to a real‐world setting where estimator performance is known. Both approaches are worse than random at selecting estimators that minimize absolute bias. They are better when selecting estimators that minimize mean squared error. However, using a simple bootstrap is at least as good and often better. For now, researchers would be best advised to use a range of estimators and compare estimates for robustness.
Does institutional ownership affect information sharing with independent board members?
Authors: Smith Deborah D. , Meier Heidi H. , Alam Pervaiz
Published: June 2019

Research Question

This is an investigation of board independence to determine whether management shares information with the board, or withholds information to retain autonomy. A key contribution is to examine the interaction of institutional ownership with the main test variables to determine whether institutional governance influences the information environment as board independence is increased.

Research Findings

The results show that information asymmetry decreases internally and increases externally as board independence increases, yet institutional ownership appears to moderate or reverse this relationship. The following variables are used to explain why managers of firms are likely to have more information than outsiders: sticky SG&A costs, bid‐ask spread, and forecast error.

Theoretical/Academic Implications

The desired oversight from independent board members appears to be associated with reduced transparency between the firm and investors. Information sharing is lower for increased board independence when the firm's ownership is less sophisticated.

Practitioner/Policy Implications

These findings suggest that requiring increased board independence may reflect reduced transparency for firms with less institutional ownership. Further research should be conducted on the influence of institutional ownership on board member selection, and the relationship between management and board members appointed with institutional support.
Computational and artificial neural network based study of functional SNPs of human LEPR protein associated with reproductive function
Authors: Gandhi Muruganandhan Saranya , Manian Rameshpathy
Published: June 2019

Genetic polymorphisms are mostly associated with inherited diseases, detecting and analyzing the biological significance of functional single‐nucleotide polymorphisms (SNPs) using wet laboratory experiments is an arduous task hence the computational analysis of putative SNPs is essential before conducting a study on a large population. SNP in the leptin receptor (LEPR) could result in the retention of intracellular signalling due to the structural and functional instability of the receptor causing abnormal reproductive function in human. In this first comprehensive computational analysis of LEPR gene mutation, we have identified and analyzed the functional consequence and structural significance of the SNPs in LEPR using recently developed several computational algorithms. Thirteen deleterious mutations such as W13C, S93G, I232R, Q307H, Y354C, E497A, Q571H, R612H, K656N, T690A, T699M V741M, and L760R were identified in the LEPR gene coding region. Backpropagation algorithm has been developed to forestall the deleterious nature of SNP and to validate the outcome of the tested computational tools. From ConSurf prediction three SNPs (Q571H, R612H, and T699M) were highly conserved on LEPR protein and the most deleterious variant R612H had one hydrogen bond abolished and severely reduced protein stability. Molecular docking suggested that the mutant (R612H) LEPR had lowest binding energy than native LEPR with the ligand molecule. Thus the energetically destructive changeover of ARG to HIS in R612H could possibly affect the LEPR protein structural stability and functional constancy due to interruption in the amino acid interactions and could result in reproductive disorders in human and increases the complication in obstetric and pregnancy outcome.
“The hook‐up”: How youth‐serving organizations facilitate network‐based social capital for urban youth of color
Authors: Dill LeConté J. , Ozer Emily J.
Published: June 2019

Young people of color residing in distressed urban contexts face challenges in accessing social capital that supports positive development and the transition to educational and employment opportunities. Youth‐serving organizations play potentially important roles for youth participants to access and leverage networks. This ethnographic study draws on qualitative interviews, conducted with adolescents at a youth‐serving organization based in East Oakland, California, to examine how network‐based social capital is activated and sustained for and by urban Black and Latinx youth. We found that relationships with supportive adult staff at the organization put youth in contact with caring, trusted adults of color outside of their families who serve as role models for them. These adults provide loving accountability to young people, serving as critical forces in distressed and stigmatized communities. We also found that adult staff activate social leverage to garner various current and future educational and professional opportunities for the youth there. These unique opportunities serve to boost young people's current self‐esteem and also to prime them to envision positive futures for themselves. Overall, these findings point to the importance of interpersonal pathways embedded within neighborhood institutions in the activation of network‐based social capital.
Endoscopic yield of chronic dyspepsia in outpatients: A single‐center experience in Cambodia
Authors: Oung Borathchakra , Chea Khang , Oung Chakravuth , Saurin Jean‐Christophe , Ko Cynthia W
Published: June 2019

Background and Aim

The diagnostic evaluation and management of patients with chronic dyspepsia may differ geographically according to patient age, prevalence of Helicobacter pylori or parasitic infection, and risk of gastric cancer. The characteristics and appropriate investigation of Cambodian patients with dyspepsia have not previously been studied. The aim of this study was to investigate the characteristics of Cambodian patients with chronic dyspepsia, the yield of upper endoscopy in these patients, and the value of alarm features in identifying patients with organic causes of dyspepsia.

Methods

We conducted a retrospective, single‐center study of 1231 adults with chronic dyspepsia who underwent upper endoscopy. We compared clinical characteristics, H. pylori prevalence, and endoscopic and histological findings of patients with functional or organic causes of dyspepsia. This study was approved by the National Ethics Committee for Health Research.

Results

The majority of patients had overlapping symptoms of epigastric pain/burning and postprandial fullness/early satiety (40.6%), followed by epigastric pain/burning alone (29.7%) and postprandial fullness/early satiety alone (29.7%). Organic lesions were diagnosed in 6.9% of patients. The overall prevalence of H. pylori infection was 46% and was similar in the three clinical subgroups. The sensitivity and specificity of alarm features for organic causes of dyspepsia were 14 and 96%, respectively. The majority of patients with gastric cancer were 40 years of age or older.

Conclusions

The majority of patients with chronic dyspepsia seen at our outpatient center were diagnosed with functional or H. pylori‐associated dyspepsia. The presence of alarm features was not sensitive or specific for differentiating organic and functional dyspepsia.
Clinical impact of the sequentially‐checked drain removal criteria on postoperative outcomes after pancreatectomy: a retrospective study
Authors: Kosaka Hisashi , Satoi Sohei , Yamamoto Tomohisa , Hirooka Satoshi , Yamaki So , Kotsuka Masaya , Sakaguchi Tatsuma , Inoue Kentaro , Matsui Yoichi , Sekimoto Mitsugu
Published: June 2019

Background

Strict criteria for impeccably safe drain management following pancreatectomy have not yet been developed. We evaluated the utility of the sequentially‐checked drain removal criteria by comparison with conventional criteria.

Methods

Postoperative outcomes of 801 patients who underwent pancreatectomy, including 395 patients for whom drain fluid amylase (DFA) < 375U/l on postoperative day (POD) 3 (control group), were used and 406 patients for whom the sequentially‐checked criteria of DFA <5,000 U/l on POD 1 and DFA <3,000 U/l on POD 3 (sequentially‐checked group) were used and were retrospectively evaluated.

Results

DFA on POD 3 and fistula risk score did not differ between groups. Significantly more patients in the sequentially‐checked group met the criteria (control, 63.8% vs. sequentially‐checked, 76.1%, P < 0.001). The incidences of clinically relevant postoperative pancreatic fistula (CR‐POPF) (17.0% vs. 11.1%), intra‐abdominal abscess (21.0% vs. 9.1%) were significantly lower in the sequentially‐checked group (all P < 0.05). Multivariate analysis revealed that use of the sequentially‐checked criteria was significantly associated with CR‐POPF (odds ratio 0.601, 95% confidence interval [CI] 0.389–0.929; P = 0.022). C‐reactive protein <15 mg/dl at POD 3 was identified as an independent predictive factor for false positive CR‐POPF results in the sequentially‐checked group (odds ratio 0.872, 95% CI 0.811–0.939; P < 0.001); thus, this criterion was added to create the new triple‐checked criteria.

Conclusions

The sequentially‐checked criteria can provide safe drain management and improve postoperative outcomes.
Efficient Solvent‐Free Synthesis of Sucrose Esters via Sand‐Milling Pretreatment on Solid–Liquid Mixtures
Authors: Chen Jiazhi , Li Yuan , Chen Xiaotian , Mai Yuliang , Gao Minjie , Zhang Junjie , Wang Xi
Published: June 2019

A general and efficient method, involving sand‐milling pretreatment and base‐catalyzed transesterification of sucrose and fatty acid methyl ester (FAME), was presented for the solvent‐free synthesis of sucrose esters. A metastable homogeneous paste with a solid particle size of 13 μm (D50) was obtained by milling at 1000 rpm for 1 h. This reaction mixture generated a total SE yield of 88.2% with a methyl stearate (MS) conversion of 91.4% using K2CO3 as a catalyst at 135 °C for 3 h at a stirring rate of 500 rpm, while those without milling (D50, 153 μm) yielded a total sucrose fatty acid esters (SE) of 49.3% with a MS conversion of 83.1% under the same reaction conditions. The reaction kinetics revealed that the reaction mixture with milling pretreatment displays a shorter induction time and a faster reaction rate for the formation of SE. The promotion of the solvent‐free synthesis of SE in the current study could be attributed to the reduction of solid particle sizes and the increased compatibility of solid–liquid phases. We believe that this strategy could be used as a general way for strengthening other heterogeneous reactions in the organic synthesis.
Percutaneous cryoablation for the treatment of extra‐abdominal desmoid tumors
Authors: Redifer Tremblay Kaila , Lea William B. , Neilson John C. , King David M. , Tutton Sean M.
Published: June 2019

Background

Desmoid tumors are rare locally invasive, benign neoplasms that develop along aponeurotic structures. Current treatment is complicated by associated morbidity and high recurrence rates.

Methods

A retrospective, single‐institution review identified 23 patients (age: 16‐77) with extra‐abdominal desmoid tumors who received CT‐guided percutaneous cryoablation as either a first‐line (61%) or salvage (39%) treatment in 30 sessions between 2014 and 2018. Median maximal lesion diameter was 69 mm (range: 11‐209). Intent was curative in 52% and palliative in 48%. Contrast‐enhanced cross‐sectional imaging was obtained before and after treatment in addition to routine clinical follow‐up.

Results

Technical success was achieved in all patients. The median follow‐up was 15.4 months (3.5‐43.4). Symptomatic improvement was demonstrated in 89% of patients. At 12 months, the average change in viable volume was  −80% (range −100% to  + 10%) and response by modified response evaluation criteria in solid tumors (mRECIST) was CR 36%, PR 36%, and SD 28% No rapid postablation growth or track seeding was observed. Four patients underwent repeat cryoablation for either residual or recurrent disease. Two patients sustained a major procedural complication consisting of significant neuropraxia.

Conclusion

Cryoablation for desmoid tumors demonstrates a high degree of symptom improvement and local tumor control on early follow‐up imaging with relatively low morbidity.