bluuebunny/crossref_metadata_2025 huggingface dataset:
Advances of TiO2 as Negative Electrode Materials for Sodium‐Ion Batteries
Authors: Wang Weigang , Liu Yu , Wu Xu , Wang Jing , Fu Lijun , Zhu Yusong , Wu Yuping , Liu Xiang
Published: August 2018

TiO2 is a naturally abundant material with versatile polymorphs, which has been investigated in various fields, such as photocatalysis, electrochromic devices, lithium‐ion batteries, amongst others. Due to the similar (but not identical) chemistry between lithium and sodium, TiO2 is considered as an interesting potential negative electrode material for sodium ion batteries (SIBs) and is being investigated in fundamental studies for potential applications. The recent advances of TiO2 as negative electrode materials for SIBs are reviewed herein. Different electrochemical behaviors of TiO2 toward lithium and sodium are introduced. The (de)sodiation mechanism and physical parameters influencing the electrochemical performance are discussed. In addition, the strategies to improve the kinetic behavior, cycling stability, and coulombic efficiency of TiO2 negative electrode material for SIBs are reviewed. Beyond the great improvement of its electrochemical performance achieved, other challenges of TiO2 negative electrode material for SIBs remain. These challenges need to be addressed through a comprehensive understanding of its electrochemical behavior in SIBs. This review will be beneficial to the advancement of TiO2 for SIBs and other applications.
Rational Design, Controlled Fabrication, and Photonic Applications of Organic Composite Nanomaterials
Authors: Zhang Chunhuan , Dong Haiyun , Zhao Yong Sheng
Published: August 2018

Nanophotonics, which mainly studies the light–matter interaction at the (sub)wavelength scale, has recently captured broad research interest because photons as information carriers may allow information density and processing speed surpassing the feasibility of the electronics. With easy processability, large optical cross‐section, and chemically tailorable optical property, organic materials have acted an important role in various photonic devices. More importantly, organic molecules possess structure versatility and excellent material compatibility, which is very beneficial for the construction of composite nanomaterials from different photofunctional organic molecules. These multicomponent microstructures are very significant not only for the investigation on basic principles of photochemistry and photophysics, but also for the realization of complex/integrated functional photonic devices. Therefore, more and more scientific researches have concentrated on the preparation and photonic applications of organic composite nanomaterials, which significantly promotes the development of the field of nanophotonics. A summary of this research area is imperative for a deep understanding on the growth/fabrication mechanism and structure–property relationship of organic composite nanomaterials, which will be instructive for the photonic function oriented nanoarchitectonics. In this review, the recent significant progress in the design and development of organic composite nanomaterials is presented, with emphasis on the rational preparation and photonic applications.
Dramatically Enhanced Photoluminescence from Femtosecond Laser Induced Micro‐/Nanostructures on MAPbBr3 Single Crystal Surface
Authors: Xing Jun , Zheng Xin , Yu Zhi , Lei Yuhao , Hou Lei , Zou Yuting , Zhao Chen , Wang Bin , Yu Haotian , Pan Dexin , Zhai Yuechen , Cheng Jinluo , Zhou Ding , Qu Songnan , Yang Jianjun , Ganeev Rashid A. , Yu Weili , Guo Chunlei
Published: August 2018

Single crystal perovskites are used in solar cells, photodetectors, and other devices due to their excellent light absorption and carrier transport characteristics. However, for light‐emitting applications, photoluminescence (PL) is usually weak for MAPbBr3 (MA = CH3NH3+) single crystals (MBSCs) compared with their polycrystalline counterpart. Therefore, developing novel techniques to process MBSCs with different morphologies for PL‐related applications is greatly needed. The current strategies for making perovskite crystals are mostly based on bottom‐up method (chemical synthesis and assembling). Here, an easy method to achieve top‐down fabrication of MBSCs, i.e., femtosecond laser processing MBSC surface by controlling the laser parameters is demonstrated. The femtosecond laser processing technology can achieve two orders of magnitude enhancement under ambient conditions in PL. In addition, the processed regions also show three times enhancement in PL under nitrogen environment. It is assumed that this is mainly due to the texture based on photon recycling and light out‐coupling mechanism, and the passivation of surface recombination centers on MBSC. This study not only provides a convenient top‐down strategy to achieve a range of morphological micro‐/nanostructures with enhanced PL on MBSC surface, but also paves the way for applications of MBSCs in light emitting or PL imaging devices.
Manipulating Aggregation‐Induced Emission with Supramolecular Macrocycles
Authors: Lou Xin‐Yue , Yang Ying‐Wei
Published: August 2018

Two essential elements of smart materials are their capabilities of responding to external stimuli and the specific recognition toward different targets, which renders supramolecular macrocycles an ideal type of building blocks for materials construction. Aggregation‐induced emission (AIE) has been intensively investigated for two decades not only for the realization of solid‐state fluorescent materials, but also for the fabrication of numerous functional luminescent materials for diverse applications. The discrepancy among aggregation states of AIE‐active molecules would bear a big influence on the emission pattern; hence, manipulation of the assembly and control of the morphologies of materials with reversibility are of great importance and should be achievable via the incorporation of macrocyclic elements into AIE systems. In this review, the marriage of AIE and supramolecular macrocyclic chemistry is introduced, leading to smart functional materials with unique fluorescent properties, such as supramolecular polymers, supramolecular nanoparticles, and host–guest complexes on surfaces. Their diverse applications are discussed and perspective on this emerging research direction is also provided.
C6‐Selective Direct Arylation of 2‐Phenylpyridine via an Activated N‐methylpyridinium Salt: A Combined Experimental and Theoretical Study
Authors: Yin Changzhen , Zhong Kangbao , Li Wenjing , Yang Xiao , Sun Rui , Zhang Chunchun , Zheng Xueli , Yuan Maolin , Li Ruixiang , Lan Yu , Fu Haiyan , Chen Hua
Published: August 2018

An elegant pre‐activation strategy, based on the formation of N‐methylpyridinium iodide salts for C6‐selective direct arylation of 2‐phenylpyridines using Pd/Cu cooperative catalysis, has been developed. By this methodology, a wide range of unsymmetrical 2, 6‐diarylpyridines were synthesized with high reactivity and regioselectivity as well as good functional group tolerance. In particular, challenging substrates bearing electron donating groups (EDGs), such as OMe, NMe2, were also successfully employed in this reaction. Deuterium incorporation studies revealed that the C−H bond acidity is improved significantly in N‐methylpyridinium salts compared with their N‐Oxide and N‐iminopyridinium ylide counterparts, thus solving the long‐standing problem associated with previous strategies for the synthesis of diaryl pyridines. Finally, the control experiments and DFT calculations supported a Pd‐catalyzed and Cu‐mediated mechanism in which a carbenoid copper species that is formed in‐situ from N‐methylpyridinium salts, participates in a Pd‐catalyzed arylation followed by an iodide‐promoted N‐demethylation process.

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Decarboxylative Tribromination for the Selective Synthesis of Tribromomethyl Ketone and Tribromovinyl Derivatives
Authors: Jayaraman Aravindan , Cho Eunjeong , Kim Jimin , Lee Sunwoo
Published: August 2018

Tribromomethyl ketone and tribromovinyl derivatives were selectively prepared from the decarboxylative tribromination. The reaction between propiolic acid derivatives and dibromoisocyanuric acid (DBCA)/H2O afforded predominantly a tribromomethyl ketone derivative in the presence of AgOAc (10 mol%). When the same reaction was conducted with 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) instead of AgOAc, tribromovinyl derivatives were exclusively formed in good yields. It was found that ethynyl bromide is an intermediate.

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Zinc‐Modified Sulfonated Polyetheretherketone Surface with Immunomodulatory Function for Guiding Cell Fate and Bone Regeneration
Authors: Liu Wei , Li Jinhua , Cheng Mengqi , Wang Qiaojie , Yeung Kelvin W. K. , Chu Paul K. , Zhang Xianlong
Published: August 2018

The cytokines released by immune cells are considered important factors to induce bone tissue regeneration. However, the pathway of those bone‐targeting macrophage cytokines induced by biomaterial surface under tissue microenvironment is rarely reported. In this study, the immunomodulatory capability of zinc ions on macrophage polarization and its effects on osteogenic differentiation are investigated. Hence, a layer of zinc ions are incorporated on sulfonated polyetheretherketone (SPEEK) biomaterials by using a customized magnetron sputtering technique. The results reveal that the microenvironment on Zn‐coated SPEEK can modulate nonactivated macrophage polarization to an anti‐inflammatory phenotype and induce the secretion of anti‐inflammatory and osteogenic cytokines. The osteogenic differentiation capability of bone marrow stromal cells (BMSCs) is therefore enhanced, leading to improved osteointegration between the zinc‐coated SPEEK and bone tissue. This study verifies that zinc ion is a promising additive in the osteoimmunomodulation process and provides knowledge that may pave the way to develop the next generation of immunomodulatory biomaterials.
Metallic Octahedral CoSe2 Threaded by N‐Doped Carbon Nanotubes: A Flexible Framework for High‐Performance Potassium‐Ion Batteries
Authors: Yu Qiyao , Jiang Bo , Hu Jun , Lao Cheng‐Yen , Gao Yunzhi , Li Peihao , Liu Zhiwei , Suo Guoquan , He Donglin , Wang Wei (Alex) , Yin Geping
Published: August 2018

Due to the abundant and low‐cost K resources, the exploration of suitable materials for potassium‐ion batteries (KIBs) is advancing as a promising alternative to lithium‐ion batteries. However, the large‐sized and sluggish‐kinetic K ions cause poor battery behavior. This work reports a metallic octahedral CoSe2 threaded by N‐doped carbon nanotubes as a flexible framework for a high‐performance KIBs anode. The metallic property of CoSe2 together with the highly conductive N‐doped carbon nanotubes greatly accelerates the electron transfer and improves the rate performance. The carbon nanotube framework serves as a backbone to inhibit the agglomeration, anchor the active materials, and stabilize the integral structure. Every octahedral CoSe2 particle arranges along the carbon nanotubes in sequence, and the zigzag void space can accommodate the volume expansion during cycling, therefore boosting the cycling stability. Density functional theory is also employed to study the K‐ion intercalation/deintercalation process. This unique structure delivers a high capacity (253 mAh g−1 at 0.2 A g−1 over 100 cycles) and enhanced rate performance (173 mAh g−1 at 2.0 A g−1 over 600 cycles) as an advanced anode material for KIBs.
In Situ Surface Oxidized Copper Mesh Electrodes for High‐Performance Transparent Electrical Heating and Electromagnetic Interference Shielding
Authors: Han Yu , Zhong Hui , Liu Nan , Liu Yuxuan , Lin Jie , Jin Peng
Published: August 2018

Metallic mesh is a significant candidate of transparent conductive electrodes (TCEs) to substitute the current state‐of‐the‐art material indium tin oxide for optoelectronic devices. However, there remains a challenge to fabricate stable and good‐visibility metallic mesh with the low‐cost copper (Cu) material. A metallic Cu mesh electrode (on glass) with a high absolute transmittance of ≈82% combined with an adjustable low electrical resistance of ≈0.2 Ω sq−1 and a low total light reflectance of 8.7% is demonstrated here. The Cu mesh TCE shows excellent visibility and good thermal, moisture, and environmental stability that can be used in practical applications. This was achieved by in situ forming an oxidation‐resistive and light‐absorptive capping layer of oxide on the surface of Cu meshes. The electrode was fabricated by UV‐lithography and electroplating, and then directly annealing in the air. To assess the application potentials, transparent electrical heating up to 100 °C under 3 V supply and transparent shielding of radiofrequency with ≈24 dB attenuation in Ku band are achieved. Good photoelectric properties, low‐cost material, and excellent stability imply that this Cu mesh electrode is a striking candidate for low‐cost TCE for efficient optoelectronic devices.
Ultraconformable Freestanding Capacitors Based on Ultrathin Polyvinyl Formal Films
Authors: Barsotti Jonathan , Hirata Ikue , Pignatelli Francesca , Caironi Mario , Greco Francesco , Mattoli Virgilio
Published: August 2018

Conformable electronics refers to a class of electronic devices that have the ability to conformally adhere onto nonplanar surfaces and materials, resulting particularly appealing for skin‐contact applications, such as the case of skin‐worn unobtrusive (bio)sensors for healthcare monitoring. Conformability can be addressed by integrating basic electronic components on ultrathin polymeric film substrates. Among other basic electronic components, capacitors are fundamental ones for energy storage, sensing, frequency tuning, impedance adaptation, and signal processing. In this work, a novel approach for conformable capacitors based on a freestanding, ultrathin, and ultraconformable nanosheet of poly(vinyl formal), which serves as both structural and dielectric component of the capacitor, is presented. A novel fabrication approach is proposed and applied to produce fully freestanding ultrathin capacitors, having an overall thickness as low as 200 nm, which represents the thinnest freestanding capacitors ever reported. Thanks to the ultralow thickness, the proposed capacitors are able to sustain flexure to extremely small curvature radii (as low as 1.5 µm) and to conform to complex surfaces without compromising their operation.
Sulfide Solid Electrolytes for Lithium Battery Applications
Authors: Lau Jonathan , DeBlock Ryan H. , Butts Danielle M. , Ashby David S. , Choi Christopher S. , Dunn Bruce S.
Published: August 2018

The use of solid electrolytes is a promising direction to improve the energy density of lithium‐ion batteries. However, the low ionic conductivity of many solid electrolytes currently hinders the performance of solid‐state batteries. Sulfide solid electrolytes can be processed in a number of forms (glass, glass‐ceramic, and crystalline) and have a wide range of available chemistries. Crystalline sulfide materials demonstrate ionic conductivity on par with those of liquid electrolytes through the utilization of near ideal conduction pathways. Low‐temperature processing is also possible for these materials due to their favorable mechanical properties. The main drawback of sulfide solid electrolytes remains their electrochemical stability, but this can be addressed through compositional tuning or the use of artificial solid electrolyte interphase (SEI). Implementation of sulfide solid electrolytes, with proper treatment for stability, can lead to substantial improvements in solid‐state battery performance leading to significant advancement in electric vehicle technology.
New Binder‐Free Metal Phosphide–Carbon Felt Composite Anodes for Sodium‐Ion Battery
Authors: Sun Dan , Zhu Xiaobo , Luo Bin , Zhang Yu , Tang Yougen , Wang Haiyan , Wang Lianzhou
Published: August 2018

Metal phosphides are promising anode candidates for sodium‐ion batteries (SIBs) due to their high specific capacity and low operating potential but suffer from poor cycling stability caused by huge volume expansion and poor solid‐state ion transfer rate. Herein, a new strategy to grow a new class of mesoporous metal phosphide nanoarrays on carbon felt (CF) as binder‐free anodes for SIBs is reported. The resultant integrated electrodes demonstrate excellent cycling life up to 1000 times (>90% retention rate) and high rate capability of 535 mAh g−1 at a current density of 4 A g−1. Detailed characterization reveals that the synergistic effect of unique mesoporous structure for accommodating huge volume expansion during sodiation/desodiation process, ultrasmall primary particle size (≈10 nm) for providing larger electrode/electrolyte contact area and shorter ion diffusion distance, and 3D conductive networks for facilitating the electrochemical reaction, leads to the extraordinary battery performance. Remarkably, a full SIB using the new CoP4/CF anode and a Na3V2(PO4)2F3 cathode delivers an average operating voltage of ≈3.0 V, a reversible capacity of 553 mAh g−1, and very high energy density of ≈280 Wh kg−1 for SIBs. A flexible SIB with outstanding mechanical strength based on this binder‐free new anode is also demonstrated.
Modulation of End Groups for Low‐Bandgap Nonfullerene Acceptors Enabling High‐Performance Organic Solar Cells
Authors: Chen Yuzhong , Liu Tao , Hu Huawei , Ma Tingxuan , Lai Joshua Yuk Lin , Zhang Jianquan , Ade Harald , Yan He
Published: August 2018

The field of nonfullerene organic solar cells (OSCs) has seen an impressive progress, largely due to advances in high‐performance small molecule acceptors (SMAs). As a large portion of the solar energy is located in the near‐infrared region, it is important to develop ultralow‐bandgap SMAs that have extended absorption in the spectral range of 800–1000 nm to maximize light absorption and efficiencies. In this work, three low‐bandgap SMAs, namely, IXIC, IXIC‐2Cl, and IXIC‐4Cl, are designed and synthesized with same fused terthieno[3,2‐b]thiophene donor unit and different end groups (EGs). The three SMAs all have low optical bandgap (Eg) of 1.35, 1.30, and 1.25 eV, respectively. The chlorination on EGs can lower the energy level and broaden absorption range of the SMAs. As a result, the Voc of the devices is reduced but the Jsc is significantly increased. In addition, the addition of chlorine atoms can enhance π–π stacking and crystallinity of the SMAs, which result in high fill factors. Overall, the optimum EGs are monochlorine‐substituted IC and OSCs based on PBDB‐T:IXIC‐2Cl that can achieve remarkable power conversion efficiencies (PCEs) of 12.2%, which is one of the highest PCEs for nonfullerene organic solar cells based on low‐bandgap SMAs.
Solution‐Processed Low‐Bandgap CuIn(S,Se)2 Absorbers for High‐Efficiency Single‐Junction and Monolithic Chalcopyrite‐Perovskite Tandem Solar Cells
Authors: Uhl Alexander R. , Rajagopal Adharsh , Clark James A. , Murray Anna , Feurer Thomas , Buecheler Stephan , Jen Alex K.‐Y. , Hillhouse Hugh W.
Published: August 2018

A novel molecular‐ink deposition route based on thiourea and N,N‐dimethylformamide (DMF) that results in a certified solar cell efficiency world record for non‐vacuum deposited CuIn(S,Se)2 (CIS) absorbers and non‐vacuum deposited absorbers with a bandgap of 1.0 eV, is presented. It is found that by substituting the widely employed solvent dimethyl sulfoxide with DMF, the coordination chemistry of InCl3 could be altered, dramatically improving ink stability, enabling up to tenfold increased concentrations, omitting the necessity for elevated ink temperatures, and radically accelerating the deposition process. Furthermore, it is shown that by introducing compositionally graded precursor films, film porosity, compositional gradients, and the surface roughness of the absorbers are effectively reduced and device conversion efficiencies are increased up to 13.8% (13.1% certified, active area). The reduced roughness is also seen as crucial to realize monolithically interconnected CIS‐perovskite tandem devices, where semitransparent MAPbI3 devices are directly deposited on the CIS bottom cell. Confirming the feasibility of this approach, monolithic devices with near perfect voltage addition between subcells of up to 1.40 V are presented.
Metal–Air Batteries: From Static to Flow System
Authors: Han Xiaopeng , Li Xiaopeng , White Jai , Zhong Cheng , Deng Yida , Hu Wenbin , Ma Tianyi
Published: August 2018

As an emerging battery technology, metal–air flow batteries inherit the advantageous features of the unique structural design of conventional redox flow batteries and the high energy density of metal–air batteries, thus showing great potential as efficient electrochemical systems for large‐scale electrical energy storage. This review summarizes the operating principles and recent progress of metal–air flow batteries from a materials and chemistry perspective, with particular emphasis on the latest advanced materials design and cell configuration engineering, which the authors divide into three categories based on the anode species: vanadium–air, zinc–air, and lithium–air flow batteries. Since some of the capabilities developed for metal–air static batteries can be leveraged for next‐generation flow systems, classical works on conventional metal–air batteries are selected and compared with the metal–air flow systems, highlighting the prominent advantages of the latter in achieving high energy capacity and long cycle performance. At the end, a general perspective on current challenges/opportunities and future research directions to promote the commercial application of the metal–air flow battery technology is provided. The aim is to provide a comprehensive overview and to set up a road map for guiding development from conventional static to advanced flow technologies of metal–air batteries.
A First‐Principles and Experimental Investigation of Nickel Solubility into the P2 NaxCoO2 Sodium‐Ion Cathode
Authors: Bianchini Matteo , Wang Jingyang , Clément Raphaële , Ceder Gerbrand
Published: August 2018

The difficulty in finding positive electrode materials for sodium‐ion (Na‐ion) batteries with a large specific energy has slowed down their commercialization. Layered transition metal (M) oxides NaxMO2 with a two‐layer oxygen stacking (P2, 0.6 ≤ x ≤ 0.75), are promising candidates. However, the high average metal oxidation state needed during synthesis means that P2 NaxMO2 cathodes often require the introduction of high‐valent cations (Mn4+, Ti4+, Sn5+, or Te6+), limiting the cathode's performance. Using a combination of first‐principles calculations and experiments, the feasibility of P2 cathodes containing only electrochemically active nickel and cobalt cations is investigated. It is found that P2 NaxNiyCo1–yO2 materials with x = 0.66, 0.75, and 0 ≤ y ≤ 0.33 are either thermodynamically stable or metastable yet close to the convex hull at typical P2 synthesis temperatures (≈1000 K). It is demonstrated that a novel P2 compound with y = 0.22 and both Ni3+/4+ and Co3+/4+ can be successfully synthesized. It is studied electrochemically and structurally, using in situ and ex situ X‐ray diffraction. It is demonstrated that the chemical space of P2 layered compounds is not fully explored yet and that ab initio phase diagrams allow the determination of new high‐specific energy positive electrodes to be targeted experimentally.
Engineering of Mesoscale Pores in Balancing Mass Loading and Rate Capability of Hematite Films for Electrochemical Capacitors
Authors: Song Yu , Liu Tianyu , Li Mingyang , Yao Bin , Kou Tianyi , Feng Dongyang , Wang Fuxin , Tong Yexiang , Liu Xiao‐Xia , Li Yat
Published: August 2018

Design and synthesis of metal oxide‐based pseudocapacitive materials to simultaneously achieve high mass loading (e.g., up to 10 mg cm−2) and excellent rate capability for electrochemical capacitors is a long‐lasting challenge. These two characteristics are usually mutually exclusive due to the poor ion diffusion kinetics of most metal oxides. Here, a glucose‐assisted hydrothermal method to prepare thick hematite film (>1 µm) with engineerable mesopore size through controlled variation of glucose concentration is demonstrated. The capability of controlling the size of mesopores offers a unique opportunity to investigate for the first time the interplay between mesopore size and electrochemical performance of hematite films. The hematite film with an average mesopore size of 3 nm at an ultrahigh loading of 10 mg cm−2 exhibits an areal capacitance of 1502 mF cm−2 at 1 mA cm−2, and retains 871.2 mF cm−2 at 50 mA cm−2. Such performance, to the best of the authors' knowledge, is at the top of the reported hematite electrodes with comparable or even lower mass loadings. The strategy demonstrated herein may be extended to fabricate diverse types of mesoporous metal oxide architectures with improved ion diffusion kinetics, which is critical for a broad range of devices for energy storage and conversion.
FeN4 Sites Embedded into Carbon Nanofiber Integrated with Electrochemically Exfoliated Graphene for Oxygen Evolution in Acidic Medium
Authors: Lei Chaojun , Chen Hengquan , Cao Junhui , Yang Jian , Qiu Ming , Xia Ying , Yuan Chris , Yang Bin , Li Zhongjian , Zhang Xingwang , Lei Lecheng , Abbott Janel , Zhong Yu , Xia Xinhui , Wu Gang , He Qinggang , Hou Yang
Published: August 2018

Development of inexpensive and efficient oxygen evolution reaction (OER) catalysts in acidic environment is very challenging, but it is important for practical proton exchange membrane water electrolyzers. A molecular iron–nitrogen coordinated carbon nanofiber is developed, which is supported on an electrochemically exfoliated graphene (FeN4/NF/EG) electrocatalyst through carbonizing the precursor composed of iron ions absorbed on polyaniline‐electrodeposited EG. Benefitting from the unique 3D structure, the FeN4/NF/EG hybrid exhibits a low overpotential of ≈294 mV at 10 mA cm−2 for the OER in acidic electrolyte, which is much lower than that of commercial Ir/C catalysts (320 mV) as well as all previously reported acid transitional metal‐derived OER electrocatalysts. X‐ray absorption spectroscopy coupled with a designed poisoning experiment reveals that the molecular FeN4 species are identified as active centers for the OER in acid. The first‐principles‐based calculations verify that the FeN4–doped carbon structure is capable of reducing the potential barriers and boosting the electrocatalytic OER activity in acid.
Are Emergency Medicine Residents Prepared to Meet the Ethical Challenges of Clinical Practice? Findings from an Exploratory National Survey
Authors: Padela Aasim I. , Davis Joshua , Hall Stephen , Dorey Alyrene , Asher Shellie
Published: August 2018

Background

Although the Accreditation Council for Graduate Medical Education and the American Board of Emergency Medicine require clinical ethics education in residency training, instruction varies widely. We assessed the educational preparedness of trainees in emergency medicine to address ethics challenges common to their field.

Methods

The survey assessed two outcomes: 1) knowledge of specific ethical challenges and 2) perceived educational preparedness, across five ethics areas: 1) informed consent and decisional‐capacity assessment, 2) surrogate decision making, 3) interpretation of advanced directives, 4) withdrawing and/or withholding life support, and 5) presumed consent for emergency treatment. Clinical vignettes, revised through expert panel review and pilot testing, were utilized to evaluate these areas. The final instrument was administered via Web link to emergency medicine residents and recent graduates through adverts within Emergency Medicine Residency Association and Society for Academic Emergency Medicine (SAEM) newsletters and social media platforms. Additionally, targeted e‐mails through the Council of Residency Directors in Emergency Medicine, the Clerkship Directors of Emergency Medicine, and the SAEM Ethics Committee listservs encouraged survey distribution. Analyses involved one‐way analysis of variance for overall knowledge scores and chi‐square tests for categorical outcomes. Multivariable regression models tested associations between respondent characteristics and outcomes.

Results

There were 302 participants of which 34% reported having a dedicated ethics module within their residency curriculum. The mean (±SD) knowledge score was 59.7% (±12.8%); assessing decisional capacity was the most difficult topic for respondents as only 1% both correctly addressed the general issue and identified the correct plan of action. Participants having a dedicated ethics module perceived themselves better prepared, although there was no association between having a dedicated ethics module and knowledge scores.

Conclusions

Gaps in clinical ethics knowledge appear prevalent among emergency medicine trainees, and few programs have dedicated ethics modules. Greater study is needed to understand and remedy clinical ethics knowledge shortfalls.
Development and Validation of a Lecture Assessment Tool for Emergency Medicine Residents
Authors: Hill Jeffery , Stull Matthew , Stettler Brian , Paulsen Robbie , Hart Kimberly , McDonough Erin
Published: August 2018

Background

Delivering quality lectures is a critical skill for residents seeking careers in academia yet no validated tools for assessing resident lecture skills exist.

Objectives

The authors sought to develop and validate a lecture assessment tool.

Methods

Using a nominal group technique, the authors derived a behaviorally anchored assessment tool. Baseline characteristics of resident lecturers including prior lecturing experience and perceived comfort with lecturing were collected. Faculty and senior residents used the tool to assess lecturer performance at weekly conference. A postintervention survey assessed the usability of the form and the quantity and quality of the feedback. Analysis of variance was used to identify relationships in performance within individual domains to baseline data. Generalizability coefficients and scatterplots with jitter were used to assess inter‐rater reliability.

Results

Of 64 residents assessed, most (68.8%) had previous lecturing experience and 6.3% had experience as a regional/national speaker. There was a significant difference in performance within the domains of Content Expertise (p < 0.001), Presentation Design/Structure (p = 0.014), and Lecture Presence (p = 0.001) for first‐year versus fourth‐year residents. Residents who had higher perceived comfort with lecturing performed better in the domains of Content Expertise (p = 0.035), Presentation Design/Structure (p = 0.037), and Lecture Presence (p < 0.001). We found fair agreement between raters in all domains except Goals and Objectives. Both lecturers and evaluators perceived the feedback delivered as specific and of adequate quantity and quality. Evaluators described the form as highly useable.

Conclusions

The derived behaviorally anchored assessment tool is a sufficiently valid instrument for the assessment of resident‐delivered lectures.
Biosynthesis of ursolic acid and oleanolic acid in Saccharomyces cerevisiae
Authors: Lu Chunzhe , Zhang Chuanbo , Zhao Fanglong , Li Dashuai , Lu Wenyu
Published: August 2018

Ursolic acid and oleanolic acid are pentacyclic triterpenoid compounds with a variety of biological activities. A mixture of ursolic acid and oleanolic acid has higher antitumor activity than the individual acids. We have developed a simultaneous biosynthesis pathway for different proportions of ursolic acid and oleanolic acid in Saccharomyces cerevisiae. The ScLCZ08 strain produced 175.15 mg/L of the ursolic acid precursor α‐amyrin, the highest amount reported. Ursolic and oleanolic acid titers and proportions were optimized using Medicago truncatula amyrin C‐28 oxidase and Arabidopsis thaliana cytochrome P450 reductase. Using glucose and ethanol fed‐batch fermentation strategies, the final ursolic acid and oleanolic acid titers were 123.27 and 155.58 mg/L, respectively, demonstrating 4.77‐fold and 4.95‐fold higher production than the parent strain. The ScLCZ11 strain displayed the highest ursolic acid production obtained via microbial fermentation in fed‐batch culture to date. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3794–3802, 2018
Multiphase isenthalpic flash: General approach and its adaptation to thermal recovery of heavy oil
Authors: Paterson Duncan , Yan Wei , Michelsen Michael L. , Stenby Erling H.
Published: August 2018

Isenthalpic flash is a basic equilibrium calculation in process simulation. The recent interest in isenthalpic multiphase flash is mainly caused by the need for simulating thermal recovery of heavy oil. We present here systematic solutions to multiphase isenthalpic flash with full thermodynamics (such as EoS models) or with correlations for K‐factors, and discuss how to tailor the general methods to systems encountered in thermal recovery of heavy oil. First, for the general situation with full thermodynamics we recommend a solution strategy which uses Newton's method for rapid convergence in the majority of cases and Q‐function maximization to safeguard convergence when Newton's method fails. The solution procedure is a generalization of Michelsen's state function based two‐phase flash to multiple phases. The general solution does not need special considerations for the components in the system and is not limited to the selected thermodynamic models and the number of phases. For thermal recovery processes where gas, oil, and aqueous phases are typically involved, the stability analysis and initialization steps are tailored to improve the efficiency. Second, as it is quite common in thermal reservoir simulators to describe phase equilibrium and heat properties with temperature‐dependent K‐factors and separate correlations for heat capacities, we propose a formulation as an extension of the ideal solution isothermal flash formulation to solve such problems. It uses a Newton–Raphson procedure to converge in the majority of cases and a nested loop procedure with the outer loop for a temperature search as a fallback approach for convergence. If the correlations for K‐factors and for heat capacities are thermodynamically consistent, the outer loop can be treated as a maximization. Finally, we present systematic tests of the proposed algorithms using examples with full thermodynamics or K‐factor based thermodynamics. The algorithms prove robust and efficient even in challenging cases including a narrow‐boiling system, a degenerate system, and a four‐phase system. The additional computational cost relative to the corresponding isothermal flash is modest and would be suitable for the purpose of thermal reservoir simulation. © 2018 American Institute of Chemical Engineers AIChE J, 65: 281–293, 2019
Mid‐Cretaceous angiosperm radiation and an asterid origin of bilaterality: diverse and extinct “Ericales” from New Jersey
Authors: Crepet William L. , Nixon Kevin C. , Weeks Andrea
Published: August 2018

Premise of the Study

Numerous fossils from the Upper Cretaceous have been confidently placed within modern crown groups. Many 95–75 Myr‐old taxa, however, including the taxon described herein, do not fit well with known extant crown or stem groups. Understanding such fossils and their possible affinities would certainly enhance our understanding of the circumstances involved in a major eudicot radiation.

Methods

Bulk samples from the Old Crossman Clay Pit were prepared using standard methodology, which includes several washing and sieving steps, and a treatment with hydrofluoric acid. The fossil taxon was coded into a matrix built from the combination of two previously published morphological matrices and was analyzed using the parsimony criterion with the computer program TNT.

Key Results

The fossils have a unique combination of characters relative to living and fossil Ericales taxa, and therefore, a new genus, Teuschestanthes, is erected. Mosaic evolution and rapid parallel changes in such groups blur taxonomic distinctions, and these issues are exacerbated by limited numbers of characters available in fossils. Teuschestanthes flowers are slightly bilaterally symmetrical and somewhat variable with regard to petal disposition, suggesting an early stage in transition to bilaterality from radial symmetry early in eudicot history under pollinator selective pressure.

Conclusions

While Teuschestanthes shares characters with modern Ericales and Sapindales, there are significant non‐overlapping differences between Teuschestanthes and modern Sapindales (notably, among others, ovule number). Based on available evidence, however, the position of Teuschestanthes is likely as an early offshoot of the stem clade of core Ericales (Ericales sensu stricto). Its relatively unstable floral plan may presage subsequent bilaterality associated with growing selective pressure by advanced pollinators.
Size‐dependent variations in individual traits and trait scaling relationships within a shade‐tolerant evergreen tree species
Authors: He Dong , Yan En‐Rong
Published: August 2018

Premise of Study

The plant size–trait relationship is a fundamental dimension in the spectrum of plant form and function. However, it remains unclear whether the trait scaling relationship within species is modified by tree size. Investigating size‐dependent trait covariations within species is crucial for understanding the ontogenetic constraints on the intraspecific economic spectrum and, more broadly, the structure and causes of intraspecific trait variations.

Methods

We measured eight morphological, stoichiometric, and hydraulic traits for 604 individual plants of a shade‐tolerant evergreen tree species, Litsea elongata, in a subtropical evergreen forest of eastern China. Individual trait values were regressed against tree basal diameter to evaluate size‐dependent trait variations. Standardized major axis regression was employed to examine trait scaling relationships and to test whether there was a common slope and elevation in the trait scaling relationship across size classes.

Key Results

Small trees tended to have larger, thinner leaves and longer, slenderer stems than larger trees, which indicates an acquisitive economic strategy in juvenile trees. Leaf nitrogen concentrations increased with plant size, which was likely due to a high ratio of structural to photosynthetic nitrogen in the evergreen leaves of large trees. Bivariate trait scaling was minimally modified by tree size, although the elevation of some relationships differed between size classes.

Conclusions

Our results suggest that there are common economic and biophysical constraints on intraspecific trait covariation, independent of tree size. Small and large trees tend to be located at opposite ends of an intraspecific plant economic spectrum.
Freeze‐induced cyanide toxicity does not maintain the cyanogenesis polymorphism in white clover (Trifolium repens)
Authors: Kooyers Nicholas J. , Hartman Bakken Bradley , Ungerer Mark C. , Olsen Kenneth M.
Published: August 2018

Premise of the Study

The maintenance of adaptive polymorphisms within species requires fitness trade‐offs reflecting selection for each morph. Cyanogenesis, the ability to produce hydrogen cyanide (HCN) after tissue damage, occurs in >3000 plant species and exists as a discrete polymorphism in white clover. This polymorphism is spatially distributed in recurrent clines, with higher frequencies of cyanogenic plants in warmer climates. The HCN autotoxicity hypothesis proposes that cyanogenic plants are selected against where frosts are common, as freezing liberates HCN and could impair cellular respiration.

Methods

We tested the HCN autotoxicity hypothesis using a freezing chamber to examine survival, tissue damage, and physiological recovery as assessed via chlorophyll fluorescence following mild and severe freezing treatments. We utilized 65 genotypes from a single polymorphic population to eliminate effects of population structure.

Key Results

Cyanogenic plants did not differ from acyanogenic plants in survival, tissue damage, or recovery following freezing. However, plants producing either of the two required cyanogenic precursors had lower survival and tissue damage after freezing than plants lacking both precursors.

Conclusions

These results suggest that freezing‐induced HCN toxicity is unlikely to be responsible for the maintenance of the cyanogenesis polymorphism in white clover. However, energetic trade‐offs associated with costs of producing the cyanogenic precursors may confer a fitness benefit to acyanogenic plants under stressful climatic conditions. The lack of evidence for HCN toxicity suggests that cyanogenic clover uses physiological mechanisms mediated by β‐cyanoalanine synthase and alternative oxidase to maintain cellular function in the presence of HCN.
Possible Congenital Zika Syndrome in Older Children Due to Earlier Circulation of Zika Virus
Authors: Chu Victoria , Petersen Lyle R. , Moore Cynthia A. , Meaney‐Delman Dana , Nelson Gregg , Christian Sonne D. , Dodge Nancy N. , Glaser Carol , Rasmussen Sonja A.
Published: August 2018

Congenital Zika syndrome (CZS) was identified following a large Zika virus (ZIKV) outbreak in Brazil in 2015. Two children with clinical presentations consistent with CZS, ages 7 and 8 years old, are described. Both mothers lived in Cambodia, a region with known ZIKV, during their pregnancies and reported fever and rash in the second trimester. The infants were born with severe microcephaly. Testing for congenital infection at birth and genetic testing were unremarkable. In 2017, serologic testing for both mothers were consistent with prior ZIKV infection. Review of infant neuroimaging demonstrated ventriculomegaly, severe cerebral atrophy, and subcortical calcifications consistent with CZS. Given the maternal symptoms suggesting ZIKV infection during pregnancy and the combination of clinical and radiological features unique to CZS, CZS is strongly suspected in these children, suggesting that CZS occurred before the 2013–2014 French Polynesia outbreak. As such, CZS should be considered in older children with congenital microcephaly of unknown etiology and a history consistent with possible ZIKV exposure.
1q24 deletion syndrome. Two cases and new insights into genotype‐phenotype correlations
Authors: Lefroy Henrietta , Fox Olivia , Javaid Muhammad K , Makaya Taffy , Shears Deborah J.
Published: August 2018

1q24q25 deletions cause a distinctive phenotype including proportionate short stature, microcephaly, brachydactyly, dysmorphic facial features and intellectual disability. We present a mother and son who have a 672 kb microdeletion at 1q24q25. They have the typical skeletal features previously described but do not have any associated intellectual disability. We compare the genes within our patients' deletion to those in the deletions of previously reported cases. This indicates two genes that may be implicated in the intellectual disability usually associated with this deletion syndrome; PIGC and C1orf105. In addition, our cases provide supporting evidence to recent published work suggesting that the skeletal features may be linked to the microRNAs miR199 and miR214, encoded within intron 14 of the Dynamin‐3 gene.
LGI1 and CASPR2 neurological autoimmunity in children
Authors: López‐Chiriboga A. Sebastian , Klein Christopher , Zekeridou Anastasia , McKeon Andrew , Dubey Divyanshu , Flanagan Eoin P. , Lennon Vanda A. , Tillema Jan‐Mendelt , Wirrell Elaine C. , Patterson Marc C. , Gadoth Avi , Aaen J. Gregory , Brenton J. Nicholas , Bui Jonathan D. , Moen Amanda , Otten Catherine , Piquet Amanda , Pittock Sean J.
Published: August 2018

The clinical phenotype of leucine‐rich glioma‐inactivated protein 1 (LGI1) and contactin‐associated proteinlike 2 (CASPR2) autoimmunity is well defined in adults. Data for children are limited (<10 cases). Among 13,319 pediatric patients serologically tested for autoimmune neurological disorders (2010–2017), 264 were seropositive for voltage‐gated potassium channel‐complex–IgG (radioimmunoprecipitation). Only 13 (4.9%) were positive by transfected cell‐binding assay for LGI1‐IgG (n = 7), CASPR2‐IgG (n = 3), or both (n = 3). This is significantly less than in adults. Encephalopathy, seizures, and peripheral nerve hyperexcitability were common, as was coexisting autoimmunity. No faciobrachial dystonic seizures or cancers were identified. Functional neurologic disorders were frequently the initial diagnosis, and immunotherapy appeared beneficial. Ann Neurol 2018;84:473–480
Reactive inkjet printing of polyethylene glycol and isocyanate based inks to create porous polyurethane structures
Authors: Schuster Fabian , Hirth Thomas , Weber Achim
Published: August 2018

Reactive inkjet printing offers a direct way to create polymeric structures in situ on a substrate. Therefore, two component polyurethane formulations can be utilized to be used in multicomponent inkjet printing. In this contribution, the use of polyethylene glycol (M = 200 g mol−1), glycerol ethoxylate (M = 1,000 g mol−1), and water (blowing agent) in combination with aliphatic 1,6‐hexamethylene diisocyanate or aromatic methylene diphenyl diisocyanate for reactive inkjet printing is evaluated. The inks are jettable on a Dimatix DMP‐3000 inkjet printer using a 10 pL piezo driven drop‐on‐demand printhead showing stable droplet formation. Solid films on glass are formed using a drop‐by‐drop printing strategy. Layer‐by‐Layer strategy gives best results on polycarbonate substrates forming porous polyurethane structures. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 46977.
Sensory Innervation of the Human Soft Palate
Authors: Mu Liancai , Chen Jingming , Li Jing , Arnold Matthew , Sobotka Stanislaw , Nyirenda Themba , Fowkes Mary , Christopherson Mark , Sanders Ira
Published: August 2018

The human soft palate plays an important role in respiration, swallowing, and speech. These motor activities depend on reflexes mediated by sensory nerve endings. To date, the details of human sensory innervation to the soft palate have not been demonstrated. In this study, eight adult human whole‐mount (soft palate‐tongue‐pharynx‐larynx‐upper esophagus) specimens were obtained from autopsy. Each specimen was bisected in the midline, forming two equal and symmetrical halves. Eight hemi‐specimens were processed with Sihler's stain, a whole‐mount nerve staining technique. The remaining eight hemi‐soft palates were used for immunohistochemical study. The soft palatal mucosa was dissected from the oral and nasal sides and prepared for neurofilament staining. Our results showed that the sensory nerve fibers formed a dense nerve plexus in the lamina propria of the soft palatal mucosa. There was a significant difference in the innervation density between both sides. Specifically, the oral side had higher density of sensory nerve fibers than the nasal side of the soft palate. The mean number and percent area of the sensory nerve fibers in the mucosa of the nasal side was 78% and 72% of those in the mucosa of the oral side, respectively (P < 0.0001). The data presented here could be helpful for further investigating the morphological and quantitative alterations in the sensory nerves in certain upper airway disorders involving the soft palate such as obstructive sleep apnea (OSA) and for designing effective therapeutic strategies to treat OSA. Anat Rec, 301:1861–1870, 2018. © 2018 Wiley Periodicals, Inc.