bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tunable exciton-polaritons emerging from WS2 monolayer excitons in a photonic lattice at room temperature
Authors: Lackner L. , Dusel M. , Egorov O. A. , Han B. , Knopf H. , Eilenberger F. , Schröder S. , Watanabe K. , Taniguchi T. , Tongay S. , Anton-Solanas C. , Höfling S. , Schneider C. 
Published: August 2021

AbstractEngineering non-linear hybrid light-matter states in tailored lattices is a central research strategy for the simulation of complex Hamiltonians. Excitons in atomically thin crystals are an ideal active medium for such purposes, since they couple strongly with light and bear the potential to harness giant non-linearities and interactions while presenting a simple sample-processing and room temperature operability. We demonstrate lattice polaritons, based on an open, high-quality optical cavity, with an imprinted photonic lattice strongly coupled to excitons in a WS2 monolayer. We experimentally observe the emergence of the canonical band-structure of particles in a one-dimensional lattice at room temperature, and demonstrate frequency reconfigurability over a spectral window exceeding 85 meV, as well as the systematic variation of the nearest-neighbour coupling, reflected by a tunability in the bandwidth of the p-band polaritons by 7 meV. The technology presented in this work is a critical demonstration towards reconfigurable photonic emulators operated with non-linear photonic fluids, offering a simple experimental implementation and working at ambient conditions.
Efficiency and selectivity of CO2 reduction to CO on gold gas diffusion electrodes in acidic media
Authors: Monteiro Mariana C. O. , Philips Matthew F. , Schouten Klaas Jan P. , Koper Marc T. M. 
Published: August 2021

AbstractThe electrochemical reduction of CO2 to CO is a promising technology for replacing production processes employing fossil fuels. Still, low energy efficiencies hinder the production of CO at commercial scale. CO2 electrolysis has mainly been performed in neutral or alkaline media, but recent fundamental work shows that high selectivities for CO can also be achieved in acidic media. Therefore, we investigate the feasibility of CO2 electrolysis at pH 2–4 at indrustrially relevant conditions, using 10 cm2 gold gas diffusion electrodes. Operating at current densities up to 200 mA cm−2, we obtain CO faradaic efficiencies between 80–90% in sulfate electrolyte, with a 30% improvement of the overall process energy efficiency, in comparison with neutral media. Additionally, we find that weakly hydrated cations are crucial for accomplishing high reaction rates and enabling CO2 electrolysis in acidic media. This study represents a step towards the application of acidic electrolyzers for CO2 electroreduction.
Toward scalable biocatalytic conversion of 5-hydroxymethylfurfural by galactose oxidase using coordinated reaction and enzyme engineering
Authors: Birmingham William R. , Toftgaard Pedersen Asbjørn , Dias Gomes Mafalda , Bøje Madsen Mathias , Breuer Michael , Woodley John M. , Turner Nicholas J. 
Published: August 2021

Abstract5-Hydroxymethylfurfural (HMF) has emerged as a crucial bio-based chemical building block in the drive towards developing materials from renewable resources, due to its direct preparation from sugars and its readily diversifiable scaffold. A key obstacle in transitioning to bio-based plastic production lies in meeting the necessary industrial production efficiency, particularly in the cost-effective conversion of HMF to valuable intermediates. Toward addressing the challenge of developing scalable technology for oxidizing crude HMF to more valuable chemicals, here we report coordinated reaction and enzyme engineering to provide a galactose oxidase (GOase) variant with remarkably high activity toward HMF, improved O2 binding and excellent productivity (>1,000,000 TTN). The biocatalyst and reaction conditions presented here for GOase catalysed selective oxidation of HMF to 2,5-diformylfuran offers a productive blueprint for further development, giving hope for the creation of a biocatalytic route to scalable production of furan-based chemical building blocks from sustainable feedstocks.
NGF-TrkA signaling dictates neural ingrowth and aberrant osteochondral differentiation after soft tissue trauma
Authors: Lee Seungyong , Hwang Charles , Marini Simone , Tower Robert J. , Qin Qizhi , Negri Stefano , Pagani Chase A. , Sun Yuxiao , Stepien David M. , Sorkin Michael , Kubiak Carrie A. , Visser Noelle D. , Meyers Carolyn A. , Wang Yiyun , Rasheed Husain A. , Xu Jiajia , Miller Sarah , Huber Amanda K. , Minichiello Liliana , Cederna Paul S. , Kemp Stephen W. P. , Clemens Thomas L. , James Aaron W. , Levi Benjamin 
Published: August 2021

AbstractPain is a central feature of soft tissue trauma, which under certain contexts, results in aberrant osteochondral differentiation of tissue-specific stem cells. Here, the role of sensory nerve fibers in this abnormal cell fate decision is investigated using a severe extremity injury model in mice. Soft tissue trauma results in NGF (Nerve growth factor) expression, particularly within perivascular cell types. Consequently, NGF-responsive axonal invasion occurs which precedes osteocartilaginous differentiation. Surgical denervation impedes axonal ingrowth, with significant delays in cartilage and bone formation. Likewise, either deletion ofNgfor two complementary methods to inhibit its receptor TrkA (Tropomyosin receptor kinase A) lead to similar delays in axonal invasion and osteochondral differentiation. Mechanistically, single-cell sequencing suggests a shift from TGFβ to FGF signaling activation among pre-chondrogenic cells after denervation. Finally, analysis of human pathologic specimens and databases confirms the relevance of NGF-TrkA signaling in human disease. In sum, NGF-mediated TrkA-expressing axonal ingrowth drives abnormal osteochondral differentiation after soft tissue trauma. NGF-TrkA signaling inhibition may have dual therapeutic use in soft tissue trauma, both as an analgesic and negative regulator of aberrant stem cell differentiation.
Lagrangian betweenness as a measure of bottlenecks in dynamical systems with oceanographic examples
Authors: Ser-Giacomi Enrico , Baudena Alberto , Rossi Vincent , Follows Mick , Clayton Sophie , Vasile Ruggero , López Cristóbal , Hernández-García Emilio 
Published: August 2021

AbstractThe study of connectivity patterns in networks has brought novel insights across diverse fields ranging from neurosciences to epidemic spreading or climate. In this context, betweenness centrality has demonstrated to be a very effective measure to identify nodes that act as focus of congestion, or bottlenecks, in the network. However, there is not a way to define betweenness outside the network framework. By analytically linking dynamical systems and network theory, we provide a trajectory-based formulation of betweenness, called Lagrangian betweenness, as a function of Lyapunov exponents. This extends the concept of betweenness beyond the context of network theory relating hyperbolic points and heteroclinic connections in any dynamical system to the structural bottlenecks of the network associated with it. Using modeled and observational velocity fields, we show that such bottlenecks are present and surprisingly persistent in the oceanic circulation across different spatio-temporal scales and we illustrate the role of these areas in driving fluid transport over vast oceanic regions. Analyzing plankton abundance data from the Kuroshio region of the Pacific Ocean, we find significant spatial correlations between measures of diversity and betweenness, suggesting promise for ecological applications.
An amphiphilic dendrimer as a light-activable immunological adjuvant for in situ cancer vaccination
Authors: Wang Yongchao , Gong Ningqiang , Ma Chi , Zhang Yuxuan , Tan Hong , Qing Guangchao , Zhang Jimei , Wang Yufei , Wang Jinjin , Chen Shizhu , Li Xianlei , Ni Qiankun , Yuan Yuan , Gan Yaling , Chen Junge , Li Fangzhou , Zhang Jinchao , Ou Caiwen , Zhao Yongxiang , Liu Xiaoxuan , Liang Xing-Jie 
Published: August 2021

AbstractImmunological adjuvants are essential for successful cancer vaccination. However, traditional adjuvants have some limitations, such as lack of controllability and induction of systemic toxicity, which restrict their broad application. Here, we present a light-activable immunological adjuvant (LIA), which is composed of a hypoxia-responsive amphiphilic dendrimer nanoparticle loaded with chlorin e6. Under irradiation with near-infrared light, the LIA not only induces tumour cell lysis and tumour antigen release, but also promotes the structural transformation of 2-nitroimidazole containing dendrimer to 2-aminoimidazole containing dendrimer which can activate dendritic cells via the Toll-like receptor 7-mediated signaling pathway. The LIA efficiently inhibits both primary and abscopal tumour growth and induces strong antigen-specific immune memory effect to prevent tumour metastasis and recurrence in vivo. Furthermore, LIA localizes the immunological adjuvant effect at the tumour site. We demonstrate this light-activable immunological adjuvant offers a safe and potent platform for in situ cancer vaccination.
Biomimetic approach to the catalytic enantioselective synthesis of tetracyclic isochroman
Authors: Lin Xiangfeng , Liu Xianghui , Wang Kai , Li Qian , Liu Yan , Li Can 
Published: August 2021

AbstractPolyketide oligomers containing the structure of tetracyclic isochroman comprise a large class of natural products with diverse activity. However, a general and stereoselective method towards the rapid construction of this structure remains challenging due to the inherent instability and complex stereochemistry of polyketide. By mimicking the biosynthetic pathway of this structurally diverse set of natural products, we herein develop an asymmetric hetero-Diels–Alder reaction of in-situ generated isochromene and ortho-quinonemethide. A broad range of tetracyclic isochroman frameworks are prepared in good yields and excellent stereoinduction (up to 95% ee) from readily available α-propargyl benzyl alcohols and 2-(hydroxylmethyl) phenols under mild conditions. This direct enantioselective cascade reaction is achieved by a Au(I)/chiral Sc(III) bimetallic catalytic system. Experimental studies indicate that the key hetero-Diels-Alder reaction involves a stepwise pathway, and the steric hindrance between in-situ generated isochromene and t-Bu group of Sc(III)/N,N’-dioxide complex is responsible for the enantioselectivity in the hetero-Diels–Alder reaction step.
Offspring born to influenza A virus infected pregnant mice have increased susceptibility to viral and bacterial infections in early life
Authors: Jacobsen Henning , Walendy-Gnirß Kerstin , Tekin-Bubenheim Nilgün , Kouassi Nancy Mounogou , Ben-Batalla Isabel , Berenbrok Nikolaus , Wolff Martin , dos Reis Vinicius Pinho , Zickler Martin , Scholl Lucas , Gries Annette , Jania Hanna , Kloetgen Andreas , Düsedau Arne , Pilnitz-Stolze Gundula , Jeridi Aicha , Yildirim Ali Önder , Fuchs Helmut , Gailus-Durner Valerie , Stoeger Claudia , de Angelis Martin Hrabe , Manuylova Tatjana , Klingel Karin , Culley Fiona J. , Behrends Jochen , Loges Sonja , Schneider Bianca , Krauss-Etschmann Susanne , Openshaw Peter , Gabriel Gülsah 
Published: August 2021

AbstractInfluenza during pregnancy can affect the health of offspring in later life, among which neurocognitive disorders are among the best described. Here, we investigate whether maternal influenza infection has adverse effects on immune responses in offspring. We establish a two-hit mouse model to study the effect of maternal influenza A virus infection (first hit) on vulnerability of offspring to heterologous infections (second hit) in later life. Offspring born to influenza A virus infected mothers are stunted in growth and more vulnerable to heterologous infections (influenza B virus and MRSA) than those born to PBS- or poly(I:C)-treated mothers. Enhanced vulnerability to infection in neonates is associated with reduced haematopoetic development and immune responses. In particular, alveolar macrophages of offspring exposed to maternal influenza have reduced capacity to clear second hit pathogens. This impaired pathogen clearance is partially reversed by adoptive transfer of alveolar macrophages from healthy offspring born to uninfected dams. These findings suggest that maternal influenza infection may impair immune ontogeny and increase susceptibility to early life infections of offspring.
On the molecular origins of the ferroelectric splay nematic phase
Authors: Mandle Richard J. , Sebastián Nerea , Martinez-Perdiguero Josu , Mertelj Alenka 
Published: August 2021

AbstractNematic liquid crystals have been known for more than a century, but it was not until the 60s–70s that, with the development of room temperature nematics, they became widely used in applications. Polar nematic phases have been long-time predicted, but have only been experimentally realized recently. Synthesis of materials with nematic polar ordering at room temperature is certainly challenging and requires a deep understanding of its formation mechanisms, presently lacking. Here, we compare two materials of similar chemical structure and demonstrate that just a subtle change in the molecular structure enables denser packing of the molecules when they exhibit polar order, which shows that reduction of excluded volume is in the origin of the polar nematic phase. Additionally, we propose that molecular dynamics simulations are potent tools for molecular design in order to predict, identify and design materials showing the polar nematic phase and its precursor nematic phases.
Decline in plankton diversity and carbon flux with reduced sea ice extent along the Western Antarctic Peninsula
Authors: Lin Yajuan , Moreno Carly , Marchetti Adrian , Ducklow Hugh , Schofield Oscar , Delage Erwan , Meredith Michael , Li Zuchuan , Eveillard Damien , Chaffron Samuel , Cassar Nicolas 
Published: August 2021

AbstractSince the middle of the past century, the Western Antarctic Peninsula has warmed rapidly with a significant loss of sea ice but the impacts on plankton biodiversity and carbon cycling remain an open question. Here, using a 5-year dataset of eukaryotic plankton DNA metabarcoding, we assess changes in biodiversity and net community production in this region. Our results show that sea-ice extent is a dominant factor influencing eukaryotic plankton community composition, biodiversity, and net community production. Species richness and evenness decline with an increase in sea surface temperature (SST). In regions with low SST and shallow mixed layers, the community was dominated by a diverse assemblage of diatoms and dinoflagellates. Conversely, less diverse plankton assemblages were observed in waters with higher SST and/or deep mixed layers when sea ice extent was lower. A genetic programming machine-learning model explained up to 80% of the net community production variability at the Western Antarctic Peninsula. Among the biological explanatory variables, the sea-ice environment associated plankton assemblage is the best predictor of net community production. We conclude that eukaryotic plankton diversity and carbon cycling at the Western Antarctic Peninsula are strongly linked to sea-ice conditions.
C. elegans colony formation as a condensation phenomenon
Authors: Chen Yuping , Ferrell James E. 
Published: August 2021

AbstractPhase separation at the molecular scale affects many biological processes. The theoretical requirements for phase separation are fairly minimal, and there is growing evidence that analogous phenomena occur at other scales in biology. Here we examine colony formation in the nematode C. elegans as a possible example of phase separation by a population of organisms. The population density of worms determines whether a colony will form in a thresholded fashion, and a simple two-compartment ordinary differential equation model correctly predicts the threshold. Furthermore, small, round colonies sometimes fuse to form larger, round colonies, and a phenomenon akin to Ostwald ripening – a coarsening process seen in many systems that undergo phase separation – also occurs. These findings support the emerging view that the principles of microscopic phase separation can also apply to collective behaviors of living organisms.
Survival of itinerant excitations and quantum spin state transitions in YbMgGaO4 with chemical disorder
Authors: Rao X. , Hussain G. , Huang Q. , Chu W. J. , Li N. , Zhao X. , Dun Z. , Choi E. S. , Asaba T. , Chen L. , Li L. , Yue X. Y. , Wang N. N. , Cheng J.-G. , Gao Y. H. , Shen Y. , Zhao J. , Chen G. , Zhou H. D. , Sun X. F. 
Published: August 2021

AbstractA recent focus of quantum spin liquid (QSL) studies is how disorder/randomness in a QSL candidate affects its true magnetic ground state. The ultimate question is whether the QSL survives disorder or the disorder leads to a “spin-liquid-like” state, such as the proposed random-singlet (RS) state. Since disorder is a standard feature of most QSL candidates, this question represents a major challenge for QSL candidates. YbMgGaO4, a triangular lattice antiferromagnet with effective spin-1/2 Yb3+ions, is an ideal system to address this question, since it shows no long-range magnetic ordering with Mg/Ga site disorder. Despite the intensive study, it remains unresolved as to whether YbMgGaO4 is a QSL or in the RS state. Here, through ultralow-temperature thermal conductivity and magnetic torque measurements, plus specific heat and DC magnetization data, we observed a residual κ0/T term and series of quantum spin state transitions in the zero temperature limit for YbMgGaO4. These observations strongly suggest that a QSL state with itinerant excitations and quantum spin fluctuations survives disorder in YbMgGaO4.
Anion-exchange-mediated internal electric field for boosting photogenerated carrier separation and utilization
Authors: Han Tong , Cao Xing , Sun Kaian , Peng Qing , Ye Chenliang , Huang Aijian , Cheong Weng-Chon , Chen Zheng , Lin Rui , Zhao Di , Tan Xin , Zhuang Zewen , Chen Chen , Wang Dingsheng , Li Yadong 
Published: August 2021

AbstractHeterojunctions modulated internal electric field (IEF) usually result in suboptimal efficiencies in carrier separation and utilization because of the narrow IEF distribution and long migration paths of photocarriers. In this work, we report distinctive bismuth oxyhydroxide compound nanorods (denoted as BOH NRs) featuring surface-exposed open channels and a simple chemical composition; by simply modifying the bulk anion layers to overcome the limitations of heterojunctions, the bulk IEF could be readily modulated. Benefiting from the unique crystal structure and the localization of valence electrons, the bulk IEF intensity increases with the atomic number of introduced halide anions. Therefore, A low exchange ratio (~10%) with halide anions (I–, Br–, Cl–) gives rise to a prominent elevation in carrier separation efficiency and better photocatalytic performance for benzylamine coupling oxidation. Here, our work offers new insights into the design and optimization of semiconductor photocatalysts.
Simultaneously enhancing the ultimate strength and ductility of high-entropy alloys via short-range ordering
Authors: Chen Shuai , Aitken Zachary H. , Pattamatta Subrahmanyam , Wu Zhaoxuan , Yu Zhi Gen , Srolovitz David J. , Liaw Peter K. , Zhang Yong-Wei 
Published: August 2021

AbstractSimultaneously enhancing strength and ductility of metals and alloys has been a tremendous challenge. Here, we investigate a CoCuFeNiPd high-entropy alloy (HEA), using a combination of Monte Carlo method, molecular dynamic simulation, and density-functional theory calculation. Our results show that this HEA is energetically favorable to undergo short-range ordering (SRO), and the SRO leads to a pseudo-composite microstructure, which surprisingly enhances both the ultimate strength and ductility. The SRO-induced composite microstructure consists of three categories of clusters: face-center-cubic-preferred (FCCP) clusters, indifferent clusters, and body-center-cubic-preferred (BCCP) clusters, with the indifferent clusters playing the role of the matrix, the FCCP clusters serving as hard fillers to enhance the strength, while the BCCP clusters acting as soft fillers to increase the ductility. Our work highlights the importance of SRO in influencing the mechanical properties of HEAs and presents a fascinating route for designing HEAs to achieve superior mechanical properties.
Metadynamics sampling in atomic environment space for collecting training data for machine learning potentials
Authors: Yoo Dongsun , Jung Jisu , Jeong Wonseok , Han Seungwu 
Published: August 2021

AbstractThe universal mathematical form of machine-learning potentials (MLPs) shifts the core of development of interatomic potentials to collecting proper training data. Ideally, the training set should encompass diverse local atomic environments but conventional approaches are prone to sampling similar configurations repeatedly, mainly due to the Boltzmann statistics. As such, practitioners handpick a large pool of distinct configurations manually, stretching the development period significantly. To overcome this hurdle, methods are being proposed that automatically generate training data. Herein, we suggest a sampling method optimized for gathering diverse yet relevant configurations semi-automatically. This is achieved by applying the metadynamics with the descriptor for the local atomic environment as a collective variable. As a result, the simulation is automatically steered toward unvisited local environment space such that each atom experiences diverse chemical environments without redundancy. We apply the proposed metadynamics sampling to H:Pt(111), GeTe, and Si systems. Throughout these examples, a small number of metadynamics trajectories can provide reference structures necessary for training high-fidelity MLPs. By proposing a semi-automatic sampling method tuned for MLPs, the present work paves the way to wider applications of MLPs to many challenging applications.
Giant room temperature elastocaloric effect in metal-free thin-film perovskites
Authors: Li Cheng , Huang Yu Hui , Wang Jian-Jun , Wang Bo , Wu Yong Jun , Tian He , Chen Long-Qing , Hong Zijian 
Published: August 2021

AbstractSolid-state refrigeration which is environmentally benign has attracted considerable attention. Mechanocaloric (mC) materials, in which the phase transitions can be induced by mechanical stresses, represent one of the most promising types of solid-state caloric materials. Herein, we have developed a thermodynamic phenomenological model and predicted extraordinarily large elastocaloric (eC) strengths for the (111)-oriented metal-free perovskite ferroelectric [MDABCO](NH4)I3 thin-films. The predicted room temperature isothermal eC ΔSeC/Δσ (eC entropy change under unit stress change) and adiabatic eC ΔTeC/Δσ (eC temperature change under unit stress change) for [MDABCO](NH4)I3 are −60.0 J K−1 kg−1 GPa−1 and 17.9 K GPa−1, respectively, which are 20 times higher than the traditional ferroelectric oxides such as BaTiO3 thin films. We have also demonstrated that the eC performance can be improved by reducing the Young’s modulus or enhancing the thermal expansion coefficient (which could be realized through chemical doping, etc.). We expect these discoveries to spur further interest in the potential applications of metal-free organic ferroelectrics materials towards next-generation eC refrigeration devices.