bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystallization Kinetics in 2D Perovskite Solar Cells
Authors: Xu Youkui , Wang Meng , Lei Yutian , Ci Zhipeng , Jin Zhiwen 
Published: October 2020

Abstract2D perovskites demonstrate higher moisture stability, oxygen content, thermal stability, and a significantly lower ion migration/phase transition occurrence in comparison to 3D perovskite. These advantages imply huge potential for 2D perovskite in commercial applications in the photovoltaic field. However, the horizontal arrangement of the organic layer severely hinders the transport of carriers, and thus, the power conversion efficiency of 2D perovskite solar cells (PSCs) is significantly lower than that of 3D. Controlling the crystallization orientation to achieve rapid carrier transport can effectively avoid or reduce such adverse effects. Hence, an in‐depth understanding of the formation mechanism and crystallization kinetics of 2D perovskite films is crucial to the development of high‐performing 2D PSCs. This review explores the studies conducted on crystallization kinetics, which is the key issue for 2D perovskite, and discusses their effects on the performance of various types of 2D PSCs to date. The crystal/natural quantum well structures and origin of the stability for 2D perovskite are also summarized. Finally, the remaining challenges in terms of development bottlenecks for 2D PSCs are discussed, alongside the proposal of possible solutions.
Engineering Micrometer‐Sized DNA Tracks for High‐Speed DNA Synthesis and Biosensing
Authors: Wang Liying , Song Kaiyun , Qu Yuanyuan , Chang Yangyang , Li Zhongping , Dong Chuan , Liu Meng , Brennan John D. , Li Yingfu 
Published: October 2020

Abstractφ29 DNA polymerase (Polφ29) is capable of synthesizing long‐chain single‐stranded (ss) DNA molecules by copying the sequence of a small ss circular DNA template (ssCDT) in a process known as rolling circle amplification (RCA). The use of a ssCDT in RCA, however, comes with a key drawback: the rate of DNA synthesis is significantly reduced. We hypothesize that this issue can be overcome using a very long linear ssDNA template with a repeating sequence. To test this idea, we engineered a DNA assembly, which we denote “micrometer‐sized DNA track” (μDT). This μDT, with an average length of ≈13.5 μm, is made of a long chain DNA with a primer‐binding domain at its 3′ end and ≈1000 repeating sequence units at its 5′ end, each carrying a DNA anchor. We find that Polφ29 copies μDT at a speed ≈5‐time faster than it does a related ssCDT. We use this to design a simple all‐in‐one printed paper device for rapid and sensitive detection of microRNA let‐7. This paper sensor is capable of detecting 1 pM let‐7a in 10 minutes.
In situ Nanoscale Infrared Spectroscopy of Water Adsorption on Nanoislands of Surface‐Anchored Metal‐Organic Frameworks
Authors: Delen Guusje , Monai Matteo , Meirer Florian , Weckhuysen Bert M. 
Published: October 2020

AbstractDespite technological advancements, probing gas‐solid interfaces at the nanoscale is still a formidable challenge. New nano‐spectroscopic methods are needed to understand the guest–host interactions of functional materials during gas sorption, separation, and conversion. Herein, we introduce in situ Photoinduced Force Microscopy (PiFM) to evidence site‐specific interaction between Metal‐Organic Frameworks (MOFs) and water. To this end, we developed amphiphilic Surface‐anchored MOF (SURMOF) model systems using self‐assembly for the side‐by‐side hetero‐growth of nanodomains of hydrophilic HKUST‐1 and hydrophobic ZIF‐8. PiFM was used to probe local uptake kinetics and to show D2O sorption isotherms on (defective) HKUST‐1 paddlewheels. By monitoring defect vibrations, we visualized in real‐time the saturation of existing defects and the creation of D2O‐induced defects. This work shows the potential of in situ PiFM to unravel gas sorption mechanisms and map active sites on functional (MOF) materials.
The yellowing mechanism of polyesteramide based on poly(ethylene terephthalate) and polyamide 6
Authors: Qi Mengyan , Zheng Liuchun , Li Chuncheng , Xiao Yaonan , Liu Jiajian , Wu Shaohua , Zhang Bo 
Published: October 2020

AbstractThe yellowing mechanism in polyesteramide based on poly(ethylene terephthalate) and polyamide 6 (PET‐PA6) has been studied. Amine model compounds were employed to react with acetaldehyde (AA), and 1H‐nuclear magnetic resonance spectrometer (1H‐NMR), fourier transform infrared spectroscopy (FT‐IR), and electrospray ionization mass spectrometry (ESI‐MS) were used to characterize the structure of the yellowing products. 13C‐NMR, laser confocal micro‐Raman spectrum, and X‐ray photoelectron spectroscopy (XPS) were used to characterize the yellowing products of the reaction of PA6 oligomers and AA. The structures of yellowing substances in the two systems are consistent. The color generation is mainly caused by the reaction of the terminal primary amine group of PA6 with AA, which is the thermal degradation product of PET, to form Schiff bases. These Schiff bases condense further to form a conjugated imine structure, which may be the main chromophore of polyesteramide. Due to the degradation of PA6 segments of the copolymer, it may further degrade to form new primary amino groups and increase yellowness during use.
A new route of cross‐linking of carboxylated acrylonitrile‐butadiene rubber via zinc oxide‐amino acid network formation
Authors: Das Mithun , Pal Sanjay , Naskar Kinsuk 
Published: October 2020

AbstractHerein, we present a strategy that leads to the formation of a high‐performance elastomeric material based on the carboxylated acrylonitrile‐butadiene rubber (XNBR). A unique cross‐linking route for XNBR has been designed, which does not involve typical cross‐linking agents such as sulfur. In this study, the show cause‐effect of zwitterionic compounds as the secondary cross‐linking agent for ionic elastomer has been investigated. Naturally occurring lysine (Ly) and tryptophan (Trp) amino acid are the zwitterionic compounds, which have been explored here. This approach results in the formation of a cross‐linked ionic elastomer that houses a dual ionic network structure formed by zinc oxide (ZnO) and amino acid. XNBR cross‐linked by ZnO and different amino acid compounds exhibit superior physical properties as compared to the conventional cross‐linking system. Fourier transform infrared spectroscopy, transmission electron microscope, and swelling study analyzes confirm the existence of zinc‐carboxylate and zwitterionic network in XNBR after the cross‐linking process. The dynamic mechanical analysis, differential scanning calorimetry, and oscillating disk rheometer analyzes show various thermal relaxations and transitions present in the dual cross‐linked XNBR. The ZnO and amino acid cross‐linked XNBR rubber with 2.5 phr of Ly and 5 phr of Trp show the highest tensile strength of 42.4 and 39.7 MPa, respectively, which is mostly higher than the previously reported values for ionic cross‐linked elastomers.
Understanding the stability of medical concept embeddings
Authors: Lee Grace E. , Sun Aixin 
Published: October 2020

AbstractFrequency is one of the major factors for training quality word embeddings. Several studies have recently discussed the stability of word embeddings in general domain and suggested factors influencing the stability. In this work, we conduct a detailed analysis on the stability of concept embeddings in medical domain, particularly in relations with concept frequency. The analysis reveals the surprising high stability of low‐frequency concepts: low‐frequency (<100) concepts have the same high stability as high‐frequency (>1,000) concepts. To develop a deeper understanding of this finding, we propose a new factor, the noisiness of context words, which influences the stability of medical concept embeddings regardless of high or low frequency. We evaluate the proposed factor by showing the linear correlation with the stability of medical concept embeddings. The correlations are clear and consistent with various groups of medical concepts. Based on the linear relations, we make suggestions on ways to adjust the noisiness of context words for the improvement of stability. Finally, we demonstrate that the linear relation of the proposed factor extends to the word embedding stability in general domain.
Ethanol to Aromatics on Modified H‐ZSM‐5 Part II: An Unexpected Low Coking
Authors: Seifert Markus , Marschall Mathias S. , Gille Torsten , Jonscher Clemens , Royla Philipp , Busse Oliver , Reschetilowski Wladimir , Weigand Jan J. 
Published: October 2020

AbstractIn this study a commercial H‐ZSM‐5 zeolite (Si/Al=11) was post‐synthetically modified by a combined dealumination procedure to adjust its catalytic properties for the selective formation of aromatics from ethanol. The solid‐state properties of original and modified zeolites are determined by structural, textural and acidity analysis. The formation of aromatics and durability of the zeolites were investigated depending on space velocity or contact time in the catalyst bed. In particular, the formation rate and desorption of aromatics from solid‐state surface as well as their tendency to form coke precursors by consecutive build‐up reactions determine the formation of coke. Therefore, the rate of build‐up and finished aromatization by hydride transfer (pre‐determined by the kind, location and geometric arrangement of surface acid sites) and the statistical number of reaction events until final desorption at the specific contact time have to be harmonized to increase aromatics yield and to decrease catalyst decay by coke simultaneously.
Bonding Relationship between Silicon and Germanium with Group 13 and Heavier Elements of Groups 14–16
Authors: Agarwal Abhishek , Bose Shubhankar Kumar 
Published: October 2020

AbstractThe topic of heavier main group compounds possessing multiple bonds is the subject of momentous interest in modern organometallic chemistry. Importantly, there is an excitement involving the discovery of unprecedented compounds with unique bonding modes. The research in this area is still expanding, particularly the reactivity aspects of these compounds. This article aims to describe the overall developments reported on the stable derivatives of silicon and germanium involved in multiple bond formation with other group 13, and heavier groups 14, 15, and 16 elements. The synthetic strategies, structural features, and their reactivity towards different nucleophiles, unsaturated organic substrates, and in small molecule activation are discussed. Further, their physical and chemical properties are described based on their spectroscopic and theoretical studies.
Frameworks for double hyperbolic function‐based robust sliding mode differentiator and observer for nonlinear dynamics
Authors: Deepika Deepika 
Published: October 2020

AbstractThis paper puts forward contemporary designs of sliding mode differentiator and state observer for evaluation of unknown nonlinear signal derivatives and unknown internal system states, respectively, by the virtue of tangential and inverse sinusoidal hyperbolic functions. The utility of the proposed frameworks is that it bestows smooth and robust estimation without inciting unacceptable oscillations (chattering), unlike high gain discontinuous function‐based preliminary observers/differentiators. Moreover, the employed double hyperbolic functions would drive the various deviations in estimations of signals or states to a very close neighborhood of origin in finite time which is substantiated via Lyapunov's energy function. To demonstrate the efficiency of the introduced techniques, two examples for estimating the derivatives of a nonlinear signal and internal states of motor are also illustrated with time varying uncertainties. At last, the attained simulation outcomes of the proposed differentiator are further compared with formerly formulated designs such as higher‐order sliding mode differentiator (HOSMD) and uniformly convergent differentiator (UCD).
Exosomal lncRNA FAM225A accelerates esophageal squamous cell carcinoma progression and angiogenesis via sponging miR‐206 to upregulate NETO2 and FOXP1 expression
Authors: Zhang Chunyu , Luo Yan , Cao Jingjing , Wang Xiaoyu , Miao Zhiwei , Shao Guoqing 
Published: October 2020

AbstractEsophageal cancer is one of the leading causes of cancer‐related deaths worldwide. FAM225A is a novel lncRNA, only has been explored in nasopharyngeal carcinoma tumorigenesis. This study aims to investigate the regulatory mechanism of FAM225A in esophageal squamous cell carcinoma (ESCC). We discovered that FAM225A exhibited higher expression in ESCC. The silence of FAM225A attenuated cell viability, migration, and invasion, but facilitated cell apoptosis in ESCC. Exosome‐mediated transfer of lncRNA FAM225A could participate in ESCC progression. In addition, we found that miR‐206 bound to FAM225A. Moreover, we further demonstrated that FAM225A absorbed miR‐206 to upregulate NETO2 and FOXP1 expression, and FOXP1 acted as a transcription factor to enhance FAM225A expression. Eventually, it was revealed that the overexpression of NETO2 or FOXP1 rescued the effects of FAM225A repression on ESCC progression. Our results suggested that FAM225A upregulated NETO2 and FOXP1 expression by sponging miR‐206 to accelerate ESCC progression and angiogenesis. These results determined the biological role of lncRNA FAM225A in ESCC tumorigenesis, and FAM225A may be a promising biomarker for ESCC treatment.
Zn2+‐Dependent DNAzymes: From Solution Chemistry to Analytical, Materials and Therapeutic Applications
Authors: Moon Woohyun J. , Yang Yongjie , Liu Juewen 
Published: October 2020

AbstractSince 1994, deoxyribozymes or DNAzymes have been in vitro selected to catalyze various types of reactions. Metal ions play a critical role in DNAzyme catalysis, and Zn2+ is a very important one among them. Zn2+ has good biocompatibility and can be used for intracellular applications. Chemically, Zn2+ is a Lewis acid and it can bind to both the phosphate backbone and the nucleobases of DNA. Zn2+ undergoes hydrolysis even at neutral pH, and the partially hydrolyzed polynuclear complexes can affect the interactions with DNA. These features have made Zn2+ a unique cofactor for DNAzyme reactions. This review summarizes Zn2+‐dependent DNAzymes with an emphasis on RNA‐/DNA‐cleaving reactions. A key feature is the sharp Zn2+ concentration and pH‐dependent activity for many of the DNAzymes. The applications of these DNAzymes as biosensors for Zn2+, as therapeutic agents to cleave intracellular RNA, and as chemical biology tools to manipulate DNA are discussed. Future studies can focus on the selection of new DNAzymes with improved performance and detailed biochemical characterizations to understand the role of Zn2+, which can facilitate practical applications of Zn2+‐dependent DNAzymes.
Palladium−Ruthenium Catalyst Complementarity Strengthens Ortho‐Directed C−H Bond Arylation of 2‐Arylpyrazines
Authors: Benzai Amal , Derridj Fazia , Doucet Henri , Soulé Jean‐François 
Published: October 2020

AbstractWe report the Pd‐ or Ru‐catalyzed C−H bond arylation at the ortho‐position of the aryl unit of 2‐arylpyrazines. The reaction proceeds with complete regioselectivity using phosphine‐free Pd(OAc)2 or [RuCl2(p‐cymene]2 as the catalysts and potassium acetate as an inexpensive base. In all cases, the mono‐arylation of 2‐arylpyrazines was obtained even with 2,3‐diphenylpyrazine. Moreover, the reaction is not sensitive to the pyrazine substitution. By selecting the proper catalytic system, a wide variety of electron‐rich and ‐poor (hetero)aryl bromides, including bromopyridine derivatives, has been successfully employed.
Iron Coordination Properties of Gramibactin as Model for the New Class of Diazeniumdiolate Based Siderophores
Authors: Gama Sofia , Hermenau Ron , Frontauria Mariachiara , Milea Demetrio , Sammartano Silvio , Hertweck Christian , Plass Winfried 
Published: October 2020

AbstractGramibactin (GBT) is an archetype for the new class of diazeniumdiolate siderophores, produced by Paraburkholderia graminis, a cereal‐associated rhizosphere bacterium, for which a detailed solution thermodynamic study exploring the iron coordination properties is reported. The acid‐base behavior of gramibactin as well as its complexing ability toward Fe3+ was studied over a wide range of pH values (2≤pH≤11). For the latter the ligand‐competition method employing EDTA was used. Only two species are formed: [Fe(GBT)]− (pH 2 to 9) and [Fe(GBT)(OH)2]3− (pH≥9). The formation of [Fe(GBT)]− and its occurrence in real systems was confirmed by LC‐HRESIMS analysis of the bacteria culture broth extract. The sequestering ability of gramibactin was also evaluated in terms of the parameters pFe and pL0.5. Gramibactin exhibits a higher sequestering ability toward Fe3+ than EDTA and of the same order of magnitude as hydroxamate‐type microbial siderophores, but smaller than most of the catecholate‐type siderophores and much higher than the most known phytosiderophores.
Flexibility of Power‐to‐Gas Plants: A Case Study
Authors: Herrmann Felix , Grünewald Marcus , Riese Julia 
Published: October 2020

AbstractDue to the increasing share of renewable energies in the power sector, the need for energy storage and flexible performance is rising. This study provides an in‐depth investigation of the flexibility of a Power‐to‐Gas plant for the production of synthetic natural gas. Model‐based analysis is conducted for the individual technologies PEM electrolysis, MEA absorption and fixed‐bed methanation as well as for the continuously operated process. This study reveals that the Power‐to‐Gas plant offers a capacity flexibility of 87–125 %, corresponding to 4.79–6.88 MW electrical input power.
About the granularity portability of block‐based Krylov methods in heterogeneous computing environments
Authors: Carracciuolo Luisa , Mele Valeria , Szustak Lukasz 
Published: October 2020

SummaryLarge‐scale problems in engineering and science often require the solution of sparse linear algebra problems and the Krylov subspace iteration methods (KM) have led to a major change in how users deal with them. But, for these solvers to use extreme‐scale hardware efficiently a lot of work was spent to redesign both the KM algorithms and their implementations to address challenges like extreme concurrency, complex memory hierarchies, costly data movement, and heterogeneous node architectures. All the redesign approaches bases the KM algorithm on block‐based strategies which lead to the Block‐KM (BKM) algorithm which has high granularity (i.e., the ratio of computation time to communication time). The work proposes novel parallel revisitation of the modules used in BKM which are based on the overlapping of communication and computation. Such revisitation is evaluated by a model of their granularity and verified on the basis of a case study related to a classical problem from numerical linear algebra.
Revised beaconing glowworm swarm optimization ant colony optimization algorithm to localize nodes and optimize the energy consumed by nodes in wireless sensor networks
Authors: Reddy Vandana , P Gayathri 
Published: October 2020

SummaryIn the wireless sensor networks energy consumption is broadest and widely explored area of research. The solution for energy optimization encompasses various techniques such as efficient routing protocols, data scheduling, clustering, hardware redesigning, supervised and unsupervised network learning algorithm, and so forth. Compared with all the methods that has been so far discussed, swarm intelligence (SI) is considered to be the optimal way to find solution for reducing energy consumption as it is simple and the network formation is understood by the natural mechanism present in nature. SI approaches include ant colony optimization (ACO), particle swarm optimization, glowworm swarm optimization (GSO), and so forth. In this article, the authors provide the solution for the energy conservation problem through efficient GSO methods combined ACO. The revised beaconing glowworm swarm optimization ant colony optimization algorithm will be applied on the sensor network divided into swarms based on glowworms, the ants are introduced in the network that would parse the network by visiting the swarm heads with the principle of ACO behind it. The algorithm is tested on MATLAB 2015a for performance comparison with the HM‐ACOPSO method with depicts energy conservation and efficiency in data collection.
Process: Failure mode and effect analysis of power module on network base station
Authors: Shuai Chun‐Jiang 
Published: October 2020

SummaryThe power module of failure modes and effects were analyzed from process, combined with the condition of field station power available, maintenance, and repair on TMB power and personal handy‐phone system, in the context of network base station power module parts machining requirements. The key factors affecting the quality of power were identified. And the improvement measures and principles to improve the power of the batch quality and reduce the damage rate were proposed. Finally, the ability of the reliability of power was improved.
Repetitive transcranial magnetic stimulation reverses reduced excitability of rat visual cortex induced by dark rearing during early critical period
Authors: Charles James Jeyanthan , Funke Klaus 
Published: October 2020

AbstractEarly critical period of visual cortex is characterized by enhanced activity‐driven neuronal plasticity establishing the specificity of neuronal connections required for optimal processing of sensory signals. Deprivation from visual input by dark rearing (DR) during this period leads to a lasting impairment of visual performance. Previously, we demonstrated that repetitive transcranial magnetic stimulation (rTMS) applied with intermittent theta‐burst (iTBS) pattern during the critical period improved the visual performance of the DR rats. In this study, we describe that the excitability of the binocular part of the visual cortex (V1b), as measured in acute brain slices by input‐output ratios of field excitatory synaptic potentials (fEPSPs), is lowered in DR rats compared to normal controls. Verum rTMS applied with the iTBS pattern during DR reversed this DR effect, while no rTMS effect was evident in the non‐DR (nDR) rats. In addition, verum rTMS reduced the number of neurons expressing the 67 kD isoform of glutamic acid decarboxylase (GAD67), the calcium‐binding protein calbindin (CB) and the zinc‐finger transcription factor zif268/EGR1, as determined via immunohistochemistry, only in DR rats but not in nDR rats. Moreover, rTMS reduced the number of neurons expressing the calcium‐binding protein parvalbumin (PV) only in nDR rats which showed more PV+ neurons compared to DR rats. This study confirms that iTBS‐rTMS may be able to prevent or reverse the effects of DR on visual cortex physiology, likely through a modulation of the activity of inhibitory interneurons.