bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental and DFT Studies of Au Deposition Over WO3/g-C3N4 Z-Scheme Heterojunction
Authors: Humayun Muhammad , Ullah Habib , Cao Junhao , Pi Wenbo , Yuan Yang , Ali Sher , Tahir Asif Ali , Yue Pang , Khan Abbas , Zheng Zhiping , Fu Qiuyun , Luo Wei
Published: January 2020

A typical Z-scheme system is composed of two photocatalysts which generate two sets of charge carriers and split water into H2 and O2 at different locations. Scientists are struggling to enhance the efficiencies of these systems by maximizing their light absorption, engineering more stable redox couples, and discovering new O2 and H2 evolutions co-catalysts. In this work, Au decorated WO3/g-C3N4 Z-scheme nanocomposites are fabricated via wet-chemical and photo-deposition methods. The nanocomposites are utilized in photocatalysis for H2 production and 2,4-dichlorophenol (2,4-DCP) degradation. It is investigated that the optimized 4Au/6% WO3/CN nanocomposite is highly efficient for production of 69.9 and 307.3 µmol h−1 g−1 H2 gas, respectively, under visible-light (λ > 420 nm) and UV–visible illumination. Further, the fabricated 4Au/6% WO3/CN nanocomposite is significant (i.e., 100% degradation in 2 h) for 2,4-DCP degradation under visible light and highly stable in photocatalysis. A significant 4.17% quantum efficiency is recorded for H2 production at wavelength 420 nm. This enhanced performance is attributed to the improved charge separation and the surface plasmon resonance effect of Au nanoparticles. Solid-state density functional theory simulations are performed to countercheck and validate our experimental data. Positive surface formation energy, high charge transfer, and strong non-bonding interaction via electrostatic forces confirm the stability of 4Au/6% WO3/CN interface.
Joint embedding of structure and features via graph convolutional networks
Authors: Lerique Sébastien , Abitbol Jacob Levy , Karsai Márton
Published: January 2020

The creation of social ties is largely determined by the entangled effects of people’s similarities in terms of individual characters and friends. However, feature and structural characters of people usually appear to be correlated, making it difficult to determine which has greater responsibility in the formation of the emergent network structure. We propose AN2VEC, a node embedding method which ultimately aims at disentangling the information shared by the structure of a network and the features of its nodes. Building on the recent developments of Graph Convolutional Networks (GCN), we develop a multitask GCN Variational Autoencoder where different dimensions of the generated embeddings can be dedicated to encoding feature information, network structure, and shared feature-network information. We explore the interaction between these disentangled characters by comparing the embedding reconstruction performance to a baseline case where no shared information is extracted. We use synthetic datasets with different levels of interdependency between feature and network characters and show (i) that shallow embeddings relying on shared information perform better than the corresponding reference with unshared information, (ii) that this performance gap increases with the correlation between network and feature structure, and (iii) that our embedding is able to capture joint information of structure and features. Our method can be relevant for the analysis and prediction of any featured network structure ranging from online social systems to network medicine.
Experimental constraints on subglacial rock friction
Authors: Hansen Dougal D. , Zoet Lucas K.
Published: January 2020

Subglacial rock friction is an important control on the sliding dynamics and erosive potential of hard-bedded glaciers, yet it remains largely unconstrained. To explore the relative influence of basal melt rate, effective stress and ice temperature on frictional resistance, we conducted abrasion experiments in which limestone beds were slid beneath a fixed slab of ice laden with granitic rock fragments. Shear stress scales linearly with melt rate and cryostatic stress, confirming that both viscous drag and effective stress are first-order controls on the contact force in drained conditions. Furthermore, temperature gradients in the ice increase the contribution of viscous drag on basal shear stress. In all experiments, the relationship between melt rate and shear stress is best explained by a model that accounts for the effects of regelation and viscous creep on the bed-normal drag force. We interpret this to mean fluid flow around entrained clasts contributed to basal drag even at subfreezing temperatures. Incorporating premelting dynamics into the Watts/Hallet model for subglacial rock friction, we find that the predicted debris-bed drag decreases by approximately an order of magnitude, with a corresponding ~3.5 × increase in the transition radius. This is lower than we observe for ice slightly below the pressure melting point.
Measurements of turbulence transfer in the near-surface layer over the Antarctic sea-ice surface from April through November in 2016
Authors: Liu Changwei , Gao Zhiqiu , Yang Qinghua , Han Bo , Wang Hong , Hao Guanghua , Zhao Jiechen , Yu Lejiang , Wang Linlin , Li Yubin
Published: January 2020

The surface energy budget over the Antarctic sea ice from 8 April 2016 through 26 November 2016 are presented. From April to October, Sensible heat flux (SH) and subsurface conductive heat flux (G) were the heat source of surface while latent heat flux (LE) and net radiation flux (Rn) were the heat sink of surface. Our results showed larger downwardSH(due to the warmer air in our site) and upwardLE(due to the drier air and higher wind speed in our site) compared with SHEBA data. However, the values ofSHin N-ICE2015 campaign, which located at a zone with stronger winds and more advection of heat in the Arctic, were comparable to our results under clear skies. The values of aerodynamic roughness length (z0m) and scalar roughness length for temperature (z0h), being 1.9 × 10−3m and 3.7 × 10−5m, were suggested in this study. It is found that snow melting might increasez0m. Our results also indicate that the value of log(z0h/z0m) was related to the stability of stratification. In addition, several representative parameterization schemes forz0hhave been tested and a couple of schemes were found to make a better performance.
Political, Social, and Cultural Capital in the Chilean Political Elite, 1990–2010
Authors: Garrido-Vergara Luis
Published: January 2020

Although sociological research has examined the reproduction of Chile’s elites, there is little empirical evidence of how different forms of capital operate among them. Using datasets for members of the Chilean political elite from 1990 to 2010, this country note examines and measures the effect of political, social, and cultural capital on the access of certain individuals to strategic positions in the political field, comparing the legislative and executive branches as represented by deputies and ministers. The empirical analysis includes logit models.
ON THE -ERROR LINEAR COMPLEXITY OF SEQUENCES FROM FUNCTION FIELDS
Authors: ZHOU YUHUI , HAN YUHUI , DING YANG
Published: January 2020

The linear complexity and the error linear complexity are two important security measures for stream ciphers. We construct periodic sequences from function fields and show that the error linear complexity of these periodic sequences is large. We also give a lower bound for the error linear complexity of a class of nonperiodic sequences.
Maurice Merleau-Ponty and the philosophy of religion
Authors: WILLIAMS JACK
Published: January 2020

This article proposes a new approach to employing Maurice Merleau-Ponty's philosophy in the philosophy of religion. Rather than finding a latent theology in Merleau-Ponty – as some interpreters do – this article argues that Merleau-Ponty's later ontology can provide the basis for a philosophical anthropology which can help us understand why human beings are drawn to religion and how this is expressed in affective and ritual practice. This ontology can help us to understand the notion of freedom as it applies to affective, embodied, and ritual religious practices and begins to sketch out how freedom might be understood in light of embodiment.
Using telecollaboration to promote intercultural competence in teacher training classrooms in Turkey and the USA
Authors: Üzüm Babürhan , Akayoglu Sedat , Yazan Bedrettin
Published: January 2020

Since advances in computer-mediated communication (CMC) tools have made virtual exchanges readily available in educational practices, telecollaboration has been gaining traction as a means to provide practical experiences and cultural exposure to language learners and, more recently, teacher trainees. Drawing upon Byram’s (1997) model of intercultural communicative competence (ICC), this study examines 48 teacher trainees’ interculturality through a telecollaborative project between two teacher training classes from Turkey and the USA. This study relies on data generated by the participants throughout this telecollaborative project: weekly online discussion board posts within groups of six and post-project reflections. Although developing ICC is an arduous and prolonged task, the data analysis suggested that the participants’ experiences in this telecollaboration contributed to their emergent ICC through discussions on the topics of multicultural education and interactions with trainees from another educational context. Their intercultural learning is evidenced by their (1) awareness of heterogeneity in their own and interactants’ culture, (2) nascent critical cultural awareness, and (3) curiosity and willingness to learn more about the other culture. Thus, this study implies that telecollaboration offers an effective teacher training venue that affords teacher trainees with first-hand intercultural encounters to engage with otherness and prepare for their ethnolinguistically diverse classrooms.
Transitional care for young adults with ADHD: transforming potential upheaval into smooth progression
Authors: Ford Tamsin
Published: January 2020

Increasing numbers of young adults need continued support for their attention deficit hyperactivity disorder (ADHD) beyond the age-boundary for children's services. The sparse literature on transition in general suggests patchy provision and huge gaps in transitional care, but also that young people with ADHD and other neurodevelopmental disorders fair particularly badly. Transition in health care coincides with many other important life-transitions while the difficulties associated with ADHD may make these challenges particularly hard to cope with. Parents or other advocates therefore often need to be involved, which can present problems in adult mental health services given that they tend to be less family oriented than children's services. Importantly, young people need help negotiating the transition from passive recipient of care to active self-management, and in building relationships with the adult team.

In addition to patchy provision of adult ADHD services, transition is currently hampered by poor understanding of ADHD as a long term condition and uncertain knowledge of what services are available among young people and parents as well as the clinicians working with them. Guidelines recommend, and more importantly young people want, access to psycho-social interventions as well as medication. However, available evidence suggests poor quality transitional care and adult services that are highly focused on medication.

Adult ADHD services need to undergo similar development to that experienced by Child and Adolescent Mental Health Services and community paediatrics over the last few decades. While we debate the relative merits of dedicated or specialistv. generic adult mental health services, for young adults with ADHD the training, experience and availability of professionals are more important than their qualifications or setting.
Methodology Development for Calibration Assessment Using Quasi‐Deep Convective Clouds With Application to Aqua MODIS TEB
Authors: Chang Tiejun , Xiong Xiaoxiong , Shrestha Ashish , Perez Diaz Carlos
Published: January 2020

Deep convective clouds (DCC) are identified by using a combination of brightness temperature (BT) and visible reflectance thresholds. Moreover, it is common practice to use daytime DCC measurements for the calibration assessment of reflective solar and longwave infrared bands. The DCC cold core is suitable for the Moderate Resolution Imaging Spectroradiometer (MODIS) thermal emissive bands (TEB) calibration assessment; more specifically, for the offset effect in the quadratic calibration function. However, the reflected solar radiance in the daytime DCC measurements affects the midwave infrared bands. Thus, an assessment over low‐BT measurements is not applicable to these bands. Because of this, a quasi‐DCC (qDCC) technique is developed for the midwave infrared bands calibration assessment. The feasibility of using nighttime DCC measurements is demonstrated by comparing the DCC and daytime qDCC techniques. A DCC normalization method is also developed to remove the DCC fluctuation impact and enhance the assessment accuracy. The DCC measurements' distribution is asymmetrical for all TEB, and their BT ranges fluctuate around 20 K. An empirical model is developed and applied to normalize the measurements over DCC to a reference temperature. After the normalization, the DCC and qDCC measurements' distributions are close to symmetrical and Gaussian in shape. These improvements are applied to the Aqua MODIS instrument. The calibration stability, noise performance, and consistency are evaluated for all Aqua MODIS TEB. Lastly, the Aqua MODIS formatter reset effect on the calibration offset bias between two mirror sides is analyzed, and a calibration coefficient correction is proposed for future calibration improvements.
Spaceborne Measurements of Formic and Acetic Acids: A Global View of the Regional Sources
Authors: Franco B. , Clarisse L. , Stavrakou T. , Müller J.‐F. , Taraborrelli D. , Hadji‐Lazaro J. , Hannigan J. W. , Hase F. , Hurtmans D. , Jones N. , Lutsch E. , Mahieu E. , Ortega I. , Schneider M. , Strong K. , Vigouroux C. , Clerbaux C. , Coheur P.‐F.
Published: January 2020

Formic (HCOOH) and acetic acids (
COOH) are the most abundant carboxylic acids in the Earth's atmosphere and key compounds to aqueous‐phase chemistry. Here we present the first distributions of
COOH retrieved from the 2007–2018 satellite observations of the nadir‐looking infrared atmospheric sounding interferometer (IASI), using a neural network‐based retrieval approach. A joint analysis with the IASI HCOOH product reveals that the two species exhibit similar distributions, seasonality, and atmospheric burden, pointing to major common sources. We show that their abundance is highly correlated to isoprene and monoterpenes emissions, as well as to biomass burning. Over Africa, evidence is provided that residual smoldering combustion might be a major driver of the HCOOH and
COOH seasonality. Earlier seasonal enhancement of HCOOH at Northern Hemisphere middle and high latitudes and late seasonal secondary peaks of
COOH in the tropics suggest that sources and production pathways specific to each species are also at play.
Resolving Complicated Faulting Process Using Multi‐Point‐Source Representation: Iterative Inversion Algorithm Improvement and Application to Recent Complex Earthquakes
Authors: Yue Han , Lay Thorne
Published: January 2020

Complicated faulting processes of large earthquakes may involve simultaneous or sequential rupture of multiple fault planes, often with different focal mechanisms. Determination of these subevent focal mechanisms is essential for multifault parameterization and complex rupture process analysis. Iterative inversion for Multi‐Point‐Source (MPS) faulting representations using broadband teleseismic body waves is an established strategy to estimate the focal mechanism variation but tends to be an unstable procedure. We enhance an iterative inversion algorithm developed by M. Kikuchi and H. Kanamori by specifying extra a priori constraints in the inversion. These constraints include the specific search time window, location, and source time function of each point source subevent to enable controls over the temporal and spatial properties of each point source. We apply the improved algorithm to seven recent earthquakes with complex faulting: the 2008 Wenchuan, 2009 Samoa, 2010 El‐Mayor Cucapah, 2010 Darfield, 2012 Indian Ocean, 2016 Kaikoura, and 2018 Gulf of Alaska earthquakes. The faulting complexity of these events has been independently constrained using geodetic, seismic, tsunami, and/or field observations, enabling tests of the MPS inversion algorithm performance. The improved iterative inversion resolves varying focal mechanisms of multiple point sources with specific timing consistent with detailed solutions, but spatial resolution tends to be relatively low (>20 km). Summation of subevent point‐source solutions recovers 30% to 95% of the long‐period point‐source seismic moments, varying with different levels of parameterization. The improved iterative MPS inversion algorithm is a promising approach for prompt (within a few hours) analysis of primary focal mechanism variation with reasonable overall space‐time distribution for complicated events.
Changes in Extreme Climate Events in China Under 1.5 °C–4 °C Global Warming Targets: Projections Using an Ensemble of Regional Climate Model Simulations
Authors: Wu Jia , Han Zhenyu , Xu Ying , Zhou Botao , Gao Xuejie
Published: January 2020

Extreme climate events in China, including its 10 main river basins, were projected under global warming of 1.5 °C–4 °C using the latest version of a regional climate model (RegCM4) for dynamical downscaling, driven by the outputs of four global climate models. Firstly, evaluation indicated that the simulations satisfactorily reproduced the spatial distribution of temperature extremes and, although with lower performance, the spatial distributions of precipitation extremes were generally captured. Additionally, a better description was achieved over areas with complex terrains by using RegCM4. Next, the model was used to make projections under global warming of 1.5 °C–4 °C. Warm extremes were projected to increase, while cold events were projected to decrease, particularly in northern and western China. In addition, the number of wet days was projected to increase in the northern part of China, and to decrease in the southern part. The maximum consecutive five‐day precipitation and the precipitation intensity were projected to increase significantly throughout China, while the consecutive number of dry days was projected to significantly decrease in northern and western China. The changes of atmospheric moisture content and atmospheric circulation lead to the increase of extreme precipitation. Specifically, the increases in the indices of wetness were closely correlated with the summer precipitation, wind, moisture flux convergence, and surface specific humidity, while the consecutive number of dry days was related to the change in summer moisture flux convergence and precipitation in dry seasons. Notably, the magnitude of the changes in extremes events was projected to increase as the warming target increases.
Resolving Small‐Scale Forest Snow Patterns Using an Energy Balance Snow Model With a One‐Layer Canopy
Authors: Mazzotti Giulia , Essery Richard , Moeser C. David , Jonas Tobias
Published: January 2020

Modeling spatiotemporal dynamics of snow in forests is challenging, as involved processes are strongly dependent on small‐scale canopy properties. In this study, we explore how local canopy structure information can be integrated in a medium‐complexity energy balance snow model to replicate observed snow patterns at very high spatial resolutions. Snow depth distributions simulated with the Flexible Snow Model (FSM2) were tested against extensive experimental data acquired in discontinuous subalpine forest stands in Eastern Switzerland over three winters. While the default canopy implementation in FSM2 fails to capture the observed snow depth variability, performance is considerably improved when local canopy cover fraction and hemispherical sky view fraction are additionally accounted for (30% reduction in root mean square error). However, realistic snow depth distribution patterns throughout the season are only achieved if effective temperatures of near and distant canopy elements are discerned and if a mechanism to mimic preferential deposition of snow in canopy gaps is included. We demonstrate that by diversifying the canopy structure input in order to reflect respective portions of the canopy relevant to different processes, even a simple model based on widely used process parameterizations and canopy metrics can be applied for high‐resolution simulations of the sub‐canopy snow cover with just a few modifications. The presented approaches could be implemented in commonly used land surface models, allowing upscaling experiments and development of sub‐grid parameterizations without necessitating complex high‐resolution models.
Bone marrow niche-derived extracellular matrix-degrading enzymes influence the progression of B-cell acute lymphoblastic leukemia
Authors: Verma Divij , Zanetti Costanza , Godavarthy Parimala Sonika , Kumar Rahul , Minciacchi Valentina R. , Pfeiffer Jakob , Metzler Markus , Lefort Sylvain , Maguer-Satta Véronique , Nicolini Franck E. , Burroni Barbara , Fontenay Michaela , Krause Daniela S.
Published: January 2020

Specific and reciprocal interactions with the bone marrow microenvironment (BMM) govern the course of hematological malignancies. Matrix metalloproteinase-9 (MMP-9), secreted by leukemia cells, facilitates tumor progression via remodeling of the extracellular matrix (ECM) of the BMM. Hypothesizing that leukemias may instruct the BMM to degrade the ECM, we show, that MMP-9-deficiency in the BMM prolongs survival of mice with BCR-ABL1-induced B-cell acute lymphoblastic leukemia (B-ALL) compared with controls and reduces leukemia-initiating cells. MMP-9-deficiency in the BMM leads to reduced degradation of proteins of the ECM and reduced invasion of B-ALL. Using various in vivo and in vitro assays, as well as recipient mice deficient for the receptor for tumor necrosis factor (TNF) α (TNFR1) we demonstrate that B-ALL cells induce MMP-9-expression in mesenchymal stem cells (MSC) and possibly other cells of the BMM via a release of TNFα. MMP-9-expression in MSC is mediated by activation of nuclear factor kappa B (NF-κB) downstream of TNFR1. Consistently, knockdown of TNF-α in B-ALL-initiating cells or pharmacological inhibition of MMP-9 led to significant prolongation of survival in mice with B-ALL. In summary, leukemia cell-derivedTnfα induced MMP-9-expression by the BMM promoting B-ALL progression. Inhibition of MMP-9 may act as an adjunct to existing therapies.
Controlled sampling of ribosomally active protistan diversity in sediment-surface layers identifies putative players in the marine carbon sink
Authors: Rodríguez-Martínez Raquel , Leonard Guy , Milner David S , Sudek Sebastian , Conway Mike , Moore Karen , Hudson Theresa , Mahé Frédéric , Keeling Patrick J , Santoro Alyson E , Worden Alexandra Z , Richards Thomas A
Published: January 2020

Marine sediments are one of the largest carbon reservoir on Earth, yet the microbial communities, especially the eukaryotes, that drive these ecosystems are poorly characterised. Here, we report implementation of a sampling system that enables injection of reagents into sediments at depth, allowing for preservation of RNA in situ. Using the RNA templates recovered, we investigate the ‘ribosomally active’ eukaryotic diversity present in sediments close to the water/sediment interface. We demonstrate that in situ preservation leads to recovery of a significantly altered community profile. Using SSU rRNA amplicon sequencing, we investigated the community structure in these environments, demonstrating a wide diversity and high relative abundance of stramenopiles and alveolates, specifically: Bacillariophyta (diatoms), labyrinthulomycetes and ciliates. The identification of abundant diatom rRNA molecules is consistent with microscopy-based studies, but demonstrates that these algae can also be exported to the sediment as active cells as opposed to dead forms. We also observe many groups that include, or branch close to, osmotrophic–saprotrophic protists (e.g. labyrinthulomycetes and Pseudofungi), microbes likely to be important for detrital decomposition. The sequence data also included a diversity of abundant amplicon-types that branch close to the Fonticula slime moulds. Taken together, our data identifies additional roles for eukaryotic microbes in the marine carbon cycle; where putative osmotrophic–saprotrophic protists represent a significant active microbial-constituent of the upper sediment layer.
Comparison of three different serum-free light-chain assays—implications on diagnostic and therapeutic monitoring of multiple myeloma
Authors: Schieferdecker Aneta , Hörber Sebastian , Ums Monika , Besemer Britta , Bokemeyer Carsten , Peter Andreas , Weisel Katja
Published: January 2020

The measurement of serum-free light chains (FLC) is standard of care in the diagnosis and management of multiple myeloma (MM). The revised international myeloma working group (IMWG) implemented the involved FLC/noninvolved FLC (iFLC/niFLC) ratio as a biomarker for MM requiring treatment. Recently, a new definition of high-risk smoldering MM (SMM) including iFLC/niFLC ratio was published. These recommendations were solely based on a single assay method (Freelite assay). Today, two additional assays, N Latex FLC and ELISA-based Sebia FLC, are available. Here, we report on a single-center-study comparing results of all three different assays for FLC correlation and its potential implications for diagnostic and clinical use. In total, 187 samples from 47 MM patients were examined, and determination of FLC was performed. Comparison analyses showed similar FLC results for Sebia FLC and N Latex FLC assay with markedly lower absolute values for κ/λ ratio compared with Freelite. Values of λ FLC exhibited high variability. The ratio of iFLC/niFLC showed significant discrepancies among these assays. Our data demonstrate that the three available assays may result in markedly discrepant results, and should not be used interchangeably to monitor patients. Furthermore, modifications of the assay-specific diagnostic (iFLC/niFLC) thresholds for SMM and MM are recommended.
Critical role of caveolin-1 in aflatoxin B1-induced hepatotoxicity via the regulation of oxidation and autophagy
Authors: Xu Qingqiang , Shi Wenwen , Lv Pan , Meng Wenqi , Mao Guanchao , Gong Chuchu , Chen Yongchun , Wei Youheng , He Xiaowen , Zhao Jie , Han Hua , Sun Mingxue , Xiao Kai
Published: January 2020

Aflatoxin B1 (AFB1) is a potent hepatocarcinogen in humans and exposure to AFB1 is known to cause both acute and chronic hepatocellular injury. As the liver is known to be the main target organ of aflatoxin, it is important to identify the key molecules that participate in AFB1-induced hepatotoxicity and to investigate their underlying mechanisms. In this study, the critical role of caveolin-1 in AFB1-induced hepatic cell apoptosis was examined. We found a decrease in cell viability and an increase in oxidation and apoptosis in human hepatocyte L02 cells after AFB1 exposure. In addition, the intracellular expression of caveolin-1 was increased in response to AFB1 treatment. Downregulation of caveolin-1 significantly alleviated AFB1-induced apoptosis and decreased cell viability, whereas overexpression of caveolin-1 reversed these effects. Further functional analysis showed that caveolin-1 participates in AFB1-induced oxidative stress through its interaction with Nrf2, leading to the downregulation of cellular antioxidant enzymes and the promotion of oxidative stress-induced apoptosis. In addition, caveolin-1 was found to regulate AFB1-induced autophagy. This finding was supported by the effect that caveolin-1 deficiency promoted autophagy after AFB1 treatment, leading to the inhibition of apoptosis, whereas overexpression of caveolin-1 inhibited autophagy and accelerated apoptosis. Interestingly, further investigation showed that caveolin-1 participates in AFB1-induced autophagy by regulating the EGFR/PI3K-AKT/mTOR signaling pathway. Taken together, our data reveal that caveolin-1 plays a crucial role in AFB1-induced hepatic cell apoptosis via the regulation of oxidation and autophagy, which provides a potential target for the development of novel treatments to combat AFB1 hepatotoxicity.
Arc silence aggravates traumatic neuronal injury via mGluR1-mediated ER stress and necroptosis
Authors: Chen Tao , Zhu Jie , Wang Yu-Hai , Hang Chun-Hua
Published: January 2020

Delayed neuronal death is associated with neurological deficits and mortality after traumatic brain injury (TBI), where post-synaptic density (PSD) proteins are thought to play key roles. The immediate-early gene (IEG) coded protein Arc is a brain-specific PSD protein that controls synaptic plasticity and learning behaviors. In this study, we investigated the expression and biological function of Arc in neuronal death after TBI in an in vitro model mimicked by traumatic neuronal injury (TNI) in cortical neurons. TNI caused a temporal increase of Arc expression at 3 and 6 h. Knockdown of Arc expression using small interfering RNA (Si-Arc-3) promoted TNI-induced cytotoxicity and apoptosis. The results of western blot showed that Si-Arc-3 transfection further enhanced the activation of endoplasmic reticulum (ER) stress-associated factors, including glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP) and caspase-12 after TNI. In addition, knockdown of Arc significantly increased expression of (receptor-interacting protein kinase 1) RIP1 and the number of necroptotic cells, which were apparently prevented by necrostatin-1 (Nec-1). The results of immunostaining and western blot showed that knockdown of Arc activated the metabotropic glutamate receptor 1 (mGluR1) and intracellular Ca2+ release in neurons. Mechanistically, the Si-Arc-3-induced activation of ER stress-associated factors, RIP1 expression, apoptosis, and necroptosis were partially reversed by the mGluR1 antagonist AIDA. In summary, our data suggest that silence of Arc expression aggravates neuronal death after TNI by promoting apoptosis and necroptosis. These data support for the first time that Arc may represent a novel candidate for therapies against TBI.
GSK3β is a key regulator of the ROS-dependent necrotic death induced by the quinone DMNQ
Authors: Ciotti Sonia , Iuliano Luca , Cefalù Sebastiano , Comelli Marina , Mavelli Irene , Di Giorgio Eros , Brancolini Claudio
Published: January 2020

Signaling pathways controlling necrosis are still mysterious and debated. We applied a shRNA-based viability screen to identify critical elements of the necrotic response. We took advantage from a small molecule (G5) that makes covalent adducts with free thiols by Michael addition and elicits multiple stresses. In cells resistant to apoptosis, G5 triggers necrosis through the induction of protein unfolding, glutathione depletion, ER stress, proteasomal impairments, and cytoskeletal stress. The kinase GSK3β was isolated among the top hits of the screening. Using the quinone DMNQ, a ROS generator, we demonstrate that GSK3β is involved in the regulation of ROS-dependent necrosis. Our results have been validated using siRNA and by knocking-out GSK3β with the CRISPR/Cas9 technology. In response to DMNQ GSK3β is activated by serine 9 dephosphorylation, concomitantly to Akt inactivation. During the quinone-induced pro-necrotic stress, GSK3β gradually accumulates into the nucleus, before the collapse of the mitochondrial membrane potential. Accumulation of ROS in response to DMNQ is impaired by the absence of GSK3β. We provide evidence that the activities of the obligatory two-electrons reducing flavoenzymes, NQO1 (NAD(P)H quinone dehydrogenase 1) and NQO2 are required to suppress DMNQ-induced necrosis. In the absence of GSK3β the expression of NQO1 and NQO2 is dramatically increased, possibly because of an increased transcriptional activity of NRF2. In summary, GSK3β by blunting the anti-oxidant response and particularly NQO1 and NQO2 expression, favors the appearance of necrosis in response to ROS, as generated by the quinone DMNQ.
Structures of lipoprotein signal peptidase II from Staphylococcus aureus complexed with antibiotics globomycin and myxovirescin
Authors: Olatunji Samir , Yu Xiaoxiao , Bailey Jonathan , Huang Chia-Ying , Zapotoczna Marta , Bowen Katherine , Remškar Maja , Müller Rolf , Scanlan Eoin M. , Geoghegan Joan A. , Olieric Vincent , Caffrey Martin
Published: January 2020

Antimicrobial resistance is a major global threat that calls for new antibiotics. Globomycin and myxovirescin are two natural antibiotics that target the lipoprotein-processing enzyme, LspA, thereby compromising the integrity of the bacterial cell envelope. As part of a project aimed at understanding their mechanism of action and for drug development, we provide high-resolution crystal structures of the enzyme from the human pathogen methicillin-resistantStaphylococcus aureus(MRSA) complexed with globomycin and with myxovirescin. Our results reveal an instance of convergent evolution. The two antibiotics possess different molecular structures. Yet, they appear to inhibit identically as non-cleavable tetrahedral intermediate analogs. Remarkably, the two antibiotics superpose along nineteen contiguous atoms that interact similarly with LspA. This 19-atom motif recapitulates a part of the substrate lipoprotein in its proposed binding mode. Incorporating this motif into a scaffold with suitable pharmacokinetic properties should enable the development of effective antibiotics with built-in resistance hardiness.
Ocean Carbon Storage across the middle Miocene: a new interpretation for the Monterey Event
Authors: Sosdian S. M. , Babila T. L. , Greenop R. , Foster G. L. , Lear C. H.
Published: January 2020

The Miocene Climatic Optimum (MCO, 14–17 Ma) was ~3–4 °C warmer than present, similar to estimates for 2100. Coincident with the MCO is the Monterey positive carbon isotope (δ13C) excursion, with oceans more depleted in 12C relative to 13C than any time in the past 50 Myrs. The long-standing Monterey Hypothesis uses this excursion to invoke massive marine organic carbon burial and draw-down of atmospheric CO2 as a cause for the subsequent Miocene Climate Transition and Antarctic glaciation. However, this hypothesis cannot explain the multi-Myr lag between the δ13C excursion and global cooling. We use planktic foraminiferal B/Ca, δ11B, δ13C, and Mg/Ca to reconstruct surface ocean carbonate chemistry and temperature. We propose that the MCO was associated with elevated oceanic dissolved inorganic carbon caused by volcanic degassing, global warming, and sea-level rise. A key negative feedback of this warm climate was the organic carbon burial on drowned continental shelves.
Epidermal control of axonal attachment via β-spectrin and the GTPase-activating protein TBC-10 prevents axonal degeneration
Authors: Coakley Sean , Ritchie Fiona K. , Galbraith Kate M. , Hilliard Massimo A.
Published: January 2020

Neurons are subjected to strain due to body movement and their location within organs and tissues. However, how they withstand these forces over the lifetime of an organism is still poorly understood. Here, focusing on touch receptor neuron-epidermis interactions usingCaenorhabditis elegansas a model system, we show that UNC-70/β-spectrin and TBC-10, a conserved GTPase-activating protein, function non-cell-autonomously within the epidermis to dynamically maintain attachment of the axon. We reveal that, in response to strain, UNC-70/β-spectrin and TBC-10 stabilize trans-epidermal hemidesmosome attachment structures which otherwise become lost, causing axonal breakage and degeneration. Furthermore, we show that TBC-10 regulates axonal attachment and maintenance by inactivating RAB-35, and reveal functional conservation of these molecules with their vertebrate orthologs. Finally, we demonstrate that β-spectrin functions in this context non-cell-autonomously. We propose a model in which mechanically resistant epidermal attachment structures are maintained by UNC-70/β-spectrin and TBC-10 during movement, preventing axonal detachment and degeneration.
Image quality guided smart rotation improves coverage in microscopy
Authors: He Jiaye , Huisken Jan
Published: January 2020

Fluorescence microscopy is an essential tool for biological discoveries. There is a constant demand for better spatial resolution across a larger field of view. Although strides have been made to improve the theoretical resolution and speed of the optical instruments, in mesoscopic samples, image quality is still largely limited by the optical properties of the sample. In Selective Plane Illumination Microscopy (SPIM), the achievable optical performance is hampered by optical degradations encountered in both the illumination and detection. Multi-view imaging, either through sample rotation or additional optical paths, is a popular strategy to improve sample coverage. In this work, we introduce a smart rotation workflow that utilizes on-the-fly image analysis to identify the optimal light sheet imaging orientations. The smart rotation workflow outperforms the conventional approach without additional hardware and achieves a better sample coverage using the same number of angles or less and thereby reduces data volume and phototoxicity.
Sensing of HIV-1 by TLR8 activates human T cells and reverses latency
Authors: Meås Hany Zekaria , Haug Markus , Beckwith Marianne Sandvold , Louet Claire , Ryan Liv , Hu Zhenyi , Landskron Johannes , Nordbø Svein Arne , Taskén Kjetil , Yin Hang , Damås Jan Kristian , Flo Trude Helen
Published: January 2020

During HIV infection, cell-to-cell transmission results in endosomal uptake of the virus by target CD4+ T cells and potential exposure of the viral ssRNA genome to endosomal Toll-like receptors (TLRs). TLRs are instrumental in activating inflammatory responses in innate immune cells, but their function in adaptive immune cells is less well understood. Here we show that synthetic ligands of TLR8 boosted T cell receptor signaling, resulting in increased cytokine production and upregulation of surface activation markers. Adjuvant TLR8 stimulation, but not TLR7 or TLR9, further promoted T helper cell differentiation towards Th1 and Th17. In addition, we found that endosomal HIV induced cytokine secretion from CD4+ T cells in a TLR8-specific manner. TLR8 engagement also enhanced HIV-1 replication and potentiated the reversal of latency in patient-derived T cells. The adjuvant TLR8 activity in T cells can contribute to viral dissemination in the lymph node and low-grade inflammation in HIV patients. In addition, it can potentially be exploited for therapeutic targeting and vaccine development.
Sub-1.4eV bandgap inorganic perovskite solar cells with long-term stability
Authors: Hu Mingyu , Chen Min , Guo Peijun , Zhou Hua , Deng Junjing , Yao Yudong , Jiang Yi , Gong Jue , Dai Zhenghong , Zhou Yunxuan , Qian Feng , Chong Xiaoyu , Feng Jing , Schaller Richard D. , Zhu Kai , Padture Nitin P. , Zhou Yuanyuan
Published: January 2020

State-of-the-art halide perovskite solar cells have bandgaps larger than 1.45 eV, which restricts their potential for realizing the Shockley-Queisser limit. Previous search for low-bandgap (1.2 to 1.4 eV) halide perovskites has resulted in several candidates, but all are hybrid organic-inorganic compositions, raising potential concern regarding device stability. Here we show the promise of an inorganic low-bandgap (1.38 eV) CsPb0.6Sn0.4I3 perovskite stabilized via interface functionalization. Device efficiency up to 13.37% is demonstrated. The device shows high operational stability under one-sun-intensity illumination, with T80 and T70 lifetimes of 653 h and 1045 h, respectively (T80 and T70 represent efficiency decays to 80% and 70% of the initial value, respectively), and long-term shelf stability under nitrogen atmosphere. Controlled exposure of the device to ambient atmosphere during a long-term (1000 h) test does not degrade the efficiency. These findings point to a promising direction for achieving low-bandgap perovskite solar cells with high stability.
Electron Bernstein waves driven by electron crescents near the electron diffusion region
Authors: Li W. Y. , Graham D. B. , Khotyaintsev Yu. V. , Vaivads A. , André M. , Min K. , Liu K. , Tang B. B. , Wang C. , Fujimoto K. , Norgren C. , Toledo-Redondo S. , Lindqvist P.-A. , Ergun R. E. , Torbert R. B. , Rager A. C. , Dorelli J. C. , Gershman D. J. , Giles B. L. , Lavraud B. , Plaschke F. , Magnes W. , Le Contel O. , Russell C. T. , Burch J. L.
Published: January 2020

The Magnetospheric Multiscale (MMS) spacecraft encounter an electron diffusion region (EDR) of asymmetric magnetic reconnection at Earth’s magnetopause. The EDR is characterized by agyrotropic electron velocity distributions on both sides of the neutral line. Various types of plasma waves are produced by the magnetic reconnection in and near the EDR. Here we report large-amplitude electron Bernstein waves (EBWs) at the electron-scale boundary of the Hall current reversal. The finite gyroradius effect of the outflow electrons generates the crescent-shaped agyrotropic electron distributions, which drive the EBWs. The EBWs propagate toward the central EDR. The amplitude of the EBWs is sufficiently large to thermalize and diffuse electrons around the EDR. The EBWs contribute to the cross-field diffusion of the electron-scale boundary of the Hall current reversal near the EDR.
Boosting fast energy storage by synergistic engineering of carbon and deficiency
Authors: Deng Shengjue , Zhu He , Wang Guizhen , Luo Mi , Shen Shenghui , Ai Changzhi , Yang Liang , Lin Shiwei , Zhang Qinghua , Gu Lin , Liu Bo , Zhang Yan , Liu Qi , Pan Guoxiang , Xiong Qinqin , Wang Xiuli , Xia Xinhui , Tu Jiangping
Published: January 2020

Exploring advanced battery materials with fast charging/discharging capability is of great significance to the development of modern electric transportation. Herein we report a powerful synergistic engineering of carbon and deficiency to construct high-quality three/two-dimensional cross-linked Ti2Nb10O29−x@C composites at primary grain level with conformal and thickness-adjustable boundary carbon. Such exquisite boundary architecture is demonstrated to be capable of regulating the mechanical stress and concentration of oxygen deficiency for desired performance. Consequently, significantly improved electronic conductivity and enlarged lithium ion diffusion path, shortened activation process and better structural stability are realized in the designed Ti2Nb10O29−x@C composites. The optimized Ti2Nb10O29−x@C composite electrode shows fast charging/discharging capability with a high capacity of 197 mA h g−1 at 20 C (∼3 min) and excellent long-term durability with 98.7% electron and Li capacity retention over 500 cycles. Most importantly, the greatest applicability of our approach has been demonstrated by various other metal oxides, with tunable morphology, structure and composition.
Conversion of a conventional superconductor into a topological superconductor by topological proximity effect
Authors: Trang C. X. , Shimamura N. , Nakayama K. , Souma S. , Sugawara K. , Watanabe I. , Yamauchi K. , Oguchi T. , Segawa K. , Takahashi T. , Ando Yoichi , Sato T.
Published: January 2020

Realization of topological superconductors (TSCs) hosting Majorana fermions is a central challenge in condensed-matter physics. One approach is to use the superconducting proximity effect (SPE) in heterostructures, where a topological insulator contacted with a superconductor hosts an effective p-wave pairing by the penetration of Cooper pairs across the interface. However, this approach suffers a difficulty in accessing the topological interface buried deep beneath the surface. Here, we propose an alternative approach to realize topological superconductivity without SPE. In a Pb(111) thin film grown on TlBiSe2, we discover that the Dirac-cone state of substrate TlBiSe2 migrates to the top surface of Pb film and obtains an energy gap below the superconducting transition temperature of Pb. This suggests that a Bardeen-Cooper-Schrieffer superconductor is converted into a TSC by the topological proximity effect. Our discovery opens a route to manipulate topological superconducting properties of materials.
Color-tunable single-fluorophore supramolecular system with assembly-encoded emission
Authors: Wang Qian , Zhang Qi , Zhang Qi-Wei , Li Xin , Zhao Cai-Xin , Xu Tian-Yi , Qu Da-Hui , Tian He
Published: January 2020

Regulating the fluorescent properties of organic small molecules in a controlled and dynamic manner has been a fundamental research goal. Although several strategies have been exploited, realizing multi-color molecular emission from a single fluorophore remains challenging. Herein, we demonstrate an emissive system by combining pyrene fluorophore and acylhydrazone units, which can generate multi-color switchable fluorescent emissions at different assembled states. Two kinds of supramolecular tools, amphiphilic self-assembly and γ-cyclodextrin mediated host-guest recognition, are used to manipulate the intermolecular aromatic stacking distances, resulting in the tunable fluorescent emission ranging from blue to yellow, including a pure white-light emission. Moreover, an external chemical signal, amylase, is introduced to control the assembly states of the system on a time scale, generating a distinct dynamic emission system. The dynamic properties of this multi-color fluorescent system can be also enabled in a hydrogel network, exhibiting a promising potential for intelligent fluorescent materials.
Realistic in silico generation and augmentation of single-cell RNA-seq data using generative adversarial networks
Authors: Marouf Mohamed , Machart Pierre , Bansal Vikas , Kilian Christoph , Magruder Daniel S. , Krebs Christian F. , Bonn Stefan
Published: January 2020

A fundamental problem in biomedical research is the low number of observations available, mostly due to a lack of available biosamples, prohibitive costs, or ethical reasons. Augmenting few real observations with generated in silico samples could lead to more robust analysis results and a higher reproducibility rate. Here, we propose the use of conditional single-cell generative adversarial neural networks (cscGAN) for the realistic generation of single-cell RNA-seq data. cscGAN learns non-linear gene–gene dependencies from complex, multiple cell type samples and uses this information to generate realistic cells of defined types. Augmenting sparse cell populations with cscGAN generated cells improves downstream analyses such as the detection of marker genes, the robustness and reliability of classifiers, the assessment of novel analysis algorithms, and might reduce the number of animal experiments and costs in consequence. cscGAN outperforms existing methods for single-cell RNA-seq data generation in quality and hold great promise for the realistic generation and augmentation of other biomedical data types.