bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hole‐Trapping‐Induced Stabilization of Ni4 + in SrNiO3/LaFeO3 Superlattices
Authors: Wang Le , Yang Zhenzhong , Bowden Mark E. , Freeland John W. , Sushko Peter V. , Spurgeon Steven R. , Matthews Bethany , Samarakoon Widitha S. , Zhou Hua , Feng Zhenxing , Engelhard Mark H. , Du Yingge , Chambers Scott A. 
Published: October 2020

AbstractCreating new functionality in materials containing transition metals is predicated on the ability to control the associated charge states. For a given transition metal, there is an upper limit on valence that is not exceeded under normal conditions. Here, it is demonstrated that this limit of 3+ for Ni and Fe can be exceeded via synthesis of (SrNiO3)m/(LaFeO3)n superlattices by tuning n and m. The Goldschmidt tolerance constraints are lifted, and SrNi4+O3 with holes on adjacent O anions is stabilized as a perovskite at the single‐unit‐cell level (m = 1). Holding m = 1, spectroscopy reveals that the n = 1 superlattice contains Ni3+ and Fe4+, whereas Ni4+ and Fe3+ are observed in the n = 5 superlattice. It is revealed that the B‐site cation valences can be tuned by controlling the magnitude of the FeO6 octahedral rotations, which, in turn, determine the energy balance between Ni3+/Fe4+ and Ni4+/Fe3+, thus controlling emergent electrical properties such as the band alignment and resulting hole confinement. This approach can be extended to other systems for synthesizing novel, metastable layered structures with new functionalities.
One‐Shot Radical Cross Coupling Between Benzyl Alcohols and Alkenyl Halides Using Ni/Ti/Mn System
Authors: Suga Takuya , Takahashi Yuuki , Ukaji Yutaka 
Published: October 2020

AbstractA “one‐shot” cross coupling between benzyl alcohols and alkenyl halides has been established. A combination of low‐valent Ti‐mediated C−OH homolysis and the prominent chemistry of Ni‐based radical catalysis afforded the desired cross‐coupled product with good efficiency. The reaction proceeded regardless of the electronic property of benzyl alcohols, and Ar−B bond remained intact throughout the reaction. Alkenyl bromides with various substitution patterns were applicable to this reaction. Attempts for utilizing sterically demanding tri‐substituted alkenes indicated that the steric hinderance mainly inhibited the radical‐trapping by Ni species. This reaction can be a simple and efficient strategy for synthesizing densely substituted allylbenzene derivatives.magnified image
Unveiling Single Atom Nucleation for Isolating Ultrafine fcc Ru Nanoclusters with Outstanding Dehydrogenation Activity
Authors: Wang Ye , Li Jia‐Luo , Shi Wen‐Xiong , Zhang Zhi‐Ming , Guo Song , Si Rui , Liu Meng , Zhou Hong‐Cai , Yao Shuang , An Chang‐Hua , Lu Tong‐Bu 
Published: October 2020

AbstractUltrafine face‐centered cubic (fcc) ruthenium nanoclusters (NCs) are of great interest due to their super high catalytic activity. However, it is extremely difficult to prepare ≈1 nm fcc ruthenium NCs with high energy atoms due to their easy aggregation. Herein, the nucleation process of ruthenium centers by confined pyrolysis of a multivariate metal–organic framework to isolate ultrafine fcc NCs (from single atom to 1.33 nm) via in situ formed stabilizers is unveiled. Systematic investigations demonstrate that preferential nucleation of Ru single atoms to fcc clusters in the initial nucleation represents a key step and makes it possible to separate ultrafine fcc Ru NCs with in situ formed N‐doped porous carbon. A record high turnover frequency of 1300.53 min−1 for methanolysis of ammonia borane is achieved by 1.33 nm NCs. This work suggests a new strategy to prepare ultrafine metal NCs by instantly capturing structure‐specific crystal nuclei with in situ formed stabilizers.
Jarzynski on work and free energy relations: The case of variable volume
Authors: Ciccotti Giovanni , Rondoni Lamberto 
Published: October 2020

AbstractDerivations of the Jarzynski equality (JE) appear to be quite general, and applicable to any particle system, whether deterministic or stochastic, under equally general perturbations of an initial equilibrium state at given temperature T. At the same time, the definitions of the quantities appearing in the JE, in particular the work, have been questioned. Answers have been given, but a deeper understanding of the range of phenomena to which the JE applies is necessary, both conceptually and in order to interpret the experiments in which it is used. In fact, domains in which the JE is not applicable have been identified. To clarify the issue, we scrutinize the applicability of the JE to a Hamiltonian particle system in a variable volume. We find that, in this case, the standard interpretation of the terms appearing in the JE is not adequate.
Signaling in Systems Chemistry: Programing Gold Nanoparticles Formation and Assembly Using a Dynamic Bistable Network
Authors: Maity Indrajit , Dev Dharm , Basu Kingshuk , Wagner Nathaniel , Ashkenasy Gonen 
Published: October 2020

AbstractLiving cells exploit bistable and oscillatory behaviors as memory mechanisms, facilitating the integration of transient stimuli into sustained molecular responses that control downstream functions. Synthetic bistable networks have also been studied as memory entities, but have rarely been utilized to control orthogonal functions in coupled dynamic systems. We herein present a new cascade pathway, for which we have exploited a well‐characterized switchable peptide‐based replicating network, operating far from equilibrium, that yields two alternative steady‐state outputs, which in turn serve as the input signals for consecutive processes that regulate various features of Au nanoparticle shape and assembly. This study further sheds light on how bridging together the fields of systems chemistry and nanotechnology may open up new opportunities for the dynamically controlled design of functional materials.
Solvation Effects on the Structure and Stability of Alkali Metal Carbenoids
Authors: Dilchert Katharina , Schmidt Michelle , Großjohann Angela , Feichtner Kai‐Stephan , Mulvey Robert E. , Gessner Viktoria H. 
Published: October 2020

Abstracts‐Block metal carbenoids are carbene synthons and applied in a myriad of organic transformations. They exhibit a strong structure–activity relationship, but this is only poorly understood due to the challenging high reactivity and sensitivity of these reagents. Here, we report on systematic VT and DOSY NMR studies, XRD analyses as well as DFT calculations on a sulfoximinoyl‐substituted model system to explain the pronounced solvent dependency of the carbenoid stability. While the sodium and potassium chloride carbenoids showed high stabilities independent of the solvent, the lithium carbenoid was stable at room temperature in THF but decomposed at −10 °C in toluene. These divergent stabilities could be explained by the different structures formed in solution. In contrast to simple organolithium reagents, the monomeric THF‐solvate was found to be more stable than the dimer in toluene, since the latter more readily forms direct Li/Cl interactions which facilitate decomposition via α‐elimination.
Electrochemical Oxidative Carbon‐Atom Difunctionalization: Towards Multisubstituted Imino Sulfide Ethers
Authors: Guan Zhipeng , Zhu Shuxiang , Wang Siyuan , Wang Huamin , Wang Siyuan , Zhong Xingxing , Bu Faxiang , Cong Hengjiang , Lei Aiwen 
Published: October 2020

AbstractEthers (C−O/S) are ubiquitously found in a wide array of functional molecules and natural products. Nonetheless, the synthesis of imino sulfide ethers, containing an N(sp2)=C(sp2)−O/S fragment, still remains a challenge because of its sensitivity to acid. Developed here in is an unprecedented electrochemical oxidative carbon‐atom difunctionalization of isocyanides, providing a series of novel multisubstituted imino sulfide ethers. Under metal‐free and external oxidant‐free conditions, isocyanides react smoothly with simple and readily available mercaptans and alcohols. Importantly, the procedure exhibited high stereoselectivities, excellent functional‐group tolerance, and good efficiency on large‐scale synthesis, as well as further derivatization of the products.
Activity and Stability Boosting of an Oxygen‐Vacancy‐Rich BiVO4 Photoanode by NiFe‐MOFs Thin Layer for Water Oxidation
Authors: Pan Jin‐Bo , Wang Bing‐Hao , Wang Jin‐Bo , Ding Hong‐Zhi , Zhou Wei , Liu Xuan , Zhang Jin‐Rong , Shen Sheng , Guo Jun‐Kang , Chen Lang , Au Chak‐Tong , Jiang Li‐Long , Yin Shuang‐Feng 
Published: October 2020

AbstractThe introduction of oxygen vacancies (Ov) has been regarded as an effective method to enhance the catalytic performance of photoanodes in oxygen evolution reaction (OER). However, their stability under highly oxidizing environment is questionable but was rarely studied. Herein, NiFe‐metal–organic framework (NiFe‐MOFs) was conformally coated on oxygen‐vacancy‐rich BiVO4 (Ov‐BiVO4) as the protective layer and cocatalyst, forming a core–shell structure with caffeic acid as bridging agent. The as‐synthesized Ov‐BiVO4@NiFe‐MOFs exhibits enhanced stability and a remarkable photocurrent density of 5.3±0.15 mA cm−2 at 1.23 V (vs. RHE). The reduced coordination number of Ni(Fe)‐O and elevated valence state of Ni(Fe) in NiFe‐MOFs layer greatly bolster OER, and the shifting of oxygen evolution sites from Ov‐BiVO4 to NiFe‐MOFs promotes Ov stabilization. Ovs can be effectively preserved by the coating of a thin NiFe‐MOFs layer, leading to a photoanode of enhanced photocurrent and stability.
High‐damping polyurethane/hollow glass microspheres sound insulation materials: Preparation and characterization
Authors: Zhang Zhijia , Jiang Hao , Li Rui , Gao Shan , Wang Qiang , Wang Guojun , Ouyang Xiao , Wei Hao 
Published: October 2020

AbstractThe high‐damping property of polyurethane elastomers and the low density of the hollow glass microspheres (HGM) were used to prepare the sound insulation materials in the present work. The transmission loss (TL) was measured to evaluate the HGM content on the sound insulation properties. The experimental results showed that the addition of HGM improved the hardness and compression modulus of the HGM‐filled polyurethane composites, and the loss factor (tan δ) of polyurethane composites were greater than 0.9. The average transmission loss (ATL, from 63 to 6300 Hz) reached 37.32 dB when the content of HGM was 10 wt%. The ATL of the HGM‐filled polyurethane composites with 15 wt% HGM in the damping control region and the mass control region were 31.94 and 46.78 dB, respectively. The synergistic effect of the microphase separation, the interfacial effect and the rigidity of polyurethane composites resulted in the improvement on sound insulation property. The polyurethane composite has a great potential application for the field of sound insulation materials.
Cure simulations of thick adhesive bondlines for wind energy applications
Authors: Cassano Alessandro G. , Dev Siddharth , Maiaru Marianna , Hansen Christopher J. , Stapleton Scott E. 
Published: October 2020

AbstractCuring of adhesive bondlines is a critical and time‐consuming operation in wind turbine blade manufacturing. Significant variation in adhesive thickness can lead to important differences in thermal histories trough the adhesive bonds due to the exothermic nature of the cure process. Reducing bondline cure cycle time and avoiding adhesive overheating are two competing factors in the design of cure temperature cycles. Predictive models on the impact of adhesive thickness variability in bondline cure temperature cycle is currently limited. Adhesive curing and temperature evolution can be simulated by finite element (FE) models coupling the heat transfer problem with the cure kinetics of the adhesive. The cure kinetics of the adhesive system was characterized by isothermal differential scanning calorimetry experiments and implemented in the FE software Abaqus/CAE by user subroutines. Predictions from the FE model were validated experimentally against temperature readings from the curing of 10, 20, and 30 mm thick adhesive bondlines. To highlight the role that predictive models potentially have in the optimization of bondline cure cycles a 2D cross section model representing the trailing edge of a wind turbine blade was used as case study. It was demonstrated that computational models enable customizing cure profiles for nonuniform adhesive thicknesses, ensuring fully cured bondlines with acceptable mechanical properties.
Mapping the biological activities of filamentous oxygenic photogranules
Authors: Ouazaite Hicham , Milferstedt Kim , Hamelin Jérôme , Desmond‐Le Quéméner Elie 
Published: October 2020

AbstractOxygenic photogranules have been suggested as alternatives to activated sludge in wastewater treatment. Challenging for modeling photogranule‐based processes is the heterogeneity of photogranule morphologies, resulting in different activities by photogranule type. The measurement of microscale‐activities of filamentous photogranules is particularly difficult because of their labile interfaces. We present here an experimental and modeling approach to quantify phototrophic O2 production, heterotrophic O2 consumption, and O2 diffusion in filamentous photogranules. We used planar optodes for the acquisition of spatio‐temporal oxygen distributions combined with two‐dimensional mathematical modeling. Light penetration into the photogranule was the factor controlling photogranule activities. The spatial distribution of heterotrophs and phototrophs had less impact. The photosynthetic response of filaments to light was detectable within seconds, emphasizing the need to analyze dynamics of light exposure of individual photogranules in photobioreactors. Studying other recurring photogranule morphologies will eventually enable the description of photogranule‐based processes as the interplay of interacting photogranule populations.
Deep learning analysis of the primary tumour and the prediction of lymph node metastases in gastric cancer
Authors: Jin C , Jiang Y , Yu H , Wang W , Li B , Chen C , Yuan Q , Hu Y , Xu Y , Zhou Z , Li G , Li R 
Published: October 2020

Abstract

Background
Lymph node metastasis (LNM) in gastric cancer is a prognostic factor and has implications for the extent of lymph node dissection. The lymphatic drainage of the stomach involves multiple nodal stations with different risks of metastases. The aim of this study was to develop a deep learning system for predicting LNMs in multiple nodal stations based on preoperative CT images in patients with gastric cancer.

Methods
Preoperative CT images from patients who underwent gastrectomy with lymph node dissection at two medical centres were analysed retrospectively. Using a discovery patient cohort, a system of deep convolutional neural networks was developed to predict pathologically confirmed LNMs at 11 regional nodal stations. To gain understanding about the networks' prediction ability, gradient-weighted class activation mapping for visualization was assessed. The performance was tested in an external cohort of patients by analysis of area under the receiver operating characteristic (ROC) curves (AUC), sensitivity and specificity.

Results
The discovery and external cohorts included 1172 and 527 patients respectively. The deep learning system demonstrated excellent prediction accuracy in the external validation cohort, with a median AUC of 0·876 (range 0·856–0·893), sensitivity of 0·743 (0·551–0·859) and specificity of 0·936 (0·672–0·966) for 11 nodal stations. The imaging models substantially outperformed clinicopathological variables for predicting LNMs (median AUC 0·652, range 0·571–0·763). By visualizing nearly 19 000 subnetworks, imaging features related to intratumoral heterogeneity and the invasive front were found to be most useful for predicting LNMs.

Conclusion
A deep learning system for the prediction of LNMs was developed based on preoperative CT images of gastric cancer. The models require further validation but may be used to inform prognosis and guide individualized surgical treatment.
How language affects consumers' processing of numerical cues
Authors: Gunasti Kunter , Kara Selcan , Ross William T. , Duclos Rod 
Published: October 2020

AbstractWe show that linguistic numeral structures affect consumers' comparative evaluations of numbers, prices, and alphanumeric brand names. For example, 80 (eighty) in English is perceived as 4 × 20 (quatre‐vingts or four twenties) in French and as 8 × 10 (ba‐shi or eight tens) in Chinese. Thus, the difference between 80 and 20 is expressed with different degrees of numerosity, the number of units into which a stimulus is divided: (a) 2 × 10 versus 8 × 10 in Chinese, (b) 20 versus 4 × 20 in French, or (c) simply 20 versus 80 in English. In four studies involving a total of 732 bilinguals who speak two of these three languages, we examine how different linguistic properties can lead to differences in comparison of numerical values and inferences made about product attributes. We demonstrate the mediating role of numerosity induced by certain linguistic structures while ruling out alternative explanations for this phenomenon such as cultural differences, processing fluency, and numeracy. Our research contributes to literatures on number cognition, numerosity, branding, and linguistics while providing insights for international marketers by encouraging practitioners to use different numbers in their marketing, branding, and pricing efforts in ways that best fit the linguistic structure of the country in which they sell a product.
Regioselectivity of Cobalamin‐Dependent Methyltransferase Can Be Tuned by Reaction Conditions and Substrate
Authors: Pompei Simona , Grimm Christopher , Farnberger Judith E. , Schober Lukas , Kroutil Wolfgang 
Published: October 2020

AbstractRegioselective reactions represent a significant challenge for organic chemistry. Here the regioselective methylation of a single hydroxy group of 4‐substituted catechols was investigated employing the cobalamin‐dependent methyltransferase from Desulfitobacterium hafniense. Catechols substituted in position four were methylated either in meta‐ or para‐position to the substituent depending whether the substituent was polar or apolar. While the biocatalytic cobalamin dependent methylation was meta‐selective with 4‐substituted catechols bearing hydrophilic groups, it was para‐selective for hydrophobic substituents. Furthermore, the presence of water miscible co‐solvents had a clear improving influence, whereby THF turned out to enable the formation of a single regioisomer in selected cases. Finally, it was found that also the pH led to an enhancement of regioselectivity for the cases investigated.
Olefin Ring‐closing Metathesis under Spatial Confinement: Morphology−Transport Relationships
Authors: Tallarek Ulrich , Hochstrasser Janika , Ziegler Felix , Huang Xiaohui , Kübel Christian , Buchmeiser Michael R. 
Published: October 2020

AbstractSpatial confinement effects on hindered transport in mesoporous silica particles are quantified using reconstructions of their morphology obtained by electron tomography as geometrical models in direct diffusion simulations for passive, finite‐size tracers. We monitor accessible porosity and effective diffusion coefficients resulting from steric and hydrodynamic interactions between tracers and pore space confinement as a function of λ=dtracer/dmeso, the ratio of tracer to mean mesopore size. For λ=0, pointlike tracers reproduce the true diffusive tortuosities. For λ>0, derived hindrance factors quantify the extent to which diffusion through the materials is hindered compared with free diffusion in the bulk liquid. Morphology‐transport relationships are then discussed with respect to the immobilization, formation, and transport of key molecular species in the ring‐closing metathesis of an α,ω‐diene to macro(mono)cyclization product and oligomer, with a 2nd‐generation Hoveyda‐Grubbs type catalyst immobilized inside the mesopores of the particles.
Surface Patterning of Biomolecules Using Click Chemistry and Light‐Activated Electrochemistry to Locally Generate Cu(I)
Authors: Gautam Shreedhar , Lian Jiaxin , R. Gonçales Vinicius , Vogel Yan B. , Ciampi Simone , Tilley Richard D. , Gooding J. Justin 
Published: October 2020

AbstractHere we report a light‐assisted variant of click chemistry suitable for chemical patterning of semiconducting surfaces. Using a visible light beam to illuminate desired locations of an electrode surface, localized electrogeneration of the Cu(I) click catalyst was achieved. It was demonstrated that surface click reactions were correlated with a user‐defined 2D light pattern projected on a silicon photoelectrode. This new process is mask‐free and parallel, i. e., separate discrete regions of a semiconducting surface can be simultaneously reacted with a range of functional molecules. The covalent patterning of azido‐poly (ethylene glycol) molecules (PEG) over alkyne‐functionalized electrodes was employed as a proof‐of‐principle. By modulating the exposed chemical group of the clicked azido‐PEGs, the adhesion of antibodies and cells was further possible with spatial control. The use of structured light, instead of physical masks, drastically reduces patterning time to a couple of hours.
Stabilization of Black Phosphorus by Sonication‐Assisted Simultaneous Exfoliation and Functionalization
Authors: van Druenen Maart , Collins Timothy , Davitt Fionán , Doherty Jessica , Collins Gillian , Sofer Zdeněk , Holmes Justin D. 
Published: October 2020

AbstractBlack phosphorus (BP) has extraordinary properties, but its ambient instability remains a critical challenge. Functionalization has been employed to overcome the sensitivity of BP to ambient conditions while preserving its properties. Herein, a simultaneous exfoliation–functionalization process is reported that functionalizes BP flakes during exfoliation and thus provides increased protection, which can be attributed to minimal exposure of the flakes to ambient oxygen and water. A tetrabutylammonium salt was employed for intercalation of BP, resulting in the formation of flakes with large lateral dimensions. The addition of an aryl iodide or an aryl iodonium salt to the exfoliation solvent creates a scalable strategy for the production of functionalized few‐layer BP flakes. The ambient stability of functionalized BP was prolonged to a period of one week, as revealed by STEM, AFM, and X‐ray photoelectron spectroscopy.
Insights on the Pseudo‐Enantiomeric Properties of Bifunctional Cinchona Alkaloid Squaramide‐Derived Organocatalyst
Authors: Ričko Sebastijan , Izzo Joseph A. , Jørgensen Karl Anker 
Published: October 2020

AbstractThe use of pseudo enantiomers is a well‐known method of achieving products of complementary stereochemistry. Only rarely can different enantiomers of a product be accessed without modulation of the catalyst. Recently, a system was reported wherein two different enantiomers of spirocycles were obtained by a cascade reaction of unsaturated pyrrolin‐4‐ones with mercaptoacetaldehyde catalyzed by a single optimized cinchona alkaloid squaramide‐derived organocatalyst. It was originally proposed that the E/Z geometry of the unsaturated pyrrolin‐4‐one dictated the stereochemistry of the spirocycle product, but this was not investigated further. In the present work, we have investigated the nature of a pseudo‐enantiomeric organocatalyst conformation applying density functional theory calculations for investigating the transition states for the reaction. Furthermore, the influence of the double‐bond geometry of the pyrrolin‐4‐one has been studied beyond what is possible to test experimentally. The results provide a greater understanding for this class of reactions that may be applicable in future methodology development.