bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of the initial particle size distribution for coal combustion simulations
Authors: Shen Haoshu , Wu Yuxin , Zhou Minmin , Smith Sean T. , Zhang Hai , Yue Guangxi
Published: April 2019

Pulverized coal generally features wide particle‐size distributions (PSD). How to set an initial PSD in coal combustion simulation remains an open question. To answer this, the Gaussian‐quadrature theory was applied to provide a discrete reconstruction of the PSD described by Rosin‐Rammler and Upper‐Limit functions. From the perspective of the moments of PSD, a theoretical analysis was conducted for mass, momentum, and energy exchange terms between gas and particle phases in pulverized coal jet flame. The analysis presented that the first, the second and the third moments of PSD were the most important to capture the flame ignition behavior. The large eddy simulations showed that the proposed method with two or more particle sizes could provide good predictions of flame ignition distances. And Sauter mean diameter (D32) could represent the complete PSD when predicting the ignition behavior of pulverized coal jet flame.
Magnesium‐Catalyzed Hydroboration of Terminal and Internal Alkynes
Authors: Magre Marc , Maity Bholanath , Falconnet Alban , Cavallo Luigi , Rueping Magnus
Published: April 2019

A magnesium‐catalyzed hydroboration of alkynes providing good yields and selectivities for a wide range of terminal and symmetrical and unsymmetrical internal alkynes has been developed. The compatibility with many functional groups makes this magnesium catalyzed procedure attractive for late stage functionalization. Experimental mechanistic investigations and DFT calculations reveal insights into the reaction mechanism of the magnesium catalyzed protocol.
Piece by Piece—Electrochemical Synthesis of Individual Nanoparticles and their Performance in ORR Electrocatalysis
Authors: Evers Mathies V. , Bernal Miguel , Roldan Cuenya Beatriz , Tschulik Kristina
Published: April 2019

The impact of individual HAuCl4 nanoreactors is measured electrochemically, which provides operando insights and precise control over the modification of electrodes with functional nanoparticles of well‐defined size. Uniformly sized micelles are loaded with a dissolved metal salt. These solution‐phase precursor entities are then reduced electrochemically—one by one—to form nanoparticles (NPs). The charge transferred during the reduction of each micelle is measured individually and allows operando sizing of each of the formed nanoparticles. Thus, particles of known number and sizes can be deposited homogenously even on nonplanar electrodes. This is demonstrated for the decoration of cylindrical carbon fibre electrodes with 25±7 nm sized Au particles from HAuCl4‐filled micelles. These Au NP‐decorated electrodes show great catalyst performance for ORR (oxygen reduction reaction) already at low catalyst loadings. Hence, collisions of individual precursor‐filled nanocontainers are presented as a new route to nanoparticle‐modified electrodes with high catalyst utilization.
Unprecedented Five‐Coordinate Iron(IV) Imides Generate Divergent Spin States Based on the Imide R‐Groups
Authors: Anneser Markus R. , Elpitiya Gaya R. , Townsend Jacob , Johnson Elizabeth J. , Powers Xian B. , DeJesus Joseph F. , Vogiatzis Konstantinos D. , Jenkins David M.
Published: April 2019

Three five‐coordinate iron(IV) imide complexes have been synthesized and characterized. These novel structures have disparate spin states on the iron as a function of the R‐group attached to the imide, with alkyl groups leading to low‐spin diamagnetic (S=0) complexes and an aryl group leading to an intermediate‐spin (S=1) complex. The different spin states lead to significant differences in the bonding about the iron center as well as the spectroscopic properties of these complexes. Mössbauer spectroscopy confirmed that all three imide complexes are in the iron(IV) oxidation state. The combination of diamagnetism and 15N labeling allowed for the first 15N NMR resonance recorded on an iron imide. Multi‐reference calculations corroborate the experimental structural findings and suggest how the bonding is distinctly different on the imide ligand between the two spin states.
Antibacterial and thermomechanical properties of composites of polylactic acid modified with capsicum oleoresin‐impregnated nanoporous silica
Authors: Techawinyutham Laongdaw , Siengchin Suchart , Parameswaranpillai Jyotishkumar , Dangtungee Rapeephun
Published: April 2019

Biodegradable composite films of poly(lactic acid) (PLA) modified with varying amounts of capsicum oleoresin (CO)‐impregnated nanoporous silica (SiCO) were prepared. The antimicrobial and thermomechanical properties of the PLA composites were carefully investigated. The Gram‐positive pathogenic bacteria (Staphylococcus aureus and Bacillus) and the Gram‐negative pathogenic bacteria (Escherichia coli and Salmonella enterica) tests established excellent antimicrobial properties of the composites even at small concentrations of SiCO. The microscopic (scanning electron micrograph) and spectroscopic (energy‐dispersive X‐ray) investigations manifested the uniformity of particle distribution. Although the addition of CO slightly decreased the thermal stability of the composite films, it marginally enhanced the mechanical properties and crystallinity. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47825.
Flexible phase change filament with ionic liquid core
Authors: Lin Chao , Yan Yurong , Liu Zhengyu , Ke Hanhan , Qiu Zhiming , Hufenus Rudolf
Published: April 2019

A flexible phase change filament with core‑sheath structure was successfully prepared by post‐filling of a polypropylene (PP) hollow fiber. The ionic liquid (IL) 1‐butyl‐4‐methylpyridinium hexafluorophosphate was chosen as core component, while copper decorated muscovite (Cu‐MVT) was synthesized via in situ reduction and used as the refining additive for the IL. Results from differential scanning calorimetry demonstrated that the encapsulation ratio of the flexible phase change filament reached 93% with a fusion latent heat of 52.7 J/g at 48.3 °C. Supercooling of the ionic liquid was suppressed effectively as shown by the crystallization in the cooling step due to the addition of Cu‐MVT. The flexible phase change material with core‑sheath structure also showed good thermal stability, durability, and mechanical property under the protection of the sheath polymer material. It is evident that the phase change filament possesses promising characteristics for thermal energy storage and thermoregulation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47830.
The ubiquitous digital file: A review of file management research
Authors: Dinneen Jesse David , Julien Charles‐Antoine
Published: April 2019

Computer users spend time every day interacting with digital files and folders, including downloading, moving, naming, navigating to, searching for, sharing, and deleting them. Such file management has been the focus of many studies across various fields, but has not been explicitly acknowledged nor made the focus of dedicated review. In this article we present the first dedicated review of this topic and its research, synthesizing more than 230 publications from various research domains to establish what is known and what remains to be investigated, particularly by examining the common motivations, methods, and findings evinced by the previously furcate body of work. We find three typical research motivations in the literature reviewed: understanding how and why users store, organize, retrieve, and share files and folders, understanding factors that determine their behavior, and attempting to improve the user experience through novel interfaces and information services. Relevant conceptual frameworks and approaches to designing and testing systems are described, and open research challenges and the significance for other research areas are discussed. We conclude that file management is a ubiquitous, challenging, and relatively unsupported activity that invites and has received attention from several disciplines and has broad importance for topics across information science.
Perceived quality and self‐identity in scholarly publishing
Authors: Moksness Lars , Olsen Svein Ottar
Published: April 2019

The purpose of the study was to understand if and how 2 proposed facets of self‐identity (work‐self and career‐self) and journals' perceived quality (impact, visibility, and content quality) influence and explain the intention to publish in open access (OA) or nonopen access (non‐OA) journals. This study integrates attitude and identity theory within a cross‐sectional survey design. The sample consists of about 1,600 researchers in Norway, and the data were collected via e‐mail invitation using a digital surveying tool and analyzed using structural equation modeling techniques. We determined that perceived impact‐quality increases the intention to publish non‐OA, while decreasing the intention to publish OA. Content quality is only associated with non‐OA journals. Perceived visibility increases the intention to publish OA, while the opposite effect is found for non‐OA. Career‐self salience has the strongest effect on impact‐quality, while content quality is most important when work‐self is salient. This research contributes to a deeper understanding about how perceived quality influences intention to publish in OA and non‐OA journals, and how self‐identity salience affects different facets of perceived quality in valence and strength. Findings have implications for policy development, implementation, and assessment and may contribute to improving OA adoption.
A LADRC based fuzzy PID approach to contour error control of networked motion control system with time‐varying delays
Authors: Wang Yao‐Wei , Zhang Wen‐An , Dong Hui , Yu Li
Published: April 2019

This paper investigate the contour error control problem for networked multi‐axis motion system (NMAMS) with time‐varying delays. Firstly, the uncertainties induced by the delays are modeled as a part of the total disturbance, and a linear active disturbance rejection controller (LADRC) is designed for the uniaxial trajectory tracking control. In the LADRC, a linear extended state observer (LESO) is designed to estimate the system state and the total disturbance simultaneously, and the effect of the total disturbance is eliminated by the designed linear feedback error control law. Then, the classical contour error estimation method is adopted, and a fuzzy PID controller is designed to compensate the contour error to achieve a better contour tracking performance. Finally, experiments are provided to verify the effectiveness of the proposed method.
Profiting from correlations: Adjusted estimators for categorical data
Authors: Niebuhr Tobias , Trabs Mathias
Published: April 2019

To take sample biases and skewness in the observations into account, practitioners frequently weight their observations according to some marginal distribution. The present paper demonstrates that such weighting can indeed improve the estimation. Studying contingency tables, estimators for marginal distributions are proposed under the assumption that another marginal is known. It is shown that the weighted estimators have a strictly smaller asymptotic variance whenever the two marginals are correlated. The finite sample performance is illustrated in a simulation study. As an application to traffic accident data the method allows for correcting a well‐known bias in the observed injury severity distribution.
Early processing (N170) of infant faces in mothers of children with autism spectrum disorder and its association with maternal sensitivity
Authors: Márquez Carla , Nicolini Humberto , Crowley Michael J. , Solís‐Vivanco Rodolfo
Published: April 2019

Individuals with autism spectrum disorder (ASD) exhibit impaired adult facial processing, as shown by the N170 event‐related potential. However, few studies explore such processing in mothers of children with ASD, and none has assessed the early processing of infant faces in these women. Moreover, whether processing of infant facial expressions in mothers of children with ASD is related to their response to their child's needs (maternal sensitivity [MS]) remains unknown. This study explored the N170 related to infant faces in a group of mothers of children with ASD (MA) and a reference group of mothers of children without ASD. For both emotional (crying, smiling) and neutral expressions, the MA group exhibited larger amplitudes of N170 in the right hemisphere, while the reference group showed similar interhemispheric amplitudes. This lateralization effect within the MA group was not present for nonfaces and was stronger in the mothers with higher MS. We propose that mothers of ASD children use specialized perceptual resources to process infant faces, and this specialization is mediated by MS. Our findings suggest that having an ASD child modulates mothers' early neurophysiological responsiveness to infant cues. Whether this modulation represents a biological marker or a response given by experience remains to be explored. Autism Research 2019, 12: 744–758. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

When mothers of children with autism spectrum disorder (ASD) see baby faces expressing emotions, they show a right‐sided electrical response in the brain. This lateralization was stronger in mothers who were more sensitive to their children's needs. We conclude that having a child with ASD and being more attuned to their behavior generates a specialized pattern of brain activity when processing infant faces. Whether this pattern is biological or given by experience remains to be explored.
A kinetic model considering the heterogeneous nature of the enzyme hydrolysis of lignocellulosic materials
Authors: Caro Ildefonso , Blandino Ana , Díaz Ana B. , Marzo Cristina
Published: April 2019

In this work, a mathematical model is proposed to predict the kinetic behaviour of the enzymatic conversion of various types of lignocellulosic biomass into fermentable sugars. Digestion of the cellulosic polymers is carried out using enzymatic hydrolysis under different conditions. Unlike other kinetic models, published previously for this process, this one considers the heterogeneous nature of the process by which a solid, in the form of small particles, is decomposed to monosaccharides by the action of a diverse set of enzymes in solution. The effect of the particle size on the hydrolysis rate has also been taken into consideration.

To assess the model's goodness of fit to any general situation, the experimental data obtained in the hydrolysis of three different lignocellulosic residues have been analysed. Thus, the hydrolysis data of wheat straw, rice husks and exhausted sugar beet pellets have been compared with the theoretical values calculated by the model. The results obtained show that this model predicts the enzyme's hydrolysis of lignocellulosic substrates under different conditions very accurately and it could therefore be used efficiently in the optimization of the hydrolysis processes implemented in the bio‐refinery industry. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd
Exhaust emissions and conversion efficiency of catalytic converter for an ethanol‐fueled spark ignition engine
Authors: Kim Jaesoo , Myung Cha‐Lee , Lee Kyung‐Hwan
Published: April 2019

The effects of the air‐fuel (A/F) ratio and spark timing on exhaust emissions and thermal efficiency were analyzed under part load conditions using an ethanol‐fueled spark ignition (SI) engine. The conversion efficiency of exhaust emissions after the application of a three‐way catalyst (TWC) to a gasoline engine was also evaluated. The cycle‐resolved measurement of hydrocarbon (HC) and NOx emissions was attempted, to investigate phenomena in the exhaust port with a fast‐response exhaust gas analyzer, and this was compared under different operating conditions. The different HC emission trends for the relative A/F ratios, as measured by a conventional exhaust gas analyzer and by the fast response analyzer, are thought to be due to differences in measuring location and the oxidation reaction of HC in the exhaust system. To optimize the ethanol A/F ratio to improve the conversion efficiency of TWC, it is thought that a slightly richer or leaner A/F ratio than stoichiometry would be better depending on the operating conditions and the levels of HC, CO, and NOx emissions, because the conversion efficiency of HC and CO is better with a leaner A/F ratio and the conversion efficiency of NOx is increased with a richer A/F ratio. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd
Engineered Skin Tissue Equivalents for Product Evaluation and Therapeutic Applications
Authors: Suhail Sana , Sardashti Naseem , Jaiswal Devina , Rudraiah Swetha , Misra Manoj , Kumbar Sangamesh G.
Published: April 2019

The current status of skin tissue equivalents that have emerged as relevant tools in commercial and therapeutic product development applications is reviewed. Due to the rise of animal welfare concerns, numerous companies have designed skin model alternatives to assess the efficacy of pharmaceutical, skincare, and cosmetic products in an in vitro setting, decreasing the dependency on such methods. Skin models have also made an impact in determining the root causes of skin diseases. When designing a skin model, there are various chemical and physical considerations that need to be considered to produce a biomimetic design. This includes designing a structure that mimics the structural characteristics and mechanical strength needed for tribological property measurement and toxicological testing. Recently, various commercial products have made significant progress towards achieving a native skin alternative. Further research involve the development of a functional bilayered model that mimics the constituent properties of the native epidermis and dermis. In this article, the skin models are divided into three categories: in vitro epidermal skin equivalents, in vitro full‐thickness skin equivalents, and clinical skin equivalents. A description of skin model characteristics, testing methods, applications, and potential improvements is presented.
The art of surgery
Authors: Sterpetti A V
Published: April 2019

Published online in Wiley Online Library (www.bjs.co.uk). DOI:  10.1002/bjs.10863

In times when art usually depicted perfection, Caravaggio (1571–1610) painted everyday reality. He used people walking the streets of Rome to represent holy figures. Caravaggio loved many women. He killed a man in a duel and had to flee from Rome to avoid being ‘beheaded by anybody who saw him’.

In this biblical scene he painted, Judith Beheading Holofernes, Judith is a portrait of Fillide Melandroni, the reason for the duel. Holofernes is a self-portrait. Judith looks cruel, in mourning clothes, seeking revenge for the assassination of her lover. The maidservant, almost an evil spirit, has a voluminous thyroid goitre, and she seems to encourage the revenge of Fillide.

Read more about Caravaggio and this painting in an essay online.
Anxa2‐ and Ctsd‐knockout CHO cell lines to diminish the risk of contamination with host cell proteins
Authors: Fukuda Nobuo , Senga Yukako , Honda Shinya
Published: April 2019

Chinese hamster ovary (CHO) cells have been used as host cells in the production of a range of recombinant therapeutic proteins, including monoclonal antibodies and Fc‐fusion proteins. Host cell proteins (HCP) represent impurities that must be removed from therapeutic formulations because of their potential risks for immunogenicity. While the majority of HCP impurities are effectively removed in typical downstream purification processes, clearance of a small population of HCP remains challenging. In this study, we knocked out the Anxa2 and Ctsd genes to assess the feasibility of knockout approaches for diminishing the risk of contamination with HCP. Using the CRISPR/Cas9 system, Anxa2‐, and Ctsd‐knockout CHO cell lines were successfully established, and we confirmed the complete elimination of the corresponding HCP in cell lysates. Importantly, all knockout cell lines showed similar growth and viability to those of the wild‐type control during 8 days of cultivation. Thus, knockout of unrequired genes can reduce contamination with HCP in the production of recombinant therapeutic proteins.
Antioxidant and Antimelanogenic Activities of Compounds Isolated from the Aerial Parts of Achillea alpina L.
Authors: Lee Hyun Joo , Sim Mi Ok , Woo Kyeong Wan , Jeong Da‐Eun , Jung Ho Kyung , An Byeongkwan , Cho Hyun Woo
Published: April 2019

Achillea alpina is widely distributed in Korea and is often used as a folk medicine for stomach disorders. Although a previous study isolated antioxidant compounds (flavonoid O‐glucoside, sesquiterpene) from this plant, no systematic study of its chemical constituents had been reported. The present study aimed to identify the phytochemicals present in a methanol extract of A. alpina, assess their potential antioxidant activities in vitro, and determine their effects on melanogenesis in B16F10 melanoma cells. Column chromatographic separation of aqueous fractions of A. alpina led to the isolation of 17 compounds. The chemical structures of these compounds were determined using spectroscopic data from electrospray ionization‐mass spectrometry and nuclear magnetic resonance. To the best of our knowledge, the present study is the first to identify compounds 2–10 and 12–17 in A. alpina. Furthermore, compound 6 possessed powerful antioxidant activity, while compound 15 suppressed intracellular tyrosinase activity and thus reduced melanogenesis in B16F10 cells. Therefore, our research suggested that these naturally occurring compounds have the potential to reduce oxidative stress and promote skin whitening. Further investigations will be required to elucidate the mechanisms underlying the antioxidant and antityrosinase activities of these compounds.
Design, Synthesis and Biological Activities of New Pyrazole Derivatives Possessing Both Coxib and Combretastatins Pharmacophores
Authors: Thi Thuy Hang Nguyen , Thi Yen Tran , Nguyen Le Anh , Vo Ngoc Binh , Ngo Quoc Anh
Published: April 2019

In our efforts to discover novel multi‐target agents having better antitumor activities than celecoxib, 21 new aryl‐substituted pyrazole derivatives possessing cis‐diphenylethylene scaffold were mostly synthesized by a one‐pot approach to ethyl 1,4,5‐triaryl‐1H‐pyrazole‐3‐carboxylates via an improved Claisen condensation – Knorr reaction sequence. The cytotoxic effects of these compounds against three human cancer cell lines HT‐29, Hep‐G2, MCF‐7 as well as their inhibition of NO production were studied. Results showed that incorporation of the important pharmacophoric groups of two original molecules celecoxib and combretastatin A‐4 in a single molecule plays an important role in determining a better biological activities of the new coxib‐hybrided compounds.
Synthesis of Erythropoietins Site‐Specifically Conjugated with Complex‐Type N‐Glycans
Authors: Streichert Katharina , Seitz Carina , Hoffmann Eugenia , Boos Irene , Jelkmann Wolfgang , Brunner Thomas , Unverzagt Carlo , Rubini Marina
Published: April 2019

The biological activity of the glycoprotein hormone erythropoietin (EPO) is dependent mainly on the structure of its N‐linked glycans. We aimed to readily attach defined N‐glycans to EPO through copper‐catalyzed azide alkyne cycloaddition. EPO variants with an alkyne‐bearing non‐natural amino acid (Plk) at the N‐glycosylation sites 24, 38, and 83 were obtained by amber suppression followed by protein purification and refolding. Click conjugation of the alkynyl EPOs with biantennary N‐glycan azides provided biologically active site‐specifically modified EPO glycoconjugates.
Role of PLD−PKCζ signaling axis in p47phox phosphorylation for activation of NADPH oxidase by angiotensin II in pulmonary artery smooth muscle cells
Authors: Chakraborti Sajal , Sarkar Jaganmay , Chakraborti Tapati
Published: April 2019

We sought to determine the mechanism by which angiotensin II (ANGII) stimulates NADPH oxidase‐mediated superoxide (O2.−) production in bovine pulmonary artery smooth muscle cells (BPASMCs). ANGII‐induced increase in phospholipase D (PLD) and NADPH oxidase activities were inhibited upon pretreatment of the cells with chemical and genetic inhibitors of PLD2, but not PLD1. Immunoblot study revealed that ANGII treatment of the cells markedly increases protein kinase C‐α (PKC‐α), ‐δ, ‐ε, and ‐ζ levels in the cell membrane. Pretreatment of the cells with chemical and genetic inhibitors of PKC‐ζ, but not PKC‐α, ‐δ, and ‐ε, attenuated ANGII‐induced increase in NADPH oxidase activity without a discernible change in PLD activity. Transfection of the cells with p47phox small interfering RNA inhibited ANGII‐induced increase in NADPH oxidase activity without a significant change in PLD activity. Pretreatment of the cells with the chemical and genetic inhibitors of PLD2 and PKC‐ζ inhibited ANGII‐induced p47phox phosphorylation and subsequently translocation from cytosol to the cell membrane, and also inhibited its association with p22phox (a component of membrane‐associated NADPH oxidase). Overall, PLD−PKCζ−p47phox signaling axis plays a crucial role in ANGII‐induced increase in NADPH oxidase‐mediated O2.− production in the cells.
Effect of cutting balloon after rotational atherectomy in severely calcified coronary artery lesions as assessed by optical coherence tomography
Authors: Amemiya Kisaki , Yamamoto Myong Hwa , Maehara Akiko , Oyama Yuji , Igawa Wataru , Ono Morio , Kido Takehiko , Ebara Seitarou , Okabe Toshitaka , Yamashita Kennosuke , Hoshimoto Koichi , Saito Shigeo , Yakushiji Tadayuki , Isomura Naoei , Araki Hiroshi , Mintz Gary S. , Ochiai Masahiko
Published: April 2019

Objectives

Using optical coherence tomography (OCT), we evaluated the effect of a cutting balloon (CB) compared with a conventional balloon after rotational atherectomy (RA) and before stenting in severely calcified coronary lesions.

Background

A CB is designed to create discrete incisions to facilitate fracture of severely calcified plaque.

Methods

OCT was performed preintervention (if possible), post‐RA, and poststent implantation. RA modification of calcium was defined as a polished, concave, round‐shaped surface. Calcium fracture was defined as a break in the calcium plate. The effects of calcium modification and stent expansion between CB (n = 18) versus conventional balloon (n = 23) following RA were compared.

Results

Median patient age was 72 years with 24% on hemodialysis. The amount of calcium and the length of RA modification were comparable between the CB and conventional balloon groups. Final poststent OCT showed that the number and thickness of calcium fracture were greater after CB versus conventional balloon, resulting better stent expansion (78.9% [IQR: 72.4–88.1] vs. 66.7% [IQR: 55.0–76.7], p < 0.01). In the multivariable model, after adjusting for the amount of calcium, CB use was an independent predictor of the presence of calcium fracture (odds ratio 30.0; 95% confidence interval 2.7–994.1, p = 0.004) and an independent predictor for greater stent expansion (regression coefficient 7.4; 95% confidence interval 0.5–14.3, p = 0.04).

Conclusion

In severely calcified lesions calcium fracture was more often associated with RA followed by CB compared with RA followed by conventional balloon predilation before stenting. CB use was also a determinant of greater stent expansion.
Leaded Bronze Alloy as a Catalyst for the Electroreduction of CO2
Authors: Gálvez‐Vázquez María de Jesús , Moreno‐García Pavel , Guo Huizhang , Hou Yuhui , Dutta Abhijit , Waldvogel Siegfried R. , Broekmann Peter
Published: April 2019

The performance of a leaded bronze alloy with CuSn7Pb15 (wt %) chemical composition is studied as a cathode material for CO2 electroreduction (CO2RR) in aqueous 0.5 M KHCO3 electrolyte. It was found that the catalytic characteristics of the proposed CO2RR electrocatalyst are dominated by elemental lead. Surface characterization by means of digital 3D optical microscopy, white light interferometry, scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX) and scanning auger microscopy (SAM) revealed that segregated Pb clusters embedded in a Cu‐rich Cu/Sn matrix are, to a large extent, dispersed on the cathode surface upon sample preparation through mechanical polishing. Identical location SEM‐EDX studies before and after CO2 electrolysis revealed that further Pb surface redistribution takes place under operando CO2RR conditions, provided sufficiently high potentials are applied. The as‐prepared electrocatalyst proved to be a suitable and powerful alternative for the selective and efficient production of formate (maximum achieved faradaic efficiency and partial current density for formate are 58.6 % and −11.08 mA cm−2 at −1.07 V and −1.17 V vs. RHE, respectively). Moreover, in comparison to neat lead, this material can be handled with less precaution.
[18F]Ethenesulfonyl Fluoride as a Practical Radiofluoride Relay Reagent
Authors: Zhang Bo , Fraser Benjamin H. , Klenner Mitchell A. , Chen Zhen , Liang Steven H. , Massi Massimiliano , Robinson Andrea J. , Pascali Giancarlo
Published: April 2019

Fluorine‐18 is the most utilized radioisotope in positron emission tomography (PET), but the wide application of fluorine‐18 radiopharmaceuticals is hindered by its challenging labelling conditions. As such, many potentially important radiotracers remain underutilized. Herein, we describe the use of [18F]ethenesulfonyl fluoride (ESF) as a novel radiofluoride relay reagent that allows radiofluorination reactions to be performed in minimally equipped satellite nuclear medicine centres. [18F]ESF has a simple and reliable production route and can be stored on inert cartridges. The cartridges can then be shipped remotely and the trapped [18F]ESF can be liberated by simple solvent elution. We have tested 18 radiolabelling precursors, inclusive of model and clinically used structures, and most precursors have demonstrated comparable radiofluorination efficiencies to those obtained using a conventionally dried [18F]fluoride source.
Additive‐Free Isomerization of Allylic Alcohols to Ketones with a Cobalt PNP Pincer Catalyst
Authors: Spiegelberg Brian , Dell'Acqua Andrea , Xia Tian , Spannenberg Anke , Tin Sergey , Hinze Sandra , de Vries Johannes G.
Published: April 2019

Catalytic isomerization of allylic alcohols in ethanol as a green solvent was achieved by using air and moisture stable cobalt (II) complexes in the absence of any additives. Under mild conditions, the cobalt PNP pincer complex substituted with phenyl groups on the phosphorus atoms appeared to be the most active. High rates were obtained at 120 °C, even though the addition of one equivalent of base increases the speed of the reaction drastically. Although some evidence was obtained supporting a dehydrogenation–hydrogenation mechanism, it was proven that this is not the major mechanism. Instead, the cobalt hydride complex formed by dehydrogenation of ethanol is capable of double‐bond isomerization through alkene insertion–elimination.
Stable Lewis Base Adducts of Tetrahalodiboranes: Synthetic Methods and Structural Diversity
Authors: Englert Lukas , Stoy Andreas , Arrowsmith Merle , Muessig Jonas H. , Thaler Melanie , Deißenberger Andrea , Häfner Alena , Böhnke Julian , Hupp Florian , Seufert Jens , Mies Jan , Damme Alexander , Dellermann Theresa , Hammond Kai , Kupfer Thomas , Radacki Krzysztof , Thiess Torsten , Braunschweig Holger
Published: April 2019

A series of 22 new bis(phosphine), bis(carbene), and bis(isonitrile) tetrahalodiborane adducts has been synthesized, either by direct adduct formation with highly sensitive B2X4 precursors (X=Cl, Br, I) or by ligand exchange at stable B2X4(SMe2)2 precursors (X=Cl, Br) with labile dimethylsulfide ligands. The isolated compounds have been fully characterized using NMR spectroscopy, elemental analysis, and, for 20 of these compounds, single‐crystal X‐ray diffraction, revealing an unexpected variation in the bonding motifs. In addition to the classical B2X4L2 diborane(4) bis‐adducts, certain more sterically demanding carbene ligands induce a halide displacement which led to the first halide‐bridged monocationic diboron species, [B2X3L2]A (A=BCl4, Br, I). Furthermore, low‐temperature 1:1 reactions of B2Cl4 with sterically demanding N‐heterocyclic carbenes led to the formation of kinetically unstable mono‐adducts, one of which was structurally characterized. A comparison of the NMR spectra and structural data of new and literature‐known bis‐adducts shows several trends pertaining to the nature of the halides and the stereoelectronic properties of the Lewis bases employed.
Deoxytrifluoromethylthiolation and Selenylation of Alcohols by Using Benzothiazolium Reagents
Authors: Dix Stefan , Jakob Michael , Hopkinson Matthew N.
Published: April 2019

Aliphatic compounds substituted with medicinally important trifluoromethylthio (SCF3) and trifluoromethylselenyl (SeCF3) groups were synthesized directly from alcohols by using the new benzothiazolium salts BT‐SCF3 and BT‐SeCF3. These bench‐stable fluorine‐containing reagents are facile to use and can be prepared in two steps from non‐fluorinated heteroaromatic starting materials. The metal‐free deoxytrifluoromethylthiolation process using BT‐SCF3 proceeds under mild conditions and the similarly efficient trifluoromethylselenylation reactions using BT‐SeCF3 are, to the best of our knowledge, the first reported examples of this transformation.
Cover Picture: Highly Regioselective Sequential 1,1‐Dihydrosilylation of Terminal Aliphatic Alkynes with Primary Silanes (Chin. J. Chem. 5/2019)
Authors: Cheng Zhaoyang , Xing Shipei , Guo Jun , Cheng Biao , Hu Lan‐Fang , Zhang Xing‐Hong , Lu Zhan
Published: April 2019

The cover picture shows that sequential 1,1‐dihydrosilylation of terminal aliphatic alkynes with primary silanes enabled by one earth‐abundant cobalt catalyst has been developed. This protocol is operationally simple using readily available aliphatic alkynes, including simple acetylene and complex drug derivative, for efficient access to valuable gem‐bis(dihydrosilyl)alkanes in highly regioselective and atom‐economic manners. Corresponding asymmetric transformations are achieved with excellent enantioselectivities. More details are discussed in the article by Lu et al. on page 457–461.

image
Design selection for strong orthogonal arrays
Authors: Shi Chenlu , Tang Boxin
Published: April 2019

Strong orthogonal arrays (SOAs) were recently introduced and studied as a class of space‐filling designs for computer experiments. An important problem that has not been addressed in the literature is that of design selection for such arrays. In this article, we conduct a systematic investigation into this problem, and we focus on the most useful SOA(n,m,4,2 + )s and SOA(n,m,4,2)s. This article first addresses the problem of design selection for SOAs of strength 2+ by examining their three‐dimensional projections. Both theoretical and computational results are presented. When SOAs of strength 2+ do not exist, we formulate a general framework for the selection of SOAs of strength 2 by looking at their two‐dimensional projections. The approach is fruitful, as it is applicable when SOAs of strength 2+ do not exist and it gives rise to them when they do. The Canadian Journal of Statistics 47: 302–314; 2019 © 2019 Statistical Society of Canada
Optimal management of gastroesophageal junction cancer
Authors: Greally Megan , Agarwal Rajiv , Ilson David H.
Published: April 2019

Although recent decades have witnessed incremental improvements in the treatment of gastroesophageal junction (GEJ) carcinoma, outcomes remain modest. For locally advanced esophageal cancer, the addition of chemotherapy and/or radiation to surgery is considered the standard of care. Chemotherapy remains the primary treatment for metastatic disease and improves survival over best supportive care. However, the prognosis for patients with GEJ cancers, which are treated along the same paradigms as esophageal and gastric carcinomas, remain poor because of the emergence of chemoresistance and limited targeted therapeutic approaches, which include agents that target the HER2 and vascular endothelial growth factor pathways. Evaluation of immune checkpoint inhibitors in the chemorefractory setting have confirmed the activity of immunotherapy in esophagogastric cancer. Ongoing immunotherapeutic strategies are being evaluated in both the locally advanced and metastatic settings. This review focuses on the treatment of locally advanced and metastatic GEJ carcinomas, which encompass all tumors that have an epicenter within 5 cm proximal or distal to the anatomical Z‐line (Siewert classification). Because the vast majority of GEJ tumors are adenocarcinoma, the management of adenocarcinoma is the focus of this review. Evolving approaches and areas of clinical equipoise are discussed.
Molecular Dynamics of Excited State Intramolecular Charge Transfer in Solution by Coherent Nuclear Wave Packets
Authors: Heo Wooseok , Joo Taiha
Published: April 2019

Revealing a proper reaction coordinate in a chemical reaction is the key step towards elucidation of the molecular reaction dynamics. In this report, we investigated the dynamics of intramolecular charge transfer (ICT) of 8‐aminopyrene‐1,3,6‐trisulfonic acid (APTS) occurring in the excited state by time‐resolved fluorescence (TF) and TF spectra. Accurate reaction rates and rate‐dependent nuclear wave packets in the product state allow detailed investigation of the molecular reaction dynamics. The ICT rate is solvent dependent: (34 fs)−1, (87 fs)−1, and (∞)−1 in water, formamide, and dimethylformamide, respectively. By recording spectra of the nuclear wave packets for different reaction rates, chemical species responsible for the emission spectra can be positively identified. The origin of the wave packets can be deduced from the amplitude change of the wave packets at different reaction rates, and the vibrational modes that are associated with the reaction coordinate could be identified. Theoretical calculations of the vibrational reorganization energies reproduce the experimental spectrum of the nuclear wave packets and corroborate the conclusions.
Understanding Regium Bonds and their Competition with Hydrogen Bonds in Au2:HX Complexes
Authors: Sánchez‐Sanz Goar , Trujillo Cristina , Alkorta Ibon , Elguero José
Published: April 2019

A theoretical study of the regium and hydrogen bonds (RB and HB, respectively) in Au2:HX complexes has been carried out by means of CCSD(T) calculations. The theoretical study shows as overall outcome that in all cases the complexes exhibiting RB are more stable that those with HB. The binding energies for RB complexes range between −24 and −180 kJ ⋅ mol−1,whereas those of the HB complexes are between −6 and −19 kJ ⋅ mol−1. DFT‐SAPT also indicated that HB complexes are governed by electrostatics, but RB complexes present larger contribution of the induction term to the total attractive forces.197Au chemical shifts have been calculated using the relativistic ZORA Hamiltonian.
Carbonyl‐Based π‐Conjugated Materials: From Synthesis to Applications in Lithium‐Ion Batteries
Authors: Oubaha Hamid , Gohy Jean‐François , Melinte Sorin
Published: April 2019

The constant growth in the global energy demand together with the increasing awareness of clean and sustainable development has strongly pushed scientists to search for metal‐free, low‐cost, environmentally friendly functional energy‐storage systems (ESSs). Among the reported organic electrode materials, carbonyl‐based π‐conjugated compounds show excellent rate capabilities and cycling stabilities and are powerful candidates for the next generation of rechargeable lithium‐ion batteries (LIBs). Benefiting from the molecular structure versatility and design feasibility, the electrochemical properties of organic and polymeric materials can be easily tuned. This Review summarizes recent efforts in the search for carbonyl‐based π‐conjugated electrode materials in LIBs with a focus on the synthetic strategies developed to improve their electrochemical performance. The use of these materials in flexible, all‐organic LIBs is highlighted as a unique direction towards widespread applications of LIBs.
Bats in a changing landscape: Linking occupancy and traits of a diverse montane bat community to fire regime
Authors: Blakey Rachel V. , Webb Elisabeth B. , Kesler Dylan C. , Siegel Rodney B. , Corcoran Derek , Johnson Matthew
Published: April 2019

Wildfires are increasing in incidence and severity across coniferous forests of the western United States, leading to changes in forest structure and wildlife habitats. Knowledge of how species respond to fire‐driven habitat changes in these landscapes is limited and generally disconnected from our understanding of adaptations that underpin responses to fire.

We aimed to investigate drivers of occupancy of a diverse bat community in a fire‐altered landscape, while identifying functional traits that underpinned these relationships.

We recorded bats acoustically at 83 sites (n = 249 recording nights) across the Plumas National Forest in the northern Sierra Nevada over 3 summers (2015–2017). We investigated relationships between fire regime, physiographic variables, forest structure and probability of bat occupancy for nine frequently detected species. We used fourth‐corner regression and RLQ analysis to identify ecomorphological traits driving species–environment relationships across 17 bat species. Traits included body mass; call frequency, bandwidth, and duration; and foraging strategy based on vegetation structure (open, edge, or clutter).

Relationships between bat traits and fire regime were underpinned by adaptations to diverse forest structure. Bats with traits adapting them to foraging in open habitats, including emitting longer duration and narrow bandwidth calls, were associated with higher severity and more frequent fires, whereas bats with traits consistent with clutter tolerance were negatively associated with fire frequency and burn severity. Relationships between edge‐adapted bat species and fire were variable and may be influenced by prey preference or habitat configuration at a landscape scale.

Predicted increases in fire frequency and severity in western US coniferous forests are likely to shift dominance in the bat community to open‐adapted species and those able to exploit postfire resource pulses (aquatic insects, beetles, and snags). Managing for pyrodiversity within the western United States is likely important for maintaining bat community diversity, as well as diversity of other biotic communities.
Sympatry and interference of divergent Microbotryum pathogen species
Authors: Hood Michael E. , Antonovics Janis , Wolf Monroe , Stern Zachariah L. , Giraud Tatiana , Abbate Jessica L.
Published: April 2019

The impact of infectious diseases in natural ecosystems is strongly influenced by the degree of pathogen specialization and by the local assemblies of potential host species. This study investigated anther‐smut disease, caused by fungi in the genus Microbotryum, among natural populations of plants in the Caryophyllaceae. A broad geographic survey focused on sites of the disease on multiple host species in sympatry. Analysis of molecular identities for the pathogens revealed that sympatric disease was most often due to co‐occurrence of distinct, host‐specific anther‐smut fungi, rather than localized cross‐species disease transmission. Flowers from sympatric populations showed that the Microbotryum spores were frequently moved between host species. Experimental inoculations to simulate cross‐species exposure to the pathogens in these plant communities showed that the anther‐smut pathogen was less able to cause disease on its regular host when following exposure of the plants to incompatible pathogens from another host species. These results indicate that multi‐host/multi‐pathogen communities are common in this system and they involve a previously hidden mechanism of interference between Microbotryum fungi, which likely affects both pathogen and host distributions.
Ecosystem processes at the watershed scale: Influence of flowpath patterns of canopy ecophysiology on emergent catchment water and carbon cycling
Authors: Lin Laurence , Band Lawrence E. , Vose James M. , Hwang Taehee , Miniat Chelcy Ford , Bolstad Paul V.
Published: April 2019

Forest canopy water use and carbon cycling traits (WCT) can vary substantially and in spatially organized patterns, with significant impacts on watershed ecohydrology. In many watersheds, WCT may vary systematically along and between hydrologic flowpaths as an adaptation to available soil water, nutrients, and microclimate‐mediated atmospheric water demand. We hypothesize that the emerging patterns of WCT at the hillslope to catchment scale provide a more resistant ecohydrological system, particularly with respect to drought stress, and the maintenance of high levels of productivity. Rather than attempting to address this hypothesis with species‐specific patterns, we outline broader functional WCT groups and explore the sensitivity of water and carbon balances to the representation of canopy WCT functional organization through a modelling approach. We use a well‐studied experimental watershed in North Carolina where detailed mapping of forest community patterns are sufficient to describe WCT functional organization. Ecohydrological models typically use broad‐scale characterizations of forest canopy composition based on remotely sensed information (e.g., evergreen vs. deciduous), which may not adequately represent the range or spatial pattern of functional group WCT at hillslope to watershed scales. We use three different representations of WCT functional organizations: (1) restricting WCT to deciduous/conifer differentiation, (2) utilizing more detailed, but aspatial, information on local forest community composition, and (3) spatially distributed representation of local forest WCT. Accounting for WCT functional organization information improves model performance not only in terms of capturing observed flow regimes (especially watershed‐scale seasonal flow dynamics) but also in terms of representing more detailed canopy ecohydrologic behaviour (e.g., root zone soil moisture, evapotranspiration, and net canopy photosynthesis), especially under dry condition. Results suggest that the well‐known zonation of forest communities over hydrologic gradients is not just a local adaptation but also provides a property that regulates hillslope to catchment‐scale behaviour of water use and drought resistance.