bluuebunny/crossref_metadata_2025 huggingface dataset:
Polygenic risk for schizophrenia and measured domains of cognition in individuals with psychosis and controls
Authors: Shafee Rebecca , Nanda Pranav , Padmanabhan Jaya L. , Tandon Neeraj , Alliey-Rodriguez Ney , Kalapurakkel Sreeja , Weiner Daniel J. , Gur Raquel E. , Keefe Richard S. E. , Hill Scot K. , Bishop Jeffrey R. , Clementz Brett A. , Tamminga Carol A. , Gershon Elliot S. , Pearlson Godfrey D. , Keshavan Matcheri S. , Sweeney John A. , McCarroll Steven A. , Robinson Elise B.
Published: April 2018

Psychotic disorders including schizophrenia are commonly accompanied by cognitive deficits. Recent studies have reported negative genetic correlations between schizophrenia and indicators of cognitive ability such as general intelligence and processing speed. Here we compare the effect of polygenetic risk for schizophrenia (PRSSCZ) on measures that differ in their relationships with psychosis onset: a measure of current cognitive abilities (the Brief Assessment of Cognition in Schizophrenia, BACS) that is greatly reduced in psychotic disorder patients, a measure of premorbid intelligence that is minimally affected by psychosis onset (the Wide-Range Achievement Test, WRAT); and educational attainment (EY), which covaries with both BACS and WRAT. Using genome-wide single nucleotide polymorphism (SNP) data from 314 psychotic and 423 healthy research participants in the Bipolar-Schizophrenia Network for Intermediate Phenotypes (B-SNIP) Consortium, we investigated the association of PRSSCZwith BACS, WRAT, and EY. Among apparently healthy individuals, greater genetic risk for schizophrenia (PRSSCZ) was significantly associated with lower BACS scores (r = −0.17,p = 6.6 × 10−4at PT = 1 × 10−4), but not with WRAT or EY. Among individuals with psychosis, PRSSCZdid not associate with variations in any of these three phenotypes. We further investigated the association between PRSSCZand WRAT in more than 4500 healthy subjects from the Philadelphia Neurodevelopmental Cohort. The association was again null (p > 0.3,N = 4511), suggesting that different cognitive phenotypes vary in their etiologic relationship with schizophrenia.
Proscription supports robust perceptual integration by suppression in human visual cortex
Authors: Rideaux Reuben , Welchman Andrew E.
Published: April 2018

Perception relies on integrating information within and between the senses, but how does the brain decide which pieces of information should be integrated and which kept separate? Here we demonstrate how proscription can be used to solve this problem: certain neurons respond best to unrealistic combinations of features to provide ‘what not’ information that drives suppression of unlikely perceptual interpretations. First, we present a model that captures both improved perception when signals are consistent (and thus should be integrated) and robust estimation when signals are conflicting. Second, we test for signatures of proscription in the human brain. We show that concentrations of inhibitory neurotransmitter GABA in a brain region intricately involved in integrating cues (V3B/KO) correlate with robust integration. Finally, we show that perturbing excitation/inhibition impairs integration. These results highlight the role of proscription in robust perception and demonstrate the functional purpose of ‘what not’ sensors in supporting sensory estimation.
Uranium transport in acidic brines under reducing conditions
Authors: Timofeev Alexander , Migdisov Artaches A. , Williams-Jones Anthony E. , Roback Robert , Nelson Andrew T. , Xu Hongwu
Published: April 2018

The behavior of uranium in environments, ranging from those of natural systems responsible for the formation of uranium deposits to those of nuclear reactors providing 11% of the world’s electricity, is governed by processes involving high-temperature aqueous solutions. It has been well documented that uranium is mobile in aqueous solutions in its oxidized, U6+ state, whereas in its reduced, U4+ state, uranium has been assumed to be immobile. Here, we present experimental evidence from high temperature (>100 °C) acidic brines that invalidates this assumption. Our experiments have identified a new uranium chloride species (UCl4°) that is more stable under reducing than oxidized conditions. These results indicate that uranium is mobile under reducing conditions and necessitate a re-evaluation of the mobility of uranium, particularly in ore deposit models involving this metal. Regardless of the scenario considered, reducing conditions can no longer be considered a guarantee of uranium immobility.
A RAB35-p85/PI3K axis controls oscillatory apical protrusions required for efficient chemotactic migration
Authors: Corallino Salvatore , Malinverno Chiara , Neumann Beate , Tischer Christian , Palamidessi Andrea , Frittoli Emanuela , Panagiotakopoulou Magdalini , Disanza Andrea , Malet-Engra Gema , Nastaly Paulina , Galli Camilla , Luise Chiara , Bertalot Giovanni , Pece Salvatore , Di Fiore Pier Paolo , Gauthier Nils , Ferrari Aldo , Maiuri Paolo , Scita Giorgio
Published: April 2018

How cells move chemotactically remains a major unmet challenge in cell biology. Emerging evidence indicates that for interpreting noisy, shallow gradients of soluble cues a system must behave as an excitable process. Here, through an RNAi-based, high-content screening approach, we identify RAB35 as necessary for the formation of growth factors (GFs)-induced waves of circular dorsal ruffles (CDRs), apically restricted actin-rich migratory protrusions. RAB35 is sufficient to induce recurrent and polarized CDRs that travel as propagating waves, thus behaving as an excitable system that can be biased to control cell steering. Consistently, RAB35 is essential for promoting directed chemotactic migration and chemoinvasion of various cells in response to gradients of motogenic GFs. Molecularly, RAB35 does so by directly regulating the activity of p85/PI3K polarity axis. We propose that RAB35 is a molecular determinant for the control of an excitable, oscillatory system that acts as a steering wheel for GF-mediated chemotaxis and chemoinvasion.
HSP27 is a partner of JAK2-STAT5 and a potential therapeutic target in myelofibrosis
Authors: Sevin Margaux , Kubovcakova Lucia , Pernet Nicolas , Causse Sébastien , Vitte Franck , Villeval Jean Luc , Lacout Catherine , Cordonnier Marine , Rodrigues-Lima Fernando , Chanteloup Gaétan , Mosca Matthieu , Chrétien Marie-Lorraine , Bastie Jean Noël , Audia Sylvain , Sagot Paul , Ramla Selim , Martin Laurent , Gleave Martin , Mezger Valérie , Skoda Radek , Plo Isabelle , Garrido Carmen , Girodon François , de Thonel Aurélie
Published: April 2018

Heat shock protein 27 (HSP27/HSPB1) is a stress-inducible chaperone that facilitates cancer development by its proliferative and anti-apoptotic functions. The OGX-427 antisense oligonucleotide against HSP27 has been reported to be beneficial against idiopathic pulmonary fibrosis. Here we show that OGX-427 is effective in two murine models of thrombopoietin- and JAKV617F-induced myelofibrosis. OGX-427 limits disease progression and is associated with a reduction in spleen weight, in megakaryocyte expansion and, for the JAKV617F model, in fibrosis. HSP27 regulates the proliferation of JAK2V617F-positive cells and interacts directly with JAK2/STAT5. We also show that its expression is increased in both CD34+ circulating progenitors and in the serum of patients with JAK2-dependent myeloproliferative neoplasms with fibrosis. Our data suggest that HSP27 plays a key role in the pathophysiology of myelofibrosis and represents a new potential therapeutic target for patients with myeloproliferative neoplasms.
PREDICTD PaRallel Epigenomics Data Imputation with Cloud-based Tensor Decomposition
Authors: Durham Timothy J. , Libbrecht Maxwell W. , Howbert J. Jeffry , Bilmes Jeff , Noble William Stafford
Published: April 2018

The Encyclopedia of DNA Elements (ENCODE) and the Roadmap Epigenomics Project seek to characterize the epigenome in diverse cell types using assays that identify, for example, genomic regions with modified histones or accessible chromatin. These efforts have produced thousands of datasets but cannot possibly measure each epigenomic factor in all cell types. To address this, we present a method, PaRallel Epigenomics Data Imputation with Cloud-based Tensor Decomposition (PREDICTD), to computationally impute missing experiments. PREDICTD leverages an elegant model called “tensor decomposition” to impute many experiments simultaneously. Compared with the current state-of-the-art method, ChromImpute, PREDICTD produces lower overall mean squared error, and combining the two methods yields further improvement. We show that PREDICTD data captures enhancer activity at noncoding human accelerated regions. PREDICTD provides reference imputed data and open-source software for investigating new cell types, and demonstrates the utility of tensor decomposition and cloud computing, both promising technologies for bioinformatics.
Neuronal SphK1 acetylates COX2 and contributes to pathogenesis in a model of Alzheimer’s Disease
Authors: Lee Ju Youn , Han Seung Hoon , Park Min Hee , Baek Bosung , Song Im-Sook , Choi Min-Koo , Takuwa Yoh , Ryu Hoon , Kim Seung Hyun , He Xingxuan , Schuchman Edward H. , Bae Jae-Sung , Jin Hee Kyung
Published: April 2018

Although many reports have revealed the importance of defective microglia-mediated amyloid β phagocytosis in Alzheimer’s disease (AD), the underlying mechanism remains to be explored. Here we demonstrate that neurons in the brains of patients with AD and AD mice show reduction of sphingosine kinase1 (SphK1), leading to defective microglial phagocytosis and dysfunction of inflammation resolution due to decreased secretion of specialized proresolving mediators (SPMs). Elevation of SphK1 increased SPMs secretion, especially 15-R-Lipoxin A4, by promoting acetylation of serine residue 565 (S565) of cyclooxygenase2 (COX2) using acetyl-CoA, resulting in improvement of AD-like pathology in APP/PS1 mice. In contrast, conditional SphK1 deficiency in neurons reduced SPMs secretion and abnormal phagocytosis similar to AD. Together, these results uncover a novel mechanism of SphK1 pathogenesis in AD, in which impaired SPMs secretion leads to defective microglial phagocytosis, and suggests that SphK1 in neurons has acetyl-CoA-dependent cytoplasmic acetyltransferase activity towards COX2.
Numerical simulations of a kilometre-thick Arctic ice shelf consistent with ice grounding observations
Authors: Gasson Edward G. W. , DeConto Robert M. , Pollard David , Clark Chris D.
Published: April 2018

Recently obtained geophysical data show sets of parallel erosional features on the Lomonosov Ridge in the central Arctic Basin, indicative of ice grounding in water depths up to 1280 m. These features have been interpreted as being formed by an ice shelf—either restricted to the Amerasian Basin (the “minimum model”) or extending across the entire Arctic Basin. Here, we use a numerical ice sheet-shelf model to explore how such an ice shelf could form. We rule out the “minimum model” and suggest that grounding on the Lomonosov Ridge requires complete Arctic ice shelf cover; this places a minimum estimate on its volume, which would have exceeded that of the modern Greenland Ice Sheet. Buttressing provided by an Arctic ice shelf would have increased volumes of the peripheral terrestrial ice sheets. An Arctic ice shelf could have formed even in the absence of a hypothesised East Siberian Ice Sheet.
TSPAN15 interacts with BTRC to promote oesophageal squamous cell carcinoma metastasis via activating NF-κB signaling
Authors: Zhang Baozhu , Zhang Zhao , Li Lei , Qin Yan-Ru , Liu Haibo , Jiang Chen , Zeng Ting-Ting , Li Meng-Qing , Xie Dan , Li Yan , Guan Xin-Yuan , Zhu Ying-Hui
Published: April 2018

Beta-transducin repeat containing E3 ubiquitin protein ligase (BTRC) is crucial for the degradation of IκBα. Our previous transcriptome sequencing analysis revealed that tetraspanin 15 (TSPAN15) was significantly upregulated in clinical oesophageal squamous cell carcinoma (OSCC) tissues. Here, we show that high TSPAN15 expression in OSCC tissues is significantly associated with lymph node and distant metastasis, advanced clinical stage, and poor prognosis. Elevated TSPAN15 expression is, in part, caused by the reduction of miR-339-5p. Functional studies demonstrate that TSPAN15 promotes metastatic capabilities of OSCC cells. We further show that TSPAN15 specifically interacts with BTRC to promote the ubiquitination and proteasomal degradation of p-IκBα, and thereby triggers NF-κB nuclear translocation and subsequent activation of transcription of several metastasis-related genes, including ICAM1, VCAM1, uPA, MMP9, TNFα, and CCL2. Collectively, our findings indicate that TSPAN15 may serve as a new biomarker and/or provide a novel therapeutic target to OSCC patients.
Autonomous robotic searching and assembly of two-dimensional crystals to build van der Waals superlattices
Authors: Masubuchi Satoru , Morimoto Masataka , Morikawa Sei , Onodera Momoko , Asakawa Yuta , Watanabe Kenji , Taniguchi Takashi , Machida Tomoki
Published: April 2018

Van der Waals heterostructures are comprised of stacked atomically thin two-dimensional crystals and serve as novel materials providing unprecedented properties. However, the random natures in positions and shapes of exfoliated two-dimensional crystals have required the repetitive manual tasks of optical microscopy-based searching and mechanical transferring, thereby severely limiting the complexity of heterostructures. To solve the problem, here we develop a robotic system that searches exfoliated two-dimensional crystals and assembles them into superlattices inside the glovebox. The system can autonomously detect 400 monolayer graphene flakes per hour with a small error rate (<7%) and stack four cycles of the designated two-dimensional crystals per hour with few minutes of human intervention for each stack cycle. The system enabled fabrication of the superlattice consisting of 29 alternating layers of the graphene and the hexagonal boron nitride. This capacity provides a scalable approach for prototyping a variety of van der Waals superlattices.
In situ X-ray imaging of defect and molten pool dynamics in laser additive manufacturing
Authors: Leung Chu Lun Alex , Marussi Sebastian , Atwood Robert C. , Towrie Michael , Withers Philip J. , Lee Peter D.
Published: April 2018

The laser–matter interaction and solidification phenomena associated with laser additive manufacturing (LAM) remain unclear, slowing its process development and optimisation. Here, through in situ and operando high-speed synchrotron X-ray imaging, we reveal the underlying physical phenomena during the deposition of the first and second layer melt tracks. We show that the laser-induced gas/vapour jet promotes the formation of melt tracks and denuded zones via spattering (at a velocity of 1 m s−1). We also uncover mechanisms of pore migration by Marangoni-driven flow (recirculating at a velocity of 0.4 m s−1), pore dissolution and dispersion by laser re-melting. We develop a mechanism map for predicting the evolution of melt features, changes in melt track morphology from a continuous hemi-cylindrical track to disconnected beads with decreasing linear energy density and improved molten pool wetting with increasing laser power. Our results clarify aspects of the physics behind LAM, which are critical for its development.
Interactions and scattering of quantum vortices in a polariton fluid
Authors: Dominici Lorenzo , Carretero-González Ricardo , Gianfrate Antonio , Cuevas-Maraver Jesús , Rodrigues Augusto S. , Frantzeskakis Dimitri J. , Lerario Giovanni , Ballarini Dario , De Giorgi Milena , Gigli Giuseppe , Kevrekidis Panayotis G. , Sanvitto Daniele
Published: April 2018

Quantum vortices, the quantized version of classical vortices, play a prominent role in superfluid and superconductor phase transitions. However, their exploration at a particle level in open quantum systems has gained considerable attention only recently. Here we study vortex pair interactions in a resonant polariton fluid created in a solid-state microcavity. By tracking the vortices on picosecond time scales, we reveal the role of nonlinearity, as well as of density and phase gradients, in driving their rotational dynamics. Such effects are also responsible for the split of composite spin–vortex molecules into elementary half-vortices, when seeding opposite vorticity between the two spinorial components. Remarkably, we also observe that vortices placed in close proximity experience a pull–push scenario leading to unusual scattering-like events that can be described by a tunable effective potential. Understanding vortex interactions can be useful in quantum hydrodynamics and in the development of vortex-based lattices, gyroscopes, and logic devices.
RETRACTED ARTICLE: Supported black phosphorus nanosheets as hydrogen-evolving photocatalyst achieving 5.4% energy conversion efficiency at 353 K
Authors: Tian Bin , Tian Bining , Smith Bethany , Scott M. C. , Hua Ruinian , Lei Qin , Tian Yue
Published: April 2018

Solar-driven water splitting using powdered catalysts is considered as the most economical means for hydrogen generation. However, four-electron-driven oxidation half-reaction showing slow kinetics, accompanying with insufficient light absorption and rapid carrier combination in photocatalysts leads to low solar-to-hydrogen energy conversion efficiency. Here, we report amorphous cobalt phosphide (Co-P)-supported black phosphorus nanosheets employed as photocatalysts can simultaneously address these issues. The nanosheets exhibit robust hydrogen evolution from pure water (pH = 6.8) without bias and hole scavengers, achieving an apparent quantum efficiency of 42.55% at 430 nm and energy conversion efficiency of over 5.4% at 353 K. This photocatalytic activity is attributed to extremely efficient utilization of solar energy (~75% of solar energy) by black phosphorus nanosheets and high-carrier separation efficiency by amorphous Co-P. The hybrid material design realizes efficient solar-to-chemical energy conversion in suspension, demonstrating the potential of black phosphorus-based materials as catalysts for solar hydrogen production.
A fully reconfigurable waveguide Bragg grating for programmable photonic signal processing
Authors: Zhang Weifeng , Yao Jianping
Published: April 2018

Since the discovery of the Bragg’s law in 1913, Bragg gratings have become important optical devices and have been extensively used in various systems. In particular, the successful inscription of a Bragg grating in a fiber core has significantly boosted its engineering applications. However, a conventional grating device is usually designed for a particular use, which limits general-purpose applications since its index modulation profile is fixed after fabrication. In this article, we propose to implement a fully reconfigurable grating, which is fast and electrically reconfigurable by field programming. The concept is verified by fabricating an integrated grating on a silicon-on-insulator platform, which is employed as a programmable signal processor to perform multiple signal processing functions including temporal differentiation, microwave time delay, and frequency identification. The availability of ultrafast and reconfigurable gratings opens new avenues for programmable optical signal processing at the speed of light.
Constant strain accumulation rate between major earthquakes on the North Anatolian Fault
Authors: Hussain Ekbal , Wright Tim J. , Walters Richard J. , Bekaert David P. S. , Lloyd Ryan , Hooper Andrew
Published: April 2018

Earthquakes are caused by the release of tectonic strain accumulated between events. Recent advances in satellite geodesy mean we can now measure this interseismic strain accumulation with a high degree of accuracy. But it remains unclear how to interpret short-term geodetic observations, measured over decades, when estimating the seismic hazard of faults accumulating strain over centuries. Here, we show that strain accumulation rates calculated from geodetic measurements around a major transform fault are constant for its entire 250-year interseismic period, except in the ~10 years following an earthquake. The shear strain rate history requires a weak fault zone embedded within a strong lower crust with viscosity greater than ~1020 Pa s. The results support the notion that short-term geodetic observations can directly contribute to long-term seismic hazard assessment and suggest that lower-crustal viscosities derived from postseismic studies are not representative of the lower crust at all spatial and temporal scales.
In silico optimization of a guava antimicrobial peptide enables combinatorial exploration for peptide design
Authors: Porto William F. , Irazazabal Luz , Alves Eliane S. F. , Ribeiro Suzana M. , Matos Carolina O. , Pires Állan S. , Fensterseifer Isabel C. M. , Miranda Vivian J. , Haney Evan F. , Humblot Vincent , Torres Marcelo D. T. , Hancock Robert E. W. , Liao Luciano M. , Ladram Ali , Lu Timothy K. , de la Fuente-Nunez Cesar , Franco Octavio L.
Published: April 2018

Plants are extensively used in traditional medicine, and several plant antimicrobial peptides have been described as potential alternatives to conventional antibiotics. However, after more than four decades of research no plant antimicrobial peptide is currently used for treating bacterial infections, due to their length, post-translational modifications or  high dose requirement for a therapeutic effect . Here we report the design of antimicrobial peptides derived from a guava glycine-rich peptide using a genetic algorithm. This approach yields guavanin peptides, arginine-rich α-helical peptides that possess an unusual hydrophobic counterpart mainly composed of tyrosine residues. Guavanin 2 is characterized as a prototype peptide in terms of structure and activity. Nuclear magnetic resonance analysis indicates that the peptide adopts an α-helical structure in hydrophobic environments. Guavanin 2 is bactericidal at low concentrations, causing membrane disruption and triggering hyperpolarization. This computational approach for the exploration of natural products could be used to design effective peptide antibiotics.
Macrophage-derived IL-1β/NF-κB signaling mediates parenteral nutrition-associated cholestasis
Authors: El Kasmi Karim C. , Vue Padade M. , Anderson Aimee L. , Devereaux Michael W. , Ghosh Swati , Balasubramaniyan Natarajan , Fillon Sophie A. , Dahrenmoeller Carola , Allawzi Ayed , Woods Crystal , McKenna Sarah , Wright Clyde J. , Johnson Linda , D’Alessandro Angelo , Reisz Julie A. , Nozik-Grayck Eva , Suchy Frederick J. , Sokol Ronald J.
Published: April 2018

In infants intolerant of enteral feeding because of intestinal disease, parenteral nutrition may be associated with cholestasis, which can progress to end-stage liver disease. Here we show the function of hepatic macrophages and phytosterols in parenteral nutrition-associated cholestasis (PNAC) pathogenesis using a mouse model that recapitulates the human pathophysiology and combines intestinal injury with parenteral nutrition. We combine genetic, molecular, and pharmacological approaches to identify an essential function of hepatic macrophages and IL-1β in PNAC. Pharmacological antagonism of  IL-1 signaling or genetic deficiency in CCR2, caspase-1 and caspase-11, or IL-1 receptor (which binds both IL-1α and IL-1β) prevents PNAC in mice. IL-1β increases hepatocyte NF-κB signaling, which interferes with farnesoid X receptor and liver X receptor bonding to respective promoters of canalicular bile and sterol transporter genes (Abcc2,Abcb11, andAbcg5/8), resulting in transcriptional suppression and subsequent cholestasis. Thus, hepatic macrophages, IL-1β, or NF-κB may be targets for restoring bile and sterol transport to treat PNAC.
PCGF5 is required for neural differentiation of embryonic stem cells
Authors: Yao Mingze , Zhou Xueke , Zhou Jiajian , Gong Shixin , Hu Gongcheng , Li Jiao , Huang Kaimeng , Lai Ping , Shi Guang , Hutchins Andrew P. , Sun Hao , Wang Huating , Yao Hongjie
Published: April 2018

Polycomb repressive complex 1 (PRC1) is an important regulator of gene expression and development. PRC1 contains the E3 ligases RING1A/B, which monoubiquitinate lysine 119 at histone H2A (H2AK119ub1), and has been sub-classified into six major complexes based on the presence of a PCGF subunit. Here, we report that PCGF5, one of six PCGF paralogs, is an important requirement in the differentiation of mouse embryonic stem cells (mESCs) towards a neural cell fate. Although PCGF5 is not required for mESC self-renewal, its loss blocks mESC neural differentiation by activating the SMAD2/TGF-β signaling pathway. PCGF5 loss-of-function impairs the reduction of H2AK119ub1 and H3K27me3 around neural specific genes and keeps them repressed. Our results suggest that PCGF5 might function as both a repressor for SMAD2/TGF-β signaling pathway and a facilitator for neural differentiation. Together, our findings reveal a critical context-specific function for PCGF5 in directing PRC1 to control cell fate.
Stabilised frequency of extreme positive Indian Ocean Dipole under 1.5 °C warming
Authors: Cai Wenju , Wang Guojian , Gan Bolan , Wu Lixin , Santoso Agus , Lin Xiaopei , Chen Zhaohui , Jia Fan , Yamagata Toshio
Published: April 2018

Extreme positive Indian Ocean Dipole (pIOD) affects weather, agriculture, ecosystems, and public health worldwide, particularly when exacerbated by an extreme El Niño. The Paris Agreement aims to limit warming below 2 °C and ideally below 1.5 °C in global mean temperature (GMT), but how extreme pIOD will respond to this target is unclear. Here we show that the frequency increases linearly as the warming proceeds, and doubles at 1.5 °C warming from the pre-industrial level (statistically significant above the 90% confidence level), underscored by a strong intermodel agreement with 11 out of 13 models producing an increase. However, in sharp contrast to a continuous increase in extreme El Niño frequency long after GMT stabilisation, the extreme pIOD frequency peaks as the GMT stabilises. The contrasting response corresponds to a 50% reduction in frequency of an extreme El Niño preceded by an extreme pIOD from that projected under a business-as-usual scenario.
Dissolved organic carbon leaching from plastics stimulates microbial activity in the ocean
Authors: Romera-Castillo Cristina , Pinto Maria , Langer Teresa M. , Álvarez-Salgado Xosé Antón , Herndl Gerhard J.
Published: April 2018

Approximately 5.25 trillion plastic pieces are floating at the sea surface. The impact of plastic pollution on the lowest trophic levels of the food web, however, remains unknown. Here we show that plastics release dissolved organic carbon (DOC) into the ambient seawater stimulating the activity of heterotrophic microbes. Our estimates indicate that globally up to 23,600 metric tons of DOC are leaching from marine plastics annually. About 60% of it is available to microbial utilization in less than 5 days. If exposed to solar radiation, however, this DOC becomes less labile. Thus, plastic pollution of marine surface waters likely alters the composition and activity of the base of the marine food webs. It is predicted that plastic waste entering the ocean will increase by a factor of ten within the next decade, resulting in an increase in plastic-derived DOC that might have unaccounted consequences for marine microbes and for the ocean system.
Author Correction: Culex pipiens crossing type diversity is governed by an amplified and polymorphic operon of Wolbachia
Authors: Bonneau Manon , Atyame Celestine , Beji Marwa , Justy Fabienne , Cohen-Gonsaud Martin , Sicard Mathieu , Weill Mylène
Published: April 2018

In the originally published HTML and PDF versions of this Article, gel images in Figures 7c and 8c were not prepared as per the Nature journal policy. These figure panels have now been corrected in both the PDF and HTML versions of the Article.

In Fig. 7c, the lane labelled ‘Ha’ was inappropriately duplicated to represent the lane labelled ‘Ich13’. The corrected version of Fig. 7c includes PCR-RFLP on DNA from the Ichkeul 13 line, which had been run on a separate gel. The original unprocessed gel images are provided in Supplementary Figure 1 associated with this correction, with the relevant corresponding bands denoted. A repeat experiment of the PCR-RFLP test is also presented as Supplementary Figure 2.

In Fig. 8c, the image was assembled from two separate gels without clear demarcation. The corrected Fig. 8c clearly separates lanes from the two gels, and the original unprocessed gel images are provided in the Supplementary Information associated with this correction.

These corrections do not alter the original meaning of the experiments, their results, their interpretation, or the conclusions of the paper. We apologize for any confusion this may have caused to the readers of Nature Communications.
Author Correction: Watt-level 10-gigahertz solid-state laser enabled by self-defocusing nonlinearities in an aperiodically poled crystal
Authors: Mayer A. S. , Phillips C. R. , Keller U.
Published: April 2018

The original version of this Article contained an error in Fig. 3a, in which the delay axis was incorrectly labeled in increments of 0.5 ps instead of the correct 0.2 ps. This has been corrected in both the PDF and HTML versions of the Article.
Publisher Correction: Recent progress and perspectives of space electric propulsion systems based on smart nanomaterials
Authors: Levchenko I. , Xu S. , Teel G. , Mariotti D. , Walker M. L. R. , Keidar M.
Published: April 2018

The original PDF version of this Article had an incorrect volume number of ‘8’; it should have been ‘9’. This has been corrected in the PDF version of the Article. The HTML version was correct from the time of publication.
Design principles for enhancing phase sensitivity and suppressing phase fluctuations simultaneously in biochemical oscillatory systems
Authors: Fei Chenyi , Cao Yuansheng , Ouyang Qi , Tu Yuhai
Published: April 2018

Biological systems need to function accurately in the presence of strong noise and at the same time respond sensitively to subtle external cues. Here we study design principles in biochemical oscillatory circuits to achieve these two seemingly incompatible goals. We show that energy dissipation can enhance phase sensitivity linearly by driving the phase-amplitude coupling and increase timing accuracy by suppressing phase diffusion. Two general design principles in the key underlying reaction loop formed by two antiparallel pathways are found to optimize oscillation performance with a given energy budget: balancing the forward-to-backward flux ratio between the two pathways to reduce phase diffusion and maximizing the net flux of the phase-advancing pathway relative to that of the phase-retreating pathway to enhance phase sensitivity. Experimental evidences consistent with these design principles are found in the circadian clock of cyanobacteria. Future experiments to test the predicted dependence of phase sensitivity on energy dissipation are proposed.
Ultra-thin high-efficiency mid-infrared transmissive Huygens meta-optics
Authors: Zhang Li , Ding Jun , Zheng Hanyu , An Sensong , Lin Hongtao , Zheng Bowen , Du Qingyang , Yin Gufan , Michon Jerome , Zhang Yifei , Fang Zhuoran , Shalaginov Mikhail Y. , Deng Longjiang , Gu Tian , Zhang Hualiang , Hu Juejun
Published: April 2018

The mid-infrared (mid-IR) is a strategically important band for numerous applications ranging from night vision to biochemical sensing. Here we theoretically analyzed and experimentally realized a Huygens metasurface platform capable of fulfilling a diverse cross-section of optical functions in the mid-IR. The meta-optical elements were constructed using high-index chalcogenide films deposited on fluoride substrates: the choices of wide-band transparent materials allow the design to be scaled across a broad infrared spectrum. Capitalizing on a two-component Huygens’ meta-atom design, the meta-optical devices feature an ultra-thin profile (λ0/8 in thickness) and measured optical efficiencies up to 75% in transmissive mode for linearly polarized light, representing major improvements over state-of-the-art. We have also demonstrated mid-IR transmissive meta-lenses with diffraction-limited focusing and imaging performance. The projected size, weight and power advantages, coupled with the manufacturing scalability leveraging standard microfabrication technologies, make the Huygens meta-optical devices promising for next-generation mid-IR system applications.
Synthesis of a molecularly defined single-active site heterogeneous catalyst for selective oxidation of N-heterocycles
Authors: Zhang Yujing , Pang Shaofeng , Wei Zhihong , Jiao Haijun , Dai Xingchao , Wang Hongli , Shi Feng
Published: April 2018

Generally, a homogeneous catalyst exhibits good activity and defined active sites but it is difficult to recycle. Meanwhile, a heterogeneous catalyst can easily be reused but its active site is difficult to reveal. It is interesting to bridge the gap between homogeneous and heterogeneous catalysis via controllable construction of a heterogeneous catalyst containing defined active sites. Here, we report that a molecularly defined, single-active site heterogeneous catalyst has been designed and prepared via the oxidative polymerization of maleimide derivatives. These polymaleimide derivatives can be active catalysts for the selective oxidation of heterocyclic compounds to quinoline and indole via the recycling of –C=O and –C–OH groups, which was confirmed by tracing the reaction with GC-MS using maleimide as the catalyst and by FT-IR analysis with polymaleimide as the catalyst. These results might promote the development of heterogeneous catalysts with molecularly defined single active sites exhibiting a comparable activity to homogeneous catalysts.
Snap evaporation of droplets on smooth topographies
Authors: Wells Gary G. , Ruiz-Gutiérrez Élfego , Le Lirzin Youen , Nourry Anthony , Orme Bethany V. , Pradas Marc , Ledesma-Aguilar Rodrigo
Published: April 2018

Droplet evaporation on solid surfaces is important in many applications including printing, micro-patterning and cooling. While seemingly simple, the configuration of evaporating droplets on solids is difficult to predict and control. This is because evaporation typically proceeds as a “stick-slip” sequence—a combination of pinning and de-pinning events dominated by static friction or “pinning”, caused by microscopic surface roughness. Here we show how smooth, pinning-free, solid surfaces of non-planar topography promote a different process called snap evaporation. During snap evaporation a droplet follows a reproducible sequence of configurations, consisting of a quasi-static phase-change controlled by mass diffusion interrupted by out-of-equilibrium snaps. Snaps are triggered by bifurcations of the equilibrium droplet shape mediated by the underlying non-planar solid. Because the evolution of droplets during snap evaporation is controlled by a smooth topography, and not by surface roughness, our ideas can inspire programmable surfaces that manage liquids in heat- and mass-transfer applications.
A mechanistic framework for auxin dependent Arabidopsis root hair elongation to low external phosphate
Authors: Bhosale Rahul , Giri Jitender , Pandey Bipin K. , Giehl Ricardo F. H. , Hartmann Anja , Traini Richard , Truskina Jekaterina , Leftley Nicola , Hanlon Meredith , Swarup Kamal , Rashed Afaf , Voß Ute , Alonso Jose , Stepanova Anna , Yun Jeonga , Ljung Karin , Brown Kathleen M. , Lynch Jonathan P. , Dolan Liam , Vernoux Teva , Bishopp Anthony , Wells Darren , von Wirén Nicolaus , Bennett Malcolm J. , Swarup Ranjan
Published: April 2018

Phosphate (P) is an essential macronutrient for plant growth. Roots employ adaptive mechanisms to forage for P in soil. Root hair elongation is particularly important since P is immobile. Here we report that auxin plays a critical role promoting root hair growth in Arabidopsis in response to low external P. Mutants disrupting auxin synthesis (taa1) and transport (aux1) attenuate the low P root hair response. Conversely, targeting AUX1 expression in lateral root cap and epidermal cells rescues this low P response in aux1. Hence auxin transport from the root apex to differentiation zone promotes auxin-dependent hair response to low P. Low external P results in induction of root hair expressed auxin-inducible transcription factors ARF19, RSL2, and RSL4. Mutants lacking these genes disrupt the low P root hair response. We conclude auxin synthesis, transport and response pathway components play critical roles regulating this low P root adaptive response.
Calculating curly arrows from ab initio wavefunctions
Authors: Liu Yu , Kilby Philip , Frankcombe Terry J. , Schmidt Timothy W.
Published: April 2018

Despite being at the heart of chemical thought, the curly arrow notation of reaction mechanisms has been treated with suspicion—the connection with rigorous molecular quantum mechanics being unclear. The connection requires a view of the wavefunction that goes beyond molecular orbitals and rests on the most fundamental property of electrons. The antisymmetry of electronic wavefunctions requires that an N-electron wavefunction repeat itself in 3N dimensions, thus exhibiting tiles. Inspection of wavefunction tiles permits insight into structure and mechanism. Here, we demonstrate that analysis of the wavefunction tile along a reaction coordinate reveals the electron movements depicted by the curly arrow notation for several reactions. The Diels–Alder reaction is revealed to involve the separation and counter propagation of electron spins. This unprecedented method of extracting the movements of electrons during a chemical reaction is a breakthrough in connecting traditional depictions of chemical mechanism with state-of-the-art quantum chemical calculations.
Multi-petahertz electron interference in Cr:Al2O3 solid-state material
Authors: Mashiko Hiroki , Chisuga Yuta , Katayama Ikufumi , Oguri Katsuya , Masuda Hiroyuki , Takeda Jun , Gotoh Hideki
Published: April 2018

Lightwave-field-induced ultrafast electric dipole oscillation is promising for realizing petahertz (1015 Hz: PHz) signal processing in the future. In building the ultrahigh-clock-rate logic operation system, one of the major challenges will be petahertz electron manipulation accompanied with multiple frequencies. Here we study multi-petahertz interference with electronic dipole oscillations in alumina with chromium dopant (Cr:Al2O3). An intense near-infrared lightwave-field induces multiple electric inter-band polarizations, which are characterized by Fourier transform extreme ultraviolet attosecond spectroscopy. The interference results from the superposition state of periodic dipole oscillations of 667 to 383 attosecond (frequency of 1.5 to 2.6 PHz) measured by direct time-dependent spectroscopy and consists of various modulations on attosecond time scale through individual electron dephasing times of the Cr donor-like and Al2O3 conduction band states. The results indicate the possible manipulation of petahertz interference signal with multiple dipole oscillations using material band engineering and such a control will contribute to the study of ultrahigh-speed signal operation.
Tuning Ising superconductivity with layer and spin–orbit coupling in two-dimensional transition-metal dichalcogenides
Authors: de la Barrera Sergio C. , Sinko Michael R. , Gopalan Devashish P. , Sivadas Nikhil , Seyler Kyle L. , Watanabe Kenji , Taniguchi Takashi , Tsen Adam W. , Xu Xiaodong , Xiao Di , Hunt Benjamin M.
Published: April 2018

Systems simultaneously exhibiting superconductivity and spin–orbit coupling are predicted to provide a route toward topological superconductivity and unconventional electron pairing, driving significant contemporary interest in these materials. Monolayer transition-metal dichalcogenide (TMD) superconductors in particular lack inversion symmetry, yielding an antisymmetric form of spin–orbit coupling that admits both spin-singlet and spin-triplet components of the superconducting wavefunction. Here, we present an experimental and theoretical study of two intrinsic TMD superconductors with large spin–orbit coupling in the atomic layer limit, metallic 2H-TaS2 and 2H-NbSe2. We investigate the superconducting properties as the material is reduced to monolayer thickness and show that high-field measurements point to the largest upper critical field thus reported for an intrinsic TMD superconductor. In few-layer samples, we find the enhancement of the upper critical field is sustained by the dominance of spin–orbit coupling over weak interlayer coupling, providing additional candidate systems for supporting unconventional superconducting states in two dimensions.
Functional crosstalk between histone H2B ubiquitylation and H2A modifications and variants
Authors: Wojcik Felix , Dann Geoffrey P. , Beh Leslie Y. , Debelouchina Galia T. , Hofmann Raphael , Muir Tom W.
Published: April 2018

Ubiquitylation of histone H2B at lysine residue 120 (H2BK120ub) is a prominent histone posttranslational modification (PTM) associated with the actively transcribed genome. Although H2BK120ub triggers several critical downstream histone modification pathways and changes in chromatin structure, less is known about the regulation of the ubiquitylation reaction itself, in particular with respect to the modification status of the chromatin substrate. Here we employ an unbiased library screening approach to profile the impact of pre-existing chromatin modifications on de novo ubiquitylation of H2BK120 by the cognate human E2:E3 ligase pair, UBE2A:RNF20/40. Deposition of H2BK120ub is found to be highly sensitive to PTMs on the N-terminal tail of histone H2A, a crosstalk that extends to the common histone variant H2A.Z. Based on a series of biochemical and cell-based studies, we propose that this crosstalk contributes to the spatial organization of H2BK120ub on gene bodies, and is thus important for transcriptional regulation.
Anchoring zero valence single atoms of nickel and iron on graphdiyne for hydrogen evolution
Authors: Xue Yurui , Huang Bolong , Yi Yuanping , Guo Yuan , Zuo Zicheng , Li Yongjun , Jia Zhiyu , Liu Huibiao , Li Yuliang
Published: April 2018

Electrocatalysis by atomic catalysts is a major focus of chemical and energy conversion effort. Although transition-metal-based bulk electrocatalysts for electrochemical application on energy conversion processes have been reported frequently, anchoring the stable transition-metal atoms (e.g. nickel and iron) still remains a practical challenge. Here we report a strategy for fabrication of ACs comprising only isolated nickel/iron atoms anchored on graphdiyne. Our findings identify the very narrow size distributions of both nickel (1.23 Å) and iron (1.02 Å), typical sizes of single-atom nickel and iron. The precision of this method motivates us to develop a general approach in the field of single-atom transition-metal catalysis. Such atomic catalysts have high catalytic activity and stability for hydrogen evolution reactions.
In vivo guiding nitrogen-doped carbon nanozyme for tumor catalytic therapy
Authors: Fan Kelong , Xi Juqun , Fan Lei , Wang Peixia , Zhu Chunhua , Tang Yan , Xu Xiangdong , Liang Minmin , Jiang Bing , Yan Xiyun , Gao Lizeng
Published: April 2018

Nanomaterials with intrinsic enzyme-like activities (nanozymes), have been widely used as artificial enzymes in biomedicine. However, how to control their in vivo performance in a target cell is still challenging. Here we report a strategy to coordinate nanozymes to target tumor cells and selectively perform their activity to destruct tumors. We develop a nanozyme using nitrogen-doped porous carbon nanospheres which possess four enzyme-like activities (oxidase, peroxidase, catalase and superoxide dismutase) responsible for reactive oxygen species regulation. We then introduce ferritin to guide nitrogen-doped porous carbon nanospheres into lysosomes and boost reactive oxygen species generation in a tumor-specific manner, resulting in significant tumor regression in human tumor xenograft mice models. Together, our study provides evidence that nitrogen-doped porous carbon nanospheres are powerful nanozymes capable of regulating intracellular reactive oxygen species, and ferritinylation is a promising strategy to render nanozymes to target tumor cells for in vivo tumor catalytic therapy.
Competition between microtubule-associated proteins directs motor transport
Authors: Monroy Brigette Y. , Sawyer Danielle L. , Ackermann Bryce E. , Borden Melissa M. , Tan Tracy C. , Ori-McKenney Kassandra M.
Published: April 2018

Within cells, motor and non-motor microtubule-associated proteins (MAPs) simultaneously converge on the microtubule. How the binding activities of non-motor MAPs are coordinated and how they contribute to the balance and distribution of motor transport is unknown. Here, we examine the relationship between MAP7 and tau owing to their antagonistic roles in vivo. We find that MAP7 and tau compete for binding to microtubules, and determine a mechanism by which MAP7 displaces tau from the lattice. MAP7 promotes kinesin-based transport in vivo and strongly recruits kinesin-1 to the microtubule in vitro, providing evidence for direct enhancement of motor motility by a MAP. Both MAP7 and tau strongly inhibit kinesin-3 and have no effect on cytoplasmic dynein, demonstrating that MAPs differentially control distinct classes of motors. Overall, these results reveal a general principle for how MAP competition dictates access to the microtubule to determine the correct distribution and balance of motor activity.
Highly stable graphene-oxide-based membranes with superior permeability
Authors: Thebo Khalid Hussain , Qian Xitang , Zhang Qing , Chen Long , Cheng Hui-Ming , Ren Wencai
Published: April 2018

Increasing fresh water demand for drinking and agriculture is one of the grand challenges of our age. Graphene oxide (GO) membranes have shown a great potential for desalination and water purification. However, it is challenging to further improve the water permeability without sacrificing the separation efficiency, and the GO membranes are easily delaminated in aqueous solutions within few hours. Here, we report a class of reduced GO membranes with enlarged interlayer distance fabricated by using theanine amino acid and tannic acid as reducing agent and cross-linker. Such membranes show water permeance over 10,000 L m−2 h−1 bar−1, which is 10–1000 times higher than those of previously reported GO-based membranes and commercial membranes, and good separation efficiency, e.g., rhodamine B and methylene blue rejection of ~100%. Moreover, they show no damage or delamination in water, acid, and basic solutions even after months.