bluuebunny/crossref_metadata_2025_split huggingface dataset:
Layered Ruddlesden–Popper Efficient Perovskite Solar Cells with Controlled Quantum and Dielectric Confinement Introduced via Doping
Authors: Li Hao , Wang Xikui , Zhang Tao , Gong Xiu , Sun Qiang , Pan Han , Shen Yan , Ahmad Shahzada , Wang Mingkui 
Published: May 2019

AbstractLayered Ruddlesden–Popper (RP) hybrid perovskite semiconductors have recently emerged as promising materials for photovoltaics application. However, the strong quantum and dielectric confinement of RP perovskite compounds increases their optical bandgap and binding energy of exciton, which limit their application in solar cells. Herein, the doping of RP‐based (BA)2(MA)3Pb4I13 perovskite materials by means of Li+ is reported for the first time, which can significantly help to reduce dielectric confinement and thus the exciton‐binding energy via reducing the dielectric constant difference between organic spacer cation and inorganic framework. Furthermore, the Li+ doping boosts the carrier mobility, reduces the trap density states, and thus allows to achieve power conversion efficiency of ≈15% via Li+‐(BA)2(MA)3Pb4I13‐based perovskite solar cell, which is the highest efficiency for layered perovskites (n = 4) so far. This work highlights the promising ionic doping engineering for further improvement of the layered perovskite materials.
Impact of Dispersity and Hydrogen Bonding on the Lubricity of Poly(acrylamide) Brushes
Authors: Mandal Joydeb , Simic Rok , Spencer Nicholas D. 
Published: May 2019

AbstractThe effects of chain‐length dispersity and monomer type on the lubricity of acrylamide‐based polymer brushes have been examined in aqueous media. The polymer brushes used have been synthesized by surface‐initiated, atom‐transfer radical polymerization of N,N‐dimethylacrylamide (DMAM), N‐hydroxyethyl acrylamide (HEAM), and N‐isopropylacrylamide. Polymerization reactions have been performed in the presence and also in the absence of CuX2 and tEtAmX (X = Cl or Br), in order to achieve polymer brushes with substantial differences in their chain‐length dispersities. While an influence of the dispersity on the lubricity of the polymer brushes can be observed, it is convoluted with the competing phenomena of hydrogen bonding and increased water content. The most hydrophilic, p(HEAM) brush exhibits the highest friction coefficient (μ) of ≈0.04 compared to ≈0.004 in the case of the p(DMAM) brush. Such a large difference is presumed to originate from the hydrogen bonding between the tribological countersurface (plasma‐oxidized poly(dimethylsiloxane)) and the p(HEAM) chains, as evidenced by the substantial reduction in μ when the friction measurements are performed in 5 m urea solution instead of pure milli‐Q water.
Sea Urchin‐Like MOF‐Derived Formation of Porous Cu3P@C as an Efficient and Stable Electrocatalyst for Oxygen Evolution and Hydrogen Evolution Reactions
Authors: Rong Jian , Xu Jinchao , Qiu Fengxian , Zhu Yao , Fang Yuanyuan , Xu Jicheng , Zhang Tao 
Published: May 2019

AbstractOwning to the energy crisis and environmental pollution, it is urgent to develop an efficient and earth‐abundant electrocatalyst for water splitting. In this work, the Cu2O cubes are first synthesized through a modified precipitation method, and it is subsequently selected as the Cu2+ source to synthesize 3D MOF (metal‐organic framework, Cu‐BDC) nanoarray by a facile and efficient bottom‐up method. Next, porous Cu3P@C is prepared via the low‐temperature phosphorization of 3D Cu‐BDC nanoarray as a high‐performance electrocatalyst for oxygen and hydrogen evolution reactions (OER and HER). In particular, the effect of reaction temperature on the morphology of 3D Cu‐BDC precursor is studied in detail. Experimental results reveal that Cu3P@C‐120 derived from sea urchin‐like Cu‐BDC exhibits excellent electrocatalytic performance owning to the high special surface area, developed porous structure, and the uniform dispersion of Cu3P nanoparticles, which affords the current density of 10 mA cm−2 at low overpotentials of 300 and 124 mV for OER (alkaline medium) and HER (acidic medium) with Tafel slopes of 24 and 29 mV dec−1, respectively. Remarkably, Cu3P@C‐120 also exhibits an excellent durability for OER and HER, making it an efficient bifunctional electrocatalyst for application in the production of clean hydrogen fuel.
High‐Performance and Stable Perovskite Solar Cells Based on Dopant‐Free Arylamine‐Substituted Copper(II) Phthalocyanine Hole‐Transporting Materials
Authors: Feng Yaomiao , Hu Qikun , Rezaee Ehsan , Li Minzhang , Xu Zong‐Xiang , Lorenzoni Andrea , Mercuri Francesco , Muccini Michele 
Published: May 2019

AbstractA power conversion efficiency (PCE) as high as 19.7% is achieved using a novel, low‐cost, dopant‐free hole transport material (HTM) in mixed‐ion solution‐processed perovskite solar cells (PSCs). Following a rational molecular design strategy, arylamine‐substituted copper(II) phthalocyanine (CuPc) derivatives are selected as HTMs, reaching the highest PCE ever reported for PSCs employing dopant‐free HTMs. The intrinsic thermal and chemical properties of dopant‐free CuPcs result in PSCs with a long‐term stability outperforming that of the benchmark doped 2,2′,7,7′‐Tetrakis‐(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐Spirobifluorene (Spiro‐OMeTAD)‐based devices. The combination of molecular modeling, synthesis, and full experimental characterization sheds light on the nanostructure and molecular aggregation of arylamine‐substituted CuPc compounds, providing a link between molecular structure and device properties. These results reveal the potential of engineering CuPc derivatives as dopant‐free HTMs to fabricate cost‐effective and highly efficient PSCs with long‐term stability, and pave the way to their commercial‐scale manufacturing. More generally, this case demonstrates how an integrated approach based on rational design and computational modeling can guide and anticipate the synthesis of new classes of materials to achieve specific functions in complex device structures.
Herbivore resistance in congeneric and sympatric Nothofagus species is not related to leaf habit
Authors: Piper Frida I. , Gundale Michael J. , Fuenzalida Tomás , Fajardo Alex 
Published: May 2019

PremiseTwo fundamental hypotheses on herbivore resistance and leaf habit are the resource availability hypothesis (RAH) and the carbon–nutrient balance hypothesis (CNBH). The RAH predicts higher constitutive resistance by evergreens, and the CNBH predicts higher induced resistance by deciduous species. Although support for these hypotheses is mixed, they have rarely been examined in congeneric species.MethodsWe compared leaf constitutive and induced resistance (as leaf polyphenol and tannin concentrations, and as damage level in non‐choice experiments) and leaf traits associated with herbivory of coexisting Nothofagus species using (1) a defoliation experiment and (2) natural defoliation caused by an outbreak of a common defoliator of Nothofagus species.ResultsIn the defoliation experiment, polyphenol and tannin concentrations were similar between deciduous and evergreen species; regardless of leaf habit, polyphenols increased in response to defoliation. In the natural defoliation survey, N. pumilio (deciduous) had significantly higher herbivory, lower carbon/nitrogen ratio and leaf mass per area, and higher nitrogen and phosphorus concentrations than N. betuloides (evergreen); N. antarctica (deciduous) had intermediate values. Polyphenol concentrations and herbivore resistance indicated by the non‐choice experiment were lower in N. pumilio than in N. antarctica and N. betuloides, which had similar values.ConclusionsHigher herbivory in N. pumilio was associated with a higher nutritional value and a lower level of leaf carbon‐based defenses compared to both the evergreen and the other deciduous species, indicating that herbivore resistance in Nothofagus species cannot be attributed to only leaf habit as predicted by the RAH or CNBH.
Gold‐Catalyzed Bicyclic Annulations of 2‐Alkynylbenzaldehydes with Vinyldiazo Carbonyls that Serve as Five‐atom Building Units
Authors: Raj Antony Sekar Kulandai , Liu Rai‐Shung 
Published: May 2019

AbstractThis work reports gold‐catalyzed bicyclic annulations of 2‐alkynyl‐1‐carbonylbenzenes with vinyldiazo ketones that serve as five‐atom building units. The importance of these reactions is to access 4,5‐dihydro‐benzo[g]indazoles, which form the structural cores of various bioactive molecules. According to our mechanistic analysis, we postulate initial [5+4]‐cycloadditions between benzopyrilium intermediates and vinyldiazo ketones, followed by 6‐π‐electrocyclizations to achieve the excellent stereoselectivity.
A Regio‐ and Stereodivergent Synthesis of Homoallylic Amines by a One‐Pot Cooperative‐Catalysis‐Based Allylic Alkylation/Hofmann Rearrangement Strategy
Authors: Pearson Colin M. , Fyfe James W. B. , Snaddon Thomas N. 
Published: May 2019

AbstractHerein, we report a modular synthetic route to linear and branched homoallylic amines that operates through a sequential one‐pot Lewis base/transition‐metal catalyzed allylic alkylation/Hofmann rearrangement strategy. This protocol is operationally trivial, proceeds from simple and easily prepared substrates and catalysts, and enables all aspects of regio‐ and stereoselectivity to be controlled through a conserved experimental protocol. Overall, the high levels of enantio‐, regio‐, and diastereoselectivity obtained, in concert with the ability to access orthogonally protected or free amines, render this a straightforward and effective approach for the preparation of useful enantioenriched homoallylic amines. We have also demonstrated the utility of the products in the context of pharmaceutical synthesis.
Low‐Temperature Growth of Carbon Nanotubes Catalyzed by Sodium‐Based Ingredients
Authors: Li Richard , Antunes Erica F. , Kalfon‐Cohen Estelle , Kudo Akira , Acauan Luiz , Yang Wei‐Chang D. , Wang Canhui , Cui Kehang , Liotta Andrew H. , Rajan Ananth Govind , Gardener Jules , Bell David C. , Strano Michael S. , Liddle J. Alexander , Sharma Renu , Wardle Brian L. 
Published: May 2019

AbstractSynthesis of low‐dimensional carbon nanomaterials such as carbon nanotubes (CNTs) is a key driver for achieving advances in energy storage, computing, and multifunctional composites, among other applications. Here, we report high‐yield thermal chemical vapor deposition (CVD) synthesis of CNTs catalyzed by reagent‐grade common sodium‐containing compounds, including NaCl, NaHCO3, Na2CO3, and NaOH, found in table salt, baking soda, and detergents, respectively. Coupled with an oxidative dehydrogenation reaction to crack acetylene at reduced temperatures, Na‐based nanoparticles have been observed to catalyze CNT growth at temperatures below 400 °C. Ex situ and in situ transmission electron microscopy (TEM) reveal unique CNT morphologies and growth characteristics, including a vaporizing Na catalyst phenomenon that we leverage to create CNTs without residual catalyst particles for applications that require metal‐free CNTs. Na is shown to synthesize CNTs on numerous substrates, and as the first alkali group metal catalyst demonstrated for CNT growth, holds great promise for expanding the understanding of nanocarbon synthesis.
Direct Prebiotic Pathway to DNA Nucleosides
Authors: Teichert Jennifer S. , Kruse Florian M. , Trapp Oliver 
Published: May 2019

AbstractIt is assumed that RNA played a key role in the origin of life, and the transition to more complex but more stable DNA for continuous information storage and replication requires the development of a ribonucleotide reductase to obtain the deoxyribonucleotides from ribonucleotides. This step, as well as an alternative path from abiotic molecules to DNA‐based life is completely unknown. Shown here is the formation of deoxyribonucleosides under relevant prebiotic conditions in water in high regio‐ and stereoselectivity, from all canonical purine and pyrimidine bases, by condensation with acetaldehyde and sugar‐forming precursors. Thus, a continuous path to deoxyribonucleosides, starting from simple, prebiotically available molecules has been discovered. Furthermore, the deoxyapionucleosides (DApiNA) were identified as a potential DNA progenitor. The results suggest that the DNA world evolved much earlier than previously assumed.
Novel 13C‐detected NMR Experiments for the Precise Detection of RNA Structure
Authors: Schnieders Robbin , Wolter Antje C. , Richter Christian , Wöhnert Jens , Schwalbe Harald , Fürtig Boris 
Published: May 2019

AbstractUp to now, NMR spectroscopic investigations of RNA have utilized imino proton resonances as reporters for base pairing and RNA structure. The nucleobase amino groups are often neglected, since most of their resonances are broadened beyond detection due to rotational motion around the C–NH2 bond. Here, we present 13C‐detected NMR experiments for the characterization of all RNA amino groups irrespective of their motional behavior. We have developed a C(N)H‐HDQC experiment that enables the observation of a complete set of sharp amino resonances through the detection of proton‐NH2 double quantum coherences. Further, we present an “amino”‐NOESY experiment to detect NOEs to amino protons, which are undetectable by any other conventional NOESY experiment. Together, these experiments allow the exploration of additional chemical shift information and inter‐residual proton distances important for high‐resolution RNA secondary and tertiary structure determination.
Output feedback control of a three‐phase four‐wire unified power quality conditioner
Authors: Benazza Bouchaib , Ouadi Hamid , Giri Fouad 
Published: May 2019

AbstractThe increasing penetration of power electronics in electrical equipment entails a significant impact on the deterioration of power supply quality. In this paper, the problem of power quality is addressed for distorted three‐phase four‐wire power grids supplying non‐linear unbalanced loads. A unified power quality conditioner (UPQC) is considered to ensure satisfactory electrical energy quality. To this end, a UPQC controller is designed to meet four control objectives: i) compensation of the harmonics and the reactive load currents; ii) compensation for the harmonic voltages at the point of common coupling (PCC); iii) cancelation of the neutral current; iv) and regulation of the inverter DC voltage. The control design relies on the UPQC nonlinear model that accounts for the electrical grid line impedance. Unlike previous works, the proposed controller features an output‐feedback nature as it combines a nonlinear regulator, designed with a sliding‐mode technique, and a state observer designed using a Lyapunov stability based technique. The latter provides the former with online estimates of the series filter AC voltages, which are not assumed to be accessible to measurements. The closed loop error system is analyzed using the average stability approach. It turns out that all (tracking and estimation) errors are asymptotically vanishing, except for the DC bus voltage tracking error, which is periodic in steady‐state with an amplitude depending on the (DC bus) capacitor, the larger the capacitor the smaller the steady‐state DC voltage tracking error level. This theoretical result is confirmed by simulations involving wide range variations of the load current.
Development of tissue‐engineered skeletal muscle manufacturing variables
Authors: Wragg Nicholas M. , Player Darren J. , Martin Neil R. W. , Liu Yang , Lewis Mark P. 
Published: May 2019

AbstractThree‐dimensional tissue‐engineered structures enable more representative determination of novel drug or material effects on tissue than traditional monolayer cell cultures. This study sought to better understand how key manufacturing variables affect the myotube characteristics of a skeletal muscle model toward reducing resource use and to develop an understanding of scaling on model consistency. C2C12 murine myoblasts were seeded in a tethered collagen scaffold from which directional myotubes form in response to lines of tension and a change in medium. Collagen polymerizing area length‐to‐width ratios greater than one were found to reduced cell–matrix attachment and remodeling forces significantly (p < .05) correlating to a reduction in cell fusion potential. Following this, utilizing a factorial design of experiment, 4 million C2C12s/ml, with a polymerizing area width 150% of the anchor point, produced the most favorable myotube characteristics and dramatically reduced the incidence of rupture. Scaled constructs showed no significant differences when compared to larger models. Approximately 20 myotubes with a variation in the alignment of <25° in the central region were consistently observed in the final models. This demonstrates the influence of initial manufacturing variables on tissue formation and has produced a benchmark model for consistent production across scaled constructs for future optimization and as a potential cost‐effective preclinical testbed.
Micropatterned substrates with physiological stiffness promote cell maturation and Pompe disease phenotype in human induced pluripotent stem cell‐derived skeletal myocytes
Authors: Jiwlawat Nunnapas , Lynch Eileen M. , Napiwocki Brett N. , Stempien Alana , Ashton Randolph S. , Kamp Timothy J. , Crone Wendy C. , Suzuki Masatoshi 
Published: May 2019

AbstractRecent advances in bioengineering have enabled cell culture systems that more closely mimic the native cellular environment. Here, we demonstrated that human induced pluripotent stem cell (iPSC)‐derived myogenic progenitors formed highly‐aligned myotubes and contracted when seeded on two‐dimensional micropatterned platforms. The differentiated cells showed clear nuclear alignment and formed elongated myotubes dependent on the width of the micropatterned lanes. Topographical cues from micropatterning and physiological substrate stiffness improved the formation of well‐aligned and multinucleated myotubes similar to myofibers. These aligned myotubes exhibited spontaneous contractions specifically along the long axis of the pattern. Notably, the micropatterned platforms developed bundle‐like myotubes using patient‐derived iPSCs with a background of Pompe disease (glycogen storage disease type II) and even enhanced the disease phenotype as shown through the specific pathology of abnormal lysosome accumulations. A highly‐aligned formation of matured myotubes holds great potential in further understanding the process of human muscle development, as well as advancing in vitro pharmacological studies for skeletal muscle diseases.
Sustainable development: The effects of environmental policy disclosure in advertising
Authors: Chang Hsiu‐Hua , Tsai Shin‐Hua , Huang Chun‐Chen 
Published: May 2019

AbstractSustainable development is a key issue for society. Beside corporate's efforts, consumers should have responsibilities for environmental protection and consider sustainable coexistences between future generations and natural ecosystems. In this study, a 4 × 2 factorial between‐subject experiment is adopted to develop eight environmental policy disclosure scenarios based on different environmental advertising claims (product orientation, process orientation, image orientation, and environmental fact) and eco‐labels (available/unavailable) to explore the effect of consumer attitudes and behaviors. This study's results show that environmental advertising claims have significant effects on consumers' attitudes. The product, process, and image orientation advertising, along with advertising with eco‐labels, can induce more positive attitudes and stronger purchase intentions. Individuals with greater environmental concerns have a significant positive attitude toward environmental advertising. Consumer attitudes toward environmental advertising also have positive effects on purchase intentions and sustainable consumption behaviors. Finally, this study offers useful findings, practical implications, and insights.
Economic evaluation of the development of a phage therapy product for the control of Salmonella in poultry
Authors: Torres‐Acosta Mario A. , Clavijo Viviana , Vaglio Christopher , González‐Barrios Andrés F. , Vives‐Flórez Martha J. , Rito‐Palomares Marco 
Published: May 2019

AbstractPoultry products are one of the major transmission media of Salmonella enteritidis to humans. A promising alternative to reduce the load of Salmonella in poultry are bacteriophages. Elsewhere, a mixture of six bacteriophages has been used successfully, but large‐scale production would be necessary to supply potential poultry market and costs analyses have not been calculated yet. For this, a powerful tool to predict production costs is bioprocess modeling coupled with economic analyses. This work aims to model the scaled‐up production of a six bacteriophages mixture based on a laboratory/pilot‐scale production using Biosolve Process. For the model construction, a combination of experimental and reported data was applied, in which different production alternatives and the range of 1–100% of the Colombian poultry market (at broiler's farm and slaughterhouse) were analyzed. Results indicate that the best cost‐effective process configuration/scale is to use one bioreactor (156 L) for the six bacteriophages, then a 0.45 μm filtration for removal of biomass, and a 0.22 μm filtration for sterility; this to supply the 35% of the market size for broiler farms (equivalent to 210 million chickens). This configuration gives a production cost per chicken of US$ 0.02. Additionally, a sensitivity analysis and a theoretical contrast for understanding the impact that titer and recovery have on production scale determined that titer affects the most the cost and requires optimization. The present works serves as a first, and required, approach for the development of phage therapy products that are alternatives to present‐day pathogens control strategies.
Multitask learning on monocular water images: Surface reconstruction and image synthesis
Authors: Xie Xueguang , Zhai Xiao , Hou Fei , Hao Aimin , Qin Hong 
Published: May 2019

AbstractIn this paper, we present a new strategy, a joint deep learning architecture, for two classic tasks in computer graphics: water surface reconstruction and water image synthesis. Modeling water surfaces from single images can be regarded as the inverse of image rendering, which converts surface geometries into photorealistic images. On the basis of this fact, we therefore consider these two problems as a cycle image‐to‐image translation and propose to tackle them together using a pair of neural networks, with the three‐dimensional surface geometries being represented as two‐dimensional surface normal maps. Furthermore, we also estimate the imaging parameters from the existing water images with a subnetwork to reuse the lighting conditions when synthesizing new images. Experiments demonstrate that our method achieves an accurate reconstruction of surfaces from monocular images efficiently and produces visually plausible new images under variable lighting conditions.