bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioinspired and osteopromotive polydopamine nanoparticle-incorporated fibrous membranes for robust bone regeneration
Authors: Deng Yi , Yang Wei-Zhong , Shi Dong , Wu Minjie , Xiong Xiao-Ling , Chen Zhi-Gang , Wei Shi-Cheng 
Published: July 2019

AbstractDue to their inherent hydrophobic and bioinert nature, synthetic degradable polymer-based membranes show inferior stem cell attachment, proliferation, and even differentiation. To overcome these limitations, bioinspired and osteopromotive polydopamine nanoparticle-incorporated fibrous membranes are developed via a two-step route: pH-induced polymerization of dopamine and co-electrospinning of polycaprolactone (PCL) with polydopamine nanoparticles (PDA NPs). Hybrid membranes with optimized PDA NP content exhibit high quantities of apatite deposition and prominent cytocompatibility (cell attachment, spreading and reproduction) and osteo-differentiation potential (alkaline phosphatase activity, calcium mineralization, and osteogenesis-related genes and protein expression) of human mesenchymal stem cells cultured without any growth factors. Importantly, in vivo assessments using a mouse calvarial critical-sized defect demonstrate that the engineered fibrous membranes remarkably boost bone reconstruction and regeneration. Accordingly, our bioinspired PCL-based hybrid fibrous membranes with robust osteoinductive ability can potentially be utilized as a clinically applicable candidate in guided tissue regeneration applications.
Highly atroposelective synthesis of nonbiaryl naphthalene-1,2-diamine N-C atropisomers through direct enantioselective C-H amination
Authors: Bai He-Yuan , Tan Fu-Xin , Liu Tuan-Qing , Zhu Guo-Dong , Tian Jin-Miao , Ding Tong-Mei , Chen Zhi-Min , Zhang Shu-Yu 
Published: July 2019

AbstractNonbiaryl N-C atropisomer is an important structural scaffold, which is present in natural products, medicines and chiral ligands. However the direct enantioselective C-H amination to access optically pure N-C atropisomer is still difficult and rare. Here we report a π-π interaction and dual H-bond concerted control strategy to develop the chiral phosphoric acids (CPAs) catalyzed direct intermolecular enantioselective C-H amination of N-aryl-2-naphthylamines with azodicarboxylates as amino sources for the construction of atroposelective naphthalene-1,2-diamines. This type of N-C atropisomers is stabilized by intramolecular hydrogen bond and the method features a broad range of substrates, high yields and ee values, providing a strategy to chirality transfer via the modification of N-C atropisomers.
Disorder-induced nonlinear Hall effect with time-reversal symmetry
Authors: Du Z. Z. , Wang C. M. , Li Shuai , Lu Hai-Zhou , Xie X. C. 
Published: July 2019

AbstractThe nonlinear Hall effect has opened the door towards deeper understanding of topological states of matter. Disorder plays indispensable roles in various linear Hall effects, such as the localization in the quantized Hall effects and the extrinsic mechanisms of the anomalous, spin, and valley Hall effects. Unlike in the linear Hall effects, disorder enters the nonlinear Hall effect even in the leading order. Here, we derive the formulas of the nonlinear Hall conductivity in the presence of disorder scattering. We apply the formulas to calculate the nonlinear Hall response of the tilted 2D Dirac model, which is the symmetry-allowed minimal model for the nonlinear Hall effect and can serve as a building block in realistic band structures. More importantly, we construct the general scaling law of the nonlinear Hall effect, which may help in experiments to distinguish disorder-induced contributions to the nonlinear Hall effect in the future.
Revealing the intrinsic nature of the mid-gap defects in amorphous Ge2Sb2Te5
Authors: Konstantinou Konstantinos , Mocanu Felix C. , Lee Tae-Hoon , Elliott Stephen R. 
Published: July 2019

AbstractUnderstanding the relation between the time-dependent resistance drift in the amorphous state of phase-change materials and the localised states in the band gap of the glass is crucial for the development of memory devices with increased storage density. Here a machine-learned interatomic potential is utilised to generate an ensemble of glass models of the prototypical phase-change alloy, Ge2Sb2Te5, to obtain reliable statistics. Hybrid density-functional theory is used to identify and characterise the geometric and electronic structures of the mid-gap states. 5-coordinated Ge atoms are the local defective bonding environments mainly responsible for these electronic states. The structural motif for the localisation of the mid-gap states is a crystalline-like atomic environment within the amorphous network. An extra electron is trapped spontaneously by these mid-gap states, creating deep traps in the band gap. The results provide significant insights that can help to rationalise the design of multi-level-storage memory devices.
Structure-based mechanism for activation of the AAA+ GTPase McrB by the endonuclease McrC
Authors: Nirwan Neha , Itoh Yuzuru , Singh Pratima , Bandyopadhyay Sutirtha , Vinothkumar Kutti R. , Amunts Alexey , Saikrishnan Kayarat 
Published: July 2019

AbstractThe AAA+ GTPase McrB powers DNA cleavage by the endonuclease McrC. The GTPase itself is activated by McrC. The architecture of the GTPase and nuclease complex, and the mechanism of their activation remained unknown. Here, we report a 3.6 Å structure of a GTPase-active and DNA-binding deficient construct of McrBC. Two hexameric rings of McrB are bridged by McrC dimer. McrC interacts asymmetrically with McrB protomers and inserts a stalk into the pore of the ring, reminiscent of the γ subunit complexed to α3β3 of F1-ATPase. Activation of the GTPase involves conformational changes of residues essential for hydrolysis. Three consecutive nucleotide-binding pockets are occupied by the GTP analogue 5’-guanylyl imidodiphosphate and the next three by GDP, which is suggestive of sequential GTP hydrolysis.
Non-conventional mechanism of ferroelectric fatigue via cation migration
Authors: Ievlev Anton V. , KC Santosh , Vasudevan Rama K. , Kim Yunseok , Lu Xiaoli , Alexe Marin , Cooper Valentino R. , Kalinin Sergei V. , Ovchinnikova Olga S. 
Published: July 2019

AbstractThe unique properties of ferroelectric materials enable a plethora of applications, which are hindered by the phenomenon known as ferroelectric fatigue that leads to the degradation of ferroelectric properties with polarization cycling. Multiple microscopic models explaining fatigue have been suggested; however, the chemical origins remain poorly understood. Here, we utilize multimodal chemical imaging that combines atomic force microscopy with time-of-flight secondary mass spectrometry to explore the chemical phenomena associated with fatigue in PbZr0.2Ti0.8O3 (PZT) thin films. Investigations reveal that the degradation of ferroelectric properties is correlated with a local chemical change and migration of electrode ions into the PZT structure. Density functional theory simulations support the experimental results and demonstrate stable doping of the thin surface PZT layer with copper ions, leading to a decrease in the spontaneous polarization. Overall, the performed research allows for the observation and understanding of the chemical phenomena associated with polarization cycling and their effects on ferroelectric functionality.
Pioneer and repressive functions of p63 during zebrafish embryonic ectoderm specification
Authors: Santos-Pereira José M. , Gallardo-Fuentes Lourdes , Neto Ana , Acemel Rafael D. , Tena Juan J. 
Published: July 2019

AbstractThe transcription factor p63 is a master regulator of ectoderm development. Although previous studies show that p63 triggers epidermal differentiation in vitro, the roles of p63 in developing embryos remain poorly understood. Here, we use zebrafish embryos to analyze in vivo how p63 regulates gene expression during development. We generate tp63-knock-out mutants that recapitulate human phenotypes and show down-regulated epidermal gene expression. Following p63-binding dynamics, we find two distinct functions clearly separated in space and time. During early development, p63 binds enhancers associated to neural genes, limiting Sox3 binding and reducing neural gene expression. Indeed, we show that p63 and Sox3 are co-expressed in the neural plate border. On the other hand, p63 acts as a pioneer factor by binding non-accessible chromatin at epidermal enhancers, promoting their opening and epidermal gene expression in later developmental stages. Therefore, our results suggest that p63 regulates cell fate decisions during vertebrate ectoderm specification.
High-dimensional optical quantum logic in large operational spaces
Authors: Imany Poolad , Jaramillo-Villegas Jose A. , Alshaykh Mohammed S. , Lukens Joseph M. , Odele Ogaga D. , Moore Alexandria J. , Leaird Daniel E. , Qi Minghao , Weiner Andrew M. 
Published: July 2019

AbstractThe probabilistic nature of single-photon sources and photon–photon interactions encourages encoding as much quantum information as possible in every photon for the purpose of photonic quantum information processing. Here, by encoding high-dimensional units of information (qudits) in time and frequency degrees of freedom using on-chip sources, we report deterministic two-qudit gates in a single photon with fidelities exceeding 0.90 in the computational basis. Constructing a two-qudit modulo SUM gate, we generate and measure a single-photon state with nonseparability between time and frequency qudits. We then employ this SUM operation on two frequency-bin entangled photons—each carrying two 32-dimensional qudits—to realize a four-party high-dimensional Greenberger–Horne–Zeilinger state, occupying a Hilbert space equivalent to that of 20 qubits. Although high-dimensional coding alone is ultimately not scalable for universal quantum computing, our design shows the potential of deterministic optical quantum operations in large encoding spaces for practical and compact quantum information processing protocols.
A seafloor habitat map for the Australian continental shelf
Authors: Lucieer Vanessa , Barrett Neville , Butler Claire , Flukes Emma , Ierodiaconou Daniel , Ingleton Tim , Jordan Alan , Monk Jacquomo , Meeuwig Jessica , Porter-Smith Rick , Smit Neil , Walsh Peter , Wright Alison , Johnson Craig 
Published: July 2019

AbstractHere we outline the genesis of Seamap Australia, which integrates spatial data of the seabed of Australia’s continental shelf (0–200 m depth) from multiple sources to provide a single national map layer of marine habitat. It is underpinned by a hierarchical classification scheme with registered vocabulary, enabling presentation of nationally consistent information at the highest resolution available for any point in space. The Seamap Australia website enables users to delineate particular areas of interest, overlay habitat maps with many other marine data layers, and to directly access the data and metadata underlying the maps they produce. This unique resource represents a step-change in capacity to access and integrate large and diverse marine data holdings and to readily derive information and products to underpin decision making around marine spatial planning and conservation prioritisation, state-of-environment reporting, and research. It is a world first fully integrated national-scale marine mapping and data service.
Core body temperature speeds up temporal processing and choice behavior under deadlines
Authors: van Maanen Leendert , van der Mijn Robbert , van Beurden Maurice H. P. H. , Roijendijk Linsey M. M. , Kingma Boris R. M. , Miletić Steven , van Rijn Hedderik 
Published: July 2019

AbstractEvidence suggests that human timing ability is compromised by heat. In particular, some studies suggest that increasing body temperature speeds up an internal clock, resulting in faster time perception. However, the consequences of this speed-up for other cognitive processes remain unknown. In the current study, we rigorously tested the speed-up hypothesis by inducing passive hyperthermia through immersion of participants in warm water. In addition, we tested how a change in time perception affects performance in decision making under deadline stress. We found that participants underestimate a prelearned temporal interval when body temperature increases, and that their performance in a two-alternative forced-choice task displays signatures of increased time pressure. These results show not only that timing plays an important role in decision-making, but also that this relationship is mediated by temperature. The consequences for decision-making in job environments that are demanding due to changes in body temperature may be considerable.
A Differential Hypofunctionality of Gαi Proteins Occurs in Adolescent Idiopathic Scoliosis and Correlates with the Risk of Disease Progression
Authors: Akoume Marie-Yvonne , Elbakry Mohamed , Veillette Maxime , Franco Anita , Nada Dina , Labelle Hubert , Mac-Thiong Jean-Marc , Grimard Guy , Ouellet Jean , Parent Stefan , Rivard Charles-Hilaire , Lombardi Giovanni , Colombini Alessandra , Banfi Giuseppe , Brayda-Bruno Marco , Gorman Kristen F. , Moreau Alain 
Published: July 2019

AbstractAdolescent idiopathic scoliosis is the most prevalent spine deformity and the molecular mechanisms underlying its pathophysiology remain poorly understood. We have previously found a differential impairment of melatonin receptor signaling in AIS osteoblasts allowing the classification of patients into three biological endophenotypes or functional groups (FG1, FG2 and FG3). Here, we provide evidence that the defect characterizing each endophenotype lies at the level of Gαi proteins leading to a systemic and generalized differential impairment of Gi-coupled receptor signaling. The three Gαi isoforms exhibited a selective serine phosphorylation patterns for each AIS endophenotype resulting in a differential reduction in Gαi protein activity as determined by cellular dielectric spectroscopy and small interfering RNA methods. We found that one endophenotype (FG2) with phosphorylated Gαi1 and Gαi2 was consistently associated with a significantly high risk of spinal deformity progression when compared to the other two endophenotypes (FG1 and FG3). We further demonstrated that each endophenotype is conserved among affected family members. This study expands our understanding of the mechanism underlying the Gi-coupled receptor signaling dysfunction occurring in AIS and provides the first evidence for its hereditary nature. Collectively, our findings offers a new perspective on Gαi hypofunctionality in a human disease by revealing specific serine phosphorylation signatures of Gαi isoforms that may facilitate the identification of AIS patients at risk of spinal deformity progression.
PARP1 regulates DNA damage-induced nucleolar-nucleoplasmic shuttling of WRN and XRCC1 in a toxicant and protein-specific manner
Authors: Veith Sebastian , Schink Andrea , Engbrecht Marina , Mack Matthias , Rank Lisa , Rossatti Pascal , Hakobyan Mariam , Goly Denise , Hefele Tanja , Frensch Marco , Fischbach Arthur , Bürkle Alexander , Mangerich Aswin 
Published: July 2019

AbstractThe prime function of nucleoli is ribogenesis, however, several other, non-canonical functions have recently been identified, including a role in genotoxic stress response. Upon DNA damage, numerous proteins shuttle dynamically between the nucleolus and the nucleoplasm, yet the underlying molecular mechanisms are incompletely understood. Here, we demonstrate that PARP1 and PARylation contribute to genotoxic stress-induced nucleolar-nucleoplasmic shuttling of key genome maintenance factors in HeLa cells. Our work revealed that the RECQ helicase, WRN, translocates from nucleoli to the nucleoplasm upon treatment with the oxidizing agent H2O2, the alkylating agent 2-chloroethyl ethyl sulfide (CEES), and the topoisomerase inhibitor camptothecin (CPT). We show that after treatment with H2O2 and CEES, but not CPT, WRN translocation was dependent on PARP1 protein, yet independent of its enzymatic activity. In contrast, nucleolar-nucleoplasmic translocation of the base excision repair protein, XRCC1, was dependent on both PARP1 protein and its enzymatic activity. Furthermore, gossypol, which inhibits PARP1 activity by disruption of PARP1-protein interactions, abolishes nucleolar-nucleoplasmic shuttling of WRN, XRCC1 and PARP1, indicating the involvement of further upstream factors. In conclusion, this study highlights a prominent role of PARP1 in the DNA damage-induced nucleolar-nucleoplasmic shuttling of genome maintenance factors in HeLa cells in a toxicant and protein-specific manner.
Future changes in extreme weather and pyroconvection risk factors for Australian wildfires
Authors: Dowdy Andrew J. , Ye Hua , Pepler Acacia , Thatcher Marcus , Osbrough Stacey L. , Evans Jason P. , Di Virgilio Giovanni , McCarthy Nicholas 
Published: July 2019

AbstractExtreme wildfires have recently caused disastrous impacts in Australia and other regions of the world, including events with strong convective processes in their plumes (i.e., strong pyroconvection). Dangerous wildfire events such as these could potentially be influenced by anthropogenic climate change, however, there are large knowledge gaps on how these events might change in the future. The McArthur Forest Fire Danger Index (FFDI) is used to represent near-surface weather conditions and the Continuous Haines index (CH) is used here to represent lower to mid-tropospheric vertical atmospheric stability and humidity measures relevant to dangerous wildfires and pyroconvective processes. Projected changes in extreme measures of CH and FFDI are examined using a multi-method approach, including an ensemble of global climate models together with two ensembles of regional climate models. The projections show a clear trend towards more dangerous near-surface fire weather conditions for Australia based on the FFDI, as well as increased pyroconvection risk factors for some regions of southern Australia based on the CH. These results have implications for fields such as disaster risk reduction, climate adaptation, ecology, policy and planning, noting that improved knowledge on how climate change can influence extreme wildfires can help reduce future impacts of these events.
The value of long-term citizen science data for monitoring koala populations
Authors: Dissanayake Ravi Bandara , Stevenson Mark , Allavena Rachel , Henning Joerg 
Published: July 2019

AbstractThe active collection of wildlife sighting data by trained observers is expensive, restricted to small geographical areas and conducted infrequently. Reporting of wildlife sightings by members of the public provides an opportunity to collect wildlife data continuously over wider geographical areas, at lower cost. We used individual koala sightings reported by members of the public between 1997 and 2013 in South-East Queensland, Australia (n = 14,076 koala sightings) to describe spatial and temporal trends in koala presence, to estimate koala sighting density and to identify biases associated with sightings. Temporal trends in sightings mirrored the breeding season of koalas. Sightings were high in residential areas (63%), followed by agricultural (15%), and parkland (12%). The study area was divided into 57,780 one-square kilometer grid cells and grid cells with no sightings of koalas decreased over time (from 35% to 21%) indicative of a greater level of spatial overlap of koala home ranges and human activity areas over time. The density of reported koala sightings decreased as distance from primary and secondary roads increased, indicative of a higher search effort near roads. Our results show that koala sighting data can be used to refine koala distribution and population estimates derived from active surveying, on the condition that appropriate bias correction techniques are applied. Collecting koala absence and search effort information and conducting repeated searches for koalas in the same areas are useful approaches to improve the quality of sighting data in citizen science programs.
Exosomes Engineered to Express a Cardiomyocyte Binding Peptide Demonstrate Improved Cardiac Retention in Vivo
Authors: Mentkowski Kyle I. , Lang Jennifer K. 
Published: July 2019

AbstractInjury to the heart results in cardiomyocyte cell death and can lead to pathological remodeling of remaining cells, contributing to heart failure. Despite the therapeutic potential of new drugs and small molecules, there remains a gap in the ability to efficiently deliver cardioprotective agents in a cell specific manner while minimizing nonspecific delivery to other organs. Exosomes derived from cardiosphere-derived cells (CDCs) have been shown to stimulate angiogenesis, induce endogenous cardiomyocyte proliferation and modulate cardiomyocyte apoptosis and hypertrophy. While innately cardioprotective at high doses, unmodified CDC-exosomes demonstrate limited cardiac tropism. To generate an efficient exosomal delivery system that can target cardiomyocytes, we engineered CDCs to express Lamp2b, an exosomal membrane protein, fused to a cardiomyocyte specific peptide (CMP), WLSEAGPVVTVRALRGTGSW. Exosomes isolated from engineered CDCs expressed CMP on their surface and retained their native physical properties. Targeted exosomes resulted in increased uptake by cardiomyocytes, decreased cardiomyocyte apoptosis, and higher cardiac retention following intramyocardial injection when compared with non-targeted exosomes. Importantly, we established a novel targeting system to improve exosomal uptake by cardiomyocytes and laid the foundation for cell-specific exosomal delivery of drug and gene therapies to improve the functional capacity of the heart following both ischemic and non-ischemic injury.
The Application of Ultrasonic Vibration in Human Sperm Cryopreservation as a Novel Method for the Modification of Physicochemical Characteristics of Freezing Media
Authors: Dariush Gholami , Gholamhossein Riazi , Rouhollah Fathi , Mahmood Ghaffari Seyed , Abdolhossein Shahverdi , Mohsen Sharafi , Loghman Alaei 
Published: July 2019

AbstractThe application of ultrasonic vibration was performed to modify the water molecules as the main compositions of the freezing medium used for human sperm cryopreservation. Different time periods of ultrasonic vibration (ULV) at the frequency of 28 kHz were applied for the evaluation of physicochemical properties of the water molecules. The most significant bubble size, zeta potential, and pH were obtained for the water molecules exposed to ultrasonic vibrations for 18 minutes and this time period was selected for further experiments due to the optimum results. In the next stage, semen samples were diluted with freezing medium containing ULV-exposed water and then cryopreserved. All the semen parameters were significantly reduced in cryopreserved groups as compared with the fresh control group. The highest percentage of total and progressive motility, viability, membrane and DNA integrity, and mitochondrial membrane potential were observed in frozen ULV compared with the frozen control. The rate of apoptosis in frozen ULV was significantly lower than that of in the frozen control. Furthermore, the gene expression ratios of α- and β-tubulins were significantly increased during cryopreservation, while the expression ratio of the tubulin polymerization promoting protein (TPPP) gene was decreased. Similar results were also observed when the protein levels of the genes mentioned earlier were evaluated by the ELISA method. Therefore, the changes in physicochemical properties of the freezing medium of human sperm cryopreservation using ULV can improve the quality of frozen products.