bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Solvent‐Free Solution: Vacuum‐Deposited Organic Monolayers Modify Work Functions of Noble Metal Electrodes
Authors: Widdascheck Felix , Hauke Alrun Aline , Witte Gregor 
Published: March 2019

AbstractThe energy level alignment between organic semiconductors (OSCs) and the respective (metal) electrodes in organic electronic devices is of key importance for efficient charge carrier injection. For many years, researchers have attempted to control this energy level alignment by means of functional self‐assembled monolayers or the insertion of thin injection layers (made, e.g., of doped OCSs or pure dopants). The present work demonstrates an alternative to these approaches, namely the use of phthalocyanine monolayers as contact primers, which are deposited onto noble metal electrodes by means of vacuum deposition. It is shown that polar as well as non‐polar phthalocyanines modify the work functions of clean Au(111) and Ag(111) surfaces as a function of their coverage and thus enable quantitative control of the metal work functions. This behavior is successfully replicated for the respective polycrystalline metal surfaces and it is found that full monolayers can even withstand air exposure when protected by sacrificial multilayers, which are afterward removed by thermal desorption.
Surface‐Driven Energy Storage Behavior of Dual‐Heteroatoms Functionalized Carbon Material
Authors: Wu Tianjing , Jing Mingjun , Tian Ye , Yang Li , Hu Jiugang , Cao Xiaoyu , Zou Guoqiang , Hou Hongshuai , Ji Xiaobo 
Published: March 2019

AbstractHeteroatom modification represents one of the major areas of carbon materials' research in electrical energy storage. However, the influence of heteroatomic state evolution on electrochemical properties remains an elusive topic. Herein, thiophene‐2,5‐dicarboxylic acid is chemically activated to prepare O,S‐diatomic hybrid carbon material (OS–C). The heteroatoms and carbon matrix coexist in the form of CO/CO and CS/SS bonds, which introduce porous networks to the partially graphitized carbon skeleton and provide abundant active sites for better ion absorption. Moreover, the heteroatoms and carbon matrix are bridged to establish stable pseudocapacitive functional groups like quinoid unit and disulfide bonds, which can be electrochemically converted into benzenoid units and mercaptan anions through Faradaic reactions to further improve the reversible capacity. Combined with the detailed kinetic exploration and in situ investigation of the electrochemical impedance spectra, the energy storage mechanism for lithium/sodium is proposed in the following steps: Faradaic reactions at a higher potential range, energy storage at active sites, and ions intercalation on the graphitized parts in the low‐voltage states. Greatly, the electrode can store lithium up to the capacity of ≈700 mAh g−1, while also delivering ≈330 mAh g−1 of sodium storage, providing lifetimes in excess of thousands of cycles.
3D Plotted Biphasic Bone Scaffolds for Growth Factor Delivery: Biological Characterization In Vitro and In Vivo
Authors: Ahlfeld Tilman , Schuster Felix Paul , Förster Yvonne , Quade Mandy , Akkineni Ashwini Rahul , Rentsch Claudia , Rammelt Stefan , Gelinsky Michael , Lode Anja 
Published: March 2019

AbstractBioprinting enables the integration of biological components into scaffolds during fabrication that has the advantage of high loading efficiency and better control of release and/or spatial positioning. In this study, a biphasic scaffold fabricated by extrusion‐based 3D multichannel plotting of a calcium phosphate cement (CPC) paste and an alginate/gellan gum (AlgGG) hydrogel paste laden with the angiogenic factor VEGF (vascular endothelial growth factor) is investigated with regard to biological response in vitro and in vivo. Rat mesenchymal stromal cells are able to adhere and grow on both CPC and AlgGG strands, and differentiate toward osteoblasts. A sustained VEGF release is observed, which is able to stimulate endothelial cell proliferation as well as angiogenesis in vitro that indicates maintenance of its biological activity. After implantation into a segmental bone defect in the femur diaphysis of rats, a clear reduction of the defect size by newly formed bone tissue occurs from the distal and proximal ends of the host bone within 12 weeks. The CPC component shows excellent osteoconductivity whereas the local VEGF release from the AlgGG hydrogel gives rise to an enhanced vascularization of the defect region. This work contributes to the development of novel therapeutic concepts for improved bone regeneration which are based on 3D bioprinting.
Implanting Niobium Carbide into Trichoderma Spore Carbon: a New Advanced Host for Sulfur Cathodes
Authors: Shen Shenghui , Xia Xinhui , Zhong Yu , Deng Shengjue , Xie Dong , Liu Bo , Zhang Yan , Pan Guoxiang , Wang Xiuli , Tu Jiangping 
Published: March 2019

AbstractTailored construction of advanced carbon hosts is playing a great role in the development of high‐performance lithium–sulfur batteries (LSBs). Herein, a novel N,P‐codoped trichoderma spore carbon (TSC) with a bowl structure, prepared by a “trichoderma bioreactor” and annealing process is reported. Moreover, TSC shows excellent compatibility with conductive niobium carbide (NbC), which is in situ implanted into the TSC matrix in the form of nanoparticles forming a highly porous TSC/NbC host. Importantly, NbC plays a dual role in TSC for not only pore formation but also enhancement of conductivity. Excitingly, the sulfur can be well accommodated in the TSC/NbC host forming a high‐performance TSC/NbC‐S cathode, which exhibits greatly enhanced rate performance (810 mAh g−1 at 5 C) and long cycling life (937.9 mAh g−1 at 0.1 C after 500 cycles), superior to TSC‐S and other carbon/S counterparts due to the larger porosity, higher conductivity, and better synergetic trapping effect for the soluble polysulfide intermediate. The synergetic work of porous the conductive architecture, heterodoped N&P polar sites in TSC and polar conductive NbC provides new opportunities for enhancing physisorption and chemisorption of polysulfides leading to higher capacity and better rate capability.
Lateral WSe2 p–n Junction Device Electrically Controlled by a Single‐Gate Electrode
Authors: Kwak Do‐Hyun , Jeong Min‐Hye , Ra Hyun‐Soo , Lee A‐Young , Lee Jong‐Soo 
Published: March 2019

AbstractSemiconductor p–n junctions are building blocks for optoelectronic devices. Recently, p–n junction devices based on 2D transition metal dichalcogenides (TMDCs) have been demonstrated in optoelectronic applications due to their thin thickness, flexibility, high carrier mobility, and high light‐absorption properties. To fabricate 2D semiconductor p–n junction devices, various methods are demonstrated, such as heterojunction structures, chemical doping, and electrostatic doping. In this work, lateral both p–n and n–p junctions in WSe2 devices, electrically controlled by using only a single‐gate electrode, are first reported. It is demonstrated that the single‐gated WSe2 p–n and n–p diodes form an internal built‐in electrical field, showing strong diode‐like current rectifying behavior and photovoltaic effect under the illumination. The resultant device exhibits a high current rectification ratio up to ≈106 and a power conversion efficiency of 0.1% under AM 1.5 illumination. A logical inverter based on the lateral and in‐plane contacted WSe2 device with a hexagonal boron nitride (h‐BN) gate dielectric is also presented. The electrode architecture engineering based on a single TMDC will be useful for applications that are more complicated such as p–n junction optoelectronic devices and inverters.
Copper Nitrate‐Mediated Selective Difunctionalization of Alkenes: A Rapid Access to β‐Bromonitrates
Authors: Gao Mingchun , Zhou Kaijing , Xu Bin 
Published: March 2019

AbstractA regioselective copper nitrate‐mediated difunctionalization of alkenes has been developed for the rapid synthesis of β‐bromonitrates, where copper nitrate is used as an ideal nitrooxy source for the first time and the products will find many applications in organic synthesis as versatile synthons. Different from the general reports that copper nitrate acts as the nitro source, the given protocol provides a direct access to functionalized nitrates, with operational simplicity, good functional group tolerance and a wide substrate scope.magnified image
Porous NiCo2S4/Co9S8 Microcubes Templated by Sacrificial ZnO Spheres as an Efficient Bifunctional Oxygen Electrocatalyst
Authors: Riaz Muhammad Sohail , Yuan Xiaotao , Zhao Yantao , Dong Chenlong , Nong Shuying , Ali Zeeshan , Huang Fuqiang 
Published: March 2019

AbstractInnovative nano/microarchitectures, owing to their promising catalytic features, such as abundant active sites, high surface area, and enhanced ion transport, are ideal for oxygen electrocatalysis. Herein, an inventive approach is put forward to fabricate ternary metal sulfide hollow microcubes by a hydrothermal method between spherical porous ZnO with transition metal cations in the presence of urea followed by etching and sulfurization. The significant electrocatalytic activity toward oxygen evolution reaction (OER) with onset potential of 1.48 V (vs reversible hydrogen electrode (RHE)) is obsereved. The objective material shows an overpotential of 320 mV, to achieve a current density of 10 mA cm−2 for OER and excellent robustness with slight variation in potential after long‐term chronopotentiometry test for 12 h. As expected, the material also exhibits oxygen reduction reaction (ORR) activity with a half wave potential of 0.8 V (vs RHE) and limited current density of 5.1 mA cm−2. Meanwhile, further investigations confirm the near four‐electron transport pathways for ORR. Such up‐bottom etching followed by sulfurization method provide a new concept for engineering porous electrocatalysts.
Achieving Ultrahigh Energy Densities of Supercapacitors with Porous Titanium Carbide/Boron‐Doped Diamond Composite Electrodes
Authors: Xu Jing , Yang Nianjun , Heuser Steffen , Yu Siyu , Schulte Anna , Schönherr Holger , Jiang Xin 
Published: March 2019

AbstractThe energy densities of most supercapacitors (SCs) are low, hindering their practical applications. To construct SCs with ultrahigh energy densities, a porous titanium carbide (TiC)/boron‐doped diamond (BDD) composite electrode is synthesized on a titanium plate that is pretreated using a plasma electrolytic oxidation (PEO) technique. The porous and nanometer‐thick TiO2 layer formed during PEO process prevents the formation of brittle titanium hydride and enhances the BDD growth during chemical vapor deposition processes. Meanwhile, the in situ conversion of TiO2 into TiC is achieved. Combination of this capacitor electrode with soluble redox electrolytes leads to the fabrication of high‐performance SCs in both aqueous and organic solutions. In 0.05 m Fe(CN)63−/4− + 1 m Na2SO4 aqueous solution, the capacitance is as high as 46.3 mF cm−2 at a current density of 1 mA cm−2; this capacitance remains 92% of its initial value even after 10 000 charge/discharge cycles; the energy density is up to 47.4 Wh kg−1 at a power density of 2236 W kg−1. The performance of constructed SCs is superior to most available SCs and some electrochemical energy storage devices like batteries. Such a porous capacitor electrode is thus promising for the construction of high‐performance SCs for practical applications.
Optimal rate allocation for production and injection wells in an oil and gas field for enhanced profitability
Authors: Epelle Emmanuel I. , Gerogiorgis Dimitrios I. 
Published: March 2019

AbstractAn oil and gas field requires careful operational planning and management via production optimization for increased recovery and long‐term project profitability. This article addresses the challenge of production optimization in a field undergoing secondary recovery by water flooding. The field operates with limited processing capacity at the surface separators, pipeline pressure constraints, and water injection constraints; an economic indicator (net present value, NPV) is used as the objective function. The formulated optimization framework adequately integrates slow‐paced subsurface dynamics using reservoir simulation, and fast‐paced surface dynamics using sophisticated multiphase flow simulation in the upstream facilities. Optimization of this holistic long‐term model is made possible by developing accurate second‐order polynomial proxy models at each time step. The resulting formulation is solved as a nonlinear program using commercially available solvers. A comparative analysis is performed using MATLAB's fmincon solver and the IPOPT solver for their robustness, speed, and convergence stability in solving the proposed problem. By implementing two synthetic case studies, our mathematical programming approach determines the optimal production and injection rates of all wells and further demonstrates considerable improvement to the NPV obtained by simultaneously applying the tools of streamline, reservoir, and surface facility simulation for well rate allocation via systematic NLP optimization.
Controllable Isomerization of Alkenes by Dual Visible‐Light‐Cobalt Catalysis
Authors: Meng Qing‐Yuan , Schirmer Tobias E. , Katou Kousuke , König Burkhard 
Published: March 2019

AbstractWe report herein that thermodynamic and kinetic isomerization of alkenes can be accomplished by the combination of visible light with Co catalysis. Utilizing Xantphos as the ligand, the most stable isomers are obtained, while isomerizing terminal alkenes over one position can be selectively controlled by using DPEphos as the ligand. The presence of the donor–acceptor dye 4CzIPN accelerates the reaction further. Transformation of exocyclic alkenes into the corresponding endocyclic products could be efficiently realized by using 4CzIPN and Co(acac)2 in the absence of any additional ligands. Spectroscopic and spectroelectrochemical investigations indicate CoI being involved in the generation of a Co hydride, which subsequently adds to alkenes initiating the isomerization.
Total Synthesis of (−)‐Indoxamycins A and B
Authors: Hu Naifeng , Dong Changming , Zhang Cuifang , Liang Guangxin 
Published: March 2019

AbstractThe concise total syntheses of (−)‐indoxamycins A and B is reported. The chemistry features a seven‐step preparation of a highly congested [5.5.6] tricyclic advanced common intermediate from a readily available R‐carvone derivative. Key steps involve a Pauson–Khand reaction for the rapid construction of a basic scaffold bearing a quaternary carbon, a copper‐catalyzed Michael addition for the introduction of another adjacent all‐carbon quaternary stereocenter, and a tandem retro‐oxa‐Michael addition/1,2‐addition/oxa‐Michael addition for the installation of a trisubstituted olefin side chain. This synthetic strategy allows for easy access to both enantiomers of this family of natural products and their analogues from cost‐effective starting material through straightforward chemical transformations.
Quantifying Chemical Structure and Machine‐Learned Atomic Energies in Amorphous and Liquid Silicon
Authors: Bernstein Noam , Bhattarai Bishal , Csányi Gábor , Drabold David A. , Elliott Stephen R. , Deringer Volker L. 
Published: March 2019

AbstractAmorphous materials are being described by increasingly powerful computer simulations, but new approaches are still needed to fully understand their intricate atomic structures. Here, we show how machine‐learning‐based techniques can give new, quantitative chemical insight into the atomic‐scale structure of amorphous silicon (a‐Si). We combine a quantitative description of the nearest‐ and next‐nearest‐neighbor structure with a quantitative description of local stability. The analysis is applied to an ensemble of a‐Si networks in which we tailor the degree of ordering by varying the quench rates down to 1010 K s−1. Our approach associates coordination defects in a‐Si with distinct stability regions and it has also been applied to liquid Si, where it traces a clear‐cut transition in local energies during vitrification. The method is straightforward and inexpensive to apply, and therefore expected to have more general significance for developing a quantitative understanding of liquid and amorphous states of matter.
Synthesis and characterization of microwave‐assisted biologically active triazole silanes
Authors: Singh Gurjaspreet , Satija Pinky , Singh Akshpreet , Sanchita  , Aulakh Darpandeep , Wriedt Mario , Ruiz Cristobal Espinosa , Esteban M. Angeles , Sinha Shweta , Sehgal Rakesh 
Published: March 2019

The alliance of new drug, green technology and public health initiatives is essential for the ecosystem. The microwave technique is used to synthesize new drugs cognate to metronidazole. A new family of triethoxysilanes (3a–3e) was synthesized after reconnaissance with terminal alkynes (2a–2e) as an array using the Huisgen 1,3‐dipolar cycloaddition. All products were obtained in excellent yield with recovery of the catalyst as well as the solvent, and in a short time span. The design feature of these compounds is the tailoring of two unsymmetrical triazole nuclei into a single scaffold. The pharmacokinetic profiles of the triazole scaffold were analyzed using MOLINSPIRATION and ADMET toolkits, which gave promising results that prompted the investigation of these compounds for anti‐parasitic activity against parasites (Giardia lamblia and Trichomonas vaginalis) in contrast to standard drug (metronidazole). Compound 3d manifested good efficacy against both strains amongst all the synthesized triazole analogs.Highlights

By using microwave methodology, a series of triazole functionalized alkynes and triazole organo silanes were synthesized. This involves tailoring of the 1,2,4‐triazole nucleus to 1,2,3‐triazole moiety.
The protocol afforded excellent yield in a short time span under eco‐friendly conditions.
The hybrid molecules were screened for their physicochemical properties using MOLINSPIRATION software and ADMET web server.
All the synthesized compounds were investigated for their antioxidant activity, anti‐giardial and anti‐trichomonal activities.
Tris triazole silane (3d) was found to be the most significant against Giardia lamblia and Trichomonas vaginalis, respectively, and this low‐price, versatile drug will hopefully lead to the eventual elimination of parasitic disease from the human population.
Thermal gravimetric analysis has been performed for compounds (2a–2e) and (3a–3e).
Synthesis of modified graphene oxide and its improvement on flame retardancy of epoxy resin
Authors: Wu Wenqian , Xu Yiting , Wu Haiyang , Chen Jinmei , Li Min , Chen Ting , Hong Jing , Dai Lizong 
Published: March 2019

ABSTRACTIn this work, the small molecule with double‐phosphaphenanthrene structure was successfully grafted on the surface of graphene oxide (GO), which is called functionalized graphene oxide (FGO). The introduction of FGO improved the poor interfacial compatibility between graphene and epoxy matrix. And FGO could be used as the highly effective flame retardant. The thermogravimetric analysis results showed a significant improvement in the char yield of cured FGO/EP. When the content of FGO was 3 wt %, the limiting oxygen index value reached 30.4%. At the same time, the three‐point bending and thermomechanical tests confirmed that the mechanical properties of the epoxy resin composites were improved. Based on the char analyses of SEM images and Raman spectroscopy, the flame retardant could promote the formation of a stable carbon layer. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 47710.
Spatial Abilities Training in Anatomy Education: A Systematic Review
Authors: Langlois Jean , Bellemare Christian , Toulouse Josée , Wells George A. 
Published: March 2019

Spatial abilities have been correlated to anatomy knowledge assessment and spatial training has been found to improve spatial abilities in previous systematic reviews. The objective of this systematic review was to evaluate spatial abilities training in anatomy education. A literature search was done from inception to 3 August 2017 in Scopus® and several databases on the EBSCOhost platform. Citations were reviewed and those involving anatomy education, an intervention, and a spatial abilities test were retained and the corresponding full‐text articles were reviewed for inclusion. Before and after training studies, as well as comparative training programs, relating a spatial training intervention to spatial abilities were eligible. Of the 2,405 citations obtained, 52 articles were identified and reviewed, yielding eight eligible articles. Instruction in anatomy and mental rotations training were found to improve spatial abilities. For the seven studies retained for the meta‐analysis that included the effect of interventions on spatial abilities test scores, the pooled treatment effect difference was 0.49 (95% CI [0.17; 0.82]; n = 11) improvement. For the two studies that included the practice effect on spatial abilities test scores in a control group, the pooled treatment effect difference was 0.47 (95% CI [−0.03; 0.97]; n = 2) improvement. In these two studies, the impact of the intervention on spatial abilities test scores was found despite the practice effect. Evidence was found for improvement of spatial abilities in anatomy education using instruction in anatomy and mental rotations training.
Self‐Assembly of Aggregation‐Induced‐Emission Molecules
Authors: Wu Tongyue , Huang Jianbin , Yan Yun 
Published: March 2019

AbstractThe last decade has witnessed rapid developments in aggregation‐induced emission (AIE). In contrast to traditional aggregation, which causes luminescence quenching (ACQ), AIE is a reverse phenomenon that allows robust luminescence to be retained in aggregated and solid states. This makes it possible to fabricate various highly efficient luminescent materials, which opens new paradigms in a number of fields, such as imaging, sensing, medical therapy, light harvesting, light‐emitting devices, and organic electronic devices. Of the various important features of AIE molecules, their self‐assembly behavior is very attractive because the formation of a well‐defined emissive nanostructure may lead to advanced applications in diverse fields. However, due to the nonplanar topology of AIEgens, it is not easy for them to self‐assemble into well‐defined structures. To date, some strategies have been proposed to achieve the self‐assembly of AIEgens. Herein, we summarize the most recent approaches for the self‐assembly of AIE molecules. These approaches can be sorted into two classes: 1) covalent molecular design and 2) noncovalent supramolecular interactions. We hope this will inspire more excellent work in the field of AIE.
Multivalent Sialosides: A Tool to Explore the Role of Sialic Acids in Biological Processes
Authors: Chaudhary Preeti Madhukar , Toraskar Suraj , Yadav Rohan , Hande Akshay , Yellin Rina‐Arad , Kikkeri Raghavendra 
Published: March 2019

AbstractSialic acids (Sias) are fascinating nine‐carbon monosaccharides that are primarily found on the terminus of the oligosaccharide chains of glycoproteins and glycolipids on cell surfaces. These Sias undergo a variety of structural modifications at their hydroxy and amine positions, thereby resulting in structural diversity and, hence, coordinating a variety of biological processes. However, deciphering the structural functions of such interactions is highly challenging, because the monovalent binding of Sias is extremely weak. Over the last decade, several multivalent Sia ligands have been synthesized to modulate their binding affinity with proteins/lectins. In this Minireview, we highlight recent developments in the synthesis of multivalent Sia probes and their potential applications. We will discuss four key multivalent families, that is, polymers, dendrimers, liposomes, and nanoparticles, and will emphasize the major parameters that are essential for the specific interactions of these molecules with proteins in biological systems.