bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diffusion Creep and Grain Growth in Forsterite +20 vol% Enstatite Aggregates: 1. High‐Resolution Experiments and Their Data Analyses
Authors: Nakakoji T. , Hiraga T. , Nagao H. , Ito S. , Kano M. 
Published: October 2018

AbstractWe conducted uniaxial compression and grain growth experiments on fine‐grained (~1 μm) forsterite +20 vol% enstatite aggregates. Based on analyses of the sensitivity of the strain rate as a function of stress, we find power law creep at low stress, Newtonian creep at intermediate stress, and again power law creep at high stress, which correspond to interface‐controlled diffusion creep, grain boundary diffusion (Coble) creep, and a dislocation‐controlled process, respectively. The creep rate of these samples is well expressed by a combination of strain rates of these three mechanisms where interface‐controlled and Coble creep rates are combined as series‐sequential processes, while the rate of the dislocation process is added with them as a parallel‐concurrent process. Mechanical data collected continuously during the application of a constant load but while slowly changing temperature were decomposed into data for every 1 °C, which allowed consideration of >600 mechanical data points from 1054 to 1370 °C. The data were analyzed using Bayesian statistics implementing a Markov chain Monte Carlo method imposed on the above constitutive equation, resulting in the best fit flow law parameters for interface‐controlled and Coble creep. Samples were annealed for 500 hr at various temperatures. A comparison of the final grain sizes as a function of temperature on an Arrhenius plot resulted in an activation energy for grain growth similar to that observed for grain boundary diffusion during Coble creep of these materials.
Diffusion Creep and Grain Growth in Forsterite +20 vol% Enstatite Aggregates: 2. Their Common Diffusional Mechanism and Its Consequence for Weak‐Temperature‐Dependent Viscosity
Authors: Nakakoji T. , Hiraga T. 
Published: October 2018

AbstractWe determined the rate‐controlling diffusivities for creep and grain growth of forsterite +20 vol% enstatite aggregates from the experimental results presented in Part 1 of this study. Both diffusivities exhibit similar values with similar temperature dependency, indicating that a common grain boundary diffusion process controls both creep and grain growth. This correspondence is due to the presence of pyroxene grains as a secondary phase in the olivine aggregate, which is the case for the majority of mantle‐derived rocks. As a consequence, the viscosity (η) of the material during deformation by grain boundary diffusion creep accompanied by grain growth changes with time (t) and temperature (T) as
where QGB is the activation energy for grain boundary diffusion and R is gas constant. This viscosity relationship is used to interpret the very low activation energy estimated for the viscosity of the oceanic mantle lithosphere.
A Seasonally Recurrent Annular Cyclone in Mars Northern Latitudes and Observations of a Companion Vortex
Authors: Sánchez‐Lavega A. , Garro A. , del Río‐Gaztelurrutia T. , Hueso R. , Ordoñez‐Etxeberria I. , Chen Chen H. , Cardesín‐Moinelo A. , Titov D. , Wood S. , Almeida M. , Spiga A. , Forget F. , Määttänen A. , Hoffmann H. , Gondet B. 
Published: October 2018

AbstractWe study a seasonally recurrent cyclone and related cloud phenomena observed on Mars at Ls ~120°, latitude ~60°N, and longitude 90°W from images obtained with cameras in different spacecraft between 1995 and 2018. A remarkable double cyclone formed in 2012 and we present a detailed study of its dynamics using images from Mars Express and Mars Reconnaissance Orbiter obtained between 6 June and 9 July. A double cyclone was also observed in 2006 and 2008. In other Martian years the primary cyclone showed an annular cloud morphology with a large water ice cloud observed eastward of it. The cyclones have a size of ~600–800 km with a cloud‐free core of a radius ~100–300 km. Tangential velocities measured from cloud tracking in 2012 images are ~5–20 m/s−1 at 10‐km altitude and double cyclone moved eastward with a velocity of 4 m/s−1 during its lifetime of one month. The vortices grow in the morning hours, but with the increasing insolation as the sol progresses, a part of the clouds evaporate, the winds weaken, and the vortices lose coherence. This phenomenon forms under high‐temperature gradients in a region with a large north‐south topographic slope and has been recurrent each Martian year between 1995 and 2018. We argue the interest of studying its changing properties each Martian year in order to explore their possible relationship to the state of the Martian atmosphere at Ls ~120°.
miR4673 improves fitness profile of neoplastic cells by induction of autophagy
Authors: Dökümcü Kağan , Simonian Mary , Farahani Ramin M. 
Published: October 2018

AbstractTherapeutic resistance of neoplasms is mainly attributed to gradual evolution of mutational profile1. Here, we demonstrate a microRNA-mediated mechanism that effectively improves fitness of SKBR3 mammary carcinoma cells by cytoplasmic reprogramming. The reprogramming is triggered by endogenous miR4673 transcribed from notch-1 locus. The miRNA downregulates cdk-18, a cyclin-dependent kinase that regulates M-G1 transition in cycling cells2,3. Suppression of cdk-18 triggers mitophagy and autophagy. Due to high autophagic flux, oestrogen receptor-1+/progesterone receptor+/p53+(Esr1+/Pr+/p53+) SKBR3 cells are coerced into an Esr1−/Prlow/p53−profile. Increased mitophagy in combination with proteasomal degradation of p53 transiently arrests the cycling cells at G0 and enhances radio-resistance of the SKBR3 population. These findings highlight the impact on cancer therapy of non-encoded neoplastic resistance, arising as a consequence of miRNA-mediated autophagic reprogramming that uncouples phenotype and genotype.
Cardiomyocyte gene programs encoding morphological and functional signatures in cardiac hypertrophy and failure
Authors: Nomura Seitaro , Satoh Masahiro , Fujita Takanori , Higo Tomoaki , Sumida Tomokazu , Ko Toshiyuki , Yamaguchi Toshihiro , Tobita Takashige , Naito Atsuhiko T. , Ito Masamichi , Fujita Kanna , Harada Mutsuo , Toko Haruhiro , Kobayashi Yoshio , Ito Kaoru , Takimoto Eiki , Akazawa Hiroshi , Morita Hiroyuki , Aburatani Hiroyuki , Komuro Issei 
Published: October 2018

AbstractPressure overload induces a transition from cardiac hypertrophy to heart failure, but its underlying mechanisms remain elusive. Here we reconstruct a trajectory of cardiomyocyte remodeling and clarify distinct cardiomyocyte gene programs encoding morphological and functional signatures in cardiac hypertrophy and failure, by integrating single-cardiomyocyte transcriptome with cell morphology, epigenomic state and heart function. During early hypertrophy, cardiomyocytes activate mitochondrial translation/metabolism genes, whose expression is correlated with cell size and linked to ERK1/2 and NRF1/2 transcriptional networks. Persistent overload leads to a bifurcation into adaptive and failing cardiomyocytes, and p53 signaling is specifically activated in late hypertrophy. Cardiomyocyte-specific p53 deletion shows that cardiomyocyte remodeling is initiated by p53-independent mitochondrial activation and morphological hypertrophy, followed by p53-dependent mitochondrial inhibition, morphological elongation, and heart failure gene program activation. Human single-cardiomyocyte analysis validates the conservation of the pathogenic transcriptional signatures. Collectively, cardiomyocyte identity is encoded in transcriptional programs that orchestrate morphological and functional phenotypes.
Mesopontine cholinergic inputs to midbrain dopamine neurons drive stress-induced depressive-like behaviors
Authors: Fernandez Sebastian P. , Broussot Loïc , Marti Fabio , Contesse Thomas , Mouska Xavier , Soiza-Reilly Mariano , Marie Hélène , Faure Philippe , Barik Jacques 
Published: October 2018

AbstractStressful life events are primary environmental factors that markedly contribute to depression by triggering brain cellular maladaptations. Dysregulation of ventral tegmental area (VTA) dopamine neurons has been causally linked to the appearance of social withdrawal and anhedonia, two classical manifestations of depression. However, the relevant inputs that shape these dopamine signals remain largely unknown. We demonstrate that chronic social defeat (CSD) stress, a preclinical paradigm of depression, causes marked hyperactivity of laterodorsal tegmentum (LDTg) excitatory neurons that project to the VTA. Selective chemogenetic-mediated inhibition of cholinergic LDTg neurons prevent CSD-induced VTA DA neurons dysregulation and depressive-like behaviors. Pro-depressant outcomes are replicated by pairing activation of LDTg cholinergic terminals in the VTA with a moderate stress. Prevention of CSD outcomes are recapitulated by blocking corticotropin-releasing factor receptor 1 within the LDTg. These data uncover a neuro-circuitry of depressive-like disorders and demonstrate that stress, via a neuroendocrine signal, profoundly dysregulates the LDTg.
Nanocardboard as a nanoscale analog of hollow sandwich plates
Authors: Lin Chen , Nicaise Samuel M. , Lilley Drew E. , Cortes Joan , Jiao Pengcheng , Singh Jaspreet , Azadi Mohsen , Lopez Gerald G. , Metzler Meredith , Purohit Prashant K. , Bargatin Igor 
Published: October 2018

AbstractCorrugated paper cardboard provides an everyday example of a lightweight, yet rigid, sandwich structure. Here we present nanocardboard, a monolithic plate mechanical metamaterial composed of nanometer-thickness (25–400 nm) face sheets that are connected by micrometer-height tubular webbing. We fabricate nanocardboard plates of up to 1 centimeter-square size, which exhibit an enhanced bending stiffness at ultralow mass of ~1 g m−2. The nanoscale thickness allows the plates to completely recover their shape after sharp bending even when the radius of curvature is comparable to the plate height. Optimally chosen geometry enhances the bending stiffness and spring constant by more than four orders of magnitude in comparison to solid plates with the same mass, far exceeding the enhancement factors previously demonstrated at both the macroscale and nanoscale. Nanocardboard may find applications as a structural component for wings of microflyers or interstellar lightsails, scanning probe cantilevers, and other microscopic and macroscopic systems.
Long-term positioning and polar preference of chemoreceptor clusters in E. coli
Authors: Koler Moriah , Peretz Eliran , Aditya Chetan , Shimizu Thomas S. , Vaknin Ady 
Published: October 2018

AbstractThe bacterial chemosensory arrays are a notable model for studying the basic principles of receptor clustering and cellular organization. Here, we provide a new perspective regarding the long-term dynamics of these clusters in growing E. coli cells. We demonstrate that pre-existing lateral clusters tend to avoid translocation to pole regions and, therefore, continually shuttle between the cell poles for many generations while being static relative to the local cell-wall matrix. We also show that the polar preference of clusters results fundamentally from reduced clustering efficiency in the lateral region, rather than a developmental-like progression of clusters. Furthermore, polar preference is surprisingly robust to structural alterations designed to probe preference due to curvature sorting, perturbing the cell envelope physiology affects the cluster-size distribution, and the size-dependent mobility of receptor complexes differs between polar and lateral regions. Thus, distinct envelope physiology in the polar and lateral cell regions may contribute to polar preference.
Host suppression of quorum sensing during catheter-associated urinary tract infections
Authors: Cole Stephanie J. , Hall Cherisse L. , Schniederberend Maren , Farrow III John M. , Goodson Jonathan R. , Pesci Everett C. , Kazmierczak Barbara I. , Lee Vincent T. 
Published: October 2018

AbstractChronic bacterial infections on medical devices, including catheter-associated urinary tract infections (CAUTI), are associated with bacterial biofilm communities that are refractory to antibiotic therapy and resistant to host immunity. Previously, we have shown that Pseudomonas aeruginosa can cause CAUTI by forming a device-associated biofilm that is independent of known biofilm exopolysaccharides. Here, we show by RNA-seq that host urine alters the transcriptome of P. aeruginosa by suppressing quorum sensing regulated genes. P. aeruginosa produces acyl homoserine lactones (AHLs) in the presence of urea, but cannot perceive AHLs. Repression of quorum sensing by urine implies that quorum sensing should be dispensable during infection of the urinary tract. Indeed, mutants defective in quorum sensing are able to colonize similarly to wild-type in a murine model of CAUTI. Quorum sensing-regulated processes in clinical isolates are also inhibited by urea. These data show that urea in urine is a natural anti-quorum sensing mechanism in mammals.
Following hearts, one cell at a time: recent applications of single-cell RNA sequencing to the understanding of heart disease
Authors: Ackers-Johnson Matthew , Tan Wilson Lek Wen , Foo Roger Sik-Yin 
Published: October 2018

AbstractThe mammalian heart contains heterogeneous cell types contributing to pathological changes in cardiac disease. In this Comment, we explore how single-cell transcriptomic approaches are unveiling intricate cellular mechanisms and gene co-expression networks that regulate the workings, and failings, of the heart.
Contribution of epigenetic variation to adaptation in Arabidopsis
Authors: Schmid Marc W. , Heichinger Christian , Coman Schmid Diana , Guthörl Daniela , Gagliardini Valeria , Bruggmann Rémy , Aluri Sirisha , Aquino Catharine , Schmid Bernhard , Turnbull Lindsay A. , Grossniklaus Ueli 
Published: October 2018

AbstractIn plants, transgenerational inheritance of some epialleles has been demonstrated but it remains controversial whether epigenetic variation is subject to selection and contributes to adaptation. Simulating selection in a rapidly changing environment, we compare phenotypic traits and epigenetic variation between Arabidopsis thaliana populations grown for five generations under selection and their genetically nearly identical ancestors. Selected populations of two distinct genotypes show significant differences in flowering time and plant architecture, which are maintained for at least 2–3 generations in the absence of selection. While we cannot detect consistent genetic changes, we observe a reduction of epigenetic diversity and changes in the methylation state of about 50,000 cytosines, some of which are associated with phenotypic changes. Thus, we propose that epigenetic variation is subject to selection and can contribute to rapid adaptive responses, although the extent to which epigenetics plays a role in adaptation is still unclear.
Adhesion to nanofibers drives cell membrane remodeling through one-dimensional wetting
Authors: Charles-Orszag Arthur , Tsai Feng-Ching , Bonazzi Daria , Manriquez Valeria , Sachse Martin , Mallet Adeline , Salles Audrey , Melican Keira , Staneva Ralitza , Bertin Aurélie , Millien Corinne , Goussard Sylvie , Lafaye Pierre , Shorte Spencer , Piel Matthieu , Krijnse-Locker Jacomine , Brochard-Wyart Françoise , Bassereau Patricia , Duménil Guillaume 
Published: October 2018

AbstractThe shape of cellular membranes is highly regulated by a set of conserved mechanisms that can be manipulated by bacterial pathogens to infect cells. Remodeling of the plasma membrane of endothelial cells by the bacterium Neisseria meningitidis is thought to be essential during the blood phase of meningococcal infection, but the underlying mechanisms are unclear. Here we show that plasma membrane remodeling occurs independently of F-actin, along meningococcal type IV pili fibers, by a physical mechanism that we term ‘one-dimensional’ membrane wetting. We provide a theoretical model that describes the physical basis of one-dimensional wetting and show that this mechanism occurs in model membranes interacting with nanofibers, and in human cells interacting with extracellular matrix meshworks. We propose one-dimensional wetting as a new general principle driving the interaction of cells with their environment at the nanoscale that is diverted by meningococci during infection.
Phase-controlled Fourier-transform spectroscopy
Authors: Hashimoto Kazuki , Ideguchi Takuro 
Published: October 2018

AbstractFourier-transform spectroscopy (FTS) has been widely used as a standard analytical technique over the past half-century. FTS is an autocorrelation-based technique that is compatible with both temporally coherent and incoherent light sources, and functions as an active or passive spectrometer. However, it has been mostly used for static measurements due to the low scan rate imposed by technological restrictions. This has impeded its application to continuous rapid measurements, which would be of significant interest for a variety of fields, especially when monitoring of non-repeating or transient complex dynamics is desirable. Here, we demonstrate highly efficient FTS operating at a high spectral acquisition rate with a simple delay line based on a dynamic phase-control technique. The independent adjustability of phase and group delays allows us to achieve the Nyquist-limited spectral acquisition rate over 10,000 spectra per second, while maintaining a large spectral bandwidth and high resolution. We also demonstrate passive spectroscopy with an incoherent light source.
Enabling nanoscale flexoelectricity at extreme temperature by tuning cation diffusion
Authors: Molina-Luna Leopoldo , Wang Shuai , Pivak Yevheniy , Zintler Alexander , Pérez-Garza Héctor H. , Spruit Ronald G. , Xu Qiang , Yi Min , Xu Bai-Xiang , Acosta Matias 
Published: October 2018

AbstractAny dielectric material under a strain gradient presents flexoelectricity. Here, we synthesized 0.75 sodium bismuth titanate −0.25 strontium titanate (NBT-25ST) core–shell nanoparticles via a solid-state chemical reaction directly inside a transmission electron microscope (TEM) and observed domain-like nanoregions (DLNRs) up to an extreme temperature of 800 °C. We attribute this abnormal phenomenon to a chemically induced lattice strain gradient present in the core–shell nanoparticle. The strain gradient was generated by controlling the diffusion of strontium cations. By combining electrical biasing and temperature-dependent in situ TEM with phase field simulations, we analyzed the resulting strain gradient and local polarization distribution within a single nanoparticle. The analysis confirms that a local symmetry breaking, occurring due to a strain gradient (i.e. flexoelectricity), accounts for switchable polarization beyond the conventional temperature range of existing polar materials. We demonstrate that polar nanomaterials can be obtained through flexoelectricity at extreme temperature by tuning the cation diffusion.
Rewriting the phase diagram of a diamagnetic liquid crystal by a magnetic field
Authors: Hajjaj Fatin , Kajitani Takashi , Ohsumi Hiroyuki , Tanaka Yoshikazu , Kato Kenichi , Takata Masaki , Kitazawa Hideaki , Arima Taka-hisa , Aida Takuzo , Fukushima Takanori 
Published: October 2018

AbstractMagnetic fields have been considered to only interact with organic materials non-destructively, leaving their fundamental structures unaffected, even when a strong magnetic field generated from a superconducting magnet is applied. Here we report an unprecedented observation that a liquid-crystalline mesophase of a diamagnetic molecular assembly with an orthorhombic or a cubic structure is formed selectively in the absence or presence of a strong magnetic field. The constituent molecule is a triphenylene derivative carrying six imidazolium bromide-terminated alkyl side chains and exhibits a cubic, orthorhombic, or hexagonal columnar mesophase when complexed with an appropriate amount of lanthanum(III) bromide. Thermal processing of the La3+-containing liquid-crystalline assembly in the presence of a 10-tesla magnetic field resulted in a phase diagram, in which the orthorhombic phase is completely replaced with the cubic phase. The discovery of this magneto-induced phase-selection offers an insight into the interactions between magnetic fields and organic material.
Self-implantable double-layered micro-drug-reservoirs for efficient and controlled ocular drug delivery
Authors: Than Aung , Liu Chenghao , Chang Hao , Duong Phan Khanh , Cheung Chui Ming Gemmy , Xu Chenjie , Wang Xiaomeng , Chen Peng 
Published: October 2018

AbstractEye diseases and injuries impose a significant clinical problem worldwide. Safe and effective ocular drug delivery is, however, challenging due to the presence of ocular barriers. Here we report a strategy using an eye patch equipped with an array of detachable microneedles. These microneedles can penetrate the ocular surface tissue, and serve as implanted micro-reservoirs for controlled drug delivery. The biphasic drug release kinetics enabled by the double-layered micro-reservoirs largely enhances therapeutic efficacy. Using corneal neovascularization as the disease model, we show that delivery of an anti-angiogenic monoclonal antibody (DC101) by such eye patch produces ~90% reduction of neovascular area. Furthermore, quick release of an anti-inflammatory compound (diclofenac) followed by a sustained release of DC101 provides synergistic therapeutic outcome. The eye patch application is easy and minimally invasive to ensure good patient compliance. Such intraocular drug delivery strategy promises effective home-based treatment of many eye diseases.