bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Blend Morphology and Energetics on Charge Separation and Recombination Dynamics in Organic Solar Cells Incorporating a Nonfullerene Acceptor
Authors: Cha Hyojung , Wheeler Scot , Holliday Sarah , Dimitrov Stoichko D. , Wadsworth Andrew , Lee Hyun Hwi , Baran Derya , McCulloch Iain , Durrant James R. 
Published: November 2017

AbstractNonfullerene acceptors (NFAs) in blends with highly crystalline donor polymers have been shown to yield particularly high device voltage outputs, but typically more modest quantum yields for photocurrent generation as well as often lower fill factors (FF). In this study, we employ transient optical and optoelectronic analysis to elucidate the factors determining device photocurrent and FF in blends of the highly crystalline donor polymer PffBT4T‐2OD with the promising NFA FBR or the more widely studied fullerene acceptor PC71BM. Geminate recombination losses, as measured by ultrafast transient absorption spectroscopy, are observed to be significantly higher for PffBT4T‐2OD:FBR blends. This is assigned to the smaller LUMO‐LUMO offset of the PffBT4T‐2OD:FBR blends relative to PffBT4T‐2OD:PC71BM, resulting in the lower photocurrent generation efficiency obtained with FBR. Employing time delayed charge extraction measurements, these geminate recombination losses are observed to be field dependent, resulting in the lower FF observed with PffBT4T‐2OD:FBR devices. These data therefore provide a detailed understanding of the impact of acceptor design, and particularly acceptor energetics, on organic solar cell performance. Our study concludes with a discussion of the implications of these results for the design of NFAs in organic solar cells.
Ultrathin IrO2 Nanoneedles for Electrochemical Water Oxidation
Authors: Lim Jinkyu , Park Dongmin , Jeon Sun Seo , Roh Chi‐Woo , Choi Juhyuk , Yoon Daejin , Park Minju , Jung Hyeyoung , Lee Hyunjoo 
Published: November 2017

AbstractElectrochemical water splitting is promising for utilizing intermittent renewable energy. The sluggish kinetics of the oxygen evolution reaction (OER), however, is a bottleneck in obtaining high efficiency. Only a few OER electrocatalysts have been developed for the use in acidic media despite the importance of a proton exchange membrane (PEM) water electrolyzer. IrO2 is the only material that is both active and stable for the OER in highly corrosive acidic conditions. Herein, a facile and scalable synthesis of ultrathin IrO2 nanoneedles is reported with a diameter of 2 nm using a modified molten salt method. The activity and durability for the OER are significantly enhanced on the ultrathin IrO2 nanoneedles, compared to conventional nanoparticles. The ultrathin nanoneedles are successfully introduced to a PEM electrolyzer single cell with the enhanced cell performance.
A Perspective on Bio‐Mediated Material Structuring
Authors: Deuerling Steffi , Kugler Sabine , Klotz Moritz , Zollfrank Cordt , Van Opdenbosch Daniel 
Published: November 2017

AbstractBioinspiration, biomorphy, biomimicry, biomimetics, bionics, and biotemplating are terms used to describe the fabrication of materials or, more generally, systems to solve technological problems by abstracting, emulating, using, or transferring structures from biological paradigms. Herein, a brief overview of how the different terminologies are being typically applied is provided. It is proposed that there is a rich field of research that can be expanded by utilizing various novel approaches for the guidance of living organisms for “bio‐mediated” material structuring purposes. As examples of contact‐based or contact‐free guidance, such as substrate patterning, the application of light, magnetic fields, or chemical gradients, potentially interesting methods of creating hierarchically structured monolithic engineering materials, using live patterned biomass, biofilms, or extracellular substances as scaffolds, are presented. The potential advantages of such materials are discussed, and examples of live self‐patterning of materials are given.
Evidence for Itinerant Carriers in an Anisotropic Narrow‐Gap Semiconductor by Angle‐Resolved Photoemission Spectroscopy
Authors: Ju Sailong , Bai Wei , Wu Liming , Lin Hua , Xiao Chong , Cui Shengtao , Li Zhou , Kong Shuai , Liu Yi , Liu Dayong , Zhang Guobin , Sun Zhe , Xie Yi 
Published: November 2017

AbstractThe ability to accurately determine the electronic structure of solids has become a key prerequisite for modern functional materials. For example, the precise determination of the electronic structure helps to balance the three thermoelectric parameters, which is the biggest challenge to design high‐performance thermoelectric materials. Herein, by high‐resolution, angle‐resolved photoemission spectroscopy (ARPES), the itinerant carriers in CsBi4Te6 (CBT) are revealed for the first time. CBT is a typical anisotropic, narrow‐gap semiconductor used as a practical candidate for low‐temperature thermoelectric applications, and p‐doped CBT series show superconductivity at relatively low carrier concentrations. The ARPES results show a significantly larger bandwidth near the Fermi surface than calculations, which means the carriers transport anisotropically and itinerantly in CBT. It is reasonable to believe that these newly discovered features of carriers in narrow‐gap semiconductors are promising for designing optimal thermoelectric materials and superconductors.
Synthesis of Carbon Dots with Multiple Color Emission by Controlled Graphitization and Surface Functionalization
Authors: Miao Xiang , Qu Dan , Yang Dongxue , Nie Bing , Zhao Yikang , Fan Hongyou , Sun Zaicheng 
Published: November 2017

AbstractMultiple‐color‐emissive carbon dots (CDots) have potential applications in various fields such as bioimaging, light‐emitting devices, and photocatalysis. The majority of the current CDots to date exhibit excitation‐wavelength‐dependent emissions with their maximum emission limited at the blue‐light region. Here, a synthesis of multiple‐color‐emission CDots by controlled graphitization and surface function is reported. The CDots are synthesized through controlled thermal pyrolysis of citric acid and urea. By regulating the thermal‐pyrolysis temperature and ratio of reactants, the maximum emission of the resulting CDots gradually shifts from blue to red light, covering the entire light spectrum. Specifically, the emission position of the CDots can be tuned from 430 to 630 nm through controlling the extent of graphitization and the amount of surface functional groups, COOH. The relative photoluminescence quantum yields of the CDots with blue, green, and red emission reach up to 52.6%, 35.1%, and 12.9%, respectively. Furthermore, it is demonstrated that the CDots can be uniformly dispersed into epoxy resins and be fabricated as transparent CDots/epoxy composites for multiple‐color‐ and white‐light‐emitting devices. This research opens a door for developing low‐cost CDots as alternative phosphors for light‐emitting devices.
(E)‐3‐(Alkoxycarbonyl‐2‐Alkyliden)‐2‐Oxindoles: Multidentate Pronucleophiles for the Organocatalytic, Vinylogous Michael Addition to Nitroolefins
Authors: Curti Claudio , Battistini Lucia , Sartori Andrea , Rassu Gloria , Pelosi Giorgio , Lombardo Marco , Zanardi Franca 
Published: November 2017

AbstractWe introduce 3‐(alkoxycarbonyl‐2‐alkyliden)‐2‐oxindoles as pronucleophilic donors in the direct, vinylogous Michael addition to nitroolefins orchestrated by a chiral, bifunctional cinchona‐thiourea organocatalyst. This reaction displays excellent levels of γ‐site‐, diastereo‐ and enantioselectivity delivering valuable enantioenriched functionalized oxindoles. Of note, the C‐γ enolization of these pronucleophiles by the organocatalyst generates a multidentate, captodative dienolate that delivers vinylogous adducts with an unprecedented Z‐selectivity through a peculiar interaction with the catalyst and the nitroolefin. The optimized procedure is operatively simple: the reaction is conducted in air, at room temperature, with low catalyst loading (up to 1 mol%). The synthetic versatility of these Michael adducts is demonstrated by several transformations leading to a valuable quaternary oxindolyl proline analogue and a chiral spirocyclic furoindolone structure. Finally, a mechanistic rationale and a suitable transition state accounting for the observed selectivities are proposed, which are supported by DFT calculations.magnified image
Inverted Design for High‐Performance Supercapacitor Via Co(OH)2‐Derived Highly Oriented MOF Electrodes
Authors: Deng Ting , Lu Yue , Zhang Wei , Sui Manling , Shi Xiaoyuan , Wang Dong , Zheng Weitao 
Published: November 2017

AbstractMetal organic frameworks (MOFs) are considered as promising candidates for supercapacitors because of high specific area and potential redox sites. However, their shuffled orientations and low conductivity nature lead to severely‐degraded performance. Designing an accessibly‐manipulated and efficient method to address those issues is of outmost significance for MOF application in supercapacitors. It is the common way that MOFs scarify themselves as templates or precursors to prepare target products. But to reversely think it, using target products to prepare MOF could be the way to unlock the bottleneck of MOFs' performance in supercapacitors. Herein, a novel strategy using Co(OH)2 as both the template and precursor to fabricate vertically‐oriented MOF electrode is proposed. The electrode shows a double high specific capacitance of 1044 Fg−1 and excellent rate capability compared to MOF in powder form. An asymmetric supercapacitor was also fabricated, which delivers a maximum energy density of 28.5 W h kg−1 at a power density of 1500 W kg−1, and the maximum of 24000 W kg−1 can be obtained with a remaining energy density of 13.3 W h kg−1. Therefore, the proposed strategy paves the way to unlock the inherent advantages of MOFs and also inspires for advanced MOF synthesis with optimum performance.
Violence against emergency medical services personnel: A systematic review of the literature
Authors: Maguire Brian J. , O'Meara Peter , O'Neill Barbara J. , Brightwell Richard 
Published: November 2017

BackgroundViolence against emergency medical services (EMS) personnel is a growing concern. The aim of this systematic review is to synthesize the current literature on violence against EMS personnel.MethodsWe examined literature from 2000 to 2016. Eligibility criteria included English‐language, peer‐reviewed studies of EMS personnel that described violence or assaults. Sixteen searches identified 2655 studies; 25 studies from nine countries met the inclusion criteria.ResultsThe evidence from this review demonstrates that violence is a common risk for EMS personnel. We identified three critical topic areas: changes in risk over time, economic impact of violence and, outcomes of risk‐reduction interventions. There is a lack of peer reviewed research of interventions, with the result that current intervention programs have no reliable evidence base.ConclusionsEMS leaders and personnel should work together with researchers to design, implement, evaluate and publish intervention studies designed to mitigate risks of violence to EMS personnel.
Temperature‐Directed Biocatalysis for the Sustainable Production of Aromatic Aldehydes or Alcohols
Authors: Ni Jun , Gao Yan‐Yan , Tao Fei , Liu Hong‐Yu , Xu Ping 
Published: November 2017

AbstractThe biosynthesis of aromatic aldehydes and alcohols from renewable resources is currently receiving considerable attention because of an increase in demand, finite fossil resources, and growing environmental concerns. Here, a temperature‐directed whole‐cell catalyst was developed by using two novel enzymes from a thermophilic actinomycete. Ferulic acid, a model lignin derivative, was efficiently converted into vanillyl alcohol at a reaction temperature at 30 °C. However, when the temperature was increased to 50 °C, ferulic acid was mainly converted into vanillin with a productivity of 1.1 g L−1 h−1. This is due to the fact that the redundant endogenous alcohol dehydrogenases (ADHs) are not active at this temperature while the functional enzymes from the thermophilic strain remain active. As the biocatalyst could convert many other renewable cinnamic acid derivatives into their corresponding aromatic aldehydes/alcohols, this novel strategy may be extended to generate a vast array of valuable aldehydes or alcohols.
Ion–Solvent Complexes Promote Gas Evolution from Electrolytes on a Sodium Metal Anode
Authors: Chen Xiang , Shen Xin , Li Bo , Peng Hong‐Jie , Cheng Xin‐Bing , Li Bo‐Quan , Zhang Xue‐Qiang , Huang Jia‐Qi , Zhang Qiang 
Published: November 2017

AbstractLithium and sodium metal batteries are considered as promising next‐generation energy storage devices due to their ultrahigh energy densities. The high reactivity of alkali metal toward organic solvents and salts results in side reactions, which further lead to undesirable electrolyte depletion, cell failure, and evolution of flammable gas. Herein, first‐principles calculations and in situ optical microscopy are used to study the mechanism of organic electrolyte decomposition and gas evolution on a sodium metal anode. Once complexed with sodium ions, solvent molecules show a reduced LUMO, which facilitates the electrolyte decomposition and gas evolution. Such a general mechanism is also applicable to lithium and other metal anodes. We uncover the critical role of ion–solvent complexation for the stability of alkali metal anodes, reveal the mechanism of electrolyte gassing, and provide a mechanistic guidance to electrolyte and lithium/sodium anode design for safe rechargeable batteries.
Lessons To Be Learned: The Molecular Basis of Kinase‐Targeted Therapies and Drug Resistance in Non‐Small Cell Lung Cancer
Authors: Lategahn Jonas , Keul Marina , Rauh Daniel 
Published: November 2017

AbstractThe treatment of non‐small cell lung cancer (NSCLC) is currently experiencing a revolution. Over the last decade, the knowledge gained about the biochemical features of biomarkers and their predictive abilities has led to the development of targeted small‐molecule inhibitors that present an alternative to harsh chemotherapy. The use of these new therapies has improved the quality of life and increased the survival of patients. The occurrence of inevitable drug resistance requires the constant development of precision medicine. The detailed understanding of the target biology and the search for innovative chemical approaches has encouraged investigations in this field. Herein, we review selected aspects of the molecular targets and present an overview of current topics and challenges in the rational development of small molecules to target NSCLC.
Immune Checkpoint PD‐1/PD‐L1: Is There Life Beyond Antibodies?
Authors: Konstantinidou Markella , Zarganes‐Tzitzikas Tryfon , Magiera‐Mularz Katarzyna , Holak Tad A. , Dömling Alexander 
Published: November 2017

AbstractThe PD‐1/PD‐L1 interaction has emerged as a significant target in cancer immunotherapy. Current medications include monoclonal antibodies, which have shown impressive clinical results in the treatment of several types of tumors. The cocrystal structure of human PD‐1 and PD‐L1 is expected to be a valuable starting point for the design of novel inhibitors, along with the recent crystal structures with monoclonal antibodies, small molecules, and macrocycles.
Evidence for Triplet Sensitization in the Visible‐Light‐Induced [2+2] Photocycloaddition of Eniminium Ions
Authors: Hörmann Fabian M. , Chung Tim S. , Rodriguez Elsa , Jakob Matthias , Bach Thorsten 
Published: November 2017

AbstractΕniminium ions were prepared from the corresponding α,β‐unsaturated carbonyl compounds (enones and enals), and were found to be promoted to their respective triplet states by energy transfer. The photoexcited intermediates underwent intra‐ or intermolecular [2+2] photocycloaddition in good yields (50–78 %) upon irradiation at λ=433 nm or λ=457 nm. Iridium or ruthenium complexes with a sufficiently high triplet energy were identified as efficient catalysts (2.5 mol % catalyst loading) for the reaction. The intermolecular [2+2] photocycloaddition of an eniminium ion derived from a chiral secondary amine proceeded with high enantioselectivity (88 % ee).
RAFT‐mediated emulsion polymerization of chloroprene and impact of chain‐end structure on chloroprene rubbers
Authors: Ishigaki Yuhei , Mori Hideharu 
Published: November 2017

ABSTRACTThe reversible addition‐fragmentation chain transfer (RAFT) polymerization of chloroprene (CP) in an emulsion system using a dithiocarbamate‐type RAFT agent was studied. The controlled RAFT‐mediated emulsion polymerization was achieved by the appropriate combination of a RAFT agent and nonionic surfactant (polyoxyethylene phenyl ether) using a water‐soluble initiator (VA‐044) at 35 °C. An almost linear first‐order kinetic plot was observed until relatively high conversion (>80%) with molecular weights between 22,300 and 33,100 and relatively narrow molecular weight distributions (Mw/Mn ≦ 1.5) were achieved. The amount of the emulsifier used and the pH of the system were found to affect the controlled character, polymerization rate, and induction period, which are related to the size of the emulsion particles. Large‐scale RAFT‐mediated emulsion polymerization was also employed to afford industrially applicable poly(CP) (Mw > 25 × 104, resulting product > 2300 g). The vulcanized CP rubber obtained from the RAFT‐synthesized poly(CP) exhibited better physical properties, particularly tensile modulus and compression set, which may be due to the presence of the reactive end groups and the absence of low‐molecular‐weight products. We also evaluated the impact of the chain‐end structure on the mechanical and physical properties of these industrially important CP rubbers with carbon black. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46008.
Starch‐graphene oxide bionanocomposites prepared through melt mixing
Authors: Ávila‐Orta Carlos A. , Soriano Corral Florentino , Fonseca‐Florido Heidi A. , Estrada Aguilar Flor I. , Solís Rosales Silvia G. , Mata Padilla José M. , González Morones Pablo , Fernández Tavizón Salvador , Hernández‐Hernández Ernesto 
Published: November 2017

ABSTRACTBionanocomposites (BNCs) of waxy corn starch, glycerol, and graphene oxide (GO) or graphite oxide (GrO) were prepared by melt mixing. First, the GrO was pre‐exfoliated in a water solution using ultrasound at 1 wt %. Small‐angle X‐ray scattering was used to determinate the interlaminar separation of GrO and transmission electron microscopy, Fourier infrared spectroscopy, and thermogravimetric analysis were used to characterized the GrO. Next, BNCs were characterized by X‐ray diffraction, scanning electron microscopy, thermogravimetric analysis, and mechanical property measurements. A complete exfoliation of GrO was obtained in the waxy corn matrix. Amorphous X‐ray patterns of the BNCs were observed, indicating that the exfoliated GO avoid the retrogradation of starch. According to scanning electron microscopy results, the BNCs showed an irregular texture and a good dispersion of GO, while thermoplastic starch showed a smooth morphology with a fragile structure. The BNCs exhibited higher thermal stability than thermoplastic starch. The tensile strength and the Young's modulus increased by 140% and 230% at a GO loading levels of 0.5% due to good interfacial interactions of GO and the waxy corn starch matrix. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46037.
Updated Estimates Suggest a Much Higher Prevalence of Arthritis in United States Adults Than Previous Ones
Authors: Jafarzadeh S. Reza , Felson David T. 
Published: November 2017

ObjectiveNational estimates of arthritis prevalence rely on a single survey question about doctor‐diagnosed arthritis without using survey information on joint symptoms, even though some subjects with only the latter have been shown to have arthritis. The sensitivity of the current surveillance definition is only 53% and 69% in subjects ages 45–64 years and ages ≥65 years, respectively, resulting in misclassification of nearly one‐half and one‐third of subjects in those age groups. This study was undertaken to estimate arthritis prevalence based on an expansive surveillance definition that is adjusted for the measurement errors in the current definition.MethodsUsing the 2015 National Health Interview Survey, we developed a Bayesian multinomial latent class model for arthritis surveillance based on doctor‐diagnosed arthritis, joint symptoms, and whether symptom duration exceeded 3 months.ResultsOf 33,672 participants, 19.3% of men and 16.7% of women ages 18–64 years and 15.7% of men and 13.5% of women ages ≥65 years affirmed joint symptoms without doctor‐diagnosed arthritis. The measurement error–adjusted prevalence of arthritis was 29.9% (95% Bayesian probability interval [95% PI] 23.4–42.3) in men ages 18–64 years, 31.2% (95% PI 25.8–44.1) in women ages 18–64 years, 55.8% (95% PI 49.9–70.4) in men ages ≥65 years, and 68.7% (95% PI 62.1–79.9) in women ages ≥65 years. Arthritis affected 91.2 million adults (of 247.7 million; 36.8%) in the US in 2015, which included 61.1 million persons between 18 and 64 years of age (of 199.9 million; 30.6%). Our arthritis prevalence estimate was 68% higher than the previously reported national estimate.ConclusionArthritis prevalence in the US population has been substantially underestimated, especially among adults younger than 65 years of age.
Exponential Stability and Delayed Impulsive Stabilization of Hybrid Impulsive Stochastic Functional Differential Systems
Authors: Li Dianqaing , Cheng Pei , Deng Feiqi 
Published: November 2017

AbstractThis paper is concerned with the stability and impulsive stabilization of hybrid impulsive stochastic functional differential systems with delayed impulses. Using the Razumikhin techniques and Lyapunov functions, some sufficient conditions for the pth moment exponential stability of the systems under consideration are established. Based on the derived stability results, impulsive controllers are designed to stabilize a given unstable linear or nonlinear hybrid stochastic delayed differential system. Different from the existing stability and impulsive stabilization results in the literature, the results obtained in this paper shown that the delayed part of impulses can make a contribution to the stability of systems. Three examples are provided to present the effectiveness and advantages of the proposed results.
A Control Architecture for Time‐Optimal Landing of a Quadrotor Onto a Moving Platform
Authors: Hu Botao , Lu Lu , Mishra Sandipan 
Published: November 2017

AbstractWe address the problem of autonomous landing of a quadrotor onto a heaving (moving vertically) platform in this paper. A control architecture that consists of a motion estimation module, a trajectory generation module and a tracking control module is proposed. The motion estimation module estimates the absolute motion of the platform and the quadrotor with the measurements from an on‐board accelerometer and vision measurements. Based on these estimates, the trajectory generation module generates a time‐optimal reference trajectory. With the reference trajectory and motion estimation, the tracking control module synthesizes a control command that enables robust tracking of the reference trajectory. Experimental results and comparison with a state‐of‐the‐art landing controller demonstrate the effectiveness of the proposed control architecture.