bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proximity control of interlayer exciton-phonon hybridization in van der Waals heterostructures
Authors: Merkl Philipp , Yong Chaw-Keong , Liebich Marlene , Hofmeister Isabella , Berghäuser Gunnar , Malic Ermin , Huber Rupert 
Published: March 2021

AbstractVan der Waals stacking has provided unprecedented flexibility in shaping many-body interactions by controlling electronic quantum confinement and orbital overlap. Theory has predicted that also electron-phonon coupling critically influences the quantum ground state of low-dimensional systems. Here we introduce proximity-controlled strong-coupling between Coulomb correlations and lattice dynamics in neighbouring van der Waals materials, creating new electrically neutral hybrid eigenmodes. Specifically, we explore how the internal orbital 1s-2p transition of Coulomb-bound electron-hole pairs in monolayer tungsten diselenide resonantly hybridizes with lattice vibrations of a polar capping layer of gypsum, giving rise to exciton-phonon mixed eigenmodes, called excitonic Lyman polarons. Tuning orbital exciton resonances across the vibrational resonances, we observe distinct anticrossing and polarons with adjustable exciton and phonon compositions. Such proximity-induced hybridization can be further controlled by quantum designing the spatial wavefunction overlap of excitons and phonons, providing a promising new strategy to engineer novel ground states of two-dimensional systems.
Quasi-continuous melting of model polymer monolayers prompts reinterpretation of polymer melting
Authors: Zhang Ruibin , Fall William S. , Hall Kyle Wm. , Gehring Gillian A. , Zeng Xiangbing , Ungar Goran 
Published: March 2021

AbstractCondensed matter textbooks teach us that melting cannot be continuous and indeed experience, including with polymers and other long-chain compounds, tells us that it is a strongly first-order transition. However, here we report nearly continuous melting of monolayers of ultralong n-alkane C390H782on graphite, observed by AFM and reproduced by mean-field theory and MD simulation. On heating, the crystal-melt interface moves steadily and reversibly from chain ends inward. Remarkably, the final melting point is 80 K above that of the bulk, and equilibrium crystallinity decreases continuously from ~100% to <50% prior to final melting. We show that the similarity in melting behavior of polymers and non-polymers is coincidental. In the bulk, the intermediate melting stages of long-chain crystals are forbidden by steric overcrowding at the crystal-liquid interface. However, there is no crowding in a monolayer as chain segments can escape to the third dimension.
Red blood cell mannoses as phagocytic ligands mediating both sickle cell anaemia and malaria resistance
Authors: Cao Huan , Antonopoulos Aristotelis , Henderson Sadie , Wassall Heather , Brewin John , Masson Alanna , Shepherd Jenna , Konieczny Gabriela , Patel Bhinal , Williams Maria-Louise , Davie Adam , Forrester Megan A. , Hall Lindsay , Minter Beverley , Tampakis Dimitris , Moss Michael , Lennon Charlotte , Pickford Wendy , Erwig Lars , Robertson Beverley , Dell Anne , Brown Gordon D. , Wilson Heather M. , Rees David C. , Haslam Stuart M. , Alexandra Rowe J. , Barker Robert N. , Vickers Mark A. 
Published: March 2021

AbstractIn both sickle cell disease and malaria, red blood cells (RBCs) are phagocytosed in the spleen, but receptor-ligand pairs mediating uptake have not been identified. Here, we report that patches of high mannose N-glycans (Man5-9GlcNAc2), expressed on diseased or oxidized RBC surfaces, bind the mannose receptor (CD206) on phagocytes to mediate clearance. We find that extravascular hemolysis in sickle cell disease correlates with high mannose glycan levels on RBCs. Furthermore, Plasmodium falciparum-infected RBCs expose surface mannose N-glycans, which occur at significantly higher levels on infected RBCs from sickle cell trait subjects compared to those lacking hemoglobin S. The glycans are associated with high molecular weight complexes and protease-resistant, lower molecular weight fragments containing spectrin. Recognition of surface N-linked high mannose glycans as a response to cellular stress is a molecular mechanism common to both the pathogenesis of sickle cell disease and resistance to severe malaria in sickle cell trait.
Controlling pairing of π-conjugated electrons in 2D covalent organic radical frameworks via in-plane strain
Authors: Alcón Isaac , Santiago Raúl , Ribas-Arino Jordi , Deumal Mercè , Moreira Ibério de P. R. , Bromley Stefan T. 
Published: March 2021

AbstractControlling the electronic states of molecules is a fundamental challenge for future sub-nanoscale device technologies. π-conjugated bi-radicals are very attractive systems in this respect as they possess two energetically close, but optically and magnetically distinct, electronic states: the open-shell antiferromagnetic/paramagnetic and the closed-shell quinoidal diamagnetic states. While it has been shown that it is possible to statically induce one electronic ground state or the other by chemical design, the external dynamical control of these states in a rapid and reproducible manner still awaits experimental realization. Here, via quantum chemical calculations, we demonstrate that in-plane uniaxial strain of 2D covalently linked arrays of radical units leads to smooth and reversible conformational changes at the molecular scale that, in turn, induce robust transitions between the two kinds of electronic distributions. Our results pave a general route towards the external control, and thus technological exploitation, of molecular-scale electronic states in organic 2D materials.
Control of a programmed cell death pathway in Pseudomonas aeruginosa by an antiterminator
Authors: Peña Jennifer M. , Prezioso Samantha M. , McFarland Kirsty A. , Kambara Tracy K. , Ramsey Kathryn M. , Deighan Padraig , Dove Simon L. 
Published: March 2021

AbstractIn Pseudomonas aeruginosa the alp system encodes a programmed cell death pathway that is switched on in a subset of cells in response to DNA damage and is linked to the virulence of the organism. Here we show that the central regulator of this pathway, AlpA, exerts its effects by acting as an antiterminator rather than a transcription activator. In particular, we present evidence that AlpA positively regulates the alpBCDE cell lysis genes, as well as genes in a second newly identified target locus, by recognizing specific DNA sites within the promoter, then binding RNA polymerase directly and allowing it to bypass intrinsic terminators positioned downstream. AlpA thus functions in a mechanistically unusual manner to control the expression of virulence genes in this opportunistic pathogen.
Sea urchin-like microstructure pressure sensors with an ultra-broad range and high sensitivity
Authors: Wang Xiu-man , Tao Lu-qi , Yuan Min , Wang Ze-ping , Yu Jiabing , Xie Dingli , Luo Feng , Chen Xianping , Wong ChingPing 
Published: March 2021

AbstractSensitivity and pressure range are two significant parameters of pressure sensors. Existing pressure sensors have difficulty achieving both high sensitivity and a wide pressure range. Therefore, we propose a new pressure sensor with a ternary nanocomposite Fe2O3/C@SnO2. The sea urchin-like Fe2O3 structure promotes signal transduction and protects Fe2O3 needles from mechanical breaking, while the acetylene carbon black improves the conductivity of Fe2O3. Moreover, one part of the SnO2 nanoparticles adheres to the surfaces of Fe2O3 needles and forms Fe2O3/SnO2 heterostructures, while its other part disperses into the carbon layer to form SnO2@C structure. Collectively, the synergistic effects of the three structures (Fe2O3/C, Fe2O3/SnO2 and SnO2@C) improves on the limited pressure response range of a single structure. The experimental results demonstrate that the Fe2O3/C@SnO2 pressure sensor exhibits high sensitivity (680 kPa−1), fast response (10 ms), broad range (up to 150 kPa), and good reproducibility (over 3500 cycles under a pressure of 110 kPa), implying that the new pressure sensor has wide application prospects especially in wearable electronic devices and health monitoring.
Basalt derived from highly refractory mantle sources during early Izu-Bonin-Mariana arc development
Authors: Li He , Arculus Richard J. , Ishizuka Osamu , Hickey-Vargas Rosemary , Yogodzinski Gene M. , McCarthy Anders , Kusano Yuki , Brandl Philipp A. , Savov Ivan P. , Tepley Frank J. , Sun Weidong 
Published: March 2021

AbstractThe magmatic character of early subduction zone and arc development is unlike mature systems. Low-Ti-K tholeiitic basalts and boninites dominate the early Izu-Bonin-Mariana (IBM) system. Basalts recovered from the Amami Sankaku Basin (ASB), underlying and located west of the IBM’s oldest remnant arc, erupted at ~49 Ma. This was 3 million years after subduction inception (51-52 Ma) represented by forearc basalt (FAB), at the tipping point between FAB-boninite and typical arc magmatism. We show ASB basalts are low-Ti-K, aluminous spinel-bearing tholeiites, distinct compared to mid-ocean ridge (MOR), backarc basin, island arc or ocean island basalts. Their upper mantle source was hot, reduced, refractory peridotite, indicating prior melt extraction. ASB basalts transferred rapidly from pressures (~0.7-2 GPa) at the plagioclase-spinel peridotite facies boundary to the surface. Vestiges of a polybaric-polythermal mineralogy are preserved in this basalt, and were not obliterated during persistent recharge-mix-tap-fractionate regimes typical of MOR or mature arcs.
Leidenfrost droplet trampolining
Authors: Graeber Gustav , Regulagadda Kartik , Hodel Pascal , Küttel Christian , Landolf Dominic , Schutzius Thomas M. , Poulikakos Dimos 
Published: March 2021

AbstractA liquid droplet dispensed over a sufficiently hot surface does not make contact but instead hovers on a cushion of its own self-generated vapor. Since its discovery in 1756, this so-called Leidenfrost effect has been intensively studied. Here we report a remarkable self-propulsion mechanism of Leidenfrost droplets against gravity, that we term Leidenfrost droplet trampolining. Leidenfrost droplets gently deposited on fully rigid surfaces experience self-induced spontaneous oscillations and start to gradually bounce from an initial resting altitude to increasing heights, thereby violating the traditionally accepted Leidenfrost equilibrium. We found that the continuously draining vapor cushion initiates and fuels Leidenfrost trampolining by inducing ripples on the droplet bottom surface, which translate into pressure oscillations and induce self-sustained periodic vertical droplet bouncing over a broad range of experimental conditions.
An engineered CRISPR-Cas12a variant and DNA-RNA hybrid guides enable robust and rapid COVID-19 testing
Authors: Ooi Kean Hean , Liu Mengying Mandy , Tay Jie Wen Douglas , Teo Seok Yee , Kaewsapsak Pornchai , Jin Shengyang , Lee Chun Kiat , Hou Jingwen , Maurer-Stroh Sebastian , Lin Weisi , Yan Benedict , Yan Gabriel , Gao Yong-Gui , Tan Meng How 
Published: March 2021

AbstractExtensive testing is essential to break the transmission of SARS-CoV-2, which causes the ongoing COVID-19 pandemic. Here, we present a CRISPR-based diagnostic assay that is robust to viral genome mutations and temperature, produces results fast, can be applied directly on nasopharyngeal (NP) specimens without RNA purification, and incorporates a human internal control within the same reaction. Specifically, we show that the use of an engineered AsCas12a enzyme enables detection of wildtype and mutated SARS-CoV-2 and allows us to perform the detection step with loop-mediated isothermal amplification (LAMP) at 60-65 °C. We also find that the use of hybrid DNA-RNA guides increases the rate of reaction, enabling our test to be completed within 30 minutes. Utilizing clinical samples from 72 patients with COVID-19 infection and 57 healthy individuals, we demonstrate that our test exhibits a specificity and positive predictive value of 100% with a sensitivity of 50 and 1000 copies per reaction (or 2 and 40 copies per microliter) for purified RNA samples and unpurified NP specimens respectively.
Diel niche variation in mammals associated with expanded trait space
Authors: Cox D. T. C. , Gardner A. S. , Gaston K. J. 
Published: March 2021

AbstractMammalian life shows huge diversity, but most groups remain nocturnal in their activity pattern. A key unresolved question is whether mammal species that have diversified into different diel niches occupy unique regions of functional trait space. For 5,104 extant mammals we show here that daytime-active species (cathemeral or diurnal) evolved trait combinations along different gradients from those of nocturnal and crepuscular species. Hypervolumes of five major functional traits (body mass, litter size, diet, foraging strata, habitat breadth) reveal that 30% of diurnal trait space is unique, compared to 55% of nocturnal trait space. Almost half of trait space (44%) of species with apparently obligate diel niches is shared with those that can switch, suggesting that more species than currently realised may be somewhat flexible in their activity patterns. Increasingly, conservation measures have focused on protecting functionally unique species; for mammals, protecting functional distinctiveness requires a focus across diel niches.
Measurement of the neutron charge radius and the role of its constituents
Authors: Atac H. , Constantinou M. , Meziani Z.-E. , Paolone M. , Sparveris N. 
Published: March 2021

AbstractThe neutron is a cornerstone in our depiction of the visible universe. Despite the neutron zero-net electric charge, the asymmetric distribution of the positively- (up) and negatively-charged (down) quarks, a result of the complex quark-gluon dynamics, lead to a negative value for its squared charge radius, $$\langle {r}_{{\rm{n}}}^{2}\rangle$$
⟨

r

n

2

⟩
. The precise measurement of the neutron’s charge radius thus emerges as an essential part of unraveling its structure. Here we report on a $$\langle {r}_{{\rm{n}}}^{2}\rangle$$
⟨

r

n

2

⟩
measurement, based on the extraction of the neutron electric form factor, $${G}_{{\rm{E}}}^{{\rm{n}}}$$

G

E

n

, at low four-momentum transfer squared (Q2) by exploiting the long known connection between the N → Δ quadrupole transitions and the neutron electric form factor. Our result, $$\langle {r}_{{\rm{n}}}^{2}\rangle =-0.110\pm 0.008\,({{\rm{fm}}}^{2})$$
⟨

r

n

2

⟩
=
−
0.110
±
0.008

(

fm

2

)

, addresses long standing unresolved discrepancies in the $$\langle {r}_{{\rm{n}}}^{2}\rangle$$
⟨

r

n

2

⟩
determination. The dynamics of the strong nuclear force can be viewed through the precise picture of the neutron’s constituent distributions that result into the non-zero $$\langle {r}_{{\rm{n}}}^{2}\rangle$$
⟨

r

n

2

⟩
value.
Adjusting the energy of interfacial states in organic photovoltaics for maximum efficiency
Authors: Gasparini Nicola , Camargo Franco V. A. , Frühwald Stefan , Nagahara Tetsuhiko , Classen Andrej , Roland Steffen , Wadsworth Andrew , Gregoriou Vasilis G. , Chochos Christos L. , Neher Dieter , Salvador Michael , Baran Derya , McCulloch Iain , Görling Andreas , Lüer Larry , Cerullo Giulio , Brabec Christoph J. 
Published: March 2021

AbstractA critical bottleneck for improving the performance of organic solar cells (OSC) is minimising non-radiative losses in the interfacial charge-transfer (CT) state via the formation of hybrid energetic states. This requires small energetic offsets often detrimental for high external quantum efficiency (EQE). Here, we obtain OSC with both non-radiative voltage losses (0.24 V) and photocurrent losses (EQE > 80%) simultaneously minimised. The interfacial CT states separate into free carriers with ≈40-ps time constant. We combine device and spectroscopic data to model the thermodynamics of charge separation and extraction, revealing that the relatively high performance of the devices arises from an optimal adjustment of the CT state energy, which determines how the available overall driving force is efficiently used to maximize both exciton splitting and charge separation. The model proposed is universal for donor:acceptor (D:A) with low driving forces and predicts which D:A will benefit from a morphology optimization for highly efficient OSC.
BioAIEgens derived from rosin: how does molecular motion affect their photophysical processes in solid state?
Authors: Cai Xu-Min , Lin Yuting , Li Ying , Chen Xinfei , Wang Zaiyu , Zhao Xueqian , Huang Shenlin , Zhao Zheng , Tang Ben Zhong 
Published: March 2021

AbstractThe exploration of artificial luminogens with bright emission has been fully developed with the advancement of synthetic chemistry. However, many of them face problems like weakened emission in the aggregated state as well as poor renewability and sustainability. Therefore, the development of renewable and sustainable luminogens with anti-quenching function in the solid state, as well as to unveil the key factors that influence their luminescence behavior become highly significant. Herein, a new class of natural rosin-derived luminogens with aggregation-induced emission property (AIEgens) have been facilely obtained with good biocompatibility and targeted organelle imaging capability as well as photochromic behavior in the solid state. Mechanistic study indicates that the introduction of the alicyclic moiety helps suppress the excited-state molecular motion to enhance the solid-state emission. The current work fundamentally elucidates the role of alicyclic moiety in luminogen design and practically demonstrates a new source to large-scalely obtain biocompatible AIEgens.
Molecular basis of V-ATPase inhibition by bafilomycin A1
Authors: Wang Rong , Wang Jin , Hassan Abdirahman , Lee Chia-Hsueh , Xie Xiao-Song , Li Xiaochun 
Published: March 2021

AbstractPharmacological inhibition of vacuolar-type H+-ATPase (V-ATPase) by its specific inhibitor can abrogate tumor metastasis, prevent autophagy, and reduce cellular signaling responses. Bafilomycin A1, a member of macrolide antibiotics and an autophagy inhibitor, serves as a specific and potent V-ATPases inhibitor. Although there are many V-ATPase structures reported, the molecular basis of specific inhibitors on V-ATPase remains unknown. Here, we report the cryo-EM structure of bafilomycin A1 bound intact bovine V-ATPase at an overall resolution of 3.6-Å. The structure reveals six bafilomycin A1 molecules bound to the c-ring. One bafilomycin A1 molecule engages with two c subunits and disrupts the interactions between the c-ring and subunit a, thereby preventing proton translocation. Structural and sequence analyses demonstrate that the bafilomycin A1-binding residues are conserved in yeast and mammalian species and the 7’-hydroxyl group of bafilomycin A1 acts as a unique feature recognized by subunit c.
The biofilm matrix scaffold of Pseudomonas aeruginosa contains G-quadruplex extracellular DNA structures
Authors: Seviour Thomas , Winnerdy Fernaldo Richtia , Wong Lan Li , Shi Xiangyan , Mugunthan Sudarsan , Foo Yong Hwee , Castaing Remi , Adav Sunil S. , Subramoni Sujatha , Kohli Gurjeet Singh , Shewan Heather M. , Stokes Jason R. , Rice Scott A. , Phan Anh Tuân , Kjelleberg Staffan 
Published: March 2021

AbstractExtracellular DNA, or eDNA, is recognised as a critical biofilm component; however, it is not understood how it forms networked matrix structures. Here, we isolate eDNA from static-culture Pseudomonas aeruginosa biofilms using ionic liquids to preserve its biophysical signatures of fluid viscoelasticity and the temperature dependency of DNA transitions. We describe a loss of eDNA network structure as resulting from a change in nucleic acid conformation, and propose that its ability to form viscoelastic structures is key to its role in building biofilm matrices. Solid-state analysis of isolated eDNA, as a proxy for eDNA structure in biofilms, reveals non-canonical Hoogsteen base pairs, triads or tetrads involving thymine or uracil, and guanine, suggesting that the eDNA forms G-quadruplex structures. These are less abundant in chromosomal DNA and disappear when eDNA undergoes conformation transition. We verify the occurrence of G-quadruplex structures in the extracellular matrix of intact static and flow-cell biofilms of P. aeruginosa, as displayed by the matrix to G-quadruplex-specific antibody binding, and validate the loss of G-quadruplex structures in vivo to occur coincident with the disappearance of eDNA fibres. Given their stability, understanding how extracellular G-quadruplex structures form will elucidate how P. aeruginosa eDNA builds viscoelastic networks, which are a foundational biofilm property.
Extracellular amoebal-vesicles: potential transmission vehicles for respiratory viruses
Authors: Dey Rafik , Folkins Melanie A. , Ashbolt Nicholas J. 
Published: March 2021

AbstractHuman respiratory syncytial virus (RSV) is a major cause of acute respiratory tract infections in children and immunocompromised adults worldwide. Here we report that amoebae-release respirable-sized vesicles containing high concentrations of infectious RSV that persisted for the duration of the experiment. Given the ubiquity of amoebae in moist environments, our results suggest that extracellular amoebal-vesicles could contribute to the environmental persistence of respiratory viruses, including potential resistance to disinfection processes and thereby offering novel pathways for viral dissemination and transmission.
Il-10 signaling reduces survival in mouse models of synucleinopathy
Authors: Cockey Samuel G. , McFarland Karen N. , Koller Emily J. , Brooks Mieu M. T. , Gonzalez De La Cruz Elsa , Cruz Pedro E. , Ceballos-Diaz Carolina , Rosario Awilda M. , Levites Yona R. , Borchelt David R. , Golde Todd E. , Giasson Benoit I. , Chakrabarty Paramita 
Published: March 2021

AbstractParkinson’s disease (PD) and related synucleinopathies are characterized by chronic neuroinflammation leading to the premise that anti-inflammatory therapies could ameliorate synucleinopathy and associated sequelae. To test this idea, we used recombinant adeno-associated viruses (AAV) to express the anti-inflammatory cytokine, Interleukin (Il)-10, in Line M83 transgenic mice that expresses the PD-associated A53T mutant human α-synuclein (αSyn). Contrary to our expectations, we observed that intraspinal Il-10 expression initiated at birth upregulated microgliosis and led to early death in homozygous M83+/+ mice. We further observed that Il-10 preconditioning led to reduced lifespan in the hemizygous M83+/− mice injected with preformed αSyn aggregates in hindlimb muscles. To determine the mechanistic basis for these adverse effects, we took advantage of the I87A variant Il-10 (vIl-10) that has predominantly immunosuppressive properties. Sustained intraspinal expression of vIl-10 in preformed αSyn-aggregate seeded M83+/− mice resulted in earlier death, accelerated αSyn pathology, pronounced microgliosis, and increased apoptosis compared to control mice. AAV-vIl-10 expression robustly induced p62 and neuronal LC3B accumulation in these mice, indicating that Il-10 signaling mediated preconditioning of the neuraxis can potentially exacerbate αSyn accumulation through autophagy dysfunction in the neurons. Together, our data demonstrate unexpected adverse effects of both Il-10 and its immunosuppressive variant, vIl-10, in a mouse model of PD, highlighting the pleiotropic functions of immune mediators and their complex role in non-cell autonomous signaling in neurodegenerative proteinopathies.