bluuebunny/crossref_metadata_2025_split huggingface dataset:
Giant electron-hole transport asymmetry in ultra-short quantum transistors
Authors: McRae A. C. , Tayari V. , Porter J. M. , Champagne A. R. 
Published: May 2017

AbstractMaking use of bipolar transport in single-wall carbon nanotube quantum transistors would permit a single device to operate as both a quantum dot and a ballistic conductor or as two quantum dots with different charging energies. Here we report ultra-clean 10 to 100 nm scale suspended nanotube transistors with a large electron-hole transport asymmetry. The devices consist of naked nanotube channels contacted with sections of tube under annealed gold. The annealed gold acts as an n-doping top gate, allowing coherent quantum transport, and can create nanometre-sharp barriers. These tunnel barriers define a single quantum dot whose charging energies to add an electron or a hole are vastly different (e−h charging energy asymmetry). We parameterize the e−h transport asymmetry by the ratio of the hole and electron charging energies ηe−h. This asymmetry is maximized for short channels and small band gap tubes. In a small band gap device, we demonstrate the fabrication of a dual functionality quantum device acting as a quantum dot for holes and a much longer quantum bus for electrons. In a 14 nm-long channel, ηe−h reaches up to 2.6 for a device with a band gap of 270 meV. The charging energies in this device exceed 100 meV.
Smooth 2D manifold extraction from 3D image stack
Authors: Shihavuddin Asm , Basu Sreetama , Rexhepaj Elton , Delestro Felipe , Menezes Nikita , Sigoillot Séverine M , Del Nery Elaine , Selimi Fekrije , Spassky Nathalie , Genovesio Auguste 
Published: May 2017

AbstractThree-dimensional fluorescence microscopy followed by image processing is routinely used to study biological objects at various scales such as cells and tissue. However, maximum intensity projection, the most broadly used rendering tool, extracts a discontinuous layer of voxels, obliviously creating important artifacts and possibly misleading interpretation. Here we propose smooth manifold extraction, an algorithm that produces a continuous focused 2D extraction from a 3D volume, hence preserving local spatial relationships. We demonstrate the usefulness of our approach by applying it to various biological applications using confocal and wide-field microscopy 3D image stacks. We provide a parameter-free ImageJ/Fiji plugin that allows 2D visualization and interpretation of 3D image stacks with maximum accuracy.
End-Triassic mass extinction started by intrusive CAMP activity
Authors: Davies J.H.F.L. , Marzoli A. , Bertrand H. , Youbi N. , Ernesto M. , Schaltegger U. 
Published: May 2017

AbstractThe end-Triassic extinction is one of the Phanerozoic’s largest mass extinctions. This extinction is typically attributed to climate change associated with degassing of basalt flows from the central Atlantic magmatic province (CAMP). However, recent work suggests that the earliest known CAMP basalts occur above the extinction horizon and that climatic and biotic changes began before the earliest known CAMP eruptions. Here we present new high-precision U-Pb ages from CAMP mafic intrusive units, showing that magmatic activity was occurring ∼100 Kyr ago before the earliest known eruptions. We correlate the early magmatic activity with the onset of changes to the climatic and biotic records. We also report ages from sills in an organic rich sedimentary basin in Brazil that intrude synchronously with the extinction suggesting that degassing of these organics contributed to the climate change which drove the extinction. Our results indicate that the intrusive record from large igneous provinces may be more important for linking to mass extinctions than the eruptive record.
WIPI3 and WIPI4 β-propellers are scaffolds for LKB1-AMPK-TSC signalling circuits in the control of autophagy
Authors: Bakula Daniela , Müller Amelie J. , Zuleger Theresia , Takacs Zsuzsanna , Franz-Wachtel Mirita , Thost Ann-Katrin , Brigger Daniel , Tschan Mario P. , Frickey Tancred , Robenek Horst , Macek Boris , Proikas-Cezanne Tassula 
Published: May 2017

AbstractAutophagy is controlled by AMPK and mTOR, both of which associate with ULK1 and control the production of phosphatidylinositol 3-phosphate (PtdIns3P), a prerequisite for autophagosome formation. Here we report that WIPI3 and WIPI4 scaffold the signal control of autophagy upstream of PtdIns3P production and have a role in the PtdIns3P effector function of WIPI1-WIPI2 at nascent autophagosomes. In response to LKB1-mediated AMPK stimulation, WIPI4-ATG2 is released from a WIPI4-ATG2/AMPK-ULK1 complex and translocates to nascent autophagosomes, controlling their size, to which WIPI3, in complex with FIP200, also contributes. Upstream, WIPI3 associates with AMPK-activated TSC complex at lysosomes, regulating mTOR. Our WIPI interactome analysis reveals the scaffold functions of WIPI proteins interconnecting autophagy signal control and autophagosome formation. Our functional kinase screen uncovers a novel regulatory link between LKB1-mediated AMPK stimulation that produces a direct signal via WIPI4, and we show that the AMPK-related kinases NUAK2 and BRSK2 regulate autophagy through WIPI4.
Real-time monitoring of hydrophobic aggregation reveals a critical role of cooperativity in hydrophobic effect
Authors: Jiang Liguo , Cao Siqin , Cheung Peter Pak-Hang , Zheng Xiaoyan , Leung Chris Wai Tung , Peng Qian , Shuai Zhigang , Tang Ben Zhong , Yao Shuhuai , Huang Xuhui 
Published: May 2017

AbstractThe hydrophobic interaction drives nonpolar solutes to aggregate in aqueous solution, and hence plays a critical role in many fundamental processes in nature. An important property intrinsic to hydrophobic interaction is its cooperative nature, which is originated from the collective motions of water hydrogen bond networks surrounding hydrophobic solutes. This property is widely believed to enhance the formation of hydrophobic core in proteins. However, cooperativity in hydrophobic interactions has not been successfully characterized by experiments. Here, we quantify cooperativity in hydrophobic interactions by real-time monitoring the aggregation of hydrophobic solute (hexaphenylsilole, HPS) in a microfluidic mixer. We show that association of a HPS molecule to its aggregate in water occurs at sub-microsecond, and the free energy change is −5.8 to −13.6 kcal mol−1. Most strikingly, we discover that cooperativity constitutes up to 40% of this free energy. Our results provide quantitative evidence for the critical role of cooperativity in hydrophobic interactions.
Inflammatory breast cancer: a model for investigating cluster-based dissemination
Authors: Jolly Mohit Kumar , Boareto Marcelo , Debeb Bisrat G. , Aceto Nicola , Farach-Carson Mary C. , Woodward Wendy A. , Levine Herbert 
Published: May 2017

AbstractMetastases claim more than 90% of cancer-related patient deaths and are usually seeded by a subset of circulating tumor cells shed off from the primary tumor. In circulation, circulating tumor cells are found both as single cells and as clusters of cells. The clusters of circulating tumor cells, although many fewer in number, possess much higher metastatic potential as compared to that of individual circulating tumor cells. In this review, we highlight recent insights into molecular mechanisms that can enable the formation of these clusters—(a) hybrid epithelial/mesenchymal phenotype of cells that couples their ability to migrate and adhere, and (b) intercellular communication that can spatially coordinate the cluster formation and provide survival signals to cancer cells. Building upon these molecular mechanisms, we also offer a possible mechanistic understanding of why clusters are endowed with a higher metastatic potential. Finally, we discuss the highly aggressive Inflammatory Breast Cancer as an example of a carcinoma that can metastasize via clusters and corroborates the proposed molecular mechanisms.
Piezoelectric Microstructured Fibers via Drawing of Multimaterial Preforms
Authors: Lu Xin , Qu Hang , Skorobogatiy Maksim 
Published: May 2017

AbstractWe demonstrate planar laminated piezoelectric generators and piezoelectric microstructured fibers based on BaTiO3-polyvinylidene and carbon-loaded-polyethylene materials combinations. The laminated piezoelectric generators were assembled by sandwiching the electrospun BaTiO3-polyvinylidene mat between two carbon-loaded-polyethylene films. The piezoelectric microstructured fiber was fabricated via drawing of the multilayer fiber preform, and features a swissroll geometry that have ~10 alternating piezoelectric and conductive layers. Both piezoelectric generators have excellent mechanical durability, and could retain their piezoelectric performance after 3 day’s cyclic bend-release tests. Compared to the laminated generators, the piezoelectric fibers are advantageous as they could be directly woven into large-area commercial fabrics. Potential applications of the proposed piezoelectric fibers include micro-power-generation and remote sensing in wearable, automotive and aerospace industries.
Myricetin protects Galleria mellonella against Staphylococcus aureus infection and inhibits multiple virulence factors
Authors: Silva L. N. , Da Hora G. C. A. , Soares T. A. , Bojer M. S. , Ingmer H. , Macedo A. J. , Trentin D. S. 
Published: May 2017

AbstractStaphylococcus aureus is an opportunistic pathogen related to a variety of life-threatening infections but for which antimicrobial resistance is liming the treatment options. We report here that myricetin, but not its glycosylated form, can remarkably decrease the production of several S. aureus virulence factors, including adhesion, biofilm formation, hemolysis and staphyloxanthin production, without interfering with growth. Myricetin affects both surface proteins and secreted proteins which indicate that its action is unrelated to inhibition of the agr quorum sensing system. Analysis of virulence related gene expression and computational simulations of pivotal proteins involved in pathogenesis demonstrate that myricetin downregulates the saeR global regulator and interacts with sortase A and α-hemolysin. Furthermore, Myr confers a significant degree of protection against staphylococcal infection in the Galleria mellonella model. The present findings reveal the potential of Myr as an alternative multi-target antivirulence candidate to control S. aureus pathogenicity.
Temporal evolution of a seismic sequence induced by a gas injection in the Eastern coast of Spain
Authors: Ruiz-Barajas S. , Sharma N. , Convertito V. , Zollo A. , Benito B. 
Published: May 2017

AbstractInduced seismicity associated with energy production is becoming an increasingly important issue worldwide for the hazard it poses to the exposed population and structures. We analyze one of the rare cases of induced seismicity associated with the underwater gas storage operations observed in the Castor platform, located in the Valencia gulf, east Spain, near a complex and important geological structure. In September 2013, some gas injection operations started at Castor, producing a series of seismic events around the reservoir area. The larger magnitude events (up to 4.2) took place some days after the end of the injection, with EMS intensities in coastal towns up to degree III. In this work, the seismic sequence is analyzed with the aim of detecting changes in statistical parameters describing the earthquake occurrence before and after the injection and identifying possible proxies to be used for monitoring the sequence evolution. Moreover, we explore the potential predictability of these statistical parameters which can be used to control the field operations in injection/storage fluid reservoirs. We firstly perform a retrospective approach and next a perspective analysis. We use different techniques for estimating the value of the expected maximum magnitude that can occur due to antropogenic activities in Castor.
Electron Ptychographic Diffractive Imaging of Boron Atoms in LaB6 Crystals
Authors: Wang Peng , Zhang Fucai , Gao Si , Zhang Mian , Kirkland Angus I. 
Published: May 2017

AbstractPtychographic diffractive imaging has the potential for structural determination of materials without the constraints of relatively small, isolated samples required for conventional coherent diffractive imaging. The increased illumination diversity introduced using multiple measurements (overlapped probe positions) also provides higher sensitivity to phase changes in weakly scattering samples. The resolution of a ptychographic reconstruction is ultimately determined by the diffraction limit for the wavelength of the radiation used. However, in practical experiments using electrons either the maximum collection angle of the detector used to record the data or the partial coherence of the source impose lower resolution limits. Nonetheless for medium energy electrons this suggests a potential sub 0.1 nm spatial resolution limit, comparable to that obtained using aberration corrected instruments. However, simultaneous visualization of light and heavier atoms in specimens using ptychography at sub 0.1 nm resolution presents a significant challenge. Here, we demonstrate a ptychographic reconstruction of a LaB6 crystal in which light B atoms were clearly resolved together with the heavy La atoms in the reconstructed phase. The technique used is general and can also be applied to non-crystalline and extended crystalline samples. As such it offers an alternative future basis for imaging the atomic structure of materials, particularly those containing low atomic number elements.
Remodeling pathway control of mitochondrial respiratory capacity by temperature in mouse heart: electron flow through the Q-junction in permeabilized fibers
Authors: Lemieux Hélène , Blier Pierre U. , Gnaiger Erich 
Published: May 2017

AbstractFuel substrate supply and oxidative phosphorylation are key determinants of muscle performance. Numerous studies of mammalian mitochondria are carried out (i) with substrate supply that limits electron flow, and (ii) far below physiological temperature. To analyze potentially implicated biases, we studied mitochondrial respiratory control in permeabilized mouse myocardial fibers using high-resolution respirometry. The capacity of oxidative phosphorylation at 37 °C was nearly two-fold higher when fueled by physiological substrate combinations reconstituting tricarboxylic acid cycle function, compared with electron flow measured separately through NADH to Complex I or succinate to Complex II. The relative contribution of the NADH pathway to physiological respiratory capacity increased with a decrease in temperature from 37 to 25 °C. The apparent excess capacity of cytochrome c oxidase above physiological pathway capacity increased sharply under hypothermia due to limitation by NADH-linked dehydrogenases. This mechanism of mitochondrial respiratory control in the hypothermic mammalian heart is comparable to the pattern in ectotherm species, pointing towards NADH-linked mt-matrix dehydrogenases and the phosphorylation system rather than electron transfer complexes as the primary drivers of thermal sensitivity at low temperature. Delineating the link between stress and remodeling of oxidative phosphorylation is important for understanding metabolic perturbations in disease evolution and cardiac protection.
De novo non-synonymous TBL1XR1 mutation alters Wnt signaling activity
Authors: Nishi Akira , Numata Shusuke , Tajima Atsushi , Zhu Xiaolei , Ito Koki , Saito Atsushi , Kato Yusuke , Kinoshita Makoto , Shimodera Shinji , Ono Shinji , Ochi Shinichiro , Imamura Akira , Kurotaki Naohiro , Ueno Shu-ichi , Iwata Nakao , Fukui Kiyoshi , Imoto Issei , Kamiya Atsushi , Ohmori Tetsuro 
Published: May 2017

AbstractHere we report de novo non-synonymous single-nucleotide variants (SNVs) by conducting whole exome sequencing of 18 trios consisting of Japanese patients with sporadic schizophrenia and their parents. Among nine SNVs, we explored the functional impact of the de novo mutation in TBL1XR1 [c.30 C > G (p.Phe10Leu)], a gene previously found to be associated with autism spectrum disorder and epilepsy. Protein structural analysis revealed that Phe10Leu mutation may decrease the structural stability of the TBL1XR1 protein. We demonstrate that Phe10Leu mutation alters the interaction of TBL1XR1 with N-CoR and β-catenin, which play critical roles in regulation of Wnt-mediated transcriptional activity. Consistently, TBL1XR1-mediated activation of Wnt signaling was up-regulated by Phe10Leu mutation. These results suggest that a de novo TBL1XR1 point mutation could alter Wnt/β-catenin signaling activity. Further studies are required to clarify the involvement of TBL1XR1 mutations in neuropsychiatric conditions.
High-resolution promoter map of human limbal epithelial cells cultured with keratinocyte growth factor and rho kinase inhibitor
Authors: Yoshihara Masahito , Sasamoto Yuzuru , Hayashi Ryuhei , Ishikawa Yuki , Tsujikawa Motokazu , Hayashizaki Yoshihide , Itoh Masayoshi , Kawaji Hideya , Nishida Kohji 
Published: May 2017

AbstractAn in vitro model of corneal epithelial cells (CECs) has been developed to study and treat corneal disorders. Nevertheless, conventional CEC culture supplemented with epidermal growth factor (EGF) results in a loss of CEC characteristics. It has recently been reported that limbal epithelial cells (LECs) cultured with keratinocyte growth factor (KGF) and the rho kinase inhibitor Y-27632 could maintain the expression of several CEC-specific markers. However, the molecular mechanism underlying the effect of culture media on LECs remains to be elucidated. To elucidate this mechanism, we performed comprehensive gene expression analysis of human LECs cultured with EGF or KGF/Y-27632, by cap analysis of gene expression (CAGE). Here, we found that LECs cultured with KGF and Y-27632 presented a gene expression profile highly similar to that of CECs in vivo. In contrast, LECs cultured with EGF lost the characteristic CEC gene expression profile. We further discovered that CEC-specific PAX6 promoters are highly activated in LECs cultured with KGF and Y-27632. Our results provide strong evidence that LECs cultured with KGF and Y-27632 would be an improved in vitro model in the context of gene expression. These findings will accelerate basic studies of CECs and clinical applications in regenerative medicine.
Comparison and immunobiological characterization of retinoic acid inducible gene-I-like receptor expression in mesenchymal stromal cells
Authors: Raicevic Gordana , Najar Mehdi , Busser Hélène , Crompot Emerence , Bron Dominique , Toungouz Michel , Lagneaux Laurence 
Published: May 2017

AbstractDue to their immunomodulatory and regenerative properties, Mesenchymal stromal cells (MSC) have generated major interests in several clinical settings including transplantation and inflammatory diseases. MSC functions can be influenced by their tissue origin. Their microenvironment strongly affects their biology notably through TLR sensing. In this study, we show that MSC isolated from four different sources express another type of cytosolic pathogen recognition receptors known as retinoic acid inducible gene-I (RIG-I)-like receptors (RLR). RLR activation in MSC induces the production of Type I IFN (IFN-β) and Type III IFN (IFN-λ1). The highest producers are adipose tissue(AT)-MSC. We further show that Interferon production is induced through TBK1/IKK-ε signaling and IRF7 phosphorylation. Depending on MSC source, the knockdown of TLR3 and/or RIG-I decreases the MSC response to RLR ligand poly(I:C)/Lyovec. Among the different MSC types, AT-MSCs display the highest sensitivity to viral stimuli as shown by the alteration of their viability after prolonged stimulation. Our work indicates that this could be linked to an increase of pro-apoptotic Noxa expression. Finally, the expression of IDO1 and LIF upon RLR activation indicate the increase of MSC immunomodulatory potential, especially in AT-MSCs. Altogether, these data should be considered when designing MSC-based therapy in clinical settings where inflammation or infection are present.
Disentangling Auger decays in O2 by photoelectron-ion coincidences
Authors: Liu Xiao-Jing , Nicolas Christophe , Patanen Minna , Miron Catalin 
Published: May 2017

AbstractIn non-resonant Auger electron spectroscopies, multi core-ionized states lead to numerous energetically close-lying electronic transitions in Auger spectra, this hampering the assignment and interpretation of the experimental results. Here we reveal a new method to overcome this intrinsic limitation of non-resonant inner-shell spectroscopies. In a proof-of-principle experiment performed for the O2 molecule, most of the Auger final states are dissociative, and we measure in coincidence the kinetic energy of the photoelectron and the kinetic energy release of the (O+, O+) ion pairs produced after the Auger decay of the O 1s−1 core-ionized states. The Auger final states are assigned using energy conservation. We fully separate the contributions from the 4Σ− and 2Σ− intermediate ionic states and conclusively demonstrate that the Auger decay probability can dramatically depend on the different O2 1s−1 intermediate multiplet states. In addition, a metastable Auger final state also exists, with lifetime longer than 3.8 μs, and clear changes are observed in both branching ratio and spectral profile of the O 1s photoelectron spectrum when they are recorded in coincidence with either $${{\bf{O}}}_{{\bf{2}}}^{{\boldsymbol{+}}{\boldsymbol{+}}}$$

O

2

+
+

or with other ionic species. These changes are attributed to the population of the metastable $${{\boldsymbol{B}}}^{{\boldsymbol{^{\prime} }}3}{{\boldsymbol{\Sigma }}}_{{\boldsymbol{u}}}^{-}({\boldsymbol{\nu }}{\boldsymbol{^{\prime\prime} }}{\boldsymbol{=}}0)$$

B

′
3

Σ

u

−

(
ν
″
=
0
)
Auger final state via different intermediate states.
Gut Dysbiosis and Neurobehavioral Alterations in Rats Exposed to Silver Nanoparticles
Authors: Javurek Angela B. , Suresh Dhananjay , Spollen William G. , Hart Marcia L. , Hansen Sarah A. , Ellersieck Mark R. , Bivens Nathan J. , Givan Scott A. , Upendran Anandhi , Kannan Raghuraman , Rosenfeld Cheryl S. 
Published: May 2017

AbstractDue to their antimicrobial properties, silver nanoparticles (AgNPs) are being used in non-edible and edible consumer products. It is not clear though if exposure to these chemicals can exert toxic effects on the host and gut microbiome. Conflicting studies have been reported on whether AgNPs result in gut dysbiosis and other changes within the host. We sought to examine whether exposure of Sprague-Dawley male rats for two weeks to different shapes of AgNPs, cube (AgNC) and sphere (AgNS) affects gut microbiota, select behaviors, and induces histopathological changes in the gastrointestinal system and brain. In the elevated plus maze (EPM), AgNS-exposed rats showed greater number of entries into closed arms and center compared to controls and those exposed to AgNC. AgNS and AgNC treated groups had select reductions in gut microbiota relative to controls. Clostridium spp., Bacteroides uniformis, Christensenellaceae, and Coprococcus eutactus were decreased in AgNC exposed group, whereas, Oscillospira spp., Dehalobacterium spp., Peptococcaeceae, Corynebacterium spp., Aggregatibacter pneumotropica were reduced in AgNS exposed group. Bacterial reductions correlated with select behavioral changes measured in the EPM. No significant histopathological changes were evident in the gastrointestinal system or brain. Findings suggest short-term exposure to AgNS or AgNC can lead to behavioral and gut microbiome changes.