bluuebunny/crossref_metadata_2025_split huggingface dataset:
Episodes of Aqueous Flooding and Effusive Volcanism Associated With Hrad Vallis, Mars
Authors: Hamilton Christopher W. , Mouginis‐Mark Peter J. , Sori Michael M. , Scheidt Stephen P. , Bramson Ali M. 
Published: May 2018

AbstractHrad Vallis is an Amazonian‐age outflow channel located in the northwestern part of the Elysium Volcanic Province of Mars. The formation of Hrad Vallis may have been associated with catastrophic aqueous floods and volcanism, which makes determining its emplacement history important for constraining the planet's hydrological and thermal evolution during the Amazonian Period. Through geological mapping, geomorphologic analysis, and numerical simulations we assess whether Hrad Vallis formed in association with mudflows (i.e., lahars), effusive volcanism, or a combination of both processes. Among the three youngest flows in the region, the lower and upper flow units are inferred to be the products of catastrophic aqueous floods, whereas the middle unit is interpreted to be pāhoehoe‐like lava flow formed through the process of inflation over the course of decades. The latter flow unit is similar to terrestrial lava‐rise plateaus, but its emplacement may have involved interactions with surficial ice deposits, which affected the flow path and resulted in a range of lava‐water interactions. We conclude that Hrad Vallis had a complex history involving episodes of both aqueous flooding and effusive volcanism and that the interactions between lava and ice in these regions may have generated ephemeral hydrothermal systems with potential astrobiological significance.
Modeling the Ionosphere with GPS and Rotation Measure Observations
Authors: Malins J. B. , White S. M. , Taylor G. B. , Stovall K. , Dowell J. 
Published: May 2018

AbstractThe ionosphere contributes time‐varying Faraday rotation (FR) to radio signals passing through it. Correction for the effect of the ionosphere is important for deriving magnetic field information from FR observations of polarized cosmic radio sources, as well as providing valuable diagnostics of the structure of the ionosphere. In this paper, we evaluate the accuracy of models commonly used to correct for its effects using new observations of pulsars at low frequencies, which provide total rotation measures (RMs) at better precision than previously available. We evaluate models of the ionosphere derived from modern digital ionosondes that provide electron density information as a function of height, as well as GPS‐derived total electron content (TEC) measurements. We combine these density models with reference global magnetic field models to derive ionospheric RM contributions. We find that the models disagree substantially with each other and seek corrections that may explain the differences in RM prediction. Additionally, we compare these models to global TEC models and find that local high‐cadence TEC measurements are superior to global models for ionospheric RM correction.
GADD45α sensitizes cervical cancer cells to radiotherapy via increasing cytoplasmic APE1 level
Authors: Li Qing , Wei Xi , Zhou Zhi-Wei , Wang Shu-Nan , Jin Hua , Chen Kui-Jun , Luo Jia , Westover Kenneth D. , Wang Jian-Min , Wang Dong , Xu Cheng-Xiong , Shan Jin-Lu 
Published: May 2018

AbstractRadioresistance remains a major clinical challenge in cervical cancer therapy. However, the mechanism for the development of radioresistance in cervical cancer is unclear. Herein, we determined that growth arrest and DNA-damage-inducible protein 45α (GADD45α) is decreased in radioresistant cervical cancer compared to radiosensitive cancer both in vitro and in vivo. In addition, silencing GADD45α prevents cervical cancer cells from undergoing radiation-induced DNA damage, cell cycle arrest, and apoptosis. More importantly, our data show that the overexpression of GADD45α significantly enhances the radiosensitivity of radioresistant cervical cancer cells. These data show that GADD45α decreases the cytoplasmic distribution of APE1, thereby enhancing the radiosensitivity of cervical cancer cells. Furthermore, we show that GADD45α inhibits the production of nitric oxide (NO), a nuclear APE1 export stimulator, by suppressing both endothelial NO synthase (eNOS) and inducible NO synthase (iNOS) in cervical cancer cells. In conclusion, our findings suggest that decreased GADD45α expression significantly contributes to the development of radioresistance and that ectopic expression of GADD45α sensitizes cervical cancer cells to radiotherapy. GADD45α inhibits the NO-regulated cytoplasmic localization of APE1 through inhibiting eNOS and iNOS, thereby enhancing the radiosensitivity of cervical cancer cells.
Inhibitor of apoptosis proteins are required for effective fusion of autophagosomes with lysosomes
Authors: Gradzka Sylwia , Thomas Oliver S. , Kretz Oliver , Haimovici Aladin , Vasilikos Lazaros. , Wong Wendy Wei-Lynn , Häcker Georg , Gentle Ian E. 
Published: May 2018

AbstractInhibitor of Apoptosis Proteins act as E3 ubiquitin ligases to regulate NF-κB signalling from multiple pattern recognition receptors including NOD2, as well as TNF Receptor Superfamily members. Loss of XIAP in humans causes X-linked Lymphoproliferative disease type 2 (XLP-2) and is often associated with Crohn’s disease. Crohn’s disease is also caused by mutations in the gene encoding NOD2 but the mechanisms behind Crohn’s disease development in XIAP and NOD2 deficient-patients are still unknown. Numerous other mutations causing Crohn’s Disease occur in genes controlling various aspects of autophagy, suggesting a strong involvement of autophagy in preventing Crohn’s disease. Here we show that the IAP proteins cIAP2 and XIAP are required for efficient fusion of lysosomes with autophagosomes. IAP inhibition or loss of both cIAP2 and XIAP resulted in a strong blockage in autophagic flux and mitophagy, suggesting that XIAP deficiency may also drive Crohn’s Disease due to defects in autophagy.
Grail is involved in adipocyte differentiation and diet-induced obesity
Authors: Liu Peiyao , Hsieh Poshiuan , Lin Huitsu , Liu Tejung , Wu Hsuehling , Chen Chengcheung , Chen Yingchuan 
Published: May 2018

AbstractGrail is a crucial regulator of various biological processes, including the development of T-cell anergy, antiviral innate immune response, and cancer. However, the role of Grail in adipogenesis and obesity remains unclear. Here, we demonstrated that Grail knockdown in vitro leads to a decrease in PPARγ expression, resulting in adipogenesis inhibition. However, Grail overexpression induced the same effects. Grail was shown to interact with PPARγ, targeting it for degradation and modulating its adipogenic activity. PPARγ expression was shown to be considerably reduced in Grail knockout (KO) mice fed normal diet or high-fat diet (HFD). The administration of both normal diet or HFD to Grail KO mice led to lower adipose mass and body weight than those in the wild-type mice. HFD-fed Grail KO mice had improved glucose and insulin tolerance. Taken together, our results indicate that Grail plays a pivotal role in adipogenesis and diet-induced obesity by regulating PPARγ activity.
A CRISPRi screen in E. coli reveals sequence-specific toxicity of dCas9
Authors: Cui Lun , Vigouroux Antoine , Rousset François , Varet Hugo , Khanna Varun , Bikard David 
Published: May 2018

AbstractHigh-throughput CRISPR-Cas9 screens have recently emerged as powerful tools to decipher gene functions and genetic interactions. Here we use a genome-wide library of guide RNAs to direct the catalytically dead Cas9 (dCas9) to block gene transcription in Escherichia coli. Using a machine-learning approach, we reveal that guide RNAs sharing specific 5-nucleotide seed sequences can produce strong fitness defects or even kill E. coli regardless of the other 15 nucleotides of guide sequence. This effect occurs at high dCas9 concentrations and can be alleviated by tuning the expression of dCas9 while maintaining strong on-target repression. Our results also highlight the fact that off-targets with as little as nine nucleotides of homology to the guide RNA can strongly block gene expression. Altogether this study provides important design rules to safely use dCas9 in E. coli.
Tracking HIV-1 recombination to resolve its contribution to HIV-1 evolution in natural infection
Authors: Song Hongshuo , Giorgi Elena E. , Ganusov Vitaly V. , Cai Fangping , Athreya Gayathri , Yoon Hyejin , Carja Oana , Hora Bhavna , Hraber Peter , Romero-Severson Ethan , Jiang Chunlai , Li Xiaojun , Wang Shuyi , Li Hui , Salazar-Gonzalez Jesus F. , Salazar Maria G. , Goonetilleke Nilu , Keele Brandon F. , Montefiori David C. , Cohen Myron S. , Shaw George M. , Hahn Beatrice H. , McMichael Andrew J. , Haynes Barton F. , Korber Bette , Bhattacharya Tanmoy , Gao Feng 
Published: May 2018

AbstractRecombination in HIV-1 is well documented, but its importance in the low-diversity setting of within-host diversification is less understood. Here we develop a novel computational tool (RAPR (Recombination Analysis PRogram)) to enable a detailed view of in vivo viral recombination during early infection, and we apply it to near-full-length HIV-1 genome sequences from longitudinal samples. Recombinant genomes rapidly replace transmitted/founder (T/F) lineages, with a median half-time of 27 days, increasing the genetic complexity of the viral population. We identify recombination hot and cold spots that differ from those observed in inter-subtype recombinants. Furthermore, RAPR analysis of longitudinal samples from an individual with well-characterized neutralizing antibody responses shows that recombination helps carry forward resistance-conferring mutations in the diversifying quasispecies. These findings provide insight into molecular mechanisms by which viral recombination contributes to HIV-1 persistence and immunopathogenesis and have implications for studies of HIV transmission and evolution in vivo.
Symmetry mismatch-driven perpendicular magnetic anisotropy for perovskite/brownmillerite heterostructures
Authors: Zhang Jing , Zhong Zhicheng , Guan Xiangxiang , Shen Xi , Zhang Jine , Han Furong , Zhang Hui , Zhang Hongrui , Yan Xi , Zhang Qinghua , Gu Lin , Hu Fengxia , Yu Richeng , Shen Baogen , Sun Jirong 
Published: May 2018

AbstractGrouping different transition metal oxides together by interface engineering is an important route toward emergent phenomenon. While most of the previous works focused on the interface effects in perovskite/perovskite heterostructures, here we reported on a symmetry mismatch-driven spin reorientation toward perpendicular magnetic anisotropy in perovskite/brownmillerite heterostructures, which is scarcely seen in tensile perovskite/perovskite heterostructures. We show that alternately stacking perovskite La2/3Sr1/3MnO3 and brownmillerite LaCoO2.5 causes a strong interface reconstruction due to symmetry discontinuity at interface: neighboring MnO6 octahedra and CoO4 tetrahedra at the perovskite/brownmillerite interface cooperatively relax in a manner that is unavailable for perovskite/perovskite interface, leading to distinct orbital reconstructions and thus the perpendicular magnetic anisotropy. Moreover, the perpendicular magnetic anisotropy is robust, with an anisotropy constant two orders of magnitude greater than the in-plane anisotropy of the perovskite/perovskite interface. The present work demonstrates the great potential of symmetry engineering in designing artificial materials on demand.
Sensible heat has significantly affected the global hydrological cycle over the historical period
Authors: Myhre G. , Samset B. H. , Hodnebrog Ø. , Andrews T. , Boucher O. , Faluvegi G. , Fläschner D. , Forster P. M. , Kasoar M. , Kharin V. , Kirkevåg A. , Lamarque J.-F. , Olivié D. , Richardson T. B. , Shawki D. , Shindell D. , Shine K. P. , Stjern C. W. , Takemura T. , Voulgarakis A. 
Published: May 2018

AbstractGlobally, latent heating associated with a change in precipitation is balanced by changes to atmospheric radiative cooling and sensible heat fluxes. Both components can be altered by climate forcing mechanisms and through climate feedbacks, but the impacts of climate forcing and feedbacks on sensible heat fluxes have received much less attention. Here we show, using a range of climate modelling results, that changes in sensible heat are the dominant contributor to the present global-mean precipitation change since preindustrial time, because the radiative impact of forcings and feedbacks approximately compensate. The model results show a dissimilar influence on sensible heat and precipitation from various drivers of climate change. Due to its strong atmospheric absorption, black carbon is found to influence the sensible heat very differently compared to other aerosols and greenhouse gases. Our results indicate that this is likely caused by differences in the impact on the lower tropospheric stability.
STT3-dependent PD-L1 accumulation on cancer stem cells promotes immune evasion
Authors: Hsu Jung-Mao , Xia Weiya , Hsu Yi-Hsin , Chan Li-Chuan , Yu Wen-Hsuan , Cha Jong-Ho , Chen Chun-Te , Liao Hsin-Wei , Kuo Chu-Wei , Khoo Kay-Hooi , Hsu Jennifer L. , Li Chia-Wei , Lim Seung-Oe , Chang Shih-Shin , Chen Yi-Chun , Ren Guo-xin , Hung Mien-Chie 
Published: May 2018

AbstractEnriched PD-L1 expression in cancer stem-like cells (CSCs) contributes to CSC immune evasion. However, the mechanisms underlying PD-L1 enrichment in CSCs remain unclear. Here, we demonstrate that epithelial–mesenchymal transition (EMT) enriches PD-L1 in CSCs by the EMT/β-catenin/STT3/PD-L1 signaling axis, in which EMT transcriptionally induces N-glycosyltransferase STT3 through β-catenin, and subsequent STT3-dependent PD-L1 N-glycosylation stabilizes and upregulates PD-L1. The axis is also utilized by the general cancer cell population, but it has much more profound effect on CSCs as EMT induces more STT3 in CSCs than in non-CSCs. We further identify a non-canonical mesenchymal–epithelial transition (MET) activity of etoposide, which suppresses the EMT/β-catenin/STT3/PD-L1 axis through TOP2B degradation-dependent nuclear β-catenin reduction, leading to PD-L1 downregulation of CSCs and non-CSCs and sensitization of cancer cells to anti-Tim-3 therapy. Together, our results link MET to PD-L1 stabilization through glycosylation regulation and reveal it as a potential strategy to enhance cancer immunotherapy efficacy.
Nanographenes as electron-deficient cores of donor-acceptor systems
Authors: Liu Yu-Min , Hou Hao , Zhou Yan-Zhen , Zhao Xin-Jing , Tang Chun , Tan Yuan-Zhi , Müllen Klaus 
Published: May 2018

AbstractConjugation of nanographenes (NGs) with electro-active molecules can establish donor-acceptor π-systems in which the former generally serve as the electron-donating moieties due to their electronic-rich nature. In contrast, here we report a series of reversed donor-acceptor structures are obtained by C–N coupling of electron-deficient perchlorinated NGs with electron-rich anilines. Selective amination at the vertexes of the NGs is unambiguously shown through X-ray crystallography. By varying the donating ability of the anilino groups, the optical and assembly properties of donor-acceptor NGs can be finely modulated. The electron-deficient concave core of the resulting conjugates can host electron-rich guest molecules by intermolecular donor-acceptor interactions and gives rise to charge-transfer supramolecular architectures.
Ratchet-free solid-state inertial rotation of a guest ball in a tight tubular host
Authors: Matsuno Taisuke , Nakai Yusuke , Sato Sota , Maniwa Yutaka , Isobe Hiroyuki 
Published: May 2018

AbstractDynamics of molecules in the solid state holds promise for connecting molecular behaviors with properties of bulk materials. Solid-state dynamics of [60]fullerene (C60) is controlled by intimate intermolecular contacts and results in restricted motions of a ratchet phase at low temperatures. Manipulation of the solid-state dynamics of fullerene molecules is thus an interesting yet challenging problem. Here we show that a tubular host for C60 liberates the solid-state dynamics of the guest from the motional restrictions. Although the intermolecular contacts between the host and C60 were present to enable a tight association with a large energy gain of –14 kcal mol–1, the dynamic rotations of C60 were simultaneously enabled by a small energy barrier of +2 kcal mol–1 for the reorientation. The solid-state rotational motions reached a non-Brownian, inertial regime with an extremely rapid rotational frequency of 213 GHz at 335 K.
Abnormal band bowing effects in phase instability crossover region of GaSe1-xTe
x
nanomaterials
Authors: Cai Hui , Chen Bin , Blei Mark , Chang Shery L. Y. , Wu Kedi , Zhuang Houlong , Tongay Sefaattin 
Published: May 2018

AbstractAkin to the enormous number of discoveries made through traditional semiconductor alloys, alloying selected 2D semiconductors enables engineering of their electronic structure for a wide range of new applications. 2D alloys have been demonstrated when two components crystallized in the same phase, and their bandgaps displayed predictable monotonic variation. By stabilizing previously unobserved compositions and phases of GaSe1−xTe
x
at nanoscales on GaAs(111), we demonstrate abnormal band bowing effects and phase instability region when components crystallize in different phases. Advanced microscopy and spectroscopy measurements show as tellurium is alloyed into GaSe, nanostructures undergo hexagonal to monoclinic and isotropic to anisotropic transition. There exists an instability region (0.56 < x < 0.67) where both phases compete and coexist, and two different bandgap values can be found at the same composition leading to anomalous band bowing effects. Results highlight unique alloying effects, not existing in single-phase alloys, and phase engineering routes for potential applications in photonic and electronics.
Coherent X-rays reveal the influence of cage effects on ultrafast water dynamics
Authors: Perakis Fivos , Camisasca Gaia , Lane Thomas J. , Späh Alexander , Wikfeldt Kjartan Thor , Sellberg Jonas A. , Lehmkühler Felix , Pathak Harshad , Kim Kyung Hwan , Amann-Winkel Katrin , Schreck Simon , Song Sanghoon , Sato Takahiro , Sikorski Marcin , Eilert Andre , McQueen Trevor , Ogasawara Hirohito , Nordlund Dennis , Roseker Wojciech , Koralek Jake , Nelson Silke , Hart Philip , Alonso-Mori Roberto , Feng Yiping , Zhu Diling , Robert Aymeric , Grübel Gerhard , Pettersson Lars G. M. , Nilsson Anders 
Published: May 2018

AbstractThe dynamics of liquid water feature a variety of time scales, ranging from extremely fast ballistic-like thermal motion, to slower molecular diffusion and hydrogen-bond rearrangements. Here, we utilize coherent X-ray pulses to investigate the sub-100 fs equilibrium dynamics of water from ambient conditions down to supercooled temperatures. This novel approach utilizes the inherent capability of X-ray speckle visibility spectroscopy to measure equilibrium intermolecular dynamics with lengthscale selectivity, by measuring oxygen motion in momentum space. The observed decay of the speckle contrast at the first diffraction peak, which reflects tetrahedral coordination, is attributed to motion on a molecular scale within the first 120 fs. Through comparison with molecular dynamics simulations, we conclude that the slowing down upon cooling from 328 K down to 253 K is not due to simple thermal ballistic-like motion, but that cage effects play an important role even on timescales over 25 fs due to hydrogen-bonding.
Tip60-mediated lipin 1 acetylation and ER translocation determine triacylglycerol synthesis rate
Authors: Li Terytty Yang , Song Lintao , Sun Yu , Li Jingyi , Yi Cong , Lam Sin Man , Xu Dijin , Zhou Linkang , Li Xiaotong , Yang Ying , Zhang Chen-Song , Xie Changchuan , Huang Xi , Shui Guanghou , Lin Shu-Yong , Reue Karen , Lin Sheng-Cai 
Published: May 2018

AbstractObesity is characterized by excessive fatty acid conversion to triacylglycerols (TAGs) in adipose tissues. However, how signaling networks sense fatty acids and connect to the stimulation of lipid synthesis remains elusive. Here, we show that homozygous knock-in mice carrying a point mutation at the Ser86 phosphorylation site of acetyltransferase Tip60 (Tip60
SA/SA
) display remarkably reduced body fat mass, and Tip60
SA/SA
females fail to nurture pups to adulthood due to severely reduced milk TAGs. Mechanistically, fatty acids stimulate Tip60-dependent acetylation and endoplasmic reticulum translocation of phosphatidic acid phosphatase lipin 1 to generate diacylglycerol for TAG synthesis, which is repressed by deacetylase Sirt1. Inhibition of Tip60 activity strongly blocks fatty acid-induced TAG synthesis while Sirt1 suppression leads to increased adiposity. Genetic analysis of loss-of-function mutants in Saccharomyces cerevisiae reveals a requirement of ESA1, yeast ortholog of Tip60, in TAG accumulation. These findings uncover a conserved mechanism linking fatty acid sensing to fat synthesis.
Linguistic measures of chemical diversity and the “keywords” of molecular collections
Authors: Woźniak Michał , Wołos Agnieszka , Modrzyk Urszula , Górski Rafał L. , Winkowski Jan , Bajczyk Michał , Szymkuć Sara , Grzybowski Bartosz A. , Eder Maciej 
Published: May 2018

AbstractComputerized linguistic analyses have proven of immense value in comparing and searching through large text collections (“corpora”), including those deposited on the Internet – indeed, it would nowadays be hard to imagine browsing the Web without, for instance, search algorithms extracting most appropriate keywords from documents. This paper describes how such corpus-linguistic concepts can be extended to chemistry based on characteristic “chemical words” that span more than traditional functional groups and, instead, look at common structural fragments molecules share. Using these words, it is possible to quantify the diversity of chemical collections/databases in new ways and to define molecular “keywords” by which such collections are best characterized and annotated.
FABRICA: A Bioreactor Platform for Printing, Perfusing, Observing, & Stimulating 3D Tissues
Authors: Smith Lester J. , Li Ping , Holland Mark R. , Ekser Burcin 
Published: May 2018

AbstractWe are introducing the FABRICA, a bioprinter-agnostic 3D-printed bioreactor platform designed for 3D-bioprinted tissue construct culture, perfusion, observation, and analysis. The computer-designed FABRICA was 3D-printed with biocompatible material and used for two studies: (1) Flow Profile Study: perfused 5 different media through a synthetic 3D-bioprinted construct and ultrasonically analyzed the flow profile at increasing volumetric flow rates (VFR); (2) Construct Perfusion Study: perfused a 3D-bioprinted tissue construct for a week and compared histologically with a non-perfused control. For the flow profile study, construct VFR increased with increasing pump VFR. Water and other media increased VFR significantly while human and pig blood showed shallow increases. For the construct perfusion study, we confirmed more viable cells in perfused 3D-bioprinted tissue compared to control. The FABRICA can be used to visualize constructs during 3D-bioprinting, incubation, and to control and ultrasonically analyze perfusion, aseptically in real-time, making the FABRICA tunable for different tissues.