bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observation of a reversal of rotation in a sunspot during a solar flare
Authors: Bi Yi , Jiang Yunchun , Yang Jiayan , Hong Junchao , Li Haidong , Yang Bo , Xu Zhe 
Published: December 2016

AbstractThe abrupt motion of the photospheric flux during a solar flare is thought to be a back reaction caused by the coronal field reconfiguration. However, the type of motion pattern and the physical mechanism responsible for the back reaction has been uncertain. Here we show that the direction of a sunspot’s rotation is reversed during an X1.6 flare using observations from the Helioseismic and Magnetic Imager. A magnetic field extrapolation model shows that the corresponding coronal magnetic field shrinks with increasing magnetic twist density. This suggests that the abrupt reversal of rotation in the sunspot may be driven by a Lorentz torque that is produced by the gradient of twist density from the solar corona to the solar interior. These results support the view that the abrupt reversal in the rotation of the sunspot is a dynamic process responding to shrinkage of the coronal magnetic field during the flare.
Neuroanatomy accounts for age-related changes in risk preferences
Authors: Grubb Michael A. , Tymula Agnieszka , Gilaie-Dotan Sharon , Glimcher Paul W. , Levy Ifat 
Published: December 2016

AbstractMany decisions involve uncertainty, or ‘risk’, regarding potential outcomes, and substantial empirical evidence has demonstrated that human aging is associated with diminished tolerance for risky rewards. Grey matter volume in a region of right posterior parietal cortex (rPPC) is predictive of preferences for risky rewards in young adults, with less grey matter volume indicating decreased tolerance for risk. That grey matter loss in parietal regions is a part of healthy aging suggests that diminished rPPC grey matter volume may have a role in modulating risk preferences in older adults. Here we report evidence for this hypothesis and show that age-related declines in rPPC grey matter volume better account for age-related changes in risk preferences than does age per se. These results provide a basis for understanding the neural mechanisms that mediate risky choice and a glimpse into the neurodevelopmental dynamics that impact decision-making in an aging population.
ATR inhibitors as a synthetic lethal therapy for tumours deficient in ARID1A
Authors: Williamson Chris T. , Miller Rowan , Pemberton Helen N. , Jones Samuel E. , Campbell James , Konde Asha , Badham Nicholas , Rafiq Rumana , Brough Rachel , Gulati Aditi , Ryan Colm J. , Francis Jeff , Vermulen Peter B. , Reynolds Andrew R. , Reaper Philip M. , Pollard John R. , Ashworth Alan , Lord Christopher J. 
Published: December 2016

AbstractIdentifying genetic biomarkers of synthetic lethal drug sensitivity effects provides one approach to the development of targeted cancer therapies. Mutations in ARID1A represent one of the most common molecular alterations in human cancer, but therapeutic approaches that target these defects are not yet clinically available. We demonstrate that defects in ARID1A sensitize tumour cells to clinical inhibitors of the DNA damage checkpoint kinase, ATR, both in vitro and in vivo. Mechanistically, ARID1A deficiency results in topoisomerase 2A and cell cycle defects, which cause an increased reliance on ATR checkpoint activity. In ARID1A mutant tumour cells, inhibition of ATR triggers premature mitotic entry, genomic instability and apoptosis. The data presented here provide the pre-clinical and mechanistic rationale for assessing ARID1A defects as a biomarker of single-agent ATR inhibitor response and represents a novel synthetic lethal approach to targeting tumour cells.
Structural Basis for Human PECAM-1-Mediated Trans-homophilic Cell Adhesion
Authors: Hu Menglong , Zhang Hongmin , Liu Qun , Hao Quan 
Published: December 2016

AbstractCell adhesion involved in signal transduction, tissue integrity and pathogen infection is mainly mediated by cell adhesion molecules (CAM). One CAM member, platelet–endothelial-cell adhesion molecule-1 (PECAM-1), plays an important role in tight junction among endothelia cells, leukocyte trafficking, and immune response through its homophilic and heterophilic binding patterns. Both kinds of interactions, which lead to endogenous and exogenous signal transmission, are derived from extracellular immunoglobulin-like (IgL) domains and cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs) of PECAM-1. To date, the mechanism of trans-homophilic interaction of PECAM-1 remains unclear. Here, we present the crystal structure of PECAM-1 IgL1-2 trans-homo dimer. Both IgL 1 and 2 adopt the classical Ig domain conformation comprised of two layers of β-sheets possessing antiparallel β-strands with each being anchored by a pair of cysteines forming a disulfide bond. The dimer interface includes hydrophobic and hydrophilic interactions. The Small-Angle X-ray Scattering (SAXS) envelope of PECAM-1 IgL1-6 supported such a dimer formation in solution. Cell adhesion assays on wildtype and mutant PECAM-1 further characterized the structural determinants in cell junction and communication.
Voltage Fluctuation in a Supercapacitor During a High-g Impact
Authors: Dai Keren , Wang Xiaofeng , Yin Yajiang , Hao Chenglong , You Zheng 
Published: December 2016

AbstractSupercapacitors (SCs) are a type of energy storage device with high power density and long lifecycles. They have widespread applications, such as powering electric vehicles and micro scale devices. Working stability is one of the most important properties of SCs, and it is of significant importance to investigate the operational characteristics of SCs working under extreme conditions, particularly during high-g acceleration. In this paper, the failure mechanism of SCs upon high-g impact is thoroughly studied. Through an analysis of the intrinsic reaction mechanism during the high-g impact, a multi-faceted physics model is established. Additionally, a multi-field coupled kinetics simulation of the SC failure during a high-g impact is presented. Experimental tests are conducted that confirm the validity of the proposed model. The key factors of failure, such as discharge currents and discharging levels, are analyzed and discussed. Finally, a possible design is proposed to avoid the failure of SCs upon high-g impact.
Temporal binding of interval markers
Authors: Derichs Christina , Zimmermann Eckart 
Published: December 2016

AbstractHow we estimate the passage of time is an unsolved mystery in neuroscience. Illusions of subjective time provide an experimental access to this question. Here we show that time compression and expansion of visually marked intervals result from a binding of temporal interval markers. Interval markers whose onset signals were artificially weakened by briefly flashing a whole-field mask were bound in time towards markers with a strong onset signal. We explain temporal compression as the consequence of summing response distributions of weak and strong onset signals. Crucially, temporal binding occurred irrespective of the temporal order of weak and strong onset markers, thus ruling out processing latencies as an explanation for changes in interval duration judgments. If both interval markers were presented together with a mask or the mask was shown in the temporal interval center, no compression occurred. In a sequence of two intervals, masking the middle marker led to time compression for the first and time expansion for the second interval. All these results are consistent with a model view of temporal binding that serves a functional role by reducing uncertainty in the final estimate of interval duration.
Improved genome-scale multi-target virtual screening via a novel collaborative filtering approach to cold-start problem
Authors: Lim Hansaim , Gray Paul , Xie Lei , Poleksic Aleksandar 
Published: December 2016

AbstractConventional one-drug-one-gene approach has been of limited success in modern drug discovery. Polypharmacology, which focuses on searching for multi-targeted drugs to perturb disease-causing networks instead of designing selective ligands to target individual proteins, has emerged as a new drug discovery paradigm. Although many methods for single-target virtual screening have been developed to improve the efficiency of drug discovery, few of these algorithms are designed for polypharmacology. Here, we present a novel theoretical framework and a corresponding algorithm for genome-scale multi-target virtual screening based on the one-class collaborative filtering technique. Our method overcomes the sparseness of the protein-chemical interaction data by means of interaction matrix weighting and dual regularization from both chemicals and proteins. While the statistical foundation behind our method is general enough to encompass genome-wide drug off-target prediction, the program is specifically tailored to find protein targets for new chemicals with little to no available interaction data. We extensively evaluate our method using a number of the most widely accepted gene-specific and cross-gene family benchmarks and demonstrate that our method outperforms other state-of-the-art algorithms for predicting the interaction of new chemicals with multiple proteins. Thus, the proposed algorithm may provide a powerful tool for multi-target drug design.
Performance Evaluation and Online Realization of Data-driven Normalization Methods Used in LC/MS based Untargeted Metabolomics Analysis
Authors: Li Bo , Tang Jing , Yang Qingxia , Cui Xuejiao , Li Shuang , Chen Sijie , Cao Quanxing , Xue Weiwei , Chen Na , Zhu Feng 
Published: December 2016

AbstractIn untargeted metabolomics analysis, several factors (e.g., unwanted experimental & biological variations and technical errors) may hamper the identification of differential metabolic features, which requires the data-driven normalization approaches before feature selection. So far, ≥16 normalization methods have been widely applied for processing the LC/MS based metabolomics data. However, the performance and the sample size dependence of those methods have not yet been exhaustively compared and no online tool for comparatively and comprehensively evaluating the performance of all 16 normalization methods has been provided. In this study, a comprehensive comparison on these methods was conducted. As a result, 16 methods were categorized into three groups based on their normalization performances across various sample sizes. The VSN, the Log Transformation and the PQN were identified as methods of the best normalization performance, while the Contrast consistently underperformed across all sub-datasets of different benchmark data. Moreover, an interactive web tool comprehensively evaluating the performance of 16 methods specifically for normalizing LC/MS based metabolomics data was constructed and hosted at http://server.idrb.cqu.edu.cn/MetaPre/. In summary, this study could serve as a useful guidance to the selection of suitable normalization methods in analyzing the LC/MS based metabolomics data.
Calcium Channels and Oxidative Stress Mediate a Synergistic Disruption of Tight Junctions by Ethanol and Acetaldehyde in Caco-2 Cell Monolayers
Authors: Samak Geetha , Gangwar Ruchika , Meena Avtar S. , Rao Roshan G. , Shukla Pradeep K. , Manda Bhargavi , Narayanan Damodaran , Jaggar Jonathan H. , Rao RadhaKrishna 
Published: December 2016

AbstractEthanol is metabolized into acetaldehyde in most tissues. In this study, we investigated the synergistic effect of ethanol and acetaldehyde on the tight junction integrity in Caco-2 cell monolayers. Expression of alcohol dehydrogenase sensitized Caco-2 cells to ethanol-induced tight junction disruption and barrier dysfunction, whereas aldehyde dehydrogenase attenuated acetaldehyde-induced tight junction disruption. Ethanol up to 150 mM did not affect tight junction integrity or barrier function, but it dose-dependently increased acetaldehyde-mediated tight junction disruption and barrier dysfunction. Src kinase and MLCK inhibitors blocked this synergistic effect of ethanol and acetaldehyde on tight junction. Ethanol and acetaldehyde caused a rapid and synergistic elevation of intracellular calcium. Calcium depletion by BAPTA or Ca2+-free medium blocked ethanol and acetaldehyde-induced barrier dysfunction and tight junction disruption. Diltiazem and selective knockdown of TRPV6 or CaV1.3 channels, by shRNA blocked ethanol and acetaldehyde-induced tight junction disruption and barrier dysfunction. Ethanol and acetaldehyde induced a rapid and synergistic increase in reactive oxygen species by a calcium-dependent mechanism. N-acetyl-L-cysteine and cyclosporine A, blocked ethanol and acetaldehyde-induced barrier dysfunction and tight junction disruption. These results demonstrate that ethanol and acetaldehyde synergistically disrupt tight junctions by a mechanism involving calcium, oxidative stress, Src kinase and MLCK.
Type 2 diabetes mellitus is associated with increased risks of sarcopenia and pre-sarcopenia in Chinese elderly
Authors: Wang Taotao , Feng Xiao , Zhou Jingjing , Gong Hongyan , Xia Song , Wei Qing , Hu Xu , Tao Ran , Li Lei , Qian Frank , Yu Li 
Published: December 2016

AbstractSarcopenia is a condition characterized by progressive and generalized loss of skeletal muscle mass and function. In this study, we used a cross-sectional study with 1090 community-dwelling Chinese citizens aged 60 years and older to evaluate the association of type 2 diabetes mellitus (T2DM) with the risk of sarcopenia and pre-sarcopenia. Sarcopenia was defined using the Asian Working Group for Sarcopenia (AWGS) criteria that include both muscle mass and muscle function/physical activity. Pre-sarcopenia was defined as having low skeletal muscle index but with normal muscle/physical activity. The prevalence of sarcopenia and pre-sarcopenia was significantly higher in T2DM patients than in healthy controls (14.8% vs. 11.2%, p = 0.035 for sarcopenia, and 14.4% vs. 8.4%, p = 0.002 for pre-sarcopenia). In multivariate logistic regression analyses adjusting by age, gender, anti-diabetic medication, energy intake, protein intake, physical activity, and visceral fat area, we found that Chinese elderly with T2DM exhibited significantly increased risks of sarcopenia (OR = 1.37, 95% CI = 1.02–2.03) and pre-sarcopenia (OR = 1.73, 95% CI = 1.10–2.83) compared to non-diabetic individuals. This is the first study to evaluate the association of T2DM with the risks of sarcopenia and pre-sarcopenia in China. Among a group of community-dwelling Chinese elderly, T2DM was significantly associated with increased risks of sarcopenia and pre-sarcopenia.
Fossil record of stem groups employed in evaluating the chronogram of insects (Arthropoda: Hexapoda)
Authors: Wang Yan-hui , Engel Michael S. , Rafael José A. , Wu Hao-yang , Rédei Dávid , Xie Qiang , Wang Gang , Liu Xiao-guang , Bu Wen-jun 
Published: December 2016

AbstractInsectas. str.(=Ectognatha), comprise the largest and most diversified group of living organisms, accounting for roughly half of the biodiversity on Earth. Understanding insect relationships and the specific time intervals for their episodes of radiation and extinction are critical to any comprehensive perspective on evolutionary events. Although some deeper nodes have been resolved congruently, the complete evolution of insects has remained obscure due to the lack of direct fossil evidence. Besides, various evolutionary phases of insects and the corresponding driving forces of diversification remain to be recognized. In this study, a comprehensive sample of all insect orders was used to reconstruct their phylogenetic relationships and estimate deep divergences. The phylogenetic relationships of insect orders were congruently recovered by Bayesian inference and maximum likelihood analyses. A complete timescale of divergences based on an uncorrelated log-normal relaxed clock model was established among all lineages of winged insects. The inferred timescale for various nodes are congruent with major historical events including the increase of atmospheric oxygen in the Late Silurian and earliest Devonian, the radiation of vascular plants in the Devonian, and with the available fossil record of the stem groups to various insect lineages in the Devonian and Carboniferous.
Assessing the potential for Bluetongue virus 8 to spread and vaccination strategies in Scotland
Authors: Bessell Paul R. , Searle Kate R. , Auty Harriet K. , Handel Ian G. , Purse Bethan V. , Bronsvoort B. Mark de C. 
Published: December 2016

AbstractEurope has seen frequent outbreaks of Bluetongue (BT) disease since 2006, including an outbreak of BT virus serotype 8 in central France during 2015 that has continued to spread in Europe during 2016. Thus, assessing the potential for BTv-8 spread and determining the optimal deployment of vaccination is critical for contingency planning. We developed a spatially explicit mathematical model of BTv-8 spread in Scotland and explored the sensitivity of transmission to key disease spread parameters for which detailed empirical data is lacking. With parameters at mean values, there is little spread of BTv-8 in Scotland. However, under a “worst case” but still feasible scenario with parameters at the limits of their ranges and temperatures 1 °C warmer than the mean, we find extensive spread with 203,000 sheep infected given virus introduction to the south of Scotland between mid-May and mid-June. Strategically targeted vaccine interventions can greatly reduce BT spread. Specifically, despite BT having most clinical impact in sheep, we show that vaccination can have the greatest impact on reducing BTv infections in sheep when administered to cattle, which has implications for disease control policy.
HBV maintains electrostatic homeostasis by modulating negative charges from phosphoserine and encapsidated nucleic acids
Authors: Su Pei-Yi , Yang Ching-Jen , Chu Tien-Hua , Chang Chih-Hsu , Chiang Chiayn , Tang Fan-Mei , Lee Chih-Yin , Shih Chiaho 
Published: December 2016

AbstractCapsid assembly and stability of hepatitis B virus (HBV) core protein (HBc) particles depend on balanced electrostatic interactions between encapsidated nucleic acids and an arginine-rich domain (ARD) of HBc in the capsid interior. Arginine-deficient ARD mutants preferentially encapsidated spliced viral RNA and shorter DNA, which can be fully or partially rescued by reducing the negative charges from acidic residues or serine phosphorylation of HBc, dose-dependently. Similarly, empty capsids without RNA encapsidation can be generated by ARD hyper-phosphorylation in insect, bacteria, and human hepatocytes. De-phosphorylation of empty capsids by phosphatase induced capsid disassembly. Empty capsids can convert into RNA-containing capsids by increasing HBc serine de-phosphorylation. In an HBV replicon system, we observed a reciprocal relationship between viral and non-viral RNA encapsidation, suggesting both non-viral RNA and serine-phosphorylation could serve as a charge balance buffer in maintaining electrostatic homeostasis. In addition, by comparing the biochemistry assay results between a replicon and a non-replicon system, we observed a correlation between HBc de-phosphorylation and viral replication. Balanced electrostatic interactions may be important to other icosahedral particles in nature.
On-Chip Optical Nonreciprocity Using an Active Microcavity
Authors: Jiang Xiaoshun , Yang Chao , Wu Hongya , Hua Shiyue , Chang Long , Ding Yang , Hua Qian , Xiao Min 
Published: December 2016

AbstractOptically nonreciprocal devices provide critical functionalities such as light isolation and circulation in integrated photonic circuits for optical communications and information processing, but have been difficult to achieve. By exploring gain-saturation nonlinearity, we demonstrate on-chip optical nonreciprocity with excellent isolation performance within telecommunication wavelengths using only one toroid microcavity. Compatible with current complementary metal-oxide-semiconductor process, our compact and simple scheme works for a very wide range of input power levels from ~10 microwatts down to ~10 nanowatts, and exhibits remarkable properties of one-way light transport with sufficiently low insertion loss. These superior features make our device become a promising critical building block indispensable for future integrated nanophotonic networks.
Local Dielectric Property Detection of the Interface between Nanoparticle and Polymer in Nanocomposite Dielectrics
Authors: Peng Simin , Zeng Qibin , Yang Xiao , Hu Jun , Qiu Xiaohui , He Jinliang 
Published: December 2016

AbstractThe interface between nanoparticles and polymer matrix is considered to have an important effect on the properties of nanocomposites. In this experimental study, electrostatic force microscopy (EFM) is used to study the local dielectric property of the interface of low density polyethylene (LDPE)/TiO2 nanocomposites at nanometer scale. The results show that the addition of TiO2 nanoparticles leads to a decrease in local permittivity. We then carry out the finite element simulation and confirm that the decrease of local permittivity is related to the effect of interface. According to the results, we propose several models and validate the dielectric effect and range effect of interface. Through the analysis of DSC and solid-state NMR results, we find TiO2 nanoparticles can suppress the mobility of local chain segments in the interface, which influences the dipolar polarization of chain segments in the interface and eventually results in a decrease in local permittivity. It is believed the results would provide important hint to the research of the interface in future research.
Laser Light-field Fusion for Wide-field Lensfree On-chip Phase Contrast Microscopy of Nanoparticles
Authors: Kazemzadeh Farnoud , Wong Alexander 
Published: December 2016

AbstractWide-field lensfree on-chip microscopy, which leverages holography principles to capture interferometric light-field encodings without lenses, is an emerging imaging modality with widespread interest given the large field-of-view compared to lens-based techniques. In this study, we introduce the idea of laser light-field fusion for lensfree on-chip phase contrast microscopy for detecting nanoparticles, where interferometric laser light-field encodings acquired using a lensfree, on-chip setup with laser pulsations at different wavelengths are fused to produce marker-free phase contrast images of particles at the nanometer scale. As a proof of concept, we demonstrate, for the first time, a wide-field lensfree on-chip instrument successfully detecting 300 nm particles across a large field-of-view of ~30 mm2 without any specialized or intricate sample preparation, or the use of synthetic aperture- or shift-based techniques.