bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recombination Dynamics Study on Nanostructured Perovskite Light‐Emitting Devices
Authors: Chen Ziming , Li Zhenchao , Zhang Chongyang , Jiang Xiao‐Fang , Chen Dongcheng , Xue Qifan , Liu Meiyue , Su Shijian , Yip Hin‐Lap , Cao Yong 
Published: August 2018

AbstractThe field of organic–inorganic hybrid perovskite light‐emitting diodes (PeLEDs) has developed rapidly in recent years. Although the performance of PeLEDs continues to improve through film quality control and device optimization, little research has been dedicated to understanding the recombination dynamics in perovskite thin films. Likewise, little has been done to investigate the effects of recombination dynamics on the overall light‐emitting behavior of PeLEDs. Therefore, this study investigates the recombination dynamics of CH3NH3PbI3 thin films with differing crystal sizes by measurement of fluence‐dependent transient absorption dynamics and time‐resolved photoluminescence. The aim is to find out the link between recombination dynamics and device behavior in PeLEDs. It is found that bimolecular and Auger recombination become more efficient as the crystal size decreases and monomolecular recombination rate is affected by the trap density of perovskite. By defining the radiative efficiency Φ(n), which relates to the monomolecular, bimolecular, and Auger recombination, the fundamental recombination properties of CH3NH3PbI3 films are discerned in quantitative terms. These findings help us to understand the light emission behavior of PeLEDs. This study takes an important step toward establishing the relationship between film structure, recombination dynamics, and device behavior for PeLEDs, thereby providing useful insights toward the design of better perovskite devices.
Two‐Component Stapling of Biologically Active and Conformationally Constrained Peptides: Past, Present, and Future
Authors: Iegre Jessica , Gaynord Josephine S. , Robertson Naomi S. , Sore Hannah F. , Hyvönen Marko , Spring David R. 
Published: August 2018

AbstractPeptides are an emerging class of therapeutics in the pharmaceutical world. Whilst small molecules have dominated the therapeutic landscape for decades, the design and application of peptide drugs is emerging among the pharmaceutical industries and academia. Although highly selective and efficacious, peptides are characterized by poor pharmacokinetic properties and amelioration of their bioavailability remains a major hurdle. Incorporation of conformational constraints within the peptide (such as peptide stapling) has been extensively used to improve the bioavailability of these molecules; consequently, it is not surprising that a plethora of stapling techniques has been developed and has had a significant impact on the development of peptide therapeutics. Among the numerous stapling techniques known, two‐component methodologies allow facile and divergent functionalization of peptides. The authors have pioneered a stapling technique that makes use of the double Cu‐catalyzed azide–alkyne cycloaddition between di‐azido peptides and functionalized di‐alkynyl staples. In recent years, the authors have created biologically active, conformationally constrained peptides functionalized with cell‐penetrating peptides, fluorescent tags, and photo cross‐linking moieties, demonstrating the wide applicability of this methodology. Herein, the impact, advantages, limitations, and future applications of this technology and other two‐component peptide stapling techniques on the development of clinically relevant peptides are highlighted.
Local Charge Distribution Engineered by Schottky Heterojunctions toward Urea Electrolysis
Authors: Li Caicai , Liu Youwen , Zhuo Zhiwen , Ju Huanxin , Li Dian , Guo Yanpeng , Wu Xiaojun , Li Huiqiao , Zhai Tianyou 
Published: August 2018

AbstractUrea electrooxidation with favorable thermodynamic potential offers great promise for decoupling H2/O2 evolution from sluggish water splitting, and simultaneously mitigating the problem of urea‐rich water pollution. However, the intrinsically slow kinetics of the six‐electron transfer process impels one to explore efficient catalysts in order to enable widespread use of this catalytic system. In response, taking CoS2/MoS2 Schottky heterojunctions as the proof‐of‐concept paradigm, a catalytic model to modulate the surface charge distribution for synergistically facilitating the adsorption and fracture of chemical group in urea molecule is proposed and the mechanism of urea electrooxidation at the molecular level is elucidated. Based on density functional calculations, the self‐driven charge transfer across CoS2/MoS2 heterointerface would induce the formation of local electrophilic/nucleophilic region, which will intelligently adsorb electron‐donating/electron‐withdrawing groups in urea molecule, activate the chemical bonds, and thus trigger the decomposition of urea. Benefiting from the regulation of local charge distribution, the constructed Schottky catalyst of CoS2‐MoS2 exhibits superior urea catalytic activities with a potential of 1.29 V (only 0.06 V higher than the thermodynamic voltage of water decomposition) to attain 10 mA cm−2 as well as robust durability over 60 h. This innovational manipulation of charge distribution via Schottky heterojunction provides a model in exploring other highly efficient electrocatalysts.
Synthesis of Chiral Sulfur‐Containing Polymers: Asymmetric Copolymerization of meso‐Epoxides and Carbonyl Sulfide
Authors: Yue Tian‐Jun , Ren Wei‐Min , Chen Li , Gu Ge‐Ge , Liu Ye , Lu Xiao‐Bing 
Published: August 2018

AbstractSynthesis of chiral sulfur‐containing polymers was realized for the first time by the asymmetric alternating copolymerization of achiral meso‐epoxides with carbonyl sulfide (COS) using catalyst systems based on enantiopure binaphthol‐linked dinuclear CoIII complexes under mild reaction conditions. The resultant poly(monothiocarbonate)s have main‐chain chirality and more than 99 % isotacticity. Notably, the stereoregular copolymers are typical semicrystalline thermoplastics with high melting temperatures up to 232 °C. Additionally, these sulfur‐containing polymers have good optical properties with refractive indices of up to 1.56 and Abbe's numbers of up to 43.
Schwefel‐Spillover auf Kohlenstoffmaterialien und mögliche Einflüsse auf Metall‐Schwefel‐Batterien
Authors: Medenbach Lukas , Escher Ines , Köwitsch Nicolas , Armbrüster Marc , Zedler Linda , Dietzek Benjamin , Adelhelm Philipp 
Published: August 2018

AbstractGängige Methoden zur Herstellung von Schwefel‐Kohlenstoff‐Kompositen als positive Elektroden für wiederaufladbare Batterien sind die Vermahlung in der Kugelmühle und das Imprägnieren des Kohlenstoffs durch flüssigen, gelösten oder gasförmigen Schwefel. Durch den so gewährleisteten, guten Kontakt der Elemente werden verbesserte Batterieeigenschaften erhofft. Hier wird über einen unerwarteten Spillover‐Effekt des Schwefels in Kontakt mit porösem Kohlenstoff bei Umgebungsbedingungen berichtet. Nach kurzem Mischen von Schwefel und porösem Kohlenstoff im Massenverhältnis 1:1 erfolgt eine vollständige Oberflächenbedeckung des Kohlenstoffs innerhalb weniger Tage. Gleichzeitig verliert Schwefel charakteristische Eigenschaften der Volumenphase wie Kristallinität, Schmelzpunkt und Raman‐Aktivität. Der Spillover kann auch bei Gegenwart einer flüssigen Phase auftreten, und Konsequenzen des Phänomens werden am Beispiel einer Natrium‐Schwefel‐Zelle mit Festelektrolytmembran diskutiert.
Annelated Cyclobutanes by Fe‐Catalyzed Cycloisomerization of Enyne Acetates
Authors: Kramm Frederik , Teske Johannes , Ullwer Franziska , Frey Wolfgang , Plietker Bernd 
Published: August 2018

AbstractCationic Fe complexes of the general type [(Ph3P)2Fe(CO)(NO)]X (X=BF4, BArF4) catalyze the redox‐neutral cycloisomerization of 1,6‐ and 1,7‐enyneacetates to afford bicyclic cyclobutanes under mild conditions in good yields and diastereoselectivities.
Pharmacokinetic, metabolic profiling and elimination of brusatol in rats
Authors: Guo Nan , Xu Xin , Yuan Guiyan , Chen Xuwang , Wen Qing , Guo Ruichen 
Published: August 2018

AbstractBrusatol, a quassinoid isolated from the traditional Chinese medicine Brucea javanica, has been reported to be an inhibitor of Nrf2 pathway and has great potential to be developed into a novel chemotherapeutic adjuvant. However, the in vivo process of brusatol has not been comprehensively explained yet. Therefore, this paper focused on the pharmacokinetic metabolism and excretion of brusatol in rats using a simple and reproducible LC–MS/MS method. The results indicated that the plasma concentration of brusatol decreased rapidly; the average cumulative excretion rate in urine was 5.82% during 24 h, and 0.71% in bile during 12 h. High‐resolution mass spectrometry was applied for the identification of metabolites; as a result, four metabolites were detected and the structure was tentatively deduced on the base of the MS2 data, Compound Discoverer 2.0 and Mass Frontier 7.0 software. Hydroxylation, hydrolysis and glucuronidation were suggested as major metabolic pathways in vivo. The in vivo process and detection of metabolites of brusatol might improve the understanding of the mechanism of its anticancer effect and provide valuable information for its safety estimation, which will be essential to the new drug development.
Checkpoint blockade‐based immunotherapy in the context of tumor microenvironment: Opportunities and challenges
Authors: Duan Jingjing , Wang Yu , Jiao Shunchang 
Published: August 2018

AbstractA dynamic and mutualistic interaction between tumor cells and tumor microenvironment (TME) promotes the progression and metastasis of solid tumors. Cancer immunotherapy is becoming a major treatment paradigm for a variety of cancers. Although immunotherapy, especially the use of immune checkpoint inhibitors, has achieved clinical success, only a minority of patients exhibits durable responses. Clinical studies directed at identifying appropriate biomarkers and immune profiles that can be used to predict immunotherapy responses are presently being conducted. Combining treatment strategies tailored to cancer‐immune interactions are designed to increase the rate of durable clinical response in patients. It is essential to establish a reasonable tumor classification strategy according to TME to improve cancer immunotherapy. In the current review, a modified classification of TME is proposed, and optimization of TME classification is needed through detailed and integrated molecular characterization of large patient cohorts in the future.
Ethylene (co)Oligomerization by Phosphine‐Pyridine Based Palladium and Nickel Catalysts
Authors: Si Guifu , Na Yinna , Chen Changle 
Published: August 2018

AbstractPhosphine and pyridine groups have been widely employed in various olefin polymerization catalysts. In this contribution, these two moieties are connected using different bridges, and the properties of their corresponding palladium and nickel complexes are investigated. A series of CH2, NH and O bridged phosphine‐pyridine ligands (2‐(diarylphosphino)methyl‐pyridine, 2‐(diarylphosphino)amino‐pyridine, 2‐diarylphosphinito‐pyridine) are synthesized and characterized. For the CH2 bridged ligand, the introduction of a C6F5 substituent leads to the generation of a mixture of diastereomers, which can be separated by column chromatography. Starting with these five phosphine‐pyridine ligands, the corresponding palladium and nickel complexes are prepared and characterized. The bridging moiety (CH2, NH and O), the substituents on the bridge, and the ligand orientations significantly influence the properties of the metal complexes in ethylene oligomerization and cooligomerization reactions. For the palladium complexes, ethylene oligomerization and cooligomerization with some polar comonomers (methyl acrylate, butyl vinyl ether, vinyltrimethoxysilane, allyl acetate and allyl choride) can be realized. For the nickel complexes, ethylene oligomerization followed by Friedel‐Crafts addition of the resulting oligomers to toluene solvent leads to the formation of branched alkylated aromatic materials.
Polymeric Metal Salen‐Type Complexes as Catalysts for Photoelectrocatalytic Hydrogen Peroxide Production
Authors: Konev Alexander S. , Kayumov Mikhail Yu. , Karushev Mikhail P. , Novoselova Yuliia V. , Lukyanov Daniil A. , Alekseeva Elena V. , Levin Oleg V. 
Published: August 2018

AbstractElectroactive and conductive polymers based on transition metal complexes with salen‐type ligands are of interest as potential materials for energy storage and solar energy conversion. The easily tunable structure of monomers allows to modify polymer properties by changing either the central metal atom or the ligand substituents. Herein we report the photoelectrocatalytic activity of [MII(L)]n complexes, where M is Ni, Cu or Pd, and L is a tetradentate N,N,O,O salen‐type ligand, in the reduction of molecular oxygen to hydrogen peroxide in water solutions on polymer‐coated ITO electrodes. The photocathodic current at 0 V vs. Ag/AgCl is pH‐dependent, reaching maximum at pH 1 and dropping almost to zero at pH 12. Hydrogen peroxide production is almost quantitative (97 % efficiency measured in 1‐compartment cell). Maximal photocurrent and H2O2 concentrations achieved comprise 23 μA/cm2 and 1.3×10−3 M respectively.
Preparation, Lithium Storage Performance and Thermal Stability of Nickel‐Rich Layered LiNi0.815Co0.15Al0.035O2/RGO Composites
Authors: Chen Rong , Zhang Haiyan , Xie Jian , Lin Yingxi , Yu Jiale , Chen Liangguang 
Published: August 2018

AbstractNi‐rich materials are promising Li‐ion battery cathodes due to their high capacity but still suffer from electrolyte corrosions and inferior thermal stability, limiting the lithium storage capability. To improve both, lithium storage performances and thermal stability, LiNi0.815Co0.15Al0.035O2 (LNCAO)/reduced graphene oxide (RGO) composites are synthesized by chemical lithiation of commercial Ni0.815Co0.15Al0.035(OH)2 precursors with LiOH ⋅ H2O, followed by simply wet coating with RGO. The effects of such RGO modifications on lithium storage performances and thermal stability of the achieved LNCAO/RGO are investigated. Compared to LNCAO, the unique LNCAO/RGO (with ∼2.5 wt.% RGO) electrodes exhibit considerably improved cycling stability and high‐rate capability (a reversible capacity of 135 mAh g−1 at 10 C), with a capacity decay rate of 0.07 % per cycle at 1 C, half of that of pristine LNCAO (0.14 %/cycle). As evidenced by differential scanning calorimetry, thermal stability is also significantly enhanced since the heat generation decreases from 912 to 586 J g−1 for pristine LNCAO and LNCAO/RGO, respectively. This could be ascribed to the unique structures and the encapsulated RGO coating layers, effectively protecting LNCAO against electrolyte corrosions and decreasing the level of Li+/Ni2+ disordering. This study helps us further understand the critical roles of RGO layers in electrochemical performances and thermal stability of Ni‐rich‐based cathodes for lithium/sodium storage.
Molecular Encapsulation Inside Microtubules Based on Tau‐Derived Peptides
Authors: Inaba Hiroshi , Yamamoto Takahisa , Kabir Arif Md. Rashedul , Kakugo Akira , Sada Kazuki , Matsuura Kazunori 
Published: August 2018

AbstractMicrotubules are cytoskeletal filaments that serve as attractive scaffolds for developing nanomaterials and nanodevices because of their unique structural properties. The functionalization of the outer surface of microtubules has been established for this purpose. However, no attempts have been made to encapsulate molecules inside microtubules with 15 nm inner diameter. The encapsulation of various molecular cargos inside microtubules constitutes a new concept for nanodevice and nanocarrier applications of microtubules. Here, we developed peptide motifs for binding to the inner surface of microtubules, based on a repeat domain of the microtubule‐associated protein Tau. One of the four Tau‐derived peptides, 2N, binds to a taxol binding pocket of β‐tubulin located inside microtubules by preincubation with tubulin dimer and subsequent polymerization of the peptide‐tubulin complex. By conjugation of 2N to gold nanoparticles, encapsulation of gold nanoparticles inside microtubules was achieved. The methodology for molecular encapsulation inside microtubules by the Tau‐derived peptide is expected to advance the development of microtubule‐based nanomaterials and nanodevices.
Investigations of Cu/Zn Oxalates from Aqueous Solution: Single‐Phase Precursors and Beyond
Authors: Zwiener Leon , Girgsdies Frank , Schlögl Robert , Frei Elias 
Published: August 2018

AbstractThe existence of a limited solid‐solution series in the Cu/Zn binary metal oxalate system is reported. Coprecipitation was applied for the preparation of a comprehensive set of mixed Cu/Zn oxalates. Rietveld refinement of the XRD data revealed the formation of mixed‐metal oxalate single phases at the compositional peripheries. Accordingly, the isomorphous substitution of ZnII into CuII oxalate takes place at Zn contents of ≤6.6 and ≥79.1 atom %. Zn incorporation leads to a pronounced unit‐cell contraction accompanied by Vegard‐type trends for the lattice parameters. Morphologically, both solid solutions show close resemblance to the corresponding pure single‐metal oxalates, and thus distinct differences are identified (SEM). The successful formation of solid solutions was further evidenced by thermal analysis. The decomposition temperature of the oxalate was taken as an approximation for ZnII incorporation into the CuII oxalate structure. Single decomposition events are observed within the stated compositional boundaries and shift to higher temperature with increasing Zn content, whereas multiple events are present near Cu/Zn parity. Moreover, these findings are supported by IR and Raman spectroscopic investigations. This study on the Cu/Zn mixed‐metal oxalate system sheds light on the important prerequisites for solid‐solution formation and identifies the structural limitations that predefine its application as catalyst precursor.
Preparation and Characterization of Graphene Oxide Aerogels: Exploring the Limits of Supercritical CO2 Fabrication Methods
Authors: Borrás Alejandro , Gonçalves Gil , Marbán Gregorio , Sandoval Stefania , Pinto Susana , Marques Paula A. A. P. , Fraile Julio , Tobias Gerard , López‐Periago Ana M. , Domingo Concepción 
Published: August 2018

AbstractThe supercritical carbon dioxide (scCO2) synthesis of non‐reduced graphene oxide (GO) aerogels from dispersions of GO in ethanol is here reported as a low‐cost, efficient, and environmentally friendly process. The preparation is carried out under the mild conditions of 333 K and 20 MPa. The high aspect ratio of the used GO sheets (ca. 30 μm lateral dimensions) allowed the preparation of aerogel monoliths by simultaneous scCO2 gelation and drying. Solid‐state characterization results indicate that a thermally‐stable mesoporous non‐reduced GO aerogel was obtained by using the supercritical procedure, keeping most of the surface oxygenated groups on the GO sheets, thus, facilitating further functionalization. Moreover, the monoliths have a very low density, high specific surface area, and excellent mechanical integrity; characteristics which rival those of most light‐weight reduced graphene aerogels reported in the literature.
Iron‐Incorporated α‐Ni(OH)2 Hierarchical Nanosheet Arrays for Electrocatalytic Urea Oxidation
Authors: Xie Junfeng , Liu Weiwei , Lei Fengcai , Zhang Xiaodong , Qu Haichao , Gao Li , Hao Pin , Tang Bo , Xie Yi 
Published: August 2018

AbstractAn iron‐incorporated α‐Ni(OH)2 nanosheet array catalyst characterized by hierarchical surface nanobelts and robust urea oxidation performance are reported. The unique single‐crystalline belt‐on‐sheet hierarchical nanostructure was identified and it endows more reactive edges for the Ni2+‐to‐Ni3+ pre‐oxidation process to boost the generation of active high‐valence species for the urea oxidation reaction (UOR). Benefitting from the optimal Fe concentration, the UOR activity was further optimized owing to the favorable reaction kinetics. With the synergistic benefits of the increased surface areas, improved charge transfer behavior, favorable reaction kinetics and excellent structural stability, the iron‐incorporated α‐Ni(OH)2 hierarchical nanosheet array catalyst displays significantly improved UOR performance with both high activity and outstanding operational stability. This work could guide the design of advanced UOR catalysts for wastewater treatment and clean energy production in the future.
Experimental Determination of Photon Fluxes in Multilayer Capillary Photoreactors
Authors: Wriedt Benjamin , Kowalczyk Daniel , Ziegenbalg Dirk 
Published: August 2018

AbstractThe aim of this study was to accurately quantify the benefit of adding extra layers to a capillary flow‐photoreactor using actinometry. A self‐built 3D‐printed FEP cap‐ illary mount was designed and each of the layers was evaluated separately. Experimental results showed that additional capillaries can be regarded as an augmented optical path length and that reflection and scattering are of minor importance for stacking of capillaries. To cope with the problem of precipitation of the ferrioxalate actinometer in intensified reactors, a new experimental method of conducting actinometric measurements with pulses was investigated and showed reasonable agreement. To make the results comparable to other literature‐known, mostly also improvised reactor setups, appropriate figures of merit (productivity, space time yield, energy efficiency and external photon efficiency) were evaluated.
Toward implementation of associative model in real time for character recognition: A hardware architecture proposal for embedded systems
Authors: Vázquez‐Cervantes Alberto , Hernández‐Díaz Teresa , Córdova‐Esparza Diana‐Margarita , Nava‐Balanzar Luciano , Soto‐Cajiga J. A. , Barriga‐Rodríguez Leonardo , Jiménez‐Hernández Hugo 
Published: August 2018

SummaryThis paper presents an algorithm with low computational complexity for classifying and recognizing characters based on a random sampling and high‐dimensional binary spaces for the development of real‐time applications. Character classification is performed using uniform random sampling as the feature selection process, subsequently performing encoding as binary strings. Associative memories are commonly used as general classifiers with linear criteria to discriminate between data points. In most classifiers, the ability to efficiently detect class membership depends entirely on the expressiveness of the attributes used to encode the data. Each binary pattern encodes the distinct characteristics of several glyphs. Character features are represented as elements of a high‐dimensional binary space, where a criterion of the cluster is defined under the L1 metric. The reduction in computational complexity is analyzed. The reduction in the number of character features through random sampling techniques makes it feasible to manage all the character information in physical architectures; therefore, this approach might use resources on a hardware platform with integer operators typically implemented at the hardware‐register level. Finally, this approach is implemented in a parallel architecture Field‐Programmable Gate Array (FPGA) and tested using a Database (DB) of different fonts, including distortions, therein showing that the efficiency is comparable to the other well‐known approaches.